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 #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/kmem.h>
36 #include <sys/uio.h>
37 #include <sys/cmn_err.h>
38 #include <sys/errno.h>
39 #include <sys/stat.h>
40 #include <sys/unistd.h>
41 #include <sys/sunddi.h>
42 #include <sys/random.h>
43 #include <sys/policy.h>
44 #include <sys/kcondvar.h>
45 #include <sys/callb.h>
46 #include <sys/smp.h>
47 #include <sys/zfs_dir.h>
48 #include <sys/zfs_acl.h>
49 #include <sys/fs/zfs.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/dnlc.h>
56 #include <sys/extdirent.h>
57
58 /*
59 * zfs_match_find() is used by zfs_dirent_lock() to peform zap lookups
60 * of names after deciding which is the appropriate lookup interface.
61 */
62 static int
63 zfs_match_find(zfsvfs_t *zfsvfs, znode_t *dzp, char *name, boolean_t exact,
64 boolean_t update, int *deflags, pathname_t *rpnp, uint64_t *zoid)
65 {
66 int error;
67
68 if (zfsvfs->z_norm) {
69 matchtype_t mt = MT_FIRST;
70 boolean_t conflict = B_FALSE;
71 size_t bufsz = 0;
72 char *buf = NULL;
73
74 if (rpnp) {
75 buf = rpnp->pn_buf;
76 bufsz = rpnp->pn_bufsize;
77 }
78 if (exact)
79 mt = MT_EXACT;
80 /*
81 * In the non-mixed case we only expect there would ever
82 * be one match, but we need to use the normalizing lookup.
83 */
84 error = zap_lookup_norm(zfsvfs->z_os, dzp->z_id, name, 8, 1,
85 zoid, mt, buf, bufsz, &conflict);
86 if (!error && deflags)
87 *deflags = conflict ? ED_CASE_CONFLICT : 0;
88 } else {
89 error = zap_lookup(zfsvfs->z_os, dzp->z_id, name, 8, 1, zoid);
90 }
91 *zoid = ZFS_DIRENT_OBJ(*zoid);
92
93 if (error == ENOENT && update)
94 dnlc_update(ZTOV(dzp), name, DNLC_NO_VNODE);
95
96 return (error);
97 }
98
99 /*
100 * Lock a directory entry. A dirlock on <dzp, name> protects that name
101 * in dzp's directory zap object. As long as you hold a dirlock, you can
102 * assume two things: (1) dzp cannot be reaped, and (2) no other thread
103 * can change the zap entry for (i.e. link or unlink) this name.
104 *
105 * Input arguments:
106 * dzp - znode for directory
107 * name - name of entry to lock
108 * flag - ZNEW: if the entry already exists, fail with EEXIST.
109 * ZEXISTS: if the entry does not exist, fail with ENOENT.
110 * ZSHARED: allow concurrent access with other ZSHARED callers.
111 * ZXATTR: we want dzp's xattr directory
112 * ZCILOOK: On a mixed sensitivity file system,
113 * this lookup should be case-insensitive.
114 * ZCIEXACT: On a purely case-insensitive file system,
115 * this lookup should be case-sensitive.
116 * ZRENAMING: we are locking for renaming, force narrow locks
117 *
118 * Output arguments:
119 * zpp - pointer to the znode for the entry (NULL if there isn't one)
120 * dlpp - pointer to the dirlock for this entry (NULL on error)
121 * direntflags - (case-insensitive lookup only)
122 * flags if multiple case-sensitive matches exist in directory
123 * realpnp - (case-insensitive lookup only)
124 * actual name matched within the directory
125 *
126 * Return value: 0 on success or errno on failure.
127 *
128 * NOTE: Always checks for, and rejects, '.' and '..'.
129 * NOTE: For case-insensitive file systems we take wide locks (see below),
130 * but return znode pointers to a single match.
131 */
132 int
133 zfs_dirent_lock(zfs_dirlock_t **dlpp, znode_t *dzp, char *name, znode_t **zpp,
134 int flag, int *direntflags, pathname_t *realpnp)
135 {
136 zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
137 zfs_dirlock_t *dl;
138 boolean_t update;
139 boolean_t exact;
140 uint64_t zoid;
141 vnode_t *vp = NULL;
142 int error = 0;
143 int cmpflags;
144
145 *zpp = NULL;
146 *dlpp = NULL;
147
148 /*
149 * Verify that we are not trying to lock '.', '..', or '.zfs'
150 */
151 if (name[0] == '.' &&
152 (name[1] == '\0' || (name[1] == '.' && name[2] == '\0')) ||
153 zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0)
154 return (EEXIST);
155
156 /*
157 * Case sensitivity and normalization preferences are set when
158 * the file system is created. These are stored in the
159 * zfsvfs->z_case and zfsvfs->z_norm fields. These choices
160 * affect what vnodes can be cached in the DNLC, how we
161 * perform zap lookups, and the "width" of our dirlocks.
