xnu-1228.5.20.tar.gz

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

/*
 * Copyright (c) 2002-2008 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/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/time.h>
#include <sys/ubc.h>
#include <sys/quota.h>
#include <sys/kdebug.h>

#include <kern/locks.h>

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

#include <hfs/hfs.h>
#include <hfs/hfs_catalog.h>
#include <hfs/hfs_cnode.h>
#include <hfs/hfs_quota.h>

extern int prtactive;

extern lck_attr_t *  hfs_lock_attr;
extern lck_grp_t *  hfs_mutex_group;
extern lck_grp_t *  hfs_rwlock_group;

static int  hfs_filedone(struct vnode *vp, vfs_context_t context);

static void  hfs_reclaim_cnode(struct cnode *);

static int hfs_isordered(struct cnode *, struct cnode *);


/*
 * Last reference to an cnode.  If necessary, write or delete it.
 */
__private_extern__
int
hfs_vnop_inactive(struct vnop_inactive_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct cnode *cp;
        struct hfsmount *hfsmp = VTOHFS(vp);
        struct proc *p = vfs_context_proc(ap->a_context);
        int error = 0;
        int recycle = 0;
        int forkcount = 0;
        int truncated = 0;
        int started_tr = 0;
        int took_trunc_lock = 0;
        cat_cookie_t cookie;
        int cat_reserve = 0;
        int lockflags;
        enum vtype v_type;

        v_type = vnode_vtype(vp);
        cp = VTOC(vp);

        if ((hfsmp->hfs_flags & HFS_READ_ONLY) || vnode_issystem(vp) ||
            (hfsmp->hfs_freezing_proc == p)) {
                return (0);
        }

        /*
         * Ignore nodes related to stale file handles.
         */
        if (cp->c_mode == 0) {
                vnode_recycle(vp);
                return (0);
        }

        if ((v_type == VREG || v_type == VLNK)) {
                hfs_lock_truncate(cp, TRUE);
                took_trunc_lock = 1;
        }

        (void) hfs_lock(cp, HFS_FORCE_LOCK);

        /*
         * We should lock cnode before checking the flags in the 
         * condition below and should unlock the cnode before calling 
         * ubc_setsize() as cluster code can call other HFS vnops which
         * will try to acquire the same cnode lock and cause deadlock.
         */
        if ((v_type == VREG || v_type == VLNK) &&
            (cp->c_flag & C_DELETED) &&
            (VTOF(vp)->ff_blocks != 0)) {
                hfs_unlock(cp); 
                ubc_setsize(vp, 0);
                (void) hfs_lock(cp, HFS_FORCE_LOCK);
        }

        if (v_type == VREG && !ISSET(cp->c_flag, C_DELETED) && VTOF(vp)->ff_blocks) {
                hfs_filedone(vp, ap->a_context);
        }
        /* 
         * Remove any directory hints or cached origins
         */
        if (v_type == VDIR) {
                hfs_reldirhints(cp, 0);
                if (cp->c_flag & C_HARDLINK)
                        hfs_relorigins(cp);
        }

        if (cp->c_datafork)
                ++forkcount;
        if (cp->c_rsrcfork)
                ++forkcount;

        /* If needed, get rid of any fork's data for a deleted file */
        if ((v_type == VREG || v_type == VLNK) && (cp->c_flag & C_DELETED)) {
                if (VTOF(vp)->ff_blocks != 0) {
                        /*
                         * Since we're already inside a transaction,
                         * tell hfs_truncate to skip the ubc_setsize.
                         */
                        error = hfs_truncate(vp, (off_t)0, IO_NDELAY, 1, ap->a_context);
                        if (error)
                                goto out;
                        truncated = 1;
                }
                recycle = 1;

                /*
                 * Check if there's any resource fork blocks that need to
                 * be reclaimed.  This covers the case where there is a
                 * resource fork but its not in core.
                 */
                if ((cp->c_blocks > 0) && (forkcount == 1) && (vp != cp->c_rsrc_vp)) {
                        struct vnode *rvp = NULLVP;

                        error = hfs_vgetrsrc(hfsmp, vp, &rvp, FALSE);
                        if (error)
                                goto out;
                        /*
                         * Defer the vnode_put and ubc_setsize on rvp until hfs_unlock().
                         */
                        cp->c_flag |= C_NEED_RVNODE_PUT | C_NEED_RSRC_SETSIZE;
                        error = hfs_truncate(rvp, (off_t)0, IO_NDELAY, 1, ap->a_context);
                        if (error)
                                goto out;
                        vnode_recycle(rvp);  /* all done with this vnode */
                }
        }

        // If needed, get rid of any xattrs that this file may have.
        // Note that this must happen outside of any other transactions
        // because it starts/ends its own transactions and grabs its
        // own locks.  This is to prevent a file with a lot of attributes
        // from creating a transaction that is too large (which panics).
        //
        if ((cp->c_attr.ca_recflags & kHFSHasAttributesMask) != 0 && (cp->c_flag & C_DELETED)) {
                hfs_removeallattr(hfsmp, cp->c_fileid);
        }

