1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 #include <sys/types.h> 29 #include <sys/param.h> 30 #include <sys/time.h> 31 #include <sys/systm.h> 32 #include <sys/sysmacros.h> 33 #include <sys/resource.h> 34 #include <sys/vfs.h> 35 #include <sys/vnode.h> 36 #include <sys/file.h> 37 #include <sys/mode.h> 38 #include <sys/kmem.h> 39 #include <sys/uio.h> 40 #include <sys/pathname.h> 41 #include <sys/cmn_err.h> 42 #include <sys/errno.h> 43 #include <sys/stat.h> 44 #include <sys/unistd.h> 45 #include <sys/random.h> 46 #include <sys/policy.h> 47 #include <sys/zfs_dir.h> 48 #include <sys/zfs_acl.h> 49 #include <sys/fs/zfs.h> 50 #include "fs/fs_subr.h" 51 #include <sys/zap.h> 52 #include <sys/dmu.h> 53 #include <sys/atomic.h> 54 #include <sys/zfs_ctldir.h> 55 #include <sys/zfs_fuid.h> 56 #include <sys/dnlc.h> 57 #include <sys/extdirent.h> 58 #include <sys/zfs_i18n.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_path; 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 (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 * 120 * Output arguments: 121 * zpp - pointer to the znode for the entry (NULL if there isn't one) 122 * dlpp - pointer to the dirlock for this entry (NULL on error) 123 * direntflags - (case-insensitive lookup only) 124 * flags if multiple case-sensitive matches exist in directory 125 * realpnp - (case-insensitive lookup only) 126 * actual name matched within the directory 127 * 128 * Return value: 0 on success or errno on failure. 129 * 130 * NOTE: Always checks for, and rejects, '.' and '..'. 131 * NOTE: For case-insensitive file systems we take wide locks (see below), 132 * but return znode pointers to a single match. 133 */ 134 int 135 zfs_dirent_lock(zfs_dirlock_t **dlpp, znode_t *dzp, char *name, znode_t **zpp, 136 int flag, int *direntflags, pathname_t *realpnp) 137 { 138 zfsvfs_t *zfsvfs = dzp->z_zfsvfs; 139 zfs_dirlock_t *dl; 140 boolean_t update; 141 boolean_t exact; 142 uint64_t zoid; 143 vnode_t *vp = NULL; 144 int error = 0; 145 int cmpflags; 146 147 *zpp = NULL; 148 *dlpp = NULL; 149 150 /* 151 * Verify that we are not trying to lock '.', '..', or '.zfs' 152 */ 153 if (name[0] == '.' && 154 (name[1] == '\0' || (name[1] == '.' && name[2] == '\0')) || 155 zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) 156 return (EEXIST); 157 158 /* 159 * Case sensitivity and normalization preferences are set when 160 * the file system is created. These are stored in the 161 * zfsvfs->z_case and zfsvfs->z_norm fields. These choices 162 * affect what vnodes can be cached in the DNLC, how we 163 * perform zap lookups, and the "width" of our dirlocks. 164 * 165 * A normal dirlock locks a single name. Note that with 166 * normalization a name can be composed multiple ways, but 167 * when normalized, these names all compare equal. A wide 168 * dirlock locks multiple names. We need these when the file 169 * system is supporting mixed-mode access. It is sometimes 170 * necessary to lock all case permutations of file name at 171 * once so that simultaneous case-insensitive/case-sensitive 172 * behaves as rationally as possible. 