xref: /linux/fs/xfs/xfs_attr_list.c (revision 3f6bc9e3ab9b127171d39f9ac6eca1abb693b731)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4  * Copyright (c) 2013 Red Hat, Inc.
5  * All Rights Reserved.
6  */
7 #include "xfs.h"
8 #include "xfs_fs.h"
9 #include "xfs_shared.h"
10 #include "xfs_format.h"
11 #include "xfs_log_format.h"
12 #include "xfs_trans_resv.h"
13 #include "xfs_mount.h"
14 #include "xfs_da_format.h"
15 #include "xfs_inode.h"
16 #include "xfs_trans.h"
17 #include "xfs_bmap.h"
18 #include "xfs_da_btree.h"
19 #include "xfs_attr.h"
20 #include "xfs_attr_sf.h"
21 #include "xfs_attr_leaf.h"
22 #include "xfs_error.h"
23 #include "xfs_trace.h"
24 #include "xfs_dir2.h"
25 #include "xfs_health.h"
26 
27 STATIC int
28 xfs_attr_shortform_compare(const void *a, const void *b)
29 {
30 	xfs_attr_sf_sort_t *sa, *sb;
31 
32 	sa = (xfs_attr_sf_sort_t *)a;
33 	sb = (xfs_attr_sf_sort_t *)b;
34 	if (sa->hash < sb->hash) {
35 		return -1;
36 	} else if (sa->hash > sb->hash) {
37 		return 1;
38 	} else {
39 		return sa->entno - sb->entno;
40 	}
41 }
42 
43 #define XFS_ISRESET_CURSOR(cursor) \
44 	(!((cursor)->initted) && !((cursor)->hashval) && \
45 	 !((cursor)->blkno) && !((cursor)->offset))
46 /*
47  * Copy out entries of shortform attribute lists for attr_list().
48  * Shortform attribute lists are not stored in hashval sorted order.
49  * If the output buffer is not large enough to hold them all, then
50  * we have to calculate each entries' hashvalue and sort them before
51  * we can begin returning them to the user.
52  */
53 static int
54 xfs_attr_shortform_list(
55 	struct xfs_attr_list_context	*context)
56 {
57 	struct xfs_attrlist_cursor_kern	*cursor = &context->cursor;
58 	struct xfs_inode		*dp = context->dp;
59 	struct xfs_attr_sf_sort		*sbuf, *sbp;
60 	struct xfs_attr_sf_hdr		*sf = dp->i_af.if_data;
61 	struct xfs_attr_sf_entry	*sfe;
62 	int				sbsize, nsbuf, count, i;
63 	int				error = 0;
64 
65 	ASSERT(sf != NULL);
66 	if (!sf->count)
67 		return 0;
68 
69 	trace_xfs_attr_list_sf(context);
70 
71 	/*
72 	 * If the buffer is large enough and the cursor is at the start,
73 	 * do not bother with sorting since we will return everything in
74 	 * one buffer and another call using the cursor won't need to be
75 	 * made.
76 	 * Note the generous fudge factor of 16 overhead bytes per entry.
77 	 * If bufsize is zero then put_listent must be a search function
78 	 * and can just scan through what we have.
79 	 */
80 	if (context->bufsize == 0 ||
81 	    (XFS_ISRESET_CURSOR(cursor) &&
82 	     (dp->i_af.if_bytes + sf->count * 16) < context->bufsize)) {
83 		for (i = 0, sfe = xfs_attr_sf_firstentry(sf); i < sf->count; i++) {
84 			if (XFS_IS_CORRUPT(context->dp->i_mount,
85 					   !xfs_attr_namecheck(sfe->flags,
86 							       sfe->nameval,
87 							       sfe->namelen))) {
88 				xfs_dirattr_mark_sick(context->dp, XFS_ATTR_FORK);
89 				return -EFSCORRUPTED;
90 			}
91 			context->put_listent(context,
92 					     sfe->flags,
93 					     sfe->nameval,
94 					     (int)sfe->namelen,
95 					     &sfe->nameval[sfe->namelen],
96 					     (int)sfe->valuelen);
97 			/*
98 			 * Either search callback finished early or
99 			 * didn't fit it all in the buffer after all.