        /*
         * Check for a postponed deletion.
         * (only delete cnode when the last fork goes inactive)
         */
        if ((cp->c_flag & C_DELETED) && (forkcount <= 1)) {                     
                /*
                 * Mark cnode in transit so that no one can get this 
                 * cnode from cnode hash.
                 */
                // hfs_chash_mark_in_transit(cp);
                // XXXdbg - remove the cnode from the hash table since it's deleted
                //          otherwise someone could go to sleep on the cnode and not
                //          be woken up until this vnode gets recycled which could be
                //          a very long time...
                hfs_chashremove(cp);

                cp->c_flag |= C_NOEXISTS;   // XXXdbg
                cp->c_rdev = 0;

                if (started_tr == 0) {
                    if (hfs_start_transaction(hfsmp) != 0) {
                        error = EINVAL;
                        goto out;
                    }
                    started_tr = 1;
                }
                
                /*
                 * Reserve some space in the Catalog file.
                 */
                if ((error = cat_preflight(hfsmp, CAT_DELETE, &cookie, p))) {
                        goto out;
                }
                cat_reserve = 1;

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

                if (cp->c_blocks > 0) {
                        printf("hfs_inactive: deleting non-empty%sfile %d, "
                               "blks %d\n", VNODE_IS_RSRC(vp) ? " rsrc " : " ",
                               (int)cp->c_fileid, (int)cp->c_blocks);
                }

                //
                // release the name pointer in the descriptor so that
                // cat_delete() will use the file-id to do the deletion.
                // in the case of hard links this is imperative (in the
                // case of regular files the fileid and cnid are the
                // same so it doesn't matter).
                //
                cat_releasedesc(&cp->c_desc);
                
                /*
                 * The descriptor name may be zero,
                 * in which case the fileid is used.
                 */
                error = cat_delete(hfsmp, &cp->c_desc, &cp->c_attr);
                
                if (error && truncated && (error != ENXIO))
                        printf("hfs_inactive: couldn't delete a truncated file!");

                /* Update HFS Private Data dir */
                if (error == 0) {
                        hfsmp->hfs_private_attr[FILE_HARDLINKS].ca_entries--;
                        if (vnode_isdir(vp)) {
                                DEC_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);
                }

                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_mode = 0;
                cp->c_flag &= ~C_DELETED;
                cp->c_touch_chgtime = TRUE;
                cp->c_touch_modtime = TRUE;

                if (error == 0)
                        hfs_volupdate(hfsmp, (v_type == VDIR) ? VOL_RMDIR : VOL_RMFILE, 0);
        }

        /*
         * A file may have had delayed allocations, in which case hfs_update
         * would not have updated the catalog record (cat_update).  We need
         * to do that now, before we lose our fork data.  We also need to
         * force the update, or hfs_update will again skip the cat_update.
         */
        if ((cp->c_flag & C_MODIFIED) ||
            cp->c_touch_acctime || cp->c_touch_chgtime || cp->c_touch_modtime) {
                if ((cp->c_flag & C_MODIFIED) || cp->c_touch_modtime){
                        cp->c_flag |= C_FORCEUPDATE;
                }
                hfs_update(vp, 0);
        }
out:
        if (cat_reserve)
                cat_postflight(hfsmp, &cookie, p);

        // XXXdbg - have to do this because a goto could have come here
        if (started_tr) {
            hfs_end_transaction(hfsmp);
            started_tr = 0;
        }

        hfs_unlock(cp);

        if (took_trunc_lock)
            hfs_unlock_truncate(cp, TRUE);

        /*
         * If we are done with the vnode, reclaim it
         * so that it can be reused immediately.
         */
        if (cp->c_mode == 0 || recycle)
                vnode_recycle(vp);

        return (error);
}

/*
 * File clean-up (zero fill and shrink peof).
 */
static int
hfs_filedone(struct vnode *vp, vfs_context_t context)
{
        struct cnode *cp;
        struct filefork *fp;
        struct hfsmount *hfsmp;
        off_t leof;
        u_long blks, blocksize;

        cp = VTOC(vp);
        fp = VTOF(vp);
        hfsmp = VTOHFS(vp);
        leof = fp->ff_size;

        if ((hfsmp->hfs_flags & HFS_READ_ONLY) || (fp->ff_blocks == 0))
                return (0);

        hfs_unlock(cp);
        (void) cluster_push(vp, IO_CLOSE);
        hfs_lock(cp, HFS_FORCE_LOCK);

        /*
         * Explicitly zero out the areas of file
         * that are currently marked invalid.
         */
        while (!CIRCLEQ_EMPTY(&fp->ff_invalidranges)) {
                struct rl_entry *invalid_range = CIRCLEQ_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);

                hfs_unlock(cp);
                (void) cluster_write(vp, (struct uio *) 0,
                                     leof, end + 1, start, (off_t)0,
                                     IO_HEADZEROFILL | IO_NOZERODIRTY | IO_NOCACHE);
                hfs_lock(cp, HFS_FORCE_LOCK);
                cp->c_flag |= C_MODIFIED;
        }
        cp->c_flag &= ~C_ZFWANTSYNC;
        cp->c_zftimeout = 0;
        blocksize = VTOVCB(vp)->blockSize;
        blks = leof / blocksize;
        if (((off_t)blks * (off_t)blocksize) != leof)
                blks++;
        /*
         * Shrink the peof to the smallest size neccessary to contain the leof.
         */
        if (blks < fp->ff_blocks)
                (void) hfs_truncate(vp, leof, IO_NDELAY, 0, context);
        hfs_unlock(cp);
        (void) cluster_push(vp, IO_CLOSE);
        hfs_lock(cp, HFS_FORCE_LOCK);
        
