xref: /linux/fs/xfs/xfs_attr_list.c (revision 9a379e77033f02c4a071891afdf0f0a01eff8ccb) 
1 /*
2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3  * Copyright (c) 2013 Red Hat, Inc.
4  * All Rights Reserved.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it would be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write the Free Software Foundation,
17  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
18  */
19 #include "xfs.h"
20 #include "xfs_fs.h"
21 #include "xfs_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_trans_resv.h"
24 #include "xfs_bit.h"
25 #include "xfs_mount.h"
26 #include "xfs_da_format.h"
27 #include "xfs_da_btree.h"
28 #include "xfs_inode.h"
29 #include "xfs_trans.h"
30 #include "xfs_inode_item.h"
31 #include "xfs_bmap.h"
32 #include "xfs_attr.h"
33 #include "xfs_attr_sf.h"
34 #include "xfs_attr_remote.h"
35 #include "xfs_attr_leaf.h"
36 #include "xfs_error.h"
37 #include "xfs_trace.h"
38 #include "xfs_buf_item.h"
39 #include "xfs_cksum.h"
40 #include "xfs_dir2.h"
41 
42 STATIC int
43 xfs_attr_shortform_compare(const void *a, const void *b)
44 {
45 	xfs_attr_sf_sort_t *sa, *sb;
46 
47 	sa = (xfs_attr_sf_sort_t *)a;
48 	sb = (xfs_attr_sf_sort_t *)b;
49 	if (sa->hash < sb->hash) {
50 		return -1;
51 	} else if (sa->hash > sb->hash) {
52 		return 1;
53 	} else {
54 		return sa->entno - sb->entno;
55 	}
56 }
57 
58 #define XFS_ISRESET_CURSOR(cursor) \
59 	(!((cursor)->initted) && !((cursor)->hashval) && \
60 	 !((cursor)->blkno) && !((cursor)->offset))
61 /*
62  * Copy out entries of shortform attribute lists for attr_list().
63  * Shortform attribute lists are not stored in hashval sorted order.
64  * If the output buffer is not large enough to hold them all, then we
65  * we have to calculate each entries' hashvalue and sort them before
66  * we can begin returning them to the user.
67  */
68 static int
69 xfs_attr_shortform_list(xfs_attr_list_context_t *context)
70 {
71 	attrlist_cursor_kern_t *cursor;
72 	xfs_attr_sf_sort_t *sbuf, *sbp;
73 	xfs_attr_shortform_t *sf;
74 	xfs_attr_sf_entry_t *sfe;
75 	xfs_inode_t *dp;
76 	int sbsize, nsbuf, count, i;
77 
78 	ASSERT(context != NULL);
79 	dp = context->dp;
80 	ASSERT(dp != NULL);
81 	ASSERT(dp->i_afp != NULL);
82 	sf = (xfs_attr_shortform_t *)dp->i_afp->if_u1.if_data;
83 	ASSERT(sf != NULL);
84 	if (!sf->hdr.count)
85 		return 0;
86 	cursor = context->cursor;
87 	ASSERT(cursor != NULL);
88 
89 	trace_xfs_attr_list_sf(context);
90 
91 	/*
92 	 * If the buffer is large enough and the cursor is at the start,
93 	 * do not bother with sorting since we will return everything in
94 	 * one buffer and another call using the cursor won't need to be
95 	 * made.
96 	 * Note the generous fudge factor of 16 overhead bytes per entry.
97 	 * If bufsize is zero then put_listent must be a search function
98 	 * and can just scan through what we have.
99 	 */
100 	if (context->bufsize == 0 ||
101 	    (XFS_ISRESET_CURSOR(cursor) &&
102              (dp->i_afp->if_bytes + sf->hdr.count * 16) < context->bufsize)) {
103 		for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
104 			context->put_listent(context,
105 					     sfe->flags,
106 					     sfe->nameval,
107 					     (int)sfe->namelen,
108 					     (int)sfe->valuelen);
109 			/*
110 			 * Either search callback finished early or
111 			 * didn't fit it all in the buffer after all.
