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) 2013 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/kmem.h>
36#include <sys/uio.h>
37#include <sys/cmn_err.h>
38#include <sys/errno.h>
39#include <sys/stat.h>
40#include <sys/unistd.h>
41#include <sys/sunddi.h>
42#include <sys/random.h>
43#include <sys/policy.h>
44#include <sys/kcondvar.h>
45#include <sys/callb.h>
46#include <sys/smp.h>
47#include <sys/zfs_dir.h>
48#include <sys/zfs_acl.h>
49#include <sys/fs/zfs.h>
50#include <sys/zap.h>
51#include <sys/dmu.h>
52#include <sys/atomic.h>
53#include <sys/zfs_ctldir.h>
54#include <sys/zfs_fuid.h>
55#include <sys/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 */
64static int
65zfs_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 */
136int
137zfs_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 (SET_ERROR(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 (SET_ERROR(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 (SET_ERROR(ENOENT));
241		}
242		if (dl == NULL)	{
243			size_t namesize;
244
245			/*
246			 * Allocate a new dirlock and add it to the list.
247			 */
248			namesize = strlen(name) + 1;
249			dl = kmem_alloc(sizeof (zfs_dirlock_t) + namesize,
250			    KM_SLEEP);
251			cv_init(&dl->dl_cv, NULL, CV_DEFAULT, NULL);
252			dl->dl_name = (char *)(dl + 1);
253			bcopy(name, dl->dl_name, namesize);
254			dl->dl_sharecnt = 0;
255			dl->dl_namelock = 0;
256			dl->dl_namesize = namesize;
257			dl->dl_dzp = dzp;
258			dl->dl_next = dzp->z_dirlocks;
259			dzp->z_dirlocks = dl;
260			break;
261		}
262		if ((flag & ZSHARED) && dl->dl_sharecnt != 0)
263			break;
264		cv_wait(&dl->dl_cv, &dzp->z_lock);
265	}
266
267	/*
268	 * If the z_name_lock was NOT held for this dirlock record it.
269	 */
270	if (flag & ZHAVELOCK)
271		dl->dl_namelock = 1;
272
273	if (flag & ZSHARED)
274		dl->dl_sharecnt++;
275
276	mutex_exit(&dzp->z_lock);
277
278	/*
279	 * We have a dirlock on the name.  (Note that it is the dirlock,
280	 * not the dzp's z_lock, that protects the name in the zap object.)
281	 * See if there's an object by this name; if so, put a hold on it.
282	 */
283	if (flag & ZXATTR) {
284		error = sa_lookup(dzp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), &zoid,
285		    sizeof (zoid));
286		if (error == 0)
287			error = (zoid == 0 ? ENOENT : 0);
288	} else {
289		if (update)
290			vp = dnlc_lookup(ZTOV(dzp), name);
291		if (vp == DNLC_NO_VNODE) {
292			VN_RELE(vp);
293			error = SET_ERROR(ENOENT);
294		} else if (vp) {
295			if (flag & ZNEW) {
296				zfs_dirent_unlock(dl);
297				VN_RELE(vp);
298				return (SET_ERROR(EEXIST));
299			}
300			*dlpp = dl;
301			*zpp = VTOZ(vp);
302			return (0);
303		} else {
304			error = zfs_match_find(zfsvfs, dzp, name, exact,
305			    update, direntflags, realpnp, &zoid);
306		}
307	}
308	if (error) {
309		if (error != ENOENT || (flag & ZEXISTS)) {
310			zfs_dirent_unlock(dl);
311			return (error);
312		}
313	} else {
314		if (flag & ZNEW) {
315			zfs_dirent_unlock(dl);
316			return (SET_ERROR(EEXIST));
317		}
318		error = zfs_zget(zfsvfs, zoid, zpp);
319		if (error) {
320			zfs_dirent_unlock(dl);
321			return (error);
322		}
323		if (!(flag & ZXATTR) && update)
324			dnlc_update(ZTOV(dzp), name, ZTOV(*zpp));
325	}
326
327	*dlpp = dl;
328
329	return (0);
330}
331
332/*
333 * Unlock this directory entry and wake anyone who was waiting for it.
