Home | History | Annotate | Download | only in zfs
      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 2007 Sun Microsystems, Inc.  All rights reserved.
     23  * Use is subject to license terms.
     24  */
     25 
     26 /* Portions Copyright 2007 Jeremy Teo */
     27 
     28 #pragma ident	"@(#)zfs_znode.c	1.32	07/12/21 SMI"
     29 
     30 #ifdef _KERNEL
     31 #include <sys/types.h>
     32 #include <sys/param.h>
     33 #include <sys/time.h>
     34 #include <sys/systm.h>
     35 #include <sys/sysmacros.h>
     36 #include <sys/resource.h>
     37 #include <sys/mntent.h>
     38 #include <sys/mkdev.h>
     39 #include <sys/u8_textprep.h>
     40 #include <sys/vfs.h>
     41 #include <sys/vfs_opreg.h>
     42 #include <sys/vnode.h>
     43 #include <sys/file.h>
     44 #include <sys/kmem.h>
     45 #include <sys/errno.h>
     46 #include <sys/unistd.h>
     47 #include <sys/mode.h>
     48 #include <sys/atomic.h>
     49 #include <vm/pvn.h>
     50 #include "fs/fs_subr.h"
     51 #include <sys/zfs_dir.h>
     52 #include <sys/zfs_acl.h>
     53 #include <sys/zfs_ioctl.h>
     54 #include <sys/zfs_rlock.h>
     55 #include <sys/zfs_fuid.h>
     56 #include <sys/fs/zfs.h>
     57 #include <sys/kidmap.h>
     58 #endif /* _KERNEL */
     59 
     60 #include <sys/dmu.h>
     61 #include <sys/refcount.h>
     62 #include <sys/stat.h>
     63 #include <sys/zap.h>
     64 #include <sys/zfs_znode.h>
     65 
     66 #include "zfs_prop.h"
     67 
     68 /*
     69  * Functions needed for userland (ie: libzpool) are not put under
     70  * #ifdef_KERNEL; the rest of the functions have dependencies
     71  * (such as VFS logic) that will not compile easily in userland.
     72  */
     73 #ifdef _KERNEL
     74 struct kmem_cache *znode_cache = NULL;
     75 
     76 /*ARGSUSED*/
     77 static void
     78 znode_evict_error(dmu_buf_t *dbuf, void *user_ptr)
     79 {
     80 	/*
     81 	 * We should never drop all dbuf refs without first clearing
     82 	 * the eviction callback.
     83 	 */
     84 	panic("evicting znode %p\n", user_ptr);
     85 }
     86 
     87 /*ARGSUSED*/
     88 static int
     89 zfs_znode_cache_constructor(void *buf, void *cdrarg, int kmflags)
     90 {
     91 	znode_t *zp = buf;
     92 
     93 	zp->z_vnode = vn_alloc(KM_SLEEP);
     94 	zp->z_vnode->v_data = (caddr_t)zp;
     95 	mutex_init(&zp->z_lock, NULL, MUTEX_DEFAULT, NULL);
     96 	rw_init(&zp->z_map_lock, NULL, RW_DEFAULT, NULL);
     97 	rw_init(&zp->z_parent_lock, NULL, RW_DEFAULT, NULL);
     98 	rw_init(&zp->z_name_lock, NULL, RW_DEFAULT, NULL);
     99 	mutex_init(&zp->z_acl_lock, NULL, MUTEX_DEFAULT, NULL);
    100 
    101 	mutex_init(&zp->z_range_lock, NULL, MUTEX_DEFAULT, NULL);
    102 	avl_create(&zp->z_range_avl, zfs_range_compare,
    103 	    sizeof (rl_t), offsetof(rl_t, r_node));
    104 
    105 	zp->z_dbuf = NULL;
    106 	zp->z_dirlocks = 0;
    107 	return (0);
    108 }
    109 
    110 /*ARGSUSED*/
    111 static void
    112 zfs_znode_cache_destructor(void *buf, void *cdarg)
    113 {
    114 	znode_t *zp = buf;
    115 
    116 	ASSERT(zp->z_dirlocks == 0);
    117 	mutex_destroy(&zp->z_lock);
    118 	rw_destroy(&zp->z_map_lock);
    119 	rw_destroy(&zp->z_parent_lock);
    120 	rw_destroy(&zp->z_name_lock);
    121 	mutex_destroy(&zp->z_acl_lock);
    122 	avl_destroy(&zp->z_range_avl);
    123 	mutex_destroy(&zp->z_range_lock);
    124 
    125 	ASSERT(zp->z_dbuf == NULL);
    126 	ASSERT(ZTOV(zp)->v_count == 0);
    127 	vn_free(ZTOV(zp));
    128 }
    129 
    130 void
    131 zfs_znode_init(void)
    132 {
    133 	/*
    134 	 * Initialize zcache
    135 	 */
    136 	ASSERT(znode_cache == NULL);
    137 	znode_cache = kmem_cache_create("zfs_znode_cache",
    138 	    sizeof (znode_t), 0, zfs_znode_cache_constructor,
    139 	    zfs_znode_cache_destructor, NULL, NULL, NULL, 0);
    140 }
    141 
    142 void
    143 zfs_znode_fini(void)
    144 {
    145 	/*
    146 	 * Cleanup vfs & vnode ops
    147 	 */
    148 	zfs_remove_op_tables();
    149 
    150 	/*
    151 	 * Cleanup zcache
    152 	 */
    153 	if (znode_cache)
    154 		kmem_cache_destroy(znode_cache);
    155 	znode_cache = NULL;
    156 }
    157 
    158 struct vnodeops *zfs_dvnodeops;
    159 struct vnodeops *zfs_fvnodeops;
    160 struct vnodeops *zfs_symvnodeops;
    161 struct vnodeops *zfs_xdvnodeops;
    162 struct vnodeops *zfs_evnodeops;
    163 
    164 void
    165 zfs_remove_op_tables()
    166 {
    167 	/*
    168 	 * Remove vfs ops
    169 	 */
    170 	ASSERT(zfsfstype);
    171 	(void) vfs_freevfsops_by_type(zfsfstype);
    172 	zfsfstype = 0;
    173 
    174 	/*
    175 	 * Remove vnode ops