        /*
         * If the hfs_truncate didn't happen to flush the vnode's
         * information out to disk, force it to be updated now that
         * all invalid ranges have been zero-filled and validated:
         */
        if (cp->c_flag & C_MODIFIED) {
                hfs_update(vp, 0);
        }
        return (0);
}


/*
 * Reclaim a cnode so that it can be used for other purposes.
 */
__private_extern__
int
hfs_vnop_reclaim(struct vnop_reclaim_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct cnode *cp;
        struct filefork *fp = NULL;
        struct filefork *altfp = NULL;
        int reclaim_cnode = 0;

        (void) hfs_lock(VTOC(vp), HFS_FORCE_LOCK);
        cp = VTOC(vp);

        /*
         * Check if a deleted resource fork vnode missed a
         * VNOP_INACTIVE call and requires truncation.
         */
        if (VNODE_IS_RSRC(vp) &&
            (cp->c_flag & C_DELETED) &&
            (VTOF(vp)->ff_blocks != 0)) {
                hfs_unlock(cp);
                ubc_setsize(vp, 0);

                hfs_lock_truncate(cp, TRUE);
                (void) hfs_lock(VTOC(vp), HFS_FORCE_LOCK);

                (void) hfs_truncate(vp, (off_t)0, IO_NDELAY, 1, ap->a_context);

                hfs_unlock_truncate(cp, TRUE);
        }
        /*
         * A file may have had delayed allocations, in which case hfs_update
         * would not have updated the catalog record (cat_update).  We need
         * to do that now, before we lose our fork data.  We also need to
         * force the update, or hfs_update will again skip the cat_update.
         */
        if ((cp->c_flag & C_MODIFIED) ||
                cp->c_touch_acctime || cp->c_touch_chgtime || cp->c_touch_modtime) {
                if ((cp->c_flag & C_MODIFIED) || cp->c_touch_modtime){
                        cp->c_flag |= C_FORCEUPDATE;
                }       
                hfs_update(vp, 0);
        }

        /*
         * Keep track of an inactive hot file.
         */
        if (!vnode_isdir(vp) &&
            !vnode_issystem(vp) &&
            !(cp->c_flag & (C_DELETED | C_NOEXISTS)) ) {
                (void) hfs_addhotfile(vp);
        }
        vnode_removefsref(vp);

        /*
         * Find file fork for this vnode (if any)
         * Also check if another fork is active
         */
        if (cp->c_vp == vp) {
                fp = cp->c_datafork;
                altfp = cp->c_rsrcfork;

                cp->c_datafork = NULL;
                cp->c_vp = NULL;
        } else if (cp->c_rsrc_vp == vp) {
                fp = cp->c_rsrcfork;
                altfp = cp->c_datafork;

                cp->c_rsrcfork = NULL;
                cp->c_rsrc_vp = NULL;
        } else {
                panic("hfs_vnop_reclaim: vp points to wrong cnode\n");
        }
        /*
         * On the last fork, remove the cnode from its hash chain.
         */
        if (altfp == NULL) {
                /* If we can't remove it then the cnode must persist! */
                if (hfs_chashremove(cp) == 0)
                        reclaim_cnode = 1;
                /* 
                 * Remove any directory hints
                 */
                if (vnode_isdir(vp)) {
                        hfs_reldirhints(cp, 0);
                }
        }
        /* Release the file fork and related data */
        if (fp) {
                /* Dump cached symlink data */
                if (vnode_islnk(vp) && (fp->ff_symlinkptr != NULL)) {
                        FREE(fp->ff_symlinkptr, M_TEMP);
                }               
                FREE_ZONE(fp, sizeof(struct filefork), M_HFSFORK);
        }

        /* 
         * If there was only one active fork then we can release the cnode.
         */
        if (reclaim_cnode) {
                hfs_chashwakeup(cp, H_ALLOC | H_TRANSIT);
                hfs_reclaim_cnode(cp);
        } else /* cnode in use */ {
                hfs_unlock(cp);
        }

        vnode_clearfsnode(vp);
        return (0);
}


extern int (**hfs_vnodeop_p) (void *);
extern int (**hfs_specop_p)  (void *);
#if FIFO
extern int (**hfs_fifoop_p)  (void *);
#endif

/*
 * hfs_getnewvnode - get new default vnode
 *
 * The vnode is returned with an iocount and the cnode locked
 */
__private_extern__
int
hfs_getnewvnode(
        struct hfsmount *hfsmp,
        struct vnode *dvp,
        struct componentname *cnp,
        struct cat_desc *descp,
        int flags,
        struct cat_attr *attrp,
        struct cat_fork *forkp,
        struct vnode **vpp)
{
        struct mount *mp = HFSTOVFS(hfsmp);
        struct vnode *vp = NULL;
        struct vnode **cvpp;
        struct vnode *tvp = NULLVP;
        struct cnode *cp = NULL;
        struct filefork *fp = NULL;
        int retval;
        int issystemfile;
        int wantrsrc;
        struct vnode_fsparam vfsp;
        enum vtype vtype;
#if QUOTA
        int i;
#endif /* QUOTA */

        if (attrp->ca_fileid == 0) {
                *vpp = NULL;
                return (ENOENT);
        }

#if !FIFO
        if (IFTOVT(attrp->ca_mode) == VFIFO) {
                *vpp = NULL;
                return (ENOTSUP);
        }
#endif /* !FIFO */
        vtype = IFTOVT(attrp->ca_mode);
        issystemfile = (descp->cd_flags & CD_ISMETA) && (vtype == VREG);
        wantrsrc = flags & GNV_WANTRSRC;