334 */
335void
336zfs_dirent_unlock(zfs_dirlock_t *dl)
337{
338	znode_t *dzp = dl->dl_dzp;
339	zfs_dirlock_t **prev_dl, *cur_dl;
340
341	mutex_enter(&dzp->z_lock);
342
343	if (!dl->dl_namelock)
344		rw_exit(&dzp->z_name_lock);
345
346	if (dl->dl_sharecnt > 1) {
347		dl->dl_sharecnt--;
348		mutex_exit(&dzp->z_lock);
349		return;
350	}
351	prev_dl = &dzp->z_dirlocks;
352	while ((cur_dl = *prev_dl) != dl)
353		prev_dl = &cur_dl->dl_next;
354	*prev_dl = dl->dl_next;
355	cv_broadcast(&dl->dl_cv);
356	mutex_exit(&dzp->z_lock);
357
358	cv_destroy(&dl->dl_cv);
359	kmem_free(dl, sizeof (*dl) + dl->dl_namesize);
360}
361
362/*
363 * Look up an entry in a directory.
364 *
365 * NOTE: '.' and '..' are handled as special cases because
366 *	no directory entries are actually stored for them.  If this is
367 *	the root of a filesystem, then '.zfs' is also treated as a
368 *	special pseudo-directory.
369 */
370int
371zfs_dirlook(znode_t *dzp, char *name, vnode_t **vpp, int flags,
372    int *deflg, pathname_t *rpnp)
373{
374	zfs_dirlock_t *dl;
375	znode_t *zp;
376	int error = 0;
377	uint64_t parent;
378	int unlinked;
379
380	if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) {
381		mutex_enter(&dzp->z_lock);
382		unlinked = dzp->z_unlinked;
383		mutex_exit(&dzp->z_lock);
384		if (unlinked)
385			return (ENOENT);
386
387		*vpp = ZTOV(dzp);
388		VN_HOLD(*vpp);
389	} else if (name[0] == '.' && name[1] == '.' && name[2] == 0) {
390		zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
391
392		/*
393		 * If we are a snapshot mounted under .zfs, return
394		 * the vp for the snapshot directory.
395		 */
396		if ((error = sa_lookup(dzp->z_sa_hdl,
397		    SA_ZPL_PARENT(zfsvfs), &parent, sizeof (parent))) != 0)
398			return (error);
399		if (parent == dzp->z_id && zfsvfs->z_parent != zfsvfs) {
400			error = zfsctl_root_lookup(zfsvfs->z_parent->z_ctldir,
401			    "snapshot", vpp, NULL, 0, NULL, kcred,
402			    NULL, NULL, NULL);
403			return (error);
404		}
405
406		mutex_enter(&dzp->z_lock);
407		unlinked = dzp->z_unlinked;
408		mutex_exit(&dzp->z_lock);
409		if (unlinked)
410			return (ENOENT);
411
412		rw_enter(&dzp->z_parent_lock, RW_READER);
413		error = zfs_zget(zfsvfs, parent, &zp);
414		if (error == 0)
415			*vpp = ZTOV(zp);
416		rw_exit(&dzp->z_parent_lock);
417	} else if (zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) {
418		*vpp = zfsctl_root(dzp);
419	} else {
420		int zf;
421
422		zf = ZEXISTS | ZSHARED;
423		if (flags & FIGNORECASE)
424			zf |= ZCILOOK;
425
426		error = zfs_dirent_lock(&dl, dzp, name, &zp, zf, deflg, rpnp);
427		if (error == 0) {
428			*vpp = ZTOV(zp);
429			zfs_dirent_unlock(dl);
430			dzp->z_zn_prefetch = B_TRUE; /* enable prefetching */
431		}
432		rpnp = NULL;
433	}
434
435	if ((flags & FIGNORECASE) && rpnp && !error)
436		(void) strlcpy(rpnp->pn_buf, name, rpnp->pn_bufsize);
437
438	return (error);
439}
440
441/*
442 * unlinked Set (formerly known as the "delete queue") Error Handling
443 *
444 * When dealing with the unlinked set, we dmu_tx_hold_zap(), but we
445 * don't specify the name of the entry that we will be manipulating.  We
446 * also fib and say that we won't be adding any new entries to the
447 * unlinked set, even though we might (this is to lower the minimum file
448 * size that can be deleted in a full filesystem).  So on the small
449 * chance that the nlink list is using a fat zap (ie. has more than
450 * 2000 entries), we *may* not pre-read a block that's needed.
