1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3 * CDDL HEADER START
4 *
5 * The contents of this file are subject to the terms of the
6 * Common Development and Distribution License (the "License").
7 * You may not use this file except in compliance with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or https://opensource.org/licenses/CDDL-1.0.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22
23 /*
24 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
25 * Copyright (c) 2013, 2016 by Delphix. All rights reserved.
26 * Copyright 2017 Nexenta Systems, Inc.
27 */
28
29 #include <sys/types.h>
30 #include <sys/param.h>
31 #include <sys/time.h>
32 #include <sys/sysmacros.h>
33 #include <sys/vfs.h>
34 #include <sys/vnode.h>
35 #include <sys/file.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/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/zfs_vnops.h>
48 #include <sys/fs/zfs.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/dmu_objset.h>
57 #include <sys/dsl_dir.h>
58
59 /*
60 * zfs_match_find() is used by zfs_dirent_lock() to perform zap lookups
61 * of names after deciding which is the appropriate lookup interface.
62 */
63 static int
zfs_match_find(zfsvfs_t * zfsvfs,znode_t * dzp,const char * name,matchtype_t mt,boolean_t update,int * deflags,pathname_t * rpnp,uint64_t * zoid)64 zfs_match_find(zfsvfs_t *zfsvfs, znode_t *dzp, const char *name,
65 matchtype_t mt, boolean_t update, int *deflags, pathname_t *rpnp,
66 uint64_t *zoid)
67 {
68 boolean_t conflict = B_FALSE;
69 int error;
70
71 if (zfsvfs->z_norm) {
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
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 } else {
87 error = zap_lookup(zfsvfs->z_os, dzp->z_id, name, 8, 1, zoid);
88 }
89
90 /*
91 * Allow multiple entries provided the first entry is
92 * the object id. Non-zpl consumers may safely make
93 * use of the additional space.
94 *
95 * XXX: This should be a feature flag for compatibility
96 */
97 if (error == EOVERFLOW)
98 error = 0;
99
100 if (zfsvfs->z_norm && !error && deflags)
101 *deflags = conflict ? ED_CASE_CONFLICT : 0;
102
103 *zoid = ZFS_DIRENT_OBJ(*zoid);
104
105 return (error);
106 }
107
108 /*
109 * Lock a directory entry. A dirlock on <dzp, name> protects that name
110 * in dzp's directory zap object. As long as you hold a dirlock, you can
111 * assume two things: (1) dzp cannot be reaped, and (2) no other thread
112 * can change the zap entry for (i.e. link or unlink) this name.
113 *
114 * Input arguments:
115 * dzp - znode for directory
116 * name - name of entry to lock
117 * flag - ZNEW: if the entry already exists, fail with EEXIST.
118 * ZEXISTS: if the entry does not exist, fail with ENOENT.
119 * ZSHARED: allow concurrent access with other ZSHARED callers.
120 * ZXATTR: we want dzp's xattr directory
121 * ZCILOOK: On a mixed sensitivity file system,
122 * this lookup should be case-insensitive.
123 * ZCIEXACT: On a purely case-insensitive file system,
124 * this lookup should be case-sensitive.
125 * ZRENAMING: we are locking for renaming, force narrow locks
126 * ZHAVELOCK: Don't grab the z_name_lock for this call. The
127 * current thread already holds it.
128 *
129 * Output arguments:
130 * zpp - pointer to the znode for the entry (NULL if there isn't one)
131 * dlpp - pointer to the dirlock for this entry (NULL on error)
132 * direntflags - (case-insensitive lookup only)
133 * flags if multiple case-sensitive matches exist in directory
134 * realpnp - (case-insensitive lookup only)
135 * actual name matched within the directory
136 *
137 * Return value: 0 on success or errno on failure.
138 *
139 * NOTE: Always checks for, and rejects, '.' and '..'.
140 * NOTE: For case-insensitive file systems we take wide locks (see below),
141 * but return znode pointers to a single match.
142 */
143 int
zfs_dirent_lock(zfs_dirlock_t ** dlpp,znode_t * dzp,char * name,znode_t ** zpp,int flag,int * direntflags,pathname_t * realpnp)144 zfs_dirent_lock(zfs_dirlock_t **dlpp, znode_t *dzp, char *name,
145 znode_t **zpp, int flag, int *direntflags, pathname_t *realpnp)
146 {
147 zfsvfs_t *zfsvfs = ZTOZSB(dzp);
148 zfs_dirlock_t *dl;
149 boolean_t update;
150 matchtype_t mt = 0;
151 uint64_t zoid;
152 int error = 0;
153 int cmpflags;
154
155 *zpp = NULL;
156 *dlpp = NULL;
157
158 /*
159 * Verify that we are not trying to lock '.', '..', or '.zfs'
160 */
161 if ((name[0] == '.' &&
162 (name[1] == '\0' || (name[1] == '.' && name[2] == '\0'))) ||
163 (zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0))
164 return (SET_ERROR(EEXIST));
165
166 /*
167 * Case sensitivity and normalization preferences are set when
168 * the file system is created. These are stored in the
169 * zfsvfs->z_case and zfsvfs->z_norm fields. These choices
170 * affect what vnodes can be cached in the DNLC, how we
171 * perform zap lookups, and the "width" of our dirlocks.
172 *
173 * A normal dirlock locks a single name. Note that with
174 * normalization a name can be composed multiple ways, but
175 * when normalized, these names all compare equal. A wide
176 * dirlock locks multiple names. We need these when the file
177 * system is supporting mixed-mode access. It is sometimes
178 * necessary to lock all case permutations of file name at
179 * once so that simultaneous case-insensitive/case-sensitive
180 * behaves as rationally as possible.
181 */
182
183 /*
184 * When matching we may need to normalize & change case according to
185 * FS settings.
186 *
187 * Note that a normalized match is necessary for a case insensitive
188 * filesystem when the lookup request is not exact because normalization
189 * can fold case independent of normalizing code point sequences.
190 *
191 * See the table above zfs_dropname().
192 */
193 if (zfsvfs->z_norm != 0) {
194 mt = MT_NORMALIZE;
195
196 /*
197 * Determine if the match needs to honor the case specified in
198 * lookup, and if so keep track of that so that during
199 * normalization we don't fold case.