112 			 */
113 			if (context->seen_enough)
114 				break;
115 			sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
116 		}
117 		trace_xfs_attr_list_sf_all(context);
118 		return 0;
119 	}
120 
121 	/* do no more for a search callback */
122 	if (context->bufsize == 0)
123 		return 0;
124 
125 	/*
126 	 * It didn't all fit, so we have to sort everything on hashval.
127 	 */
128 	sbsize = sf->hdr.count * sizeof(*sbuf);
129 	sbp = sbuf = kmem_alloc(sbsize, KM_SLEEP | KM_NOFS);
130 
131 	/*
132 	 * Scan the attribute list for the rest of the entries, storing
133 	 * the relevant info from only those that match into a buffer.
134 	 */
135 	nsbuf = 0;
136 	for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
137 		if (unlikely(
138 		    ((char *)sfe < (char *)sf) ||
139 		    ((char *)sfe >= ((char *)sf + dp->i_afp->if_bytes)))) {
140 			XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
141 					     XFS_ERRLEVEL_LOW,
142 					     context->dp->i_mount, sfe);
143 			kmem_free(sbuf);
144 			return -EFSCORRUPTED;
145 		}
146 
147 		sbp->entno = i;
148 		sbp->hash = xfs_da_hashname(sfe->nameval, sfe->namelen);
149 		sbp->name = sfe->nameval;
150 		sbp->namelen = sfe->namelen;
151 		/* These are bytes, and both on-disk, don't endian-flip */
152 		sbp->valuelen = sfe->valuelen;
153 		sbp->flags = sfe->flags;
154 		sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
155 		sbp++;
156 		nsbuf++;
157 	}
158 
159 	/*
160 	 * Sort the entries on hash then entno.
161 	 */
162 	xfs_sort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);
163 
164 	/*
165 	 * Re-find our place IN THE SORTED LIST.
166 	 */
167 	count = 0;
168 	cursor->initted = 1;
169 	cursor->blkno = 0;
170 	for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
171 		if (sbp->hash == cursor->hashval) {
172 			if (cursor->offset == count) {
173 				break;
174 			}
175 			count++;
176 		} else if (sbp->hash > cursor->hashval) {
177 			break;
178 		}
179 	}
180 	if (i == nsbuf) {
181 		kmem_free(sbuf);
182 		return 0;
183 	}
184 
185 	/*
186 	 * Loop putting entries into the user buffer.
187 	 */
188 	for ( ; i < nsbuf; i++, sbp++) {
189 		if (cursor->hashval != sbp->hash) {
190 			cursor->hashval = sbp->hash;
191 			cursor->offset = 0;
192 		}
193 		context->put_listent(context,
194 				     sbp->flags,
195 				     sbp->name,
196 				     sbp->namelen,
197 				     sbp->valuelen);
198 		if (context->seen_enough)
199 			break;
200 		cursor->offset++;
201 	}
202 
203 	kmem_free(sbuf);
204 	return 0;
205 }
206 
207 /*
208  * We didn't find the block & hash mentioned in the cursor state, so
209  * walk down the attr btree looking for the hash.
