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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 */ 24 25 #include <sys/types.h> 26 #include <sys/param.h> 27 #include <sys/time.h> 28 #include <sys/systm.h> 29 #include <sys/sysmacros.h> 30 #include <sys/resource.h> 31 #include <sys/vfs.h> 32 #include <sys/vnode.h> 33 #include <sys/file.h> 34 #include <sys/kmem.h> 35 #include <sys/uio.h> 36 #include <sys/cmn_err.h> 37 #include <sys/errno.h> 38 #include <sys/stat.h> 39 #include <sys/unistd.h> 40 #include <sys/sunddi.h> 41 #include <sys/random.h> 42 #include <sys/policy.h> 43 #include <sys/kcondvar.h> 44 #include <sys/callb.h> 45 #include <sys/smp.h> 46 #include <sys/zfs_dir.h> 47 #include <sys/zfs_acl.h> 48 #include <sys/fs/zfs.h> 49 #include <sys/zap.h> 50 #include <sys/dmu.h> 51 #include <sys/atomic.h> 52 #include <sys/zfs_ctldir.h> 53 #include <sys/zfs_fuid.h> 54 #include <sys/sa.h> 55 #include <sys/zfs_sa.h> 56 #include <sys/dnlc.h> 57 #include <sys/extdirent.h> 58 59 /* 60 * zfs_match_find() is used by zfs_dirent_lock() to peform zap lookups 61 * of names after deciding which is the appropriate lookup interface. 62 */ 63 static int 64 zfs_match_find(zfsvfs_t *zfsvfs, znode_t *dzp, char *name, boolean_t exact, 65 boolean_t update, int *deflags, pathname_t *rpnp, uint64_t *zoid) 66 { 67 int error; 68 69 if (zfsvfs->z_norm) { 70 matchtype_t mt = MT_FIRST; 71 boolean_t conflict = B_FALSE; 72 size_t bufsz = 0; 73 char *buf = NULL; 74 75 if (rpnp) { 76 buf = rpnp->pn_buf; 77 bufsz = rpnp->pn_bufsize; 78 } 79 if (exact) 80 mt = MT_EXACT; 81 /* 82 * In the non-mixed case we only expect there would ever 83 * be one match, but we need to use the normalizing lookup. 84 */ 85 error = zap_lookup_norm(zfsvfs->z_os, dzp->z_id, name, 8, 1, 86 zoid, mt, buf, bufsz, &conflict); 87 if (!error && deflags) 88 *deflags = conflict ? ED_CASE_CONFLICT : 0; 89 } else { 90 error = zap_lookup(zfsvfs->z_os, dzp->z_id, name, 8, 1, zoid); 91 } 92 *zoid = ZFS_DIRENT_OBJ(*zoid); 93 94 if (error == ENOENT && update) 95 dnlc_update(ZTOV(dzp), name, DNLC_NO_VNODE); 96 97 return (error); 98 } 99 100 /* 101 * Lock a directory entry. A dirlock on <dzp, name> protects that name 102 * in dzp's directory zap object. As long as you hold a dirlock, you can 103 * assume two things: (1) dzp cannot be reaped, and (2) no other thread 104 * can change the zap entry for (i.e. link or unlink) this name. 105 * 106 * Input arguments: 107 * dzp - znode for directory 108 * name - name of entry to lock 109 * flag - ZNEW: if the entry already exists, fail with EEXIST. 110 * ZEXISTS: if the entry does not exist, fail with ENOENT. 111 * ZSHARED: allow concurrent access with other ZSHARED callers. 112 * ZXATTR: we want dzp's xattr directory 113 * ZCILOOK: On a mixed sensitivity file system, 114 * this lookup should be case-insensitive. 115 * ZCIEXACT: On a purely case-insensitive file system, 116 * this lookup should be case-sensitive. 117 * ZRENAMING: we are locking for renaming, force narrow locks 118 * ZHAVELOCK: Don't grab the z_name_lock for this call. The 119 * current thread already holds it. 120 * 121 * Output arguments: 122 * zpp - pointer to the znode for the entry (NULL if there isn't one) 123 * dlpp - pointer to the dirlock for this entry (NULL on error) 124 * direntflags - (case-insensitive lookup only) 125 * flags if multiple case-sensitive matches exist in directory 126 * realpnp - (case-insensitive lookup only) 127 * actual name matched within the directory 128 * 129 * Return value: 0 on success or errno on failure. 130 * 131 * NOTE: Always checks for, and rejects, '.' and '..'. 132 * NOTE: For case-insensitive file systems we take wide locks (see below), 133 * but return znode pointers to a single match. 