200 */
201 if ((zfsvfs->z_case == ZFS_CASE_INSENSITIVE &&
202 (flag & ZCIEXACT)) ||
203 (zfsvfs->z_case == ZFS_CASE_MIXED && !(flag & ZCILOOK))) {
204 mt |= MT_MATCH_CASE;
205 }
206 }
207
208 /*
209 * Only look in or update the DNLC if we are looking for the
210 * name on a file system that does not require normalization
211 * or case folding. We can also look there if we happen to be
212 * on a non-normalizing, mixed sensitivity file system IF we
213 * are looking for the exact name.
214 *
215 * Maybe can add TO-UPPERed version of name to dnlc in ci-only
216 * case for performance improvement?
217 */
218 update = !zfsvfs->z_norm ||
219 (zfsvfs->z_case == ZFS_CASE_MIXED &&
220 !(zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER) && !(flag & ZCILOOK));
221
222 /*
223 * ZRENAMING indicates we are in a situation where we should
224 * take narrow locks regardless of the file system's
225 * preferences for normalizing and case folding. This will
226 * prevent us deadlocking trying to grab the same wide lock
227 * twice if the two names happen to be case-insensitive
228 * matches.
229 */
230 if (flag & ZRENAMING)
231 cmpflags = 0;
232 else
233 cmpflags = zfsvfs->z_norm;
234
235 /*
236 * Wait until there are no locks on this name.
237 *
238 * Don't grab the lock if it is already held. However, cannot
239 * have both ZSHARED and ZHAVELOCK together.
240 */
241 ASSERT(!(flag & ZSHARED) || !(flag & ZHAVELOCK));
242 if (!(flag & ZHAVELOCK))
243 rw_enter(&dzp->z_name_lock, RW_READER);
244
245 mutex_enter(&dzp->z_lock);
246 for (;;) {
247 if (dzp->z_unlinked && !(flag & ZXATTR)) {
248 mutex_exit(&dzp->z_lock);
249 if (!(flag & ZHAVELOCK))
250 rw_exit(&dzp->z_name_lock);
251 return (SET_ERROR(ENOENT));
252 }
253 for (dl = dzp->z_dirlocks; dl != NULL; dl = dl->dl_next) {
254 if ((u8_strcmp(name, dl->dl_name, 0, cmpflags,
255 U8_UNICODE_LATEST, &error) == 0) || error != 0)
256 break;
257 }
258 if (error != 0) {
259 mutex_exit(&dzp->z_lock);
260 if (!(flag & ZHAVELOCK))
261 rw_exit(&dzp->z_name_lock);
262 return (SET_ERROR(ENOENT));
263 }
264 if (dl == NULL) {
265 /*
266 * Allocate a new dirlock and add it to the list.
267 */
268 dl = kmem_alloc(sizeof (zfs_dirlock_t), KM_SLEEP);
269 cv_init(&dl->dl_cv, NULL, CV_DEFAULT, NULL);
270 dl->dl_name = name;
271 dl->dl_sharecnt = 0;
272 dl->dl_namelock = 0;
273 dl->dl_namesize = 0;
274 dl->dl_dzp = dzp;
275 dl->dl_next = dzp->z_dirlocks;
276 dzp->z_dirlocks = dl;
277 break;
278 }
279 if ((flag & ZSHARED) && dl->dl_sharecnt != 0)
280 break;
281 cv_wait(&dl->dl_cv, &dzp->z_lock);
282 }
283
284 /*
285 * If the z_name_lock was NOT held for this dirlock record it.
286 */
287 if (flag & ZHAVELOCK)
288 dl->dl_namelock = 1;
289
290 if ((flag & ZSHARED) && ++dl->dl_sharecnt > 1 && dl->dl_namesize == 0) {
291 /*
292 * We're the second shared reference to dl. Make a copy of
293 * dl_name in case the first thread goes away before we do.
294 * Note that we initialize the new name before storing its
295 * pointer into dl_name, because the first thread may load
296 * dl->dl_name at any time. It'll either see the old value,
297 * which belongs to it, or the new shared copy; either is OK.
298 */
299 dl->dl_namesize = strlen(dl->dl_name) + 1;
300 name = kmem_alloc(dl->dl_namesize, KM_SLEEP);
301 memcpy(name, dl->dl_name, dl->dl_namesize);
302 dl->dl_name = name;
303 }
304
305 mutex_exit(&dzp->z_lock);
306
307 /*
308 * We have a dirlock on the name. (Note that it is the dirlock,
309 * not the dzp's z_lock, that protects the name in the zap object.)
310 * See if there's an object by this name; if so, put a hold on it.
311 */
312 if (flag & ZXATTR) {
313 error = sa_lookup(dzp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), &zoid,
314 sizeof (zoid));
315 if (error == 0)
316 error = (zoid == 0 ? SET_ERROR(ENOENT) : 0);
317 } else {
318 error = zfs_match_find(zfsvfs, dzp, name, mt,
319 update, direntflags, realpnp, &zoid);
320 }
321 if (error) {
322 if (error != ENOENT || (flag & ZEXISTS)) {
323 zfs_dirent_unlock(dl);
324 return (error);
325 }
326 } else {
327 if (flag & ZNEW) {
328 zfs_dirent_unlock(dl);
329 return (SET_ERROR(EEXIST));
330 }
331 error = zfs_zget(zfsvfs, zoid, zpp);
332 if (error) {
333 zfs_dirent_unlock(dl);
334 return (error);
335 }
336 }
337
338 *dlpp = dl;
339
340 return (0);
341 }
342
343 /*
344 * Unlock this directory entry and wake anyone who was waiting for it.
