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 #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/sunddi.h> 46 #include <sys/random.h> 47 #include <sys/policy.h> 48 #include <sys/zfs_dir.h> 49 #include <sys/zfs_acl.h> 50 #include <sys/fs/zfs.h> 51 #include "fs/fs_subr.h" 52 #include <sys/zap.h> 53 #include <sys/dmu.h> 54 #include <sys/atomic.h> 55 #include <sys/zfs_ctldir.h> 56 #include <sys/zfs_fuid.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 * 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 = 181 ((zfsvfs->z_case == ZFS_CASE_INSENSITIVE) && (flag & ZCIEXACT)) || 182 ((zfsvfs->z_case == ZFS_CASE_MIXED) && !(flag & ZCILOOK)); 183 184 /* 185 * Only look in or update the DNLC if we are looking for the 186 * name on a file system that does not require normalization 187 * or case folding. We can also look there if we happen to be 188 * on a non-normalizing, mixed sensitivity file system IF we 189 * are looking for the exact name. 190 * 191 * Maybe can add TO-UPPERed version of name to dnlc in ci-only 192 * case for performance improvement? 193 */ 194 update = !zfsvfs->z_norm || 195 ((zfsvfs->z_case == ZFS_CASE_MIXED) && 196 !(zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER) && !(flag & ZCILOOK)); 197 198 /* 199 * ZRENAMING indicates we are in a situation where we should 200 * take narrow locks regardless of the file system's 201 * preferences for normalizing and case folding. This will 202 * prevent us deadlocking trying to grab the same wide lock 203 * twice if the two names happen to be case-insensitive 204 * matches. 205 */ 206 if (flag & ZRENAMING) 207 cmpflags = 0; 208 else 209 cmpflags = zfsvfs->z_norm; 210 211 /* 212 * Wait until there are no locks on this name. 213 */ 214 rw_enter(&dzp->z_name_lock, RW_READER); 215 mutex_enter(&dzp->z_lock); 216 for (;;) { 217 if (dzp->z_unlinked) { 218 mutex_exit(&dzp->z_lock); 219 rw_exit(&dzp->z_name_lock); 220 return (ENOENT); 221 } 222 for (dl = dzp->z_dirlocks; dl != NULL; dl = dl->dl_next) { 223 if ((u8_strcmp(name, dl->dl_name, 0, cmpflags, 224 U8_UNICODE_LATEST, &error) == 0) || error != 0) 225 break; 226 } 227 if (error != 0) { 228 mutex_exit(&dzp->z_lock); 229 rw_exit(&dzp->z_name_lock); 230 return (ENOENT); 231 } 232 if (dl == NULL) { 233 /* 234 * Allocate a new dirlock and add it to the list. 235 */ 236 dl = kmem_alloc(sizeof (zfs_dirlock_t), KM_SLEEP); 237 cv_init(&dl->dl_cv, NULL, CV_DEFAULT, NULL); 238 dl->dl_name = name; 239 dl->dl_sharecnt = 0; 240 dl->dl_namesize = 0; 241 dl->dl_dzp = dzp; 242 dl->dl_next = dzp->z_dirlocks; 243 dzp->z_dirlocks = dl; 244 break; 245 } 246 if ((flag & ZSHARED) && dl->dl_sharecnt != 0) 247 break; 248 cv_wait(&dl->dl_cv, &dzp->z_lock); 249 } 250 251 if ((flag & ZSHARED) && ++dl->dl_sharecnt > 1 && dl->dl_namesize == 0) { 252 /* 253 * We're the second shared reference to dl. Make a copy of 254 * dl_name in case the first thread goes away before we do. 255 * Note that we initialize the new name before storing its 256 * pointer into dl_name, because the first thread may load 257 * dl->dl_name at any time. He'll either see the old value, 258 * which is his, or the new shared copy; either is OK. 259 */ 260 dl->dl_namesize = strlen(dl->dl_name) + 1; 261 name = kmem_alloc(dl->dl_namesize, KM_SLEEP); 262 bcopy(dl->dl_name, name, dl->dl_namesize); 263 dl->dl_name = name; 264 } 265 266 mutex_exit(&dzp->z_lock); 267 268 /* 269 * We have a dirlock on the name. (Note that it is the dirlock, 270 * not the dzp's z_lock, that protects the name in the zap object.) 