100 			 */
101 			if (context->seen_enough)
102 				break;
103 			sfe = xfs_attr_sf_nextentry(sfe);
104 		}
105 		trace_xfs_attr_list_sf_all(context);
106 		return 0;
107 	}
108 
109 	/* do no more for a search callback */
110 	if (context->bufsize == 0)
111 		return 0;
112 
113 	/*
114 	 * It didn't all fit, so we have to sort everything on hashval.
115 	 */
116 	sbsize = sf->count * sizeof(*sbuf);
117 	sbp = sbuf = kmalloc(sbsize,
118 			GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_NOFAIL);
119 
120 	/*
121 	 * Scan the attribute list for the rest of the entries, storing
122 	 * the relevant info from only those that match into a buffer.
123 	 */
124 	nsbuf = 0;
125 	for (i = 0, sfe = xfs_attr_sf_firstentry(sf); i < sf->count; i++) {
126 		if (unlikely(
127 		    ((char *)sfe < (char *)sf) ||
128 		    ((char *)sfe >= ((char *)sf + dp->i_af.if_bytes)) ||
129 		    !xfs_attr_check_namespace(sfe->flags))) {
130 			XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
131 					     XFS_ERRLEVEL_LOW,
132 					     context->dp->i_mount, sfe,
133 					     sizeof(*sfe));
134 			kfree(sbuf);
135 			xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
136 			return -EFSCORRUPTED;
137 		}
138 
139 		sbp->entno = i;
140 		sbp->name = sfe->nameval;
141 		sbp->namelen = sfe->namelen;
142 		/* These are bytes, and both on-disk, don't endian-flip */
143 		sbp->value = &sfe->nameval[sfe->namelen];
144 		sbp->valuelen = sfe->valuelen;
145 		sbp->flags = sfe->flags;
146 		sbp->hash = xfs_attr_hashval(dp->i_mount, sfe->flags,
147 					     sfe->nameval, sfe->namelen,
148 					     sfe->nameval + sfe->namelen,
149 					     sfe->valuelen);
150 		sfe = xfs_attr_sf_nextentry(sfe);
151 		sbp++;
152 		nsbuf++;
153 	}
154 
155 	/*
156 	 * Sort the entries on hash then entno.
157 	 */
158 	xfs_sort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);
159 
160 	/*
161 	 * Re-find our place IN THE SORTED LIST.
162 	 */
163 	count = 0;
164 	cursor->initted = 1;
165 	cursor->blkno = 0;
166 	for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
167 		if (sbp->hash == cursor->hashval) {
168 			if (cursor->offset == count) {
169 				break;
170 			}
171 			count++;
172 		} else if (sbp->hash > cursor->hashval) {
173 			break;
174 		}
175 	}
176 	if (i == nsbuf)
177 		goto out;
178 
179 	/*
180 	 * Loop putting entries into the user buffer.
181 	 */
182 	for ( ; i < nsbuf; i++, sbp++) {
183 		if (cursor->hashval != sbp->hash) {
184 			cursor->hashval = sbp->hash;
185 			cursor->offset = 0;
186 		}
187 		if (XFS_IS_CORRUPT(context->dp->i_mount,
188 				   !xfs_attr_namecheck(sbp->flags, sbp->name,
189 						       sbp->namelen))) {
190 			xfs_dirattr_mark_sick(context->dp, XFS_ATTR_FORK);
191 			error = -EFSCORRUPTED;
192 			goto out;
193 		}
194 		context->put_listent(context,
195 				     sbp->flags,
196 				     sbp->name,
197 				     sbp->namelen,
198 				     sbp->value,
199 				     sbp->valuelen);
200 		if (context->seen_enough)
201 			break;
202 		cursor->offset++;
203 	}
204 out:
205 	kfree(sbuf);
206 	return error;
207 }
208 
209 /*
210  * We didn't find the block & hash mentioned in the cursor state, so
211  * walk down the attr btree looking for the hash.
