hfs-407.1.3.tar.gz

[apple/hfs.git] / core / hfs_vnops.c

/*
 * Copyright (c) 2000-2017 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#include <libkern/OSAtomic.h>
#include <stdbool.h>
#include <sys/systm.h>
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/dirent.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/mount.h>
#include <sys/vnode_if.h>
#include <sys/malloc.h>
#include <sys/ubc.h>
#include <sys/paths.h>
#include <sys/quota.h>
#include <sys/time.h>
#include <sys/disk.h>
#include <sys/kauth.h>
#include <sys/fsctl.h>
#include <sys/xattr.h>
#include <sys/decmpfs.h>
#include <sys/mman.h>
#include <sys/doc_tombstone.h>
#include <sys/namei.h>
#include <string.h>
#include <sys/fsevents.h>

#include <miscfs/specfs/specdev.h>
#include <miscfs/fifofs/fifo.h>
#include <vfs/vfs_support.h>

#include <sys/kdebug.h>
#include <sys/sysctl.h>
#include <stdbool.h>

#include "hfs.h"
#include "hfs_catalog.h"
#include "hfs_cnode.h"
#include "hfs_dbg.h"
#include "hfs_mount.h"
#include "hfs_quota.h"
#include "hfs_endian.h"
#include "hfs_kdebug.h"
#include "hfs_cprotect.h"

#if HFS_CONFIG_KEY_ROLL
#include "hfs_key_roll.h"
#endif

#include "BTreesInternal.h"
#include "FileMgrInternal.h"

/* Global vfs data structures for hfs */

/*
 * Always F_FULLFSYNC? 1=yes,0=no (default due to "various" reasons is
 * 'no').  At some point this might need to move into VFS and we might
 * need to provide an API to get at it, but for now, this is only used
 * by HFS+.
 */
int always_do_fullfsync = 0;
SYSCTL_DECL(_vfs_generic);
HFS_SYSCTL(INT, _vfs_generic, OID_AUTO, always_do_fullfsync, CTLFLAG_RW | CTLFLAG_LOCKED, &always_do_fullfsync, 0, "always F_FULLFSYNC when fsync is called")

int hfs_makenode(struct vnode *dvp, struct vnode **vpp,
                        struct componentname *cnp, struct vnode_attr *vap,
                        vfs_context_t ctx);
int hfs_metasync(struct hfsmount *hfsmp, daddr64_t node, __unused struct proc *p);
int hfs_metasync_all(struct hfsmount *hfsmp);

int hfs_removedir(struct vnode *, struct vnode *, struct componentname *,
                         int, int);
int hfs_removefile(struct vnode *, struct vnode *, struct componentname *,
                          int, int, int, struct vnode *, int);

/* Used here and in cnode teardown -- for symlinks */
int hfs_removefile_callback(struct buf *bp, void *hfsmp);

enum {
        HFS_MOVE_DATA_INCLUDE_RSRC              = 1,
};
typedef uint32_t hfs_move_data_options_t;

static int hfs_move_data(cnode_t *from_cp, cnode_t *to_cp, 
                                                 hfs_move_data_options_t options);
static int hfs_move_fork(filefork_t *srcfork, cnode_t *src, 
                                                 filefork_t *dstfork, cnode_t *dst);


static int hfs_exchangedata_getxattr (struct vnode *vp, uint32_t name_selector, void **buffer, size_t *xattr_size);
static int hfs_exchangedata_setxattr (struct hfsmount *hfsmp, uint32_t fileid, 
                                                                                uint32_t name_selector, void *buffer, size_t xattr_size);

enum XATTR_NAME_ENTRIES {
        quarantine = 0,
        MAX_NUM_XATTR_NAMES     //must be last
};


/* These are special EAs that follow the content in exchangedata(2). */
const char *XATTR_NAMES [MAX_NUM_XATTR_NAMES] = { "com.apple.quarantine" };

#define MAX_EXCHANGE_EA_SIZE 4096

#if HFS_COMPRESSION
static int hfs_move_compressed(cnode_t *from_vp, cnode_t *to_vp);
#endif

decmpfs_cnode* hfs_lazy_init_decmpfs_cnode (struct cnode *cp);

#if FIFO
static int hfsfifo_read(struct vnop_read_args *);
static int hfsfifo_write(struct vnop_write_args *);
static int hfsfifo_close(struct vnop_close_args *);

extern int (**fifo_vnodeop_p)(void *);
#endif /* FIFO */

int hfs_vnop_close(struct vnop_close_args*);
int hfs_vnop_exchange(struct vnop_exchange_args*);
int hfs_vnop_fsync(struct vnop_fsync_args*);
int hfs_vnop_mkdir(struct vnop_mkdir_args*);
int hfs_vnop_mknod(struct vnop_mknod_args*);
int hfs_vnop_getattr(struct vnop_getattr_args*);
int hfs_vnop_open(struct vnop_open_args*);
int hfs_vnop_readdir(struct vnop_readdir_args*);
int hfs_vnop_rename(struct vnop_rename_args*);
int hfs_vnop_renamex(struct vnop_renamex_args*);
int hfs_vnop_rmdir(struct vnop_rmdir_args*);
int hfs_vnop_symlink(struct vnop_symlink_args*);
int hfs_vnop_setattr(struct vnop_setattr_args*);
int hfs_vnop_readlink(struct vnop_readlink_args *);
int hfs_vnop_pathconf(struct vnop_pathconf_args *);
int hfs_vnop_mmap(struct vnop_mmap_args *ap);
int hfsspec_read(struct vnop_read_args *);
int hfsspec_write(struct vnop_write_args *);
int hfsspec_close(struct vnop_close_args *);

/* Options for hfs_removedir and hfs_removefile */
#define HFSRM_SKIP_RESERVE  0x01



/*****************************************************************************
*
* Common Operations on vnodes
*
*****************************************************************************/

/*
 * Is the given cnode either the .journal or .journal_info_block file on
 * a volume with an active journal?  Many VNOPs use this to deny access
 * to those files.
 *
 * Note: the .journal file on a volume with an external journal still
 * returns true here, even though it does not actually hold the contents
 * of the volume's journal.
 */
static _Bool
hfs_is_journal_file(struct hfsmount *hfsmp, struct cnode *cp)
{
        if (hfsmp->jnl != NULL &&
            (cp->c_fileid == hfsmp->hfs_jnlinfoblkid ||
             cp->c_fileid == hfsmp->hfs_jnlfileid)) {
                return true;
        } else {
                return false;
        }
}

/*
 * Create a regular file.
 */
int
hfs_vnop_create(struct vnop_create_args *ap)
{
        /*
         * We leave handling of certain race conditions here to the caller
         * which will have a better understanding of the semantics it
         * requires.  For example, if it turns out that the file exists,
         * it would be wrong of us to return a reference to the existing
         * file because the caller might not want that and it would be
         * misleading to suggest the file had been created when it hadn't
         * been.  Note that our NFS server code does not set the
         * VA_EXCLUSIVE flag so you cannot assume that callers don't want
         * EEXIST errors if it's not set.  The common case, where users
         * are calling open with the O_CREAT mode, is handled in VFS; when
         * we return EEXIST, it will loop and do the look-up again.
         */
        return hfs_makenode(ap->a_dvp, ap->a_vpp, ap->a_cnp, ap->a_vap, ap->a_context);
}

/*
 * Make device special file.
 */
int
hfs_vnop_mknod(struct vnop_mknod_args *ap)
{
        struct vnode_attr *vap = ap->a_vap;
        struct vnode *dvp = ap->a_dvp;
        struct vnode **vpp = ap->a_vpp;
        struct cnode *cp;
        int error;

        if (VTOVCB(dvp)->vcbSigWord != kHFSPlusSigWord) {
                return (ENOTSUP);
        }

        /* Create the vnode */
        error = hfs_makenode(dvp, vpp, ap->a_cnp, vap, ap->a_context);
        if (error)
                return (error);

        cp = VTOC(*vpp);
        cp->c_touch_acctime = TRUE;
        cp->c_touch_chgtime = TRUE;
        cp->c_touch_modtime = TRUE;

        if ((vap->va_rdev != VNOVAL) &&
            (vap->va_type == VBLK || vap->va_type == VCHR))
                cp->c_rdev = vap->va_rdev;

        return (0);
}

#if HFS_COMPRESSION
/* 
 *      hfs_ref_data_vp(): returns the data fork vnode for a given cnode. 
 *      In the (hopefully rare) case where the data fork vnode is not 
 *      present, it will use hfs_vget() to create a new vnode for the
 *      data fork. 
 *      
 *      NOTE: If successful and a vnode is returned, the caller is responsible
 *      for releasing the returned vnode with vnode_rele().
 */
static int
hfs_ref_data_vp(struct cnode *cp, struct vnode **data_vp, int skiplock)
{
        int vref = 0;

        if (!data_vp || !cp) /* sanity check incoming parameters */
                return EINVAL;
        
        /* maybe we should take the hfs cnode lock here, and if so, use the skiplock parameter to tell us not to */

        if (!skiplock) hfs_lock(cp, HFS_SHARED_LOCK, HFS_LOCK_DEFAULT);
        struct vnode *c_vp = cp->c_vp;
        if (c_vp) {
                /* we already have a data vnode */
                *data_vp = c_vp;
                vref = vnode_ref(*data_vp);
                if (!skiplock) hfs_unlock(cp);
                if (vref == 0) {
                        return 0;
                }
                return EINVAL;
        }
        /* no data fork vnode in the cnode, so ask hfs for one. */

        if (!cp->c_rsrc_vp) {
                /* if we don't have either a c_vp or c_rsrc_vp, we can't really do anything useful */
                *data_vp = NULL;
                if (!skiplock) hfs_unlock(cp);
                return EINVAL;
        }
        
        if (0 == hfs_vget(VTOHFS(cp->c_rsrc_vp), cp->c_cnid, data_vp, 1, 0) &&
                0 != data_vp) {
                vref = vnode_ref(*data_vp);
                vnode_put(*data_vp);
                if (!skiplock) hfs_unlock(cp);
                if (vref == 0) {
                        return 0;
                }
                return EINVAL;
        }
        /* there was an error getting the vnode */
        *data_vp = NULL;
        if (!skiplock) hfs_unlock(cp);
        return EINVAL;
}

/*
 *      hfs_lazy_init_decmpfs_cnode(): returns the decmpfs_cnode for a cnode,
 *      allocating it if necessary; returns NULL if there was an allocation error.
 *  function is non-static so that it can be used from the FCNTL handler.
 */
decmpfs_cnode *
hfs_lazy_init_decmpfs_cnode(struct cnode *cp)
{
        if (!cp->c_decmp) {
                decmpfs_cnode *dp = decmpfs_cnode_alloc();
                decmpfs_cnode_init(dp);
                if (!OSCompareAndSwapPtr(NULL, dp, (void * volatile *)&cp->c_decmp)) {
                        /* another thread got here first, so free the decmpfs_cnode we allocated */
                        decmpfs_cnode_destroy(dp);
                        decmpfs_cnode_free(dp);
                }
        }
        
        return cp->c_decmp;
}

/*
 *      hfs_file_is_compressed(): returns 1 if the file is compressed, and 0 (zero) if not.
 *      if the file's compressed flag is set, makes sure that the decmpfs_cnode field
 *      is allocated by calling hfs_lazy_init_decmpfs_cnode(), then makes sure it is populated,
 *      or else fills it in via the decmpfs_file_is_compressed() function.
 */
int
hfs_file_is_compressed(struct cnode *cp, int skiplock)
{
        int ret = 0;
        
        /* fast check to see if file is compressed. If flag is clear, just answer no */
        if (!(cp->c_bsdflags & UF_COMPRESSED)) {
                return 0;
        }

        decmpfs_cnode *dp = hfs_lazy_init_decmpfs_cnode(cp);
        if (!dp) {
                /* error allocating a decmpfs cnode, treat the file as uncompressed */
                return 0;
        }
        
        /* flag was set, see if the decmpfs_cnode state is valid (zero == invalid) */
        uint32_t decmpfs_state = decmpfs_cnode_get_vnode_state(dp);
        switch(decmpfs_state) {
                case FILE_IS_COMPRESSED:
                case FILE_IS_CONVERTING: /* treat decompressing files as if they are compressed */
                        return 1;
                case FILE_IS_NOT_COMPRESSED:
                        return 0;
                /* otherwise the state is not cached yet */
        }
        
        /* decmpfs hasn't seen this file yet, so call decmpfs_file_is_compressed() to init the decmpfs_cnode struct */
        struct vnode *data_vp = NULL;
        if (0 == hfs_ref_data_vp(cp, &data_vp, skiplock)) {
                if (data_vp) {
                        ret = decmpfs_file_is_compressed(data_vp, VTOCMP(data_vp)); // fill in decmpfs_cnode
                        vnode_rele(data_vp);
                }
        }
        return ret;
}

/*      hfs_uncompressed_size_of_compressed_file() - get the uncompressed size of the file.
 *      if the caller has passed a valid vnode (has a ref count > 0), then hfsmp and fid are not required.
 *      if the caller doesn't have a vnode, pass NULL in vp, and pass valid hfsmp and fid.
 *      files size is returned in size (required)
 *      if the indicated file is a directory (or something that doesn't have a data fork), then this call
 *      will return an error and the caller should fall back to treating the item as an uncompressed file
 */
int
hfs_uncompressed_size_of_compressed_file(struct hfsmount *hfsmp, struct vnode *vp, cnid_t fid, off_t *size, int skiplock)
{
        int ret = 0;
        int putaway = 0;                                                                        /* flag to remember if we used hfs_vget() */

        if (!size) {
                return EINVAL;                                                                  /* no place to put the file size */
        }

        if (NULL == vp) {
                if (!hfsmp || !fid) {                                                   /* make sure we have the required parameters */
                        return EINVAL;
                }
                if (0 != hfs_vget(hfsmp, fid, &vp, skiplock, 0)) {              /* vnode is null, use hfs_vget() to get it */
                        vp = NULL;
                } else {
                        putaway = 1;                                                            /* note that hfs_vget() was used to aquire the vnode */
                }
        }
        /* this double check for compression (hfs_file_is_compressed)
         * ensures the cached size is present in case decmpfs hasn't 
         * encountered this node yet.
         */
        if (vp) {
                if (hfs_file_is_compressed(VTOC(vp), skiplock) ) {
                        *size = decmpfs_cnode_get_vnode_cached_size(VTOCMP(vp));        /* file info will be cached now, so get size */
                } else if (VTOCMP(vp)) {
                        uint32_t cmp_type = decmpfs_cnode_cmp_type(VTOCMP(vp));

                        if (cmp_type == DATALESS_CMPFS_TYPE) {
                                *size = decmpfs_cnode_get_vnode_cached_size(VTOCMP(vp));        /* file info will be cached now, so get size */
                                ret = 0;
                        } else if (cmp_type >= CMP_MAX && VTOC(vp)->c_datafork) {
                                // if we don't recognize this type, just use the real data fork size
                                *size = VTOC(vp)->c_datafork->ff_size;
                                ret = 0;
                        } else
                                ret = EINVAL;
                } else
                        ret = EINVAL;
        }

        if (putaway) {          /* did we use hfs_vget() to get this vnode? */
                vnode_put(vp);  /* if so, release it and set it to null */
                vp = NULL;
        }
        return ret;
}

int
hfs_hides_rsrc(vfs_context_t ctx, struct cnode *cp, int skiplock)
{
        if (ctx == decmpfs_ctx)
                return 0;
        if (!hfs_file_is_compressed(cp, skiplock))
                return 0;
        return decmpfs_hides_rsrc(ctx, cp->c_decmp);
}

int
hfs_hides_xattr(vfs_context_t ctx, struct cnode *cp, const char *name, int skiplock)
{
        if (ctx == decmpfs_ctx)
                return 0;
        if (!hfs_file_is_compressed(cp, skiplock))
                return 0;
        return decmpfs_hides_xattr(ctx, cp->c_decmp, name);
}
#endif /* HFS_COMPRESSION */

/*
 * Open a file/directory.
 */
int
hfs_vnop_open(struct vnop_open_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct filefork *fp;
        struct timeval tv;
        int error;
        static int past_bootup = 0;
        struct cnode *cp = VTOC(vp);
        struct hfsmount *hfsmp = VTOHFS(vp);

#if CONFIG_PROTECT
        error = cp_handle_open(vp, ap->a_mode);
        if (error)
                return error;
#endif

#if HFS_COMPRESSION
        if (ap->a_mode & FWRITE) {
                /* open for write */
                if ( hfs_file_is_compressed(cp, 1) ) { /* 1 == don't take the cnode lock */
                        /* opening a compressed file for write, so convert it to decompressed */
                        struct vnode *data_vp = NULL;
                        error = hfs_ref_data_vp(cp, &data_vp, 1); /* 1 == don't take the cnode lock */
                        if (0 == error) {
                                if (data_vp) {
                                        error = decmpfs_decompress_file(data_vp, VTOCMP(data_vp), -1, 1, 0);
                                        vnode_rele(data_vp);
                                } else {
                                        error = EINVAL;
                                }
                        }
                        if (error != 0)
                                return error;
                }
        } else {
                /* open for read */
                if (hfs_file_is_compressed(cp, 1) ) { /* 1 == don't take the cnode lock */
                        if (VNODE_IS_RSRC(vp)) {
                                /* opening the resource fork of a compressed file, so nothing to do */
                        } else {
                                /* opening a compressed file for read, make sure it validates */
                                error = decmpfs_validate_compressed_file(vp, VTOCMP(vp));
                                if (error != 0)
                                        return error;
                        }
                }
        }
#endif

        /*
         * Files marked append-only must be opened for appending.
         */
        if ((cp->c_bsdflags & APPEND) && !vnode_isdir(vp) &&
            (ap->a_mode & (FWRITE | O_APPEND)) == FWRITE)
                return (EPERM);

        if (vnode_issystem(vp))
                return (EBUSY);  /* file is in use by the kernel */

        /* Don't allow journal to be opened externally. */
        if (hfs_is_journal_file(hfsmp, cp))
                return (EPERM);

        bool have_lock = false;

#if CONFIG_PROTECT
        if (ISSET(ap->a_mode, FENCRYPTED) && cp->c_cpentry && vnode_isreg(vp)) {
                bool have_trunc_lock = false;

#if HFS_CONFIG_KEY_ROLL
        again:
#endif

                if ((error = hfs_lock(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT))) {
                        if (have_trunc_lock)
                                hfs_unlock_truncate(cp, 0);
                        return error;
                }

                have_lock = true;

                if (cp->c_cpentry->cp_raw_open_count + 1
                        < cp->c_cpentry->cp_raw_open_count) {
                        // Overflow; too many raw opens on this file
                        hfs_unlock(cp);
                        if (have_trunc_lock)
                                hfs_unlock_truncate(cp, 0);
                        return ENFILE;
                }

#if HFS_CONFIG_KEY_ROLL
                if (cp_should_auto_roll(hfsmp, cp->c_cpentry)) {
                        if (!have_trunc_lock) {
                                hfs_unlock(cp);
                                hfs_lock_truncate(cp, HFS_EXCLUSIVE_LOCK, 0);
                                have_trunc_lock = true;
                                goto again;
                        }

                        error = hfs_key_roll_start(cp);
                        if (error) {
                                hfs_unlock(cp);
                                hfs_unlock_truncate(cp, 0);
                                return error;
                        }
                }
#endif

                if (have_trunc_lock)
                        hfs_unlock_truncate(cp, 0);

                ++cp->c_cpentry->cp_raw_open_count;
        }
#endif

        if (ISSET(hfsmp->hfs_flags, HFS_READ_ONLY)
                || !vnode_isreg(vp)
#if NAMEDSTREAMS
                || vnode_isnamedstream(vp)
#endif
                || !hfsmp->jnl || vnode_isinuse(vp, 0)) {

#if CONFIG_PROTECT
                if (have_lock)
                        hfs_unlock(cp);
#endif

                return (0);
        }

        if (!have_lock && (error = hfs_lock(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT)))
                return (error);

#if QUOTA
        /* If we're going to write to the file, initialize quotas. */
        if ((ap->a_mode & FWRITE) && (hfsmp->hfs_flags & HFS_QUOTAS))
                (void)hfs_getinoquota(cp);
#endif /* QUOTA */

        /*
         * On the first (non-busy) open of a fragmented
         * file attempt to de-frag it, if it's less than hfs_defrag_max bytes.
         * That field is initially set to 20MB.
         */
        fp = VTOF(vp);
        if (fp->ff_blocks &&
            fp->ff_extents[7].blockCount != 0 &&
            fp->ff_size <= hfsmp->hfs_defrag_max) { 
                
                int no_mods = 0;
                struct timeval now;
                /* 
                 * Wait until system bootup is done (3 min).
                 * And don't relocate a file that's been modified
                 * within the past minute -- this can lead to
                 * system thrashing.
                 */

                if (hfsmp->hfs_defrag_nowait) {
                        /* If this is toggled, then issue the defrag if appropriate */
                        past_bootup = 1;
                        no_mods = 1;
                }

                if (!past_bootup) {
                        microuptime(&tv);
                        if (tv.tv_sec > (60*3)) {
                                past_bootup = 1;
                        }
                }
                
                microtime(&now);
                if ((now.tv_sec - cp->c_mtime) > 60) {  
                        no_mods = 1;
                } 
                
                if (past_bootup && no_mods) {
                        (void) hfs_relocate(vp, hfsmp->nextAllocation + 4096,
                                        vfs_context_ucred(ap->a_context),
                                        vfs_context_proc(ap->a_context));
                }
        }

        hfs_unlock(cp);

        return (0);
}


/*
 * Close a file/directory.
 */
int
hfs_vnop_close(struct vnop_close_args *ap)
{
        register struct vnode *vp = ap->a_vp;
        register struct cnode *cp;
        struct proc *p = vfs_context_proc(ap->a_context);
        struct hfsmount *hfsmp;
        int busy;
        int tooktrunclock = 0;
        int knownrefs = 0;

        if ( hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT) != 0)
                return (0);
        cp = VTOC(vp);
        hfsmp = VTOHFS(vp);

#if CONFIG_PROTECT
        if (cp->c_cpentry && ISSET(ap->a_fflag, FENCRYPTED) && vnode_isreg(vp)) {
                hfs_assert(cp->c_cpentry->cp_raw_open_count > 0);
                --cp->c_cpentry->cp_raw_open_count;
        }
#endif

        /* 
         * If the rsrc fork is a named stream, it can cause the data fork to
         * stay around, preventing de-allocation of these blocks. 
         * Do checks for truncation on close. Purge extra extents if they exist.
         * Make sure the vp is not a directory, and that it has a resource fork,
         * and that resource fork is also a named stream.
         */

        if ((vnode_vtype(vp) == VREG) && (cp->c_rsrc_vp)
                        && (vnode_isnamedstream(cp->c_rsrc_vp))) {
                uint32_t blks;

                blks = howmany(VTOF(vp)->ff_size, VTOVCB(vp)->blockSize);
                /*
                 * If there are extra blocks and there are only 2 refs on
                 * this vp (ourselves + rsrc fork holding ref on us), go ahead
                 * and try to truncate.
                 */
                if ((blks < VTOF(vp)->ff_blocks) && (!vnode_isinuse(vp, 2))) {
                        // release cnode lock; must acquire truncate lock BEFORE cnode lock
                        hfs_unlock(cp);

                        hfs_lock_truncate(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT);
                        tooktrunclock = 1;

                        if (hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT) != 0) { 
                                hfs_unlock_truncate(cp, HFS_LOCK_DEFAULT);
                                // bail out if we can't re-acquire cnode lock
                                return 0;
                        }
                        // now re-test to make sure it's still valid
                        if (cp->c_rsrc_vp) {
                                knownrefs = 1 + vnode_isnamedstream(cp->c_rsrc_vp);
                                if (!vnode_isinuse(vp, knownrefs)){
                                        // now we can truncate the file, if necessary
                                        blks = howmany(VTOF(vp)->ff_size, VTOVCB(vp)->blockSize);
                                        if (blks < VTOF(vp)->ff_blocks){
                                                (void) hfs_truncate(vp, VTOF(vp)->ff_size, IO_NDELAY,
                                                                                        0, ap->a_context);
                                        }
                                }
                        }
                }
        }


        // if we froze the fs and we're exiting, then "thaw" the fs 
        if (hfsmp->hfs_freeze_state == HFS_FROZEN
            && hfsmp->hfs_freezing_proc == p && proc_exiting(p)) {
                hfs_thaw(hfsmp, p);
        }

        busy = vnode_isinuse(vp, 1);

        if (busy) {
                hfs_touchtimes(VTOHFS(vp), cp); 
        }
        if (vnode_isdir(vp)) {
                hfs_reldirhints(cp, busy);
        } else if (vnode_issystem(vp) && !busy) {
                vnode_recycle(vp);
        }

        if (tooktrunclock){
                hfs_unlock_truncate(cp, HFS_LOCK_DEFAULT);
        }
        hfs_unlock(cp);

        if (ap->a_fflag & FWASWRITTEN) {
                hfs_sync_ejectable(hfsmp);
        }

        return (0);
}

static bool hfs_should_generate_document_id(hfsmount_t *hfsmp, cnode_t *cp)
{
        return (!ISSET(hfsmp->hfs_flags, HFS_READ_ONLY)
                        && ISSET(cp->c_bsdflags, UF_TRACKED)
                        && cp->c_desc.cd_cnid != kHFSRootFolderID
                        && (S_ISDIR(cp->c_mode) || S_ISREG(cp->c_mode) || S_ISLNK(cp->c_mode)));
}

/*
 * Get basic attributes.
 */
int
hfs_vnop_getattr(struct vnop_getattr_args *ap)
{
#define VNODE_ATTR_TIMES  \
        (VNODE_ATTR_va_access_time|VNODE_ATTR_va_change_time|VNODE_ATTR_va_modify_time)
#define VNODE_ATTR_AUTH  \
        (VNODE_ATTR_va_mode | VNODE_ATTR_va_uid | VNODE_ATTR_va_gid | \
         VNODE_ATTR_va_flags | VNODE_ATTR_va_acl)

        struct vnode *vp = ap->a_vp;
        struct vnode_attr *vap = ap->a_vap;
        struct vnode *rvp = NULLVP;
        struct hfsmount *hfsmp;
        struct cnode *cp;
        uint64_t data_size;
        enum vtype v_type;
        int error = 0;
        cp = VTOC(vp);

#if HFS_COMPRESSION
        /* we need to inspect the decmpfs state of the file before we take the hfs cnode lock */
        int compressed = 0;
        int hide_size = 0;
        off_t uncompressed_size = -1;
        if (VATTR_IS_ACTIVE(vap, va_data_size) || VATTR_IS_ACTIVE(vap, va_total_alloc) || VATTR_IS_ACTIVE(vap, va_data_alloc) || VATTR_IS_ACTIVE(vap, va_total_size)) {
                /* we only care about whether the file is compressed if asked for the uncompressed size */
                if (VNODE_IS_RSRC(vp)) {
                        /* if it's a resource fork, decmpfs may want us to hide the size */
                        hide_size = hfs_hides_rsrc(ap->a_context, cp, 0);
                } else {
                        /* if it's a data fork, we need to know if it was compressed so we can report the uncompressed size */
                        compressed = hfs_file_is_compressed(cp, 0);
                }
                if ((VATTR_IS_ACTIVE(vap, va_data_size) || VATTR_IS_ACTIVE(vap, va_total_size))) {
                        // if it's compressed 
                        if (compressed || (!VNODE_IS_RSRC(vp) && cp->c_decmp && decmpfs_cnode_cmp_type(cp->c_decmp) >= CMP_MAX)) {
                                if (0 != hfs_uncompressed_size_of_compressed_file(NULL, vp, 0, &uncompressed_size, 0)) {
                                        /* failed to get the uncompressed size, we'll check for this later */
                                        uncompressed_size = -1;
                                } else {
                                        // fake that it's compressed
                                        compressed = 1;
                                }
                        }
                }
        }
#endif

        /*
         * Shortcut for vnode_authorize path.  Each of the attributes
         * in this set is updated atomically so we don't need to take
         * the cnode lock to access them.
         */
        if ((vap->va_active & ~VNODE_ATTR_AUTH) == 0) {
                /* Make sure file still exists. */
                if (cp->c_flag & C_NOEXISTS)
                        return (ENOENT);

                vap->va_uid = cp->c_uid;
                vap->va_gid = cp->c_gid;
                vap->va_mode = cp->c_mode;
                vap->va_flags = cp->c_bsdflags;
                vap->va_supported |= VNODE_ATTR_AUTH & ~VNODE_ATTR_va_acl;

                if ((cp->c_attr.ca_recflags & kHFSHasSecurityMask) == 0) {
                        vap->va_acl = (kauth_acl_t) KAUTH_FILESEC_NONE;
                        VATTR_SET_SUPPORTED(vap, va_acl);
                }
        
                return (0);
        }

        hfsmp = VTOHFS(vp);
        v_type = vnode_vtype(vp);

        if (VATTR_IS_ACTIVE(vap, va_document_id)) {
                uint32_t document_id;

                if (cp->c_desc.cd_cnid == kHFSRootFolderID)
                        document_id = kHFSRootFolderID;
                else {
                        /*
                         * This is safe without a lock because we're just reading
                         * a 32 bit aligned integer which should be atomic on all
                         * platforms we support.
                         */
                        document_id = hfs_get_document_id(cp);

                        if (!document_id && hfs_should_generate_document_id(hfsmp, cp)) {
                                uint32_t new_document_id;

                                error = hfs_generate_document_id(hfsmp, &new_document_id);
                                if (error)
                                        return error;

                                error = hfs_lock(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT);
                                if (error)
                                        return error;

                                bool want_docid_fsevent = false;

                                // Need to check again now that we have the lock
                                document_id = hfs_get_document_id(cp);
                                if (!document_id && hfs_should_generate_document_id(hfsmp, cp)) {
                                        cp->c_attr.ca_finderextendeddirinfo.document_id = document_id = new_document_id;
                                        want_docid_fsevent = true;
                                        SET(cp->c_flag, C_MODIFIED);
                                }

                                hfs_unlock(cp);

                                if (want_docid_fsevent) {
                                        add_fsevent(FSE_DOCID_CHANGED, ap->a_context,
                                                                FSE_ARG_DEV,   hfsmp->hfs_raw_dev,
                                                                FSE_ARG_INO,   (ino64_t)0,             // src inode #
                                                                FSE_ARG_INO,   (ino64_t)cp->c_fileid,  // dst inode #
                                                                FSE_ARG_INT32, document_id,
                                                                FSE_ARG_DONE);

                                        if (need_fsevent(FSE_STAT_CHANGED, vp)) {
                                                add_fsevent(FSE_STAT_CHANGED, ap->a_context, 
                                                                        FSE_ARG_VNODE, vp, FSE_ARG_DONE);
                                        }
                                }
                        }
                }

                vap->va_document_id = document_id;
                VATTR_SET_SUPPORTED(vap, va_document_id);
        }

        /*
         * If time attributes are requested and we have cnode times
         * that require updating, then acquire an exclusive lock on
         * the cnode before updating the times.  Otherwise we can
         * just acquire a shared lock.
         */
        if ((vap->va_active & VNODE_ATTR_TIMES) &&
            (cp->c_touch_acctime || cp->c_touch_chgtime || cp->c_touch_modtime)) {
                if ((error = hfs_lock(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT)))
                        return (error);
                hfs_touchtimes(hfsmp, cp);

                // downgrade to a shared lock since that's all we need from here on out
                cp->c_lockowner = HFS_SHARED_OWNER;
                lck_rw_lock_exclusive_to_shared(&cp->c_rwlock);

        } else if ((error = hfs_lock(cp, HFS_SHARED_LOCK, HFS_LOCK_DEFAULT))) {
                return (error);
        }

        if (v_type == VDIR) {
                data_size = (cp->c_entries + 2) * AVERAGE_HFSDIRENTRY_SIZE;

                if (VATTR_IS_ACTIVE(vap, va_nlink)) {
                        int nlink;
        
                        /*
                         * For directories, the va_nlink is esentially a count
                         * of the ".." references to a directory plus the "."
                         * reference and the directory itself. So for HFS+ this
                         * becomes the sub-directory count plus two.
                         *
                         * In the absence of a sub-directory count we use the
                         * directory's item count.  This will be too high in
                         * most cases since it also includes files.
                         */
                        if ((hfsmp->hfs_flags & HFS_FOLDERCOUNT) && 
                            (cp->c_attr.ca_recflags & kHFSHasFolderCountMask))
                                nlink = cp->c_attr.ca_dircount;  /* implied ".." entries */
                        else
                                nlink = cp->c_entries;

                        /* Account for ourself and our "." entry */
                        nlink += 2;  
                         /* Hide our private directories. */
                        if (cp->c_cnid == kHFSRootFolderID) {
                                if (hfsmp->hfs_private_desc[FILE_HARDLINKS].cd_cnid != 0) {
                                        --nlink;    
                                }
                                if (hfsmp->hfs_private_desc[DIR_HARDLINKS].cd_cnid != 0) {
                                        --nlink;
                                }
                        }
                        VATTR_RETURN(vap, va_nlink, (u_int64_t)nlink);
                }               
                if (VATTR_IS_ACTIVE(vap, va_nchildren)) {
                        int entries;
        
                        entries = cp->c_entries;
                        /* Hide our private files and directories. */
                        if (cp->c_cnid == kHFSRootFolderID) {
                                if (hfsmp->hfs_private_desc[FILE_HARDLINKS].cd_cnid != 0)
                                        --entries;
                                if (hfsmp->hfs_private_desc[DIR_HARDLINKS].cd_cnid != 0)
                                        --entries;
                                if (hfsmp->jnl || ((hfsmp->vcbAtrb & kHFSVolumeJournaledMask) && (hfsmp->hfs_flags & HFS_READ_ONLY)))
                                        entries -= 2;   /* hide the journal files */
                        }
                        VATTR_RETURN(vap, va_nchildren, entries);
                }
                /*
                 * The va_dirlinkcount is the count of real directory hard links.
                 * (i.e. its not the sum of the implied "." and ".." references)
                 */
                if (VATTR_IS_ACTIVE(vap, va_dirlinkcount)) {
                        VATTR_RETURN(vap, va_dirlinkcount, (uint32_t)cp->c_linkcount);
                }
        } else /* !VDIR */ {
                data_size = VCTOF(vp, cp)->ff_size;

                VATTR_RETURN(vap, va_nlink, (u_int64_t)cp->c_linkcount);
                if (VATTR_IS_ACTIVE(vap, va_data_alloc)) {
                        u_int64_t blocks;
        
#if HFS_COMPRESSION
                        if (hide_size) {
                                VATTR_RETURN(vap, va_data_alloc, 0);
                        } else if (compressed) {
                                /* for compressed files, we report all allocated blocks as belonging to the data fork */
                                blocks = cp->c_blocks;
                                VATTR_RETURN(vap, va_data_alloc, blocks * (u_int64_t)hfsmp->blockSize);
                        }
                        else
#endif
                        {
                                blocks = VCTOF(vp, cp)->ff_blocks;
                                VATTR_RETURN(vap, va_data_alloc, blocks * (u_int64_t)hfsmp->blockSize);
                        }
                }
        }

        /* conditional because 64-bit arithmetic can be expensive */
        if (VATTR_IS_ACTIVE(vap, va_total_size)) {
                if (v_type == VDIR) {
                        VATTR_RETURN(vap, va_total_size, (cp->c_entries + 2) * AVERAGE_HFSDIRENTRY_SIZE);
                } else {
                        u_int64_t total_size = ~0ULL;
                        struct cnode *rcp;
#if HFS_COMPRESSION
                        if (hide_size) {
                                /* we're hiding the size of this file, so just return 0 */
                                total_size = 0;
                        } else if (compressed) {
                                if (uncompressed_size == -1) {
                                        /*
                                         * We failed to get the uncompressed size above,
                                         * so we'll fall back to the standard path below
                                         * since total_size is still -1
                                         */
                                } else {
                                        /* use the uncompressed size we fetched above */
                                        total_size = uncompressed_size;
                                }
                        }
#endif
                        if (total_size == ~0ULL) {
                                if (cp->c_datafork) {
                                        total_size = cp->c_datafork->ff_size;
                                }
                                
