[apple/xnu.git] / bsd / hfs / hfs_vnops.c

/*
 * Copyright (c) 2000-2009 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 <sys/systm.h>
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/file_internal.h>
#include <sys/dirent.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/mount.h>
#include <sys/vnode_if.h>
#include <sys/vnode_internal.h>
#include <sys/malloc.h>
#include <sys/ubc.h>
#include <sys/ubc_internal.h>
#include <sys/paths.h>
#include <sys/quota.h>
#include <sys/time.h>
#include <sys/disk.h>
#include <sys/kauth.h>
#include <sys/uio_internal.h>

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

#include <sys/kdebug.h>
#include <sys/sysctl.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 "hfscommon/headers/BTreesInternal.h"
#include "hfscommon/headers/FileMgrInternal.h"

#define KNDETACH_VNLOCKED 0x00000001

/* Global vfs data structures for hfs */

/* Always F_FULLFSYNC? 1=yes,0=no (default due to "various" reasons is 'no') */
int always_do_fullfsync = 0;
SYSCTL_DECL(_vfs_generic);
SYSCTL_INT (_vfs_generic, OID_AUTO, always_do_fullfsync, CTLFLAG_RW, &always_do_fullfsync, 0, "always F_FULLFSYNC when fsync is called");

static int hfs_makenode(struct vnode *dvp, struct vnode **vpp,
                        struct componentname *cnp, struct vnode_attr *vap,
                        vfs_context_t ctx);

static int hfs_metasync(struct hfsmount *hfsmp, daddr64_t node, __unused struct proc *p);
static int hfs_metasync_all(struct hfsmount *hfsmp);

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

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

#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 */

static int hfs_vnop_close(struct vnop_close_args*);
static int hfs_vnop_create(struct vnop_create_args*);
static int hfs_vnop_exchange(struct vnop_exchange_args*);
static int hfs_vnop_fsync(struct vnop_fsync_args*);
static int hfs_vnop_mkdir(struct vnop_mkdir_args*);
static int hfs_vnop_mknod(struct vnop_mknod_args*);
static int hfs_vnop_getattr(struct vnop_getattr_args*);
static int hfs_vnop_open(struct vnop_open_args*);
static int hfs_vnop_readdir(struct vnop_readdir_args*);
static int hfs_vnop_remove(struct vnop_remove_args*);
static int hfs_vnop_rename(struct vnop_rename_args*);
static int hfs_vnop_rmdir(struct vnop_rmdir_args*);
static int hfs_vnop_symlink(struct vnop_symlink_args*);
static int hfs_vnop_setattr(struct vnop_setattr_args*);
static int hfs_vnop_readlink(struct vnop_readlink_args *);
static int hfs_vnop_pathconf(struct vnop_pathconf_args *);
static int hfs_vnop_whiteout(struct vnop_whiteout_args *);
static int hfsspec_read(struct vnop_read_args *);
static int hfsspec_write(struct vnop_write_args *);
static int hfsspec_close(struct vnop_close_args *);

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




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

/*
 * Create a regular file.
 */
static int
hfs_vnop_create(struct vnop_create_args *ap)
{
        int error;

again:
        error = hfs_makenode(ap->a_dvp, ap->a_vpp, ap->a_cnp, ap->a_vap, ap->a_context);

        /*
         * We speculatively skipped the original lookup of the leaf
         * for CREATE.  Since it exists, go get it as long as they
         * didn't want an exclusive create.
         */
        if ((error == EEXIST) && !(ap->a_vap->va_vaflags & VA_EXCLUSIVE)) {
                struct vnop_lookup_args args;

                args.a_desc = &vnop_lookup_desc;
                args.a_dvp = ap->a_dvp;
                args.a_vpp = ap->a_vpp;
                args.a_cnp = ap->a_cnp;
                args.a_context = ap->a_context;
                args.a_cnp->cn_nameiop = LOOKUP;
                error = hfs_vnop_lookup(&args);
                /*
                 * We can also race with remove for this file.
                 */
                if (error == ENOENT) {
                        goto again;
                }

                /* Make sure it was file. */
                if ((error == 0) && !vnode_isreg(*args.a_vpp)) {
                        vnode_put(*args.a_vpp);
                        error = EEXIST;
                }
                args.a_cnp->cn_nameiop = CREATE;
        }
        return (error);
}

/*
 * Make device special file.
 */
static 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);
        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 != 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
 */
static decmpfs_cnode *
hfs_lazy_init_decmpfs_cnode(struct cnode *cp)
{
        if (!cp->c_decmp) {
                decmpfs_cnode *dp = NULL;
                MALLOC_ZONE(dp, decmpfs_cnode *, sizeof(decmpfs_cnode), M_DECMPFS_CNODE, M_WAITOK);
                if (!dp) {
                        /* error allocating a decmpfs cnode */
                        return NULL;
                }
                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);
                        FREE_ZONE(dp, sizeof(*dp), M_DECMPFS_CNODE);
                }
        }
        
        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_flags & 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)
 */
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)) {         /* 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 ( ( NULL != vp ) && 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 {
                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.
 */
static 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 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_flags & APPEND) && !vnode_isdir(vp) &&
            (ap->a_mode & (FWRITE | O_APPEND)) == FWRITE)
                return (EPERM);

        if (vnode_isreg(vp) && !UBCINFOEXISTS(vp))
                return (EBUSY);  /* file is in use by the kernel */

        /* Don't allow journal file to be opened externally. */
        if (cp->c_fileid == hfsmp->hfs_jnlfileid)
                return (EPERM);

        /* If we're going to write to the file, initialize quotas. */
#if QUOTA
        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 its less than 20MB).
         */
        if ((hfsmp->hfs_flags & HFS_READ_ONLY) ||
            (hfsmp->jnl == NULL) ||
#if NAMEDSTREAMS
            !vnode_isreg(vp) || vnode_isinuse(vp, 0) || vnode_isnamedstream(vp)) {
#else
            !vnode_isreg(vp) || vnode_isinuse(vp, 0)) {
#endif
                return (0);
        }

        if ((error = hfs_lock(cp, HFS_EXCLUSIVE_LOCK)))
                return (error);
        fp = VTOF(vp);
        if (fp->ff_blocks &&
            fp->ff_extents[7].blockCount != 0 &&
            fp->ff_size <= (20 * 1024 * 1024)) {
                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 (!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.
 */
static int
hfs_vnop_close(ap)
        struct vnop_close_args /* {
                struct vnode *a_vp;
                int a_fflag;
                vfs_context_t a_context;
        } */ *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) != 0)
                return (0);
        cp = VTOC(vp);
        hfsmp = VTOHFS(vp);

        /* 
         * 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 ((vp->v_type == 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, TRUE);
                        tooktrunclock = 1;

                        if (hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK) != 0) { 
                                hfs_unlock_truncate(cp, TRUE);
                                // 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, 0, ap->a_context);
                                        }
                                }
                        }
                }
        }


        // if we froze the fs and we're exiting, then "thaw" the fs 
        if (hfsmp->hfs_freezing_proc == p && proc_exiting(p)) {
            hfsmp->hfs_freezing_proc = NULL;
            hfs_global_exclusive_lock_release(hfsmp);
            lck_rw_unlock_exclusive(&hfsmp->hfs_insync);
        }

        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, TRUE);
        }
        hfs_unlock(cp);

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

        return (0);
}

/*
 * Get basic attributes.
 */
static 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 (compressed && (VATTR_IS_ACTIVE(vap, va_data_size) || VATTR_IS_ACTIVE(vap, va_total_size))) {
                        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;
                        }
                }
        }
#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_flags;
                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 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)))
                        return (error);
                hfs_touchtimes(hfsmp, cp);
        }
        else {
                if ((error = hfs_lock(cp, HFS_SHARED_LOCK)))
                        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, TRUE, TRUE);
                                        if (error) {
                                                /* 
                                                 * hfs_vgetrsrc may have returned a vnode in rvp even though
                                                 * we got an error, because we specified error_on_unlinked.
                                                 * We need to drop the iocount after we release the cnode lock, so
                                                 * it will be taken care of at the end of the function if it's needed.
                                                 */
                                                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);
                }
        }
        if (VATTR_IS_ACTIVE(vap, va_access_time)) {
                /* Access times are lazily updated, get current time if needed */
                if (cp->c_touch_acctime) {
                        struct timeval tv;
        