173 */ 174 175 /* 176 * Decide if exact matches should be requested when performing 177 * a zap lookup on file systems supporting case-insensitive 178 * access. 179 */ 180 exact = ((zfsvfs->z_case & ZFS_CI_ONLY) && (flag & ZCIEXACT)) || 181 ((zfsvfs->z_case & ZFS_CI_MIXD) && !(flag & ZCILOOK)); 182 183 /* 184 * Only look in or update the DNLC if we are looking for the 185 * name on a file system that does not require normalization 186 * or case folding. We can also look there if we happen to be 187 * on a non-normalizing, mixed sensitivity file system IF we 188 * are looking for the exact name. 189 * 190 * Maybe can add TO-UPPERed version of name to dnlc in ci-only 191 * case for performance improvement? 192 */ 193 update = !zfsvfs->z_norm || 194 ((zfsvfs->z_case & ZFS_CI_MIXD) && 195 !(zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER) && !(flag & ZCILOOK)); 196 197 /* 198 * ZRENAMING indicates we are in a situation where we should 199 * take narrow locks regardless of the file system's 200 * preferences for normalizing and case folding. This will 201 * prevent us deadlocking trying to grab the same wide lock 202 * twice if the two names happen to be case-insensitive 203 * matches. 204 */ 205 if (flag & ZRENAMING) 206 cmpflags = 0; 207 else 208 cmpflags = zfsvfs->z_norm; 209 210 /* 211 * Wait until there are no locks on this name. 212 */ 213 rw_enter(&dzp->z_name_lock, RW_READER); 214 mutex_enter(&dzp->z_lock); 215 for (;;) { 216 if (dzp->z_unlinked) { 217 mutex_exit(&dzp->z_lock); 218 rw_exit(&dzp->z_name_lock); 219 return (ENOENT); 220 } 221 for (dl = dzp->z_dirlocks; dl != NULL; dl = dl->dl_next) { 222 if ((u8_strcmp(name, dl->dl_name, 0, cmpflags, 223 U8_UNICODE_LATEST, &error) == 0) || error != 0) 224 break; 225 } 226 if (error != 0) { 227 mutex_exit(&dzp->z_lock); 228 rw_exit(&dzp->z_name_lock); 229 return (ENOENT); 230 } 231 if (dl == NULL) { 232 /* 233 * Allocate a new dirlock and add it to the list. 234 */ 235 dl = kmem_alloc(sizeof (zfs_dirlock_t), KM_SLEEP); 236 cv_init(&dl->dl_cv, NULL, CV_DEFAULT, NULL); 237 dl->dl_name = name; 238 dl->dl_sharecnt = 0; 239 dl->dl_namesize = 0; 240 dl->dl_dzp = dzp; 241 dl->dl_next = dzp->z_dirlocks; 242 dzp->z_dirlocks = dl; 243 break; 244 } 245 if ((flag & ZSHARED) && dl->dl_sharecnt != 0) 246 break; 247 cv_wait(&dl->dl_cv, &dzp->z_lock); 248 } 249 250 if ((flag & ZSHARED) && ++dl->dl_sharecnt > 1 && dl->dl_namesize == 0) { 251 /* 252 * We're the second shared reference to dl. Make a copy of 253 * dl_name in case the first thread goes away before we do. 254 * Note that we initialize the new name before storing its 255 * pointer into dl_name, because the first thread may load 256 * dl->dl_name at any time. He'll either see the old value, 257 * which is his, or the new shared copy; either is OK. 258 */ 259 dl->dl_namesize = strlen(dl->dl_name) + 1; 260 name = kmem_alloc(dl->dl_namesize, KM_SLEEP); 261 bcopy(dl->dl_name, name, dl->dl_namesize); 262 dl->dl_name = name; 263 } 264 265 mutex_exit(&dzp->z_lock); 266 267 /* 268 * We have a dirlock on the name. (Note that it is the dirlock, 269 * not the dzp's z_lock, that protects the name in the zap object.) 