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 * Copyright (c) 2012 by Delphix. All rights reserved.
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/mode.h>
36 #include <sys/kmem.h>
37 #include <sys/uio.h>
38 #include <sys/pathname.h>
39 #include <sys/cmn_err.h>
40 #include <sys/errno.h>
41 #include <sys/stat.h>
42 #include <sys/unistd.h>
43 #include <sys/sunddi.h>
44 #include <sys/random.h>
45 #include <sys/policy.h>
46 #include <sys/zfs_dir.h>
47 #include <sys/zfs_acl.h>
48 #include <sys/fs/zfs.h>
49 #include "fs/fs_subr.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/sa.h>
56 #include <sys/zfs_sa.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 * ZHAVELOCK: Don't grab the z_name_lock for this call. The
120 * current thread already holds it.
121 *
122 * Output arguments:
123 * zpp - pointer to the znode for the entry (NULL if there isn't one)
124 * dlpp - pointer to the dirlock for this entry (NULL on error)
125 * direntflags - (case-insensitive lookup only)
126 * flags if multiple case-sensitive matches exist in directory
127 * realpnp - (case-insensitive lookup only)
128 * actual name matched within the directory
129 *
130 * Return value: 0 on success or errno on failure.
131 *
132 * NOTE: Always checks for, and rejects, '.' and '..'.
133 * NOTE: For case-insensitive file systems we take wide locks (see below),
134 * but return znode pointers to a single match.
135 */
136 int
137 zfs_dirent_lock(zfs_dirlock_t **dlpp, znode_t *dzp, char *name, znode_t **zpp,
138 int flag, int *direntflags, pathname_t *realpnp)
139 {
140 zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
141 zfs_dirlock_t *dl;
142 boolean_t update;
143 boolean_t exact;
144 uint64_t zoid;
145 vnode_t *vp = NULL;
146 int error = 0;
147 int cmpflags;
148
149 *zpp = NULL;
150 *dlpp = NULL;
151
152 /*
153 * Verify that we are not trying to lock '.', '..', or '.zfs'
154 */
155 if (name[0] == '.' &&
156 (name[1] == '\0' || (name[1] == '.' && name[2] == '\0')) ||
157 zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0)
158 return (EEXIST);
159
160 /*
161 * Case sensitivity and normalization preferences are set when
162 * the file system is created. These are stored in the
163 * zfsvfs->z_case and zfsvfs->z_norm fields. These choices
164 * affect what vnodes can be cached in the DNLC, how we
165 * perform zap lookups, and the "width" of our dirlocks.
166 *
167 * A normal dirlock locks a single name. Note that with
168 * normalization a name can be composed multiple ways, but
169 * when normalized, these names all compare equal. A wide
170 * dirlock locks multiple names. We need these when the file
171 * system is supporting mixed-mode access. It is sometimes
172 * necessary to lock all case permutations of file name at
173 * once so that simultaneous case-insensitive/case-sensitive
174 * behaves as rationally as possible.
175 */
176
177 /*
178 * Decide if exact matches should be requested when performing
179 * a zap lookup on file systems supporting case-insensitive
180 * access.
181 */
182 exact =
183 ((zfsvfs->z_case == ZFS_CASE_INSENSITIVE) && (flag & ZCIEXACT)) ||
184 ((zfsvfs->z_case == ZFS_CASE_MIXED) && !(flag & ZCILOOK));
185
186 /*
187 * Only look in or update the DNLC if we are looking for the
188 * name on a file system that does not require normalization
189 * or case folding. We can also look there if we happen to be
190 * on a non-normalizing, mixed sensitivity file system IF we
191 * are looking for the exact name.
192 *
193 * Maybe can add TO-UPPERed version of name to dnlc in ci-only
194 * case for performance improvement?
195 */
196 update = !zfsvfs->z_norm ||
197 ((zfsvfs->z_case == ZFS_CASE_MIXED) &&
198 !(zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER) && !(flag & ZCILOOK));
199
200 /*
201 * ZRENAMING indicates we are in a situation where we should
202 * take narrow locks regardless of the file system's
203 * preferences for normalizing and case folding. This will
204 * prevent us deadlocking trying to grab the same wide lock
205 * twice if the two names happen to be case-insensitive
206 * matches.
207 */
208 if (flag & ZRENAMING)
209 cmpflags = 0;
210 else
211 cmpflags = zfsvfs->z_norm;
212
213 /*
214 * Wait until there are no locks on this name.
