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Cross Reference: zfs_vfsops.c
xref: /onnv/onnv-gate/usr/src/uts/common/fs/zfs/zfs_vfsops.c
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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 /*
     22  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
     23  */
     24 
     25 /* Portions Copyright 2010 Robert Milkowski */
     26 
     27 #include <sys/types.h>
     28 #include <sys/param.h>
     29 #include <sys/systm.h>
     30 #include <sys/sysmacros.h>
     31 #include <sys/kmem.h>
     32 #include <sys/pathname.h>
     33 #include <sys/vnode.h>
     34 #include <sys/vfs.h>
     35 #include <sys/vfs_opreg.h>
     36 #include <sys/mntent.h>
     37 #include <sys/mount.h>
     38 #include <sys/cmn_err.h>
     39 #include "fs/fs_subr.h"
     40 #include <sys/zfs_znode.h>
     41 #include <sys/zfs_dir.h>
     42 #include <sys/zil.h>
     43 #include <sys/fs/zfs.h>
     44 #include <sys/dmu.h>
     45 #include <sys/dsl_prop.h>
     46 #include <sys/dsl_dataset.h>
     47 #include <sys/dsl_deleg.h>
     48 #include <sys/spa.h>
     49 #include <sys/zap.h>
     50 #include <sys/sa.h>
     51 #include <sys/varargs.h>
     52 #include <sys/policy.h>
     53 #include <sys/atomic.h>
     54 #include <sys/mkdev.h>
     55 #include <sys/modctl.h>
     56 #include <sys/refstr.h>
     57 #include <sys/zfs_ioctl.h>
     58 #include <sys/zfs_ctldir.h>
     59 #include <sys/zfs_fuid.h>
     60 #include <sys/bootconf.h>
     61 #include <sys/sunddi.h>
     62 #include <sys/dnlc.h>
     63 #include <sys/dmu_objset.h>
     64 #include <sys/spa_boot.h>
     65 #include <sys/sa.h>
     66 #include "zfs_comutil.h"
     67 
     68 int zfsfstype;
     69 vfsops_t *zfs_vfsops = NULL;
     70 static major_t zfs_major;
     71 static minor_t zfs_minor;
     72 static kmutex_t	zfs_dev_mtx;
     73 
     74 extern int sys_shutdown;
     75 
     76 static int zfs_mount(vfs_t *vfsp, vnode_t *mvp, struct mounta *uap, cred_t *cr);
     77 static int zfs_umount(vfs_t *vfsp, int fflag, cred_t *cr);
     78 static int zfs_mountroot(vfs_t *vfsp, enum whymountroot);
     79 static int zfs_root(vfs_t *vfsp, vnode_t **vpp);
     80 static int zfs_statvfs(vfs_t *vfsp, struct statvfs64 *statp);
     81 static int zfs_vget(vfs_t *vfsp, vnode_t **vpp, fid_t *fidp);
     82 static void zfs_freevfs(vfs_t *vfsp);
     83 
     84 static const fs_operation_def_t zfs_vfsops_template[] = {
     85 	VFSNAME_MOUNT,		{ .vfs_mount = zfs_mount },
     86 	VFSNAME_MOUNTROOT,	{ .vfs_mountroot = zfs_mountroot },
     87 	VFSNAME_UNMOUNT,	{ .vfs_unmount = zfs_umount },
     88 	VFSNAME_ROOT,		{ .vfs_root = zfs_root },
     89 	VFSNAME_STATVFS,	{ .vfs_statvfs = zfs_statvfs },
     90 	VFSNAME_SYNC,		{ .vfs_sync = zfs_sync },
     91 	VFSNAME_VGET,		{ .vfs_vget = zfs_vget },
     92 	VFSNAME_FREEVFS,	{ .vfs_freevfs = zfs_freevfs },
     93 	NULL,			NULL
     94 };
     95 
     96 static const fs_operation_def_t zfs_vfsops_eio_template[] = {
     97 	VFSNAME_FREEVFS,	{ .vfs_freevfs =  zfs_freevfs },
     98 	NULL,			NULL
     99 };
    100 
    101 /*
    102  * We need to keep a count of active fs's.
    103  * This is necessary to prevent our module
    104  * from being unloaded after a umount -f
    105  */
    106 static uint32_t	zfs_active_fs_count = 0;
    107 
    108 static char *noatime_cancel[] = { MNTOPT_ATIME, NULL };
    109 static char *atime_cancel[] = { MNTOPT_NOATIME, NULL };
    110 static char *noxattr_cancel[] = { MNTOPT_XATTR, NULL };
    111 static char *xattr_cancel[] = { MNTOPT_NOXATTR, NULL };
    112 
    113 /*
    114  * MO_DEFAULT is not used since the default value is determined
    115  * by the equivalent property.
    116  */
    117 static mntopt_t mntopts[] = {
    118 	{ MNTOPT_NOXATTR, noxattr_cancel, NULL, 0, NULL },
    119 	{ MNTOPT_XATTR, xattr_cancel, NULL, 0, NULL },
    120 	{ MNTOPT_NOATIME, noatime_cancel, NULL, 0, NULL },
    121 	{ MNTOPT_ATIME, atime_cancel, NULL, 0, NULL }
    122 };
    123 
    124 static mntopts_t zfs_mntopts = {
    125 	sizeof (mntopts) / sizeof (mntopt_t),
    126 	mntopts
    127 };
    128 
    129 /*ARGSUSED*/
    130 int
    131 zfs_sync(vfs_t *vfsp, short flag, cred_t *cr)
    132 {
    133 	/*
    134 	 * Data integrity is job one.  We don't want a compromised kernel
    135 	 * writing to the storage pool, so we never sync during panic.
    136 	 */
    137 	if (panicstr)
    138 		return (0);
    139 
    140 	/*
    141 	 * SYNC_ATTR is used by fsflush() to force old filesystems like UFS
    142 	 * to sync metadata, which they would otherwise cache indefinitely.
    143 	 * Semantically, the only requirement is that the sync be initiated.
    144 	 * The DMU syncs out txgs frequently, so there's nothing to do.
    145 	 */
    146 	if (flag & SYNC_ATTR)
    147 		return (0);
    148 
    149 	if (vfsp != NULL) {
    150 		/*
    151 		 * Sync a specific filesystem.
    152 		 */
    153 		zfsvfs_t *zfsvfs = vfsp->vfs_data;
    154 		dsl_pool_t *dp;
    155 
    156 		ZFS_ENTER(zfsvfs);
    157 		dp = dmu_objset_pool(zfsvfs->z_os);
    158 
    159 		/*
    160 		 * If the system is shutting down, then skip any
    161 		 * filesystems which may exist on a suspended pool.
    162 		 */
    163 		if (sys_shutdown && spa_suspended(dp->dp_spa)) {
    164 			ZFS_EXIT(zfsvfs);
    165 			return (0);
    166 		}
    167 
    168 		if (zfsvfs->z_log != NULL)
    169 			zil_commit(zfsvfs->z_log, 0);
    170 
    171 		ZFS_EXIT(zfsvfs);
    172 	} else {
    173 		/*
    174 		 * Sync all ZFS filesystems.  This is what happens when you
    175 		 * run sync(1M).  Unlike other filesystems, ZFS honors the
    176 		 * request by waiting for all pools to commit all dirty data.
    177 		 */
    178 		spa_sync_allpools();
    179 	}
    180 
    181 	return (0);
    182 }
    183 
    184 static int
    185 zfs_create_unique_device(dev_t *dev)
    186 {
    187 	major_t new_major;
    188 
    189 	do {
    190 		ASSERT3U(zfs_minor, <=, MAXMIN32);
    191 		minor_t start = zfs_minor;
    192 		do {
    193 			mutex_enter(&zfs_dev_mtx);
    194 			if (zfs_minor >= MAXMIN32) {
    195 				/*
    196 				 * If we're still using the real major
    197 				 * keep out of /dev/zfs and /dev/zvol minor
    198 				 * number space.  If we're using a getudev()'ed
    199 				 * major number, we can use all of its minors.
    200 				 */
    201 				if (zfs_major == ddi_name_to_major(ZFS_DRIVER))
    202 					zfs_minor = ZFS_MIN_MINOR;
    203 				else
    204 					zfs_minor = 0;
    205 			} else {
    206 				zfs_minor++;
    207 			}
    208 			*dev = makedevice(zfs_major, zfs_minor);
    209 			mutex_exit(&zfs_dev_mtx);
    210 		} while (vfs_devismounted(*dev) && zfs_minor != start);
    211 		if (zfs_minor == start) {
    212 			/*
    213 			 * We are using all ~262,000 minor numbers for the
    214 			 * current major number.  Create a new major number.
    215 			 */
    216 			if ((new_major = getudev()) == (major_t)-1) {
    217 				cmn_err(CE_WARN,
    218 				    "zfs_mount: Can't get unique major "
    219 				    "device number.");
    220 				return (-1);
    221 			}
    222 			mutex_enter(&zfs_dev_mtx);
    223 			zfs_major = new_major;
    224 			zfs_minor = 0;
    225 
    226 			mutex_exit(&zfs_dev_mtx);
    227 		} else {
    228 			break;
    229 		}
    230 		/* CONSTANTCONDITION */
    231 	} while (1);
    232 
    233 	return (0);
    234 }
    235 
    236 static void
    237 atime_changed_cb(void *arg, uint64_t newval)
    238 {
    239 	zfsvfs_t *zfsvfs = arg;
    240 
    241 	if (newval == TRUE) {
    242 		zfsvfs->z_atime = TRUE;
    243 		vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_NOATIME);
    244 		vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_ATIME, NULL, 0);
    245 	} else {
    246 		zfsvfs->z_atime = FALSE;
    247 		vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_ATIME);
    248 		vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_NOATIME, NULL, 0);
    249 	}
    250 }
    251 
    252 static void
    253 xattr_changed_cb(void *arg, uint64_t newval)
    254 {
    255 	zfsvfs_t *zfsvfs = arg;
    256 
    257 	if (newval == TRUE) {
    258 		/* XXX locking on vfs_flag? */
    259 		zfsvfs->z_vfs->vfs_flag |= VFS_XATTR;
    260 		vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_NOXATTR);
    261 		vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_XATTR, NULL, 0);
    262 	} else {
    263 		/* XXX locking on vfs_flag? */
    264 		zfsvfs->z_vfs->vfs_flag &= ~VFS_XATTR;
    265 		vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_XATTR);
    266 		vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_NOXATTR, NULL, 0);
    267 	}
    268 }
    269 
    270 static void
    271 blksz_changed_cb(void *arg, uint64_t newval)
    272 {
    273 	zfsvfs_t *zfsvfs = arg;
    274 
    275 	if (newval < SPA_MINBLOCKSIZE ||
    276 	    newval > SPA_MAXBLOCKSIZE || !ISP2(newval))
    277 		newval = SPA_MAXBLOCKSIZE;
    278 
    279 	zfsvfs->z_max_blksz = newval;
    280 	zfsvfs->z_vfs->vfs_bsize = newval;
    281 }
    282 
    283 static void
    284 readonly_changed_cb(void *arg, uint64_t newval)
    285 {
    286 	zfsvfs_t *zfsvfs = arg;
    287 
    288 	if (newval) {
    289 		/* XXX locking on vfs_flag? */
    290 		zfsvfs->z_vfs->vfs_flag |= VFS_RDONLY;
    291 		vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_RW);
    292 		vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_RO, NULL, 0);
    293 	} else {
    294 		/* XXX locking on vfs_flag? */
    295 		zfsvfs->z_vfs->vfs_flag &= ~VFS_RDONLY;
    296 		vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_RO);
    297 		vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_RW, NULL, 0);
    298 	}
    299 }
    300 
    301 static void
    302 devices_changed_cb(void *arg, uint64_t newval)
    303 {
    304 	zfsvfs_t *zfsvfs = arg;
    305 
    306 	if (newval == FALSE) {
    307 		zfsvfs->z_vfs->vfs_flag |= VFS_NODEVICES;
    308 		vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_DEVICES);
    309 		vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_NODEVICES, NULL, 0);
    310 	} else {
    311 		zfsvfs->z_vfs->vfs_flag &= ~VFS_NODEVICES;
    312 		vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_NODEVICES);
    313 		vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_DEVICES, NULL, 0);
    314 	}
    315 }
    316 
    317 static void
    318 setuid_changed_cb(void *arg, uint64_t newval)
    319 {
    320 	zfsvfs_t *zfsvfs = arg;
    321 
    322 	if (newval == FALSE) {
    323 		zfsvfs->z_vfs->vfs_flag |= VFS_NOSETUID;
    324 		vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_SETUID);
    325 		vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_NOSETUID, NULL, 0);
    326 	} else {
    327 		zfsvfs->z_vfs->vfs_flag &= ~VFS_NOSETUID;
    328 		vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_NOSETUID);
    329 		vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_SETUID, NULL, 0);
    330 	}
    331 }
    332 
    333 static void
    334 exec_changed_cb(void *arg, uint64_t newval)
    335 {
    336 	zfsvfs_t *zfsvfs = arg;
    337 
    338 	if (newval == FALSE) {
    339 		zfsvfs->z_vfs->vfs_flag |= VFS_NOEXEC;
    340 		vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_EXEC);
    341 		vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_NOEXEC, NULL, 0);
    342 	} else {
    343 		zfsvfs->z_vfs->vfs_flag &= ~VFS_NOEXEC;
    344 		vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_NOEXEC);
    345 		vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_EXEC, NULL, 0);
    346 	}
    347 }
    348 
    349 /*
    350  * The nbmand mount option can be changed at mount time.
