xnu-517.3.15.tar.gz

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

/*
 * Copyright (c) 1999-2003 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * 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. 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_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1991, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      hfs_vfsops.c
 *  derived from        @(#)ufs_vfsops.c        8.8 (Berkeley) 5/20/95
 *
 *      (c) Copyright 1997-2002 Apple Computer, Inc. All rights reserved.
 *
 *      hfs_vfsops.c -- VFS layer for loadable HFS file system.
 *
 */
#include <sys/param.h>
#include <sys/systm.h>

#include <sys/ubc.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/stat.h>
#include <sys/lock.h>
#include <sys/quota.h>
#include <sys/disk.h>
#include <sys/paths.h>
#include <sys/utfconv.h>

// XXXdbg
#include <vfs/vfs_journal.h>

#include <miscfs/specfs/specdev.h>
#include <hfs/hfs_mount.h>

#include "hfs.h"
#include "hfs_catalog.h"
#include "hfs_cnode.h"
#include "hfs_dbg.h"
#include "hfs_endian.h"
#include "hfs_quota.h"

#include "hfscommon/headers/FileMgrInternal.h"
#include "hfscommon/headers/BTreesInternal.h"


#if     HFS_DIAGNOSTIC
int hfs_dbg_all = 0;
int hfs_dbg_err = 0;
#endif


extern struct vnodeopv_desc hfs_vnodeop_opv_desc;

extern void hfs_converterinit(void);

extern void inittodr( time_t base);


static int hfs_changefs __P((struct mount *mp, struct hfs_mount_args *args,
                struct proc *p));
static int hfs_reload __P((struct mount *mp, struct ucred *cred, struct proc *p));

static int hfs_mountfs __P((struct vnode *devvp, struct mount *mp, struct proc *p,
                struct hfs_mount_args *args));
static int hfs_statfs __P((struct mount *mp, register struct statfs *sbp,
                struct proc *p));
static int hfs_flushfiles __P((struct mount *, int, struct proc *));

static int hfs_extendfs __P((struct mount *, u_int64_t, struct proc *));

/*
 * Called by vfs_mountroot when mounting HFS Plus as root.
 */
__private_extern__
int
hfs_mountroot()
{
        extern struct vnode *rootvp;
        struct mount *mp;
        struct proc *p = current_proc();        /* XXX */
        struct hfsmount *hfsmp;
        ExtendedVCB *vcb;
        int error;
        
        /*
         * Get vnode for rootdev.
         */
        if ((error = bdevvp(rootdev, &rootvp))) {
                printf("hfs_mountroot: can't setup bdevvp");
                return (error);
        }
        if ((error = vfs_rootmountalloc("hfs", "root_device", &mp))) {
                vrele(rootvp); /* release the reference from bdevvp() */
                return (error);
        }
        if ((error = hfs_mountfs(rootvp, mp, p, NULL))) {
                mp->mnt_vfc->vfc_refcount--;

                if (mp->mnt_kern_flag & MNTK_IO_XINFO)
                        FREE(mp->mnt_xinfo_ptr, M_TEMP);
                vfs_unbusy(mp, p);

                vrele(rootvp); /* release the reference from bdevvp() */
                FREE_ZONE(mp, sizeof (struct mount), M_MOUNT);
                return (error);
        }
        simple_lock(&mountlist_slock);
        CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list);
        simple_unlock(&mountlist_slock);
        
        /* Init hfsmp */
        hfsmp = VFSTOHFS(mp);

        hfsmp->hfs_uid = UNKNOWNUID;
        hfsmp->hfs_gid = UNKNOWNGID;
        hfsmp->hfs_dir_mask = (S_IRWXU | S_IRGRP|S_IXGRP | S_IROTH|S_IXOTH); /* 0755 */
        hfsmp->hfs_file_mask = (S_IRWXU | S_IRGRP|S_IXGRP | S_IROTH|S_IXOTH); /* 0755 */

        /* Establish the free block reserve. */
        vcb = HFSTOVCB(hfsmp);
        vcb->reserveBlocks = ((u_int64_t)vcb->totalBlocks * HFS_MINFREE) / 100;
        vcb->reserveBlocks = MIN(vcb->reserveBlocks, HFS_MAXRESERVE / vcb->blockSize);

        (void)hfs_statfs(mp, &mp->mnt_stat, p);
        
        vfs_unbusy(mp, p);
        inittodr(HFSTOVCB(hfsmp)->vcbLsMod);
        return (0);
}


/*
 * VFS Operations.
 *
 * mount system call
 */

static int
hfs_mount(mp, path, data, ndp, p)
        register struct mount *mp;
        char *path;
        caddr_t data;
        struct nameidata *ndp;
        struct proc *p;
{
        struct hfsmount *hfsmp = NULL;
        struct vnode *devvp;
        struct hfs_mount_args args;
        size_t size;
        int retval = E_NONE;
        int flags;
        mode_t accessmode;

        if ((retval = copyin(data, (caddr_t)&args, sizeof(args))))
                goto error_exit;

        /*
         * If updating, check whether changing from read-only to
         * read/write; if there is no device name, that's all we do.
         */
        if (mp->mnt_flag & MNT_UPDATE) {
                
                hfsmp = VFSTOHFS(mp);
                if (((hfsmp->hfs_flags & HFS_READ_ONLY) == 0) &&
                    (mp->mnt_flag & MNT_RDONLY)) {
                
                        /* use VFS_SYNC to push out System (btree) files */
                        retval = VFS_SYNC(mp, MNT_WAIT, p->p_ucred, p);
                        if (retval && ((mp->mnt_flag & MNT_FORCE) == 0))
                                goto error_exit;
                
                        flags = WRITECLOSE;
                        if (mp->mnt_flag & MNT_FORCE)
                                flags |= FORCECLOSE;
                                
                        if ((retval = hfs_flushfiles(mp, flags, p)))
                                goto error_exit;
                        hfsmp->hfs_flags |= HFS_READ_ONLY;
                        retval = hfs_flushvolumeheader(hfsmp, MNT_WAIT, 0);

                        /* also get the volume bitmap blocks */
                        if (!retval)
                                retval = VOP_FSYNC(hfsmp->hfs_devvp, NOCRED, MNT_WAIT, p);

                        if (retval) {
                                hfsmp->hfs_flags &= ~HFS_READ_ONLY;
                                goto error_exit;
                        }

                        if (hfsmp->jnl) {
                            hfs_global_exclusive_lock_acquire(hfsmp);

                            journal_close(hfsmp->jnl);
                            hfsmp->jnl = NULL;

                            // Note: we explicitly don't want to shutdown
                            //       access to the jvp because we may need
                            //       it later if we go back to being read-write.

                            hfs_global_exclusive_lock_release(hfsmp);
                        }
                }

                if ((mp->mnt_flag & MNT_RELOAD) &&
                        (retval = hfs_reload(mp, ndp->ni_cnd.cn_cred, p)))
                        goto error_exit;

                if ((hfsmp->hfs_flags & HFS_READ_ONLY) &&
                    (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
                        /*
                         * If upgrade to read-write by non-root, then verify
                         * that user has necessary permissions on the device.
                         */
                        if (p->p_ucred->cr_uid != 0) {
                                devvp = hfsmp->hfs_devvp;
                                vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, p);
                                if ((retval = VOP_ACCESS(devvp, VREAD | VWRITE, p->p_ucred, p))) {
                                        VOP_UNLOCK(devvp, 0, p);
                                        goto error_exit;
                                }
                                VOP_UNLOCK(devvp, 0, p);
                        }
                        retval = hfs_flushvolumeheader(hfsmp, MNT_WAIT, 0);
        
                        if (retval != E_NONE)
                                goto error_exit;

                        // If the journal was shut-down previously because we were
                        // asked to be read-only, let's start it back up again now
                        
                        if (   (HFSTOVCB(hfsmp)->vcbAtrb & kHFSVolumeJournaledMask)
                            && hfsmp->jnl == NULL
                            && hfsmp->jvp != NULL) {
                            int flags;

                            if (hfsmp->hfs_flags & HFS_NEED_JNL_RESET) {
                                flags = JOURNAL_RESET;
                            } else {
                                flags = 0;
                            }
                            
                            hfs_global_exclusive_lock_acquire(hfsmp);

                            hfsmp->jnl = journal_open(hfsmp->jvp,
                                                      (hfsmp->jnl_start * HFSTOVCB(hfsmp)->blockSize) + (off_t)HFSTOVCB(hfsmp)->hfsPlusIOPosOffset,
                                                      hfsmp->jnl_size,
                                                      hfsmp->hfs_devvp,
                                                      hfsmp->hfs_phys_block_size,
                                                      flags,
                                                      0,
                                                      hfs_sync_metadata, hfsmp->hfs_mp);

                            hfs_global_exclusive_lock_release(hfsmp);

                            if (hfsmp->jnl == NULL) {
                                retval = EINVAL;
                                goto error_exit;
                            } else {
                                hfsmp->hfs_flags &= ~HFS_NEED_JNL_RESET;
                            }

                        }

                        /* Only clear HFS_READ_ONLY after a successfull write */
                        hfsmp->hfs_flags &= ~HFS_READ_ONLY;
                }

                if (((hfsmp->hfs_flags & HFS_READ_ONLY) == 0) &&
                    (HFSTOVCB(hfsmp)->vcbSigWord == kHFSPlusSigWord)) {
                        /* setup private/hidden directory for unlinked files */
                        FindMetaDataDirectory(HFSTOVCB(hfsmp));
                        if (hfsmp->jnl)
                                hfs_remove_orphans(hfsmp);
                        
                        /*
                         * Allow hot file clustering if conditions allow.
                         */
                        if ((hfsmp->hfs_flags & HFS_METADATA_ZONE) &&
                            (mp->mnt_flag & MNT_RDONLY) &&
                            (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
                                (void) hfs_recording_init(hfsmp, p);
                        }
                }

                if (args.fspec == 0) {
                        /*
                         * Process export requests.
                         */
                        return vfs_export(mp, &hfsmp->hfs_export, &args.export);
                }
        }

        /*
         * Not an update, or updating the name: look up the name
         * and verify that it refers to a sensible block device.
         */
        NDINIT(ndp, LOOKUP, FOLLOW, UIO_USERSPACE, args.fspec, p);
        retval = namei(ndp);
        if (retval != E_NONE) {
                DBG_ERR(("hfs_mount: CAN'T GET DEVICE: %s, %x\n", args.fspec, ndp->ni_vp->v_rdev));
                goto error_exit;
        }

        devvp = ndp->ni_vp;

        if (devvp->v_type != VBLK) {
                vrele(devvp);
                retval = ENOTBLK;
                goto error_exit;
        }
        if (major(devvp->v_rdev) >= nblkdev) {
                vrele(devvp);
                retval = ENXIO;
                goto error_exit;
        }

        /*
         * If mount by non-root, then verify that user has necessary
         * permissions on the device.
         */
        if (p->p_ucred->cr_uid != 0) {
                accessmode = VREAD;
                if ((mp->mnt_flag & MNT_RDONLY) == 0)
                        accessmode |= VWRITE;
                vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, p);
                if ((retval = VOP_ACCESS(devvp, accessmode, p->p_ucred, p))) {
                        vput(devvp);
                        goto error_exit;
                }
                VOP_UNLOCK(devvp, 0, p);
        }

        if ((mp->mnt_flag & MNT_UPDATE) == 0) {
                retval = hfs_mountfs(devvp, mp, p, &args);
                if (retval != E_NONE)
                        vrele(devvp);
        } else {
                if (devvp != hfsmp->hfs_devvp)
                        retval = EINVAL;        /* needs translation */
                else
                        retval = hfs_changefs(mp, &args, p);
                vrele(devvp);
        }

        if (retval != E_NONE) {
                goto error_exit;
        }

        /* Set the mount flag to indicate that we support volfs  */
        mp->mnt_flag |= MNT_DOVOLFS;
    if (VFSTOVCB(mp)->vcbSigWord == kHFSSigWord) {
        /* HFS volumes only want roman-encoded names: */
        mp->mnt_flag |= MNT_FIXEDSCRIPTENCODING;
    }
        (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN-1, &size);

        bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
        (void) copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, &size);
        bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
        (void)hfs_statfs(mp, &mp->mnt_stat, p);
        return (E_NONE);

error_exit:

        return (retval);
}


/* Change fs mount parameters */
static int
hfs_changefs(mp, args, p)
        struct mount *mp;
        struct hfs_mount_args *args;
        struct proc *p;
{
        int retval = 0;
        int namefix, permfix, permswitch;
        struct hfsmount *hfsmp;
        struct cnode *cp;
        ExtendedVCB *vcb;
        register struct vnode *vp, *nvp;
        hfs_to_unicode_func_t   get_unicode_func;
        unicode_to_hfs_func_t   get_hfsname_func;
        struct cat_desc cndesc;
        struct cat_attr cnattr;
        u_long old_encoding;

        hfsmp = VFSTOHFS(mp);
        vcb = HFSTOVCB(hfsmp);
        permswitch = (((hfsmp->hfs_flags & HFS_UNKNOWN_PERMS) &&
                       ((mp->mnt_flag & MNT_UNKNOWNPERMISSIONS) == 0)) ||
                      (((hfsmp->hfs_flags & HFS_UNKNOWN_PERMS) == 0) &&
                       (mp->mnt_flag & MNT_UNKNOWNPERMISSIONS)));

        /* The root filesystem must operate with actual permissions: */
        if (permswitch && (mp->mnt_flag & MNT_ROOTFS) && (mp->mnt_flag & MNT_UNKNOWNPERMISSIONS)) {
                mp->mnt_flag &= ~MNT_UNKNOWNPERMISSIONS;        /* Just say "No". */
                return EINVAL;
        }
        if (mp->mnt_flag & MNT_UNKNOWNPERMISSIONS)
                hfsmp->hfs_flags |= HFS_UNKNOWN_PERMS;
        else
                hfsmp->hfs_flags &= ~HFS_UNKNOWN_PERMS;

        namefix = permfix = 0;

        /* Change the timezone (Note: this affects all hfs volumes and hfs+ volume create dates) */
        if (args->hfs_timezone.tz_minuteswest != VNOVAL) {
                gTimeZone = args->hfs_timezone;
        }