215 *
216 * Don't grab the the lock if it is already held. However, cannot
217 * have both ZSHARED and ZHAVELOCK together.
218 */
219 ASSERT(!(flag & ZSHARED) || !(flag & ZHAVELOCK));
220 if (!(flag & ZHAVELOCK))
221 rw_enter(&dzp->z_name_lock, RW_READER);
222
223 mutex_enter(&dzp->z_lock);
224 for (;;) {
225 if (dzp->z_unlinked) {
226 mutex_exit(&dzp->z_lock);
227 if (!(flag & ZHAVELOCK))
228 rw_exit(&dzp->z_name_lock);
229 return (ENOENT);
230 }
231 for (dl = dzp->z_dirlocks; dl != NULL; dl = dl->dl_next) {
232 if ((u8_strcmp(name, dl->dl_name, 0, cmpflags,
233 U8_UNICODE_LATEST, &error) == 0) || error != 0)
234 break;
235 }
236 if (error != 0) {
237 mutex_exit(&dzp->z_lock);
238 if (!(flag & ZHAVELOCK))
239 rw_exit(&dzp->z_name_lock);
240 return (ENOENT);
241 }
242 if (dl == NULL) {
243 /*
244 * Allocate a new dirlock and add it to the list.
245 */
246 dl = kmem_alloc(sizeof (zfs_dirlock_t), KM_SLEEP);
247 cv_init(&dl->dl_cv, NULL, CV_DEFAULT, NULL);
248 dl->dl_name = name;
249 dl->dl_sharecnt = 0;
250 dl->dl_namelock = 0;
251 dl->dl_namesize = 0;
252 dl->dl_dzp = dzp;
253 dl->dl_next = dzp->z_dirlocks;
254 dzp->z_dirlocks = dl;
255 break;
256 }
257 if ((flag & ZSHARED) && dl->dl_sharecnt != 0)
258 break;
259 cv_wait(&dl->dl_cv, &dzp->z_lock);
260 }
261
262 /*
263 * If the z_name_lock was NOT held for this dirlock record it.
264 */
265 if (flag & ZHAVELOCK)
266 dl->dl_namelock = 1;
267
268 if ((flag & ZSHARED) && ++dl->dl_sharecnt > 1 && dl->dl_namesize == 0) {
269 /*
270 * We're the second shared reference to dl. Make a copy of
271 * dl_name in case the first thread goes away before we do.
272 * Note that we initialize the new name before storing its
273 * pointer into dl_name, because the first thread may load
274 * dl->dl_name at any time. He'll either see the old value,
275 * which is his, or the new shared copy; either is OK.
276 */
277 dl->dl_namesize = strlen(dl->dl_name) + 1;
278 name = kmem_alloc(dl->dl_namesize, KM_SLEEP);
279 bcopy(dl->dl_name, name, dl->dl_namesize);
280 dl->dl_name = name;
281 }
282
283 mutex_exit(&dzp->z_lock);
284
285 /*
286 * We have a dirlock on the name. (Note that it is the dirlock,
287 * not the dzp's z_lock, that protects the name in the zap object.)
288 * See if there's an object by this name; if so, put a hold on it.
289 */
290 if (flag & ZXATTR) {
291 error = sa_lookup(dzp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), &zoid,
292 sizeof (zoid));
293 if (error == 0)
294 error = (zoid == 0 ? ENOENT : 0);
295 } else {
296 if (update)
297 vp = dnlc_lookup(ZTOV(dzp), name);
298 if (vp == DNLC_NO_VNODE) {
299 VN_RELE(vp);
300 error = ENOENT;
301 } else if (vp) {
302 if (flag & ZNEW) {
303 zfs_dirent_unlock(dl);
304 VN_RELE(vp);
305 return (EEXIST);
306 }
307 *dlpp = dl;
308 *zpp = VTOZ(vp);
309 return (0);
310 } else {
311 error = zfs_match_find(zfsvfs, dzp, name, exact,
312 update, direntflags, realpnp, &zoid);
313 }
314 }
315 if (error) {
316 if (error != ENOENT || (flag & ZEXISTS)) {
317 zfs_dirent_unlock(dl);
318 return (error);
319 }
320 } else {
321 if (flag & ZNEW) {
322 zfs_dirent_unlock(dl);
323 return (EEXIST);
324 }
325 error = zfs_zget(zfsvfs, zoid, zpp);
326 if (error) {
327 zfs_dirent_unlock(dl);
328 return (error);
329 }
330 if (!(flag & ZXATTR) && update)
331 dnlc_update(ZTOV(dzp), name, ZTOV(*zpp));
332 }
333
334 *dlpp = dl;
335
336 return (0);
337 }
338
339 /*
340 * Unlock this directory entry and wake anyone who was waiting for it.
