Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_dir.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 2008 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #include <sys/types.h> 27 #include <sys/param.h> 28 #include <sys/time.h> 29 #include <sys/systm.h> 30 #include <sys/sysmacros.h> 31 #include <sys/resource.h> 32 #include <sys/vfs.h> 33 #include <sys/vnode.h> 34 #include <sys/file.h> 35 #include <sys/kmem.h> 36 #include <sys/uio.h> 37 #include <sys/cmn_err.h> 38 #include <sys/errno.h> 39 #include <sys/stat.h> 40 #include <sys/unistd.h> 41 #include <sys/sunddi.h> 42 #include <sys/random.h> 43 #include <sys/policy.h> 44 #include <sys/kcondvar.h> 45 #include <sys/callb.h> 46 #include <sys/smp.h> 47 #include <sys/zfs_dir.h> 48 #include <sys/zfs_acl.h> 49 #include <sys/fs/zfs.h> 50 #include <sys/zap.h> 51 #include <sys/dmu.h> 52 #include <sys/atomic.h> 53 #include <sys/zfs_ctldir.h> 54 #include <sys/zfs_fuid.h> 55 #include <sys/dnlc.h> 56 #include <sys/extdirent.h> 57 58 /* 59 * zfs_match_find() is used by zfs_dirent_lock() to peform zap lookups 60 * of names after deciding which is the appropriate lookup interface. 61 */ 62 static int 63 zfs_match_find(zfsvfs_t *zfsvfs, znode_t *dzp, char *name, boolean_t exact, 64 boolean_t update, int *deflags, pathname_t *rpnp, uint64_t *zoid) 65 { 66 int error; 67 68 if (zfsvfs->z_norm) { 69 matchtype_t mt = MT_FIRST; 70 boolean_t conflict = B_FALSE; 71 size_t bufsz = 0; 72 char *buf = NULL; 73 74 if (rpnp) { 75 buf = rpnp->pn_buf; 76 bufsz = rpnp->pn_bufsize; 77 } 78 if (exact) 79 mt = MT_EXACT; 80 /* 81 * In the non-mixed case we only expect there would ever 82 * be one match, but we need to use the normalizing lookup. 83 */ 84 error = zap_lookup_norm(zfsvfs->z_os, dzp->z_id, name, 8, 1, 85 zoid, mt, buf, bufsz, &conflict); 86 if (!error && deflags) 87 *deflags = conflict ? ED_CASE_CONFLICT : 0; 88 } else { 89 error = zap_lookup(zfsvfs->z_os, dzp->z_id, name, 8, 1, zoid); 90 } 91 *zoid = ZFS_DIRENT_OBJ(*zoid); 92 93 if (error == ENOENT && update) 94 dnlc_update(ZTOV(dzp), name, DNLC_NO_VNODE); 95 96 return (error); 97 } 98 99 /* 100 * Lock a directory entry. A dirlock on <dzp, name> protects that name 101 * in dzp's directory zap object. As long as you hold a dirlock, you can 102 * assume two things: (1) dzp cannot be reaped, and (2) no other thread 103 * can change the zap entry for (i.e. link or unlink) this name. 104 * 105 * Input arguments: 106 * dzp - znode for directory 107 * name - name of entry to lock 108 * flag - ZNEW: if the entry already exists, fail with EEXIST. 109 * ZEXISTS: if the entry does not exist, fail with ENOENT. 110 * ZSHARED: allow concurrent access with other ZSHARED callers. 111 * ZXATTR: we want dzp's xattr directory 112 * ZCILOOK: On a mixed sensitivity file system, 113 * this lookup should be case-insensitive. 114 * ZCIEXACT: On a purely case-insensitive file system, 115 * this lookup should be case-sensitive. 116 * ZRENAMING: we are locking for renaming, force narrow locks 117 * 118 * Output arguments: 119 * zpp - pointer to the znode for the entry (NULL if there isn't one) 120 * dlpp - pointer to the dirlock for this entry (NULL on error) 121 * direntflags - (case-insensitive lookup only) 122 * flags if multiple case-sensitive matches exist in directory 123 * realpnp - (case-insensitive lookup only) 124 * actual name matched within the directory 125 * 126 * Return value: 0 on success or errno on failure. 127 * 128 * NOTE: Always checks for, and rejects, '.' and '..'. 129 * NOTE: For case-insensitive file systems we take wide locks (see below), 130 * but return znode pointers to a single match. 