Patrick Welche <prlw1@cam.ac.uk>

[netbsd-mini2440.git] / external / cddl / osnet / dist / uts / common / fs / zfs / zfs_vfsops.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysmacros.h>
#include <sys/kmem.h>
#include <sys/pathname.h>
#include <sys/vnode.h>
#include <sys/vfs.h>
#include <sys/vfs_opreg.h>
#include <sys/mntent.h>
#include <sys/mount.h>
#include <sys/cmn_err.h>
#include <sys/zfs_znode.h>
#include <sys/zfs_dir.h>
#include <sys/zil.h>
#include <sys/fs/zfs.h>
#include <sys/dmu.h>
#include <sys/dsl_prop.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_deleg.h>
#include <sys/spa.h>
#include <sys/zap.h>
#include <sys/varargs.h>
#include <sys/policy.h>
#include <sys/atomic.h>
#include <sys/mkdev.h>
#include <sys/modctl.h>
#include <sys/zfs_ioctl.h>
#include <sys/zfs_ctldir.h>
#include <sys/zfs_fuid.h>
#include <sys/sunddi.h>
#include <sys/dnlc.h>
#include <sys/dmu_objset.h>
#include <sys/spa_boot.h>

#ifdef __NetBSD__
/* include ddi_name_to_major function is there better place for it ?*/
#include <sys/ddi.h>
#include <sys/systm.h>
#endif

int zfsfstype;
vfsops_t *zfs_vfsops = NULL;
static major_t zfs_major;
static minor_t zfs_minor;
static kmutex_t zfs_dev_mtx;

int zfs_debug_level;
kmutex_t zfs_debug_mtx;

/* XXX NetBSD static int zfs_mount(vfs_t *vfsp, vnode_t *mvp, struct mounta *uap, cred_t *cr);*/
static int zfs_mount(vfs_t *vfsp, const char *path, void *data, size_t *data_len);
static int zfs_umount(vfs_t *vfsp, int fflag);
static int zfs_root(vfs_t *vfsp, vnode_t **vpp);
static int zfs_statvfs(vfs_t *vfsp, struct statvfs *statp);
static int zfs_fhtovp(vfs_t *vfsp, fid_t *fidp, vnode_t **vpp);
static int zfs_vget(vfs_t *vfsp, ino_t ino, vnode_t **vpp);
static int zfs_start(vfs_t *vfsp, int flags);
static void zfs_freevfs(vfs_t *vfsp);

void zfs_init(void);
void zfs_fini(void);


extern const struct vnodeopv_desc zfs_vnodeop_opv_desc;

static const struct vnodeopv_desc * const zfs_vnodeop_descs[] = {
        &zfs_vnodeop_opv_desc,
        NULL,
};

static struct vfsops zfs_vfsops_template = {
        .vfs_name = MOUNT_ZFS,
        .vfs_min_mount_data = sizeof(struct zfs_args),
        .vfs_opv_descs = zfs_vnodeop_descs,
        .vfs_mount = zfs_mount,
        .vfs_unmount = zfs_umount,
        .vfs_root = zfs_root,
        .vfs_statvfs = zfs_statvfs,
        .vfs_sync = zfs_sync,
        .vfs_vget = zfs_vget,
        .vfs_fhtovp = zfs_fhtovp,
        .vfs_init = zfs_init,
        .vfs_done = zfs_fini,
        .vfs_start = zfs_start,
        .vfs_renamelock_enter = (void*)nullop,
        .vfs_renamelock_exit = (void*)nullop,
        .vfs_reinit = (void *)nullop,
        .vfs_vptofh = (void *)eopnotsupp,
        .vfs_fhtovp = (void *)eopnotsupp,
        .vfs_quotactl = (void *)eopnotsupp,
        .vfs_extattrctl = (void *)eopnotsupp,
        .vfs_snapshot = (void *)eopnotsupp,
        .vfs_fsync = (void *)eopnotsupp,
};

/*
 * We need to keep a count of active fs's.
 * This is necessary to prevent our module
 * from being unloaded after a umount -f
 */
static uint32_t zfs_active_fs_count = 0;

static char *noatime_cancel[] = { MNTOPT_ATIME, NULL };
static char *atime_cancel[] = { MNTOPT_NOATIME, NULL };
static char *noxattr_cancel[] = { MNTOPT_XATTR, NULL };
static char *xattr_cancel[] = { MNTOPT_NOXATTR, NULL };

/*
 * MO_DEFAULT is not used since the default value is determined
 * by the equivalent property.
 */
static mntopt_t mntopts[] = {
        { MNTOPT_NOXATTR, noxattr_cancel, NULL, 0, NULL },
        { MNTOPT_XATTR, xattr_cancel, NULL, 0, NULL },
        { MNTOPT_NOATIME, noatime_cancel, NULL, 0, NULL },
        { MNTOPT_ATIME, atime_cancel, NULL, 0, NULL }
};

static mntopts_t zfs_mntopts = {
        sizeof (mntopts) / sizeof (mntopt_t),
        mntopts
};

/*ARGSUSED*/
int
zfs_sync(vfs_t *vfsp, int flag, cred_t *cr)
{
        zfsvfs_t *zfsvfs = vfsp->vfs_data;
        znode_t *zp;
        vnode_t *vp, *nvp, *mvp;
        dmu_tx_t *tx;
        int error;
        
        
        error = 0;
        
        /*
         * Data integrity is job one.  We don't want a compromised kernel
         * writing to the storage pool, so we never sync during panic.
         */
        if (panicstr)
                return (0);

        /* Allocate a marker vnode. */
        if ((mvp = vnalloc(vfsp)) == NULL)
                return (ENOMEM);
        
        
        /*
         * On NetBSD, we need to push out atime updates.  Solaris does
         * this during VOP_INACTIVE, but that does not work well with the
         * BSD VFS, so we do it in batch here.
         */
        mutex_enter(&mntvnode_lock);
loop:
        for (vp = TAILQ_FIRST(&vfsp->mnt_vnodelist); vp; vp = nvp) {
                nvp = TAILQ_NEXT(vp, v_mntvnodes);
                /*
                 * If the vnode that we are about to sync is no
                 * longer associated with this mount point, start
                 * over.
                 */
                if (vp->v_mount != vfsp)
                        goto loop;
                /*
                 * Don't interfere with concurrent scans of this FS.
                 */
                if (vismarker(vp))
                        continue;
                /*
                 * Skip the vnode/inode if inaccessible, or if the
                 * atime is clean.
                 */
                mutex_enter(&vp->v_interlock);
                zp = VTOZ(vp);
                if (zp == NULL || vp->v_type == VNON ||
                   (vp->v_iflag & (VI_XLOCK | VI_CLEAN)) != 0 ||
                   zp->z_atime_dirty == 0 || zp->z_unlinked) {
                        mutex_exit(&vp->v_interlock);
                        continue;
                }
                vmark(mvp, vp);
                mutex_exit(&mntvnode_lock);
                error = vget(vp, LK_EXCLUSIVE | LK_INTERLOCK);
                if (error) {
                        mutex_enter(&mntvnode_lock);
                        nvp = vunmark(mvp);
                        if (error == ENOENT) {
                                goto loop;
                        }
                        continue;
                }
                tx = dmu_tx_create(zfsvfs->z_os);
                dmu_tx_hold_bonus(tx, zp->z_id);
                error = dmu_tx_assign(tx, TXG_WAIT);
                if (error) {
                        dmu_tx_abort(tx);
                } else {
                        dmu_buf_will_dirty(zp->z_dbuf, tx);
                        mutex_enter(&zp->z_lock);
                        zp->z_atime_dirty = 0;
                        mutex_exit(&zp->z_lock);
                        dmu_tx_commit(tx);
                }
                vput(vp);
                mutex_enter(&mntvnode_lock);
                nvp = vunmark(mvp);
        }
        mutex_exit(&mntvnode_lock);