                        microtime(&tv);
                        vap->va_access_time.tv_sec = tv.tv_sec;
                } else {
                        vap->va_access_time.tv_sec = cp->c_atime;
                }
                vap->va_access_time.tv_nsec = 0;
                VATTR_SET_SUPPORTED(vap, va_access_time);
        }
        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;        

        /* 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_flags;

        /*
         * 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);
        } 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;
        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;
//              vap->va_supported |= VNODE_ATTR_va_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
    
        /* Mark them all at once instead of individual VATTR_SET_SUPPORTED calls. */
        vap->va_supported |= 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_lookuplink(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);
}

static int
hfs_vnop_setattr(ap)
        struct vnop_setattr_args /* {
                struct vnode *a_vp;
                struct vnode_attr *a_vap;
                vfs_context_t a_context;
        } */ *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;

#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

        hfsmp = VTOHFS(vp);

        /* Don't allow modification of the journal file. */
        if (hfsmp->hfs_jnlfileid == VTOC(vp)->c_fileid) {
                return (EPERM);
        }

        /*
         * 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) && !vnode_islnk(vp)) {
#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? */
                        }
                }
                
                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 before taking cnode lock. */
                hfs_lock_truncate(VTOC(vp), TRUE);
                
                /* Perform the ubc_setsize before taking the cnode lock. */
                ubc_setsize(vp, vap->va_data_size);

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

                error = hfs_truncate(vp, vap->va_data_size, vap->va_vaflags & 0xffff, 1, 0, ap->a_context);

                hfs_unlock_truncate(cp, TRUE);
#if HFS_COMPRESSION
                decmpfs_unlock_compressed_data(dp, 1);
#endif
                if (error)
                        goto out;
        }
        if (cp == NULL) {
                if ((error = hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK)))
                        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_flags ^ 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

                cp->c_flags = vap->va_flags;
                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;

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

        if ((error = hfs_update(vp, TRUE)) != 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) && (vp->v_type != 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
        }
        return (error);
}


/*
 * Change the mode on a file.
 * cnode must be locked before calling.
 */
__private_extern__
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);

        // XXXdbg - don't allow modification of the journal or journal_info_block
        if (VTOHFS(vp)->jnl && cp && cp->c_datafork) {
                struct HFSPlusExtentDescriptor *extd;

                extd = &cp->c_datafork->ff_extents[0];
                if (extd->startBlock == VTOVCB(vp)->vcbJinfoBlock || extd->startBlock == VTOHFS(vp)->jnl_start) {
                        return EPERM;
                }
        }

#if OVERRIDE_UNKNOWN_PERMISSIONS
        if (((unsigned int)vfs_flags(VTOVFS(vp))) & MNT_UNKNOWNPERMISSIONS) {
                return (0);
        };
#endif
        cp->c_mode &= ~ALLPERMS;
        cp->c_mode |= (mode & ALLPERMS);
        cp->c_touch_chgtime = TRUE;
        return (0);
}


__private_extern__
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_flags & 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.
 */
__private_extern__
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 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 */


        /*
          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);
}


/*
 * The hfs_exchange routine swaps the fork data in two files by
 * exchanging some of the information in the cnode.  It is used
 * to preserve the file ID when updating an existing file, in
 * case the file is being tracked through its file ID. Typically
 * its used after creating a new file during a safe-save.
 */
static int
hfs_vnop_exchange(ap)
        struct vnop_exchange_args /* {
                struct vnode *a_fvp;
                struct vnode *a_tvp;
                int a_options;
                vfs_context_t a_context;
        } */ *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];
        u_int32_t tempflag;
        cnid_t  from_parid;
        cnid_t  to_parid;
        int lockflags;
        int error = 0, started_tr = 0, got_cookie = 0;
        cat_cookie_t cookie;

        /* The files must be on the same volume. */
        if (vnode_mount(from_vp) != vnode_mount(to_vp))
                return (EXDEV);

        if (from_vp == to_vp)
                return (EINVAL);

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

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

        /* Only normal files can be exchanged. */
        if (!vnode_isreg(from_vp) || !vnode_isreg(to_vp) ||
            VNODE_IS_RSRC(from_vp) || VNODE_IS_RSRC(to_vp)) {
                error = EINVAL;
                goto exit;
        }

        // XXXdbg - don't allow modification of the journal or journal_info_block
        if (hfsmp->jnl) {
                struct HFSPlusExtentDescriptor *extd;

                if (from_cp->c_datafork) {
                        extd = &from_cp->c_datafork->ff_extents[0];
                        if (extd->startBlock == VTOVCB(from_vp)->vcbJinfoBlock || extd->startBlock == hfsmp->jnl_start) {
                                error = EPERM;
                                goto exit;
                        }
                }

                if (to_cp->c_datafork) {
                        extd = &to_cp->c_datafork->ff_extents[0];
                        if (extd->startBlock == VTOVCB(to_vp)->vcbJinfoBlock || extd->startBlock == hfsmp->jnl_start) {
                                error = EPERM;
                                goto exit;
                        }
                }
        }

        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;
        }

        /* Do the exchange */
        error = ExchangeFileIDs(hfsmp, from_nameptr, to_nameptr, from_parid,
                                to_parid, from_cp->c_hint, to_cp->c_hint);
        hfs_systemfile_unlock(hfsmp, lockflags);

        /*
         * Note that we don't need to exchange any extended attributes
         * since the attributes are keyed by file ID.
         */

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

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

        /* 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));
        tempflag = from_cp->c_flag & (C_HARDLINK | C_HASXATTRS);

        /*
         * Swap the descriptors and all non-fork related attributes.
         * (except the modify date)
         */
        bcopy(&to_cp->c_desc, &from_cp->c_desc, sizeof(struct cat_desc));

        from_cp->c_hint = 0;
        from_cp->c_fileid = from_cp->c_cnid;
        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_flags = to_cp->c_flags;
        from_cp->c_mode = to_cp->c_mode;
        from_cp->c_linkcount = to_cp->c_linkcount;
        from_cp->c_flag = to_cp->c_flag & (C_HARDLINK | C_HASXATTRS);
        from_cp->c_attr.ca_recflags = to_cp->c_attr.ca_recflags;
        bcopy(to_cp->c_finderinfo, from_cp->c_finderinfo, 32);

        bcopy(&tempdesc, &to_cp->c_desc, sizeof(struct cat_desc));
        to_cp->c_hint = 0;
        to_cp->c_fileid = to_cp->c_cnid;
        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_flags = tempattr.ca_flags;
        to_cp->c_mode = tempattr.ca_mode;
        to_cp->c_linkcount = tempattr.ca_linkcount;
        to_cp->c_flag = tempflag;
        to_cp->c_attr.ca_recflags = tempattr.ca_recflags;
        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_flags & UF_NODUMP) &&
            (from_cp->c_parentcnid != to_cp->c_parentcnid)) {
                from_cp->c_flags &= ~UF_NODUMP;
                from_cp->c_touch_chgtime = TRUE;
        }
        if ((to_cp->c_flags & UF_NODUMP) &&
            (to_cp->c_parentcnid != from_cp->c_parentcnid)) {
                to_cp->c_flags &= ~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);
        }

        hfs_unlockpair(from_cp, to_cp);
        return (error);
}


/*
 *  cnode must be locked
 */
__private_extern__
int
hfs_fsync(struct vnode *vp, int waitfor, int fullsync, struct proc *p)
{
        struct cnode *cp = VTOC(vp);
        struct filefork *fp = NULL;
        int retval = 0;
        struct hfsmount *hfsmp = VTOHFS(vp);
        struct rl_entry *invalid_range;
        struct timeval tv;
        int waitdata;           /* attributes necessary for data retrieval */
        int wait;               /* all other attributes (e.g. atime, etc.) */
        int lockflag;
        int took_trunc_lock = 0;
        boolean_t trunc_lock_exclusive = FALSE;