    176 	 */
    177 	if (zfs_dvnodeops)
    178 		vn_freevnodeops(zfs_dvnodeops);
    179 	if (zfs_fvnodeops)
    180 		vn_freevnodeops(zfs_fvnodeops);
    181 	if (zfs_symvnodeops)
    182 		vn_freevnodeops(zfs_symvnodeops);
    183 	if (zfs_xdvnodeops)
    184 		vn_freevnodeops(zfs_xdvnodeops);
    185 	if (zfs_evnodeops)
    186 		vn_freevnodeops(zfs_evnodeops);
    187 
    188 	zfs_dvnodeops = NULL;
    189 	zfs_fvnodeops = NULL;
    190 	zfs_symvnodeops = NULL;
    191 	zfs_xdvnodeops = NULL;
    192 	zfs_evnodeops = NULL;
    193 }
    194 
    195 extern const fs_operation_def_t zfs_dvnodeops_template[];
    196 extern const fs_operation_def_t zfs_fvnodeops_template[];
    197 extern const fs_operation_def_t zfs_xdvnodeops_template[];
    198 extern const fs_operation_def_t zfs_symvnodeops_template[];
    199 extern const fs_operation_def_t zfs_evnodeops_template[];
    200 
    201 int
    202 zfs_create_op_tables()
    203 {
    204 	int error;
    205 
    206 	/*
    207 	 * zfs_dvnodeops can be set if mod_remove() calls mod_installfs()
    208 	 * due to a failure to remove the the 2nd modlinkage (zfs_modldrv).
    209 	 * In this case we just return as the ops vectors are already set up.
    210 	 */
    211 	if (zfs_dvnodeops)
    212 		return (0);
    213 
    214 	error = vn_make_ops(MNTTYPE_ZFS, zfs_dvnodeops_template,
    215 	    &zfs_dvnodeops);
    216 	if (error)
    217 		return (error);
    218 
    219 	error = vn_make_ops(MNTTYPE_ZFS, zfs_fvnodeops_template,
    220 	    &zfs_fvnodeops);
    221 	if (error)
    222 		return (error);
    223 
    224 	error = vn_make_ops(MNTTYPE_ZFS, zfs_symvnodeops_template,
    225 	    &zfs_symvnodeops);
    226 	if (error)
    227 		return (error);
    228 
    229 	error = vn_make_ops(MNTTYPE_ZFS, zfs_xdvnodeops_template,
    230 	    &zfs_xdvnodeops);
    231 	if (error)
    232 		return (error);
    233 
    234 	error = vn_make_ops(MNTTYPE_ZFS, zfs_evnodeops_template,
    235 	    &zfs_evnodeops);
    236 
    237 	return (error);
    238 }
    239 
    240 /*
    241  * zfs_init_fs - Initialize the zfsvfs struct and the file system
    242  *	incore "master" object.  Verify version compatibility.
    243  */
    244 int
    245 zfs_init_fs(zfsvfs_t *zfsvfs, znode_t **zpp, cred_t *cr)
    246 {
    247 	extern int zfsfstype;
    248 
    249 	objset_t	*os = zfsvfs->z_os;
    250 	int		i, error;
    251 	dmu_object_info_t doi;
    252 	uint64_t fsid_guid;
    253 	uint64_t zval;
    254 
    255 	*zpp = NULL;
    256 
    257 	/*
    258 	 * XXX - hack to auto-create the pool root filesystem at
    259 	 * the first attempted mount.
    260 	 */
    261 	if (dmu_object_info(os, MASTER_NODE_OBJ, &doi) == ENOENT) {
    262 		dmu_tx_t *tx = dmu_tx_create(os);
    263 		uint64_t zpl_version;
    264 		nvlist_t *zprops;
    265 
    266 		dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, TRUE, NULL); /* master */
    267 		dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, TRUE, NULL); /* del queue */
    268 		dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); /* root node */
    269 		error = dmu_tx_assign(tx, TXG_WAIT);
    270 		ASSERT3U(error, ==, 0);
    271 		if (spa_version(dmu_objset_spa(os)) >= SPA_VERSION_FUID)
    272 			zpl_version = ZPL_VERSION;
    273 		else
    274 			zpl_version = ZPL_VERSION_FUID - 1;
    275 
    276 		VERIFY(nvlist_alloc(&zprops, NV_UNIQUE_NAME, KM_SLEEP) == 0);
    277 		VERIFY(nvlist_add_uint64(zprops,
    278 		    zfs_prop_to_name(ZFS_PROP_VERSION), zpl_version) == 0);
    279 		zfs_create_fs(os, cr, zprops, tx);
    280 		nvlist_free(zprops);
    281 		dmu_tx_commit(tx);
    282 	}
    283 
    284 	error = zfs_get_zplprop(os, ZFS_PROP_VERSION, &zfsvfs->z_version);
    285 	if (error) {
    286 		return (error);
    287 	} else if (zfsvfs->z_version > ZPL_VERSION) {
    288 		(void) printf("Mismatched versions:  File system "
    289 		    "is version %llu on-disk format, which is "
    290 		    "incompatible with this software version %lld!",
    291 		    (u_longlong_t)zfsvfs->z_version, ZPL_VERSION);
    292 		return (ENOTSUP);
    293 	}
    294 
    295 	if ((error = zfs_get_zplprop(os, ZFS_PROP_NORMALIZE, &zval)) != 0)
    296 		return (error);
    297 	zfsvfs->z_norm = (int)zval;
    298 	if ((error = zfs_get_zplprop(os, ZFS_PROP_UTF8ONLY, &zval)) != 0)
    299 		return (error);
    300 	zfsvfs->z_utf8 = (zval != 0);
    301 	if ((error = zfs_get_zplprop(os, ZFS_PROP_CASE, &zval)) != 0)
    302 		return (error);
    303 	zfsvfs->z_case = (uint_t)zval;
    304 	/*
    305 	 * Fold case on file systems that are always or sometimes case
    306 	 * insensitive.
