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 /*
23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Copyright (c) 2013, 2016 by Delphix. All rights reserved.
25 * Copyright 2017 Nexenta Systems, Inc.
26 * Copyright (c) 2015, Joyent, Inc.
27 */
28
29 #include <sys/types.h>
30 #include <sys/param.h>
31 #include <sys/time.h>
32 #include <sys/systm.h>
33 #include <sys/sysmacros.h>
34 #include <sys/resource.h>
35 #include <sys/vfs.h>
36 #include <sys/vnode.h>
37 #include <sys/file.h>
38 #include <sys/mode.h>
39 #include <sys/kmem.h>
40 #include <sys/uio.h>
41 #include <sys/pathname.h>
42 #include <sys/cmn_err.h>
43 #include <sys/errno.h>
44 #include <sys/stat.h>
45 #include <sys/unistd.h>
46 #include <sys/sunddi.h>
47 #include <sys/random.h>
48 #include <sys/policy.h>
49 #include <sys/zfs_dir.h>
50 #include <sys/zfs_acl.h>
51 #include <sys/fs/zfs.h>
52 #include "fs/fs_subr.h"
53 #include <sys/zap.h>
54 #include <sys/dmu.h>
55 #include <sys/atomic.h>
56 #include <sys/zfs_ctldir.h>
57 #include <sys/zfs_fuid.h>
58 #include <sys/sa.h>
59 #include <sys/zfs_sa.h>
60 #include <sys/dnlc.h>
61 #include <sys/extdirent.h>
62
63 /*
64 * zfs_match_find() is used by zfs_dirent_lock() to peform zap lookups
65 * of names after deciding which is the appropriate lookup interface.
66 */
67 static int
68 zfs_match_find(zfsvfs_t *zfsvfs, znode_t *dzp, char *name, matchtype_t mt,
69 boolean_t update, int *deflags, pathname_t *rpnp, uint64_t *zoid)
70 {
71 int error;
72
73 if (zfsvfs->z_norm) {
74 boolean_t conflict = B_FALSE;
75 size_t bufsz = 0;
76 char *buf = NULL;
77
78 if (rpnp) {
79 buf = rpnp->pn_buf;
80 bufsz = rpnp->pn_bufsize;
81 }
82
83 /*
84 * In the non-mixed case we only expect there would ever
85 * be one match, but we need to use the normalizing lookup.
86 */
87 error = zap_lookup_norm(zfsvfs->z_os, dzp->z_id, name, 8, 1,
88 zoid, mt, buf, bufsz, &conflict);
89 if (!error && deflags)
90 *deflags = conflict ? ED_CASE_CONFLICT : 0;
91 } else {
92 error = zap_lookup(zfsvfs->z_os, dzp->z_id, name, 8, 1, zoid);
93 }
94 *zoid = ZFS_DIRENT_OBJ(*zoid);
95
96 if (error == ENOENT && update)
97 dnlc_update(ZTOV(dzp), name, DNLC_NO_VNODE);
98
99 return (error);
100 }
101
102 /*
103 * Lock a directory entry. A dirlock on <dzp, name> protects that name
104 * in dzp's directory zap object. As long as you hold a dirlock, you can
105 * assume two things: (1) dzp cannot be reaped, and (2) no other thread
106 * can change the zap entry for (i.e. link or unlink) this name.
107 *
108 * Input arguments:
109 * dzp - znode for directory
110 * name - name of entry to lock
111 * flag - ZNEW: if the entry already exists, fail with EEXIST.
112 * ZEXISTS: if the entry does not exist, fail with ENOENT.
113 * ZSHARED: allow concurrent access with other ZSHARED callers.
114 * ZXATTR: we want dzp's xattr directory
115 * ZCILOOK: On a mixed sensitivity file system,
116 * this lookup should be case-insensitive.
117 * ZCIEXACT: On a purely case-insensitive file system,
118 * this lookup should be case-sensitive.
119 * ZRENAMING: we are locking for renaming, force narrow locks
120 * ZHAVELOCK: Don't grab the z_name_lock for this call. The
121 * current thread already holds it.
122 *
123 * Output arguments:
124 * zpp - pointer to the znode for the entry (NULL if there isn't one)
125 * dlpp - pointer to the dirlock for this entry (NULL on error)
126 * direntflags - (case-insensitive lookup only)
127 * flags if multiple case-sensitive matches exist in directory
128 * realpnp - (case-insensitive lookup only)
129 * actual name matched within the directory
130 *
131 * Return value: 0 on success or errno on failure.
132 *
133 * NOTE: Always checks for, and rejects, '.' and '..'.
134 * NOTE: For case-insensitive file systems we take wide locks (see below),
135 * but return znode pointers to a single match.