131 */ 132 int 133 zfs_dirent_lock(zfs_dirlock_t **dlpp, znode_t *dzp, char *name, znode_t **zpp, 134 int flag, int *direntflags, pathname_t *realpnp) 135 { 136 zfsvfs_t *zfsvfs = dzp->z_zfsvfs; 137 zfs_dirlock_t *dl; 138 boolean_t update; 139 boolean_t exact; 140 uint64_t zoid; 141 vnode_t *vp = NULL; 142 int error = 0; 143 int cmpflags; 144 145 *zpp = NULL; 146 *dlpp = NULL; 147 148 /* 149 * Verify that we are not trying to lock '.', '..', or '.zfs' 150 */ 151 if (name[0] == '.' && 152 (name[1] == '\0' || (name[1] == '.' && name[2] == '\0')) || 153 zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) 154 return (EEXIST); 155 156 /* 157 * Case sensitivity and normalization preferences are set when 158 * the file system is created. These are stored in the 159 * zfsvfs->z_case and zfsvfs->z_norm fields. These choices 160 * affect what vnodes can be cached in the DNLC, how we 161 * perform zap lookups, and the "width" of our dirlocks. 162 * 163 * A normal dirlock locks a single name. Note that with 164 * normalization a name can be composed multiple ways, but 165 * when normalized, these names all compare equal. A wide 166 * dirlock locks multiple names. We need these when the file 167 * system is supporting mixed-mode access. It is sometimes 168 * necessary to lock all case permutations of file name at 169 * once so that simultaneous case-insensitive/case-sensitive 170 * behaves as rationally as possible. 171 */ 172 173 /* 174 * Decide if exact matches should be requested when performing 175 * a zap lookup on file systems supporting case-insensitive 176 * access. 177 */ 178 exact = 179 ((zfsvfs->z_case == ZFS_CASE_INSENSITIVE) && (flag & ZCIEXACT)) || 180 ((zfsvfs->z_case == ZFS_CASE_MIXED) && !(flag & ZCILOOK)); 181 182 /* 183 * Only look in or update the DNLC if we are looking for the 184 * name on a file system that does not require normalization 185 * or case folding. We can also look there if we happen to be 186 * on a non-normalizing, mixed sensitivity file system IF we 187 * are looking for the exact name. 188 * 189 * Maybe can add TO-UPPERed version of name to dnlc in ci-only 190 * case for performance improvement? 191 */ 192 update = !zfsvfs->z_norm || 193 ((zfsvfs->z_case == ZFS_CASE_MIXED) && 194 !(zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER) && !(flag & ZCILOOK)); 195 196 /* 197 * ZRENAMING indicates we are in a situation where we should 198 * take narrow locks regardless of the file system's 199 * preferences for normalizing and case folding. This will 200 * prevent us deadlocking trying to grab the same wide lock 201 * twice if the two names happen to be case-insensitive 202 * matches. 203 */ 204 if (flag & ZRENAMING) 205 cmpflags = 0; 206 else 207 cmpflags = zfsvfs->z_norm; 208 209 /* 210 * Wait until there are no locks on this name. 211 */ 212 rw_enter(&dzp->z_name_lock, RW_READER); 213 mutex_enter(&dzp->z_lock); 214 for (;;) { 215 if (dzp->z_unlinked) { 216 mutex_exit(&dzp->z_lock); 217 rw_exit(&dzp->z_name_lock); 218 return (ENOENT); 219 } 220 for (dl = dzp->z_dirlocks; dl != NULL; dl = dl->dl_next) { 221 if ((u8_strcmp(name, dl->dl_name, 0, cmpflags, 222 U8_UNICODE_LATEST, &error) == 0) || error != 0) 223 break; 224 } 225 if (error != 0) { 226 mutex_exit(&dzp->z_lock); 227 rw_exit(&dzp->z_name_lock); 228 return (ENOENT); 229 } 230 if (dl == NULL) { 231 /* 232 * Allocate a new dirlock and add it to the list. 233 */ 234 dl = kmem_alloc(sizeof (zfs_dirlock_t), KM_SLEEP); 235 cv_init(&dl->dl_cv, NULL, CV_DEFAULT, NULL); 236 dl->dl_name = name; 237 