#ifdef HFS_CHECK_LOCK_ORDER
        /*
         * The only case were its permissible to hold the parent cnode
         * lock is during a create operation (hfs_makenode) or when
         * we don't need the cnode lock (GNV_SKIPLOCK).
         */
        if ((dvp != NULL) &&
            (flags & (GNV_CREATE | GNV_SKIPLOCK)) == 0 &&
            VTOC(dvp)->c_lockowner == current_thread()) {
                panic("hfs_getnewvnode: unexpected hold of parent cnode %p", VTOC(dvp));
        }
#endif /* HFS_CHECK_LOCK_ORDER */

        /*
         * Get a cnode (new or existing)
         */
        cp = hfs_chash_getcnode(hfsmp->hfs_raw_dev, attrp->ca_fileid, vpp, wantrsrc, (flags & GNV_SKIPLOCK));

        /*
         * If the id is no longer valid for lookups we'll get back a NULL cp.
         */
        if (cp == NULL) {
                return (ENOENT);
        }

        /* Hardlinks may need an updated catalog descriptor */
        if ((cp->c_flag & C_HARDLINK) && descp->cd_nameptr && descp->cd_namelen > 0) {
                replace_desc(cp, descp);
        }
        /* Check if we found a matching vnode */
        if (*vpp != NULL)
                return (0);

        /*
         * If this is a new cnode then initialize it.
         */
        if (ISSET(cp->c_hflag, H_ALLOC)) {
                lck_rw_init(&cp->c_truncatelock, hfs_rwlock_group, hfs_lock_attr);

                /* Make sure its still valid (ie exists on disk). */
                if (!(flags & GNV_CREATE) &&
                    !hfs_valid_cnode(hfsmp, dvp, (wantrsrc ? NULL : cnp), cp->c_fileid)) {
                        hfs_chash_abort(cp);
                        hfs_reclaim_cnode(cp);
                        *vpp = NULL;
                        return (ENOENT);
                }
                bcopy(attrp, &cp->c_attr, sizeof(struct cat_attr));
                bcopy(descp, &cp->c_desc, sizeof(struct cat_desc));

                /* The name was inherited so clear descriptor state... */
                descp->cd_namelen = 0;
                descp->cd_nameptr = NULL;
                descp->cd_flags &= ~CD_HASBUF;

                /* Tag hardlinks */
                if ((vtype == VREG || vtype == VDIR) &&
                    ((descp->cd_cnid != attrp->ca_fileid) ||
                     (attrp->ca_recflags & kHFSHasLinkChainMask))) {
                        cp->c_flag |= C_HARDLINK;
                }
                /*
                 * Fix-up dir link counts.
                 *
                 * Earlier versions of Leopard used ca_linkcount for posix
                 * nlink support (effectively the sub-directory count + 2).
                 * That is now accomplished using the ca_dircount field with
                 * the corresponding kHFSHasFolderCountMask flag.
                 *
                 * For directories the ca_linkcount is the true link count,
                 * tracking the number of actual hardlinks to a directory.
                 *
                 * We only do this if the mount has HFS_FOLDERCOUNT set;
                 * at the moment, we only set that for HFSX volumes.
                 */
                if ((hfsmp->hfs_flags & HFS_FOLDERCOUNT) && 
                    (vtype == VDIR) &&
                    !(attrp->ca_recflags & kHFSHasFolderCountMask) &&
                    (cp->c_attr.ca_linkcount > 1)) {
                        if (cp->c_attr.ca_entries == 0)
                                cp->c_attr.ca_dircount = 0;
                        else
                                cp->c_attr.ca_dircount = cp->c_attr.ca_linkcount - 2;

                        cp->c_attr.ca_linkcount = 1;
                        cp->c_attr.ca_recflags |= kHFSHasFolderCountMask;
                        if ( !(hfsmp->hfs_flags & HFS_READ_ONLY) )
                                cp->c_flag |= C_MODIFIED;
                }
#if QUOTA
                if (hfsmp->hfs_flags & HFS_QUOTAS) {
                        for (i = 0; i < MAXQUOTAS; i++)
                                cp->c_dquot[i] = NODQUOT;
                }
#endif /* QUOTA */
        }

        if (vtype == VDIR) {
                if (cp->c_vp != NULL)
                        panic("hfs_getnewvnode: orphaned vnode (data)");
                cvpp = &cp->c_vp;
        } else {
                if (forkp && attrp->ca_blocks < forkp->cf_blocks)
                        panic("hfs_getnewvnode: bad ca_blocks (too small)");
                /*
                 * Allocate and initialize a file fork...
                 */
                MALLOC_ZONE(fp, struct filefork *, sizeof(struct filefork),
                        M_HFSFORK, M_WAITOK);
                fp->ff_cp = cp;
                if (forkp)
                        bcopy(forkp, &fp->ff_data, sizeof(struct cat_fork));
                else
                        bzero(&fp->ff_data, sizeof(struct cat_fork));
                rl_init(&fp->ff_invalidranges);
                fp->ff_sysfileinfo = 0;