162 *
163 * A normal dirlock locks a single name. Note that with
164 * normalization a name can be composed multiple ways, but
165 * when normalized, these names all compare equal. A wide
166 * dirlock locks multiple names. We need these when the file
167 * system is supporting mixed-mode access. It is sometimes
168 * necessary to lock all case permutations of file name at
169 * once so that simultaneous case-insensitive/case-sensitive
170 * behaves as rationally as possible.
171 */
172
173 /*
174 * Decide if exact matches should be requested when performing
175 * a zap lookup on file systems supporting case-insensitive
176 * access.
177 */
178 exact =
179 ((zfsvfs->z_case == ZFS_CASE_INSENSITIVE) && (flag & ZCIEXACT)) ||
180 ((zfsvfs->z_case == ZFS_CASE_MIXED) && !(flag & ZCILOOK));
181
182 /*
183 * Only look in or update the DNLC if we are looking for the
184 * name on a file system that does not require normalization
185 * or case folding. We can also look there if we happen to be
186 * on a non-normalizing, mixed sensitivity file system IF we
187 * are looking for the exact name.
188 *
189 * Maybe can add TO-UPPERed version of name to dnlc in ci-only
190 * case for performance improvement?
191 */
192 update = !zfsvfs->z_norm ||
193 ((zfsvfs->z_case == ZFS_CASE_MIXED) &&
194 !(zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER) && !(flag & ZCILOOK));
195
196 /*
197 * ZRENAMING indicates we are in a situation where we should
198 * take narrow locks regardless of the file system's
199 * preferences for normalizing and case folding. This will
200 * prevent us deadlocking trying to grab the same wide lock
201 * twice if the two names happen to be case-insensitive
202 * matches.
203 */
204 if (flag & ZRENAMING)
205 cmpflags = 0;
206 else
207 cmpflags = zfsvfs->z_norm;
208
209 /*
210 * Wait until there are no locks on this name.
211 */
212 rw_enter(&dzp->z_name_lock, RW_READER);
213 mutex_enter(&dzp->z_lock);
214 for (;;) {
215 if (dzp->z_unlinked) {
216 mutex_exit(&dzp->z_lock);
217 rw_exit(&dzp->z_name_lock);
218 return (ENOENT);
219 }
220 for (dl = dzp->z_dirlocks; dl != NULL; dl = dl->dl_next) {
221 if ((u8_strcmp(name, dl->dl_name, 0, cmpflags,
222 U8_UNICODE_LATEST, &error) == 0) || error != 0)
223 break;
224 }
225 if (error != 0) {
226 mutex_exit(&dzp->z_lock);
227 rw_exit(&dzp->z_name_lock);
228 return (ENOENT);
229 }
230 if (dl == NULL) {
231 /*
232 * Allocate a new dirlock and add it to the list.
233 */
234 dl = kmem_alloc(sizeof (zfs_dirlock_t), KM_SLEEP);
235 cv_init(&dl->dl_cv, NULL, CV_DEFAULT, NULL);
236 dl->dl_name = name;
237 dl->dl_sharecnt = 0;
238 dl->dl_namesize = 0;
239 dl->dl_dzp = dzp;
240 dl->dl_next = dzp->z_dirlocks;
241 dzp->z_dirlocks = dl;
242 break;
243 }
244 if ((flag & ZSHARED) && dl->dl_sharecnt != 0)
245 break;
246 cv_wait(&dl->dl_cv, &dzp->z_lock);
247 }
248
249 if ((flag & ZSHARED) && ++dl->dl_sharecnt > 1 && dl->dl_namesize == 0) {
250 /*
251 * We're the second shared reference to dl. Make a copy of
252 * dl_name in case the first thread goes away before we do.
253 * Note that we initialize the new name before storing its
254 * pointer into dl_name, because the first thread may load
255 * dl->dl_name at any time. He'll either see the old value,
256 * which is his, or the new shared copy; either is OK.