dl->dl_sharecnt = 0; 238 dl->dl_namesize = 0; 239 dl->dl_dzp = dzp; 240 dl->dl_next = dzp->z_dirlocks; 241 dzp->z_dirlocks = dl; 242 break; 243 } 244 if ((flag & ZSHARED) && dl->dl_sharecnt != 0) 245 break; 246 cv_wait(&dl->dl_cv, &dzp->z_lock); 247 } 248 249 if ((flag & ZSHARED) && ++dl->dl_sharecnt > 1 && dl->dl_namesize == 0) { 250 /* 251 * We're the second shared reference to dl. Make a copy of 252 * dl_name in case the first thread goes away before we do. 253 * Note that we initialize the new name before storing its 254 * pointer into dl_name, because the first thread may load 255 * dl->dl_name at any time. He'll either see the old value, 256 * which is his, or the new shared copy; either is OK. 257 */ 258 dl->dl_namesize = strlen(dl->dl_name) + 1; 259 name = kmem_alloc(dl->dl_namesize, KM_SLEEP); 260 bcopy(dl->dl_name, name, dl->dl_namesize); 261 dl->dl_name = name; 262 } 263 264 mutex_exit(&dzp->z_lock); 265 266 /* 267 * We have a dirlock on the name. (Note that it is the dirlock, 268 * not the dzp's z_lock, that protects the name in the zap object.) 269 * See if there's an object by this name; if so, put a hold on it. 270 */ 271 if (flag & ZXATTR) { 272 zoid = dzp->z_phys->zp_xattr; 273 error = (zoid == 0 ? ENOENT : 0); 274 } else { 275 if (update) 276 vp = dnlc_lookup(ZTOV(dzp), name); 277 if (vp == DNLC_NO_VNODE) { 278 VN_RELE(vp); 279 error = ENOENT; 280 } else if (vp) { 281 if (flag & ZNEW) { 282 zfs_dirent_unlock(dl); 283 VN_RELE(vp); 284 return (EEXIST); 285 } 286 *dlpp = dl; 287 *zpp = VTOZ(vp); 288 return (0); 289 } else { 290 error = zfs_match_find(zfsvfs, dzp, name, exact, 291 update, direntflags, realpnp, &zoid); 292 } 293 } 294 if (error) { 295 if (error != ENOENT || (flag & ZEXISTS)) { 296 zfs_dirent_unlock(dl); 297 return (error); 298 } 299 } else { 300 if (flag & ZNEW) { 301 zfs_dirent_unlock(dl); 302 return (EEXIST); 303 } 304 error = zfs_zget(zfsvfs, zoid, zpp); 305 if (error) { 306 zfs_dirent_unlock(dl); 307 return (error); 308 } 309 if (!(flag & ZXATTR) && update) 310 dnlc_update(ZTOV(dzp), name, ZTOV(*zpp)); 311 } 312 313 *dlpp = dl; 314 315 return (0); 316 } 317 318 /* 319 * Unlock this directory entry and wake anyone who was waiting for it. 320 */ 321 void 322 zfs_dirent_unlock(zfs_dirlock_t *dl) 323 { 324 znode_t *dzp = dl->dl_dzp; 325 zfs_dirlock_t **prev_dl, *cur_dl; 326 327 mutex_enter(&dzp->z_lock); 328 rw_exit(&dzp->z_name_lock); 329 if (dl->dl_sharecnt > 1) { 330 dl->dl_sharecnt--; 331 mutex_exit(&dzp->z_lock); 332 return; 333 } 334 prev_dl = &dzp->z_dirlocks; 335 while ((cur_dl = *prev_dl) != dl) 336 prev_dl = &cur_dl->dl_next; 337 *prev_dl = dl->dl_next; 338 cv_broadcast(&dl->dl_cv); 339 mutex_exit(&dzp->z_lock); 340 341 if (dl->dl_namesize != 0) 342 kmem_free(dl->dl_name, dl->dl_namesize); 343 cv_destroy(&dl->dl_cv); 344 kmem_free(dl, sizeof (*dl)); 345 } 346 347 /* 348 * Look up an entry in a directory. 349 * 350 * NOTE: '.' and '..' are handled as special cases because 351 * no directory entries are actually stored for them. If this is 352 * the root of a filesystem, then '.zfs' is also treated as a 353 * special pseudo-directory. 354 */ 355 int 356 zfs_dirlook(znode_t *dzp, char *name, vnode_t **vpp, int flags, 357 int *deflg, pathname_t *rpnp) 358 { 359 zfs_dirlock_t *dl; 360 znode_t *zp; 361 int error = 0; 362 363 if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) { 364 *vpp = ZTOV(dzp); 365 VN_HOLD(*vpp); 366 } else if (name[0] == '.' && name[1] == '.' && name[2] == 0) { 367 zfsvfs_t *zfsvfs = dzp->z_zfsvfs; 368 /* 369 * If we are a snapshot mounted under .zfs, return 370 * the vp for the snapshot directory. 