134 */ 135 int 136 zfs_dirent_lock(zfs_dirlock_t **dlpp, znode_t *dzp, char *name, znode_t **zpp, 137 int flag, int *direntflags, pathname_t *realpnp) 138 { 139 zfsvfs_t *zfsvfs = dzp->z_zfsvfs; 140 zfs_dirlock_t *dl; 141 boolean_t update; 142 boolean_t exact; 143 uint64_t zoid; 144 vnode_t *vp = NULL; 145 int error = 0; 146 int cmpflags; 147 148 *zpp = NULL; 149 *dlpp = NULL; 150 151 /* 152 * Verify that we are not trying to lock '.', '..', or '.zfs' 153 */ 154 if (name[0] == '.' && 155 (name[1] == '\0' || (name[1] == '.' && name[2] == '\0')) || 156 zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) 157 return (EEXIST); 158 159 /* 160 * Case sensitivity and normalization preferences are set when 161 * the file system is created. These are stored in the 162 * zfsvfs->z_case and zfsvfs->z_norm fields. These choices 163 * affect what vnodes can be cached in the DNLC, how we 164 * perform zap lookups, and the "width" of our dirlocks. 165 * 166 * A normal dirlock locks a single name. Note that with 167 * normalization a name can be composed multiple ways, but 168 * when normalized, these names all compare equal. A wide 169 * dirlock locks multiple names. We need these when the file 170 * system is supporting mixed-mode access. It is sometimes 171 * necessary to lock all case permutations of file name at 172 * once so that simultaneous case-insensitive/case-sensitive 173 * behaves as rationally as possible. 174 */ 175 176 /* 177 * Decide if exact matches should be requested when performing 178 * a zap lookup on file systems supporting case-insensitive 179 * access. 180 */ 181 exact = 182 ((zfsvfs->z_case == ZFS_CASE_INSENSITIVE) && (flag & ZCIEXACT)) || 183 ((zfsvfs->z_case == ZFS_CASE_MIXED) && !(flag & ZCILOOK)); 184 185 /* 186 * Only look in or update the DNLC if we are looking for the 187 * name on a file system that does not require normalization 188 * or case folding. We can also look there if we happen to be 189 * on a non-normalizing, mixed sensitivity file system IF we 190 * are looking for the exact name. 191 * 192 * Maybe can add TO-UPPERed version of name to dnlc in ci-only 193 * case for performance improvement? 194 */ 195 update = !zfsvfs->z_norm || 196 ((zfsvfs->z_case == ZFS_CASE_MIXED) && 197 !(zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER) && !(flag & ZCILOOK)); 198 199 /* 200 * ZRENAMING indicates we are in a situation where we should 201 * take narrow locks regardless of the file system's 202 * preferences for normalizing and case folding. This will 203 * prevent us deadlocking trying to grab the same wide lock 204 * twice if the two names happen to be case-insensitive 205 * matches. 206 */ 207 if (flag & ZRENAMING) 208 cmpflags = 0; 209 else 210 cmpflags = zfsvfs->z_norm; 211 212 /* 213 * Wait until there are no locks on this name. 214 * 215 * Don't grab the the lock if it is already held. However, cannot 216 * have both ZSHARED and ZHAVELOCK together. 217 */ 218 ASSERT(!(flag & ZSHARED) || !(flag & ZHAVELOCK)); 219 if (!(flag & ZHAVELOCK)) 220 rw_enter(&dzp->z_name_lock, RW_READER); 221 222 mutex_enter(&dzp->z_lock); 223 for (;;) { 224 if (dzp->z_unlinked) { 225 mutex_exit(&dzp->z_lock); 226 if (!(flag & ZHAVELOCK)) 227 rw_exit(&dzp->z_name_lock); 228 return (ENOENT); 229 } 230 for (dl = dzp->z_dirlocks; dl != NULL; dl = dl->dl_next) { 231 if ((u8_strcmp(name, dl->dl_name, 0, cmpflags, 232 U8_UNICODE_LATEST, &error) == 0) || error != 0) 233 break; 234 } 235 if (error != 0) { 236 mutex_exit(&dzp->z_lock); 237 if (!(flag & ZHAVELOCK)) 238 rw_exit(&dzp->z_name_lock); 239 return (ENOENT); 240 } 241 if (dl == NULL) { 242 size_t namesize; 243 244 /* 245 * Allocate a new dirlock and add it to the list. 246 */ 247 namesize = strlen(name) + 1; 248 dl = kmem_alloc(sizeof (zfs_dirlock_t) + namesize, 249 KM_SLEEP); 250 cv_init(&dl->dl_cv, NULL, CV_DEFAULT, NULL); 251 dl->dl_name = (char *)(dl + 1); 252 bcopy(name, dl->dl_name, namesize); 253 dl->dl_sharecnt = 0; 254 dl->dl_namelock = 0; 255 dl->dl_namesize = namesize; 256 dl->dl_dzp = dzp; 257 dl->dl_next = dzp->z_dirlocks; 258 dzp->z_dirlocks = dl; 259 break; 260 } 261 if ((flag & ZSHARED) && dl->dl_sharecnt != 0) 262 break; 263 cv_wait(&dl->dl_cv, &dzp->z_lock); 264 } 265 266 /* 267 * If the z_name_lock was NOT held for this dirlock record it. 268 */ 269 if (flag & ZHAVELOCK) 270 dl->dl_namelock = 1; 271 272 if (flag & ZSHARED) 273 dl->dl_sharecnt++; 274 275 mutex_exit(&dzp->z_lock); 276 277 /* 278 * We have a dirlock on the name. (Note that it is the dirlock, 279 * not the dzp's z_lock, that protects the name in the zap object.) 