                if (wantrsrc) {
                        if (cp->c_rsrcfork != NULL)
                                panic("hfs_getnewvnode: orphaned rsrc fork");
                        if (cp->c_rsrc_vp != NULL)
                                panic("hfs_getnewvnode: orphaned vnode (rsrc)");
                        cp->c_rsrcfork = fp;
                        cvpp = &cp->c_rsrc_vp;
                        if ( (tvp = cp->c_vp) != NULLVP )
                                cp->c_flag |= C_NEED_DVNODE_PUT;
                } else {
                        if (cp->c_datafork != NULL)
                                panic("hfs_getnewvnode: orphaned data fork");
                        if (cp->c_vp != NULL)
                                panic("hfs_getnewvnode: orphaned vnode (data)");
                        cp->c_datafork = fp;
                        cvpp = &cp->c_vp;
                        if ( (tvp = cp->c_rsrc_vp) != NULLVP)
                                cp->c_flag |= C_NEED_RVNODE_PUT;
                }
        }
        if (tvp != NULLVP) {
                /*
                 * grab an iocount on the vnode we weren't
                 * interested in (i.e. we want the resource fork
                 * but the cnode already has the data fork)
                 * to prevent it from being
                 * recycled by us when we call vnode_create
                 * which will result in a deadlock when we
                 * try to take the cnode lock in hfs_vnop_fsync or
                 * hfs_vnop_reclaim... vnode_get can be called here
                 * because we already hold the cnode lock which will
                 * prevent the vnode from changing identity until
                 * we drop it.. vnode_get will not block waiting for
                 * a change of state... however, it will return an
                 * error if the current iocount == 0 and we've already
                 * started to terminate the vnode... we don't need/want to
                 * grab an iocount in the case since we can't cause
                 * the fileystem to be re-entered on this thread for this vp
                 *
                 * the matching vnode_put will happen in hfs_unlock
                 * after we've dropped the cnode lock
                 */
                if ( vnode_get(tvp) != 0)
                        cp->c_flag &= ~(C_NEED_RVNODE_PUT | C_NEED_DVNODE_PUT);
        }
        vfsp.vnfs_mp = mp;
        vfsp.vnfs_vtype = vtype;
        vfsp.vnfs_str = "hfs";
        if ((cp->c_flag & C_HARDLINK) && (vtype == VDIR)) {
                vfsp.vnfs_dvp = NULL;  /* no parent for me! */
                vfsp.vnfs_cnp = NULL;  /* no name for me! */
        } else {
                vfsp.vnfs_dvp = dvp;
                vfsp.vnfs_cnp = cnp;
        }
        vfsp.vnfs_fsnode = cp;
#if FIFO
        if (vtype == VFIFO )
                vfsp.vnfs_vops = hfs_fifoop_p;
        else
#endif
        if (vtype == VBLK || vtype == VCHR)
                vfsp.vnfs_vops = hfs_specop_p;
        else
                vfsp.vnfs_vops = hfs_vnodeop_p;
                
        if (vtype == VBLK || vtype == VCHR)
                vfsp.vnfs_rdev = attrp->ca_rdev;
        else
                vfsp.vnfs_rdev = 0;

        if (forkp) 
                vfsp.vnfs_filesize = forkp->cf_size;
        else
                vfsp.vnfs_filesize = 0;

        vfsp.vnfs_flags = VNFS_ADDFSREF;
        if (dvp == NULLVP || cnp == NULL || !(cnp->cn_flags & MAKEENTRY))
                vfsp.vnfs_flags |= VNFS_NOCACHE;

        /* Tag system files */
        vfsp.vnfs_marksystem = issystemfile;

        /* Tag root directory */
        if (descp->cd_cnid == kHFSRootFolderID)
                vfsp.vnfs_markroot = 1;
        else    
                vfsp.vnfs_markroot = 0;

        if ((retval = vnode_create(VNCREATE_FLAVOR, VCREATESIZE, &vfsp, cvpp))) {
                if (fp) {
                        if (fp == cp->c_datafork)
                                cp->c_datafork = NULL;
                        else
                                cp->c_rsrcfork = NULL;

                        FREE_ZONE(fp, sizeof(struct filefork), M_HFSFORK);
                }
                /*
                 * If this is a newly created cnode or a vnode reclaim
                 * occurred during the attachment, then cleanup the cnode.
                 */
                if ((cp->c_vp == NULL) && (cp->c_rsrc_vp == NULL)) {
                        hfs_chash_abort(cp);
                        hfs_reclaim_cnode(cp);
                } 
                else {
                        hfs_chashwakeup(cp, H_ALLOC | H_ATTACH);
                        if ((flags & GNV_SKIPLOCK) == 0){
                                hfs_unlock(cp);
                        }
                }
                *vpp = NULL;
                return (retval);
        }
        vp = *cvpp;
        vnode_settag(vp, VT_HFS);
        if (cp->c_flag & C_HARDLINK) {
                vnode_setmultipath(vp);
        }
        /*
         * Tag resource fork vnodes as needing an VNOP_INACTIVE
         * so that any deferred removes (open unlinked files)
         * have the chance to process the resource fork.
         */
        if (VNODE_IS_RSRC(vp)) {
                /* Force VL_NEEDINACTIVE on this vnode */
                vnode_ref(vp);
                vnode_rele(vp);
        }
        hfs_chashwakeup(cp, H_ALLOC | H_ATTACH);

        /*
         * Stop tracking an active hot file.
         */
        if (!(flags & GNV_CREATE) && (vtype != VDIR) && !issystemfile) {
                (void) hfs_removehotfile(vp);
        }