371 */ 372 if (dzp->z_phys->zp_parent == dzp->z_id && 373 zfsvfs->z_parent != zfsvfs) { 374 error = zfsctl_root_lookup(zfsvfs->z_parent->z_ctldir, 375 "snapshot", vpp, NULL, 0, NULL, kcred, 376 NULL, NULL, NULL); 377 return (error); 378 } 379 rw_enter(&dzp->z_parent_lock, RW_READER); 380 error = zfs_zget(zfsvfs, dzp->z_phys->zp_parent, &zp); 381 if (error == 0) 382 *vpp = ZTOV(zp); 383 rw_exit(&dzp->z_parent_lock); 384 } else if (zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) { 385 *vpp = zfsctl_root(dzp); 386 } else { 387 int zf; 388 389 zf = ZEXISTS | ZSHARED; 390 if (flags & FIGNORECASE) 391 zf |= ZCILOOK; 392 393 error = zfs_dirent_lock(&dl, dzp, name, &zp, zf, deflg, rpnp); 394 if (error == 0) { 395 *vpp = ZTOV(zp); 396 zfs_dirent_unlock(dl); 397 dzp->z_zn_prefetch = B_TRUE; /* enable prefetching */ 398 } 399 rpnp = NULL; 400 } 401 402 if ((flags & FIGNORECASE) && rpnp && !error) 403 (void) strlcpy(rpnp->pn_buf, name, rpnp->pn_bufsize); 404 405 return (error); 406 } 407 408 /* 409 * unlinked Set (formerly known as the "delete queue") Error Handling 410 * 411 * When dealing with the unlinked set, we dmu_tx_hold_zap(), but we 412 * don't specify the name of the entry that we will be manipulating. We 413 * also fib and say that we won't be adding any new entries to the 414 * unlinked set, even though we might (this is to lower the minimum file 415 * size that can be deleted in a full filesystem). So on the small 416 * chance that the nlink list is using a fat zap (ie. has more than 417 * 2000 entries), we *may* not pre-read a block that's needed. 418 * Therefore it is remotely possible for some of the assertions 419 * regarding the unlinked set below to fail due to i/o error. On a 420 * nondebug system, this will result in the space being leaked. 421 */ 422 void 423 zfs_unlinked_add(znode_t *zp, dmu_tx_t *tx) 424 { 425 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 426 427 ASSERT(zp->z_unlinked); 428 ASSERT3U(zp->z_phys->zp_links, ==, 0); 429 430 VERIFY3U(0, ==, 431 zap_add_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx)); 432 } 433 434 /* 435 * Clean up any znodes that had no links when we either crashed or 436 * (force) umounted the file system. 437 */ 438 void 439 zfs_unlinked_drain(zfsvfs_t *zfsvfs) 440 { 441 zap_cursor_t zc; 442 zap_attribute_t zap; 443 dmu_object_info_t doi; 444 znode_t *zp; 445 int error; 446 447 /* 448 * Interate over the contents of the unlinked set. 449 */ 450 for (zap_cursor_init(&zc, zfsvfs->z_os, zfsvfs->z_unlinkedobj); 451 zap_cursor_retrieve(&zc, &zap) == 0; 452 zap_cursor_advance(&zc)) { 453 454 /* 455 * See what kind of object we have in list 456 */ 457 458 error = dmu_object_info(zfsvfs->z_os, 459 zap.za_first_integer, &doi); 460 if (error != 0) 461 continue; 462 463 ASSERT((doi.doi_type == DMU_OT_PLAIN_FILE_CONTENTS) || 464 (doi.doi_type == DMU_OT_DIRECTORY_CONTENTS)); 465 /* 466 * We need to re-mark these list entries for deletion, 467 * so we pull them back into core and set zp->z_unlinked. 468 */ 469 error = zfs_zget(zfsvfs, zap.za_first_integer, &zp); 470 471 /* 472 * We may pick up znodes that are already marked for deletion. 473 * This could happen during the purge of an extended attribute 474 * directory. All we need to do is skip over them, since they 475 * are already in the system marked z_unlinked. 