        /*
         * SYNC_ATTR is used by fsflush() to force old filesystems like UFS
         * to sync metadata, which they would otherwise cache indefinitely.
         * Semantically, the only requirement is that the sync be initiated.
         * The DMU syncs out txgs frequently, so there's nothing to do.
         */
        if ((flag & MNT_LAZY) != 0)
                return (0);
        
        if (vfsp != NULL) {
                /*
                 * Sync a specific filesystem.
                 */
                

                ZFS_ENTER(zfsvfs);
                if (zfsvfs->z_log != NULL)
                        zil_commit(zfsvfs->z_log, UINT64_MAX, 0);
                else
                        txg_wait_synced(dmu_objset_pool(zfsvfs->z_os), 0);
                ZFS_EXIT(zfsvfs);
        } else {
                /*
                 * Sync all ZFS filesystems.  This is what happens when you
                 * run sync(1M).  Unlike other filesystems, ZFS honors the
                 * request by waiting for all pools to commit all dirty data.
                 */
                spa_sync_allpools();
        }

        vnfree(nvp);
        
        return (0);
}

static int
zfs_create_unique_device(dev_t *dev)
{
        major_t new_major;

        do {
                ASSERT3U(zfs_minor, <=, MAXMIN);
                minor_t start = zfs_minor;
                do {
                        mutex_enter(&zfs_dev_mtx);
                        if (zfs_minor >= MAXMIN) {
                                /*
                                 * If we're still using the real major
                                 * keep out of /dev/zfs and /dev/zvol minor
                                 * number space.  If we're using a getudev()'ed
                                 * major number, we can use all of its minors.
                                 */
                                if (zfs_major == ddi_name_to_major(ZFS_DRIVER))
                                        zfs_minor = ZFS_MIN_MINOR;
                                else
                                        zfs_minor = 0;
                        } else {
                                zfs_minor++;
                        }
                        *dev = makedevice(zfs_major, zfs_minor);
                        mutex_exit(&zfs_dev_mtx);
                } while (vfs_devismounted(*dev) && zfs_minor != start);
                break;
#ifndef __NetBSD__
                if (zfs_minor == start) {
                        /*
                         * We are using all ~262,000 minor numbers for the
                         * current major number.  Create a new major number.
                         */
                        if ((new_major = getudev()) == (major_t)-1) {
                                cmn_err(CE_WARN,
                                    "zfs_mount: Can't get unique major "
                                    "device number.");
                                return (-1);
                        }
                        mutex_enter(&zfs_dev_mtx);
                        zfs_major = new_major;
                        zfs_minor = 0;

                        mutex_exit(&zfs_dev_mtx);
                } else {
                        break;
                }
                /* CONSTANTCONDITION */
#endif
        } while (1);

        return (0);
}

static void
atime_changed_cb(void *arg, uint64_t newval)
{
        zfsvfs_t *zfsvfs = arg;

        if (newval == TRUE) {
                zfsvfs->z_atime = TRUE;
                vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_NOATIME);
                vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_ATIME, NULL, 0);
        } else {
                zfsvfs->z_atime = FALSE;
                vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_ATIME);
                vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_NOATIME, NULL, 0);
        }
}

static void
xattr_changed_cb(void *arg, uint64_t newval)
{
        zfsvfs_t *zfsvfs = arg;

        if (newval == TRUE) {
                /* XXX locking on vfs_flag? */
#ifdef TODO
                zfsvfs->z_vfs->vfs_flag |= VFS_XATTR;
#endif          
                vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_NOXATTR);
                vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_XATTR, NULL, 0);
        } else {
                /* XXX locking on vfs_flag? */
#ifdef TODO
                zfsvfs->z_vfs->vfs_flag &= ~VFS_XATTR;
#endif          
                vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_XATTR);
                vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_NOXATTR, NULL, 0);
        }
}

static void
blksz_changed_cb(void *arg, uint64_t newval)
{
        zfsvfs_t *zfsvfs = arg;

        if (newval < SPA_MINBLOCKSIZE ||
            newval > SPA_MAXBLOCKSIZE || !ISP2(newval))
                newval = SPA_MAXBLOCKSIZE;

        zfsvfs->z_max_blksz = newval;
        zfsvfs->z_vfs->vfs_bsize = newval;
}

static void
readonly_changed_cb(void *arg, uint64_t newval)
{
        zfsvfs_t *zfsvfs = arg;

        if (newval) {
                /* XXX locking on vfs_flag? */
                zfsvfs->z_vfs->vfs_flag |= VFS_RDONLY;
                vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_RW);
                vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_RO, NULL, 0);
        } else {
                /* XXX locking on vfs_flag? */
                zfsvfs->z_vfs->vfs_flag &= ~VFS_RDONLY;
                vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_RO);
                vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_RW, NULL, 0);
        }
}

static void
devices_changed_cb(void *arg, uint64_t newval)
{
        zfsvfs_t *zfsvfs = arg;

        if (newval == FALSE) {
                zfsvfs->z_vfs->vfs_flag |= VFS_NODEVICES;
                vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_DEVICES);
                vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_NODEVICES, NULL, 0);
        } else {
                zfsvfs->z_vfs->vfs_flag &= ~VFS_NODEVICES;
                vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_NODEVICES);
                vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_DEVICES, NULL, 0);
        }
}

static void
setuid_changed_cb(void *arg, uint64_t newval)
{
        zfsvfs_t *zfsvfs = arg;

        if (newval == FALSE) {
                zfsvfs->z_vfs->vfs_flag |= VFS_NOSETUID;
                vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_SETUID);
                vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_NOSETUID, NULL, 0);
        } else {
                zfsvfs->z_vfs->vfs_flag &= ~VFS_NOSETUID;
                vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_NOSETUID);
                vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_SETUID, NULL, 0);
        }
}

static void
exec_changed_cb(void *arg, uint64_t newval)
{
        zfsvfs_t *zfsvfs = arg;

        if (newval == FALSE) {
                zfsvfs->z_vfs->vfs_flag |= VFS_NOEXEC;
                vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_EXEC);
                vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_NOEXEC, NULL, 0);
        } else {
                zfsvfs->z_vfs->vfs_flag &= ~VFS_NOEXEC;
                vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_NOEXEC);
                vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_EXEC, NULL, 0);
        }
}

/*
 * The nbmand mount option can be changed at mount time.
 * We can't allow it to be toggled on live file systems or incorrect
 * behavior may be seen from cifs clients
 *
 * This property isn't registered via dsl_prop_register(), but this callback
 * will be called when a file system is first mounted
 */
static void
nbmand_changed_cb(void *arg, uint64_t newval)
{
        zfsvfs_t *zfsvfs = arg;
        if (newval == FALSE) {
                vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_NBMAND);
                vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_NONBMAND, NULL, 0);
        } else {
                vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_NONBMAND);
                vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_NBMAND, NULL, 0);
        }
}

static void
snapdir_changed_cb(void *arg, uint64_t newval)
{
        zfsvfs_t *zfsvfs = arg;

        zfsvfs->z_show_ctldir = newval;
}

static void
vscan_changed_cb(void *arg, uint64_t newval)
{
        zfsvfs_t *zfsvfs = arg;

        zfsvfs->z_vscan = newval;
}

static void
acl_mode_changed_cb(void *arg, uint64_t newval)
{
        zfsvfs_t *zfsvfs = arg;

        zfsvfs->z_acl_mode = newval;
}

static void
acl_inherit_changed_cb(void *arg, uint64_t newval)
{
        zfsvfs_t *zfsvfs = arg;

        zfsvfs->z_acl_inherit = newval;
}

static int
zfs_register_callbacks(vfs_t *vfsp)
{
        struct dsl_dataset *ds = NULL;
        objset_t *os = NULL;
        zfsvfs_t *zfsvfs = NULL;
        uint64_t nbmand;
        int readonly, do_readonly = B_FALSE;
        int setuid, do_setuid = B_FALSE;
        int exec, do_exec = B_FALSE;
        int devices, do_devices = B_FALSE;
        int xattr, do_xattr = B_FALSE;
        int atime, do_atime = B_FALSE;
        int error = 0;

