Move the world out of /zfs/ and seperate out module build tree

1 files changed, 1652 insertions, 0 deletions

diff --git a/module/zfs/zfs_vfsops.c b/module/zfs/zfs_vfsops.c
new file mode 100644
index 000000000..06b4dee46
--- /dev/null
+++ b/module/zfs/zfs_vfsops.c
@@ -0,0 +1,1652 @@
+/*
+ * 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 "fs/fs_subr.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/refstr.h>
+#include <sys/zfs_ioctl.h>
+#include <sys/zfs_ctldir.h>
+#include <sys/zfs_fuid.h>
+#include <sys/bootconf.h>
+#include <sys/sunddi.h>
+#include <sys/dnlc.h>
+#include <sys/dmu_objset.h>
+#include <sys/spa_boot.h>
+
+int zfsfstype;
+vfsops_t *zfs_vfsops = NULL;
+static major_t zfs_major;
+static minor_t zfs_minor;
+static kmutex_t	zfs_dev_mtx;
+
+static int zfs_mount(vfs_t *vfsp, vnode_t *mvp, struct mounta *uap, cred_t *cr);
+static int zfs_umount(vfs_t *vfsp, int fflag, cred_t *cr);
+static int zfs_mountroot(vfs_t *vfsp, enum whymountroot);
+static int zfs_root(vfs_t *vfsp, vnode_t **vpp);
+static int zfs_statvfs(vfs_t *vfsp, struct statvfs64 *statp);
+static int zfs_vget(vfs_t *vfsp, vnode_t **vpp, fid_t *fidp);
+static void zfs_freevfs(vfs_t *vfsp);
+
+static const fs_operation_def_t zfs_vfsops_template[] = {
+	VFSNAME_MOUNT,		{ .vfs_mount = zfs_mount },
+	VFSNAME_MOUNTROOT,	{ .vfs_mountroot = zfs_mountroot },
+	VFSNAME_UNMOUNT,	{ .vfs_unmount = zfs_umount },
+	VFSNAME_ROOT,		{ .vfs_root = zfs_root },
+	VFSNAME_STATVFS,	{ .vfs_statvfs = zfs_statvfs },
+	VFSNAME_SYNC,		{ .vfs_sync = zfs_sync },
+	VFSNAME_VGET,		{ .vfs_vget = zfs_vget },
+	VFSNAME_FREEVFS,	{ .vfs_freevfs = zfs_freevfs },
+	NULL,			NULL
+};
+
+static const fs_operation_def_t zfs_vfsops_eio_template[] = {
+	VFSNAME_FREEVFS,	{ .vfs_freevfs =  zfs_freevfs },
+	NULL,			NULL
+};
+
+/*
+ * 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, short flag, cred_t *cr)
+{
+	/*
+	 * 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);
+
+	/*
+	 * 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 & SYNC_ATTR)
+		return (0);
+
+	if (vfsp != NULL) {
+		/*
+		 * Sync a specific filesystem.
+		 */
+		zfsvfs_t *zfsvfs = vfsp->vfs_data;
+
+		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();
+	}
+
+	return (0);
+}
+
+static int
+zfs_create_unique_device(dev_t *dev)
+{
+	major_t new_major;
+
+	do {
+		ASSERT3U(zfs_minor, <=, MAXMIN32);
+		minor_t start = zfs_minor;
+		do {
+			mutex_enter(&zfs_dev_mtx);
+			if (zfs_minor >= MAXMIN32) {
+				/*
+				 * 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);
+		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 */
+	} 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? */
+		zfsvfs->z_vfs->vfs_flag |= VFS_XATTR;
+		vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_NOXATTR);
+		vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_XATTR, NULL, 0);
+	} else {
+		/* XXX locking on vfs_flag? */
+		zfsvfs->z_vfs->vfs_flag &= ~VFS_XATTR;
+		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;
+
+	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_bcount = 0;
+	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_dev = mount_dev;
+	vfsp->vfs_fstype = zfsfstype;
+	vfsp->vfs_bsize = recordsize;
+	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;
+
+	/* The call to zfs_init_fs leaves the vnode held, release it here. */
+	VN_RELE(ZTOV(zp));
+
+	/*
+	 * 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);
+	}
+
+	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);
+}
+
+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);
+}
+
+/*ARGSUSED*/
+static int
+zfs_mount(vfs_t *vfsp, vnode_t *mvp, struct mounta *uap, cred_t *cr)
+{
+	char		*osname;
+	pathname_t	spn;
+	int		error = 0;
+	uio_seg_t	fromspace = (uap->flags & MS_SYSSPACE) ?