476 */ 477 if (error != 0) 478 continue; 479 480 zp->z_unlinked = B_TRUE; 481 VN_RELE(ZTOV(zp)); 482 } 483 zap_cursor_fini(&zc); 484 } 485 486 /* 487 * Delete the entire contents of a directory. Return a count 488 * of the number of entries that could not be deleted. If we encounter 489 * an error, return a count of at least one so that the directory stays 490 * in the unlinked set. 491 * 492 * NOTE: this function assumes that the directory is inactive, 493 * so there is no need to lock its entries before deletion. 494 * Also, it assumes the directory contents is *only* regular 495 * files. 496 */ 497 static int 498 zfs_purgedir(znode_t *dzp) 499 { 500 zap_cursor_t zc; 501 zap_attribute_t zap; 502 znode_t *xzp; 503 dmu_tx_t *tx; 504 zfsvfs_t *zfsvfs = dzp->z_zfsvfs; 505 zfs_dirlock_t dl; 506 int skipped = 0; 507 int error; 508 509 for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id); 510 (error = zap_cursor_retrieve(&zc, &zap)) == 0; 511 zap_cursor_advance(&zc)) { 512 error = zfs_zget(zfsvfs, 513 ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp); 514 if (error) { 515 skipped += 1; 516 continue; 517 } 518 519 ASSERT((ZTOV(xzp)->v_type == VREG) || 520 (ZTOV(xzp)->v_type == VLNK)); 521 522 tx = dmu_tx_create(zfsvfs->z_os); 523 dmu_tx_hold_bonus(tx, dzp->z_id); 524 dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name); 525 dmu_tx_hold_bonus(tx, xzp->z_id); 526 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL); 527 error = dmu_tx_assign(tx, TXG_WAIT); 528 if (error) { 529 dmu_tx_abort(tx); 530 VN_RELE(ZTOV(xzp)); 531 skipped += 1; 532 continue; 533 } 534 bzero(&dl, sizeof (dl)); 535 dl.dl_dzp = dzp; 536 dl.dl_name = zap.za_name; 537 538 error = zfs_link_destroy(&dl, xzp, tx, 0, NULL); 539 if (error) 540 skipped += 1; 541 dmu_tx_commit(tx); 542 543 VN_RELE(ZTOV(xzp)); 544 } 545 zap_cursor_fini(&zc); 546 if (error != ENOENT) 547 skipped += 1; 548 return (skipped); 549 } 550 551 void 552 zfs_rmnode(znode_t *zp) 553 { 554 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 555 objset_t *os = zfsvfs->z_os; 556 znode_t *xzp = NULL; 557 dmu_tx_t *tx; 558 uint64_t acl_obj; 559 int error; 560 561 ASSERT(zp->z_phys->zp_links == 0); 562 563 /* 564 * If this is a ZIL replay then leave the object in the unlinked set. 565 * Otherwise we can get a deadlock, because the delete can be 566 * quite large and span multiple tx's and txgs, but each replay 567 * creates a tx to atomically run the replay function and mark the 568 * replay record as complete. We deadlock trying to start a tx in 569 * a new txg to further the deletion but can't because the replay 570 * tx hasn't finished. 571 * 572 * We actually delete the object if we get a failure to create an 573 * object in zil_replay_log_record(), or after calling zil_replay(). 574 */ 575 if (zfsvfs->z_assign >= TXG_INITIAL) { 576 zfs_znode_dmu_fini(zp); 577 zfs_znode_free(zp); 578 return; 579 } 580 581 /* 582 * If this is an attribute directory, purge its contents. 583 */ 584 if (ZTOV(zp) != NULL && ZTOV(zp)->v_type == VDIR && 585 (zp->z_phys->zp_flags & ZFS_XATTR)) { 586 if (zfs_purgedir(zp) != 0) { 587 /* 588 * Not enough space to delete some xattrs. 589 * Leave it in the unlinked set. 590 */ 591 zfs_znode_dmu_fini(zp); 592 zfs_znode_free(zp); 593 return; 594 } 595 } 596 597 /* 598 * Free up all the data in the file. 599 */ 600 error = dmu_free_long_range(os, zp->z_id, 0, DMU_OBJECT_END); 601 if (error) { 602 /* 603 * Not enough space. Leave the file in the unlinked set. 604 */ 605 zfs_znode_dmu_fini(zp); 606 zfs_znode_free(zp); 607 return; 608 } 609 610 /* 611 * If the file has extended attributes, we're going to unlink 612 * the xattr dir. 613 */ 614 if (zp->z_phys->zp_xattr) { 615 error = zfs_zget(zfsvfs, zp->z_phys->zp_xattr, &xzp); 616 ASSERT(error == 0); 617 } 618 619 acl_obj = zp->z_phys->zp_acl.z_acl_extern_obj; 620 621 /* 622 * Set up the final transaction. 