        /* Change the default uid, gid and/or mask */
        if ((args->hfs_uid != (uid_t)VNOVAL) && (hfsmp->hfs_uid != args->hfs_uid)) {
                hfsmp->hfs_uid = args->hfs_uid;
                if (HFSTOVCB(hfsmp)->vcbSigWord == kHFSPlusSigWord)
                        ++permfix;
        }
        if ((args->hfs_gid != (gid_t)VNOVAL) && (hfsmp->hfs_gid != args->hfs_gid)) {
                hfsmp->hfs_gid = args->hfs_gid;
                if (HFSTOVCB(hfsmp)->vcbSigWord == kHFSPlusSigWord)
                        ++permfix;
        }
        if (args->hfs_mask != (mode_t)VNOVAL) {
                if (hfsmp->hfs_dir_mask != (args->hfs_mask & ALLPERMS)) {
                        hfsmp->hfs_dir_mask = args->hfs_mask & ALLPERMS;
                        hfsmp->hfs_file_mask = args->hfs_mask & ALLPERMS;
                        if ((args->flags != VNOVAL) && (args->flags & HFSFSMNT_NOXONFILES))
                                hfsmp->hfs_file_mask = (args->hfs_mask & DEFFILEMODE);
                        if (HFSTOVCB(hfsmp)->vcbSigWord == kHFSPlusSigWord)
                                ++permfix;
                }
        }
        
        /* Change the hfs encoding value (hfs only) */
        if ((HFSTOVCB(hfsmp)->vcbSigWord == kHFSSigWord)        &&
            (args->hfs_encoding != (u_long)VNOVAL)              &&
            (hfsmp->hfs_encoding != args->hfs_encoding)) {

                retval = hfs_getconverter(args->hfs_encoding, &get_unicode_func, &get_hfsname_func);
                if (retval)
                        goto exit;

                /*
                 * Connect the new hfs_get_unicode converter but leave
                 * the old hfs_get_hfsname converter in place so that
                 * we can lookup existing vnodes to get their correctly
                 * encoded names.
                 *
                 * When we're all finished, we can then connect the new
                 * hfs_get_hfsname converter and release our interest
                 * in the old converters.
                 */
                hfsmp->hfs_get_unicode = get_unicode_func;
                old_encoding = hfsmp->hfs_encoding;
                hfsmp->hfs_encoding = args->hfs_encoding;
                ++namefix;
        }

        if (!(namefix || permfix || permswitch))
                goto exit;

        /*
         * For each active vnode fix things that changed
         *
         * Note that we can visit a vnode more than once
         * and we can race with fsync.
         */
        simple_lock(&mntvnode_slock);
loop:
        for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nvp) {
                /*
                 * If the vnode that we are about to fix is no longer
                 * associated with this mount point, start over.
                 */
                if (vp->v_mount != mp)
                    goto loop;
         
                simple_lock(&vp->v_interlock);
                nvp = vp->v_mntvnodes.le_next;
                if (vp->v_flag & VSYSTEM) {
                        simple_unlock(&vp->v_interlock);
                        continue;
                }
                simple_unlock(&mntvnode_slock);
                retval = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, p);
                if (retval) {
                    simple_lock(&mntvnode_slock);
                    if (retval == ENOENT)
                        goto loop;
                    continue;
                }
        
                cp = VTOC(vp);

                retval = cat_lookup(hfsmp, &cp->c_desc, 0, &cndesc, &cnattr, NULL);
                /* If we couldn't find this guy skip to the next one */
                if (retval) {
                        if (namefix)
                                cache_purge(vp);
                        vput(vp);
                        simple_lock(&mntvnode_slock);
                        continue;
                }

                /* Get the real uid/gid and perm mask from disk. */
                if (permswitch || permfix) {
                        cp->c_uid = cnattr.ca_uid;
                        cp->c_gid = cnattr.ca_gid;
                        cp->c_mode = cnattr.ca_mode;
                }
                
                /*
                 * If we're switching name converters then...
                 *   Remove the existing entry from the namei cache.
                 *   Update name to one based on new encoder.
                 */
                if (namefix) {
                        cache_purge(vp);
                        replace_desc(cp, &cndesc);

                        if (cndesc.cd_cnid == kHFSRootFolderID) {
                                strncpy(vcb->vcbVN, cp->c_desc.cd_nameptr, NAME_MAX);
                                cp->c_desc.cd_encoding = hfsmp->hfs_encoding;
                        }
                } else {
                        cat_releasedesc(&cndesc);
                }
                vput(vp);
                simple_lock(&mntvnode_slock);

        } /* end for (vp...) */
        simple_unlock(&mntvnode_slock);
        /*
         * If we're switching name converters we can now
         * connect the new hfs_get_hfsname converter and
         * release our interest in the old converters.
         */
        if (namefix) {
                hfsmp->hfs_get_hfsname = get_hfsname_func;
                vcb->volumeNameEncodingHint = args->hfs_encoding;
                (void) hfs_relconverter(old_encoding);
        }
exit:
        return (retval);
}


/*
 * Reload all incore data for a filesystem (used after running fsck on
 * the root filesystem and finding things to fix). The filesystem must
 * be mounted read-only.
 *
 * Things to do to update the mount:
 *      invalidate all cached meta-data.
 *      invalidate all inactive vnodes.
 *      invalidate all cached file data.
 *      re-read volume header from disk.
 *      re-load meta-file info (extents, file size).
 *      re-load B-tree header data.
 *      re-read cnode data for all active vnodes.
 */
static int
hfs_reload(mountp, cred, p)
        register struct mount *mountp;
        struct ucred *cred;
        struct proc *p;
{
        register struct vnode *vp, *nvp, *devvp;
        struct cnode *cp;
        struct buf *bp;
        int sectorsize;
        int error, i;
        struct hfsmount *hfsmp;
        struct HFSPlusVolumeHeader *vhp;
        ExtendedVCB *vcb;
        struct filefork *forkp;
        struct cat_desc cndesc;

        if ((mountp->mnt_flag & MNT_RDONLY) == 0)
                return (EINVAL);

        hfsmp = VFSTOHFS(mountp);
        vcb = HFSTOVCB(hfsmp);

        if (vcb->vcbSigWord == kHFSSigWord)
                return (EINVAL);        /* rooting from HFS is not supported! */

        /*
         * Invalidate all cached meta-data.
         */
        devvp = hfsmp->hfs_devvp;
        if (vinvalbuf(devvp, 0, cred, p, 0, 0))
                panic("hfs_reload: dirty1");
        InvalidateCatalogCache(vcb);

loop:
        simple_lock(&mntvnode_slock);
        for (vp = mountp->mnt_vnodelist.lh_first; vp != NULL; vp = nvp) {
                if (vp->v_mount != mountp) {
                        simple_unlock(&mntvnode_slock);
                        goto loop;
                }
                nvp = vp->v_mntvnodes.le_next;

                /*
                 * Invalidate all inactive vnodes.
                 */
                if (vrecycle(vp, &mntvnode_slock, p))
                        goto loop;

                /*
                 * Invalidate all cached file data.
                 */
                simple_lock(&vp->v_interlock);
                simple_unlock(&mntvnode_slock);
                if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p)) {
                        goto loop;
                }
                if (vinvalbuf(vp, 0, cred, p, 0, 0))
                        panic("hfs_reload: dirty2");

                /*
                 * Re-read cnode data for all active vnodes (non-metadata files).
                 */
                cp = VTOC(vp);
                if ((vp->v_flag & VSYSTEM) == 0 && !VNODE_IS_RSRC(vp)) {
                        struct cat_fork *datafork;
                        struct cat_desc desc;

                        datafork = cp->c_datafork ? &cp->c_datafork->ff_data : NULL;

                        /* lookup by fileID since name could have changed */
                        if ((error = cat_idlookup(hfsmp, cp->c_fileid, &desc, &cp->c_attr, datafork))) {
                                vput(vp);
                                return (error);
                        }

                        /* update cnode's catalog descriptor */
                        (void) replace_desc(cp, &desc);
                }
                vput(vp);
                simple_lock(&mntvnode_slock);
        }
        simple_unlock(&mntvnode_slock);

        /*
         * Re-read VolumeHeader from disk.
         */
        sectorsize = hfsmp->hfs_phys_block_size;

        error = meta_bread(hfsmp->hfs_devvp,
                        (vcb->hfsPlusIOPosOffset / sectorsize) + HFS_PRI_SECTOR(sectorsize),
                        sectorsize, NOCRED, &bp);
        if (error) {
                if (bp != NULL)
                        brelse(bp);
                return (error);
        }

        vhp = (HFSPlusVolumeHeader *) (bp->b_data + HFS_PRI_OFFSET(sectorsize));

        /* Do a quick sanity check */
        if ((SWAP_BE16(vhp->signature) != kHFSPlusSigWord &&
             SWAP_BE16(vhp->signature) != kHFSXSigWord) ||
            (SWAP_BE16(vhp->version) != kHFSPlusVersion &&
             SWAP_BE16(vhp->version) != kHFSXVersion) ||
            SWAP_BE32(vhp->blockSize) != vcb->blockSize) {
                brelse(bp);
                return (EIO);
        }

        vcb->vcbLsMod           = to_bsd_time(SWAP_BE32(vhp->modifyDate));
        vcb->vcbAtrb            = (UInt16) SWAP_BE32 (vhp->attributes); /* VCB only uses lower 16 bits */
        vcb->vcbJinfoBlock  = SWAP_BE32(vhp->journalInfoBlock);
        vcb->vcbClpSiz          = SWAP_BE32 (vhp->rsrcClumpSize);
        vcb->vcbNxtCNID         = SWAP_BE32 (vhp->nextCatalogID);
        vcb->vcbVolBkUp         = to_bsd_time(SWAP_BE32(vhp->backupDate));
        vcb->vcbWrCnt           = SWAP_BE32 (vhp->writeCount);
        vcb->vcbFilCnt          = SWAP_BE32 (vhp->fileCount);
        vcb->vcbDirCnt          = SWAP_BE32 (vhp->folderCount);
        vcb->nextAllocation     = SWAP_BE32 (vhp->nextAllocation);
        vcb->totalBlocks        = SWAP_BE32 (vhp->totalBlocks);
        vcb->freeBlocks         = SWAP_BE32 (vhp->freeBlocks);
        vcb->encodingsBitmap    = SWAP_BE64 (vhp->encodingsBitmap);
        bcopy(vhp->finderInfo, vcb->vcbFndrInfo, sizeof(vhp->finderInfo));    
        vcb->localCreateDate    = SWAP_BE32 (vhp->createDate); /* hfs+ create date is in local time */ 

        /*
         * Re-load meta-file vnode data (extent info, file size, etc).
         */
        forkp = VTOF((struct vnode *)vcb->extentsRefNum);
        for (i = 0; i < kHFSPlusExtentDensity; i++) {
                forkp->ff_extents[i].startBlock =
                        SWAP_BE32 (vhp->extentsFile.extents[i].startBlock);
                forkp->ff_extents[i].blockCount =
                        SWAP_BE32 (vhp->extentsFile.extents[i].blockCount);
        }
        forkp->ff_size      = SWAP_BE64 (vhp->extentsFile.logicalSize);
        forkp->ff_blocks    = SWAP_BE32 (vhp->extentsFile.totalBlocks);
        forkp->ff_clumpsize = SWAP_BE32 (vhp->extentsFile.clumpSize);


        forkp = VTOF((struct vnode *)vcb->catalogRefNum);
        for (i = 0; i < kHFSPlusExtentDensity; i++) {
                forkp->ff_extents[i].startBlock =
                        SWAP_BE32 (vhp->catalogFile.extents[i].startBlock);
                forkp->ff_extents[i].blockCount =
                        SWAP_BE32 (vhp->catalogFile.extents[i].blockCount);
        }
        forkp->ff_size      = SWAP_BE64 (vhp->catalogFile.logicalSize);
        forkp->ff_blocks    = SWAP_BE32 (vhp->catalogFile.totalBlocks);
        forkp->ff_clumpsize = SWAP_BE32 (vhp->catalogFile.clumpSize);


        forkp = VTOF((struct vnode *)vcb->allocationsRefNum);
        for (i = 0; i < kHFSPlusExtentDensity; i++) {
                forkp->ff_extents[i].startBlock =
                        SWAP_BE32 (vhp->allocationFile.extents[i].startBlock);
                forkp->ff_extents[i].blockCount =
                        SWAP_BE32 (vhp->allocationFile.extents[i].blockCount);
        }
        forkp->ff_size      = SWAP_BE64 (vhp->allocationFile.logicalSize);
        forkp->ff_blocks    = SWAP_BE32 (vhp->allocationFile.totalBlocks);
        forkp->ff_clumpsize = SWAP_BE32 (vhp->allocationFile.clumpSize);

        brelse(bp);
        vhp = NULL;

        /*
         * Re-load B-tree header data
         */
        forkp = VTOF((struct vnode *)vcb->extentsRefNum);
        if (error = MacToVFSError( BTReloadData((FCB*)forkp) ))
                return (error);

        forkp = VTOF((struct vnode *)vcb->catalogRefNum);
        if (error = MacToVFSError( BTReloadData((FCB*)forkp) ))
                return (error);

        /* Reload the volume name */
        if ((error = cat_idlookup(hfsmp, kHFSRootFolderID, &cndesc, NULL, NULL)))
                return (error);
        vcb->volumeNameEncodingHint = cndesc.cd_encoding;
        bcopy(cndesc.cd_nameptr, vcb->vcbVN, min(255, cndesc.cd_namelen));
        cat_releasedesc(&cndesc);

        /* Re-establish private/hidden directory for unlinked files */
        FindMetaDataDirectory(vcb);

        /* In case any volume information changed to trigger a notification */
        hfs_generate_volume_notifications(hfsmp);
    
        return (0);
}


static int
get_raw_device(char *fspec, int is_user, int ronly, struct vnode **rvp, struct ucred *cred, struct proc *p)
{
        char            *rawbuf;
        char            *dp;
        size_t           namelen;
        struct nameidata nd;
        int               retval;

        *rvp = NULL;

        MALLOC(rawbuf, char *, MAXPATHLEN, M_HFSMNT, M_WAITOK);
        if (rawbuf == NULL) {
                retval = ENOMEM;
                goto error_exit;
        }

        if (is_user) {
                retval = copyinstr(fspec, rawbuf, MAXPATHLEN - 1, &namelen);
                if (retval != E_NONE) {
                        FREE(rawbuf, M_HFSMNT);
                        goto error_exit;
                }
        } else {
                strcpy(rawbuf, fspec);
                namelen = strlen(rawbuf);
        }