257 */
258 dl->dl_namesize = strlen(dl->dl_name) + 1;
259 name = kmem_alloc(dl->dl_namesize, KM_SLEEP);
260 bcopy(dl->dl_name, name, dl->dl_namesize);
261 dl->dl_name = name;
262 }
263
264 mutex_exit(&dzp->z_lock);
265
266 /*
267 * We have a dirlock on the name. (Note that it is the dirlock,
268 * not the dzp's z_lock, that protects the name in the zap object.)
269 * See if there's an object by this name; if so, put a hold on it.
270 */
271 if (flag & ZXATTR) {
272 zoid = dzp->z_phys->zp_xattr;
273 error = (zoid == 0 ? ENOENT : 0);
274 } else {
275 if (update)
276 vp = dnlc_lookup(ZTOV(dzp), name);
277 if (vp == DNLC_NO_VNODE) {
278 VN_RELE(vp);
279 error = ENOENT;
280 } else if (vp) {
281 if (flag & ZNEW) {
282 zfs_dirent_unlock(dl);
283 VN_RELE(vp);
284 return (EEXIST);
285 }
286 *dlpp = dl;
287 *zpp = VTOZ(vp);
288 return (0);
289 } else {
290 error = zfs_match_find(zfsvfs, dzp, name, exact,
291 update, direntflags, realpnp, &zoid);
292 }
293 }
294 if (error) {
295 if (error != ENOENT || (flag & ZEXISTS)) {
296 zfs_dirent_unlock(dl);
297 return (error);
298 }
299 } else {
300 if (flag & ZNEW) {
301 zfs_dirent_unlock(dl);
302 return (EEXIST);
303 }
304 error = zfs_zget(zfsvfs, zoid, zpp);
305 if (error) {
306 zfs_dirent_unlock(dl);
307 return (error);
308 }
309 if (!(flag & ZXATTR) && update)
310 dnlc_update(ZTOV(dzp), name, ZTOV(*zpp));
311 }
312
313 *dlpp = dl;
314
315 return (0);
316 }
317
318 /*
319 * Unlock this directory entry and wake anyone who was waiting for it.
320 */
321 void
322 zfs_dirent_unlock(zfs_dirlock_t *dl)
323 {
324 znode_t *dzp = dl->dl_dzp;
325 zfs_dirlock_t **prev_dl, *cur_dl;
326
327 mutex_enter(&dzp->z_lock);
328 rw_exit(&dzp->z_name_lock);
329 if (dl->dl_sharecnt > 1) {
330 dl->dl_sharecnt--;
331 mutex_exit(&dzp->z_lock);
332 return;
333 }
334 prev_dl = &dzp->z_dirlocks;
335 while ((cur_dl = *prev_dl) != dl)
336 prev_dl = &cur_dl->dl_next;
337 *prev_dl = dl->dl_next;
338 cv_broadcast(&dl->dl_cv);
339 mutex_exit(&dzp->z_lock);
340
341 if (dl->dl_namesize != 0)
342 kmem_free(dl->dl_name, dl->dl_namesize);
343 cv_destroy(&dl->dl_cv);
344 kmem_free(dl, sizeof (*dl));
345 }
346
347 /*
348 * Look up an entry in a directory.
349 *
350 * NOTE: '.' and '..' are handled as special cases because
351 * no directory entries are actually stored for them. If this is
352 * the root of a filesystem, then '.zfs' is also treated as a
353 * special pseudo-directory.
354 */
355 int
356 zfs_dirlook(znode_t *dzp, char *name, vnode_t **vpp, int flags,
357 int *deflg, pathname_t *rpnp)
358 {
359 zfs_dirlock_t *dl;
360 znode_t *zp;
361 int error = 0;
362
363 if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) {
364 *vpp = ZTOV(dzp);
365 VN_HOLD(*vpp);
366 } else if (name[0] == '.' && name[1] == '.' && name[2] == 0) {
367 zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
368 /*
369 * If we are a snapshot mounted under .zfs, return
370 * the vp for the snapshot directory.