        ASSERT(vfsp);
        zfsvfs = vfsp->vfs_data;
        ASSERT(zfsvfs);
        os = zfsvfs->z_os;

        /*
         * The act of registering our callbacks will destroy any mount
         * options we may have.  In order to enable temporary overrides
         * of mount options, we stash away the current values and
         * restore them after we register the callbacks.
         */
        if (vfs_optionisset(vfsp, MNTOPT_RO, NULL)) {
                readonly = B_TRUE;
                do_readonly = B_TRUE;
        } else if (vfs_optionisset(vfsp, MNTOPT_RW, NULL)) {
                readonly = B_FALSE;
                do_readonly = B_TRUE;
        }
        if (vfs_optionisset(vfsp, MNTOPT_NOSUID, NULL)) {
                devices = B_FALSE;
                setuid = B_FALSE;
                do_devices = B_TRUE;
                do_setuid = B_TRUE;
        } else {
                if (vfs_optionisset(vfsp, MNTOPT_NODEVICES, NULL)) {
                        devices = B_FALSE;
                        do_devices = B_TRUE;
                } else if (vfs_optionisset(vfsp, MNTOPT_DEVICES, NULL)) {
                        devices = B_TRUE;
                        do_devices = B_TRUE;
                }

                if (vfs_optionisset(vfsp, MNTOPT_NOSETUID, NULL)) {
                        setuid = B_FALSE;
                        do_setuid = B_TRUE;
                } else if (vfs_optionisset(vfsp, MNTOPT_SETUID, NULL)) {
                        setuid = B_TRUE;
                        do_setuid = B_TRUE;
                }
        }
        if (vfs_optionisset(vfsp, MNTOPT_NOEXEC, NULL)) {
                exec = B_FALSE;
                do_exec = B_TRUE;
        } else if (vfs_optionisset(vfsp, MNTOPT_EXEC, NULL)) {
                exec = B_TRUE;
                do_exec = B_TRUE;
        }
        if (vfs_optionisset(vfsp, MNTOPT_NOXATTR, NULL)) {
                xattr = B_FALSE;
                do_xattr = B_TRUE;
        } else if (vfs_optionisset(vfsp, MNTOPT_XATTR, NULL)) {
                xattr = B_TRUE;
                do_xattr = B_TRUE;
        }
        if (vfs_optionisset(vfsp, MNTOPT_NOATIME, NULL)) {
                atime = B_FALSE;
                do_atime = B_TRUE;
        } else if (vfs_optionisset(vfsp, MNTOPT_ATIME, NULL)) {
                atime = B_TRUE;
                do_atime = B_TRUE;
        }

        /*
         * nbmand is a special property.  It can only be changed at
         * mount time.
         *
         * This is weird, but it is documented to only be changeable
         * at mount time.
         */
        if (vfs_optionisset(vfsp, MNTOPT_NONBMAND, NULL)) {
                nbmand = B_FALSE;
        } else if (vfs_optionisset(vfsp, MNTOPT_NBMAND, NULL)) {
                nbmand = B_TRUE;
        } else {
                char osname[MAXNAMELEN];

                dmu_objset_name(os, osname);
                if (error = dsl_prop_get_integer(osname, "nbmand", &nbmand,
                    NULL)) {
                        return (error);
                }
        }

        /*
         * Register property callbacks.
         *
         * It would probably be fine to just check for i/o error from
         * the first prop_register(), but I guess I like to go
         * overboard...
         */
        ds = dmu_objset_ds(os);
        error = dsl_prop_register(ds, "atime", atime_changed_cb, zfsvfs);
        error = error ? error : dsl_prop_register(ds,
            "xattr", xattr_changed_cb, zfsvfs);
        error = error ? error : dsl_prop_register(ds,
            "recordsize", blksz_changed_cb, zfsvfs);
        error = error ? error : dsl_prop_register(ds,
            "readonly", readonly_changed_cb, zfsvfs);
        error = error ? error : dsl_prop_register(ds,
            "devices", devices_changed_cb, zfsvfs);
        error = error ? error : dsl_prop_register(ds,
            "setuid", setuid_changed_cb, zfsvfs);
        error = error ? error : dsl_prop_register(ds,
            "exec", exec_changed_cb, zfsvfs);
        error = error ? error : dsl_prop_register(ds,
            "snapdir", snapdir_changed_cb, zfsvfs);
        error = error ? error : dsl_prop_register(ds,
            "aclmode", acl_mode_changed_cb, zfsvfs);
        error = error ? error : dsl_prop_register(ds,
            "aclinherit", acl_inherit_changed_cb, zfsvfs);
        error = error ? error : dsl_prop_register(ds,
            "vscan", vscan_changed_cb, zfsvfs);
        if (error)
                goto unregister;

        /*
         * Invoke our callbacks to restore temporary mount options.
         */
        if (do_readonly)
                readonly_changed_cb(zfsvfs, readonly);
        if (do_setuid)
                setuid_changed_cb(zfsvfs, setuid);
        if (do_exec)
                exec_changed_cb(zfsvfs, exec);
        if (do_devices)
                devices_changed_cb(zfsvfs, devices);
        if (do_xattr)
                xattr_changed_cb(zfsvfs, xattr);
        if (do_atime)
                atime_changed_cb(zfsvfs, atime);

        nbmand_changed_cb(zfsvfs, nbmand);

        return (0);

unregister:
        /*
         * We may attempt to unregister some callbacks that are not
         * registered, but this is OK; it will simply return ENOMSG,
         * which we will ignore.
         */
        (void) dsl_prop_unregister(ds, "atime", atime_changed_cb, zfsvfs);
        (void) dsl_prop_unregister(ds, "xattr", xattr_changed_cb, zfsvfs);
        (void) dsl_prop_unregister(ds, "recordsize", blksz_changed_cb, zfsvfs);
        (void) dsl_prop_unregister(ds, "readonly", readonly_changed_cb, zfsvfs);
        (void) dsl_prop_unregister(ds, "devices", devices_changed_cb, zfsvfs);
        (void) dsl_prop_unregister(ds, "setuid", setuid_changed_cb, zfsvfs);
        (void) dsl_prop_unregister(ds, "exec", exec_changed_cb, zfsvfs);
        (void) dsl_prop_unregister(ds, "snapdir", snapdir_changed_cb, zfsvfs);
        (void) dsl_prop_unregister(ds, "aclmode", acl_mode_changed_cb, zfsvfs);
        (void) dsl_prop_unregister(ds, "aclinherit", acl_inherit_changed_cb,
            zfsvfs);
        (void) dsl_prop_unregister(ds, "vscan", vscan_changed_cb, zfsvfs);
        return (error);

}

static int
zfsvfs_setup(zfsvfs_t *zfsvfs, boolean_t mounting)
{
        int error;

        error = zfs_register_callbacks(zfsvfs->z_vfs);
        if (error)
                return (error);

        /*
         * Set the objset user_ptr to track its zfsvfs.
         */
        mutex_enter(&zfsvfs->z_os->os->os_user_ptr_lock);
        dmu_objset_set_user(zfsvfs->z_os, zfsvfs);
        mutex_exit(&zfsvfs->z_os->os->os_user_ptr_lock);

        /*
         * If we are not mounting (ie: online recv), then we don't
         * have to worry about replaying the log as we blocked all
         * operations out since we closed the ZIL.
         */
        if (mounting) {
                boolean_t readonly;

                /*
                 * During replay we remove the read only flag to
                 * allow replays to succeed.
                 */
                readonly = zfsvfs->z_vfs->vfs_flag & VFS_RDONLY;
                zfsvfs->z_vfs->vfs_flag &= ~VFS_RDONLY;