        /* make sure it's null terminated */
        rawbuf[MAXPATHLEN-1] = '\0';   

        dp = &rawbuf[namelen-1];
        while(dp >= rawbuf && *dp != '/') {
                dp--;
        }
                        
        if (dp != NULL) {
                dp++;
        } else {
                dp = rawbuf;
        }
                        
        /* make room for and insert the 'r' for the raw device */
        memmove(dp+1, dp, strlen(dp)+1);
        *dp = 'r';

        NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, rawbuf, p);
        retval = namei(&nd);
        if (retval != E_NONE) {
                DBG_ERR(("hfs_mountfs: can't open raw device for journal: %s, %x\n", rawbuf, nd.ni_vp->v_rdev));
                FREE(rawbuf, M_HFSMNT);
                goto error_exit;
        }

        *rvp = nd.ni_vp;
        if ((retval = VOP_OPEN(*rvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, p))) {
                *rvp = NULL;
                goto error_exit;
        }

        // don't need this any more
        FREE(rawbuf, M_HFSMNT);

        return 0;

  error_exit:
        if (*rvp) {
            (void)VOP_CLOSE(*rvp, ronly ? FREAD : FREAD|FWRITE, cred, p);
        }

        if (rawbuf) {
                FREE(rawbuf, M_HFSMNT);
        }
        return retval;
}



/*
 * Common code for mount and mountroot
 */
static int
hfs_mountfs(struct vnode *devvp, struct mount *mp, struct proc *p,
        struct hfs_mount_args *args)
{
        int retval = E_NONE;
        struct hfsmount *hfsmp;
        struct buf *bp;
        dev_t dev;
        HFSMasterDirectoryBlock *mdbp;
        int ronly;
        int i;
        int mntwrapper;
        struct ucred *cred;
        u_int64_t disksize;
        u_int64_t blkcnt;
        u_int32_t blksize;
        u_int32_t minblksize;
        u_int32_t iswritable;
        daddr_t   mdb_offset;

        dev = devvp->v_rdev;
        cred = p ? p->p_ucred : NOCRED;
        mntwrapper = 0;
    /*
     * Disallow multiple mounts of the same device.
     * Disallow mounting of a device that is currently in use
     * (except for root, which might share swap device for miniroot).
     * Flush out any old buffers remaining from a previous use.
     */
    if ((retval = vfs_mountedon(devvp)))
        return (retval);
    if ((vcount(devvp) > 1) && (devvp != rootvp))
                return (EBUSY);
    if ((retval = vinvalbuf(devvp, V_SAVE, cred, p, 0, 0)))
        return (retval);

    ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
    if ((retval = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, p)))
        return (retval);

        bp = NULL;
        hfsmp = NULL;
        mdbp = NULL;
        minblksize = kHFSBlockSize;

        /* Get the real physical block size. */
        if (VOP_IOCTL(devvp, DKIOCGETBLOCKSIZE, (caddr_t)&blksize, 0, cred, p)) {
                retval = ENXIO;
                goto error_exit;
        }
        /* Switch to 512 byte sectors (temporarily) */
        if (blksize > 512) {
                u_int32_t size512 = 512;

                if (VOP_IOCTL(devvp, DKIOCSETBLOCKSIZE, (caddr_t)&size512, FWRITE, cred, p)) {
                        retval = ENXIO;
                        goto error_exit;
                }
        }
        /* Get the number of 512 byte physical blocks. */
        if (VOP_IOCTL(devvp, DKIOCGETBLOCKCOUNT, (caddr_t)&blkcnt, 0, cred, p)) {
                retval = ENXIO;
                goto error_exit;
        }
        /* Compute an accurate disk size (i.e. within 512 bytes) */
        disksize = blkcnt * (u_int64_t)512;

        /*
         * There are only 31 bits worth of block count in
         * the buffer cache.  So for large volumes a 4K
         * physical block size is needed.
         */
        if (blkcnt > (u_int64_t)0x000000007fffffff) {
                minblksize = blksize = 4096;
        }
        /* Now switch to our prefered physical block size. */
        if (blksize > 512) {
                if (VOP_IOCTL(devvp, DKIOCSETBLOCKSIZE, (caddr_t)&blksize, FWRITE, cred, p)) {
                        retval = ENXIO;
                        goto error_exit;
                }
                /* Get the count of physical blocks. */
                if (VOP_IOCTL(devvp, DKIOCGETBLOCKCOUNT, (caddr_t)&blkcnt, 0, cred, p)) {
                        retval = ENXIO;
                        goto error_exit;
                }
        }

        /*
         * At this point:
         *   minblksize is the minimum physical block size
         *   blksize has our prefered physical block size
         *   blkcnt has the total number of physical blocks
         */
        devvp->v_specsize = blksize;

        /* cache the IO attributes */
        if ((retval = vfs_init_io_attributes(devvp, mp))) {
                printf("hfs_mountfs: vfs_init_io_attributes returned %d\n",
                        retval);
                return (retval);
        }

        mdb_offset = HFS_PRI_SECTOR(blksize);
        if ((retval = meta_bread(devvp, HFS_PRI_SECTOR(blksize), blksize, cred, &bp))) {
                goto error_exit;
        }
        MALLOC(mdbp, HFSMasterDirectoryBlock *, kMDBSize, M_TEMP, M_WAITOK);
        bcopy(bp->b_data + HFS_PRI_OFFSET(blksize), mdbp, kMDBSize);
        brelse(bp);
        bp = NULL;

        MALLOC(hfsmp, struct hfsmount *, sizeof(struct hfsmount), M_HFSMNT, M_WAITOK);
        bzero(hfsmp, sizeof(struct hfsmount));
        
        /*
        *  Init the volume information structure
        */
        mp->mnt_data = (qaddr_t)hfsmp;
        hfsmp->hfs_mp = mp;                     /* Make VFSTOHFS work */
        hfsmp->hfs_vcb.vcb_hfsmp = hfsmp;       /* Make VCBTOHFS work */
        hfsmp->hfs_raw_dev = devvp->v_rdev;
        hfsmp->hfs_devvp = devvp;
        hfsmp->hfs_phys_block_size = blksize;
        hfsmp->hfs_phys_block_count = blkcnt;
        hfsmp->hfs_flags |= HFS_WRITEABLE_MEDIA;
        if (ronly)
                hfsmp->hfs_flags |= HFS_READ_ONLY;
        if (mp->mnt_flag & MNT_UNKNOWNPERMISSIONS)
                hfsmp->hfs_flags |= HFS_UNKNOWN_PERMS;
        for (i = 0; i < MAXQUOTAS; i++)
                hfsmp->hfs_qfiles[i].qf_vp = NULLVP;

        if (args) {
                hfsmp->hfs_uid = (args->hfs_uid == (uid_t)VNOVAL) ? UNKNOWNUID : args->hfs_uid;
                if (hfsmp->hfs_uid == 0xfffffffd) hfsmp->hfs_uid = UNKNOWNUID;
                hfsmp->hfs_gid = (args->hfs_gid == (gid_t)VNOVAL) ? UNKNOWNGID : args->hfs_gid;
                if (hfsmp->hfs_gid == 0xfffffffd) hfsmp->hfs_gid = UNKNOWNGID;
                if (args->hfs_mask != (mode_t)VNOVAL) {
                        hfsmp->hfs_dir_mask = args->hfs_mask & ALLPERMS;
                        if (args->flags & HFSFSMNT_NOXONFILES) {
                                hfsmp->hfs_file_mask = (args->hfs_mask & DEFFILEMODE);
                        } else {
                                hfsmp->hfs_file_mask = args->hfs_mask & ALLPERMS;
                        }
                } else {
                        hfsmp->hfs_dir_mask = UNKNOWNPERMISSIONS & ALLPERMS;            /* 0777: rwx---rwx */
                        hfsmp->hfs_file_mask = UNKNOWNPERMISSIONS & DEFFILEMODE;        /* 0666: no --x by default? */
                }
                if ((args->flags != (int)VNOVAL) && (args->flags & HFSFSMNT_WRAPPER))
                        mntwrapper = 1;
        } else {
                /* Even w/o explicit mount arguments, MNT_UNKNOWNPERMISSIONS requires setting up uid, gid, and mask: */
                if (mp->mnt_flag & MNT_UNKNOWNPERMISSIONS) {
                        hfsmp->hfs_uid = UNKNOWNUID;
                        hfsmp->hfs_gid = UNKNOWNGID;
                        hfsmp->hfs_dir_mask = UNKNOWNPERMISSIONS & ALLPERMS;            /* 0777: rwx---rwx */
                        hfsmp->hfs_file_mask = UNKNOWNPERMISSIONS & DEFFILEMODE;        /* 0666: no --x by default? */
                }
        }

        /* Find out if disk media is writable. */
        if (VOP_IOCTL(devvp, DKIOCISWRITABLE, (caddr_t)&iswritable, 0, cred, p) == 0) {
                if (iswritable)
                        hfsmp->hfs_flags |= HFS_WRITEABLE_MEDIA;
                else
                        hfsmp->hfs_flags &= ~HFS_WRITEABLE_MEDIA;
        }

        /* Mount a standard HFS disk */
        if ((SWAP_BE16(mdbp->drSigWord) == kHFSSigWord) &&
            (mntwrapper || (SWAP_BE16(mdbp->drEmbedSigWord) != kHFSPlusSigWord))) {
                if (devvp == rootvp) {
                        retval = EINVAL;  /* Cannot root from HFS standard disks */
                        goto error_exit;
                }
                /* HFS disks can only use 512 byte physical blocks */
                if (blksize > kHFSBlockSize) {
                        blksize = kHFSBlockSize;
                        if (VOP_IOCTL(devvp, DKIOCSETBLOCKSIZE, (caddr_t)&blksize, FWRITE, cred, p)) {
                                retval = ENXIO;
                                goto error_exit;
                        }
                        if (VOP_IOCTL(devvp, DKIOCGETBLOCKCOUNT, (caddr_t)&blkcnt, 0, cred, p)) {
                                retval = ENXIO;
                                goto error_exit;
                        }
                        devvp->v_specsize = blksize;
                        hfsmp->hfs_phys_block_size = blksize;
                        hfsmp->hfs_phys_block_count = blkcnt;
                }
                if (args) {
                        hfsmp->hfs_encoding = args->hfs_encoding;
                        HFSTOVCB(hfsmp)->volumeNameEncodingHint = args->hfs_encoding;

                        /* establish the timezone */
                        gTimeZone = args->hfs_timezone;
                }

                retval = hfs_getconverter(hfsmp->hfs_encoding, &hfsmp->hfs_get_unicode,
                                        &hfsmp->hfs_get_hfsname);
                if (retval)
                        goto error_exit;

                retval = hfs_MountHFSVolume(hfsmp, mdbp, p);
                if (retval)
                        (void) hfs_relconverter(hfsmp->hfs_encoding);

        } else /* Mount an HFS Plus disk */ {
                HFSPlusVolumeHeader *vhp;
                off_t embeddedOffset;
                int   jnl_disable = 0;
        
                /* Get the embedded Volume Header */
                if (SWAP_BE16(mdbp->drEmbedSigWord) == kHFSPlusSigWord) {
                        embeddedOffset = SWAP_BE16(mdbp->drAlBlSt) * kHFSBlockSize;
                        embeddedOffset += (u_int64_t)SWAP_BE16(mdbp->drEmbedExtent.startBlock) *
                                          (u_int64_t)SWAP_BE32(mdbp->drAlBlkSiz);

                        /*
                         * If the embedded volume doesn't start on a block
                         * boundary, then switch the device to a 512-byte
                         * block size so everything will line up on a block
                         * boundary.
                         */
                        if ((embeddedOffset % blksize) != 0) {
                                printf("HFS Mount: embedded volume offset not"
                                    " a multiple of physical block size (%d);"
                                    " switching to 512\n", blksize);
                                blksize = 512;
                                if (VOP_IOCTL(devvp, DKIOCSETBLOCKSIZE,
                                    (caddr_t)&blksize, FWRITE, cred, p)) {
                                        retval = ENXIO;
                                        goto error_exit;
                                }
                                if (VOP_IOCTL(devvp, DKIOCGETBLOCKCOUNT,
                                    (caddr_t)&blkcnt, 0, cred, p)) {
                                        retval = ENXIO;
                                        goto error_exit;
                                }
                                /* XXX do we need to call vfs_init_io_attributes again? */
                                devvp->v_specsize = blksize;
                                /* Note: relative block count adjustment */
                                hfsmp->hfs_phys_block_count *=
                                    hfsmp->hfs_phys_block_size / blksize;
                                hfsmp->hfs_phys_block_size = blksize;
                        }

                        disksize = (u_int64_t)SWAP_BE16(mdbp->drEmbedExtent.blockCount) *
                                   (u_int64_t)SWAP_BE32(mdbp->drAlBlkSiz);

                        hfsmp->hfs_phys_block_count = disksize / blksize;
        
                        mdb_offset = (embeddedOffset / blksize) + HFS_PRI_SECTOR(blksize);
                        retval = meta_bread(devvp, mdb_offset, blksize, cred, &bp);
                        if (retval)
                                goto error_exit;
                        bcopy(bp->b_data + HFS_PRI_OFFSET(blksize), mdbp, 512);
                        brelse(bp);
                        bp = NULL;
                        vhp = (HFSPlusVolumeHeader*) mdbp;

                } else /* pure HFS+ */ {
                        embeddedOffset = 0;
                        vhp = (HFSPlusVolumeHeader*) mdbp;
                }

                // XXXdbg
                //
                hfsmp->jnl = NULL;
                hfsmp->jvp = NULL;
                if (args != NULL && (args->flags & HFSFSMNT_EXTENDED_ARGS) && args->journal_disable) {
                    jnl_disable = 1;
                }
                                
                //
                // We only initialize the journal here if the last person
                // to mount this volume was journaling aware.  Otherwise
                // we delay journal initialization until later at the end
                // of hfs_MountHFSPlusVolume() because the last person who
                // mounted it could have messed things up behind our back
                // (so we need to go find the .journal file, make sure it's
                // the right size, re-sync up if it was moved, etc).
                //
                if (   (SWAP_BE32(vhp->lastMountedVersion) == kHFSJMountVersion)
                        && (SWAP_BE32(vhp->attributes) & kHFSVolumeJournaledMask)
                        && !jnl_disable) {
                        