270 * See if there's an object by this name; if so, put a hold on it. 271 */ 272 if (flag & ZXATTR) { 273 zoid = dzp->z_phys->zp_xattr; 274 error = (zoid == 0 ? ENOENT : 0); 275 } else { 276 if (update) 277 vp = dnlc_lookup(ZTOV(dzp), name); 278 if (vp == DNLC_NO_VNODE) { 279 VN_RELE(vp); 280 error = ENOENT; 281 } else if (vp) { 282 if (flag & ZNEW) { 283 zfs_dirent_unlock(dl); 284 VN_RELE(vp); 285 return (EEXIST); 286 } 287 *dlpp = dl; 288 *zpp = VTOZ(vp); 289 return (0); 290 } else { 291 error = zfs_match_find(zfsvfs, dzp, name, exact, 292 update, direntflags, realpnp, &zoid); 293 } 294 } 295 if (error) { 296 if (error != ENOENT || (flag & ZEXISTS)) { 297 zfs_dirent_unlock(dl); 298 return (error); 299 } 300 } else { 301 if (flag & ZNEW) { 302 zfs_dirent_unlock(dl); 303 return (EEXIST); 304 } 305 error = zfs_zget(zfsvfs, zoid, zpp); 306 if (error) { 307 zfs_dirent_unlock(dl); 308 return (error); 309 } 310 if (!(flag & ZXATTR) && update) 311 dnlc_update(ZTOV(dzp), name, ZTOV(*zpp)); 312 } 313 314 *dlpp = dl; 315 316 return (0); 317 } 318 319 /* 320 * Unlock this directory entry and wake anyone who was waiting for it. 321 */ 322 void 323 zfs_dirent_unlock(zfs_dirlock_t *dl) 324 { 325 znode_t *dzp = dl->dl_dzp; 326 zfs_dirlock_t **prev_dl, *cur_dl; 327 328 mutex_enter(&dzp->z_lock); 329 rw_exit(&dzp->z_name_lock); 330 if (dl->dl_sharecnt > 1) { 331 dl->dl_sharecnt--; 332 mutex_exit(&dzp->z_lock); 333 return; 334 } 335 prev_dl = &dzp->z_dirlocks; 336 while ((cur_dl = *prev_dl) != dl) 337 prev_dl = &cur_dl->dl_next; 338 *prev_dl = dl->dl_next; 339 cv_broadcast(&dl->dl_cv); 340 mutex_exit(&dzp->z_lock); 341 342 if (dl->dl_namesize != 0) 343 kmem_free(dl->dl_name, dl->dl_namesize); 344 cv_destroy(&dl->dl_cv); 345 kmem_free(dl, sizeof (*dl)); 346 } 347 348 /* 349 * Look up an entry in a directory. 350 * 351 * NOTE: '.' and '..' are handled as special cases because 352 * no directory entries are actually stored for them. If this is 353 * the root of a filesystem, then '.zfs' is also treated as a 354 * special pseudo-directory. 355 */ 356 int 357 zfs_dirlook(znode_t *dzp, char *name, vnode_t **vpp, int flags, 358 int *deflg, pathname_t *rpnp) 359 { 360 zfs_dirlock_t *dl; 361 znode_t *zp; 362 int error = 0; 363 364 if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) { 365 *vpp = ZTOV(dzp); 366 VN_HOLD(*vpp); 367 } else if (name[0] == '.' && name[1] == '.' && name[2] == 0) { 368 zfsvfs_t *zfsvfs = dzp->z_zfsvfs; 369 /* 370 * If we are a snapshot mounted under .zfs, return 371 * the vp for the snapshot directory. 372 */ 373 if (dzp->z_phys->zp_parent == dzp->z_id && 374 zfsvfs->z_parent != zfsvfs) { 375 error = zfsctl_root_lookup(zfsvfs->z_parent->z_ctldir, 376 "snapshot", vpp, NULL, 0, NULL, kcred, 377 NULL, NULL, NULL); 378 return (error); 379 } 380 rw_enter(&dzp->z_parent_lock, RW_READER); 381 error = zfs_zget(zfsvfs, dzp->z_phys->zp_parent, &zp); 382 if (error == 0) 383 *vpp = ZTOV(zp); 384 rw_exit(&dzp->z_parent_lock); 385 } else if (zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) { 386 *vpp = zfsctl_root(dzp); 387 } else { 388 int zf; 389 390 zf = ZEXISTS | ZSHARED; 391 if (flags & FIGNORECASE) 392 zf |= ZCILOOK; 393 394 error = zfs_dirent_lock(&dl, dzp, name, &zp, zf, deflg, rpnp); 395 if (error == 0) { 396 *vpp = ZTOV(zp); 