136 */
137 int
138 zfs_dirent_lock(zfs_dirlock_t **dlpp, znode_t *dzp, char *name, znode_t **zpp,
139 int flag, int *direntflags, pathname_t *realpnp)
140 {
141 zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
142 zfs_dirlock_t *dl;
143 boolean_t update;
144 matchtype_t mt = 0;
145 uint64_t zoid;
146 vnode_t *vp = NULL;
147 int error = 0;
148 int cmpflags;
149
150 *zpp = NULL;
151 *dlpp = NULL;
152
153 /*
154 * Verify that we are not trying to lock '.', '..', or '.zfs'
155 */
156 if (name[0] == '.' &&
157 (name[1] == '\0' || (name[1] == '.' && name[2] == '\0')) ||
158 zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0)
159 return (SET_ERROR(EEXIST));
160
161 /*
162 * Case sensitivity and normalization preferences are set when
163 * the file system is created. These are stored in the
164 * zfsvfs->z_case and zfsvfs->z_norm fields. These choices
165 * affect what vnodes can be cached in the DNLC, how we
166 * perform zap lookups, and the "width" of our dirlocks.
167 *
168 * A normal dirlock locks a single name. Note that with
169 * normalization a name can be composed multiple ways, but
170 * when normalized, these names all compare equal. A wide
171 * dirlock locks multiple names. We need these when the file
172 * system is supporting mixed-mode access. It is sometimes
173 * necessary to lock all case permutations of file name at
174 * once so that simultaneous case-insensitive/case-sensitive
175 * behaves as rationally as possible.
176 */
177
178 /*
179 * When matching we may need to normalize & change case according to
180 * FS settings.
181 *
182 * Note that a normalized match is necessary for a case insensitive
183 * filesystem when the lookup request is not exact because normalization
184 * can fold case independent of normalizing code point sequences.
185 *
186 * See the table above zfs_dropname().
187 */
188 if (zfsvfs->z_norm != 0) {
189 mt = MT_NORMALIZE;
190
191 /*
192 * Determine if the match needs to honor the case specified in
193 * lookup, and if so keep track of that so that during
194 * normalization we don't fold case.
195 */
196 if ((zfsvfs->z_case == ZFS_CASE_INSENSITIVE &&
197 (flag & ZCIEXACT)) ||
198 (zfsvfs->z_case == ZFS_CASE_MIXED && !(flag & ZCILOOK))) {
199 mt |= MT_MATCH_CASE;
200 }
201 }
202
203 /*
204 * Only look in or update the DNLC if we are looking for the
205 * name on a file system that does not require normalization
206 * or case folding. We can also look there if we happen to be
207 * on a non-normalizing, mixed sensitivity file system IF we
208 * are looking for the exact name.
209 *
210 * Maybe can add TO-UPPERed version of name to dnlc in ci-only
211 * case for performance improvement?
212 */
213 update = !zfsvfs->z_norm ||
214 (zfsvfs->z_case == ZFS_CASE_MIXED &&
215 !(zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER) && !(flag & ZCILOOK));
216
217 /*
218 * ZRENAMING indicates we are in a situation where we should
219 * take narrow locks regardless of the file system's
220 * preferences for normalizing and case folding. This will
221 * prevent us deadlocking trying to grab the same wide lock
222 * twice if the two names happen to be case-insensitive
223 * matches.
224 */
225 if (flag & ZRENAMING)
226 cmpflags = 0;
227 else
228 cmpflags = zfsvfs->z_norm;
229
230 /*
231 * Wait until there are no locks on this name.
232 *
233 * Don't grab the the lock if it is already held. However, cannot
234 * have both ZSHARED and ZHAVELOCK together.
235 */
236 ASSERT(!(flag & ZSHARED) || !(flag & ZHAVELOCK));
237 if (!(flag & ZHAVELOCK))
238 rw_enter(&dzp->z_name_lock, RW_READER);
239
240 mutex_enter(&dzp->z_lock);
241 for (;;) {
242 if (dzp->z_unlinked) {
243 mutex_exit(&dzp->z_lock);
244 if (!(flag & ZHAVELOCK))
245 rw_exit(&dzp->z_name_lock);
246 return (SET_ERROR(ENOENT));
247 }
248 for (dl = dzp->z_dirlocks; dl != NULL; dl = dl->dl_next) {
249 if ((u8_strcmp(name, dl->dl_name, 0, cmpflags,
250 U8_UNICODE_LATEST, &error) == 0) || error != 0)
251 break;
252 }
253 if (error != 0) {
254 mutex_exit(&dzp->z_lock);
255 if (!(flag & ZHAVELOCK))
256 rw_exit(&dzp->z_name_lock);
257 return (SET_ERROR(ENOENT));
258 }
259 if (dl == NULL) {
260 /*
261 * Allocate a new dirlock and add it to the list.
262 */
263 dl = kmem_alloc(sizeof (zfs_dirlock_t), KM_SLEEP);
264 cv_init(&dl->dl_cv, NULL, CV_DEFAULT, NULL);
265 dl->dl_name = name;
266 dl->dl_sharecnt = 0;
267 dl->dl_namelock = 0;
268 dl->dl_namesize = 0;
269 dl->dl_dzp = dzp;
270 dl->dl_next = dzp->z_dirlocks;
271 dzp->z_dirlocks = dl;
272 break;
273 }
274 if ((flag & ZSHARED) && dl->dl_sharecnt != 0)
275 break;
276 cv_wait(&dl->dl_cv, &dzp->z_lock);
277 }
278
279 /*
280 * If the z_name_lock was NOT held for this dirlock record it.