                        // if we're able to init the journal, mark the mount
                        // point as journaled.
                        //
                        if (hfs_early_journal_init(hfsmp, vhp, args, embeddedOffset, mdb_offset, mdbp, cred) == 0) {
                                mp->mnt_flag |= MNT_JOURNALED;
                        } else {
                                // if the journal failed to open, then set the lastMountedVersion
                                // to be "FSK!" which fsck_hfs will see and force the fsck instead
                                // of just bailing out because the volume is journaled.
                                if (ronly != 0 || devvp == rootvp) {
                                    HFSPlusVolumeHeader *vhp;

                                    hfsmp->hfs_flags |= HFS_NEED_JNL_RESET;
                                    
                                    if (mdb_offset == 0) {
                                        mdb_offset = (embeddedOffset / blksize) + HFS_PRI_SECTOR(blksize);
                                    }

                                    bp = NULL;
                                    retval = meta_bread(devvp, mdb_offset, blksize, cred, &bp);
                                    if (retval == 0) {
                                        vhp = (HFSPlusVolumeHeader *)(bp->b_data + HFS_PRI_OFFSET(blksize));
                                            
                                        if (SWAP_BE16(vhp->signature) == kHFSPlusSigWord || SWAP_BE16(vhp->signature) == kHFSXSigWord) {
                                            vhp->lastMountedVersion = SWAP_BE32('FSK!');
                                            bwrite(bp);
                                        } else {
                                            brelse(bp);
                                        }
                                        bp = NULL;
                                    } else if (bp) {
                                        brelse(bp);
                                    }
                                }

                                // if this isn't the root device just bail out.
                                // if it is the root device we just continue on
                                // in the hopes that fsck_hfs will be able to
                                // fix any damage that exists on the volume.
                                if (devvp != rootvp) {
                                    retval = EINVAL;
                                    goto error_exit;
                                }
                        }
                }
                // XXXdbg
        
                (void) hfs_getconverter(0, &hfsmp->hfs_get_unicode, &hfsmp->hfs_get_hfsname);

                retval = hfs_MountHFSPlusVolume(hfsmp, vhp, embeddedOffset, disksize, p, args);
                /*
                 * If the backend didn't like our physical blocksize
                 * then retry with physical blocksize of 512.
                 */
                if ((retval == ENXIO) && (blksize > 512) && (blksize != minblksize)) {
                        printf("HFS Mount: could not use physical block size "
                                "(%d) switching to 512\n", blksize);
                        blksize = 512;
                        if (VOP_IOCTL(devvp, DKIOCSETBLOCKSIZE, (caddr_t)&blksize, FWRITE, cred, p)) {
                                retval = ENXIO;
                                goto error_exit;
                        }
                        if (VOP_IOCTL(devvp, DKIOCGETBLOCKCOUNT, (caddr_t)&blkcnt, 0, cred, p)) {
                                retval = ENXIO;
                                goto error_exit;
                        }
                        devvp->v_specsize = blksize;
                        /* Note: relative block count adjustment (in case this is an embedded volume). */
                        hfsmp->hfs_phys_block_count *= hfsmp->hfs_phys_block_size / blksize;
                        hfsmp->hfs_phys_block_size = blksize;
 
                        if (hfsmp->jnl) {
                            // close and re-open this with the new block size
                            journal_close(hfsmp->jnl);
                            hfsmp->jnl = NULL;
                            if (hfs_early_journal_init(hfsmp, vhp, args, embeddedOffset, mdb_offset, mdbp, cred) == 0) {
                                mp->mnt_flag |= MNT_JOURNALED;
                            }
                        }

                        /* Try again with a smaller block size... */
                        retval = hfs_MountHFSPlusVolume(hfsmp, vhp, embeddedOffset, disksize, p, args);
                }
                if (retval)
                        (void) hfs_relconverter(0);
        }

        if ( retval ) {
                goto error_exit;
        }

        mp->mnt_stat.f_fsid.val[0] = (long)dev;
        mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
        mp->mnt_maxsymlinklen = 0;
        devvp->v_specflags |= SI_MOUNTEDON;

        if (args) {
                /*
                 * Set the free space warning levels for a non-root volume:
                 *
                 * Set the lower freespace limit (the level that will trigger a warning)
                 * to 5% of the volume size or 250MB, whichever is less, and the desired
                 * level (which will cancel the alert request) to 1/2 above that limit.
                 * Start looking for free space to drop below this level and generate a
                 * warning immediately if needed:
                 */
                hfsmp->hfs_freespace_notify_warninglimit =
                        MIN(HFS_LOWDISKTRIGGERLEVEL / HFSTOVCB(hfsmp)->blockSize,
                                (HFSTOVCB(hfsmp)->totalBlocks / 100) * HFS_LOWDISKTRIGGERFRACTION);
                hfsmp->hfs_freespace_notify_desiredlevel =
                        MIN(HFS_LOWDISKSHUTOFFLEVEL / HFSTOVCB(hfsmp)->blockSize,
                                (HFSTOVCB(hfsmp)->totalBlocks / 100) * HFS_LOWDISKSHUTOFFFRACTION);
        } else {
                /*
                 * Set the free space warning levels for the root volume:
                 *
                 * Set the lower freespace limit (the level that will trigger a warning)
                 * to 1% of the volume size or 50MB, whichever is less, and the desired
                 * level (which will cancel the alert request) to 2% or 75MB, whichever is less.
                 */
                hfsmp->hfs_freespace_notify_warninglimit =
                        MIN(HFS_ROOTLOWDISKTRIGGERLEVEL / HFSTOVCB(hfsmp)->blockSize,
                                (HFSTOVCB(hfsmp)->totalBlocks / 100) * HFS_ROOTLOWDISKTRIGGERFRACTION);
                hfsmp->hfs_freespace_notify_desiredlevel =
                        MIN(HFS_ROOTLOWDISKSHUTOFFLEVEL / HFSTOVCB(hfsmp)->blockSize,
                                (HFSTOVCB(hfsmp)->totalBlocks / 100) * HFS_ROOTLOWDISKSHUTOFFFRACTION);
        };
        
        /*
         * Start looking for free space to drop below this level and generate a
         * warning immediately if needed:
         */
        hfsmp->hfs_notification_conditions = 0;
        hfs_generate_volume_notifications(hfsmp);
        
        if (ronly == 0) {
                (void) hfs_flushvolumeheader(hfsmp, MNT_WAIT, 0);
        }
        FREE(mdbp, M_TEMP);
        return (0);

error_exit:
        if (bp)
                brelse(bp);
        if (mdbp)
                FREE(mdbp, M_TEMP);
        (void)VOP_CLOSE(devvp, ronly ? FREAD : FREAD|FWRITE, cred, p);
        if (hfsmp && hfsmp->jvp && hfsmp->jvp != hfsmp->hfs_devvp) {
            (void)VOP_CLOSE(hfsmp->jvp, ronly ? FREAD : FREAD|FWRITE, cred, p);
                hfsmp->jvp = NULL;
        }
        if (hfsmp) {
                FREE(hfsmp, M_HFSMNT);
                mp->mnt_data = (qaddr_t)0;
        }
        return (retval);
}


/*
 * Make a filesystem operational.
 * Nothing to do at the moment.
 */
/* ARGSUSED */
static int
hfs_start(mp, flags, p)
        struct mount *mp;
        int flags;
        struct proc *p;
{
        return (0);
}


/*
 * unmount system call
 */
static int
hfs_unmount(mp, mntflags, p)
        struct mount *mp;
        int mntflags;
        struct proc *p;
{
        struct hfsmount *hfsmp = VFSTOHFS(mp);
        int retval = E_NONE;
        int flags;
        int force;
        int started_tr = 0, grabbed_lock = 0;

        flags = 0;
        force = 0;
        if (mntflags & MNT_FORCE) {
                flags |= FORCECLOSE;
                force = 1;
        }

        if ((retval = hfs_flushfiles(mp, flags, p)) && !force)
                return (retval);

        if (hfsmp->hfs_flags & HFS_METADATA_ZONE)
                (void) hfs_recording_suspend(hfsmp, p);

        /*
         * Flush out the b-trees, volume bitmap and Volume Header
         */
        if ((hfsmp->hfs_flags & HFS_READ_ONLY) == 0) {
                hfs_global_shared_lock_acquire(hfsmp);
                grabbed_lock = 1;
                if (hfsmp->jnl) {
                        journal_start_transaction(hfsmp->jnl);
                        started_tr = 1;
                }
                
                retval = VOP_FSYNC(HFSTOVCB(hfsmp)->catalogRefNum, NOCRED, MNT_WAIT, p);
                if (retval && !force)
                        goto err_exit;
                
                retval = VOP_FSYNC(HFSTOVCB(hfsmp)->extentsRefNum, NOCRED, MNT_WAIT, p);
                if (retval && !force)
                        goto err_exit;
                        
                // if we have an allocation file, sync it too so we don't leave dirty
                // blocks around
                if (HFSTOVCB(hfsmp)->allocationsRefNum) {
                    if (retval = VOP_FSYNC(HFSTOVCB(hfsmp)->allocationsRefNum, NOCRED, MNT_WAIT, p)) {
                        if (!force)
                            goto err_exit;
                    }
                }

                if (hfsmp->hfc_filevp && (hfsmp->hfc_filevp->v_flag & VSYSTEM)) {
                        retval = VOP_FSYNC(hfsmp->hfc_filevp, NOCRED, MNT_WAIT, p);
                        if (retval && !force)
                                goto err_exit;
                }

                if (retval = VOP_FSYNC(hfsmp->hfs_devvp, NOCRED, MNT_WAIT, p)) {
                        if (!force)
                                goto err_exit;
                }

#if 0           
                /* See if this volume is damaged, is so do not unmount cleanly */
                if (HFSTOVCB(hfsmp)->vcbFlags & kHFS_DamagedVolume) {
                        HFSTOVCB(hfsmp)->vcbAtrb &= ~kHFSVolumeUnmountedMask;
                } else {
                        HFSTOVCB(hfsmp)->vcbAtrb |= kHFSVolumeUnmountedMask;
                }
#else
                HFSTOVCB(hfsmp)->vcbAtrb |= kHFSVolumeUnmountedMask;
#endif
                retval = hfs_flushvolumeheader(hfsmp, MNT_WAIT, 1);
                if (retval) {
                        HFSTOVCB(hfsmp)->vcbAtrb &= ~kHFSVolumeUnmountedMask;
                        if (!force)
                                goto err_exit;  /* could not flush everything */
                }

                if (hfsmp->jnl) {
                        journal_end_transaction(hfsmp->jnl);
                        started_tr = 0;
                }
                if (grabbed_lock) {
                        hfs_global_shared_lock_release(hfsmp);
                        grabbed_lock = 0;
                }
        }

        if (hfsmp->jnl) {
                journal_flush(hfsmp->jnl);
        }
        
        /*
         *      Invalidate our caches and release metadata vnodes
         */
        (void) hfsUnmount(hfsmp, p);

        /*
         * Last chance to dump unreferenced system files.
         */
        (void) vflush(mp, NULLVP, FORCECLOSE);

        if (HFSTOVCB(hfsmp)->vcbSigWord == kHFSSigWord)
                (void) hfs_relconverter(hfsmp->hfs_encoding);

        // XXXdbg
        if (hfsmp->jnl) {
            journal_close(hfsmp->jnl);
            hfsmp->jnl = NULL;
        }

        if (hfsmp->jvp && hfsmp->jvp != hfsmp->hfs_devvp) {
            retval = VOP_CLOSE(hfsmp->jvp,
                               hfsmp->hfs_flags & HFS_READ_ONLY ? FREAD : FREAD|FWRITE,
                               NOCRED, p);
            vrele(hfsmp->jvp);
            hfsmp->jvp = NULL;
        }
        // XXXdbg

#ifdef HFS_SPARSE_DEV
        /* Drop our reference on the backing fs (if any). */
        if ((hfsmp->hfs_flags & HFS_HAS_SPARSE_DEVICE) && hfsmp->hfs_backingfs_rootvp) {
                struct vnode * tmpvp;

                hfsmp->hfs_flags &= ~HFS_HAS_SPARSE_DEVICE;
                tmpvp = hfsmp->hfs_backingfs_rootvp;
                hfsmp->hfs_backingfs_rootvp = NULLVP;
                vrele(tmpvp);
        }
#endif /* HFS_SPARSE_DEV */

        hfsmp->hfs_devvp->v_specflags &= ~SI_MOUNTEDON;
        retval = VOP_CLOSE(hfsmp->hfs_devvp,
                           hfsmp->hfs_flags & HFS_READ_ONLY ? FREAD : FREAD|FWRITE,
                           NOCRED, p);
        if (retval && !force)
                return(retval);

        vrele(hfsmp->hfs_devvp);
        FREE(hfsmp, M_HFSMNT);
        mp->mnt_data = (qaddr_t)0;
        return (0);

  err_exit:
        if (hfsmp->jnl && started_tr) {
                journal_end_transaction(hfsmp->jnl);
        }
        if (grabbed_lock) {
                hfs_global_shared_lock_release(hfsmp);
        }
        return retval;
}


/*
 * Return the root of a filesystem.
 *
 *              OUT - vpp, should be locked and vget()'d (to increment usecount and lock)
 */
static int
hfs_root(mp, vpp)
        struct mount *mp;
        struct vnode **vpp;
{
        struct vnode *nvp;
        int retval;
        UInt32 rootObjID = kRootDirID;

        if ((retval = VFS_VGET(mp, &rootObjID, &nvp)))
                return (retval);

        *vpp = nvp;
        return (0);
}


/*
 * Do operations associated with quotas
 */
int
hfs_quotactl(mp, cmds, uid, arg, p)
        struct mount *mp;
        int cmds;
        uid_t uid;
        caddr_t arg;
        struct proc *p;
{
        int cmd, type, error;

