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, 2015 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_lookup() 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, const char *name,
66    boolean_t exact, uint64_t *zoid)
67{
68	int error;
69
70	if (zfsvfs->z_norm) {
71		matchtype_t mt = exact? MT_EXACT : MT_FIRST;
72
73		/*
74		 * In the non-mixed case we only expect there would ever
75		 * be one match, but we need to use the normalizing lookup.
76		 */
77		error = zap_lookup_norm(zfsvfs->z_os, dzp->z_id, name, 8, 1,
78		    zoid, mt, NULL, 0, NULL);
79	} else {
80		error = zap_lookup(zfsvfs->z_os, dzp->z_id, name, 8, 1, zoid);
81	}
82	*zoid = ZFS_DIRENT_OBJ(*zoid);
83
84	return (error);
85}
86
87/*
88 * Look up a directory entry under a locked vnode.
89 * dvp being locked gives us a guarantee that there are no concurrent
90 * modification of the directory and, thus, if a node can be found in
91 * the directory, then it must not be unlinked.
92 *
93 * Input arguments:
94 *	dzp	- znode for directory
95 *	name	- name of entry to lock
96 *	flag	- ZNEW: if the entry already exists, fail with EEXIST.
97 *		  ZEXISTS: if the entry does not exist, fail with ENOENT.
98 *		  ZXATTR: we want dzp's xattr directory
99 *
100 * Output arguments:
101 *	zpp	- pointer to the znode for the entry (NULL if there isn't one)
102 *
103 * Return value: 0 on success or errno on failure.
104 *
105 * NOTE: Always checks for, and rejects, '.' and '..'.
106 */
107int
108zfs_dirent_lookup(znode_t *dzp, const char *name, znode_t **zpp, int flag)
109{
110	zfsvfs_t	*zfsvfs = dzp->z_zfsvfs;
111	boolean_t	exact;
112	uint64_t	zoid;
113	vnode_t		*vp = NULL;
114	int		error = 0;
115
116	ASSERT_VOP_LOCKED(ZTOV(dzp), __func__);
117
118	*zpp = NULL;
119
120	/*
121	 * Verify that we are not trying to lock '.', '..', or '.zfs'
122	 */
123	if (name[0] == '.' &&
124	    (name[1] == '\0' || (name[1] == '.' && name[2] == '\0')) ||
125	    zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0)
126		return (SET_ERROR(EEXIST));
127
128	/*
129	 * Case sensitivity and normalization preferences are set when
130	 * the file system is created.  These are stored in the
131	 * zfsvfs->z_case and zfsvfs->z_norm fields.  These choices
132	 * affect how we perform zap lookups.
133	 *
134	 * Decide if exact matches should be requested when performing
135	 * a zap lookup on file systems supporting case-insensitive
136	 * access.
137	 *
138	 * NB: we do not need to worry about this flag for ZFS_CASE_SENSITIVE
139	 * because in that case MT_EXACT and MT_FIRST should produce exactly
140	 * the same result.
