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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 */
24
25 #include <sys/types.h>
26 #include <sys/param.h>
27 #include <sys/time.h>
28 #include <sys/systm.h>
29 #include <sys/sysmacros.h>
30 #include <sys/resource.h>
31 #include <sys/vfs.h>
32 #include <sys/vnode.h>
33 #include <sys/file.h>
34 #include <sys/mode.h>
35 #include <sys/kmem.h>
36 #include <sys/uio.h>
37 #include <sys/pathname.h>
38 #include <sys/cmn_err.h>
39 #include <sys/errno.h>
40 #include <sys/stat.h>
41 #include <sys/unistd.h>
42 #include <sys/sunddi.h>
43 #include <sys/random.h>
44 #include <sys/policy.h>
45 #include <sys/zfs_dir.h>
46 #include <sys/zfs_acl.h>
47 #include <sys/fs/zfs.h>
48 #include "fs/fs_subr.h"
49 #include <sys/zap.h>
50 #include <sys/dmu.h>
51 #include <sys/atomic.h>
52 #include <sys/zfs_ctldir.h>
53 #include <sys/zfs_fuid.h>
54 #include <sys/sa.h>
55 #include <sys/zfs_sa.h>
56 #include <sys/dnlc.h>
57 #include <sys/extdirent.h>
58
59 /*
60 * zfs_match_find() is used by zfs_dirent_lock() to peform zap lookups
61 * of names after deciding which is the appropriate lookup interface.
62 */
63 static int
64 zfs_match_find(zfsvfs_t *zfsvfs, znode_t *dzp, char *name, boolean_t exact,
65 boolean_t update, int *deflags, pathname_t *rpnp, uint64_t *zoid)
66 {
67 int error;
68
69 if (zfsvfs->z_norm) {
70 matchtype_t mt = MT_FIRST;
71 boolean_t conflict = B_FALSE;
72 size_t bufsz = 0;
73 char *buf = NULL;
74
75 if (rpnp) {
76 buf = rpnp->pn_buf;
77 bufsz = rpnp->pn_bufsize;
78 }
79 if (exact)
80 mt = MT_EXACT;
81 /*
82 * In the non-mixed case we only expect there would ever
83 * be one match, but we need to use the normalizing lookup.
84 */
85 error = zap_lookup_norm(zfsvfs->z_os, dzp->z_id, name, 8, 1,
86 zoid, mt, buf, bufsz, &conflict);
87 if (!error && deflags)
88 *deflags = conflict ? ED_CASE_CONFLICT : 0;
89 } else {
90 error = zap_lookup(zfsvfs->z_os, dzp->z_id, name, 8, 1, zoid);
91 }
92 *zoid = ZFS_DIRENT_OBJ(*zoid);
93
94 if (error == ENOENT && update)
95 dnlc_update(ZTOV(dzp), name, DNLC_NO_VNODE);
96
97 return (error);
98 }
99
100 /*
101 * Lock a directory entry. A dirlock on <dzp, name> protects that name
102 * in dzp's directory zap object. As long as you hold a dirlock, you can
103 * assume two things: (1) dzp cannot be reaped, and (2) no other thread
104 * can change the zap entry for (i.e. link or unlink) this name.
105 *
106 * Input arguments:
107 * dzp - znode for directory
108 * name - name of entry to lock
109 * flag - ZNEW: if the entry already exists, fail with EEXIST.
110 * ZEXISTS: if the entry does not exist, fail with ENOENT.
111 * ZSHARED: allow concurrent access with other ZSHARED callers.
112 * ZXATTR: we want dzp's xattr directory
113 * ZCILOOK: On a mixed sensitivity file system,
114 * this lookup should be case-insensitive.
115 * ZCIEXACT: On a purely case-insensitive file system,
116 * this lookup should be case-sensitive.
117 * ZRENAMING: we are locking for renaming, force narrow locks
118 * ZHAVELOCK: Don't grab the z_name_lock for this call. The
119 * current thread already holds it.
120 *
121 * Output arguments:
122 * zpp - pointer to the znode for the entry (NULL if there isn't one)
123 * dlpp - pointer to the dirlock for this entry (NULL on error)
124 * direntflags - (case-insensitive lookup only)
125 * flags if multiple case-sensitive matches exist in directory
126 * realpnp - (case-insensitive lookup only)
127 * actual name matched within the directory
128 *
129 * Return value: 0 on success or errno on failure.
130 *
131 * NOTE: Always checks for, and rejects, '.' and '..'.
132 * NOTE: For case-insensitive file systems we take wide locks (see below),
133 * but return znode pointers to a single match.