#if !QUOTA
        return (EOPNOTSUPP);
#else
        if (uid == -1)
                uid = p->p_cred->p_ruid;
        cmd = cmds >> SUBCMDSHIFT;

        switch (cmd) {
        case Q_SYNC:
        case Q_QUOTASTAT:
                break;
        case Q_GETQUOTA:
                if (uid == p->p_cred->p_ruid)
                        break;
                /* fall through */
        default:
                if (error = suser(p->p_ucred, &p->p_acflag))
                        return (error);
        }

        type = cmds & SUBCMDMASK;
        if ((u_int)type >= MAXQUOTAS)
                return (EINVAL);
        if (vfs_busy(mp, LK_NOWAIT, 0, p))
                return (0);

        switch (cmd) {

        case Q_QUOTAON:
                error = hfs_quotaon(p, mp, type, arg, UIO_USERSPACE);
                break;

        case Q_QUOTAOFF:
                error = hfs_quotaoff(p, mp, type);
                break;

        case Q_SETQUOTA:
                error = hfs_setquota(mp, uid, type, arg);
                break;

        case Q_SETUSE:
                error = hfs_setuse(mp, uid, type, arg);
                break;

        case Q_GETQUOTA:
                error = hfs_getquota(mp, uid, type, arg);
                break;

        case Q_SYNC:
                error = hfs_qsync(mp);
                break;

        case Q_QUOTASTAT:
                error = hfs_quotastat(mp, type, arg);
                break;

        default:
                error = EINVAL;
                break;
        }
        vfs_unbusy(mp, p);
        return (error);
#endif /* QUOTA */
}




/*
 * Get file system statistics.
 */
static int
hfs_statfs(mp, sbp, p)
        struct mount *mp;
        register struct statfs *sbp;
        struct proc *p;
{
        ExtendedVCB *vcb = VFSTOVCB(mp);
        struct hfsmount *hfsmp = VFSTOHFS(mp);
        u_long freeCNIDs;

        freeCNIDs = (u_long)0xFFFFFFFF - (u_long)vcb->vcbNxtCNID;

        sbp->f_bsize = vcb->blockSize;
        sbp->f_iosize = hfsmp->hfs_logBlockSize;
        sbp->f_blocks = vcb->totalBlocks;
        sbp->f_bfree = hfs_freeblks(hfsmp, 0);
        sbp->f_bavail = hfs_freeblks(hfsmp, 1);
        sbp->f_files = vcb->totalBlocks - 2;  /* max files is constrained by total blocks */
        sbp->f_ffree = MIN(freeCNIDs, sbp->f_bavail);
        
        sbp->f_type = 0;
        if (sbp != &mp->mnt_stat) {
                sbp->f_type = mp->mnt_vfc->vfc_typenum;
                bcopy((caddr_t)mp->mnt_stat.f_mntonname,
                        (caddr_t)&sbp->f_mntonname[0], MNAMELEN);
                bcopy((caddr_t)mp->mnt_stat.f_mntfromname,
                        (caddr_t)&sbp->f_mntfromname[0], MNAMELEN);
        }
        return (0);
}


//
// XXXdbg -- this is a callback to be used by the journal to
//           get meta data blocks flushed out to disk.
//
// XXXdbg -- be smarter and don't flush *every* block on each
//           call.  try to only flush some so we don't wind up
//           being too synchronous.
//
__private_extern__
void
hfs_sync_metadata(void *arg)
{
        struct mount *mp = (struct mount *)arg;
        struct cnode *cp;
        struct hfsmount *hfsmp;
        ExtendedVCB *vcb;
        struct vnode *meta_vp[3];
        struct buf *bp;
        int i, sectorsize, priIDSector, altIDSector, retval;
        int error, allerror = 0;

        hfsmp = VFSTOHFS(mp);
        vcb = HFSTOVCB(hfsmp);

        bflushq(BQ_META, mp);


#if 1     // XXXdbg - I do not believe this is necessary...
          //          but if I pull it out, then the journal
              //          does not seem to get flushed properly
              //          when it is closed....
        
        // now make sure the super block is flushed
        sectorsize = hfsmp->hfs_phys_block_size;
        priIDSector = (vcb->hfsPlusIOPosOffset / sectorsize) +
                  HFS_PRI_SECTOR(sectorsize);
        retval = meta_bread(hfsmp->hfs_devvp, priIDSector, sectorsize, NOCRED, &bp);
        if (retval != 0) {
                panic("hfs: sync_metadata: can't read super-block?! (retval 0x%x, priIDSector)\n",
                          retval, priIDSector);
        }

        if (retval == 0 && (bp->b_flags & B_DELWRI) && (bp->b_flags & B_LOCKED) == 0) {
            bwrite(bp);
        } else if (bp) {
            brelse(bp);
        }

        // the alternate super block...
        // XXXdbg - we probably don't need to do this each and every time.
        //          hfs_btreeio.c:FlushAlternate() should flag when it was
        //          written...
        altIDSector = (vcb->hfsPlusIOPosOffset / sectorsize) +
                        HFS_ALT_SECTOR(sectorsize, hfsmp->hfs_phys_block_count);
        retval = meta_bread(hfsmp->hfs_devvp, altIDSector, sectorsize, NOCRED, &bp);
        if (retval == 0 && (bp->b_flags & B_DELWRI) && (bp->b_flags & B_LOCKED) == 0) {
            bwrite(bp);
        } else if (bp) {
            brelse(bp);
        }
#endif
        
}

/*
 * Go through the disk queues to initiate sandbagged IO;
 * go through the inodes to write those that have been modified;
 * initiate the writing of the super block if it has been modified.
 *
 * Note: we are always called with the filesystem marked `MPBUSY'.
 */
static int
hfs_sync(mp, waitfor, cred, p)
        struct mount *mp;
        int waitfor;
        struct ucred *cred;
        struct proc *p;
{
        struct vnode *nvp, *vp;
        struct cnode *cp;
        struct hfsmount *hfsmp;
        ExtendedVCB *vcb;
        struct vnode *meta_vp[3];
        int i;
        int error, allerror = 0;

        /*
         * During MNT_UPDATE hfs_changefs might be manipulating
         * vnodes so back off
         */
        if (mp->mnt_flag & MNT_UPDATE)
                return (0);

        hfsmp = VFSTOHFS(mp);
        if (hfsmp->hfs_flags & HFS_READ_ONLY)
                return (EROFS);

#if 0
        // XXXdbg first go through and flush out any modified
        //        meta data blocks so they go out in order...
        bflushq(BQ_META, mp);
        bflushq(BQ_LRU,  mp);
        // only flush locked blocks if we're not doing journaling
        if (hfsmp->jnl == NULL) {
            bflushq(BQ_LOCKED, mp);
        }
#endif

        /*
         * Write back each 'modified' vnode
         */

loop:
        simple_lock(&mntvnode_slock);
        for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nvp) {
                 int didhold;
                /*
                 * If the vnode that we are about to sync is no longer
                 * associated with this mount point, start over.
                 */
                if (vp->v_mount != mp) {
                        simple_unlock(&mntvnode_slock);
                        goto loop;
                }

                simple_lock(&vp->v_interlock);
                nvp = vp->v_mntvnodes.le_next;

                cp = VTOC(vp);

                // restart our whole search if this guy is locked
                // or being reclaimed.
                if (vp->v_tag != VT_HFS || cp == NULL || vp->v_flag & (VXLOCK|VORECLAIM)) {
                        simple_unlock(&vp->v_interlock);
                        continue;
                }

                if ((vp->v_flag & VSYSTEM) || (vp->v_type == VNON) ||
                    (((cp->c_flag & (C_ACCESS | C_CHANGE | C_MODIFIED | C_UPDATE)) == 0) &&
                    (vp->v_dirtyblkhd.lh_first == NULL) && !(vp->v_flag & VHASDIRTY))) {
                        simple_unlock(&vp->v_interlock);
                        simple_unlock(&mntvnode_slock);
                        simple_lock(&mntvnode_slock);
                        continue;
                }

                simple_unlock(&mntvnode_slock);
                error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, p);
                if (error) {
                        if (error == ENOENT) {
                                /*
                                 * If vnode is being reclaimed, yield so
                                 * that it can be removed from our list.
                                 */
                                if (UBCISVALID(vp))
                                        (void) tsleep((caddr_t)&lbolt, PINOD, "hfs_sync", 0);
                                goto loop;
                        }
                        simple_lock(&mntvnode_slock);
                        continue;
                }
                
                didhold = ubc_hold(vp);

                // mark the cnode so that fsync won't flush
                // the journal since we're going to do that...
                cp->c_flag |= C_FROMSYNC;
                if ((error = VOP_FSYNC(vp, cred, waitfor, p))) {
                        allerror = error;
                };
                cp->c_flag &= ~C_FROMSYNC;

                VOP_UNLOCK(vp, 0, p);
                if (didhold)
                        ubc_rele(vp);
                vrele(vp);
                simple_lock(&mntvnode_slock);
        };

        vcb = HFSTOVCB(hfsmp);

        meta_vp[0] = vcb->extentsRefNum;
        meta_vp[1] = vcb->catalogRefNum;
        meta_vp[2] = vcb->allocationsRefNum;  /* This is NULL for standard HFS */

        /* Now sync our three metadata files */
        for (i = 0; i < 3; ++i) {
                struct vnode *btvp;

                btvp = btvp = meta_vp[i];;
                if ((btvp==0) || (btvp->v_type == VNON) || (btvp->v_mount != mp))
                        continue;

                simple_lock(&btvp->v_interlock);
                cp = VTOC(btvp);
                if (((cp->c_flag & (C_ACCESS | C_CHANGE | C_MODIFIED | C_UPDATE)) == 0) &&
                    (btvp->v_dirtyblkhd.lh_first == NULL) && !(btvp->v_flag & VHASDIRTY)) {
                        simple_unlock(&btvp->v_interlock);
                        continue;
                }
                simple_unlock(&mntvnode_slock);
                error = vget(btvp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, p);
                if (error) {
                        simple_lock(&mntvnode_slock);
                        continue;
                }
                if ((error = VOP_FSYNC(btvp, cred, waitfor, p)))
                        allerror = error;
                VOP_UNLOCK(btvp, 0, p);
                vrele(btvp);
                simple_lock(&mntvnode_slock);
        };

        simple_unlock(&mntvnode_slock);

        /*
         * Force stale file system control information to be flushed.
         */
        if (vcb->vcbSigWord == kHFSSigWord) {
                if ((error = VOP_FSYNC(hfsmp->hfs_devvp, cred, waitfor, p)))
                        allerror = error;
        }
#if QUOTA
        hfs_qsync(mp);
#endif /* QUOTA */

        hfs_hotfilesync(hfsmp, p);
        /*
         * Write back modified superblock.
         */

        if (IsVCBDirty(vcb)) {
                // XXXdbg - debugging, remove
                if (hfsmp->jnl) {
                        //printf("hfs: sync: strange, a journaled volume w/dirty VCB? jnl 0x%x hfsmp 0x%x\n",
                        //        hfsmp->jnl, hfsmp);
                }

                error = hfs_flushvolumeheader(hfsmp, waitfor, 0);
                if (error)
                        allerror = error;
        }

        if (hfsmp->jnl) {
            journal_flush(hfsmp->jnl);
        }
        
  err_exit:
        return (allerror);
}


/*
 * File handle to vnode
 *
 * Have to be really careful about stale file handles:
 * - check that the cnode id is valid
 * - call hfs_vget() to get the locked cnode
 * - check for an unallocated cnode (i_mode == 0)
 * - check that the given client host has export rights and return
 *   those rights via. exflagsp and credanonp
 */
static int
hfs_fhtovp(mp, fhp, nam, vpp, exflagsp, credanonp)
        register struct mount *mp;
        struct fid *fhp;
        struct mbuf *nam;
        struct vnode **vpp;
        int *exflagsp;
        struct ucred **credanonp;
{
        struct hfsfid *hfsfhp;
        struct vnode *nvp;
        int result;
        struct netcred *np;

        *vpp = NULL;
        hfsfhp = (struct hfsfid *)fhp;

        /*
         * Get the export permission structure for this <mp, client> tuple.
         */
        np = vfs_export_lookup(mp, &VFSTOHFS(mp)->hfs_export, nam);
        if (nam && (np == NULL)) {
                return EACCES;
        };

        result = VFS_VGET(mp, &hfsfhp->hfsfid_cnid, &nvp);
        if (result) return result;
        if (nvp == NULL) return ESTALE;
        
        /* The createtime can be changed by hfs_setattr or hfs_setattrlist.
         * For NFS, we are assuming that only if the createtime was moved
         * forward would it mean the fileID got reused in that session by
         * wrapping. We don't have a volume ID or other unique identifier to
         * to use here for a generation ID across reboots, crashes where 
         * metadata noting lastFileID didn't make it to disk but client has
         * it, or volume erasures where fileIDs start over again. Lastly,
         * with HFS allowing "wraps" of fileIDs now, this becomes more
         * error prone. Future, would be change the "wrap bit" to a unique
         * wrap number and use that for generation number. For now do this.
         */  
        if ((hfsfhp->hfsfid_gen < VTOC(nvp)->c_itime)) {
                vput(nvp);
                return (ESTALE);
        };
        
        if (VNAME(nvp) == NULL) {
            struct cnode *cp = VTOC(nvp);
            
            if (nvp == cp->c_rsrc_vp) {
                // the +1/-2 thing is to skip the leading "/" on the rsrc fork spec
                // and to not count the trailing null byte at the end of the string.
                VNAME(nvp) = add_name(_PATH_RSRCFORKSPEC+1, sizeof(_PATH_RSRCFORKSPEC)-2, 0, 0);
            } else {
                VNAME(nvp) = add_name(cp->c_desc.cd_nameptr, cp->c_desc.cd_namelen, 0, 0);
            }
        }

        *vpp = nvp;
        if (np) {
                *exflagsp = np->netc_exflags;
                *credanonp = &np->netc_anon;
        }
        
        return (0);
}


/*
 * Vnode pointer to File handle
 */
/* ARGSUSED */
static int
hfs_vptofh(vp, fhp)
        struct vnode *vp;
        struct fid *fhp;
{
        struct cnode *cp;
        struct hfsfid *hfsfhp;

        if (ISHFS(VTOVCB(vp)))
                return (EOPNOTSUPP);    /* hfs standard is not exportable */

        cp = VTOC(vp);
        hfsfhp = (struct hfsfid *)fhp;
        hfsfhp->hfsfid_len = sizeof(struct hfsfid);
        hfsfhp->hfsfid_pad = 0;
        hfsfhp->hfsfid_cnid = cp->c_fileid;
        hfsfhp->hfsfid_gen = cp->c_itime;
        
        return (0);
}


/*
 * Initial HFS filesystems, done only once.
 */
static int
hfs_init(vfsp)
        struct vfsconf *vfsp;
{
        static int done = 0;

        if (done)
                return (0);
        done = 1;
        hfs_chashinit();
        hfs_converterinit();
#if QUOTA
        dqinit();
#endif /* QUOTA */