397 zfs_dirent_unlock(dl); 398 dzp->z_zn_prefetch = B_TRUE; /* enable prefetching */ 399 } 400 rpnp = NULL; 401 } 402 403 if ((flags & FIGNORECASE) && rpnp) 404 (void) strlcpy(rpnp->pn_path, name, rpnp->pn_bufsize); 405 406 return (error); 407 } 408 409 static char * 410 zfs_unlinked_hexname(char namebuf[17], uint64_t x) 411 { 412 char *name = &namebuf[16]; 413 const char digits[16] = "0123456789abcdef"; 414 415 *name = '\0'; 416 do { 417 *--name = digits[x & 0xf]; 418 x >>= 4; 419 } while (x != 0); 420 421 return (name); 422 } 423 424 /* 425 * unlinked Set (formerly known as the "delete queue") Error Handling 426 * 427 * When dealing with the unlinked set, we dmu_tx_hold_zap(), but we 428 * don't specify the name of the entry that we will be manipulating. We 429 * also fib and say that we won't be adding any new entries to the 430 * unlinked set, even though we might (this is to lower the minimum file 431 * size that can be deleted in a full filesystem). So on the small 432 * chance that the nlink list is using a fat zap (ie. has more than 433 * 2000 entries), we *may* not pre-read a block that's needed. 434 * Therefore it is remotely possible for some of the assertions 435 * regarding the unlinked set below to fail due to i/o error. On a 436 * nondebug system, this will result in the space being leaked. 437 */ 438 void 439 zfs_unlinked_add(znode_t *zp, dmu_tx_t *tx) 440 { 441 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 442 char obj_name[17]; 443 int error; 444 445 ASSERT(zp->z_unlinked); 446 ASSERT3U(zp->z_phys->zp_links, ==, 0); 447 448 error = zap_add(zfsvfs->z_os, zfsvfs->z_unlinkedobj, 449 zfs_unlinked_hexname(obj_name, zp->z_id), 8, 1, &zp->z_id, tx); 450 ASSERT3U(error, ==, 0); 451 } 452 453 /* 454 * Clean up any znodes that had no links when we either crashed or 455 * (force) umounted the file system. 456 */ 457 void 458 zfs_unlinked_drain(zfsvfs_t *zfsvfs) 459 { 460 zap_cursor_t zc; 461 zap_attribute_t zap; 462 dmu_object_info_t doi; 463 znode_t *zp; 464 int error; 465 466 /* 467 * Interate over the contents of the unlinked set. 468 */ 469 for (zap_cursor_init(&zc, zfsvfs->z_os, zfsvfs->z_unlinkedobj); 470 zap_cursor_retrieve(&zc, &zap) == 0; 471 zap_cursor_advance(&zc)) { 472 473 /* 474 * See what kind of object we have in list 475 */ 476 477 error = dmu_object_info(zfsvfs->z_os, 478 zap.za_first_integer, &doi); 479 if (error != 0) 480 continue; 481 482 ASSERT((doi.doi_type == DMU_OT_PLAIN_FILE_CONTENTS) || 483 (doi.doi_type == DMU_OT_DIRECTORY_CONTENTS)); 484 /* 485 * We need to re-mark these list entries for deletion, 486 * so we pull them back into core and set zp->z_unlinked. 487 */ 488 error = zfs_zget(zfsvfs, zap.za_first_integer, &zp); 489 490 /* 491 * We may pick up znodes that are already marked for deletion. 492 * This could happen during the purge of an extended attribute 493 * directory. All we need to do is skip over them, since they 494 * are already in the system marked z_unlinked. 495 */ 496 if (error != 0) 497 continue; 498 499 zp->z_unlinked = B_TRUE; 500 VN_RELE(ZTOV(zp)); 501 } 502 zap_cursor_fini(&zc); 503 } 504 505 /* 506 * Delete the entire contents of a directory. Return a count 507 * of the number of entries that could not be deleted. 