+	    UIO_SYSSPACE : UIO_USERSPACE;
+	int		canwrite;
+
+	if (mvp->v_type != VDIR)
+		return (ENOTDIR);
+
+	mutex_enter(&mvp->v_lock);
+	if ((uap->flags & MS_REMOUNT) == 0 &&
+	    (uap->flags & MS_OVERLAY) == 0 &&
+	    (mvp->v_count != 1 || (mvp->v_flag & VROOT))) {
+		mutex_exit(&mvp->v_lock);
+		return (EBUSY);
+	}
+	mutex_exit(&mvp->v_lock);
+
+	/*
+	 * 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);
+
+	/*
+	 * Get the objset name (the "special" mount argument).
+	 */
+	if (error = pn_get(uap->spec, fromspace, &spn))
+		return (error);
+
+	osname = spn.pn_path;
+
+	/*
+	 * 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, 0, cr, NULL) != 0) {
+				error = EPERM;
+				goto out;
+			}
+
+			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;
+	}
+
+	/*
+	 * 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;
+	}
+
+	error = zfs_domount(vfsp, osname);
+
+out:
+	pn_free(&spn);
+	return (error);
+}
+
+static int
+zfs_statvfs(vfs_t *vfsp, struct statvfs64 *statp)
+{
+	zfsvfs_t *zfsvfs = vfsp->vfs_data;
+	dev32_t d32;
+	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;
+
+	(void) cmpldev(&d32, vfsp->vfs_dev);
+	statp->f_fsid = d32;
+
+	/*
+	 * We're a zfs filesystem.
+	 */
+	(void) strcpy(statp->f_basetype, vfssw[vfsp->vfs_fstype].vsw_name);
+
+	statp->f_flag = vf_to_stf(vfsp->vfs_flag);
+
+	statp->f_namemax = ZFS_MAXNAMELEN;
+
+	/*
+	 * We have all of 32 characters to stuff a string here.
+	 * Is there anything useful we could/should provide?
+	 */
+	bzero(statp->f_fstr, sizeof (statp->f_fstr));
+
+	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);
+
+	error = zfs_zget(zfsvfs, zfsvfs->z_root, &rootzp);
+	if (error == 0)
+		*vpp = ZTOV(rootzp);
+
+	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, cred_t *cr)
+{
+	zfsvfs_t *zfsvfs = vfsp->vfs_data;
+	objset_t *os;
+	int ret;
+
+	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);
+	}
+
+	/*
+	 * 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 (!(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);
+		}
+	}
+
+	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);
+
+	return (0);
+}
+
+static int
+zfs_vget(vfs_t *vfsp, vnode_t **vpp, fid_t *fidp)
+{
+	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;
+
+	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);
+		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);
+	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, CRED());
+	}
+	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*/
+static 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);
+	if (error != 0) {
+		cmn_err(CE_WARN, "zfs: bad vfs ops template");
+	}
+
+	error = zfs_create_op_tables();
+	if (error) {
+		zfs_remove_op_tables();
+		cmn_err(CE_WARN, "zfs: bad vnode ops template");
+		(void) vfs_freevfsops_by_type(zfsfstype);
+		return (error);
+	}
+
+	mutex_init(&zfs_dev_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);
+}
+
+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 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
+};