        *vpp = vp;
        return (0);
}


static void
hfs_reclaim_cnode(struct cnode *cp)
{
#if QUOTA
        int i;

        for (i = 0; i < MAXQUOTAS; i++) {
                if (cp->c_dquot[i] != NODQUOT) {
                        dqreclaim(cp->c_dquot[i]);
                        cp->c_dquot[i] = NODQUOT;
                }
        }
#endif /* QUOTA */

        /* 
         * If the descriptor has a name then release it
         */
        if ((cp->c_desc.cd_flags & CD_HASBUF) && (cp->c_desc.cd_nameptr != 0)) {
                const char *nameptr;

                nameptr = (const char *) cp->c_desc.cd_nameptr;
                cp->c_desc.cd_nameptr = 0;
                cp->c_desc.cd_flags &= ~CD_HASBUF;
                cp->c_desc.cd_namelen = 0;
                vfs_removename(nameptr);
        }

        lck_rw_destroy(&cp->c_rwlock, hfs_rwlock_group);
        lck_rw_destroy(&cp->c_truncatelock, hfs_rwlock_group);
        bzero(cp, sizeof(struct cnode));
        FREE_ZONE(cp, sizeof(struct cnode), M_HFSNODE);
}


__private_extern__
int
hfs_valid_cnode(struct hfsmount *hfsmp, struct vnode *dvp, struct componentname *cnp, cnid_t cnid)
{
        struct cat_attr attr;
        struct cat_desc cndesc;
        int stillvalid = 0;
        int lockflags;

        /* System files are always valid */
        if (cnid < kHFSFirstUserCatalogNodeID)
                return (1);

        /* XXX optimization:  check write count in dvp */

        lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG, HFS_SHARED_LOCK);

        if (dvp && cnp) {
                bzero(&cndesc, sizeof(cndesc));
                cndesc.cd_nameptr = (const u_int8_t *)cnp->cn_nameptr;
                cndesc.cd_namelen = cnp->cn_namelen;
                cndesc.cd_parentcnid = VTOC(dvp)->c_fileid;
                cndesc.cd_hint = VTOC(dvp)->c_childhint;

                if ((cat_lookup(hfsmp, &cndesc, 0, NULL, &attr, NULL, NULL) == 0) &&
                    (cnid == attr.ca_fileid)) {
                        stillvalid = 1;
                }
        } else {
                if (cat_idlookup(hfsmp, cnid, 0, NULL, NULL, NULL) == 0) {
                        stillvalid = 1;
                }
        }
        hfs_systemfile_unlock(hfsmp, lockflags);

        return (stillvalid);
}

/*
 * Touch cnode times based on c_touch_xxx flags
 *
 * cnode must be locked exclusive
 *
 * This will also update the volume modify time
 */
__private_extern__
void
hfs_touchtimes(struct hfsmount *hfsmp, struct cnode* cp)
{
        /* don't modify times if volume is read-only */
        if (hfsmp->hfs_flags & HFS_READ_ONLY) {
                cp->c_touch_acctime = FALSE;
                cp->c_touch_chgtime = FALSE;
                cp->c_touch_modtime = FALSE;
        }
        else if (hfsmp->hfs_flags & HFS_STANDARD) {
        /* HFS Standard doesn't support access times */
                cp->c_touch_acctime = FALSE;
        }

        /*
         * Skip access time updates if:
         *      . MNT_NOATIME is set
         *      . a file system freeze is in progress
         *      . a file system resize is in progress
         */
        if (cp->c_touch_acctime) {
                if ((vfs_flags(hfsmp->hfs_mp) & MNT_NOATIME) ||
                    (hfsmp->hfs_freezing_proc != NULL) ||
                    (hfsmp->hfs_flags & HFS_RESIZE_IN_PROGRESS))
                        cp->c_touch_acctime = FALSE;
        }
        if (cp->c_touch_acctime || cp->c_touch_chgtime || cp->c_touch_modtime) {
                struct timeval tv;
                int touchvol = 0;

                microtime(&tv);
                    
                if (cp->c_touch_acctime) {
                        cp->c_atime = tv.tv_sec;
                        /*
                         * When the access time is the only thing changing
                         * then make sure its sufficiently newer before
                         * committing it to disk.
                         */
                        if ((((u_int32_t)cp->c_atime - (u_int32_t)(cp)->c_attr.ca_atimeondisk) >
                              ATIME_ONDISK_ACCURACY)) {
                                cp->c_flag |= C_MODIFIED;
                        }
                        cp->c_touch_acctime = FALSE;
                }
                if (cp->c_touch_modtime) {
                        cp->c_mtime = tv.tv_sec;
                        cp->c_touch_modtime = FALSE;
                        cp->c_flag |= C_MODIFIED;
                        touchvol = 1;
#if 1
                        /*
                         * HFS dates that WE set must be adjusted for DST
                         */
                        if ((hfsmp->hfs_flags & HFS_STANDARD) && gTimeZone.tz_dsttime) {
                                cp->c_mtime += 3600;
                        }
#endif
                }
                if (cp->c_touch_chgtime) {
                        cp->c_ctime = tv.tv_sec;
                        cp->c_touch_chgtime = FALSE;
                        cp->c_flag |= C_MODIFIED;
                        touchvol = 1;
                }