271 * See if there's an object by this name; if so, put a hold on it. 272 */ 273 if (flag & ZXATTR) { 274 zoid = dzp->z_phys->zp_xattr; 275 error = (zoid == 0 ? ENOENT : 0); 276 } else { 277 if (update) 278 vp = dnlc_lookup(ZTOV(dzp), name); 279 if (vp == DNLC_NO_VNODE) { 280 VN_RELE(vp); 281 error = ENOENT; 282 } else if (vp) { 283 if (flag & ZNEW) { 284 zfs_dirent_unlock(dl); 285 VN_RELE(vp); 286 return (EEXIST); 287 } 288 *dlpp = dl; 289 *zpp = VTOZ(vp); 290 return (0); 291 } else { 292 error = zfs_match_find(zfsvfs, dzp, name, exact, 293 update, direntflags, realpnp, &zoid); 294 } 295 } 296 if (error) { 297 if (error != ENOENT || (flag & ZEXISTS)) { 298 zfs_dirent_unlock(dl); 299 return (error); 300 } 301 } else { 302 if (flag & ZNEW) { 303 zfs_dirent_unlock(dl); 304 return (EEXIST); 305 } 306 error = zfs_zget(zfsvfs, zoid, zpp); 307 if (error) { 308 zfs_dirent_unlock(dl); 309 return (error); 310 } 311 if (!(flag & ZXATTR) && update) 312 dnlc_update(ZTOV(dzp), name, ZTOV(*zpp)); 313 } 314 315 *dlpp = dl; 316 317 return (0); 318 } 319 320 /* 321 * Unlock this directory entry and wake anyone who was waiting for it. 322 */ 323 void 324 zfs_dirent_unlock(zfs_dirlock_t *dl) 325 { 326 znode_t *dzp = dl->dl_dzp; 327 zfs_dirlock_t **prev_dl, *cur_dl; 328 329 mutex_enter(&dzp->z_lock); 330 rw_exit(&dzp->z_name_lock); 331 if (dl->dl_sharecnt > 1) { 332 dl->dl_sharecnt--; 333 mutex_exit(&dzp->z_lock); 334 return; 335 } 336 prev_dl = &dzp->z_dirlocks; 337 while ((cur_dl = *prev_dl) != dl) 338 prev_dl = &cur_dl->dl_next; 339 *prev_dl = dl->dl_next; 340 cv_broadcast(&dl->dl_cv); 341 mutex_exit(&dzp->z_lock); 342 343 if (dl->dl_namesize != 0) 344 kmem_free(dl->dl_name, dl->dl_namesize); 345 cv_destroy(&dl->dl_cv); 346 kmem_free(dl, sizeof (*dl)); 347 } 348 349 /* 350 * Look up an entry in a directory. 351 * 352 * NOTE: '.' and '..' are handled as special cases because 353 * no directory entries are actually stored for them. If this is 354 * the root of a filesystem, then '.zfs' is also treated as a 355 * special pseudo-directory. 356 */ 357 int 358 zfs_dirlook(znode_t *dzp, char *name, vnode_t **vpp, int flags, 359 int *deflg, pathname_t *rpnp) 360 { 361 zfs_dirlock_t *dl; 362 znode_t *zp; 363 int error = 0; 364 365 if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) { 366 *vpp = ZTOV(dzp); 367 VN_HOLD(*vpp); 368 } else if (name[0] == '.' && name[1] == '.' && name[2] == 0) { 369 zfsvfs_t *zfsvfs = dzp->z_zfsvfs; 370 /* 371 * If we are a snapshot mounted under .zfs, return 372 * the vp for the snapshot directory. 