        /*
         * 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)
                fullsync = 1;
        
        /* 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 if (UBCINFOEXISTS(vp)) {
                hfs_unlock(cp);
                hfs_lock_truncate(cp, trunc_lock_exclusive);
                took_trunc_lock = 1;

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

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

                hfs_lock(cp, HFS_FORCE_LOCK);
        }
        /*
         * 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_flags & UF_NODUMP) == 0) &&
                UBCINFOEXISTS(vp) && (vnode_issystem(vp) ==0) &&
                cp->c_zftimeout != 0))) {

                microuptime(&tv);
                if ((cp->c_flag & C_ALWAYS_ZEROFILL) == 0 && !fullsync && 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 || trunc_lock_exclusive == FALSE) {
                                hfs_unlock(cp);
                                if (took_trunc_lock)
                                        hfs_unlock_truncate(cp, trunc_lock_exclusive);

                                trunc_lock_exclusive = TRUE;
                                hfs_lock_truncate(cp, trunc_lock_exclusive);
                                hfs_lock(cp, HFS_FORCE_LOCK);
                                took_trunc_lock = 1;
                        }
                        while ((invalid_range = TAILQ_FIRST(&fp->ff_invalidranges))) {
                                off_t start = invalid_range->rl_start;
                                off_t end = invalid_range->rl_end;
                
                                /* The range about to be written must be validated
                                 * first, so that VNOP_BLOCKMAP() will return the
                                 * appropriate mapping for the cluster code:
                                 */
                                rl_remove(start, end, &fp->ff_invalidranges);

                                /* Don't hold cnode lock when calling into cluster layer. */
                                hfs_unlock(cp);
                                (void) cluster_write(vp, (struct uio *) 0,
                                                     fp->ff_size, end + 1, start, (off_t)0,
                                                     IO_HEADZEROFILL | IO_NOZERODIRTY | IO_NOCACHE);
                                hfs_lock(cp, HFS_FORCE_LOCK);
                                cp->c_flag |= C_MODIFIED;
                        }
                        hfs_unlock(cp);
                        (void) cluster_push(vp, waitdata ? IO_SYNC : 0);
                        hfs_lock(cp, HFS_FORCE_LOCK);
                }
                cp->c_flag &= ~C_ZFWANTSYNC;
                cp->c_zftimeout = 0;
        }
datasync:
        if (took_trunc_lock) {
                hfs_unlock_truncate(cp, trunc_lock_exclusive);
                took_trunc_lock = 0;
        }
        /*
         * if we have a journal and if journal_active() returns != 0 then the
         * we shouldn't do anything to a locked block (because it is part 
         * of a transaction).  otherwise we'll just go through the normal 
         * code path and flush the buffer.  note journal_active() can return
         * -1 if the journal is invalid -- however we still need to skip any 
         * locked blocks as they get cleaned up when we finish the transaction
         * or close the journal.
         */
        // if (hfsmp->jnl && journal_active(hfsmp->jnl) >= 0)
        if (hfsmp->jnl)
                lockflag = BUF_SKIP_LOCKED;
        else
                lockflag = 0;

        /*
         * Flush all dirty buffers associated with a vnode.
         */
        buf_flushdirtyblks(vp, waitdata, lockflag, "hfs_fsync");

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 ( !(vp->v_flag & VSWAP) ) /* User file */ {
                retval = hfs_update(vp, wait);

                /*
                 * 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 && !fullsync && 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 (fullsync) {
                    if (hfsmp->jnl) {
                        hfs_journal_flush(hfsmp);
                    } else {
                        retval = hfs_metasync_all(hfsmp);
                        /* XXX need to pass context! */
                        VNOP_IOCTL(hfsmp->hfs_devvp, DKIOCSYNCHRONIZECACHE, NULL, FWRITE, NULL);
                    }
                }
        }

        return (retval);
}


/* Sync an hfs catalog b-tree node */
static 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).
 */
static 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);
}


__private_extern__
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.
 */
static int
hfs_vnop_rmdir(ap)
        struct vnop_rmdir_args /* {
                struct vnode *a_dvp;
                struct vnode *a_vp;
                struct componentname *a_cnp;
                vfs_context_t a_context;
        } */ *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;

        if (!S_ISDIR(cp->c_mode)) {
                return (ENOTDIR);
        }
        if (dvp == vp) {
                return (EINVAL);
        }
        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;
        }
        error = hfs_removedir(dvp, vp, ap->a_cnp, 0);

        hfs_unlockpair(dcp, cp);

        return (error);
}

/*
 * Remove a directory
 *
 * Both dvp and vp cnodes are locked
 */
static int
hfs_removedir(struct vnode *dvp, struct vnode *vp, struct componentname *cnp,
              int skip_reserve)
{
        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);
        }

        /* Check if we're removing the last link to an empty directory. */
        if (cp->c_flag & C_HARDLINK) {
                /* We could also return EBUSY here */
                return hfs_unlink(hfsmp, dvp, vp, cnp, skip_reserve);
        }
        
        /*
         * We want to make sure that if the directory has a lot of attributes, we process them
         * in separate transactions to ensure we don't panic in the journal with a gigantic
         * transaction. This means we'll let hfs_removefile deal with the directory, which generally
         * follows the same codepath as open-unlinked files.  Note that the last 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) {

            return hfs_removefile(dvp, vp, cnp, 0, 0, 1, NULL);
        }

        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_flags & APPEND) || (cp->c_flags & (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)) {
            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 == 0) {
                /* The parent lost a child */
                if (dcp->c_entries > 0)
                        dcp->c_entries--;
                DEC_FOLDERCOUNT(hfsmp, dcp->c_attr);
                dcp->c_dirchangecnt++;
                dcp->c_touch_chgtime = TRUE;
                dcp->c_touch_modtime = TRUE;
                hfs_touchtimes(hfsmp, cp);
                (void) cat_update(hfsmp, &dcp->c_desc, &dcp->c_attr, NULL, NULL);
                cp->c_flag &= ~(C_MODIFIED | C_FORCEUPDATE);
        }

        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));

        /*
         * directory open or in use (e.g. opendir() or current working
         * directory for some process); wait for inactive to actually
         * remove catalog entry
         */
        if (vnode_isinuse(vp, 0)) {
                cp->c_flag |= C_DELETED;
        } else {
                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.
 */
static int
hfs_vnop_remove(ap)
        struct vnop_remove_args /* {
                struct vnode *a_dvp;
                struct vnode *a_vp;
                struct componentname *a_cnp;
                int a_flags;
                vfs_context_t a_context;
        } */ *ap;
{
        struct vnode *dvp = ap->a_dvp;
        struct vnode *vp = ap->a_vp;
        struct cnode *dcp = VTOC(dvp);
        struct cnode *cp = VTOC(vp);
        struct vnode *rvp = NULL;
        struct hfsmount *hfsmp = VTOHFS(vp);    
        int error=0, recycle_rsrc=0;
        int drop_rsrc_vnode = 0;
        int vref;