    351  * We can't allow it to be toggled on live file systems or incorrect
    352  * behavior may be seen from cifs clients
    353  *
    354  * This property isn't registered via dsl_prop_register(), but this callback
    355  * will be called when a file system is first mounted
    356  */
    357 static void
    358 nbmand_changed_cb(void *arg, uint64_t newval)
    359 {
    360 	zfsvfs_t *zfsvfs = arg;
    361 	if (newval == FALSE) {
    362 		vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_NBMAND);
    363 		vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_NONBMAND, NULL, 0);
    364 	} else {
    365 		vfs_clearmntopt(zfsvfs->z_vfs, MNTOPT_NONBMAND);
    366 		vfs_setmntopt(zfsvfs->z_vfs, MNTOPT_NBMAND, NULL, 0);
    367 	}
    368 }
    369 
    370 static void
    371 snapdir_changed_cb(void *arg, uint64_t newval)
    372 {
    373 	zfsvfs_t *zfsvfs = arg;
    374 
    375 	zfsvfs->z_show_ctldir = newval;
    376 }
    377 
    378 static void
    379 vscan_changed_cb(void *arg, uint64_t newval)
    380 {
    381 	zfsvfs_t *zfsvfs = arg;
    382 
    383 	zfsvfs->z_vscan = newval;
    384 }
    385 
    386 static void
    387 acl_inherit_changed_cb(void *arg, uint64_t newval)
    388 {
    389 	zfsvfs_t *zfsvfs = arg;
    390 
    391 	zfsvfs->z_acl_inherit = newval;
    392 }
    393 
    394 static int
    395 zfs_register_callbacks(vfs_t *vfsp)
    396 {
    397 	struct dsl_dataset *ds = NULL;
    398 	objset_t *os = NULL;
    399 	zfsvfs_t *zfsvfs = NULL;
    400 	uint64_t nbmand;
    401 	int readonly, do_readonly = B_FALSE;
    402 	int setuid, do_setuid = B_FALSE;
    403 	int exec, do_exec = B_FALSE;
    404 	int devices, do_devices = B_FALSE;
    405 	int xattr, do_xattr = B_FALSE;
    406 	int atime, do_atime = B_FALSE;
    407 	int error = 0;
    408 
    409 	ASSERT(vfsp);
    410 	zfsvfs = vfsp->vfs_data;
    411 	ASSERT(zfsvfs);
    412 	os = zfsvfs->z_os;
    413 
    414 	/*
    415 	 * The act of registering our callbacks will destroy any mount
    416 	 * options we may have.  In order to enable temporary overrides
    417 	 * of mount options, we stash away the current values and
    418 	 * restore them after we register the callbacks.
    419 	 */
    420 	if (vfs_optionisset(vfsp, MNTOPT_RO, NULL) ||
    421 	    !spa_writeable(dmu_objset_spa(os))) {
    422 		readonly = B_TRUE;
    423 		do_readonly = B_TRUE;
    424 	} else if (vfs_optionisset(vfsp, MNTOPT_RW, NULL)) {
    425 		readonly = B_FALSE;
    426 		do_readonly = B_TRUE;
    427 	}
    428 	if (vfs_optionisset(vfsp, MNTOPT_NOSUID, NULL)) {
    429 		devices = B_FALSE;
    430 		setuid = B_FALSE;
    431 		do_devices = B_TRUE;
    432 		do_setuid = B_TRUE;
    433 	} else {
    434 		if (vfs_optionisset(vfsp, MNTOPT_NODEVICES, NULL)) {
    435 			devices = B_FALSE;
    436 			do_devices = B_TRUE;
    437 		} else if (vfs_optionisset(vfsp, MNTOPT_DEVICES, NULL)) {
    438 			devices = B_TRUE;
    439 			do_devices = B_TRUE;
    440 		}
    441 
    442 		if (vfs_optionisset(vfsp, MNTOPT_NOSETUID, NULL)) {
    443 			setuid = B_FALSE;
    444 			do_setuid = B_TRUE;
    445 		} else if (vfs_optionisset(vfsp, MNTOPT_SETUID, NULL)) {
    446 			setuid = B_TRUE;
    447 			do_setuid = B_TRUE;
    448 		}
    449 	}
    450 	if (vfs_optionisset(vfsp, MNTOPT_NOEXEC, NULL)) {
    451 		exec = B_FALSE;
    452 		do_exec = B_TRUE;
    453 	} else if (vfs_optionisset(vfsp, MNTOPT_EXEC, NULL)) {
    454 		exec = B_TRUE;
    455 		do_exec = B_TRUE;
    456 	}
    457 	if (vfs_optionisset(vfsp, MNTOPT_NOXATTR, NULL)) {
    458 		xattr = B_FALSE;
    459 		do_xattr = B_TRUE;
    460 	} else if (vfs_optionisset(vfsp, MNTOPT_XATTR, NULL)) {
    461 		xattr = B_TRUE;
    462 		do_xattr = B_TRUE;
    463 	}
    464 	if (vfs_optionisset(vfsp, MNTOPT_NOATIME, NULL)) {
    465 		atime = B_FALSE;
    466 		do_atime = B_TRUE;
    467 	} else if (vfs_optionisset(vfsp, MNTOPT_ATIME, NULL)) {
    468 		atime = B_TRUE;
    469 		do_atime = B_TRUE;
    470 	}
    471 
    472 	/*
    473 	 * nbmand is a special property.  It can only be changed at
    474 	 * mount time.
    475 	 *
    476 	 * This is weird, but it is documented to only be changeable
    477 	 * at mount time.
    478 	 */
    479 	if (vfs_optionisset(vfsp, MNTOPT_NONBMAND, NULL)) {
    480 		nbmand = B_FALSE;
    481 	} else if (vfs_optionisset(vfsp, MNTOPT_NBMAND, NULL)) {
    482 		nbmand = B_TRUE;
    483 	} else {
    484 		char osname[MAXNAMELEN];
    485 
    486 		dmu_objset_name(os, osname);
    487 		if (error = dsl_prop_get_integer(osname, "nbmand", &nbmand,
    488 		    NULL)) {
    489 			return (error);
    490 		}
    491 	}
    492 
    493 	/*
    494 	 * Register property callbacks.
    495 	 *
    496 	 * It would probably be fine to just check for i/o error from
    497 	 * the first prop_register(), but I guess I like to go
    498 	 * overboard...
    499 	 */
    500 	ds = dmu_objset_ds(os);
    501 	error = dsl_prop_register(ds, "atime", atime_changed_cb, zfsvfs);
    502 	error = error ? error : dsl_prop_register(ds,
    503 	    "xattr", xattr_changed_cb, zfsvfs);
    504 	error = error ? error : dsl_prop_register(ds,
    505 	    "recordsize", blksz_changed_cb, zfsvfs);
    506 	error = error ? error : dsl_prop_register(ds,
    507 	    "readonly", readonly_changed_cb, zfsvfs);
    508 	error = error ? error : dsl_prop_register(ds,
    509 	    "devices", devices_changed_cb, zfsvfs);
    510 	error = error ? error : dsl_prop_register(ds,
    511 	    "setuid", setuid_changed_cb, zfsvfs);
    512 	error = error ? error : dsl_prop_register(ds,
    513 	    "exec", exec_changed_cb, zfsvfs);
    514 	error = error ? error : dsl_prop_register(ds,
    515 	    "snapdir", snapdir_changed_cb, zfsvfs);
    516 	error = error ? error : dsl_prop_register(ds,
    517 	    "aclinherit", acl_inherit_changed_cb, zfsvfs);
    518 	error = error ? error : dsl_prop_register(ds,
    519 	    "vscan", vscan_changed_cb, zfsvfs);
    520 	if (error)
    521 		goto unregister;
    522 
    523 	/*
    524 	 * Invoke our callbacks to restore temporary mount options.
    525 	 */
    526 	if (do_readonly)
    527 		readonly_changed_cb(zfsvfs, readonly);
    528 	if (do_setuid)
    529 		setuid_changed_cb(zfsvfs, setuid);
    530 	if (do_exec)
    531 		exec_changed_cb(zfsvfs, exec);
    532 	if (do_devices)
    533 		devices_changed_cb(zfsvfs, devices);
    534 	if (do_xattr)
    535 		xattr_changed_cb(zfsvfs, xattr);
    536 	if (do_atime)
    537 		atime_changed_cb(zfsvfs, atime);
    538 
    539 	nbmand_changed_cb(zfsvfs, nbmand);
    540 
    541 	return (0);
    542 
    543 unregister:
    544 	/*
    545 	 * We may attempt to unregister some callbacks that are not
    546 	 * registered, but this is OK; it will simply return ENOMSG,
    547 	 * which we will ignore.
    548 	 */
    549 	(void) dsl_prop_unregister(ds, "atime", atime_changed_cb, zfsvfs);
    550 	(void) dsl_prop_unregister(ds, "xattr", xattr_changed_cb, zfsvfs);
    551 	(void) dsl_prop_unregister(ds, "recordsize", blksz_changed_cb, zfsvfs);
    552 	(void) dsl_prop_unregister(ds, "readonly", readonly_changed_cb, zfsvfs);
    553 	(void) dsl_prop_unregister(ds, "devices", devices_changed_cb, zfsvfs);
    554 	(void) dsl_prop_unregister(ds, "setuid", setuid_changed_cb, zfsvfs);
    555 	(void) dsl_prop_unregister(ds, "exec", exec_changed_cb, zfsvfs);
    556 	(void) dsl_prop_unregister(ds, "snapdir", snapdir_changed_cb, zfsvfs);
    557 	(void) dsl_prop_unregister(ds, "aclinherit", acl_inherit_changed_cb,
    558 	    zfsvfs);
    559 	(void) dsl_prop_unregister(ds, "vscan", vscan_changed_cb, zfsvfs);
    560 	return (error);
    561 
    562 }
    563 
    564 static int
    565 zfs_space_delta_cb(dmu_object_type_t bonustype, void *data,
    566     uint64_t *userp, uint64_t *groupp)
    567 {
    568 	znode_phys_t *znp = data;
    569 	int error = 0;
    570 
    571 	/*
    572 	 * Is it a valid type of object to track?
    573 	 */
    574 	if (bonustype != DMU_OT_ZNODE && bonustype != DMU_OT_SA)
    575 		return (ENOENT);
    576 
    577 	/*
    578 	 * If we have a NULL data pointer
    579 	 * then assume the id's aren't changing and
    580 	 * return EEXIST to the dmu to let it know to
    581 	 * use the same ids
    582 	 */
    583 	if (data == NULL)
    584 		return (EEXIST);
    585 
    586 	if (bonustype == DMU_OT_ZNODE) {
    587 		*userp = znp->zp_uid;
    588 		*groupp = znp->zp_gid;
    589 	} else {
    590 		int hdrsize;
    591 
    592 		ASSERT(bonustype == DMU_OT_SA);
    593 		hdrsize = sa_hdrsize(data);
    594 
    595 		if (hdrsize != 0) {
    596 			*userp = *((uint64_t *)((uintptr_t)data + hdrsize +
    597 			    SA_UID_OFFSET));
    598 			*groupp = *((uint64_t *)((uintptr_t)data + hdrsize +
    599 			    SA_GID_OFFSET));
    600 		} else {
    601 			/*
    602 			 * This should only happen for newly created
    603 			 * files that haven't had the znode data filled
    604 			 * in yet.