    307 	 */
    308 	if (zfsvfs->z_case == ZFS_CASE_INSENSITIVE ||
    309 	    zfsvfs->z_case == ZFS_CASE_MIXED)
    310 		zfsvfs->z_norm |= U8_TEXTPREP_TOUPPER;
    311 
    312 	/*
    313 	 * The fsid is 64 bits, composed of an 8-bit fs type, which
    314 	 * separates our fsid from any other filesystem types, and a
    315 	 * 56-bit objset unique ID.  The objset unique ID is unique to
    316 	 * all objsets open on this system, provided by unique_create().
    317 	 * The 8-bit fs type must be put in the low bits of fsid[1]
    318 	 * because that's where other Solaris filesystems put it.
    319 	 */
    320 	fsid_guid = dmu_objset_fsid_guid(os);
    321 	ASSERT((fsid_guid & ~((1ULL<<56)-1)) == 0);
    322 	zfsvfs->z_vfs->vfs_fsid.val[0] = fsid_guid;
    323 	zfsvfs->z_vfs->vfs_fsid.val[1] = ((fsid_guid>>32) << 8) |
    324 	    zfsfstype & 0xFF;
    325 
    326 	error = zap_lookup(os, MASTER_NODE_OBJ, ZFS_ROOT_OBJ, 8, 1,
    327 	    &zfsvfs->z_root);
    328 	if (error)
    329 		return (error);
    330 	ASSERT(zfsvfs->z_root != 0);
    331 
    332 	error = zap_lookup(os, MASTER_NODE_OBJ, ZFS_UNLINKED_SET, 8, 1,
    333 	    &zfsvfs->z_unlinkedobj);
    334 	if (error)
    335 		return (error);
    336 
    337 	/*
    338 	 * Initialize zget mutex's
    339 	 */
    340 	for (i = 0; i != ZFS_OBJ_MTX_SZ; i++)
    341 		mutex_init(&zfsvfs->z_hold_mtx[i], NULL, MUTEX_DEFAULT, NULL);
    342 
    343 	error = zfs_zget(zfsvfs, zfsvfs->z_root, zpp);
    344 	if (error) {
    345 		/*
    346 		 * On error, we destroy the mutexes here since it's not
    347 		 * possible for the caller to determine if the mutexes were
    348 		 * initialized properly.
    349 		 */
    350 		for (i = 0; i != ZFS_OBJ_MTX_SZ; i++)
    351 			mutex_destroy(&zfsvfs->z_hold_mtx[i]);
    352 		return (error);
    353 	}
    354 	ASSERT3U((*zpp)->z_id, ==, zfsvfs->z_root);
    355 	error = zap_lookup(os, MASTER_NODE_OBJ, ZFS_FUID_TABLES, 8, 1,
    356 	    &zfsvfs->z_fuid_obj);
    357 	if (error == ENOENT)
    358 		error = 0;
    359 
    360 	return (0);
    361 }
    362 
    363 /*
    364  * define a couple of values we need available
    365  * for both 64 and 32 bit environments.
    366  */
    367 #ifndef NBITSMINOR64
    368 #define	NBITSMINOR64	32
    369 #endif
    370 #ifndef MAXMAJ64
    371 #define	MAXMAJ64	0xffffffffUL
    372 #endif
    373 #ifndef	MAXMIN64
    374 #define	MAXMIN64	0xffffffffUL
    375 #endif
    376 
    377 /*
    378  * Create special expldev for ZFS private use.
    379  * Can't use standard expldev since it doesn't do
    380  * what we want.  The standard expldev() takes a
    381  * dev32_t in LP64 and expands it to a long dev_t.
    382  * We need an interface that takes a dev32_t in ILP32
    383  * and expands it to a long dev_t.
    384  */
    385 static uint64_t
    386 zfs_expldev(dev_t dev)
    387 {
    388 #ifndef _LP64
    389 	major_t major = (major_t)dev >> NBITSMINOR32 & MAXMAJ32;
    390 	return (((uint64_t)major << NBITSMINOR64) |
    391 	    ((minor_t)dev & MAXMIN32));
    392 #else
    393 	return (dev);
    394 #endif
    395 }
    396 
    397 /*
    398  * Special cmpldev for ZFS private use.
    399  * Can't use standard cmpldev since it takes
    400  * a long dev_t and compresses it to dev32_t in
    401  * LP64.  We need to do a compaction of a long dev_t
    402  * to a dev32_t in ILP32.