141	 */
142	exact = zfsvfs->z_case == ZFS_CASE_MIXED;
143
144	if (dzp->z_unlinked && !(flag & ZXATTR))
145		return (ENOENT);
146	if (flag & ZXATTR) {
147		error = sa_lookup(dzp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), &zoid,
148		    sizeof (zoid));
149		if (error == 0)
150			error = (zoid == 0 ? ENOENT : 0);
151	} else {
152		error = zfs_match_find(zfsvfs, dzp, name, exact, &zoid);
153	}
154	if (error) {
155		if (error != ENOENT || (flag & ZEXISTS)) {
156			return (error);
157		}
158	} else {
159		if (flag & ZNEW) {
160			return (SET_ERROR(EEXIST));
161		}
162		error = zfs_zget(zfsvfs, zoid, zpp);
163		if (error)
164			return (error);
165		ASSERT(!(*zpp)->z_unlinked);
166	}
167
168	return (0);
169}
170
171static int
172zfs_dd_lookup(znode_t *dzp, znode_t **zpp)
173{
174	zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
175	znode_t *zp;
176	uint64_t parent;
177	int error;
178
179	ASSERT_VOP_LOCKED(ZTOV(dzp), __func__);
180	ASSERT(RRM_READ_HELD(&zfsvfs->z_teardown_lock));
181
182	if (dzp->z_unlinked)
183		return (ENOENT);
184
185	if ((error = sa_lookup(dzp->z_sa_hdl,
186	    SA_ZPL_PARENT(zfsvfs), &parent, sizeof (parent))) != 0)
187		return (error);
188
189	error = zfs_zget(zfsvfs, parent, &zp);
190	if (error == 0)
191		*zpp = zp;
192	return (error);
193}
194
195int
196zfs_dirlook(znode_t *dzp, const char *name, znode_t **zpp)
197{
198	zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
199	znode_t *zp;
200	int error = 0;
201
202	ASSERT_VOP_LOCKED(ZTOV(dzp), __func__);
203	ASSERT(RRM_READ_HELD(&zfsvfs->z_teardown_lock));
204
205	if (dzp->z_unlinked)
206		return (SET_ERROR(ENOENT));
207
208	if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) {
209		*zpp = dzp;
210	} else if (name[0] == '.' && name[1] == '.' && name[2] == 0) {
211		error = zfs_dd_lookup(dzp, zpp);
212	} else {
213		error = zfs_dirent_lookup(dzp, name, &zp, ZEXISTS);
214		if (error == 0) {
215			dzp->z_zn_prefetch = B_TRUE; /* enable prefetching */
216			*zpp = zp;
217		}
218	}
219	return (error);
220}
221
222/*
223 * unlinked Set (formerly known as the "delete queue") Error Handling
224 *
225 * When dealing with the unlinked set, we dmu_tx_hold_zap(), but we
226 * don't specify the name of the entry that we will be manipulating.  We
227 * also fib and say that we won't be adding any new entries to the
228 * unlinked set, even though we might (this is to lower the minimum file
229 * size that can be deleted in a full filesystem).  So on the small
230 * chance that the nlink list is using a fat zap (ie. has more than
231 * 2000 entries), we *may* not pre-read a block that's needed.
232 * Therefore it is remotely possible for some of the assertions
233 * regarding the unlinked set below to fail due to i/o error.  On a
234 * nondebug system, this will result in the space being leaked.
235 */
236void
237zfs_unlinked_add(znode_t *zp, dmu_tx_t *tx)
238{
239	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
240
241	ASSERT(zp->z_unlinked);
242	ASSERT(zp->z_links == 0);
243
244	VERIFY3U(0, ==,
245	    zap_add_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx));
246}
247
248/*
249 * Clean up any znodes that had no links when we either crashed or
250 * (force) umounted the file system.
251 */
252void
253zfs_unlinked_drain(zfsvfs_t *zfsvfs)
254{
255	zap_cursor_t	zc;
256	zap_attribute_t zap;
257	dmu_object_info_t doi;
258	znode_t		*zp;
259	int		error;
260
261	/*
262	 * Interate over the contents of the unlinked set.
263	 */
264	for (zap_cursor_init(&zc, zfsvfs->z_os, zfsvfs->z_unlinkedobj);
265	    zap_cursor_retrieve(&zc, &zap) == 0;
266	    zap_cursor_advance(&zc)) {
267
268		/*
269		 * See what kind of object we have in list
270		 */
271
272		error = dmu_object_info(zfsvfs->z_os,
273		    zap.za_first_integer, &doi);
274		if (error != 0)
275			continue;
276
277		ASSERT((doi.doi_type == DMU_OT_PLAIN_FILE_CONTENTS) ||
278		    (doi.doi_type == DMU_OT_DIRECTORY_CONTENTS));
279		/*
280		 * We need to re-mark these list entries for deletion,
281		 * so we pull them back into core and set zp->z_unlinked.