                /*
                 * Parse and replay the intent log.
                 */
                zil_replay(zfsvfs->z_os, zfsvfs, &zfsvfs->z_assign,
                    zfs_replay_vector, zfs_unlinked_drain);

                zfs_unlinked_drain(zfsvfs);
                zfsvfs->z_vfs->vfs_flag |= readonly; /* restore readonly bit */
        }

        if (!zil_disable)
                zfsvfs->z_log = zil_open(zfsvfs->z_os, zfs_get_data);

        return (0);
}

static void
zfs_freezfsvfs(zfsvfs_t *zfsvfs)
{

        mutex_destroy(&zfsvfs->z_znodes_lock);
        mutex_destroy(&zfsvfs->z_online_recv_lock);
        list_destroy(&zfsvfs->z_all_znodes);
        rrw_destroy(&zfsvfs->z_teardown_lock);
        rw_destroy(&zfsvfs->z_teardown_inactive_lock);
        rw_destroy(&zfsvfs->z_fuid_lock);
        kmem_free(zfsvfs, sizeof (zfsvfs_t));
}

static int
zfs_domount(vfs_t *vfsp, char *osname)
{
        dev_t mount_dev;
        uint64_t recordsize, readonly;
        int error = 0;
        int mode;
        zfsvfs_t *zfsvfs;
        znode_t *zp = NULL;

        ASSERT(vfsp);
        ASSERT(osname);

        /*
         * Initialize the zfs-specific filesystem structure.
         * Should probably make this a kmem cache, shuffle fields,
         * and just bzero up to z_hold_mtx[].
         */
        zfsvfs = kmem_zalloc(sizeof (zfsvfs_t), KM_SLEEP);
        zfsvfs->z_vfs = vfsp;
        zfsvfs->z_parent = zfsvfs;
        zfsvfs->z_assign = TXG_NOWAIT;
        zfsvfs->z_max_blksz = SPA_MAXBLOCKSIZE;
        zfsvfs->z_show_ctldir = ZFS_SNAPDIR_VISIBLE;
        
        dprintf("Creating zfsvfs %p\n", zfsvfs);
        mutex_init(&zfsvfs->z_znodes_lock, NULL, MUTEX_DEFAULT, NULL);
        mutex_init(&zfsvfs->z_online_recv_lock, NULL, MUTEX_DEFAULT, NULL);
        list_create(&zfsvfs->z_all_znodes, sizeof (znode_t),
            offsetof(znode_t, z_link_node));
        rrw_init(&zfsvfs->z_teardown_lock);
        rw_init(&zfsvfs->z_teardown_inactive_lock, NULL, RW_DEFAULT, NULL);
        rw_init(&zfsvfs->z_fuid_lock, NULL, RW_DEFAULT, NULL);

        /* Initialize the generic filesystem structure. */
        vfsp->vfs_data = NULL;

        if (zfs_create_unique_device(&mount_dev) == -1) {
                error = ENODEV;
                goto out;
        }
        ASSERT(vfs_devismounted(mount_dev) == 0);

        if (error = dsl_prop_get_integer(osname, "recordsize", &recordsize,
            NULL))
            goto out;

        vfsp->vfs_bsize = DEV_BSIZE;
        vfsp->vfs_flag |= VFS_NOTRUNC;
        vfsp->vfs_data = zfsvfs;

        if (error = dsl_prop_get_integer(osname, "readonly", &readonly, NULL))
                goto out;

        mode = DS_MODE_OWNER;
        if (readonly)
                mode |= DS_MODE_READONLY;

        error = dmu_objset_open(osname, DMU_OST_ZFS, mode, &zfsvfs->z_os);
        if (error == EROFS) {
                mode = DS_MODE_OWNER | DS_MODE_READONLY;
                error = dmu_objset_open(osname, DMU_OST_ZFS, mode,
                    &zfsvfs->z_os);
        }

        if (error)
                goto out;

        if (error = zfs_init_fs(zfsvfs, &zp))
                goto out;

        dprintf("zfs_domount vrele before vfsp->vfs_count %d\n", vfsp->vfs_count);
        /* The call to zfs_init_fs leaves the vnode held, release it here. */
        VN_RELE(ZTOV(zp));

        dprintf("zfs_domount vrele after vfsp->vfs_count %d\n", vfsp->vfs_count);
        /*
         * Set features for file system.
         */
        zfsvfs->z_use_fuids = USE_FUIDS(zfsvfs->z_version, zfsvfs->z_os);
        if (zfsvfs->z_use_fuids) {
                vfs_set_feature(vfsp, VFSFT_XVATTR);
                vfs_set_feature(vfsp, VFSFT_SYSATTR_VIEWS);
                vfs_set_feature(vfsp, VFSFT_ACEMASKONACCESS);
                vfs_set_feature(vfsp, VFSFT_ACLONCREATE);
        }
        if (zfsvfs->z_case == ZFS_CASE_INSENSITIVE) {
                vfs_set_feature(vfsp, VFSFT_DIRENTFLAGS);
                vfs_set_feature(vfsp, VFSFT_CASEINSENSITIVE);
                vfs_set_feature(vfsp, VFSFT_NOCASESENSITIVE);
        } else if (zfsvfs->z_case == ZFS_CASE_MIXED) {
                vfs_set_feature(vfsp, VFSFT_DIRENTFLAGS);
                vfs_set_feature(vfsp, VFSFT_CASEINSENSITIVE);
        }

        if (dmu_objset_is_snapshot(zfsvfs->z_os)) {
                uint64_t pval;
                ASSERT(mode & DS_MODE_READONLY);
                atime_changed_cb(zfsvfs, B_FALSE);
                readonly_changed_cb(zfsvfs, B_TRUE);
                if (error = dsl_prop_get_integer(osname, "xattr", &pval, NULL))
                        goto out;
                xattr_changed_cb(zfsvfs, pval);
                zfsvfs->z_issnap = B_TRUE;
        } else {
                error = zfsvfs_setup(zfsvfs, B_TRUE);
        }

        dprintf("zfs_vfsops.c zfs_domount called\n");   
        dprintf("vfsp->vfs_count %d\n", vfsp->vfs_count);
        
        if (!zfsvfs->z_issnap)
                zfsctl_create(zfsvfs);
out:
        if (error) {
                if (zfsvfs->z_os)
                        dmu_objset_close(zfsvfs->z_os);
                zfs_freezfsvfs(zfsvfs);
        } else {
                atomic_add_32(&zfs_active_fs_count, 1);
        }
        return (error);
}

void
zfs_unregister_callbacks(zfsvfs_t *zfsvfs)
{
        objset_t *os = zfsvfs->z_os;
        struct dsl_dataset *ds;

        /*
         * Unregister properties.
         */
        if (!dmu_objset_is_snapshot(os)) {
                ds = dmu_objset_ds(os);
                VERIFY(dsl_prop_unregister(ds, "atime", atime_changed_cb,
                    zfsvfs) == 0);

                VERIFY(dsl_prop_unregister(ds, "xattr", xattr_changed_cb,
                    zfsvfs) == 0);

                VERIFY(dsl_prop_unregister(ds, "recordsize", blksz_changed_cb,
                    zfsvfs) == 0);

                VERIFY(dsl_prop_unregister(ds, "readonly", readonly_changed_cb,
                    zfsvfs) == 0);

                VERIFY(dsl_prop_unregister(ds, "devices", devices_changed_cb,
                    zfsvfs) == 0);

                VERIFY(dsl_prop_unregister(ds, "setuid", setuid_changed_cb,
                    zfsvfs) == 0);

                VERIFY(dsl_prop_unregister(ds, "exec", exec_changed_cb,
                    zfsvfs) == 0);

                VERIFY(dsl_prop_unregister(ds, "snapdir", snapdir_changed_cb,
                    zfsvfs) == 0);