373 */ 374 if (dzp->z_phys->zp_parent == dzp->z_id && 375 zfsvfs->z_parent != zfsvfs) { 376 error = zfsctl_root_lookup(zfsvfs->z_parent->z_ctldir, 377 "snapshot", vpp, NULL, 0, NULL, kcred, 378 NULL, NULL, NULL); 379 return (error); 380 } 381 rw_enter(&dzp->z_parent_lock, RW_READER); 382 error = zfs_zget(zfsvfs, dzp->z_phys->zp_parent, &zp); 383 if (error == 0) 384 *vpp = ZTOV(zp); 385 rw_exit(&dzp->z_parent_lock); 386 } else if (zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) { 387 *vpp = zfsctl_root(dzp); 388 } else { 389 int zf; 390 391 zf = ZEXISTS | ZSHARED; 392 if (flags & FIGNORECASE) 393 zf |= ZCILOOK; 394 395 error = zfs_dirent_lock(&dl, dzp, name, &zp, zf, deflg, rpnp); 396 if (error == 0) { 397 *vpp = ZTOV(zp); 398 zfs_dirent_unlock(dl); 399 dzp->z_zn_prefetch = B_TRUE; /* enable prefetching */ 400 } 401 rpnp = NULL; 402 } 403 404 if ((flags & FIGNORECASE) && rpnp && !error) 405 (void) strlcpy(rpnp->pn_buf, name, rpnp->pn_bufsize); 406 407 return (error); 408 } 409 410 static char * 411 zfs_unlinked_hexname(char namebuf[17], uint64_t x) 412 { 413 char *name = &namebuf[16]; 414 const char digits[16] = "0123456789abcdef"; 415 416 *name = '\0'; 417 do { 418 *--name = digits[x & 0xf]; 419 x >>= 4; 420 } while (x != 0); 421 422 return (name); 423 } 424 425 /* 426 * unlinked Set (formerly known as the "delete queue") Error Handling 427 * 428 * When dealing with the unlinked set, we dmu_tx_hold_zap(), but we 429 * don't specify the name of the entry that we will be manipulating. We 430 * also fib and say that we won't be adding any new entries to the 431 * unlinked set, even though we might (this is to lower the minimum file 432 * size that can be deleted in a full filesystem). So on the small 433 * chance that the nlink list is using a fat zap (ie. has more than 434 * 2000 entries), we *may* not pre-read a block that's needed. 435 * Therefore it is remotely possible for some of the assertions 436 * regarding the unlinked set below to fail due to i/o error. On a 437 * nondebug system, this will result in the space being leaked. 438 */ 439 void 440 zfs_unlinked_add(znode_t *zp, dmu_tx_t *tx) 441 { 442 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 443 char obj_name[17]; 444 int error; 445 446 ASSERT(zp->z_unlinked); 447 ASSERT3U(zp->z_phys->zp_links, ==, 0); 448 449 error = zap_add(zfsvfs->z_os, zfsvfs->z_unlinkedobj, 450 zfs_unlinked_hexname(obj_name, zp->z_id), 8, 1, &zp->z_id, tx); 451 ASSERT3U(error, ==, 0); 452 } 453 454 /* 455 * Clean up any znodes that had no links when we either crashed or 456 * (force) umounted the file system. 457 */ 458 void 459 zfs_unlinked_drain(zfsvfs_t *zfsvfs) 460 { 461 zap_cursor_t zc; 462 zap_attribute_t zap; 463 dmu_object_info_t doi; 464 znode_t *zp; 465 int error; 466 467 /* 468 * Interate over the contents of the unlinked set. 469 */ 470 for (zap_cursor_init(&zc, zfsvfs->z_os, zfsvfs->z_unlinkedobj); 471 zap_cursor_retrieve(&zc, &zap) == 0; 472 zap_cursor_advance(&zc)) { 473 474 /* 475 * See what kind of object we have in list 476 */ 477 478 error = dmu_object_info(zfsvfs->z_os, 479 zap.za_first_integer, &doi); 480 if (error != 0) 481 continue; 482 483 ASSERT((doi.doi_type == DMU_OT_PLAIN_FILE_CONTENTS) || 484 (doi.doi_type == DMU_OT_DIRECTORY_CONTENTS)); 485 /* 486 * We need to re-mark these list entries for deletion, 487 * so we pull them back into core and set zp->z_unlinked. 488 */ 489 error = zfs_zget(zfsvfs, zap.za_first_integer, &zp); 490 491 /* 492 * We may pick up znodes that are already marked for deletion. 