282		 */
283		error = zfs_zget(zfsvfs, zap.za_first_integer, &zp);
284
285		/*
286		 * We may pick up znodes that are already marked for deletion.
287		 * This could happen during the purge of an extended attribute
288		 * directory.  All we need to do is skip over them, since they
289		 * are already in the system marked z_unlinked.
290		 */
291		if (error != 0)
292			continue;
293
294		vn_lock(ZTOV(zp), LK_EXCLUSIVE | LK_RETRY);
295		zp->z_unlinked = B_TRUE;
296		vput(ZTOV(zp));
297	}
298	zap_cursor_fini(&zc);
299}
300
301/*
302 * Delete the entire contents of a directory.  Return a count
303 * of the number of entries that could not be deleted. If we encounter
304 * an error, return a count of at least one so that the directory stays
305 * in the unlinked set.
306 *
307 * NOTE: this function assumes that the directory is inactive,
308 *	so there is no need to lock its entries before deletion.
309 *	Also, it assumes the directory contents is *only* regular
310 *	files.
311 */
312static int
313zfs_purgedir(znode_t *dzp)
314{
315	zap_cursor_t	zc;
316	zap_attribute_t	zap;
317	znode_t		*xzp;
318	dmu_tx_t	*tx;
319	zfsvfs_t	*zfsvfs = dzp->z_zfsvfs;
320	int skipped = 0;
321	int error;
322
323	for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id);
324	    (error = zap_cursor_retrieve(&zc, &zap)) == 0;
325	    zap_cursor_advance(&zc)) {
326		error = zfs_zget(zfsvfs,
327		    ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp);
328		if (error) {
329			skipped += 1;
330			continue;
331		}
332
333		vn_lock(ZTOV(xzp), LK_EXCLUSIVE | LK_RETRY);
334		ASSERT((ZTOV(xzp)->v_type == VREG) ||
335		    (ZTOV(xzp)->v_type == VLNK));
336
337		tx = dmu_tx_create(zfsvfs->z_os);
338		dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
339		dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name);
340		dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
341		dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
342		/* Is this really needed ? */
343		zfs_sa_upgrade_txholds(tx, xzp);
344		dmu_tx_mark_netfree(tx);
345		error = dmu_tx_assign(tx, TXG_WAIT);
346		if (error) {
347			dmu_tx_abort(tx);
348			vput(ZTOV(xzp));
349			skipped += 1;
350			continue;
351		}
352
353		error = zfs_link_destroy(dzp, zap.za_name, xzp, tx, 0, NULL);
354		if (error)
355			skipped += 1;
356		dmu_tx_commit(tx);
357
358		vput(ZTOV(xzp));
359	}
360	zap_cursor_fini(&zc);
361	if (error != ENOENT)
362		skipped += 1;
363	return (skipped);
364}
365
366void
367zfs_rmnode(znode_t *zp)
368{
369	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
370	objset_t	*os = zfsvfs->z_os;
371	znode_t		*xzp = NULL;
372	dmu_tx_t	*tx;
373	uint64_t	acl_obj;
374	uint64_t	xattr_obj;
375	int		error;
376
377	ASSERT(zp->z_links == 0);
378	ASSERT_VOP_ELOCKED(ZTOV(zp), __func__);
379
380	/*
381	 * If this is an attribute directory, purge its contents.
382	 */
383	if (ZTOV(zp) != NULL && ZTOV(zp)->v_type == VDIR &&
384	    (zp->z_pflags & ZFS_XATTR)) {
385		if (zfs_purgedir(zp) != 0) {
386			/*
387			 * Not enough space to delete some xattrs.
388			 * Leave it in the unlinked set.
389			 */
390			zfs_znode_dmu_fini(zp);
391			zfs_znode_free(zp);
392			return;
393		}
394	}
395
396	/*
397	 * Free up all the data in the file.