134 */
135 int
136 zfs_dirent_lock(zfs_dirlock_t **dlpp, znode_t *dzp, char *name, znode_t **zpp,
137 int flag, int *direntflags, pathname_t *realpnp)
138 {
139 zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
140 zfs_dirlock_t *dl;
141 boolean_t update;
142 boolean_t exact;
143 uint64_t zoid;
144 vnode_t *vp = NULL;
145 int error = 0;
146 int cmpflags;
147
148 *zpp = NULL;
149 *dlpp = NULL;
150
151 /*
152 * Verify that we are not trying to lock '.', '..', or '.zfs'
153 */
154 if (name[0] == '.' &&
155 (name[1] == '\0' || (name[1] == '.' && name[2] == '\0')) ||
156 zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0)
157 return (EEXIST);
158
159 /*
160 * Case sensitivity and normalization preferences are set when
161 * the file system is created. These are stored in the
162 * zfsvfs->z_case and zfsvfs->z_norm fields. These choices
163 * affect what vnodes can be cached in the DNLC, how we
164 * perform zap lookups, and the "width" of our dirlocks.
165 *
166 * A normal dirlock locks a single name. Note that with
167 * normalization a name can be composed multiple ways, but
168 * when normalized, these names all compare equal. A wide
169 * dirlock locks multiple names. We need these when the file
170 * system is supporting mixed-mode access. It is sometimes
171 * necessary to lock all case permutations of file name at
172 * once so that simultaneous case-insensitive/case-sensitive
173 * behaves as rationally as possible.
174 */
175
176 /*
177 * Decide if exact matches should be requested when performing
178 * a zap lookup on file systems supporting case-insensitive
179 * access.
180 */
181 exact =
182 ((zfsvfs->z_case == ZFS_CASE_INSENSITIVE) && (flag & ZCIEXACT)) ||
183 ((zfsvfs->z_case == ZFS_CASE_MIXED) && !(flag & ZCILOOK));
184
185 /*
186 * Only look in or update the DNLC if we are looking for the
187 * name on a file system that does not require normalization
188 * or case folding. We can also look there if we happen to be
189 * on a non-normalizing, mixed sensitivity file system IF we
190 * are looking for the exact name.
191 *
192 * Maybe can add TO-UPPERed version of name to dnlc in ci-only
193 * case for performance improvement?
194 */
195 update = !zfsvfs->z_norm ||
196 ((zfsvfs->z_case == ZFS_CASE_MIXED) &&
197 !(zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER) && !(flag & ZCILOOK));
198
199 /*
200 * ZRENAMING indicates we are in a situation where we should
201 * take narrow locks regardless of the file system's
202 * preferences for normalizing and case folding. This will
203 * prevent us deadlocking trying to grab the same wide lock
204 * twice if the two names happen to be case-insensitive
205 * matches.
206 */
207 if (flag & ZRENAMING)
208 cmpflags = 0;
209 else
210 cmpflags = zfsvfs->z_norm;
211
212 /*
213 * Wait until there are no locks on this name.
214 *
215 * Don't grab the the lock if it is already held. However, cannot
216 * have both ZSHARED and ZHAVELOCK together.
217 */
218 ASSERT(!(flag & ZSHARED) || !(flag & ZHAVELOCK));
219 if (!(flag & ZHAVELOCK))
220 rw_enter(&dzp->z_name_lock, RW_READER);
221
222 mutex_enter(&dzp->z_lock);
223 for (;;) {
224 if (dzp->z_unlinked) {
225 mutex_exit(&dzp->z_lock);
226 if (!(flag & ZHAVELOCK))
227 rw_exit(&dzp->z_name_lock);
228 return (ENOENT);
229 }
230 for (dl = dzp->z_dirlocks; dl != NULL; dl = dl->dl_next) {
231 if ((u8_strcmp(name, dl->dl_name, 0, cmpflags,
232 U8_UNICODE_LATEST, &error) == 0) || error != 0)
233 break;
234 }
235 if (error != 0) {
236 mutex_exit(&dzp->z_lock);
237 if (!(flag & ZHAVELOCK))
238 rw_exit(&dzp->z_name_lock);
239 return (ENOENT);
240 }
241 if (dl == NULL) {
242 /*
243 * Allocate a new dirlock and add it to the list.
244 */
245 dl = kmem_alloc(sizeof (zfs_dirlock_t), KM_SLEEP);
246 cv_init(&dl->dl_cv, NULL, CV_DEFAULT, NULL);
247 dl->dl_name = name;
248 dl->dl_sharecnt = 0;
249 dl->dl_namelock = 0;
250 dl->dl_namesize = 0;
251 dl->dl_dzp = dzp;
252 dl->dl_next = dzp->z_dirlocks;
253 dzp->z_dirlocks = dl;
254 break;
255 }
256 if ((flag & ZSHARED) && dl->dl_sharecnt != 0)
257 break;
258 cv_wait(&dl->dl_cv, &dzp->z_lock);
259 }
260
261 /*
262 * If the z_name_lock was NOT held for this dirlock record it.