                                if (cp->c_blocks - VTOF(vp)->ff_blocks) {
                                        /* We deal with rsrc fork vnode iocount at the end of the function */
                                        error = hfs_vgetrsrc(hfsmp, vp, &rvp);
                                        if (error) {
                                                /*
                                                 * Note that we call hfs_vgetrsrc with error_on_unlinked
                                                 * set to FALSE.  This is because we may be invoked via
                                                 * fstat() on an open-unlinked file descriptor and we must 
                                                 * continue to support access to the rsrc fork until it disappears.
                                                 * The code at the end of this function will be
                                                 * responsible for releasing the iocount generated by 
                                                 * hfs_vgetrsrc.  This is because we can't drop the iocount
                                                 * without unlocking the cnode first.
                                                 */
                                                goto out;
                                        }
                                        
                                        rcp = VTOC(rvp);
                                        if (rcp && rcp->c_rsrcfork) {
                                                total_size += rcp->c_rsrcfork->ff_size;
                                        }
                                }
                        }
                        
                        VATTR_RETURN(vap, va_total_size, total_size);
                }
        }
        if (VATTR_IS_ACTIVE(vap, va_total_alloc)) {
                if (v_type == VDIR) {
                        VATTR_RETURN(vap, va_total_alloc, 0);
                } else {
                        VATTR_RETURN(vap, va_total_alloc, (u_int64_t)cp->c_blocks * (u_int64_t)hfsmp->blockSize);
                }
        }

        /*
         * If the VFS wants extended security data, and we know that we
         * don't have any (because it never told us it was setting any)
         * then we can return the supported bit and no data.  If we do
         * have extended security, we can just leave the bit alone and
         * the VFS will use the fallback path to fetch it.
         */
        if (VATTR_IS_ACTIVE(vap, va_acl)) {
                if ((cp->c_attr.ca_recflags & kHFSHasSecurityMask) == 0) {
                        vap->va_acl = (kauth_acl_t) KAUTH_FILESEC_NONE;
                        VATTR_SET_SUPPORTED(vap, va_acl);
                }
        }

        vap->va_access_time.tv_sec = cp->c_atime;
        vap->va_access_time.tv_nsec = 0;
        vap->va_create_time.tv_sec = cp->c_itime;
        vap->va_create_time.tv_nsec = 0;
        vap->va_modify_time.tv_sec = cp->c_mtime;
        vap->va_modify_time.tv_nsec = 0;
        vap->va_change_time.tv_sec = cp->c_ctime;
        vap->va_change_time.tv_nsec = 0;
        vap->va_backup_time.tv_sec = cp->c_btime;
        vap->va_backup_time.tv_nsec = 0;        

        /* See if we need to emit the date added field to the user */
        if (VATTR_IS_ACTIVE(vap, va_addedtime)) {
                u_int32_t dateadded = hfs_get_dateadded (cp);
                if (dateadded) {
                        vap->va_addedtime.tv_sec = dateadded;
                        vap->va_addedtime.tv_nsec = 0;
                        VATTR_SET_SUPPORTED (vap, va_addedtime);
                }
        }

        /* XXX is this really a good 'optimal I/O size'? */
        vap->va_iosize = hfsmp->hfs_logBlockSize;
        vap->va_uid = cp->c_uid;
        vap->va_gid = cp->c_gid;
        vap->va_mode = cp->c_mode;
        vap->va_flags = cp->c_bsdflags;

        /*
         * Exporting file IDs from HFS Plus:
         *
         * For "normal" files the c_fileid is the same value as the
         * c_cnid.  But for hard link files, they are different - the
         * c_cnid belongs to the active directory entry (ie the link)
         * and the c_fileid is for the actual inode (ie the data file).
         *
         * The stat call (getattr) uses va_fileid and the Carbon APIs,
         * which are hardlink-ignorant, will ask for va_linkid.
         */
        vap->va_fileid = (u_int64_t)cp->c_fileid;
        /* 
         * We need to use the origin cache for both hardlinked files 
         * and directories. Hardlinked directories have multiple cnids 
         * and parents (one per link). Hardlinked files also have their 
         * own parents and link IDs separate from the indirect inode number. 
         * If we don't use the cache, we could end up vending the wrong ID 
         * because the cnode will only reflect the link that was looked up most recently.
         */
        if (cp->c_flag & C_HARDLINK) {
                vap->va_linkid = (u_int64_t)hfs_currentcnid(cp);
                vap->va_parentid = (u_int64_t)hfs_currentparent(cp, /* have_lock: */ true);
        } else {
                vap->va_linkid = (u_int64_t)cp->c_cnid;
                vap->va_parentid = (u_int64_t)cp->c_parentcnid;
        }

        vap->va_fsid = hfsmp->hfs_raw_dev;
        if (VATTR_IS_ACTIVE(vap, va_devid)) {
                VATTR_RETURN(vap, va_devid, hfsmp->hfs_raw_dev);
        }
        vap->va_filerev = 0;
        vap->va_encoding = cp->c_encoding;
        vap->va_rdev = (v_type == VBLK || v_type == VCHR) ? cp->c_rdev : 0;
#if HFS_COMPRESSION
        if (VATTR_IS_ACTIVE(vap, va_data_size)) {
                if (hide_size)
                        vap->va_data_size = 0;
                else if (compressed) {
                        if (uncompressed_size == -1) {
                                /* failed to get the uncompressed size above, so just return data_size */
                                vap->va_data_size = data_size;
                        } else {
                                /* use the uncompressed size we fetched above */
                                vap->va_data_size = uncompressed_size;
                        }
                } else
                        vap->va_data_size = data_size;
                VATTR_SET_SUPPORTED(vap, va_data_size);
        }
#else
        vap->va_data_size = data_size;
        vap->va_supported |= VNODE_ATTR_va_data_size;
#endif

#if CONFIG_PROTECT
        if (VATTR_IS_ACTIVE(vap, va_dataprotect_class)) {
                vap->va_dataprotect_class = cp->c_cpentry ? CP_CLASS(cp->c_cpentry->cp_pclass) : 0;
                VATTR_SET_SUPPORTED(vap, va_dataprotect_class);
        }       
#endif
        if (VATTR_IS_ACTIVE(vap, va_write_gencount)) {
                if (ubc_is_mapped_writable(vp)) {
                        /*
                         * Return 0 to the caller to indicate the file may be
                         * changing.  There is no need for us to increment the
                         * generation counter here because it gets done as part of
                         * page-out and also when the file is unmapped (to account
                         * for changes we might not have seen).
                         */
                        vap->va_write_gencount = 0;
                } else {
                        vap->va_write_gencount = hfs_get_gencount(cp);
                }

                VATTR_SET_SUPPORTED(vap, va_write_gencount);
        }

        /* Mark them all at once instead of individual VATTR_SET_SUPPORTED calls. */
        vap->va_supported |= VNODE_ATTR_va_access_time |
                                                 VNODE_ATTR_va_create_time | VNODE_ATTR_va_modify_time |
                             VNODE_ATTR_va_change_time| VNODE_ATTR_va_backup_time |
                             VNODE_ATTR_va_iosize | VNODE_ATTR_va_uid |
                             VNODE_ATTR_va_gid | VNODE_ATTR_va_mode |
                             VNODE_ATTR_va_flags |VNODE_ATTR_va_fileid |
                             VNODE_ATTR_va_linkid | VNODE_ATTR_va_parentid |
                             VNODE_ATTR_va_fsid | VNODE_ATTR_va_filerev |
                             VNODE_ATTR_va_encoding | VNODE_ATTR_va_rdev;

        /* If this is the root, let VFS to find out the mount name, which 
         * may be different from the real name.  Otherwise, we need to take care
         * for hardlinked files, which need to be looked up, if necessary 
         */
        if (VATTR_IS_ACTIVE(vap, va_name) && (cp->c_cnid != kHFSRootFolderID)) {
                struct cat_desc linkdesc;
                int lockflags;
                int uselinkdesc = 0;
                cnid_t nextlinkid = 0;
                cnid_t prevlinkid = 0;

                /* Get the name for ATTR_CMN_NAME.  We need to take special care for hardlinks      
                 * here because the info. for the link ID requested by getattrlist may be
                 * different than what's currently in the cnode.  This is because the cnode     
                 * will be filled in with the information for the most recent link ID that went
                 * through namei/lookup().  If there are competing lookups for hardlinks that point 
                 * to the same inode, one (or more) getattrlists could be vended incorrect name information.
                 * Also, we need to beware of open-unlinked files which could have a namelen of 0.     
                 */

                if ((cp->c_flag & C_HARDLINK) && 
                                ((cp->c_desc.cd_namelen == 0) || (vap->va_linkid != cp->c_cnid))) {
                        /* 
                         * If we have no name and our link ID is the raw inode number, then we may
                         * have an open-unlinked file.  Go to the next link in this case.
                         */
                        if ((cp->c_desc.cd_namelen == 0) && (vap->va_linkid == cp->c_fileid)) {
                                if ((error = hfs_lookup_siblinglinks(hfsmp, vap->va_linkid, &prevlinkid, &nextlinkid))){
                                        goto out;
                                }
                        }       
                        else {
                                /* just use link obtained from vap above */
                                nextlinkid = vap->va_linkid;
                        }

                        /* We need to probe the catalog for the descriptor corresponding to the link ID
                         * stored in nextlinkid.  Note that we don't know if we have the exclusive lock
                         * for the cnode here, so we can't just update the descriptor.  Instead,
                         * we should just store the descriptor's value locally and then use it to pass
                         * out the name value as needed below. 
                         */ 
                        if (nextlinkid){
                                lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG, HFS_SHARED_LOCK);
                                error = cat_findname(hfsmp, nextlinkid, &linkdesc);
                                hfs_systemfile_unlock(hfsmp, lockflags);        
                                if (error == 0) {
                                        uselinkdesc = 1;
                                }
                        }
                }

                /* By this point, we've either patched up the name above and the c_desc
                 * points to the correct data, or it already did, in which case we just proceed
                 * by copying the name into the vap.  Note that we will never set va_name to
                 * supported if nextlinkid is never initialized.  This could happen in the degenerate
                 * case above involving the raw inode number, where it has no nextlinkid.  In this case
                 * we will simply not mark the name bit as supported.
                 */
                if (uselinkdesc) {
                        strlcpy(vap->va_name, (const char*) linkdesc.cd_nameptr, MAXPATHLEN);
                        VATTR_SET_SUPPORTED(vap, va_name);
                        cat_releasedesc(&linkdesc);
                }       
                else if (cp->c_desc.cd_namelen) {
                        strlcpy(vap->va_name, (const char*) cp->c_desc.cd_nameptr, MAXPATHLEN);
                        VATTR_SET_SUPPORTED(vap, va_name);
                }
        }

out:
        hfs_unlock(cp);
        /*
         * We need to vnode_put the rsrc fork vnode only *after* we've released
         * the cnode lock, since vnode_put can trigger an inactive call, which 
         * will go back into HFS and try to acquire a cnode lock.
         */
        if (rvp) {
                vnode_put (rvp);
        }

        return (error);
}

int
hfs_vnop_setattr(struct vnop_setattr_args *ap)
{
        struct vnode_attr *vap = ap->a_vap;
        struct vnode *vp = ap->a_vp;
        struct cnode *cp = NULL;
        struct hfsmount *hfsmp;
        kauth_cred_t cred = vfs_context_ucred(ap->a_context);
        struct proc *p = vfs_context_proc(ap->a_context);
        int error = 0;
        uid_t nuid;
        gid_t ngid;
        time_t orig_ctime;

        orig_ctime = VTOC(vp)->c_ctime;
        
#if HFS_COMPRESSION
        int decmpfs_reset_state = 0;
        /*
         we call decmpfs_update_attributes even if the file is not compressed
         because we want to update the incoming flags if the xattrs are invalid
         */
        error = decmpfs_update_attributes(vp, vap);
        if (error)
                return error;
#endif
        //
        // if this is not a size-changing setattr and it is not just
        // an atime update, then check for a snapshot.
        //
        if (!VATTR_IS_ACTIVE(vap, va_data_size) && !(vap->va_active == VNODE_ATTR_va_access_time)) {
                nspace_snapshot_event(vp, orig_ctime, NAMESPACE_HANDLER_METADATA_MOD, NSPACE_REARM_NO_ARG);
        }

#if CONFIG_PROTECT
        /*
         * All metadata changes should be allowed except a size-changing setattr, which
         * has effects on file content and requires calling into cp_handle_vnop
         * to have content protection check.
         */
        if (VATTR_IS_ACTIVE(vap, va_data_size)) {
                if ((error = cp_handle_vnop(vp, CP_WRITE_ACCESS, 0)) != 0) {
                        return (error);
                }
        }
#endif /* CONFIG_PROTECT */

        hfsmp = VTOHFS(vp);

        /* Don't allow modification of the journal. */
        if (hfs_is_journal_file(hfsmp, VTOC(vp))) {
                return (EPERM);
        }

        //
        // Check if we'll need a document_id and if so, get it before we lock the
        // the cnode to avoid any possible deadlock with the root vnode which has
        // to get locked to get the document id
        //
        u_int32_t document_id=0;
        if (VATTR_IS_ACTIVE(vap, va_flags) && (vap->va_flags & UF_TRACKED) && !(VTOC(vp)->c_bsdflags & UF_TRACKED)) {
                struct FndrExtendedDirInfo *fip = (struct FndrExtendedDirInfo *)((char *)&(VTOC(vp)->c_attr.ca_finderinfo) + 16);
                //
                // If the document_id is not set, get a new one.  It will be set
                // on the file down below once we hold the cnode lock.
                //
                if (fip->document_id == 0) {
                        if (hfs_generate_document_id(hfsmp, &document_id) != 0) {
                                document_id = 0;
                        }
                }
        }


        /*
         * File size change request.
         * We are guaranteed that this is not a directory, and that
         * the filesystem object is writeable.
         *
         * NOTE: HFS COMPRESSION depends on the data_size being set *before* the bsd flags are updated
         */
        VATTR_SET_SUPPORTED(vap, va_data_size);
        if (VATTR_IS_ACTIVE(vap, va_data_size)) {
                if (!vnode_isreg(vp)) {
                        if (vnode_isdir(vp)) {
                                return EISDIR;
                        }
                        //otherwise return EINVAL
                        return EINVAL;
                }

#if HFS_COMPRESSION
                /* keep the compressed state locked until we're done truncating the file */
                decmpfs_cnode *dp = VTOCMP(vp);
                if (!dp) {
                        /*
                         * call hfs_lazy_init_decmpfs_cnode() to make sure that the decmpfs_cnode
                         * is filled in; we need a decmpfs_cnode to lock out decmpfs state changes
                         * on this file while it's truncating
                         */
                        dp = hfs_lazy_init_decmpfs_cnode(VTOC(vp));
                        if (!dp) {
                                /* failed to allocate a decmpfs_cnode */
                                return ENOMEM; /* what should this be? */
                        }
                }
                
                nspace_snapshot_event(vp, orig_ctime, vap->va_data_size == 0 ? NAMESPACE_HANDLER_TRUNCATE_OP|NAMESPACE_HANDLER_DELETE_OP : NAMESPACE_HANDLER_TRUNCATE_OP, NULL);

                decmpfs_lock_compressed_data(dp, 1);
                if (hfs_file_is_compressed(VTOC(vp), 1)) {
                        error = decmpfs_decompress_file(vp, dp, -1/*vap->va_data_size*/, 0, 1);
                        if (error != 0) {
                                decmpfs_unlock_compressed_data(dp, 1);
                                return error;
                        }
                }
#endif

                // Take truncate lock
                hfs_lock_truncate(VTOC(vp), HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT);

                // hfs_truncate will deal with the cnode lock
                error = hfs_truncate(vp, vap->va_data_size, vap->va_vaflags & 0xffff, 
                                                         0, ap->a_context);

                hfs_unlock_truncate(VTOC(vp), HFS_LOCK_DEFAULT);
#if HFS_COMPRESSION
                decmpfs_unlock_compressed_data(dp, 1);
#endif
                if (error)
                        return error;
        }
        if (cp == NULL) {
                if ((error = hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT)))
                        return (error);
                cp = VTOC(vp);
        }

        /*
         * If it is just an access time update request by itself
         * we know the request is from kernel level code, and we
         * can delay it without being as worried about consistency.
         * This change speeds up mmaps, in the rare case that they
         * get caught behind a sync.
         */

        if (vap->va_active == VNODE_ATTR_va_access_time) {
                cp->c_touch_acctime=TRUE;
                goto out;
        }



        /*
         * Owner/group change request.
         * We are guaranteed that the new owner/group is valid and legal.
         */
        VATTR_SET_SUPPORTED(vap, va_uid);
        VATTR_SET_SUPPORTED(vap, va_gid);
        nuid = VATTR_IS_ACTIVE(vap, va_uid) ? vap->va_uid : (uid_t)VNOVAL;
        ngid = VATTR_IS_ACTIVE(vap, va_gid) ? vap->va_gid : (gid_t)VNOVAL;
        if (((nuid != (uid_t)VNOVAL) || (ngid != (gid_t)VNOVAL)) &&
            ((error = hfs_chown(vp, nuid, ngid, cred, p)) != 0))
                goto out;

        /*
         * Mode change request.
         * We are guaranteed that the mode value is valid and that in
         * conjunction with the owner and group, this change is legal.
        */
        VATTR_SET_SUPPORTED(vap, va_mode);
        if (VATTR_IS_ACTIVE(vap, va_mode) &&
            ((error = hfs_chmod(vp, (int)vap->va_mode, cred, p)) != 0))
            goto out;

        /*
         * File flags change.
         * We are guaranteed that only flags allowed to change given the
         * current securelevel are being changed.
         */
        VATTR_SET_SUPPORTED(vap, va_flags);
        if (VATTR_IS_ACTIVE(vap, va_flags)) {
                u_int16_t *fdFlags;

#if HFS_COMPRESSION
                if ((cp->c_bsdflags ^ vap->va_flags) & UF_COMPRESSED) {
                        /*
                         * the UF_COMPRESSED was toggled, so reset our cached compressed state
                         * but we don't want to actually do the update until we've released the cnode lock down below
                         * NOTE: turning the flag off doesn't actually decompress the file, so that we can
                         * turn off the flag and look at the "raw" file for debugging purposes
                         */
                        decmpfs_reset_state = 1;
                }
#endif
                if ((vap->va_flags & UF_TRACKED) && !(cp->c_bsdflags & UF_TRACKED)) {
                        struct FndrExtendedDirInfo *fip = (struct FndrExtendedDirInfo *)((char *)&cp->c_attr.ca_finderinfo + 16);

                        //
                        // we're marking this item UF_TRACKED.  if the document_id is
                        // not set, get a new one and put it on the file.
                        //
                        if (fip->document_id == 0) {
                                if (document_id != 0) {
                                        // printf("SETATTR: assigning doc-id %d to %s (ino %d)\n", document_id, vp->v_name, cp->c_desc.cd_cnid);
                                        fip->document_id = (uint32_t)document_id;
                                        add_fsevent(FSE_DOCID_CHANGED, ap->a_context,
                                                    FSE_ARG_DEV, hfsmp->hfs_raw_dev,
                                                    FSE_ARG_INO, (ino64_t)0,                // src inode #
                                                    FSE_ARG_INO, (ino64_t)cp->c_fileid,     // dst inode #
                                                    FSE_ARG_INT32, document_id,
                                                    FSE_ARG_DONE);
                                } else {
                                        // printf("hfs: could not acquire a new document_id for %s (ino %d)\n", vp->v_name, cp->c_desc.cd_cnid);
                                }
                        }

                } else if (!(vap->va_flags & UF_TRACKED) && (cp->c_bsdflags & UF_TRACKED)) {
                        //
                        // UF_TRACKED is being cleared so clear the document_id
                        //
                        struct FndrExtendedDirInfo *fip = (struct FndrExtendedDirInfo *)((char *)&cp->c_attr.ca_finderinfo + 16);
                        if (fip->document_id) {
                                // printf("SETATTR: clearing doc-id %d from %s (ino %d)\n", fip->document_id, vp->v_name, cp->c_desc.cd_cnid);
                                add_fsevent(FSE_DOCID_CHANGED, ap->a_context,
                                            FSE_ARG_DEV, hfsmp->hfs_raw_dev,
                                            FSE_ARG_INO, (ino64_t)cp->c_fileid,          // src inode #
                                            FSE_ARG_INO, (ino64_t)0,                     // dst inode #
                                            FSE_ARG_INT32, fip->document_id,             // document id
                                            FSE_ARG_DONE);
                                fip->document_id = 0;
                                cp->c_bsdflags &= ~UF_TRACKED;
                        }
                }

                cp->c_bsdflags = vap->va_flags;
                cp->c_flag |= C_MODIFIED;
                cp->c_touch_chgtime = TRUE;

                
                /*
                 * Mirror the UF_HIDDEN flag to the invisible bit of the Finder Info.
                 *
                 * The fdFlags for files and frFlags for folders are both 8 bytes
                 * into the userInfo (the first 16 bytes of the Finder Info).  They
                 * are both 16-bit fields.
                 */
                fdFlags = (u_int16_t *) &cp->c_finderinfo[8];
                if (vap->va_flags & UF_HIDDEN)
                        *fdFlags |= OSSwapHostToBigConstInt16(kFinderInvisibleMask);
                else
                        *fdFlags &= ~OSSwapHostToBigConstInt16(kFinderInvisibleMask);
        }

        /*
         * Timestamp updates.
         */
        VATTR_SET_SUPPORTED(vap, va_create_time);
        VATTR_SET_SUPPORTED(vap, va_access_time);
        VATTR_SET_SUPPORTED(vap, va_modify_time);
        VATTR_SET_SUPPORTED(vap, va_backup_time);
        VATTR_SET_SUPPORTED(vap, va_change_time);
        if (VATTR_IS_ACTIVE(vap, va_create_time) ||
            VATTR_IS_ACTIVE(vap, va_access_time) ||
            VATTR_IS_ACTIVE(vap, va_modify_time) ||
            VATTR_IS_ACTIVE(vap, va_backup_time)) {
                if (VATTR_IS_ACTIVE(vap, va_create_time))
                        cp->c_itime = vap->va_create_time.tv_sec;
                if (VATTR_IS_ACTIVE(vap, va_access_time)) {
                        cp->c_atime = vap->va_access_time.tv_sec;
                        cp->c_touch_acctime = FALSE;
                }
                if (VATTR_IS_ACTIVE(vap, va_modify_time)) {
                        cp->c_mtime = vap->va_modify_time.tv_sec;
                        cp->c_touch_modtime = FALSE;
                        cp->c_touch_chgtime = TRUE;

                        hfs_clear_might_be_dirty_flag(cp);

                        /*
                         * The utimes system call can reset the modification
                         * time but it doesn't know about HFS create times.
                         * So we need to ensure that the creation time is
                         * always at least as old as the modification time.
                         */
                        if ((VTOVCB(vp)->vcbSigWord == kHFSPlusSigWord) &&
                            (cp->c_cnid != kHFSRootFolderID) &&
                                !VATTR_IS_ACTIVE(vap, va_create_time) &&
                            (cp->c_mtime < cp->c_itime)) {
                                cp->c_itime = cp->c_mtime;
                        }
                }
                if (VATTR_IS_ACTIVE(vap, va_backup_time))
                        cp->c_btime = vap->va_backup_time.tv_sec;
                cp->c_flag |= C_MINOR_MOD;
        }

        // Set the date added time
        VATTR_SET_SUPPORTED(vap, va_addedtime);
        if (VATTR_IS_ACTIVE(vap, va_addedtime)) {
                hfs_write_dateadded(&cp->c_attr, vap->va_addedtime.tv_sec);
                cp->c_flag &= ~C_NEEDS_DATEADDED;
                cp->c_touch_chgtime = true;
        }

        /*
         * Set name encoding.
         */
        VATTR_SET_SUPPORTED(vap, va_encoding);
        if (VATTR_IS_ACTIVE(vap, va_encoding)) {
                cp->c_encoding = vap->va_encoding;
                cp->c_flag |= C_MODIFIED;
                hfs_setencodingbits(hfsmp, cp->c_encoding);
        }

        if ((error = hfs_update(vp, 0)) != 0)
                goto out;

out:
        if (cp) {
                /* Purge origin cache for cnode, since caller now has correct link ID for it 
                 * We purge it here since it was acquired for us during lookup, and we no longer need it.
                 */
                if ((cp->c_flag & C_HARDLINK) && (vnode_vtype(vp) != VDIR)){
                        hfs_relorigin(cp, 0);
                }

                hfs_unlock(cp);
#if HFS_COMPRESSION
                if (decmpfs_reset_state) {
                        /*
                         * we've changed the UF_COMPRESSED flag, so reset the decmpfs state for this cnode
                         * but don't do it while holding the hfs cnode lock
                         */
                        decmpfs_cnode *dp = VTOCMP(vp);
                        if (!dp) {
                                /*
                                 * call hfs_lazy_init_decmpfs_cnode() to make sure that the decmpfs_cnode
                                 * is filled in; we need a decmpfs_cnode to prevent decmpfs state changes
                                 * on this file if it's locked
                                 */
                                dp = hfs_lazy_init_decmpfs_cnode(VTOC(vp));
                                if (!dp) {
                                        /* failed to allocate a decmpfs_cnode */
                                        return ENOMEM; /* what should this be? */
                                }
                        }
                        decmpfs_cnode_set_vnode_state(dp, FILE_TYPE_UNKNOWN, 0);
                }
#endif
        }

#if CONFIG_PROTECT
        VATTR_SET_SUPPORTED(vap, va_dataprotect_class);
        if (!error && VATTR_IS_ACTIVE(vap, va_dataprotect_class))
                error = cp_vnode_setclass(vp, vap->va_dataprotect_class);
#endif

        return (error);
}


/*
 * Change the mode on a file.
 * cnode must be locked before calling.
 */
int
hfs_chmod(struct vnode *vp, int mode, __unused kauth_cred_t cred, __unused struct proc *p)
{
        register struct cnode *cp = VTOC(vp);

        if (VTOVCB(vp)->vcbSigWord != kHFSPlusSigWord)
                return (0);

        // Don't allow modification of the journal or journal_info_block
        if (hfs_is_journal_file(VTOHFS(vp), cp)) {
                return EPERM;
        }

#if OVERRIDE_UNKNOWN_PERMISSIONS
        if (((unsigned int)vfs_flags(VTOVFS(vp))) & MNT_UNKNOWNPERMISSIONS) {
                return (0);
        };
#endif

        mode_t new_mode = (cp->c_mode & ~ALLPERMS) | (mode & ALLPERMS);
        if (new_mode != cp->c_mode) {
                cp->c_mode = new_mode;
                cp->c_flag |= C_MINOR_MOD;
        }
        cp->c_touch_chgtime = TRUE;
        return (0);
}


int
hfs_write_access(struct vnode *vp, kauth_cred_t cred, struct proc *p, Boolean considerFlags)
{
        struct cnode *cp = VTOC(vp);
        int retval = 0;
        int is_member;

        /*
         * Disallow write attempts on read-only file systems;
         * unless the file is a socket, fifo, or a block or
         * character device resident on the file system.
         */
        switch (vnode_vtype(vp)) {
        case VDIR:
        case VLNK:
        case VREG:
                if (VTOHFS(vp)->hfs_flags & HFS_READ_ONLY)
                        return (EROFS);
                break;
        default:
                break;
        }
 
        /* If immutable bit set, nobody gets to write it. */
        if (considerFlags && (cp->c_bsdflags & IMMUTABLE))
                return (EPERM);

        /* Otherwise, user id 0 always gets access. */
        if (!suser(cred, NULL))
                return (0);

        /* Otherwise, check the owner. */
        if ((retval = hfs_owner_rights(VTOHFS(vp), cp->c_uid, cred, p, false)) == 0)
                return ((cp->c_mode & S_IWUSR) == S_IWUSR ? 0 : EACCES);
 
        /* Otherwise, check the groups. */
        if (kauth_cred_ismember_gid(cred, cp->c_gid, &is_member) == 0 && is_member) {
                return ((cp->c_mode & S_IWGRP) == S_IWGRP ? 0 : EACCES);
        }
 
        /* Otherwise, check everyone else. */
        return ((cp->c_mode & S_IWOTH) == S_IWOTH ? 0 : EACCES);
}


/*
 * Perform chown operation on cnode cp;
 * code must be locked prior to call.
 */
int
#if !QUOTA
hfs_chown(struct vnode *vp, uid_t uid, gid_t gid, __unused kauth_cred_t cred,
        __unused struct proc *p)
#else 
hfs_chown(struct vnode *vp, uid_t uid, gid_t gid, kauth_cred_t cred,
        __unused struct proc *p)
#endif
{
        register struct cnode *cp = VTOC(vp);
        uid_t ouid;
        gid_t ogid;
#if QUOTA
        int error = 0;
        register int i;
        int64_t change;
#endif /* QUOTA */

        if (VTOVCB(vp)->vcbSigWord != kHFSPlusSigWord)
                return (ENOTSUP);

        if (((unsigned int)vfs_flags(VTOVFS(vp))) & MNT_UNKNOWNPERMISSIONS)
                return (0);
        
        if (uid == (uid_t)VNOVAL)
                uid = cp->c_uid;
        if (gid == (gid_t)VNOVAL)
                gid = cp->c_gid;

#if 0   /* we are guaranteed that this is already the case */
        /*
         * If we don't own the file, are trying to change the owner
         * of the file, or are not a member of the target group,
         * the caller must be superuser or the call fails.
         */
        if ((kauth_cred_getuid(cred) != cp->c_uid || uid != cp->c_uid ||
            (gid != cp->c_gid &&
             (kauth_cred_ismember_gid(cred, gid, &is_member) || !is_member))) &&
            (error = suser(cred, 0)))
                return (error);
#endif

        ogid = cp->c_gid;
        ouid = cp->c_uid;

        if (ouid == uid && ogid == gid) {
                // No change, just set change time
                cp->c_touch_chgtime = TRUE;
                return 0;
        }

#if QUOTA
        if ((error = hfs_getinoquota(cp)))
                return (error);
        if (ouid == uid) {
                dqrele(cp->c_dquot[USRQUOTA]);
                cp->c_dquot[USRQUOTA] = NODQUOT;
        }
        if (ogid == gid) {
                dqrele(cp->c_dquot[GRPQUOTA]);
                cp->c_dquot[GRPQUOTA] = NODQUOT;
        }

        /*
         * Eventually need to account for (fake) a block per directory
         * if (vnode_isdir(vp))
         *     change = VTOHFS(vp)->blockSize;
         * else
         */

        change = (int64_t)(cp->c_blocks) * (int64_t)VTOVCB(vp)->blockSize;
        (void) hfs_chkdq(cp, -change, cred, CHOWN);
        (void) hfs_chkiq(cp, -1, cred, CHOWN);
        for (i = 0; i < MAXQUOTAS; i++) {
                dqrele(cp->c_dquot[i]);
                cp->c_dquot[i] = NODQUOT;
        }
#endif /* QUOTA */
        cp->c_gid = gid;
        cp->c_uid = uid;
#if QUOTA
        if ((error = hfs_getinoquota(cp)) == 0) {
                if (ouid == uid) {
                        dqrele(cp->c_dquot[USRQUOTA]);
                        cp->c_dquot[USRQUOTA] = NODQUOT;
                }
                if (ogid == gid) {
                        dqrele(cp->c_dquot[GRPQUOTA]);
                        cp->c_dquot[GRPQUOTA] = NODQUOT;
                }
                if ((error = hfs_chkdq(cp, change, cred, CHOWN)) == 0) {
                        if ((error = hfs_chkiq(cp, 1, cred, CHOWN)) == 0)
                                goto good;
                        else
                                (void) hfs_chkdq(cp, -change, cred, CHOWN|FORCE);
                }
                for (i = 0; i < MAXQUOTAS; i++) {
                        dqrele(cp->c_dquot[i]);
                        cp->c_dquot[i] = NODQUOT;
                }
        }
        cp->c_gid = ogid;
        cp->c_uid = ouid;
        if (hfs_getinoquota(cp) == 0) {
                if (ouid == uid) {
                        dqrele(cp->c_dquot[USRQUOTA]);
                        cp->c_dquot[USRQUOTA] = NODQUOT;
                }
                if (ogid == gid) {
                        dqrele(cp->c_dquot[GRPQUOTA]);
                        cp->c_dquot[GRPQUOTA] = NODQUOT;
                }
                (void) hfs_chkdq(cp, change, cred, FORCE|CHOWN);
                (void) hfs_chkiq(cp, 1, cred, FORCE|CHOWN);
                (void) hfs_getinoquota(cp);
        }
        return (error);
good:
        if (hfs_getinoquota(cp))
                panic("hfs_chown: lost quota");
#endif /* QUOTA */

        /*
         * Without quotas, we could probably make this a minor
         * modification.
         */
        cp->c_flag |= C_MODIFIED;

        /*
          According to the SUSv3 Standard, chown() shall mark
          for update the st_ctime field of the file.
          (No exceptions mentioned)
        */
                cp->c_touch_chgtime = TRUE;
        return (0);
}

#if HFS_COMPRESSION
/*
 * Flush the resource fork if it exists.  vp is the data fork and has
 * an iocount.
 */
static int hfs_flush_rsrc(vnode_t vp, vfs_context_t ctx)
{
        cnode_t *cp = VTOC(vp);

        hfs_lock(cp, HFS_SHARED_LOCK, 0);

        vnode_t rvp = cp->c_rsrc_vp;

        if (!rvp) {
                hfs_unlock(cp);
                return 0;
        }

        int vid = vnode_vid(rvp);

        hfs_unlock(cp);

        int error = vnode_getwithvid(rvp, vid);

        if (error)
                return error == ENOENT ? 0 : error;

        hfs_lock_truncate(cp, HFS_EXCLUSIVE_LOCK, 0);
        hfs_lock_always(cp, HFS_EXCLUSIVE_LOCK);
        hfs_filedone(rvp, ctx, HFS_FILE_DONE_NO_SYNC);
        hfs_unlock(cp);
        hfs_unlock_truncate(cp, 0);

        error = ubc_msync(rvp, 0, ubc_getsize(rvp), NULL,
                                          UBC_PUSHALL | UBC_SYNC);

        vnode_put(rvp);

        return error;
}
#endif // HFS_COMPRESSION


/* Helper Functions for exchangedata(2) */

/*
 * hfs_exchangedata_getxattr
 * arguments: 
 *      vp: vnode to extract the EA for
 *      name_selector: the index into the array of EA name entries.     
 *  buffer: address for output buffer to store the output EA
 *      NOTE: This function will allocate the buffer, it is the caller's responsibility to free it.
 * xattr_size: output argument; will return the size of the EA, to correspond with the buffer. 
 * 
 * Return: 0 on success.
 * errno on error.  If we return any error, the buffer is guaranteed to be NULL. 
 * 
 * Assumes CNODE lock held on cnode for 'vp'
 */
static 
int hfs_exchangedata_getxattr (struct vnode *vp, uint32_t name_selector,  void **buffer, size_t *xattr_size) {
        void *xattr_rawdata = NULL;
        void *extracted_xattr = NULL;
        uio_t uio;
        size_t memsize = MAX_EXCHANGE_EA_SIZE;
        size_t attrsize;
        int error = 0;
        struct hfsmount *hfsmp = NULL;

        /* Sanity check inputs */
        if (name_selector > MAX_NUM_XATTR_NAMES) {
                return EINVAL;
        }

        if (buffer == NULL || xattr_size == NULL) {
                return EINVAL;
        }

        hfsmp = VTOHFS(vp);

        //allocate 4k memory to hold the EA.  We don't use this for "large" EAs, and the default
        //EA B-tree size should produce inline attributes of size < 4K
        xattr_rawdata = hfs_malloc (MAX_EXCHANGE_EA_SIZE);      
        if (!xattr_rawdata) {
                return ENOMEM;
        }       

        //now create the UIO
        uio = uio_create (1, 0, UIO_SYSSPACE, UIO_READ);
        if (!uio) {
                hfs_free (xattr_rawdata, memsize);
                return ENOMEM;
        }
        uio_addiov(uio, CAST_USER_ADDR_T(xattr_rawdata), memsize);
        attrsize = memsize;
        
        struct vnop_getxattr_args vga = {
                .a_uio = uio,
                .a_name = XATTR_NAMES[name_selector],
                .a_size = &attrsize
        };