398	 */
399	error = dmu_free_long_range(os, zp->z_id, 0, DMU_OBJECT_END);
400	if (error) {
401		/*
402		 * Not enough space.  Leave the file in the unlinked set.
403		 */
404		zfs_znode_dmu_fini(zp);
405		zfs_znode_free(zp);
406		return;
407	}
408
409	/*
410	 * If the file has extended attributes, we're going to unlink
411	 * the xattr dir.
412	 */
413	error = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
414	    &xattr_obj, sizeof (xattr_obj));
415	if (error == 0 && xattr_obj) {
416		error = zfs_zget(zfsvfs, xattr_obj, &xzp);
417		ASSERT3S(error, ==, 0);
418		vn_lock(ZTOV(xzp), LK_EXCLUSIVE | LK_RETRY);
419	}
420
421	acl_obj = zfs_external_acl(zp);
422
423	/*
424	 * Set up the final transaction.
425	 */
426	tx = dmu_tx_create(os);
427	dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END);
428	dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
429	if (xzp) {
430		dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, TRUE, NULL);
431		dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
432	}
433	if (acl_obj)
434		dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END);
435
436	zfs_sa_upgrade_txholds(tx, zp);
437	error = dmu_tx_assign(tx, TXG_WAIT);
438	if (error) {
439		/*
440		 * Not enough space to delete the file.  Leave it in the
441		 * unlinked set, leaking it until the fs is remounted (at
442		 * which point we'll call zfs_unlinked_drain() to process it).
443		 */
444		dmu_tx_abort(tx);
445		zfs_znode_dmu_fini(zp);
446		zfs_znode_free(zp);
447		goto out;
448	}
449
450	if (xzp) {
451		ASSERT(error == 0);
452		xzp->z_unlinked = B_TRUE;	/* mark xzp for deletion */
453		xzp->z_links = 0;	/* no more links to it */
454		VERIFY(0 == sa_update(xzp->z_sa_hdl, SA_ZPL_LINKS(zfsvfs),
455		    &xzp->z_links, sizeof (xzp->z_links), tx));
456		zfs_unlinked_add(xzp, tx);
457	}
458
459	/* Remove this znode from the unlinked set */
460	VERIFY3U(0, ==,
461	    zap_remove_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx));
462
463	zfs_znode_delete(zp, tx);
464
465	dmu_tx_commit(tx);
466out:
467	if (xzp)
468		vput(ZTOV(xzp));
469}
470
471static uint64_t
472zfs_dirent(znode_t *zp, uint64_t mode)
473{
474	uint64_t de = zp->z_id;
475
476	if (zp->z_zfsvfs->z_version >= ZPL_VERSION_DIRENT_TYPE)
477		de |= IFTODT(mode) << 60;
478	return (de);
479}
480
481/*
482 * Link zp into dzp.  Can only fail if zp has been unlinked.
483 */
484int
485zfs_link_create(znode_t *dzp, const char *name, znode_t *zp, dmu_tx_t *tx,
486    int flag)
487{
488	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
489	vnode_t *vp = ZTOV(zp);
490	uint64_t value;
491	int zp_is_dir = (vp->v_type == VDIR);
492	sa_bulk_attr_t bulk[5];
493	uint64_t mtime[2], ctime[2];
494	int count = 0;
495	int error;
496
497	ASSERT_VOP_ELOCKED(ZTOV(dzp), __func__);
498	ASSERT_VOP_ELOCKED(ZTOV(zp), __func__);
499#if 0
500	if (zp_is_dir) {
501		error = 0;
502		if (dzp->z_links >= LINK_MAX)
503			error = SET_ERROR(EMLINK);
504		return (error);
505	}
506#endif
507	if (!(flag & ZRENAMING)) {
508		if (zp->z_unlinked) {	/* no new links to unlinked zp */
509			ASSERT(!(flag & (ZNEW | ZEXISTS)));
510			return (SET_ERROR(ENOENT));
511		}
512#if 0
513		if (zp->z_links >= LINK_MAX) {
514			return (SET_ERROR(EMLINK));
515		}
516#endif
517		zp->z_links++;
518		SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL,