281 */
282 if (flag & ZHAVELOCK)
283 dl->dl_namelock = 1;
284
285 if ((flag & ZSHARED) && ++dl->dl_sharecnt > 1 && dl->dl_namesize == 0) {
286 /*
287 * We're the second shared reference to dl. Make a copy of
288 * dl_name in case the first thread goes away before we do.
289 * Note that we initialize the new name before storing its
290 * pointer into dl_name, because the first thread may load
291 * dl->dl_name at any time. It'll either see the old value,
292 * which belongs to it, or the new shared copy; either is OK.
293 */
294 dl->dl_namesize = strlen(dl->dl_name) + 1;
295 name = kmem_alloc(dl->dl_namesize, KM_SLEEP);
296 bcopy(dl->dl_name, name, dl->dl_namesize);
297 dl->dl_name = name;
298 }
299
300 mutex_exit(&dzp->z_lock);
301
302 /*
303 * We have a dirlock on the name. (Note that it is the dirlock,
304 * not the dzp's z_lock, that protects the name in the zap object.)
305 * See if there's an object by this name; if so, put a hold on it.
306 */
307 if (flag & ZXATTR) {
308 error = sa_lookup(dzp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), &zoid,
309 sizeof (zoid));
310 if (error == 0)
311 error = (zoid == 0 ? ENOENT : 0);
312 } else {
313 if (update)
314 vp = dnlc_lookup(ZTOV(dzp), name);
315 if (vp == DNLC_NO_VNODE) {
316 VN_RELE(vp);
317 error = SET_ERROR(ENOENT);
318 } else if (vp) {
319 if (flag & ZNEW) {
320 zfs_dirent_unlock(dl);
321 VN_RELE(vp);
322 return (SET_ERROR(EEXIST));
323 }
324 *dlpp = dl;
325 *zpp = VTOZ(vp);
326 return (0);
327 } else {
328 error = zfs_match_find(zfsvfs, dzp, name, mt,
329 update, direntflags, realpnp, &zoid);
330 }
331 }
332 if (error) {
333 if (error != ENOENT || (flag & ZEXISTS)) {
334 zfs_dirent_unlock(dl);
335 return (error);
336 }
337 } else {
338 if (flag & ZNEW) {
339 zfs_dirent_unlock(dl);
340 return (SET_ERROR(EEXIST));
341 }
342 error = zfs_zget(zfsvfs, zoid, zpp);
343 if (error) {
344 zfs_dirent_unlock(dl);
345 return (error);
346 }
347 if (!(flag & ZXATTR) && update)
348 dnlc_update(ZTOV(dzp), name, ZTOV(*zpp));
349 }
350
351 *dlpp = dl;
352
353 return (0);
354 }
355
356 /*
357 * Unlock this directory entry and wake anyone who was waiting for it.
358 */
359 void
360 zfs_dirent_unlock(zfs_dirlock_t *dl)
361 {
362 znode_t *dzp = dl->dl_dzp;
363 zfs_dirlock_t **prev_dl, *cur_dl;
364
365 mutex_enter(&dzp->z_lock);
366
367 if (!dl->dl_namelock)
368 rw_exit(&dzp->z_name_lock);
369
370 if (dl->dl_sharecnt > 1) {
371 dl->dl_sharecnt--;
372 mutex_exit(&dzp->z_lock);
373 return;
374 }
375 prev_dl = &dzp->z_dirlocks;
376 while ((cur_dl = *prev_dl) != dl)
377 prev_dl = &cur_dl->dl_next;
378 *prev_dl = dl->dl_next;
379 cv_broadcast(&dl->dl_cv);
380 mutex_exit(&dzp->z_lock);
381
382 if (dl->dl_namesize != 0)
383 kmem_free(dl->dl_name, dl->dl_namesize);
384 cv_destroy(&dl->dl_cv);
385 kmem_free(dl, sizeof (*dl));
386 }
387
388 /*
389 * Look up an entry in a directory.
390 *
391 * NOTE: '.' and '..' are handled as special cases because
392 * no directory entries are actually stored for them. If this is
393 * the root of a filesystem, then '.zfs' is also treated as a
394 * special pseudo-directory.
395 */
396 int
397 zfs_dirlook(znode_t *dzp, char *name, vnode_t **vpp, int flags,
398 int *deflg, pathname_t *rpnp)
399 {
400 zfs_dirlock_t *dl;
401 znode_t *zp;
402 int error = 0;
403 uint64_t parent;
404
405 if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) {
406 *vpp = ZTOV(dzp);
407 VN_HOLD(*vpp);
408 } else if (name[0] == '.' && name[1] == '.' && name[2] == 0) {
409 zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
410
411 /*
412 * If we are a snapshot mounted under .zfs, return
413 * the vp for the snapshot directory.