    605 			 */
    606 			*userp = 0;
    607 			*groupp = 0;
    608 		}
    609 	}
    610 	return (error);
    611 }
    612 
    613 static void
    614 fuidstr_to_sid(zfsvfs_t *zfsvfs, const char *fuidstr,
    615     char *domainbuf, int buflen, uid_t *ridp)
    616 {
    617 	uint64_t fuid;
    618 	const char *domain;
    619 
    620 	fuid = strtonum(fuidstr, NULL);
    621 
    622 	domain = zfs_fuid_find_by_idx(zfsvfs, FUID_INDEX(fuid));
    623 	if (domain)
    624 		(void) strlcpy(domainbuf, domain, buflen);
    625 	else
    626 		domainbuf[0] = '\0';
    627 	*ridp = FUID_RID(fuid);
    628 }
    629 
    630 static uint64_t
    631 zfs_userquota_prop_to_obj(zfsvfs_t *zfsvfs, zfs_userquota_prop_t type)
    632 {
    633 	switch (type) {
    634 	case ZFS_PROP_USERUSED:
    635 		return (DMU_USERUSED_OBJECT);
    636 	case ZFS_PROP_GROUPUSED:
    637 		return (DMU_GROUPUSED_OBJECT);
    638 	case ZFS_PROP_USERQUOTA:
    639 		return (zfsvfs->z_userquota_obj);
    640 	case ZFS_PROP_GROUPQUOTA:
    641 		return (zfsvfs->z_groupquota_obj);
    642 	}
    643 	return (0);
    644 }
    645 
    646 int
    647 zfs_userspace_many(zfsvfs_t *zfsvfs, zfs_userquota_prop_t type,
    648     uint64_t *cookiep, void *vbuf, uint64_t *bufsizep)
    649 {
    650 	int error;
    651 	zap_cursor_t zc;
    652 	zap_attribute_t za;
    653 	zfs_useracct_t *buf = vbuf;
    654 	uint64_t obj;
    655 
    656 	if (!dmu_objset_userspace_present(zfsvfs->z_os))
    657 		return (ENOTSUP);
    658 
    659 	obj = zfs_userquota_prop_to_obj(zfsvfs, type);
    660 	if (obj == 0) {
    661 		*bufsizep = 0;
    662 		return (0);
    663 	}
    664 
    665 	for (zap_cursor_init_serialized(&zc, zfsvfs->z_os, obj, *cookiep);
    666 	    (error = zap_cursor_retrieve(&zc, &za)) == 0;
    667 	    zap_cursor_advance(&zc)) {
    668 		if ((uintptr_t)buf - (uintptr_t)vbuf + sizeof (zfs_useracct_t) >
    669 		    *bufsizep)
    670 			break;
    671 
    672 		fuidstr_to_sid(zfsvfs, za.za_name,
    673 		    buf->zu_domain, sizeof (buf->zu_domain), &buf->zu_rid);
    674 
    675 		buf->zu_space = za.za_first_integer;
    676 		buf++;
    677 	}
    678 	if (error == ENOENT)
    679 		error = 0;
    680 
    681 	ASSERT3U((uintptr_t)buf - (uintptr_t)vbuf, <=, *bufsizep);
    682 	*bufsizep = (uintptr_t)buf - (uintptr_t)vbuf;
    683 	*cookiep = zap_cursor_serialize(&zc);
    684 	zap_cursor_fini(&zc);
    685 	return (error);
    686 }
    687 
    688 /*
    689  * buf must be big enough (eg, 32 bytes)
    690  */
    691 static int
    692 id_to_fuidstr(zfsvfs_t *zfsvfs, const char *domain, uid_t rid,
    693     char *buf, boolean_t addok)
    694 {
    695 	uint64_t fuid;
    696 	int domainid = 0;
    697 
    698 	if (domain && domain[0]) {
    699 		domainid = zfs_fuid_find_by_domain(zfsvfs, domain, NULL, addok);
    700 		if (domainid == -1)
    701 			return (ENOENT);
    702 	}
    703 	fuid = FUID_ENCODE(domainid, rid);
    704 	(void) sprintf(buf, "%llx", (longlong_t)fuid);
    705 	return (0);
    706 }
    707 
    708 int
    709 zfs_userspace_one(zfsvfs_t *zfsvfs, zfs_userquota_prop_t type,
    710     const char *domain, uint64_t rid, uint64_t *valp)
    711 {
    712 	char buf[32];
    713 	int err;
    714 	uint64_t obj;
    715 
    716 	*valp = 0;
    717 
    718 	if (!dmu_objset_userspace_present(zfsvfs->z_os))
    719 		return (ENOTSUP);
    720 
    721 	obj = zfs_userquota_prop_to_obj(zfsvfs, type);
    722 	if (obj == 0)
    723 		return (0);
    724 
    725 	err = id_to_fuidstr(zfsvfs, domain, rid, buf, B_FALSE);
    726 	if (err)
    727 		return (err);
    728 
    729 	err = zap_lookup(zfsvfs->z_os, obj, buf, 8, 1, valp);
    730 	if (err == ENOENT)
    731 		err = 0;
    732 	return (err);
    733 }
    734 
    735 int
    736 zfs_set_userquota(zfsvfs_t *zfsvfs, zfs_userquota_prop_t type,
    737     const char *domain, uint64_t rid, uint64_t quota)
    738 {
    739 	char buf[32];
    740 	int err;
    741 	dmu_tx_t *tx;
    742 	uint64_t *objp;
    743 	boolean_t fuid_dirtied;
    744 
    745 	if (type != ZFS_PROP_USERQUOTA && type != ZFS_PROP_GROUPQUOTA)
    746 		return (EINVAL);
    747 
    748 	if (zfsvfs->z_version < ZPL_VERSION_USERSPACE)
    749 		return (ENOTSUP);
    750 
    751 	objp = (type == ZFS_PROP_USERQUOTA) ? &zfsvfs->z_userquota_obj :
    752 	    &zfsvfs->z_groupquota_obj;
    753 
    754 	err = id_to_fuidstr(zfsvfs, domain, rid, buf, B_TRUE);
    755 	if (err)
    756 		return (err);
    757 	fuid_dirtied = zfsvfs->z_fuid_dirty;
    758 
    759 	tx = dmu_tx_create(zfsvfs->z_os);
    760 	dmu_tx_hold_zap(tx, *objp ? *objp : DMU_NEW_OBJECT, B_TRUE, NULL);
    761 	if (*objp == 0) {
    762 		dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, B_TRUE,
    763 		    zfs_userquota_prop_prefixes[type]);
    764 	}
    765 	if (fuid_dirtied)
    766 		zfs_fuid_txhold(zfsvfs, tx);
    767 	err = dmu_tx_assign(tx, TXG_WAIT);
    768 	if (err) {
    769 		dmu_tx_abort(tx);
    770 		return (err);
    771 	}
    772 
    773 	mutex_enter(&zfsvfs->z_lock);
    774 	if (*objp == 0) {
    775 		*objp = zap_create(zfsvfs->z_os, DMU_OT_USERGROUP_QUOTA,
    776 		    DMU_OT_NONE, 0, tx);
    777 		VERIFY(0 == zap_add(zfsvfs->z_os, MASTER_NODE_OBJ,
    778 		    zfs_userquota_prop_prefixes[type], 8, 1, objp, tx));
    779 	}
    780 	mutex_exit(&zfsvfs->z_lock);
    781 
    782 	if (quota == 0) {
    783 		err = zap_remove(zfsvfs->z_os, *objp, buf, tx);
    784 		if (err == ENOENT)
    785 			err = 0;
    786 	} else {
    787 		err = zap_update(zfsvfs->z_os, *objp, buf, 8, 1, &quota, tx);
    788 	}
    789 	ASSERT(err == 0);
    790 	if (fuid_dirtied)
    791 		zfs_fuid_sync(zfsvfs, tx);
    792 	dmu_tx_commit(tx);
    793 	return (err);
    794 }
    795 
    796 boolean_t
    797 zfs_fuid_overquota(zfsvfs_t *zfsvfs, boolean_t isgroup, uint64_t fuid)
    798 {
    799 	char buf[32];
    800 	uint64_t used, quota, usedobj, quotaobj;
    801 	int err;
    802 
    803 	usedobj = isgroup ? DMU_GROUPUSED_OBJECT : DMU_USERUSED_OBJECT;
    804 	quotaobj = isgroup ? zfsvfs->z_groupquota_obj : zfsvfs->z_userquota_obj;
    805 
    806 	if (quotaobj == 0 || zfsvfs->z_replay)
    807 		return (B_FALSE);
    808 
    809 	(void) sprintf(buf, "%llx", (longlong_t)fuid);
    810 	err = zap_lookup(zfsvfs->z_os, quotaobj, buf, 8, 1, &quota);
    811 	if (err != 0)
    812 		return (B_FALSE);
    813 
    814 	err = zap_lookup(zfsvfs->z_os, usedobj, buf, 8, 1, &used);
    815 	if (err != 0)
    816 		return (B_FALSE);
    817 	return (used >= quota);
    818 }
    819 
    820 boolean_t
    821 zfs_owner_overquota(zfsvfs_t *zfsvfs, znode_t *zp, boolean_t isgroup)
    822 {
    823 	uint64_t fuid;
    824 	uint64_t quotaobj;
    825 
    826 	quotaobj = isgroup ? zfsvfs->z_groupquota_obj : zfsvfs->z_userquota_obj;
    827 
    828 	fuid = isgroup ? zp->z_gid : zp->z_uid;
    829 
    830 	if (quotaobj == 0 || zfsvfs->z_replay)
    831 		return (B_FALSE);
    832 
    833 	return (zfs_fuid_overquota(zfsvfs, isgroup, fuid));
    834 }
    835 
    836 int
    837 zfsvfs_create(const char *osname, zfsvfs_t **zfvp)
    838 {
    839 	objset_t *os;
    840 	zfsvfs_t *zfsvfs;
    841 	uint64_t zval;
    842 	int i, error;
    843 	uint64_t sa_obj;
    844 
    845 	zfsvfs = kmem_zalloc(sizeof (zfsvfs_t), KM_SLEEP);
    846 
    847 	/*
    848 	 * We claim to always be readonly so we can open snapshots;
    849 	 * other ZPL code will prevent us from writing to snapshots.
    850 	 */
    851 	error = dmu_objset_own(osname, DMU_OST_ZFS, B_TRUE, zfsvfs, &os);
    852 	if (error) {
    853 		kmem_free(zfsvfs, sizeof (zfsvfs_t));
    854 		return (error);
    855 	}
    856 
    857 	/*
    858 	 * Initialize the zfs-specific filesystem structure.
    859 	 * Should probably make this a kmem cache, shuffle fields,
    860 	 * and just bzero up to z_hold_mtx[].
    861 	 */
    862 	zfsvfs->z_vfs = NULL;
    863 	zfsvfs->z_parent = zfsvfs;
    864 	zfsvfs->z_max_blksz = SPA_MAXBLOCKSIZE;
    865 	zfsvfs->z_show_ctldir = ZFS_SNAPDIR_VISIBLE;
    866 	zfsvfs->z_os = os;
    867 
    868 	error = zfs_get_zplprop(os, ZFS_PROP_VERSION, &zfsvfs->z_version);
    869 	if (error) {
    870 		goto out;
    871 	} else if (zfsvfs->z_version >
    872 	    zfs_zpl_version_map(spa_version(dmu_objset_spa(os)))) {
    873 		(void) printf("Can't mount a version %lld file system "
    874 		    "on a version %lld pool\n. Pool must be upgraded to mount "
    875 		    "this file system.", (u_longlong_t)zfsvfs->z_version,
    876 		    (u_longlong_t)spa_version(dmu_objset_spa(os)));
    877 		error = ENOTSUP;
    878 		goto out;
    879 	}
    880 	if ((error = zfs_get_zplprop(os, ZFS_PROP_NORMALIZE, &zval)) != 0)
    881 		goto out;
    882 	zfsvfs->z_norm = (int)zval;
    883 
    884 	if ((error = zfs_get_zplprop(os, ZFS_PROP_UTF8ONLY, &zval)) != 0)
    885 		goto out;
    886 	zfsvfs->z_utf8 = (zval != 0);
    887 
    888 	if ((error = zfs_get_zplprop(os, ZFS_PROP_CASE, &zval)) != 0)
    889 		goto out;
    890 	zfsvfs->z_case = (uint_t)zval;
    891 
    892 	/*
    893 	 * Fold case on file systems that are always or sometimes case
    894 	 * insensitive.