        // this takes care of grabbing the systemfile locks for us. 
        error = hfs_getxattr_internal (VTOC(vp), &vga, hfsmp, 0); 

        if (error) {
                /* 
                 * We could have gotten a variety of errors back from the XATTR tree:
                 * is it too big? (bigger than 4k?) == ERANGE
                 * was the EA not found? == ENOATTR
                 */
                uio_free(uio);
                hfs_free (xattr_rawdata, memsize);
                return error;
        }

        //free the UIO
        uio_free(uio);

        //upon success, a_size/attrsize now contains the actua/exported EA size
        extracted_xattr = hfs_malloc (attrsize);
        memcpy (extracted_xattr, xattr_rawdata, attrsize);
        hfs_free (xattr_rawdata, memsize);

        *xattr_size = attrsize;
        *buffer = extracted_xattr;

        return error;           
}
        

/*
 * hfs_exchangedata_setxattr
 * 
 * Note: This function takes fileIDs in as inputs, because exchangedata does
 * swizzly things with the two cnodes (See big block comment in hfs_vnop_exchange)
 * so we operate with FileIDs more or less directly on the XATTR b-tree.
 * 
 * arguments: 
 *      hfsmp: the mount we're working on
 *      fileid: the fileID of the EA to store into the tree.
 *      name_selector: selector into the EA name array. 
 *      buffer: pointer to the memory of the EA to write. 
 *      xattr_size: size of the EA to write.
 * 
 * Returns 0 on success
 * errno on failure
 *
 * Assumes that a transaction has already begun when this is called
 */

static 
int hfs_exchangedata_setxattr (struct hfsmount *hfsmp, uint32_t fileid, 
                uint32_t name_selector, void *buffer, size_t xattr_size) {

        int error = 0;


        /* Sanity check arguments */
        if (name_selector > MAX_NUM_XATTR_NAMES) {
                return EINVAL;
        }

        if (buffer == NULL  || xattr_size == 0 || fileid < kHFSFirstUserCatalogNodeID ) {
                return EINVAL;
        }

        // is the size too big?
        if (xattr_size > hfsmp->hfs_max_inline_attrsize) {
                return EINVAL;
        }

        /* setup the arguments to setxattr*/
        struct vnop_setxattr_args vsa = {
                .a_desc = NULL,
                .a_vp = NULL,
                .a_name = XATTR_NAMES[name_selector], 
                .a_uio = NULL, // we use the data_ptr argument to setxattr_internal instead 
                .a_options = 0,
                .a_context = NULL // no context needed, only done from within exchangedata
        };      

        /*
         * Since we must be in a transaction to guard the exchangedata operation, this will start
         * a nested transaction within the exchangedata one.
         */
        error = hfs_setxattr_internal (NULL, (caddr_t) buffer, xattr_size, &vsa, hfsmp, fileid);

        return error;

}

/*
 * hfs_vnop_exchange:
 * 
 * Inputs: 
 *              'from' vnode/cnode
 *              'to' vnode/cnode
 *              options flag bits
 *              vfs_context
 * 
 * Discussion:
 * hfs_vnop_exchange is used to service the exchangedata(2) system call.
 * Per the requirements of that system call, this function "swaps" some
 * of the information that lives in one catalog record for some that
 * lives in another.  Note that not everything is swapped; in particular, 
 * the extent information stored in each cnode is kept local to that 
 * cnode.  This allows existing file descriptor references to continue
 * to operate on the same content, regardless of the location in the
 * namespace that the file may have moved to.  See inline comments
 * in the function for more information.
 */
int
hfs_vnop_exchange(struct vnop_exchange_args *ap)
{
        struct vnode *from_vp = ap->a_fvp;
        struct vnode *to_vp = ap->a_tvp;
        struct cnode *from_cp;
        struct cnode *to_cp;
        struct hfsmount *hfsmp;
        struct cat_desc tempdesc;
        struct cat_attr tempattr;
        const unsigned char *from_nameptr;
        const unsigned char *to_nameptr;
        char from_iname[32];
        char to_iname[32];
        uint32_t to_flag_special;
        uint32_t from_flag_special;

        uint16_t to_recflags_special;
        uint16_t from_recflags_special;
        
        cnid_t  from_parid;
        cnid_t  to_parid;
        int lockflags;
        int error = 0, started_tr = 0, got_cookie = 0;
        cat_cookie_t cookie;
        time_t orig_from_ctime, orig_to_ctime;
        bool have_cnode_locks = false, have_from_trunc_lock = false, have_to_trunc_lock = false;
        
        /* For the quarantine EA */
        void *from_xattr = NULL;
        void *to_xattr = NULL;
        size_t from_attrsize = 0;
        size_t to_attrsize = 0;


        /*
         * VFS does the following checks:
         * 1. Validate that both are files.
         * 2. Validate that both are on the same mount.
         * 3. Validate that they're not the same vnode.
         */

        from_cp = VTOC(from_vp);
        to_cp = VTOC(to_vp);
        hfsmp = VTOHFS(from_vp);

        orig_from_ctime = from_cp->c_ctime;
        orig_to_ctime = to_cp->c_ctime;

#if CONFIG_PROTECT
        /* 
         * Do not allow exchangedata/F_MOVEDATAEXTENTS on data-protected filesystems 
         * because the EAs will not be swapped.  As a result, the persistent keys would not
         * match and the files will be garbage.
         */
        if (cp_fs_protected (vnode_mount(from_vp))) {
                return EINVAL;
        }
#endif

#if HFS_COMPRESSION
        if (!ISSET(ap->a_options, FSOPT_EXCHANGE_DATA_ONLY)) {
                if ( hfs_file_is_compressed(from_cp, 0) ) {
                        if ( 0 != ( error = decmpfs_decompress_file(from_vp, VTOCMP(from_vp), -1, 0, 1) ) ) {
                                return error;
                        }
                }

                if ( hfs_file_is_compressed(to_cp, 0) ) {
                        if ( 0 != ( error = decmpfs_decompress_file(to_vp, VTOCMP(to_vp), -1, 0, 1) ) ) {
                                return error;
                        }
                }
        }
#endif // HFS_COMPRESSION

        // Resource forks cannot be exchanged.
        if (VNODE_IS_RSRC(from_vp) || VNODE_IS_RSRC(to_vp))
                return EINVAL;

        /* 
         * Normally, we want to notify the user handlers about the event,
         * except if it's a handler driving the event.
         */
        if ((ap->a_options & FSOPT_EXCHANGE_DATA_ONLY) == 0) {
                nspace_snapshot_event(from_vp, orig_from_ctime, NAMESPACE_HANDLER_WRITE_OP, NULL);
                nspace_snapshot_event(to_vp, orig_to_ctime, NAMESPACE_HANDLER_WRITE_OP, NULL);
        } else {
                /*
                 * This is currently used by mtmd so we should tidy up the
                 * file now because the data won't be used again in the
                 * destination file.
                 */
                hfs_lock_truncate(from_cp, HFS_EXCLUSIVE_LOCK, 0);
                hfs_lock_always(from_cp, HFS_EXCLUSIVE_LOCK);
                hfs_filedone(from_vp, ap->a_context, HFS_FILE_DONE_NO_SYNC);
                hfs_unlock(from_cp);
                hfs_unlock_truncate(from_cp, 0);

                // Flush all the data from the source file
                error = ubc_msync(from_vp, 0, ubc_getsize(from_vp), NULL,
                                                  UBC_PUSHALL | UBC_SYNC);
                if (error)
                        goto exit;

#if HFS_COMPRESSION
                /*
                 * If this is a compressed file, we need to do the same for
                 * the resource fork.
                 */
                if (ISSET(from_cp->c_bsdflags, UF_COMPRESSED)) {
                        error = hfs_flush_rsrc(from_vp, ap->a_context);
                        if (error)
                                goto exit;
                }
#endif

                /*
                 * We're doing a data-swap so we need to take the truncate
                 * lock exclusively.  We need an exclusive lock because we
                 * will be completely truncating the source file and we must
                 * make sure nobody else sneaks in and trys to issue I/O
                 * whilst we don't have the cnode lock.
                 *
                 * After taking the truncate lock we do a quick check to
                 * verify there are no other references (including mmap
                 * references), but we must remember that this does not stop
                 * anybody coming in later and taking a reference.  We will
                 * have the truncate lock exclusively so that will prevent
                 * them from issuing any I/O.
                 */

                if (to_cp < from_cp) {
                        hfs_lock_truncate(to_cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT);
                        have_to_trunc_lock = true;
                }

                hfs_lock_truncate(from_cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT);
                have_from_trunc_lock = true;

                /*
                 * Do an early check to verify the source is not in use by
                 * anyone.  We should be called from an FD opened as F_EVTONLY
                 * so that doesn't count as a reference.
                 */
                if (vnode_isinuse(from_vp, 0)) {
                        error = EBUSY;
                        goto exit;
                }

                if (to_cp >= from_cp) {
                        hfs_lock_truncate(to_cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT);
                        have_to_trunc_lock = true;
                }
        }

        if ((error = hfs_lockpair(from_cp, to_cp, HFS_EXCLUSIVE_LOCK)))
                goto exit;
        have_cnode_locks = true;

        // Don't allow modification of the journal or journal_info_block
        if (hfs_is_journal_file(hfsmp, from_cp) ||
            hfs_is_journal_file(hfsmp, to_cp)) {
                error = EPERM;
                goto exit;
        }

        /* 
         * If doing a data move, then call the underlying function. 
         */
        if (ISSET(ap->a_options, FSOPT_EXCHANGE_DATA_ONLY)) {
#if HFS_COMPRESSION
                if (ISSET(from_cp->c_bsdflags, UF_COMPRESSED)) {
                        error = hfs_move_compressed(from_cp, to_cp);
                        goto exit;
                }
#endif

                error = hfs_move_data(from_cp, to_cp, 0);
                goto exit;
        }

        /* 
         * If we're doing a normal exchangedata, then get the source/dst quarantine
         * EAs as needed. We do it here before we start the transaction. 
         */

        //get the EA for the 'from' vnode if it exists.
        error = hfs_exchangedata_getxattr (from_vp, quarantine, &from_xattr, &from_attrsize);
        if (error) {
                if (error == ENOATTR) { 
                        //it's OK for the quarantine EA to not exist
                        error = 0;
                }
                else {
                        goto exit;
                }
        }


        //get the EA from the 'to' vnode if it exists
        error = hfs_exchangedata_getxattr (to_vp, quarantine, &to_xattr, &to_attrsize);
        if (error) {
                if (error == ENOATTR) { 
                        //it's OK for the quarantine EA to not exist
                        error = 0;
                }
                else {
                        goto exit;
                }
        }
        

        /* Start a transaction; we have to do all of this atomically */
        if ((error = hfs_start_transaction(hfsmp)) != 0) {
            goto exit;
        }
        started_tr = 1;
        
        /*
         * Reserve some space in the Catalog file.
         */
        if ((error = cat_preflight(hfsmp, CAT_EXCHANGE, &cookie, vfs_context_proc(ap->a_context)))) {
                goto exit;
        }
        got_cookie = 1;

        /* The backend code always tries to delete the virtual
         * extent id for exchanging files so we need to lock
         * the extents b-tree.
         */
        lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG | SFL_EXTENTS | SFL_ATTRIBUTE, HFS_EXCLUSIVE_LOCK);

        /* Account for the location of the catalog objects. */
        if (from_cp->c_flag & C_HARDLINK) {
                MAKE_INODE_NAME(from_iname, sizeof(from_iname),
                                from_cp->c_attr.ca_linkref);
                from_nameptr = (unsigned char *)from_iname;
                from_parid = hfsmp->hfs_private_desc[FILE_HARDLINKS].cd_cnid;
                from_cp->c_hint = 0;
        } else {
                from_nameptr = from_cp->c_desc.cd_nameptr;
                from_parid = from_cp->c_parentcnid;
        }
        if (to_cp->c_flag & C_HARDLINK) {
                MAKE_INODE_NAME(to_iname, sizeof(to_iname),
                                to_cp->c_attr.ca_linkref);
                to_nameptr = (unsigned char *)to_iname;
                to_parid = hfsmp->hfs_private_desc[FILE_HARDLINKS].cd_cnid;
                to_cp->c_hint = 0;
        } else {
                to_nameptr = to_cp->c_desc.cd_nameptr;
                to_parid = to_cp->c_parentcnid;
        }

        /*
         * ExchangeFileIDs swaps the on-disk, or in-BTree extent information 
         * attached to two different file IDs.  It also swaps the extent 
         * information that may live in the extents-overflow B-Tree.
         *
         * We do this in a transaction as this may require a lot of B-Tree nodes
         * to do completely, particularly if one of the files in question
         * has a lot of extents. 
         *
         * For example, assume "file1" has fileID 50, and "file2" has fileID 52.
         * For the on-disk records, which are assumed to be synced, we will
         * first swap the resident inline-8 extents as part of the catalog records.
         * Then we will swap any extents overflow records for each file.
         * 
         * When ExchangeFileIDs returns successfully, "file1" will have fileID 52, 
         * and "file2" will have fileID 50.  However, note that this is only 
         * approximately half of the work that exchangedata(2) will need to 
         * accomplish.  In other words, we swap "too much" of the information 
         * because if we only called ExchangeFileIDs, both the fileID and extent 
         * information would be the invariants of this operation.  We don't 
         * actually want that; we want to conclude with "file1" having 
         * file ID 50, and "file2" having fileID 52.
         * 
         * The remainder of hfs_vnop_exchange will swap the file ID and other cnode
         * data back to the proper ownership, while still allowing the cnode to remain
         * pointing at the same set of extents that it did originally.
         */
        error = ExchangeFileIDs(hfsmp, from_nameptr, to_nameptr, from_parid,
                                to_parid, from_cp->c_hint, to_cp->c_hint);
        hfs_systemfile_unlock(hfsmp, lockflags);        

        if (error != E_NONE) {
                error = MacToVFSError(error);
                goto exit;
        }

        /* 
         * Now, we have to swap the quarantine EA. 
         * 
         * Ordinarily, we would not have to swap/exchange any extended attributes, 
         * since they are keyed by the file ID, and this function is supposed
     * to manipulate the main data stream/fork only. 
         * 
         * However, we want the quarantine EA to follow the file content.
         */

        int from_xattr_status = 0;
        if (from_xattr) {
                /* 
                 * Caution! 
                 * We've crossed a point of no return here, because if we
                 * have successfully swapped the file content above, we need to continue here
                 * to swap the rest of the cnode content, which is not subject to failure.
                 * Failing the whole function because the xattr swap will result in perceived
                 * data loss to the caller, so we swallow the error case here. 
                 */ 
                from_xattr_status = hfs_removexattr_by_id (hfsmp, from_cp->c_fileid, XATTR_NAMES[quarantine]);  
                if (from_xattr_status == 0) {
                        int xattr_lockflags;
                        int remaining_eas;
                        /* 
                         * Check to see if we need to remove the xattr bit from the catalog record flags while
                         * 'from_cp' still tracks with its original file ID. Once the cnodes' contents are swapped
                         * and they are ready to be re-hashed, we will OR in the bit if we know that we moved the
                         * EA to the counterpart. 
                         */ 
                        xattr_lockflags = hfs_systemfile_lock (hfsmp, SFL_ATTRIBUTE, HFS_SHARED_LOCK);
                        remaining_eas = file_attribute_exist (hfsmp, from_cp->c_fileid);
                        if (remaining_eas == 0) {
                                from_cp->c_attr.ca_recflags &= ~kHFSHasAttributesMask;
                                //the cnode will be pushed out to disk LATER on.
                        }
                        hfs_systemfile_unlock (hfsmp, xattr_lockflags);

                }       
        }

        //and the same for to_xattr
        if (to_xattr) {
                int xattr_status = hfs_removexattr_by_id (hfsmp, to_cp->c_fileid, XATTR_NAMES[quarantine]);     
                
                if (xattr_status == 0) {
                        int xattr_lockflags;
                        int remaining_eas;
                        /* 
                         * Check to see if we need to remove the xattr bit from the catalog record flags while
                         * 'to_cp' still tracks with its original file ID. Once the cnodes' contents are swapped
                         * and they are ready to be re-hashed, we will OR in the bit if we know that we moved the
                         * EA to the counterpart. 
                         */
                        xattr_lockflags = hfs_systemfile_lock (hfsmp, SFL_ATTRIBUTE, HFS_SHARED_LOCK);
                        remaining_eas = file_attribute_exist (hfsmp, from_cp->c_fileid);
                        if (remaining_eas == 0) {
                                to_cp->c_attr.ca_recflags &= ~kHFSHasAttributesMask;
                                //the cnode will be pushed out to disk LATER on.
                        }
                        hfs_systemfile_unlock (hfsmp, xattr_lockflags);

                        /* Now move the EA to the counterparty fileID. We piggyback on the larger transaction here */
                        hfs_exchangedata_setxattr (hfsmp, from_cp->c_fileid, quarantine, to_xattr, to_attrsize);
                }
        }

        if (from_xattr && from_xattr_status == 0) {
                /* 
                 * if the from EA got removed properly, then attach it to the 'to' file.  We do it at this point
                 * to ensure that it got removed properly above before re-setting it again.
                 */ 
                hfs_exchangedata_setxattr (hfsmp, to_cp->c_fileid, quarantine, from_xattr, from_attrsize);
        }


        /* Purge the vnodes from the name cache */
        if (from_vp)
                cache_purge(from_vp);
        if (to_vp)
                cache_purge(to_vp);

        /* Bump both source and destination write counts before any swaps. */
        {
                hfs_incr_gencount (from_cp);
                hfs_incr_gencount (to_cp);
        }

        /* Save a copy of "from" attributes before swapping. */
        bcopy(&from_cp->c_desc, &tempdesc, sizeof(struct cat_desc));
        bcopy(&from_cp->c_attr, &tempattr, sizeof(struct cat_attr));
        
        /* Save whether or not each cnode is a hardlink or has EAs */
        from_flag_special = from_cp->c_flag & (C_HARDLINK | C_HASXATTRS);
        from_recflags_special = (from_cp->c_attr.ca_recflags & kHFSHasAttributesMask);

        to_flag_special = to_cp->c_flag & (C_HARDLINK | C_HASXATTRS);
        to_recflags_special = (to_cp->c_attr.ca_recflags & kHFSHasAttributesMask);

        /* Drop the special bits from each cnode */
        from_cp->c_flag &= ~(C_HARDLINK | C_HASXATTRS);
        to_cp->c_flag &= ~(C_HARDLINK | C_HASXATTRS);
        from_cp->c_attr.ca_recflags &= ~(kHFSHasAttributesMask);
        to_cp->c_attr.ca_recflags &= ~(kHFSHasAttributesMask);

        /*
         * Now complete the in-memory portion of the copy.
         *
         * ExchangeFileIDs swaps the on-disk records involved.  We complete the
         * operation by swapping the in-memory contents of the two files here.
         * We swap the cnode descriptors, which contain name, BSD attributes,
         * timestamps, etc, about the file.  
         * 
         * NOTE: We do *NOT* swap the fileforks of the two cnodes.  We have
         * already swapped the on-disk extent information.  As long as we swap the 
         * IDs, the in-line resident 8 extents that live in the filefork data
         * structure will point to the right data for the new file ID if we leave 
         * them alone.
         *
         * As a result, any file descriptor that points to a particular
         * vnode (even though it should change names), will continue
         * to point to the same content. 
         */

        /* Copy the "to" -> "from" cnode */
        bcopy(&to_cp->c_desc, &from_cp->c_desc, sizeof(struct cat_desc));

        from_cp->c_hint = 0;
        /*
         * If 'to' was a hardlink, then we copied over its link ID/CNID/(namespace ID) 
         * when we bcopy'd the descriptor above.  However, the cnode attributes
         * are not bcopied.  As a result, make sure to swap the file IDs of each item.
         *
         * Further, other hardlink attributes must be moved along in this swap:
         * the linkcount, the linkref, and the firstlink all need to move
         * along with the file IDs.  See note below regarding the flags and
         * what moves vs. what does not.
         *
         * For Reference:
         * linkcount == total # of hardlinks.
         * linkref == the indirect inode pointer.
         * firstlink == the first hardlink in the chain (written to the raw inode).
         * These three are tied to the fileID and must move along with the rest of the data.
         */ 
        from_cp->c_fileid = to_cp->c_attr.ca_fileid;

        from_cp->c_itime = to_cp->c_itime;
        from_cp->c_btime = to_cp->c_btime;
        from_cp->c_atime = to_cp->c_atime;
        from_cp->c_ctime = to_cp->c_ctime;
        from_cp->c_gid = to_cp->c_gid;
        from_cp->c_uid = to_cp->c_uid;
        from_cp->c_bsdflags = to_cp->c_bsdflags;
        from_cp->c_mode = to_cp->c_mode;
        from_cp->c_linkcount = to_cp->c_linkcount;
        from_cp->c_attr.ca_linkref = to_cp->c_attr.ca_linkref;
        from_cp->c_attr.ca_firstlink = to_cp->c_attr.ca_firstlink;

        /* 
         * The cnode flags need to stay with the cnode and not get transferred
         * over along with everything else because they describe the content; they are
         * not attributes that reflect changes specific to the file ID.  In general, 
         * fields that are tied to the file ID are the ones that will move.
         * 
         * This reflects the fact that the file may have borrowed blocks, dirty metadata, 
         * or other extents, which may not yet have been written to the catalog.  If 
         * they were, they would have been transferred above in the ExchangeFileIDs call above...
         *
         * The flags that are special are:
         * C_HARDLINK, C_HASXATTRS
         * 
         * and the c_attr recflag:
         *  kHFSHasAttributesMask
         * 
         * These flags move with the item and file ID in the namespace since their
         * state is tied to that of the file ID.
         * 
         * So to transfer the flags, we have to take the following steps
         * 1) Store in a localvar whether or not the special bits are set.
         * 2) Drop the special bits from the current flags
         * 3) swap the special flag bits to their destination
         */      
        from_cp->c_flag |= to_flag_special | C_MODIFIED;
        from_cp->c_attr.ca_recflags = to_cp->c_attr.ca_recflags;
        from_cp->c_attr.ca_recflags |= to_recflags_special;
        if (from_xattr) {
                /* 
                 * NOTE:
                 * This is counter-intuitive and part of the complexity of exchangedata.
                 * if 'from_cp' originally had a quarantine EA, then ensure that the cnode
                 * pointed to by 'from_cp' CONTINUES to keep the "has EAs" bit. This is because
                 * the cnode is about to be re-hashed with a new ID, but the file CONTENT 
                 * (i.e. the file fork) stayed put.  And we want the quarantine EA to follow
                 * the content.  The check above is correct. 
                 */
                from_cp->c_attr.ca_recflags |= kHFSHasAttributesMask;
        }

        bcopy(to_cp->c_finderinfo, from_cp->c_finderinfo, 32);


        /* Copy the "from" -> "to" cnode */
        bcopy(&tempdesc, &to_cp->c_desc, sizeof(struct cat_desc));
        to_cp->c_hint = 0;
        /* 
         * Pull the file ID from the tempattr we copied above. We can't assume 
         * it is the same as the CNID.
         */
        to_cp->c_fileid = tempattr.ca_fileid;
        to_cp->c_itime = tempattr.ca_itime;
        to_cp->c_btime = tempattr.ca_btime;
        to_cp->c_atime = tempattr.ca_atime;
        to_cp->c_ctime = tempattr.ca_ctime;
        to_cp->c_gid = tempattr.ca_gid;
        to_cp->c_uid = tempattr.ca_uid;
        to_cp->c_bsdflags = tempattr.ca_flags;
        to_cp->c_mode = tempattr.ca_mode;
        to_cp->c_linkcount = tempattr.ca_linkcount;
        to_cp->c_attr.ca_linkref = tempattr.ca_linkref;
        to_cp->c_attr.ca_firstlink = tempattr.ca_firstlink;

        /* 
         * Only OR in the "from" flags into our cnode flags below. 
         * Leave the rest of the flags alone.
         */
        to_cp->c_flag |= from_flag_special | C_MODIFIED;
        to_cp->c_attr.ca_recflags = tempattr.ca_recflags;
        to_cp->c_attr.ca_recflags |= from_recflags_special;

        if (to_xattr) {
                /* 
                 * NOTE:
                 * This is counter-intuitive and part of the complexity of exchangedata.
                 * if 'to_cp' originally had a quarantine EA, then ensure that the cnode
                 * pointed to by 'to_cp' CONTINUES to keep the "has EAs" bit. This is because
                 * the cnode is about to be re-hashed with a new ID, but the file CONTENT 
                 * (i.e. the file fork) stayed put.  And we want the quarantine EA to follow
                 * the content.  The check above is correct. 
                 */
                to_cp->c_attr.ca_recflags |= kHFSHasAttributesMask;
        }

        bcopy(tempattr.ca_finderinfo, to_cp->c_finderinfo, 32);


        /* Rehash the cnodes using their new file IDs */
        hfs_chash_rehash(hfsmp, from_cp, to_cp);

        /*
         * When a file moves out of "Cleanup At Startup"
         * we can drop its NODUMP status.
         */
        if ((from_cp->c_bsdflags & UF_NODUMP) &&
            (from_cp->c_parentcnid != to_cp->c_parentcnid)) {
                from_cp->c_bsdflags &= ~UF_NODUMP;
                from_cp->c_touch_chgtime = TRUE;
        }
        if ((to_cp->c_bsdflags & UF_NODUMP) &&
            (to_cp->c_parentcnid != from_cp->c_parentcnid)) {
                to_cp->c_bsdflags &= ~UF_NODUMP;
                to_cp->c_touch_chgtime = TRUE;
        }

exit:
        if (got_cookie) {
                cat_postflight(hfsmp, &cookie, vfs_context_proc(ap->a_context));
        }
        if (started_tr) {
            hfs_end_transaction(hfsmp);
        }

        if (have_cnode_locks)
                hfs_unlockpair(from_cp, to_cp);

        if (have_from_trunc_lock)
                hfs_unlock_truncate(from_cp, 0);

        if (have_to_trunc_lock)
                hfs_unlock_truncate(to_cp, 0);

        /* Free the memory used by the EAs */
        if (from_xattr) {
                hfs_free (from_xattr, from_attrsize);
                from_xattr = NULL;
        }

        if (to_xattr) {
                hfs_free (to_xattr, to_attrsize);
                to_xattr = NULL;
        }

        return (error);
}

#if HFS_COMPRESSION
/*
 * This function is used specifically for the case when a namespace
 * handler is trying to steal data before it's deleted.  Note that we
 * don't bother deleting the xattr from the source because it will get
 * deleted a short time later anyway.
 *
 * cnodes must be locked
 */
static int hfs_move_compressed(cnode_t *from_cp, cnode_t *to_cp)
{
        int     ret;
        void   *data    = NULL;

        CLR(from_cp->c_bsdflags, UF_COMPRESSED);
        SET(from_cp->c_flag, C_MODIFIED);

        ret = hfs_move_data(from_cp, to_cp, HFS_MOVE_DATA_INCLUDE_RSRC);
        if (ret)
                goto exit;

        /*
         * Transfer the xattr that decmpfs uses.  Ideally, this code
         * should be with the other decmpfs code but it's file system
         * agnostic and this path is currently, and likely to remain, HFS+
         * specific.  It's easier and more performant if we implement it
         * here.
         */

        size_t size;
        data = hfs_malloc(size = MAX_DECMPFS_XATTR_SIZE);

        ret = hfs_xattr_read(from_cp->c_vp, DECMPFS_XATTR_NAME, data, &size);
        if (ret)
                goto exit;

        ret = hfs_xattr_write(to_cp->c_vp, DECMPFS_XATTR_NAME, data, size);
        if (ret)
                goto exit;

        SET(to_cp->c_bsdflags, UF_COMPRESSED);
        SET(to_cp->c_flag, C_MODIFIED);

exit:
        hfs_free(data, MAX_DECMPFS_XATTR_SIZE);

        return ret;
}
#endif // HFS_COMPRESSION

int
hfs_vnop_mmap(struct vnop_mmap_args *ap)
{
        struct vnode *vp = ap->a_vp;
        cnode_t *cp = VTOC(vp);
        int error;
        
        if (VNODE_IS_RSRC(vp)) {
                /* allow pageins of the resource fork */
        } else {
                int compressed = hfs_file_is_compressed(cp, 1); /* 1 == don't take the cnode lock */
                time_t orig_ctime = cp->c_ctime;
                
                if (!compressed && (cp->c_bsdflags & UF_COMPRESSED)) {
                        error = check_for_dataless_file(vp, NAMESPACE_HANDLER_READ_OP);
                        if (error != 0) {
                                return error;
                        }
                }

                if (ap->a_fflags & PROT_WRITE) {
                        nspace_snapshot_event(vp, orig_ctime, NAMESPACE_HANDLER_WRITE_OP, NULL);
                }
        }

#if CONFIG_PROTECT
        error = cp_handle_vnop(vp, (ap->a_fflags & PROT_WRITE
                                                                ? CP_WRITE_ACCESS : 0) | CP_READ_ACCESS, 0);
        if (error)
                return error;
#endif

        //
        // NOTE: we return ENOTSUP because we want the cluster layer
        //       to actually do all the real work.
        //
        return (ENOTSUP);
}

static errno_t hfs_vnop_mnomap(struct vnop_mnomap_args *ap)
{
        vnode_t vp = ap->a_vp;

        /*
         * Whilst the file was mapped, there may not have been any
         * page-outs so we need to increment the generation counter now.
         * Unfortunately this may lead to a change in the generation
         * counter when no actual change has been made, but there is
         * little we can do about that with our current architecture.
         */
        if (ubc_is_mapped_writable(vp)) {
                cnode_t *cp = VTOC(vp);
                hfs_lock(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_ALLOW_NOEXISTS);
                hfs_incr_gencount(cp);

                /*
                 * We don't want to set the modification time here since a
                 * change to that is not acceptable if no changes were made.
                 * Instead we set a flag so that if we get any page-outs we
                 * know to update the modification time.  It's possible that
                 * they weren't actually because of changes made whilst the
                 * file was mapped but that's not easy to fix now.
                 */
                SET(cp->c_flag, C_MIGHT_BE_DIRTY_FROM_MAPPING);

                hfs_unlock(cp);
        }

        return 0;
}

/*
 * Mark the resource fork as needing a ubc_setsize when we drop the
 * cnode lock later.
 */
static void hfs_rsrc_setsize(cnode_t *cp)
{
        /*
         * We need to take an iocount if we don't have one.  vnode_get
         * will return ENOENT if the vnode is terminating which is what we
         * want as it's not safe to call ubc_setsize in that case.
         */
        if (cp->c_rsrc_vp && !vnode_get(cp->c_rsrc_vp)) {
                // Shouldn't happen, but better safe...
                if (ISSET(cp->c_flag, C_NEED_RVNODE_PUT))
                        vnode_put(cp->c_rsrc_vp);
                SET(cp->c_flag, C_NEED_RVNODE_PUT | C_NEED_RSRC_SETSIZE);
        }
}

/*
 * hfs_move_data
 *
 * This is a non-symmetric variant of exchangedata.  In this function,
 * the contents of the data fork (and optionally the resource fork)
 * are moved from from_cp to to_cp.
 * 
 * The cnodes must be locked. 
 *
 * The cnode pointed to by 'to_cp' *must* be empty prior to invoking
 * this function.  We impose this restriction because we may not be
 * able to fully delete the entire file's contents in a single
 * transaction, particularly if it has a lot of extents.  In the
 * normal file deletion codepath, the file is screened for two
 * conditions: 1) bigger than 400MB, and 2) more than 8 extents.  If
 * so, the file is relocated to the hidden directory and the deletion
 * is broken up into multiple truncates.  We can't do that here
 * because both files need to exist in the namespace. The main reason
 * this is imposed is that we may have to touch a whole lot of bitmap
 * blocks if there are many extents.
 * 
 * Any data written to 'from_cp' after this call completes is not
 * guaranteed to be moved.
 * 
 * Arguments:
 * cnode_t *from_cp : source file
 * cnode_t *to_cp   : destination file; must be empty
 * 
 * Returns:
 *  
 *  EBUSY - File has been deleted or is in use
 *      EFBIG - Destination file was not empty
 *  EIO   - An I/O error
 *      0         - success
 *  other - Other errors that can be returned from called functions
 */
int hfs_move_data(cnode_t *from_cp, cnode_t *to_cp, 
                                  hfs_move_data_options_t options)
{       
        hfsmount_t *hfsmp                       = VTOHFS(from_cp->c_vp);
        int error                                       = 0;
        int lockflags                           = 0;
        bool return_EIO_on_error        = false;
        const bool include_rsrc         = ISSET(options, HFS_MOVE_DATA_INCLUDE_RSRC);

        /* Verify that neither source/dest file is open-unlinked */
        if (ISSET(from_cp->c_flag, C_DELETED | C_NOEXISTS)
                || ISSET(to_cp->c_flag, C_DELETED | C_NOEXISTS)) {
                return EBUSY;
        }

        /* 
         * Verify the source file is not in use by anyone besides us.
         *
         * This function is typically invoked by a namespace handler 
         * process responding to a temporarily stalled system call.  
         * The FD that it is working off of is opened O_EVTONLY, so
         * it really has no active usecounts (the kusecount from O_EVTONLY
         * is subtracted from the total usecounts).
         * 
         * As a result, we shouldn't have any active usecounts against
         * this vnode when we go to check it below.
         */
        if (vnode_isinuse(from_cp->c_vp, 0))
                return EBUSY;

        if (include_rsrc && from_cp->c_rsrc_vp) {
                if (vnode_isinuse(from_cp->c_rsrc_vp, 0))
                        return EBUSY;

                /* 
                 * In the code below, if the destination file doesn't have a
                 * c_rsrcfork then we don't create it which means we we cannot
                 * transfer the ff_invalidranges and cf_vblocks fields.  These
                 * shouldn't be set because we flush the resource fork before
                 * calling this function but there is a tiny window when we
                 * did not have any locks...
                 */
                if (!to_cp->c_rsrcfork
                        && (!TAILQ_EMPTY(&from_cp->c_rsrcfork->ff_invalidranges)
                                || from_cp->c_rsrcfork->ff_unallocblocks)) {
                        /*
                         * The file isn't really busy now but something did slip
                         * in and tinker with the file while we didn't have any
                         * locks, so this is the most meaningful return code for
                         * the caller.
                         */
                        return EBUSY;
                }
        }

        // Check the destination file is empty
        if (to_cp->c_datafork->ff_blocks 
                || to_cp->c_datafork->ff_size
                || (include_rsrc
                        && (to_cp->c_blocks
                                || (to_cp->c_rsrcfork && to_cp->c_rsrcfork->ff_size)))) {
                return EFBIG;
        }

        if ((error = hfs_start_transaction (hfsmp)))
                return error;

        lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG | SFL_EXTENTS | SFL_ATTRIBUTE, 
                                                                        HFS_EXCLUSIVE_LOCK);

        // filefork_t is 128 bytes which should be OK
        filefork_t rfork_buf, *from_rfork = NULL;

        if (include_rsrc) {
                from_rfork = from_cp->c_rsrcfork;

                /*
                 * Creating resource fork vnodes is expensive, so just get get
                 * the fork data if we need it.
                 */
                if (!from_rfork && hfs_has_rsrc(from_cp)) {
                        from_rfork = &rfork_buf;

                        from_rfork->ff_cp = from_cp;
                        TAILQ_INIT(&from_rfork->ff_invalidranges);

                        error = cat_idlookup(hfsmp, from_cp->c_fileid, 0, 1, NULL, NULL,
                                                                 &from_rfork->ff_data);

                        if (error)
                                goto exit;
                }
        }

        /*
         * From here on, any failures mean that we might be leaving things
         * in a weird or inconsistent state.  Ideally, we should back out
         * all the changes, but to do that properly we need to fix
         * MoveData.  We'll save fixing that for another time.  For now,
         * just return EIO in all cases to the caller so that they know.
         */
        return_EIO_on_error = true;

        bool data_overflow_extents = overflow_extents(from_cp->c_datafork);

        // Move the data fork
        if ((error = hfs_move_fork (from_cp->c_datafork, from_cp,
                                                                to_cp->c_datafork, to_cp))) {
                goto exit;
        }

        SET(from_cp->c_flag, C_NEED_DATA_SETSIZE);
        SET(to_cp->c_flag, C_NEED_DATA_SETSIZE);