280 * See if there's an object by this name; if so, put a hold on it. 281 */ 282 if (flag & ZXATTR) { 283 error = sa_lookup(dzp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), &zoid, 284 sizeof (zoid)); 285 if (error == 0) 286 error = (zoid == 0 ? ENOENT : 0); 287 } else { 288 if (update) 289 vp = dnlc_lookup(ZTOV(dzp), name); 290 if (vp == DNLC_NO_VNODE) { 291 VN_RELE(vp); 292 error = ENOENT; 293 } else if (vp) { 294 if (flag & ZNEW) { 295 zfs_dirent_unlock(dl); 296 VN_RELE(vp); 297 return (EEXIST); 298 } 299 *dlpp = dl; 300 *zpp = VTOZ(vp); 301 return (0); 302 } else { 303 error = zfs_match_find(zfsvfs, dzp, name, exact, 304 update, direntflags, realpnp, &zoid); 305 } 306 } 307 if (error) { 308 if (error != ENOENT || (flag & ZEXISTS)) { 309 zfs_dirent_unlock(dl); 310 return (error); 311 } 312 } else { 313 if (flag & ZNEW) { 314 zfs_dirent_unlock(dl); 315 return (EEXIST); 316 } 317 error = zfs_zget(zfsvfs, zoid, zpp); 318 if (error) { 319 zfs_dirent_unlock(dl); 320 return (error); 321 } 322 if (!(flag & ZXATTR) && update) 323 dnlc_update(ZTOV(dzp), name, ZTOV(*zpp)); 324 } 325 326 *dlpp = dl; 327 328 return (0); 329 } 330 331 /* 332 * Unlock this directory entry and wake anyone who was waiting for it. 333 */ 334 void 335 zfs_dirent_unlock(zfs_dirlock_t *dl) 336 { 337 znode_t *dzp = dl->dl_dzp; 338 zfs_dirlock_t **prev_dl, *cur_dl; 339 340 mutex_enter(&dzp->z_lock); 341 342 if (!dl->dl_namelock) 343 rw_exit(&dzp->z_name_lock); 344 345 if (dl->dl_sharecnt > 1) { 346 dl->dl_sharecnt--; 347 mutex_exit(&dzp->z_lock); 348 return; 349 } 350 prev_dl = &dzp->z_dirlocks; 351 while ((cur_dl = *prev_dl) != dl) 352 prev_dl = &cur_dl->dl_next; 353 *prev_dl = dl->dl_next; 354 cv_broadcast(&dl->dl_cv); 355 mutex_exit(&dzp->z_lock); 356 357 cv_destroy(&dl->dl_cv); 358 kmem_free(dl, sizeof (*dl) + dl->dl_namesize); 359 } 360 361 /* 362 * Look up an entry in a directory. 363 * 364 * NOTE: '.' and '..' are handled as special cases because 365 * no directory entries are actually stored for them. If this is 366 * the root of a filesystem, then '.zfs' is also treated as a 367 * special pseudo-directory. 368 */ 369 int 370 zfs_dirlook(znode_t *dzp, char *name, vnode_t **vpp, int flags, 371 int *deflg, pathname_t *rpnp) 372 { 373 zfs_dirlock_t *dl; 374 znode_t *zp; 375 int error = 0; 376 uint64_t parent; 377 378 if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) { 379 *vpp = ZTOV(dzp); 380 VN_HOLD(*vpp); 381 } else if (name[0] == '.' && name[1] == '.' && name[2] == 0) { 382 zfsvfs_t *zfsvfs = dzp->z_zfsvfs; 383 384 /* 385 * If we are a snapshot mounted under .zfs, return 386 * the vp for the snapshot directory. 387 */ 388 if ((error = sa_lookup(dzp->z_sa_hdl, 389 SA_ZPL_PARENT(zfsvfs), &parent, sizeof (parent))) != 0) 390 return (error); 391 if (parent == dzp->z_id && zfsvfs->z_parent != zfsvfs) { 392 error = zfsctl_root_lookup(zfsvfs->z_parent->z_ctldir, 393 "snapshot", vpp, NULL, 0, NULL, kcred, 394 NULL, NULL, NULL); 395 return (error); 396 } 397 rw_enter(&dzp->z_parent_lock, RW_READER); 398 error = zfs_zget(zfsvfs, parent, &zp); 399 if (error == 0) 400 *vpp = ZTOV(zp); 401 rw_exit(&dzp->z_parent_lock); 402 } else if (zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) { 403 *vpp = zfsctl_root(dzp); 404 } else { 405 int zf; 406 407 zf = ZEXISTS | ZSHARED; 408 if (flags & FIGNORECASE) 409 zf |= ZCILOOK; 410 411 error = zfs_dirent_lock(&dl, dzp, name, &zp, zf, deflg, rpnp); 412 if (error == 0) { 413 *vpp = ZTOV(zp); 414 zfs_dirent_unlock(dl); 