519		    &zp->z_links, sizeof (zp->z_links));
520
521	} else {
522		ASSERT(zp->z_unlinked == 0);
523	}
524	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_PARENT(zfsvfs), NULL,
525	    &dzp->z_id, sizeof (dzp->z_id));
526	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
527	    &zp->z_pflags, sizeof (zp->z_pflags));
528
529	if (!(flag & ZNEW)) {
530		SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
531		    ctime, sizeof (ctime));
532		zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime,
533		    ctime, B_TRUE);
534	}
535	error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
536	ASSERT0(error);
537
538	dzp->z_size++;
539	dzp->z_links += zp_is_dir;
540	count = 0;
541	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs), NULL,
542	    &dzp->z_size, sizeof (dzp->z_size));
543	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL,
544	    &dzp->z_links, sizeof (dzp->z_links));
545	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
546	    mtime, sizeof (mtime));
547	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
548	    ctime, sizeof (ctime));
549	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
550	    &dzp->z_pflags, sizeof (dzp->z_pflags));
551	zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime, B_TRUE);
552	error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx);
553	ASSERT0(error);
554
555	value = zfs_dirent(zp, zp->z_mode);
556	error = zap_add(zp->z_zfsvfs->z_os, dzp->z_id, name,
557	    8, 1, &value, tx);
558	VERIFY0(error);
559
560	return (0);
561}
562
563static int
564zfs_dropname(znode_t *dzp, const char *name, znode_t *zp, dmu_tx_t *tx,
565    int flag)
566{
567	int error;
568
569	if (zp->z_zfsvfs->z_norm) {
570		if (zp->z_zfsvfs->z_case == ZFS_CASE_MIXED)
571			error = zap_remove_norm(zp->z_zfsvfs->z_os,
572			    dzp->z_id, name, MT_EXACT, tx);
573		else
574			error = zap_remove_norm(zp->z_zfsvfs->z_os,
575			    dzp->z_id, name, MT_FIRST, tx);
576	} else {
577		error = zap_remove(zp->z_zfsvfs->z_os,
578		    dzp->z_id, name, tx);
579	}
580
581	return (error);
582}
583
584/*
585 * Unlink zp from dzp, and mark zp for deletion if this was the last link.
586 * Can fail if zp is a mount point (EBUSY) or a non-empty directory (EEXIST).
587 * If 'unlinkedp' is NULL, we put unlinked znodes on the unlinked list.
588 * If it's non-NULL, we use it to indicate whether the znode needs deletion,
589 * and it's the caller's job to do it.
590 */
591int
592zfs_link_destroy(znode_t *dzp, const char *name, znode_t *zp, dmu_tx_t *tx,
593    int flag, boolean_t *unlinkedp)
594{
595	zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
596	vnode_t *vp = ZTOV(zp);
597	int zp_is_dir = (vp->v_type == VDIR);
598	boolean_t unlinked = B_FALSE;
599	sa_bulk_attr_t bulk[5];
600	uint64_t mtime[2], ctime[2];
601	int count = 0;
602	int error;
603
604	ASSERT_VOP_ELOCKED(ZTOV(dzp), __func__);
605	ASSERT_VOP_ELOCKED(ZTOV(zp), __func__);
606
607	if (!(flag & ZRENAMING)) {
608
609		if (zp_is_dir && !zfs_dirempty(zp)) {
610#ifdef illumos
611			return (SET_ERROR(EEXIST));
612#else
613			return (SET_ERROR(ENOTEMPTY));
614#endif
615		}
616
617		/*
618		 * If we get here, we are going to try to remove the object.
619		 * First try removing the name from the directory; if that
620		 * fails, return the error.