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

        /* 
         * We need to grab the cnode lock on 'cp' before the lockpair() 
         * to get an iocount on the rsrc fork BEFORE we enter hfs_removefile.
         * To prevent other deadlocks, it's best to call hfs_vgetrsrc in a way that
         * allows it to drop the cnode lock that it expects to be held coming in.  
         * If we don't, we could commit a lock order violation, causing a deadlock.  
         * In order to safely get the rsrc vnode with an iocount, we need to only hold the 
         * lock on the file temporarily.  Unlike hfs_vnop_rename, we don't have to worry 
         * about one rsrc fork getting recycled for another, but we do want to ensure
         * that there are no deadlocks due to lock ordering issues.
         * 
         * Note: this function may be invoked for directory hardlinks, so just skip these
         * steps if 'vp' is a directory.
         */


        if ((vp->v_type == VLNK) || (vp->v_type == VREG)) {

                if ((error = hfs_lock (cp, HFS_EXCLUSIVE_LOCK))) {
                        return (error);
                }
                error = hfs_vgetrsrc(hfsmp, vp, &rvp, TRUE, TRUE);
                hfs_unlock(cp);
                if (error) {
                        /* We may have gotten a rsrc vp out even though we got an error back. */
                        if (rvp) {
                                vnode_put(rvp);
                                rvp = NULL;
                        }
                        return error;
                }
                drop_rsrc_vnode = 1;
        }
        /* Now that we may have an iocount on rvp, do the lock pair */
        hfs_lock_truncate(cp, TRUE);

        if ((error = hfs_lockpair(dcp, cp, HFS_EXCLUSIVE_LOCK))) {
                hfs_unlock_truncate(cp, TRUE);
                /* drop the iocount on rvp if necessary */
                if (drop_rsrc_vnode) {
                        vnode_put (rvp);
                }
                return (error);
        }

        /* 
         * 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, rvp);

        //
        // If the remove succeeded and it's an open-unlinked file that has
        // a resource fork vnode that's not in use, we will want to recycle
        // the rvp *after* we're done unlocking everything.  Otherwise the
        // resource vnode will keep a v_parent reference on this vnode which
        // prevents it from going through inactive/reclaim which means that
        // the disk space associated with this file won't get free'd until
        // something forces the resource vnode to get recycled (and that can
        // take a very long time).
        //
        if (error == 0 && (cp->c_flag & C_DELETED) && 
                        (rvp) && !vnode_isinuse(rvp, 0)) {
            recycle_rsrc = 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_unlock_truncate(cp, TRUE);
        hfs_unlockpair(dcp, cp);

        if (recycle_rsrc) {
                vref = vnode_ref(rvp);
                if (vref == 0) {
                        /* vnode_ref could return an error, only release if we got a ref */
                        vnode_rele(rvp);
                }
                vnode_recycle(rvp);
        } 
        
        if (drop_rsrc_vnode) {
                /* drop iocount on rsrc fork, was obtained at beginning of fxn */
                vnode_put(rvp);
        }

        return (error);
}


static 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.
 *
 * The 'rvp' argument is used to pass in a resource fork vnode with
 * an iocount to prevent it from getting recycled during usage.  If it
 * is NULL, then it is assumed the caller is a VNOP that cannot operate
 * on resource forks, like hfs_vnop_symlink or hfs_removedir. Otherwise in 
 * a VNOP that takes multiple vnodes, we could violate lock order and 
 * cause a deadlock.  
 *
 * Requires cnode and truncate locks to be held.
 */
static int
hfs_removefile(struct vnode *dvp, struct vnode *vp, struct componentname *cnp,
               int flags, int skip_reserve, int allow_dirs, struct vnode *rvp)
{
        struct cnode *cp;
        struct cnode *dcp;
        struct hfsmount *hfsmp;
        struct cat_desc desc;
        struct timeval tv;
        vfs_context_t ctx = cnp->cn_context;
        int dataforkbusy = 0;
        int rsrcforkbusy = 0;
        int truncated = 0;
        int lockflags;
        int error = 0;
        int started_tr = 0;
        int isbigfile = 0, defer_remove=0, isdir=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)) {
            return 0;
        }

        /* Make sure a remove is permitted */
        if (VNODE_IS_RSRC(vp)) {
                return (EPERM);
        }
        /* Don't allow deleting the journal or journal_info_block. */
        if (hfsmp->jnl &&
            (cp->c_fileid == hfsmp->hfs_jnlfileid || cp->c_fileid == hfsmp->hfs_jnlinfoblkid)) {
                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);

        /*
         * We expect the caller, if operating on files,
         * will have passed in a resource fork vnode with
         * an iocount, even if there was no content.
         * We only do the hfs_truncate on the rsrc fork
         * if we know that it DID have content, however.
         * This has the bonus of not requiring us to defer
         * its removal, unless it is in use.
         */

        /* Check if this file is being used. */
        if (isdir == 0) {
                dataforkbusy = vnode_isinuse(vp, 0);
                /* Only need to defer resource fork removal if in use and has content */
                if (rvp && (cp->c_blocks - VTOF(vp)->ff_blocks)) {
                        rsrcforkbusy = vnode_isinuse(rvp, 0);
                }
        }
        
        /* Check if we have to break the deletion into multiple pieces. */
        if (isdir == 0) {
                isbigfile = ((cp->c_datafork->ff_size >= HFS_BIGFILE_SIZE) && overflow_extents(VTOF(vp)));
        }

        /* 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;
        }

        /*
         * 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 */

        /* Check if we need a ubc_setsize. */
        if (isdir == 0 && (!dataforkbusy || !rsrcforkbusy)) {
                /*
                 * 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 && rvp) {
                        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))
                buf_iterate(vp, hfs_removefile_callback, BUF_SKIP_NONLOCKED, (void *)hfsmp);

        /*
         * 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're already inside a transaction,
         * tell hfs_truncate to skip the ubc_setsize.
         */
        if (isdir == 0 && (!dataforkbusy && !rsrcforkbusy)) {
                /* 
                 * Note that 5th argument to hfs_truncate indicates whether or not 
                 * hfs_update calls should be suppressed in call to do_hfs_truncate
                 */
                if (!dataforkbusy && !isbigfile && cp->c_datafork->ff_blocks != 0) {
                        /* skip update in hfs_truncate */
                        error = hfs_truncate(vp, (off_t)0, IO_NDELAY, 1, 1, ctx);
                        if (error)
                                goto out;
                        truncated = 1;
                }
                if (!rsrcforkbusy && rvp) {
                        /* skip update in hfs_truncate */
                        error = hfs_truncate(rvp, (off_t)0, IO_NDELAY, 1, 1, ctx);
                        if (error)
                                goto out;
                        truncated = 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++;
                        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 /* Not busy */ {

                if (cp->c_blocks > 0) {
                        printf("hfs_remove: attempting to delete a non-empty file %s\n",
                                cp->c_desc.cd_nameptr);
                        error = EBUSY;
                        goto out;
                }

                lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG | SFL_ATTRIBUTE | SFL_BITMAP, HFS_EXCLUSIVE_LOCK);
                if (!skip_reserve) {
                        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 && error != ENXIO && error != ENOENT && truncated) {
                        if ((cp->c_datafork && cp->c_datafork->ff_size != 0) ||
                                        (cp->c_rsrcfork && cp->c_rsrcfork->ff_size != 0)) {
                                off_t data_size = 0;
                                off_t rsrc_size = 0;
                                if (cp->c_datafork) {
                                        data_size = cp->c_datafork->ff_size;
                                }
                                if (cp->c_rsrcfork) {
                                        rsrc_size = cp->c_rsrcfork->ff_size;
                                }
                                printf("hfs: remove: couldn't delete a truncated file (%s)" 
                                                "(error %d, data sz %lld; rsrc sz %lld)",
                                        cp->c_desc.cd_nameptr, error, data_size, rsrc_size);
                                hfs_mark_volume_inconsistent(hfsmp);
                        } else {
                                printf("hfs: remove: strangely enough, deleting truncated file %s (%d) got err %d\n",
                                                cp->c_desc.cd_nameptr, cp->c_attr.ca_fileid, error);
                        }       
                }

                if (error == 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);
                }
                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 */

                cp->c_flag |= C_NOEXISTS;
                cp->c_flag &= ~C_DELETED;
                truncated = 0;  // because the catalog entry is gone

                cp->c_touch_chgtime = TRUE;   /* XXX needed ? */
                --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));
        }