415 dzp->z_zn_prefetch = B_TRUE; /* enable prefetching */ 416 } 417 rpnp = NULL; 418 } 419 420 if ((flags & FIGNORECASE) && rpnp && !error) 421 (void) strlcpy(rpnp->pn_buf, name, rpnp->pn_bufsize); 422 423 return (error); 424 } 425 426 /* 427 * unlinked Set (formerly known as the "delete queue") Error Handling 428 * 429 * When dealing with the unlinked set, we dmu_tx_hold_zap(), but we 430 * don't specify the name of the entry that we will be manipulating. We 431 * also fib and say that we won't be adding any new entries to the 432 * unlinked set, even though we might (this is to lower the minimum file 433 * size that can be deleted in a full filesystem). So on the small 434 * chance that the nlink list is using a fat zap (ie. has more than 435 * 2000 entries), we *may* not pre-read a block that's needed. 436 * Therefore it is remotely possible for some of the assertions 437 * regarding the unlinked set below to fail due to i/o error. On a 438 * nondebug system, this will result in the space being leaked. 439 */ 440 void 441 zfs_unlinked_add(znode_t *zp, dmu_tx_t *tx) 442 { 443 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 444 445 ASSERT(zp->z_unlinked); 446 ASSERT(zp->z_links == 0); 447 448 VERIFY3U(0, ==, 449 zap_add_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx)); 450 } 451 452 /* 453 * Clean up any znodes that had no links when we either crashed or 454 * (force) umounted the file system. 455 */ 456 void 457 zfs_unlinked_drain(zfsvfs_t *zfsvfs) 458 { 459 zap_cursor_t zc; 460 zap_attribute_t zap; 461 dmu_object_info_t doi; 462 znode_t *zp; 463 int error; 464 465 /* 466 * Interate over the contents of the unlinked set. 467 */ 468 for (zap_cursor_init(&zc, zfsvfs->z_os, zfsvfs->z_unlinkedobj); 469 zap_cursor_retrieve(&zc, &zap) == 0; 470 zap_cursor_advance(&zc)) { 471 472 /* 473 * See what kind of object we have in list 474 */ 475 476 error = dmu_object_info(zfsvfs->z_os, 477 zap.za_first_integer, &doi); 478 if (error != 0) 479 continue; 480 481 ASSERT((doi.doi_type == DMU_OT_PLAIN_FILE_CONTENTS) || 482 (doi.doi_type == DMU_OT_DIRECTORY_CONTENTS)); 483 /* 484 * We need to re-mark these list entries for deletion, 485 * so we pull them back into core and set zp->z_unlinked. 486 */ 487 error = zfs_zget(zfsvfs, zap.za_first_integer, &zp); 488 489 /* 490 * We may pick up znodes that are already marked for deletion. 491 * This could happen during the purge of an extended attribute 492 * directory. All we need to do is skip over them, since they 493 * are already in the system marked z_unlinked. 494 */ 495 if (error != 0) 496 continue; 497 498 zp->z_unlinked = B_TRUE; 499 VN_RELE(ZTOV(zp)); 500 } 501 zap_cursor_fini(&zc); 502 } 503 504 /* 505 * Delete the entire contents of a directory. Return a count 506 * of the number of entries that could not be deleted. If we encounter 507 * an error, return a count of at least one so that the directory stays 508 * in the unlinked set. 509 * 510 * NOTE: this function assumes that the directory is inactive, 511 * so there is no need to lock its entries before deletion. 512 * Also, it assumes the directory contents is *only* regular 513 * files. 514 */ 515 static int 516 zfs_purgedir(znode_t *dzp) 517 { 518 zap_cursor_t zc; 519 zap_attribute_t zap; 520 znode_t *xzp; 521 dmu_tx_t *tx; 522 zfsvfs_t *zfsvfs = dzp->z_zfsvfs; 523 zfs_dirlock_t dl; 524 int skipped = 0; 525 int error; 526 527 for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id); 528 (error = zap_cursor_retrieve(&zc, &zap)) == 0; 529 zap_cursor_advance(&zc)) { 530 error = zfs_zget(zfsvfs, 531 ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp); 532 if (error) { 533 skipped += 1; 534 continue; 535 } 536 537 ASSERT((ZTOV(xzp)->v_type == VREG) || 538 (ZTOV(xzp)->v_type == VLNK)); 539 540 tx = dmu_tx_create(zfsvfs->z_os); 541 dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE); 542 dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name); 