621		 */
622		error = zfs_dropname(dzp, name, zp, tx, flag);
623		if (error != 0) {
624			return (error);
625		}
626
627		if (zp->z_links <= zp_is_dir) {
628			zfs_panic_recover("zfs: link count on vnode %p is %u, "
629			    "should be at least %u", zp->z_vnode,
630			    (int)zp->z_links,
631			    zp_is_dir + 1);
632			zp->z_links = zp_is_dir + 1;
633		}
634		if (--zp->z_links == zp_is_dir) {
635			zp->z_unlinked = B_TRUE;
636			zp->z_links = 0;
637			unlinked = B_TRUE;
638		} else {
639			SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs),
640			    NULL, &ctime, sizeof (ctime));
641			SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
642			    NULL, &zp->z_pflags, sizeof (zp->z_pflags));
643			zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime, ctime,
644			    B_TRUE);
645		}
646		SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs),
647		    NULL, &zp->z_links, sizeof (zp->z_links));
648		error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
649		count = 0;
650		ASSERT0(error);
651	} else {
652		ASSERT(zp->z_unlinked == 0);
653		error = zfs_dropname(dzp, name, zp, tx, flag);
654		if (error != 0)
655			return (error);
656	}
657
658	dzp->z_size--;		/* one dirent removed */
659	dzp->z_links -= zp_is_dir;	/* ".." link from zp */
660	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs),
661	    NULL, &dzp->z_links, sizeof (dzp->z_links));
662	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs),
663	    NULL, &dzp->z_size, sizeof (dzp->z_size));
664	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs),
665	    NULL, ctime, sizeof (ctime));
666	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs),
667	    NULL, mtime, sizeof (mtime));
668	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
669	    NULL, &dzp->z_pflags, sizeof (dzp->z_pflags));
670	zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime, B_TRUE);
671	error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx);
672	ASSERT0(error);
673
674	if (unlinkedp != NULL)
675		*unlinkedp = unlinked;
676	else if (unlinked)
677		zfs_unlinked_add(zp, tx);
678
679	return (0);
680}
681
682/*
683 * Indicate whether the directory is empty.
684 */
685boolean_t
686zfs_dirempty(znode_t *dzp)
687{
688	return (dzp->z_size == 2);
689}
690
691int
692zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr)
693{
694	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
695	znode_t *xzp;
696	dmu_tx_t *tx;
697	int error;
698	zfs_acl_ids_t acl_ids;
699	boolean_t fuid_dirtied;
700	uint64_t parent;
701
702	*xvpp = NULL;
703
704	/*
705	 * In FreeBSD, access checking for creating an EA is being done
706	 * in zfs_setextattr(),
707	 */
708#ifndef __FreeBSD_kernel__
709	if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, 0, B_FALSE, cr))
710		return (error);
711#endif
712
713	if ((error = zfs_acl_ids_create(zp, IS_XATTR, vap, cr, NULL,
714	    &acl_ids)) != 0)
715		return (error);
716	if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
717		zfs_acl_ids_free(&acl_ids);
718		return (SET_ERROR(EDQUOT));
719	}
720
721	getnewvnode_reserve(1);
722
723	tx = dmu_tx_create(zfsvfs->z_os);
724	dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
725	    ZFS_SA_BASE_ATTR_SIZE);
726	dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
727	dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
728	fuid_dirtied = zfsvfs->z_fuid_dirty;
729	if (fuid_dirtied)
730		zfs_fuid_txhold(zfsvfs, tx);
731	error = dmu_tx_assign(tx, TXG_WAIT);
732	if (error) {
733		zfs_acl_ids_free(&acl_ids);
734		dmu_tx_abort(tx);
735		return (error);
736	}
737	zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, &acl_ids);
738
739	if (fuid_dirtied)
740		zfs_fuid_sync(zfsvfs, tx);
741
742#ifdef DEBUG
743	error = sa_lookup(xzp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
744	    &parent, sizeof (parent));
745	ASSERT(error == 0 && parent == zp->z_id);
746#endif
747
748	VERIFY(0 == sa_update(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), &xzp->z_id,
749	    sizeof (xzp->z_id), tx));
750
751	(void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp,
752	    xzp, "", NULL, acl_ids.z_fuidp, vap);
753
754	zfs_acl_ids_free(&acl_ids);
755	dmu_tx_commit(tx);
756
757	getnewvnode_drop_reserve();
758
759	*xvpp = ZTOV(xzp);
760
761	return (0);
762}
763
764/*
765 * Return a znode for the extended attribute directory for zp.