                VERIFY(dsl_prop_unregister(ds, "aclmode", acl_mode_changed_cb,
                    zfsvfs) == 0);

                VERIFY(dsl_prop_unregister(ds, "aclinherit",
                    acl_inherit_changed_cb, zfsvfs) == 0);

                VERIFY(dsl_prop_unregister(ds, "vscan",
                    vscan_changed_cb, zfsvfs) == 0);
        }
}

/*
 * Convert a decimal digit string to a uint64_t integer.
 */
static int
str_to_uint64(char *str, uint64_t *objnum)
{
        uint64_t num = 0;

        while (*str) {
                if (*str < '0' || *str > '9')
                        return (EINVAL);

                num = num*10 + *str++ - '0';
        }

        *objnum = num;
        return (0);
}

/*
 * The boot path passed from the boot loader is in the form of
 * "rootpool-name/root-filesystem-object-number'. Convert this
 * string to a dataset name: "rootpool-name/root-filesystem-name".
 */
static int
zfs_parse_bootfs(char *bpath, char *outpath)
{
        char *slashp;
        uint64_t objnum;
        int error;

        if (*bpath == 0 || *bpath == '/')
                return (EINVAL);

        (void) strcpy(outpath, bpath);

        slashp = strchr(bpath, '/');

        /* if no '/', just return the pool name */
        if (slashp == NULL) {
                return (0);
        }

        /* if not a number, just return the root dataset name */
        if (str_to_uint64(slashp+1, &objnum)) {
                return (0);
        }

        *slashp = '\0';
        error = dsl_dsobj_to_dsname(bpath, objnum, outpath);
        *slashp = '/';

        return (error);
}

#ifndef __NetBSD__
static int
zfs_mountroot(vfs_t *vfsp, enum whymountroot why)
{
        int error = 0;
        static int zfsrootdone = 0;
        zfsvfs_t *zfsvfs = NULL;
        znode_t *zp = NULL;
        vnode_t *vp = NULL;
        char *zfs_bootfs;
        char *zfs_devid;

        ASSERT(vfsp);

        /*
         * The filesystem that we mount as root is defined in the
         * boot property "zfs-bootfs" with a format of
         * "poolname/root-dataset-objnum".
         */
        if (why == ROOT_INIT) {
                if (zfsrootdone++)
                        return (EBUSY);
                /*
                 * the process of doing a spa_load will require the
                 * clock to be set before we could (for example) do
                 * something better by looking at the timestamp on
                 * an uberblock, so just set it to -1.
                 */
                clkset(-1);

                if ((zfs_bootfs = spa_get_bootprop("zfs-bootfs")) == NULL) {
                        cmn_err(CE_NOTE, "spa_get_bootfs: can not get "
                            "bootfs name");
                        return (EINVAL);
                }
                zfs_devid = spa_get_bootprop("diskdevid");
                error = spa_import_rootpool(rootfs.bo_name, zfs_devid);
                if (zfs_devid)
                        spa_free_bootprop(zfs_devid);
                if (error) {
                        spa_free_bootprop(zfs_bootfs);
                        cmn_err(CE_NOTE, "spa_import_rootpool: error %d",
                            error);
                        return (error);
                }
                if (error = zfs_parse_bootfs(zfs_bootfs, rootfs.bo_name)) {
                        spa_free_bootprop(zfs_bootfs);
                        cmn_err(CE_NOTE, "zfs_parse_bootfs: error %d",
                            error);
                        return (error);
                }

                spa_free_bootprop(zfs_bootfs);

                if (error = vfs_lock(vfsp))
                        return (error);

                if (error = zfs_domount(vfsp, rootfs.bo_name)) {
                        cmn_err(CE_NOTE, "zfs_domount: error %d", error);
                        goto out;
                }

                zfsvfs = (zfsvfs_t *)vfsp->vfs_data;
                ASSERT(zfsvfs);
                if (error = zfs_zget(zfsvfs, zfsvfs->z_root, &zp)) {
                        cmn_err(CE_NOTE, "zfs_zget: error %d", error);
                        goto out;
                }

                vp = ZTOV(zp);
                mutex_enter(&vp->v_lock);
                vp->v_flag |= VROOT;
                mutex_exit(&vp->v_lock);
                rootvp = vp;

                /*
                 * Leave rootvp held.  The root file system is never unmounted.
                 */

                vfs_add((struct vnode *)0, vfsp,
                    (vfsp->vfs_flag & VFS_RDONLY) ? MS_RDONLY : 0);
out:
                vfs_unlock(vfsp);
                return (error);
        } else if (why == ROOT_REMOUNT) {
                readonly_changed_cb(vfsp->vfs_data, B_FALSE);
                vfsp->vfs_flag |= VFS_REMOUNT;

                /* refresh mount options */
                zfs_unregister_callbacks(vfsp->vfs_data);
                return (zfs_register_callbacks(vfsp));

        } else if (why == ROOT_UNMOUNT) {
                zfs_unregister_callbacks((zfsvfs_t *)vfsp->vfs_data);
                (void) zfs_sync(vfsp, 0, 0);
                return (0);
        }

        /*
         * if "why" is equal to anything else other than ROOT_INIT,
         * ROOT_REMOUNT, or ROOT_UNMOUNT, we do not support it.
         */
        return (ENOTSUP);
}
#endif /*__NetBSD__ */

/*ARGSUSED*/
static int
zfs_mount(vfs_t *vfsp, const char *path, void *data, size_t *data_len)
{
        char            *osname;
        pathname_t      spn;
        vnode_t         *mvp = vfsp->mnt_vnodecovered;
        struct mounta   *uap = data;
        int             error = 0;
        int             canwrite;
        cred_t          *cr;

        crget(cr);
        dprintf("zfs_vfsops.c zfs_mount called\n");     
        dprintf("vfsp->vfs_count %d\n", vfsp->vfs_count);
        if (mvp->v_type != VDIR)
                return (ENOTDIR);

        mutex_enter(&mvp->v_interlock);
        if ((uap->flags & MS_REMOUNT) == 0 &&
            (uap->flags & MS_OVERLAY) == 0 &&
            (mvp->v_count != 1 || (mvp->v_flag & VROOT))) {
                mutex_exit(&mvp->v_interlock);
                return (EBUSY);
        }
        mutex_exit(&mvp->v_interlock);

        /*
         * ZFS does not support passing unparsed data in via MS_DATA.
         * Users should use the MS_OPTIONSTR interface; this means
         * that all option parsing is already done and the options struct
         * can be interrogated.
         */
        if ((uap->flags & MS_DATA) && uap->datalen > 0)
                return (EINVAL);

        osname = PNBUF_GET();

        strlcpy(osname, uap->fspec, strlen(uap->fspec) + 1);

        /*
         * Check for mount privilege?
         *
         * If we don't have privilege then see if
         * we have local permission to allow it
         */
        error = secpolicy_fs_mount(cr, mvp, vfsp);
        if (error) {
                error = dsl_deleg_access(osname, ZFS_DELEG_PERM_MOUNT, cr);
                if (error == 0) {
                        vattr_t         vattr;

                        /*
                         * Make sure user is the owner of the mount point
                         * or has sufficient privileges.
                         */

                        vattr.va_mask = AT_UID;

                        if (error = VOP_GETATTR(mvp, &vattr, 0, cr, NULL)) {
                                goto out;
                        }

                        if (secpolicy_vnode_owner(cr, vattr.va_uid) != 0 &&
                            VOP_ACCESS(mvp, VWRITE, cr) != 0) {
                                error = EPERM;
                                goto out;
                        }

/* XXX NetBSD                   secpolicy_fs_mount_clearopts(cr, vfsp);*/
                } else {
                        goto out;
                }
        }