371 */
372 if (dzp->z_phys->zp_parent == dzp->z_id &&
373 zfsvfs->z_parent != zfsvfs) {
374 error = zfsctl_root_lookup(zfsvfs->z_parent->z_ctldir,
375 "snapshot", vpp, NULL, 0, NULL, kcred,
376 NULL, NULL, NULL);
377 return (error);
378 }
379 rw_enter(&dzp->z_parent_lock, RW_READER);
380 error = zfs_zget(zfsvfs, dzp->z_phys->zp_parent, &zp);
381 if (error == 0)
382 *vpp = ZTOV(zp);
383 rw_exit(&dzp->z_parent_lock);
384 } else if (zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) {
385 *vpp = zfsctl_root(dzp);
386 } else {
387 int zf;
388
389 zf = ZEXISTS | ZSHARED;
390 if (flags & FIGNORECASE)
391 zf |= ZCILOOK;
392
393 error = zfs_dirent_lock(&dl, dzp, name, &zp, zf, deflg, rpnp);
394 if (error == 0) {
395 *vpp = ZTOV(zp);
396 zfs_dirent_unlock(dl);
397 dzp->z_zn_prefetch = B_TRUE; /* enable prefetching */
398 }
399 rpnp = NULL;
400 }
401
402 if ((flags & FIGNORECASE) && rpnp && !error)
403 (void) strlcpy(rpnp->pn_buf, name, rpnp->pn_bufsize);
404
405 return (error);
406 }
407
408 /*
409 * unlinked Set (formerly known as the "delete queue") Error Handling
410 *
411 * When dealing with the unlinked set, we dmu_tx_hold_zap(), but we
412 * don't specify the name of the entry that we will be manipulating. We
413 * also fib and say that we won't be adding any new entries to the
414 * unlinked set, even though we might (this is to lower the minimum file
415 * size that can be deleted in a full filesystem). So on the small
416 * chance that the nlink list is using a fat zap (ie. has more than
417 * 2000 entries), we *may* not pre-read a block that's needed.
418 * Therefore it is remotely possible for some of the assertions
419 * regarding the unlinked set below to fail due to i/o error. On a
420 * nondebug system, this will result in the space being leaked.
421 */
422 void
423 zfs_unlinked_add(znode_t *zp, dmu_tx_t *tx)
424 {
425 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
426
427 ASSERT(zp->z_unlinked);
428 ASSERT3U(zp->z_phys->zp_links, ==, 0);
429
430 VERIFY3U(0, ==,
431 zap_add_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx));
432 }
433
434 /*
435 * Clean up any znodes that had no links when we either crashed or
436 * (force) umounted the file system.
437 */
438 void
439 zfs_unlinked_drain(zfsvfs_t *zfsvfs)
440 {
441 zap_cursor_t zc;
442 zap_attribute_t zap;
443 dmu_object_info_t doi;
444 znode_t *zp;
445 int error;
446
447 /*
448 * Interate over the contents of the unlinked set.
449 */
450 for (zap_cursor_init(&zc, zfsvfs->z_os, zfsvfs->z_unlinkedobj);
451 zap_cursor_retrieve(&zc, &zap) == 0;
452 zap_cursor_advance(&zc)) {
453
454 /*
455 * See what kind of object we have in list
456 */
457
458 error = dmu_object_info(zfsvfs->z_os,
459 zap.za_first_integer, &doi);
460 if (error != 0)
461 continue;
462
463 ASSERT((doi.doi_type == DMU_OT_PLAIN_FILE_CONTENTS) ||
464 (doi.doi_type == DMU_OT_DIRECTORY_CONTENTS));
465 /*
466 * We need to re-mark these list entries for deletion,
467 * so we pull them back into core and set zp->z_unlinked.
468 */
469 error = zfs_zget(zfsvfs, zap.za_first_integer, &zp);
470
471 /*
472 * We may pick up znodes that are already marked for deletion.
473 * This could happen during the purge of an extended attribute
474 * directory. All we need to do is skip over them, since they
475 * are already in the system marked z_unlinked.
476 */
477 if (error != 0)
478 continue;
479
480 zp->z_unlinked = B_TRUE;
481 VN_RELE(ZTOV(zp));
482 }
483 zap_cursor_fini(&zc);
484 }
485
486 /*
487 * Delete the entire contents of a directory. Return a count
488 * of the number of entries that could not be deleted. If we encounter
489 * an error, return a count of at least one so that the directory stays
490 * in the unlinked set.
491 *
492 * NOTE: this function assumes that the directory is inactive,
493 * so there is no need to lock its entries before deletion.
494 * Also, it assumes the directory contents is *only* regular
495 * files.