451 * Therefore it is remotely possible for some of the assertions
452 * regarding the unlinked set below to fail due to i/o error.  On a
453 * nondebug system, this will result in the space being leaked.
454 */
455void
456zfs_unlinked_add(znode_t *zp, dmu_tx_t *tx)
457{
458	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
459
460	ASSERT(zp->z_unlinked);
461	ASSERT(zp->z_links == 0);
462
463	VERIFY3U(0, ==,
464	    zap_add_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx));
465}
466
467/*
468 * Clean up any znodes that had no links when we either crashed or
469 * (force) umounted the file system.
470 */
471void
472zfs_unlinked_drain(zfsvfs_t *zfsvfs)
473{
474	zap_cursor_t	zc;
475	zap_attribute_t zap;
476	dmu_object_info_t doi;
477	znode_t		*zp;
478	int		error;
479
480	/*
481	 * Interate over the contents of the unlinked set.
482	 */
483	for (zap_cursor_init(&zc, zfsvfs->z_os, zfsvfs->z_unlinkedobj);
484	    zap_cursor_retrieve(&zc, &zap) == 0;
485	    zap_cursor_advance(&zc)) {
486
487		/*
488		 * See what kind of object we have in list
489		 */
490
491		error = dmu_object_info(zfsvfs->z_os,
492		    zap.za_first_integer, &doi);
493		if (error != 0)
494			continue;
495
496		ASSERT((doi.doi_type == DMU_OT_PLAIN_FILE_CONTENTS) ||
497		    (doi.doi_type == DMU_OT_DIRECTORY_CONTENTS));
498		/*
499		 * We need to re-mark these list entries for deletion,
500		 * so we pull them back into core and set zp->z_unlinked.
501		 */
502		error = zfs_zget(zfsvfs, zap.za_first_integer, &zp);
503
504		/*
505		 * We may pick up znodes that are already marked for deletion.
506		 * This could happen during the purge of an extended attribute
507		 * directory.  All we need to do is skip over them, since they
508		 * are already in the system marked z_unlinked.
509		 */
510		if (error != 0)
511			continue;
512
513		zp->z_unlinked = B_TRUE;
514		VN_RELE(ZTOV(zp));
515	}
516	zap_cursor_fini(&zc);
517}
518
519/*
520 * Delete the entire contents of a directory.  Return a count
521 * of the number of entries that could not be deleted. If we encounter
522 * an error, return a count of at least one so that the directory stays
523 * in the unlinked set.
524 *
525 * NOTE: this function assumes that the directory is inactive,
526 *	so there is no need to lock its entries before deletion.
527 *	Also, it assumes the directory contents is *only* regular
528 *	files.