345 */
346 void
zfs_dirent_unlock(zfs_dirlock_t * dl)347 zfs_dirent_unlock(zfs_dirlock_t *dl)
348 {
349 znode_t *dzp = dl->dl_dzp;
350 zfs_dirlock_t **prev_dl, *cur_dl;
351
352 mutex_enter(&dzp->z_lock);
353
354 if (!dl->dl_namelock)
355 rw_exit(&dzp->z_name_lock);
356
357 if (dl->dl_sharecnt > 1) {
358 dl->dl_sharecnt--;
359 mutex_exit(&dzp->z_lock);
360 return;
361 }
362 prev_dl = &dzp->z_dirlocks;
363 while ((cur_dl = *prev_dl) != dl)
364 prev_dl = &cur_dl->dl_next;
365 *prev_dl = dl->dl_next;
366 cv_broadcast(&dl->dl_cv);
367 mutex_exit(&dzp->z_lock);
368
369 if (dl->dl_namesize != 0)
370 kmem_free(dl->dl_name, dl->dl_namesize);
371 cv_destroy(&dl->dl_cv);
372 kmem_free(dl, sizeof (*dl));
373 }
374
375 /*
376 * Look up an entry in a directory.
377 *
378 * NOTE: '.' and '..' are handled as special cases because
379 * no directory entries are actually stored for them. If this is
380 * the root of a filesystem, then '.zfs' is also treated as a
381 * special pseudo-directory.
382 */
383 int
zfs_dirlook(znode_t * dzp,char * name,znode_t ** zpp,int flags,int * deflg,pathname_t * rpnp)384 zfs_dirlook(znode_t *dzp, char *name, znode_t **zpp, int flags,
385 int *deflg, pathname_t *rpnp)
386 {
387 zfs_dirlock_t *dl;
388 znode_t *zp;
389 struct inode *ip;
390 int error = 0;
391 uint64_t parent;
392
393 if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) {
394 *zpp = dzp;
395 zhold(*zpp);
396 } else if (name[0] == '.' && name[1] == '.' && name[2] == 0) {
397 zfsvfs_t *zfsvfs = ZTOZSB(dzp);
398
399 /*
400 * If we are a snapshot mounted under .zfs, return
401 * the inode pointer for the snapshot directory.
402 */
403 if ((error = sa_lookup(dzp->z_sa_hdl,
404 SA_ZPL_PARENT(zfsvfs), &parent, sizeof (parent))) != 0)
405 return (error);
406
407 if (parent == dzp->z_id && zfsvfs->z_parent != zfsvfs) {
408 error = zfsctl_root_lookup(zfsvfs->z_parent->z_ctldir,
409 "snapshot", &ip, 0, kcred, NULL, NULL);
410 *zpp = ITOZ(ip);
411 return (error);
412 }
413 rw_enter(&dzp->z_parent_lock, RW_READER);
414 error = zfs_zget(zfsvfs, parent, &zp);
415 if (error == 0)
416 *zpp = zp;
417 rw_exit(&dzp->z_parent_lock);
418 } else if (zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) {
419 if (ZTOZSB(dzp)->z_show_ctldir == ZFS_SNAPDIR_DISABLED) {
420 return (SET_ERROR(ENOENT));
421 }
422 ip = zfsctl_root(dzp);
423 *zpp = ITOZ(ip);
424 } else {
425 int zf;
426
427 zf = ZEXISTS | ZSHARED;
428 if (flags & FIGNORECASE)
429 zf |= ZCILOOK;
430
431 error = zfs_dirent_lock(&dl, dzp, name, &zp, zf, deflg, rpnp);
432 if (error == 0) {
433 *zpp = zp;
434 zfs_dirent_unlock(dl);
435 dzp->z_zn_prefetch = B_TRUE; /* enable prefetching */
436 }
437 rpnp = NULL;
438 }
439
440 if ((flags & FIGNORECASE) && rpnp && !error)
441 (void) strlcpy(rpnp->pn_buf, name, rpnp->pn_bufsize);
442
443 return (error);
444 }
445
446 /*
447 * unlinked Set (formerly known as the "delete queue") Error Handling
448 *
449 * When dealing with the unlinked set, we dmu_tx_hold_zap(), but we
450 * don't specify the name of the entry that we will be manipulating. We
451 * also fib and say that we won't be adding any new entries to the
452 * unlinked set, even though we might (this is to lower the minimum file
453 * size that can be deleted in a full filesystem). So on the small
454 * chance that the nlink list is using a fat zap (ie. has more than
455 * 2000 entries), we *may* not pre-read a block that's needed.
456 * Therefore it is remotely possible for some of the assertions
457 * regarding the unlinked set below to fail due to i/o error. On a
458 * nondebug system, this will result in the space being leaked.
459 */
460 void
zfs_unlinked_add(znode_t * zp,dmu_tx_t * tx)461 zfs_unlinked_add(znode_t *zp, dmu_tx_t *tx)
462 {
463 zfsvfs_t *zfsvfs = ZTOZSB(zp);
464
465 ASSERT(zp->z_unlinked);
466 ASSERT0(ZTOI(zp)->i_nlink);
467
468 VERIFY3U(0, ==,
469 zap_add_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx));
470
471 dataset_kstats_update_nunlinks_kstat(&zfsvfs->z_kstat, 1);
472 }
473
474 /*
475 * Clean up any znodes that had no links when we either crashed or
476 * (force) umounted the file system.
477 */
478 static void
zfs_unlinked_drain_task(void * arg)479 zfs_unlinked_drain_task(void *arg)
480 {
481 zfsvfs_t *zfsvfs = arg;
482 zap_cursor_t zc;
483 zap_attribute_t *zap = zap_attribute_alloc();
484 dmu_object_info_t doi;
485 znode_t *zp;
486 int error;
487
488 ASSERT3B(zfsvfs->z_draining, ==, B_TRUE);
489
490 /*
491 * Iterate over the contents of the unlinked set.
492 */
493 for (zap_cursor_init(&zc, zfsvfs->z_os, zfsvfs->z_unlinkedobj);
494 zap_cursor_retrieve(&zc, zap) == 0 && !zfsvfs->z_drain_cancel;
495 zap_cursor_advance(&zc)) {
496
497 /*
498 * See what kind of object we have in list
499 */
500
501 error = dmu_object_info(zfsvfs->z_os,
502 zap->za_first_integer, &doi);
503 if (error != 0)
504 continue;
505
506 ASSERT((doi.doi_type == DMU_OT_PLAIN_FILE_CONTENTS) ||
507 (doi.doi_type == DMU_OT_DIRECTORY_CONTENTS));
508 /*
509 * We need to re-mark these list entries for deletion,
510 * so we pull them back into core and set zp->z_unlinked.