        // We move the resource fork later

        /* 
         * Note that because all we're doing is moving the extents around,
         * we can probably do this in a single transaction: Each extent
         * record (group of 8) is 64 bytes.  A extent overflow B-Tree node
         * is typically 4k.  This means each node can hold roughly ~60
         * extent records == (480 extents).
         *
         * If a file was massively fragmented and had 20k extents, this
         * means we'd roughly touch 20k/480 == 41 to 42 nodes, plus the
         * index nodes, for half of the operation.  (inserting or
         * deleting). So if we're manipulating 80-100 nodes, this is
         * basically 320k of data to write to the journal in a bad case.
         */
        if (data_overflow_extents) {
                if ((error = MoveData(hfsmp, from_cp->c_cnid, to_cp->c_cnid, 0)))
                        goto exit;
        }

        if (from_rfork && overflow_extents(from_rfork)) {
                if ((error = MoveData(hfsmp, from_cp->c_cnid, to_cp->c_cnid, 1)))
                        goto exit;
        }

        // Touch times
        from_cp->c_touch_acctime = TRUE;
        from_cp->c_touch_chgtime = TRUE;
        from_cp->c_touch_modtime = TRUE;
        hfs_touchtimes(hfsmp, from_cp);

        to_cp->c_touch_acctime = TRUE;
        to_cp->c_touch_chgtime = TRUE;
        to_cp->c_touch_modtime = TRUE;
        hfs_touchtimes(hfsmp, to_cp);

        struct cat_fork dfork_buf;
        const struct cat_fork *dfork, *rfork;

        dfork = hfs_prepare_fork_for_update(to_cp->c_datafork, NULL,
                                                                                &dfork_buf, hfsmp->blockSize);
        rfork = hfs_prepare_fork_for_update(from_rfork, NULL,
                                                                                &rfork_buf.ff_data, hfsmp->blockSize);

        // Update the catalog nodes, to_cp first
        if ((error = cat_update(hfsmp, &to_cp->c_desc, &to_cp->c_attr, 
                                                        dfork, rfork))) {
                goto exit;
        }

        CLR(to_cp->c_flag, C_MODIFIED | C_MINOR_MOD);

        // Update in-memory resource fork data here
        if (from_rfork) {
                // Update c_blocks
                uint32_t moving = from_rfork->ff_blocks + from_rfork->ff_unallocblocks;

                from_cp->c_blocks -= moving;
                to_cp->c_blocks   += moving;

                // Update to_cp's resource data if it has it
                filefork_t *to_rfork = to_cp->c_rsrcfork;
                if (to_rfork) {
                        TAILQ_SWAP(&to_rfork->ff_invalidranges,
                                           &from_rfork->ff_invalidranges, rl_entry, rl_link);
                        to_rfork->ff_data = from_rfork->ff_data;

                        // Deal with ubc_setsize
                        hfs_rsrc_setsize(to_cp);
                }

                // Wipe out the resource fork in from_cp
                rl_init(&from_rfork->ff_invalidranges);
                bzero(&from_rfork->ff_data, sizeof(from_rfork->ff_data));

                // Deal with ubc_setsize
                hfs_rsrc_setsize(from_cp);
        }

        // Currently unnecessary, but might be useful in future...
        dfork = hfs_prepare_fork_for_update(from_cp->c_datafork, NULL, &dfork_buf,
                                                                                hfsmp->blockSize);
        rfork = hfs_prepare_fork_for_update(from_rfork, NULL, &rfork_buf.ff_data,
                                                                                hfsmp->blockSize);

        // Update from_cp
        if ((error = cat_update(hfsmp, &from_cp->c_desc, &from_cp->c_attr, 
                                                        dfork, rfork))) {
                goto exit;
        }

        CLR(from_cp->c_flag, C_MODIFIED | C_MINOR_MOD);

exit:
        if (lockflags) {
                hfs_systemfile_unlock(hfsmp, lockflags);
                hfs_end_transaction(hfsmp);
        }

        if (error && error != EIO && return_EIO_on_error) {
                printf("hfs_move_data: encountered error %d\n", error);
                error = EIO;
        }

        return error;
}

/* 
 * Move all of the catalog and runtime data in srcfork to dstfork.
 * 
 * This allows us to maintain the invalid ranges across the move data
 * operation so we don't need to force all of the pending IO right
 * now. In addition, we move all non overflow-extent extents into the
 * destination here.
 *
 * The destination fork must be empty and should have been checked
 * prior to calling this.
 */
static int hfs_move_fork(filefork_t *srcfork, cnode_t *src_cp,
                                                 filefork_t *dstfork, cnode_t *dst_cp) 
{
        // Move the invalid ranges
        TAILQ_SWAP(&dstfork->ff_invalidranges, &srcfork->ff_invalidranges,
                           rl_entry, rl_link);
        rl_remove_all(&srcfork->ff_invalidranges);

        // Move the fork data (copy whole structure)
        dstfork->ff_data = srcfork->ff_data;
        bzero(&srcfork->ff_data, sizeof(srcfork->ff_data));

        // Update c_blocks
        src_cp->c_blocks -= dstfork->ff_blocks + dstfork->ff_unallocblocks;
        dst_cp->c_blocks += dstfork->ff_blocks + dstfork->ff_unallocblocks;

        return 0;
}

/*
 *  cnode must be locked
 */
int
hfs_fsync(struct vnode *vp, int waitfor, hfs_fsync_mode_t fsyncmode, struct proc *p)
{
        struct cnode *cp = VTOC(vp);
        struct filefork *fp = NULL;
        int retval = 0;
        struct hfsmount *hfsmp = VTOHFS(vp);
        struct timeval tv;
        int waitdata;           /* attributes necessary for data retrieval */
        int wait;               /* all other attributes (e.g. atime, etc.) */
        int took_trunc_lock = 0;
        int fsync_default = 1;

        /*
         * Applications which only care about data integrity rather than full
         * file integrity may opt out of (delay) expensive metadata update
         * operations as a performance optimization.
         */
        wait = (waitfor == MNT_WAIT);
        waitdata = (waitfor == MNT_DWAIT) | wait;

        if (always_do_fullfsync)
                fsyncmode = HFS_FSYNC_FULL;
        if (fsyncmode != HFS_FSYNC)
                fsync_default = 0;
        
        /* HFS directories don't have any data blocks. */
        if (vnode_isdir(vp))
                goto metasync;
        fp = VTOF(vp);

        /*
         * For system files flush the B-tree header and
         * for regular files write out any clusters
         */
        if (vnode_issystem(vp)) {
            if (VTOF(vp)->fcbBTCBPtr != NULL) {
                        // XXXdbg
                        if (hfsmp->jnl == NULL) {
                                BTFlushPath(VTOF(vp));
                        }
            }
        } else {
                hfs_unlock(cp);
                hfs_lock_truncate(cp, HFS_SHARED_LOCK, HFS_LOCK_DEFAULT);
                took_trunc_lock = 1;

                if (fp->ff_unallocblocks != 0) {
                        hfs_unlock_truncate(cp, HFS_LOCK_DEFAULT);

                        hfs_lock_truncate(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT);
                }

                /* Don't hold cnode lock when calling into cluster layer. */
                (void) cluster_push(vp, waitdata ? IO_SYNC : 0);

                hfs_lock(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_ALLOW_NOEXISTS);
        }
        /*
         * When MNT_WAIT is requested and the zero fill timeout
         * has expired then we must explicitly zero out any areas
         * that are currently marked invalid (holes).
         *
         * Files with NODUMP can bypass zero filling here.
         */
        if (fp && (((cp->c_flag & C_ALWAYS_ZEROFILL) && !TAILQ_EMPTY(&fp->ff_invalidranges)) ||
            ((wait || (cp->c_flag & C_ZFWANTSYNC)) &&
                ((cp->c_bsdflags & UF_NODUMP) == 0) &&
                 (vnode_issystem(vp) ==0) &&
                cp->c_zftimeout != 0))) {

                microuptime(&tv);
                if ((cp->c_flag & C_ALWAYS_ZEROFILL) == 0 && fsync_default && tv.tv_sec < (long)cp->c_zftimeout) {
                        /* Remember that a force sync was requested. */
                        cp->c_flag |= C_ZFWANTSYNC;
                        goto datasync;
                }
                if (!TAILQ_EMPTY(&fp->ff_invalidranges)) {
                        if (!took_trunc_lock || (cp->c_truncatelockowner == HFS_SHARED_OWNER)) {
                                hfs_unlock(cp);
                                if (took_trunc_lock) {
                                        hfs_unlock_truncate(cp, HFS_LOCK_DEFAULT);
                                }
                                hfs_lock_truncate(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT);
                                hfs_lock(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_ALLOW_NOEXISTS);
                                took_trunc_lock = 1;
                        }
                        hfs_flush_invalid_ranges(vp);
                        hfs_unlock(cp);
                        (void) cluster_push(vp, waitdata ? IO_SYNC : 0);
                        hfs_lock(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_ALLOW_NOEXISTS);
                }
        }
datasync:
        if (took_trunc_lock) {
                hfs_unlock_truncate(cp, HFS_LOCK_DEFAULT);
                took_trunc_lock = 0;
        }

        if (!hfsmp->jnl)
                buf_flushdirtyblks(vp, waitdata, 0, "hfs_fsync");
        else if (fsync_default && vnode_islnk(vp)
                         && vnode_hasdirtyblks(vp) && vnode_isrecycled(vp)) {
                /*
                 * If it's a symlink that's dirty and is about to be recycled,
                 * we need to flush the journal.
                 */
                fsync_default = 0;
        }

metasync:
        if (vnode_isreg(vp) && vnode_issystem(vp)) {
                if (VTOF(vp)->fcbBTCBPtr != NULL) {
                        microuptime(&tv);
                        BTSetLastSync(VTOF(vp), tv.tv_sec);
                }
                cp->c_touch_acctime = FALSE;
                cp->c_touch_chgtime = FALSE;
                cp->c_touch_modtime = FALSE;
        } else if (!vnode_isswap(vp)) {
                retval = hfs_update(vp, HFS_UPDATE_FORCE);

                /*
                 * When MNT_WAIT is requested push out the catalog record for
                 * this file.  If they asked for a full fsync, we can skip this
                 * because the journal_flush or hfs_metasync_all will push out
                 * all of the metadata changes.
                 */
                if ((retval == 0) && wait && fsync_default && cp->c_hint &&
                    !ISSET(cp->c_flag, C_DELETED | C_NOEXISTS)) {
                        hfs_metasync(VTOHFS(vp), (daddr64_t)cp->c_hint, p);
                }

                /*
                 * If this was a full fsync, make sure all metadata
                 * changes get to stable storage.
                 */
                if (!fsync_default) {
                        if (hfsmp->jnl) {
                                if (fsyncmode == HFS_FSYNC_FULL)
                                        hfs_flush(hfsmp, HFS_FLUSH_FULL);
                                else
                                        hfs_flush(hfsmp, HFS_FLUSH_JOURNAL_BARRIER);
                        } else {
                                retval = hfs_metasync_all(hfsmp);
                                /* XXX need to pass context! */
                                hfs_flush(hfsmp, HFS_FLUSH_CACHE);
                        }
                }
        }

        if (!hfs_is_dirty(cp) && !ISSET(cp->c_flag, C_DELETED))
                vnode_cleardirty(vp);

        return (retval);
}


/* Sync an hfs catalog b-tree node */
int
hfs_metasync(struct hfsmount *hfsmp, daddr64_t node, __unused struct proc *p)
{
        vnode_t vp;
        buf_t   bp;
        int lockflags;

        vp = HFSTOVCB(hfsmp)->catalogRefNum;

        // XXXdbg - don't need to do this on a journaled volume
        if (hfsmp->jnl) {
                return 0;
        }

        lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG, HFS_EXCLUSIVE_LOCK);
        /*
         * Look for a matching node that has been delayed
         * but is not part of a set (B_LOCKED).
         *
         * BLK_ONLYVALID causes buf_getblk to return a
         * buf_t for the daddr64_t specified only if it's
         * currently resident in the cache... the size
         * parameter to buf_getblk is ignored when this flag
         * is set
         */
        bp = buf_getblk(vp, node, 0, 0, 0, BLK_META | BLK_ONLYVALID);

        if (bp) {
                if ((buf_flags(bp) & (B_LOCKED | B_DELWRI)) == B_DELWRI)
                        (void) VNOP_BWRITE(bp);
                else
                        buf_brelse(bp);
        }

        hfs_systemfile_unlock(hfsmp, lockflags);

        return (0);
}


/*
 * Sync all hfs B-trees.  Use this instead of journal_flush for a volume
 * without a journal.  Note that the volume bitmap does not get written;
 * we rely on fsck_hfs to fix that up (which it can do without any loss
 * of data).
 */
int
hfs_metasync_all(struct hfsmount *hfsmp)
{
        int lockflags;

        /* Lock all of the B-trees so we get a mutually consistent state */
        lockflags = hfs_systemfile_lock(hfsmp,
                SFL_CATALOG|SFL_EXTENTS|SFL_ATTRIBUTE, HFS_EXCLUSIVE_LOCK);

        /* Sync each of the B-trees */
        if (hfsmp->hfs_catalog_vp)
                hfs_btsync(hfsmp->hfs_catalog_vp, 0);
        if (hfsmp->hfs_extents_vp)
                hfs_btsync(hfsmp->hfs_extents_vp, 0);
        if (hfsmp->hfs_attribute_vp)
                hfs_btsync(hfsmp->hfs_attribute_vp, 0);
        
        /* Wait for all of the writes to complete */
        if (hfsmp->hfs_catalog_vp)
                vnode_waitforwrites(hfsmp->hfs_catalog_vp, 0, 0, 0, "hfs_metasync_all");
        if (hfsmp->hfs_extents_vp)
                vnode_waitforwrites(hfsmp->hfs_extents_vp, 0, 0, 0, "hfs_metasync_all");
        if (hfsmp->hfs_attribute_vp)
                vnode_waitforwrites(hfsmp->hfs_attribute_vp, 0, 0, 0, "hfs_metasync_all");

        hfs_systemfile_unlock(hfsmp, lockflags);
        
        return 0;
}


/*ARGSUSED 1*/
static int
hfs_btsync_callback(struct buf *bp, __unused void *dummy)
{
        buf_clearflags(bp, B_LOCKED);
        (void) buf_bawrite(bp);

        return(BUF_CLAIMED);
}


int
hfs_btsync(struct vnode *vp, int sync_transaction)
{
        struct cnode *cp = VTOC(vp);
        struct timeval tv;
        int    flags = 0;

        if (sync_transaction)
                flags |= BUF_SKIP_NONLOCKED;
        /*
         * Flush all dirty buffers associated with b-tree.
         */
        buf_iterate(vp, hfs_btsync_callback, flags, 0);

        microuptime(&tv);
        if (vnode_issystem(vp) && (VTOF(vp)->fcbBTCBPtr != NULL))
                (void) BTSetLastSync(VTOF(vp), tv.tv_sec);
        cp->c_touch_acctime = FALSE;
        cp->c_touch_chgtime = FALSE;
        cp->c_touch_modtime = FALSE;

        return 0;
}

/*
 * Remove a directory.
 */
int
hfs_vnop_rmdir(struct vnop_rmdir_args *ap)
{
        struct vnode *dvp = ap->a_dvp;
        struct vnode *vp = ap->a_vp;
        struct cnode *dcp = VTOC(dvp);
        struct cnode *cp = VTOC(vp);
        int error;
        time_t orig_ctime;

        orig_ctime = VTOC(vp)->c_ctime;

        if (!S_ISDIR(cp->c_mode)) {
                return (ENOTDIR);
        }
        if (dvp == vp) {
                return (EINVAL);
        }

        nspace_snapshot_event(vp, orig_ctime, NAMESPACE_HANDLER_DELETE_OP, NULL);
        cp = VTOC(vp);

        if ((error = hfs_lockpair(dcp, cp, HFS_EXCLUSIVE_LOCK))) {
                return (error);
        }

        /* Check for a race with rmdir on the parent directory */
        if (dcp->c_flag & (C_DELETED | C_NOEXISTS)) {
                hfs_unlockpair (dcp, cp);
                return ENOENT;
        }

        //
        // if the item is tracked but doesn't have a document_id, assign one and generate an fsevent for it
        //
        if ((cp->c_bsdflags & UF_TRACKED) && ((struct FndrExtendedDirInfo *)((char *)&cp->c_attr.ca_finderinfo + 16))->document_id == 0) {
                uint32_t newid;

                hfs_unlockpair(dcp, cp);

                if (hfs_generate_document_id(VTOHFS(vp), &newid) == 0) {
                        hfs_lockpair(dcp, cp, HFS_EXCLUSIVE_LOCK);
                        ((struct FndrExtendedDirInfo *)((char *)&cp->c_attr.ca_finderinfo + 16))->document_id = newid;
                        add_fsevent(FSE_DOCID_CHANGED, vfs_context_current(),
                                    FSE_ARG_DEV,   VTOHFS(vp)->hfs_raw_dev,
                                    FSE_ARG_INO,   (ino64_t)0,             // src inode #
                                    FSE_ARG_INO,   (ino64_t)cp->c_fileid,  // dst inode #
                                    FSE_ARG_INT32, newid,
                                    FSE_ARG_DONE);
                } else {
                        // XXXdbg - couldn't get a new docid... what to do?  can't really fail the rm...
                        hfs_lockpair(dcp, cp, HFS_EXCLUSIVE_LOCK);
                }
        }

        error = hfs_removedir(dvp, vp, ap->a_cnp, 0, 0);

        hfs_unlockpair(dcp, cp);

        return (error);
}

/*
 * Remove a directory
 *
 * Both dvp and vp cnodes are locked
 */
int
hfs_removedir(struct vnode *dvp, struct vnode *vp, struct componentname *cnp,
              int skip_reserve, int only_unlink)
{
        struct cnode *cp;
        struct cnode *dcp;
        struct hfsmount * hfsmp;
        struct cat_desc desc;
        int lockflags;
        int error = 0, started_tr = 0;

        cp = VTOC(vp);
        dcp = VTOC(dvp);
        hfsmp = VTOHFS(vp);

        if (dcp == cp) {
                return (EINVAL);        /* cannot remove "." */
        }
        if (cp->c_flag & (C_NOEXISTS | C_DELETED)) {
                return (0);
        }
        if (cp->c_entries != 0) {
                return (ENOTEMPTY);
        }
        
        /*
         * If the directory is open or in use (e.g. opendir() or current working
         * directory for some process); wait for inactive/reclaim to actually
         * remove cnode from the catalog.  Both inactive and reclaim codepaths are capable
         * of removing open-unlinked directories from the catalog, as well as getting rid
         * of EAs still on the element.  So change only_unlink to true, so that it will get 
         * cleaned up below.
         *
         * Otherwise, we can get into a weird old mess where the directory has C_DELETED,
         * but it really means C_NOEXISTS because the item was actually removed from the 
         * catalog.  Then when we try to remove the entry from the catalog later on, it won't
         * really be there anymore.  
         */
        if (vnode_isinuse(vp, 0))  {
                only_unlink = 1;
        }

        /* Deal with directory hardlinks */
        if (cp->c_flag & C_HARDLINK) {
                /* 
                 * Note that if we have a directory which was a hardlink at any point,
                 * its actual directory data is stored in the directory inode in the hidden
                 * directory rather than the leaf element(s) present in the namespace.
                 * 
                 * If there are still other hardlinks to this directory, 
                 * then we'll just eliminate this particular link and the vnode will still exist.
                 * If this is the last link to an empty directory, then we'll open-unlink the 
                 * directory and it will be only tagged with C_DELETED (as opposed to C_NOEXISTS).
                 * 
                 * We could also return EBUSY here. 
                 */
                
                return hfs_unlink(hfsmp, dvp, vp, cnp, skip_reserve);
        }
        
        /*
         * In a few cases, we may want to allow the directory to persist in an
         * open-unlinked state.  If the directory is being open-unlinked (still has usecount
         * references), or if it has EAs, or if it was being deleted as part of a rename, 
         * then we go ahead and move it to the hidden directory. 
         *
         * If the directory is being open-unlinked, then we want to keep the catalog entry 
         * alive so that future EA calls and fchmod/fstat etc. do not cause issues later.
         * 
         * If the directory had EAs, then we want to use the open-unlink trick so that the 
         * EA removal is not done in one giant transaction.  Otherwise, it could cause a panic
         * due to overflowing the journal.
         * 
         * Finally, if it was deleted as part of a rename, we move it to the hidden directory
         * in order to maintain rename atomicity.  
         * 
         * Note that the allow_dirs argument to hfs_removefile specifies that it is
         * supposed to handle directories for this case.
     */
                
        if (((hfsmp->hfs_attribute_vp != NULL) &&
            ((cp->c_attr.ca_recflags & kHFSHasAttributesMask) != 0)) ||
                (only_unlink != 0)) {
                
                int ret = hfs_removefile(dvp, vp, cnp, 0, 0, 1, NULL, only_unlink);
                /* 
                 * Even though hfs_vnop_rename calls vnode_recycle for us on tvp we call 
                 * it here just in case we were invoked by rmdir() on a directory that had 
                 * EAs.  To ensure that we start reclaiming the space as soon as possible,
                 * we call vnode_recycle on the directory.
                 */
                vnode_recycle(vp);
                
                return ret;
                
        }

        dcp->c_flag |= C_DIR_MODIFICATION;

#if QUOTA
        if (hfsmp->hfs_flags & HFS_QUOTAS)
                (void)hfs_getinoquota(cp);
#endif
        if ((error = hfs_start_transaction(hfsmp)) != 0) {
            goto out;
        }
        started_tr = 1;

        /*
         * Verify the directory is empty (and valid).
         * (Rmdir ".." won't be valid since
         *  ".." will contain a reference to
         *  the current directory and thus be
         *  non-empty.)
         */
        if ((dcp->c_bsdflags & APPEND) || (cp->c_bsdflags & (IMMUTABLE | APPEND))) {
                error = EPERM;
                goto out;
        }

        /* Remove the entry from the namei cache: */
        cache_purge(vp);

        /* 
         * Protect against a race with rename by using the component
         * name passed in and parent id from dvp (instead of using 
         * the cp->c_desc which may have changed).
         */
        desc.cd_nameptr = (const u_int8_t *)cnp->cn_nameptr;
        desc.cd_namelen = cnp->cn_namelen;
        desc.cd_parentcnid = dcp->c_fileid;
        desc.cd_cnid = cp->c_cnid;
        desc.cd_flags = CD_ISDIR;
        desc.cd_encoding = cp->c_encoding;
        desc.cd_hint = 0;

        if (!hfs_valid_cnode(hfsmp, dvp, cnp, cp->c_fileid, NULL, &error)) {
            error = 0;
            goto out;
        }

        /* Remove entry from catalog */
        lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG | SFL_ATTRIBUTE | SFL_BITMAP, HFS_EXCLUSIVE_LOCK);

        if (!skip_reserve) {
                /*
                 * Reserve some space in the Catalog file.
                 */
                if ((error = cat_preflight(hfsmp, CAT_DELETE, NULL, 0))) {
                        hfs_systemfile_unlock(hfsmp, lockflags);
                        goto out;
                }
        }

        error = cat_delete(hfsmp, &desc, &cp->c_attr);

        if (!error) {
                //
                // if skip_reserve == 1 then we're being called from hfs_vnop_rename() and thus
                // we don't need to touch the document_id as it's handled by the rename code.
                // otherwise it's a normal remove and we need to save the document id in the
                // per thread struct and clear it from the cnode.
                //
                struct  doc_tombstone *ut;
                ut = doc_tombstone_get();
                if (!skip_reserve && (cp->c_bsdflags & UF_TRACKED)
                        && doc_tombstone_should_save(ut, vp, cnp)) {

                        uint32_t doc_id = hfs_get_document_id(cp);

                        // this event is more of a "pending-delete"
                        if (ut->t_lastop_document_id) {
                                add_fsevent(FSE_DOCID_CHANGED, vfs_context_current(),
                                                        FSE_ARG_DEV, hfsmp->hfs_raw_dev,
                                                        FSE_ARG_INO, (ino64_t)cp->c_fileid,       // src inode #
                                                        FSE_ARG_INO, (ino64_t)0,                  // dst inode #
                                                        FSE_ARG_INT32, doc_id,
                                                        FSE_ARG_DONE);
                        }

                        doc_tombstone_save(dvp, vp, cnp, doc_id, cp->c_fileid);

                        struct FndrExtendedFileInfo *fip = (struct FndrExtendedFileInfo *)((char *)&cp->c_attr.ca_finderinfo + 16);

                        // clear this so it's never returned again
                        fip->document_id = 0;
                        cp->c_bsdflags &= ~UF_TRACKED;
                }

                /* The parent lost a child */
                if (dcp->c_entries > 0)
                        dcp->c_entries--;
                DEC_FOLDERCOUNT(hfsmp, dcp->c_attr);
                dcp->c_dirchangecnt++;
                hfs_incr_gencount(dcp);

                dcp->c_touch_chgtime = TRUE;
                dcp->c_touch_modtime = TRUE;
                dcp->c_flag |= C_MODIFIED;

                hfs_update(dcp->c_vp, 0);
        }

        hfs_systemfile_unlock(hfsmp, lockflags);

        if (error)
                goto out;

#if QUOTA
        if (hfsmp->hfs_flags & HFS_QUOTAS)
                (void)hfs_chkiq(cp, -1, NOCRED, 0);
#endif /* QUOTA */

        hfs_volupdate(hfsmp, VOL_RMDIR, (dcp->c_cnid == kHFSRootFolderID));

        /* Mark C_NOEXISTS since the catalog entry is now gone */
        cp->c_flag |= C_NOEXISTS;

out:
        dcp->c_flag &= ~C_DIR_MODIFICATION;
        wakeup((caddr_t)&dcp->c_flag);

        if (started_tr) { 
            hfs_end_transaction(hfsmp);
        }

        return (error);
}


/*
 * Remove a file or link.
 */
int
hfs_vnop_remove(struct vnop_remove_args *ap)
{
        struct vnode *dvp = ap->a_dvp;
        struct vnode *vp = ap->a_vp;
        struct cnode *dcp = VTOC(dvp);
        struct cnode *cp;
        struct vnode *rvp = NULL;
        int error=0, recycle_rsrc=0;
        int recycle_vnode = 0;
        uint32_t rsrc_vid = 0;
        time_t orig_ctime;

        if (dvp == vp) {
                return (EINVAL);
        }

        orig_ctime = VTOC(vp)->c_ctime;
        if (!vnode_isnamedstream(vp) && ((ap->a_flags & VNODE_REMOVE_SKIP_NAMESPACE_EVENT) == 0)) {
                error = nspace_snapshot_event(vp, orig_ctime, NAMESPACE_HANDLER_DELETE_OP, NULL);
                if (error) {
                        // XXXdbg - decide on a policy for handling namespace handler failures!
                        // for now we just let them proceed.
                }               
        }
        error = 0;

        cp = VTOC(vp);

relock:

        hfs_lock_truncate(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT);

        if ((error = hfs_lockpair(dcp, cp, HFS_EXCLUSIVE_LOCK))) {
                hfs_unlock_truncate(cp, HFS_LOCK_DEFAULT);
                if (rvp) {
                        vnode_put (rvp);
                }       
                return (error);
        }
        //
        // if the item is tracked but doesn't have a document_id, assign one and generate an fsevent for it
        //
        if ((cp->c_bsdflags & UF_TRACKED) && ((struct FndrExtendedDirInfo *)((char *)&cp->c_attr.ca_finderinfo + 16))->document_id == 0) {
                uint32_t newid;

                hfs_unlockpair(dcp, cp);

                if (hfs_generate_document_id(VTOHFS(vp), &newid) == 0) {
                        hfs_lockpair(dcp, cp, HFS_EXCLUSIVE_LOCK);
                        ((struct FndrExtendedDirInfo *)((char *)&cp->c_attr.ca_finderinfo + 16))->document_id = newid;
                        add_fsevent(FSE_DOCID_CHANGED, vfs_context_current(),
                                    FSE_ARG_DEV,   VTOHFS(vp)->hfs_raw_dev,
                                    FSE_ARG_INO,   (ino64_t)0,             // src inode #
                                    FSE_ARG_INO,   (ino64_t)cp->c_fileid,  // dst inode #
                                    FSE_ARG_INT32, newid,
                                    FSE_ARG_DONE);
                } else {
                        // XXXdbg - couldn't get a new docid... what to do?  can't really fail the rm...
                        hfs_lockpair(dcp, cp, HFS_EXCLUSIVE_LOCK);
                }
        }
        
        /*
         * Lazily respond to determining if there is a valid resource fork
         * vnode attached to 'cp' if it is a regular file or symlink.  
         * If the vnode does not exist, then we may proceed without having to
         * create it.
         *
         * If, however, it does exist, then we need to acquire an iocount on the
         * vnode after acquiring its vid.  This ensures that if we have to do I/O
         * against it, it can't get recycled from underneath us in the middle
         * of this call.
         *
         * Note: this function may be invoked for directory hardlinks, so just skip these
         * steps if 'vp' is a directory.
         */

        enum vtype vtype = vnode_vtype(vp);
        if ((vtype == VLNK) || (vtype == VREG)) {
                if ((cp->c_rsrc_vp) && (rvp == NULL)) {
                        /* We need to acquire the rsrc vnode */
                        rvp = cp->c_rsrc_vp;
                        rsrc_vid = vnode_vid (rvp);

                        /* Unlock everything to acquire iocount on the rsrc vnode */    
                        hfs_unlock_truncate (cp, HFS_LOCK_DEFAULT);
                        hfs_unlockpair (dcp, cp);
                        /* Use the vid to maintain identity on rvp */
                        if (vnode_getwithvid(rvp, rsrc_vid)) {
                                /*
                                 * If this fails, then it was recycled or 
                                 * reclaimed in the interim.  Reset fields and
                                 * start over.
                                 */
                                rvp = NULL;
                                rsrc_vid = 0;
                        }
                        goto relock;
                }
        }

        /* 
         * Check to see if we raced rmdir for the parent directory 
         * hfs_removefile already checks for a race on vp/cp
         */
        if (dcp->c_flag & (C_DELETED | C_NOEXISTS)) {
                error = ENOENT;
                goto rm_done;   
        }

        error = hfs_removefile(dvp, vp, ap->a_cnp, ap->a_flags, 0, 0, NULL, 0);
        
        /*
         * If the remove succeeded in deleting the file, then we may need to mark
         * the resource fork for recycle so that it is reclaimed as quickly
         * as possible.  If it were not recycled quickly, then this resource fork
         * vnode could keep a v_parent reference on the data fork, which prevents it
         * from going through reclaim (by giving it extra usecounts), except in the force-
         * unmount case.  
         * 
         * However, a caveat:  we need to continue to supply resource fork
         * access to open-unlinked files even if the resource fork is not open.  This is
         * a requirement for the compressed files work.  Luckily, hfs_vgetrsrc will handle
         * this already if the data fork has been re-parented to the hidden directory.
         * 
         * As a result, all we really need to do here is mark the resource fork vnode
         * for recycle.  If it goes out of core, it can be brought in again if needed.  
         * If the cnode was instead marked C_NOEXISTS, then there wouldn't be any 
         * more work.
         */
        if (error == 0) {
                hfs_hotfile_deleted(vp);
                
                if (rvp) {
                recycle_rsrc = 1;
                }
                /* 
                 * If the target was actually removed from the catalog schedule it for
                 * full reclamation/inactivation.  We hold an iocount on it so it should just
                 * get marked with MARKTERM
                 */
                if (cp->c_flag & C_NOEXISTS) {
                        recycle_vnode = 1;
                }
        }


        /*
         * Drop the truncate lock before unlocking the cnode
         * (which can potentially perform a vnode_put and
         * recycle the vnode which in turn might require the
         * truncate lock)
         */
rm_done:
        hfs_unlockpair(dcp, cp);
        hfs_unlock_truncate(cp, HFS_LOCK_DEFAULT);

        if (recycle_rsrc) {
                /* inactive or reclaim on rvp will clean up the blocks from the rsrc fork */
                vnode_recycle(rvp);
        } 
        if (recycle_vnode) {
                vnode_recycle (vp);
        }

        if (rvp) {
                /* drop iocount on rsrc fork, was obtained at beginning of fxn */
                vnode_put(rvp);
        }

        return (error);
}


int
hfs_removefile_callback(struct buf *bp, void *hfsmp) {

        if ( !(buf_flags(bp) & B_META))
                panic("hfs: symlink bp @ %p is not marked meta-data!\n", bp);
        /*
         * it's part of the current transaction, kill it.
         */
        journal_kill_block(((struct hfsmount *)hfsmp)->jnl, bp);

        return (BUF_CLAIMED);
}

/*
 * hfs_removefile
 *
 * Similar to hfs_vnop_remove except there are additional options.
 * This function may be used to remove directories if they have
 * lots of EA's -- note the 'allow_dirs' argument.
 *
 * This function is able to delete blocks & fork data for the resource
 * fork even if it does not exist in core (and have a backing vnode).  
 * It should infer the correct behavior based on the number of blocks
 * in the cnode and whether or not the resource fork pointer exists or 
 * not.  As a result, one only need pass in the 'vp' corresponding to the
 * data fork of this file (or main vnode in the case of a directory).  
 * Passing in a resource fork will result in an error.
 *
 * Because we do not create any vnodes in this function, we are not at 
 * risk of deadlocking against ourselves by double-locking.
 *
 * Requires cnode and truncate locks to be held.
 */
int
hfs_removefile(struct vnode *dvp, struct vnode *vp, struct componentname *cnp,
               int flags, int skip_reserve, int allow_dirs, 
                           __unused struct vnode *rvp, int only_unlink)
{
        struct cnode *cp;
        struct cnode *dcp;
        struct vnode *rsrc_vp = NULL;
        struct hfsmount *hfsmp;
        struct cat_desc desc;
        struct timeval tv;
        int dataforkbusy = 0;
        int rsrcforkbusy = 0;
        int lockflags;
        int error = 0;
        int started_tr = 0;
        int isbigfile = 0, defer_remove=0, isdir=0;
        int update_vh = 0;

        cp = VTOC(vp);
        dcp = VTOC(dvp);
        hfsmp = VTOHFS(vp);

        /* Check if we lost a race post lookup. */
        if (cp->c_flag & (C_NOEXISTS | C_DELETED)) {
                return (0);
        }

        if (!hfs_valid_cnode(hfsmp, dvp, cnp, cp->c_fileid, NULL, &error)) {
            return 0;
        }

        /* Make sure a remove is permitted */
        if (VNODE_IS_RSRC(vp)) {
                return (EPERM);
        }
        else {
                /* 
                 * We know it's a data fork.
                 * Probe the cnode to see if we have a valid resource fork
                 * in hand or not.
                 */
                rsrc_vp = cp->c_rsrc_vp;
        }

        /* Don't allow deleting the journal or journal_info_block. */
        if (hfs_is_journal_file(hfsmp, cp)) {
                return (EPERM);
        }

        /*
         * Hard links require special handling.
         */
        if (cp->c_flag & C_HARDLINK) {
                if ((flags & VNODE_REMOVE_NODELETEBUSY) && vnode_isinuse(vp, 0)) {
                        return (EBUSY);
                } else {
                        /* A directory hard link with a link count of one is 
                         * treated as a regular directory.  Therefore it should 
                         * only be removed using rmdir().
                         */
                        if ((vnode_isdir(vp) == 1) && (cp->c_linkcount == 1) && 
                            (allow_dirs == 0)) {
                                return (EPERM);
                        }
                        return hfs_unlink(hfsmp, dvp, vp, cnp, skip_reserve);
                }
        }

        /* Directories should call hfs_rmdir! (unless they have a lot of attributes) */
        if (vnode_isdir(vp)) {
                if (allow_dirs == 0)
                        return (EPERM);  /* POSIX */
                isdir = 1;
        }
        /* Sanity check the parent ids. */
        if ((cp->c_parentcnid != hfsmp->hfs_private_desc[FILE_HARDLINKS].cd_cnid) &&
            (cp->c_parentcnid != dcp->c_fileid)) {
                return (EINVAL);
        }

        dcp->c_flag |= C_DIR_MODIFICATION;

        // this guy is going away so mark him as such
        cp->c_flag |= C_DELETED;


        /* Remove our entry from the namei cache. */
        cache_purge(vp);
        
