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 * Copyright (c) 2012, 2015 by Delphix. All rights reserved. 24 * Copyright 2015, OmniTI Computer Consulting, Inc. All rights reserved. 25 */ 26 27 /* 28 * ZFS control directory (a.k.a. ".zfs") 29 * 30 * This directory provides a common location for all ZFS meta-objects. 31 * Currently, this is only the 'snapshot' directory, but this may expand in the 32 * future. The elements are built using the GFS primitives, as the hierarchy 33 * does not actually exist on disk. 34 * 35 * For 'snapshot', we don't want to have all snapshots always mounted, because 36 * this would take up a huge amount of space in /etc/mnttab. We have three 37 * types of objects: 38 * 39 * ctldir ------> snapshotdir -------> snapshot 40 * | 41 * | 42 * V 43 * mounted fs 44 * 45 * The 'snapshot' node contains just enough information to lookup '..' and act 46 * as a mountpoint for the snapshot. Whenever we lookup a specific snapshot, we 47 * perform an automount of the underlying filesystem and return the 48 * corresponding vnode. 49 * 50 * All mounts are handled automatically by the kernel, but unmounts are 51 * (currently) handled from user land. The main reason is that there is no 52 * reliable way to auto-unmount the filesystem when it's "no longer in use". 53 * When the user unmounts a filesystem, we call zfsctl_unmount(), which 54 * unmounts any snapshots within the snapshot directory. 55 * 56 * The '.zfs', '.zfs/snapshot', and all directories created under 57 * '.zfs/snapshot' (ie: '.zfs/snapshot/<snapname>') are all GFS nodes and 58 * share the same vfs_t as the head filesystem (what '.zfs' lives under). 59 * 60 * File systems mounted ontop of the GFS nodes '.zfs/snapshot/<snapname>' 61 * (ie: snapshots) are ZFS nodes and have their own unique vfs_t. 62 * However, vnodes within these mounted on file systems have their v_vfsp 63 * fields set to the head filesystem to make NFS happy (see 64 * zfsctl_snapdir_lookup()). We VFS_HOLD the head filesystem's vfs_t 65 * so that it cannot be freed until all snapshots have been unmounted. 66 */ 67 68 #include <fs/fs_subr.h> 69 #include <sys/zfs_ctldir.h> 70 #include <sys/zfs_ioctl.h> 71 #include <sys/zfs_vfsops.h> 72 #include <sys/vfs_opreg.h> 73 #include <sys/gfs.h> 74 #include <sys/stat.h> 75 #include <sys/dmu.h> 76 #include <sys/dsl_destroy.h> 77 #include <sys/dsl_deleg.h> 78 #include <sys/mount.h> 79 #include <sys/sunddi.h> 80 81 #include "zfs_namecheck.h" 82 83 typedef struct zfsctl_node { 84 gfs_dir_t zc_gfs_private; 85 uint64_t zc_id; 86 timestruc_t zc_cmtime; /* ctime and mtime, always the same */ 87 } zfsctl_node_t; 88 89 typedef struct zfsctl_snapdir { 90 zfsctl_node_t sd_node; 91 kmutex_t sd_lock; 92 avl_tree_t sd_snaps; 93 } zfsctl_snapdir_t; 94 95 typedef struct { 96 char *se_name; 97 vnode_t *se_root; 98 avl_node_t se_node; 99 } zfs_snapentry_t; 100 101 static int 102 snapentry_compare(const void *a, const void *b) 103 { 104 const zfs_snapentry_t *sa = a; 105 const zfs_snapentry_t *sb = b; 106 int ret = strcmp(sa->se_name, sb->se_name); 107 108 if (ret < 0) 109 return (-1); 110 else if (ret > 0) 111 return (1); 112 else 113 return (0); 114 } 115 116 vnodeops_t *zfsctl_ops_root; 117 vnodeops_t *zfsctl_ops_snapdir; 118 vnodeops_t *zfsctl_ops_snapshot; 119 vnodeops_t *zfsctl_ops_shares; 120 vnodeops_t *zfsctl_ops_shares_dir; 121 122 static const fs_operation_def_t zfsctl_tops_root[]; 123 static const fs_operation_def_t zfsctl_tops_snapdir[]; 124 static const fs_operation_def_t zfsctl_tops_snapshot[]; 125 static const fs_operation_def_t zfsctl_tops_shares[]; 126 127 static vnode_t *zfsctl_mknode_snapdir(vnode_t *); 128 static vnode_t *zfsctl_mknode_shares(vnode_t *); 129 static vnode_t *zfsctl_snapshot_mknode(vnode_t *, uint64_t objset); 130 static int zfsctl_unmount_snap(zfs_snapentry_t *, int, cred_t *); 131 132 static gfs_opsvec_t zfsctl_opsvec[] = { 133 { ".zfs", zfsctl_tops_root, &zfsctl_ops_root }, 134 { ".zfs/snapshot", zfsctl_tops_snapdir, &zfsctl_ops_snapdir }, 135 { ".zfs/snapshot/vnode", zfsctl_tops_snapshot, &zfsctl_ops_snapshot }, 136 { ".zfs/shares", zfsctl_tops_shares, &zfsctl_ops_shares_dir }, 137 { ".zfs/shares/vnode", zfsctl_tops_shares, &zfsctl_ops_shares }, 138 { NULL } 139 }; 140 141 /* 142 * Root directory elements. We only have two entries 143 * snapshot and shares. 144 */ 145 static gfs_dirent_t zfsctl_root_entries[] = { 146 { "snapshot", zfsctl_mknode_snapdir, GFS_CACHE_VNODE }, 147 { "shares", zfsctl_mknode_shares, GFS_CACHE_VNODE }, 148 { NULL } 149 }; 150 151 /* include . and .. in the calculation */ 152 #define NROOT_ENTRIES ((sizeof (zfsctl_root_entries) / \ 153 sizeof (gfs_dirent_t)) + 1) 154 155 156 /* 157 * Initialize the various GFS pieces we'll need to create and manipulate .zfs 158 * directories. This is called from the ZFS init routine, and initializes the 159 * vnode ops vectors that we'll be using. 