496 */
497 static int
498 zfs_purgedir(znode_t *dzp)
499 {
500 zap_cursor_t zc;
501 zap_attribute_t zap;
502 znode_t *xzp;
503 dmu_tx_t *tx;
504 zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
505 zfs_dirlock_t dl;
506 int skipped = 0;
507 int error;
508
509 for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id);
510 (error = zap_cursor_retrieve(&zc, &zap)) == 0;
511 zap_cursor_advance(&zc)) {
512 error = zfs_zget(zfsvfs,
513 ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp);
514 if (error) {
515 skipped += 1;
516 continue;
517 }
518
519 ASSERT((ZTOV(xzp)->v_type == VREG) ||
520 (ZTOV(xzp)->v_type == VLNK));
521
522 tx = dmu_tx_create(zfsvfs->z_os);
523 dmu_tx_hold_bonus(tx, dzp->z_id);
524 dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name);
525 dmu_tx_hold_bonus(tx, xzp->z_id);
526 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
527 error = dmu_tx_assign(tx, TXG_WAIT);
528 if (error) {
529 dmu_tx_abort(tx);
530 VN_RELE(ZTOV(xzp));
531 skipped += 1;
532 continue;
533 }
534 bzero(&dl, sizeof (dl));
535 dl.dl_dzp = dzp;
536 dl.dl_name = zap.za_name;
537
538 error = zfs_link_destroy(&dl, xzp, tx, 0, NULL);
539 if (error)
540 skipped += 1;
541 dmu_tx_commit(tx);
542
543 VN_RELE(ZTOV(xzp));
544 }
545 zap_cursor_fini(&zc);
546 if (error != ENOENT)
547 skipped += 1;
548 return (skipped);
549 }
550
551 void
552 zfs_rmnode(znode_t *zp)
553 {
554 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
555 objset_t *os = zfsvfs->z_os;
556 znode_t *xzp = NULL;
557 dmu_tx_t *tx;
558 uint64_t acl_obj;
559 int error;
560
561 ASSERT(zp->z_phys->zp_links == 0);
562
563 /*
564 * If this is a ZIL replay then leave the object in the unlinked set.
565 * Otherwise we can get a deadlock, because the delete can be
566 * quite large and span multiple tx's and txgs, but each replay
567 * creates a tx to atomically run the replay function and mark the
568 * replay record as complete. We deadlock trying to start a tx in
569 * a new txg to further the deletion but can't because the replay
570 * tx hasn't finished.
571 *
572 * We actually delete the object if we get a failure to create an
573 * object in zil_replay_log_record(), or after calling zil_replay().
574 */
575 if (zfsvfs->z_assign >= TXG_INITIAL) {
576 zfs_znode_dmu_fini(zp);
577 zfs_znode_free(zp);
578 return;
579 }
580
581 /*
582 * If this is an attribute directory, purge its contents.
583 */
584 if (ZTOV(zp) != NULL && ZTOV(zp)->v_type == VDIR &&
585 (zp->z_phys->zp_flags & ZFS_XATTR)) {
586 if (zfs_purgedir(zp) != 0) {
587 /*
588 * Not enough space to delete some xattrs.
589 * Leave it in the unlinked set.
590 */
591 zfs_znode_dmu_fini(zp);
592 zfs_znode_free(zp);
593 return;
594 }
595 }
596
597 /*
598 * Free up all the data in the file.
599 */
600 error = dmu_free_long_range(os, zp->z_id, 0, DMU_OBJECT_END);
601 if (error) {
602 /*
603 * Not enough space. Leave the file in the unlinked set.
604 */
605 zfs_znode_dmu_fini(zp);
606 zfs_znode_free(zp);
607 return;
608 }
609
610 /*
611 * If the file has extended attributes, we're going to unlink
612 * the xattr dir.
613 */
614 if (zp->z_phys->zp_xattr) {
615 error = zfs_zget(zfsvfs, zp->z_phys->zp_xattr, &xzp);
616 ASSERT(error == 0);
617 }
618
619 acl_obj = zp->z_phys->zp_acl.z_acl_extern_obj;
620
621 /*
622 * Set up the final transaction.
623 */
624 tx = dmu_tx_create(os);
625 dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END);
626 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
627 if (xzp) {
628 dmu_tx_hold_bonus(tx, xzp->z_id);
629 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, TRUE, NULL);
630 }
631 if (acl_obj)
632 dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END);
633 error = dmu_tx_assign(tx, TXG_WAIT);
634 if (error) {
635 /*
636 * Not enough space to delete the file. Leave it in the
637 * unlinked set, leaking it until the fs is remounted (at
638 * which point we'll call zfs_unlinked_drain() to process it).