529 */
530static int
531zfs_purgedir(znode_t *dzp)
532{
533	zap_cursor_t	zc;
534	zap_attribute_t	zap;
535	znode_t		*xzp;
536	dmu_tx_t	*tx;
537	zfsvfs_t	*zfsvfs = dzp->z_zfsvfs;
538	zfs_dirlock_t	dl;
539	int skipped = 0;
540	int error;
541
542	for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id);
543	    (error = zap_cursor_retrieve(&zc, &zap)) == 0;
544	    zap_cursor_advance(&zc)) {
545		error = zfs_zget(zfsvfs,
546		    ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp);
547		if (error) {
548			skipped += 1;
549			continue;
550		}
551
552		ASSERT((ZTOV(xzp)->v_type == VREG) ||
553		    (ZTOV(xzp)->v_type == VLNK));
554
555		tx = dmu_tx_create(zfsvfs->z_os);
556		dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
557		dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name);
558		dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
559		dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
560		/* Is this really needed ? */
561		zfs_sa_upgrade_txholds(tx, xzp);
562		error = dmu_tx_assign(tx, TXG_WAIT);
563		if (error) {
564			dmu_tx_abort(tx);
565			VN_RELE(ZTOV(xzp));
566			skipped += 1;
567			continue;
568		}
569		bzero(&dl, sizeof (dl));
570		dl.dl_dzp = dzp;
571		dl.dl_name = zap.za_name;
572
573		error = zfs_link_destroy(&dl, xzp, tx, 0, NULL);
574		if (error)
575			skipped += 1;
576		dmu_tx_commit(tx);
577
578		VN_RELE(ZTOV(xzp));
579	}
580	zap_cursor_fini(&zc);
581	if (error != ENOENT)
582		skipped += 1;
583	return (skipped);
584}
585
586void
587zfs_rmnode(znode_t *zp)
588{
589	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
590	objset_t	*os = zfsvfs->z_os;
591	znode_t		*xzp = NULL;
592	dmu_tx_t	*tx;
593	uint64_t	acl_obj;
594	uint64_t	xattr_obj;
595	int		error;
596
597	ASSERT(zp->z_links == 0);
598
599	/*
600	 * If this is an attribute directory, purge its contents.
601	 */
602	if (ZTOV(zp) != NULL && ZTOV(zp)->v_type == VDIR &&
603	    (zp->z_pflags & ZFS_XATTR)) {
604		if (zfs_purgedir(zp) != 0) {
605			/*
606			 * Not enough space to delete some xattrs.
607			 * Leave it in the unlinked set.
608			 */
609			zfs_znode_dmu_fini(zp);
610			zfs_znode_free(zp);
611			return;
612		}
613	}
614
615	/*
616	 * Free up all the data in the file.
617	 */
618	error = dmu_free_long_range(os, zp->z_id, 0, DMU_OBJECT_END);
619	if (error) {
620		/*
621		 * Not enough space.  Leave the file in the unlinked set.
622		 */
623		zfs_znode_dmu_fini(zp);
624		zfs_znode_free(zp);
625		return;
626	}
627
628	/*
629	 * If the file has extended attributes, we're going to unlink
630	 * the xattr dir.
631	 */
632	error = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
633	    &xattr_obj, sizeof (xattr_obj));
634	if (error == 0 && xattr_obj) {
635		error = zfs_zget(zfsvfs, xattr_obj, &xzp);
636		ASSERT(error == 0);
637	}
638
639	acl_obj = zfs_external_acl(zp);
640
641	/*
642	 * Set up the final transaction.
643	 */
644	tx = dmu_tx_create(os);
645	dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END);
646	dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
647	if (xzp) {
648		dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, TRUE, NULL);
649		dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
650	}
651	if (acl_obj)
652		dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END);
653
654	zfs_sa_upgrade_txholds(tx, zp);
655	error = dmu_tx_assign(tx, TXG_WAIT);
656	if (error) {
657		/*
658		 * Not enough space to delete the file.  Leave it in the
659		 * unlinked set, leaking it until the fs is remounted (at
660		 * which point we'll call zfs_unlinked_drain() to process it).