160 */ 161 void 162 zfsctl_init(void) 163 { 164 VERIFY(gfs_make_opsvec(zfsctl_opsvec) == 0); 165 } 166 167 void 168 zfsctl_fini(void) 169 { 170 /* 171 * Remove vfsctl vnode ops 172 */ 173 if (zfsctl_ops_root) 174 vn_freevnodeops(zfsctl_ops_root); 175 if (zfsctl_ops_snapdir) 176 vn_freevnodeops(zfsctl_ops_snapdir); 177 if (zfsctl_ops_snapshot) 178 vn_freevnodeops(zfsctl_ops_snapshot); 179 if (zfsctl_ops_shares) 180 vn_freevnodeops(zfsctl_ops_shares); 181 if (zfsctl_ops_shares_dir) 182 vn_freevnodeops(zfsctl_ops_shares_dir); 183 184 zfsctl_ops_root = NULL; 185 zfsctl_ops_snapdir = NULL; 186 zfsctl_ops_snapshot = NULL; 187 zfsctl_ops_shares = NULL; 188 zfsctl_ops_shares_dir = NULL; 189 } 190 191 boolean_t 192 zfsctl_is_node(vnode_t *vp) 193 { 194 return (vn_matchops(vp, zfsctl_ops_root) || 195 vn_matchops(vp, zfsctl_ops_snapdir) || 196 vn_matchops(vp, zfsctl_ops_snapshot) || 197 vn_matchops(vp, zfsctl_ops_shares) || 198 vn_matchops(vp, zfsctl_ops_shares_dir)); 199 200 } 201 202 /* 203 * Return the inode number associated with the 'snapshot' or 204 * 'shares' directory. 205 */ 206 /* ARGSUSED */ 207 static ino64_t 208 zfsctl_root_inode_cb(vnode_t *vp, int index) 209 { 210 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 211 212 ASSERT(index <= 2); 213 214 if (index == 0) 215 return (ZFSCTL_INO_SNAPDIR); 216 217 return (zfsvfs->z_shares_dir); 218 } 219 220 /* 221 * Create the '.zfs' directory. This directory is cached as part of the VFS 222 * structure. This results in a hold on the vfs_t. The code in zfs_umount() 223 * therefore checks against a vfs_count of 2 instead of 1. This reference 224 * is removed when the ctldir is destroyed in the unmount. 225 */ 226 void 227 zfsctl_create(zfsvfs_t *zfsvfs) 228 { 229 vnode_t *vp, *rvp; 230 zfsctl_node_t *zcp; 231 uint64_t crtime[2]; 232 233 ASSERT(zfsvfs->z_ctldir == NULL); 234 235 vp = gfs_root_create(sizeof (zfsctl_node_t), zfsvfs->z_vfs, 236 zfsctl_ops_root, ZFSCTL_INO_ROOT, zfsctl_root_entries, 237 zfsctl_root_inode_cb, MAXNAMELEN, NULL, NULL); 238 zcp = vp->v_data; 239 zcp->zc_id = ZFSCTL_INO_ROOT; 240 241 VERIFY(VFS_ROOT(zfsvfs->z_vfs, &rvp) == 0); 242 VERIFY(0 == sa_lookup(VTOZ(rvp)->z_sa_hdl, SA_ZPL_CRTIME(zfsvfs), 243 &crtime, sizeof (crtime))); 244 ZFS_TIME_DECODE(&zcp->zc_cmtime, crtime); 245 VN_RELE(rvp); 246 247 /* 248 * We're only faking the fact that we have a root of a filesystem for 249 * the sake of the GFS interfaces. Undo the flag manipulation it did 250 * for us. 251 */ 252 vp->v_flag &= ~(VROOT | VNOCACHE | VNOMAP | VNOSWAP | VNOMOUNT); 253 254 zfsvfs->z_ctldir = vp; 255 } 256 257 /* 258 * Destroy the '.zfs' directory. Only called when the filesystem is unmounted. 259 * There might still be more references if we were force unmounted, but only 260 * new zfs_inactive() calls can occur and they don't reference .zfs 261 */ 262 void 263 zfsctl_destroy(zfsvfs_t *zfsvfs) 264 { 265 VN_RELE(zfsvfs->z_ctldir); 266 zfsvfs->z_ctldir = NULL; 267 } 268 269 /* 270 * Given a root znode, retrieve the associated .zfs directory. 271 * Add a hold to the vnode and return it. 272 */ 273 vnode_t * 274 zfsctl_root(znode_t *zp) 275 { 276 ASSERT(zfs_has_ctldir(zp)); 277 VN_HOLD(zp->z_zfsvfs->z_ctldir); 278 return (zp->z_zfsvfs->z_ctldir); 279 } 280 281 /* 282 * Common open routine. Disallow any write access. 283 */ 284 /* ARGSUSED */ 285 static int 286 zfsctl_common_open(vnode_t **vpp, int flags, cred_t *cr, caller_context_t *ct) 287 { 288 if (flags & FWRITE) 289 return (SET_ERROR(EACCES)); 290 291 return (0); 292 } 293 294 /* 295 * Common close routine. Nothing to do here. 296 */ 297 /* ARGSUSED */ 298 static int 299 zfsctl_common_close(vnode_t *vpp, int flags, int count, offset_t off, 300 cred_t *cr, caller_context_t *ct) 301 { 302 return (0); 303 } 304 305 /* 306 * Common access routine. Disallow writes. 307 */ 308 /* ARGSUSED */ 309 static int 310 zfsctl_common_access(vnode_t *vp, int mode, int flags, cred_t *cr, 311 caller_context_t *ct) 312 { 313 if (flags & V_ACE_MASK) { 314 if (mode & ACE_ALL_WRITE_PERMS) 315 return (SET_ERROR(EACCES)); 316 } else { 317 if (mode & VWRITE) 318 return (SET_ERROR(EACCES)); 319 } 320 321 return (0); 322 } 323 324 /* 325 * Common getattr function. Fill in basic information. 326 */ 327 static void 328 zfsctl_common_getattr(vnode_t *vp, vattr_t *vap) 329 { 330 timestruc_t now; 331 332 vap->va_uid = 0; 333 vap->va_gid = 0; 334 vap->va_rdev = 0; 335 /* 336 * We are a purely virtual object, so we have no 337 * blocksize or allocated blocks. 