                /* Touch the volume modtime if needed */
                if (touchvol) {
                        MarkVCBDirty(hfsmp);
                        HFSTOVCB(hfsmp)->vcbLsMod = tv.tv_sec;
                }
        }
}

/*
 * Lock a cnode.
 */
__private_extern__
int
hfs_lock(struct cnode *cp, enum hfslocktype locktype)
{
        void * thread = current_thread();

        if (cp->c_lockowner == thread) {
                /*
                 * Only the extents and bitmap file's support lock recursion.
                 */
                if ((cp->c_fileid == kHFSExtentsFileID) ||
                    (cp->c_fileid == kHFSAllocationFileID)) {
                        cp->c_syslockcount++;
                } else {
                        panic("hfs_lock: locking against myself!");
                }
        } else if (locktype == HFS_SHARED_LOCK) {
                lck_rw_lock_shared(&cp->c_rwlock);
                cp->c_lockowner = HFS_SHARED_OWNER;

        } else /* HFS_EXCLUSIVE_LOCK */ {
                lck_rw_lock_exclusive(&cp->c_rwlock);
                cp->c_lockowner = thread;

                /*
                 * Only the extents and bitmap file's support lock recursion.
                 */
                if ((cp->c_fileid == kHFSExtentsFileID) ||
                    (cp->c_fileid == kHFSAllocationFileID)) {
                        cp->c_syslockcount = 1;
                }
        }

#ifdef HFS_CHECK_LOCK_ORDER
        /*
         * Regular cnodes (non-system files) cannot be locked
         * while holding the journal lock or a system file lock.
         */
        if (!(cp->c_desc.cd_flags & CD_ISMETA) &&
            ((cp->c_fileid > kHFSFirstUserCatalogNodeID) || (cp->c_fileid == kHFSRootFolderID))) {
                vnode_t vp = NULLVP;

                /* Find corresponding vnode. */
                if (cp->c_vp != NULLVP && VTOC(cp->c_vp) == cp) {
                        vp = cp->c_vp;
                } else if (cp->c_rsrc_vp != NULLVP && VTOC(cp->c_rsrc_vp) == cp) {
                        vp = cp->c_rsrc_vp;
                }
                if (vp != NULLVP) {
                        struct hfsmount *hfsmp = VTOHFS(vp);

                        if (hfsmp->jnl && (journal_owner(hfsmp->jnl) == thread)) {
                                /* This will eventually be a panic here. */
                                printf("hfs_lock: bad lock order (cnode after journal)\n");
                        }
                        if (hfsmp->hfs_catalog_cp && hfsmp->hfs_catalog_cp->c_lockowner == thread) {
                                panic("hfs_lock: bad lock order (cnode after catalog)");
                        }
                        if (hfsmp->hfs_attribute_cp && hfsmp->hfs_attribute_cp->c_lockowner == thread) {
                                panic("hfs_lock: bad lock order (cnode after attribute)");
                        }
                        if (hfsmp->hfs_extents_cp && hfsmp->hfs_extents_cp->c_lockowner == thread) {
                                panic("hfs_lock: bad lock order (cnode after extents)");
                        }
                }
        }
#endif /* HFS_CHECK_LOCK_ORDER */
        
        /*
         * Skip cnodes that no longer exist (were deleted).
         */
        if ((locktype != HFS_FORCE_LOCK) &&
            ((cp->c_desc.cd_flags & CD_ISMETA) == 0) &&
            (cp->c_flag & C_NOEXISTS)) {
                hfs_unlock(cp);
                return (ENOENT);
        }
        return (0);
}

/*
 * Lock a pair of cnodes.
 */
__private_extern__
int
hfs_lockpair(struct cnode *cp1, struct cnode *cp2, enum hfslocktype locktype)
{
        struct cnode *first, *last;
        int error;

        /*
         * If cnodes match then just lock one.
         */
        if (cp1 == cp2) {
                return hfs_lock(cp1, locktype);
        }

        /*
         * Lock in cnode address order.
         */
        if (cp1 < cp2) {
                first = cp1;
                last = cp2;
        } else {
                first = cp2;
                last = cp1;
        }

        if ( (error = hfs_lock(first, locktype))) {
                return (error);
        }
        if ( (error = hfs_lock(last, locktype))) {
                hfs_unlock(first);
                return (error);
        }
        return (0);
}

/*
 * Check ordering of two cnodes. Return true if they are are in-order.
 */
static int
hfs_isordered(struct cnode *cp1, struct cnode *cp2)
{
        if (cp1 == cp2)
                return (0);
        if (cp1 == NULL || cp2 == (struct cnode *)0xffffffff)
                return (1);
        if (cp2 == NULL || cp1 == (struct cnode *)0xffffffff)
                return (0);
        /*
         * Locking order is cnode address order.
         */
        return (cp1 < cp2);
}

/*
 * Acquire 4 cnode locks.
 *   - locked in cnode address order (lesser address first).
 *   - all or none of the locks are taken
 *   - only one lock taken per cnode (dup cnodes are skipped)
 *   - some of the cnode pointers may be null
 */
__private_extern__
int
hfs_lockfour(struct cnode *cp1, struct cnode *cp2, struct cnode *cp3,
             struct cnode *cp4, enum hfslocktype locktype)
{
        struct cnode * a[3];
        struct cnode * b[3];
        struct cnode * list[4];
        struct cnode * tmp;
        int i, j, k;
        int error;

        if (hfs_isordered(cp1, cp2)) {
                a[0] = cp1; a[1] = cp2;
        } else {
                a[0] = cp2; a[1] = cp1;
        }
        if (hfs_isordered(cp3, cp4)) {
                b[0] = cp3; b[1] = cp4;
        } else {
                b[0] = cp4; b[1] = cp3;
        }
        a[2] = (struct cnode *)0xffffffff;  /* sentinel value */
        b[2] = (struct cnode *)0xffffffff;  /* sentinel value */