623 */ 624 tx = dmu_tx_create(os); 625 dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END); 626 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL); 627 if (xzp) { 628 dmu_tx_hold_bonus(tx, xzp->z_id); 629 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, TRUE, NULL); 630 } 631 if (acl_obj) 632 dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END); 633 error = dmu_tx_assign(tx, TXG_WAIT); 634 if (error) { 635 /* 636 * Not enough space to delete the file. Leave it in the 637 * unlinked set, leaking it until the fs is remounted (at 638 * which point we'll call zfs_unlinked_drain() to process it). 639 */ 640 dmu_tx_abort(tx); 641 zfs_znode_dmu_fini(zp); 642 zfs_znode_free(zp); 643 goto out; 644 } 645 646 if (xzp) { 647 dmu_buf_will_dirty(xzp->z_dbuf, tx); 648 mutex_enter(&xzp->z_lock); 649 xzp->z_unlinked = B_TRUE; /* mark xzp for deletion */ 650 xzp->z_phys->zp_links = 0; /* no more links to it */ 651 mutex_exit(&xzp->z_lock); 652 zfs_unlinked_add(xzp, tx); 653 } 654 655 /* Remove this znode from the unlinked set */ 656 VERIFY3U(0, ==, 657 zap_remove_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx)); 658 659 zfs_znode_delete(zp, tx); 660 661 dmu_tx_commit(tx); 662 out: 663 if (xzp) 664 VN_RELE(ZTOV(xzp)); 665 } 666 667 static uint64_t 668 zfs_dirent(znode_t *zp) 669 { 670 uint64_t de = zp->z_id; 671 if (zp->z_zfsvfs->z_version >= ZPL_VERSION_DIRENT_TYPE) 672 de |= IFTODT((zp)->z_phys->zp_mode) << 60; 673 return (de); 674 } 675 676 /* 677 * Link zp into dl. Can only fail if zp has been unlinked. 678 */ 679 int 680 zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag) 681 { 682 znode_t *dzp = dl->dl_dzp; 683 vnode_t *vp = ZTOV(zp); 684 uint64_t value; 685 int zp_is_dir = (vp->v_type == VDIR); 686 int error; 687 688 dmu_buf_will_dirty(zp->z_dbuf, tx); 689 mutex_enter(&zp->z_lock); 690 691 if (!(flag & ZRENAMING)) { 692 if (zp->z_unlinked) { /* no new links to unlinked zp */ 693 ASSERT(!(flag & (ZNEW | ZEXISTS))); 694 mutex_exit(&zp->z_lock); 695 return (ENOENT); 696 } 697 zp->z_phys->zp_links++; 698 } 699 zp->z_phys->zp_parent = dzp->z_id; /* dzp is now zp's parent */ 700 701 if (!(flag & ZNEW)) 702 zfs_time_stamper_locked(zp, STATE_CHANGED, tx); 703 mutex_exit(&zp->z_lock); 704 705 dmu_buf_will_dirty(dzp->z_dbuf, tx); 706 mutex_enter(&dzp->z_lock); 707 dzp->z_phys->zp_size++; /* one dirent added */ 708 dzp->z_phys->zp_links += zp_is_dir; /* ".." link from zp */ 709 zfs_time_stamper_locked(dzp, CONTENT_MODIFIED, tx); 710 mutex_exit(&dzp->z_lock); 711 712 value = zfs_dirent(zp); 713 error = zap_add(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name, 714 8, 1, &value, tx); 715 ASSERT(error == 0); 716 717 dnlc_update(ZTOV(dzp), dl->dl_name, vp); 718 719 return (0); 720 } 721 722 /* 723 * Unlink zp from dl, and mark zp for deletion if this was the last link. 724 * Can fail if zp is a mount point (EBUSY) or a non-empty directory (EEXIST). 725 * If 'unlinkedp' is NULL, we put unlinked znodes on the unlinked list. 726 * If it's non-NULL, we use it to indicate whether the znode needs deletion, 727 * and it's the caller's job to do it. 728 */ 729 int 730 zfs_link_destroy(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag, 731 boolean_t *unlinkedp) 732 { 733 znode_t *dzp = dl->dl_dzp; 734 vnode_t *vp = ZTOV(zp); 735 int zp_is_dir = (vp->v_type == VDIR); 736 boolean_t unlinked = B_FALSE; 737 int error; 738 739 dnlc_remove(ZTOV(dzp), dl->dl_name); 740 741 if (!