543 dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE); 544 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL); 545 /* Is this really needed ? */ 546 zfs_sa_upgrade_txholds(tx, xzp); 547 error = dmu_tx_assign(tx, TXG_WAIT); 548 if (error) { 549 dmu_tx_abort(tx); 550 VN_RELE(ZTOV(xzp)); 551 skipped += 1; 552 continue; 553 } 554 bzero(&dl, sizeof (dl)); 555 dl.dl_dzp = dzp; 556 dl.dl_name = zap.za_name; 557 558 error = zfs_link_destroy(&dl, xzp, tx, 0, NULL); 559 if (error) 560 skipped += 1; 561 dmu_tx_commit(tx); 562 563 VN_RELE(ZTOV(xzp)); 564 } 565 zap_cursor_fini(&zc); 566 if (error != ENOENT) 567 skipped += 1; 568 return (skipped); 569 } 570 571 void 572 zfs_rmnode(znode_t *zp) 573 { 574 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 575 objset_t *os = zfsvfs->z_os; 576 znode_t *xzp = NULL; 577 dmu_tx_t *tx; 578 uint64_t acl_obj; 579 uint64_t xattr_obj; 580 int error; 581 582 ASSERT(zp->z_links == 0); 583 584 /* 585 * If this is an attribute directory, purge its contents. 586 */ 587 if (ZTOV(zp) != NULL && ZTOV(zp)->v_type == VDIR && 588 (zp->z_pflags & ZFS_XATTR)) { 589 if (zfs_purgedir(zp) != 0) { 590 /* 591 * Not enough space to delete some xattrs. 592 * Leave it in the unlinked set. 593 */ 594 zfs_znode_dmu_fini(zp); 595 zfs_znode_free(zp); 596 return; 597 } 598 } 599 600 /* 601 * Free up all the data in the file. 602 */ 603 error = dmu_free_long_range(os, zp->z_id, 0, DMU_OBJECT_END); 604 if (error) { 605 /* 606 * Not enough space. Leave the file in the unlinked set. 607 */ 608 zfs_znode_dmu_fini(zp); 609 zfs_znode_free(zp); 610 return; 611 } 612 613 /* 614 * If the file has extended attributes, we're going to unlink 615 * the xattr dir. 616 */ 617 error = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), 618 &xattr_obj, sizeof (xattr_obj)); 619 if (error == 0 && xattr_obj) { 620 error = zfs_zget(zfsvfs, xattr_obj, &xzp); 621 ASSERT(error == 0); 622 } 623 624 acl_obj = zfs_external_acl(zp); 625 626 /* 627 * Set up the final transaction. 628 */ 629 tx = dmu_tx_create(os); 630 dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END); 631 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL); 632 if (xzp) { 633 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, TRUE, NULL); 634 dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE); 635 } 636 if (acl_obj) 637 dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END); 638 639 zfs_sa_upgrade_txholds(tx, zp); 640 error = dmu_tx_assign(tx, TXG_WAIT); 641 if (error) { 642 /* 643 * Not enough space to delete the file. Leave it in the 644 * unlinked set, leaking it until the fs is remounted (at 645 * which point we'll call zfs_unlinked_drain() to process it). 646 */ 647 dmu_tx_abort(tx); 648 zfs_znode_dmu_fini(zp); 649 zfs_znode_free(zp); 650 goto out; 651 } 652 653 if (xzp) { 654 ASSERT(error == 0); 655 mutex_enter(&xzp->z_lock); 656 xzp->z_unlinked = B_TRUE; /* mark xzp for deletion */ 657 xzp->z_links = 0; /* no more links to it */ 658 VERIFY(0 == sa_update(xzp->z_sa_hdl, SA_ZPL_LINKS(zfsvfs), 659 &xzp->z_links, sizeof (xzp->z_links), tx)); 660 mutex_exit(&xzp->z_lock); 661 zfs_unlinked_add(xzp, tx); 662 } 663 664 /* Remove this znode from the unlinked set */ 665 VERIFY3U(0, ==, 666 zap_remove_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx)); 667 668 zfs_znode_delete(zp, tx); 669 670 dmu_tx_commit(tx); 671 out: 672 if (xzp) 673 VN_RELE(ZTOV(xzp)); 674 } 675 676 static uint64_t 677 zfs_dirent(znode_t *zp, uint64_t mode) 678 { 679 uint64_t de = zp->z_id; 680 681 if (zp->z_zfsvfs->z_version >= ZPL_VERSION_DIRENT_TYPE) 682 de |= IFTODT(mode) << 60; 683 return (de); 684 } 685 686 /* 687 * Link zp into dl. Can only fail if zp has been unlinked. 688 */ 689 int 690 zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag) 691 { 692 znode_t *dzp = dl->dl_dzp; 693 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 694 vnode_t *vp = ZTOV(zp); 695 uint64_t value; 696 int zp_is_dir = (vp->v_type == VDIR); 697 sa_bulk_attr_t bulk[5]; 698 uint64_t mtime[2], ctime[2]; 699 int count = 0; 700 int error; 701 702 mutex_enter(&zp->z_lock); 703 704 if (!