263 */
264 if (flag & ZHAVELOCK)
265 dl->dl_namelock = 1;
266
267 if ((flag & ZSHARED) && ++dl->dl_sharecnt > 1 && dl->dl_namesize == 0) {
268 /*
269 * We're the second shared reference to dl. Make a copy of
270 * dl_name in case the first thread goes away before we do.
271 * Note that we initialize the new name before storing its
272 * pointer into dl_name, because the first thread may load
273 * dl->dl_name at any time. He'll either see the old value,
274 * which is his, or the new shared copy; either is OK.
275 */
276 dl->dl_namesize = strlen(dl->dl_name) + 1;
277 name = kmem_alloc(dl->dl_namesize, KM_SLEEP);
278 bcopy(dl->dl_name, name, dl->dl_namesize);
279 dl->dl_name = name;
280 }
281
282 mutex_exit(&dzp->z_lock);
283
284 /*
285 * We have a dirlock on the name. (Note that it is the dirlock,
286 * not the dzp's z_lock, that protects the name in the zap object.)
287 * See if there's an object by this name; if so, put a hold on it.
288 */
289 if (flag & ZXATTR) {
290 error = sa_lookup(dzp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), &zoid,
291 sizeof (zoid));
292 if (error == 0)
293 error = (zoid == 0 ? ENOENT : 0);
294 } else {
295 if (update)
296 vp = dnlc_lookup(ZTOV(dzp), name);
297 if (vp == DNLC_NO_VNODE) {
298 VN_RELE(vp);
299 error = ENOENT;
300 } else if (vp) {
301 if (flag & ZNEW) {
302 zfs_dirent_unlock(dl);
303 VN_RELE(vp);
304 return (EEXIST);
305 }
306 *dlpp = dl;
307 *zpp = VTOZ(vp);
308 return (0);
309 } else {
310 error = zfs_match_find(zfsvfs, dzp, name, exact,
311 update, direntflags, realpnp, &zoid);
312 }
313 }
314 if (error) {
315 if (error != ENOENT || (flag & ZEXISTS)) {
316 zfs_dirent_unlock(dl);
317 return (error);
318 }
319 } else {
320 if (flag & ZNEW) {
321 zfs_dirent_unlock(dl);
322 return (EEXIST);
323 }
324 error = zfs_zget(zfsvfs, zoid, zpp);
325 if (error) {
326 zfs_dirent_unlock(dl);
327 return (error);
328 }
329 if (!(flag & ZXATTR) && update)
330 dnlc_update(ZTOV(dzp), name, ZTOV(*zpp));
331 }
332
333 *dlpp = dl;
334
335 return (0);
336 }
337
338 /*
339 * Unlock this directory entry and wake anyone who was waiting for it.
340 */
341 void
342 zfs_dirent_unlock(zfs_dirlock_t *dl)
343 {
344 znode_t *dzp = dl->dl_dzp;
345 zfs_dirlock_t **prev_dl, *cur_dl;
346
347 mutex_enter(&dzp->z_lock);
348
349 if (!dl->dl_namelock)
350 rw_exit(&dzp->z_name_lock);
351
352 if (dl->dl_sharecnt > 1) {
353 dl->dl_sharecnt--;
354 mutex_exit(&dzp->z_lock);
355 return;
356 }
357 prev_dl = &dzp->z_dirlocks;
358 while ((cur_dl = *prev_dl) != dl)
359 prev_dl = &cur_dl->dl_next;
360 *prev_dl = dl->dl_next;
361 cv_broadcast(&dl->dl_cv);
362 mutex_exit(&dzp->z_lock);
363
364 if (dl->dl_namesize != 0)
365 kmem_free(dl->dl_name, dl->dl_namesize);
366 cv_destroy(&dl->dl_cv);
367 kmem_free(dl, sizeof (*dl));
368 }
369
370 /*
371 * Look up an entry in a directory.
372 *
373 * NOTE: '.' and '..' are handled as special cases because
374 * no directory entries are actually stored for them. If this is
375 * the root of a filesystem, then '.zfs' is also treated as a
376 * special pseudo-directory.