    403  */
    404 dev_t
    405 zfs_cmpldev(uint64_t dev)
    406 {
    407 #ifndef _LP64
    408 	minor_t minor = (minor_t)dev & MAXMIN64;
    409 	major_t major = (major_t)(dev >> NBITSMINOR64) & MAXMAJ64;
    410 
    411 	if (major > MAXMAJ32 || minor > MAXMIN32)
    412 		return (NODEV32);
    413 
    414 	return (((dev32_t)major << NBITSMINOR32) | minor);
    415 #else
    416 	return (dev);
    417 #endif
    418 }
    419 
    420 static void
    421 zfs_znode_dmu_init(znode_t *zp, dmu_buf_t *db)
    422 {
    423 	znode_t		*nzp;
    424 	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
    425 
    426 	ASSERT(MUTEX_HELD(ZFS_OBJ_MUTEX(zp)));
    427 
    428 	mutex_enter(&zp->z_lock);
    429 
    430 	ASSERT(zp->z_dbuf == NULL);
    431 	zp->z_dbuf = db;
    432 	nzp = dmu_buf_set_user_ie(db, zp, &zp->z_phys, znode_evict_error);
    433 
    434 	/*
    435 	 * there should be no
    436 	 * concurrent zgets on this object.
    437 	 */
    438 	if (nzp != NULL)
    439 		panic("existing znode %p for dbuf %p", nzp, db);
    440 
    441 	/*
    442 	 * Slap on VROOT if we are the root znode
    443 	 */
    444 	if (zp->z_id == zfsvfs->z_root)
    445 		ZTOV(zp)->v_flag |= VROOT;
    446 
    447 	mutex_exit(&zp->z_lock);
    448 	vn_exists(ZTOV(zp));
    449 }
    450 
    451 void
    452 zfs_znode_dmu_fini(znode_t *zp)
    453 {
    454 	dmu_buf_t *db = zp->z_dbuf;
    455 	ASSERT(MUTEX_HELD(ZFS_OBJ_MUTEX(zp)) || zp->z_unlinked ||
    456 	    RW_WRITE_HELD(&zp->z_zfsvfs->z_teardown_inactive_lock));
    457 	ASSERT(zp->z_dbuf != NULL);
    458 	zp->z_dbuf = NULL;
    459 	VERIFY(zp == dmu_buf_update_user(db, zp, NULL, NULL, NULL));
    460 	dmu_buf_rele(db, NULL);
    461 }
    462 
    463 /*
    464  * Construct a new znode/vnode and intialize.
    465  *
    466  * This does not do a call to dmu_set_user() that is
    467  * up to the caller to do, in case you don't want to
    468  * return the znode
    469  */
    470 static znode_t *
    471 zfs_znode_alloc(zfsvfs_t *zfsvfs, dmu_buf_t *db, int blksz)
    472 {
    473 	znode_t	*zp;
    474 	vnode_t *vp;
    475 
    476 	zp = kmem_cache_alloc(znode_cache, KM_SLEEP);
    477 
    478 	ASSERT(zp->z_dirlocks == NULL);
    479 	ASSERT(zp->z_dbuf == NULL);
    480 
    481 	zp->z_phys = NULL;
    482 	zp->z_zfsvfs = zfsvfs;
    483 	zp->z_unlinked = 0;
    484 	zp->z_atime_dirty = 0;
    485 	zp->z_mapcnt = 0;
    486 	zp->z_last_itx = 0;
    487 	zp->z_id = db->db_object;
    488 	zp->z_blksz = blksz;
    489 	zp->z_seq = 0x7A4653;
    490 	zp->z_sync_cnt = 0;
    491 
    492 	vp = ZTOV(zp);
    493 	vn_reinit(vp);
    494 
    495 	zfs_znode_dmu_init(zp, db);
    496 
    497 	zp->z_gen = zp->z_phys->zp_gen;
    498 
    499 	mutex_enter(&zfsvfs->z_znodes_lock);
    500 	list_insert_tail(&zfsvfs->z_all_znodes, zp);
    501 	mutex_exit(&zfsvfs->z_znodes_lock);
    502 
    503 	vp->v_vfsp = zfsvfs->z_parent->z_vfs;
    504 	vp->v_type = IFTOVT((mode_t)zp->z_phys->zp_mode);
    505 
    506 	switch (vp->v_type) {
    507 	case VDIR:
    508 		if (zp->z_phys->zp_flags & ZFS_XATTR) {
    509 			vn_setops(vp, zfs_xdvnodeops);
    510 			vp->v_flag |= V_XATTRDIR;
    511 		} else {
    512 			vn_setops(vp, zfs_dvnodeops);
    513 		}
    514 		zp->z_zn_prefetch = B_TRUE; /* z_prefetch default is enabled */
    515 		break;
    516 	case VBLK:
    517 	case VCHR:
    518 		vp->v_rdev = zfs_cmpldev(zp->z_phys->zp_rdev);
    519 		/*FALLTHROUGH*/
    520 	case VFIFO:
    521 	case VSOCK:
    522 	case VDOOR:
    523 		vn_setops(vp, zfs_fvnodeops);
    524 		break;
    525 	case VREG:
    526 		vp->v_flag |= VMODSORT;
    527 		vn_setops(vp, zfs_fvnodeops);
    528 		break;
    529 	case VLNK:
    530 		vn_setops(vp, zfs_symvnodeops);
    531 		break;
    532 	default:
    533 		vn_setops(vp, zfs_evnodeops);
    534 		break;
    535 	}
    536 
    537 	VFS_HOLD(zfsvfs->z_vfs);
    538 	return (zp);
    539 }
    540 
    541 /*
    542  * Create a new DMU object to hold a zfs znode.