661		 */
662		dmu_tx_abort(tx);
663		zfs_znode_dmu_fini(zp);
664		zfs_znode_free(zp);
665		goto out;
666	}
667
668	if (xzp) {
669		ASSERT(error == 0);
670		mutex_enter(&xzp->z_lock);
671		xzp->z_unlinked = B_TRUE;	/* mark xzp for deletion */
672		xzp->z_links = 0;	/* no more links to it */
673		VERIFY(0 == sa_update(xzp->z_sa_hdl, SA_ZPL_LINKS(zfsvfs),
674		    &xzp->z_links, sizeof (xzp->z_links), tx));
675		mutex_exit(&xzp->z_lock);
676		zfs_unlinked_add(xzp, tx);
677	}
678
679	/* Remove this znode from the unlinked set */
680	VERIFY3U(0, ==,
681	    zap_remove_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx));
682
683	zfs_znode_delete(zp, tx);
684
685	dmu_tx_commit(tx);
686out:
687	if (xzp)
688		VN_RELE(ZTOV(xzp));
689}
690
691static uint64_t
692zfs_dirent(znode_t *zp, uint64_t mode)
693{
694	uint64_t de = zp->z_id;
695
696	if (zp->z_zfsvfs->z_version >= ZPL_VERSION_DIRENT_TYPE)
697		de |= IFTODT(mode) << 60;
698	return (de);
699}
700
701/*
702 * Link zp into dl.  Can only fail if zp has been unlinked.
703 */
704int
705zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag)
706{
707	znode_t *dzp = dl->dl_dzp;
708	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
709	vnode_t *vp = ZTOV(zp);
710	uint64_t value;
711	int zp_is_dir = (vp->v_type == VDIR);
712	sa_bulk_attr_t bulk[5];
713	uint64_t mtime[2], ctime[2];
714	int count = 0;
715	int error;
716
717	mutex_enter(&zp->z_lock);
718
719	if (!(flag & ZRENAMING)) {
720		if (zp->z_unlinked) {	/* no new links to unlinked zp */
721			ASSERT(!(flag & (ZNEW | ZEXISTS)));
722			mutex_exit(&zp->z_lock);
723			return (SET_ERROR(ENOENT));
724		}
725		zp->z_links++;
726		SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL,
727		    &zp->z_links, sizeof (zp->z_links));
728
729	}
730	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_PARENT(zfsvfs), NULL,
731	    &dzp->z_id, sizeof (dzp->z_id));
732	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
733	    &zp->z_pflags, sizeof (zp->z_pflags));
734
735	if (!(flag & ZNEW)) {
736		SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
737		    ctime, sizeof (ctime));
738		zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime,
739		    ctime, B_TRUE);
740	}
741	error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
742	ASSERT(error == 0);
743
744	mutex_exit(&zp->z_lock);
745
746	mutex_enter(&dzp->z_lock);
747	dzp->z_size++;
748	dzp->z_links += zp_is_dir;
749	count = 0;
750	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs), NULL,
751	    &dzp->z_size, sizeof (dzp->z_size));
752	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL,
753	    &dzp->z_links, sizeof (dzp->z_links));
754	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
755	    mtime, sizeof (mtime));
756	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
757	    ctime, sizeof (ctime));
758	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
759	    &dzp->z_pflags, sizeof (dzp->z_pflags));
760	zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime, B_TRUE);
761	error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx);
762	ASSERT(error == 0);
763	mutex_exit(&dzp->z_lock);
764
765	value = zfs_dirent(zp, zp->z_mode);
766	error = zap_add(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name,
767	    8, 1, &value, tx);
768	ASSERT(error == 0);
769
770	dnlc_update(ZTOV(dzp), dl->dl_name, vp);
771
772	return (0);
773}
774
775static int
776zfs_dropname(zfs_dirlock_t *dl, znode_t *zp, znode_t *dzp, dmu_tx_t *tx,
777    int flag)
778{
779	int error;
780
781	if (zp->z_zfsvfs->z_norm) {
782		if (((zp->z_zfsvfs->z_case == ZFS_CASE_INSENSITIVE) &&
783		    (flag & ZCIEXACT)) ||
784		    ((zp->z_zfsvfs->z_case == ZFS_CASE_MIXED) &&
785		    !(flag & ZCILOOK)))
786			error = zap_remove_norm(zp->z_zfsvfs->z_os,
787			    dzp->z_id, dl->dl_name, MT_EXACT, tx);
788		else
789			error = zap_remove_norm(zp->z_zfsvfs->z_os,
790			    dzp->z_id, dl->dl_name, MT_FIRST, tx);
791	} else {
792		error = zap_remove(zp->z_zfsvfs->z_os,
793		    dzp->z_id, dl->dl_name, tx);
794	}
795
796	return (error);
797}
798
799/*
800 * Unlink zp from dl, and mark zp for deletion if this was the last link.