    895 	 */
    896 	if (zfsvfs->z_case == ZFS_CASE_INSENSITIVE ||
    897 	    zfsvfs->z_case == ZFS_CASE_MIXED)
    898 		zfsvfs->z_norm |= U8_TEXTPREP_TOUPPER;
    899 
    900 	zfsvfs->z_use_fuids = USE_FUIDS(zfsvfs->z_version, zfsvfs->z_os);
    901 	zfsvfs->z_use_sa = USE_SA(zfsvfs->z_version, zfsvfs->z_os);
    902 
    903 	if (zfsvfs->z_use_sa) {
    904 		/* should either have both of these objects or none */
    905 		error = zap_lookup(os, MASTER_NODE_OBJ, ZFS_SA_ATTRS, 8, 1,
    906 		    &sa_obj);
    907 		if (error)
    908 			return (error);
    909 	} else {
    910 		/*
    911 		 * Pre SA versions file systems should never touch
    912 		 * either the attribute registration or layout objects.
    913 		 */
    914 		sa_obj = 0;
    915 	}
    916 
    917 	error = sa_setup(os, sa_obj, zfs_attr_table, ZPL_END,
    918 	    &zfsvfs->z_attr_table);
    919 	if (error)
    920 		goto out;
    921 
    922 	if (zfsvfs->z_version >= ZPL_VERSION_SA)
    923 		sa_register_update_callback(os, zfs_sa_upgrade);
    924 
    925 	error = zap_lookup(os, MASTER_NODE_OBJ, ZFS_ROOT_OBJ, 8, 1,
    926 	    &zfsvfs->z_root);
    927 	if (error)
    928 		goto out;
    929 	ASSERT(zfsvfs->z_root != 0);
    930 
    931 	error = zap_lookup(os, MASTER_NODE_OBJ, ZFS_UNLINKED_SET, 8, 1,
    932 	    &zfsvfs->z_unlinkedobj);
    933 	if (error)
    934 		goto out;
    935 
    936 	error = zap_lookup(os, MASTER_NODE_OBJ,
    937 	    zfs_userquota_prop_prefixes[ZFS_PROP_USERQUOTA],
    938 	    8, 1, &zfsvfs->z_userquota_obj);
    939 	if (error && error != ENOENT)
    940 		goto out;
    941 
    942 	error = zap_lookup(os, MASTER_NODE_OBJ,
    943 	    zfs_userquota_prop_prefixes[ZFS_PROP_GROUPQUOTA],
    944 	    8, 1, &zfsvfs->z_groupquota_obj);
    945 	if (error && error != ENOENT)
    946 		goto out;
    947 
    948 	error = zap_lookup(os, MASTER_NODE_OBJ, ZFS_FUID_TABLES, 8, 1,
    949 	    &zfsvfs->z_fuid_obj);
    950 	if (error && error != ENOENT)
    951 		goto out;
    952 
    953 	error = zap_lookup(os, MASTER_NODE_OBJ, ZFS_SHARES_DIR, 8, 1,
    954 	    &zfsvfs->z_shares_dir);
    955 	if (error && error != ENOENT)
    956 		goto out;
    957 
    958 	mutex_init(&zfsvfs->z_znodes_lock, NULL, MUTEX_DEFAULT, NULL);
    959 	mutex_init(&zfsvfs->z_lock, NULL, MUTEX_DEFAULT, NULL);
    960 	list_create(&zfsvfs->z_all_znodes, sizeof (znode_t),
    961 	    offsetof(znode_t, z_link_node));
    962 	rrw_init(&zfsvfs->z_teardown_lock);
    963 	rw_init(&zfsvfs->z_teardown_inactive_lock, NULL, RW_DEFAULT, NULL);
    964 	rw_init(&zfsvfs->z_fuid_lock, NULL, RW_DEFAULT, NULL);
    965 	for (i = 0; i != ZFS_OBJ_MTX_SZ; i++)
    966 		mutex_init(&zfsvfs->z_hold_mtx[i], NULL, MUTEX_DEFAULT, NULL);
    967 
    968 	*zfvp = zfsvfs;
    969 	return (0);
    970 
    971 out:
    972 	dmu_objset_disown(os, zfsvfs);
    973 	*zfvp = NULL;
    974 	kmem_free(zfsvfs, sizeof (zfsvfs_t));
    975 	return (error);
    976 }
    977 
    978 static int
    979 zfsvfs_setup(zfsvfs_t *zfsvfs, boolean_t mounting)
    980 {
    981 	int error;
    982 
    983 	error = zfs_register_callbacks(zfsvfs->z_vfs);
    984 	if (error)
    985 		return (error);
    986 
    987 	/*
    988 	 * Set the objset user_ptr to track its zfsvfs.
    989 	 */
    990 	mutex_enter(&zfsvfs->z_os->os_user_ptr_lock);
    991 	dmu_objset_set_user(zfsvfs->z_os, zfsvfs);
    992 	mutex_exit(&zfsvfs->z_os->os_user_ptr_lock);
    993 
    994 	zfsvfs->z_log = zil_open(zfsvfs->z_os, zfs_get_data);
    995 
    996 	/*
    997 	 * If we are not mounting (ie: online recv), then we don't
    998 	 * have to worry about replaying the log as we blocked all
    999 	 * operations out since we closed the ZIL.
   1000 	 */
   1001 	if (mounting) {
   1002 		boolean_t readonly;
   1003 
   1004 		/*
   1005 		 * During replay we remove the read only flag to
   1006 		 * allow replays to succeed.
   1007 		 */
   1008 		readonly = zfsvfs->z_vfs->vfs_flag & VFS_RDONLY;
   1009 		if (readonly != 0)
   1010 			zfsvfs->z_vfs->vfs_flag &= ~VFS_RDONLY;
   1011 		else
   1012 			zfs_unlinked_drain(zfsvfs);
   1013 
   1014 		/*
   1015 		 * Parse and replay the intent log.
   1016 		 *
   1017 		 * Because of ziltest, this must be done after
   1018 		 * zfs_unlinked_drain().  (Further note: ziltest
   1019 		 * doesn't use readonly mounts, where
   1020 		 * zfs_unlinked_drain() isn't called.)  This is because
   1021 		 * ziltest causes spa_sync() to think it's committed,
   1022 		 * but actually it is not, so the intent log contains
   1023 		 * many txg's worth of changes.
   1024 		 *
   1025 		 * In particular, if object N is in the unlinked set in
   1026 		 * the last txg to actually sync, then it could be
   1027 		 * actually freed in a later txg and then reallocated
   1028 		 * in a yet later txg.  This would write a "create
   1029 		 * object N" record to the intent log.  Normally, this
   1030 		 * would be fine because the spa_sync() would have
   1031 		 * written out the fact that object N is free, before
   1032 		 * we could write the "create object N" intent log
   1033 		 * record.
   1034 		 *
   1035 		 * But when we are in ziltest mode, we advance the "open
   1036 		 * txg" without actually spa_sync()-ing the changes to
   1037 		 * disk.  So we would see that object N is still
   1038 		 * allocated and in the unlinked set, and there is an
   1039 		 * intent log record saying to allocate it.
   1040 		 */
   1041 		if (spa_writeable(dmu_objset_spa(zfsvfs->z_os))) {
   1042 			if (zil_replay_disable) {
   1043 				zil_destroy(zfsvfs->z_log, B_FALSE);
   1044 			} else {
   1045 				zfsvfs->z_replay = B_TRUE;
   1046 				zil_replay(zfsvfs->z_os, zfsvfs,
   1047 				    zfs_replay_vector);
   1048 				zfsvfs->z_replay = B_FALSE;
   1049 			}
   1050 		}
   1051 		zfsvfs->z_vfs->vfs_flag |= readonly; /* restore readonly bit */
   1052 	}
   1053 
   1054 	return (0);
   1055 }
   1056 
   1057 void
   1058 zfsvfs_free(zfsvfs_t *zfsvfs)
   1059 {
   1060 	int i;
   1061 	extern krwlock_t zfsvfs_lock; /* in zfs_znode.c */
   1062 
   1063 	/*
   1064 	 * This is a barrier to prevent the filesystem from going away in
   1065 	 * zfs_znode_move() until we can safely ensure that the filesystem is
   1066 	 * not unmounted. We consider the filesystem valid before the barrier
   1067 	 * and invalid after the barrier.
   1068 	 */
   1069 	rw_enter(&zfsvfs_lock, RW_READER);
   1070 	rw_exit(&zfsvfs_lock);
   1071 
   1072 	zfs_fuid_destroy(zfsvfs);
   1073 
   1074 	mutex_destroy(&zfsvfs->z_znodes_lock);
   1075 	mutex_destroy(&zfsvfs->z_lock);
   1076 	list_destroy(&zfsvfs->z_all_znodes);
   1077 	rrw_destroy(&zfsvfs->z_teardown_lock);
   1078 	rw_destroy(&zfsvfs->z_teardown_inactive_lock);
   1079 	rw_destroy(&zfsvfs->z_fuid_lock);
   1080 	for (i = 0; i != ZFS_OBJ_MTX_SZ; i++)
   1081 		mutex_destroy(&zfsvfs->z_hold_mtx[i]);
   1082 	kmem_free(zfsvfs, sizeof (zfsvfs_t));
   1083 }
   1084 
   1085 static void
   1086 zfs_set_fuid_feature(zfsvfs_t *zfsvfs)
   1087 {
   1088 	zfsvfs->z_use_fuids = USE_FUIDS(zfsvfs->z_version, zfsvfs->z_os);
   1089 	if (zfsvfs->z_vfs) {
   1090 		if (zfsvfs->z_use_fuids) {
   1091 			vfs_set_feature(zfsvfs->z_vfs, VFSFT_XVATTR);
   1092 			vfs_set_feature(zfsvfs->z_vfs, VFSFT_SYSATTR_VIEWS);
   1093 			vfs_set_feature(zfsvfs->z_vfs, VFSFT_ACEMASKONACCESS);
   1094 			vfs_set_feature(zfsvfs->z_vfs, VFSFT_ACLONCREATE);
   1095 			vfs_set_feature(zfsvfs->z_vfs, VFSFT_ACCESS_FILTER);
   1096 			vfs_set_feature(zfsvfs->z_vfs, VFSFT_REPARSE);
   1097 		} else {
   1098 			vfs_clear_feature(zfsvfs->z_vfs, VFSFT_XVATTR);
   1099 			vfs_clear_feature(zfsvfs->z_vfs, VFSFT_SYSATTR_VIEWS);
   1100 			vfs_clear_feature(zfsvfs->z_vfs, VFSFT_ACEMASKONACCESS);
   1101 			vfs_clear_feature(zfsvfs->z_vfs, VFSFT_ACLONCREATE);
   1102 			vfs_clear_feature(zfsvfs->z_vfs, VFSFT_ACCESS_FILTER);
   1103 			vfs_clear_feature(zfsvfs->z_vfs, VFSFT_REPARSE);
   1104 		}
   1105 	}
   1106 	zfsvfs->z_use_sa = USE_SA(zfsvfs->z_version, zfsvfs->z_os);
   1107 }
   1108 
   1109 static int
   1110 zfs_domount(vfs_t *vfsp, char *osname)
   1111 {
   1112 	dev_t mount_dev;
   1113 	uint64_t recordsize, fsid_guid;
   1114 	int error = 0;
   1115 	zfsvfs_t *zfsvfs;
   1116 
   1117 	ASSERT(vfsp);
   1118 	ASSERT(osname);
   1119 
   1120 	error = zfsvfs_create(osname, &zfsvfs);
   1121 	if (error)
   1122 		return (error);
   1123 	zfsvfs->z_vfs = vfsp;
   1124 
   1125 	/* Initialize the generic filesystem structure. */
   1126 	vfsp->vfs_bcount = 0;
   1127 	vfsp->vfs_data = NULL;
   1128 
   1129 	if (zfs_create_unique_device(&mount_dev) == -1) {
   1130 		error = ENODEV;
   1131 		goto out;
   1132 	}
   1133 	ASSERT(vfs_devismounted(mount_dev) == 0);
   1134 
   1135 	if (error = dsl_prop_get_integer(osname, "recordsize", &recordsize,
   1136 	    NULL))
   1137 		goto out;
   1138 
   1139 	vfsp->vfs_dev = mount_dev;
   1140 	vfsp->vfs_fstype = zfsfstype;
   1141 	vfsp->vfs_bsize = recordsize;
   1142 	vfsp->vfs_flag |= VFS_NOTRUNC;
   1143 	vfsp->vfs_data = zfsvfs;
   1144 
   1145 	/*
   1146 	 * The fsid is 64 bits, composed of an 8-bit fs type, which
   1147 	 * separates our fsid from any other filesystem types, and a
   1148 	 * 56-bit objset unique ID.  The objset unique ID is unique to
   1149 	 * all objsets open on this system, provided by unique_create().