        BTReserveSetup();

        /*
         * Allocate Catalog Iterator cache...
         */
        (void) InitCatalogCache();

        return (0);
}

static int
hfs_getmountpoint(vp, hfsmpp)
        struct vnode *vp;
        struct hfsmount **hfsmpp;
{
        struct hfsmount * hfsmp;

        if (vp == NULL)
                return (EINVAL);
        
        if ((vp->v_flag & VROOT) == 0)
                return (EINVAL);

        if (strcmp(vp->v_mount->mnt_stat.f_fstypename, "hfs") != 0)
                return (EINVAL);

        hfsmp = VTOHFS(vp);

        if (HFSTOVCB(hfsmp)->vcbSigWord == kHFSSigWord)
                return (EINVAL);

        *hfsmpp = hfsmp;

        return (0);
}

// XXXdbg
#include <sys/filedesc.h>


/*
 * HFS filesystem related variables.
 */
static int
hfs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
        int *name;
        u_int namelen;
        void *oldp;
        size_t *oldlenp;
        void *newp;
        size_t newlen;
        struct proc *p;
{
        extern u_int32_t  hfs_getencodingbias(void);
        extern void  hfs_setencodingbias(u_int32_t);

        int error;
        struct sysctl_req *req;
        struct vfsidctl vc;
        struct mount *mp;
        struct hfsmount *hfsmp;
        struct vfsquery vq;

        /* all sysctl names at this level are terminal */

        if (name[0] == HFS_ENCODINGBIAS) {
                u_int32_t bias;

                bias = hfs_getencodingbias();
                error = sysctl_int(oldp, oldlenp, newp, newlen, &bias);
                if (error == 0 && newp)
                        hfs_setencodingbias(bias);
                return (error);

        } else if (name[0] == HFS_EXTEND_FS) {
                u_int64_t  newsize;
                
                if (newp == NULL)
                        return (EINVAL);
                if ((error = hfs_getmountpoint(p->p_fd->fd_cdir, &hfsmp)))
                        return (error);
                error = sysctl_quad(oldp, oldlenp, newp, newlen, &newsize);
                if (error)
                        return (error);
        
                error = hfs_extendfs(HFSTOVFS(hfsmp), newsize, p);              
                return (error);

        } else if (name[0] == HFS_ENCODINGHINT) {
                size_t bufsize;
                size_t bytes;
                u_int32_t hint;
                u_int16_t *unicode_name;
                char *filename;

                bufsize = MAX(newlen * 3, MAXPATHLEN);
                MALLOC(filename, char *, newlen, M_TEMP, M_WAITOK);
                MALLOC(unicode_name, u_int16_t *, bufsize, M_TEMP, M_WAITOK);

                error = copyin(newp, (caddr_t)filename, newlen);
                if (error == 0) {
                        error = utf8_decodestr(filename, newlen - 1, unicode_name,
                                               &bytes, bufsize, 0, UTF_DECOMPOSED);
                        if (error == 0) {
                                hint = hfs_pickencoding(unicode_name, bytes / 2);
                                error = sysctl_int(oldp, oldlenp, NULL, NULL, &hint);
                        }
                }
                FREE(unicode_name, M_TEMP);
                FREE(filename, M_TEMP);
                return (error);

        } else if (name[0] == HFS_ENABLE_JOURNALING) {
                // make the file system journaled...
                struct vnode *vp = p->p_fd->fd_cdir, *jvp;
                ExtendedVCB *vcb;
                int retval;
                struct cat_attr jnl_attr, jinfo_attr;
                struct cat_fork jnl_fork, jinfo_fork;
                void *jnl = NULL;

                /* Only root can enable journaling */
                if (current_proc()->p_ucred->cr_uid != 0) {
                        return (EPERM);
                }

                hfsmp = VTOHFS(vp);
                if (hfsmp->hfs_flags & HFS_READ_ONLY) {
                        return EROFS;
                }
                if (HFSTOVCB(hfsmp)->vcbSigWord == kHFSSigWord) {
                        printf("hfs: can't make a plain hfs volume journaled.\n");
                        return EINVAL;
                }

                if (hfsmp->jnl) {
                    printf("hfs: volume @ mp 0x%x is already journaled!\n", vp->v_mount);
                    return EAGAIN;
                }

                vcb = HFSTOVCB(hfsmp);
                if (BTHasContiguousNodes(VTOF(vcb->catalogRefNum)) == 0 ||
                        BTHasContiguousNodes(VTOF(vcb->extentsRefNum)) == 0) {

                        printf("hfs: volume has a btree w/non-contiguous nodes.  can not enable journaling.\n");
                        return EINVAL;
                }

                // make sure these both exist!
                if (   GetFileInfo(vcb, kRootDirID, ".journal_info_block", &jinfo_attr, &jinfo_fork) == 0
                        || GetFileInfo(vcb, kRootDirID, ".journal", &jnl_attr, &jnl_fork) == 0) {

                        return EINVAL;
                }

                hfs_sync(hfsmp->hfs_mp, MNT_WAIT, FSCRED, p);
                bflushq(BQ_META);

                printf("hfs: Initializing the journal (joffset 0x%llx sz 0x%llx)...\n",
                           (off_t)name[2], (off_t)name[3]);

                jvp = hfsmp->hfs_devvp;
                jnl = journal_create(jvp,
                                                         (off_t)name[2] * (off_t)HFSTOVCB(hfsmp)->blockSize
                                                         + HFSTOVCB(hfsmp)->hfsPlusIOPosOffset,
                                                         (off_t)((unsigned)name[3]),
                                                         hfsmp->hfs_devvp,
                                                         hfsmp->hfs_phys_block_size,
                                                         0,
                                                         0,
                                                         hfs_sync_metadata, hfsmp->hfs_mp);

                if (jnl == NULL) {
                        printf("hfs: FAILED to create the journal!\n");
                        if (jvp && jvp != hfsmp->hfs_devvp) {
                                VOP_CLOSE(jvp, hfsmp->hfs_flags & HFS_READ_ONLY ? FREAD : FREAD|FWRITE, FSCRED, p);
                        }
                        jvp = NULL;

                        return EINVAL;
                } 

                hfs_global_exclusive_lock_acquire(hfsmp);
                
                HFSTOVCB(hfsmp)->vcbJinfoBlock = name[1];
                HFSTOVCB(hfsmp)->vcbAtrb |= kHFSVolumeJournaledMask;
                hfsmp->jvp = jvp;
                hfsmp->jnl = jnl;

                // save this off for the hack-y check in hfs_remove()
                hfsmp->jnl_start        = (u_int32_t)name[2];
                hfsmp->jnl_size         = (off_t)((unsigned)name[3]);
                hfsmp->hfs_jnlinfoblkid = jinfo_attr.ca_fileid;
                hfsmp->hfs_jnlfileid    = jnl_attr.ca_fileid;

                hfsmp->hfs_mp->mnt_flag |= MNT_JOURNALED;

                hfs_global_exclusive_lock_release(hfsmp);
                hfs_flushvolumeheader(hfsmp, MNT_WAIT, 1);

                return 0;
        } else if (name[0] == HFS_DISABLE_JOURNALING) {
                // clear the journaling bit 
                struct vnode *vp = p->p_fd->fd_cdir;
                void *jnl;
                int retval;
                
                /* Only root can disable journaling */
                if (current_proc()->p_ucred->cr_uid != 0) {
                        return (EPERM);
                }

                hfsmp = VTOHFS(vp);

                printf("hfs: disabling journaling for mount @ 0x%x\n", vp->v_mount);

                jnl = hfsmp->jnl;
                
                hfs_global_exclusive_lock_acquire(hfsmp);

                // Lights out for you buddy!
                hfsmp->jnl = NULL;
                journal_close(jnl);

                if (hfsmp->jvp && hfsmp->jvp != hfsmp->hfs_devvp) {
                        VOP_CLOSE(hfsmp->jvp, hfsmp->hfs_flags & HFS_READ_ONLY ? FREAD : FREAD|FWRITE, FSCRED, p);
                }
                hfsmp->jnl = NULL;
                hfsmp->jvp = NULL;
                hfsmp->hfs_mp->mnt_flag &= ~MNT_JOURNALED;
                hfsmp->jnl_start        = 0;
                hfsmp->hfs_jnlinfoblkid = 0;
                hfsmp->hfs_jnlfileid    = 0;
                
                HFSTOVCB(hfsmp)->vcbAtrb &= ~kHFSVolumeJournaledMask;
                
                hfs_global_exclusive_lock_release(hfsmp);
                hfs_flushvolumeheader(hfsmp, MNT_WAIT, 1);

                return 0;
        } else if (name[0] == HFS_GET_JOURNAL_INFO) {
                struct vnode *vp = p->p_fd->fd_cdir;
                off_t jnl_start, jnl_size;

                hfsmp = VTOHFS(vp);
            if (hfsmp->jnl == NULL) {
                        jnl_start = 0;
                        jnl_size  = 0;
            } else {
                        jnl_start = (off_t)(hfsmp->jnl_start * HFSTOVCB(hfsmp)->blockSize) + (off_t)HFSTOVCB(hfsmp)->hfsPlusIOPosOffset;
                        jnl_size  = (off_t)hfsmp->jnl_size;
            }

            if ((error = copyout((caddr_t)&jnl_start, (void *)name[1], sizeof(off_t))) != 0) {
                        return error;
                }
            if ((error = copyout((caddr_t)&jnl_size, (void *)name[2], sizeof(off_t))) != 0) {
                        return error;
                }

                return 0;
        } else if (name[0] == HFS_SET_PKG_EXTENSIONS) {

            return set_package_extensions_table((void *)name[1], name[2], name[3]);
            
        } else if (name[0] == VFS_CTL_QUERY) {
                req = oldp;     /* we're new style vfs sysctl. */
        
                error = SYSCTL_IN(req, &vc, sizeof(vc));
                if (error) return (error);
        
                mp = vfs_getvfs(&vc.vc_fsid);
                if (mp == NULL) return (ENOENT);
        
                hfsmp = VFSTOHFS(mp);
                bzero(&vq, sizeof(vq));
                vq.vq_flags = hfsmp->hfs_notification_conditions;
                return SYSCTL_OUT(req, &vq, sizeof(vq));;
        };

        return (EOPNOTSUPP);
}


/*      This will return a vnode of either a directory or a data vnode based on an object id. If
 *  it is a file id, its data fork will be returned.
 */
static int
hfs_vget(mp, ino, vpp)
        struct mount *mp;
        void *ino;
        struct vnode **vpp;
{
        cnid_t cnid = *(cnid_t *)ino;
        
        /* Check for cnids that should't be exported. */
        if ((cnid < kHFSFirstUserCatalogNodeID)
        &&  (cnid != kHFSRootFolderID && cnid != kHFSRootParentID))
                return (ENOENT);
        /* Don't export HFS Private Data dir. */
        if (cnid == VFSTOHFS(mp)->hfs_privdir_desc.cd_cnid)
                return (ENOENT);

        return (hfs_getcnode(VFSTOHFS(mp), cnid, NULL, 0, NULL, NULL, vpp));
}

/*
 * Check to see if a given vnode is only referenced for events:
 * [ entered with vp->v_interlock locked ]
 */
static int
hfs_evtonly(struct vnode *vp)
{
    int ubc_refcount;

    ubc_refcount = UBCINFOEXISTS(vp) ? 1 : 0;
    return (vp->v_usecount == (ubc_refcount + EVTONLYREFS(vp)));
}

/*
 * Check to see if all non-system vnodes for a given mountpoint are events-only
 */
static int
hfs_flush_evtonly(struct mount *mp, int flags, int dispose, struct proc *p)
{
        struct vnode *vp, *nvp;
        int busy = 0;
    
        simple_lock(&mntvnode_slock);
loop:
        for (vp = LIST_FIRST(&mp->mnt_vnodelist); vp; vp = nvp) {
                if (vp->v_mount != mp) goto loop;
                nvp = vp->v_mntvnodes.le_next;
        
                simple_lock(&vp->v_interlock);
        /*
         * Skip over a vnodes marked VSYSTEM or VNOFLUSH.
         */
        if ((flags & SKIPSYSTEM) && ((vp->v_flag & VSYSTEM) || (vp->v_flag & VNOFLUSH))) {
            simple_unlock(&vp->v_interlock);
            continue;
        };
                /*
                 * Skip over a vnodes marked VSWAP.
                 */
                if ((flags & SKIPSWAP) && (vp->v_flag & VSWAP)) {
                        simple_unlock(&vp->v_interlock);
                        continue;
                }
        if (hfs_evtonly(vp)) {
            if (dispose) {
                /* "dispose" implies "forcibly", a la "FORCECLOSE": */
                simple_unlock(&mntvnode_slock);
                vgonel(vp, p);
                simple_lock(&mntvnode_slock);
            } else {
                simple_unlock(&vp->v_interlock);
            };
            continue;
        };
        
        simple_unlock(&vp->v_interlock);
        ++busy;
        /* If asked to dispose, keep trying.  If only checking, the answer is now known. */
        if (dispose) {
            continue;
        } else {
            break;
        };
    }
        simple_unlock(&mntvnode_slock);
    
    return (busy == 0);
}

/*
 * Flush out all the files in a filesystem.
 */
static int
hfs_flushfiles(struct mount *mp, int flags, struct proc *p)
{
        struct hfsmount *hfsmp;
        struct vnode *skipvp = NULLVP;
        struct vnode *rsrcvp;
        int quotafilecnt;
        int i;
        int error;

        hfsmp = VFSTOHFS(mp);

#if QUOTA
        /*
         * The open quota files have an indirect reference on
         * the root directory vnode.  We must account for this
         * extra reference when doing the intial vflush.
         */
        quotafilecnt = 0;
        if (mp->mnt_flag & MNT_QUOTA) {

                /* Find out how many quota files we have open. */
                for (i = 0; i < MAXQUOTAS; i++) {
                        if (hfsmp->hfs_qfiles[i].qf_vp != NULLVP)
                                ++quotafilecnt;
                }