801 * Can fail if zp is a mount point (EBUSY) or a non-empty directory (EEXIST).
802 * If 'unlinkedp' is NULL, we put unlinked znodes on the unlinked list.
803 * If it's non-NULL, we use it to indicate whether the znode needs deletion,
804 * and it's the caller's job to do it.
805 */
806int
807zfs_link_destroy(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag,
808	boolean_t *unlinkedp)
809{
810	znode_t *dzp = dl->dl_dzp;
811	zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
812	vnode_t *vp = ZTOV(zp);
813	int zp_is_dir = (vp->v_type == VDIR);
814	boolean_t unlinked = B_FALSE;
815	sa_bulk_attr_t bulk[5];
816	uint64_t mtime[2], ctime[2];
817	int count = 0;
818	int error;
819
820	dnlc_remove(ZTOV(dzp), dl->dl_name);
821
822	if (!(flag & ZRENAMING)) {
823		if (vn_vfswlock(vp))		/* prevent new mounts on zp */
824			return (SET_ERROR(EBUSY));
825
826		if (vn_ismntpt(vp)) {		/* don't remove mount point */
827			vn_vfsunlock(vp);
828			return (SET_ERROR(EBUSY));
829		}
830
831		mutex_enter(&zp->z_lock);
832
833		if (zp_is_dir && !zfs_dirempty(zp)) {
834			mutex_exit(&zp->z_lock);
835			vn_vfsunlock(vp);
836#ifdef illumos
837			return (SET_ERROR(EEXIST));
838#else
839			return (SET_ERROR(ENOTEMPTY));
840#endif
841		}
842
843		/*
844		 * If we get here, we are going to try to remove the object.
845		 * First try removing the name from the directory; if that
846		 * fails, return the error.
847		 */
848		error = zfs_dropname(dl, zp, dzp, tx, flag);
849		if (error != 0) {
850			mutex_exit(&zp->z_lock);
851			vn_vfsunlock(vp);
852			return (error);
853		}
854
855		if (zp->z_links <= zp_is_dir) {
856			zfs_panic_recover("zfs: link count on vnode %p is %u, "
857			    "should be at least %u", zp->z_vnode,
858			    (int)zp->z_links,
859			    zp_is_dir + 1);
860			zp->z_links = zp_is_dir + 1;
861		}
862		if (--zp->z_links == zp_is_dir) {
863			zp->z_unlinked = B_TRUE;
864			zp->z_links = 0;
865			unlinked = B_TRUE;
866		} else {
867			SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs),
868			    NULL, &ctime, sizeof (ctime));
869			SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
870			    NULL, &zp->z_pflags, sizeof (zp->z_pflags));
871			zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime, ctime,
872			    B_TRUE);
873		}
874		SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs),
875		    NULL, &zp->z_links, sizeof (zp->z_links));
876		error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
877		count = 0;
878		ASSERT(error == 0);
879		mutex_exit(&zp->z_lock);
880		vn_vfsunlock(vp);
881	} else {
882		error = zfs_dropname(dl, zp, dzp, tx, flag);
883		if (error != 0)
884			return (error);
885	}
886
887	mutex_enter(&dzp->z_lock);
888	dzp->z_size--;		/* one dirent removed */
889	dzp->z_links -= zp_is_dir;	/* ".." link from zp */
890	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs),
891	    NULL, &dzp->z_links, sizeof (dzp->z_links));
892	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs),
893	    NULL, &dzp->z_size, sizeof (dzp->z_size));
