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_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 = 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) 405 (void) strlcpy(rpnp->pn_path, 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. 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 ASSERT3U(error, ==, 0); 533 534 ASSERT((ZTOV(xzp)->v_type == VREG) || 535 (ZTOV(xzp)->v_type == VLNK)); 536 537 tx = dmu_tx_create(zfsvfs->z_os); 538 dmu_tx_hold_bonus(tx, dzp->z_id); 539 dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name); 540 dmu_tx_hold_bonus(tx, xzp->z_id); 541 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL); 542 error = dmu_tx_assign(tx, TXG_WAIT); 543 if (error) { 544 dmu_tx_abort(tx); 545 VN_RELE(ZTOV(xzp)); 546 skipped += 1; 547 continue; 548 } 549 bzero(&dl, sizeof (dl)); 550 dl.dl_dzp = dzp; 551 dl.dl_name = zap.za_name; 552 553 error = zfs_link_destroy(&dl, xzp, tx, 0, NULL); 554 ASSERT3U(error, ==, 0); 555 dmu_tx_commit(tx); 556 557 VN_RELE(ZTOV(xzp)); 558 } 559 zap_cursor_fini(&zc); 560 ASSERT(error == ENOENT); 561 return (skipped); 562 } 563 564 void 565 zfs_rmnode(znode_t *zp) 566 { 567 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 568 objset_t *os = zfsvfs->z_os; 569 znode_t *xzp = NULL; 570 char obj_name[17]; 571 dmu_tx_t *tx; 572 uint64_t acl_obj; 573 int error; 574 575 ASSERT(ZTOV(zp)->v_count == 0); 576 ASSERT(zp->z_phys->zp_links == 0); 577 578 /* 579 * If this is an attribute directory, purge its contents. 580 */ 581 if (ZTOV(zp)->v_type == VDIR && (zp->z_phys->zp_flags & ZFS_XATTR)) { 582 if (zfs_purgedir(zp) != 0) { 583 /* 584 * Not enough space to delete some xattrs. 585 * Leave it on the unlinked set. 586 */ 587 zfs_znode_dmu_fini(zp); 588 zfs_znode_free(zp); 589 return; 590 } 591 } 592 593 /* 594 * If the file has extended attributes, we're going to unlink 595 * the xattr dir. 596 */ 597 if (zp->z_phys->zp_xattr) { 598 error = zfs_zget(zfsvfs, zp->z_phys->zp_xattr, &xzp); 599 ASSERT(error == 0); 600 } 601 602 acl_obj = zp->z_phys->zp_acl.z_acl_extern_obj; 603 604 /* 605 * Set up the transaction. 606 */ 607 tx = dmu_tx_create(os); 608 dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END); 609 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL); 610 if (xzp) { 611 dmu_tx_hold_bonus(tx, xzp->z_id); 612 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, TRUE, NULL); 613 } 614 if (acl_obj) 615 dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END); 616 error = dmu_tx_assign(tx, TXG_WAIT); 617 if (error) { 618 /* 619 * Not enough space to delete the file. Leave it in the 620 * unlinked set, leaking it until the fs is remounted (at 621 * which point we'll call zfs_unlinked_drain() to process it). 