(flag & ZRENAMING)) { 742 dmu_buf_will_dirty(zp->z_dbuf, tx); 743 744 if (vn_vfswlock(vp)) /* prevent new mounts on zp */ 745 return (EBUSY); 746 747 if (vn_ismntpt(vp)) { /* don't remove mount point */ 748 vn_vfsunlock(vp); 749 return (EBUSY); 750 } 751 752 mutex_enter(&zp->z_lock); 753 if (zp_is_dir && !zfs_dirempty(zp)) { /* dir not empty */ 754 mutex_exit(&zp->z_lock); 755 vn_vfsunlock(vp); 756 return (ENOTEMPTY); 757 } 758 if (zp->z_phys->zp_links <= zp_is_dir) { 759 zfs_panic_recover("zfs: link count on vnode %p is %u, " 760 "should be at least %u", zp->z_vnode, 761 (int)zp->z_phys->zp_links, 762 zp_is_dir + 1); 763 zp->z_phys->zp_links = zp_is_dir + 1; 764 } 765 if (--zp->z_phys->zp_links == zp_is_dir) { 766 zp->z_unlinked = B_TRUE; 767 zp->z_phys->zp_links = 0; 768 unlinked = B_TRUE; 769 } else { 770 zfs_time_stamper_locked(zp, STATE_CHANGED, tx); 771 } 772 mutex_exit(&zp->z_lock); 773 vn_vfsunlock(vp); 774 } 775 776 dmu_buf_will_dirty(dzp->z_dbuf, tx); 777 mutex_enter(&dzp->z_lock); 778 dzp->z_phys->zp_size--; /* one dirent removed */ 779 dzp->z_phys->zp_links -= zp_is_dir; /* ".." link from zp */ 780 zfs_time_stamper_locked(dzp, CONTENT_MODIFIED, tx); 781 mutex_exit(&dzp->z_lock); 782 783 if (zp->z_zfsvfs->z_norm) { 784 if (((zp->z_zfsvfs->z_case == ZFS_CASE_INSENSITIVE) && 785 (flag & ZCIEXACT)) || 786 ((zp->z_zfsvfs->z_case == ZFS_CASE_MIXED) && 787 !(flag & ZCILOOK))) 788 error = zap_remove_norm(zp->z_zfsvfs->z_os, 789 dzp->z_id, dl->dl_name, MT_EXACT, tx); 790 else 791 error = zap_remove_norm(zp->z_zfsvfs->z_os, 792 dzp->z_id, dl->dl_name, MT_FIRST, tx); 793 } else { 794 error = zap_remove(zp->z_zfsvfs->z_os, 795 dzp->z_id, dl->dl_name, tx); 796 } 797 ASSERT(error == 0); 798 799 if (unlinkedp != NULL) 800 *unlinkedp = unlinked; 801 else if (unlinked) 802 zfs_unlinked_add(zp, tx); 803 804 return (0); 805 } 806 807 /* 808 * Indicate whether the directory is empty. Works with or without z_lock 809 * held, but can only be consider a hint in the latter case. Returns true 810 * if only "." and ".." remain and there's no work in progress. 811 */ 812 boolean_t 813 zfs_dirempty(znode_t *dzp) 814 { 815 return (dzp->z_phys->zp_size == 2 && dzp->z_dirlocks == 0); 816 } 817 818 int 819 zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr) 820 { 821 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 822 znode_t *xzp; 823 dmu_tx_t *tx; 824 int error; 825 zfs_fuid_info_t *fuidp = NULL; 826 827 *xvpp = NULL; 828 829 /* 830 * In FreeBSD, access checking for creating an EA is being done 831 * in zfs_setextattr(), 832 */ 833 #ifndef __FreeBSD__ 834 if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, 0, B_FALSE, cr)) 835 return (error); 836 #endif 837 838 tx = dmu_tx_create(zfsvfs->z_os); 839 dmu_tx_hold_bonus(tx, zp->z_id); 840 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL); 841 if (IS_EPHEMERAL(crgetuid(cr)) || IS_EPHEMERAL(crgetgid(cr))) { 842 if (zfsvfs->z_fuid_obj == 0) { 843 dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); 844 dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, 845 FUID_SIZE_ESTIMATE(zfsvfs)); 846 dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, FALSE, NULL); 847 } else { 848 dmu_tx_hold_bonus(tx, zfsvfs->z_fuid_obj); 849 dmu_tx_hold_write(tx, zfsvfs->z_fuid_obj, 0, 850 FUID_SIZE_ESTIMATE(zfsvfs)); 851 } 852 } 853 error = dmu_tx_assign(tx, zfsvfs->z_assign); 854 if (error) { 855 if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) 856 dmu_tx_wait(tx); 857 dmu_tx_abort(tx); 858 return (error); 859 } 860 zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, 0, NULL, &fuidp); 861 ASSERT(xzp->z_phys->zp_parent == zp->z_id); 862 