210  */
211 STATIC int
212 xfs_attr_node_list_lookup(
213 	struct xfs_attr_list_context	*context,
214 	struct attrlist_cursor_kern	*cursor,
215 	struct xfs_buf			**pbp)
216 {
217 	struct xfs_da3_icnode_hdr	nodehdr;
218 	struct xfs_da_intnode		*node;
219 	struct xfs_da_node_entry	*btree;
220 	struct xfs_inode		*dp = context->dp;
221 	struct xfs_mount		*mp = dp->i_mount;
222 	struct xfs_trans		*tp = context->tp;
223 	struct xfs_buf			*bp;
224 	int				i;
225 	int				error = 0;
226 	unsigned int			expected_level = 0;
227 	uint16_t			magic;
228 
229 	ASSERT(*pbp == NULL);
230 	cursor->blkno = 0;
231 	for (;;) {
232 		error = xfs_da3_node_read(tp, dp, cursor->blkno, -1, &bp,
233 				XFS_ATTR_FORK);
234 		if (error)
235 			return error;
236 		node = bp->b_addr;
237 		magic = be16_to_cpu(node->hdr.info.magic);
238 		if (magic == XFS_ATTR_LEAF_MAGIC ||
239 		    magic == XFS_ATTR3_LEAF_MAGIC)
240 			break;
241 		if (magic != XFS_DA_NODE_MAGIC &&
242 		    magic != XFS_DA3_NODE_MAGIC) {
243 			XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
244 					node);
245 			goto out_corruptbuf;
246 		}
247 
248 		dp->d_ops->node_hdr_from_disk(&nodehdr, node);
249 
250 		/* Tree taller than we can handle; bail out! */
251 		if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH)
252 			goto out_corruptbuf;
253 
254 		/* Check the level from the root node. */
255 		if (cursor->blkno == 0)
256 			expected_level = nodehdr.level - 1;
257 		else if (expected_level != nodehdr.level)
258 			goto out_corruptbuf;
259 		else
260 			expected_level--;
261 
262 		btree = dp->d_ops->node_tree_p(node);
263 		for (i = 0; i < nodehdr.count; btree++, i++) {
264 			if (cursor->hashval <= be32_to_cpu(btree->hashval)) {
265 				cursor->blkno = be32_to_cpu(btree->before);
266 				trace_xfs_attr_list_node_descend(context,
267 						btree);
268 				break;
269 			}
270 		}
271 		xfs_trans_brelse(tp, bp);
272 
273 		if (i == nodehdr.count)
274 			return 0;
275 
276 		/* We can't point back to the root. */
277 		if (cursor->blkno == 0)
278 			return -EFSCORRUPTED;
279 	}
280 
281 	if (expected_level != 0)
282 		goto out_corruptbuf;
283 
284 	*pbp = bp;
285 	return 0;
286 
287 out_corruptbuf:
288 	xfs_trans_brelse(tp, bp);
289 	return -EFSCORRUPTED;
290 }
291 
292 STATIC int
293 xfs_attr_node_list(
294 	struct xfs_attr_list_context	*context)
295 {
296 	struct xfs_attr3_icleaf_hdr	leafhdr;
297 	struct attrlist_cursor_kern	*cursor;
298 	struct xfs_attr_leafblock	*leaf;
299 	struct xfs_da_intnode		*node;
300 	struct xfs_buf			*bp;
301 	struct xfs_inode		*dp = context->dp;
302 	struct xfs_mount		*mp = dp->i_mount;
303 	int				error;
304 
305 	trace_xfs_attr_node_list(context);
306 
307 	cursor = context->cursor;
308 	cursor->initted = 1;
309 
310 	/*
311 	 * Do all sorts of validation on the passed-in cursor structure.
312 	 * If anything is amiss, ignore the cursor and look up the hashval
313 	 * starting from the btree root.
314 	 */
315 	bp = NULL;
316 	if (cursor->blkno > 0) {
317 		error = xfs_da3_node_read(context->tp, dp, cursor->blkno, -1,
318 					      &bp, XFS_ATTR_FORK);
319 		if ((error != 0) && (error != -EFSCORRUPTED))
320 			return error;
321 		if (bp) {
322 			struct xfs_attr_leaf_entry *entries;
323 
324 			node = bp->b_addr;
325 			switch (be16_to_cpu(node->hdr.info.magic)) {
326 			case XFS_DA_NODE_MAGIC:
327 			case XFS_DA3_NODE_MAGIC:
328 				trace_xfs_attr_list_wrong_blk(context);
329 				xfs_trans_brelse(context->tp, bp);
330 				bp = NULL;
331 				break;
332 			case XFS_ATTR_LEAF_MAGIC:
333 			case XFS_ATTR3_LEAF_MAGIC:
334 				leaf = bp->b_addr;
335 				xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo,
336 							     &leafhdr, leaf);
337 				entries = xfs_attr3_leaf_entryp(leaf);
338 				if (cursor->hashval > be32_to_cpu(
339 						entries[leafhdr.count - 1].hashval)) {
340 					trace_xfs_attr_list_wrong_blk(context);
341 					xfs_trans_brelse(context->tp, bp);
342 					bp = NULL;
343 				} else if (cursor->hashval <= be32_to_cpu(
344 						entries[0].hashval)) {
345 					trace_xfs_attr_list_wrong_blk(context);
346 					xfs_trans_brelse(context->tp, bp);
347 					bp = NULL;
348 				}
349 				break;
350 			default:
351 				trace_xfs_attr_list_wrong_blk(context);
352 				xfs_trans_brelse(context->tp, bp);
353 				bp = NULL;
354 			}
355 		}
356 	}
357 
358 	/*
359 	 * We did not find what we expected given the cursor's contents,
360 	 * so we start from the top and work down based on the hash value.