766 * ** If the directory does not already exist, it is created **
767 *
768 *	IN:	zp	- znode to obtain attribute directory from
769 *		cr	- credentials of caller
770 *		flags	- flags from the VOP_LOOKUP call
771 *
772 *	OUT:	xzpp	- pointer to extended attribute znode
773 *
774 *	RETURN:	0 on success
775 *		error number on failure
776 */
777int
778zfs_get_xattrdir(znode_t *zp, vnode_t **xvpp, cred_t *cr, int flags)
779{
780	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
781	znode_t		*xzp;
782	vattr_t		va;
783	int		error;
784top:
785	error = zfs_dirent_lookup(zp, "", &xzp, ZXATTR);
786	if (error)
787		return (error);
788
789	if (xzp != NULL) {
790		*xvpp = ZTOV(xzp);
791		return (0);
792	}
793
794
795	if (!(flags & CREATE_XATTR_DIR)) {
796#ifdef illumos
797		return (SET_ERROR(ENOENT));
798#else
799		return (SET_ERROR(ENOATTR));
800#endif
801	}
802
803	if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
804		return (SET_ERROR(EROFS));
805	}
806
807	/*
808	 * The ability to 'create' files in an attribute
809	 * directory comes from the write_xattr permission on the base file.
810	 *
811	 * The ability to 'search' an attribute directory requires
812	 * read_xattr permission on the base file.
813	 *
814	 * Once in a directory the ability to read/write attributes
815	 * is controlled by the permissions on the attribute file.
816	 */
817	va.va_mask = AT_TYPE | AT_MODE | AT_UID | AT_GID;
818	va.va_type = VDIR;
819	va.va_mode = S_IFDIR | S_ISVTX | 0777;
820	zfs_fuid_map_ids(zp, cr, &va.va_uid, &va.va_gid);
821
822	error = zfs_make_xattrdir(zp, &va, xvpp, cr);
823
824	if (error == ERESTART) {
825		/* NB: we already did dmu_tx_wait() if necessary */
826		goto top;
827	}
828	if (error == 0)
829		VOP_UNLOCK(*xvpp, 0);
830
831	return (error);
832}
833
834/*
835 * Decide whether it is okay to remove within a sticky directory.
836 *
837 * In sticky directories, write access is not sufficient;
838 * you can remove entries from a directory only if:
839 *
840 *	you own the directory,
841 *	you own the entry,
842 *	the entry is a plain file and you have write access,
843 *	or you are privileged (checked in secpolicy...).
844 *
845 * The function returns 0 if remove access is granted.
846 */
847int
848zfs_sticky_remove_access(znode_t *zdp, znode_t *zp, cred_t *cr)
849{
850	uid_t  		uid;
851	uid_t		downer;
852	uid_t		fowner;
853	zfsvfs_t	*zfsvfs = zdp->z_zfsvfs;
854
855	if (zdp->z_zfsvfs->z_replay)
856		return (0);
857
858	if ((zdp->z_mode & S_ISVTX) == 0)
859		return (0);
860
861	downer = zfs_fuid_map_id(zfsvfs, zdp->z_uid, cr, ZFS_OWNER);
862	fowner = zfs_fuid_map_id(zfsvfs, zp->z_uid, cr, ZFS_OWNER);
863
864	if ((uid = crgetuid(cr)) == downer || uid == fowner ||
865	    (ZTOV(zp)->v_type == VREG &&
866	    zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr) == 0))
867		return (0);
868	else
869		return (secpolicy_vnode_remove(ZTOV(zp), cr));
870}
871