414 */
415 if ((error = sa_lookup(dzp->z_sa_hdl,
416 SA_ZPL_PARENT(zfsvfs), &parent, sizeof (parent))) != 0)
417 return (error);
418 if (parent == dzp->z_id && zfsvfs->z_parent != zfsvfs) {
419 error = zfsctl_root_lookup(zfsvfs->z_parent->z_ctldir,
420 "snapshot", vpp, NULL, 0, NULL, kcred,
421 NULL, NULL, NULL);
422 return (error);
423 }
424 rw_enter(&dzp->z_parent_lock, RW_READER);
425 error = zfs_zget(zfsvfs, parent, &zp);
426 if (error == 0)
427 *vpp = ZTOV(zp);
428 rw_exit(&dzp->z_parent_lock);
429 } else if (zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) {
430 *vpp = zfsctl_root(dzp);
431 } else {
432 int zf;
433
434 zf = ZEXISTS | ZSHARED;
435 if (flags & FIGNORECASE)
436 zf |= ZCILOOK;
437
438 error = zfs_dirent_lock(&dl, dzp, name, &zp, zf, deflg, rpnp);
439 if (error == 0) {
440 *vpp = ZTOV(zp);
441 zfs_dirent_unlock(dl);
442 dzp->z_zn_prefetch = B_TRUE; /* enable prefetching */
443 }
444 rpnp = NULL;
445 }
446
447 if ((flags & FIGNORECASE) && rpnp && !error)
448 (void) strlcpy(rpnp->pn_buf, name, rpnp->pn_bufsize);
449
450 return (error);
451 }
452
453 /*
454 * unlinked Set (formerly known as the "delete queue") Error Handling
455 *
456 * When dealing with the unlinked set, we dmu_tx_hold_zap(), but we
457 * don't specify the name of the entry that we will be manipulating. We
458 * also fib and say that we won't be adding any new entries to the
459 * unlinked set, even though we might (this is to lower the minimum file
460 * size that can be deleted in a full filesystem). So on the small
461 * chance that the nlink list is using a fat zap (ie. has more than
462 * 2000 entries), we *may* not pre-read a block that's needed.
463 * Therefore it is remotely possible for some of the assertions
464 * regarding the unlinked set below to fail due to i/o error. On a
465 * nondebug system, this will result in the space being leaked.
466 */
467 void
468 zfs_unlinked_add(znode_t *zp, dmu_tx_t *tx)
469 {
470 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
471
472 ASSERT(zp->z_unlinked);
473 ASSERT(zp->z_links == 0);
474
475 VERIFY3U(0, ==,
476 zap_add_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx));
477 }
478
479 /*
480 * Clean up any znodes that had no links when we either crashed or
481 * (force) umounted the file system.
482 */
483 void
484 zfs_unlinked_drain(zfsvfs_t *zfsvfs)
485 {
486 zap_cursor_t zc;
487 zap_attribute_t zap;
488 dmu_object_info_t doi;
489 znode_t *zp;
490 int error;
491
492 /*
493 * Interate over the contents of the unlinked set.
494 */
495 for (zap_cursor_init(&zc, zfsvfs->z_os, zfsvfs->z_unlinkedobj);
496 zap_cursor_retrieve(&zc, &zap) == 0;
497 zap_cursor_advance(&zc)) {
498
499 /*
500 * See what kind of object we have in list
501 */
502
503 error = dmu_object_info(zfsvfs->z_os,
504 zap.za_first_integer, &doi);
505 if (error != 0)
506 continue;
507
508 ASSERT((doi.doi_type == DMU_OT_PLAIN_FILE_CONTENTS) ||
509 (doi.doi_type == DMU_OT_DIRECTORY_CONTENTS));
510 /*
511 * We need to re-mark these list entries for deletion,
512 * so we pull them back into core and set zp->z_unlinked.
513 */
514 error = zfs_zget(zfsvfs, zap.za_first_integer, &zp);
515
516 /*
517 * We may pick up znodes that are already marked for deletion.
518 * This could happen during the purge of an extended attribute
519 * directory. All we need to do is skip over them, since they
520 * are already in the system marked z_unlinked.
521 */
522 if (error != 0)
523 continue;
524
525 zp->z_unlinked = B_TRUE;
526 VN_RELE(ZTOV(zp));
527 }
528 zap_cursor_fini(&zc);
529 }
530
531 /*
532 * Delete the entire contents of a directory. Return a count
533 * of the number of entries that could not be deleted. If we encounter
534 * an error, return a count of at least one so that the directory stays
535 * in the unlinked set.
536 *
537 * NOTE: this function assumes that the directory is inactive,
538 * so there is no need to lock its entries before deletion.
539 * Also, it assumes the directory contents is *only* regular
540 * files.