   1150 	 * The 8-bit fs type must be put in the low bits of fsid[1]
   1151 	 * because that's where other Solaris filesystems put it.
   1152 	 */
   1153 	fsid_guid = dmu_objset_fsid_guid(zfsvfs->z_os);
   1154 	ASSERT((fsid_guid & ~((1ULL<<56)-1)) == 0);
   1155 	vfsp->vfs_fsid.val[0] = fsid_guid;
   1156 	vfsp->vfs_fsid.val[1] = ((fsid_guid>>32) << 8) |
   1157 	    zfsfstype & 0xFF;
   1158 
   1159 	/*
   1160 	 * Set features for file system.
   1161 	 */
   1162 	zfs_set_fuid_feature(zfsvfs);
   1163 	if (zfsvfs->z_case == ZFS_CASE_INSENSITIVE) {
   1164 		vfs_set_feature(vfsp, VFSFT_DIRENTFLAGS);
   1165 		vfs_set_feature(vfsp, VFSFT_CASEINSENSITIVE);
   1166 		vfs_set_feature(vfsp, VFSFT_NOCASESENSITIVE);
   1167 	} else if (zfsvfs->z_case == ZFS_CASE_MIXED) {
   1168 		vfs_set_feature(vfsp, VFSFT_DIRENTFLAGS);
   1169 		vfs_set_feature(vfsp, VFSFT_CASEINSENSITIVE);
   1170 	}
   1171 	vfs_set_feature(vfsp, VFSFT_ZEROCOPY_SUPPORTED);
   1172 
   1173 	if (dmu_objset_is_snapshot(zfsvfs->z_os)) {
   1174 		uint64_t pval;
   1175 
   1176 		atime_changed_cb(zfsvfs, B_FALSE);
   1177 		readonly_changed_cb(zfsvfs, B_TRUE);
   1178 		if (error = dsl_prop_get_integer(osname, "xattr", &pval, NULL))
   1179 			goto out;
   1180 		xattr_changed_cb(zfsvfs, pval);
   1181 		zfsvfs->z_issnap = B_TRUE;
   1182 		zfsvfs->z_os->os_sync = ZFS_SYNC_DISABLED;
   1183 
   1184 		mutex_enter(&zfsvfs->z_os->os_user_ptr_lock);
   1185 		dmu_objset_set_user(zfsvfs->z_os, zfsvfs);
   1186 		mutex_exit(&zfsvfs->z_os->os_user_ptr_lock);
   1187 	} else {
   1188 		error = zfsvfs_setup(zfsvfs, B_TRUE);
   1189 	}
   1190 
   1191 	if (!zfsvfs->z_issnap)
   1192 		zfsctl_create(zfsvfs);
   1193 out:
   1194 	if (error) {
   1195 		dmu_objset_disown(zfsvfs->z_os, zfsvfs);
   1196 		zfsvfs_free(zfsvfs);
   1197 	} else {
   1198 		atomic_add_32(&zfs_active_fs_count, 1);
   1199 	}
   1200 
   1201 	return (error);
   1202 }
   1203 
   1204 void
   1205 zfs_unregister_callbacks(zfsvfs_t *zfsvfs)
   1206 {
   1207 	objset_t *os = zfsvfs->z_os;
   1208 	struct dsl_dataset *ds;
   1209 
   1210 	/*
   1211 	 * Unregister properties.
   1212 	 */
   1213 	if (!dmu_objset_is_snapshot(os)) {
   1214 		ds = dmu_objset_ds(os);
   1215 		VERIFY(dsl_prop_unregister(ds, "atime", atime_changed_cb,
   1216 		    zfsvfs) == 0);
   1217 
   1218 		VERIFY(dsl_prop_unregister(ds, "xattr", xattr_changed_cb,
   1219 		    zfsvfs) == 0);
   1220 
   1221 		VERIFY(dsl_prop_unregister(ds, "recordsize", blksz_changed_cb,
   1222 		    zfsvfs) == 0);
   1223 
   1224 		VERIFY(dsl_prop_unregister(ds, "readonly", readonly_changed_cb,
   1225 		    zfsvfs) == 0);
   1226 
   1227 		VERIFY(dsl_prop_unregister(ds, "devices", devices_changed_cb,
   1228 		    zfsvfs) == 0);
   1229 
   1230 		VERIFY(dsl_prop_unregister(ds, "setuid", setuid_changed_cb,
   1231 		    zfsvfs) == 0);
   1232 
   1233 		VERIFY(dsl_prop_unregister(ds, "exec", exec_changed_cb,
   1234 		    zfsvfs) == 0);
   1235 
   1236 		VERIFY(dsl_prop_unregister(ds, "snapdir", snapdir_changed_cb,
   1237 		    zfsvfs) == 0);
   1238 
   1239 		VERIFY(dsl_prop_unregister(ds, "aclinherit",
   1240 		    acl_inherit_changed_cb, zfsvfs) == 0);
   1241 
   1242 		VERIFY(dsl_prop_unregister(ds, "vscan",
   1243 		    vscan_changed_cb, zfsvfs) == 0);
   1244 	}
   1245 }
   1246 
   1247 /*
   1248  * Convert a decimal digit string to a uint64_t integer.
   1249  */
   1250 static int
   1251 str_to_uint64(char *str, uint64_t *objnum)
   1252 {
   1253 	uint64_t num = 0;
   1254 
   1255 	while (*str) {
   1256 		if (*str < '0' || *str > '9')
   1257 			return (EINVAL);
   1258 
   1259 		num = num*10 + *str++ - '0';
   1260 	}
   1261 
   1262 	*objnum = num;
   1263 	return (0);
   1264 }
   1265 
   1266 /*
   1267  * The boot path passed from the boot loader is in the form of
   1268  * "rootpool-name/root-filesystem-object-number'. Convert this
   1269  * string to a dataset name: "rootpool-name/root-filesystem-name".
   1270  */
   1271 static int
   1272 zfs_parse_bootfs(char *bpath, char *outpath)
   1273 {
   1274 	char *slashp;
   1275 	uint64_t objnum;
   1276 	int error;
   1277 
   1278 	if (*bpath == 0 || *bpath == '/')
   1279 		return (EINVAL);
   1280 
   1281 	(void) strcpy(outpath, bpath);
   1282 
   1283 	slashp = strchr(bpath, '/');
   1284 
   1285 	/* if no '/', just return the pool name */
   1286 	if (slashp == NULL) {
   1287 		return (0);
   1288 	}
   1289 
   1290 	/* if not a number, just return the root dataset name */
   1291 	if (str_to_uint64(slashp+1, &objnum)) {
   1292 		return (0);
   1293 	}
   1294 
   1295 	*slashp = '\0';
   1296 	error = dsl_dsobj_to_dsname(bpath, objnum, outpath);
   1297 	*slashp = '/';
   1298 
   1299 	return (error);
   1300 }
   1301 
   1302 /*
   1303  * zfs_check_global_label:
   1304  *	Check that the hex label string is appropriate for the dataset
   1305  *	being mounted into the global_zone proper.
   1306  *
   1307  *	Return an error if the hex label string is not default or
   1308  *	admin_low/admin_high.  For admin_low labels, the corresponding
   1309  *	dataset must be readonly.
   1310  */
   1311 int
   1312 zfs_check_global_label(const char *dsname, const char *hexsl)
   1313 {
   1314 	if (strcasecmp(hexsl, ZFS_MLSLABEL_DEFAULT) == 0)
   1315 		return (0);
   1316 	if (strcasecmp(hexsl, ADMIN_HIGH) == 0)
   1317 		return (0);
   1318 	if (strcasecmp(hexsl, ADMIN_LOW) == 0) {
   1319 		/* must be readonly */
   1320 		uint64_t rdonly;
   1321 
   1322 		if (dsl_prop_get_integer(dsname,
   1323 		    zfs_prop_to_name(ZFS_PROP_READONLY), &rdonly, NULL))
   1324 			return (EACCES);
   1325 		return (rdonly ? 0 : EACCES);
   1326 	}
   1327 	return (EACCES);
   1328 }
   1329 
   1330 /*
   1331  * zfs_mount_label_policy:
   1332  *	Determine whether the mount is allowed according to MAC check.
   1333  *	by comparing (where appropriate) label of the dataset against
   1334  *	the label of the zone being mounted into.  If the dataset has
   1335  *	no label, create one.
   1336  *
   1337  *	Returns:
   1338  *		 0 :	access allowed
   1339  *		>0 :	error code, such as EACCES
   1340  */
   1341 static int
   1342 zfs_mount_label_policy(vfs_t *vfsp, char *osname)
   1343 {
   1344 	int		error, retv;
   1345 	zone_t		*mntzone = NULL;
   1346 	ts_label_t	*mnt_tsl;
   1347 	bslabel_t	*mnt_sl;
   1348 	bslabel_t	ds_sl;
   1349 	char		ds_hexsl[MAXNAMELEN];
   1350 
   1351 	retv = EACCES;				/* assume the worst */
   1352 
   1353 	/*
   1354 	 * Start by getting the dataset label if it exists.
   1355 	 */
   1356 	error = dsl_prop_get(osname, zfs_prop_to_name(ZFS_PROP_MLSLABEL),
   1357 	    1, sizeof (ds_hexsl), &ds_hexsl, NULL);
   1358 	if (error)
   1359 		return (EACCES);
   1360 
   1361 	/*
   1362 	 * If labeling is NOT enabled, then disallow the mount of datasets
   1363 	 * which have a non-default label already.  No other label checks
   1364 	 * are needed.
   1365 	 */
   1366 	if (!is_system_labeled()) {
   1367 		if (strcasecmp(ds_hexsl, ZFS_MLSLABEL_DEFAULT) == 0)
   1368 			return (0);
   1369 		return (EACCES);
   1370 	}
   1371 
   1372 	/*
   1373 	 * Get the label of the mountpoint.  If mounting into the global
   1374 	 * zone (i.e. mountpoint is not within an active zone and the
   1375 	 * zoned property is off), the label must be default or
   1376 	 * admin_low/admin_high only; no other checks are needed.
   1377 	 */
   1378 	mntzone = zone_find_by_any_path(refstr_value(vfsp->vfs_mntpt), B_FALSE);
   1379 	if (mntzone->zone_id == GLOBAL_ZONEID) {
   1380 		uint64_t zoned;
   1381 
   1382 		zone_rele(mntzone);
   1383 
   1384 		if (dsl_prop_get_integer(osname,
   1385 		    zfs_prop_to_name(ZFS_PROP_ZONED), &zoned, NULL))
   1386 			return (EACCES);
   1387 		if (!zoned)
   1388 			return (zfs_check_global_label(osname, ds_hexsl));
   1389 		else
   1390 			/*
   1391 			 * This is the case of a zone dataset being mounted
   1392 			 * initially, before the zone has been fully created;
   1393 			 * allow this mount into global zone.
   1394 			 */
   1395 			return (0);
   1396 	}
   1397 
   1398 	mnt_tsl = mntzone->zone_slabel;
   1399 	ASSERT(mnt_tsl != NULL);
   1400 	label_hold(mnt_tsl);
   1401 	mnt_sl = label2bslabel(mnt_tsl);
   1402 
   1403 	if (strcasecmp(ds_hexsl, ZFS_MLSLABEL_DEFAULT) == 0) {
   1404 		/*
   1405 		 * The dataset doesn't have a real label, so fabricate one.
   1406 		 */
   1407 		char *str = NULL;
   1408 
   1409 		if (l_to_str_internal(mnt_sl, &str) == 0 &&
   1410 		    dsl_prop_set(osname, zfs_prop_to_name(ZFS_PROP_MLSLABEL),
   1411 		    ZPROP_SRC_LOCAL, 1, strlen(str) + 1, str) == 0)
   1412 			retv = 0;
   1413 		if (str != NULL)
   1414 			kmem_free(str, strlen(str) + 1);
   1415 	} else if (hexstr_to_label(ds_hexsl, &ds_sl) == 0) {
   1416 		/*
   1417 		 * Now compare labels to complete the MAC check.  If the
   1418 		 * labels are equal then allow access.  If the mountpoint
   1419 		 * label dominates the dataset label, allow readonly access.
   1420 		 * Otherwise, access is denied.