361 	 * Note that start of node block is same as start of leaf block.
362 	 */
363 	if (bp == NULL) {
364 		error = xfs_attr_node_list_lookup(context, cursor, &bp);
365 		if (error || !bp)
366 			return error;
367 	}
368 	ASSERT(bp != NULL);
369 
370 	/*
371 	 * Roll upward through the blocks, processing each leaf block in
372 	 * order.  As long as there is space in the result buffer, keep
373 	 * adding the information.
374 	 */
375 	for (;;) {
376 		leaf = bp->b_addr;
377 		xfs_attr3_leaf_list_int(bp, context);
378 		xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
379 		if (context->seen_enough || leafhdr.forw == 0)
380 			break;
381 		cursor->blkno = leafhdr.forw;
382 		xfs_trans_brelse(context->tp, bp);
383 		error = xfs_attr3_leaf_read(context->tp, dp, cursor->blkno, -1, &bp);
384 		if (error)
385 			return error;
386 	}
387 	xfs_trans_brelse(context->tp, bp);
388 	return 0;
389 }
390 
391 /*
392  * Copy out attribute list entries for attr_list(), for leaf attribute lists.
393  */
394 void
395 xfs_attr3_leaf_list_int(
396 	struct xfs_buf			*bp,
397 	struct xfs_attr_list_context	*context)
398 {
399 	struct attrlist_cursor_kern	*cursor;
400 	struct xfs_attr_leafblock	*leaf;
401 	struct xfs_attr3_icleaf_hdr	ichdr;
402 	struct xfs_attr_leaf_entry	*entries;
403 	struct xfs_attr_leaf_entry	*entry;
404 	int				i;
405 	struct xfs_mount		*mp = context->dp->i_mount;
406 
407 	trace_xfs_attr_list_leaf(context);
408 
409 	leaf = bp->b_addr;
410 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
411 	entries = xfs_attr3_leaf_entryp(leaf);
412 
413 	cursor = context->cursor;
414 	cursor->initted = 1;
415 
416 	/*
417 	 * Re-find our place in the leaf block if this is a new syscall.
418 	 */
419 	if (context->resynch) {
420 		entry = &entries[0];
421 		for (i = 0; i < ichdr.count; entry++, i++) {
422 			if (be32_to_cpu(entry->hashval) == cursor->hashval) {
423 				if (cursor->offset == context->dupcnt) {
424 					context->dupcnt = 0;
425 					break;
426 				}
427 				context->dupcnt++;
428 			} else if (be32_to_cpu(entry->hashval) >
429 					cursor->hashval) {
430 				context->dupcnt = 0;
431 				break;
432 			}
433 		}
434 		if (i == ichdr.count) {
435 			trace_xfs_attr_list_notfound(context);
436 			return;
437 		}
438 	} else {
439 		entry = &entries[0];
440 		i = 0;
441 	}
442 	context->resynch = 0;
443 
444 	/*
445 	 * We have found our place, start copying out the new attributes.