508 * 509 * NOTE: this function assumes that the directory is inactive, 510 * so there is no need to lock its entries before deletion. 511 * Also, it assumes the directory contents is *only* regular 512 * files. 513 */ 514 static int 515 zfs_purgedir(znode_t *dzp) 516 { 517 zap_cursor_t zc; 518 zap_attribute_t zap; 519 znode_t *xzp; 520 dmu_tx_t *tx; 521 zfsvfs_t *zfsvfs = dzp->z_zfsvfs; 522 zfs_dirlock_t dl; 523 int skipped = 0; 524 int error; 525 526 for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id); 527 (error = zap_cursor_retrieve(&zc, &zap)) == 0; 528 zap_cursor_advance(&zc)) { 529 error = zfs_zget(zfsvfs, 530 ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp); 531 ASSERT3U(error, ==, 0); 532 533 ASSERT((ZTOV(xzp)->v_type == VREG) || 534 (ZTOV(xzp)->v_type == VLNK)); 535 536 tx = dmu_tx_create(zfsvfs->z_os); 537 dmu_tx_hold_bonus(tx, dzp->z_id); 538 dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name); 539 dmu_tx_hold_bonus(tx, xzp->z_id); 540 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL); 541 error = dmu_tx_assign(tx, TXG_WAIT); 542 if (error) { 543 dmu_tx_abort(tx); 544 VN_RELE(ZTOV(xzp)); 545 skipped += 1; 546 continue; 547 } 548 bzero(&dl, sizeof (dl)); 549 dl.dl_dzp = dzp; 550 dl.dl_name = zap.za_name; 551 552 error = zfs_link_destroy(&dl, xzp, tx, 0, NULL); 553 ASSERT3U(error, ==, 0); 554 dmu_tx_commit(tx); 555 556 VN_RELE(ZTOV(xzp)); 557 } 558 zap_cursor_fini(&zc); 559 ASSERT(error == ENOENT); 560 return (skipped); 561 } 562 563 void 564 zfs_rmnode(znode_t *zp) 565 { 566 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 567 objset_t *os = zfsvfs->z_os; 568 znode_t *xzp = NULL; 569 char obj_name[17]; 570 dmu_tx_t *tx; 571 uint64_t acl_obj; 572 int error; 573 574 ASSERT(ZTOV(zp)->v_count == 0); 575 ASSERT(zp->z_phys->zp_links == 0); 576 577 /* 578 * If this is an attribute directory, purge its contents. 579 */ 580 if (ZTOV(zp)->v_type == VDIR && (zp->z_phys->zp_flags & ZFS_XATTR)) { 581 if (zfs_purgedir(zp) != 0) { 582 /* 583 * Not enough space to delete some xattrs. 584 * Leave it on the unlinked set. 585 */ 586 return; 587 } 588 } 589 590 /* 591 * If the file has extended attributes, we're going to unlink 592 * the xattr dir. 593 */ 594 if (zp->z_phys->zp_xattr) { 595 error = zfs_zget(zfsvfs, zp->z_phys->zp_xattr, &xzp); 596 ASSERT(error == 0); 597 } 598 599 acl_obj = zp->z_phys->zp_acl.z_acl_extern_obj; 600 601 /* 602 * Set up the transaction. 603 */ 604 tx = dmu_tx_create(os); 605 dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END); 606 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL); 607 if (xzp) { 608 dmu_tx_hold_bonus(tx, xzp->z_id); 609 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, TRUE, NULL); 610 } 611 if (acl_obj) 612 dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END); 613 error = dmu_tx_assign(tx, TXG_WAIT); 614 if (error) { 615 /* 616 * Not enough space to delete the file. Leave it in the 617 * unlinked set, leaking it until the fs is remounted (at 618 * which point we'll call zfs_unlinked_drain() to process it). 