341 */
342 void
343 zfs_dirent_unlock(zfs_dirlock_t *dl)
344 {
345 znode_t *dzp = dl->dl_dzp;
346 zfs_dirlock_t **prev_dl, *cur_dl;
347
348 mutex_enter(&dzp->z_lock);
349
350 if (!dl->dl_namelock)
351 rw_exit(&dzp->z_name_lock);
352
353 if (dl->dl_sharecnt > 1) {
354 dl->dl_sharecnt--;
355 mutex_exit(&dzp->z_lock);
356 return;
357 }
358 prev_dl = &dzp->z_dirlocks;
359 while ((cur_dl = *prev_dl) != dl)
360 prev_dl = &cur_dl->dl_next;
361 *prev_dl = dl->dl_next;
362 cv_broadcast(&dl->dl_cv);
363 mutex_exit(&dzp->z_lock);
364
365 if (dl->dl_namesize != 0)
366 kmem_free(dl->dl_name, dl->dl_namesize);
367 cv_destroy(&dl->dl_cv);
368 kmem_free(dl, sizeof (*dl));
369 }
370
371 /*
372 * Look up an entry in a directory.
373 *
374 * NOTE: '.' and '..' are handled as special cases because
375 * no directory entries are actually stored for them. If this is
376 * the root of a filesystem, then '.zfs' is also treated as a
377 * special pseudo-directory.
378 */
379 int
380 zfs_dirlook(znode_t *dzp, char *name, vnode_t **vpp, int flags,
381 int *deflg, pathname_t *rpnp)
382 {
383 zfs_dirlock_t *dl;
384 znode_t *zp;
385 int error = 0;
386 uint64_t parent;
387
388 if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) {
389 *vpp = ZTOV(dzp);
390 VN_HOLD(*vpp);
391 } else if (name[0] == '.' && name[1] == '.' && name[2] == 0) {
392 zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
393
394 /*
395 * If we are a snapshot mounted under .zfs, return
396 * the vp for the snapshot directory.
397 */
398 if ((error = sa_lookup(dzp->z_sa_hdl,
399 SA_ZPL_PARENT(zfsvfs), &parent, sizeof (parent))) != 0)
400 return (error);
401 if (parent == dzp->z_id && zfsvfs->z_parent != zfsvfs) {
402 error = zfsctl_root_lookup(zfsvfs->z_parent->z_ctldir,
403 "snapshot", vpp, NULL, 0, NULL, kcred,
404 NULL, NULL, NULL);
405 return (error);
406 }
407 rw_enter(&dzp->z_parent_lock, RW_READER);
408 error = zfs_zget(zfsvfs, parent, &zp);
409 if (error == 0)
410 *vpp = ZTOV(zp);
411 rw_exit(&dzp->z_parent_lock);
412 } else if (zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) {
413 *vpp = zfsctl_root(dzp);
414 } else {
415 int zf;
416
417 zf = ZEXISTS | ZSHARED;
418 if (flags & FIGNORECASE)
419 zf |= ZCILOOK;
420
421 error = zfs_dirent_lock(&dl, dzp, name, &zp, zf, deflg, rpnp);
422 if (error == 0) {
423 *vpp = ZTOV(zp);
424 zfs_dirent_unlock(dl);
425 dzp->z_zn_prefetch = B_TRUE; /* enable prefetching */
426 }
427 rpnp = NULL;
428 }
429
430 if ((flags & FIGNORECASE) && rpnp && !error)
431 (void) strlcpy(rpnp->pn_buf, name, rpnp->pn_bufsize);
432
433 return (error);
434 }
435
436 /*
437 * unlinked Set (formerly known as the "delete queue") Error Handling
438 *
439 * When dealing with the unlinked set, we dmu_tx_hold_zap(), but we
440 * don't specify the name of the entry that we will be manipulating. We
441 * also fib and say that we won't be adding any new entries to the
442 * unlinked set, even though we might (this is to lower the minimum file
443 * size that can be deleted in a full filesystem). So on the small
444 * chance that the nlink list is using a fat zap (ie. has more than
445 * 2000 entries), we *may* not pre-read a block that's needed.