        /*
         * Refuse to mount a filesystem if we are in a local zone and the
         * dataset is not visible.
         */
        if (!INGLOBALZONE(curproc) &&
            (!zone_dataset_visible(osname, &canwrite) || !canwrite)) {
                error = EPERM;
                goto out;
        }

        dprintf("uap->flags %d -- mflag %d -- MS_REMOUNT %d -- MTN_UPDATE %d\n", uap->flags, uap->mflag, MS_REMOUNT, MNT_UPDATE);
        /*
         * When doing a remount, we simply refresh our temporary properties
         * according to those options set in the current VFS options.
         */
        if (uap->flags & MS_REMOUNT) {
                /* refresh mount options */
                zfs_unregister_callbacks(vfsp->vfs_data);
                error = zfs_register_callbacks(vfsp);
                goto out;
        }

        /* Mark ZFS as MP SAFE */
        vfsp->mnt_iflag |= IMNT_MPSAFE;
        
        error = zfs_domount(vfsp, osname);

        vfs_getnewfsid(vfsp);

        /* setup zfs mount info */
        strlcpy(vfsp->mnt_stat.f_mntfromname, osname,
            sizeof(vfsp->mnt_stat.f_mntfromname));
        set_statvfs_info(path, UIO_USERSPACE, vfsp->mnt_stat.f_mntfromname,
            UIO_SYSSPACE, vfsp->mnt_op->vfs_name, vfsp, curlwp);

        
out:
        PNBUF_PUT(osname);
        return (error);
}

static int
zfs_statvfs(vfs_t *vfsp, struct statvfs *statp)
{
        zfsvfs_t *zfsvfs = vfsp->vfs_data;
        dev_t dev;
        uint64_t refdbytes, availbytes, usedobjs, availobjs;

        ZFS_ENTER(zfsvfs);

        dmu_objset_space(zfsvfs->z_os,
            &refdbytes, &availbytes, &usedobjs, &availobjs);

        /*
         * The underlying storage pool actually uses multiple block sizes.
         * We report the fragsize as the smallest block size we support,
         * and we report our blocksize as the filesystem's maximum blocksize.
         */
        statp->f_frsize = 1UL << SPA_MINBLOCKSHIFT;
        statp->f_bsize = zfsvfs->z_max_blksz;

        /*
         * The following report "total" blocks of various kinds in the
         * file system, but reported in terms of f_frsize - the
         * "fragment" size.
         */

        statp->f_blocks = (refdbytes + availbytes) >> SPA_MINBLOCKSHIFT;
        statp->f_bfree = availbytes >> SPA_MINBLOCKSHIFT;
        statp->f_bavail = statp->f_bfree; /* no root reservation */

        /*
         * statvfs() should really be called statufs(), because it assumes
         * static metadata.  ZFS doesn't preallocate files, so the best
         * we can do is report the max that could possibly fit in f_files,
         * and that minus the number actually used in f_ffree.
         * For f_ffree, report the smaller of the number of object available
         * and the number of blocks (each object will take at least a block).
         */
        statp->f_ffree = MIN(availobjs, statp->f_bfree);
        statp->f_favail = statp->f_ffree;       /* no "root reservation" */
        statp->f_files = statp->f_ffree + usedobjs;

        statp->f_fsid = vfsp->mnt_stat.f_fsidx.__fsid_val[0];
        
        /*
         * We're a zfs filesystem.
         */
        (void) strlcpy(statp->f_fstypename, "zfs", sizeof(statp->f_fstypename));
        (void) strlcpy(statp->f_mntfromname, vfsp->mnt_stat.f_mntfromname,
            sizeof(statp->f_mntfromname));
        (void) strlcpy(statp->f_mntonname, vfsp->mnt_stat.f_mntonname,
            sizeof(statp->f_mntonname));

        statp->f_namemax = ZFS_MAXNAMELEN;

        /*
         * We have all of 32 characters to stuff a string here.
         * Is there anything useful we could/should provide?
         */
#ifndef __NetBSD__      
        bzero(statp->f_fstr, sizeof (statp->f_fstr));
#endif
        ZFS_EXIT(zfsvfs);
        return (0);
}

static int
zfs_root(vfs_t *vfsp, vnode_t **vpp)
{
        zfsvfs_t *zfsvfs = vfsp->vfs_data;
        znode_t *rootzp;
        int error;

        ZFS_ENTER(zfsvfs);
        dprintf("zfs_root called\n");
        error = zfs_zget(zfsvfs, zfsvfs->z_root, &rootzp);
        if (error == 0)
                *vpp = ZTOV(rootzp);
        dprintf("vpp -> %d, error %d -- %p\n", (*vpp)->v_type, error, *vpp);
        ZFS_EXIT(zfsvfs);
        return (error);
}

/*
 * Teardown the zfsvfs::z_os.
 *
 * Note, if 'unmounting' if FALSE, we return with the 'z_teardown_lock'
 * and 'z_teardown_inactive_lock' held.
 */
static int
zfsvfs_teardown(zfsvfs_t *zfsvfs, boolean_t unmounting)
{
        znode_t *zp;

        rrw_enter(&zfsvfs->z_teardown_lock, RW_WRITER, FTAG);

        if (!unmounting) {
                /*
                 * We purge the parent filesystem's vfsp as the parent
                 * filesystem and all of its snapshots have their vnode's
                 * v_vfsp set to the parent's filesystem's vfsp.  Note,
                 * 'z_parent' is self referential for non-snapshots.
                 */
                (void) dnlc_purge_vfsp(zfsvfs->z_parent->z_vfs, 0);
        }

        /*
         * Close the zil. NB: Can't close the zil while zfs_inactive
         * threads are blocked as zil_close can call zfs_inactive.
         */
        if (zfsvfs->z_log) {
                zil_close(zfsvfs->z_log);
                zfsvfs->z_log = NULL;
        }

        rw_enter(&zfsvfs->z_teardown_inactive_lock, RW_WRITER);

        /*
         * If we are not unmounting (ie: online recv) and someone already
         * unmounted this file system while we were doing the switcheroo,
         * or a reopen of z_os failed then just bail out now.
         */
        if (!unmounting && (zfsvfs->z_unmounted || zfsvfs->z_os == NULL)) {
                rw_exit(&zfsvfs->z_teardown_inactive_lock);
                rrw_exit(&zfsvfs->z_teardown_lock, FTAG);
                return (EIO);
        }

        /*
         * At this point there are no vops active, and any new vops will
         * fail with EIO since we have z_teardown_lock for writer (only
         * relavent for forced unmount).
         *
         * Release all holds on dbufs.
         */
        mutex_enter(&zfsvfs->z_znodes_lock);
        for (zp = list_head(&zfsvfs->z_all_znodes); zp != NULL;
            zp = list_next(&zfsvfs->z_all_znodes, zp))
                if (zp->z_dbuf) {
                        ASSERT(ZTOV(zp)->v_count > 0);
                        zfs_znode_dmu_fini(zp);
                }
        mutex_exit(&zfsvfs->z_znodes_lock);

        /*
         * If we are unmounting, set the unmounted flag and let new vops
         * unblock.  zfs_inactive will have the unmounted behavior, and all
         * other vops will fail with EIO.
         */
        if (unmounting) {
                zfsvfs->z_unmounted = B_TRUE;
                rrw_exit(&zfsvfs->z_teardown_lock, FTAG);
                rw_exit(&zfsvfs->z_teardown_inactive_lock);
        }

        /*
         * z_os will be NULL if there was an error in attempting to reopen
         * zfsvfs, so just return as the properties had already been
         * unregistered and cached data had been evicted before.
         */
        if (zfsvfs->z_os == NULL)
                return (0);

        /*
         * Unregister properties.
         */
        zfs_unregister_callbacks(zfsvfs);