    543  *
    544  *	IN:	dzp	- parent directory for new znode
    545  *		vap	- file attributes for new znode
    546  *		tx	- dmu transaction id for zap operations
    547  *		cr	- credentials of caller
    548  *		flag	- flags:
    549  *			  IS_ROOT_NODE	- new object will be root
    550  *			  IS_XATTR	- new object is an attribute
    551  *			  IS_REPLAY	- intent log replay
    552  *		bonuslen - length of bonus buffer
    553  *		setaclp  - File/Dir initial ACL
    554  *		fuidp	 - Tracks fuid allocation.
    555  *
    556  *	OUT:	zpp	- allocated znode
    557  *
    558  */
    559 void
    560 zfs_mknode(znode_t *dzp, vattr_t *vap, dmu_tx_t *tx, cred_t *cr,
    561     uint_t flag, znode_t **zpp, int bonuslen, zfs_acl_t *setaclp,
    562     zfs_fuid_info_t **fuidp)
    563 {
    564 	dmu_buf_t	*db;
    565 	znode_phys_t	*pzp;
    566 	zfsvfs_t	*zfsvfs = dzp->z_zfsvfs;
    567 	timestruc_t	now;
    568 	uint64_t	gen, obj;
    569 	int		err;
    570 
    571 	ASSERT(vap && (vap->va_mask & (AT_TYPE|AT_MODE)) == (AT_TYPE|AT_MODE));
    572 
    573 	if (zfsvfs->z_assign >= TXG_INITIAL) {		/* ZIL replay */
    574 		obj = vap->va_nodeid;
    575 		flag |= IS_REPLAY;
    576 		now = vap->va_ctime;		/* see zfs_replay_create() */
    577 		gen = vap->va_nblocks;		/* ditto */
    578 	} else {
    579 		obj = 0;
    580 		gethrestime(&now);
    581 		gen = dmu_tx_get_txg(tx);
    582 	}
    583 
    584 	/*
    585 	 * Create a new DMU object.
    586 	 */
    587 	/*
    588 	 * There's currently no mechanism for pre-reading the blocks that will
    589 	 * be to needed allocate a new object, so we accept the small chance
    590 	 * that there will be an i/o error and we will fail one of the
    591 	 * assertions below.
    592 	 */
    593 	if (vap->va_type == VDIR) {
    594 		if (flag & IS_REPLAY) {
    595 			err = zap_create_claim_norm(zfsvfs->z_os, obj,
    596 			    zfsvfs->z_norm, DMU_OT_DIRECTORY_CONTENTS,
    597 			    DMU_OT_ZNODE, sizeof (znode_phys_t) + bonuslen, tx);
    598 			ASSERT3U(err, ==, 0);
    599 		} else {
    600 			obj = zap_create_norm(zfsvfs->z_os,
    601 			    zfsvfs->z_norm, DMU_OT_DIRECTORY_CONTENTS,
    602 			    DMU_OT_ZNODE, sizeof (znode_phys_t) + bonuslen, tx);
    603 		}
    604 	} else {
    605 		if (flag & IS_REPLAY) {
    606 			err = dmu_object_claim(zfsvfs->z_os, obj,
    607 			    DMU_OT_PLAIN_FILE_CONTENTS, 0,
    608 			    DMU_OT_ZNODE, sizeof (znode_phys_t) + bonuslen, tx);
    609 			ASSERT3U(err, ==, 0);
    610 		} else {
    611 			obj = dmu_object_alloc(zfsvfs->z_os,
    612 			    DMU_OT_PLAIN_FILE_CONTENTS, 0,
    613 			    DMU_OT_ZNODE, sizeof (znode_phys_t) + bonuslen, tx);
    614 		}
    615 	}
    616 	VERIFY(0 == dmu_bonus_hold(zfsvfs->z_os, obj, NULL, &db));
    617 	dmu_buf_will_dirty(db, tx);
    618 
    619 	/*
    620 	 * Initialize the znode physical data to zero.
    621 	 */
    622 	ASSERT(db->db_size >= sizeof (znode_phys_t));
    623 	bzero(db->db_data, db->db_size);
    624 	pzp = db->db_data;
    625 
    626 	/*
    627 	 * If this is the root, fix up the half-initialized parent pointer
    628 	 * to reference the just-allocated physical data area.
    629 	 */
    630 	if (flag & IS_ROOT_NODE) {
    631 		dzp->z_dbuf = db;
    632 		dzp->z_phys = pzp;
    633 		dzp->z_id = obj;
    634 	}
    635 
    636 	/*
    637 	 * If parent is an xattr, so am I.