446 * Therefore it is remotely possible for some of the assertions
447 * regarding the unlinked set below to fail due to i/o error. On a
448 * nondebug system, this will result in the space being leaked.
449 */
450 void
451 zfs_unlinked_add(znode_t *zp, dmu_tx_t *tx)
452 {
453 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
454
455 ASSERT(zp->z_unlinked);
456 ASSERT(zp->z_links == 0);
457
458 VERIFY0(zap_add_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj,
459 zp->z_id, tx));
460 }
461
462 /*
463 * Clean up any znodes that had no links when we either crashed or
464 * (force) umounted the file system.
465 */
466 void
467 zfs_unlinked_drain(zfsvfs_t *zfsvfs)
468 {
469 zap_cursor_t zc;
470 zap_attribute_t zap;
471 dmu_object_info_t doi;
472 znode_t *zp;
473 int error;
474
475 /*
476 * Interate over the contents of the unlinked set.
477 */
478 for (zap_cursor_init(&zc, zfsvfs->z_os, zfsvfs->z_unlinkedobj);
479 zap_cursor_retrieve(&zc, &zap) == 0;
480 zap_cursor_advance(&zc)) {
481
482 /*
483 * See what kind of object we have in list
484 */
485
486 error = dmu_object_info(zfsvfs->z_os,
487 zap.za_first_integer, &doi);
488 if (error != 0)
489 continue;
490
491 ASSERT((doi.doi_type == DMU_OT_PLAIN_FILE_CONTENTS) ||
492 (doi.doi_type == DMU_OT_DIRECTORY_CONTENTS));
493 /*
494 * We need to re-mark these list entries for deletion,
495 * so we pull them back into core and set zp->z_unlinked.
496 */
497 error = zfs_zget(zfsvfs, zap.za_first_integer, &zp);
498
499 /*
500 * We may pick up znodes that are already marked for deletion.
501 * This could happen during the purge of an extended attribute
502 * directory. All we need to do is skip over them, since they
503 * are already in the system marked z_unlinked.
504 */
505 if (error != 0)
506 continue;
507
508 zp->z_unlinked = B_TRUE;
509 VN_RELE(ZTOV(zp));
510 }
511 zap_cursor_fini(&zc);
512 }
513
514 /*
515 * Delete the entire contents of a directory. Return a count
516 * of the number of entries that could not be deleted. If we encounter
517 * an error, return a count of at least one so that the directory stays
518 * in the unlinked set.
519 *
520 * NOTE: this function assumes that the directory is inactive,
521 * so there is no need to lock its entries before deletion.
522 * Also, it assumes the directory contents is *only* regular
523 * files.
524 */
525 static int
526 zfs_purgedir(znode_t *dzp)
527 {
528 zap_cursor_t zc;
529 zap_attribute_t zap;
530 znode_t *xzp;
531 dmu_tx_t *tx;
532 zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
533 zfs_dirlock_t dl;
534 int skipped = 0;
535 int error;
536
537 for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id);
538 (error = zap_cursor_retrieve(&zc, &zap)) == 0;
539 zap_cursor_advance(&zc)) {
540 error = zfs_zget(zfsvfs,
541 ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp);
542 if (error) {
543 skipped += 1;
544 continue;
545 }
546
547 ASSERT((ZTOV(xzp)->v_type == VREG) ||
548 (ZTOV(xzp)->v_type == VLNK));
549
550 tx = dmu_tx_create(zfsvfs->z_os);
551 dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
552 dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name);
553 dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
554 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
555 /* Is this really needed ? */
556 zfs_sa_upgrade_txholds(tx, xzp);
557 error = dmu_tx_assign(tx, TXG_WAIT);
558 if (error) {
559 dmu_tx_abort(tx);
560 VN_RELE(ZTOV(xzp));
561 skipped += 1;
562 continue;
563 }
564 bzero(&dl, sizeof (dl));
565 dl.dl_dzp = dzp;
566 dl.dl_name = zap.za_name;
567
568 error = zfs_link_destroy(&dl, xzp, tx, 0, NULL);
569 if (error)
570 skipped += 1;
571 dmu_tx_commit(tx);
572
573 VN_RELE(ZTOV(xzp));
574 }
575 zap_cursor_fini(&zc);
576 if (error != ENOENT)
577 skipped += 1;
578 return (skipped);
579 }
580
581 void
582 zfs_rmnode(znode_t *zp)
583 {
584 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
585 objset_t *os = zfsvfs->z_os;
586 znode_t *xzp = NULL;
587 dmu_tx_t *tx;
588 uint64_t acl_obj;
589 uint64_t xattr_obj;
590 int error;
591
592 ASSERT(zp->z_links == 0);
593 ASSERT(ZTOV(zp)->v_count == 0);
594
595 /*
596 * If this is an attribute directory, purge its contents.