        /*
         * If the caller was operating on a file (as opposed to a 
         * directory with EAs), then we need to figure out
         * whether or not it has a valid resource fork vnode.
         * 
         * If there was a valid resource fork vnode, then we need
         * to use hfs_truncate to eliminate its data.  If there is
         * no vnode, then we hold the cnode lock which would
         * prevent it from being created.  As a result, 
         * we can use the data deletion functions which do not
         * require that a cnode/vnode pair exist.
         */

        /* Check if this file is being used. */
        if (isdir == 0) {
                dataforkbusy = vnode_isinuse(vp, 0);
                /*  
                 * At this point, we know that 'vp' points to the 
                 * a data fork because we checked it up front. And if 
                 * there is no rsrc fork, rsrc_vp will be NULL.
                 */
                if (rsrc_vp && (cp->c_blocks - VTOF(vp)->ff_blocks)) {
                        rsrcforkbusy = vnode_isinuse(rsrc_vp, 0);
                }
        }
        
        /* Check if we have to break the deletion into multiple pieces. */
        if (isdir == 0)
                isbigfile = cp->c_datafork->ff_size >= HFS_BIGFILE_SIZE;

        /* Check if the file has xattrs.  If it does we'll have to delete them in
           individual transactions in case there are too many */
        if ((hfsmp->hfs_attribute_vp != NULL) &&
            (cp->c_attr.ca_recflags & kHFSHasAttributesMask) != 0) {
            defer_remove = 1;
        }
        
        /* If we are explicitly told to only unlink item and move to hidden dir, then do it */
        if (only_unlink) {
                defer_remove = 1;
        }

        /*
         * Carbon semantics prohibit deleting busy files.
         * (enforced when VNODE_REMOVE_NODELETEBUSY is requested)
         */
        if (dataforkbusy || rsrcforkbusy) {
                if ((flags & VNODE_REMOVE_NODELETEBUSY) ||
                    (hfsmp->hfs_private_desc[FILE_HARDLINKS].cd_cnid == 0)) {
                        error = EBUSY;
                        goto out;
                }
        }

#if QUOTA
        if (hfsmp->hfs_flags & HFS_QUOTAS)
                (void)hfs_getinoquota(cp);
#endif /* QUOTA */
        
        /* 
         * Do a ubc_setsize to indicate we need to wipe contents if:
         *  1) item is a regular file.
         *  2) Neither fork is busy AND we are not told to unlink this. 
         *
         * We need to check for the defer_remove since it can be set without 
         * having a busy data or rsrc fork   
         */
        if (isdir == 0 && (!dataforkbusy || !rsrcforkbusy) && (defer_remove == 0)) {
                /*
                 * A ubc_setsize can cause a pagein so defer it
                 * until after the cnode lock is dropped.  The
                 * cnode lock cannot be dropped/reacquired here
                 * since we might already hold the journal lock.
                 */
                if (!dataforkbusy && cp->c_datafork->ff_blocks && !isbigfile) {
                        cp->c_flag |= C_NEED_DATA_SETSIZE;
                }
                if (!rsrcforkbusy && rsrc_vp) {
                        cp->c_flag |= C_NEED_RSRC_SETSIZE;
                }
        }

        if ((error = hfs_start_transaction(hfsmp)) != 0) {
            goto out;
        }
        started_tr = 1;

        // XXXdbg - if we're journaled, kill any dirty symlink buffers 
        if (hfsmp->jnl && vnode_islnk(vp) && (defer_remove == 0)) {
                buf_iterate(vp, hfs_removefile_callback, BUF_SKIP_NONLOCKED, (void *)hfsmp);
        }

        /*
         * Prepare to truncate any non-busy forks.  Busy forks will
         * get truncated when their vnode goes inactive.
         * Note that we will only enter this region if we
         * can avoid creating an open-unlinked file.  If 
         * either region is busy, we will have to create an open
         * unlinked file.
         *
         * Since we are deleting the file, we need to stagger the runtime
         * modifications to do things in such a way that a crash won't 
         * result in us getting overlapped extents or any other 
         * bad inconsistencies.  As such, we call prepare_release_storage
         * which updates the UBC, updates quota information, and releases
         * any loaned blocks that belong to this file.  No actual 
         * truncation or bitmap manipulation is done until *AFTER*
         * the catalog record is removed. 
         */
        if (isdir == 0 && (!dataforkbusy && !rsrcforkbusy) && (only_unlink == 0)) {
                
                if (!dataforkbusy && !isbigfile && cp->c_datafork->ff_blocks != 0) {
                        
                        error = hfs_prepare_release_storage (hfsmp, vp);
                        if (error) {
                                goto out;
                        }
                        update_vh = 1;
                }
                
                /*
                 * If the resource fork vnode does not exist, we can skip this step.
                 */
                if (!rsrcforkbusy && rsrc_vp) {
                        error = hfs_prepare_release_storage (hfsmp, rsrc_vp);
                        if (error) {
                                goto out;
                        }
                        update_vh = 1;
                }
        }
        
        /* 
         * Protect against a race with rename by using the component
         * name passed in and parent id from dvp (instead of using 
         * the cp->c_desc which may have changed).   Also, be aware that
         * because we allow directories to be passed in, we need to special case
         * this temporary descriptor in case we were handed a directory.
         */
        if (isdir) {
                desc.cd_flags = CD_ISDIR;
        }
        else {
                desc.cd_flags = 0;
        }
        desc.cd_encoding = cp->c_desc.cd_encoding;
        desc.cd_nameptr = (const u_int8_t *)cnp->cn_nameptr;
        desc.cd_namelen = cnp->cn_namelen;
        desc.cd_parentcnid = dcp->c_fileid;
        desc.cd_hint = cp->c_desc.cd_hint;
        desc.cd_cnid = cp->c_cnid;
        microtime(&tv);

        /*
         * There are two cases to consider:
         *  1. File/Dir is busy/big/defer_remove ==> move/rename the file/dir
         *  2. File is not in use ==> remove the file
         * 
         * We can get a directory in case 1 because it may have had lots of attributes,
         * which need to get removed here.
         */
        if (dataforkbusy || rsrcforkbusy || isbigfile || defer_remove) {
                char delname[32];
                struct cat_desc to_desc;
                struct cat_desc todir_desc;

                /*
                 * Orphan this file or directory (move to hidden directory).
                 * Again, we need to take care that we treat directories as directories,
                 * and files as files.  Because directories with attributes can be passed in
                 * check to make sure that we have a directory or a file before filling in the 
                 * temporary descriptor's flags.  We keep orphaned directories AND files in
                 * the FILE_HARDLINKS private directory since we're generalizing over all
                 * orphaned filesystem objects.
                 */
                bzero(&todir_desc, sizeof(todir_desc));
                todir_desc.cd_parentcnid = 2;

                MAKE_DELETED_NAME(delname, sizeof(delname), cp->c_fileid);
                bzero(&to_desc, sizeof(to_desc));
                to_desc.cd_nameptr = (const u_int8_t *)delname;
                to_desc.cd_namelen = strlen(delname);
                to_desc.cd_parentcnid = hfsmp->hfs_private_desc[FILE_HARDLINKS].cd_cnid;
                if (isdir) {
                        to_desc.cd_flags = CD_ISDIR;
                }
                else {
                        to_desc.cd_flags = 0;
                }
                to_desc.cd_cnid = cp->c_cnid;

                lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG, HFS_EXCLUSIVE_LOCK);
                if (!skip_reserve) {
                        if ((error = cat_preflight(hfsmp, CAT_RENAME, NULL, 0))) {
                                hfs_systemfile_unlock(hfsmp, lockflags);
                                goto out;
                        }
                }

                error = cat_rename(hfsmp, &desc, &todir_desc,
                                &to_desc, (struct cat_desc *)NULL);

                if (error == 0) {
                        hfsmp->hfs_private_attr[FILE_HARDLINKS].ca_entries++;
                        if (isdir == 1) {
                                INC_FOLDERCOUNT(hfsmp, hfsmp->hfs_private_attr[FILE_HARDLINKS]);
                        }
                        (void) cat_update(hfsmp, &hfsmp->hfs_private_desc[FILE_HARDLINKS],
                                          &hfsmp->hfs_private_attr[FILE_HARDLINKS], NULL, NULL);

                        /* Update the parent directory */
                        if (dcp->c_entries > 0)
                                dcp->c_entries--;
                        if (isdir == 1) {
                                DEC_FOLDERCOUNT(hfsmp, dcp->c_attr);
                        }
                        dcp->c_dirchangecnt++;
                        hfs_incr_gencount(dcp);

                        dcp->c_ctime = tv.tv_sec;
                        dcp->c_mtime = tv.tv_sec;
                        (void) cat_update(hfsmp, &dcp->c_desc, &dcp->c_attr, NULL, NULL);

                        /* Update the file or directory's state */
                        cp->c_flag |= C_DELETED;
                        cp->c_ctime = tv.tv_sec;
                        --cp->c_linkcount;
                        (void) cat_update(hfsmp, &to_desc, &cp->c_attr, NULL, NULL);
                }
                hfs_systemfile_unlock(hfsmp, lockflags);
                if (error)
                        goto out;

        } 
        else {
                /*
                 * Nobody is using this item; we can safely remove everything.
                 */
                struct filefork *temp_rsrc_fork = NULL;
#if QUOTA
                off_t savedbytes;
                int blksize = hfsmp->blockSize;
#endif
                u_int32_t fileid = cp->c_fileid;
        
                /* 
                 * Figure out if we need to read the resource fork data into 
                 * core before wiping out the catalog record.  
                 *
                 * 1) Must not be a directory
                 * 2) cnode's c_rsrcfork ptr must be NULL.
                 * 3) rsrc fork must have actual blocks 
                 */
                if ((isdir == 0) && (cp->c_rsrcfork == NULL) && 
                                (cp->c_blocks - VTOF(vp)->ff_blocks)) {
                        /*
                         * The resource fork vnode & filefork did not exist.
                         * Create a temporary one for use in this function only. 
                         */
                        temp_rsrc_fork = hfs_zalloc(HFS_FILEFORK_ZONE);
                        bzero(temp_rsrc_fork, sizeof(struct filefork));
                        temp_rsrc_fork->ff_cp = cp;
                        rl_init(&temp_rsrc_fork->ff_invalidranges);
                }       

                lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG | SFL_ATTRIBUTE | SFL_BITMAP, HFS_EXCLUSIVE_LOCK);

                /* Look up the resource fork first, if necessary */
                if (temp_rsrc_fork) {
                        error = cat_lookup (hfsmp, &desc, 1, 0, (struct cat_desc*) NULL, 
                                        (struct cat_attr*) NULL, &temp_rsrc_fork->ff_data, NULL);
                        if (error) {
                                hfs_zfree(temp_rsrc_fork, HFS_FILEFORK_ZONE);
                                hfs_systemfile_unlock (hfsmp, lockflags);
                                goto out;
                        }
                }

                if (!skip_reserve) {
                        if ((error = cat_preflight(hfsmp, CAT_DELETE, NULL, 0))) {
                                if (temp_rsrc_fork) {
                                        hfs_zfree(temp_rsrc_fork, HFS_FILEFORK_ZONE);
                                }
                                hfs_systemfile_unlock(hfsmp, lockflags);
                                goto out;
                        }
                }
                
                error = cat_delete(hfsmp, &desc, &cp->c_attr);
                
                if (error && error != ENXIO && error != ENOENT) {
                        printf("hfs_removefile: deleting file %s (id=%d) vol=%s err=%d\n",
                                   cp->c_desc.cd_nameptr, cp->c_attr.ca_fileid, hfsmp->vcbVN, error);
                }
                
                if (error == 0) {
                        /* Update the parent directory */
                        if (dcp->c_entries > 0)
                                dcp->c_entries--;
                        dcp->c_dirchangecnt++;
                        hfs_incr_gencount(dcp);

                        dcp->c_ctime = tv.tv_sec;
                        dcp->c_mtime = tv.tv_sec;
                        (void) cat_update(hfsmp, &dcp->c_desc, &dcp->c_attr, NULL, NULL);
                }
                hfs_systemfile_unlock(hfsmp, lockflags);

                if (error) {
                        if (temp_rsrc_fork) {
                                hfs_zfree(temp_rsrc_fork, HFS_FILEFORK_ZONE);
                        }
                        goto out;
                }
                
                /* 
                 * Now that we've wiped out the catalog record, the file effectively doesn't
                 * exist anymore. So update the quota records to reflect the loss of the 
                 * data fork and the resource fork. 
                 */
#if QUOTA
                if (cp->c_datafork->ff_blocks > 0) {
                        savedbytes = ((off_t)cp->c_datafork->ff_blocks * (off_t)blksize);
                        (void) hfs_chkdq(cp, (int64_t)-(savedbytes), NOCRED, 0);
                }
                
                /*
                 * We may have just deleted the catalog record for a resource fork even 
                 * though it did not exist in core as a vnode. However, just because there 
                 * was a resource fork pointer in the cnode does not mean that it had any blocks.
                 */
                if (temp_rsrc_fork || cp->c_rsrcfork) {
                        if (cp->c_rsrcfork) {
                                if (cp->c_rsrcfork->ff_blocks > 0) {
                                        savedbytes = ((off_t)cp->c_rsrcfork->ff_blocks * (off_t)blksize);
                                        (void) hfs_chkdq(cp, (int64_t)-(savedbytes), NOCRED, 0);
                                }
                        }       
                        else {
                                /* we must have used a temporary fork */
                                savedbytes = ((off_t)temp_rsrc_fork->ff_blocks * (off_t)blksize);       
                                (void) hfs_chkdq(cp, (int64_t)-(savedbytes), NOCRED, 0);
                        }
                }
                
                if (hfsmp->hfs_flags & HFS_QUOTAS) {
                        (void)hfs_chkiq(cp, -1, NOCRED, 0);
                }
#endif

                if (vnode_islnk(vp) && cp->c_datafork->ff_symlinkptr) {
                        hfs_free(cp->c_datafork->ff_symlinkptr, cp->c_datafork->ff_size);
                        cp->c_datafork->ff_symlinkptr = NULL;
                }

                /* 
                 * If we didn't get any errors deleting the catalog entry, then go ahead
                 * and release the backing store now.  The filefork pointers are still valid.
                 */
                if (temp_rsrc_fork) {   
                        error = hfs_release_storage (hfsmp, cp->c_datafork, temp_rsrc_fork, fileid);
                }
                else {
                        /* if cp->c_rsrcfork == NULL, hfs_release_storage will skip over it. */
                        error = hfs_release_storage (hfsmp, cp->c_datafork, cp->c_rsrcfork, fileid);
                }
                if (error) {
                        /* 
                         * If we encountered an error updating the extents and bitmap,
                         * mark the volume inconsistent.  At this point, the catalog record has
                         * already been deleted, so we can't recover it at this point. We need
                         * to proceed and update the volume header and mark the cnode C_NOEXISTS.
                         * The subsequent fsck should be able to recover the free space for us.
                         */
                        hfs_mark_inconsistent(hfsmp, HFS_OP_INCOMPLETE);
                }
                else {
                        /* reset update_vh to 0, since hfs_release_storage should have done it for us */
                        update_vh = 0;
                }

                /* Get rid of the temporary rsrc fork */
                if (temp_rsrc_fork) {
                        hfs_zfree(temp_rsrc_fork, HFS_FILEFORK_ZONE);
                }

                cp->c_flag |= C_NOEXISTS;
                cp->c_flag &= ~C_DELETED;
                
                cp->c_touch_chgtime = TRUE;
                --cp->c_linkcount;
                
                /* 
                 * We must never get a directory if we're in this else block.  We could 
                 * accidentally drop the number of files in the volume header if we did.
                 */
                hfs_volupdate(hfsmp, VOL_RMFILE, (dcp->c_cnid == kHFSRootFolderID));
                
        }

        //
        // if skip_reserve == 1 then we're being called from hfs_vnop_rename() and thus
        // we don't need to touch the document_id as it's handled by the rename code.
        // otherwise it's a normal remove and we need to save the document id in the
        // per thread struct and clear it from the cnode.
        //
        if (!error && !skip_reserve && (cp->c_bsdflags & UF_TRACKED)
                && cp->c_linkcount <= 1) {
                struct  doc_tombstone *ut;
                ut = doc_tombstone_get();
                if (doc_tombstone_should_save(ut, vp, cnp)) {
                        add_fsevent(FSE_DOCID_CHANGED, vfs_context_current(),
                                                FSE_ARG_DEV, hfsmp->hfs_raw_dev,
                                                FSE_ARG_INO, (ino64_t)cp->c_fileid,       // src inode #
                                                FSE_ARG_INO, (ino64_t)0,                  // dst inode #
                                                FSE_ARG_INT32, hfs_get_document_id(cp),   // document id
                                                FSE_ARG_DONE);

                        doc_tombstone_save(dvp, vp, cnp, hfs_get_document_id(cp),
                                                           cp->c_fileid);

                        struct FndrExtendedFileInfo *fip = (struct FndrExtendedFileInfo *)((char *)&cp->c_attr.ca_finderinfo + 16);

                        fip->document_id = 0;
                        cp->c_bsdflags &= ~UF_TRACKED;
                }
        }

        /*
         * All done with this cnode's descriptor...
         *
         * Note: all future catalog calls for this cnode must be by
         * fileid only.  This is OK for HFS (which doesn't have file
         * thread records) since HFS doesn't support the removal of
         * busy files.
         */
        cat_releasedesc(&cp->c_desc);

out:
        if (error) {
            cp->c_flag &= ~C_DELETED;
        }
        
        if (update_vh) {
                /* 
                 * If we bailed out earlier, we may need to update the volume header
                 * to deal with the borrowed blocks accounting. 
                 */
                hfs_volupdate (hfsmp, VOL_UPDATE, 0);
        }       

        if (started_tr) {
            hfs_end_transaction(hfsmp);
        }

        dcp->c_flag &= ~C_DIR_MODIFICATION;
        wakeup((caddr_t)&dcp->c_flag);

        return (error);
}


void
replace_desc(struct cnode *cp, struct cat_desc *cdp)
{
        // fixes 4348457 and 4463138
        if (&cp->c_desc == cdp) {
            return;
        }

        /* First release allocated name buffer */
        if (cp->c_desc.cd_flags & CD_HASBUF && cp->c_desc.cd_nameptr != 0) {
                const u_int8_t *name = cp->c_desc.cd_nameptr;

                cp->c_desc.cd_nameptr = 0;
                cp->c_desc.cd_namelen = 0;
                cp->c_desc.cd_flags &= ~CD_HASBUF;
                vfs_removename((const char *)name);
        }
        bcopy(cdp, &cp->c_desc, sizeof(cp->c_desc));

        /* Cnode now owns the name buffer */
        cdp->cd_nameptr = 0;
        cdp->cd_namelen = 0;
        cdp->cd_flags &= ~CD_HASBUF;
}

/*
 * hfs_vnop_rename
 *
 * Just forwards the arguments from VNOP_RENAME into those of 
 * VNOP_RENAMEX but zeros out the flags word.
 */
int hfs_vnop_rename (struct vnop_rename_args *args) {
        struct vnop_renamex_args vrx;

        vrx.a_desc = args->a_desc; // we aren't using it to switch into the vnop array, so fine as is.
        vrx.a_fdvp = args->a_fdvp;
        vrx.a_fvp = args->a_fvp;
        vrx.a_fcnp = args->a_fcnp;
        vrx.a_tdvp = args->a_tdvp;
        vrx.a_tvp = args->a_tvp;
        vrx.a_tcnp = args->a_tcnp;
        vrx.a_vap = NULL; // not used
        vrx.a_flags = 0; //zero out the flags. 
        vrx.a_context = args->a_context;

        return hfs_vnop_renamex (&vrx);
}



/*
 * Rename a cnode.
 *
 * The VFS layer guarantees that:
 *   - source and destination will either both be directories, or
 *     both not be directories.
 *   - all the vnodes are from the same file system
 *
 * When the target is a directory, HFS must ensure that its empty.
 *
 * Note that this function requires up to 6 vnodes in order to work properly
 * if it is operating on files (and not on directories).  This is because only
 * files can have resource forks, and we now require iocounts to be held on the
 * vnodes corresponding to the resource forks (if applicable) as well as
 * the files or directories undergoing rename.  The problem with not holding 
 * iocounts on the resource fork vnodes is that it can lead to a deadlock 
 * situation: The rsrc fork of the source file may be recycled and reclaimed 
 * in order to provide a vnode for the destination file's rsrc fork.  Since
 * data and rsrc forks share the same cnode, we'd eventually try to lock the
 * source file's cnode in order to sync its rsrc fork to disk, but it's already 
 * been locked.  By taking the rsrc fork vnodes up front we ensure that they 
 * cannot be recycled, and that the situation mentioned above cannot happen.
 */
int
hfs_vnop_renamex(struct vnop_renamex_args *ap)
{
        struct vnode *tvp = ap->a_tvp;
        struct vnode *tdvp = ap->a_tdvp;
        struct vnode *fvp = ap->a_fvp;
        struct vnode *fdvp = ap->a_fdvp;
        /*
         * Note that we only need locals for the target/destination's
         * resource fork vnode (and only if necessary).  We don't care if the
         * source has a resource fork vnode or not.
         */
        struct vnode *tvp_rsrc = NULLVP;        
        uint32_t tvp_rsrc_vid = 0;
        struct componentname *tcnp = ap->a_tcnp;
        struct componentname *fcnp = ap->a_fcnp;
        struct proc *p = vfs_context_proc(ap->a_context);
        struct cnode *fcp;
        struct cnode *fdcp;
        struct cnode *tdcp;
        struct cnode *tcp;
        struct cnode *error_cnode;
        struct cat_desc from_desc;
        struct cat_desc to_desc;
        struct cat_desc out_desc;
        struct hfsmount *hfsmp;
        cat_cookie_t cookie;
        int tvp_deleted = 0;
        int started_tr = 0, got_cookie = 0;
        int took_trunc_lock = 0;
        int lockflags;
        int error;
        time_t orig_from_ctime, orig_to_ctime;
        int emit_rename = 1;
        int emit_delete = 1;
        int is_tracked = 0;
        int unlocked;
        vnode_t old_doc_vp = NULL;
        int rename_exclusive = 0;

        orig_from_ctime = VTOC(fvp)->c_ctime;
        if (tvp && VTOC(tvp)) {
                orig_to_ctime = VTOC(tvp)->c_ctime;
        } else {
                orig_to_ctime = ~0;
        }

        hfsmp = VTOHFS(tdvp);
        
        /* Check the flags first, so we can avoid grabbing locks if necessary */
        if (ap->a_flags) {
                /* These are the only flags we support for now */
                if ((ap->a_flags & (VFS_RENAME_EXCL)) == 0) {
                        return ENOTSUP; 
                }
                
                /* The rename flags are mutually exclusive for HFS+ */
                switch (ap->a_flags & VFS_RENAME_FLAGS_MASK) {
                        case VFS_RENAME_EXCL: 
                                rename_exclusive = true;                        
                                break;
                        default: 
                                return ENOTSUP;
                }
        }       
        
        /* 
         * Do special case checks here.  If fvp == tvp then we need to check the
         * cnode with locks held.
         */
        if (fvp == tvp) {
                int is_hardlink = 0;
                /* 
                 * In this case, we do *NOT* ever emit a DELETE event.  
                 * We may not necessarily emit a RENAME event 
                 */     
                emit_delete = 0;
                if ((error = hfs_lock(VTOC(fvp), HFS_SHARED_LOCK, HFS_LOCK_DEFAULT))) {
                        return error;
                }
                /* Check to see if the item is a hardlink or not */
                is_hardlink = (VTOC(fvp)->c_flag & C_HARDLINK);
                hfs_unlock (VTOC(fvp));
                
                /* 
                 * If the item is not a hardlink, then case sensitivity must be off, otherwise
                 * two names should not resolve to the same cnode unless they were case variants.
                 */
                if (is_hardlink) {
                        emit_rename = 0;
                        /*
                         * Hardlinks are a little trickier.  We only want to emit a rename event
                         * if the item is a hardlink, the parent directories are the same, case sensitivity
                         * is off, and the case folded names are the same.  See the fvp == tvp case below for more
                         * info.
                         */

                        if ((fdvp == tdvp) && ((hfsmp->hfs_flags & HFS_CASE_SENSITIVE) == 0)) {
                                if (hfs_namecmp((const u_int8_t *)fcnp->cn_nameptr, fcnp->cn_namelen,
                                                        (const u_int8_t *)tcnp->cn_nameptr, tcnp->cn_namelen) == 0) {
                                        /* Then in this case only it is ok to emit a rename */
                                        emit_rename = 1;
                                }
                        }
                }
        }
        if (emit_rename) {
                /* c_bsdflags should only be assessed while holding the cnode lock.  
                 * This is not done consistently throughout the code and can result 
                 * in race.  This will be fixed via rdar://12181064
                 */
                if (VTOC(fvp)->c_bsdflags & UF_TRACKED) {
                        is_tracked = 1;
                }
                nspace_snapshot_event(fvp, orig_from_ctime, NAMESPACE_HANDLER_RENAME_OP, NULL);
        }

        if (tvp && VTOC(tvp)) {
                if (emit_delete) {
                        nspace_snapshot_event(tvp, orig_to_ctime, NAMESPACE_HANDLER_DELETE_OP, NULL);
                }
        }

retry:
        /* When tvp exists, take the truncate lock for hfs_removefile(). */
        if (tvp && (vnode_isreg(tvp) || vnode_islnk(tvp))) {
                hfs_lock_truncate(VTOC(tvp), HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT);
                took_trunc_lock = 1;
        }

relock:
        error = hfs_lockfour(VTOC(fdvp), VTOC(fvp), VTOC(tdvp), tvp ? VTOC(tvp) : NULL,
                             HFS_EXCLUSIVE_LOCK, &error_cnode);
        if (error) {
                if (took_trunc_lock) {
                        hfs_unlock_truncate(VTOC(tvp), HFS_LOCK_DEFAULT);
                        took_trunc_lock = 0;
                }

                /* 
                 * We hit an error path.  If we were trying to re-acquire the locks
                 * after coming through here once, we might have already obtained
                 * an iocount on tvp's resource fork vnode.  Drop that before dealing
                 * with the failure.  Note this is safe -- since we are in an
                 * error handling path, we can't be holding the cnode locks.
                 */
                if (tvp_rsrc) {
                        vnode_put (tvp_rsrc);
                        tvp_rsrc_vid = 0;
                        tvp_rsrc = NULL;
                }

                /* 
                 * tvp might no longer exist.  If the cause of the lock failure 
                 * was tvp, then we can try again with tvp/tcp set to NULL.  
                 * This is ok because the vfs syscall will vnode_put the vnodes 
                 * after we return from hfs_vnop_rename.
                 */
                if ((error == ENOENT) && (tvp != NULL) && (error_cnode == VTOC(tvp))) { 
                        tcp = NULL;
                        tvp = NULL;
                        goto retry;
                }

                /* If we want to reintroduce notifications for failed renames, this
                   is the place to do it. */

                return (error);
        }

        fdcp = VTOC(fdvp);
        fcp = VTOC(fvp);
        tdcp = VTOC(tdvp);
        tcp = tvp ? VTOC(tvp) : NULL;


        /*
         * If caller requested an exclusive rename (VFS_RENAME_EXCL) and 'tcp' exists
         * then we must fail the operation. 
         */
        if (tcp && rename_exclusive) {
                error = EEXIST;
                goto out;
        }

        //
        // if the item is tracked but doesn't have a document_id, assign one and generate an fsevent for it
        //
        unlocked = 0;
        if ((fcp->c_bsdflags & UF_TRACKED) && ((struct FndrExtendedDirInfo *)((char *)&fcp->c_attr.ca_finderinfo + 16))->document_id == 0) {
                uint32_t newid;

                hfs_unlockfour(VTOC(fdvp), VTOC(fvp), VTOC(tdvp), tvp ? VTOC(tvp) : NULL);
                unlocked = 1;

                if (hfs_generate_document_id(hfsmp, &newid) == 0) {
                        hfs_lock(fcp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT);
                        ((struct FndrExtendedDirInfo *)((char *)&fcp->c_attr.ca_finderinfo + 16))->document_id = newid;
                        add_fsevent(FSE_DOCID_CHANGED, vfs_context_current(),
                                    FSE_ARG_DEV,   hfsmp->hfs_raw_dev,
                                    FSE_ARG_INO,   (ino64_t)0,             // src inode #
                                    FSE_ARG_INO,   (ino64_t)fcp->c_fileid,  // dst inode #
                                    FSE_ARG_INT32, newid,
                                    FSE_ARG_DONE);
                        hfs_unlock(fcp);
                } else {
                        // XXXdbg - couldn't get a new docid... what to do?  can't really fail the rename...
                }

                //
                // check if we're going to need to fix tcp as well.  if we aren't, go back relock
                // everything.  otherwise continue on and fix up tcp as well before relocking.
                //
                if (tcp == NULL || !(tcp->c_bsdflags & UF_TRACKED) || ((struct FndrExtendedDirInfo *)((char *)&tcp->c_attr.ca_finderinfo + 16))->document_id != 0) {
                        goto relock;
                }
        }

        //
        // same thing for tcp if it's set
        //
        if (tcp && (tcp->c_bsdflags & UF_TRACKED) && ((struct FndrExtendedDirInfo *)((char *)&tcp->c_attr.ca_finderinfo + 16))->document_id == 0) {
                uint32_t newid;

                if (!unlocked) {
                        hfs_unlockfour(VTOC(fdvp), VTOC(fvp), VTOC(tdvp), tvp ? VTOC(tvp) : NULL);
                        unlocked = 1;
                }

                if (hfs_generate_document_id(hfsmp, &newid) == 0) {
                        hfs_lock(tcp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT);
                        ((struct FndrExtendedDirInfo *)((char *)&tcp->c_attr.ca_finderinfo + 16))->document_id = newid;
                        add_fsevent(FSE_DOCID_CHANGED, vfs_context_current(),
                                    FSE_ARG_DEV,   hfsmp->hfs_raw_dev,
                                    FSE_ARG_INO,   (ino64_t)0,             // src inode #
                                    FSE_ARG_INO,   (ino64_t)tcp->c_fileid,  // dst inode #
                                    FSE_ARG_INT32, newid,
                                    FSE_ARG_DONE);
                        hfs_unlock(tcp);
                } else {
                        // XXXdbg - couldn't get a new docid... what to do?  can't really fail the rename...
                }

                // go back up and relock everything.  next time through the if statement won't be true
                // and we'll skip over this block of code.
                goto relock;
        }



        /* 
         * Acquire iocounts on the destination's resource fork vnode 
         * if necessary. If dst/src are files and the dst has a resource 
         * fork vnode, then we need to try and acquire an iocount on the rsrc vnode. 
         * If it does not exist, then we don't care and can skip it.
         */
        if ((vnode_isreg(fvp)) || (vnode_islnk(fvp))) {
                if ((tvp) && (tcp->c_rsrc_vp) && (tvp_rsrc == NULL)) {
                        tvp_rsrc = tcp->c_rsrc_vp;
                        /*
                         * We can look at the vid here because we're holding the 
                         * cnode lock on the underlying cnode for this rsrc vnode. 
                         */
                        tvp_rsrc_vid = vnode_vid (tvp_rsrc);

                        /* Unlock everything to acquire iocount on this rsrc vnode */
                        if (took_trunc_lock) {
                                hfs_unlock_truncate (VTOC(tvp), HFS_LOCK_DEFAULT);
                                took_trunc_lock = 0;    
                        }       
                        hfs_unlockfour(fdcp, fcp, tdcp, tcp);

                        if (vnode_getwithvid (tvp_rsrc, tvp_rsrc_vid)) {
                                /* iocount acquisition failed.  Reset fields and start over.. */
                                tvp_rsrc_vid = 0;
                                tvp_rsrc = NULL;
                        }
                        goto retry;
                }
        }



        /* Ensure we didn't race src or dst parent directories with rmdir. */
        if (fdcp->c_flag & (C_NOEXISTS | C_DELETED)) {
                error = ENOENT;
                goto out;
        }

        if (tdcp->c_flag & (C_NOEXISTS | C_DELETED)) {
                error = ENOENT;
                goto out;       
        }


        /* Check for a race against unlink.  The hfs_valid_cnode checks validate
         * the parent/child relationship with fdcp and tdcp, as well as the
         * component name of the target cnodes.  
         */
        if ((fcp->c_flag & (C_NOEXISTS | C_DELETED)) || !hfs_valid_cnode(hfsmp, fdvp, fcnp, fcp->c_fileid, NULL, &error)) {
                error = ENOENT;
                goto out;
        }

        if (tcp && ((tcp->c_flag & (C_NOEXISTS | C_DELETED)) || !hfs_valid_cnode(hfsmp, tdvp, tcnp, tcp->c_fileid, NULL, &error))) {
            //
            // hmm, the destination vnode isn't valid any more.
            // in this case we can just drop him and pretend he
            // never existed in the first place.
            //
            if (took_trunc_lock) {
                        hfs_unlock_truncate(VTOC(tvp), HFS_LOCK_DEFAULT);
                        took_trunc_lock = 0;
            }
                error = 0;

            hfs_unlockfour(fdcp, fcp, tdcp, tcp);

            tcp = NULL;
            tvp = NULL;
            
            // retry the locking with tvp null'ed out
            goto retry;
        }

        fdcp->c_flag |= C_DIR_MODIFICATION;
        if (fdvp != tdvp) {
            tdcp->c_flag |= C_DIR_MODIFICATION;
        }

        /*
         * Disallow renaming of a directory hard link if the source and 
         * destination parent directories are different, or a directory whose 
         * descendant is a directory hard link and the one of the ancestors
         * of the destination directory is a directory hard link.
         */
        if (vnode_isdir(fvp) && (fdvp != tdvp)) {
                if (fcp->c_flag & C_HARDLINK) {
                        error = EPERM;
                        goto out;
                }
                if (fcp->c_attr.ca_recflags & kHFSHasChildLinkMask) {
                    lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG, HFS_SHARED_LOCK);
                    if (cat_check_link_ancestry(hfsmp, tdcp->c_fileid, 0)) {
                                error = EPERM;
                                hfs_systemfile_unlock(hfsmp, lockflags);
                                goto out;
                        }
                        hfs_systemfile_unlock(hfsmp, lockflags);
                }
        }

        /*
         * The following edge case is caught here:
         * (to cannot be a descendent of from)
         *
         *       o fdvp
         *      /
         *     /
         *    o fvp
         *     \
         *      \
         *       o tdvp
         *      /
         *     /
         *    o tvp
         */
        if (tdcp->c_parentcnid == fcp->c_fileid) {
                error = EINVAL;
                goto out;
        }

        /*
         * The following two edge cases are caught here:
         * (note tvp is not empty)
         *
         *       o tdvp               o tdvp
         *      /                    /
         *     /                    /
         *    o tvp            tvp o fdvp
         *     \                    \
         *      \                    \
         *       o fdvp               o fvp
         *      /
         *     /
         *    o fvp
         */
        if (tvp && vnode_isdir(tvp) && (tcp->c_entries != 0) && fvp != tvp) {
                error = ENOTEMPTY;
                goto out;
        }

        /*
         * The following edge case is caught here:
         * (the from child and parent are the same)
         *
         *          o tdvp
         *         /
         *        /
         *  fdvp o fvp
         */
        if (fdvp == fvp) {
                error = EINVAL;
                goto out;
        }

        /*
         * Make sure "from" vnode and its parent are changeable.
         */
        if ((fcp->c_bsdflags & (IMMUTABLE | APPEND)) || (fdcp->c_bsdflags & APPEND)) {
                error = EPERM;
                goto out;
        }

        /*
         * If the destination parent directory is "sticky", then the
         * user must own the parent directory, or the destination of
         * the rename, otherwise the destination may not be changed
         * (except by root). This implements append-only directories.
         *
         * Note that checks for immutable and write access are done
         * by the call to hfs_removefile.
         */
        if (tvp && (tdcp->c_mode & S_ISTXT) &&
            (suser(vfs_context_ucred(ap->a_context), NULL)) &&
            (kauth_cred_getuid(vfs_context_ucred(ap->a_context)) != tdcp->c_uid) &&
            (hfs_owner_rights(hfsmp, tcp->c_uid, vfs_context_ucred(ap->a_context), p, false)) ) {
                error = EPERM;
                goto out;
        }