    638 	 */
    639 	if (dzp->z_phys->zp_flags & ZFS_XATTR)
    640 		flag |= IS_XATTR;
    641 
    642 	if (vap->va_type == VBLK || vap->va_type == VCHR) {
    643 		pzp->zp_rdev = zfs_expldev(vap->va_rdev);
    644 	}
    645 
    646 	if (zfsvfs->z_use_fuids)
    647 		pzp->zp_flags = ZFS_ARCHIVE | ZFS_AV_MODIFIED;
    648 
    649 	if (vap->va_type == VDIR) {
    650 		pzp->zp_size = 2;		/* contents ("." and "..") */
    651 		pzp->zp_links = (flag & (IS_ROOT_NODE | IS_XATTR)) ? 2 : 1;
    652 	}
    653 
    654 	pzp->zp_parent = dzp->z_id;
    655 	if (flag & IS_XATTR)
    656 		pzp->zp_flags |= ZFS_XATTR;
    657 
    658 	pzp->zp_gen = gen;
    659 
    660 	ZFS_TIME_ENCODE(&now, pzp->zp_crtime);
    661 	ZFS_TIME_ENCODE(&now, pzp->zp_ctime);
    662 
    663 	if (vap->va_mask & AT_ATIME) {
    664 		ZFS_TIME_ENCODE(&vap->va_atime, pzp->zp_atime);
    665 	} else {
    666 		ZFS_TIME_ENCODE(&now, pzp->zp_atime);
    667 	}
    668 
    669 	if (vap->va_mask & AT_MTIME) {
    670 		ZFS_TIME_ENCODE(&vap->va_mtime, pzp->zp_mtime);
    671 	} else {
    672 		ZFS_TIME_ENCODE(&now, pzp->zp_mtime);
    673 	}
    674 
    675 	pzp->zp_mode = MAKEIMODE(vap->va_type, vap->va_mode);
    676 	if (!(flag & IS_ROOT_NODE)) {
    677 		ZFS_OBJ_HOLD_ENTER(zfsvfs, obj)
    678 		*zpp = zfs_znode_alloc(zfsvfs, db, 0);
    679 		ZFS_OBJ_HOLD_EXIT(zfsvfs, obj);
    680 	} else {
    681 		/*
    682 		 * If we are creating the root node, the "parent" we
    683 		 * passed in is the znode for the root.
    684 		 */
    685 		*zpp = dzp;
    686 	}
    687 	zfs_perm_init(*zpp, dzp, flag, vap, tx, cr, setaclp, fuidp);
    688 }
    689 
    690 void
    691 zfs_xvattr_set(znode_t *zp, xvattr_t *xvap)
    692 {
    693 	xoptattr_t *xoap;
    694 
    695 	xoap = xva_getxoptattr(xvap);
    696 	ASSERT(xoap);
    697 
    698 	if (XVA_ISSET_REQ(xvap, XAT_CREATETIME)) {
    699 		ZFS_TIME_ENCODE(&xoap->xoa_createtime, zp->z_phys->zp_crtime);
    700 		XVA_SET_RTN(xvap, XAT_CREATETIME);
    701 	}
    702 	if (XVA_ISSET_REQ(xvap, XAT_READONLY)) {
    703 		ZFS_ATTR_SET(zp, ZFS_READONLY, xoap->xoa_readonly);
    704 		XVA_SET_RTN(xvap, XAT_READONLY);
    705 	}
    706 	if (XVA_ISSET_REQ(xvap, XAT_HIDDEN)) {
    707 		ZFS_ATTR_SET(zp, ZFS_HIDDEN, xoap->xoa_hidden);
    708 		XVA_SET_RTN(xvap, XAT_HIDDEN);
    709 	}
    710 	if (XVA_ISSET_REQ(xvap, XAT_SYSTEM)) {
    711 		ZFS_ATTR_SET(zp, ZFS_SYSTEM, xoap->xoa_system);
    712 		XVA_SET_RTN(xvap, XAT_SYSTEM);
    713 	}
    714 	if (XVA_ISSET_REQ(xvap, XAT_ARCHIVE)) {
    715 		ZFS_ATTR_SET(zp, ZFS_ARCHIVE, xoap->xoa_archive);
    716 		XVA_SET_RTN(xvap, XAT_ARCHIVE);
    717 	}
    718 	if (XVA_ISSET_REQ(xvap, XAT_IMMUTABLE)) {
    719 		ZFS_ATTR_SET(zp, ZFS_IMMUTABLE, xoap->xoa_immutable);
    720 		XVA_SET_RTN(xvap, XAT_IMMUTABLE);
    721 	}
    722 	if (XVA_ISSET_REQ(xvap, XAT_NOUNLINK)) {
    723 		ZFS_ATTR_SET(zp, ZFS_NOUNLINK, xoap->xoa_nounlink);
    724 		XVA_SET_RTN(xvap, XAT_NOUNLINK);
    725 	}
    726 	if (XVA_ISSET_REQ(xvap, XAT_APPENDONLY)) {
    727 		ZFS_ATTR_SET(zp, ZFS_APPENDONLY, xoap->xoa_appendonly);
    728 		XVA_SET_RTN(xvap, XAT_APPENDONLY);
    729 	}
    730 	if (XVA_ISSET_REQ(xvap, XAT_NODUMP)) {
    731 		ZFS_ATTR_SET(zp, ZFS_NODUMP, xoap->xoa_nodump);
    732 		XVA_SET_RTN(xvap, XAT_NODUMP);
    733 	}
    734 	if (XVA_ISSET_REQ(xvap, XAT_OPAQUE)) {
    735 		ZFS_ATTR_SET(zp, ZFS_OPAQUE, xoap->xoa_opaque);
    736 		XVA_SET_RTN(xvap, XAT_OPAQUE);
    737 	}
    738 	if (XVA_ISSET_REQ(xvap, XAT_AV_QUARANTINED)) {
    739 		ZFS_ATTR_SET(zp, ZFS_AV_QUARANTINED,
    740 		    xoap->xoa_av_quarantined);
    741 		XVA_SET_RTN(xvap, XAT_AV_QUARANTINED);
    742 	}
    743 	if (XVA_ISSET_REQ(xvap, XAT_AV_MODIFIED)) {
    744 		ZFS_ATTR_SET(zp, ZFS_AV_MODIFIED, xoap->xoa_av_modified);
    745 		XVA_SET_RTN(xvap, XAT_AV_MODIFIED);
    746 	}
    747 	if (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP)) {
    748 		(void) memcpy(zp->z_phys + 1, xoap->xoa_av_scanstamp,
    749 		    sizeof (xoap->xoa_av_scanstamp));
    750 		zp->z_phys->zp_flags |= ZFS_BONUS_SCANSTAMP;
    751 		XVA_SET_RTN(xvap, XAT_AV_SCANSTAMP);
    752 	}
    753 }
    754 
    755 int
    756 zfs_zget(zfsvfs_t *zfsvfs, uint64_t obj_num, znode_t **zpp)
    757 {
    758 	dmu_object_info_t doi;
    759 	dmu_buf_t	*db;
    760 	znode_t		*zp;
    761 	int err;
    762 
    763 	*zpp = NULL;
    764 
    765 	ZFS_OBJ_HOLD_ENTER(zfsvfs, obj_num);
    766 
    767 	err = dmu_bonus_hold(zfsvfs->z_os, obj_num, NULL, &db);
    768 	if (err) {
    769 		ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
    770 		return (err);
    771 	}
    772 
    773 	dmu_object_info_from_db(db, &doi);
    774 	if (doi.doi_bonus_type != DMU_OT_ZNODE ||
    775 	    doi.doi_bonus_size < sizeof (znode_phys_t)) {
    776 		dmu_buf_rele(db, NULL);
    777 		ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
    778 		return (EINVAL);
    779 	}
    780 
    781 	zp = dmu_buf_get_user(db);
    782 	if (zp != NULL) {
    783 		mutex_enter(&zp->z_lock);
    784 
    785 		/*
    786 		 * Since we do immediate eviction of the z_dbuf, we
    787 		 * should never find a dbuf with a znode that doesn't
    788 		 * know about the dbuf.