338 */ 339 vap->va_blksize = 0; 340 vap->va_nblocks = 0; 341 vap->va_seq = 0; 342 vap->va_fsid = vp->v_vfsp->vfs_dev; 343 vap->va_mode = S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP | 344 S_IROTH | S_IXOTH; 345 vap->va_type = VDIR; 346 /* 347 * We live in the now (for atime). 348 */ 349 gethrestime(&now); 350 vap->va_atime = now; 351 } 352 353 /*ARGSUSED*/ 354 static int 355 zfsctl_common_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct) 356 { 357 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 358 zfsctl_node_t *zcp = vp->v_data; 359 uint64_t object = zcp->zc_id; 360 zfid_short_t *zfid; 361 int i; 362 363 ZFS_ENTER(zfsvfs); 364 365 if (fidp->fid_len < SHORT_FID_LEN) { 366 fidp->fid_len = SHORT_FID_LEN; 367 ZFS_EXIT(zfsvfs); 368 return (SET_ERROR(ENOSPC)); 369 } 370 371 zfid = (zfid_short_t *)fidp; 372 373 zfid->zf_len = SHORT_FID_LEN; 374 375 for (i = 0; i < sizeof (zfid->zf_object); i++) 376 zfid->zf_object[i] = (uint8_t)(object >> (8 * i)); 377 378 /* .zfs znodes always have a generation number of 0 */ 379 for (i = 0; i < sizeof (zfid->zf_gen); i++) 380 zfid->zf_gen[i] = 0; 381 382 ZFS_EXIT(zfsvfs); 383 return (0); 384 } 385 386 387 /*ARGSUSED*/ 388 static int 389 zfsctl_shares_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct) 390 { 391 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 392 znode_t *dzp; 393 int error; 394 395 ZFS_ENTER(zfsvfs); 396 397 if (zfsvfs->z_shares_dir == 0) { 398 ZFS_EXIT(zfsvfs); 399 return (SET_ERROR(ENOTSUP)); 400 } 401 402 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { 403 error = VOP_FID(ZTOV(dzp), fidp, ct); 404 VN_RELE(ZTOV(dzp)); 405 } 406 407 ZFS_EXIT(zfsvfs); 408 return (error); 409 } 410 /* 411 * .zfs inode namespace 412 * 413 * We need to generate unique inode numbers for all files and directories 414 * within the .zfs pseudo-filesystem. We use the following scheme: 415 * 416 * ENTRY ZFSCTL_INODE 417 * .zfs 1 418 * .zfs/snapshot 2 419 * .zfs/snapshot/<snap> objectid(snap) 420 */ 421 422 #define ZFSCTL_INO_SNAP(id) (id) 423 424 /* 425 * Get root directory attributes. 426 */ 427 /* ARGSUSED */ 428 static int 429 zfsctl_root_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr, 430 caller_context_t *ct) 431 { 432 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 433 zfsctl_node_t *zcp = vp->v_data; 434 435 ZFS_ENTER(zfsvfs); 436 vap->va_nodeid = ZFSCTL_INO_ROOT; 437 vap->va_nlink = vap->va_size = NROOT_ENTRIES; 438 vap->va_mtime = vap->va_ctime = zcp->zc_cmtime; 439 440 zfsctl_common_getattr(vp, vap); 441 ZFS_EXIT(zfsvfs); 442 443 return (0); 444 } 445 446 /* 447 * Special case the handling of "..". 448 */ 449 /* ARGSUSED */ 450 int 451 zfsctl_root_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp, 452 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct, 453 int *direntflags, pathname_t *realpnp) 454 { 455 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 456 int err; 457 458 /* 459 * No extended attributes allowed under .zfs 460 */ 461 if (flags & LOOKUP_XATTR) 462 return (SET_ERROR(EINVAL)); 463 464 ZFS_ENTER(zfsvfs); 465 466 if (strcmp(nm, "..") == 0) { 467 err = VFS_ROOT(dvp->v_vfsp, vpp); 468 } else { 469 err = gfs_vop_lookup(dvp, nm, vpp, pnp, flags, rdir, 470 cr, ct, direntflags, realpnp); 471 } 472 473 ZFS_EXIT(zfsvfs); 474 475 return (err); 476 } 477 478 static int 479 zfsctl_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr, 480 caller_context_t *ct) 481 { 482 /* 483 * We only care about ACL_ENABLED so that libsec can 484 * display ACL correctly and not default to POSIX draft. 485 */ 486 if (cmd == _PC_ACL_ENABLED) { 487 *valp = _ACL_ACE_ENABLED; 488 return (0); 489 } 490 491 return (fs_pathconf(vp, cmd, valp, cr, ct)); 492 } 493 494 static const fs_operation_def_t zfsctl_tops_root[] = { 495 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, 496 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, 497 { VOPNAME_IOCTL, { .error = fs_inval } }, 498 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_root_getattr } }, 499 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, 500 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } }, 501 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_root_lookup } }, 502 { VOPNAME_SEEK, { .vop_seek = fs_seek } }, 503 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } }, 504 { VOPNAME_PATHCONF, { .vop_pathconf = zfsctl_pathconf } }, 505 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } }, 506 { NULL } 507 }; 508 509 /* 510 * Gets the full dataset name that corresponds to the given snapshot name 511 * Example: 512 * zfsctl_snapshot_zname("snap1") -> "mypool/myfs@snap1" 513 */ 514 static int 515 zfsctl_snapshot_zname(vnode_t *vp, const char *name, int len, char *zname) 516 { 517 objset_t *os = ((zfsvfs_t *)((vp)->v_vfsp->vfs_data))->z_os; 518 519 if (zfs_component_namecheck(name, NULL, NULL) != 0) 520 return (SET_ERROR(EILSEQ)); 521 dmu_objset_name(os, zname); 522 if (strlen(zname) + 1 + strlen(name) >= len) 523 return (SET_ERROR(ENAMETOOLONG)); 524 (void) strcat(zname, "@"); 525 (void) strcat(zname, name); 526 return (0); 527 } 528 529 static int 530 zfsctl_unmount_snap(zfs_snapentry_t *sep, int fflags, cred_t *cr) 531 { 532 vnode_t *svp = sep->se_root; 533 int error; 534 535 ASSERT(vn_ismntpt(svp)); 536 537 /* this will be dropped by dounmount() */ 538 if ((error = vn_vfswlock(svp)) != 0) 539 return (error); 540 541 VN_HOLD(svp); 542 error = dounmount(vn_mountedvfs(svp), fflags, cr); 543 if (error) { 544 VN_RELE(svp); 545 return (error); 546 } 547 548 /* 549 * We can't use VN_RELE(), as that will try to invoke 550 * zfsctl_snapdir_inactive(), which would cause us to destroy 551 * the sd_lock mutex held by our caller. 552 */ 553 ASSERT(svp->v_count == 1); 554 gfs_vop_inactive(svp, cr, NULL); 555 556 kmem_free(sep->se_name, strlen(sep->se_name) + 1); 557 kmem_free(sep, sizeof (zfs_snapentry_t)); 558 559 return (0); 560 } 561 562 static void 563 zfsctl_rename_snap(zfsctl_snapdir_t *sdp, zfs_snapentry_t *sep, const char *nm) 564 { 565 avl_index_t where; 566 vfs_t *vfsp; 567 refstr_t *pathref; 568 char newpath[MAXNAMELEN]; 569 char *tail; 570 571 ASSERT(MUTEX_HELD(&sdp->sd_lock)); 572 ASSERT(sep != NULL); 573 574 vfsp = vn_mountedvfs(sep->se_root); 575 ASSERT(vfsp != NULL); 576 577 vfs_lock_wait(vfsp); 578 579 /* 580 * Change the name in the AVL tree. 581 */ 582 avl_remove(&sdp->sd_snaps, sep); 583 kmem_free(sep->se_name, strlen(sep->se_name) + 1); 584 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP); 585 (void) strcpy(sep->se_name, nm); 586 VERIFY(avl_find(&sdp->sd_snaps, sep, &where) == NULL); 587 avl_insert(&sdp->sd_snaps, sep, where); 588 589 /* 590 * Change the current mountpoint info: 591 * - update the tail of the mntpoint path 592 * - update the tail of the resource path 593 */ 594 pathref = vfs_getmntpoint(vfsp); 595 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath)); 596 VERIFY((tail = strrchr(newpath, '/')) != NULL); 597 *(tail+1) = '\0'; 598 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath)); 599 (void) strcat(newpath, nm); 600 refstr_rele(pathref); 601 vfs_setmntpoint(vfsp, newpath, 0); 602 603 pathref = vfs_getresource(vfsp); 604 (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath)); 605 VERIFY((tail = strrchr(newpath, '@')) != NULL); 606 *(tail+1) = '\0'; 607 ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath)); 608 (void) strcat(newpath, nm); 609 refstr_rele(pathref); 610 vfs_setresource(vfsp, newpath, 0); 611 612 vfs_unlock(vfsp); 613 } 614 615 /*ARGSUSED*/ 616 static int 617 zfsctl_snapdir_rename(vnode_t *sdvp, char *snm, vnode_t *tdvp, char *tnm, 618 cred_t *cr, caller_context_t *ct, int flags) 619 { 620 zfsctl_snapdir_t *sdp = sdvp->v_data; 621 zfs_snapentry_t search, *sep; 622 zfsvfs_t *zfsvfs; 623 avl_index_t where; 624 char from[ZFS_MAX_DATASET_NAME_LEN], to[ZFS_MAX_DATASET_NAME_LEN]; 625 char real[ZFS_MAX_DATASET_NAME_LEN], fsname[ZFS_MAX_DATASET_NAME_LEN]; 626 int err; 627 628 zfsvfs = sdvp->v_vfsp->vfs_data; 629 ZFS_ENTER(zfsvfs); 630 631 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) { 632 err = dmu_snapshot_realname(zfsvfs->z_os, snm, real, 633 sizeof (real), NULL); 634 if (err == 0) { 635 snm = real; 636 } else if (err != ENOTSUP) { 637 ZFS_EXIT(zfsvfs); 638 return (err); 639 } 640 } 641 642 ZFS_EXIT(zfsvfs); 643 644 dmu_objset_name(zfsvfs->z_os, fsname); 645 646 err = zfsctl_snapshot_zname(sdvp, snm, sizeof (from), from); 647 if (err == 0) 648 err = zfsctl_snapshot_zname(tdvp, tnm, sizeof (to), to); 649 if (err == 0) 650 err = zfs_secpolicy_rename_perms(from, to, cr); 651 if (err != 0) 652 return (err); 653 654 /* 655 * Cannot move snapshots out of the snapdir. 656 */ 657 if (sdvp != tdvp) 658 return (SET_ERROR(EINVAL)); 659 660 if (strcmp(snm, tnm) == 0) 661 return (0); 662 663 mutex_enter(&sdp->sd_lock); 664 665 search.se_name = (char *)snm; 666 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) == NULL) { 667 mutex_exit(&sdp->sd_lock); 668 return (SET_ERROR(ENOENT)); 669 } 670 671 err = dsl_dataset_rename_snapshot(fsname, snm, tnm, B_FALSE); 672 if (err == 0) 673 zfsctl_rename_snap(sdp, sep, tnm); 674 675 mutex_exit(&sdp->sd_lock); 676 677 return (err); 678 } 679 680 /* ARGSUSED */ 681 static int 682 zfsctl_snapdir_remove(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr, 683 caller_context_t *ct, int flags) 684 { 685 zfsctl_snapdir_t *sdp = dvp->v_data; 686 zfs_snapentry_t *sep; 687 zfs_snapentry_t search; 688 zfsvfs_t *zfsvfs; 689 char snapname[ZFS_MAX_DATASET_NAME_LEN]; 690 char real[ZFS_MAX_DATASET_NAME_LEN]; 691 int err; 692 693 zfsvfs = dvp->v_vfsp->vfs_data; 694 ZFS_ENTER(zfsvfs); 695 696 