(flag & ZRENAMING)) { 705 if (zp->z_unlinked) { /* no new links to unlinked zp */ 706 ASSERT(!(flag & (ZNEW | ZEXISTS))); 707 mutex_exit(&zp->z_lock); 708 return (ENOENT); 709 } 710 zp->z_links++; 711 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL, 712 &zp->z_links, sizeof (zp->z_links)); 713 714 } 715 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_PARENT(zfsvfs), NULL, 716 &dzp->z_id, sizeof (dzp->z_id)); 717 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL, 718 &zp->z_pflags, sizeof (zp->z_pflags)); 719 720 if (!(flag & ZNEW)) { 721 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL, 722 ctime, sizeof (ctime)); 723 zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime, 724 ctime, B_TRUE); 725 } 726 error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx); 727 ASSERT(error == 0); 728 729 mutex_exit(&zp->z_lock); 730 731 mutex_enter(&dzp->z_lock); 732 dzp->z_size++; 733 dzp->z_links += zp_is_dir; 734 count = 0; 735 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs), NULL, 736 &dzp->z_size, sizeof (dzp->z_size)); 737 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL, 738 &dzp->z_links, sizeof (dzp->z_links)); 739 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL, 740 mtime, sizeof (mtime)); 741 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL, 742 ctime, sizeof (ctime)); 743 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL, 744 &dzp->z_pflags, sizeof (dzp->z_pflags)); 745 zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime, B_TRUE); 746 error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx); 747 ASSERT(error == 0); 748 mutex_exit(&dzp->z_lock); 749 750 value = zfs_dirent(zp, zp->z_mode); 751 error = zap_add(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name, 752 8, 1, &value, tx); 753 ASSERT(error == 0); 754 755 dnlc_update(ZTOV(dzp), dl->dl_name, vp); 756 757 return (0); 758 } 759 760 static int 761 zfs_dropname(zfs_dirlock_t *dl, znode_t *zp, znode_t *dzp, dmu_tx_t *tx, 762 int flag) 763 { 764 int error; 765 766 if (zp->z_zfsvfs->z_norm) { 767 if (((zp->z_zfsvfs->z_case == ZFS_CASE_INSENSITIVE) && 768 (flag & ZCIEXACT)) || 769 ((zp->z_zfsvfs->z_case == ZFS_CASE_MIXED) && 770 !(flag & ZCILOOK))) 771 error = zap_remove_norm(zp->z_zfsvfs->z_os, 772 dzp->z_id, dl->dl_name, MT_EXACT, tx); 773 else 774 error = zap_remove_norm(zp->z_zfsvfs->z_os, 775 dzp->z_id, dl->dl_name, MT_FIRST, tx); 776 } else { 777 error = zap_remove(zp->z_zfsvfs->z_os, 778 dzp->z_id, dl->dl_name, tx); 779 } 780 781 return (error); 782 } 783 784 /* 785 * Unlink zp from dl, and mark zp for deletion if this was the last link. 786 * Can fail if zp is a mount point (EBUSY) or a non-empty directory (EEXIST). 787 * If 'unlinkedp' is NULL, we put unlinked znodes on the unlinked list. 788 * If it's non-NULL, we use it to indicate whether the znode needs deletion, 789 * and it's the caller's job to do it. 790 */ 791 int 792 zfs_link_destroy(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag, 793 boolean_t *unlinkedp) 794 { 795 znode_t *dzp = dl->dl_dzp; 796 zfsvfs_t *zfsvfs = dzp->z_zfsvfs; 797 vnode_t *vp = ZTOV(zp); 798 int zp_is_dir = (vp->v_type == VDIR); 799 boolean_t unlinked = B_FALSE; 800 sa_bulk_attr_t bulk[5]; 801 uint64_t mtime[2], ctime[2]; 802 int count = 0; 803 int error; 804 805 dnlc_remove(ZTOV(dzp), dl->dl_name); 806 807 if (!(flag & ZRENAMING)) { 808 if (vn_vfswlock(vp)) /* prevent new mounts on zp */ 809 return (EBUSY); 810 811 if (vn_ismntpt(vp)) { /* don't remove mount point */ 812 vn_vfsunlock(vp); 813 return (EBUSY); 814 } 815 816 mutex_enter(&zp->z_lock); 817 818 if (zp_is_dir && !zfs_dirempty(zp)) { 819 mutex_exit(&zp->z_lock); 820 vn_vfsunlock(vp); 821 return (ENOTEMPTY); 822 } 823 824 /* 825 * If we get here, we are going to try to remove the object. 