        /*
         * 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;
        }

        /* Commit the truncation to the catalog record */
        if (truncated) {
            cp->c_flag |= C_FORCEUPDATE;
            cp->c_touch_chgtime = TRUE;
            cp->c_touch_modtime = TRUE;
            (void) hfs_update(vp, 0);
        }

        if (started_tr) {
            hfs_end_transaction(hfsmp);
        }

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

        return (error);
}


__private_extern__ 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;
}


/*
 * 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.
 */
static int
hfs_vnop_rename(ap)
        struct vnop_rename_args  /* {
                struct vnode *a_fdvp;
                struct vnode *a_fvp;
                struct componentname *a_fcnp;
                struct vnode *a_tdvp;
                struct vnode *a_tvp;
                struct componentname *a_tcnp;
                vfs_context_t a_context;
        } */ *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;
        struct vnode *fvp_rsrc = NULLVP;
        struct vnode *tvp_rsrc = NULLVP;
        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;
        int recycle_rsrc = 0;


        /* 
         * Before grabbing the four locks, we may need to get an iocount on the resource fork
         * vnodes in question, just like hfs_vnop_remove.  If fvp and tvp are not
         * directories, then go ahead and grab the resource fork vnodes now
         * one at a time.  We don't actively need the fvp_rsrc to do the rename operation,
         * but we need the iocount to prevent the vnode from getting recycled/reclaimed
         * during the middle of the VNOP.
         */


        if ((vnode_isreg(fvp)) || (vnode_islnk(fvp))) {

                if ((error = hfs_lock (VTOC(fvp), HFS_EXCLUSIVE_LOCK))) {
                        return (error);
                }
                
                /*
                 * We care if we race against rename/delete with this cnode, so we'll
                 * error out if this file becomes open-unlinked during this call.
                 */
                error = hfs_vgetrsrc(VTOHFS(fvp), fvp, &fvp_rsrc, TRUE, TRUE);
                hfs_unlock (VTOC(fvp));
                if (error) {
                        if (fvp_rsrc) {
                                vnode_put (fvp_rsrc);
                        }
                        return error;
                }
        }
                
        if (tvp && (vnode_isreg(tvp) || vnode_islnk(tvp))) {
                /* 
                 * Lock failure is OK on tvp, since we may race with a remove on the dst.
                 * But this shouldn't stop rename from proceeding, so only try to
                 * grab the resource fork if the lock succeeded.
                 */
                if (hfs_lock (VTOC(tvp), HFS_EXCLUSIVE_LOCK) == 0) {
                        tcp = VTOC(tvp);
                        
                        /* 
                         * We only care if we get an open-unlinked file on the dst so we 
                         * know to null out tvp/tcp to make the rename operation act 
                         * as if they never existed.  Because they're effectively out of the
                         * namespace already it's fine to do this.  If this is true, then
                         * make sure to unlock the cnode and drop the iocount only after the unlock.
                         */
                        error = hfs_vgetrsrc(VTOHFS(tvp), tvp, &tvp_rsrc, TRUE, TRUE);
                        hfs_unlock (tcp);
                        if (error) {
                                /*
                                 * Since we specify TRUE for error-on-unlinked in hfs_vgetrsrc,
                                 * we can get a rsrc fork vp even if it returns an error.
                                 */
                                tcp = NULL;
                                tvp = NULL;
                                if (tvp_rsrc) {
                                        vnode_put (tvp_rsrc);
                                        tvp_rsrc = NULLVP;
                                }
                                /* just bypass truncate lock and act as if we never got tcp/tvp */
                                goto retry;
                        }
                }
        }

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

  retry:
        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), TRUE);
                        took_trunc_lock = 0;
                }
                /* 
                 * 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;
                }
                /* otherwise, drop iocounts on the rsrc forks and bail out */
                if (fvp_rsrc) {
                        vnode_put (fvp_rsrc);
                }
                if (tvp_rsrc) {
                        vnode_put (tvp_rsrc);
                }
                return (error);
        }

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

        /* 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)) {
                error = ENOENT;
                goto out;
        }

        if (tcp && ((tcp->c_flag & (C_NOEXISTS | C_DELETED)) || !hfs_valid_cnode(hfsmp, tdvp, tcnp, tcp->c_fileid))) {
            //
            // 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), TRUE);
                took_trunc_lock = 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_flags & (IMMUTABLE | APPEND)) || (fdcp->c_flags & 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(tcnp->cn_context), NULL)) &&
            (kauth_cred_getuid(vfs_context_ucred(tcnp->cn_context)) != tdcp->c_uid) &&
            (hfs_owner_rights(hfsmp, tcp->c_uid, vfs_context_ucred(tcnp->cn_context), p, false)) ) {
                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);

        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, 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.
         */
        if (tvp) {
                /*
                 * When fvp matches tvp they could be case variants
                 * or matching hard links.
                 */
                if (fvp == tvp) {
                        if (!(fcp->c_flag & C_HARDLINK)) {
                                goto skip_rm;  /* simple case variant */

                        } else if ((fdvp != tdvp) ||
                                   (hfsmp->hfs_flags & HFS_CASE_SENSITIVE)) {
                                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) {
                                goto skip_rm;  /* case-variant hardlink in the same dir */
                        } else {
                                goto out;  /* matching hardlink, nothing to do */
                        }
                }

                if (vnode_isdir(tvp))
                        error = hfs_removedir(tdvp, tvp, tcnp, HFSRM_SKIP_RESERVE);
                else {
                        error = hfs_removefile(tdvp, tvp, tcnp, 0, HFSRM_SKIP_RESERVE, 0, tvp_rsrc);

                        /* 
                         * If the destination file had a rsrc fork vnode, it may have been cleaned up
                         * in hfs_removefile if it was not busy (had no usecounts).  This is possible
                         * because we grabbed the iocount on the rsrc fork safely at the beginning
                         * of the function before we did the lockfour.  However, we may still need
                         * to take action to prevent block leaks, so aggressively recycle the vnode
                         * if possible.  The vnode cannot be recycled because we hold an iocount on it.
                         */

                        if ((error == 0) && (tcp->c_flag & C_DELETED) && tvp_rsrc && !vnode_isinuse(tvp_rsrc, 0)) {
                                recycle_rsrc = 1;
                        }       
                }

                if (error)
                        goto out;
                tvp_deleted = 1;
        }
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;

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

                fdcp->c_flag |= C_FORCEUPDATE;  // XXXdbg - force it out!
                (void) hfs_update(fdvp, 0);
        }
        tdcp->c_childhint = out_desc.cd_hint;   /* Cache directory's location */
        tdcp->c_touch_chgtime = TRUE;
        tdcp->c_touch_modtime = TRUE;

        tdcp->c_flag |= C_FORCEUPDATE;  // XXXdbg - force it out!
        (void) hfs_update(tdvp, 0);
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);
        }

        if (took_trunc_lock)
                hfs_unlock_truncate(VTOC(tvp), TRUE);   

        hfs_unlockfour(fdcp, fcp, tdcp, tcp);
        
        /* 
         * Now that we've dropped all of the locks, we need to force an inactive and a recycle 
         * on the old destination's rsrc fork to prevent a leak of its blocks.  Note that
         * doing the ref/rele is to twiddle the VL_NEEDINACTIVE bit of the vnode's flags, so that
         * on the last vnode_put for this vnode, we will force inactive to get triggered.
         * We hold an iocount from the beginning of this function so we know it couldn't have been
         * recycled already. 
         */
        if (recycle_rsrc) {
                int vref; 
                vref = vnode_ref(tvp_rsrc);
                if (vref == 0) {
                        vnode_rele(tvp_rsrc);
                }
                vnode_recycle(tvp_rsrc);
        }

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

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

        return (error);
}


/*
 * Make a directory.
 */
static 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.
 */
static 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);