if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) { 697 698 err = dmu_snapshot_realname(zfsvfs->z_os, name, real, 699 sizeof (real), NULL); 700 if (err == 0) { 701 name = real; 702 } else if (err != ENOTSUP) { 703 ZFS_EXIT(zfsvfs); 704 return (err); 705 } 706 } 707 708 ZFS_EXIT(zfsvfs); 709 710 err = zfsctl_snapshot_zname(dvp, name, sizeof (snapname), snapname); 711 if (err == 0) 712 err = zfs_secpolicy_destroy_perms(snapname, cr); 713 if (err != 0) 714 return (err); 715 716 mutex_enter(&sdp->sd_lock); 717 718 search.se_name = name; 719 sep = avl_find(&sdp->sd_snaps, &search, NULL); 720 if (sep) { 721 avl_remove(&sdp->sd_snaps, sep); 722 err = zfsctl_unmount_snap(sep, MS_FORCE, cr); 723 if (err != 0) 724 avl_add(&sdp->sd_snaps, sep); 725 else 726 err = dsl_destroy_snapshot(snapname, B_FALSE); 727 } else { 728 err = SET_ERROR(ENOENT); 729 } 730 731 mutex_exit(&sdp->sd_lock); 732 733 return (err); 734 } 735 736 /* 737 * This creates a snapshot under '.zfs/snapshot'. 738 */ 739 /* ARGSUSED */ 740 static int 741 zfsctl_snapdir_mkdir(vnode_t *dvp, char *dirname, vattr_t *vap, vnode_t **vpp, 742 cred_t *cr, caller_context_t *cc, int flags, vsecattr_t *vsecp) 743 { 744 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 745 char name[ZFS_MAX_DATASET_NAME_LEN]; 746 int err; 747 static enum symfollow follow = NO_FOLLOW; 748 static enum uio_seg seg = UIO_SYSSPACE; 749 750 if (zfs_component_namecheck(dirname, NULL, NULL) != 0) 751 return (SET_ERROR(EILSEQ)); 752 753 dmu_objset_name(zfsvfs->z_os, name); 754 755 *vpp = NULL; 756 757 err = zfs_secpolicy_snapshot_perms(name, cr); 758 if (err != 0) 759 return (err); 760 761 if (err == 0) { 762 err = dmu_objset_snapshot_one(name, dirname); 763 if (err != 0) 764 return (err); 765 err = lookupnameat(dirname, seg, follow, NULL, vpp, dvp); 766 } 767 768 return (err); 769 } 770 771 /* 772 * Lookup entry point for the 'snapshot' directory. Try to open the 773 * snapshot if it exist, creating the pseudo filesystem vnode as necessary. 774 * Perform a mount of the associated dataset on top of the vnode. 775 */ 776 /* ARGSUSED */ 777 static int 778 zfsctl_snapdir_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp, 779 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct, 780 int *direntflags, pathname_t *realpnp) 781 { 782 zfsctl_snapdir_t *sdp = dvp->v_data; 783 objset_t *snap; 784 char snapname[ZFS_MAX_DATASET_NAME_LEN]; 785 char real[ZFS_MAX_DATASET_NAME_LEN]; 786 char *mountpoint; 787 zfs_snapentry_t *sep, search; 788 struct mounta margs; 789 vfs_t *vfsp; 790 size_t mountpoint_len; 791 avl_index_t where; 792 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 793 int err; 794 795 /* 796 * No extended attributes allowed under .zfs 797 */ 798 if (flags & LOOKUP_XATTR) 799 return (SET_ERROR(EINVAL)); 800 801 ASSERT(dvp->v_type == VDIR); 802 803 /* 804 * If we get a recursive call, that means we got called 805 * from the domount() code while it was trying to look up the 806 * spec (which looks like a local path for zfs). We need to 807 * add some flag to domount() to tell it not to do this lookup. 808 */ 809 if (MUTEX_HELD(&sdp->sd_lock)) 810 return (SET_ERROR(ENOENT)); 811 812 ZFS_ENTER(zfsvfs); 813 814 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) { 815 ZFS_EXIT(zfsvfs); 816 return (0); 817 } 818 819 if (flags & FIGNORECASE) { 820 boolean_t conflict = B_FALSE; 821 822 err = dmu_snapshot_realname(zfsvfs->z_os, nm, real, 823 sizeof (real), &conflict); 824 if (err == 0) { 825 nm = real; 826 } else if (err != ENOTSUP) { 827 ZFS_EXIT(zfsvfs); 828 return (err); 829 } 830 if (realpnp) 831 (void) strlcpy(realpnp->pn_buf, nm, 832 realpnp->pn_bufsize); 833 if (conflict && direntflags) 834 *direntflags = ED_CASE_CONFLICT; 835 } 836 837 mutex_enter(&sdp->sd_lock); 838 search.se_name = (char *)nm; 839 if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) != NULL) { 840 *vpp = sep->se_root; 841 VN_HOLD(*vpp); 842 err = traverse(vpp); 843 if (err != 0) { 844 VN_RELE(*vpp); 845 *vpp = NULL; 846 } else if (*vpp == sep->se_root) { 847 /* 848 * The snapshot was unmounted behind our backs, 849 * try to remount it. 850 */ 851 goto domount; 852 } else { 853 /* 854 * VROOT was set during the traverse call. We need 855 * to clear it since we're pretending to be part 856 * of our parent's vfs. 857 */ 858 (*vpp)->v_flag &= ~VROOT; 859 } 860 mutex_exit(&sdp->sd_lock); 861 ZFS_EXIT(zfsvfs); 862 return (err); 863 } 864 865 /* 866 * The requested snapshot is not currently mounted, look it up. 867 */ 868 err = zfsctl_snapshot_zname(dvp, nm, sizeof (snapname), snapname); 869 if (err != 0) { 870 mutex_exit(&sdp->sd_lock); 871 ZFS_EXIT(zfsvfs); 872 /* 873 * handle "ls *" or "?" in a graceful manner, 874 * forcing EILSEQ to ENOENT. 