597 */
598 if (ZTOV(zp)->v_type == VDIR && (zp->z_pflags & ZFS_XATTR)) {
599 if (zfs_purgedir(zp) != 0) {
600 /*
601 * Not enough space to delete some xattrs.
602 * Leave it in the unlinked set.
603 */
604 zfs_znode_dmu_fini(zp);
605 zfs_znode_free(zp);
606 return;
607 }
608 }
609
610 /*
611 * Free up all the data in the file.
612 */
613 error = dmu_free_long_range(os, zp->z_id, 0, DMU_OBJECT_END);
614 if (error) {
615 /*
616 * Not enough space. Leave the file in the unlinked set.
617 */
618 zfs_znode_dmu_fini(zp);
619 zfs_znode_free(zp);
620 return;
621 }
622
623 /*
624 * If the file has extended attributes, we're going to unlink
625 * the xattr dir.
626 */
627 error = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
628 &xattr_obj, sizeof (xattr_obj));
629 if (error == 0 && xattr_obj) {
630 error = zfs_zget(zfsvfs, xattr_obj, &xzp);
631 ASSERT(error == 0);
632 }
633
634 acl_obj = zfs_external_acl(zp);
635
636 /*
637 * Set up the final transaction.
638 */
639 tx = dmu_tx_create(os);
640 dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END);
641 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
642 if (xzp) {
643 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, TRUE, NULL);
644 dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
645 }
646 if (acl_obj)
647 dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END);
648
649 zfs_sa_upgrade_txholds(tx, zp);
650 error = dmu_tx_assign(tx, TXG_WAIT);
651 if (error) {
652 /*
653 * Not enough space to delete the file. Leave it in the
654 * unlinked set, leaking it until the fs is remounted (at
655 * which point we'll call zfs_unlinked_drain() to process it).
656 */
657 dmu_tx_abort(tx);
658 zfs_znode_dmu_fini(zp);
659 zfs_znode_free(zp);
660 goto out;
661 }
662
663 if (xzp) {
664 ASSERT(error == 0);
665 mutex_enter(&xzp->z_lock);
666 xzp->z_unlinked = B_TRUE; /* mark xzp for deletion */
667 xzp->z_links = 0; /* no more links to it */
668 VERIFY(0 == sa_update(xzp->z_sa_hdl, SA_ZPL_LINKS(zfsvfs),
669 &xzp->z_links, sizeof (xzp->z_links), tx));
670 mutex_exit(&xzp->z_lock);
671 zfs_unlinked_add(xzp, tx);
672 }
673
674 /* Remove this znode from the unlinked set */
675 VERIFY0(zap_remove_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj,
676 xzp->z_id, tx));
677
678 zfs_znode_delete(zp, tx);
679
680 dmu_tx_commit(tx);
681 out:
682 if (xzp)
683 VN_RELE(ZTOV(xzp));
684 }
685
686 static uint64_t
687 zfs_dirent(znode_t *zp, uint64_t mode)
688 {
689 uint64_t de = zp->z_id;
690
691 if (zp->z_zfsvfs->z_version >= ZPL_VERSION_DIRENT_TYPE)
692 de |= IFTODT(mode) << 60;
693 return (de);
694 }
695
696 /*
697 * Link zp into dl. Can only fail if zp has been unlinked.