        /*
         * Evict cached data
         */
        if (dmu_objset_evict_dbufs(zfsvfs->z_os)) {
                txg_wait_synced(dmu_objset_pool(zfsvfs->z_os), 0);
                (void) dmu_objset_evict_dbufs(zfsvfs->z_os);
        }

        return (0);
}

/*ARGSUSED*/
static int
zfs_umount(vfs_t *vfsp, int fflag)
{
        zfsvfs_t *zfsvfs = vfsp->vfs_data;
        objset_t *os;
        int ret, flags = 0;
        cred_t *cr;

        vnode_t *vpp;
        int counter;

        counter = 0;
        
        dprintf("ZFS_UMOUNT called\n");

        /*TAILQ_FOREACH(vpp, &vfsp->mnt_vnodelist, v_mntvnodes) {
                printf("vnode list vnode number %d -- vnode address %p\n", counter, vpp);
                vprint("ZFS vfsp vnode list", vpp);
                counter++;
                } */
        
        crget(cr);
#ifdef TODO     
        ret = secpolicy_fs_unmount(cr, vfsp);
        if (ret) {
                ret = dsl_deleg_access((char *)refstr_value(vfsp->vfs_resource),
                    ZFS_DELEG_PERM_MOUNT, cr);
                if (ret)
                        return (ret);
        }
#endif
        /*
         * We purge the parent filesystem's vfsp as the parent filesystem
         * and all of its snapshots have their vnode's v_vfsp set to the
         * parent's filesystem's vfsp.  Note, 'z_parent' is self
         * referential for non-snapshots.
         */
        (void) dnlc_purge_vfsp(zfsvfs->z_parent->z_vfs, 0);

        /*
         * Unmount any snapshots mounted under .zfs before unmounting the
         * dataset itself.
         */
        if (zfsvfs->z_ctldir != NULL &&
            (ret = zfsctl_umount_snapshots(vfsp, fflag, cr)) != 0) {
                return (ret);
        }

#if 0
        if (!(fflag & MS_FORCE)) {
                /*
                 * Check the number of active vnodes in the file system.
                 * Our count is maintained in the vfs structure, but the
                 * number is off by 1 to indicate a hold on the vfs
                 * structure itself.
                 *
                 * The '.zfs' directory maintains a reference of its
                 * own, and any active references underneath are
                 * reflected in the vnode count.
                 */
                if (zfsvfs->z_ctldir == NULL) {
                        if (vfsp->vfs_count > 1){
                                return (EBUSY);
                        }
                } else {
                        if (vfsp->vfs_count > 2 ||
                            zfsvfs->z_ctldir->v_count > 1) {
                                return (EBUSY);
                        }
                }
        }
#endif
        vfsp->vfs_flag |= VFS_UNMOUNTED;

        VERIFY(zfsvfs_teardown(zfsvfs, B_TRUE) == 0);
        os = zfsvfs->z_os;

        /*
         * z_os will be NULL if there was an error in
         * attempting to reopen zfsvfs.
         */
        if (os != NULL) {
                /*
                 * Unset the objset user_ptr.
                 */
                mutex_enter(&os->os->os_user_ptr_lock);
                dmu_objset_set_user(os, NULL);
                mutex_exit(&os->os->os_user_ptr_lock);

                /*
                 * Finally release the objset
                 */
                dmu_objset_close(os);
        }

        /*
         * We can now safely destroy the '.zfs' directory node.
         */
        if (zfsvfs->z_ctldir != NULL)
                zfsctl_destroy(zfsvfs);

        if (fflag & MS_FORCE)
                flags |= FORCECLOSE;
        
        ret = vflush(vfsp, NULL, 0);
        if (ret != 0)
                return ret;
        
        return (0);
}

static int
zfs_vget(vfs_t *vfsp, ino_t ino, vnode_t **vpp)
{
        zfsvfs_t *zfsvfs = vfsp->vfs_data;
        znode_t *zp;
        int err;

        dprintf("zfs_vget called\n");
        dprintf("vfsp->vfs_count %d\n", vfsp->vfs_count);
        
        ZFS_ENTER(zfsvfs);
        err = zfs_zget(zfsvfs, ino, &zp);
        if (err == 0 && zp->z_unlinked) {
                VN_RELE(ZTOV(zp));
                err = EINVAL;
        }
        if (err != 0)
                *vpp = NULL;
        else {
                *vpp = ZTOV(zp);
                /* XXX NetBSD how to get flags for vn_lock ? */
                vn_lock(*vpp, 0);
        }
        ZFS_EXIT(zfsvfs);
        return (err);
}

static int
zfs_fhtovp(vfs_t *vfsp, fid_t *fidp, vnode_t **vpp)
{
        zfsvfs_t *zfsvfs = vfsp->vfs_data;
        znode_t *zp;
        uint64_t object = 0;
        uint64_t fid_gen = 0;
        uint64_t gen_mask;
        uint64_t zp_gen;
        int i, err;

        *vpp = NULL;

        dprintf("zfs_fhtovp called\n");
        dprintf("vfsp->vfs_count %d\n", vfsp->vfs_count);
        
        ZFS_ENTER(zfsvfs);

        if (fidp->fid_len == LONG_FID_LEN) {
                zfid_long_t *zlfid = (zfid_long_t *)fidp;
                uint64_t objsetid = 0;
                uint64_t setgen = 0;

                for (i = 0; i < sizeof (zlfid->zf_setid); i++)
                        objsetid |= ((uint64_t)zlfid->zf_setid[i]) << (8 * i);

                for (i = 0; i < sizeof (zlfid->zf_setgen); i++)
                        setgen |= ((uint64_t)zlfid->zf_setgen[i]) << (8 * i);

                ZFS_EXIT(zfsvfs);

                err = zfsctl_lookup_objset(vfsp, objsetid, &zfsvfs);
                if (err)
                        return (EINVAL);
                ZFS_ENTER(zfsvfs);
        }

        if (fidp->fid_len == SHORT_FID_LEN || fidp->fid_len == LONG_FID_LEN) {
                zfid_short_t *zfid = (zfid_short_t *)fidp;

                for (i = 0; i < sizeof (zfid->zf_object); i++)
                        object |= ((uint64_t)zfid->zf_object[i]) << (8 * i);

                for (i = 0; i < sizeof (zfid->zf_gen); i++)
                        fid_gen |= ((uint64_t)zfid->zf_gen[i]) << (8 * i);
        } else {
                ZFS_EXIT(zfsvfs);
                return (EINVAL);
        }

        /* A zero fid_gen means we are in the .zfs control directories */
        if (fid_gen == 0 &&
            (object == ZFSCTL_INO_ROOT || object == ZFSCTL_INO_SNAPDIR)) {
                *vpp = zfsvfs->z_ctldir;
                ASSERT(*vpp != NULL);
                if (object == ZFSCTL_INO_SNAPDIR) {
                        VERIFY(zfsctl_root_lookup(*vpp, "snapshot", vpp, NULL,
                                0, NULL, NULL, NULL, NULL, NULL) == 0);
                } else {
                        VN_HOLD(*vpp);
                }
                ZFS_EXIT(zfsvfs);
                /* XXX: LK_RETRY? */
                vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY);
                return (0);
        }

        gen_mask = -1ULL >> (64 - 8 * i);

        dprintf("getting %llu [%u mask %llx]\n", object, fid_gen, gen_mask);
        if (err = zfs_zget(zfsvfs, object, &zp)) {
                ZFS_EXIT(zfsvfs);
                return (err);
        }
        zp_gen = zp->z_phys->zp_gen & gen_mask;
        if (zp_gen == 0)
                zp_gen = 1;
        if (zp->z_unlinked || zp_gen != fid_gen) {
                dprintf("znode gen (%u) != fid gen (%u)\n", zp_gen, fid_gen);
                VN_RELE(ZTOV(zp));
                ZFS_EXIT(zfsvfs);
                return (EINVAL);
        }

        *vpp = ZTOV(zp);
        /* XXX: LK_RETRY? */
        vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY);
        ZFS_EXIT(zfsvfs);
        return (0);
}