875 * Since shell ultimately passes "*" or "?" as name to lookup 876 */ 877 return (err == EILSEQ ? ENOENT : err); 878 } 879 if (dmu_objset_hold(snapname, FTAG, &snap) != 0) { 880 mutex_exit(&sdp->sd_lock); 881 ZFS_EXIT(zfsvfs); 882 return (SET_ERROR(ENOENT)); 883 } 884 885 sep = kmem_alloc(sizeof (zfs_snapentry_t), KM_SLEEP); 886 sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP); 887 (void) strcpy(sep->se_name, nm); 888 *vpp = sep->se_root = zfsctl_snapshot_mknode(dvp, dmu_objset_id(snap)); 889 avl_insert(&sdp->sd_snaps, sep, where); 890 891 dmu_objset_rele(snap, FTAG); 892 domount: 893 mountpoint_len = strlen(refstr_value(dvp->v_vfsp->vfs_mntpt)) + 894 strlen("/.zfs/snapshot/") + strlen(nm) + 1; 895 mountpoint = kmem_alloc(mountpoint_len, KM_SLEEP); 896 (void) snprintf(mountpoint, mountpoint_len, "%s/.zfs/snapshot/%s", 897 refstr_value(dvp->v_vfsp->vfs_mntpt), nm); 898 899 margs.spec = snapname; 900 margs.dir = mountpoint; 901 margs.flags = MS_SYSSPACE | MS_NOMNTTAB; 902 margs.fstype = "zfs"; 903 margs.dataptr = NULL; 904 margs.datalen = 0; 905 margs.optptr = NULL; 906 margs.optlen = 0; 907 908 err = domount("zfs", &margs, *vpp, kcred, &vfsp); 909 kmem_free(mountpoint, mountpoint_len); 910 911 if (err == 0) { 912 /* 913 * Return the mounted root rather than the covered mount point. 914 * Takes the GFS vnode at .zfs/snapshot/<snapname> and returns 915 * the ZFS vnode mounted on top of the GFS node. This ZFS 916 * vnode is the root of the newly created vfsp. 917 */ 918 VFS_RELE(vfsp); 919 err = traverse(vpp); 920 } 921 922 if (err == 0) { 923 /* 924 * Fix up the root vnode mounted on .zfs/snapshot/<snapname>. 925 * 926 * This is where we lie about our v_vfsp in order to 927 * make .zfs/snapshot/<snapname> accessible over NFS 928 * without requiring manual mounts of <snapname>. 929 */ 930 ASSERT(VTOZ(*vpp)->z_zfsvfs != zfsvfs); 931 VTOZ(*vpp)->z_zfsvfs->z_parent = zfsvfs; 932 (*vpp)->v_vfsp = zfsvfs->z_vfs; 933 (*vpp)->v_flag &= ~VROOT; 934 } 935 mutex_exit(&sdp->sd_lock); 936 ZFS_EXIT(zfsvfs); 937 938 /* 939 * If we had an error, drop our hold on the vnode and 940 * zfsctl_snapshot_inactive() will clean up. 941 */ 942 if (err != 0) { 943 VN_RELE(*vpp); 944 *vpp = NULL; 945 } 946 return (err); 947 } 948 949 /* ARGSUSED */ 950 static int 951 zfsctl_shares_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp, 952 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct, 953 int *direntflags, pathname_t *realpnp) 954 { 955 zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; 956 znode_t *dzp; 957 int error; 958 959 ZFS_ENTER(zfsvfs); 960 961 if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) { 962 ZFS_EXIT(zfsvfs); 963 return (0); 964 } 965 966 if (zfsvfs->z_shares_dir == 0) { 967 ZFS_EXIT(zfsvfs); 968 return (SET_ERROR(ENOTSUP)); 969 } 970 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { 971 error = VOP_LOOKUP(ZTOV(dzp), nm, vpp, pnp, 972 flags, rdir, cr, ct, direntflags, realpnp); 973 VN_RELE(ZTOV(dzp)); 974 } 975 976 ZFS_EXIT(zfsvfs); 977 978 return (error); 979 } 980 981 /* ARGSUSED */ 982 static int 983 zfsctl_snapdir_readdir_cb(vnode_t *vp, void *dp, int *eofp, 984 offset_t *offp, offset_t *nextp, void *data, int flags) 985 { 986 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 987 char snapname[ZFS_MAX_DATASET_NAME_LEN]; 988 uint64_t id, cookie; 989 boolean_t case_conflict; 990 int error; 991 992 ZFS_ENTER(zfsvfs); 993 994 cookie = *offp; 995 dsl_pool_config_enter(dmu_objset_pool(zfsvfs->z_os), FTAG); 996 error = dmu_snapshot_list_next(zfsvfs->z_os, 997 sizeof (snapname), snapname, &id, &cookie, &case_conflict); 998 dsl_pool_config_exit(dmu_objset_pool(zfsvfs->z_os), FTAG); 999 if (error) { 1000 ZFS_EXIT(zfsvfs); 1001 if (error == ENOENT) { 1002 *eofp = 1; 1003 return (0); 1004 } 1005 return (error); 1006 } 1007 1008 if (flags & V_RDDIR_ENTFLAGS) { 1009 edirent_t *eodp = dp; 1010 1011 (void) strcpy(eodp->ed_name, snapname); 1012 eodp->ed_ino = ZFSCTL_INO_SNAP(id); 1013 eodp->ed_eflags = case_conflict ? ED_CASE_CONFLICT : 0; 1014 } else { 1015 struct dirent64 *odp = dp; 1016 1017 (void) strcpy(odp->d_name, snapname); 1018 odp->d_ino = ZFSCTL_INO_SNAP(id); 1019 } 1020 *nextp = cookie; 1021 1022 ZFS_EXIT(zfsvfs); 1023 1024 return (0); 1025 } 1026 1027 /* ARGSUSED */ 1028 static int 1029 zfsctl_shares_readdir(vnode_t *vp, uio_t *uiop, cred_t *cr, int *eofp, 1030 caller_context_t *ct, int flags) 1031 { 1032 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 1033 znode_t *dzp; 1034 int error; 1035 1036 ZFS_ENTER(zfsvfs); 1037 1038 if (zfsvfs->z_shares_dir == 0) { 1039 ZFS_EXIT(zfsvfs); 1040 return (SET_ERROR(ENOTSUP)); 1041 } 1042 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { 1043 error = VOP_READDIR(ZTOV(dzp), uiop, cr, eofp, ct, flags); 1044 VN_RELE(ZTOV(dzp)); 1045 } else { 1046 *eofp = 1; 1047 error = SET_ERROR(ENOENT); 1048 } 1049 1050 ZFS_EXIT(zfsvfs); 1051 return (error); 1052 } 1053 1054 /* 1055 * pvp is the '.zfs' directory (zfsctl_node_t). 