698 */
699 int
700 zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag)
701 {
702 znode_t *dzp = dl->dl_dzp;
703 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
704 vnode_t *vp = ZTOV(zp);
705 uint64_t value;
706 int zp_is_dir = (vp->v_type == VDIR);
707 sa_bulk_attr_t bulk[5];
708 uint64_t mtime[2], ctime[2];
709 int count = 0;
710 int error;
711
712 mutex_enter(&zp->z_lock);
713
714 if (!(flag & ZRENAMING)) {
715 if (zp->z_unlinked) { /* no new links to unlinked zp */
716 ASSERT(!(flag & (ZNEW | ZEXISTS)));
717 mutex_exit(&zp->z_lock);
718 return (ENOENT);
719 }
720 zp->z_links++;
721 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL,
722 &zp->z_links, sizeof (zp->z_links));
723
724 }
725 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_PARENT(zfsvfs), NULL,
726 &dzp->z_id, sizeof (dzp->z_id));
727 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
728 &zp->z_pflags, sizeof (zp->z_pflags));
729
730 if (!(flag & ZNEW)) {
731 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
732 ctime, sizeof (ctime));
733 zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime,
734 ctime, B_TRUE);
735 }
736 error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
737 ASSERT(error == 0);
738
739 mutex_exit(&zp->z_lock);
740
741 mutex_enter(&dzp->z_lock);
742 dzp->z_size++;
743 dzp->z_links += zp_is_dir;
744 count = 0;
745 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs), NULL,
746 &dzp->z_size, sizeof (dzp->z_size));
747 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL,
748 &dzp->z_links, sizeof (dzp->z_links));
749 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
750 mtime, sizeof (mtime));
751 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
752 ctime, sizeof (ctime));
753 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
754 &dzp->z_pflags, sizeof (dzp->z_pflags));
755 zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime, B_TRUE);
756 error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx);
757 ASSERT(error == 0);
758 mutex_exit(&dzp->z_lock);
759
760 value = zfs_dirent(zp, zp->z_mode);
761 error = zap_add(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name,
762 8, 1, &value, tx);
763 ASSERT(error == 0);
764
765 dnlc_update(ZTOV(dzp), dl->dl_name, vp);
766
767 return (0);
768 }
769
770 static int
771 zfs_dropname(zfs_dirlock_t *dl, znode_t *zp, znode_t *dzp, dmu_tx_t *tx,
772 int flag)
773 {
774 int error;
775
776 if (zp->z_zfsvfs->z_norm) {
777 if (((zp->z_zfsvfs->z_case == ZFS_CASE_INSENSITIVE) &&
778 (flag & ZCIEXACT)) ||
779 ((zp->z_zfsvfs->z_case == ZFS_CASE_MIXED) &&
780 !(flag & ZCILOOK)))
781 error = zap_remove_norm(zp->z_zfsvfs->z_os,
782 dzp->z_id, dl->dl_name, MT_EXACT, tx);
783 else
784 error = zap_remove_norm(zp->z_zfsvfs->z_os,
785 dzp->z_id, dl->dl_name, MT_FIRST, tx);
786 } else {
787 error = zap_remove(zp->z_zfsvfs->z_os,
788 dzp->z_id, dl->dl_name, tx);
789 }
790
791 return (error);
792 }
793
794 /*
795 * Unlink zp from dl, and mark zp for deletion if this was the last link.
796 * Can fail if zp is a mount point (EBUSY) or a non-empty directory (EEXIST).
797 * If 'unlinkedp' is NULL, we put unlinked znodes on the unlinked list.
798 * If it's non-NULL, we use it to indicate whether the znode needs deletion,
799 * and it's the caller's job to do it.
800 */
801 int
802 zfs_link_destroy(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag,
803 boolean_t *unlinkedp)
804 {
805 znode_t *dzp = dl->dl_dzp;
806 zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
807 vnode_t *vp = ZTOV(zp);
808 int zp_is_dir = (vp->v_type == VDIR);
809 boolean_t unlinked = B_FALSE;
810 sa_bulk_attr_t bulk[5];
811 uint64_t mtime[2], ctime[2];
812 int count = 0;
813 int error;
814
815 dnlc_remove(ZTOV(dzp), dl->dl_name);
816
817 if (!(flag & ZRENAMING)) {
818 if (vn_vfswlock(vp)) /* prevent new mounts on zp */
819 return (EBUSY);
820
821 if (vn_ismntpt(vp)) { /* don't remove mount point */
822 vn_vfsunlock(vp);
823 return (EBUSY);
824 }
825
826 mutex_enter(&zp->z_lock);
827
828 if (zp_is_dir && !zfs_dirempty(zp)) {
829 mutex_exit(&zp->z_lock);
830 vn_vfsunlock(vp);
831 return (EEXIST);
832 }
833
834 /*
835 * If we get here, we are going to try to remove the object.