639 */
640 dmu_tx_abort(tx);
641 zfs_znode_dmu_fini(zp);
642 zfs_znode_free(zp);
643 goto out;
644 }
645
646 if (xzp) {
647 dmu_buf_will_dirty(xzp->z_dbuf, tx);
648 mutex_enter(&xzp->z_lock);
649 xzp->z_unlinked = B_TRUE; /* mark xzp for deletion */
650 xzp->z_phys->zp_links = 0; /* no more links to it */
651 mutex_exit(&xzp->z_lock);
652 zfs_unlinked_add(xzp, tx);
653 }
654
655 /* Remove this znode from the unlinked set */
656 VERIFY3U(0, ==,
657 zap_remove_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx));
658
659 zfs_znode_delete(zp, tx);
660
661 dmu_tx_commit(tx);
662 out:
663 if (xzp)
664 VN_RELE(ZTOV(xzp));
665 }
666
667 static uint64_t
668 zfs_dirent(znode_t *zp)
669 {
670 uint64_t de = zp->z_id;
671 if (zp->z_zfsvfs->z_version >= ZPL_VERSION_DIRENT_TYPE)
672 de |= IFTODT((zp)->z_phys->zp_mode) << 60;
673 return (de);
674 }
675
676 /*
677 * Link zp into dl. Can only fail if zp has been unlinked.
678 */
679 int
680 zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag)
681 {
682 znode_t *dzp = dl->dl_dzp;
683 vnode_t *vp = ZTOV(zp);
684 uint64_t value;
685 int zp_is_dir = (vp->v_type == VDIR);
686 int error;
687
688 dmu_buf_will_dirty(zp->z_dbuf, tx);
689 mutex_enter(&zp->z_lock);
690
691 if (!(flag & ZRENAMING)) {
692 if (zp->z_unlinked) { /* no new links to unlinked zp */
693 ASSERT(!(flag & (ZNEW | ZEXISTS)));
694 mutex_exit(&zp->z_lock);
695 return (ENOENT);
696 }
697 zp->z_phys->zp_links++;
698 }
699 zp->z_phys->zp_parent = dzp->z_id; /* dzp is now zp's parent */
700
701 if (!(flag & ZNEW))
702 zfs_time_stamper_locked(zp, STATE_CHANGED, tx);
703 mutex_exit(&zp->z_lock);
704
705 dmu_buf_will_dirty(dzp->z_dbuf, tx);
706 mutex_enter(&dzp->z_lock);
707 dzp->z_phys->zp_size++; /* one dirent added */
708 dzp->z_phys->zp_links += zp_is_dir; /* ".." link from zp */
709 zfs_time_stamper_locked(dzp, CONTENT_MODIFIED, tx);
710 mutex_exit(&dzp->z_lock);
711
712 value = zfs_dirent(zp);
713 error = zap_add(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name,
714 8, 1, &value, tx);
715 ASSERT(error == 0);
716
717 dnlc_update(ZTOV(dzp), dl->dl_name, vp);
718
719 return (0);
720 }
721
722 /*
723 * Unlink zp from dl, and mark zp for deletion if this was the last link.
724 * Can fail if zp is a mount point (EBUSY) or a non-empty directory (EEXIST).
725 * If 'unlinkedp' is NULL, we put unlinked znodes on the unlinked list.
726 * If it's non-NULL, we use it to indicate whether the znode needs deletion,
727 * and it's the caller's job to do it.