        /* 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))) {
                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,
         * tell hfs_truncate to skip the ubc_setsize.
         *
         * Don't need truncate lock since a symlink is treated as a system file.
         */
        error = hfs_truncate(vp, len, IO_NOZEROFILL, 1, 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, TRUE);
                hfs_lock(cp, HFS_FORCE_LOCK);

                if (hfs_start_transaction(hfsmp) != 0) {
                        started_tr = 0;
                        hfs_unlock_truncate(cp, TRUE);
                        goto out;
                }
                
                (void) hfs_removefile(dvp, vp, ap->a_cnp, 0, 0, 0, NULL);
                hfs_unlock_truncate(cp, TRUE);
                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);
        }
        /*
         * We defered the ubc_setsize for hfs_truncate
         * since we were inside a transaction.
         *
         * We don't need to drop the cnode lock here
         * since this is a symlink.
         */
        ubc_setsize(vp, len);
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 "..".
 */
static int
hfs_vnop_readdir(ap)
        struct vnop_readdir_args /* {
                vnode_t a_vp;
                uio_t a_uio;
                int a_flags;
                int *a_eofflag;
                int *a_numdirent;
                vfs_context_t a_context;
        } */ *ap;
{
        struct vnode *vp = ap->a_vp;
        uio_t uio = ap->a_uio;
        struct cnode *cp;
        struct hfsmount *hfsmp;
        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;
        int index;
        unsigned int tag;
        int items;
        int lockflags;
        int extended;
        int nfs_cookies;
        cnid_t cnid_hint = 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);
        /* Note that the dirhint calls require an exclusive lock. */
        if ((error = hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK)))
                return (error);
        cp = VTOC(vp);
        hfsmp = VTOHFS(vp);

        /* 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)) {
                hfs_dotentry_t  dotentry[2];
                size_t  uiosize;

                if (extended) {
                        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);
                } else {
                        struct hfs_stddotentry *entry = &dotentry[0].std;

                        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)&dotentry, uiosize, uio))) {
                        goto out;
                }
                offset += 2;
        }

        /* If there are no real entries then we're done. */
        if (cp->c_entries == 0) {
                error = 0;
                eofflag = 1;
                uio_setoffset(uio, offset);
                goto seekoffcalc;
        }

        //
        // 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);

                if ((error = vslock(user_start, user_len)) != 0) {
                        user_start = 0;
                        goto out;
                }
        }
        /* 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);
                        hfs_systemfile_unlock (hfsmp, lockflags);

                        goto seekoffcalc;
                }
        }

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

        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;
        }

        /* 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) {
                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);
        }
        hfs_unlock(cp);
        return (error);
}


/*
 * Read contents of a symbolic link.
 */
static int
hfs_vnop_readlink(ap)
        struct vnop_readlink_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                vfs_context_t a_context;
        } */ *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)))
                return (error);
        cp = VTOC(vp);
        fp = VTOF(vp);
   
        /* Zero length sym links are not allowed */
        if (fp->ff_size == 0 || fp->ff_size > MAXPATHLEN) {
                printf("hfs: zero length symlink on fileid %d\n", cp->c_fileid);
                error = EINVAL;
                goto exit;
        }
    
        /* Cache the path so we don't waste buffer cache resources */
        if (fp->ff_symlinkptr == NULL) {
                struct buf *bp = NULL;

                MALLOC(fp->ff_symlinkptr, char *, fp->ff_size, M_TEMP, M_WAITOK);
                if (fp->ff_symlinkptr == NULL) {
                        error = ENOMEM;
                        goto exit;
                }
                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) {
                                FREE(fp->ff_symlinkptr, M_TEMP);
                                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.
 */
static int
hfs_vnop_pathconf(ap)
        struct vnop_pathconf_args /* {
                struct vnode *a_vp;
                int a_name;
                int *a_retval;
                vfs_context_t a_context;
        } */ *ap;
{
        switch (ap->a_name) {
        case _PC_LINK_MAX:
                if (VTOHFS(ap->a_vp)->hfs_flags & HFS_STANDARD)
                        *ap->a_retval = 1;
                else
                        *ap->a_retval = HFS_LINK_MAX;
                break;
        case _PC_NAME_MAX:
                if (VTOHFS(ap->a_vp)->hfs_flags & HFS_STANDARD)
                        *ap->a_retval = kHFSMaxFileNameChars;  /* 255 */
                else
                        *ap->a_retval = kHFSPlusMaxFileNameChars;  /* 31 */
                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:
                *ap->a_retval = kHFSPlusMaxFileNameChars;
                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:
                if (VTOHFS(ap->a_vp)->hfs_flags & HFS_STANDARD)
                        *ap->a_retval = 32;
                else
                        *ap->a_retval = 64;     /* number of bits to store max file size */
                break;
        default:
                return (EINVAL);
        }

        return (0);
}


/*
 * Update a cnode's on-disk metadata.
 *
 * If waitfor is set, then wait for the disk write of
 * the node to complete.
 *
 * The cnode must be locked exclusive
 */
__private_extern__
int
hfs_update(struct vnode *vp, __unused int waitfor)
{
        struct cnode *cp = VTOC(vp);
        struct proc *p;
        struct cat_fork *dataforkp = NULL;
        struct cat_fork *rsrcforkp = NULL;
        struct cat_fork datafork;
        struct cat_fork rsrcfork;
        struct hfsmount *hfsmp;
        int lockflags;
        int error;

        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)) {
                cp->c_flag &= ~C_MODIFIED;
                cp->c_touch_acctime = 0;
                cp->c_touch_chgtime = 0;
                cp->c_touch_modtime = 0;
                return (0);
        }

        hfs_touchtimes(hfsmp, cp);

        /* Nothing to update. */
        if ((cp->c_flag & (C_MODIFIED | C_FORCEUPDATE)) == 0) {
                return (0);
        }
        
        if (cp->c_datafork)
                dataforkp = &cp->c_datafork->ff_data;
        if (cp->c_rsrcfork)
                rsrcforkp = &cp->c_rsrcfork->ff_data;

        /*
         * For delayed allocations updates are
         * postponed until an fsync or the file
         * gets written to disk.
         *
         * Deleted files can defer meta data updates until inactive.
         *
         * If we're ever called with the C_FORCEUPDATE flag though
         * we have to do the update.
         */
        if (ISSET(cp->c_flag, C_FORCEUPDATE) == 0 &&
            (ISSET(cp->c_flag, C_DELETED) || 
            (dataforkp && cp->c_datafork->ff_unallocblocks) ||
            (rsrcforkp && cp->c_rsrcfork->ff_unallocblocks))) {
        //      cp->c_flag &= ~(C_ACCESS | C_CHANGE | C_UPDATE);
                cp->c_flag |= C_MODIFIED;

                return (0);
        }

        if ((error = hfs_start_transaction(hfsmp)) != 0) {
            return error;
        }

        /*
         * For files with invalid ranges (holes) the on-disk
         * field representing the size of the file (cf_size)
         * must be no larger than the start of the first hole.
         */
        if (dataforkp && !TAILQ_EMPTY(&cp->c_datafork->ff_invalidranges)) {
                bcopy(dataforkp, &datafork, sizeof(datafork));
                datafork.cf_size = TAILQ_FIRST(&cp->c_datafork->ff_invalidranges)->rl_start;
                dataforkp = &datafork;
        } else if (dataforkp && (cp->c_datafork->ff_unallocblocks != 0)) {
                // always make sure the block count and the size 
                // of the file match the number of blocks actually
                // allocated to the file on disk
                bcopy(dataforkp, &datafork, sizeof(datafork));
                // make sure that we don't assign a negative block count
                if (cp->c_datafork->ff_blocks < cp->c_datafork->ff_unallocblocks) {
                    panic("hfs: ff_blocks %d is less than unalloc blocks %d\n",
                          cp->c_datafork->ff_blocks, cp->c_datafork->ff_unallocblocks);
                }
                datafork.cf_blocks = (cp->c_datafork->ff_blocks - cp->c_datafork->ff_unallocblocks);
                datafork.cf_size   = datafork.cf_blocks * HFSTOVCB(hfsmp)->blockSize;
                dataforkp = &datafork;
        }