dmu_buf_will_dirty(zp->z_dbuf, tx); 863 zp->z_phys->zp_xattr = xzp->z_id; 864 865 (void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp, 866 xzp, "", NULL, fuidp, vap); 867 if (fuidp) 868 zfs_fuid_info_free(fuidp); 869 dmu_tx_commit(tx); 870 871 *xvpp = ZTOV(xzp); 872 873 return (0); 874 } 875 876 /* 877 * Return a znode for the extended attribute directory for zp. 878 * ** If the directory does not already exist, it is created ** 879 * 880 * IN: zp - znode to obtain attribute directory from 881 * cr - credentials of caller 882 * flags - flags from the VOP_LOOKUP call 883 * 884 * OUT: xzpp - pointer to extended attribute znode 885 * 886 * RETURN: 0 on success 887 * error number on failure 888 */ 889 int 890 zfs_get_xattrdir(znode_t *zp, vnode_t **xvpp, cred_t *cr, int flags) 891 { 892 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 893 znode_t *xzp; 894 zfs_dirlock_t *dl; 895 vattr_t va; 896 int error; 897 top: 898 error = zfs_dirent_lock(&dl, zp, "", &xzp, ZXATTR, NULL, NULL); 899 if (error) 900 return (error); 901 902 if (xzp != NULL) { 903 *xvpp = ZTOV(xzp); 904 zfs_dirent_unlock(dl); 905 return (0); 906 } 907 908 ASSERT(zp->z_phys->zp_xattr == 0); 909 910 if (!(flags & CREATE_XATTR_DIR)) { 911 zfs_dirent_unlock(dl); 912 #ifdef __FreeBSD__ 913 return (ENOATTR); 914 #else 915 return (ENOENT); 916 #endif 917 } 918 919 if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) { 920 zfs_dirent_unlock(dl); 921 return (EROFS); 922 } 923 924 /* 925 * The ability to 'create' files in an attribute 926 * directory comes from the write_xattr permission on the base file. 927 * 928 * The ability to 'search' an attribute directory requires 929 * read_xattr permission on the base file. 930 * 931 * Once in a directory the ability to read/write attributes 932 * is controlled by the permissions on the attribute file. 933 */ 934 va.va_mask = AT_TYPE | AT_MODE | AT_UID | AT_GID; 935 va.va_type = VDIR; 936 va.va_mode = S_IFDIR | S_ISVTX | 0777; 937 zfs_fuid_map_ids(zp, cr, &va.va_uid, &va.va_gid); 938 939 error = zfs_make_xattrdir(zp, &va, xvpp, cr); 940 zfs_dirent_unlock(dl); 941 942 if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { 943 /* NB: we already did dmu_tx_wait() if necessary */ 944 goto top; 945 } 946 if (error == 0) 947 VOP_UNLOCK(*xvpp, 0, curthread); 948 949 return (error); 950 } 951 952 /* 953 * Decide whether it is okay to remove within a sticky directory. 954 * 955 * In sticky directories, write access is not sufficient; 956 * you can remove entries from a directory only if: 957 * 958 * you own the directory, 959 * you own the entry, 960 * the entry is a plain file and you have write access, 961 * or you are privileged (checked in secpolicy...). 962 * 963 * The function returns 0 if remove access is granted. 964 */ 965 int 966 zfs_sticky_remove_access(znode_t *zdp, znode_t *zp, cred_t *cr) 967 { 968 uid_t uid; 969 uid_t downer; 970 uid_t fowner; 971 zfsvfs_t *zfsvfs = zdp->z_zfsvfs; 972 973 if (zdp->z_zfsvfs->z_assign >= TXG_INITIAL) /* ZIL replay */ 974 return (0); 975 976 if ((zdp->z_phys->zp_mode & S_ISVTX) == 0) 977 return (0); 978 979 downer = zfs_fuid_map_id(zfsvfs, zdp->z_phys->zp_uid, cr, ZFS_OWNER); 980 fowner = zfs_fuid_map_id(zfsvfs, zp->z_phys->zp_uid, cr, ZFS_OWNER); 981 982 if ((uid = crgetuid(cr)) == downer || uid == fowner || 983 (ZTOV(zp)->v_type == VREG && 984 zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr) == 0)) 985 return (0); 986 else 987 return (secpolicy_vnode_remove(ZTOV(zp), cr)); 988 }
Cache object: d25d588f8b3eaacfd4f243ce229772fd
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