541 */
542 static int
543 zfs_purgedir(znode_t *dzp)
544 {
545 zap_cursor_t zc;
546 zap_attribute_t zap;
547 znode_t *xzp;
548 dmu_tx_t *tx;
549 zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
550 zfs_dirlock_t dl;
551 int skipped = 0;
552 int error;
553
554 for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id);
555 (error = zap_cursor_retrieve(&zc, &zap)) == 0;
556 zap_cursor_advance(&zc)) {
557 error = zfs_zget(zfsvfs,
558 ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp);
559 if (error) {
560 skipped += 1;
561 continue;
562 }
563
564 ASSERT((ZTOV(xzp)->v_type == VREG) ||
565 (ZTOV(xzp)->v_type == VLNK));
566
567 tx = dmu_tx_create(zfsvfs->z_os);
568 dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
569 dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name);
570 dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
571 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
572 /* Is this really needed ? */
573 zfs_sa_upgrade_txholds(tx, xzp);
574 dmu_tx_mark_netfree(tx);
575 error = dmu_tx_assign(tx, TXG_WAIT);
576 if (error) {
577 dmu_tx_abort(tx);
578 VN_RELE(ZTOV(xzp));
579 skipped += 1;
580 continue;
581 }
582 bzero(&dl, sizeof (dl));
583 dl.dl_dzp = dzp;
584 dl.dl_name = zap.za_name;
585
586 error = zfs_link_destroy(&dl, xzp, tx, 0, NULL);
587 if (error)
588 skipped += 1;
589 dmu_tx_commit(tx);
590
591 VN_RELE(ZTOV(xzp));
592 }
593 zap_cursor_fini(&zc);
594 if (error != ENOENT)
595 skipped += 1;
596 return (skipped);
597 }
598
599 void
600 zfs_rmnode(znode_t *zp)
601 {
602 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
603 objset_t *os = zfsvfs->z_os;
604 znode_t *xzp = NULL;
605 dmu_tx_t *tx;
606 uint64_t acl_obj;
607 uint64_t xattr_obj;
608 int error;
609
610 ASSERT(zp->z_links == 0);
611 ASSERT(ZTOV(zp)->v_count == 0);
612
613 /*
614 * If this is an attribute directory, purge its contents.
615 */
616 if (ZTOV(zp)->v_type == VDIR && (zp->z_pflags & ZFS_XATTR)) {
617 if (zfs_purgedir(zp) != 0) {
618 /*
619 * Not enough space to delete some xattrs.
620 * Leave it in the unlinked set.
621 */
622 zfs_znode_dmu_fini(zp);
623 zfs_znode_free(zp);
624 return;
625 }
626 } else {
627 /*
628 * Free up all the data in the file. We don't do this for
629 * XATTR directories because we need truncate and remove to be
630 * in the same tx, like in zfs_znode_delete(). Otherwise, if
631 * we crash here we'll end up with an inconsistent truncated
632 * zap object in the delete queue. Note a truncated file is
633 * harmless since it only contains user data.
634 */
635 error = dmu_free_long_range(os, zp->z_id, 0, DMU_OBJECT_END);
636 if (error) {
637 /*
638 * Not enough space or we were interrupted by unmount.
639 * Leave the file in the unlinked set.
640 */
641 zfs_znode_dmu_fini(zp);
642 zfs_znode_free(zp);
643 return;
644 }
645 }
646
647 /*
648 * If the file has extended attributes, we're going to unlink
649 * the xattr dir.
650 */
651 error = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
652 &xattr_obj, sizeof (xattr_obj));
653 if (error == 0 && xattr_obj) {
654 error = zfs_zget(zfsvfs, xattr_obj, &xzp);
655 ASSERT(error == 0);
656 }
657
658 acl_obj = zfs_external_acl(zp);
659
660 /*
661 * Set up the final transaction.
662 */
663 tx = dmu_tx_create(os);
664 dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END);
665 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
666 if (xzp) {
667 dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, TRUE, NULL);
668 dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
669 }
670 if (acl_obj)
671 dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END);
672
673 zfs_sa_upgrade_txholds(tx, zp);
674 error = dmu_tx_assign(tx, TXG_WAIT);
675 if (error) {
676 /*
677 * Not enough space to delete the file. Leave it in the
678 * unlinked set, leaking it until the fs is remounted (at
679 * which point we'll call zfs_unlinked_drain() to process it).
680 */
681 dmu_tx_abort(tx);
682 zfs_znode_dmu_fini(zp);
683 zfs_znode_free(zp);
684 goto out;
685 }
686
687 if (xzp) {
688 ASSERT(error == 0);
689 mutex_enter(&xzp->z_lock);
690 xzp->z_unlinked = B_TRUE; /* mark xzp for deletion */
691 xzp->z_links = 0; /* no more links to it */
692 VERIFY(0 == sa_update(xzp->z_sa_hdl, SA_ZPL_LINKS(zfsvfs),
693 &xzp->z_links, sizeof (xzp->z_links), tx));
694 mutex_exit(&xzp->z_lock);
695 zfs_unlinked_add(xzp, tx);
696 }
697
698 /* Remove this znode from the unlinked set */
699 VERIFY3U(0, ==,
700 zap_remove_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx));
701
702 zfs_znode_delete(zp, tx);
703
704 dmu_tx_commit(tx);
705 out:
706 if (xzp)
707 VN_RELE(ZTOV(xzp));
708 }
709
710 static uint64_t
711 zfs_dirent(znode_t *zp, uint64_t mode)
712 {
713 uint64_t de = zp->z_id;
714
715 if (zp->z_zfsvfs->z_version >= ZPL_VERSION_DIRENT_TYPE)
716 de |= IFTODT(mode) << 60;
717 return (de);
718 }
719
720 /*
721 * Link zp into dl. Can only fail if zp has been unlinked.