493 * This could happen during the purge of an extended attribute 494 * directory. All we need to do is skip over them, since they 495 * are already in the system marked z_unlinked. 496 */ 497 if (error != 0) 498 continue; 499 500 zp->z_unlinked = B_TRUE; 501 VN_RELE(ZTOV(zp)); 502 } 503 zap_cursor_fini(&zc); 504 } 505 506 /* 507 * Delete the entire contents of a directory. Return a count 508 * of the number of entries that could not be deleted. If we encounter 509 * an error, return a count of at least one so that the directory stays 510 * in the unlinked set. 511 * 512 * NOTE: this function assumes that the directory is inactive, 513 * so there is no need to lock its entries before deletion. 514 * Also, it assumes the directory contents is *only* regular 515 * files. 516 */ 517 static int 518 zfs_purgedir(znode_t *dzp) 519 { 520 zap_cursor_t zc; 521 zap_attribute_t zap; 522 znode_t *xzp; 523 dmu_tx_t *tx; 524 zfsvfs_t *zfsvfs = dzp->z_zfsvfs; 525 zfs_dirlock_t dl; 526 int skipped = 0; 527 int error; 528 529 for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id); 530 (error = zap_cursor_retrieve(&zc, &zap)) == 0; 531 zap_cursor_advance(&zc)) { 532 error = zfs_zget(zfsvfs, 533 ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp); 534 if (error) { 535 skipped += 1; 536 continue; 537 } 538 539 ASSERT((ZTOV(xzp)->v_type == VREG) || 540 (ZTOV(xzp)->v_type == VLNK)); 541 542 tx = dmu_tx_create(zfsvfs->z_os); 543 dmu_tx_hold_bonus(tx, dzp->z_id); 544 dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name); 545 dmu_tx_hold_bonus(tx, xzp->z_id); 546 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL); 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 char obj_name[17]; 578 dmu_tx_t *tx; 579 uint64_t acl_obj; 580 int error; 581 582 ASSERT(ZTOV(zp)->v_count == 0); 583 ASSERT(zp->z_phys->zp_links == 0); 584 585 /* 586 * If this is an attribute directory, purge its contents. 587 */ 588 if (ZTOV(zp)->v_type == VDIR && (zp->z_phys->zp_flags & ZFS_XATTR)) { 589 if (zfs_purgedir(zp) != 0) { 590 /* 591 * Not enough space to delete some xattrs. 592 * Leave it on the unlinked set. 593 */ 594 zfs_znode_dmu_fini(zp); 595 zfs_znode_free(zp); 596 return; 597 } 598 } 599 600 /* 601 * If the file has extended attributes, we're going to unlink 602 * the xattr dir. 603 */ 604 if (zp->z_phys->zp_xattr) { 605 error = zfs_zget(zfsvfs, zp->z_phys->zp_xattr, &xzp); 606 ASSERT(error == 0); 607 } 608 609 acl_obj = zp->z_phys->zp_acl.z_acl_extern_obj; 610 611 /* 612 * Set up the transaction. 613 */ 614 tx = dmu_tx_create(os); 615 dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END); 616 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL); 617 if (xzp) { 618 dmu_tx_hold_bonus(tx, xzp->z_id); 619 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, TRUE, NULL); 620 } 621 if (acl_obj) 622 dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END); 623 error = dmu_tx_assign(tx, TXG_WAIT); 624 if (error) { 625 /* 626 * Not enough space to delete the file. Leave it in the 627 * unlinked set, leaking it until the fs is remounted (at 628 * which point we'll call zfs_unlinked_drain() to process it). 