/*
 * Block out VOPs and close zfsvfs_t::z_os
 *
 * Note, if successful, then we return with the 'z_teardown_lock' and
 * 'z_teardown_inactive_lock' write held.
 */
int
zfs_suspend_fs(zfsvfs_t *zfsvfs, char *name, int *mode)
{
        int error;

        if ((error = zfsvfs_teardown(zfsvfs, B_FALSE)) != 0)
                return (error);

        *mode = zfsvfs->z_os->os_mode;
        dmu_objset_name(zfsvfs->z_os, name);
        dmu_objset_close(zfsvfs->z_os);

        return (0);
}

/*
 * Reopen zfsvfs_t::z_os and release VOPs.
 */
int
zfs_resume_fs(zfsvfs_t *zfsvfs, const char *osname, int mode)
{
        int err;

        ASSERT(RRW_WRITE_HELD(&zfsvfs->z_teardown_lock));
        ASSERT(RW_WRITE_HELD(&zfsvfs->z_teardown_inactive_lock));

        err = dmu_objset_open(osname, DMU_OST_ZFS, mode, &zfsvfs->z_os);
        if (err) {
                zfsvfs->z_os = NULL;
        } else {
                znode_t *zp;

                VERIFY(zfsvfs_setup(zfsvfs, B_FALSE) == 0);

                /*
                 * Attempt to re-establish all the active znodes with
                 * their dbufs.  If a zfs_rezget() fails, then we'll let
                 * any potential callers discover that via ZFS_ENTER_VERIFY_VP
                 * when they try to use their znode.
                 */
                mutex_enter(&zfsvfs->z_znodes_lock);
                for (zp = list_head(&zfsvfs->z_all_znodes); zp;
                    zp = list_next(&zfsvfs->z_all_znodes, zp)) {
                        (void) zfs_rezget(zp);
                }
                mutex_exit(&zfsvfs->z_znodes_lock);

        }

        /* release the VOPs */
        rw_exit(&zfsvfs->z_teardown_inactive_lock);
        rrw_exit(&zfsvfs->z_teardown_lock, FTAG);

        if (err) {
                /*
                 * Since we couldn't reopen zfsvfs::z_os, force
                 * unmount this file system.
                 */
                if (vn_vfswlock(zfsvfs->z_vfs->vfs_vnodecovered) == 0)
                        (void) dounmount(zfsvfs->z_vfs, MS_FORCE, curlwp);
        }
        return (err);
}

static void
zfs_freevfs(vfs_t *vfsp)
{
        zfsvfs_t *zfsvfs = vfsp->vfs_data;
        int i;

        for (i = 0; i != ZFS_OBJ_MTX_SZ; i++)
                mutex_destroy(&zfsvfs->z_hold_mtx[i]);

        zfs_fuid_destroy(zfsvfs);
        zfs_freezfsvfs(zfsvfs);

        atomic_add_32(&zfs_active_fs_count, -1);
}

/*
 * VFS_INIT() initialization.  Note that there is no VFS_FINI(),
 * so we can't safely do any non-idempotent initialization here.
 * Leave that to zfs_init() and zfs_fini(), which are called
 * from the module's _init() and _fini() entry points.
 */
/*ARGSUSED*/
int
zfs_vfsinit(int fstype, char *name)
{
        int error;

        zfsfstype = fstype;

        /*
         * Setup vfsops and vnodeops tables.
         */
        error = vfs_setfsops(fstype, zfs_vfsops_template, &zfs_vfsops);

        error = zfs_create_op_tables();
        if (error) {
                zfs_remove_op_tables();
                cmn_err(CE_WARN, "zfs: bad vnode ops template");
                vfs_freevfsops_by_type(zfsfstype);
                return (error);
        }

        mutex_init(&zfs_dev_mtx, NULL, MUTEX_DEFAULT, NULL);
        mutex_init(&zfs_debug_mtx, NULL, MUTEX_DEFAULT, NULL);
        
        /*
         * Unique major number for all zfs mounts.
         * If we run out of 32-bit minors, we'll getudev() another major.
         */
        zfs_major = ddi_name_to_major(ZFS_DRIVER);
        zfs_minor = ZFS_MIN_MINOR;

        return (0);
}

int
zfs_vfsfini(void)
{
        int err;

        err = vfs_detach(&zfs_vfsops_template);
        if (err != 0)
                return err;

        mutex_destroy(&zfs_debug_mtx);
        mutex_destroy(&zfs_dev_mtx);    

        return 0;
}

void
zfs_init(void)
{
        /*
         * Initialize .zfs directory structures
         */
        zfsctl_init();

        /*
         * Initialize znode cache, vnode ops, etc...
         */
        zfs_znode_init();
}

void
zfs_fini(void)
{
        zfsctl_fini();
        zfs_znode_fini();
}

int
zfs_busy(void)
{
        return (zfs_active_fs_count != 0);
}

int
zfs_set_version(const char *name, uint64_t newvers)
{
        int error;
        objset_t *os;
        dmu_tx_t *tx;
        uint64_t curvers;

        /*
         * XXX for now, require that the filesystem be unmounted.  Would
         * be nice to find the zfsvfs_t and just update that if
         * possible.
         */

        if (newvers < ZPL_VERSION_INITIAL || newvers > ZPL_VERSION)
                return (EINVAL);

        error = dmu_objset_open(name, DMU_OST_ZFS, DS_MODE_OWNER, &os);
        if (error)
                return (error);

        error = zap_lookup(os, MASTER_NODE_OBJ, ZPL_VERSION_STR,
            8, 1, &curvers);
        if (error)
                goto out;
        if (newvers < curvers) {
                error = EINVAL;
                goto out;
        }

        tx = dmu_tx_create(os);
        dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, 0, ZPL_VERSION_STR);
        error = dmu_tx_assign(tx, TXG_WAIT);
        if (error) {
                dmu_tx_abort(tx);
                goto out;
        }
        error = zap_update(os, MASTER_NODE_OBJ, ZPL_VERSION_STR, 8, 1,
            &newvers, tx);

        spa_history_internal_log(LOG_DS_UPGRADE,
            dmu_objset_spa(os), tx, CRED(),
            "oldver=%llu newver=%llu dataset = %llu", curvers, newvers,
            dmu_objset_id(os));
        dmu_tx_commit(tx);

out:
        dmu_objset_close(os);
        return (error);
}

/*
 * Read a property stored within the master node.
 */
int
zfs_get_zplprop(objset_t *os, zfs_prop_t prop, uint64_t *value)
{
        const char *pname;
        int error = ENOENT;

        /*
         * Look up the file system's value for the property.  For the
         * version property, we look up a slightly different string.
         */
        if (prop == ZFS_PROP_VERSION)
                pname = ZPL_VERSION_STR;
        else
                pname = zfs_prop_to_name(prop);

        if (os != NULL)
                error = zap_lookup(os, MASTER_NODE_OBJ, pname, 8, 1, value);

        if (error == ENOENT) {
                /* No value set, use the default value */
                switch (prop) {
                case ZFS_PROP_VERSION:
                        *value = ZPL_VERSION;
                        break;
                case ZFS_PROP_NORMALIZE:
                case ZFS_PROP_UTF8ONLY:
                        *value = 0;
                        break;
                case ZFS_PROP_CASE:
                        *value = ZFS_CASE_SENSITIVE;
                        break;
                default:
                        return (error);
                }
                error = 0;
        }
        return (error);
}

static int
zfs_start(vfs_t *vfsp, int flags)
{

        return (0);
}


#ifdef TODO
static vfsdef_t vfw = {
        VFSDEF_VERSION,
        MNTTYPE_ZFS,
        zfs_vfsinit,
        VSW_HASPROTO|VSW_CANRWRO|VSW_CANREMOUNT|VSW_VOLATILEDEV|VSW_STATS|
            VSW_XID,
        &zfs_mntopts
};

struct modlfs zfs_modlfs = {
        &mod_fsops, "ZFS filesystem version " SPA_VERSION_STRING, &vfw
};
#endif