722 */
723 int
724 zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag)
725 {
726 znode_t *dzp = dl->dl_dzp;
727 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
728 vnode_t *vp = ZTOV(zp);
729 uint64_t value;
730 int zp_is_dir = (vp->v_type == VDIR);
731 sa_bulk_attr_t bulk[5];
732 uint64_t mtime[2], ctime[2];
733 int count = 0;
734 int error;
735
736 mutex_enter(&zp->z_lock);
737
738 if (!(flag & ZRENAMING)) {
739 if (zp->z_unlinked) { /* no new links to unlinked zp */
740 ASSERT(!(flag & (ZNEW | ZEXISTS)));
741 mutex_exit(&zp->z_lock);
742 return (SET_ERROR(ENOENT));
743 }
744 zp->z_links++;
745 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL,
746 &zp->z_links, sizeof (zp->z_links));
747
748 }
749 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_PARENT(zfsvfs), NULL,
750 &dzp->z_id, sizeof (dzp->z_id));
751 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
752 &zp->z_pflags, sizeof (zp->z_pflags));
753
754 if (!(flag & ZNEW)) {
755 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
756 ctime, sizeof (ctime));
757 zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime,
758 ctime, B_TRUE);
759 }
760 error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
761 ASSERT(error == 0);
762
763 mutex_exit(&zp->z_lock);
764
765 mutex_enter(&dzp->z_lock);
766 dzp->z_size++;
767 dzp->z_links += zp_is_dir;
768 count = 0;
769 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs), NULL,
770 &dzp->z_size, sizeof (dzp->z_size));
771 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL,
772 &dzp->z_links, sizeof (dzp->z_links));
773 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
774 mtime, sizeof (mtime));
775 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
776 ctime, sizeof (ctime));
777 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
778 &dzp->z_pflags, sizeof (dzp->z_pflags));
779 zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime, B_TRUE);
780 error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx);
781 ASSERT(error == 0);
782 mutex_exit(&dzp->z_lock);
783
784 value = zfs_dirent(zp, zp->z_mode);
785 error = zap_add(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name,
786 8, 1, &value, tx);
787 ASSERT(error == 0);
788
789 dnlc_update(ZTOV(dzp), dl->dl_name, vp);
790
791 return (0);
792 }
793
794 /*
795 * The match type in the code for this function should conform to:
796 *
797 * ------------------------------------------------------------------------
798 * fs type | z_norm | lookup type | match type
799 * ---------|-------------|-------------|----------------------------------
800 * CS !norm | 0 | 0 | 0 (exact)
801 * CS norm | formX | 0 | MT_NORMALIZE
802 * CI !norm | upper | !ZCIEXACT | MT_NORMALIZE
803 * CI !norm | upper | ZCIEXACT | MT_NORMALIZE | MT_MATCH_CASE
804 * CI norm | upper|formX | !ZCIEXACT | MT_NORMALIZE
805 * CI norm | upper|formX | ZCIEXACT | MT_NORMALIZE | MT_MATCH_CASE
806 * CM !norm | upper | !ZCILOOK | MT_NORMALIZE | MT_MATCH_CASE
807 * CM !norm | upper | ZCILOOK | MT_NORMALIZE
808 * CM norm | upper|formX | !ZCILOOK | MT_NORMALIZE | MT_MATCH_CASE
809 * CM norm | upper|formX | ZCILOOK | MT_NORMALIZE
810 *
811 * Abbreviations:
812 * CS = Case Sensitive, CI = Case Insensitive, CM = Case Mixed
813 * upper = case folding set by fs type on creation (U8_TEXTPREP_TOUPPER)
814 * formX = unicode normalization form set on fs creation
815 */
816 static int
817 zfs_dropname(zfs_dirlock_t *dl, znode_t *zp, znode_t *dzp, dmu_tx_t *tx,
818 int flag)
819 {
820 int error;
821
822 if (zp->z_zfsvfs->z_norm) {
823 matchtype_t mt = MT_NORMALIZE;
824
825 if ((zp->z_zfsvfs->z_case == ZFS_CASE_INSENSITIVE &&
826 (flag & ZCIEXACT)) ||
827 (zp->z_zfsvfs->z_case == ZFS_CASE_MIXED &&
828 !(flag & ZCILOOK))) {
829 mt |= MT_MATCH_CASE;
830 }
831
832 error = zap_remove_norm(zp->z_zfsvfs->z_os, dzp->z_id,
833 dl->dl_name, mt, tx);
834 } else {
835 error = zap_remove(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name,
836 tx);
837 }
838
839 return (error);
840 }
841
842 /*
843 * Unlink zp from dl, and mark zp for deletion if this was the last link.
844 * Can fail if zp is a mount point (EBUSY) or a non-empty directory (EEXIST).