511 */
512 error = zfs_zget(zfsvfs, zap->za_first_integer, &zp);
513
514 /*
515 * We may pick up znodes that are already marked for deletion.
516 * This could happen during the purge of an extended attribute
517 * directory. All we need to do is skip over them, since they
518 * are already in the system marked z_unlinked.
519 */
520 if (error != 0)
521 continue;
522
523 zp->z_unlinked = B_TRUE;
524
525 /*
526 * zrele() decrements the znode's ref count and may cause
527 * it to be synchronously freed. We interrupt freeing
528 * of this znode by checking the return value of
529 * dmu_objset_zfs_unmounting() in dmu_free_long_range()
530 * when an unmount is requested.
531 */
532 zrele(zp);
533 ASSERT3B(zfsvfs->z_unmounted, ==, B_FALSE);
534 }
535 zap_cursor_fini(&zc);
536
537 zfsvfs->z_draining = B_FALSE;
538 zfsvfs->z_drain_task = TASKQID_INVALID;
539 zap_attribute_free(zap);
540 }
541
542 /*
543 * Sets z_draining then tries to dispatch async unlinked drain.
544 * If that fails executes synchronous unlinked drain.
545 */
546 void
zfs_unlinked_drain(zfsvfs_t * zfsvfs)547 zfs_unlinked_drain(zfsvfs_t *zfsvfs)
548 {
549 ASSERT3B(zfsvfs->z_unmounted, ==, B_FALSE);
550 ASSERT3B(zfsvfs->z_draining, ==, B_FALSE);
551
552 zfsvfs->z_draining = B_TRUE;
553 zfsvfs->z_drain_cancel = B_FALSE;
554
555 zfsvfs->z_drain_task = taskq_dispatch(
556 dsl_pool_unlinked_drain_taskq(dmu_objset_pool(zfsvfs->z_os)),
557 zfs_unlinked_drain_task, zfsvfs, TQ_SLEEP);
558 if (zfsvfs->z_drain_task == TASKQID_INVALID) {
559 zfs_dbgmsg("async zfs_unlinked_drain dispatch failed");
560 zfs_unlinked_drain_task(zfsvfs);
561 }
562 }
563
564 /*
565 * Wait for the unlinked drain taskq task to stop. This will interrupt the
566 * unlinked set processing if it is in progress.
567 */
568 void
zfs_unlinked_drain_stop_wait(zfsvfs_t * zfsvfs)569 zfs_unlinked_drain_stop_wait(zfsvfs_t *zfsvfs)
570 {
571 ASSERT3B(zfsvfs->z_unmounted, ==, B_FALSE);
572
573 if (zfsvfs->z_draining) {
574 zfsvfs->z_drain_cancel = B_TRUE;
575 taskq_cancel_id(dsl_pool_unlinked_drain_taskq(
576 dmu_objset_pool(zfsvfs->z_os)), zfsvfs->z_drain_task,
577 B_TRUE);
578 zfsvfs->z_drain_task = TASKQID_INVALID;
579 zfsvfs->z_draining = B_FALSE;
580 }
581 }
582
583 /*
584 * Delete the entire contents of a directory. Return a count
585 * of the number of entries that could not be deleted. If we encounter
586 * an error, return a count of at least one so that the directory stays
587 * in the unlinked set.
588 *
589 * NOTE: this function assumes that the directory is inactive,
590 * so there is no need to lock its entries before deletion.
591 * Also, it assumes the directory contents is *only* regular
592 * files.
593 */
594 static int
zfs_purgedir(znode_t * dzp)595 zfs_purgedir(znode_t *dzp)
596 {
597 zap_cursor_t zc;
598 zap_attribute_t *zap = zap_attribute_alloc();
599 znode_t *xzp;
600 dmu_tx_t *tx;
601 zfsvfs_t *zfsvfs = ZTOZSB(dzp);
602 zfs_dirlock_t dl;
603 int skipped = 0;
604 int error;
605
606 for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id);
607 (error = zap_cursor_retrieve(&zc, zap)) == 0;
608 zap_cursor_advance(&zc)) {
609 error = zfs_zget(zfsvfs,
610 ZFS_DIRENT_OBJ(zap->za_first_integer), &xzp);
611 if (error) {
612 skipped += 1;
613 continue;
614 }
615
616 ASSERT(S_ISREG(ZTOI(xzp)->i_mode) ||
617 S_ISLNK(ZTOI(xzp)->i_mode));
618
619 tx = dmu_tx_create(zfsvfs->z_os);
620 dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
621 dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap->za_name);
622 dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
623 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
624 /* Is this really needed ? */
625 zfs_sa_upgrade_txholds(tx, xzp);
626 dmu_tx_mark_netfree(tx);
627 error = dmu_tx_assign(tx, DMU_TX_WAIT);
628 if (error) {
629 dmu_tx_abort(tx);
630 zfs_zrele_async(xzp);
631 skipped += 1;
632 continue;
633 }
634 memset(&dl, 0, sizeof (dl));
635 dl.dl_dzp = dzp;
636 dl.dl_name = zap->za_name;
637
638 error = zfs_link_destroy(&dl, xzp, tx, 0, NULL);
639 if (error)
640 skipped += 1;
641 dmu_tx_commit(tx);
642
643 zfs_zrele_async(xzp);
644 }
645 zap_cursor_fini(&zc);
646 zap_attribute_free(zap);
647 if (error != ENOENT)
648 skipped += 1;
649 return (skipped);
650 }
651
652 void
zfs_rmnode(znode_t * zp)653 zfs_rmnode(znode_t *zp)
654 {
655 zfsvfs_t *zfsvfs = ZTOZSB(zp);
656 objset_t *os = zfsvfs->z_os;
657 znode_t *xzp = NULL;
658 dmu_tx_t *tx;
659 znode_hold_t *zh;
660 uint64_t z_id = zp->z_id;
661 uint64_t acl_obj;
662 uint64_t xattr_obj;
663 uint64_t links;
664 int error;
665
666 ASSERT0(ZTOI(zp)->i_nlink);
667 ASSERT0(atomic_read(&ZTOI(zp)->i_count));
668
669 /*
670 * If this is an attribute directory, purge its contents.