        /* Don't allow modification of the journal or journal_info_block */
        if (hfs_is_journal_file(hfsmp, fcp) ||
            (tcp && hfs_is_journal_file(hfsmp, tcp))) {
                error = EPERM;
                goto out;
        }

#if QUOTA
        if (tvp)
                (void)hfs_getinoquota(tcp);
#endif
        /* Preflighting done, take fvp out of the name space. */
        cache_purge(fvp);

#if CONFIG_SECLUDED_RENAME
        /*
         * Check for "secure" rename that imposes additional restrictions on the
         * source vnode.  We wait until here to check in order to prevent a race
         * with other threads that manage to look up fvp, but their open or link
         * is blocked by our locks.  At this point, with fvp out of the name cache,
         * and holding the lock on fdvp, no other thread can find fvp.
         *
         * TODO: Do we need to limit these checks to regular files only?
         */
        if (fcnp->cn_flags & CN_SECLUDE_RENAME) {
                if (vnode_isdir(fvp)) {
                        error = EISDIR;
                        goto out;
                }
            
                /*
                 * Neither fork of source may be open or memory mapped.
                 * We also don't want it in use by any other system call.
                 * The file must not have hard links.
                 *
                 * We can't simply use vnode_isinuse() because that does not
                 * count opens with O_EVTONLY.  We don't want a malicious
                 * process using O_EVTONLY to subvert a secluded rename.
                 */
                if (fcp->c_linkcount != 1) {
                        error = EMLINK;
                        goto out;
                }

                if (fcp->c_rsrc_vp && (vnode_usecount(fcp->c_rsrc_vp) > 0 ||
                                       vnode_iocount(fcp->c_rsrc_vp) > 0)) {
                        /* Resource fork is in use (including O_EVTONLY) */
                        error = EBUSY;
                        goto out;
                }
                if (fcp->c_vp && (vnode_usecount(fcp->c_vp) > (fcp->c_rsrc_vp ? 1 : 0) ||
                                  vnode_iocount(fcp->c_vp) > 1)) {
                        /*
                         * Data fork is in use, including O_EVTONLY, but not
                         * including a reference from the resource fork.
                         */
                        error = EBUSY;
                        goto out;
                }
        }
#endif

        bzero(&from_desc, sizeof(from_desc));
        from_desc.cd_nameptr = (const u_int8_t *)fcnp->cn_nameptr;
        from_desc.cd_namelen = fcnp->cn_namelen;
        from_desc.cd_parentcnid = fdcp->c_fileid;
        from_desc.cd_flags = fcp->c_desc.cd_flags & ~(CD_HASBUF | CD_DECOMPOSED);
        from_desc.cd_cnid = fcp->c_cnid;

        bzero(&to_desc, sizeof(to_desc));
        to_desc.cd_nameptr = (const u_int8_t *)tcnp->cn_nameptr;
        to_desc.cd_namelen = tcnp->cn_namelen;
        to_desc.cd_parentcnid = tdcp->c_fileid;
        to_desc.cd_flags = fcp->c_desc.cd_flags & ~(CD_HASBUF | CD_DECOMPOSED);
        to_desc.cd_cnid = fcp->c_cnid;

        if ((error = hfs_start_transaction(hfsmp)) != 0) {
            goto out;
        }
        started_tr = 1;

        /* hfs_vnop_link() and hfs_vnop_rename() set kHFSHasChildLinkMask 
         * inside a journal transaction and without holding a cnode lock.  
         * As setting of this bit depends on being in journal transaction for 
         * concurrency, check this bit again after we start journal transaction for rename
         * to ensure that this directory does not have any descendant that
         * is a directory hard link. 
         */
        if (vnode_isdir(fvp) && (fdvp != tdvp)) {
                if (fcp->c_attr.ca_recflags & kHFSHasChildLinkMask) {
                    lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG, HFS_SHARED_LOCK);
                    if (cat_check_link_ancestry(hfsmp, tdcp->c_fileid, 0)) {
                                error = EPERM;
                                hfs_systemfile_unlock(hfsmp, lockflags);
                                goto out;
                        }
                        hfs_systemfile_unlock(hfsmp, lockflags);
                }
        }

        // if it's a hardlink then re-lookup the name so
        // that we get the correct cnid in from_desc (see
        // the comment in hfs_removefile for more details)
        //
        if (fcp->c_flag & C_HARDLINK) {
            struct cat_desc tmpdesc;
            cnid_t real_cnid;

            tmpdesc.cd_nameptr = (const u_int8_t *)fcnp->cn_nameptr;
            tmpdesc.cd_namelen = fcnp->cn_namelen;
            tmpdesc.cd_parentcnid = fdcp->c_fileid;
            tmpdesc.cd_hint = fdcp->c_childhint;
            tmpdesc.cd_flags = fcp->c_desc.cd_flags & CD_ISDIR;
            tmpdesc.cd_encoding = 0;
            
            lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG, HFS_SHARED_LOCK);

            if (cat_lookup(hfsmp, &tmpdesc, 0, 0, NULL, NULL, NULL, &real_cnid) != 0) {
                hfs_systemfile_unlock(hfsmp, lockflags);
                goto out;
            }

            // use the real cnid instead of whatever happened to be there
            from_desc.cd_cnid = real_cnid;
            hfs_systemfile_unlock(hfsmp, lockflags);
        }

        /*
         * Reserve some space in the Catalog file.
         */
        if ((error = cat_preflight(hfsmp, CAT_RENAME + CAT_DELETE, &cookie, p))) {
                goto out;
        }
        got_cookie = 1;

        /*
         * If the destination exists then it may need to be removed.  
         * 
         * Due to HFS's locking system, we should always move the 
         * existing 'tvp' element to the hidden directory in hfs_vnop_rename.
         * Because the VNOP_LOOKUP call enters and exits the filesystem independently
         * of the actual vnop that it was trying to do (stat, link, readlink),
         * we must release the cnode lock of that element during the interim to 
         * do MAC checking, vnode authorization, and other calls.  In that time, 
         * the item can be deleted (or renamed over). However, only in the rename 
         * case is it inappropriate to return ENOENT from any of those calls.  Either 
         * the call should return information about the old element (stale), or get 
         * information about the newer element that we are about to write in its place.  
         * 
         * HFS lookup has been modified to detect a rename and re-drive its 
         * lookup internally. For other calls that have already succeeded in 
         * their lookup call and are waiting to acquire the cnode lock in order 
         * to proceed, that cnode lock will not fail due to the cnode being marked 
         * C_NOEXISTS, because it won't have been marked as such.  It will only 
         * have C_DELETED.  Thus, they will simply act on the stale open-unlinked
         * element.  All future callers will get the new element.
         *
         * To implement this behavior, we pass the "only_unlink" argument to 
         * hfs_removefile and hfs_removedir.  This will result in the vnode acting 
         * as though it is open-unlinked.  Additionally, when we are done moving the 
         * element to the hidden directory, we vnode_recycle the target so that it is 
         * reclaimed as soon as possible.  Reclaim and inactive are both 
         * capable of clearing out unused blocks for an open-unlinked file or dir.
         */
        if (tvp) {
                //
                // if the destination has a document id, we need to preserve it
                //
                if (fvp != tvp) {
                        uint32_t document_id;
                        struct FndrExtendedDirInfo *ffip = (struct FndrExtendedDirInfo *)((char *)&fcp->c_attr.ca_finderinfo + 16);
                        struct FndrExtendedDirInfo *tfip = (struct FndrExtendedDirInfo *)((char *)&tcp->c_attr.ca_finderinfo + 16);
                        
                        if (ffip->document_id && tfip->document_id) {
                                // both documents are tracked.  only save a tombstone from tcp and do nothing else.
                                doc_tombstone_save(tdvp, tvp, tcnp, hfs_get_document_id(tcp),
                                                                   tcp->c_fileid);
                        } else {
                                struct  doc_tombstone *ut;
                                ut = doc_tombstone_get();

                                document_id = tfip->document_id;
                                tfip->document_id = 0;
                        
                                if (document_id != 0) {
                                        // clear UF_TRACKED as well since tcp is now no longer tracked
                                        tcp->c_bsdflags &= ~UF_TRACKED;
                                        (void) cat_update(hfsmp, &tcp->c_desc, &tcp->c_attr, NULL, NULL);
                                }

                                if (ffip->document_id == 0 && document_id != 0) {
                                        // printf("RENAME: preserving doc-id %d onto %s (from ino %d, to ino %d)\n", document_id, tcp->c_desc.cd_nameptr, tcp->c_desc.cd_cnid, fcp->c_desc.cd_cnid);
                                        fcp->c_bsdflags |= UF_TRACKED;
                                        ffip->document_id = document_id;
                                        
                                        (void) cat_update(hfsmp, &fcp->c_desc, &fcp->c_attr, NULL, NULL);
                                        add_fsevent(FSE_DOCID_CHANGED, vfs_context_current(),
                                                    FSE_ARG_DEV, hfsmp->hfs_raw_dev,
                                                    FSE_ARG_INO, (ino64_t)tcp->c_fileid,           // src inode #
                                                    FSE_ARG_INO, (ino64_t)fcp->c_fileid,           // dst inode #
                                                    FSE_ARG_INT32, (uint32_t)ffip->document_id,
                                                    FSE_ARG_DONE);
                                }
                                else if ((fcp->c_bsdflags & UF_TRACKED) && doc_tombstone_should_save(ut, fvp, fcnp)) {

                                        if (ut->t_lastop_document_id) {
                                                doc_tombstone_clear(ut, NULL);
                                        }
                                        doc_tombstone_save(fdvp, fvp, fcnp,
                                                                           hfs_get_document_id(fcp), fcp->c_fileid);

                                        //printf("RENAME: (dest-exists): saving tombstone doc-id %lld @ %s (ino %d)\n",
                                        //       ut->t_lastop_document_id, ut->t_lastop_filename, fcp->c_desc.cd_cnid);
                                }
                        }
                }

                /*
                 * When fvp matches tvp they could be case variants
                 * or matching hard links.
                 */
                if (fvp == tvp) {
                        if (!(fcp->c_flag & C_HARDLINK)) {
                                /* 
                                 * If they're not hardlinks, then fvp == tvp must mean we 
                                 * are using case-insensitive HFS because case-sensitive would
                                 * not use the same vnode for both.  In this case we just update
                                 * the catalog for: a -> A
                                 */
                                goto skip_rm;  /* simple case variant */

                        }
                        /* For all cases below, we must be using hardlinks */   
                        else if ((fdvp != tdvp) ||
                                   (hfsmp->hfs_flags & HFS_CASE_SENSITIVE)) {
                                /*
                                 * If the parent directories are not the same, AND the two items
                                 * are hardlinks, posix says to do nothing:
                                 * dir1/fred <-> dir2/bob   and the op was mv dir1/fred -> dir2/bob
                                 * We just return 0 in this case.
                                 *
                                 * If case sensitivity is on, and we are using hardlinks 
                                 * then renaming is supposed to do nothing.
                                 * dir1/fred <-> dir2/FRED, and op == mv dir1/fred -> dir2/FRED
                                 */
                                goto out;  /* matching hardlinks, nothing to do */

                        } else if (hfs_namecmp((const u_int8_t *)fcnp->cn_nameptr, fcnp->cn_namelen,
                                               (const u_int8_t *)tcnp->cn_nameptr, tcnp->cn_namelen) == 0) {
                                /*
                                 * If we get here, then the following must be true:
                                 * a) We are running case-insensitive HFS+.
                                 * b) Both paths 'fvp' and 'tvp' are in the same parent directory.
                                 * c) the two names are case-variants of each other.
                                 *
                                 * In this case, we are really only dealing with a single catalog record
                                 * whose name is being updated.
                                 * 
                                 * op is dir1/fred -> dir1/FRED
                                 * 
                                 * We need to special case the name matching, because if
                                 * dir1/fred <-> dir1/bob were the two links, and the 
                                 * op was dir1/fred -> dir1/bob
                                 * That would fail/do nothing.
                                 */
                                goto skip_rm;  /* case-variant hardlink in the same dir */
                        } else {
                                goto out;  /* matching hardlink, nothing to do */
                        }
                }

                
                if (vnode_isdir(tvp)) {
                        /*
                         * hfs_removedir will eventually call hfs_removefile on the directory
                         * we're working on, because only hfs_removefile does the renaming of the
                         * item to the hidden directory.  The directory will stay around in the
                         * hidden directory with C_DELETED until it gets an inactive or a reclaim.
                         * That way, we can destroy all of the EAs as needed and allow new ones to be
                         * written.
                         */
                        error = hfs_removedir(tdvp, tvp, tcnp, HFSRM_SKIP_RESERVE, 1);
                }
                else {
                        error = hfs_removefile(tdvp, tvp, tcnp, 0, HFSRM_SKIP_RESERVE, 0, NULL, 1);
                        
                        /*
                         * If the destination file had a resource fork vnode, then we need to get rid of
                         * its blocks when there are no more references to it.  Because the call to
                         * hfs_removefile above always open-unlinks things, we need to force an inactive/reclaim
                         * on the resource fork vnode, in order to prevent block leaks.  Otherwise,
                         * the resource fork vnode could prevent the data fork vnode from going out of scope
                         * because it holds a v_parent reference on it.  So we mark it for termination
                         * with a call to vnode_recycle. hfs_vnop_reclaim has been modified so that it 
                         * can clean up the blocks of open-unlinked files and resource forks. 
                         *
                         * We can safely call vnode_recycle on the resource fork because we took an iocount
                         * reference on it at the beginning of the function. 
                         */ 
                        
                        if ((error == 0) && (tcp->c_flag & C_DELETED) && (tvp_rsrc)) {
                                vnode_recycle(tvp_rsrc);
                        }
                }

                if (error) {
                        goto out;
                }
                
                tvp_deleted = 1;
                
                /* Mark 'tcp' as being deleted due to a rename */
                tcp->c_flag |= C_RENAMED;
                
                /*
                 * Aggressively mark tvp/tcp for termination to ensure that we recover all blocks
                 * as quickly as possible.
                 */
                vnode_recycle(tvp);
        } else {
                struct  doc_tombstone *ut;
                ut = doc_tombstone_get();
                
                //
                // There is nothing at the destination.  If the file being renamed is
                // tracked, save a "tombstone" of the document_id.  If the file is
                // not a tracked file, then see if it needs to inherit a tombstone.
                //
                // NOTE: we do not save a tombstone if the file being renamed begins
                //       with "atmp" which is done to work-around AutoCad's bizarre
                //       5-step un-safe save behavior
                //
                if (fcp->c_bsdflags & UF_TRACKED) {
                        if (doc_tombstone_should_save(ut, fvp, fcnp)) {
                                doc_tombstone_save(fdvp, fvp, fcnp, hfs_get_document_id(fcp),
                                                                   fcp->c_fileid);

                                //printf("RENAME: (no dest): saving tombstone doc-id %lld @ %s (ino %d)\n",
                                //       ut->t_lastop_document_id, ut->t_lastop_filename, fcp->c_desc.cd_cnid);
                        } else {
                                // intentionally do nothing
                        }
                } else if (   ut->t_lastop_document_id != 0
                           && tdvp == ut->t_lastop_parent
                           && vnode_vid(tdvp) == ut->t_lastop_parent_vid
                           && strcmp((char *)ut->t_lastop_filename, (char *)tcnp->cn_nameptr) == 0) {

                        //printf("RENAME: %s (ino %d) inheriting doc-id %lld\n", tcnp->cn_nameptr, fcp->c_desc.cd_cnid, ut->t_lastop_document_id);
                        struct FndrExtendedFileInfo *fip = (struct FndrExtendedFileInfo *)((char *)&fcp->c_attr.ca_finderinfo + 16);
                        fcp->c_bsdflags |= UF_TRACKED;
                        fip->document_id = ut->t_lastop_document_id;
                        cat_update(hfsmp, &fcp->c_desc, &fcp->c_attr, NULL, NULL);

                        doc_tombstone_clear(ut, &old_doc_vp);
                } else if (ut->t_lastop_document_id && doc_tombstone_should_save(ut, fvp, fcnp) && doc_tombstone_should_save(ut, tvp, tcnp)) {
                        // no match, clear the tombstone
                        //printf("RENAME: clearing the tombstone %lld @ %s\n", ut->t_lastop_document_id, ut->t_lastop_filename);
                        doc_tombstone_clear(ut, NULL);
                }

        }
skip_rm:
        /*
         * All done with tvp and fvp. 
         * 
         * We also jump to this point if there was no destination observed during lookup and namei.
         * However, because only iocounts are held at the VFS layer, there is nothing preventing a 
         * competing thread from racing us and creating a file or dir at the destination of this rename 
         * operation.  If this occurs, it may cause us to get a spurious EEXIST out of the cat_rename 
         * call below.  To preserve rename's atomicity, we need to signal VFS to re-drive the 
         * namei/lookup and restart the rename operation.  EEXIST is an allowable errno to be bubbled 
         * out of the rename syscall, but not for this reason, since it is a synonym errno for ENOTEMPTY.
         * To signal VFS, we return ERECYCLE (which is also used for lookup restarts). This errno
         * will be swallowed and it will restart the operation.
         */
        
        lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG, HFS_EXCLUSIVE_LOCK);
        error = cat_rename(hfsmp, &from_desc, &tdcp->c_desc, &to_desc, &out_desc);
        hfs_systemfile_unlock(hfsmp, lockflags);

        if (error) {
                if (error == EEXIST) {
                        error = ERECYCLE;
                }
                goto out;
        }

        /* Invalidate negative cache entries in the destination directory */
        if (tdcp->c_flag & C_NEG_ENTRIES) {
                cache_purge_negatives(tdvp);
                tdcp->c_flag &= ~C_NEG_ENTRIES;
        }

        /* Update cnode's catalog descriptor */
        replace_desc(fcp, &out_desc);
        fcp->c_parentcnid = tdcp->c_fileid;
        fcp->c_hint = 0;

        /*
         * Now indicate this cnode needs to have date-added written to the
         * finderinfo, but only if moving to a different directory, or if
         * it doesn't already have it.
         */
        if (fdvp != tdvp || !ISSET(fcp->c_attr.ca_recflags, kHFSHasDateAddedMask))
                fcp->c_flag |= C_NEEDS_DATEADDED;

        (void) hfs_update (fvp, 0);

        hfs_volupdate(hfsmp, vnode_isdir(fvp) ? VOL_RMDIR : VOL_RMFILE,
                      (fdcp->c_cnid == kHFSRootFolderID));
        hfs_volupdate(hfsmp, vnode_isdir(fvp) ? VOL_MKDIR : VOL_MKFILE,
                      (tdcp->c_cnid == kHFSRootFolderID));

        /* Update both parent directories. */
        if (fdvp != tdvp) {
                if (vnode_isdir(fvp)) {
                        /* If the source directory has directory hard link 
                         * descendants, set the kHFSHasChildLinkBit in the 
                         * destination parent hierarchy 
                         */
                        if ((fcp->c_attr.ca_recflags & kHFSHasChildLinkMask) && 
                            !(tdcp->c_attr.ca_recflags & kHFSHasChildLinkMask)) {

                                tdcp->c_attr.ca_recflags |= kHFSHasChildLinkMask;

                                error = cat_set_childlinkbit(hfsmp, tdcp->c_parentcnid);
                                if (error) {
                                        printf ("hfs_vnop_rename: error updating parent chain for %u\n", tdcp->c_cnid);
                                        error = 0;
                                }
                        }
                        INC_FOLDERCOUNT(hfsmp, tdcp->c_attr);
                        DEC_FOLDERCOUNT(hfsmp, fdcp->c_attr);
                }
                tdcp->c_entries++;
                tdcp->c_dirchangecnt++;
                tdcp->c_flag |= C_MODIFIED;
                hfs_incr_gencount(tdcp);

                if (fdcp->c_entries > 0)
                        fdcp->c_entries--;
                fdcp->c_dirchangecnt++;
                fdcp->c_flag |= C_MODIFIED;
                fdcp->c_touch_chgtime = TRUE;
                fdcp->c_touch_modtime = TRUE;

                if (ISSET(fcp->c_flag, C_HARDLINK)) {
                        hfs_relorigin(fcp, fdcp->c_fileid);
                        if (fdcp->c_fileid != fdcp->c_cnid)
                                hfs_relorigin(fcp, fdcp->c_cnid);
                }

                (void) hfs_update(fdvp, 0);
        }
        hfs_incr_gencount(fdcp);
                
        tdcp->c_childhint = out_desc.cd_hint;   /* Cache directory's location */
        tdcp->c_touch_chgtime = TRUE;
        tdcp->c_touch_modtime = TRUE;

        (void) hfs_update(tdvp, 0);

        /* Update the vnode's name now that the rename has completed. */
        vnode_update_identity(fvp, tdvp, tcnp->cn_nameptr, tcnp->cn_namelen, 
                        tcnp->cn_hash, (VNODE_UPDATE_PARENT | VNODE_UPDATE_NAME));
        
        /* 
         * At this point, we may have a resource fork vnode attached to the 
         * 'from' vnode.  If it exists, we will want to update its name, because
         * it contains the old name + _PATH_RSRCFORKSPEC. ("/..namedfork/rsrc").
         *
         * Note that the only thing we need to update here is the name attached to
         * the vnode, since a resource fork vnode does not have a separate resource
         * cnode -- it's still 'fcp'.
         */
        if (fcp->c_rsrc_vp) {
                char* rsrc_path = NULL;
                int len;

                /* Create a new temporary buffer that's going to hold the new name */
                rsrc_path = hfs_malloc(MAXPATHLEN);
                len = snprintf (rsrc_path, MAXPATHLEN, "%s%s", tcnp->cn_nameptr, _PATH_RSRCFORKSPEC);
                len = MIN(len, MAXPATHLEN);

                /* 
                 * vnode_update_identity will do the following for us:
                 * 1) release reference on the existing rsrc vnode's name.
                 * 2) copy/insert new name into the name cache
                 * 3) attach the new name to the resource vnode
                 * 4) update the vnode's vid
                 */
                vnode_update_identity (fcp->c_rsrc_vp, fvp, rsrc_path, len, 0, (VNODE_UPDATE_NAME | VNODE_UPDATE_CACHE));
                
                /* Free the memory associated with the resource fork's name */
                hfs_free(rsrc_path, MAXPATHLEN);
        }
out:
        if (got_cookie) {
                cat_postflight(hfsmp, &cookie, p);
        }
        if (started_tr) {
            hfs_end_transaction(hfsmp);
        }

        fdcp->c_flag &= ~C_DIR_MODIFICATION;
        wakeup((caddr_t)&fdcp->c_flag);
        if (fdvp != tdvp) {
            tdcp->c_flag &= ~C_DIR_MODIFICATION;
            wakeup((caddr_t)&tdcp->c_flag);
        }

        const ino64_t file_id = fcp->c_fileid;

        hfs_unlockfour(fdcp, fcp, tdcp, tcp);

        if (took_trunc_lock) {
                hfs_unlock_truncate(VTOC(tvp), HFS_LOCK_DEFAULT);       
        }

        /* Now vnode_put the resource forks vnodes if necessary */
        if (tvp_rsrc) {
                vnode_put(tvp_rsrc);
                tvp_rsrc = NULL;        
        }

        /* After tvp is removed the only acceptable error is EIO */
        if (error && tvp_deleted)
                error = EIO;

        /* If we want to reintroduce notifications for renames, this is the
           place to do it. */

        if (old_doc_vp) {
                cnode_t *ocp = VTOC(old_doc_vp);
                hfs_lock_always(ocp, HFS_EXCLUSIVE_LOCK);
                struct FndrExtendedFileInfo *ofip = (struct FndrExtendedFileInfo *)((char *)&ocp->c_attr.ca_finderinfo + 16);

                const uint32_t doc_id = ofip->document_id;
                const ino64_t old_file_id = ocp->c_fileid;

                // printf("clearing doc-id from ino %d\n", ocp->c_desc.cd_cnid);
                ofip->document_id = 0;
                ocp->c_bsdflags &= ~UF_TRACKED;
                ocp->c_flag |= C_MODIFIED;

                hfs_unlock(ocp);
                vnode_put(old_doc_vp);

                add_fsevent(FSE_DOCID_CHANGED, vfs_context_current(),
                                        FSE_ARG_DEV, hfsmp->hfs_raw_dev,
                                        FSE_ARG_INO, old_file_id,     // src inode #
                                        FSE_ARG_INO, file_id,             // dst inode #
                                        FSE_ARG_INT32, doc_id,
                                        FSE_ARG_DONE);
        }

        return (error);
}


/*
 * Make a directory.
 */
int
hfs_vnop_mkdir(struct vnop_mkdir_args *ap)
{
        /***** HACK ALERT ********/
        ap->a_cnp->cn_flags |= MAKEENTRY;
        return hfs_makenode(ap->a_dvp, ap->a_vpp, ap->a_cnp, ap->a_vap, ap->a_context);
}


/*
 * Create a symbolic link.
 */
int
hfs_vnop_symlink(struct vnop_symlink_args *ap)
{
        struct vnode **vpp = ap->a_vpp;
        struct vnode *dvp = ap->a_dvp;
        struct vnode *vp = NULL;
        struct cnode *cp = NULL;
        struct hfsmount *hfsmp;
        struct filefork *fp;
        struct buf *bp = NULL;
        char *datap;
        int started_tr = 0;
        u_int32_t len;
        int error;

        /* HFS standard disks don't support symbolic links */
        if (VTOVCB(dvp)->vcbSigWord != kHFSPlusSigWord)
                return (ENOTSUP);

        /* Check for empty target name */
        if (ap->a_target[0] == 0)
                return (EINVAL);

        hfsmp = VTOHFS(dvp);
        
        len = strlen(ap->a_target);
        if (len > MAXPATHLEN)
                return (ENAMETOOLONG);

        /* Check for free space */
        if (((u_int64_t)hfs_freeblks(hfsmp, 0) * (u_int64_t)hfsmp->blockSize) < len) {
                return (ENOSPC);
        }

        /* Create the vnode */
        ap->a_vap->va_mode |= S_IFLNK;
        if ((error = hfs_makenode(dvp, vpp, ap->a_cnp, ap->a_vap, ap->a_context))) {
                goto out;
        }
        vp = *vpp;
        if ((error = hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT))) {
                goto out;
        }
        cp = VTOC(vp);
        fp = VTOF(vp);

        if (cp->c_flag & (C_NOEXISTS | C_DELETED)) {
            goto out;
        }

#if QUOTA
        (void)hfs_getinoquota(cp);
#endif /* QUOTA */

        if ((error = hfs_start_transaction(hfsmp)) != 0) {
            goto out;
        }
        started_tr = 1;

        /*
         * Allocate space for the link.
         *
         * Since we're already inside a transaction,
         *
         * Don't need truncate lock since a symlink is treated as a system file.
         */
        error = hfs_truncate(vp, len, IO_NOZEROFILL, 0, ap->a_context);

        /* On errors, remove the symlink file */
        if (error) {
                /*
                 * End the transaction so we don't re-take the cnode lock
                 * below while inside a transaction (lock order violation).
                 */
                hfs_end_transaction(hfsmp);

                /* hfs_removefile() requires holding the truncate lock */
                hfs_unlock(cp);
                hfs_lock_truncate(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT);
                hfs_lock(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_ALLOW_NOEXISTS);

                if (hfs_start_transaction(hfsmp) != 0) {
                        started_tr = 0;
                        hfs_unlock_truncate(cp, HFS_LOCK_DEFAULT);
                        goto out;
                }
                
                (void) hfs_removefile(dvp, vp, ap->a_cnp, 0, 0, 0, NULL, 0);
                hfs_unlock_truncate(cp, HFS_LOCK_DEFAULT);
                goto out;       
        }

        /* Write the link to disk */
        bp = buf_getblk(vp, (daddr64_t)0, roundup((int)fp->ff_size, hfsmp->hfs_physical_block_size),
                        0, 0, BLK_META);
        if (hfsmp->jnl) {
                journal_modify_block_start(hfsmp->jnl, bp);
        }
        datap = (char *)buf_dataptr(bp);
        bzero(datap, buf_size(bp));
        bcopy(ap->a_target, datap, len);

        if (hfsmp->jnl) {
                journal_modify_block_end(hfsmp->jnl, bp, NULL, NULL);
        } else {
                buf_bawrite(bp);
        }
out:
        if (started_tr)
            hfs_end_transaction(hfsmp);
        if ((cp != NULL) && (vp != NULL)) {
                hfs_unlock(cp);
        }
        if (error) {
                if (vp) {
                        vnode_put(vp);
                }
                *vpp = NULL;
        }
        return (error);
}


/* structures to hold a "." or ".." directory entry */
struct hfs_stddotentry {
        u_int32_t       d_fileno;   /* unique file number */
        u_int16_t       d_reclen;   /* length of this structure */
        u_int8_t        d_type;     /* dirent file type */
        u_int8_t        d_namlen;   /* len of filename */
        char            d_name[4];  /* "." or ".." */
};

struct hfs_extdotentry {
        u_int64_t  d_fileno;   /* unique file number */
        u_int64_t  d_seekoff;  /* seek offset (optional, used by servers) */
        u_int16_t  d_reclen;   /* length of this structure */
        u_int16_t  d_namlen;   /* len of filename */
        u_int8_t   d_type;     /* dirent file type */
        u_char     d_name[3];  /* "." or ".." */
};

typedef union {
        struct hfs_stddotentry  std;
        struct hfs_extdotentry  ext;
} hfs_dotentry_t;

/*
 *  hfs_vnop_readdir reads directory entries into the buffer pointed
 *  to by uio, in a filesystem independent format.  Up to uio_resid
 *  bytes of data can be transferred.  The data in the buffer is a
 *  series of packed dirent structures where each one contains the
 *  following entries:
 *
 *      u_int32_t   d_fileno;              // file number of entry
 *      u_int16_t   d_reclen;              // length of this record
 *      u_int8_t    d_type;                // file type
 *      u_int8_t    d_namlen;              // length of string in d_name
 *      char        d_name[MAXNAMELEN+1];  // null terminated file name
 *
 *  The current position (uio_offset) refers to the next block of
 *  entries.  The offset can only be set to a value previously
 *  returned by hfs_vnop_readdir or zero.  This offset does not have
 *  to match the number of bytes returned (in uio_resid).
 *
 *  In fact, the offset used by HFS is essentially an index (26 bits)
 *  with a tag (6 bits).  The tag is for associating the next request
  *  with the current request.  This enables us to have multiple threads
 *  reading the directory while the directory is also being modified.
 *
 *  Each tag/index pair is tied to a unique directory hint.  The hint
 *  contains information (filename) needed to build the catalog b-tree
 *  key for finding the next set of entries.
 *
 * If the directory is marked as deleted-but-in-use (cp->c_flag & C_DELETED),
 * do NOT synthesize entries for "." and "..".
 */
int
hfs_vnop_readdir(struct vnop_readdir_args *ap)
{
        struct vnode *vp = ap->a_vp;
        uio_t uio = ap->a_uio;
        struct cnode *cp = VTOC(vp);
        struct hfsmount *hfsmp = VTOHFS(vp);
        directoryhint_t *dirhint = NULL;
        directoryhint_t localhint;
        off_t offset;
        off_t startoffset;
        int error = 0;
        int eofflag = 0;
        user_addr_t user_start = 0;
        user_size_t user_len = 0;
        user_size_t user_original_resid = 0;
        int index;
        unsigned int tag;
        int items;
        int lockflags;
        int extended;
        int nfs_cookies;
        cnid_t cnid_hint = 0;
        int bump_valence = 0;

        items = 0;
        startoffset = offset = uio_offset(uio);
        extended = (ap->a_flags & VNODE_READDIR_EXTENDED);
        nfs_cookies = extended && (ap->a_flags & VNODE_READDIR_REQSEEKOFF);

        /* Sanity check the uio data. */
        if (uio_iovcnt(uio) > 1)
                return (EINVAL);

        if (VTOC(vp)->c_bsdflags & UF_COMPRESSED) {
                int compressed = hfs_file_is_compressed(VTOC(vp), 0);  /* 0 == take the cnode lock */
                if (VTOCMP(vp) != NULL && !compressed) {
                        error = check_for_dataless_file(vp, NAMESPACE_HANDLER_READ_OP);
                        if (error) {
                                return error;
                        }
                }
        }

        //
        // We have to lock the user's buffer here so that we won't
        // fault on it after we've acquired a shared lock on the
        // catalog file.  The issue is that you can get a 3-way
        // deadlock if someone else starts a transaction and then
        // tries to lock the catalog file but can't because we're
        // here and we can't service our page fault because VM is
        // blocked trying to start a transaction as a result of
        // trying to free up pages for our page fault.  It's messy
        // but it does happen on dual-processors that are paging
        // heavily (see radar 3082639 for more info).  By locking
        // the buffer up-front we prevent ourselves from faulting
        // while holding the shared catalog file lock.
        //
        // Fortunately this and hfs_search() are the only two places
        // currently (10/30/02) that can fault on user data with a
        // shared lock on the catalog file.
        //
        if (hfsmp->jnl && uio_isuserspace(uio)) {
                user_start = uio_curriovbase(uio);
                user_len = uio_curriovlen(uio);

                /* Bounds check the user buffer */
                if (user_len > (256 * 1024)) {
                        /* only allow the user to wire down at most 256k */
                        user_len = (256 * 1024);
                        user_original_resid = uio_resid(uio);
                        uio_setresid (uio, (user_ssize_t)(256 * 1024));
                }

                if ((error = vslock(user_start, user_len)) != 0) {
                        if (user_original_resid > 0) {
                                uio_setresid(uio, user_original_resid);
                                user_original_resid = 0;
                        }
                        return error;
                }
        }

        /* Note that the dirhint calls require an exclusive lock. */
        if ((error = hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT))) {
                if (user_start) {
                        if (user_original_resid > 0) {
                                uio_setresid(uio, user_original_resid);
                                user_original_resid = 0;
                        }
                        vsunlock(user_start, user_len, TRUE);
                }
                return error;
        }

        /* Pick up cnid hint (if any). */
        if (nfs_cookies) {
                cnid_hint = (cnid_t)(uio_offset(uio) >> 32);
                uio_setoffset(uio, uio_offset(uio) & 0x00000000ffffffffLL);
                if (cnid_hint == INT_MAX) { /* searching pass the last item */
                        eofflag = 1;
                        goto out;
                }
        }
        /*
         * Synthesize entries for "." and "..", unless the directory has
         * been deleted, but not closed yet (lazy delete in progress).
         */
        if (offset == 0 && !(cp->c_flag & C_DELETED)) { 
                
                size_t  uiosize;

                /* 
                 * We could use a union of the two types of dot entries (HFS / HFS+)
                 * but it makes static analysis of this code difficult.  The problem is that
                 * the HFS standard dot entry is smaller than the HFS+ one, and we also ideally
                 * want the uiomove to operate on a two-element adjacent array. If we used the
                 * array of unions, we would have to do two separate uiomoves because the memory 
                 * for the hfs standard dot entries would not be adjacent to one another.
                 * So just allocate the entries on the stack in separate cases.
                 */

                if (extended) {
                        hfs_dotentry_t  dotentry[2];
                        
                        /* HFS Plus */
                        struct hfs_extdotentry *entry = &dotentry[0].ext;

                        entry->d_fileno = cp->c_cnid;
                        entry->d_reclen = sizeof(struct hfs_extdotentry);
                        entry->d_type = DT_DIR;
                        entry->d_namlen = 1;
                        entry->d_name[0] = '.';
                        entry->d_name[1] = '\0';
                        entry->d_name[2] = '\0';
                        entry->d_seekoff = 1;

                        ++entry;
                        entry->d_fileno = cp->c_parentcnid;
                        entry->d_reclen = sizeof(struct hfs_extdotentry);
                        entry->d_type = DT_DIR;
                        entry->d_namlen = 2;
                        entry->d_name[0] = '.';
                        entry->d_name[1] = '.';
                        entry->d_name[2] = '\0';
                        entry->d_seekoff = 2;
                        uiosize = 2 * sizeof(struct hfs_extdotentry);
        
                        if ((error = uiomove((caddr_t)dotentry, uiosize, uio))) {
                                goto out;
                        }

                } else {
                        struct hfs_stddotentry hfs_std_dotentries[2];

                        /* HFS Standard */
                        struct hfs_stddotentry *entry = &hfs_std_dotentries[0];