   1421 		 */
   1422 		if (blequal(mnt_sl, &ds_sl))
   1423 			retv = 0;
   1424 		else if (bldominates(mnt_sl, &ds_sl)) {
   1425 			vfs_setmntopt(vfsp, MNTOPT_RO, NULL, 0);
   1426 			retv = 0;
   1427 		}
   1428 	}
   1429 
   1430 	label_rele(mnt_tsl);
   1431 	zone_rele(mntzone);
   1432 	return (retv);
   1433 }
   1434 
   1435 static int
   1436 zfs_mountroot(vfs_t *vfsp, enum whymountroot why)
   1437 {
   1438 	int error = 0;
   1439 	static int zfsrootdone = 0;
   1440 	zfsvfs_t *zfsvfs = NULL;
   1441 	znode_t *zp = NULL;
   1442 	vnode_t *vp = NULL;
   1443 	char *zfs_bootfs;
   1444 	char *zfs_devid;
   1445 
   1446 	ASSERT(vfsp);
   1447 
   1448 	/*
   1449 	 * The filesystem that we mount as root is defined in the
   1450 	 * boot property "zfs-bootfs" with a format of
   1451 	 * "poolname/root-dataset-objnum".
   1452 	 */
   1453 	if (why == ROOT_INIT) {
   1454 		if (zfsrootdone++)
   1455 			return (EBUSY);
   1456 		/*
   1457 		 * the process of doing a spa_load will require the
   1458 		 * clock to be set before we could (for example) do
   1459 		 * something better by looking at the timestamp on
   1460 		 * an uberblock, so just set it to -1.
   1461 		 */
   1462 		clkset(-1);
   1463 
   1464 		if ((zfs_bootfs = spa_get_bootprop("zfs-bootfs")) == NULL) {
   1465 			cmn_err(CE_NOTE, "spa_get_bootfs: can not get "
   1466 			    "bootfs name");
   1467 			return (EINVAL);
   1468 		}
   1469 		zfs_devid = spa_get_bootprop("diskdevid");
   1470 		error = spa_import_rootpool(rootfs.bo_name, zfs_devid);
   1471 		if (zfs_devid)
   1472 			spa_free_bootprop(zfs_devid);
   1473 		if (error) {
   1474 			spa_free_bootprop(zfs_bootfs);
   1475 			cmn_err(CE_NOTE, "spa_import_rootpool: error %d",
   1476 			    error);
   1477 			return (error);
   1478 		}
   1479 		if (error = zfs_parse_bootfs(zfs_bootfs, rootfs.bo_name)) {
   1480 			spa_free_bootprop(zfs_bootfs);
   1481 			cmn_err(CE_NOTE, "zfs_parse_bootfs: error %d",
   1482 			    error);
   1483 			return (error);
   1484 		}
   1485 
   1486 		spa_free_bootprop(zfs_bootfs);
   1487 
   1488 		if (error = vfs_lock(vfsp))
   1489 			return (error);
   1490 
   1491 		if (error = zfs_domount(vfsp, rootfs.bo_name)) {
   1492 			cmn_err(CE_NOTE, "zfs_domount: error %d", error);
   1493 			goto out;
   1494 		}
   1495 
   1496 		zfsvfs = (zfsvfs_t *)vfsp->vfs_data;
   1497 		ASSERT(zfsvfs);
   1498 		if (error = zfs_zget(zfsvfs, zfsvfs->z_root, &zp)) {
   1499 			cmn_err(CE_NOTE, "zfs_zget: error %d", error);
   1500 			goto out;
   1501 		}
   1502 
   1503 		vp = ZTOV(zp);
   1504 		mutex_enter(&vp->v_lock);
   1505 		vp->v_flag |= VROOT;
   1506 		mutex_exit(&vp->v_lock);
   1507 		rootvp = vp;
   1508 
   1509 		/*
   1510 		 * Leave rootvp held.  The root file system is never unmounted.
   1511 		 */
   1512 
   1513 		vfs_add((struct vnode *)0, vfsp,
   1514 		    (vfsp->vfs_flag & VFS_RDONLY) ? MS_RDONLY : 0);
   1515 out:
   1516 		vfs_unlock(vfsp);
   1517 		return (error);
   1518 	} else if (why == ROOT_REMOUNT) {
   1519 		readonly_changed_cb(vfsp->vfs_data, B_FALSE);
   1520 		vfsp->vfs_flag |= VFS_REMOUNT;
   1521 
   1522 		/* refresh mount options */
   1523 		zfs_unregister_callbacks(vfsp->vfs_data);
   1524 		return (zfs_register_callbacks(vfsp));
   1525 
   1526 	} else if (why == ROOT_UNMOUNT) {
   1527 		zfs_unregister_callbacks((zfsvfs_t *)vfsp->vfs_data);
   1528 		(void) zfs_sync(vfsp, 0, 0);
   1529 		return (0);
   1530 	}
   1531 
   1532 	/*
   1533 	 * if "why" is equal to anything else other than ROOT_INIT,
   1534 	 * ROOT_REMOUNT, or ROOT_UNMOUNT, we do not support it.
   1535 	 */
   1536 	return (ENOTSUP);
   1537 }
   1538 
   1539 /*ARGSUSED*/
   1540 static int
   1541 zfs_mount(vfs_t *vfsp, vnode_t *mvp, struct mounta *uap, cred_t *cr)
   1542 {
   1543 	char		*osname;
   1544 	pathname_t	spn;
   1545 	int		error = 0;
   1546 	uio_seg_t	fromspace = (uap->flags & MS_SYSSPACE) ?
   1547 	    UIO_SYSSPACE : UIO_USERSPACE;
   1548 	int		canwrite;
   1549 
   1550 	if (mvp->v_type != VDIR)
   1551 		return (ENOTDIR);
   1552 
   1553 	mutex_enter(&mvp->v_lock);
   1554 	if ((uap->flags & MS_REMOUNT) == 0 &&
   1555 	    (uap->flags & MS_OVERLAY) == 0 &&
   1556 	    (mvp->v_count != 1 || (mvp->v_flag & VROOT))) {
   1557 		mutex_exit(&mvp->v_lock);
   1558 		return (EBUSY);
   1559 	}
   1560 	mutex_exit(&mvp->v_lock);
   1561 
   1562 	/*
   1563 	 * ZFS does not support passing unparsed data in via MS_DATA.
   1564 	 * Users should use the MS_OPTIONSTR interface; this means
   1565 	 * that all option parsing is already done and the options struct
   1566 	 * can be interrogated.
   1567 	 */
   1568 	if ((uap->flags & MS_DATA) && uap->datalen > 0)
   1569 		return (EINVAL);
   1570 
   1571 	/*
   1572 	 * Get the objset name (the "special" mount argument).
   1573 	 */
   1574 	if (error = pn_get(uap->spec, fromspace, &spn))
   1575 		return (error);
   1576 
   1577 	osname = spn.pn_path;
   1578 
   1579 	/*
   1580 	 * Check for mount privilege?
   1581 	 *
   1582 	 * If we don't have privilege then see if
   1583 	 * we have local permission to allow it
   1584 	 */
   1585 	error = secpolicy_fs_mount(cr, mvp, vfsp);
   1586 	if (error) {
   1587 		if (dsl_deleg_access(osname, ZFS_DELEG_PERM_MOUNT, cr) == 0) {
   1588 			vattr_t		vattr;
   1589 
   1590 			/*
   1591 			 * Make sure user is the owner of the mount point
   1592 			 * or has sufficient privileges.
   1593 			 */
   1594 
   1595 			vattr.va_mask = AT_UID;
   1596 
   1597 			if (VOP_GETATTR(mvp, &vattr, 0, cr, NULL)) {
   1598 				goto out;
   1599 			}
   1600 
   1601 			if (secpolicy_vnode_owner(cr, vattr.va_uid) != 0 &&
   1602 			    VOP_ACCESS(mvp, VWRITE, 0, cr, NULL) != 0) {
   1603 				goto out;
   1604 			}
   1605 			secpolicy_fs_mount_clearopts(cr, vfsp);
   1606 		} else {
   1607 			goto out;
   1608 		}
   1609 	}
   1610 
   1611 	/*
   1612 	 * Refuse to mount a filesystem if we are in a local zone and the
   1613 	 * dataset is not visible.
   1614 	 */
   1615 	if (!INGLOBALZONE(curproc) &&
   1616 	    (!zone_dataset_visible(osname, &canwrite) || !canwrite)) {
   1617 		error = EPERM;
   1618 		goto out;
   1619 	}
   1620 
   1621 	error = zfs_mount_label_policy(vfsp, osname);
   1622 	if (error)
   1623 		goto out;
   1624 
   1625 	/*
   1626 	 * When doing a remount, we simply refresh our temporary properties
   1627 	 * according to those options set in the current VFS options.
   1628 	 */
   1629 	if (uap->flags & MS_REMOUNT) {
   1630 		/* refresh mount options */
   1631 		zfs_unregister_callbacks(vfsp->vfs_data);
   1632 		error = zfs_register_callbacks(vfsp);
   1633 		goto out;
   1634 	}
   1635 
   1636 	error = zfs_domount(vfsp, osname);
   1637 
   1638 	/*
   1639 	 * Add an extra VFS_HOLD on our parent vfs so that it can't
   1640 	 * disappear due to a forced unmount.
   1641 	 */
   1642 	if (error == 0 && ((zfsvfs_t *)vfsp->vfs_data)->z_issnap)
   1643 		VFS_HOLD(mvp->v_vfsp);
   1644 
   1645 out:
   1646 	pn_free(&spn);
   1647 	return (error);
   1648 }
   1649 
   1650 static int
   1651 zfs_statvfs(vfs_t *vfsp, struct statvfs64 *statp)
   1652 {
   1653 	zfsvfs_t *zfsvfs = vfsp->vfs_data;
   1654 	dev32_t d32;
   1655 	uint64_t refdbytes, availbytes, usedobjs, availobjs;
   1656 
   1657 	ZFS_ENTER(zfsvfs);
   1658 
   1659 	dmu_objset_space(zfsvfs->z_os,
   1660 	    &refdbytes, &availbytes, &usedobjs, &availobjs);
   1661 
   1662 	/*
   1663 	 * The underlying storage pool actually uses multiple block sizes.
   1664 	 * We report the fragsize as the smallest block size we support,
   1665 	 * and we report our blocksize as the filesystem's maximum blocksize.
   1666 	 */
   1667 	statp->f_frsize = 1UL << SPA_MINBLOCKSHIFT;
   1668 	statp->f_bsize = zfsvfs->z_max_blksz;
   1669 
   1670 	/*
   1671 	 * The following report "total" blocks of various kinds in the
   1672 	 * file system, but reported in terms of f_frsize - the
   1673 	 * "fragment" size.
   1674 	 */
   1675 
   1676 	statp->f_blocks = (refdbytes + availbytes) >> SPA_MINBLOCKSHIFT;
   1677 	statp->f_bfree = availbytes >> SPA_MINBLOCKSHIFT;
   1678 	statp->f_bavail = statp->f_bfree; /* no root reservation */
   1679 
   1680 	/*
   1681 	 * statvfs() should really be called statufs(), because it assumes
   1682 	 * static metadata.  ZFS doesn't preallocate files, so the best
   1683 	 * we can do is report the max that could possibly fit in f_files,
   1684 	 * and that minus the number actually used in f_ffree.
   1685 	 * For f_ffree, report the smaller of the number of object available
   1686 	 * and the number of blocks (each object will take at least a block).
   1687 	 */
   1688 	statp->f_ffree = MIN(availobjs, statp->f_bfree);
   1689 	statp->f_favail = statp->f_ffree;	/* no "root reservation" */
   1690 	statp->f_files = statp->f_ffree + usedobjs;
   1691 
   1692 	(void) cmpldev(&d32, vfsp->vfs_dev);
   1693 	statp->f_fsid = d32;
   1694 
   1695 	/*
   1696 	 * We're a zfs filesystem.
   1697 	 */
   1698 	(void) strcpy(statp->f_basetype, vfssw[vfsp->vfs_fstype].vsw_name);
   1699 
   1700 	statp->f_flag = vf_to_stf(vfsp->vfs_flag);
   1701 
   1702 	statp->f_namemax = ZFS_MAXNAMELEN;
   1703 
   1704 	/*
   1705 	 * We have all of 32 characters to stuff a string here.
   1706 	 * Is there anything useful we could/should provide?
   1707 	 */
   1708 	bzero(statp->f_fstr, sizeof (statp->f_fstr));
   1709 
   1710 	ZFS_EXIT(zfsvfs);
   1711 	return (0);
   1712 }
   1713 
   1714 static int
   1715 zfs_root(vfs_t *vfsp, vnode_t **vpp)
   1716 {
   1717 	zfsvfs_t *zfsvfs = vfsp->vfs_data;
   1718 	znode_t *rootzp;
   1719 	int error;
   1720 
   1721 	ZFS_ENTER(zfsvfs);
   1722 
   1723 	error = zfs_zget(zfsvfs, zfsvfs->z_root, &rootzp);
   1724 	if (error == 0)
   1725 		*vpp = ZTOV(rootzp);
   1726 
   1727 	ZFS_EXIT(zfsvfs);
   1728 	return (error);
   1729 }
   1730 
   1731 /*
   1732  * Teardown the zfsvfs::z_os.