629 */ 630 dmu_tx_abort(tx); 631 zfs_znode_dmu_fini(zp); 632 zfs_znode_free(zp); 633 goto out; 634 } 635 636 if (xzp) { 637 dmu_buf_will_dirty(xzp->z_dbuf, tx); 638 mutex_enter(&xzp->z_lock); 639 xzp->z_unlinked = B_TRUE; /* mark xzp for deletion */ 640 xzp->z_phys->zp_links = 0; /* no more links to it */ 641 mutex_exit(&xzp->z_lock); 642 zfs_unlinked_add(xzp, tx); 643 } 644 645 /* Remove this znode from the unlinked set */ 646 error = zap_remove(os, zfsvfs->z_unlinkedobj, 647 zfs_unlinked_hexname(obj_name, zp->z_id), tx); 648 ASSERT3U(error, ==, 0); 649 650 zfs_znode_delete(zp, tx); 651 652 dmu_tx_commit(tx); 653 out: 654 if (xzp) 655 VN_RELE(ZTOV(xzp)); 656 } 657 658 static uint64_t 659 zfs_dirent(znode_t *zp) 660 { 661 uint64_t de = zp->z_id; 662 if (zp->z_zfsvfs->z_version >= ZPL_VERSION_DIRENT_TYPE) 663 de |= IFTODT((zp)->z_phys->zp_mode) << 60; 664 return (de); 665 } 666 667 /* 668 * Link zp into dl. Can only fail if zp has been unlinked. 669 */ 670 int 671 zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag) 672 { 673 znode_t *dzp = dl->dl_dzp; 674 vnode_t *vp = ZTOV(zp); 675 uint64_t value; 676 int zp_is_dir = (vp->v_type == VDIR); 677 int error; 678 679 dmu_buf_will_dirty(zp->z_dbuf, tx); 680 mutex_enter(&zp->z_lock); 681 682 if (!(flag & ZRENAMING)) { 683 if (zp->z_unlinked) { /* no new links to unlinked zp */ 684 ASSERT(!(flag & (ZNEW | ZEXISTS))); 685 mutex_exit(&zp->z_lock); 686 return (ENOENT); 687 } 688 zp->z_phys->zp_links++; 689 } 690 zp->z_phys->zp_parent = dzp->z_id; /* dzp is now zp's parent */ 691 692 if (!(flag & ZNEW)) 693 zfs_time_stamper_locked(zp, STATE_CHANGED, tx); 694 mutex_exit(&zp->z_lock); 695 696 dmu_buf_will_dirty(dzp->z_dbuf, tx); 697 mutex_enter(&dzp->z_lock); 698 dzp->z_phys->zp_size++; /* one dirent added */ 699 dzp->z_phys->zp_links += zp_is_dir; /* ".." link from zp */ 700 zfs_time_stamper_locked(dzp, CONTENT_MODIFIED, tx); 701 mutex_exit(&dzp->z_lock); 702 703 value = zfs_dirent(zp); 704 error = zap_add(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name, 705 8, 1, &value, tx); 706 ASSERT(error == 0); 707 708 dnlc_update(ZTOV(dzp), dl->dl_name, vp); 709 710 return (0); 711 } 712 713 /* 714 * Unlink zp from dl, and mark zp for deletion if this was the last link. 715 * Can fail if zp is a mount point (EBUSY) or a non-empty directory (EEXIST). 716 * If 'unlinkedp' is NULL, we put unlinked znodes on the unlinked list. 717 * If it's non-NULL, we use it to indicate whether the znode needs deletion, 718 * and it's the caller's job to do it. 719 */ 720 int 721 zfs_link_destroy(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag, 722 boolean_t *unlinkedp) 723 { 724 znode_t *dzp = dl->dl_dzp; 725 vnode_t *vp = ZTOV(zp); 726 int zp_is_dir = (vp->v_type == VDIR); 727 boolean_t unlinked = B_FALSE; 728 int error; 729 730 dnlc_remove(ZTOV(dzp), dl->dl_name); 731 732 if (!