377 */
378 int
379 zfs_dirlook(znode_t *dzp, char *name, vnode_t **vpp, int flags,
380 int *deflg, pathname_t *rpnp)
381 {
382 zfs_dirlock_t *dl;
383 znode_t *zp;
384 int error = 0;
385 uint64_t parent;
386
387 if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) {
388 *vpp = ZTOV(dzp);
389 VN_HOLD(*vpp);
390 } else if (name[0] == '.' && name[1] == '.' && name[2] == 0) {
391 zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
392
393 /*
394 * If we are a snapshot mounted under .zfs, return
395 * the vp for the snapshot directory.
396 */
397 if ((error = sa_lookup(dzp->z_sa_hdl,
398 SA_ZPL_PARENT(zfsvfs), &parent, sizeof (parent))) != 0)
399 return (error);
400 if (parent == dzp->z_id && zfsvfs->z_parent != zfsvfs) {
401 error = zfsctl_root_lookup(zfsvfs->z_parent->z_ctldir,
402 "snapshot", vpp, NULL, 0, NULL, kcred,
403 NULL, NULL, NULL);
404 return (error);
405 }
406 rw_enter(&dzp->z_parent_lock, RW_READER);
407 error = zfs_zget(zfsvfs, parent, &zp);
408 if (error == 0)
409 *vpp = ZTOV(zp);
410 rw_exit(&dzp->z_parent_lock);
411 } else if (zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) {
412 *vpp = zfsctl_root(dzp);
413 } else {
414 int zf;
415
416 zf = ZEXISTS | ZSHARED;
417 if (flags & FIGNORECASE)
418 zf |= ZCILOOK;
419
420 error = zfs_dirent_lock(&dl, dzp, name, &zp, zf, deflg, rpnp);
421 if (error == 0) {
422 *vpp = ZTOV(zp);
423 zfs_dirent_unlock(dl);
424 dzp->z_zn_prefetch = B_TRUE; /* enable prefetching */
425 }
426 rpnp = NULL;
427 }
428
429 if ((flags & FIGNORECASE) && rpnp && !error)
430 (void) strlcpy(rpnp->pn_buf, name, rpnp->pn_bufsize);
431
432 return (error);
433 }
434
435 /*
436 * unlinked Set (formerly known as the "delete queue") Error Handling
437 *
438 * When dealing with the unlinked set, we dmu_tx_hold_zap(), but we
439 * don't specify the name of the entry that we will be manipulating. We
440 * also fib and say that we won't be adding any new entries to the
441 * unlinked set, even though we might (this is to lower the minimum file
442 * size that can be deleted in a full filesystem). So on the small
443 * chance that the nlink list is using a fat zap (ie. has more than
444 * 2000 entries), we *may* not pre-read a block that's needed.
445 * Therefore it is remotely possible for some of the assertions
446 * regarding the unlinked set below to fail due to i/o error. On a
447 * nondebug system, this will result in the space being leaked.
448 */
449 void
450 zfs_unlinked_add(znode_t *zp, dmu_tx_t *tx)
451 {
452 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
453
454 ASSERT(zp->z_unlinked);
455 ASSERT(zp->z_links == 0);
456
457 VERIFY3U(0, ==,
458 zap_add_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx));
459 }
460
461 /*
462 * Clean up any znodes that had no links when we either crashed or
463 * (force) umounted the file system.
464 */
465 void
466 zfs_unlinked_drain(zfsvfs_t *zfsvfs)
467 {
468 zap_cursor_t zc;
469 zap_attribute_t zap;
470 dmu_object_info_t doi;
471 znode_t *zp;
472 int error;
473
474 /*
475 * Interate over the contents of the unlinked set.
476 */
477 for (zap_cursor_init(&zc, zfsvfs->z_os, zfsvfs->z_unlinkedobj);
478 zap_cursor_retrieve(&zc, &zap) == 0;
479 zap_cursor_advance(&zc)) {
480
481 /*
482 * See what kind of object we have in list
483 */
484
485 error = dmu_object_info(zfsvfs->z_os,
486 zap.za_first_integer, &doi);
487 if (error != 0)
488 continue;
489
490 ASSERT((doi.doi_type == DMU_OT_PLAIN_FILE_CONTENTS) ||
491 (doi.doi_type == DMU_OT_DIRECTORY_CONTENTS));
492 /*
493 * We need to re-mark these list entries for deletion,
494 * so we pull them back into core and set zp->z_unlinked.
495 */
496 error = zfs_zget(zfsvfs, zap.za_first_integer, &zp);
497
498 /*
499 * We may pick up znodes that are already marked for deletion.
500 * This could happen during the purge of an extended attribute
501 * directory. All we need to do is skip over them, since they
502 * are already in the system marked z_unlinked.