836 * First try removing the name from the directory; if that
837 * fails, return the error.
838 */
839 error = zfs_dropname(dl, zp, dzp, tx, flag);
840 if (error != 0) {
841 mutex_exit(&zp->z_lock);
842 vn_vfsunlock(vp);
843 return (error);
844 }
845
846 if (zp->z_links <= zp_is_dir) {
847 zfs_panic_recover("zfs: link count on %s is %u, "
848 "should be at least %u",
849 zp->z_vnode->v_path ? zp->z_vnode->v_path :
850 "<unknown>", (int)zp->z_links,
851 zp_is_dir + 1);
852 zp->z_links = zp_is_dir + 1;
853 }
854 if (--zp->z_links == zp_is_dir) {
855 zp->z_unlinked = B_TRUE;
856 zp->z_links = 0;
857 unlinked = B_TRUE;
858 } else {
859 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs),
860 NULL, &ctime, sizeof (ctime));
861 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
862 NULL, &zp->z_pflags, sizeof (zp->z_pflags));
863 zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime, ctime,
864 B_TRUE);
865 }
866 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs),
867 NULL, &zp->z_links, sizeof (zp->z_links));
868 error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
869 count = 0;
870 ASSERT(error == 0);
871 mutex_exit(&zp->z_lock);
872 vn_vfsunlock(vp);
873 } else {
874 error = zfs_dropname(dl, zp, dzp, tx, flag);
875 if (error != 0)
876 return (error);
877 }
878
879 mutex_enter(&dzp->z_lock);
880 dzp->z_size--; /* one dirent removed */
881 dzp->z_links -= zp_is_dir; /* ".." link from zp */
882 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs),
883 NULL, &dzp->z_links, sizeof (dzp->z_links));
884 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs),
885 NULL, &dzp->z_size, sizeof (dzp->z_size));
886 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs),
887 NULL, ctime, sizeof (ctime));
888 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs),
889 NULL, mtime, sizeof (mtime));
890 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
891 NULL, &dzp->z_pflags, sizeof (dzp->z_pflags));
892 zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime, B_TRUE);
893 error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx);
894 ASSERT(error == 0);
895 mutex_exit(&dzp->z_lock);
896
897 if (unlinkedp != NULL)
898 *unlinkedp = unlinked;
899 else if (unlinked)
900 zfs_unlinked_add(zp, tx);
901
902 return (0);
903 }
904
905 /*
906 * Indicate whether the directory is empty. Works with or without z_lock
907 * held, but can only be consider a hint in the latter case. Returns true
908 * if only "." and ".." remain and there's no work in progress.
909 */
910 boolean_t
911 zfs_dirempty(znode_t *dzp)
912 {
913 return (dzp->z_size == 2 && dzp->z_dirlocks == 0);
914 }
915
916 int
917 zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr)
918 {
919 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
920 znode_t *xzp;
921 dmu_tx_t *tx;
922 int error;
923 zfs_acl_ids_t acl_ids;
924 boolean_t fuid_dirtied;
925 uint64_t parent;
926
927 *xvpp = NULL;
928
929 if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, 0, B_FALSE, cr))
930 return (error);
931
932 if ((error = zfs_acl_ids_create(zp, IS_XATTR, vap, cr, NULL,
933 &acl_ids)) != 0)
934 return (error);
935 if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
936 zfs_acl_ids_free(&acl_ids);
937 return (EDQUOT);
938 }
939
940 top:
941 tx = dmu_tx_create(zfsvfs->z_os);
942 dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
943 ZFS_SA_BASE_ATTR_SIZE);
944 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
945 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
946 fuid_dirtied = zfsvfs->z_fuid_dirty;
947 if (fuid_dirtied)
948 zfs_fuid_txhold(zfsvfs, tx);
949 error = dmu_tx_assign(tx, TXG_NOWAIT);
950 if (error) {
951 if (error == ERESTART) {
952 dmu_tx_wait(tx);
953 dmu_tx_abort(tx);
954 goto top;
955 }
956 zfs_acl_ids_free(&acl_ids);
957 dmu_tx_abort(tx);
958 return (error);
959 }
960 zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, &acl_ids);
961
962 if (fuid_dirtied)
963 zfs_fuid_sync(zfsvfs, tx);
964
965 #ifdef DEBUG
966 error = sa_lookup(xzp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
967 &parent, sizeof (parent));
968 ASSERT(error == 0 && parent == zp->z_id);
969 #endif
970
971 VERIFY(0 == sa_update(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), &xzp->z_id,
972 sizeof (xzp->z_id), tx));
973
974 (void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp,
975 xzp, "", NULL, acl_ids.z_fuidp, vap);
976
977 zfs_acl_ids_free(&acl_ids);
978 dmu_tx_commit(tx);
979
980 *xvpp = ZTOV(xzp);
981
982 return (0);
983 }
984
985 /*
986 * Return a znode for the extended attribute directory for zp.