1056 * 1057 * Creates vp, which is '.zfs/snapshot' (zfsctl_snapdir_t). 1058 * 1059 * This function is the callback to create a GFS vnode for '.zfs/snapshot' 1060 * when a lookup is performed on .zfs for "snapshot". 1061 */ 1062 vnode_t * 1063 zfsctl_mknode_snapdir(vnode_t *pvp) 1064 { 1065 vnode_t *vp; 1066 zfsctl_snapdir_t *sdp; 1067 1068 vp = gfs_dir_create(sizeof (zfsctl_snapdir_t), pvp, 1069 zfsctl_ops_snapdir, NULL, NULL, MAXNAMELEN, 1070 zfsctl_snapdir_readdir_cb, NULL); 1071 sdp = vp->v_data; 1072 sdp->sd_node.zc_id = ZFSCTL_INO_SNAPDIR; 1073 sdp->sd_node.zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime; 1074 mutex_init(&sdp->sd_lock, NULL, MUTEX_DEFAULT, NULL); 1075 avl_create(&sdp->sd_snaps, snapentry_compare, 1076 sizeof (zfs_snapentry_t), offsetof(zfs_snapentry_t, se_node)); 1077 return (vp); 1078 } 1079 1080 vnode_t * 1081 zfsctl_mknode_shares(vnode_t *pvp) 1082 { 1083 vnode_t *vp; 1084 zfsctl_node_t *sdp; 1085 1086 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp, 1087 zfsctl_ops_shares, NULL, NULL, MAXNAMELEN, 1088 NULL, NULL); 1089 sdp = vp->v_data; 1090 sdp->zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime; 1091 return (vp); 1092 1093 } 1094 1095 /* ARGSUSED */ 1096 static int 1097 zfsctl_shares_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr, 1098 caller_context_t *ct) 1099 { 1100 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 1101 znode_t *dzp; 1102 int error; 1103 1104 ZFS_ENTER(zfsvfs); 1105 if (zfsvfs->z_shares_dir == 0) { 1106 ZFS_EXIT(zfsvfs); 1107 return (SET_ERROR(ENOTSUP)); 1108 } 1109 if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { 1110 error = VOP_GETATTR(ZTOV(dzp), vap, flags, cr, ct); 1111 VN_RELE(ZTOV(dzp)); 1112 } 1113 ZFS_EXIT(zfsvfs); 1114 return (error); 1115 1116 1117 } 1118 1119 /* ARGSUSED */ 1120 static int 1121 zfsctl_snapdir_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr, 1122 caller_context_t *ct) 1123 { 1124 zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; 1125 zfsctl_snapdir_t *sdp = vp->v_data; 1126 1127 ZFS_ENTER(zfsvfs); 1128 zfsctl_common_getattr(vp, vap); 1129 vap->va_nodeid = gfs_file_inode(vp); 1130 vap->va_nlink = vap->va_size = avl_numnodes(&sdp->sd_snaps) + 2; 1131 vap->va_ctime = vap->va_mtime = dmu_objset_snap_cmtime(zfsvfs->z_os); 1132 ZFS_EXIT(zfsvfs); 1133 1134 return (0); 1135 } 1136 1137 /* ARGSUSED */ 1138 static void 1139 zfsctl_snapdir_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct) 1140 { 1141 zfsctl_snapdir_t *sdp = vp->v_data; 1142 void *private; 1143 1144 private = gfs_dir_inactive(vp); 1145 if (private != NULL) { 1146 ASSERT(avl_numnodes(&sdp->sd_snaps) == 0); 1147 mutex_destroy(&sdp->sd_lock); 1148 avl_destroy(&sdp->sd_snaps); 1149 kmem_free(private, sizeof (zfsctl_snapdir_t)); 1150 } 1151 } 1152 1153 static const fs_operation_def_t zfsctl_tops_snapdir[] = { 1154 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, 1155 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, 1156 { VOPNAME_IOCTL, { .error = fs_inval } }, 1157 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_snapdir_getattr } }, 1158 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, 1159 { VOPNAME_RENAME, { .vop_rename = zfsctl_snapdir_rename } }, 1160 { VOPNAME_RMDIR, { .vop_rmdir = zfsctl_snapdir_remove } }, 1161 { VOPNAME_MKDIR, { .vop_mkdir = zfsctl_snapdir_mkdir } }, 1162 { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } }, 1163 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_snapdir_lookup } }, 1164 { VOPNAME_SEEK, { .vop_seek = fs_seek } }, 1165 { VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapdir_inactive } }, 1166 { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } }, 1167 { NULL } 1168 }; 1169 1170 static const fs_operation_def_t zfsctl_tops_shares[] = { 1171 { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, 1172 { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, 1173 { VOPNAME_IOCTL, { .error = fs_inval } }, 1174 { VOPNAME_GETATTR, { .vop_getattr = zfsctl_shares_getattr } }, 1175 { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, 1176 { VOPNAME_READDIR, { .vop_readdir = zfsctl_shares_readdir } }, 1177 { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_shares_lookup } }, 1178 { VOPNAME_SEEK, { .vop_seek = fs_seek } }, 1179 { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } }, 1180 { VOPNAME_FID, { .vop_fid = zfsctl_shares_fid } }, 1181 { NULL } 1182 }; 1183 1184 /* 1185 * pvp is the GFS vnode '.zfs/snapshot'. 