826 * First try removing the name from the directory; if that 827 * fails, return the error. 828 */ 829 error = zfs_dropname(dl, zp, dzp, tx, flag); 830 if (error != 0) { 831 mutex_exit(&zp->z_lock); 832 vn_vfsunlock(vp); 833 return (error); 834 } 835 836 if (zp->z_links <= zp_is_dir) { 837 zfs_panic_recover("zfs: link count on vnode %p is %u, " 838 "should be at least %u", zp->z_vnode, 839 (int)zp->z_links, 840 zp_is_dir + 1); 841 zp->z_links = zp_is_dir + 1; 842 } 843 if (--zp->z_links == zp_is_dir) { 844 zp->z_unlinked = B_TRUE; 845 zp->z_links = 0; 846 unlinked = B_TRUE; 847 } else { 848 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), 849 NULL, &ctime, sizeof (ctime)); 850 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), 851 NULL, &zp->z_pflags, sizeof (zp->z_pflags)); 852 zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime, ctime, 853 B_TRUE); 854 } 855 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), 856 NULL, &zp->z_links, sizeof (zp->z_links)); 857 error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx); 858 count = 0; 859 ASSERT(error == 0); 860 mutex_exit(&zp->z_lock); 861 vn_vfsunlock(vp); 862 } else { 863 error = zfs_dropname(dl, zp, dzp, tx, flag); 864 if (error != 0) 865 return (error); 866 } 867 868 mutex_enter(&dzp->z_lock); 869 dzp->z_size--; /* one dirent removed */ 870 dzp->z_links -= zp_is_dir; /* ".." link from zp */ 871 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), 872 NULL, &dzp->z_links, sizeof (dzp->z_links)); 873 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs), 874 NULL, &dzp->z_size, sizeof (dzp->z_size)); 875 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), 876 NULL, ctime, sizeof (ctime)); 877 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), 878 NULL, mtime, sizeof (mtime)); 879 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), 880 NULL, &dzp->z_pflags, sizeof (dzp->z_pflags)); 881 zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime, B_TRUE); 882 error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx); 883 ASSERT(error == 0); 884 mutex_exit(&dzp->z_lock); 885 886 if (unlinkedp != NULL) 887 *unlinkedp = unlinked; 888 else if (unlinked) 889 zfs_unlinked_add(zp, tx); 890 891 return (0); 892 } 893 894 /* 895 * Indicate whether the directory is empty. Works with or without z_lock 896 * held, but can only be consider a hint in the latter case. Returns true 897 * if only "." and ".." remain and there's no work in progress. 898 */ 899 boolean_t 900 zfs_dirempty(znode_t *dzp) 901 { 902 return (dzp->z_size == 2 && dzp->z_dirlocks == 0); 903 } 904 905 int 906 zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr) 907 { 908 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 909 znode_t *xzp; 910 dmu_tx_t *tx; 911 int error; 912 zfs_acl_ids_t acl_ids; 913 boolean_t fuid_dirtied; 914 uint64_t parent; 915 916 *xvpp = NULL; 917 918 /* 919 * In FreeBSD, access checking for creating an EA is being done 920 * in zfs_setextattr(), 921 */ 922 #ifndef __FreeBSD__ 923 if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, 0, B_FALSE, cr)) 924 return (error); 925 #endif 926 927 if ((error = zfs_acl_ids_create(zp, IS_XATTR, vap, cr, NULL, 928 &acl_ids)) != 0) 929 return (error); 930 if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) { 931 zfs_acl_ids_free(&acl_ids); 932 return (EDQUOT); 933 } 934 935 top: 936 tx = dmu_tx_create(zfsvfs->z_os); 937 dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes + 938 ZFS_SA_BASE_ATTR_SIZE); 939 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE); 940 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL); 941 fuid_dirtied = zfsvfs->z_fuid_dirty; 942 if (fuid_dirtied) 943 zfs_fuid_txhold(zfsvfs, tx); 944 error = dmu_tx_assign(tx, TXG_NOWAIT); 945 if (error) { 946 if (error == ERESTART) { 947 dmu_tx_wait(tx); 948 dmu_tx_abort(tx); 949 goto top; 950 } 951 zfs_acl_ids_free(&acl_ids); 952 dmu_tx_abort(tx); 953 return (error); 954 } 955 zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, &acl_ids); 956 957 if (fuid_dirtied) 958 zfs_fuid_sync(zfsvfs, tx); 959 960 #ifdef DEBUG 961 error = sa_lookup(xzp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs), 962 &parent, sizeof (parent)); 963 ASSERT(error == 0 && parent == zp->z_id); 964 #endif 965 966 VERIFY(0 == sa_update(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), &xzp->z_id, 967 sizeof (xzp->z_id), tx)); 968 969 (void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp, 970 xzp, "", NULL, acl_ids.z_fuidp, vap); 971 972 zfs_acl_ids_free(&acl_ids); 973 dmu_tx_commit(tx); 974 975 *xvpp = ZTOV(xzp); 976 977 return (0); 978 } 979 980 /* 981 * Return a znode for the extended attribute directory for zp. 982 * ** If the directory does not already exist, it is created ** 983 * 984 * IN: zp - znode to obtain attribute directory from 985 * cr - credentials of caller 986 * flags - flags from the VOP_LOOKUP call 987 * 988 * OUT: xzpp - pointer to extended attribute znode 989 * 990 * RETURN: 0 on success 991 * error number on failure 992 */ 993 int 994 zfs_get_xattrdir(znode_t *zp, vnode_t **xvpp, cred_t *cr, int flags) 995 { 996 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 997 znode_t *xzp; 998 zfs_dirlock_t *dl; 999 vattr_t va; 1000 int error; 1001 top: 1002 error = zfs_dirent_lock(&dl, zp, "", &xzp, ZXATTR, NULL, NULL); 1003 if (error) 1004 return (error); 1005 1006 if (xzp != NULL) { 1007 *xvpp = ZTOV(xzp); 1008 zfs_dirent_unlock(dl); 1009 return (0); 1010 } 1011 1012 1013 if (!(flags & CREATE_XATTR_DIR)) { 1014 zfs_dirent_unlock(dl); 1015 #ifdef __FreeBSD__ 1016 return (ENOATTR); 1017 #else 1018 return (ENOENT); 1019 #endif 1020 } 1021 1022 if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) { 1023 zfs_dirent_unlock(dl); 1024 return (EROFS); 1025 } 1026 1027 /* 1028 * The ability to 'create' files in an attribute 1029 * directory comes from the write_xattr permission on the base file. 1030 * 1031 * The ability to 'search' an attribute directory requires 1032 * read_xattr permission on the base file. 1033 * 1034 * Once in a directory the ability to read/write attributes 1035 * is controlled by the permissions on the attribute file. 1036 */ 1037 va.va_mask = AT_TYPE | AT_MODE | AT_UID | AT_GID; 1038 va.va_type = VDIR; 1039 va.va_mode = S_IFDIR | S_ISVTX | 0777; 1040 zfs_fuid_map_ids(zp, cr, &va.va_uid, &va.va_gid); 1041 1042 error = zfs_make_xattrdir(zp, &va, xvpp, cr); 1043 zfs_dirent_unlock(dl); 1044 1045 if (error == ERESTART) { 1046 /* NB: we already did dmu_tx_wait() if necessary */ 1047 goto top; 1048 } 1049 if (error == 0) 1050 VOP_UNLOCK(*xvpp, 0); 1051 1052 return (error); 1053 } 1054 1055 /* 1056 * Decide whether it is okay to remove within a sticky directory. 1057 * 1058 * In sticky directories, write access is not sufficient; 1059 * you can remove entries from a directory only if: 1060 * 1061 * you own the directory, 1062 * you own the entry, 1063 * the entry is a plain file and you have write access, 1064 * or you are privileged (checked in secpolicy...). 1065 * 1066 * The function returns 0 if remove access is granted. 1067 */ 1068 int 1069 zfs_sticky_remove_access(znode_t *zdp, znode_t *zp, cred_t *cr) 1070 { 1071 uid_t uid; 1072 uid_t downer; 1073 uid_t fowner; 1074 zfsvfs_t *zfsvfs = zdp->z_zfsvfs; 1075 1076 if (zdp->z_zfsvfs->z_replay) 1077 return (0); 1078 1079 if ((zdp->z_mode & S_ISVTX) == 0) 1080 return (0); 1081 1082 downer = zfs_fuid_map_id(zfsvfs, zdp->z_uid, cr, ZFS_OWNER); 1083 fowner = zfs_fuid_map_id(zfsvfs, zp->z_uid, cr, ZFS_OWNER); 1084 1085 if ((uid = crgetuid(cr)) == downer || uid == fowner || 1086 (ZTOV(zp)->v_type == VREG && 1087 zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr) == 0)) 1088 return (0); 1089 else 1090 return (secpolicy_vnode_remove(ZTOV(zp), cr)); 1091 }
Cache object: 559a585f1ce6376aa2a2b60bf64f19a8
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