671 */
672 if (S_ISDIR(ZTOI(zp)->i_mode) && (zp->z_pflags & ZFS_XATTR)) {
673 if (zfs_purgedir(zp) != 0) {
674 /*
675 * Not enough space to delete some xattrs.
676 * Leave it in the unlinked set.
677 */
678 zh = zfs_znode_hold_enter(zfsvfs, z_id);
679 zfs_znode_dmu_fini(zp);
680 zfs_znode_hold_exit(zfsvfs, zh);
681 return;
682 }
683 }
684
685 /*
686 * Free up all the data in the file. We don't do this for directories
687 * because we need truncate and remove to be in the same tx, like in
688 * zfs_znode_delete(). Otherwise, if we crash here we'll end up with
689 * an inconsistent truncated zap object in the delete queue. Note a
690 * truncated file is harmless since it only contains user data.
691 */
692 if (S_ISREG(ZTOI(zp)->i_mode)) {
693 error = dmu_free_long_range(os, zp->z_id, 0, DMU_OBJECT_END);
694 if (error) {
695 /*
696 * Not enough space or we were interrupted by unmount.
697 * Leave the file in the unlinked set.
698 */
699 zh = zfs_znode_hold_enter(zfsvfs, z_id);
700 zfs_znode_dmu_fini(zp);
701 zfs_znode_hold_exit(zfsvfs, zh);
702 return;
703 }
704 }
705
706 /*
707 * If the file has extended attributes, we're going to unlink
708 * the xattr dir.
709 */
710 error = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
711 &xattr_obj, sizeof (xattr_obj));
712 if (error == 0 && xattr_obj) {
713 error = zfs_zget(zfsvfs, xattr_obj, &xzp);
714 ASSERT0(error);
715 }
716
717 acl_obj = zfs_external_acl(zp);
718
719 /*
720 * Set up the final transaction.
721 */
722 tx = dmu_tx_create(os);
723 dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END);
724 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
725 if (xzp) {
726 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, TRUE, NULL);
727 dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
728 }
729 if (acl_obj)
730 dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END);
731
732 zfs_sa_upgrade_txholds(tx, zp);
733 error = dmu_tx_assign(tx, DMU_TX_WAIT);
734 if (error) {
735 /*
736 * Not enough space to delete the file. Leave it in the
737 * unlinked set, leaking it until the fs is remounted (at
738 * which point we'll call zfs_unlinked_drain() to process it).
739 */
740 dmu_tx_abort(tx);
741 zh = zfs_znode_hold_enter(zfsvfs, z_id);
742 zfs_znode_dmu_fini(zp);
743 zfs_znode_hold_exit(zfsvfs, zh);
744 goto out;
745 }
746
747 if (xzp) {
748 ASSERT0(error);
749 mutex_enter(&xzp->z_lock);
750 xzp->z_unlinked = B_TRUE; /* mark xzp for deletion */
751 clear_nlink(ZTOI(xzp)); /* no more links to it */
752 links = 0;
753 VERIFY0(sa_update(xzp->z_sa_hdl, SA_ZPL_LINKS(zfsvfs),
754 &links, sizeof (links), tx));
755 mutex_exit(&xzp->z_lock);
756 zfs_unlinked_add(xzp, tx);
757 }
758
759 mutex_enter(&os->os_dsl_dataset->ds_dir->dd_activity_lock);
760
761 /*
762 * Remove this znode from the unlinked set. If a has rollback has
763 * occurred while a file is open and unlinked. Then when the file
764 * is closed post rollback it will not exist in the rolled back
765 * version of the unlinked object.
766 */
767 error = zap_remove_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj,
768 zp->z_id, tx);
769 VERIFY(error == 0 || error == ENOENT);
770
771 uint64_t count;
772 if (zap_count(os, zfsvfs->z_unlinkedobj, &count) == 0 && count == 0) {
773 cv_broadcast(&os->os_dsl_dataset->ds_dir->dd_activity_cv);
774 }
775
776 mutex_exit(&os->os_dsl_dataset->ds_dir->dd_activity_lock);
777
778 dataset_kstats_update_nunlinked_kstat(&zfsvfs->z_kstat, 1);
779
780 zfs_znode_delete(zp, tx);
781
782 dmu_tx_commit(tx);
783 out:
784 if (xzp)
785 zfs_zrele_async(xzp);
786 }
787
788 static uint64_t
zfs_dirent(znode_t * zp,uint64_t mode)789 zfs_dirent(znode_t *zp, uint64_t mode)
790 {
791 uint64_t de = zp->z_id;
792
793 if (ZTOZSB(zp)->z_version >= ZPL_VERSION_DIRENT_TYPE)
794 de |= IFTODT(mode) << 60;
795 return (de);
796 }
797
798 /*
799 * Link zp into dl. Can fail in the following cases :
800 * - if zp has been unlinked.
801 * - if the number of entries with the same hash (aka. colliding entries)
802 * exceed the capacity of a leaf-block of fatzap and splitting of the
803 * leaf-block does not help.
804 */
805 int
zfs_link_create(zfs_dirlock_t * dl,znode_t * zp,dmu_tx_t * tx,int flag)806 zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag)
807 {
808 znode_t *dzp = dl->dl_dzp;
809 zfsvfs_t *zfsvfs = ZTOZSB(zp);
810 uint64_t value;
811 int zp_is_dir = S_ISDIR(ZTOI(zp)->i_mode);
812 sa_bulk_attr_t bulk[5];
813 uint64_t mtime[2], ctime[2];
814 uint64_t links;
815 int count = 0;
816 int error;
817
818 mutex_enter(&zp->z_lock);
819
820 if (!(flag & ZRENAMING)) {
821 if (zp->z_unlinked) { /* no new links to unlinked zp */
822 ASSERT(!(flag & (ZNEW | ZEXISTS)));
823 mutex_exit(&zp->z_lock);
824 return (SET_ERROR(ENOENT));
825 }
826 if (!(flag & ZNEW)) {
827 /*
828 * ZNEW nodes come from zfs_mknode() where the link
829 * count has already been initialised
830 */
831 inc_nlink(ZTOI(zp));
832 links = ZTOI(zp)->i_nlink;
833 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs),
834 NULL, &links, sizeof (links));
835 }
836 }
837
838 value = zfs_dirent(zp, zp->z_mode);
839 error = zap_add(ZTOZSB(zp)->z_os, dzp->z_id, dl->dl_name, 8, 1,
840 &value, tx);
841
842 /*
843 * zap_add could fail to add the entry if it exceeds the capacity of the
844 * leaf-block and zap_leaf_split() failed to help.