894	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs),
895	    NULL, ctime, sizeof (ctime));
896	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs),
897	    NULL, mtime, sizeof (mtime));
898	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
899	    NULL, &dzp->z_pflags, sizeof (dzp->z_pflags));
900	zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime, B_TRUE);
901	error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx);
902	ASSERT(error == 0);
903	mutex_exit(&dzp->z_lock);
904
905	if (unlinkedp != NULL)
906		*unlinkedp = unlinked;
907	else if (unlinked)
908		zfs_unlinked_add(zp, tx);
909
910	return (0);
911}
912
913/*
914 * Indicate whether the directory is empty.  Works with or without z_lock
915 * held, but can only be consider a hint in the latter case.  Returns true
916 * if only "." and ".." remain and there's no work in progress.
917 */
918boolean_t
919zfs_dirempty(znode_t *dzp)
920{
921	return (dzp->z_size == 2 && dzp->z_dirlocks == 0);
922}
923
924int
925zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr)
926{
927	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
928	znode_t *xzp;
929	dmu_tx_t *tx;
930	int error;
931	zfs_acl_ids_t acl_ids;
932	boolean_t fuid_dirtied;
933	uint64_t parent;
934
935	*xvpp = NULL;
936
937	/*
938	 * In FreeBSD, access checking for creating an EA is being done
939	 * in zfs_setextattr(),
940	 */
941#ifndef __FreeBSD__
942	if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, 0, B_FALSE, cr))
943		return (error);
944#endif
945
946	if ((error = zfs_acl_ids_create(zp, IS_XATTR, vap, cr, NULL,
947	    &acl_ids)) != 0)
948		return (error);
949	if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
950		zfs_acl_ids_free(&acl_ids);
951		return (SET_ERROR(EDQUOT));
952	}
953
954	getnewvnode_reserve(1);
955
956	tx = dmu_tx_create(zfsvfs->z_os);
957	dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
958	    ZFS_SA_BASE_ATTR_SIZE);
959	dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
960	dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
961	fuid_dirtied = zfsvfs->z_fuid_dirty;
962	if (fuid_dirtied)
963		zfs_fuid_txhold(zfsvfs, tx);
964	error = dmu_tx_assign(tx, TXG_WAIT);
965	if (error) {
966		zfs_acl_ids_free(&acl_ids);
967		dmu_tx_abort(tx);
968		return (error);
969	}
970	zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, &acl_ids);
971
972	if (fuid_dirtied)
973		zfs_fuid_sync(zfsvfs, tx);
974
975#ifdef DEBUG
976	error = sa_lookup(xzp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
977	    &parent, sizeof (parent));
978	ASSERT(error == 0 && parent == zp->z_id);
979#endif
980
981	VERIFY(0 == sa_update(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), &xzp->z_id,
982	    sizeof (xzp->z_id), tx));
983
984	(void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp,
985	    xzp, "", NULL, acl_ids.z_fuidp, vap);
986
987	zfs_acl_ids_free(&acl_ids);
988	dmu_tx_commit(tx);
989
990	getnewvnode_drop_reserve();
991
992	*xvpp = ZTOV(xzp);
993
994	return (0);
995}
996
997/*
998 * Return a znode for the extended attribute directory for zp.