503 */
504 if (error != 0)
505 continue;
506
507 zp->z_unlinked = B_TRUE;
508 VN_RELE(ZTOV(zp));
509 }
510 zap_cursor_fini(&zc);
511 }
512
513 /*
514 * Delete the entire contents of a directory. Return a count
515 * of the number of entries that could not be deleted. If we encounter
516 * an error, return a count of at least one so that the directory stays
517 * in the unlinked set.
518 *
519 * NOTE: this function assumes that the directory is inactive,
520 * so there is no need to lock its entries before deletion.
521 * Also, it assumes the directory contents is *only* regular
522 * files.
523 */
524 static int
525 zfs_purgedir(znode_t *dzp)
526 {
527 zap_cursor_t zc;
528 zap_attribute_t zap;
529 znode_t *xzp;
530 dmu_tx_t *tx;
531 zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
532 zfs_dirlock_t dl;
533 int skipped = 0;
534 int error;
535
536 for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id);
537 (error = zap_cursor_retrieve(&zc, &zap)) == 0;
538 zap_cursor_advance(&zc)) {
539 error = zfs_zget(zfsvfs,
540 ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp);
541 if (error) {
542 skipped += 1;
543 continue;
544 }
545
546 ASSERT((ZTOV(xzp)->v_type == VREG) ||
547 (ZTOV(xzp)->v_type == VLNK));
548
549 tx = dmu_tx_create(zfsvfs->z_os);
550 dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
551 dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name);
552 dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
553 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
554 /* Is this really needed ? */
555 zfs_sa_upgrade_txholds(tx, xzp);
556 error = dmu_tx_assign(tx, TXG_WAIT);
557 if (error) {
558 dmu_tx_abort(tx);
559 VN_RELE(ZTOV(xzp));
560 skipped += 1;
561 continue;
562 }
563 bzero(&dl, sizeof (dl));
564 dl.dl_dzp = dzp;
565 dl.dl_name = zap.za_name;
566
567 error = zfs_link_destroy(&dl, xzp, tx, 0, NULL);
568 if (error)
569 skipped += 1;
570 dmu_tx_commit(tx);
571
572 VN_RELE(ZTOV(xzp));
573 }
574 zap_cursor_fini(&zc);
575 if (error != ENOENT)
576 skipped += 1;
577 return (skipped);
578 }
579
580 void
581 zfs_rmnode(znode_t *zp)
582 {
583 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
584 objset_t *os = zfsvfs->z_os;
585 znode_t *xzp = NULL;
586 dmu_tx_t *tx;
587 uint64_t acl_obj;
588 uint64_t xattr_obj;
589 int error;
590
591 ASSERT(zp->z_links == 0);
592 ASSERT(ZTOV(zp)->v_count == 0);
593
594 /*
595 * If this is an attribute directory, purge its contents.
596 */
597 if (ZTOV(zp)->v_type == VDIR && (zp->z_pflags & ZFS_XATTR)) {
598 if (zfs_purgedir(zp) != 0) {
599 /*
600 * Not enough space to delete some xattrs.
601 * Leave it in the unlinked set.
602 */
603 zfs_znode_dmu_fini(zp);
604 zfs_znode_free(zp);
605 return;
606 }
607 }
608
609 /*
610 * Free up all the data in the file.
611 */
612 error = dmu_free_long_range(os, zp->z_id, 0, DMU_OBJECT_END);
613 if (error) {
614 /*
615 * Not enough space. Leave the file in the unlinked set.
616 */
617 zfs_znode_dmu_fini(zp);
618 zfs_znode_free(zp);
619 return;
620 }
621
622 /*
623 * If the file has extended attributes, we're going to unlink
624 * the xattr dir.
625 */
626 error = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
627 &xattr_obj, sizeof (xattr_obj));
628 if (error == 0 && xattr_obj) {
629 error = zfs_zget(zfsvfs, xattr_obj, &xzp);
630 ASSERT(error == 0);
631 }
632
633 acl_obj = zfs_external_acl(zp);
634
635 /*
636 * Set up the final transaction.
637 */
638 tx = dmu_tx_create(os);
639 dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END);
640 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
641 if (xzp) {
642 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, TRUE, NULL);
643 dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
644 }
645 if (acl_obj)
646 dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END);
647
648 zfs_sa_upgrade_txholds(tx, zp);
649 error = dmu_tx_assign(tx, TXG_WAIT);
650 if (error) {
651 /*
652 * Not enough space to delete the file. Leave it in the
653 * unlinked set, leaking it until the fs is remounted (at
654 * which point we'll call zfs_unlinked_drain() to process it).