728 */
729 int
730 zfs_link_destroy(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag,
731 boolean_t *unlinkedp)
732 {
733 znode_t *dzp = dl->dl_dzp;
734 vnode_t *vp = ZTOV(zp);
735 int zp_is_dir = (vp->v_type == VDIR);
736 boolean_t unlinked = B_FALSE;
737 int error;
738
739 dnlc_remove(ZTOV(dzp), dl->dl_name);
740
741 if (!(flag & ZRENAMING)) {
742 dmu_buf_will_dirty(zp->z_dbuf, tx);
743
744 if (vn_vfswlock(vp)) /* prevent new mounts on zp */
745 return (EBUSY);
746
747 if (vn_ismntpt(vp)) { /* don't remove mount point */
748 vn_vfsunlock(vp);
749 return (EBUSY);
750 }
751
752 mutex_enter(&zp->z_lock);
753 if (zp_is_dir && !zfs_dirempty(zp)) { /* dir not empty */
754 mutex_exit(&zp->z_lock);
755 vn_vfsunlock(vp);
756 return (ENOTEMPTY);
757 }
758 if (zp->z_phys->zp_links <= zp_is_dir) {
759 zfs_panic_recover("zfs: link count on vnode %p is %u, "
760 "should be at least %u", zp->z_vnode,
761 (int)zp->z_phys->zp_links,
762 zp_is_dir + 1);
763 zp->z_phys->zp_links = zp_is_dir + 1;
764 }
765 if (--zp->z_phys->zp_links == zp_is_dir) {
766 zp->z_unlinked = B_TRUE;
767 zp->z_phys->zp_links = 0;
768 unlinked = B_TRUE;
769 } else {
770 zfs_time_stamper_locked(zp, STATE_CHANGED, tx);
771 }
772 mutex_exit(&zp->z_lock);
773 vn_vfsunlock(vp);
774 }
775
776 dmu_buf_will_dirty(dzp->z_dbuf, tx);
777 mutex_enter(&dzp->z_lock);
778 dzp->z_phys->zp_size--; /* one dirent removed */
779 dzp->z_phys->zp_links -= zp_is_dir; /* ".." link from zp */
780 zfs_time_stamper_locked(dzp, CONTENT_MODIFIED, tx);
781 mutex_exit(&dzp->z_lock);
782
783 if (zp->z_zfsvfs->z_norm) {
784 if (((zp->z_zfsvfs->z_case == ZFS_CASE_INSENSITIVE) &&
785 (flag & ZCIEXACT)) ||
786 ((zp->z_zfsvfs->z_case == ZFS_CASE_MIXED) &&
787 !(flag & ZCILOOK)))
788 error = zap_remove_norm(zp->z_zfsvfs->z_os,
789 dzp->z_id, dl->dl_name, MT_EXACT, tx);
790 else
791 error = zap_remove_norm(zp->z_zfsvfs->z_os,
792 dzp->z_id, dl->dl_name, MT_FIRST, tx);
793 } else {
794 error = zap_remove(zp->z_zfsvfs->z_os,
795 dzp->z_id, dl->dl_name, tx);
796 }
797 ASSERT(error == 0);
798
799 if (unlinkedp != NULL)
800 *unlinkedp = unlinked;
801 else if (unlinked)
802 zfs_unlinked_add(zp, tx);
803
804 return (0);
805 }
806
807 /*
808 * Indicate whether the directory is empty. Works with or without z_lock
809 * held, but can only be consider a hint in the latter case. Returns true
810 * if only "." and ".." remain and there's no work in progress.
811 */
812 boolean_t
813 zfs_dirempty(znode_t *dzp)
814 {
815 return (dzp->z_phys->zp_size == 2 && dzp->z_dirlocks == 0);
816 }
817
818 int
819 zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr)
820 {
821 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
822 znode_t *xzp;
823 dmu_tx_t *tx;
824 int error;
825 zfs_fuid_info_t *fuidp = NULL;
826
827 *xvpp = NULL;
828
829 /*
830 * In FreeBSD, access checking for creating an EA is being done
831 * in zfs_setextattr(),
832 */
833 #ifndef __FreeBSD__
834 if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, 0, B_FALSE, cr))
835 return (error);
836 #endif
837
838 tx = dmu_tx_create(zfsvfs->z_os);
839 dmu_tx_hold_bonus(tx, zp->z_id);
840 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
841 if (IS_EPHEMERAL(crgetuid(cr)) || IS_EPHEMERAL(crgetgid(cr))) {
842 if (zfsvfs->z_fuid_obj == 0) {
843 dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
844 dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
845 FUID_SIZE_ESTIMATE(zfsvfs));
846 dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, FALSE, NULL);
847 } else {
848 dmu_tx_hold_bonus(tx, zfsvfs->z_fuid_obj);
849 dmu_tx_hold_write(tx, zfsvfs->z_fuid_obj, 0,
850 FUID_SIZE_ESTIMATE(zfsvfs));
851 }
852 }
853 error = dmu_tx_assign(tx, zfsvfs->z_assign);
854 if (error) {
855 if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT)
856 dmu_tx_wait(tx);
857 dmu_tx_abort(tx);
858 return (error);
859 }
860 zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, 0, NULL, &fuidp);
861 ASSERT(xzp->z_phys->zp_parent == zp->z_id);
862 dmu_buf_will_dirty(zp->z_dbuf, tx);
863 zp->z_phys->zp_xattr = xzp->z_id;
864
865 (void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp,
866 xzp, "", NULL, fuidp, vap);
867 if (fuidp)
868 zfs_fuid_info_free(fuidp);
869 dmu_tx_commit(tx);
870
871 *xvpp = ZTOV(xzp);
872
873 return (0);
874 }
875
876 /*
877 * Return a znode for the extended attribute directory for zp.