                /* Obtain the root vnode so we can skip over it. */
                if (hfs_chashget(hfsmp->hfs_raw_dev, kRootDirID, 0,
                                 &skipvp, &rsrcvp) == NULL) {
                        skipvp = NULLVP;
                }
        }
#endif /* QUOTA */

        error = vflush(mp, skipvp, SKIPSYSTEM | SKIPSWAP | flags);
        /*
         * If the vflush() call failed solely because there are
         * some event-only vnodes in the list, then forcibly get
         * rid of those vnodes before the final vflush() pass.
         */
        if ((error == EBUSY) && hfs_flush_evtonly(mp, SKIPSYSTEM | SKIPSWAP, 0, p)) {
                (void) hfs_flush_evtonly(mp, SKIPSYSTEM | SKIPSWAP, 1, p);
        };
        error = vflush(mp, skipvp, SKIPSYSTEM | flags);

#if QUOTA
        if (mp->mnt_flag & MNT_QUOTA) {
                if (skipvp) {
                        /*
                         * See if there are additional references on the
                         * root vp besides the ones obtained from the open
                         * quota files and the hfs_chashget call above.
                         */
                        if ((error == 0) &&
                            (skipvp->v_usecount > (1 + quotafilecnt))) {
                                error = EBUSY;  /* root directory is still open */
                        }
                        vput(skipvp);
                }
                if (error && (flags & FORCECLOSE) == 0)
                        return (error);

                for (i = 0; i < MAXQUOTAS; i++) {
                        if (hfsmp->hfs_qfiles[i].qf_vp == NULLVP)
                                continue;
                        hfs_quotaoff(p, mp, i);
                }
                error = vflush(mp, NULLVP, SKIPSYSTEM | flags);
        }
#endif /* QUOTA */

        return (error);
}

/*
 * Update volume encoding bitmap (HFS Plus only)
 */
__private_extern__
void
hfs_setencodingbits(struct hfsmount *hfsmp, u_int32_t encoding)
{
#define  kIndexMacUkrainian     48  /* MacUkrainian encoding is 152 */
#define  kIndexMacFarsi         49  /* MacFarsi encoding is 140 */

        UInt32  index;

        switch (encoding) {
        case kTextEncodingMacUkrainian:
                index = kIndexMacUkrainian;
                break;
        case kTextEncodingMacFarsi:
                index = kIndexMacFarsi;
                break;
        default:
                index = encoding;
                break;
        }

        if (index < 64) {
                HFSTOVCB(hfsmp)->encodingsBitmap |= (u_int64_t)(1ULL << index);
                HFSTOVCB(hfsmp)->vcbFlags |= 0xFF00;
        }
}

/*
 * Update volume stats
 */
__private_extern__
int
hfs_volupdate(struct hfsmount *hfsmp, enum volop op, int inroot)
{
        ExtendedVCB *vcb;

        vcb = HFSTOVCB(hfsmp);
        vcb->vcbFlags |= 0xFF00;
        vcb->vcbLsMod = time.tv_sec;

        switch (op) {
        case VOL_UPDATE:
                break;
        case VOL_MKDIR:
                if (vcb->vcbDirCnt != 0xFFFFFFFF)
                        ++vcb->vcbDirCnt;
                if (inroot && vcb->vcbNmRtDirs != 0xFFFF)
                        ++vcb->vcbNmRtDirs;
                break;
        case VOL_RMDIR:
                if (vcb->vcbDirCnt != 0)
                        --vcb->vcbDirCnt;
                if (inroot && vcb->vcbNmRtDirs != 0xFFFF)
                        --vcb->vcbNmRtDirs;
                break;
        case VOL_MKFILE:
                if (vcb->vcbFilCnt != 0xFFFFFFFF)
                        ++vcb->vcbFilCnt;
                if (inroot && vcb->vcbNmFls != 0xFFFF)
                        ++vcb->vcbNmFls;
                break;
        case VOL_RMFILE:
                if (vcb->vcbFilCnt != 0)
                        --vcb->vcbFilCnt;
                if (inroot && vcb->vcbNmFls != 0xFFFF)
                        --vcb->vcbNmFls;
                break;
        }

        if (hfsmp->jnl) {
                hfs_flushvolumeheader(hfsmp, 0, 0);
        }

        return (0);
}


static int
hfs_flushMDB(struct hfsmount *hfsmp, int waitfor, int altflush)
{
        ExtendedVCB *vcb = HFSTOVCB(hfsmp);
        struct filefork *fp;
        HFSMasterDirectoryBlock *mdb;
        struct buf *bp = NULL;
        int retval;
        int sectorsize;
        ByteCount namelen;

        sectorsize = hfsmp->hfs_phys_block_size;
        retval = bread(hfsmp->hfs_devvp, HFS_PRI_SECTOR(sectorsize), sectorsize, NOCRED, &bp);
        if (retval) {
                if (bp)
                        brelse(bp);
                return retval;
        }

        DBG_ASSERT(bp != NULL);
        DBG_ASSERT(bp->b_data != NULL);
        DBG_ASSERT(bp->b_bcount == size);

        if (hfsmp->jnl) {
                panic("hfs: standard hfs volumes should not be journaled!\n");
        }

        mdb = (HFSMasterDirectoryBlock *)(bp->b_data + HFS_PRI_OFFSET(sectorsize));
    
        mdb->drCrDate   = SWAP_BE32 (UTCToLocal(to_hfs_time(vcb->vcbCrDate)));
        mdb->drLsMod    = SWAP_BE32 (UTCToLocal(to_hfs_time(vcb->vcbLsMod)));
        mdb->drAtrb     = SWAP_BE16 (vcb->vcbAtrb);
        mdb->drNmFls    = SWAP_BE16 (vcb->vcbNmFls);
        mdb->drAllocPtr = SWAP_BE16 (vcb->nextAllocation);
        mdb->drClpSiz   = SWAP_BE32 (vcb->vcbClpSiz);
        mdb->drNxtCNID  = SWAP_BE32 (vcb->vcbNxtCNID);
        mdb->drFreeBks  = SWAP_BE16 (vcb->freeBlocks);

        namelen = strlen(vcb->vcbVN);
        retval = utf8_to_hfs(vcb, namelen, vcb->vcbVN, mdb->drVN);
        /* Retry with MacRoman in case that's how it was exported. */
        if (retval)
                retval = utf8_to_mac_roman(namelen, vcb->vcbVN, mdb->drVN);
        
        mdb->drVolBkUp  = SWAP_BE32 (UTCToLocal(to_hfs_time(vcb->vcbVolBkUp)));
        mdb->drWrCnt    = SWAP_BE32 (vcb->vcbWrCnt);
        mdb->drNmRtDirs = SWAP_BE16 (vcb->vcbNmRtDirs);
        mdb->drFilCnt   = SWAP_BE32 (vcb->vcbFilCnt);
        mdb->drDirCnt   = SWAP_BE32 (vcb->vcbDirCnt);
        
        bcopy(vcb->vcbFndrInfo, mdb->drFndrInfo, sizeof(mdb->drFndrInfo));

        fp = VTOF(vcb->extentsRefNum);
        mdb->drXTExtRec[0].startBlock = SWAP_BE16 (fp->ff_extents[0].startBlock);
        mdb->drXTExtRec[0].blockCount = SWAP_BE16 (fp->ff_extents[0].blockCount);
        mdb->drXTExtRec[1].startBlock = SWAP_BE16 (fp->ff_extents[1].startBlock);
        mdb->drXTExtRec[1].blockCount = SWAP_BE16 (fp->ff_extents[1].blockCount);
        mdb->drXTExtRec[2].startBlock = SWAP_BE16 (fp->ff_extents[2].startBlock);
        mdb->drXTExtRec[2].blockCount = SWAP_BE16 (fp->ff_extents[2].blockCount);
        mdb->drXTFlSize = SWAP_BE32 (fp->ff_blocks * vcb->blockSize);
        mdb->drXTClpSiz = SWAP_BE32 (fp->ff_clumpsize);
        
        fp = VTOF(vcb->catalogRefNum);
        mdb->drCTExtRec[0].startBlock = SWAP_BE16 (fp->ff_extents[0].startBlock);
        mdb->drCTExtRec[0].blockCount = SWAP_BE16 (fp->ff_extents[0].blockCount);
        mdb->drCTExtRec[1].startBlock = SWAP_BE16 (fp->ff_extents[1].startBlock);
        mdb->drCTExtRec[1].blockCount = SWAP_BE16 (fp->ff_extents[1].blockCount);
        mdb->drCTExtRec[2].startBlock = SWAP_BE16 (fp->ff_extents[2].startBlock);
        mdb->drCTExtRec[2].blockCount = SWAP_BE16 (fp->ff_extents[2].blockCount);
        mdb->drCTFlSize = SWAP_BE32 (fp->ff_blocks * vcb->blockSize);
        mdb->drCTClpSiz = SWAP_BE32 (fp->ff_clumpsize);

        /* If requested, flush out the alternate MDB */
        if (altflush) {
                struct buf *alt_bp = NULL;
                u_long altIDSector;

                altIDSector = HFS_ALT_SECTOR(sectorsize, hfsmp->hfs_phys_block_count);

                if (meta_bread(hfsmp->hfs_devvp, altIDSector, sectorsize, NOCRED, &alt_bp) == 0) {
                        bcopy(mdb, alt_bp->b_data + HFS_ALT_OFFSET(sectorsize), kMDBSize);

                        (void) VOP_BWRITE(alt_bp);
                } else if (alt_bp)
                        brelse(alt_bp);
        }

        if (waitfor != MNT_WAIT)
                bawrite(bp);
        else 
                retval = VOP_BWRITE(bp);
 
        MarkVCBClean( vcb );

        return (retval);
}

/*
 *  Flush any dirty in-memory mount data to the on-disk
 *  volume header.
 *
 *  Note: the on-disk volume signature is intentionally
 *  not flushed since the on-disk "H+" and "HX" signatures
 *  are always stored in-memory as "H+".
 */
__private_extern__
int
hfs_flushvolumeheader(struct hfsmount *hfsmp, int waitfor, int altflush)
{
        ExtendedVCB *vcb = HFSTOVCB(hfsmp);
        struct filefork *fp;
        HFSPlusVolumeHeader *volumeHeader;
        int retval;
        struct buf *bp;
        int i;
        int sectorsize;
        int priIDSector;
        int critical = 0;
        u_int16_t  signature;
        u_int16_t  version;

        if (hfsmp->hfs_flags & HFS_READ_ONLY) {
                return(0);
        }
        if (vcb->vcbSigWord == kHFSSigWord)
                return hfs_flushMDB(hfsmp, waitfor, altflush);

        if (altflush)
                critical = 1;
        sectorsize = hfsmp->hfs_phys_block_size;
        priIDSector = (vcb->hfsPlusIOPosOffset / sectorsize) +
                        HFS_PRI_SECTOR(sectorsize);

        // XXXdbg
        hfs_global_shared_lock_acquire(hfsmp);
        if (hfsmp->jnl) {
                if (journal_start_transaction(hfsmp->jnl) != 0) {
                        hfs_global_shared_lock_release(hfsmp);
                    return EINVAL;
            }
        }

        retval = meta_bread(hfsmp->hfs_devvp, priIDSector, sectorsize, NOCRED, &bp);
        if (retval) {
                if (bp)
                        brelse(bp);

                if (hfsmp->jnl) {
                        journal_end_transaction(hfsmp->jnl);
                }
                hfs_global_shared_lock_release(hfsmp);

                printf("HFS: err %d reading VH blk (%s)\n", retval, vcb->vcbVN);
                return (retval);
        }

        if (hfsmp->jnl) {
                journal_modify_block_start(hfsmp->jnl, bp);
        }

        volumeHeader = (HFSPlusVolumeHeader *)((char *)bp->b_data + HFS_PRI_OFFSET(sectorsize));

        /*
         * Sanity check what we just read.
         */
        signature = SWAP_BE16 (volumeHeader->signature);
        version   = SWAP_BE16 (volumeHeader->version);
        if ((signature != kHFSPlusSigWord && signature != kHFSXSigWord) ||
            (version < kHFSPlusVersion) || (version > 100) ||
            (SWAP_BE32 (volumeHeader->blockSize) != vcb->blockSize)) {
#if 1
                panic("HFS: corrupt VH on %s, sig 0x%04x, ver %d, blksize %d",
                      vcb->vcbVN, signature, version,
                      SWAP_BE32 (volumeHeader->blockSize));
#endif
                printf("HFS: corrupt VH blk (%s)\n", vcb->vcbVN);
                brelse(bp);
                return (EIO);
        }

        /*
         * For embedded HFS+ volumes, update create date if it changed
         * (ie from a setattrlist call)
         */
        if ((vcb->hfsPlusIOPosOffset != 0) &&
            (SWAP_BE32 (volumeHeader->createDate) != vcb->localCreateDate)) {
                struct buf *bp2;
                HFSMasterDirectoryBlock *mdb;

                retval = meta_bread(hfsmp->hfs_devvp, HFS_PRI_SECTOR(sectorsize),
                                sectorsize, NOCRED, &bp2);
                if (retval) {
                        if (bp2)
                                brelse(bp2);
                        retval = 0;
                } else {
                        mdb = (HFSMasterDirectoryBlock *)(bp2->b_data +
                                HFS_PRI_OFFSET(sectorsize));

                        if ( SWAP_BE32 (mdb->drCrDate) != vcb->localCreateDate )
                          {
                                // XXXdbg
                                if (hfsmp->jnl) {
                                    journal_modify_block_start(hfsmp->jnl, bp2);
                                }

                                mdb->drCrDate = SWAP_BE32 (vcb->localCreateDate);       /* pick up the new create date */

                                // XXXdbg
                                if (hfsmp->jnl) {
                                        journal_modify_block_end(hfsmp->jnl, bp2);
                                } else {
                                        (void) VOP_BWRITE(bp2);         /* write out the changes */
                                }
                          }
                        else
                          {
                                brelse(bp2);                                            /* just release it */
                          }
                  }     
        }