987 * ** If the directory does not already exist, it is created **
988 *
989 * IN: zp - znode to obtain attribute directory from
990 * cr - credentials of caller
991 * flags - flags from the VOP_LOOKUP call
992 *
993 * OUT: xzpp - pointer to extended attribute znode
994 *
995 * RETURN: 0 on success
996 * error number on failure
997 */
998 int
999 zfs_get_xattrdir(znode_t *zp, vnode_t **xvpp, cred_t *cr, int flags)
1000 {
1001 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
1002 znode_t *xzp;
1003 zfs_dirlock_t *dl;
1004 vattr_t va;
1005 int error;
1006 top:
1007 error = zfs_dirent_lock(&dl, zp, "", &xzp, ZXATTR, NULL, NULL);
1008 if (error)
1009 return (error);
1010
1011 if (xzp != NULL) {
1012 *xvpp = ZTOV(xzp);
1013 zfs_dirent_unlock(dl);
1014 return (0);
1015 }
1016
1017
1018 if (!(flags & CREATE_XATTR_DIR)) {
1019 zfs_dirent_unlock(dl);
1020 return (ENOENT);
1021 }
1022
1023 if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
1024 zfs_dirent_unlock(dl);
1025 return (EROFS);
1026 }
1027
1028 /*
1029 * The ability to 'create' files in an attribute
1030 * directory comes from the write_xattr permission on the base file.
1031 *
1032 * The ability to 'search' an attribute directory requires
1033 * read_xattr permission on the base file.
1034 *
1035 * Once in a directory the ability to read/write attributes
1036 * is controlled by the permissions on the attribute file.
1037 */
1038 va.va_mask = AT_TYPE | AT_MODE | AT_UID | AT_GID;
1039 va.va_type = VDIR;
1040 va.va_mode = S_IFDIR | S_ISVTX | 0777;
1041 zfs_fuid_map_ids(zp, cr, &va.va_uid, &va.va_gid);
1042
1043 error = zfs_make_xattrdir(zp, &va, xvpp, cr);
1044 zfs_dirent_unlock(dl);
1045
1046 if (error == ERESTART) {
1047 /* NB: we already did dmu_tx_wait() if necessary */
1048 goto top;
1049 }
1050
1051 return (error);
1052 }
1053
1054 /*
1055 * Decide whether it is okay to remove within a sticky directory.
1056 *
1057 * In sticky directories, write access is not sufficient;
1058 * you can remove entries from a directory only if:
1059 *
1060 * you own the directory,
1061 * you own the entry,
1062 * the entry is a plain file and you have write access,
1063 * or you are privileged (checked in secpolicy...).
1064 *
1065 * The function returns 0 if remove access is granted.
1066 */
1067 int
1068 zfs_sticky_remove_access(znode_t *zdp, znode_t *zp, cred_t *cr)
1069 {
1070 uid_t uid;
1071 uid_t downer;
1072 uid_t fowner;
1073 zfsvfs_t *zfsvfs = zdp->z_zfsvfs;
1074
1075 if (zdp->z_zfsvfs->z_replay)
1076 return (0);
1077
1078 if ((zdp->z_mode & S_ISVTX) == 0)
1079 return (0);
1080
1081 downer = zfs_fuid_map_id(zfsvfs, zdp->z_uid, cr, ZFS_OWNER);
1082 fowner = zfs_fuid_map_id(zfsvfs, zp->z_uid, cr, ZFS_OWNER);
1083
1084 if ((uid = crgetuid(cr)) == downer || uid == fowner ||
1085 (ZTOV(zp)->v_type == VREG &&
1086 zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr) == 0))
1087 return (0);
1088 else
1089 return (secpolicy_vnode_remove(cr));
1090 }