655 */
656 dmu_tx_abort(tx);
657 zfs_znode_dmu_fini(zp);
658 zfs_znode_free(zp);
659 goto out;
660 }
661
662 if (xzp) {
663 ASSERT(error == 0);
664 mutex_enter(&xzp->z_lock);
665 xzp->z_unlinked = B_TRUE; /* mark xzp for deletion */
666 xzp->z_links = 0; /* no more links to it */
667 VERIFY(0 == sa_update(xzp->z_sa_hdl, SA_ZPL_LINKS(zfsvfs),
668 &xzp->z_links, sizeof (xzp->z_links), tx));
669 mutex_exit(&xzp->z_lock);
670 zfs_unlinked_add(xzp, tx);
671 }
672
673 /* Remove this znode from the unlinked set */
674 VERIFY3U(0, ==,
675 zap_remove_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx));
676
677 zfs_znode_delete(zp, tx);
678
679 dmu_tx_commit(tx);
680 out:
681 if (xzp)
682 VN_RELE(ZTOV(xzp));
683 }
684
685 static uint64_t
686 zfs_dirent(znode_t *zp, uint64_t mode)
687 {
688 uint64_t de = zp->z_id;
689
690 if (zp->z_zfsvfs->z_version >= ZPL_VERSION_DIRENT_TYPE)
691 de |= IFTODT(mode) << 60;
692 return (de);
693 }
694
695 /*
696 * Link zp into dl. Can only fail if zp has been unlinked.
697 */
698 int
699 zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag)
700 {
701 znode_t *dzp = dl->dl_dzp;
702 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
703 vnode_t *vp = ZTOV(zp);
704 uint64_t value;
705 int zp_is_dir = (vp->v_type == VDIR);
706 sa_bulk_attr_t bulk[5];
707 uint64_t mtime[2], ctime[2];
708 int count = 0;
709 int error;
710
711 mutex_enter(&zp->z_lock);
712
713 if (!(flag & ZRENAMING)) {
714 if (zp->z_unlinked) { /* no new links to unlinked zp */
715 ASSERT(!(flag & (ZNEW | ZEXISTS)));
716 mutex_exit(&zp->z_lock);
717 return (ENOENT);
718 }
719 zp->z_links++;
720 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL,
721 &zp->z_links, sizeof (zp->z_links));
722
723 }
724 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_PARENT(zfsvfs), NULL,
725 &dzp->z_id, sizeof (dzp->z_id));
726 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
727 &zp->z_pflags, sizeof (zp->z_pflags));
728
729 if (!(flag & ZNEW)) {
730 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
731 ctime, sizeof (ctime));
732 zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime,
733 ctime, B_TRUE);
734 }
735 error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
736 ASSERT(error == 0);
737
738 mutex_exit(&zp->z_lock);
739
740 mutex_enter(&dzp->z_lock);
741 dzp->z_size++;
742 dzp->z_links += zp_is_dir;
743 count = 0;
744 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs), NULL,
745 &dzp->z_size, sizeof (dzp->z_size));
746 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL,
747 &dzp->z_links, sizeof (dzp->z_links));
748 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
749 mtime, sizeof (mtime));
750 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
751 ctime, sizeof (ctime));
752 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
753 &dzp->z_pflags, sizeof (dzp->z_pflags));
754 zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime, B_TRUE);
755 error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx);
756 ASSERT(error == 0);
757 mutex_exit(&dzp->z_lock);
758
759 value = zfs_dirent(zp, zp->z_mode);
760 error = zap_add(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name,
761 8, 1, &value, tx);
762 ASSERT(error == 0);
763
764 dnlc_update(ZTOV(dzp), dl->dl_name, vp);
765
766 return (0);
767 }
768
769 static int
770 zfs_dropname(zfs_dirlock_t *dl, znode_t *zp, znode_t *dzp, dmu_tx_t *tx,
771 int flag)
772 {
773 int error;
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
790 return (error);
791 }
792
793 /*
794 * Unlink zp from dl, and mark zp for deletion if this was the last link.
795 * Can fail if zp is a mount point (EBUSY) or a non-empty directory (EEXIST).
796 * If 'unlinkedp' is NULL, we put unlinked znodes on the unlinked list.
797 * If it's non-NULL, we use it to indicate whether the znode needs deletion,
798 * and it's the caller's job to do it.