619 */ 620 dmu_tx_abort(tx); 621 return; 622 } 623 624 if (xzp) { 625 dmu_buf_will_dirty(xzp->z_dbuf, tx); 626 mutex_enter(&xzp->z_lock); 627 xzp->z_unlinked = B_TRUE; /* mark xzp for deletion */ 628 xzp->z_phys->zp_links = 0; /* no more links to it */ 629 mutex_exit(&xzp->z_lock); 630 zfs_unlinked_add(xzp, tx); 631 } 632 633 /* Remove this znode from the unlinked set */ 634 error = zap_remove(os, zfsvfs->z_unlinkedobj, 635 zfs_unlinked_hexname(obj_name, zp->z_id), tx); 636 ASSERT3U(error, ==, 0); 637 638 zfs_znode_delete(zp, tx); 639 640 dmu_tx_commit(tx); 641 642 if (xzp) 643 VN_RELE(ZTOV(xzp)); 644 } 645 646 static uint64_t 647 zfs_dirent(znode_t *zp) 648 { 649 uint64_t de = zp->z_id; 650 if (zp->z_zfsvfs->z_version >= ZPL_VERSION_DIRENT_TYPE) 651 de |= IFTODT((zp)->z_phys->zp_mode) << 60; 652 return (de); 653 } 654 655 /* 656 * Link zp into dl. Can only fail if zp has been unlinked. 657 */ 658 int 659 zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag) 660 { 661 znode_t *dzp = dl->dl_dzp; 662 vnode_t *vp = ZTOV(zp); 663 uint64_t value; 664 int zp_is_dir = (vp->v_type == VDIR); 665 int error; 666 667 dmu_buf_will_dirty(zp->z_dbuf, tx); 668 mutex_enter(&zp->z_lock); 669 670 if (!(flag & ZRENAMING)) { 671 if (zp->z_unlinked) { /* no new links to unlinked zp */ 672 ASSERT(!(flag & (ZNEW | ZEXISTS))); 673 mutex_exit(&zp->z_lock); 674 return (ENOENT); 675 } 676 zp->z_phys->zp_links++; 677 } 678 zp->z_phys->zp_parent = dzp->z_id; /* dzp is now zp's parent */ 679 680 if (!(flag & ZNEW)) 681 zfs_time_stamper_locked(zp, STATE_CHANGED, tx); 682 mutex_exit(&zp->z_lock); 683 684 dmu_buf_will_dirty(dzp->z_dbuf, tx); 685 mutex_enter(&dzp->z_lock); 686 dzp->z_phys->zp_size++; /* one dirent added */ 687 dzp->z_phys->zp_links += zp_is_dir; /* ".." link from zp */ 688 zfs_time_stamper_locked(dzp, CONTENT_MODIFIED, tx); 689 mutex_exit(&dzp->z_lock); 690 691 value = zfs_dirent(zp); 692 error = zap_add(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name, 693 8, 1, &value, tx); 694 ASSERT(error == 0); 695 696 dnlc_update(ZTOV(dzp), dl->dl_name, vp); 697 698 return (0); 699 } 700 701 /* 702 * Unlink zp from dl, and mark zp for deletion if this was the last link. 703 * Can fail if zp is a mount point (EBUSY) or a non-empty directory (EEXIST). 704 * If 'unlinkedp' is NULL, we put unlinked znodes on the unlinked list. 705 * If it's non-NULL, we use it to indicate whether the znode needs deletion, 706 * and it's the caller's job to do it. 707 */ 708 int 709 zfs_link_destroy(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag, 710 boolean_t *unlinkedp) 711 { 712 znode_t *dzp = dl->dl_dzp; 713 vnode_t *vp = ZTOV(zp); 714 int zp_is_dir = (vp->v_type == VDIR); 715 boolean_t unlinked = B_FALSE; 716 int error; 717 718 dnlc_remove(ZTOV(dzp), dl->dl_name); 719 720 if (!