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