845 * If 'unlinkedp' is NULL, we put unlinked znodes on the unlinked list.
846 * If it's non-NULL, we use it to indicate whether the znode needs deletion,
847 * and it's the caller's job to do it.
848 */
849 int
850 zfs_link_destroy(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag,
851 boolean_t *unlinkedp)
852 {
853 znode_t *dzp = dl->dl_dzp;
854 zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
855 vnode_t *vp = ZTOV(zp);
856 int zp_is_dir = (vp->v_type == VDIR);
857 boolean_t unlinked = B_FALSE;
858 sa_bulk_attr_t bulk[5];
859 uint64_t mtime[2], ctime[2];
860 int count = 0;
861 int error;
862
863 dnlc_remove(ZTOV(dzp), dl->dl_name);
864
865 if (!(flag & ZRENAMING)) {
866 if (vn_vfswlock(vp)) /* prevent new mounts on zp */
867 return (SET_ERROR(EBUSY));
868
869 if (vn_ismntpt(vp)) { /* don't remove mount point */
870 vn_vfsunlock(vp);
871 return (SET_ERROR(EBUSY));
872 }
873
874 mutex_enter(&zp->z_lock);
875
876 if (zp_is_dir && !zfs_dirempty(zp)) {
877 mutex_exit(&zp->z_lock);
878 vn_vfsunlock(vp);
879 return (SET_ERROR(EEXIST));
880 }
881
882 /*
883 * If we get here, we are going to try to remove the object.
884 * First try removing the name from the directory; if that
885 * fails, return the error.
886 */
887 error = zfs_dropname(dl, zp, dzp, tx, flag);
888 if (error != 0) {
889 mutex_exit(&zp->z_lock);
890 vn_vfsunlock(vp);
891 return (error);
892 }
893
894 if (zp->z_links <= zp_is_dir) {
895 zfs_panic_recover("zfs: link count on %s is %u, "
896 "should be at least %u",
897 zp->z_vnode->v_path != vn_vpath_empty ?
898 zp->z_vnode->v_path : "<unknown>",
899 (int)zp->z_links, zp_is_dir + 1);
900 zp->z_links = zp_is_dir + 1;
901 }
902 if (--zp->z_links == zp_is_dir) {
903 zp->z_unlinked = B_TRUE;
904 zp->z_links = 0;
905 unlinked = B_TRUE;
906 } else {
907 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs),
908 NULL, &ctime, sizeof (ctime));
909 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
910 NULL, &zp->z_pflags, sizeof (zp->z_pflags));
911 zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime, ctime,
912 B_TRUE);
913 }
914 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs),
915 NULL, &zp->z_links, sizeof (zp->z_links));
916 error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
917 count = 0;
918 ASSERT(error == 0);
919 mutex_exit(&zp->z_lock);
920 vn_vfsunlock(vp);
921 } else {
922 error = zfs_dropname(dl, zp, dzp, tx, flag);
923 if (error != 0)
924 return (error);
925 }
926
927 mutex_enter(&dzp->z_lock);
928 dzp->z_size--; /* one dirent removed */
929 dzp->z_links -= zp_is_dir; /* ".." link from zp */
930 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs),
931 NULL, &dzp->z_links, sizeof (dzp->z_links));
932 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs),
933 NULL, &dzp->z_size, sizeof (dzp->z_size));
934 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs),
935 NULL, ctime, sizeof (ctime));
936 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs),
937 NULL, mtime, sizeof (mtime));
938 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
939 NULL, &dzp->z_pflags, sizeof (dzp->z_pflags));
940 zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime, B_TRUE);
941 error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx);
942 ASSERT(error == 0);
943 mutex_exit(&dzp->z_lock);
944
945 if (unlinkedp != NULL)
946 *unlinkedp = unlinked;
947 else if (unlinked)
948 zfs_unlinked_add(zp, tx);
949
950 return (0);
951 }
952
953 /*
954 * Indicate whether the directory is empty. Works with or without z_lock
955 * held, but can only be consider a hint in the latter case. Returns true
956 * if only "." and ".." remain and there's no work in progress.