                        entry->d_fileno = cp->c_cnid;
                        entry->d_reclen = sizeof(struct hfs_stddotentry);
                        entry->d_type = DT_DIR;
                        entry->d_namlen = 1;
                        *(int *)&entry->d_name[0] = 0;
                        entry->d_name[0] = '.';
        
                        ++entry;
                        entry->d_fileno = cp->c_parentcnid;
                        entry->d_reclen = sizeof(struct hfs_stddotentry);
                        entry->d_type = DT_DIR;
                        entry->d_namlen = 2;
                        *(int *)&entry->d_name[0] = 0;
                        entry->d_name[0] = '.';
                        entry->d_name[1] = '.';
                        uiosize = 2 * sizeof(struct hfs_stddotentry);
        
                        if ((error = uiomove((caddr_t)hfs_std_dotentries, uiosize, uio))) {
                                goto out;
                        }
                }
        
                offset += 2;
        }

        /* 
         * Intentionally avoid checking the valence here.  If we
         * have FS corruption that reports the valence is 0, even though it
         * has contents, we might artificially skip over iterating 
         * this directory.
         */
        
        /* Convert offset into a catalog directory index. */
        index = (offset & HFS_INDEX_MASK) - 2;
        tag = offset & ~HFS_INDEX_MASK;

        /* Lock catalog during cat_findname and cat_getdirentries. */
        lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG, HFS_SHARED_LOCK);

        /* When called from NFS, try and resolve a cnid hint. */
        if (nfs_cookies && cnid_hint != 0) {
                if (cat_findname(hfsmp, cnid_hint, &localhint.dh_desc) == 0) {
                        if ( localhint.dh_desc.cd_parentcnid == cp->c_fileid) {
                                localhint.dh_index = index - 1;
                                localhint.dh_time = 0;
                                bzero(&localhint.dh_link, sizeof(localhint.dh_link));
                                dirhint = &localhint;  /* don't forget to release the descriptor */
                        } else {
                                cat_releasedesc(&localhint.dh_desc);
                        }
                }
        }

        /* Get a directory hint (cnode must be locked exclusive) */
        if (dirhint == NULL) {
                dirhint = hfs_getdirhint(cp, ((index - 1) & HFS_INDEX_MASK) | tag, 0);

                /* Hide tag from catalog layer. */
                dirhint->dh_index &= HFS_INDEX_MASK;
                if (dirhint->dh_index == HFS_INDEX_MASK) {
                        dirhint->dh_index = -1;
                }
        }
        
        if (index == 0) {
                dirhint->dh_threadhint = cp->c_dirthreadhint;
        } 
        else {
                /*
                 * If we have a non-zero index, there is a possibility that during the last
                 * call to hfs_vnop_readdir we hit EOF for this directory.  If that is the case
                 * then we don't want to return any new entries for the caller.  Just return 0
                 * items, mark the eofflag, and bail out.  Because we won't have done any work, the 
                 * code at the end of the function will release the dirhint for us.  
                 *
                 * Don't forget to unlock the catalog lock on the way out, too.
                 */
                if (dirhint->dh_desc.cd_flags & CD_EOF) {
                        error = 0;
                        eofflag = 1;
                        uio_setoffset(uio, startoffset);
                        if (user_original_resid > 0) {
                                uio_setresid(uio, user_original_resid);
                                user_original_resid = 0;
                        }
                        hfs_systemfile_unlock (hfsmp, lockflags);

                        goto seekoffcalc;
                }
        }

        /* Pack the buffer with dirent entries. */
        error = cat_getdirentries(hfsmp, cp->c_entries, dirhint, uio, ap->a_flags, &items, &eofflag);

        if (user_original_resid > 0) {
                user_original_resid = user_original_resid - ((user_ssize_t)256*1024 - uio_resid(uio));
                uio_setresid(uio, user_original_resid);
                user_original_resid = 0;
        }

        if (index == 0 && error == 0) {
                cp->c_dirthreadhint = dirhint->dh_threadhint;
        }

        hfs_systemfile_unlock(hfsmp, lockflags);

        if (error != 0) {
                goto out;
        }
        
        /* Get index to the next item */
        index += items;
        
        if (items >= (int)cp->c_entries) {
                eofflag = 1;
        }
        
        /* 
         * Detect valence FS corruption.
         *
         * We are holding the cnode lock exclusive, so there should not be
         * anybody modifying the valence field of this cnode.  If we enter
         * this block, that means we observed filesystem corruption, because
         * this directory reported a valence of 0, yet we found at least one
         * item.  In this case, we need to minimally self-heal this
         * directory to prevent userland from tripping over a directory
         * that appears empty (getattr of valence reports 0), but actually 
         * has contents. 
         *
         * We'll force the cnode update at the end of the function after 
         * completing all of the normal getdirentries steps.
         */ 
        if ((cp->c_entries == 0) && (items > 0)) {
                /* disk corruption */
                cp->c_entries++;
                /* Mark the cnode as dirty. */
                cp->c_flag |= C_MODIFIED;
                printf("hfs_vnop_readdir: repairing valence to non-zero! \n");
                bump_valence++;
        }


        /* Convert catalog directory index back into an offset. */
        while (tag == 0)
                tag = (++cp->c_dirhinttag) << HFS_INDEX_BITS;   
        uio_setoffset(uio, (index + 2) | tag);
        dirhint->dh_index |= tag;

seekoffcalc:
        cp->c_touch_acctime = TRUE;

        if (ap->a_numdirent) {
                if (startoffset == 0)
                        items += 2;
                *ap->a_numdirent = items;
        }

out:
        if (user_start) {
                if (user_original_resid > 0) {
                        uio_setresid(uio, user_original_resid);
                        user_original_resid = 0;
                }
                vsunlock(user_start, user_len, TRUE);
        }
        /* If we didn't do anything then go ahead and dump the hint. */
        if ((dirhint != NULL) &&
            (dirhint != &localhint) &&
            (uio_offset(uio) == startoffset)) {
                hfs_reldirhint(cp, dirhint);
                eofflag = 1;
        }
        if (ap->a_eofflag) {
                *ap->a_eofflag = eofflag;
        }
        if (dirhint == &localhint) {
                cat_releasedesc(&localhint.dh_desc);
        }

        if (bump_valence) {
                /* force the update before dropping the cnode lock*/
                hfs_update(vp, 0);
        }

        hfs_unlock(cp);
        
        return (error);
}


/*
 * Read contents of a symbolic link.
 */
int
hfs_vnop_readlink(struct vnop_readlink_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct cnode *cp;
        struct filefork *fp;
        int error;

        if (!vnode_islnk(vp))
                return (EINVAL);
 
        if ((error = hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT)))
                return (error);
        cp = VTOC(vp);
        fp = VTOF(vp);
   
        /* Zero length sym links are not allowed */
        if (fp->ff_size == 0 || fp->ff_size > MAXPATHLEN) {
                error = EINVAL;
                goto exit;
        }
    
        /* Cache the path so we don't waste buffer cache resources */
        if (fp->ff_symlinkptr == NULL) {
                struct buf *bp = NULL;

                fp->ff_symlinkptr = hfs_malloc(fp->ff_size);
                error = (int)buf_meta_bread(vp, (daddr64_t)0,
                                            roundup((int)fp->ff_size, VTOHFS(vp)->hfs_physical_block_size),
                                            vfs_context_ucred(ap->a_context), &bp);
                if (error) {
                        if (bp)
                                buf_brelse(bp);
                        if (fp->ff_symlinkptr) {
                                hfs_free(fp->ff_symlinkptr, fp->ff_size);
                                fp->ff_symlinkptr = NULL;
                        }
                        goto exit;
                }
                bcopy((char *)buf_dataptr(bp), fp->ff_symlinkptr, (size_t)fp->ff_size);

                if (VTOHFS(vp)->jnl && (buf_flags(bp) & B_LOCKED) == 0) {
                        buf_markinvalid(bp);            /* data no longer needed */
                }
                buf_brelse(bp);
        }
        error = uiomove((caddr_t)fp->ff_symlinkptr, (int)fp->ff_size, ap->a_uio);

        /*
         * Keep track blocks read
         */
        if ((VTOHFS(vp)->hfc_stage == HFC_RECORDING) && (error == 0)) {
                
                /*
                 * If this file hasn't been seen since the start of
                 * the current sampling period then start over.
                 */
                if (cp->c_atime < VTOHFS(vp)->hfc_timebase)
                        VTOF(vp)->ff_bytesread = fp->ff_size;
                else
                        VTOF(vp)->ff_bytesread += fp->ff_size;
                
        //      if (VTOF(vp)->ff_bytesread > fp->ff_size)
        //              cp->c_touch_acctime = TRUE;
        }

exit:
        hfs_unlock(cp);
        return (error);
}


/*
 * Get configurable pathname variables.
 */
int
hfs_vnop_pathconf(struct vnop_pathconf_args *ap)
{

#if CONFIG_HFS_STD
        int std_hfs = (VTOHFS(ap->a_vp)->hfs_flags & HFS_STANDARD);
#endif

        switch (ap->a_name) {
        case _PC_LINK_MAX:
#if CONFIG_HFS_STD
                if (std_hfs) {
                        *ap->a_retval = 1;
                } else
#endif
                {
                        *ap->a_retval = HFS_LINK_MAX;
                }
                break;
        case _PC_NAME_MAX:
#if CONFIG_HFS_STD
                if (std_hfs) {
                        *ap->a_retval = kHFSMaxFileNameChars;  /* 31 */
                } else
#endif
                {
                        *ap->a_retval = kHFSPlusMaxFileNameChars;  /* 255 */
                }
                break;
        case _PC_PATH_MAX:
                *ap->a_retval = PATH_MAX;  /* 1024 */
                break;
        case _PC_PIPE_BUF:
                *ap->a_retval = PIPE_BUF;
                break;
        case _PC_CHOWN_RESTRICTED:
                *ap->a_retval = 200112;         /* _POSIX_CHOWN_RESTRICTED */
                break;
        case _PC_NO_TRUNC:
                *ap->a_retval = 200112;         /* _POSIX_NO_TRUNC */
                break;
        case _PC_NAME_CHARS_MAX:
#if CONFIG_HFS_STD
                if (std_hfs) {
                        *ap->a_retval = kHFSMaxFileNameChars; /* 31 */
                } else
#endif
                {
                        *ap->a_retval = kHFSPlusMaxFileNameChars; /* 255 */
                }
                break;
        case _PC_CASE_SENSITIVE:
                if (VTOHFS(ap->a_vp)->hfs_flags & HFS_CASE_SENSITIVE)
                        *ap->a_retval = 1;
                else
                        *ap->a_retval = 0;
                break;
        case _PC_CASE_PRESERVING:
                *ap->a_retval = 1;
                break;
        case _PC_FILESIZEBITS:
                /* number of bits to store max file size */
#if CONFIG_HFS_STD
                if (std_hfs) {
                        *ap->a_retval = 32;
                } else
#endif
                {
                        *ap->a_retval = 64;     
                }
                break;
        case _PC_XATTR_SIZE_BITS:
                /* Number of bits to store maximum extended attribute size */
                *ap->a_retval = HFS_XATTR_SIZE_BITS;
                break;
        default:
                return (EINVAL);
        }

        return (0);
}

/*
 * Prepares a fork for cat_update by making sure ff_size and ff_blocks
 * are no bigger than the valid data on disk thus reducing the chance
 * of exposing uninitialised data in the event of a non clean unmount.
 * fork_buf is where to put the temporary copy if required.  (It can
 * be inside pfork.)
 */
const struct cat_fork *
hfs_prepare_fork_for_update(filefork_t *ff,
                                                        const struct cat_fork *cf,
                                                        struct cat_fork *cf_buf,
                                                        uint32_t block_size)
{
        if (!ff)
                return NULL;

        if (!cf)
                cf = &ff->ff_data;
        if (!cf_buf)
                cf_buf = &ff->ff_data;

        off_t max_size = ff->ff_size;

        // Check first invalid range
        if (!TAILQ_EMPTY(&ff->ff_invalidranges))
                max_size = TAILQ_FIRST(&ff->ff_invalidranges)->rl_start;

        if (!ff->ff_unallocblocks && ff->ff_size <= max_size)
                return cf; // Nothing to do

        if (ff->ff_blocks < ff->ff_unallocblocks) {
                panic("hfs: ff_blocks %d is less than unalloc blocks %d\n",
                          ff->ff_blocks, ff->ff_unallocblocks);
        }

        struct cat_fork *out = cf_buf;

        if (out != cf)
                bcopy(cf, out, sizeof(*cf));

        // Adjust cf_blocks for cf_vblocks
        out->cf_blocks -= out->cf_vblocks;

        /*
         * Here we trim the size with the updated cf_blocks.  This is
         * probably unnecessary now because the invalid ranges should
         * catch this (but that wasn't always the case).
         */
        off_t alloc_bytes = hfs_blk_to_bytes(out->cf_blocks, block_size);
        if (out->cf_size > alloc_bytes)
                out->cf_size = alloc_bytes;

        // Trim cf_size to first invalid range
        if (out->cf_size > max_size)
                out->cf_size = max_size;

        return out;
}

/*
 * Update a cnode's on-disk metadata.
 *
 * The cnode must be locked exclusive.  See declaration for possible
 * options.
 */
int
hfs_update(struct vnode *vp, int options)
{
        struct cnode *cp = VTOC(vp);
        struct proc *p;
        const struct cat_fork *dataforkp = NULL;
        const struct cat_fork *rsrcforkp = NULL;
        struct cat_fork datafork;
        struct cat_fork rsrcfork;
        struct hfsmount *hfsmp;
        int lockflags;
        int error;
        uint32_t tstate = 0;

        if (ISSET(cp->c_flag, C_NOEXISTS))
                return 0;

        p = current_proc();
        hfsmp = VTOHFS(vp);

        if (((vnode_issystem(vp) && (cp->c_cnid < kHFSFirstUserCatalogNodeID))) || 
                hfsmp->hfs_catalog_vp == NULL){
                return (0);
        }
        if ((hfsmp->hfs_flags & HFS_READ_ONLY) || (cp->c_mode == 0)) {
                CLR(cp->c_flag, C_MODIFIED | C_MINOR_MOD | C_NEEDS_DATEADDED);
                cp->c_touch_acctime = 0;
                cp->c_touch_chgtime = 0;
                cp->c_touch_modtime = 0;
                return (0);
        }
        if (kdebug_enable) {
                if (cp->c_touch_acctime || cp->c_atime != cp->c_attr.ca_atimeondisk)
                        tstate |= DBG_HFS_UPDATE_ACCTIME;
                if (cp->c_touch_modtime)
                        tstate |= DBG_HFS_UPDATE_MODTIME;
                if (cp->c_touch_chgtime)
                        tstate |= DBG_HFS_UPDATE_CHGTIME;

                if (cp->c_flag & C_MODIFIED)
                        tstate |= DBG_HFS_UPDATE_MODIFIED;
                if (ISSET(options, HFS_UPDATE_FORCE))
                        tstate |= DBG_HFS_UPDATE_FORCE;
                if (cp->c_flag & C_NEEDS_DATEADDED)
                        tstate |= DBG_HFS_UPDATE_DATEADDED;
                if (cp->c_flag & C_MINOR_MOD)
                        tstate |= DBG_HFS_UPDATE_MINOR;
        }
        hfs_touchtimes(hfsmp, cp);

        if (!ISSET(cp->c_flag, C_MODIFIED | C_MINOR_MOD)
                && !hfs_should_save_atime(cp)) {
                // Nothing to update
                return 0;
        }

        KDBG(HFSDBG_UPDATE | DBG_FUNC_START, kdebug_vnode(vp), tstate);

        bool check_txn = false;

        if (!ISSET(options, HFS_UPDATE_FORCE) && !ISSET(cp->c_flag, C_MODIFIED)) {
                /*
                 * This must be a minor modification.  If the current
                 * transaction already has an update for this node, then we
                 * bundle in the modification.
                 */
                if (hfsmp->jnl
                        && journal_current_txn(hfsmp->jnl) == cp->c_update_txn) {
                        check_txn = true;
                } else {
                        tstate |= DBG_HFS_UPDATE_SKIPPED;
                        error = 0;
                        goto exit;
                }
        }

        if ((error = hfs_start_transaction(hfsmp)) != 0)
                goto exit;

        if (check_txn
                && journal_current_txn(hfsmp->jnl) != cp->c_update_txn) {
                hfs_end_transaction(hfsmp);
                tstate |= DBG_HFS_UPDATE_SKIPPED;
                error = 0;
                goto exit;
        }

        if (cp->c_datafork)
                dataforkp = &cp->c_datafork->ff_data;
        if (cp->c_rsrcfork)
                rsrcforkp = &cp->c_rsrcfork->ff_data;

    /*
     * Modify the values passed to cat_update based on whether or not
     * the file has invalid ranges or borrowed blocks.
     */
    dataforkp = hfs_prepare_fork_for_update(cp->c_datafork, NULL, &datafork, hfsmp->blockSize);
        rsrcforkp = hfs_prepare_fork_for_update(cp->c_rsrcfork, NULL, &rsrcfork, hfsmp->blockSize);

        if (__builtin_expect(kdebug_enable & KDEBUG_TRACE, 0)) {
                long dbg_parms[NUMPARMS];
                int  dbg_namelen;

                dbg_namelen = NUMPARMS * sizeof(long);
                vn_getpath(vp, (char *)dbg_parms, &dbg_namelen);

                if (dbg_namelen < (int)sizeof(dbg_parms))
                        memset((char *)dbg_parms + dbg_namelen, 0, sizeof(dbg_parms) - dbg_namelen);

                kdebug_lookup_gen_events(dbg_parms, dbg_namelen, (void *)vp, TRUE);
        }

        /*
         * Lock the Catalog b-tree file.
         */
        lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG, HFS_EXCLUSIVE_LOCK);

        error = cat_update(hfsmp, &cp->c_desc, &cp->c_attr, dataforkp, rsrcforkp);

        if (hfsmp->jnl)
                cp->c_update_txn = journal_current_txn(hfsmp->jnl);

        hfs_systemfile_unlock(hfsmp, lockflags);

        CLR(cp->c_flag, C_MODIFIED | C_MINOR_MOD);

        hfs_end_transaction(hfsmp);

exit:

        KDBG(HFSDBG_UPDATE | DBG_FUNC_END, kdebug_vnode(vp), tstate, error);

        return error;
}

/*
 * Allocate a new node
 */
int
hfs_makenode(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp,
             struct vnode_attr *vap, vfs_context_t ctx)
{
        struct cnode *cp = NULL;
        struct cnode *dcp = NULL;
        struct vnode *tvp;
        struct hfsmount *hfsmp;
        struct cat_desc in_desc, out_desc;
        struct cat_attr attr;
        struct timeval tv;
        int lockflags;
        int error, started_tr = 0;
        enum vtype vnodetype;
        int mode;
        int newvnode_flags = 0;
        u_int32_t gnv_flags = 0;
        int protectable_target = 0;
        int nocache = 0;
        vnode_t old_doc_vp = NULL;

#if CONFIG_PROTECT
        struct cprotect *entry = NULL;
        int32_t cp_class = -1;

        /* 
         * By default, it's OK for AKS to overrride our target class preferences.
         */
        uint32_t keywrap_flags = CP_KEYWRAP_DIFFCLASS;

        if (VATTR_IS_ACTIVE(vap, va_dataprotect_class)) {
                cp_class = (int32_t)vap->va_dataprotect_class;
                /* 
                 * Since the user specifically requested this target class be used,
                 * we want to fail this creation operation if we cannot wrap to their 
                 * target class. The CP_KEYWRAP_DIFFCLASS bit says that it is OK to
                 * use a different class than the one specified, so we turn that off
                 * now.
                 */
                keywrap_flags &= ~CP_KEYWRAP_DIFFCLASS;
        }
        int protected_mount = 0;        
#endif


        if ((error = hfs_lock(VTOC(dvp), HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT)))
                return (error);

        /* set the cnode pointer only after successfully acquiring lock */
        dcp = VTOC(dvp);

        /* Don't allow creation of new entries in open-unlinked directories */
        if ((error = hfs_checkdeleted(dcp))) {
                hfs_unlock(dcp);
                return error;
        }

        dcp->c_flag |= C_DIR_MODIFICATION;

        hfsmp = VTOHFS(dvp);

        *vpp = NULL;
        tvp = NULL;
        out_desc.cd_flags = 0;
        out_desc.cd_nameptr = NULL;

        vnodetype = vap->va_type;
        if (vnodetype == VNON)
                vnodetype = VREG;
        mode = MAKEIMODE(vnodetype, vap->va_mode);

        if (S_ISDIR (mode) || S_ISREG (mode)) {
                protectable_target = 1;
        }
        

        /* Check if were out of usable disk space. */
        if ((hfs_freeblks(hfsmp, 1) == 0) && (vfs_context_suser(ctx) != 0)) {
                error = ENOSPC;
                goto exit;
        }

        microtime(&tv);

        /* Setup the default attributes */
        bzero(&attr, sizeof(attr));
        attr.ca_mode = mode;
        attr.ca_linkcount = 1;
        if (VATTR_IS_ACTIVE(vap, va_rdev)) {
                attr.ca_rdev = vap->va_rdev;
        }
        if (VATTR_IS_ACTIVE(vap, va_create_time)) {
                VATTR_SET_SUPPORTED(vap, va_create_time);
                attr.ca_itime = vap->va_create_time.tv_sec;
        } else {
                attr.ca_itime = tv.tv_sec;
        }
#if CONFIG_HFS_STD
        if ((hfsmp->hfs_flags & HFS_STANDARD) && gTimeZone.tz_dsttime) {
                attr.ca_itime += 3600;  /* Same as what hfs_update does */
        }
#endif
        attr.ca_atime = attr.ca_ctime = attr.ca_mtime = attr.ca_itime;
        attr.ca_atimeondisk = attr.ca_atime;
        if (VATTR_IS_ACTIVE(vap, va_flags)) {
                VATTR_SET_SUPPORTED(vap, va_flags);
                attr.ca_flags = vap->va_flags;
        }
        
        /* 
         * HFS+ only: all files get ThreadExists
         * HFSX only: dirs get HasFolderCount
         */
#if CONFIG_HFS_STD
        if (!(hfsmp->hfs_flags & HFS_STANDARD))
#endif
        {
                if (vnodetype == VDIR) {
                        if (hfsmp->hfs_flags & HFS_FOLDERCOUNT)
                                attr.ca_recflags = kHFSHasFolderCountMask;
                } else {
                        attr.ca_recflags = kHFSThreadExistsMask;
                }
        }

#if CONFIG_PROTECT      
        if (cp_fs_protected(hfsmp->hfs_mp)) {
                protected_mount = 1;
        }
        /*
         * On a content-protected HFS+/HFSX filesystem, files and directories
         * cannot be created without atomically setting/creating the EA that 
         * contains the protection class metadata and keys at the same time, in
         * the same transaction.  As a result, pre-set the "EAs exist" flag
         * on the cat_attr for protectable catalog record creations.  This will
         * cause the cnode creation routine in hfs_getnewvnode to mark the cnode
         * as having EAs.
         */
        if ((protected_mount) && (protectable_target)) {
                attr.ca_recflags |= kHFSHasAttributesMask;
                /* delay entering in the namecache */
                nocache = 1;
        }
#endif


        /* 
         * Add the date added to the item. See above, as
         * all of the dates are set to the itime.
         */
        hfs_write_dateadded (&attr, attr.ca_atime);

        /* Initialize the gen counter to 1 */
        hfs_write_gencount(&attr, (uint32_t)1);

        attr.ca_uid = vap->va_uid;
        attr.ca_gid = vap->va_gid;
        VATTR_SET_SUPPORTED(vap, va_mode);
        VATTR_SET_SUPPORTED(vap, va_uid);
        VATTR_SET_SUPPORTED(vap, va_gid);

#if QUOTA
        /* check to see if this node's creation would cause us to go over
         * quota.  If so, abort this operation.
         */
        if (hfsmp->hfs_flags & HFS_QUOTAS) {
                if ((error = hfs_quotacheck(hfsmp, 1, attr.ca_uid, attr.ca_gid,
                                                                        vfs_context_ucred(ctx)))) {
                        goto exit;
                }
        }       
#endif


        /* Tag symlinks with a type and creator. */
        if (vnodetype == VLNK) {
                struct FndrFileInfo *fip;

                fip = (struct FndrFileInfo *)&attr.ca_finderinfo;
                fip->fdType    = SWAP_BE32(kSymLinkFileType);
                fip->fdCreator = SWAP_BE32(kSymLinkCreator);
        }

        /* Setup the descriptor */
        in_desc.cd_nameptr = (const u_int8_t *)cnp->cn_nameptr;
        in_desc.cd_namelen = cnp->cn_namelen;
        in_desc.cd_parentcnid = dcp->c_fileid;
        in_desc.cd_flags = S_ISDIR(mode) ? CD_ISDIR : 0;
        in_desc.cd_hint = dcp->c_childhint;
        in_desc.cd_encoding = 0;

#if CONFIG_PROTECT
        /*
         * To preserve file creation atomicity with regards to the content protection EA,
         * we must create the file in the catalog and then write out its EA in the same
         * transaction.  
         * 
         * We only denote the target class in this EA; key generation is not completed
         * until the file has been inserted into the catalog and will be done
         * in a separate transaction.
         */
        if ((protected_mount) && (protectable_target)) {
                error = cp_setup_newentry(hfsmp, dcp, cp_class, attr.ca_mode, &entry);
                if (error) {
                        goto exit;
                }
        }
#endif

        if ((error = hfs_start_transaction(hfsmp)) != 0) {
            goto exit;
        }
        started_tr = 1;

        // have to also lock the attribute file because cat_create() needs
        // to check that any fileID it wants to use does not have orphaned
        // attributes in it.
        lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG | SFL_ATTRIBUTE, HFS_EXCLUSIVE_LOCK);
        cnid_t new_id;

        /* Reserve some space in the Catalog file. */
        if ((error = cat_preflight(hfsmp, CAT_CREATE, NULL, 0))) {
                hfs_systemfile_unlock(hfsmp, lockflags);
                goto exit;
        }

        if ((error = cat_acquire_cnid(hfsmp, &new_id))) {
                hfs_systemfile_unlock (hfsmp, lockflags);
                goto exit;
        }

        error = cat_create(hfsmp, new_id, &in_desc, &attr, &out_desc);
        if (error == 0) {
                /* Update the parent directory */
                dcp->c_childhint = out_desc.cd_hint;    /* Cache directory's location */
                dcp->c_entries++;

                if (vnodetype == VDIR) {
                        INC_FOLDERCOUNT(hfsmp, dcp->c_attr);
                }
                dcp->c_dirchangecnt++;
                hfs_incr_gencount(dcp);

                dcp->c_touch_chgtime = dcp->c_touch_modtime = true;
                dcp->c_flag |= C_MODIFIED;

                hfs_update(dcp->c_vp, 0);

#if CONFIG_PROTECT
                /*
                 * If we are creating a content protected file, now is when
                 * we create the EA. We must create it in the same transaction
                 * that creates the file.  We can also guarantee that the file 
                 * MUST exist because we are still holding the catalog lock
                 * at this point.
                 */
                if ((attr.ca_fileid != 0) && (protected_mount) && (protectable_target)) {
                        error = cp_setxattr (NULL, entry, hfsmp, attr.ca_fileid, XATTR_CREATE);
                        
                        if (error) {
                                int delete_err;
                                /* 
                                 * If we fail the EA creation, then we need to delete the file. 
                                 * Luckily, we are still holding all of the right locks.
                                 */
                                delete_err = cat_delete (hfsmp, &out_desc, &attr);
                                if (delete_err == 0) {
                                        /* Update the parent directory */
                                        if (dcp->c_entries > 0)
                                                dcp->c_entries--;
                                        dcp->c_dirchangecnt++;
                                        dcp->c_ctime = tv.tv_sec;
                                        dcp->c_mtime = tv.tv_sec;
                                        (void) cat_update(hfsmp, &dcp->c_desc, &dcp->c_attr, NULL, NULL);
                                }

                                /* Emit EINVAL if we fail to create EA*/
                                error = EINVAL;
                        }
                }               
#endif
        }
        hfs_systemfile_unlock(hfsmp, lockflags);
        if (error)
                goto exit;

        uint32_t txn = hfsmp->jnl ? journal_current_txn(hfsmp->jnl) : 0;

        /* Invalidate negative cache entries in the directory */
        if (dcp->c_flag & C_NEG_ENTRIES) {
                cache_purge_negatives(dvp);
                dcp->c_flag &= ~C_NEG_ENTRIES;
        }

        hfs_volupdate(hfsmp, vnodetype == VDIR ? VOL_MKDIR : VOL_MKFILE,
                (dcp->c_cnid == kHFSRootFolderID));

        // XXXdbg
        // have to end the transaction here before we call hfs_getnewvnode()
        // because that can cause us to try and reclaim a vnode on a different
        // file system which could cause us to start a transaction which can
        // deadlock with someone on that other file system (since we could be
        // holding two transaction locks as well as various vnodes and we did
        // not obtain the locks on them in the proper order).
        //
        // NOTE: this means that if the quota check fails or we have to update
        //       the change time on a block-special device that those changes
        //       will happen as part of independent transactions.
        //
        if (started_tr) {
            hfs_end_transaction(hfsmp);
            started_tr = 0;
        }

#if CONFIG_PROTECT
        /* 
         * At this point, we must have encountered success with writing the EA.
         * Destroy our temporary cprotect (which had no keys). 
         */

        if ((attr.ca_fileid != 0) && (protected_mount) && (protectable_target))  {
                cp_entry_destroy (hfsmp, entry);
                entry = NULL;
        }
#endif
        gnv_flags |= GNV_CREATE;
        if (nocache) {
                gnv_flags |= GNV_NOCACHE;
        }

        /*
         * Create a vnode for the object just created.
         * 
         * NOTE: Maintaining the cnode lock on the parent directory is important,
         * as it prevents race conditions where other threads want to look up entries 
         * in the directory and/or add things as we are in the process of creating
         * the vnode below.  However, this has the potential for causing a 
         * double lock panic when dealing with shadow files on a HFS boot partition. 
         * The panic could occur if we are not cleaning up after ourselves properly 
         * when done with a shadow file or in the error cases.  The error would occur if we 
         * try to create a new vnode, and then end up reclaiming another shadow vnode to 
         * create the new one.  However, if everything is working properly, this should
         * be a non-issue as we would never enter that reclaim codepath.
         * 
         * The cnode is locked on successful return.
         */
        error = hfs_getnewvnode(hfsmp, dvp, cnp, &out_desc, gnv_flags, &attr, 
                                                        NULL, &tvp, &newvnode_flags);
        if (error)
                goto exit;

        cp = VTOC(tvp);

        cp->c_update_txn = txn;

        struct doc_tombstone *ut;
        ut = doc_tombstone_get();
        if (   ut->t_lastop_document_id != 0 
            && ut->t_lastop_parent == dvp
            && ut->t_lastop_parent_vid == vnode_vid(dvp)
            && strcmp((char *)ut->t_lastop_filename, (const char *)cp->c_desc.cd_nameptr) == 0) {
                struct FndrExtendedDirInfo *fip = (struct FndrExtendedDirInfo *)((char *)&cp->c_attr.ca_finderinfo + 16);

                //printf("CREATE: preserving doc-id %lld on %s\n", ut->t_lastop_document_id, ut->t_lastop_filename);
                fip->document_id = (uint32_t)(ut->t_lastop_document_id & 0xffffffff);

                cp->c_bsdflags |= UF_TRACKED;
                cp->c_flag |= C_MODIFIED;

                if ((error = hfs_start_transaction(hfsmp)) == 0) {
                        lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG, HFS_EXCLUSIVE_LOCK);

                        (void) cat_update(hfsmp, &cp->c_desc, &cp->c_attr, NULL, NULL);

                        hfs_systemfile_unlock (hfsmp, lockflags);
                        (void) hfs_end_transaction(hfsmp);
                }

                doc_tombstone_clear(ut, &old_doc_vp);
        } else if (ut->t_lastop_document_id != 0) {
                int len = cnp->cn_namelen;
                if (len == 0) {
                        len = strlen(cnp->cn_nameptr);
                }

                if (doc_tombstone_should_ignore_name(cnp->cn_nameptr, cnp->cn_namelen)) {
                        // printf("CREATE: not clearing tombstone because %s is a temp name.\n", cnp->cn_nameptr);
                } else {
                        // Clear the tombstone because the thread is not recreating the same path
                        // printf("CREATE: clearing tombstone because %s is NOT a temp name.\n", cnp->cn_nameptr);
                        doc_tombstone_clear(ut, NULL);
                }
        }

        if ((hfsmp->hfs_flags & HFS_CS_HOTFILE_PIN) && (vnode_isfastdevicecandidate(dvp) && !vnode_isautocandidate(dvp))) {

                //printf("hfs: flagging %s (fileid: %d) as VFASTDEVCANDIDATE (dvp name: %s)\n",
                //       cnp->cn_nameptr ? cnp->cn_nameptr : "<NONAME>",
                //       cp->c_fileid,
                //       dvp->v_name ? dvp->v_name : "no-dir-name");

                //
                // On new files we set the FastDevCandidate flag so that
                // any new blocks allocated to it will be pinned.
                //
                cp->c_attr.ca_recflags |= kHFSFastDevCandidateMask;
                vnode_setfastdevicecandidate(tvp);

                //
                // properly inherit auto-cached flags
                //
                if (vnode_isautocandidate(dvp)) {
                        cp->c_attr.ca_recflags |= kHFSAutoCandidateMask;
                        vnode_setautocandidate(tvp);
                }


                //
                // We also want to add it to the hotfile adoption list so
                // that it will eventually land in the hotfile btree
                //
                (void) hfs_addhotfile(tvp);
        }
        
        *vpp = tvp;

#if CONFIG_PROTECT
        /* 
         * Now that we have a vnode-in-hand, generate keys for this namespace item.
         * If we fail to create the keys, then attempt to delete the item from the 
         * namespace.  If we can't delete the item, that's not desirable but also not fatal..
         *  All of the places which deal with restoring/unwrapping keys must also be 
         * prepared to encounter an entry that does not have keys. 
         */
        if ((protectable_target) && (protected_mount)) {
                struct cprotect *keyed_entry = NULL;

                if (cp->c_cpentry == NULL) {
                        panic ("hfs_makenode: no cpentry for cnode (%p)", cp);
                }

                error = cp_generate_keys (hfsmp, cp, CP_CLASS(cp->c_cpentry->cp_pclass), keywrap_flags, &keyed_entry);
                if (error == 0) {
                        /* 
                         * Upon success, the keys were generated and written out. 
                         * Update the cp pointer in the cnode.
                         */
                        cp_replace_entry (hfsmp, cp, keyed_entry);
                        if (nocache) {
                                cache_enter (dvp, tvp, cnp);
                        }
                }
                else {
                        /* If key creation OR the setxattr failed, emit EPERM to userland */
                        error = EPERM;

                        /* 
                         * Beware! This slightly violates the lock ordering for the
                         * cnode/vnode 'tvp'.  Ordinarily, you must acquire the truncate lock
                         * which guards file size changes before acquiring the normal cnode lock
                         * and calling hfs_removefile on an item.  
                         * 
                         * However, in this case, we are still holding the directory lock so 
                         * 'tvp' is not lookup-able and it was a newly created vnode so it 
                         * cannot have any content yet. The only reason we are initiating 
                         * the removefile is because we could not generate content protection keys
                         * for this namespace item. Note also that we pass a '1' in the allow_dirs
                         * argument for hfs_removefile because we may be creating a directory here.
                         * 
                         * All this to say that while it is technically a violation it is 
                         * impossible to race with another thread for this cnode so it is safe.
                         */
                        int err = hfs_removefile (dvp, tvp, cnp, 0, 0, 1, NULL, 0); 
                        if (err) {
                                printf("hfs_makenode: removefile failed (%d) for CP entry %p\n", err, tvp);
                        }

                        /* Release the cnode lock and mark the vnode for termination */ 
                        hfs_unlock (cp);
                        err = vnode_recycle (tvp);
                        if (err) {
                                printf("hfs_makenode: vnode_recycle failed (%d) for CP entry %p\n", err, tvp);
                        }