446 	 */
447 	for (; i < ichdr.count; entry++, i++) {
448 		char *name;
449 		int namelen, valuelen;
450 
451 		if (be32_to_cpu(entry->hashval) != cursor->hashval) {
452 			cursor->hashval = be32_to_cpu(entry->hashval);
453 			cursor->offset = 0;
454 		}
455 
456 		if ((entry->flags & XFS_ATTR_INCOMPLETE) &&
457 		    !(context->flags & ATTR_INCOMPLETE))
458 			continue;		/* skip incomplete entries */
459 
460 		if (entry->flags & XFS_ATTR_LOCAL) {
461 			xfs_attr_leaf_name_local_t *name_loc;
462 
463 			name_loc = xfs_attr3_leaf_name_local(leaf, i);
464 			name = name_loc->nameval;
465 			namelen = name_loc->namelen;
466 			valuelen = be16_to_cpu(name_loc->valuelen);
467 		} else {
468 			xfs_attr_leaf_name_remote_t *name_rmt;
469 
470 			name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
471 			name = name_rmt->name;
472 			namelen = name_rmt->namelen;
473 			valuelen = be32_to_cpu(name_rmt->valuelen);
474 		}
475 
476 		context->put_listent(context, entry->flags,
477 					      name, namelen, valuelen);
478 		if (context->seen_enough)
479 			break;
480 		cursor->offset++;
481 	}
482 	trace_xfs_attr_list_leaf_end(context);
483 	return;
484 }
485 
486 /*
487  * Copy out attribute entries for attr_list(), for leaf attribute lists.
488  */
489 STATIC int
490 xfs_attr_leaf_list(xfs_attr_list_context_t *context)
491 {
492 	int error;
493 	struct xfs_buf *bp;
494 
495 	trace_xfs_attr_leaf_list(context);
496 
497 	context->cursor->blkno = 0;
498 	error = xfs_attr3_leaf_read(context->tp, context->dp, 0, -1, &bp);
499 	if (error)
500 		return error;
501 
502 	xfs_attr3_leaf_list_int(bp, context);
503 	xfs_trans_brelse(context->tp, bp);
504 	return 0;
505 }
506 
507 int
508 xfs_attr_list_int_ilocked(
509 	struct xfs_attr_list_context	*context)
510 {
511 	struct xfs_inode		*dp = context->dp;
512 
513 	ASSERT(xfs_isilocked(dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
514 
515 	/*
516 	 * Decide on what work routines to call based on the inode size.
517 	 */
518 	if (!xfs_inode_hasattr(dp))
519 		return 0;
520 	else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL)
521 		return xfs_attr_shortform_list(context);
522 	else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK))
523 		return xfs_attr_leaf_list(context);
524 	return xfs_attr_node_list(context);
525 }
526 
527 int
528 xfs_attr_list_int(
529 	xfs_attr_list_context_t *context)
530 {
531 	int error;
532 	xfs_inode_t *dp = context->dp;
533 	uint		lock_mode;
534 
535 	XFS_STATS_INC(dp->i_mount, xs_attr_list);
536 
537 	if (XFS_FORCED_SHUTDOWN(dp->i_mount))
538 		return -EIO;
539 
540 	lock_mode = xfs_ilock_attr_map_shared(dp);
541 	error = xfs_attr_list_int_ilocked(context);
542 	xfs_iunlock(dp, lock_mode);
543 	return error;
544 }
545 
546 #define	ATTR_ENTBASESIZE		/* minimum bytes used by an attr */ \
547 	(((struct attrlist_ent *) 0)->a_name - (char *) 0)
548 #define	ATTR_ENTSIZE(namelen)		/* actual bytes used by an attr */ \
549 	((ATTR_ENTBASESIZE + (namelen) + 1 + sizeof(uint32_t)-1) \
550 	 & ~(sizeof(uint32_t)-1))
551 
552 /*
553  * Format an attribute and copy it out to the user's buffer.
554  * Take care to check values and protect against them changing later,
555  * we may be reading them directly out of a user buffer.