845 * The caller of this routine is responsible for failing the transaction
846 * which will rollback the SA updates done above.
847 */
848 if (error != 0) {
849 if (!(flag & ZRENAMING) && !(flag & ZNEW))
850 drop_nlink(ZTOI(zp));
851 mutex_exit(&zp->z_lock);
852 return (error);
853 }
854
855 /*
856 * If we added a longname activate the SPA_FEATURE_LONGNAME.
857 */
858 if (strlen(dl->dl_name) >= ZAP_MAXNAMELEN) {
859 dsl_dataset_t *ds = dmu_objset_ds(zfsvfs->z_os);
860 ds->ds_feature_activation[SPA_FEATURE_LONGNAME] =
861 (void *)B_TRUE;
862 }
863
864 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_PARENT(zfsvfs), NULL,
865 &dzp->z_id, sizeof (dzp->z_id));
866 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
867 &zp->z_pflags, sizeof (zp->z_pflags));
868
869 if (!(flag & ZNEW)) {
870 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
871 ctime, sizeof (ctime));
872 zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime,
873 ctime);
874 }
875 error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
876 ASSERT0(error);
877
878 mutex_exit(&zp->z_lock);
879
880 mutex_enter(&dzp->z_lock);
881 dzp->z_size++;
882 if (zp_is_dir)
883 inc_nlink(ZTOI(dzp));
884 links = ZTOI(dzp)->i_nlink;
885 count = 0;
886 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs), NULL,
887 &dzp->z_size, sizeof (dzp->z_size));
888 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL,
889 &links, sizeof (links));
890 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
891 mtime, sizeof (mtime));
892 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
893 ctime, sizeof (ctime));
894 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
895 &dzp->z_pflags, sizeof (dzp->z_pflags));
896 zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime);
897 error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx);
898 ASSERT0(error);
899 mutex_exit(&dzp->z_lock);
900
901 return (0);
902 }
903
904 /*
905 * The match type in the code for this function should conform to:
906 *
907 * ------------------------------------------------------------------------
908 * fs type | z_norm | lookup type | match type
909 * ---------|-------------|-------------|----------------------------------
910 * CS !norm | 0 | 0 | 0 (exact)
911 * CS norm | formX | 0 | MT_NORMALIZE
912 * CI !norm | upper | !ZCIEXACT | MT_NORMALIZE
913 * CI !norm | upper | ZCIEXACT | MT_NORMALIZE | MT_MATCH_CASE
914 * CI norm | upper|formX | !ZCIEXACT | MT_NORMALIZE
915 * CI norm | upper|formX | ZCIEXACT | MT_NORMALIZE | MT_MATCH_CASE
916 * CM !norm | upper | !ZCILOOK | MT_NORMALIZE | MT_MATCH_CASE
917 * CM !norm | upper | ZCILOOK | MT_NORMALIZE
918 * CM norm | upper|formX | !ZCILOOK | MT_NORMALIZE | MT_MATCH_CASE
919 * CM norm | upper|formX | ZCILOOK | MT_NORMALIZE
920 *
921 * Abbreviations:
922 * CS = Case Sensitive, CI = Case Insensitive, CM = Case Mixed
923 * upper = case folding set by fs type on creation (U8_TEXTPREP_TOUPPER)
924 * formX = unicode normalization form set on fs creation
925 */
926 static int
zfs_dropname(zfs_dirlock_t * dl,znode_t * zp,znode_t * dzp,dmu_tx_t * tx,int flag)927 zfs_dropname(zfs_dirlock_t *dl, znode_t *zp, znode_t *dzp, dmu_tx_t *tx,
928 int flag)
929 {
930 int error;
931
932 if (ZTOZSB(zp)->z_norm) {
933 matchtype_t mt = MT_NORMALIZE;
934
935 if ((ZTOZSB(zp)->z_case == ZFS_CASE_INSENSITIVE &&
936 (flag & ZCIEXACT)) ||
937 (ZTOZSB(zp)->z_case == ZFS_CASE_MIXED &&
938 !(flag & ZCILOOK))) {
939 mt |= MT_MATCH_CASE;
940 }
941
942 error = zap_remove_norm(ZTOZSB(zp)->z_os, dzp->z_id,
943 dl->dl_name, mt, tx);
944 } else {
945 error = zap_remove(ZTOZSB(zp)->z_os, dzp->z_id, dl->dl_name,
946 tx);
947 }
948
949 return (error);
950 }
951
952 static int
zfs_drop_nlink_locked(znode_t * zp,dmu_tx_t * tx,boolean_t * unlinkedp)953 zfs_drop_nlink_locked(znode_t *zp, dmu_tx_t *tx, boolean_t *unlinkedp)
954 {
955 zfsvfs_t *zfsvfs = ZTOZSB(zp);
956 int zp_is_dir = S_ISDIR(ZTOI(zp)->i_mode);
957 boolean_t unlinked = B_FALSE;
958 sa_bulk_attr_t bulk[3];
959 uint64_t mtime[2], ctime[2];
960 uint64_t links;
961 int count = 0;
962 int error;
963
964 if (zp_is_dir && !zfs_dirempty(zp))
965 return (SET_ERROR(ENOTEMPTY));
966
967 if (ZTOI(zp)->i_nlink <= zp_is_dir) {
968 zfs_panic_recover("zfs: link count on %lu is %u, "
969 "should be at least %u", zp->z_id,
970 (int)ZTOI(zp)->i_nlink, zp_is_dir + 1);
971 set_nlink(ZTOI(zp), zp_is_dir + 1);
972 }
973 drop_nlink(ZTOI(zp));
974 if (ZTOI(zp)->i_nlink == zp_is_dir) {
975 zp->z_unlinked = B_TRUE;
976 clear_nlink(ZTOI(zp));
977 unlinked = B_TRUE;
978 } else {
979 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs),
980 NULL, &ctime, sizeof (ctime));
981 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
982 NULL, &zp->z_pflags, sizeof (zp->z_pflags));
983 zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime,
984 ctime);
985 }
986 links = ZTOI(zp)->i_nlink;
987 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs),
988 NULL, &links, sizeof (links));
989 error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
990 ASSERT0(error);
991
992 if (unlinkedp != NULL)
993 *unlinkedp = unlinked;
994 else if (unlinked)
995 zfs_unlinked_add(zp, tx);
996
997 return (0);
998 }
999
1000 /*
1001 * Forcefully drop an nlink reference from (zp) and mark it for deletion if it
1002 * was the last link. This *must* only be done to znodes which have already
1003 * been zfs_link_destroy()'d with ZRENAMING. This is explicitly only used in
1004 * the error path of zfs_rename(), where we have to correct the nlink count if
1005 * we failed to link the target as well as failing to re-link the original
1006 * znodes.