957 */
958 boolean_t
959 zfs_dirempty(znode_t *dzp)
960 {
961 return (dzp->z_size == 2 && dzp->z_dirlocks == 0);
962 }
963
964 int
965 zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr)
966 {
967 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
968 znode_t *xzp;
969 dmu_tx_t *tx;
970 int error;
971 zfs_acl_ids_t acl_ids;
972 boolean_t fuid_dirtied;
973 uint64_t parent;
974
975 *xvpp = NULL;
976
977 if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, 0, B_FALSE, cr))
978 return (error);
979
980 if ((error = zfs_acl_ids_create(zp, IS_XATTR, vap, cr, NULL,
981 &acl_ids)) != 0)
982 return (error);
983 if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
984 zfs_acl_ids_free(&acl_ids);
985 return (SET_ERROR(EDQUOT));
986 }
987
988 tx = dmu_tx_create(zfsvfs->z_os);
989 dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
990 ZFS_SA_BASE_ATTR_SIZE);
991 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
992 dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
993 fuid_dirtied = zfsvfs->z_fuid_dirty;
994 if (fuid_dirtied)
995 zfs_fuid_txhold(zfsvfs, tx);
996 error = dmu_tx_assign(tx, TXG_WAIT);
997 if (error) {
998 zfs_acl_ids_free(&acl_ids);
999 dmu_tx_abort(tx);
1000 return (error);
1001 }
1002 zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, &acl_ids);
1003
1004 if (fuid_dirtied)
1005 zfs_fuid_sync(zfsvfs, tx);
1006
1007 #ifdef DEBUG
1008 error = sa_lookup(xzp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
1009 &parent, sizeof (parent));
1010 ASSERT(error == 0 && parent == zp->z_id);
1011 #endif
1012
1013 VERIFY(0 == sa_update(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), &xzp->z_id,
1014 sizeof (xzp->z_id), tx));
1015
1016 (void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp,
1017 xzp, "", NULL, acl_ids.z_fuidp, vap);
1018
1019 zfs_acl_ids_free(&acl_ids);
1020 dmu_tx_commit(tx);
1021
1022 *xvpp = ZTOV(xzp);
1023
1024 return (0);
1025 }
1026
1027 /*
1028 * Return a znode for the extended attribute directory for zp.
1029 * ** If the directory does not already exist, it is created **
1030 *
1031 * IN: zp - znode to obtain attribute directory from
1032 * cr - credentials of caller
1033 * flags - flags from the VOP_LOOKUP call
1034 *
1035 * OUT: xzpp - pointer to extended attribute znode
1036 *
1037 * RETURN: 0 on success
1038 * error number on failure
1039 */
1040 int
1041 zfs_get_xattrdir(znode_t *zp, vnode_t **xvpp, cred_t *cr, int flags)
1042 {
1043 zfsvfs_t *zfsvfs = zp->z_zfsvfs;
1044 znode_t *xzp;
1045 zfs_dirlock_t *dl;
1046 vattr_t va;
1047 int error;
1048 top:
1049 error = zfs_dirent_lock(&dl, zp, "", &xzp, ZXATTR, NULL, NULL);
1050 if (error)
1051 return (error);
1052
1053 if (xzp != NULL) {
1054 *xvpp = ZTOV(xzp);
1055 zfs_dirent_unlock(dl);
1056 return (0);
1057 }
1058
1059
1060 if (!(flags & CREATE_XATTR_DIR)) {
1061 zfs_dirent_unlock(dl);
1062 return (SET_ERROR(ENOENT));
1063 }
1064
1065 if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
1066 zfs_dirent_unlock(dl);
1067 return (SET_ERROR(EROFS));
1068 }
1069
1070 /*
1071 * The ability to 'create' files in an attribute
1072 * directory comes from the write_xattr permission on the base file.
1073 *
1074 * The ability to 'search' an attribute directory requires
1075 * read_xattr permission on the base file.
1076 *
1077 * Once in a directory the ability to read/write attributes
1078 * is controlled by the permissions on the attribute file.
1079 */
1080 va.va_mask = AT_TYPE | AT_MODE | AT_UID | AT_GID;
1081 va.va_type = VDIR;
1082 va.va_mode = S_IFDIR | S_ISVTX | 0777;
1083 zfs_fuid_map_ids(zp, cr, &va.va_uid, &va.va_gid);
1084
1085 error = zfs_make_xattrdir(zp, &va, xvpp, cr);
1086 zfs_dirent_unlock(dl);
1087
1088 if (error == ERESTART) {
1089 /* NB: we already did dmu_tx_wait() if necessary */
1090 goto top;
1091 }
1092
1093 return (error);
1094 }
1095
1096 /*
1097 * Decide whether it is okay to remove within a sticky directory.
1098 *
1099 * In sticky directories, write access is not sufficient;
1100 * you can remove entries from a directory only if:
1101 *
1102 * you own the directory,
1103 * you own the entry,
1104 * the entry is a plain file and you have write access,
1105 * or you are privileged (checked in secpolicy...).
1106 *
1107 * The function returns 0 if remove access is granted.
1108 */
1109 int
1110 zfs_sticky_remove_access(znode_t *zdp, znode_t *zp, cred_t *cr)
1111 {
1112 uid_t uid;
1113 uid_t downer;
1114 uid_t fowner;
1115 zfsvfs_t *zfsvfs = zdp->z_zfsvfs;
1116
1117 if (zdp->z_zfsvfs->z_replay)
1118 return (0);
1119
1120 if ((zdp->z_mode & S_ISVTX) == 0)
1121 return (0);
1122
1123 downer = zfs_fuid_map_id(zfsvfs, zdp->z_uid, cr, ZFS_OWNER);
1124 fowner = zfs_fuid_map_id(zfsvfs, zp->z_uid, cr, ZFS_OWNER);
1125
1126 if ((uid = crgetuid(cr)) == downer || uid == fowner ||
1127 (ZTOV(zp)->v_type == VREG &&
1128 zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr) == 0))
1129 return (0);
1130 else
1131 return (secpolicy_vnode_remove(cr));
1132 }