622 */ 623 dmu_tx_abort(tx); 624 zfs_znode_dmu_fini(zp); 625 zfs_znode_free(zp); 626 goto out; 627 } 628 629 if (xzp) { 630 dmu_buf_will_dirty(xzp->z_dbuf, tx); 631 mutex_enter(&xzp->z_lock); 632 xzp->z_unlinked = B_TRUE; /* mark xzp for deletion */ 633 xzp->z_phys->zp_links = 0; /* no more links to it */ 634 mutex_exit(&xzp->z_lock); 635 zfs_unlinked_add(xzp, tx); 636 } 637 638 /* Remove this znode from the unlinked set */ 639 error = zap_remove(os, zfsvfs->z_unlinkedobj, 640 zfs_unlinked_hexname(obj_name, zp->z_id), tx); 641 ASSERT3U(error, ==, 0); 642 643 zfs_znode_delete(zp, tx); 644 645 dmu_tx_commit(tx); 646 out: 647 if (xzp) 648 VN_RELE(ZTOV(xzp)); 649 } 650 651 static uint64_t 652 zfs_dirent(znode_t *zp) 653 { 654 uint64_t de = zp->z_id; 655 if (zp->z_zfsvfs->z_version >= ZPL_VERSION_DIRENT_TYPE) 656 de |= IFTODT((zp)->z_phys->zp_mode) << 60; 657 return (de); 658 } 659 660 /* 661 * Link zp into dl. Can only fail if zp has been unlinked. 662 */ 663 int 664 zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag) 665 { 666 znode_t *dzp = dl->dl_dzp; 667 vnode_t *vp = ZTOV(zp); 668 uint64_t value; 669 int zp_is_dir = (vp->v_type == VDIR); 670 int error; 671 672 dmu_buf_will_dirty(zp->z_dbuf, tx); 673 mutex_enter(&zp->z_lock); 674 675 if (!(flag & ZRENAMING)) { 676 if (zp->z_unlinked) { /* no new links to unlinked zp */ 677 ASSERT(!(flag & (ZNEW | ZEXISTS))); 678 mutex_exit(&zp->z_lock); 679 return (ENOENT); 680 } 681 zp->z_phys->zp_links++; 682 } 683 zp->z_phys->zp_parent = dzp->z_id; /* dzp is now zp's parent */ 684 685 if (!(flag & ZNEW)) 686 zfs_time_stamper_locked(zp, STATE_CHANGED, tx); 687 mutex_exit(&zp->z_lock); 688 689 dmu_buf_will_dirty(dzp->z_dbuf, tx); 690 mutex_enter(&dzp->z_lock); 691 dzp->z_phys->zp_size++; /* one dirent added */ 692 dzp->z_phys->zp_links += zp_is_dir; /* ".." link from zp */ 693 zfs_time_stamper_locked(dzp, CONTENT_MODIFIED, tx); 694 mutex_exit(&dzp->z_lock); 695 696 value = zfs_dirent(zp); 697 error = zap_add(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name, 698 8, 1, &value, tx); 699 ASSERT(error == 0); 700 701 dnlc_update(ZTOV(dzp), dl->dl_name, vp); 702 703 return (0); 704 } 705 706 /* 707 * Unlink zp from dl, and mark zp for deletion if this was the last link. 708 * Can fail if zp is a mount point (EBUSY) or a non-empty directory (EEXIST). 709 * If 'unlinkedp' is NULL, we put unlinked znodes on the unlinked list. 710 * If it's non-NULL, we use it to indicate whether the znode needs deletion, 711 * and it's the caller's job to do it. 712 */ 713 int 714 zfs_link_destroy(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag, 715 boolean_t *unlinkedp) 716 { 717 znode_t *dzp = dl->dl_dzp; 718 vnode_t *vp = ZTOV(zp); 719 int zp_is_dir = (vp->v_type == VDIR); 720 boolean_t unlinked = B_FALSE; 721 int error; 722 723 dnlc_remove(ZTOV(dzp), dl->dl_name); 724 725 if (!(flag & ZRENAMING)) { 726 dmu_buf_will_dirty(zp->z_dbuf, tx); 727 728 if (vn_vfswlock(vp)) /* prevent new mounts on zp */ 729 return (EBUSY); 730 731 if (vn_ismntpt(vp)) { /* don't remove mount point */ 732 vn_vfsunlock(vp); 733 return (EBUSY); 734 } 735 736 mutex_enter(&zp->z_lock); 737 if (zp_is_dir && !zfs_dirempty(zp)) { /* dir not empty */ 738 mutex_exit(&zp->z_lock); 739 vn_vfsunlock(vp); 740 return (EEXIST); 741 } 742 if (zp->z_phys->zp_links <= zp_is_dir) { 743 zfs_panic_recover("zfs: link count on %s is %u, " 744 "should be at least %u", 745 zp->z_vnode->v_path ? zp->z_vnode->v_path : 746 "<unknown>", (int)zp->z_phys->zp_links, 747 zp_is_dir + 1); 748 zp->z_phys->zp_links = zp_is_dir + 1; 749 } 750 if (--zp->z_phys->zp_links == zp_is_dir) { 751 zp->z_unlinked = B_TRUE; 752 zp->z_phys->zp_links = 0; 753 unlinked = B_TRUE; 754 } else { 755 zfs_time_stamper_locked(zp, STATE_CHANGED, tx); 756 } 757 mutex_exit(&zp->z_lock); 758 vn_vfsunlock(vp); 759 } 760 761 dmu_buf_will_dirty(dzp->z_dbuf, tx); 762 mutex_enter(&dzp->z_lock); 763 dzp->z_phys->zp_size--; /* one dirent removed */ 764 dzp->z_phys->zp_links -= zp_is_dir; /* ".." link from zp */ 765 zfs_time_stamper_locked(dzp, CONTENT_MODIFIED, tx); 766 mutex_exit(&dzp->z_lock); 767 768 if (zp->z_zfsvfs->z_norm) { 769 if (((zp->z_zfsvfs->z_case == ZFS_CASE_INSENSITIVE) && 770 (flag & ZCIEXACT)) || 771 ((zp->z_zfsvfs->z_case == ZFS_CASE_MIXED) && 772 !(flag & ZCILOOK))) 773 error = zap_remove_norm(zp->z_zfsvfs->z_os, 774 dzp->z_id, dl->dl_name, MT_EXACT, tx); 775 else 776 error = zap_remove_norm(zp->z_zfsvfs->z_os, 777 dzp->z_id, dl->dl_name, MT_FIRST, tx); 778 } else { 779 error = zap_remove(zp->z_zfsvfs->z_os, 780 dzp->z_id, dl->dl_name, tx); 781 } 782 ASSERT(error == 0); 783 784 if (unlinkedp != NULL) 785 *unlinkedp = unlinked; 786 else if (unlinked) 787 zfs_unlinked_add(zp, tx); 788 789 return (0); 790 } 791 792 /* 793 * Indicate whether the directory is empty. Works with or without z_lock 794 * held, but can only be consider a hint in the latter case. Returns true 795 * if only "." and ".." remain and there's no work in progress. 796 */ 797 boolean_t 798 zfs_dirempty(znode_t *dzp) 799 { 800 return (dzp->z_phys->zp_size == 2 && dzp->z_dirlocks == 0); 801 } 802 803 int 804 zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr) 805 { 806 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 807 znode_t *xzp; 808 dmu_tx_t *tx; 809 int error; 810 zfs_fuid_info_t *fuidp = NULL; 811 812 *xvpp = NULL; 813 814 if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, 0, B_FALSE, cr)) 815 return (error); 816 817 tx = dmu_tx_create(zfsvfs->z_os); 818 dmu_tx_hold_bonus(tx, zp->z_id); 819 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL); 820 if (zfsvfs->z_fuid_obj == 0) { 821 dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); 822 dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, SPA_MAXBLOCKSIZE); 823 dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, FALSE, NULL); 824 } else { 825 dmu_tx_hold_bonus(tx, zfsvfs->z_fuid_obj); 826 dmu_tx_hold_write(tx, zfsvfs->z_fuid_obj, 0, SPA_MAXBLOCKSIZE); 827 } 828 error = dmu_tx_assign(tx, zfsvfs->z_assign); 829 if (error) { 830 if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) 831 dmu_tx_wait(tx); 832 dmu_tx_abort(tx); 833 return (error); 834 } 835 zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, 0, NULL, &fuidp); 836 ASSERT(xzp->z_phys->zp_parent == zp->z_id); 837 dmu_buf_will_dirty(zp->z_dbuf, tx); 838 zp->z_phys->zp_xattr = xzp->z_id; 839 840 (void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp, 841 xzp, "", NULL, fuidp, vap); 842 if (fuidp) 843 zfs_fuid_info_free(fuidp); 844 dmu_tx_commit(tx); 845 846 *xvpp = ZTOV(xzp); 847 848 return (0); 849 } 850 851 /* 852 * Return a znode for the extended attribute directory for zp. 853 * ** If the directory does not already exist, it is created ** 854 * 855 * IN: zp - znode to obtain attribute directory from 856 * cr - credentials of caller 857 * flags - flags from the VOP_LOOKUP call 858 * 859 * OUT: xzpp - pointer to extended attribute znode 860 * 861 * RETURN: 0 on success 862 * error number on failure 863 */ 864 int 865 zfs_get_xattrdir(znode_t *zp, vnode_t **xvpp, cred_t *cr, int flags) 866 { 867 zfsvfs_t *zfsvfs = zp->z_zfsvfs; 868 znode_t *xzp; 869 zfs_dirlock_t *dl; 870 vattr_t va; 871 int error; 872 top: 873 error = zfs_dirent_lock(&dl, zp, "", &xzp, ZXATTR, NULL, NULL); 874 if (error) 875 return (error); 876 877 if (xzp != NULL) { 878 *xvpp = ZTOV(xzp); 879 zfs_dirent_unlock(dl); 880 return (0); 881 } 882 883 ASSERT(zp->z_phys->zp_xattr == 0); 884 885 if (!(flags & CREATE_XATTR_DIR)) { 886 zfs_dirent_unlock(dl); 887 return (ENOENT); 888 } 889 890 if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) { 891 zfs_dirent_unlock(dl); 892 return (EROFS); 893 } 894 895 /* 896 * The ability to 'create' files in an attribute 897 * directory comes from the write_xattr permission on the base file. 898 * 899 * The ability to 'search' an attribute directory requires 900 * read_xattr permission on the base file. 901 * 902 * Once in a directory the ability to read/write attributes 903 * is controlled by the permissions on the attribute file. 904 */ 905 va.va_mask = AT_TYPE | AT_MODE | AT_UID | AT_GID; 906 va.va_type = VDIR; 907 va.va_mode = S_IFDIR | S_ISVTX | 0777; 908 zfs_fuid_map_ids(zp, cr, &va.va_uid, &va.va_gid); 909 910 error = zfs_make_xattrdir(zp, &va, xvpp, cr); 911 zfs_dirent_unlock(dl); 912 913 if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { 914 /* NB: we already did dmu_tx_wait() if necessary */ 915 goto top; 916 } 917 918 return (error); 919 } 920 921 /* 922 * Decide whether it is okay to remove within a sticky directory. 923 * 924 * In sticky directories, write access is not sufficient; 925 * you can remove entries from a directory only if: 926 * 927 * you own the directory, 928 * you own the entry, 929 * the entry is a plain file and you have write access, 930 * or you are privileged (checked in secpolicy...). 931 * 932 * The function returns 0 if remove access is granted. 933 */ 934 int 935 zfs_sticky_remove_access(znode_t *zdp, znode_t *zp, cred_t *cr) 936 { 937 uid_t uid; 938 uid_t downer; 939 uid_t fowner; 940 zfsvfs_t *zfsvfs = zdp->z_zfsvfs; 941 942 if (zdp->z_zfsvfs->z_assign >= TXG_INITIAL) /* ZIL replay */ 943 return (0); 944 945 if ((zdp->z_phys->zp_mode & S_ISVTX) == 0) 946 return (0); 947 948 zfs_fuid_map_id(zfsvfs, zdp->z_phys->zp_uid, cr, ZFS_OWNER, &downer); 949 zfs_fuid_map_id(zfsvfs, zp->z_phys->zp_uid, cr, ZFS_OWNER, &fowner); 950 951 if ((uid = crgetuid(cr)) == downer || uid == fowner || 952 (ZTOV(zp)->v_type == VREG && 953 zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr) == 0)) 954 return (0); 955 else 956 return (secpolicy_vnode_remove(cr)); 957 } 958