1007 */
1008 int
zfs_drop_nlink(znode_t * zp,dmu_tx_t * tx,boolean_t * unlinkedp)1009 zfs_drop_nlink(znode_t *zp, dmu_tx_t *tx, boolean_t *unlinkedp)
1010 {
1011 int error;
1012
1013 mutex_enter(&zp->z_lock);
1014 error = zfs_drop_nlink_locked(zp, tx, unlinkedp);
1015 mutex_exit(&zp->z_lock);
1016
1017 return (error);
1018 }
1019
1020 /*
1021 * Unlink zp from dl, and mark zp for deletion if this was the last link. Can
1022 * fail if zp is a mount point (EBUSY) or a non-empty directory (ENOTEMPTY).
1023 * If 'unlinkedp' is NULL, we put unlinked znodes on the unlinked list.
1024 * If it's non-NULL, we use it to indicate whether the znode needs deletion,
1025 * and it's the caller's job to do it.
1026 */
1027 int
zfs_link_destroy(zfs_dirlock_t * dl,znode_t * zp,dmu_tx_t * tx,int flag,boolean_t * unlinkedp)1028 zfs_link_destroy(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag,
1029 boolean_t *unlinkedp)
1030 {
1031 znode_t *dzp = dl->dl_dzp;
1032 zfsvfs_t *zfsvfs = ZTOZSB(dzp);
1033 int zp_is_dir = S_ISDIR(ZTOI(zp)->i_mode);
1034 boolean_t unlinked = B_FALSE;
1035 sa_bulk_attr_t bulk[5];
1036 uint64_t mtime[2], ctime[2];
1037 uint64_t links;
1038 int count = 0;
1039 int error;
1040
1041 if (!(flag & ZRENAMING)) {
1042 mutex_enter(&zp->z_lock);
1043
1044 if (zp_is_dir && !zfs_dirempty(zp)) {
1045 mutex_exit(&zp->z_lock);
1046 return (SET_ERROR(ENOTEMPTY));
1047 }
1048
1049 /*
1050 * If we get here, we are going to try to remove the object.
1051 * First try removing the name from the directory; if that
1052 * fails, return the error.
1053 */
1054 error = zfs_dropname(dl, zp, dzp, tx, flag);
1055 if (error != 0) {
1056 mutex_exit(&zp->z_lock);
1057 return (error);
1058 }
1059
1060 /* The only error is !zfs_dirempty() and we checked earlier. */
1061 error = zfs_drop_nlink_locked(zp, tx, &unlinked);
1062 ASSERT0(error);
1063 mutex_exit(&zp->z_lock);
1064 } else {
1065 error = zfs_dropname(dl, zp, dzp, tx, flag);
1066 if (error != 0)
1067 return (error);
1068 }
1069
1070 mutex_enter(&dzp->z_lock);
1071 dzp->z_size--; /* one dirent removed */
1072 if (zp_is_dir)
1073 drop_nlink(ZTOI(dzp)); /* ".." link from zp */
1074 links = ZTOI(dzp)->i_nlink;
1075 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs),
1076 NULL, &links, sizeof (links));
1077 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs),
1078 NULL, &dzp->z_size, sizeof (dzp->z_size));
1079 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs),
1080 NULL, ctime, sizeof (ctime));
1081 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs),
1082 NULL, mtime, sizeof (mtime));
1083 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
1084 NULL, &dzp->z_pflags, sizeof (dzp->z_pflags));
1085 zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime);
1086 error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx);
1087 ASSERT0(error);
1088 mutex_exit(&dzp->z_lock);
1089
1090 if (unlinkedp != NULL)
1091 *unlinkedp = unlinked;
1092 else if (unlinked)
1093 zfs_unlinked_add(zp, tx);
1094
1095 return (0);
1096 }
1097
1098 /*
1099 * Indicate whether the directory is empty. Works with or without z_lock
1100 * held, but can only be consider a hint in the latter case. Returns true
1101 * if only "." and ".." remain and there's no work in progress.
1102 *
1103 * The internal ZAP size, rather than zp->z_size, needs to be checked since
1104 * some consumers (Lustre) do not strictly maintain an accurate SA_ZPL_SIZE.