    789 		 */
    790 		ASSERT3P(zp->z_dbuf, ==, db);
    791 		ASSERT3U(zp->z_id, ==, obj_num);
    792 		if (zp->z_unlinked) {
    793 			err = ENOENT;
    794 		} else {
    795 			VN_HOLD(ZTOV(zp));
    796 			*zpp = zp;
    797 			err = 0;
    798 		}
    799 		dmu_buf_rele(db, NULL);
    800 		mutex_exit(&zp->z_lock);
    801 		ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
    802 		return (err);
    803 	}
    804 
    805 	/*
    806 	 * Not found create new znode/vnode
    807 	 */
    808 	zp = zfs_znode_alloc(zfsvfs, db, doi.doi_data_block_size);
    809 	ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
    810 	*zpp = zp;
    811 	return (0);
    812 }
    813 
    814 int
    815 zfs_rezget(znode_t *zp)
    816 {
    817 	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
    818 	dmu_object_info_t doi;
    819 	dmu_buf_t *db;
    820 	uint64_t obj_num = zp->z_id;
    821 	int err;
    822 
    823 	ZFS_OBJ_HOLD_ENTER(zfsvfs, obj_num);
    824 
    825 	err = dmu_bonus_hold(zfsvfs->z_os, obj_num, NULL, &db);
    826 	if (err) {
    827 		ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
    828 		return (err);
    829 	}
    830 
    831 	dmu_object_info_from_db(db, &doi);
    832 	if (doi.doi_bonus_type != DMU_OT_ZNODE ||
    833 	    doi.doi_bonus_size < sizeof (znode_phys_t)) {
    834 		dmu_buf_rele(db, NULL);
    835 		ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
    836 		return (EINVAL);
    837 	}
    838 
    839 	if (((znode_phys_t *)db->db_data)->zp_gen != zp->z_gen) {
    840 		dmu_buf_rele(db, NULL);
    841 		ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
    842 		return (EIO);
    843 	}
    844 
    845 	zfs_znode_dmu_init(zp, db);
    846 	zp->z_unlinked = (zp->z_phys->zp_links == 0);
    847 
    848 	ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
    849 
    850 	return (0);
    851 }
    852 
    853 void
    854 zfs_znode_delete(znode_t *zp, dmu_tx_t *tx)
    855 {
    856 	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
    857 	uint64_t obj = zp->z_id;
    858 
    859 	ZFS_OBJ_HOLD_ENTER(zfsvfs, obj);
    860 	if (zp->z_phys->zp_acl.z_acl_extern_obj) {
    861 		VERIFY(0 == dmu_object_free(zfsvfs->z_os,
    862 		    zp->z_phys->zp_acl.z_acl_extern_obj, tx));
    863 	}
    864 	VERIFY(0 == dmu_object_free(zfsvfs->z_os, obj, tx));
    865 	zfs_znode_dmu_fini(zp);
    866 	ZFS_OBJ_HOLD_EXIT(zfsvfs, obj);
    867 	zfs_znode_free(zp);
    868 }
    869 
    870 void
    871 zfs_zinactive(znode_t *zp)
    872 {
    873 	vnode_t	*vp = ZTOV(zp);
    874 	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
    875 	uint64_t z_id = zp->z_id;
    876 
    877 	ASSERT(zp->z_dbuf && zp->z_phys);
    878 
    879 	/*
    880 	 * Don't allow a zfs_zget() while were trying to release this znode
    881 	 */
    882 	ZFS_OBJ_HOLD_ENTER(zfsvfs, z_id);
    883 
    884 	mutex_enter(&zp->z_lock);
    885 	mutex_enter(&vp->v_lock);
    886 	vp->v_count--;
    887 	if (vp->v_count > 0 || vn_has_cached_data(vp)) {
    888 		/*
    889 		 * If the hold count is greater than zero, somebody has
    890 		 * obtained a new reference on this znode while we were
    891 		 * processing it here, so we are done.  If we still have
    892 		 * mapped pages then we are also done, since we don't
    893 		 * want to inactivate the znode until the pages get pushed.
    894 		 *
    895 		 * XXX - if vn_has_cached_data(vp) is true, but count == 0,
    896 		 * this seems like it would leave the znode hanging with
    897 		 * no chance to go inactive...