        /* Note: only update the lower 16 bits worth of attributes */
        volumeHeader->attributes        = SWAP_BE32 ((SWAP_BE32 (volumeHeader->attributes) & 0xFFFF0000) + (UInt16) vcb->vcbAtrb);
        volumeHeader->journalInfoBlock = SWAP_BE32(vcb->vcbJinfoBlock);
        if (hfsmp->jnl) {
                volumeHeader->lastMountedVersion = SWAP_BE32 (kHFSJMountVersion);
        } else {
                volumeHeader->lastMountedVersion = SWAP_BE32 (kHFSPlusMountVersion);
        }
        volumeHeader->createDate        = SWAP_BE32 (vcb->localCreateDate);  /* volume create date is in local time */
        volumeHeader->modifyDate        = SWAP_BE32 (to_hfs_time(vcb->vcbLsMod));
        volumeHeader->backupDate        = SWAP_BE32 (to_hfs_time(vcb->vcbVolBkUp));
        volumeHeader->fileCount         = SWAP_BE32 (vcb->vcbFilCnt);
        volumeHeader->folderCount       = SWAP_BE32 (vcb->vcbDirCnt);
        volumeHeader->freeBlocks        = SWAP_BE32 (vcb->freeBlocks);
        volumeHeader->nextAllocation    = SWAP_BE32 (vcb->nextAllocation);
        volumeHeader->rsrcClumpSize     = SWAP_BE32 (vcb->vcbClpSiz);
        volumeHeader->dataClumpSize     = SWAP_BE32 (vcb->vcbClpSiz);
        volumeHeader->nextCatalogID     = SWAP_BE32 (vcb->vcbNxtCNID);
        volumeHeader->writeCount        = SWAP_BE32 (vcb->vcbWrCnt);
        volumeHeader->encodingsBitmap   = SWAP_BE64 (vcb->encodingsBitmap);

        if (bcmp(vcb->vcbFndrInfo, volumeHeader->finderInfo, sizeof(volumeHeader->finderInfo)) != 0)
                critical = 1;
        bcopy(vcb->vcbFndrInfo, volumeHeader->finderInfo, sizeof(volumeHeader->finderInfo));

        /* Sync Extents over-flow file meta data */
        fp = VTOF(vcb->extentsRefNum);
        for (i = 0; i < kHFSPlusExtentDensity; i++) {
                volumeHeader->extentsFile.extents[i].startBlock =
                        SWAP_BE32 (fp->ff_extents[i].startBlock);
                volumeHeader->extentsFile.extents[i].blockCount =
                        SWAP_BE32 (fp->ff_extents[i].blockCount);
        }
        FTOC(fp)->c_flag &= ~C_MODIFIED;
        volumeHeader->extentsFile.logicalSize = SWAP_BE64 (fp->ff_size);
        volumeHeader->extentsFile.totalBlocks = SWAP_BE32 (fp->ff_blocks);
        volumeHeader->extentsFile.clumpSize   = SWAP_BE32 (fp->ff_clumpsize);

        /* Sync Catalog file meta data */
        fp = VTOF(vcb->catalogRefNum);
        for (i = 0; i < kHFSPlusExtentDensity; i++) {
                volumeHeader->catalogFile.extents[i].startBlock =
                        SWAP_BE32 (fp->ff_extents[i].startBlock);
                volumeHeader->catalogFile.extents[i].blockCount =
                        SWAP_BE32 (fp->ff_extents[i].blockCount);
        }
        FTOC(fp)->c_flag &= ~C_MODIFIED;
        volumeHeader->catalogFile.logicalSize = SWAP_BE64 (fp->ff_size);
        volumeHeader->catalogFile.totalBlocks = SWAP_BE32 (fp->ff_blocks);
        volumeHeader->catalogFile.clumpSize   = SWAP_BE32 (fp->ff_clumpsize);

        /* Sync Allocation file meta data */
        fp = VTOF(vcb->allocationsRefNum);
        for (i = 0; i < kHFSPlusExtentDensity; i++) {
                volumeHeader->allocationFile.extents[i].startBlock =
                        SWAP_BE32 (fp->ff_extents[i].startBlock);
                volumeHeader->allocationFile.extents[i].blockCount =
                        SWAP_BE32 (fp->ff_extents[i].blockCount);
        }
        FTOC(fp)->c_flag &= ~C_MODIFIED;
        volumeHeader->allocationFile.logicalSize = SWAP_BE64 (fp->ff_size);
        volumeHeader->allocationFile.totalBlocks = SWAP_BE32 (fp->ff_blocks);
        volumeHeader->allocationFile.clumpSize   = SWAP_BE32 (fp->ff_clumpsize);

        /* If requested, flush out the alternate volume header */
        if (altflush) {
                struct buf *alt_bp = NULL;
                u_long altIDSector;

                altIDSector = (vcb->hfsPlusIOPosOffset / sectorsize) +
                        HFS_ALT_SECTOR(sectorsize, hfsmp->hfs_phys_block_count);

                if (meta_bread(hfsmp->hfs_devvp, altIDSector, sectorsize, NOCRED, &alt_bp) == 0) {
                        if (hfsmp->jnl) {
                                journal_modify_block_start(hfsmp->jnl, alt_bp);
                        }

                        bcopy(volumeHeader, alt_bp->b_data + HFS_ALT_OFFSET(sectorsize), kMDBSize);

                        if (hfsmp->jnl) {
                                journal_modify_block_end(hfsmp->jnl, alt_bp);
                        } else {
                                (void) VOP_BWRITE(alt_bp);
                        }
                } else if (alt_bp)
                        brelse(alt_bp);
        }

        // XXXdbg
        if (hfsmp->jnl) {
                journal_modify_block_end(hfsmp->jnl, bp);
                journal_end_transaction(hfsmp->jnl);
        } else {
                if (waitfor != MNT_WAIT)
                        bawrite(bp);
                else {
                    retval = VOP_BWRITE(bp);
                    /* When critical data changes, flush the device cache */
                    if (critical && (retval == 0)) {
                        (void) VOP_IOCTL(hfsmp->hfs_devvp, DKIOCSYNCHRONIZECACHE,
                                         NULL, FWRITE, NOCRED, current_proc());
                    }
                }
        }
        hfs_global_shared_lock_release(hfsmp);
 
        vcb->vcbFlags &= 0x00FF;
        return (retval);
}


/*
 * Extend a file system.
 */
static int
hfs_extendfs(struct mount *mp, u_int64_t newsize, struct proc *p)
{
        struct  vnode *vp;
        struct  vnode *devvp;
        struct  buf *bp;
        struct  hfsmount *hfsmp;
        struct  filefork *fp = NULL;
        ExtendedVCB  *vcb;
        struct  cat_fork forkdata;
        u_int64_t  oldsize;
        u_int64_t  newblkcnt;
        u_int32_t  addblks;
        u_int64_t  sectorcnt;
        u_int32_t  sectorsize;
        daddr_t  prev_alt_sector;
        daddr_t  bitmapblks;
        int  error;

        hfsmp = VFSTOHFS(mp);
        devvp = hfsmp->hfs_devvp;
        vcb = HFSTOVCB(hfsmp);

        /*
         * - HFS Plus file systems only. 
         * - Journaling must be enabled.
         * - No embedded volumes.
         */
        if ((vcb->vcbSigWord == kHFSSigWord) ||
             (hfsmp->jnl == NULL) ||
             (vcb->hfsPlusIOPosOffset != 0)) {
                return (EPERM);
        }
        /*
         * If extending file system by non-root, then verify
         * ownership and check permissions.
         */
        if (p->p_ucred->cr_uid != 0) {
                error = hfs_root(mp, &vp);
                if (error)
                        return (error);
                error = hfs_owner_rights(hfsmp, VTOC(vp)->c_uid, p->p_ucred, p, 0);
                if (error == 0) {
                        error = hfs_write_access(vp, p->p_ucred, p, false);
                }
                vput(vp);
                if (error)
                        return (error);

                vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, p);
                error = VOP_ACCESS(devvp, VREAD | VWRITE, p->p_ucred, p);
                VOP_UNLOCK(devvp, 0, p);
                if (error)
                        return (error);
        }
        if (VOP_IOCTL(devvp, DKIOCGETBLOCKSIZE, (caddr_t)&sectorsize, 0, FSCRED, p)) {
                return (ENXIO);
        }
        if (sectorsize != hfsmp->hfs_phys_block_size) {
                return (ENXIO);
        }
        if (VOP_IOCTL(devvp, DKIOCGETBLOCKCOUNT, (caddr_t)&sectorcnt, 0, FSCRED, p)) {
                return (ENXIO);
        }
        if ((sectorsize * sectorcnt) < newsize) {
                printf("hfs_extendfs: not enough space on device\n");
                return (ENOSPC);
        }
        oldsize = (u_int64_t)hfsmp->hfs_phys_block_count *
                  (u_int64_t)hfsmp->hfs_phys_block_size;

        /*
         * Validate new size.
         */
        if ((newsize <= oldsize) || (newsize % vcb->blockSize)) {
                printf("hfs_extendfs: invalid size\n");
                return (EINVAL);
        }
        newblkcnt = newsize / vcb->blockSize;
        if (newblkcnt > (u_int64_t)0xFFFFFFFF)
                return (EOVERFLOW);

        addblks = newblkcnt - vcb->totalBlocks;

        printf("hfs_extendfs: growing %s by %d blocks\n", vcb->vcbVN, addblks);
        /*
         * Enclose changes inside a transaction.
         */
        hfs_global_shared_lock_acquire(hfsmp);
        if (journal_start_transaction(hfsmp->jnl) != 0) {
                hfs_global_shared_lock_release(hfsmp);
                return (EINVAL);
        }

        /*
         * Remember the location of existing alternate VH.
         */
        prev_alt_sector = (vcb->hfsPlusIOPosOffset / sectorsize) +
                           HFS_ALT_SECTOR(sectorsize, hfsmp->hfs_phys_block_count);

        vp = vcb->allocationsRefNum;
        error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
        if (error) {
                goto out2;
        }
        fp = VTOF(vp);
        bcopy(&fp->ff_data, &forkdata, sizeof(forkdata));

        /*
         * Calculate additional space required (if any) by allocation bitmap.
         */
        bitmapblks = roundup(newblkcnt / 8, vcb->vcbVBMIOSize) / vcb->blockSize;
        if (bitmapblks > fp->ff_blocks)
                bitmapblks -= fp->ff_blocks;
        else
                bitmapblks = 0;

        if (bitmapblks > 0) {
                daddr_t blkno;
                daddr_t blkcnt;

                /*
                 * Add a new extent to the allocation bitmap file.
                 */
                error = AddFileExtent(vcb, fp, vcb->totalBlocks, bitmapblks);
                if (error) {
                        printf("hfs_extendfs: error %d adding extents\n", error);
                        goto out;
                }
                blkcnt = bitmapblks;
                blkno = fp->ff_blocks;
                fp->ff_blocks += bitmapblks;
                fp->ff_size += (u_int64_t)bitmapblks * (u_int64_t)vcb->blockSize;
                VTOC(vp)->c_blocks = fp->ff_blocks;
                /*
                 * Zero out the new bitmap blocks.
                 */
                {
        
                        bp = NULL;
                        while (blkcnt > 0) {
                                error = meta_bread(vp, blkno, vcb->blockSize, NOCRED, &bp);
                                if (error) {
                                        if (bp) {
                                                brelse(bp);
                                        }
                                        break;
                                }
                                bzero((char *)bp->b_data, vcb->blockSize);
                                bp->b_flags |= B_AGE;
                                error = bwrite(bp);
                                if (error)
                                        break;
                                --blkcnt;
                                ++blkno;
                        }
                }
                if (error) {
                        printf("hfs_extendfs: error %d  clearing blocks\n", error);
                        goto out;
                }
                /*
                 * Mark the new bitmap space as allocated.
                 */
                error = BlockMarkAllocated(vcb, vcb->totalBlocks, bitmapblks);
                if (error) {
                        printf("hfs_extendfs: error %d setting bitmap\n", error);
                        goto out;
                }
        }
        /*
         * Mark the new alternate VH as allocated.
         */
        if (vcb->blockSize == 512)
                error = BlockMarkAllocated(vcb, vcb->totalBlocks + addblks - 2, 2);
        else
                error = BlockMarkAllocated(vcb, vcb->totalBlocks + addblks - 1, 1);
        if (error) {
                printf("hfs_extendfs: error %d setting bitmap (VH)\n", error);
                goto out;
        }
        /*
         * Mark the old alternate VH as free.
         */
        if (vcb->blockSize == 512)
                (void) BlockMarkFree(vcb, vcb->totalBlocks - 2, 2);
        else 
                (void) BlockMarkFree(vcb, vcb->totalBlocks - 1, 1);

        /*
         * Adjust file system variables for new space.
         */
        vcb->totalBlocks += addblks;
        vcb->freeBlocks += addblks - bitmapblks;
        hfsmp->hfs_phys_block_count = newsize / sectorsize;

        MarkVCBDirty(vcb);
        error = hfs_flushvolumeheader(hfsmp, MNT_WAIT, HFS_ALTFLUSH);
        if (error) {
                printf("hfs_extendfs: couldn't flush volume headers (%d)", error);
                /*
                 * Restore to old state.
                 */
                fp->ff_size -= (u_int64_t)bitmapblks * (u_int64_t)vcb->blockSize;
                vcb->totalBlocks -= addblks;
                vcb->freeBlocks -= addblks - bitmapblks;
                hfsmp->hfs_phys_block_count = oldsize / sectorsize;
                MarkVCBDirty(vcb);
                if (vcb->blockSize == 512)
                        (void) BlockMarkAllocated(vcb, vcb->totalBlocks - 2, 2);
                else
                        (void) BlockMarkAllocated(vcb, vcb->totalBlocks - 1, 1);
                goto out;
        }
        /*
         * Invalidate the old alternate volume header.
         */
        bp = NULL;
        if (meta_bread(hfsmp->hfs_devvp, prev_alt_sector, sectorsize,
                       NOCRED, &bp) == 0) {
                journal_modify_block_start(hfsmp->jnl, bp);
                bzero(bp->b_data + HFS_ALT_OFFSET(sectorsize), kMDBSize);
                journal_modify_block_end(hfsmp->jnl, bp);
        } else if (bp) {
                brelse(bp);
        }
out:
        if (error && fp) {
                /* Restore allocation fork. */
                bcopy(&forkdata, &fp->ff_data, sizeof(forkdata));
                VTOC(vp)->c_blocks = fp->ff_blocks;

        }
        VOP_UNLOCK(vp, 0, p);
out2:
        journal_end_transaction(hfsmp->jnl);
        hfs_global_shared_lock_release(hfsmp);

        return (error);
}


/*
 * hfs vfs operations.
 */
struct vfsops hfs_vfsops = {
        hfs_mount,
        hfs_start,
        hfs_unmount,
        hfs_root,
        hfs_quotactl,
        hfs_statfs,
        hfs_sync,
        hfs_vget,
        hfs_fhtovp,
        hfs_vptofh,
        hfs_init,
        hfs_sysctl
};