        /*
         * Build the lock list, skipping over duplicates
         */
        for (i = 0, j = 0, k = 0; (i < 2 || j < 2); ) {
                tmp = hfs_isordered(a[i], b[j]) ? a[i++] : b[j++];
                if (k == 0 || tmp != list[k-1])
                        list[k++] = tmp;
        }

        /*
         * Now we can lock using list[0 - k].
         * Skip over NULL entries.
         */
        for (i = 0; i < k; ++i) {
                if (list[i])
                        if ((error = hfs_lock(list[i], locktype))) {
                                /* Drop any locks we acquired. */
                                while (--i >= 0) {
                                        if (list[i])
                                                hfs_unlock(list[i]);
                                }
                                return (error);
                        }
        }
        return (0);
}


/*
 * Unlock a cnode.
 */
__private_extern__
void
hfs_unlock(struct cnode *cp)
{
        vnode_t rvp = NULLVP;
        vnode_t vp = NULLVP;
        u_int32_t c_flag;
        void *lockowner;

        /*
         * Only the extents and bitmap file's support lock recursion.
         */
        if ((cp->c_fileid == kHFSExtentsFileID) ||
            (cp->c_fileid == kHFSAllocationFileID)) {
                if (--cp->c_syslockcount > 0) {
                        return;
                }
        }
        c_flag = cp->c_flag;
        cp->c_flag &= ~(C_NEED_DVNODE_PUT | C_NEED_RVNODE_PUT | C_NEED_DATA_SETSIZE | C_NEED_RSRC_SETSIZE);

        if (c_flag & (C_NEED_DVNODE_PUT | C_NEED_DATA_SETSIZE)) {
                vp = cp->c_vp;
        }
        if (c_flag & (C_NEED_RVNODE_PUT | C_NEED_RSRC_SETSIZE)) {
                rvp = cp->c_rsrc_vp;
        }

        lockowner = cp->c_lockowner;
        if (lockowner == current_thread()) {
            cp->c_lockowner = NULL;
            lck_rw_unlock_exclusive(&cp->c_rwlock);
        } else {
            lck_rw_unlock_shared(&cp->c_rwlock);
        }

        /* Perform any vnode post processing after cnode lock is dropped. */
        if (vp) {
                if (c_flag & C_NEED_DATA_SETSIZE)
                        ubc_setsize(vp, 0);
                if (c_flag & C_NEED_DVNODE_PUT)
                        vnode_put(vp);
        }
        if (rvp) {
                if (c_flag & C_NEED_RSRC_SETSIZE)
                        ubc_setsize(rvp, 0);
                if (c_flag & C_NEED_RVNODE_PUT)
                        vnode_put(rvp);
        }
}

/*
 * Unlock a pair of cnodes.
 */
__private_extern__
void
hfs_unlockpair(struct cnode *cp1, struct cnode *cp2)
{
        hfs_unlock(cp1);
        if (cp2 != cp1)
                hfs_unlock(cp2);
}

/*
 * Unlock a group of cnodes.
 */
__private_extern__
void
hfs_unlockfour(struct cnode *cp1, struct cnode *cp2, struct cnode *cp3, struct cnode *cp4)
{
        struct cnode * list[4];
        int i, k = 0;

        if (cp1) {
                hfs_unlock(cp1);
                list[k++] = cp1;
        }
        if (cp2) {
                for (i = 0; i < k; ++i) {
                        if (list[i] == cp2)
                                goto skip1;
                }
                hfs_unlock(cp2);
                list[k++] = cp2;
        }
skip1:
        if (cp3) {
                for (i = 0; i < k; ++i) {
                        if (list[i] == cp3)
                                goto skip2;
                }
                hfs_unlock(cp3);
                list[k++] = cp3;
        }
skip2:
        if (cp4) {
                for (i = 0; i < k; ++i) {
                        if (list[i] == cp4)
                                return;
                }
                hfs_unlock(cp4);
        }
}


/*
 * Protect a cnode against a truncation.
 *
 * Used mainly by read/write since they don't hold the
 * cnode lock across calls to the cluster layer.
 *
 * The process doing a truncation must take the lock
 * exclusive. The read/write processes can take it
 * non-exclusive.
 */
__private_extern__
void
hfs_lock_truncate(struct cnode *cp, int exclusive)
{
#ifdef HFS_CHECK_LOCK_ORDER
        if (cp->c_lockowner == current_thread())
                panic("hfs_lock_truncate: cnode %p locked!", cp);
#endif /* HFS_CHECK_LOCK_ORDER */

        if (exclusive)
                lck_rw_lock_exclusive(&cp->c_truncatelock);
        else
                lck_rw_lock_shared(&cp->c_truncatelock);
}

__private_extern__
void
hfs_unlock_truncate(struct cnode *cp, int exclusive)
{
    if (exclusive) {
        lck_rw_unlock_exclusive(&cp->c_truncatelock);
    } else {
        lck_rw_unlock_shared(&cp->c_truncatelock);
    }
}