(flag & ZRENAMING)) { 733 dmu_buf_will_dirty(zp->z_dbuf, tx); 734 735 if (vn_vfswlock(vp)) /* prevent new mounts on zp */ 736 return (EBUSY); 737 738 if (vn_ismntpt(vp)) { /* don't remove mount point */ 739 vn_vfsunlock(vp); 740 return (EBUSY); 741 } 742 743 mutex_enter(&zp->z_lock); 744 if (zp_is_dir && !zfs_dirempty(zp)) { /* dir not empty */ 745 mutex_exit(&zp->z_lock); 746 vn_vfsunlock(vp); 747 return (EEXIST); 748 } 749 if (zp->z_phys->zp_links <= zp_is_dir) { 750 zfs_panic_recover("zfs: link count on %s is %u, " 751 "should be at least %u", 752 zp->z_vnode->v_path ? zp->z_vnode->v_path : 753 "<unknown>", (int)zp->z_phys->zp_links, 754 zp_is_dir + 1); 755 zp->z_phys->zp_links = zp_is_dir + 1; 756 } 757 if (--zp->z_phys->zp_links == zp_is_dir) { 758 zp->z_unlinked = B_TRUE; 759 zp->z_phys->zp_links = 0; 760 unlinked = B_TRUE; 761 } else { 762 zfs_time_stamper_locked(zp, STATE_CHANGED, tx); 763 } 764 mutex_exit(&zp->z_lock); 765 vn_vfsunlock(vp); 766 } 767 768 dmu_buf_will_dirty(dzp->z_dbuf, tx); 769 mutex_enter(&dzp->z_lock); 770 dzp->z_phys->zp_size--; /* one dirent removed */ 771 dzp->z_phys->zp_links -= zp_is_dir; /* ".." link from zp */ 772 zfs_time_stamper_locked(dzp, CONTENT_MODIFIED, tx); 773 mutex_exit(&dzp->z_lock); 774 775 if (zp->z_zfsvfs->z_norm) { 776 if (((zp->z_zfsvfs->z_case == ZFS_CASE_INSENSITIVE) && 777 (flag & ZCIEXACT)) || 778 ((zp->z_zfsvfs->z_case == ZFS_CASE_MIXED) && 779 !(flag & ZCILOOK))) 780 error = zap_remove_norm(zp->z_zfsvfs->z_os, 781 dzp->z_id, dl->dl_name, MT_EXACT, tx); 782 else 783 error = zap_remove_norm(zp->z_zfsvfs->z_os, 784 dzp->z_id, dl->dl_name, MT_FIRST, tx); 785 } else { 786 error = zap_remove(zp->z_zfsvfs->z_os, 787 dzp->z_id, dl->dl_name, tx); 788 } 789 ASSERT(error == 0); 790 791 if (unlinkedp != NULL) 792 *unlinkedp = unlinked; 793 else if (unlinked) 794 zfs_unlinked_add(zp, tx); 795 796 return (0); 797 } 798 799 /* 800 * Indicate whether the directory is empty. Works with or without z_lock 801 * held, but can only be consider a hint in the latter case. Returns true 802 * if only "." and ".." remain and there's no work in progress. 803 */ 804 boolean_t 805 zfs_dirempty(znode_t *dzp) 806 { 807 return (dzp->z_phys->zp_size == 2 && dzp->z_dirlocks == 0); 808 } 809 810 int 811 zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr) 812 { 813 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 814 znode_t *xzp; 815 dmu_tx_t *tx; 816 int error; 817 zfs_fuid_info_t *fuidp = NULL; 818 819 *xvpp = NULL; 820 821 if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, 0, B_FALSE, cr)) 822 return (error); 823 824 tx = dmu_tx_create(zfsvfs->z_os); 825 dmu_tx_hold_bonus(tx, zp->z_id); 826 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL); 827 if (IS_EPHEMERAL(crgetuid(cr)) || IS_EPHEMERAL(crgetgid(cr))) { 828 if (zfsvfs->z_fuid_obj == 0) { 829 dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); 830 dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, 831 FUID_SIZE_ESTIMATE(zfsvfs)); 832 dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, FALSE, NULL); 833 } else { 834 dmu_tx_hold_bonus(tx, zfsvfs->z_fuid_obj); 835 dmu_tx_hold_write(tx, zfsvfs->z_fuid_obj, 0, 836 FUID_SIZE_ESTIMATE(zfsvfs)); 837 } 838 } 839 error = dmu_tx_assign(tx, zfsvfs->z_assign); 840 if (error) { 841 if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) 842 dmu_tx_wait(tx); 843 dmu_tx_abort(tx); 844 return (error); 845 } 846 zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, 0, NULL, &fuidp); 847 ASSERT(xzp->z_phys->zp_parent == zp->z_id); 848 dmu_buf_will_dirty(zp->z_dbuf, tx); 849 zp->z_phys->zp_xattr = xzp->z_id; 850 851 (void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp, 852 