    898 		 */
    899 		mutex_exit(&vp->v_lock);
    900 		mutex_exit(&zp->z_lock);
    901 		ZFS_OBJ_HOLD_EXIT(zfsvfs, z_id);
    902 		return;
    903 	}
    904 	mutex_exit(&vp->v_lock);
    905 
    906 	/*
    907 	 * If this was the last reference to a file with no links,
    908 	 * remove the file from the file system.
    909 	 */
    910 	if (zp->z_unlinked) {
    911 		mutex_exit(&zp->z_lock);
    912 		ZFS_OBJ_HOLD_EXIT(zfsvfs, z_id);
    913 		zfs_rmnode(zp);
    914 		return;
    915 	}
    916 	mutex_exit(&zp->z_lock);
    917 	zfs_znode_dmu_fini(zp);
    918 	ZFS_OBJ_HOLD_EXIT(zfsvfs, z_id);
    919 	zfs_znode_free(zp);
    920 }
    921 
    922 void
    923 zfs_znode_free(znode_t *zp)
    924 {
    925 	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
    926 
    927 	vn_invalid(ZTOV(zp));
    928 
    929 	mutex_enter(&zfsvfs->z_znodes_lock);
    930 	list_remove(&zfsvfs->z_all_znodes, zp);
    931 	mutex_exit(&zfsvfs->z_znodes_lock);
    932 
    933 	kmem_cache_free(znode_cache, zp);
    934 
    935 	VFS_RELE(zfsvfs->z_vfs);
    936 }
    937 
    938 void
    939 zfs_time_stamper_locked(znode_t *zp, uint_t flag, dmu_tx_t *tx)
    940 {
    941 	timestruc_t	now;
    942 
    943 	ASSERT(MUTEX_HELD(&zp->z_lock));
    944 
    945 	gethrestime(&now);
    946 
    947 	if (tx) {
    948 		dmu_buf_will_dirty(zp->z_dbuf, tx);
    949 		zp->z_atime_dirty = 0;
    950 		zp->z_seq++;
    951 	} else {
    952 		zp->z_atime_dirty = 1;
    953 	}
    954 
    955 	if (flag & AT_ATIME)
    956 		ZFS_TIME_ENCODE(&now, zp->z_phys->zp_atime);
    957 
    958 	if (flag & AT_MTIME) {
    959 		ZFS_TIME_ENCODE(&now, zp->z_phys->zp_mtime);
    960 		if (zp->z_zfsvfs->z_use_fuids)
    961 			zp->z_phys->zp_flags |= (ZFS_ARCHIVE | ZFS_AV_MODIFIED);
    962 	}
    963 
    964 	if (flag & AT_CTIME) {
    965 		ZFS_TIME_ENCODE(&now, zp->z_phys->zp_ctime);
    966 		if (zp->z_zfsvfs->z_use_fuids)
    967 			zp->z_phys->zp_flags |= ZFS_ARCHIVE;
    968 	}
    969 }
    970 
    971 /*
    972  * Update the requested znode timestamps with the current time.
    973  * If we are in a transaction, then go ahead and mark the znode
    974  * dirty in the transaction so the timestamps will go to disk.
    975  * Otherwise, we will get pushed next time the znode is updated
    976  * in a transaction, or when this znode eventually goes inactive.
    977  *
    978  * Why is this OK?
    979  *  1 - Only the ACCESS time is ever updated outside of a transaction.
    980  *  2 - Multiple consecutive updates will be collapsed into a single
    981  *	znode update by the transaction grouping semantics of the DMU.
    982  */
    983 void
    984 zfs_time_stamper(znode_t *zp, uint_t flag, dmu_tx_t *tx)
    985 {
    986 	mutex_enter(&zp->z_lock);
    987 	zfs_time_stamper_locked(zp, flag, tx);
    988 	mutex_exit(&zp->z_lock);
    989 }
    990 
    991 /*
    992  * Grow the block size for a file.
    993  *
    994  *	IN:	zp	- znode of file to free data in.
    995  *		size	- requested block size
    996  *		tx	- open transaction.
    997  *
    998  * NOTE: this function assumes that the znode is write locked.
    999  */
   1000 void
   1001 zfs_grow_blocksize(znode_t *zp, uint64_t size, dmu_tx_t *tx)
   1002 {
   1003 	int		error;
   1004 	u_longlong_t	dummy;
   1005 
   1006 	if (size <= zp->z_blksz)
   1007 		return;
   1008 	/*
   1009 	 * If the file size is already greater than the current blocksize,
   1010 	 * we will not grow.  If there is more than one block in a file,
   1011 	 * the blocksize cannot change.
   1012 	 */
   1013 	if (zp->z_blksz && zp->z_phys->zp_size > zp->z_blksz)
   1014 		return;
   1015 
   1016 	error = dmu_object_set_blocksize(zp->z_zfsvfs->z_os, zp->z_id,
   1017 	    size, 0, tx);
   1018 	if (error == ENOTSUP)
   1019 		return;
   1020 	ASSERT3U(error, ==, 0);
   1021 
   1022 	/* What blocksize did we actually get? */
   1023 	dmu_object_size_from_db(zp->z_dbuf, &zp->z_blksz, &dummy);
   1024 }
   1025 
   1026 /*
   1027  * This is a dummy interface used when pvn_vplist_dirty() should *not*
   1028  * be calling back into the fs for a putpage().  E.g.: when truncating
   1029  * a file, the pages being "thrown away* don't need to be written out.
   1030  */
   1031 /* ARGSUSED */
   1032 static int
   1033 zfs_no_putpage(