999 * ** If the directory does not already exist, it is created **
1000 *
1001 *	IN:	zp	- znode to obtain attribute directory from
1002 *		cr	- credentials of caller
1003 *		flags	- flags from the VOP_LOOKUP call
1004 *
1005 *	OUT:	xzpp	- pointer to extended attribute znode
1006 *
1007 *	RETURN:	0 on success
1008 *		error number on failure
1009 */
1010int
1011zfs_get_xattrdir(znode_t *zp, vnode_t **xvpp, cred_t *cr, int flags)
1012{
1013	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
1014	znode_t		*xzp;
1015	zfs_dirlock_t	*dl;
1016	vattr_t		va;
1017	int		error;
1018top:
1019	error = zfs_dirent_lock(&dl, zp, "", &xzp, ZXATTR, NULL, NULL);
1020	if (error)
1021		return (error);
1022
1023	if (xzp != NULL) {
1024		*xvpp = ZTOV(xzp);
1025		zfs_dirent_unlock(dl);
1026		return (0);
1027	}
1028
1029
1030	if (!(flags & CREATE_XATTR_DIR)) {
1031		zfs_dirent_unlock(dl);
1032#ifdef illumos
1033		return (SET_ERROR(ENOENT));
1034#else
1035		return (SET_ERROR(ENOATTR));
1036#endif
1037	}
1038
1039	if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
1040		zfs_dirent_unlock(dl);
1041		return (SET_ERROR(EROFS));
1042	}
1043
1044	/*
1045	 * The ability to 'create' files in an attribute
1046	 * directory comes from the write_xattr permission on the base file.
1047	 *
1048	 * The ability to 'search' an attribute directory requires
1049	 * read_xattr permission on the base file.
1050	 *
1051	 * Once in a directory the ability to read/write attributes
1052	 * is controlled by the permissions on the attribute file.
1053	 */
1054	va.va_mask = AT_TYPE | AT_MODE | AT_UID | AT_GID;
1055	va.va_type = VDIR;
1056	va.va_mode = S_IFDIR | S_ISVTX | 0777;
1057	zfs_fuid_map_ids(zp, cr, &va.va_uid, &va.va_gid);
1058
1059	error = zfs_make_xattrdir(zp, &va, xvpp, cr);
1060	zfs_dirent_unlock(dl);
1061
1062	if (error == ERESTART) {
1063		/* NB: we already did dmu_tx_wait() if necessary */
1064		goto top;
1065	}
1066	if (error == 0)
1067		VOP_UNLOCK(*xvpp, 0);
1068
1069	return (error);
1070}
1071
1072/*
1073 * Decide whether it is okay to remove within a sticky directory.
1074 *
1075 * In sticky directories, write access is not sufficient;
1076 * you can remove entries from a directory only if:
1077 *
1078 *	you own the directory,
1079 *	you own the entry,
1080 *	the entry is a plain file and you have write access,
1081 *	or you are privileged (checked in secpolicy...).
1082 *
1083 * The function returns 0 if remove access is granted.
1084 */
1085int
1086zfs_sticky_remove_access(znode_t *zdp, znode_t *zp, cred_t *cr)
1087{
1088	uid_t  		uid;
1089	uid_t		downer;
1090	uid_t		fowner;
1091	zfsvfs_t	*zfsvfs = zdp->z_zfsvfs;
1092
1093	if (zdp->z_zfsvfs->z_replay)
1094		return (0);
1095
1096	if ((zdp->z_mode & S_ISVTX) == 0)
1097		return (0);
1098
1099	downer = zfs_fuid_map_id(zfsvfs, zdp->z_uid, cr, ZFS_OWNER);
1100	fowner = zfs_fuid_map_id(zfsvfs, zp->z_uid, cr, ZFS_OWNER);
1101
1102	if ((uid = crgetuid(cr)) == downer || uid == fowner ||
1103	    (ZTOV(zp)->v_type == VREG &&
1104	    zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr) == 0))
1105		return (0);
1106	else
1107		return (secpolicy_vnode_remove(ZTOV(zp), cr));
1108}
1109