556  */
557 STATIC void
558 xfs_attr_put_listent(
559 	xfs_attr_list_context_t *context,
560 	int		flags,
561 	unsigned char	*name,
562 	int		namelen,
563 	int		valuelen)
564 {
565 	struct attrlist *alist = (struct attrlist *)context->alist;
566 	attrlist_ent_t *aep;
567 	int arraytop;
568 
569 	ASSERT(!(context->flags & ATTR_KERNOVAL));
570 	ASSERT(context->count >= 0);
571 	ASSERT(context->count < (ATTR_MAX_VALUELEN/8));
572 	ASSERT(context->firstu >= sizeof(*alist));
573 	ASSERT(context->firstu <= context->bufsize);
574 
575 	/*
576 	 * Only list entries in the right namespace.
577 	 */
578 	if (((context->flags & ATTR_SECURE) == 0) !=
579 	    ((flags & XFS_ATTR_SECURE) == 0))
580 		return;
581 	if (((context->flags & ATTR_ROOT) == 0) !=
582 	    ((flags & XFS_ATTR_ROOT) == 0))
583 		return;
584 
585 	arraytop = sizeof(*alist) +
586 			context->count * sizeof(alist->al_offset[0]);
587 	context->firstu -= ATTR_ENTSIZE(namelen);
588 	if (context->firstu < arraytop) {
589 		trace_xfs_attr_list_full(context);
590 		alist->al_more = 1;
591 		context->seen_enough = 1;
592 		return;
593 	}
594 
595 	aep = (attrlist_ent_t *)&context->alist[context->firstu];
596 	aep->a_valuelen = valuelen;
597 	memcpy(aep->a_name, name, namelen);
598 	aep->a_name[namelen] = 0;
599 	alist->al_offset[context->count++] = context->firstu;
600 	alist->al_count = context->count;
601 	trace_xfs_attr_list_add(context);
602 	return;
603 }
604 
605 /*
606  * Generate a list of extended attribute names and optionally
607  * also value lengths.  Positive return value follows the XFS
608  * convention of being an error, zero or negative return code
609  * is the length of the buffer returned (negated), indicating
610  * success.
611  */
612 int
613 xfs_attr_list(
614 	xfs_inode_t	*dp,
615 	char		*buffer,
616 	int		bufsize,
617 	int		flags,
618 	attrlist_cursor_kern_t *cursor)
619 {
620 	xfs_attr_list_context_t context;
621 	struct attrlist *alist;
622 	int error;
623 
624 	/*
625 	 * Validate the cursor.
626 	 */
627 	if (cursor->pad1 || cursor->pad2)
628 		return -EINVAL;
629 	if ((cursor->initted == 0) &&
630 	    (cursor->hashval || cursor->blkno || cursor->offset))
631 		return -EINVAL;
632 
633 	/* Only internal consumers can retrieve incomplete attrs. */
634 	if (flags & ATTR_INCOMPLETE)
635 		return -EINVAL;
636 
637 	/*
638 	 * Check for a properly aligned buffer.
639 	 */
640 	if (((long)buffer) & (sizeof(int)-1))
641 		return -EFAULT;
642 	if (flags & ATTR_KERNOVAL)
643 		bufsize = 0;
644 
645 	/*
646 	 * Initialize the output buffer.
647 	 */
648 	memset(&context, 0, sizeof(context));
649 	context.dp = dp;
650 	context.cursor = cursor;
651 	context.resynch = 1;
652 	context.flags = flags;
653 	context.alist = buffer;
654 	context.bufsize = (bufsize & ~(sizeof(int)-1));  /* align */
655 	context.firstu = context.bufsize;
656 	context.put_listent = xfs_attr_put_listent;
657 
658 	alist = (struct attrlist *)context.alist;
659 	alist->al_count = 0;
660 	alist->al_more = 0;
661 	alist->al_offset[0] = context.bufsize;
662 
663 	error = xfs_attr_list_int(&context);
664 	ASSERT(error <= 0);
665 	return error;
666 }
667