                        /* Drop the iocount on the new vnode to force reclamation/recycling */
                        vnode_put (tvp);
                        cp = NULL;
                        *vpp = NULL;
                }       
        }
#endif

#if QUOTA
        /* 
         * Once we create this vnode, we need to initialize its quota data 
         * structures, if necessary.  We know that it is OK to just go ahead and 
         * initialize because we've already validated earlier (through the hfs_quotacheck 
         * function) to see if creating this cnode/vnode would cause us to go over quota. 
         */
        if (hfsmp->hfs_flags & HFS_QUOTAS) {
                if (cp) {
                        /* cp could have been zeroed earlier */ 
                        (void) hfs_getinoquota(cp); 
                }
        }
#endif

exit:
        cat_releasedesc(&out_desc);
        
#if CONFIG_PROTECT
        /*  
         * We may have jumped here in error-handling various situations above.
         * If we haven't already dumped the temporary CP used to initialize
         * the file atomically, then free it now. cp_entry_destroy should null
         * out the pointer if it was called already.
         */
        if (entry) {
                cp_entry_destroy (hfsmp, entry);
                entry = NULL;
        }       
#endif

        /*
         * Make sure we release cnode lock on dcp.
         */
        if (dcp) {
                dcp->c_flag &= ~C_DIR_MODIFICATION;
                wakeup((caddr_t)&dcp->c_flag);
                
                hfs_unlock(dcp);
        }
        ino64_t file_id = 0;
        if (error == 0 && cp != NULL) {
                file_id = cp->c_fileid;
                hfs_unlock(cp);
        }
        if (started_tr) {
            hfs_end_transaction(hfsmp);
            started_tr = 0;
        }

        if (old_doc_vp) {
                cnode_t *ocp = VTOC(old_doc_vp);
                hfs_lock_always(ocp, HFS_EXCLUSIVE_LOCK);
                struct FndrExtendedFileInfo *ofip = (struct FndrExtendedFileInfo *)((char *)&ocp->c_attr.ca_finderinfo + 16);

                const uint32_t doc_id = ofip->document_id;
                const ino64_t old_file_id = ocp->c_fileid;

                // printf("clearing doc-id from ino %d\n", ocp->c_desc.cd_cnid);
                ofip->document_id = 0;
                ocp->c_bsdflags &= ~UF_TRACKED;
                ocp->c_flag |= C_MODIFIED;

                hfs_unlock(ocp);
                vnode_put(old_doc_vp);

                add_fsevent(FSE_DOCID_CHANGED, vfs_context_current(),
                                        FSE_ARG_DEV, hfsmp->hfs_raw_dev,
                                        FSE_ARG_INO, old_file_id,     // src inode #
                                        FSE_ARG_INO, file_id,             // dst inode #
                                        FSE_ARG_INT32, doc_id,
                                        FSE_ARG_DONE);
        }

        return (error);
}


/*
 * hfs_vgetrsrc acquires a resource fork vnode corresponding to the
 * cnode that is found in 'vp'.  The cnode should be locked upon entry
 * and will be returned locked, but it may be dropped temporarily.
 *
 * If the resource fork vnode does not exist, HFS will attempt to acquire an
 * empty (uninitialized) vnode from VFS so as to avoid deadlocks with
 * jetsam. If we let the normal getnewvnode code produce the vnode for us
 * we would be doing so while holding the cnode lock of our cnode.
 * 
 * On success, *rvpp wlll hold the resource fork vnode with an
 * iocount.  *Don't* forget the vnode_put.
 */
int
hfs_vgetrsrc(struct hfsmount *hfsmp, struct vnode *vp, struct vnode **rvpp)
{
        struct vnode *rvp = NULLVP;
        struct vnode *empty_rvp = NULLVP;
        struct vnode *dvp = NULLVP;
        struct cnode *cp = VTOC(vp);
        int error;
        int vid;

        if (vnode_vtype(vp) == VDIR) {
                return EINVAL;
        }
        
restart:
        /* Attempt to use existing vnode */
        if ((rvp = cp->c_rsrc_vp)) {
                vid = vnode_vid(rvp);

                // vnode_getwithvid can block so we need to drop the cnode lock
                hfs_unlock(cp);

                error = vnode_getwithvid(rvp, vid);

                hfs_lock_always(cp, HFS_EXCLUSIVE_LOCK);

                /*
                 * When our lock was relinquished, the resource fork
                 * could have been recycled.  Check for this and try
                 * again.
                 */
                if (error == ENOENT)
                        goto restart;

                if (error) {
                        const char * name = (const char *)VTOC(vp)->c_desc.cd_nameptr;

                        if (name)
                                printf("hfs_vgetrsrc: couldn't get resource"
                                       " fork for %s, vol=%s, err=%d\n", name, hfsmp->vcbVN, error);
                        return (error);
                }
        } else {
                struct cat_fork rsrcfork;
                struct componentname cn;
                struct cat_desc *descptr = NULL;
                struct cat_desc to_desc;
                char delname[32];
                int lockflags;
                int newvnode_flags = 0;

                /* 
                 * In this case, we don't currently see a resource fork vnode attached
                 * to this cnode.  In most cases, we were called from a read-only VNOP
                 * like getattr, so it should be safe to drop the cnode lock and then 
                 * re-acquire it.  
                 *
                 * Here, we drop the lock so that we can acquire an empty/husk
                 * vnode so that we don't deadlock against jetsam.  
                 *
                 * It does not currently appear possible to hold the truncate lock via
                 * FS re-entrancy when we get to this point. (8/2014)
                 */
                hfs_unlock (cp);

                error = vnode_create_empty (&empty_rvp); 

                hfs_lock_always (cp, HFS_EXCLUSIVE_LOCK);

                if (error) {
                        /* If acquiring the 'empty' vnode failed, then nothing to clean up */
                        return error;
                }

                /* 
                 * We could have raced with another thread here while we dropped our cnode
                 * lock.  See if the cnode now has a resource fork vnode and restart if appropriate.
                 *
                 * Note: We just released the cnode lock, so there is a possibility that the
                 * cnode that we just acquired has been deleted or even removed from disk
                 * completely, though this is unlikely. If the file is open-unlinked, the 
                 * check below will resolve it for us.  If it has been completely 
                 * removed (even from the catalog!), then when we examine the catalog 
                 * directly, below, while holding the catalog lock, we will not find the
                 * item and we can fail out properly.
                 */
                if (cp->c_rsrc_vp) {
                        /* Drop the empty vnode before restarting */
                        vnode_put (empty_rvp);
                        empty_rvp = NULL;
                        rvp = NULL;
                        goto restart;
                }
        
                /*
                 * hfs_vgetsrc may be invoked for a cnode that has already been marked
                 * C_DELETED.  This is because we need to continue to provide rsrc
                 * fork access to open-unlinked files.  In this case, build a fake descriptor
                 * like in hfs_removefile.  If we don't do this, buildkey will fail in
                 * cat_lookup because this cnode has no name in its descriptor.
                 */
                if ((cp->c_flag & C_DELETED ) && (cp->c_desc.cd_namelen == 0)) {
                        bzero (&to_desc, sizeof(to_desc));
                        bzero (delname, 32);
                        MAKE_DELETED_NAME(delname, sizeof(delname), cp->c_fileid);
                        to_desc.cd_nameptr = (const u_int8_t*) delname;
                        to_desc.cd_namelen = strlen(delname);
                        to_desc.cd_parentcnid = hfsmp->hfs_private_desc[FILE_HARDLINKS].cd_cnid;
                        to_desc.cd_flags = 0;
                        to_desc.cd_cnid = cp->c_cnid;

                        descptr = &to_desc;
                }
                else {
                        descptr = &cp->c_desc;
                }


                lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG, HFS_SHARED_LOCK);

                /*
                 * We call cat_idlookup (instead of cat_lookup) below because we can't
                 * trust the descriptor in the provided cnode for lookups at this point.  
                 * Between the time of the original lookup of this vnode and now, the 
                 * descriptor could have gotten swapped or replaced.  If this occurred, 
                 * the parent/name combo originally desired may not necessarily be provided
                 * if we use the descriptor.  Even worse, if the vnode represents
                 * a hardlink, we could have removed one of the links from the namespace
                 * but left the descriptor alone, since hfs_unlink does not invalidate
                 * the descriptor in the cnode if other links still point to the inode.
                 * 
                 * Consider the following (slightly contrived) scenario:
                 * /tmp/a <--> /tmp/b (hardlinks).
                 * 1. Thread A: open rsrc fork on /tmp/b.
                 * 1a. Thread A: does lookup, goes out to lunch right before calling getnamedstream.
                 * 2. Thread B does 'mv /foo/b /tmp/b'
                 * 2. Thread B succeeds.
                 * 3. Thread A comes back and wants rsrc fork info for /tmp/b.  
                 * 
                 * Even though the hardlink backing /tmp/b is now eliminated, the descriptor
                 * is not removed/updated during the unlink process.  So, if you were to
                 * do a lookup on /tmp/b, you'd acquire an entirely different record's resource
                 * fork.
                 * 
                 * As a result, we use the fileid, which should be invariant for the lifetime
                 * of the cnode (possibly barring calls to exchangedata).
                 *
                 * Addendum: We can't do the above for HFS standard since we aren't guaranteed to
                 * have thread records for files.  They were only required for directories.  So
                 * we need to do the lookup with the catalog name. This is OK since hardlinks were
                 * never allowed on HFS standard.
                 */

                /* Get resource fork data */
#if CONFIG_HFS_STD
                if (ISSET(hfsmp->hfs_flags, HFS_STANDARD)) {
                        /*
                         * HFS standard only:
                         *
                         * Get the resource fork for this item with a cat_lookup call, but do not
                         * force a case lookup since HFS standard is case-insensitive only. We
                         * don't want the descriptor; just the fork data here. If we tried to
                         * do a ID lookup (via thread record -> catalog record), then we might fail
                         * prematurely since, as noted above, thread records were not strictly required
                         * on files in HFS.
                         */
                        error = cat_lookup (hfsmp, descptr, 1, 0, (struct cat_desc*)NULL,
                                                                (struct cat_attr*)NULL, &rsrcfork, NULL);
                } else
#endif
                {
                        error = cat_idlookup (hfsmp, cp->c_fileid, 0, 1, NULL, NULL, &rsrcfork);
                }

                hfs_systemfile_unlock(hfsmp, lockflags);
                if (error) {
                        /* Drop our 'empty' vnode ! */
                        vnode_put (empty_rvp);
                        return (error);
                }
                /*
                 * Supply hfs_getnewvnode with a component name. 
                 */
                cn.cn_pnbuf = NULL;
                if (descptr->cd_nameptr) {
                        void *buf = hfs_malloc(MAXPATHLEN);

                        cn = (struct componentname){
                                .cn_nameiop = LOOKUP,
                                .cn_flags       = ISLASTCN,
                                .cn_pnlen       = MAXPATHLEN,
                                .cn_pnbuf       = buf,
                                .cn_nameptr = buf,
                                .cn_namelen = snprintf(buf, MAXPATHLEN,
                                                                           "%s%s", descptr->cd_nameptr,
                                                                           _PATH_RSRCFORKSPEC)
                        };

                        // Should never happen because cn.cn_nameptr won't ever be long...
                        if (cn.cn_namelen >= MAXPATHLEN) {
                                hfs_free(buf, MAXPATHLEN);
                                /* Drop our 'empty' vnode ! */
                                vnode_put (empty_rvp);
                                return ENAMETOOLONG;
                                
                        }
                }
                dvp = vnode_getparent(vp);
                
                /* 
                 * We are about to call hfs_getnewvnode and pass in the vnode that we acquired
                 * earlier when we were not holding any locks. The semantics of GNV_USE_VP require that
                 * either hfs_getnewvnode consume the vnode and vend it back to us, properly initialized,
                 * or it will consume/dispose of it properly if it errors out.
                 */ 
                rvp = empty_rvp;
                
                error = hfs_getnewvnode(hfsmp, dvp, cn.cn_pnbuf ? &cn : NULL,
                                        descptr, (GNV_WANTRSRC | GNV_SKIPLOCK | GNV_USE_VP), 
                                                                &cp->c_attr, &rsrcfork, &rvp, &newvnode_flags);
                        
                if (dvp)
                        vnode_put(dvp);
                hfs_free(cn.cn_pnbuf, MAXPATHLEN);
                if (error)
                        return (error);
        }  /* End 'else' for rsrc fork not existing */

        *rvpp = rvp;
        return (0);
}

/*
 * Wrapper for special device reads
 */
int
hfsspec_read(struct vnop_read_args *ap)
{
        /*
         * Set access flag.
         */
        cnode_t *cp = VTOC(ap->a_vp);

        if (cp)
                cp->c_touch_acctime = TRUE;

        return spec_read(ap);
}

/*
 * Wrapper for special device writes
 */
int
hfsspec_write(struct vnop_write_args *ap)
{
        /*
         * Set update and change flags.
         */
        cnode_t *cp = VTOC(ap->a_vp);

        if (cp) {
                cp->c_touch_chgtime = TRUE;
                cp->c_touch_modtime = TRUE;
        }

        return spec_write(ap);
}

/*
 * Wrapper for special device close
 *
 * Update the times on the cnode then do device close.
 */
int
hfsspec_close(struct vnop_close_args *ap)
{
        struct vnode *vp = ap->a_vp;
        cnode_t *cp = VTOC(vp);

        if (cp && vnode_isinuse(ap->a_vp, 0)) {
                if (hfs_lock(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT) == 0) {
                        hfs_touchtimes(VTOHFS(vp), cp);
                        hfs_unlock(cp);
                }
        }
        return spec_close(ap);
}

#if FIFO
/*
 * Wrapper for fifo reads
 */
static int
hfsfifo_read(struct vnop_read_args *ap)
{
        /*
         * Set access flag.
         */
        VTOC(ap->a_vp)->c_touch_acctime = TRUE;
        return fifo_read(ap);
}

/*
 * Wrapper for fifo writes
 */
static int
hfsfifo_write(struct vnop_write_args *ap)
{
        /*
         * Set update and change flags.
         */
        VTOC(ap->a_vp)->c_touch_chgtime = TRUE;
        VTOC(ap->a_vp)->c_touch_modtime = TRUE;
        return fifo_write(ap);
}

/*
 * Wrapper for fifo close
 *
 * Update the times on the cnode then do device close.
 */
static int
hfsfifo_close(struct vnop_close_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct cnode *cp;

        if (vnode_isinuse(ap->a_vp, 1)) {
                if (hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT) == 0) {
                        cp = VTOC(vp);
                        hfs_touchtimes(VTOHFS(vp), cp);
                        hfs_unlock(cp);
                }
        }
        return fifo_close(ap);
}


#endif /* FIFO */

/* 
 * Getter for the document_id 
 * the document_id is stored in FndrExtendedFileInfo/FndrExtendedDirInfo
 */
static u_int32_t 
hfs_get_document_id_internal(const uint8_t *finderinfo, mode_t mode)
{
        const uint8_t *finfo = NULL;
        u_int32_t doc_id = 0;
        
        /* overlay the FinderInfo to the correct pointer, and advance */
        finfo = finderinfo + 16;

        if (S_ISDIR(mode) || S_ISREG(mode)) {
                const struct FndrExtendedFileInfo *extinfo = (const struct FndrExtendedFileInfo *)finfo;
                doc_id = extinfo->document_id;
        }

        return doc_id;
}


/* getter(s) for document id */
u_int32_t
hfs_get_document_id(struct cnode *cp)
{
        return (hfs_get_document_id_internal((u_int8_t*)cp->c_finderinfo,
            cp->c_attr.ca_mode));
}

/* If you have finderinfo and mode, you can use this */
u_int32_t
hfs_get_document_id_from_blob(const uint8_t *finderinfo, mode_t mode)
{
        return (hfs_get_document_id_internal(finderinfo, mode));
}

/*
 * Synchronize a file's in-core state with that on disk.
 */
int
hfs_vnop_fsync(struct vnop_fsync_args *ap)
{
        struct vnode* vp = ap->a_vp;
        int error;

        /* Note: We check hfs flags instead of vfs mount flag because during 
         * read-write update, hfs marks itself read-write much earlier than
         * the vfs, and hence won't result in skipping of certain writes like 
         * zero'ing out of unused nodes, creation of hotfiles btree, etc. 
         */
        if (VTOHFS(vp)->hfs_flags & HFS_READ_ONLY) {
                return 0;               
        }

        /*
         * No need to call cp_handle_vnop to resolve fsync().  Any dirty data
         * should have caused the keys to be unwrapped at the time the data was
         * put into the UBC, either at mmap/pagein/read-write.  If we did manage
         * to let this by, then strategy will auto-resolve for us.
         * 
         * We also need to allow ENOENT lock errors since unlink
         * system call can call VNOP_FSYNC during vclean.
         */
        error = hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT);
        if (error)
                return (0);

        error = hfs_fsync(vp, ap->a_waitfor, 0, vfs_context_proc(ap->a_context));

        hfs_unlock(VTOC(vp));
        return (error);
}

int (**hfs_vnodeop_p)(void *);

#define VOPFUNC int (*)(void *)


#if CONFIG_HFS_STD
int (**hfs_std_vnodeop_p) (void *);
static int hfs_readonly_op (__unused void* ap) { return (EROFS); }

/* 
 * In 10.6 and forward, HFS Standard is read-only and deprecated.  The vnop table below
 * is for use with HFS standard to block out operations that would modify the file system
 */

struct vnodeopv_entry_desc hfs_standard_vnodeop_entries[] = {
    { &vnop_default_desc, (VOPFUNC)vn_default_error },
    { &vnop_lookup_desc, (VOPFUNC)hfs_vnop_lookup },            /* lookup */
    { &vnop_create_desc, (VOPFUNC)hfs_readonly_op },            /* create (READONLY) */
    { &vnop_mknod_desc, (VOPFUNC)hfs_readonly_op },             /* mknod (READONLY) */
    { &vnop_open_desc, (VOPFUNC)hfs_vnop_open },                        /* open */
    { &vnop_close_desc, (VOPFUNC)hfs_vnop_close },              /* close */
    { &vnop_getattr_desc, (VOPFUNC)hfs_vnop_getattr },          /* getattr */
    { &vnop_setattr_desc, (VOPFUNC)hfs_readonly_op },           /* setattr */
    { &vnop_read_desc, (VOPFUNC)hfs_vnop_read },                        /* read */
    { &vnop_write_desc, (VOPFUNC)hfs_readonly_op },             /* write (READONLY) */
    { &vnop_ioctl_desc, (VOPFUNC)hfs_vnop_ioctl },              /* ioctl */
    { &vnop_select_desc, (VOPFUNC)hfs_vnop_select },            /* select */
    { &vnop_revoke_desc, (VOPFUNC)nop_revoke },                 /* revoke */
    { &vnop_exchange_desc, (VOPFUNC)hfs_readonly_op },          /* exchange  (READONLY)*/
    { &vnop_mmap_desc, (VOPFUNC)err_mmap },                     /* mmap */
    { &vnop_fsync_desc, (VOPFUNC)hfs_readonly_op},              /* fsync (READONLY) */
    { &vnop_remove_desc, (VOPFUNC)hfs_readonly_op },            /* remove (READONLY) */
    { &vnop_link_desc, (VOPFUNC)hfs_readonly_op },                      /* link ( READONLLY) */
    { &vnop_rename_desc, (VOPFUNC)hfs_readonly_op },            /* rename (READONLY)*/
    { &vnop_mkdir_desc, (VOPFUNC)hfs_readonly_op },             /* mkdir (READONLY) */
    { &vnop_rmdir_desc, (VOPFUNC)hfs_readonly_op },             /* rmdir (READONLY) */
    { &vnop_symlink_desc, (VOPFUNC)hfs_readonly_op },         /* symlink (READONLY) */
    { &vnop_readdir_desc, (VOPFUNC)hfs_vnop_readdir },          /* readdir */
    { &vnop_readdirattr_desc, (VOPFUNC)hfs_vnop_readdirattr },  /* readdirattr */
    { &vnop_readlink_desc, (VOPFUNC)hfs_vnop_readlink },                /* readlink */
    { &vnop_inactive_desc, (VOPFUNC)hfs_vnop_inactive },                /* inactive */
    { &vnop_reclaim_desc, (VOPFUNC)hfs_vnop_reclaim },          /* reclaim */
    { &vnop_strategy_desc, (VOPFUNC)hfs_vnop_strategy },                /* strategy */
    { &vnop_pathconf_desc, (VOPFUNC)hfs_vnop_pathconf },                /* pathconf */
    { &vnop_advlock_desc, (VOPFUNC)err_advlock },               /* advlock */
    { &vnop_allocate_desc, (VOPFUNC)hfs_readonly_op },          /* allocate (READONLY) */
#if CONFIG_SEARCHFS
    { &vnop_searchfs_desc, (VOPFUNC)hfs_vnop_search },          /* search fs */
#else
    { &vnop_searchfs_desc, (VOPFUNC)err_searchfs },             /* search fs */
#endif
    { &vnop_bwrite_desc, (VOPFUNC)hfs_readonly_op },            /* bwrite (READONLY) */
    { &vnop_pagein_desc, (VOPFUNC)hfs_vnop_pagein },            /* pagein */
    { &vnop_pageout_desc,(VOPFUNC) hfs_readonly_op },           /* pageout (READONLY)  */
    { &vnop_copyfile_desc, (VOPFUNC)hfs_readonly_op },          /* copyfile (READONLY)*/
    { &vnop_blktooff_desc, (VOPFUNC)hfs_vnop_blktooff },                /* blktooff */
    { &vnop_offtoblk_desc, (VOPFUNC)hfs_vnop_offtoblk },                /* offtoblk */
    { &vnop_blockmap_desc, (VOPFUNC)hfs_vnop_blockmap },                        /* blockmap */
    { &vnop_getxattr_desc, (VOPFUNC)hfs_vnop_getxattr},
    { &vnop_setxattr_desc, (VOPFUNC)hfs_readonly_op},         /* set xattr (READONLY) */
    { &vnop_removexattr_desc, (VOPFUNC)hfs_readonly_op},      /* remove xattr (READONLY) */
    { &vnop_listxattr_desc, (VOPFUNC)hfs_vnop_listxattr},
#if NAMEDSTREAMS
    { &vnop_getnamedstream_desc, (VOPFUNC)hfs_vnop_getnamedstream },
    { &vnop_makenamedstream_desc, (VOPFUNC)hfs_readonly_op }, 
    { &vnop_removenamedstream_desc, (VOPFUNC)hfs_readonly_op },
#endif
    { &vnop_getattrlistbulk_desc, (VOPFUNC)hfs_vnop_getattrlistbulk },  /* getattrlistbulk */
    { NULL, (VOPFUNC)NULL }
};

struct vnodeopv_desc hfs_std_vnodeop_opv_desc =
{ &hfs_std_vnodeop_p, hfs_standard_vnodeop_entries };
#endif

/* VNOP table for HFS+ */
struct vnodeopv_entry_desc hfs_vnodeop_entries[] = {
    { &vnop_default_desc, (VOPFUNC)vn_default_error },
    { &vnop_lookup_desc, (VOPFUNC)hfs_vnop_lookup },            /* lookup */
    { &vnop_create_desc, (VOPFUNC)hfs_vnop_create },            /* create */
    { &vnop_mknod_desc, (VOPFUNC)hfs_vnop_mknod },             /* mknod */
    { &vnop_open_desc, (VOPFUNC)hfs_vnop_open },                        /* open */
    { &vnop_close_desc, (VOPFUNC)hfs_vnop_close },              /* close */
    { &vnop_getattr_desc, (VOPFUNC)hfs_vnop_getattr },          /* getattr */
    { &vnop_setattr_desc, (VOPFUNC)hfs_vnop_setattr },          /* setattr */
    { &vnop_read_desc, (VOPFUNC)hfs_vnop_read },                        /* read */
    { &vnop_write_desc, (VOPFUNC)hfs_vnop_write },              /* write */
    { &vnop_ioctl_desc, (VOPFUNC)hfs_vnop_ioctl },              /* ioctl */
    { &vnop_select_desc, (VOPFUNC)hfs_vnop_select },            /* select */
    { &vnop_revoke_desc, (VOPFUNC)nop_revoke },                 /* revoke */
    { &vnop_exchange_desc, (VOPFUNC)hfs_vnop_exchange },                /* exchange */
    { &vnop_mmap_desc, (VOPFUNC)hfs_vnop_mmap },                        /* mmap */
    { &vnop_fsync_desc, (VOPFUNC)hfs_vnop_fsync },              /* fsync */
    { &vnop_remove_desc, (VOPFUNC)hfs_vnop_remove },            /* remove */
    { &vnop_link_desc, (VOPFUNC)hfs_vnop_link },                        /* link */
    { &vnop_rename_desc, (VOPFUNC)hfs_vnop_rename },            /* rename */
    { &vnop_renamex_desc, (VOPFUNC)hfs_vnop_renamex },          /* renamex (with flags) */
    { &vnop_mkdir_desc, (VOPFUNC)hfs_vnop_mkdir },             /* mkdir */
    { &vnop_rmdir_desc, (VOPFUNC)hfs_vnop_rmdir },              /* rmdir */
    { &vnop_symlink_desc, (VOPFUNC)hfs_vnop_symlink },         /* symlink */
    { &vnop_readdir_desc, (VOPFUNC)hfs_vnop_readdir },          /* readdir */
    { &vnop_readdirattr_desc, (VOPFUNC)hfs_vnop_readdirattr },  /* readdirattr */
    { &vnop_readlink_desc, (VOPFUNC)hfs_vnop_readlink },                /* readlink */
    { &vnop_inactive_desc, (VOPFUNC)hfs_vnop_inactive },                /* inactive */
    { &vnop_reclaim_desc, (VOPFUNC)hfs_vnop_reclaim },          /* reclaim */
    { &vnop_strategy_desc, (VOPFUNC)hfs_vnop_strategy },                /* strategy */
    { &vnop_pathconf_desc, (VOPFUNC)hfs_vnop_pathconf },                /* pathconf */
    { &vnop_advlock_desc, (VOPFUNC)err_advlock },               /* advlock */
    { &vnop_allocate_desc, (VOPFUNC)hfs_vnop_allocate },                /* allocate */
#if CONFIG_SEARCHFS
    { &vnop_searchfs_desc, (VOPFUNC)hfs_vnop_search },          /* search fs */
#else
    { &vnop_searchfs_desc, (VOPFUNC)err_searchfs },             /* search fs */
#endif
    { &vnop_bwrite_desc, (VOPFUNC)hfs_vnop_bwrite },            /* bwrite */
    { &vnop_pagein_desc, (VOPFUNC)hfs_vnop_pagein },            /* pagein */
    { &vnop_pageout_desc,(VOPFUNC) hfs_vnop_pageout },          /* pageout */
    { &vnop_copyfile_desc, (VOPFUNC)err_copyfile },             /* copyfile */
    { &vnop_blktooff_desc, (VOPFUNC)hfs_vnop_blktooff },                /* blktooff */
    { &vnop_offtoblk_desc, (VOPFUNC)hfs_vnop_offtoblk },                /* offtoblk */
    { &vnop_blockmap_desc, (VOPFUNC)hfs_vnop_blockmap },                        /* blockmap */
    { &vnop_getxattr_desc, (VOPFUNC)hfs_vnop_getxattr},
    { &vnop_setxattr_desc, (VOPFUNC)hfs_vnop_setxattr},
    { &vnop_removexattr_desc, (VOPFUNC)hfs_vnop_removexattr},
    { &vnop_listxattr_desc, (VOPFUNC)hfs_vnop_listxattr},
#if NAMEDSTREAMS
    { &vnop_getnamedstream_desc, (VOPFUNC)hfs_vnop_getnamedstream },
    { &vnop_makenamedstream_desc, (VOPFUNC)hfs_vnop_makenamedstream },
    { &vnop_removenamedstream_desc, (VOPFUNC)hfs_vnop_removenamedstream },
#endif
    { &vnop_getattrlistbulk_desc, (VOPFUNC)hfs_vnop_getattrlistbulk },  /* getattrlistbulk */
        { &vnop_mnomap_desc, (VOPFUNC)hfs_vnop_mnomap },
    { NULL, (VOPFUNC)NULL }
};

struct vnodeopv_desc hfs_vnodeop_opv_desc =
{ &hfs_vnodeop_p, hfs_vnodeop_entries };


/* Spec Op vnop table for HFS+ */
int (**hfs_specop_p)(void *);
struct vnodeopv_entry_desc hfs_specop_entries[] = {
        { &vnop_default_desc, (VOPFUNC)vn_default_error },
        { &vnop_lookup_desc, (VOPFUNC)spec_lookup },            /* lookup */
        { &vnop_create_desc, (VOPFUNC)spec_create },            /* create */
        { &vnop_mknod_desc, (VOPFUNC)spec_mknod },              /* mknod */
        { &vnop_open_desc, (VOPFUNC)spec_open },                        /* open */
        { &vnop_close_desc, (VOPFUNC)hfsspec_close },           /* close */
        { &vnop_getattr_desc, (VOPFUNC)hfs_vnop_getattr },      /* getattr */
        { &vnop_setattr_desc, (VOPFUNC)hfs_vnop_setattr },      /* setattr */
        { &vnop_read_desc, (VOPFUNC)hfsspec_read },             /* read */
        { &vnop_write_desc, (VOPFUNC)hfsspec_write },           /* write */
        { &vnop_ioctl_desc, (VOPFUNC)spec_ioctl },              /* ioctl */
        { &vnop_select_desc, (VOPFUNC)spec_select },            /* select */
        { &vnop_revoke_desc, (VOPFUNC)spec_revoke },            /* revoke */
        { &vnop_mmap_desc, (VOPFUNC)spec_mmap },                        /* mmap */
        { &vnop_fsync_desc, (VOPFUNC)hfs_vnop_fsync },          /* fsync */
        { &vnop_remove_desc, (VOPFUNC)spec_remove },            /* remove */
        { &vnop_link_desc, (VOPFUNC)spec_link },                        /* link */
        { &vnop_rename_desc, (VOPFUNC)spec_rename },            /* rename */
        { &vnop_mkdir_desc, (VOPFUNC)spec_mkdir },              /* mkdir */
        { &vnop_rmdir_desc, (VOPFUNC)spec_rmdir },              /* rmdir */
        { &vnop_symlink_desc, (VOPFUNC)spec_symlink },          /* symlink */
        { &vnop_readdir_desc, (VOPFUNC)spec_readdir },          /* readdir */
        { &vnop_readlink_desc, (VOPFUNC)spec_readlink },                /* readlink */
        { &vnop_inactive_desc, (VOPFUNC)hfs_vnop_inactive },    /* inactive */
        { &vnop_reclaim_desc, (VOPFUNC)hfs_vnop_reclaim },      /* reclaim */
        { &vnop_strategy_desc, (VOPFUNC)spec_strategy },                /* strategy */
        { &vnop_pathconf_desc, (VOPFUNC)spec_pathconf },                /* pathconf */
        { &vnop_advlock_desc, (VOPFUNC)err_advlock },           /* advlock */
        { &vnop_bwrite_desc, (VOPFUNC)hfs_vnop_bwrite },
        { &vnop_pagein_desc, (VOPFUNC)hfs_vnop_pagein },                /* Pagein */
        { &vnop_pageout_desc, (VOPFUNC)hfs_vnop_pageout },      /* Pageout */
    { &vnop_copyfile_desc, (VOPFUNC)err_copyfile },             /* copyfile */
        { &vnop_blktooff_desc, (VOPFUNC)hfs_vnop_blktooff },    /* blktooff */
        { &vnop_offtoblk_desc, (VOPFUNC)hfs_vnop_offtoblk },    /* offtoblk */
        { &vnop_getxattr_desc, (VOPFUNC)hfs_vnop_getxattr},
        { &vnop_setxattr_desc, (VOPFUNC)hfs_vnop_setxattr},
        { &vnop_removexattr_desc, (VOPFUNC)hfs_vnop_removexattr},
        { &vnop_listxattr_desc, (VOPFUNC)hfs_vnop_listxattr},
        { (struct vnodeop_desc*)NULL, (VOPFUNC)NULL }
};
struct vnodeopv_desc hfs_specop_opv_desc =
        { &hfs_specop_p, hfs_specop_entries };

#if FIFO
/* HFS+ FIFO VNOP table  */
int (**hfs_fifoop_p)(void *);
struct vnodeopv_entry_desc hfs_fifoop_entries[] = {
        { &vnop_default_desc, (VOPFUNC)vn_default_error },
        { &vnop_lookup_desc, (VOPFUNC)fifo_lookup },            /* lookup */
        { &vnop_create_desc, (VOPFUNC)fifo_create },            /* create */
        { &vnop_mknod_desc, (VOPFUNC)fifo_mknod },              /* mknod */
        { &vnop_open_desc, (VOPFUNC)fifo_open },                        /* open */
        { &vnop_close_desc, (VOPFUNC)hfsfifo_close },           /* close */
        { &vnop_getattr_desc, (VOPFUNC)hfs_vnop_getattr },      /* getattr */
        { &vnop_setattr_desc, (VOPFUNC)hfs_vnop_setattr },      /* setattr */
        { &vnop_read_desc, (VOPFUNC)hfsfifo_read },             /* read */
        { &vnop_write_desc, (VOPFUNC)hfsfifo_write },           /* write */
        { &vnop_ioctl_desc, (VOPFUNC)fifo_ioctl },              /* ioctl */
        { &vnop_select_desc, (VOPFUNC)fifo_select },            /* select */
        { &vnop_revoke_desc, (VOPFUNC)fifo_revoke },            /* revoke */
        { &vnop_mmap_desc, (VOPFUNC)fifo_mmap },                        /* mmap */
        { &vnop_fsync_desc, (VOPFUNC)hfs_vnop_fsync },          /* fsync */
        { &vnop_remove_desc, (VOPFUNC)fifo_remove },            /* remove */
        { &vnop_link_desc, (VOPFUNC)fifo_link },                        /* link */
        { &vnop_rename_desc, (VOPFUNC)fifo_rename },            /* rename */
        { &vnop_mkdir_desc, (VOPFUNC)fifo_mkdir },              /* mkdir */
        { &vnop_rmdir_desc, (VOPFUNC)fifo_rmdir },              /* rmdir */
        { &vnop_symlink_desc, (VOPFUNC)fifo_symlink },          /* symlink */
        { &vnop_readdir_desc, (VOPFUNC)fifo_readdir },          /* readdir */
        { &vnop_readlink_desc, (VOPFUNC)fifo_readlink },                /* readlink */
        { &vnop_inactive_desc, (VOPFUNC)hfs_vnop_inactive },    /* inactive */
        { &vnop_reclaim_desc, (VOPFUNC)hfs_vnop_reclaim },      /* reclaim */
        { &vnop_strategy_desc, (VOPFUNC)fifo_strategy },                /* strategy */
        { &vnop_pathconf_desc, (VOPFUNC)fifo_pathconf },                /* pathconf */
        { &vnop_advlock_desc, (VOPFUNC)err_advlock },           /* advlock */
        { &vnop_bwrite_desc, (VOPFUNC)hfs_vnop_bwrite },
        { &vnop_pagein_desc, (VOPFUNC)hfs_vnop_pagein },                /* Pagein */
        { &vnop_pageout_desc, (VOPFUNC)hfs_vnop_pageout },      /* Pageout */
        { &vnop_copyfile_desc, (VOPFUNC)err_copyfile },                 /* copyfile */
        { &vnop_blktooff_desc, (VOPFUNC)hfs_vnop_blktooff },    /* blktooff */
        { &vnop_offtoblk_desc, (VOPFUNC)hfs_vnop_offtoblk },    /* offtoblk */
        { &vnop_blockmap_desc, (VOPFUNC)hfs_vnop_blockmap },            /* blockmap */
        { &vnop_getxattr_desc, (VOPFUNC)hfs_vnop_getxattr},
        { &vnop_setxattr_desc, (VOPFUNC)hfs_vnop_setxattr},
        { &vnop_removexattr_desc, (VOPFUNC)hfs_vnop_removexattr},
        { &vnop_listxattr_desc, (VOPFUNC)hfs_vnop_listxattr},
        { (struct vnodeop_desc*)NULL, (VOPFUNC)NULL }
};
struct vnodeopv_desc hfs_fifoop_opv_desc =
        { &hfs_fifoop_p, hfs_fifoop_entries };
#endif /* FIFO */