        /*
         * For resource forks with delayed allocations, make sure
         * the block count and file size match the number of blocks
         * actually allocated to the file on disk.
         */
        if (rsrcforkp && (cp->c_rsrcfork->ff_unallocblocks != 0)) {
                bcopy(rsrcforkp, &rsrcfork, sizeof(rsrcfork));
                rsrcfork.cf_blocks = (cp->c_rsrcfork->ff_blocks - cp->c_rsrcfork->ff_unallocblocks);
                rsrcfork.cf_size   = rsrcfork.cf_blocks * HFSTOVCB(hfsmp)->blockSize;
                rsrcforkp = &rsrcfork;
        }

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

        /* XXX - waitfor is not enforced */
        error = cat_update(hfsmp, &cp->c_desc, &cp->c_attr, dataforkp, rsrcforkp);

        hfs_systemfile_unlock(hfsmp, lockflags);

        /* After the updates are finished, clear the flags */
        cp->c_flag &= ~(C_MODIFIED | C_FORCEUPDATE);

        hfs_end_transaction(hfsmp);

        return (error);
}

/*
 * Allocate a new node
 * Note - Function does not create and return a vnode for whiteout creation.
 */
static 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;

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

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

        /* 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 ((hfsmp->hfs_flags & HFS_STANDARD) && gTimeZone.tz_dsttime) {
                attr.ca_itime += 3600;  /* Same as what hfs_update does */
        }
        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 (!(hfsmp->hfs_flags & HFS_STANDARD)) {
                if (vnodetype == VDIR) {
                        if (hfsmp->hfs_flags & HFS_FOLDERCOUNT)
                                attr.ca_recflags = kHFSHasFolderCountMask;
                } else {
                        attr.ca_recflags = kHFSThreadExistsMask;
                }
        }

        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);
        }
        if (cnp->cn_flags & ISWHITEOUT)
                attr.ca_flags |= UF_OPAQUE;

        /* 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 ((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);

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

        /* Do not create vnode for whiteouts */
        if (S_ISWHT(mode)) {
                goto exit;
        }

        /*
         * 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_CREATE, &attr, NULL, &tvp);
        if (error)
                goto exit;

        cp = VTOC(tvp);
        *vpp = tvp;
exit:
        cat_releasedesc(&out_desc);
        
        /*
         * 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);
        }
        if (error == 0 && cp != NULL) {
                hfs_unlock(cp);
        }
        if (started_tr) {
            hfs_end_transaction(hfsmp);
            started_tr = 0;
        }

        return (error);
}



/* hfs_vgetrsrc acquires a resource fork vnode corresponding to the cnode that is
 * found in 'vp'.  The rsrc fork vnode is returned with the cnode locked and iocount
 * on the rsrc vnode.
 * 
 * *rvpp is an output argument for returning the pointer to the resource fork vnode.
 * In most cases, the resource fork vnode will not be set if we return an error. 
 * However, if error_on_unlinked is set, we may have already acquired the resource fork vnode
 * before we discover the error (the file has gone open-unlinked).  In this case only,
 * we may return a vnode in the output argument despite an error.
 * 
 * If can_drop_lock is set, then it is safe for this function to temporarily drop
 * and then re-acquire the cnode lock.  We may need to do this, for example, in order to 
 * acquire an iocount or promote our lock.  
 * 
 * error_on_unlinked is an argument which indicates that we are to return an error if we 
 * discover that the cnode has gone into an open-unlinked state ( C_DELETED or C_NOEXISTS)
 * is set in the cnode flags.  This is only necessary if can_drop_lock is true, otherwise 
 * there's really no reason to double-check for errors on the cnode.
 */

__private_extern__
int
hfs_vgetrsrc(struct hfsmount *hfsmp, struct vnode *vp, 
                struct vnode **rvpp, int can_drop_lock, int error_on_unlinked)
{
        struct vnode *rvp;
        struct vnode *dvp = NULLVP;
        struct cnode *cp = VTOC(vp);
        int error;
        int vid;
        int delete_status = 0;


        /*
         * Need to check the status of the cnode to validate it hasn't
         * gone open-unlinked on us before we can actually do work with it.
         */
        delete_status = hfs_checkdeleted (cp);
        if ((delete_status) && (error_on_unlinked)) {
                return delete_status;
        }

restart:
        /* Attempt to use exising vnode */
        if ((rvp = cp->c_rsrc_vp)) {
                vid = vnode_vid(rvp);

                /*
                 * It is not safe to hold the cnode lock when calling vnode_getwithvid()
                 * for the alternate fork -- vnode_getwithvid() could deadlock waiting
                 * for a VL_WANTTERM while another thread has an iocount on the alternate
                 * fork vnode and is attempting to acquire the common cnode lock.
                 *
                 * But it's also not safe to drop the cnode lock when we're holding
                 * multiple cnode locks, like during a hfs_removefile() operation
                 * since we could lock out of order when re-acquiring the cnode lock.
                 *
                 * So we can only drop the lock here if its safe to drop it -- which is
                 * most of the time with the exception being hfs_removefile().
                 */
                if (can_drop_lock)
                        hfs_unlock(cp);

                error = vnode_getwithvid(rvp, vid);

                if (can_drop_lock) {
                        (void) hfs_lock(cp, HFS_FORCE_LOCK);

                        /*
                         * When we relinquished our cnode lock, the cnode could have raced
                         * with a delete and gotten deleted.  If the caller did not want
                         * us to ignore open-unlinked files, then re-check the C_DELETED
                         * state and see if we need to return an ENOENT here because the item
                         * got deleted in the intervening time.
                         */
                        if (error_on_unlinked) {
                                if ((delete_status = hfs_checkdeleted(cp))) {
                                        /* 
                                         * If error == 0, this means that we succeeded in acquiring an iocount on the 
                                         * rsrc fork vnode.  However, if we're in this block of code, that 
                                         * means that we noticed that the cnode has gone open-unlinked.  In 
                                         * this case, the caller requested that we not do any other work and 
                                         * return an errno.  The caller will be responsible for dropping the 
                                         * iocount we just acquired because we can't do it until we've released 
                                         * the cnode lock.  
                                         */
                                        if (error == 0) {
                                                *rvpp = rvp;
                                        }
                                        return delete_status;
                                }
                        }

                        /*
                         * 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, err %d\n", name, 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;

                /*
                 * Make sure cnode lock is exclusive, if not upgrade it.
                 *
                 * We assume that we were called from a read-only VNOP (getattr)
                 * and that its safe to have the cnode lock dropped and reacquired.
                 */
                if (cp->c_lockowner != current_thread()) {
                        if (!can_drop_lock) {                           
                                return (EINVAL);
                        }
                        /*
                         * If the upgrade fails we lose the lock and
                         * have to take the exclusive lock on our own.
                         */
                        if (lck_rw_lock_shared_to_exclusive(&cp->c_rwlock) == FALSE)
                                lck_rw_lock_exclusive(&cp->c_rwlock);
                        cp->c_lockowner = current_thread();
                }

                /*
                 * 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. However,
                 * only do this if the caller did not specify that they wanted us to
                 * error out upon encountering open-unlinked files.
                 */

                if ((error_on_unlinked) && (can_drop_lock)) {
                        if ((error = hfs_checkdeleted (cp))) {
                                return error;
                        }
                }

                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);