   1733  *
   1734  * Note, if 'unmounting' if FALSE, we return with the 'z_teardown_lock'
   1735  * and 'z_teardown_inactive_lock' held.
   1736  */
   1737 static int
   1738 zfsvfs_teardown(zfsvfs_t *zfsvfs, boolean_t unmounting)
   1739 {
   1740 	znode_t	*zp;
   1741 
   1742 	rrw_enter(&zfsvfs->z_teardown_lock, RW_WRITER, FTAG);
   1743 
   1744 	if (!unmounting) {
   1745 		/*
   1746 		 * We purge the parent filesystem's vfsp as the parent
   1747 		 * filesystem and all of its snapshots have their vnode's
   1748 		 * v_vfsp set to the parent's filesystem's vfsp.  Note,
   1749 		 * 'z_parent' is self referential for non-snapshots.
   1750 		 */
   1751 		(void) dnlc_purge_vfsp(zfsvfs->z_parent->z_vfs, 0);
   1752 	}
   1753 
   1754 	/*
   1755 	 * Close the zil. NB: Can't close the zil while zfs_inactive
   1756 	 * threads are blocked as zil_close can call zfs_inactive.
   1757 	 */
   1758 	if (zfsvfs->z_log) {
   1759 		zil_close(zfsvfs->z_log);
   1760 		zfsvfs->z_log = NULL;
   1761 	}
   1762 
   1763 	rw_enter(&zfsvfs->z_teardown_inactive_lock, RW_WRITER);
   1764 
   1765 	/*
   1766 	 * If we are not unmounting (ie: online recv) and someone already
   1767 	 * unmounted this file system while we were doing the switcheroo,
   1768 	 * or a reopen of z_os failed then just bail out now.
   1769 	 */
   1770 	if (!unmounting && (zfsvfs->z_unmounted || zfsvfs->z_os == NULL)) {
   1771 		rw_exit(&zfsvfs->z_teardown_inactive_lock);
   1772 		rrw_exit(&zfsvfs->z_teardown_lock, FTAG);
   1773 		return (EIO);
   1774 	}
   1775 
   1776 	/*
   1777 	 * At this point there are no vops active, and any new vops will
   1778 	 * fail with EIO since we have z_teardown_lock for writer (only
   1779 	 * relavent for forced unmount).
   1780 	 *
   1781 	 * Release all holds on dbufs.
   1782 	 */
   1783 	mutex_enter(&zfsvfs->z_znodes_lock);
   1784 	for (zp = list_head(&zfsvfs->z_all_znodes); zp != NULL;
   1785 	    zp = list_next(&zfsvfs->z_all_znodes, zp))
   1786 		if (zp->z_sa_hdl) {
   1787 			ASSERT(ZTOV(zp)->v_count > 0);
   1788 			zfs_znode_dmu_fini(zp);
   1789 		}
   1790 	mutex_exit(&zfsvfs->z_znodes_lock);
   1791 
   1792 	/*
   1793 	 * If we are unmounting, set the unmounted flag and let new vops
   1794 	 * unblock.  zfs_inactive will have the unmounted behavior, and all
   1795 	 * other vops will fail with EIO.
   1796 	 */
   1797 	if (unmounting) {
   1798 		zfsvfs->z_unmounted = B_TRUE;
   1799 		rrw_exit(&zfsvfs->z_teardown_lock, FTAG);
   1800 		rw_exit(&zfsvfs->z_teardown_inactive_lock);
   1801 	}
   1802 
   1803 	/*
   1804 	 * z_os will be NULL if there was an error in attempting to reopen
   1805 	 * zfsvfs, so just return as the properties had already been
   1806 	 * unregistered and cached data had been evicted before.
   1807 	 */
   1808 	if (zfsvfs->z_os == NULL)
   1809 		return (0);
   1810 
   1811 	/*
   1812 	 * Unregister properties.
   1813 	 */
   1814 	zfs_unregister_callbacks(zfsvfs);
   1815 
   1816 	/*
   1817 	 * Evict cached data
   1818 	 */
   1819 	if (dmu_objset_is_dirty_anywhere(zfsvfs->z_os))
   1820 		if (!(zfsvfs->z_vfs->vfs_flag & VFS_RDONLY))
   1821 			txg_wait_synced(dmu_objset_pool(zfsvfs->z_os), 0);
   1822 	(void) dmu_objset_evict_dbufs(zfsvfs->z_os);
   1823 
   1824 	return (0);
   1825 }
   1826 
   1827 /*ARGSUSED*/
   1828 static int
   1829 zfs_umount(vfs_t *vfsp, int fflag, cred_t *cr)
   1830 {
   1831 	zfsvfs_t *zfsvfs = vfsp->vfs_data;
   1832 	objset_t *os;
   1833 	int ret;
   1834 
   1835 	ret = secpolicy_fs_unmount(cr, vfsp);
   1836 	if (ret) {
   1837 		if (dsl_deleg_access((char *)refstr_value(vfsp->vfs_resource),
   1838 		    ZFS_DELEG_PERM_MOUNT, cr))
   1839 			return (ret);
   1840 	}
   1841 
   1842 	/*
   1843 	 * We purge the parent filesystem's vfsp as the parent filesystem
   1844 	 * and all of its snapshots have their vnode's v_vfsp set to the
   1845 	 * parent's filesystem's vfsp.  Note, 'z_parent' is self
   1846 	 * referential for non-snapshots.
   1847 	 */
   1848 	(void) dnlc_purge_vfsp(zfsvfs->z_parent->z_vfs, 0);
   1849 
   1850 	/*
   1851 	 * Unmount any snapshots mounted under .zfs before unmounting the
   1852 	 * dataset itself.
   1853 	 */
   1854 	if (zfsvfs->z_ctldir != NULL &&
   1855 	    (ret = zfsctl_umount_snapshots(vfsp, fflag, cr)) != 0) {
   1856 		return (ret);
   1857 	}
   1858 
   1859 	if (!(fflag & MS_FORCE)) {
   1860 		/*
   1861 		 * Check the number of active vnodes in the file system.
   1862 		 * Our count is maintained in the vfs structure, but the
   1863 		 * number is off by 1 to indicate a hold on the vfs
   1864 		 * structure itself.
   1865 		 *
   1866 		 * The '.zfs' directory maintains a reference of its
   1867 		 * own, and any active references underneath are
   1868 		 * reflected in the vnode count.
   1869 		 */
   1870 		if (zfsvfs->z_ctldir == NULL) {
   1871 			if (vfsp->vfs_count > 1)
   1872 				return (EBUSY);
   1873 		} else {
   1874 			if (vfsp->vfs_count > 2 ||
   1875 			    zfsvfs->z_ctldir->v_count > 1)
   1876 				return (EBUSY);
   1877 		}
   1878 	}
   1879 
   1880 	vfsp->vfs_flag |= VFS_UNMOUNTED;
   1881 
   1882 	VERIFY(zfsvfs_teardown(zfsvfs, B_TRUE) == 0);
   1883 	os = zfsvfs->z_os;
   1884 
   1885 	/*
   1886 	 * z_os will be NULL if there was an error in
   1887 	 * attempting to reopen zfsvfs.
   1888 	 */
   1889 	if (os != NULL) {
   1890 		/*
   1891 		 * Unset the objset user_ptr.
   1892 		 */
   1893 		mutex_enter(&os->os_user_ptr_lock);
   1894 		dmu_objset_set_user(os, NULL);
   1895 		mutex_exit(&os->os_user_ptr_lock);
   1896 
   1897 		/*
   1898 		 * Finally release the objset
   1899 		 */
   1900 		dmu_objset_disown(os, zfsvfs);
   1901 	}
   1902 
   1903 	/*
   1904 	 * We can now safely destroy the '.zfs' directory node.
   1905 	 */
   1906 	if (zfsvfs->z_ctldir != NULL)
   1907 		zfsctl_destroy(zfsvfs);
   1908 
   1909 	return (0);
   1910 }
   1911 
   1912 static int
   1913 zfs_vget(vfs_t *vfsp, vnode_t **vpp, fid_t *fidp)
   1914 {
   1915 	zfsvfs_t	*zfsvfs = vfsp->vfs_data;
   1916 	znode_t		*zp;
   1917 	uint64_t	object = 0;
   1918 	uint64_t	fid_gen = 0;
   1919 	uint64_t	gen_mask;
   1920 	uint64_t	zp_gen;
   1921 	int 		i, err;
   1922 
   1923 	*vpp = NULL;
   1924 
   1925 	ZFS_ENTER(zfsvfs);
   1926 
   1927 	if (fidp->fid_len == LONG_FID_LEN) {
   1928 		zfid_long_t	*zlfid = (zfid_long_t *)fidp;
   1929 		uint64_t	objsetid = 0;
   1930 		uint64_t	setgen = 0;
   1931 
   1932 		for (i = 0; i < sizeof (zlfid->zf_setid); i++)
   1933 			objsetid |= ((uint64_t)zlfid->zf_setid[i]) << (8 * i);
   1934 
   1935 		for (i = 0; i < sizeof (zlfid->zf_setgen); i++)
   1936 			setgen |= ((uint64_t)zlfid->zf_setgen[i]) << (8 * i);
   1937 
   1938 		ZFS_EXIT(zfsvfs);
   1939 
   1940 		err = zfsctl_lookup_objset(vfsp, objsetid, &zfsvfs);
   1941 		if (err)
   1942 			return (EINVAL);
   1943 		ZFS_ENTER(zfsvfs);
   1944 	}
   1945 
   1946 	if (fidp->fid_len == SHORT_FID_LEN || fidp->fid_len == LONG_FID_LEN) {
   1947 		zfid_short_t	*zfid = (zfid_short_t *)fidp;
   1948 
   1949 		for (i = 0; i < sizeof (zfid->zf_object); i++)
   1950 			object |= ((uint64_t)zfid->zf_object[i]) << (8 * i);
   1951 
   1952 		for (i = 0; i < sizeof (zfid->zf_gen); i++)
   1953 			fid_gen |= ((uint64_t)zfid->zf_gen[i]) << (8 * i);
   1954 	} else {
   1955 		ZFS_EXIT(zfsvfs);
   1956 		return (EINVAL);
   1957 	}
   1958 
   1959 	/* A zero fid_gen means we are in the .zfs control directories */
   1960 	if (fid_gen == 0 &&
   1961 	    (object == ZFSCTL_INO_ROOT || object == ZFSCTL_INO_SNAPDIR)) {
   1962 		*vpp = zfsvfs->z_ctldir;
   1963 		ASSERT(*vpp != NULL);
   1964 		if (object == ZFSCTL_INO_SNAPDIR) {
   1965 			VERIFY(zfsctl_root_lookup(*vpp, "snapshot", vpp, NULL,
   1966 			    0, NULL, NULL, NULL, NULL, NULL) == 0);
   1967 		} else {
   1968 			VN_HOLD(*vpp);
   1969 		}
   1970 		ZFS_EXIT(zfsvfs);
   1971 		return (0);
   1972 	}
   1973 
   1974 	gen_mask = -1ULL >> (64 - 8 * i);
   1975 
   1976 	dprintf("getting %llu [%u mask %llx]\n", object, fid_gen, gen_mask);
   1977 	if (err = zfs_zget(zfsvfs, object, &zp)) {
   1978 		ZFS_EXIT(zfsvfs);
   1979 		return (err);
   1980 	}
   1981 	(void) sa_lookup(zp->z_sa_hdl, SA_ZPL_GEN(zfsvfs), &zp_gen,
   1982 	    sizeof (uint64_t));
   1983 	zp_gen = zp_gen & gen_mask;
   1984 	if (zp_gen == 0)
   1985 		zp_gen = 1;
   1986 	if (zp->z_unlinked || zp_gen != fid_gen) {
   1987 		dprintf("znode gen (%u) != fid gen (%u)\n", zp_gen, fid_gen);
   1988 		VN_RELE(ZTOV(zp));
   1989 		ZFS_EXIT(zfsvfs);
   1990 		return (EINVAL);
   1991 	}
   1992 
   1993 	*vpp = ZTOV(zp);
   1994 	ZFS_EXIT(zfsvfs);
   1995 	return (0);
   1996 }
   1997 
   1998 /*
   1999  * Block out VOPs and close zfsvfs_t::z_os
   2000  *
   2001  * Note, if successful, then we return with the 'z_teardown_lock' and
   2002  * 'z_teardown_inactive_lock' write held.