799 */
800 int
801 zfs_link_destroy(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag,
802 boolean_t *unlinkedp)
803 {
804 znode_t *dzp = dl->dl_dzp;
805 zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
806 vnode_t *vp = ZTOV(zp);
807 int zp_is_dir = (vp->v_type == VDIR);
808 boolean_t unlinked = B_FALSE;
809 sa_bulk_attr_t bulk[5];
810 uint64_t mtime[2], ctime[2];
811 int count = 0;
812 int error;
813
814 dnlc_remove(ZTOV(dzp), dl->dl_name);
815
816 if (!(flag & ZRENAMING)) {
817 if (vn_vfswlock(vp)) /* prevent new mounts on zp */
818 return (EBUSY);
819
820 if (vn_ismntpt(vp)) { /* don't remove mount point */
821 vn_vfsunlock(vp);
822 return (EBUSY);
823 }
824
825 mutex_enter(&zp->z_lock);
826
827 if (zp_is_dir && !zfs_dirempty(zp)) {
828 mutex_exit(&zp->z_lock);
829 vn_vfsunlock(vp);
830 return (EEXIST);
831 }
832
833 /*
834 * If we get here, we are going to try to remove the object.
835 * First try removing the name from the directory; if that
836 * fails, return the error.
837 */
838 error = zfs_dropname(dl, zp, dzp, tx, flag);
839 if (error != 0) {
840 mutex_exit(&zp->z_lock);
841 vn_vfsunlock(vp);
842 return (error);
843 }
844
845 if (zp->z_links <= zp_is_dir) {
846 zfs_panic_recover("zfs: link count on %s is %u, "
847 "should be at least %u",
848 zp->z_vnode->v_path ? zp->z_vnode->v_path :
849 "<unknown>", (int)zp->z_links,
850 zp_is_dir + 1);
851 zp->z_links = zp_is_dir + 1;
852 }
853 if (--zp->z_links == zp_is_dir) {
854 zp->z_unlinked = B_TRUE;
855 zp->z_links = 0;
856 unlinked = B_TRUE;
857 } else {
858 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs),
859 NULL, &ctime, sizeof (ctime));
860 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
861 NULL, &zp->z_pflags, sizeof (zp->z_pflags));
862 zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime, ctime,
863 B_TRUE);
864 }
865 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs),
866 NULL, &zp->z_links, sizeof (zp->z_links));
867 error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
868 count = 0;
869 ASSERT(error == 0);
870 mutex_exit(&zp->z_lock);
871 vn_vfsunlock(vp);
872 } else {
873 error = zfs_dropname(dl, zp, dzp, tx, flag);
874 if (error != 0)
875 return (error);
876 }
877
878 mutex_enter(&dzp->z_lock);
879 dzp->z_size--; /* one dirent removed */
880 dzp->z_links -= zp_is_dir; /* ".." link from zp */
881 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs),
882 NULL, &dzp->z_links, sizeof (dzp->z_links));
883 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs),
884 NULL, &dzp->z_size, sizeof (dzp->z_size));
885 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs),
886 NULL, ctime, sizeof (ctime));
887 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs),
888 NULL, mtime, sizeof (mtime));
889 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
890 NULL, &dzp->z_pflags, sizeof (dzp->z_pflags));
891 zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime, B_TRUE);
892 error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx);
893 ASSERT(error == 0);
894 mutex_exit(&dzp->z_lock);
895
896 if (unlinkedp != NULL)
897 *unlinkedp = unlinked;
898 else if (unlinked)
899 zfs_unlinked_add(zp, tx);
900
901 return (0);
902 }
903
904 /*
905 * Indicate whether the directory is empty. Works with or without z_lock
906 * held, but can only be consider a hint in the latter case. Returns true
907 * if only "." and ".." remain and there's no work in progress.
908 */
909 boolean_t
910 zfs_dirempty(znode_t *dzp)
911 {
912 return (dzp->z_size == 2 && dzp->z_dirlocks == 0);
913 }
914
915 int
916 zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr)
917 {
918 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
919 znode_t *xzp;
920 dmu_tx_t *tx;
921 int error;
922 zfs_acl_ids_t acl_ids;
923 boolean_t fuid_dirtied;
924 uint64_t parent;
925
926 *xvpp = NULL;
927
928 if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, 0, B_FALSE, cr))
929 return (error);
930
931 if ((error = zfs_acl_ids_create(zp, IS_XATTR, vap, cr, NULL,
932 &acl_ids)) != 0)
933 return (error);
934 if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
935 zfs_acl_ids_free(&acl_ids);
936 return (EDQUOT);
937 }
938
939 top:
940 tx = dmu_tx_create(zfsvfs->z_os);
941 dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
942 ZFS_SA_BASE_ATTR_SIZE);
943 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
944 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
945 fuid_dirtied = zfsvfs->z_fuid_dirty;
946 if (fuid_dirtied)
947 zfs_fuid_txhold(zfsvfs, tx);
948 error = dmu_tx_assign(tx, TXG_NOWAIT);
949 if (error) {
950 if (error == ERESTART) {
951 dmu_tx_wait(tx);
952 dmu_tx_abort(tx);
953 goto top;
954 }
955 zfs_acl_ids_free(&acl_ids);
956 dmu_tx_abort(tx);
957 return (error);
958 }
959 zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, &acl_ids);
960
961 if (fuid_dirtied)
962 zfs_fuid_sync(zfsvfs, tx);
963
964 #ifdef DEBUG
965 error = sa_lookup(xzp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
966 &parent, sizeof (parent));
967 ASSERT(error == 0 && parent == zp->z_id);
968 #endif
969
970 VERIFY(0 == sa_update(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), &xzp->z_id,
971 sizeof (xzp->z_id), tx));
972
973 (void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp,
974 xzp, "", NULL, acl_ids.z_fuidp, vap);
975
976 zfs_acl_ids_free(&acl_ids);
977 dmu_tx_commit(tx);
978
979 *xvpp = ZTOV(xzp);
980
981 return (0);
982 }
983
984 /*
985 * Return a znode for the extended attribute directory for zp.