                /* Get resource fork data */
                error = cat_lookup(hfsmp, descptr, 1, (struct cat_desc *)0,
                                (struct cat_attr *)0, &rsrcfork, NULL);

                hfs_systemfile_unlock(hfsmp, lockflags);
                if (error) {
                        return (error);
                }
                /*
                 * Supply hfs_getnewvnode with a component name. 
                 */
                cn.cn_pnbuf = NULL;
                if (descptr->cd_nameptr) {
                        MALLOC_ZONE(cn.cn_pnbuf, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK);
                        cn.cn_nameiop = LOOKUP;
                        cn.cn_flags = ISLASTCN | HASBUF;
                        cn.cn_context = NULL;
                        cn.cn_pnlen = MAXPATHLEN;
                        cn.cn_nameptr = cn.cn_pnbuf;
                        cn.cn_hash = 0;
                        cn.cn_consume = 0;
                        cn.cn_namelen = snprintf(cn.cn_nameptr, MAXPATHLEN,
                                                 "%s%s", descptr->cd_nameptr,
                                                 _PATH_RSRCFORKSPEC);
                }
                dvp = vnode_getparent(vp);
                error = hfs_getnewvnode(hfsmp, dvp, cn.cn_pnbuf ? &cn : NULL,
                                        descptr, GNV_WANTRSRC | GNV_SKIPLOCK, &cp->c_attr,
                                        &rsrcfork, &rvp);
                if (dvp)
                        vnode_put(dvp);
                if (cn.cn_pnbuf)
                        FREE_ZONE(cn.cn_pnbuf, cn.cn_pnlen, M_NAMEI);
                if (error)
                        return (error);
        }

        *rvpp = rvp;
        return (0);
}

/*
 * Wrapper for special device reads
 */
static int
hfsspec_read(ap)
        struct vnop_read_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int  a_ioflag;
                vfs_context_t a_context;
        } */ *ap;
{
        /*
         * Set access flag.
         */
        VTOC(ap->a_vp)->c_touch_acctime = TRUE;
        return (VOCALL (spec_vnodeop_p, VOFFSET(vnop_read), ap));
}

/*
 * Wrapper for special device writes
 */
static int
hfsspec_write(ap)
        struct vnop_write_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int  a_ioflag;
                vfs_context_t a_context;
        } */ *ap;
{
        /*
         * Set update and change flags.
         */
        VTOC(ap->a_vp)->c_touch_chgtime = TRUE;
        VTOC(ap->a_vp)->c_touch_modtime = TRUE;
        return (VOCALL (spec_vnodeop_p, VOFFSET(vnop_write), ap));
}

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

        if (vnode_isinuse(ap->a_vp, 0)) {
                if (hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK) == 0) {
                        cp = VTOC(vp);
                        hfs_touchtimes(VTOHFS(vp), cp);
                        hfs_unlock(cp);
                }
        }
        return (VOCALL (spec_vnodeop_p, VOFFSET(vnop_close), ap));
}

#if FIFO
/*
 * Wrapper for fifo reads
 */
static int
hfsfifo_read(ap)
        struct vnop_read_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int  a_ioflag;
                vfs_context_t a_context;
        } */ *ap;
{
        /*
         * Set access flag.
         */
        VTOC(ap->a_vp)->c_touch_acctime = TRUE;
        return (VOCALL (fifo_vnodeop_p, VOFFSET(vnop_read), ap));
}

/*
 * Wrapper for fifo writes
 */
static int
hfsfifo_write(ap)
        struct vnop_write_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int  a_ioflag;
                vfs_context_t a_context;
        } */ *ap;
{
        /*
         * Set update and change flags.
         */
        VTOC(ap->a_vp)->c_touch_chgtime = TRUE;
        VTOC(ap->a_vp)->c_touch_modtime = TRUE;
        return (VOCALL (fifo_vnodeop_p, VOFFSET(vnop_write), ap));
}

/*
 * Wrapper for fifo close
 *
 * Update the times on the cnode then do device close.
 */
static int
hfsfifo_close(ap)
        struct vnop_close_args /* {
                struct vnode *a_vp;
                int  a_fflag;
                vfs_context_t a_context;
        } */ *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) == 0) {
                        cp = VTOC(vp);
                        hfs_touchtimes(VTOHFS(vp), cp);
                        hfs_unlock(cp);
                }
        }
        return (VOCALL (fifo_vnodeop_p, VOFFSET(vnop_close), ap));
}


#endif /* FIFO */

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

        /*
         * We need to allow ENOENT lock errors since unlink
         * systenm call can call VNOP_FSYNC during vclean.
         */
        error = hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK);
        if (error)
                return (0);

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

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


static int
hfs_vnop_whiteout(ap) 
        struct vnop_whiteout_args /* {
                struct vnode *a_dvp;
                struct componentname *a_cnp;
                int a_flags;
                vfs_context_t a_context;
        } */ *ap;
{
        int error = 0;
        struct vnode *vp = NULL;
        struct vnode_attr va;
        struct vnop_lookup_args lookup_args;
        struct vnop_remove_args remove_args;
        struct hfsmount *hfsmp;

        hfsmp = VTOHFS(ap->a_dvp);
        if (hfsmp->hfs_flags & HFS_STANDARD) {
                error = ENOTSUP;
                goto exit;
        }

        switch (ap->a_flags) {
                case LOOKUP:
                        error = 0;
                        break;

                case CREATE: 
                        VATTR_INIT(&va);
                        VATTR_SET(&va, va_type, VREG);
                        VATTR_SET(&va, va_mode, S_IFWHT);
                        VATTR_SET(&va, va_uid, 0);
                        VATTR_SET(&va, va_gid, 0);
                        
                        error = hfs_makenode(ap->a_dvp, &vp, ap->a_cnp, &va, ap->a_context);
                        /* No need to release the vnode as no vnode is created for whiteouts */
                        break;

                case DELETE:
                        lookup_args.a_dvp = ap->a_dvp;
                        lookup_args.a_vpp = &vp;
                        lookup_args.a_cnp = ap->a_cnp;
                        lookup_args.a_context = ap->a_context;

                        error = hfs_vnop_lookup(&lookup_args);
                        if (error) {
                                break;
                        }
                        
                        remove_args.a_dvp = ap->a_dvp;
                        remove_args.a_vp = vp;
                        remove_args.a_cnp = ap->a_cnp;
                        remove_args.a_flags = 0;
                        remove_args.a_context = ap->a_context;

                        error = hfs_vnop_remove(&remove_args);
                        vnode_put(vp);
                        break;

                default:
                        panic("hfs_vnop_whiteout: unknown operation (flag = %x)\n", ap->a_flags);
        };
        
exit:
        return (error);
}

int (**hfs_vnodeop_p)(void *);
int (**hfs_std_vnodeop_p) (void *);

#define VOPFUNC int (*)(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) */
    { &vnop_searchfs_desc, (VOPFUNC)hfs_vnop_search },          /* search fs */
    { &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},
    { &vnop_whiteout_desc, (VOPFUNC)hfs_readonly_op},       /* whiteout (READONLY) */
#if NAMEDSTREAMS
    { &vnop_getnamedstream_desc, (VOPFUNC)hfs_vnop_getnamedstream },
    { &vnop_makenamedstream_desc, (VOPFUNC)hfs_readonly_op }, 
    { &vnop_removenamedstream_desc, (VOPFUNC)hfs_readonly_op },
#endif
    { NULL, (VOPFUNC)NULL }
};

struct vnodeopv_desc hfs_std_vnodeop_opv_desc =
{ &hfs_std_vnodeop_p, hfs_standard_vnodeop_entries };


/* 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)err_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_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 */
    { &vnop_searchfs_desc, (VOPFUNC)hfs_vnop_search },          /* search fs */
    { &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},
    { &vnop_whiteout_desc, (VOPFUNC)hfs_vnop_whiteout},
#if NAMEDSTREAMS
    { &vnop_getnamedstream_desc, (VOPFUNC)hfs_vnop_getnamedstream },
    { &vnop_makenamedstream_desc, (VOPFUNC)hfs_vnop_makenamedstream },
    { &vnop_removenamedstream_desc, (VOPFUNC)hfs_vnop_removenamedstream },
#endif
    { 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 */
        { (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 */
        { (struct vnodeop_desc*)NULL, (VOPFUNC)NULL }
};
struct vnodeopv_desc hfs_fifoop_opv_desc =
        { &hfs_fifoop_p, hfs_fifoop_entries };
#endif /* FIFO */