1186 * 1187 * This creates a GFS node under '.zfs/snapshot' representing each 1188 * snapshot. This newly created GFS node is what we mount snapshot 1189 * vfs_t's ontop of. 1190 */ 1191 static vnode_t * 1192 zfsctl_snapshot_mknode(vnode_t *pvp, uint64_t objset) 1193 { 1194 vnode_t *vp; 1195 zfsctl_node_t *zcp; 1196 1197 vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp, 1198 zfsctl_ops_snapshot, NULL, NULL, MAXNAMELEN, NULL, NULL); 1199 zcp = vp->v_data; 1200 zcp->zc_id = objset; 1201 1202 return (vp); 1203 } 1204 1205 static void 1206 zfsctl_snapshot_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct) 1207 { 1208 zfsctl_snapdir_t *sdp; 1209 zfs_snapentry_t *sep, *next; 1210 vnode_t *dvp; 1211 1212 VERIFY(gfs_dir_lookup(vp, "..", &dvp, cr, 0, NULL, NULL) == 0); 1213 sdp = dvp->v_data; 1214 1215 mutex_enter(&sdp->sd_lock); 1216 1217 mutex_enter(&vp->v_lock); 1218 if (vp->v_count > 1) { 1219 vp->v_count--; 1220 mutex_exit(&vp->v_lock); 1221 mutex_exit(&sdp->sd_lock); 1222 VN_RELE(dvp); 1223 return; 1224 } 1225 mutex_exit(&vp->v_lock); 1226 ASSERT(!vn_ismntpt(vp)); 1227 1228 sep = avl_first(&sdp->sd_snaps); 1229 while (sep != NULL) { 1230 next = AVL_NEXT(&sdp->sd_snaps, sep); 1231 1232 if (sep->se_root == vp) { 1233 avl_remove(&sdp->sd_snaps, sep); 1234 kmem_free(sep->se_name, strlen(sep->se_name) + 1); 1235 kmem_free(sep, sizeof (zfs_snapentry_t)); 1236 break; 1237 } 1238 sep = next; 1239 } 1240 ASSERT(sep != NULL); 1241 1242 mutex_exit(&sdp->sd_lock); 1243 VN_RELE(dvp); 1244 1245 /* 1246 * Dispose of the vnode for the snapshot mount point. 1247 * This is safe to do because once this entry has been removed 1248 * from the AVL tree, it can't be found again, so cannot become 1249 * "active". If we lookup the same name again we will end up 1250 * creating a new vnode. 1251 */ 1252 gfs_vop_inactive(vp, cr, ct); 1253 } 1254 1255 1256 /* 1257 * These VP's should never see the light of day. They should always 1258 * be covered. 1259 */ 1260 static const fs_operation_def_t zfsctl_tops_snapshot[] = { 1261 VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapshot_inactive }, 1262 NULL, NULL 1263 }; 1264 1265 int 1266 zfsctl_lookup_objset(vfs_t *vfsp, uint64_t objsetid, zfsvfs_t **zfsvfsp) 1267 { 1268 zfsvfs_t *zfsvfs = vfsp->vfs_data; 1269 vnode_t *dvp, *vp; 1270 zfsctl_snapdir_t *sdp; 1271 zfsctl_node_t *zcp; 1272 zfs_snapentry_t *sep; 1273 int error; 1274 1275 ASSERT(zfsvfs->z_ctldir != NULL); 1276 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp, 1277 NULL, 0, NULL, kcred, NULL, NULL, NULL); 1278 if (error != 0) 1279 return (error); 1280 sdp = dvp->v_data; 1281 1282 mutex_enter(&sdp->sd_lock); 1283 sep = avl_first(&sdp->sd_snaps); 1284 while (sep != NULL) { 1285 vp = sep->se_root; 1286 zcp = vp->v_data; 1287 if (zcp->zc_id == objsetid) 1288 break; 1289 1290 sep = AVL_NEXT(&sdp->sd_snaps, sep); 1291 } 1292 1293 if (sep != NULL) { 1294 VN_HOLD(vp); 1295 /* 1296 * Return the mounted root rather than the covered mount point. 1297 * Takes the GFS vnode at .zfs/snapshot/<snapshot objsetid> 1298 * and returns the ZFS vnode mounted on top of the GFS node. 1299 * This ZFS vnode is the root of the vfs for objset 'objsetid'. 1300 */ 1301 error = traverse(&vp); 1302 if (error == 0) { 1303 if (vp == sep->se_root) 1304 error = SET_ERROR(EINVAL); 1305 else 1306 *zfsvfsp = VTOZ(vp)->z_zfsvfs; 1307 } 1308 mutex_exit(&sdp->sd_lock); 1309 VN_RELE(vp); 1310 } else { 1311 error = SET_ERROR(EINVAL); 1312 mutex_exit(&sdp->sd_lock); 1313 } 1314 1315 VN_RELE(dvp); 1316 1317 return (error); 1318 } 1319 1320 /* 1321 * Unmount any snapshots for the given filesystem. This is called from 1322 * zfs_umount() - if we have a ctldir, then go through and unmount all the 1323 * snapshots. 1324 */ 1325 int 1326 zfsctl_umount_snapshots(vfs_t *vfsp, int fflags, cred_t *cr) 1327 { 1328 zfsvfs_t *zfsvfs = vfsp->vfs_data; 1329 vnode_t *dvp; 1330 zfsctl_snapdir_t *sdp; 1331 zfs_snapentry_t *sep, *next; 1332 int error; 1333 1334 ASSERT(zfsvfs->z_ctldir != NULL); 1335 error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp, 1336 NULL, 0, NULL, cr, NULL, NULL, NULL); 1337 if (error != 0) 1338 return (error); 1339 sdp = dvp->v_data; 1340 1341 mutex_enter(&sdp->sd_lock); 1342 1343 sep = avl_first(&sdp->sd_snaps); 1344 while (sep != NULL) { 1345 next = AVL_NEXT(&sdp->sd_snaps, sep); 1346 1347 /* 1348 * If this snapshot is not mounted, then it must 1349 * have just been unmounted by somebody else, and 1350 * will be cleaned up by zfsctl_snapdir_inactive(). 1351 */ 1352 if (vn_ismntpt(sep->se_root)) { 1353 avl_remove(&sdp->sd_snaps, sep); 1354 error = zfsctl_unmount_snap(sep, fflags, cr); 1355 if (error) { 1356 avl_add(&sdp->sd_snaps, sep); 1357 break; 1358 } 1359 } 1360 sep = next; 1361 } 1362 1363 mutex_exit(&sdp->sd_lock); 1364 VN_RELE(dvp); 1365 1366 return (error); 1367 } 1368