878 * ** If the directory does not already exist, it is created **
879 *
880 * IN: zp - znode to obtain attribute directory from
881 * cr - credentials of caller
882 * flags - flags from the VOP_LOOKUP call
883 *
884 * OUT: xzpp - pointer to extended attribute znode
885 *
886 * RETURN: 0 on success
887 * error number on failure
888 */
889 int
890 zfs_get_xattrdir(znode_t *zp, vnode_t **xvpp, cred_t *cr, int flags)
891 {
892 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
893 znode_t *xzp;
894 zfs_dirlock_t *dl;
895 vattr_t va;
896 int error;
897 top:
898 error = zfs_dirent_lock(&dl, zp, "", &xzp, ZXATTR, NULL, NULL);
899 if (error)
900 return (error);
901
902 if (xzp != NULL) {
903 *xvpp = ZTOV(xzp);
904 zfs_dirent_unlock(dl);
905 return (0);
906 }
907
908 ASSERT(zp->z_phys->zp_xattr == 0);
909
910 if (!(flags & CREATE_XATTR_DIR)) {
911 zfs_dirent_unlock(dl);
912 #ifdef __FreeBSD__
913 return (ENOATTR);
914 #else
915 return (ENOENT);
916 #endif
917 }
918
919 if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
920 zfs_dirent_unlock(dl);
921 return (EROFS);
922 }
923
924 /*
925 * The ability to 'create' files in an attribute
926 * directory comes from the write_xattr permission on the base file.
927 *
928 * The ability to 'search' an attribute directory requires
929 * read_xattr permission on the base file.
930 *
931 * Once in a directory the ability to read/write attributes
932 * is controlled by the permissions on the attribute file.
933 */
934 va.va_mask = AT_TYPE | AT_MODE | AT_UID | AT_GID;
935 va.va_type = VDIR;
936 va.va_mode = S_IFDIR | S_ISVTX | 0777;
937 zfs_fuid_map_ids(zp, cr, &va.va_uid, &va.va_gid);
938
939 error = zfs_make_xattrdir(zp, &va, xvpp, cr);
940 zfs_dirent_unlock(dl);
941
942 if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) {
943 /* NB: we already did dmu_tx_wait() if necessary */
944 goto top;
945 }
946 if (error == 0)
947 VOP_UNLOCK(*xvpp, 0, curthread);
948
949 return (error);
950 }
951
952 /*
953 * Decide whether it is okay to remove within a sticky directory.
954 *
955 * In sticky directories, write access is not sufficient;
956 * you can remove entries from a directory only if:
957 *
958 * you own the directory,
959 * you own the entry,
960 * the entry is a plain file and you have write access,
961 * or you are privileged (checked in secpolicy...).
962 *
963 * The function returns 0 if remove access is granted.
964 */
965 int
966 zfs_sticky_remove_access(znode_t *zdp, znode_t *zp, cred_t *cr)
967 {
968 uid_t uid;
969 uid_t downer;
970 uid_t fowner;
971 zfsvfs_t *zfsvfs = zdp->z_zfsvfs;
972
973 if (zdp->z_zfsvfs->z_assign >= TXG_INITIAL) /* ZIL replay */
974 return (0);
975
976 if ((zdp->z_phys->zp_mode & S_ISVTX) == 0)
977 return (0);
978
979 downer = zfs_fuid_map_id(zfsvfs, zdp->z_phys->zp_uid, cr, ZFS_OWNER);
980 fowner = zfs_fuid_map_id(zfsvfs, zp->z_phys->zp_uid, cr, ZFS_OWNER);
981
982 if ((uid = crgetuid(cr)) == downer || uid == fowner ||
983 (ZTOV(zp)->v_type == VREG &&
984 zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr) == 0))
985 return (0);
986 else
987 return (secpolicy_vnode_remove(ZTOV(zp), cr));
988 }
Cache object: 87675bc4886213f5d9bddb0fdba02d59
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