   2003  */
   2004 int
   2005 zfs_suspend_fs(zfsvfs_t *zfsvfs)
   2006 {
   2007 	int error;
   2008 
   2009 	if ((error = zfsvfs_teardown(zfsvfs, B_FALSE)) != 0)
   2010 		return (error);
   2011 	dmu_objset_disown(zfsvfs->z_os, zfsvfs);
   2012 
   2013 	return (0);
   2014 }
   2015 
   2016 /*
   2017  * Reopen zfsvfs_t::z_os and release VOPs.
   2018  */
   2019 int
   2020 zfs_resume_fs(zfsvfs_t *zfsvfs, const char *osname)
   2021 {
   2022 	int err;
   2023 
   2024 	ASSERT(RRW_WRITE_HELD(&zfsvfs->z_teardown_lock));
   2025 	ASSERT(RW_WRITE_HELD(&zfsvfs->z_teardown_inactive_lock));
   2026 
   2027 	err = dmu_objset_own(osname, DMU_OST_ZFS, B_FALSE, zfsvfs,
   2028 	    &zfsvfs->z_os);
   2029 	if (err) {
   2030 		zfsvfs->z_os = NULL;
   2031 	} else {
   2032 		znode_t *zp;
   2033 		uint64_t sa_obj = 0;
   2034 
   2035 		/*
   2036 		 * Make sure version hasn't changed
   2037 		 */
   2038 
   2039 		err = zfs_get_zplprop(zfsvfs->z_os, ZFS_PROP_VERSION,
   2040 		    &zfsvfs->z_version);
   2041 
   2042 		if (err)
   2043 			goto bail;
   2044 
   2045 		err = zap_lookup(zfsvfs->z_os, MASTER_NODE_OBJ,
   2046 		    ZFS_SA_ATTRS, 8, 1, &sa_obj);
   2047 
   2048 		if (err && zfsvfs->z_version >= ZPL_VERSION_SA)
   2049 			goto bail;
   2050 
   2051 		if ((err = sa_setup(zfsvfs->z_os, sa_obj,
   2052 		    zfs_attr_table,  ZPL_END, &zfsvfs->z_attr_table)) != 0)
   2053 			goto bail;
   2054 
   2055 		if (zfsvfs->z_version >= ZPL_VERSION_SA)
   2056 			sa_register_update_callback(zfsvfs->z_os,
   2057 			    zfs_sa_upgrade);
   2058 
   2059 		VERIFY(zfsvfs_setup(zfsvfs, B_FALSE) == 0);
   2060 
   2061 		zfs_set_fuid_feature(zfsvfs);
   2062 
   2063 		/*
   2064 		 * Attempt to re-establish all the active znodes with
   2065 		 * their dbufs.  If a zfs_rezget() fails, then we'll let
   2066 		 * any potential callers discover that via ZFS_ENTER_VERIFY_VP
   2067 		 * when they try to use their znode.
   2068 		 */
   2069 		mutex_enter(&zfsvfs->z_znodes_lock);
   2070 		for (zp = list_head(&zfsvfs->z_all_znodes); zp;
   2071 		    zp = list_next(&zfsvfs->z_all_znodes, zp)) {
   2072 			(void) zfs_rezget(zp);
   2073 		}
   2074 		mutex_exit(&zfsvfs->z_znodes_lock);
   2075 	}
   2076 
   2077 bail:
   2078 	/* release the VOPs */
   2079 	rw_exit(&zfsvfs->z_teardown_inactive_lock);
   2080 	rrw_exit(&zfsvfs->z_teardown_lock, FTAG);
   2081 
   2082 	if (err) {
   2083 		/*
   2084 		 * Since we couldn't reopen zfsvfs::z_os, or
   2085 		 * setup the sa framework force unmount this file system.
   2086 		 */
   2087 		if (vn_vfswlock(zfsvfs->z_vfs->vfs_vnodecovered) == 0)
   2088 			(void) dounmount(zfsvfs->z_vfs, MS_FORCE, CRED());
   2089 	}
   2090 	return (err);
   2091 }
   2092 
   2093 static void
   2094 zfs_freevfs(vfs_t *vfsp)
   2095 {
   2096 	zfsvfs_t *zfsvfs = vfsp->vfs_data;
   2097 
   2098 	/*
   2099 	 * If this is a snapshot, we have an extra VFS_HOLD on our parent
   2100 	 * from zfs_mount().  Release it here.  If we came through
   2101 	 * zfs_mountroot() instead, we didn't grab an extra hold, so
   2102 	 * skip the VFS_RELE for rootvfs.
   2103 	 */
   2104 	if (zfsvfs->z_issnap && (vfsp != rootvfs))
   2105 		VFS_RELE(zfsvfs->z_parent->z_vfs);
   2106 
   2107 	zfsvfs_free(zfsvfs);
   2108 
   2109 	atomic_add_32(&zfs_active_fs_count, -1);
   2110 }
   2111 
   2112 /*
   2113  * VFS_INIT() initialization.  Note that there is no VFS_FINI(),
   2114  * so we can't safely do any non-idempotent initialization here.
   2115  * Leave that to zfs_init() and zfs_fini(), which are called
   2116  * from the module's _init() and _fini() entry points.
   2117  */
   2118 /*ARGSUSED*/
   2119 static int
   2120 zfs_vfsinit(int fstype, char *name)
   2121 {
   2122 	int error;
   2123 
   2124 	zfsfstype = fstype;
   2125 
   2126 	/*
   2127 	 * Setup vfsops and vnodeops tables.
   2128 	 */
   2129 	error = vfs_setfsops(fstype, zfs_vfsops_template, &zfs_vfsops);
   2130 	if (error != 0) {
   2131 		cmn_err(CE_WARN, "zfs: bad vfs ops template");
   2132 	}
   2133 
   2134 	error = zfs_create_op_tables();
   2135 	if (error) {
   2136 		zfs_remove_op_tables();
   2137 		cmn_err(CE_WARN, "zfs: bad vnode ops template");
   2138 		(void) vfs_freevfsops_by_type(zfsfstype);
   2139 		return (error);
   2140 	}
   2141 
   2142 	mutex_init(&zfs_dev_mtx, NULL, MUTEX_DEFAULT, NULL);
   2143 
   2144 	/*
   2145 	 * Unique major number for all zfs mounts.
   2146 	 * If we run out of 32-bit minors, we'll getudev() another major.
   2147 	 */
   2148 	zfs_major = ddi_name_to_major(ZFS_DRIVER);
   2149 	zfs_minor = ZFS_MIN_MINOR;
   2150 
   2151 	return (0);
   2152 }
   2153 
   2154 void
   2155 zfs_init(void)
   2156 {
   2157 	/*
   2158 	 * Initialize .zfs directory structures
   2159 	 */
   2160 	zfsctl_init();
   2161 
   2162 	/*
   2163 	 * Initialize znode cache, vnode ops, etc...
   2164 	 */
   2165 	zfs_znode_init();
   2166 
   2167 	dmu_objset_register_type(DMU_OST_ZFS, zfs_space_delta_cb);
   2168 }
   2169 
   2170 void
   2171 zfs_fini(void)
   2172 {
   2173 	zfsctl_fini();
   2174 	zfs_znode_fini();
   2175 }
   2176 
   2177 int
   2178 zfs_busy(void)
   2179 {
   2180 	return (zfs_active_fs_count != 0);
   2181 }
   2182 
   2183 int
   2184 zfs_set_version(zfsvfs_t *zfsvfs, uint64_t newvers)
   2185 {
   2186 	int error;
   2187 	objset_t *os = zfsvfs->z_os;
   2188 	dmu_tx_t *tx;
   2189 
   2190 	if (newvers < ZPL_VERSION_INITIAL || newvers > ZPL_VERSION)
   2191 		return (EINVAL);
   2192 
   2193 	if (newvers < zfsvfs->z_version)
   2194 		return (EINVAL);
   2195 
   2196 	if (zfs_spa_version_map(newvers) >
   2197 	    spa_version(dmu_objset_spa(zfsvfs->z_os)))
   2198 		return (ENOTSUP);
   2199 
   2200 	tx = dmu_tx_create(os);
   2201 	dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, B_FALSE, ZPL_VERSION_STR);
   2202 	if (newvers >= ZPL_VERSION_SA && !zfsvfs->z_use_sa) {
   2203 		dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, B_TRUE,
   2204 		    ZFS_SA_ATTRS);
   2205 		dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
   2206 	}
   2207 	error = dmu_tx_assign(tx, TXG_WAIT);
   2208 	if (error) {
   2209 		dmu_tx_abort(tx);
   2210 		return (error);
   2211 	}
   2212 
   2213 	error = zap_update(os, MASTER_NODE_OBJ, ZPL_VERSION_STR,
   2214 	    8, 1, &newvers, tx);
   2215 
   2216 	if (error) {
   2217 		dmu_tx_commit(tx);
   2218 		return (error);
   2219 	}
   2220 
   2221 	if (newvers >= ZPL_VERSION_SA && !zfsvfs->z_use_sa) {
   2222 		uint64_t sa_obj;
   2223 
   2224 		ASSERT3U(spa_version(dmu_objset_spa(zfsvfs->z_os)), >=,
   2225 		    SPA_VERSION_SA);
   2226 		sa_obj = zap_create(os, DMU_OT_SA_MASTER_NODE,
   2227 		    DMU_OT_NONE, 0, tx);
   2228 
   2229 		error = zap_add(os, MASTER_NODE_OBJ,
   2230 		    ZFS_SA_ATTRS, 8, 1, &sa_obj, tx);
   2231 		ASSERT3U(error, ==, 0);
   2232 
   2233 		VERIFY(0 == sa_set_sa_object(os, sa_obj));
   2234 		sa_register_update_callback(os, zfs_sa_upgrade);
   2235 	}
   2236 
   2237 	spa_history_log_internal(LOG_DS_UPGRADE,
   2238 	    dmu_objset_spa(os), tx, "oldver=%llu newver=%llu dataset = %llu",
   2239 	    zfsvfs->z_version, newvers, dmu_objset_id(os));
   2240 
   2241 	dmu_tx_commit(tx);
   2242 
   2243 	zfsvfs->z_version = newvers;
   2244 
   2245 	zfs_set_fuid_feature(zfsvfs);
   2246 
   2247 	return (0);
   2248 }
   2249 
   2250 /*
   2251  * Read a property stored within the master node.
   2252  */
   2253 int
   2254 zfs_get_zplprop(objset_t *os, zfs_prop_t prop, uint64_t *value)
   2255 {
   2256 	const char *pname;
   2257 	int error = ENOENT;
   2258 
   2259 	/*
   2260 	 * Look up the file system's value for the property.  For the
   2261 	 * version property, we look up a slightly different string.
   2262 	 */
   2263 	if (prop == ZFS_PROP_VERSION)
   2264 		pname = ZPL_VERSION_STR;
   2265 	else
   2266 		pname = zfs_prop_to_name(prop);
   2267 
   2268 	if (os != NULL)
   2269 		error = zap_lookup(os, MASTER_NODE_OBJ, pname, 8, 1, value);
   2270 
   2271 	if (error == ENOENT) {
   2272 		/* No value set, use the default value */
   2273 		switch (prop) {
   2274 		case ZFS_PROP_VERSION:
   2275 			*value = ZPL_VERSION;
   2276 			break;
   2277 		case ZFS_PROP_NORMALIZE:
   2278 		case ZFS_PROP_UTF8ONLY:
   2279 			*value = 0;
   2280 			break;
   2281 		case ZFS_PROP_CASE:
   2282 			*value = ZFS_CASE_SENSITIVE;
   2283 			break;
   2284 		default:
   2285 			return (error);
   2286 		}
   2287 		error = 0;
   2288 	}
   2289 	return (error);
   2290 }
   2291 
   2292 static vfsdef_t vfw = {
   2293 	VFSDEF_VERSION,
   2294 	MNTTYPE_ZFS,
   2295 	zfs_vfsinit,
   2296 	VSW_HASPROTO|VSW_CANRWRO|VSW_CANREMOUNT|VSW_VOLATILEDEV|VSW_STATS|
   2297 	    VSW_XID|VSW_ZMOUNT,
   2298 	&zfs_mntopts
   2299 };
   2300 
   2301 struct modlfs zfs_modlfs = {
   2302 	&mod_fsops, "ZFS filesystem version " SPA_VERSION_STRING, &vfw
   2303 };
   2304