986 * ** If the directory does not already exist, it is created **
987 *
988 * IN: zp - znode to obtain attribute directory from
989 * cr - credentials of caller
990 * flags - flags from the VOP_LOOKUP call
991 *
992 * OUT: xzpp - pointer to extended attribute znode
993 *
994 * RETURN: 0 on success
995 * error number on failure
996 */
997 int
998 zfs_get_xattrdir(znode_t *zp, vnode_t **xvpp, cred_t *cr, int flags)
999 {
1000 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
1001 znode_t *xzp;
1002 zfs_dirlock_t *dl;
1003 vattr_t va;
1004 int error;
1005 top:
1006 error = zfs_dirent_lock(&dl, zp, "", &xzp, ZXATTR, NULL, NULL);
1007 if (error)
1008 return (error);
1009
1010 if (xzp != NULL) {
1011 *xvpp = ZTOV(xzp);
1012 zfs_dirent_unlock(dl);
1013 return (0);
1014 }
1015
1016
1017 if (!(flags & CREATE_XATTR_DIR)) {
1018 zfs_dirent_unlock(dl);
1019 return (ENOENT);
1020 }
1021
1022 if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
1023 zfs_dirent_unlock(dl);
1024 return (EROFS);
1025 }
1026
1027 /*
1028 * The ability to 'create' files in an attribute
1029 * directory comes from the write_xattr permission on the base file.
1030 *
1031 * The ability to 'search' an attribute directory requires
1032 * read_xattr permission on the base file.
1033 *
1034 * Once in a directory the ability to read/write attributes
1035 * is controlled by the permissions on the attribute file.
1036 */
1037 va.va_mask = AT_TYPE | AT_MODE | AT_UID | AT_GID;
1038 va.va_type = VDIR;
1039 va.va_mode = S_IFDIR | S_ISVTX | 0777;
1040 zfs_fuid_map_ids(zp, cr, &va.va_uid, &va.va_gid);
1041
1042 error = zfs_make_xattrdir(zp, &va, xvpp, cr);
1043 zfs_dirent_unlock(dl);
1044
1045 if (error == ERESTART) {
1046 /* NB: we already did dmu_tx_wait() if necessary */
1047 goto top;
1048 }
1049
1050 return (error);
1051 }
1052
1053 /*
1054 * Decide whether it is okay to remove within a sticky directory.
1055 *
1056 * In sticky directories, write access is not sufficient;
1057 * you can remove entries from a directory only if:
1058 *
1059 * you own the directory,
1060 * you own the entry,
1061 * the entry is a plain file and you have write access,
1062 * or you are privileged (checked in secpolicy...).
1063 *
1064 * The function returns 0 if remove access is granted.
1065 */
1066 int
1067 zfs_sticky_remove_access(znode_t *zdp, znode_t *zp, cred_t *cr)
1068 {
1069 uid_t uid;
1070 uid_t downer;
1071 uid_t fowner;
1072 zfsvfs_t *zfsvfs = zdp->z_zfsvfs;
1073
1074 if (zdp->z_zfsvfs->z_replay)
1075 return (0);
1076
1077 if ((zdp->z_mode & S_ISVTX) == 0)
1078 return (0);
1079
1080 downer = zfs_fuid_map_id(zfsvfs, zdp->z_uid, cr, ZFS_OWNER);
1081 fowner = zfs_fuid_map_id(zfsvfs, zp->z_uid, cr, ZFS_OWNER);
1082
1083 if ((uid = crgetuid(cr)) == downer || uid == fowner ||
1084 (ZTOV(zp)->v_type == VREG &&
1085 zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr) == 0))
1086 return (0);
1087 else
1088 return (secpolicy_vnode_remove(cr));
1089 }