1105 */
1106 boolean_t
zfs_dirempty(znode_t * dzp)1107 zfs_dirempty(znode_t *dzp)
1108 {
1109 zfsvfs_t *zfsvfs = ZTOZSB(dzp);
1110 uint64_t count;
1111 int error;
1112
1113 if (dzp->z_dirlocks != NULL)
1114 return (B_FALSE);
1115
1116 error = zap_count(zfsvfs->z_os, dzp->z_id, &count);
1117 if (error != 0 || count != 0)
1118 return (B_FALSE);
1119
1120 return (B_TRUE);
1121 }
1122
1123 int
zfs_make_xattrdir(znode_t * zp,vattr_t * vap,znode_t ** xzpp,cred_t * cr)1124 zfs_make_xattrdir(znode_t *zp, vattr_t *vap, znode_t **xzpp, cred_t *cr)
1125 {
1126 zfsvfs_t *zfsvfs = ZTOZSB(zp);
1127 znode_t *xzp;
1128 dmu_tx_t *tx;
1129 int error;
1130 zfs_acl_ids_t acl_ids;
1131 boolean_t fuid_dirtied;
1132 #ifdef ZFS_DEBUG
1133 uint64_t parent;
1134 #endif
1135
1136 *xzpp = NULL;
1137
1138 if ((error = zfs_acl_ids_create(zp, IS_XATTR, vap, cr, NULL,
1139 &acl_ids, zfs_init_idmap)) != 0)
1140 return (error);
1141 if (zfs_acl_ids_overquota(zfsvfs, &acl_ids, zp->z_projid)) {
1142 zfs_acl_ids_free(&acl_ids);
1143 return (SET_ERROR(EDQUOT));
1144 }
1145
1146 tx = dmu_tx_create(zfsvfs->z_os);
1147 dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
1148 ZFS_SA_BASE_ATTR_SIZE);
1149 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
1150 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
1151 fuid_dirtied = zfsvfs->z_fuid_dirty;
1152 if (fuid_dirtied)
1153 zfs_fuid_txhold(zfsvfs, tx);
1154 error = dmu_tx_assign(tx, DMU_TX_WAIT);
1155 if (error) {
1156 zfs_acl_ids_free(&acl_ids);
1157 dmu_tx_abort(tx);
1158 return (error);
1159 }
1160 zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, &acl_ids);
1161
1162 if (fuid_dirtied)
1163 zfs_fuid_sync(zfsvfs, tx);
1164
1165 #ifdef ZFS_DEBUG
1166 error = sa_lookup(xzp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
1167 &parent, sizeof (parent));
1168 ASSERT(error == 0 && parent == zp->z_id);
1169 #endif
1170
1171 VERIFY0(sa_update(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), &xzp->z_id,
1172 sizeof (xzp->z_id), tx));
1173
1174 if (!zp->z_unlinked)
1175 zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp, xzp, "", NULL,
1176 acl_ids.z_fuidp, vap);
1177
1178 zfs_acl_ids_free(&acl_ids);
1179 dmu_tx_commit(tx);
1180
1181 *xzpp = xzp;
1182
1183 return (0);
1184 }
1185
1186 /*
1187 * Return a znode for the extended attribute directory for zp.
1188 * ** If the directory does not already exist, it is created **
1189 *
1190 * IN: zp - znode to obtain attribute directory from
1191 * cr - credentials of caller
1192 * flags - flags from the VOP_LOOKUP call
1193 *
1194 * OUT: xipp - pointer to extended attribute znode
1195 *
1196 * RETURN: 0 on success
1197 * error number on failure
1198 */
1199 int
zfs_get_xattrdir(znode_t * zp,znode_t ** xzpp,cred_t * cr,int flags)1200 zfs_get_xattrdir(znode_t *zp, znode_t **xzpp, cred_t *cr, int flags)
1201 {
1202 zfsvfs_t *zfsvfs = ZTOZSB(zp);
1203 znode_t *xzp;
1204 zfs_dirlock_t *dl;
1205 vattr_t va;
1206 int error;
1207 top:
1208 error = zfs_dirent_lock(&dl, zp, "", &xzp, ZXATTR, NULL, NULL);
1209 if (error)
1210 return (error);
1211
1212 if (xzp != NULL) {
1213 *xzpp = xzp;
1214 zfs_dirent_unlock(dl);
1215 return (0);
1216 }
1217
1218 if (!(flags & CREATE_XATTR_DIR)) {
1219 zfs_dirent_unlock(dl);
1220 return (SET_ERROR(ENOENT));
1221 }
1222
1223 if (zfs_is_readonly(zfsvfs)) {
1224 zfs_dirent_unlock(dl);
1225 return (SET_ERROR(EROFS));
1226 }
1227
1228 /*
1229 * The ability to 'create' files in an attribute
1230 * directory comes from the write_xattr permission on the base file.
1231 *
1232 * The ability to 'search' an attribute directory requires
1233 * read_xattr permission on the base file.
1234 *
1235 * Once in a directory the ability to read/write attributes
1236 * is controlled by the permissions on the attribute file.
1237 */
1238 va.va_mask = ATTR_MODE | ATTR_UID | ATTR_GID;
1239 va.va_mode = S_IFDIR | S_ISVTX | 0777;
1240 zfs_fuid_map_ids(zp, cr, &va.va_uid, &va.va_gid);
1241
1242 va.va_dentry = NULL;
1243 error = zfs_make_xattrdir(zp, &va, xzpp, cr);
1244 zfs_dirent_unlock(dl);
1245
1246 if (error == ERESTART) {
1247 /* NB: we already did dmu_tx_wait() if necessary */
1248 goto top;
1249 }
1250
1251 return (error);
1252 }
1253
1254 /*
1255 * Decide whether it is okay to remove within a sticky directory.
1256 *
1257 * In sticky directories, write access is not sufficient;
1258 * you can remove entries from a directory only if:
1259 *
1260 * you own the directory,
1261 * you own the entry,
1262 * you have write access to the entry,
1263 * or you are privileged (checked in secpolicy...).
1264 *
1265 * The function returns 0 if remove access is granted.
1266 */
1267 int
zfs_sticky_remove_access(znode_t * zdp,znode_t * zp,cred_t * cr)1268 zfs_sticky_remove_access(znode_t *zdp, znode_t *zp, cred_t *cr)
1269 {
1270 uid_t uid;
1271 uid_t downer;
1272 uid_t fowner;
1273 zfsvfs_t *zfsvfs = ZTOZSB(zdp);
1274
1275 if (zfsvfs->z_replay)
1276 return (0);
1277
1278 if ((zdp->z_mode & S_ISVTX) == 0)
1279 return (0);
1280
1281 downer = zfs_fuid_map_id(zfsvfs, KUID_TO_SUID(ZTOI(zdp)->i_uid),
1282 cr, ZFS_OWNER);
1283 fowner = zfs_fuid_map_id(zfsvfs, KUID_TO_SUID(ZTOI(zp)->i_uid),
1284 cr, ZFS_OWNER);
1285
1286 if ((uid = crgetuid(cr)) == downer || uid == fowner ||
1287 zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr,
1288 zfs_init_idmap) == 0)
1289 return (0);
1290 else
1291 return (secpolicy_vnode_remove(cr));
1292 }
1293