xzp, "", NULL, fuidp, vap); 853 if (fuidp) 854 zfs_fuid_info_free(fuidp); 855 dmu_tx_commit(tx); 856 857 *xvpp = ZTOV(xzp); 858 859 return (0); 860 } 861 862 /* 863 * Return a znode for the extended attribute directory for zp. 864 * ** If the directory does not already exist, it is created ** 865 * 866 * IN: zp - znode to obtain attribute directory from 867 * cr - credentials of caller 868 * flags - flags from the VOP_LOOKUP call 869 * 870 * OUT: xzpp - pointer to extended attribute znode 871 * 872 * RETURN: 0 on success 873 * error number on failure 874 */ 875 int 876 zfs_get_xattrdir(znode_t *zp, vnode_t **xvpp, cred_t *cr, int flags) 877 { 878 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 879 znode_t *xzp; 880 zfs_dirlock_t *dl; 881 vattr_t va; 882 int error; 883 top: 884 error = zfs_dirent_lock(&dl, zp, "", &xzp, ZXATTR, NULL, NULL); 885 if (error) 886 return (error); 887 888 if (xzp != NULL) { 889 *xvpp = ZTOV(xzp); 890 zfs_dirent_unlock(dl); 891 return (0); 892 } 893 894 ASSERT(zp->z_phys->zp_xattr == 0); 895 896 if (!(flags & CREATE_XATTR_DIR)) { 897 zfs_dirent_unlock(dl); 898 return (ENOENT); 899 } 900 901 if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) { 902 zfs_dirent_unlock(dl); 903 return (EROFS); 904 } 905 906 /* 907 * The ability to 'create' files in an attribute 908 * directory comes from the write_xattr permission on the base file. 909 * 910 * The ability to 'search' an attribute directory requires 911 * read_xattr permission on the base file. 912 * 913 * Once in a directory the ability to read/write attributes 914 * is controlled by the permissions on the attribute file. 915 */ 916 va.va_mask = AT_TYPE | AT_MODE | AT_UID | AT_GID; 917 va.va_type = VDIR; 918 va.va_mode = S_IFDIR | S_ISVTX | 0777; 919 zfs_fuid_map_ids(zp, cr, &va.va_uid, &va.va_gid); 920 921 error = zfs_make_xattrdir(zp, &va, xvpp, cr); 922 zfs_dirent_unlock(dl); 923 924 if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { 925 /* NB: we already did dmu_tx_wait() if necessary */ 926 goto top; 927 } 928 929 return (error); 930 } 931 932 /* 933 * Decide whether it is okay to remove within a sticky directory. 934 * 935 * In sticky directories, write access is not sufficient; 936 * you can remove entries from a directory only if: 937 * 938 * you own the directory, 939 * you own the entry, 940 * the entry is a plain file and you have write access, 941 * or you are privileged (checked in secpolicy...). 942 * 943 * The function returns 0 if remove access is granted. 944 */ 945 int 946 zfs_sticky_remove_access(znode_t *zdp, znode_t *zp, cred_t *cr) 947 { 948 uid_t uid; 949 uid_t downer; 950 uid_t fowner; 951 zfsvfs_t *zfsvfs = zdp->z_zfsvfs; 952 953 if (zdp->z_zfsvfs->z_assign >= TXG_INITIAL) /* ZIL replay */ 954 return (0); 955 956 if ((zdp->z_phys->zp_mode & S_ISVTX) == 0) 957 return (0); 958 959 downer = zfs_fuid_map_id(zfsvfs, zdp->z_phys->zp_uid, cr, ZFS_OWNER); 960 fowner = zfs_fuid_map_id(zfsvfs, zp->z_phys->zp_uid, cr, ZFS_OWNER); 961 962 if ((uid = crgetuid(cr)) == downer || uid == fowner || 963 (ZTOV(zp)->v_type == VREG && 964 zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr) == 0)) 965 return (0); 966 else 967 return (secpolicy_vnode_remove(cr)); 968 } 969