(flag & ZRENAMING)) { 721 dmu_buf_will_dirty(zp->z_dbuf, tx); 722 723 if (vn_vfswlock(vp)) /* prevent new mounts on zp */ 724 return (EBUSY); 725 726 if (vn_ismntpt(vp)) { /* don't remove mount point */ 727 vn_vfsunlock(vp); 728 return (EBUSY); 729 } 730 731 mutex_enter(&zp->z_lock); 732 if (zp_is_dir && !zfs_dirempty(zp)) { /* dir not empty */ 733 mutex_exit(&zp->z_lock); 734 vn_vfsunlock(vp); 735 return (EEXIST); 736 } 737 if (zp->z_phys->zp_links <= zp_is_dir) { 738 zfs_panic_recover("zfs: link count on %s is %u, " 739 "should be at least %u", 740 zp->z_vnode->v_path ? zp->z_vnode->v_path : 741 "<unknown>", (int)zp->z_phys->zp_links, 742 zp_is_dir + 1); 743 zp->z_phys->zp_links = zp_is_dir + 1; 744 } 745 if (--zp->z_phys->zp_links == zp_is_dir) { 746 zp->z_unlinked = B_TRUE; 747 zp->z_phys->zp_links = 0; 748 unlinked = B_TRUE; 749 } else { 750 zfs_time_stamper_locked(zp, STATE_CHANGED, tx); 751 } 752 mutex_exit(&zp->z_lock); 753 vn_vfsunlock(vp); 754 } 755 756 dmu_buf_will_dirty(dzp->z_dbuf, tx); 757 mutex_enter(&dzp->z_lock); 758 dzp->z_phys->zp_size--; /* one dirent removed */ 759 dzp->z_phys->zp_links -= zp_is_dir; /* ".." link from zp */ 760 zfs_time_stamper_locked(dzp, CONTENT_MODIFIED, tx); 761 mutex_exit(&dzp->z_lock); 762 763 if (zp->z_zfsvfs->z_norm) { 764 if (((zp->z_zfsvfs->z_case & ZFS_CI_ONLY) && 765 (flag & ZCIEXACT)) || 766 ((zp->z_zfsvfs->z_case & ZFS_CI_MIXD) && 767 !(flag & ZCILOOK))) 768 error = zap_remove_norm(zp->z_zfsvfs->z_os, 769 dzp->z_id, dl->dl_name, MT_EXACT, tx); 770 else 771 error = zap_remove_norm(zp->z_zfsvfs->z_os, 772 dzp->z_id, dl->dl_name, MT_FIRST, tx); 773 } else { 774 error = zap_remove(zp->z_zfsvfs->z_os, 775 dzp->z_id, dl->dl_name, tx); 776 } 777 ASSERT(error == 0); 778 779 if (unlinkedp != NULL) 780 *unlinkedp = unlinked; 781 else if (unlinked) 782 zfs_unlinked_add(zp, tx); 783 784 return (0); 785 } 786 787 /* 788 * Indicate whether the directory is empty. Works with or without z_lock 789 * held, but can only be consider a hint in the latter case. Returns true 790 * if only "." and ".." remain and there's no work in progress. 791 */ 792 boolean_t 793 zfs_dirempty(znode_t *dzp) 794 { 795 return (dzp->z_phys->zp_size == 2 && dzp->z_dirlocks == 0); 796 } 797 798 int 799 zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr) 800 { 801 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 802 znode_t *xzp; 803 dmu_tx_t *tx; 804 uint64_t xoid; 805 int error; 806 zfs_fuid_info_t *fuidp = NULL; 807 808 *xvpp = NULL; 809 810 if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, 0, B_FALSE, cr)) 811 return (error); 812 813 tx = dmu_tx_create(zfsvfs->z_os); 814 dmu_tx_hold_bonus(tx, zp->z_id); 815 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL); 816 if (zfsvfs->z_fuid_obj == 0) { 817 dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); 818 dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, SPA_MAXBLOCKSIZE); 819 dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, FALSE, NULL); 820 } else { 821 dmu_tx_hold_bonus(tx, zfsvfs->z_fuid_obj); 822 dmu_tx_hold_write(tx, zfsvfs->z_fuid_obj, 0, SPA_MAXBLOCKSIZE); 823 } 824 error = dmu_tx_assign(tx, zfsvfs->z_assign); 825 if (error) { 826 if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) 827 dmu_tx_wait(tx); 828 dmu_tx_abort(tx); 829 return (error); 830 } 831 zfs_mknode(zp, vap, &xoid, tx, cr, IS_XATTR, &xzp, 0, NULL, &fuidp); 832 ASSERT(xzp->z_id == xoid); 833 ASSERT(xzp->z_phys->zp_parent == zp->z_id); 834 dmu_buf_will_dirty(zp->z_dbuf, tx); 835 zp->z_phys->zp_xattr = xoid; 836 837 (void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp, 838 xzp, "", NULL, fuidp, vap); 839 if (fuidp) 840 zfs_fuid_info_free(fuidp); 841 dmu_tx_commit(tx); 842 843 *xvpp = ZTOV(xzp); 844 845 return (0); 846 } 847 848 /* 849 * Return a znode for the extended attribute directory for zp. 850 * ** If the directory does not already exist, it is created ** 851 * 852 * IN: zp - znode to obtain attribute directory from 853 * cr - credentials of caller 854 * flags - flags from the VOP_LOOKUP call 855 * 856 * OUT: xzpp - pointer to extended attribute znode 857 * 858 * RETURN: 0 on success 859 * error number on failure 860 */ 861 int 862 zfs_get_xattrdir(znode_t *zp, vnode_t **xvpp, cred_t *cr, int flags) 863 { 864 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 865 znode_t *xzp; 866 zfs_dirlock_t *dl; 867 vattr_t va; 868 int error; 869 top: 870 error = zfs_dirent_lock(&dl, zp, "", &xzp, ZXATTR, NULL, NULL); 871 if (error) 872 return (error); 873 874 if (xzp != NULL) { 875 *xvpp = ZTOV(xzp); 876 zfs_dirent_unlock(dl); 877 return (0); 878 } 879 880 ASSERT(zp->z_phys->zp_xattr == 0); 881 882 if (!(flags & CREATE_XATTR_DIR)) { 883 zfs_dirent_unlock(dl); 884 return (ENOENT); 885 } 886 887 if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) { 888 zfs_dirent_unlock(dl); 889 return (EROFS); 890 } 891 892 /* 893 * The ability to 'create' files in an attribute 894 * directory comes from the write_xattr permission on the base file. 895 * 896 * The ability to 'search' an attribute directory requires 897 * read_xattr permission on the base file. 898 * 899 * Once in a directory the ability to read/write attributes 900 * is controlled by the permissions on the attribute file. 901 */ 902 va.va_mask = AT_TYPE | AT_MODE | AT_UID | AT_GID; 903 va.va_type = VDIR; 904 va.va_mode = S_IFDIR | S_ISVTX | 0777; 905 zfs_fuid_map_ids(zp, &va.va_uid, &va.va_gid); 906 907 error = zfs_make_xattrdir(zp, &va, xvpp, cr); 908 zfs_dirent_unlock(dl); 909 910 if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { 911 /* NB: we already did dmu_tx_wait() if necessary */ 912 goto top; 913 } 914 915 return (error); 916 } 917 918 /* 919 * Decide whether it is okay to remove within a sticky directory. 920 * 921 * In sticky directories, write access is not sufficient; 922 * you can remove entries from a directory only if: 923 * 924 * you own the directory, 925 * you own the entry, 926 * the entry is a plain file and you have write access, 927 * or you are privileged (checked in secpolicy...). 928 * 929 * The function returns 0 if remove access is granted. 930 */ 931 int 932 zfs_sticky_remove_access(znode_t *zdp, znode_t *zp, cred_t *cr) 933 { 934 uid_t uid; 935 uid_t downer; 936 uid_t fowner; 937 zfsvfs_t *zfsvfs = zdp->z_zfsvfs; 938 939 if (zdp->z_zfsvfs->z_assign >= TXG_INITIAL) /* ZIL replay */ 940 return (0); 941 942 if ((zdp->z_phys->zp_mode & S_ISVTX) == 0) 943 return (0); 944 945 zfs_fuid_map_id(zfsvfs, zdp->z_phys->zp_uid, ZFS_OWNER, &downer); 946 zfs_fuid_map_id(zfsvfs, zp->z_phys->zp_uid, ZFS_OWNER, &fowner); 947 948 if ((uid = crgetuid(cr)) == downer || uid == fowner || 949 (ZTOV(zp)->v_type == VREG && 950 zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr) == 0)) 951 return (0); 952 else 953 return (secpolicy_vnode_remove(cr)); 954 } 955