212  */
213 STATIC int
214 xfs_attr_node_list_lookup(
215 	struct xfs_attr_list_context	*context,
216 	struct xfs_attrlist_cursor_kern	*cursor,
217 	struct xfs_buf			**pbp)
218 {
219 	struct xfs_da3_icnode_hdr	nodehdr;
220 	struct xfs_da_intnode		*node;
221 	struct xfs_da_node_entry	*btree;
222 	struct xfs_inode		*dp = context->dp;
223 	struct xfs_mount		*mp = dp->i_mount;
224 	struct xfs_trans		*tp = context->tp;
225 	struct xfs_buf			*bp;
226 	xfs_failaddr_t			fa;
227 	int				i;
228 	int				error = 0;
229 	unsigned int			expected_level = 0;
230 	uint16_t			magic;
231 
232 	ASSERT(*pbp == NULL);
233 	cursor->blkno = 0;
234 	for (;;) {
235 		error = xfs_da3_node_read(tp, dp, cursor->blkno, &bp,
236 				XFS_ATTR_FORK);
237 		if (error)
238 			return error;
239 		node = bp->b_addr;
240 		magic = be16_to_cpu(node->hdr.info.magic);
241 		if (magic == XFS_ATTR_LEAF_MAGIC ||
242 		    magic == XFS_ATTR3_LEAF_MAGIC)
243 			break;
244 		if (magic != XFS_DA_NODE_MAGIC &&
245 		    magic != XFS_DA3_NODE_MAGIC) {
246 			XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
247 					node, sizeof(*node));
248 			goto out_corruptbuf;
249 		}
250 
251 		fa = xfs_da3_node_header_check(bp, dp->i_ino);
252 		if (fa)
253 			goto out_corruptbuf;
254 
255 		xfs_da3_node_hdr_from_disk(mp, &nodehdr, node);
256 
257 		/* Tree taller than we can handle; bail out! */
258 		if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH)
259 			goto out_corruptbuf;
260 
261 		/* Check the level from the root node. */
262 		if (cursor->blkno == 0)
263 			expected_level = nodehdr.level - 1;
264 		else if (expected_level != nodehdr.level)
265 			goto out_corruptbuf;
266 		else
267 			expected_level--;
268 
269 		btree = nodehdr.btree;
270 		for (i = 0; i < nodehdr.count; btree++, i++) {
271 			if (cursor->hashval <= be32_to_cpu(btree->hashval)) {
272 				cursor->blkno = be32_to_cpu(btree->before);
273 				trace_xfs_attr_list_node_descend(context,
274 						btree);
275 				break;
276 			}
277 		}
278 		xfs_trans_brelse(tp, bp);
279 
280 		if (i == nodehdr.count)
281 			return 0;
282 
283 		/* We can't point back to the root. */
284 		if (XFS_IS_CORRUPT(mp, cursor->blkno == 0)) {
285 			xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
286 			return -EFSCORRUPTED;
287 		}
288 	}
289 
290 	fa = xfs_attr3_leaf_header_check(bp, dp->i_ino);
291 	if (fa) {
292 		__xfs_buf_mark_corrupt(bp, fa);
293 		goto out_releasebuf;
294 	}
295 
296 	if (expected_level != 0)
297 		goto out_corruptbuf;
298 
299 	*pbp = bp;
300 	return 0;
301 
302 out_corruptbuf:
303 	xfs_buf_mark_corrupt(bp);
304 out_releasebuf:
305 	xfs_trans_brelse(tp, bp);
306 	xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
307 	return -EFSCORRUPTED;
308 }
309 
310 STATIC int
311 xfs_attr_node_list(
312 	struct xfs_attr_list_context	*context)
313 {
314 	struct xfs_attrlist_cursor_kern	*cursor = &context->cursor;
315 	struct xfs_attr3_icleaf_hdr	leafhdr;
316 	struct xfs_attr_leafblock	*leaf;
317 	struct xfs_da_intnode		*node;
318 	struct xfs_buf			*bp;
319 	struct xfs_inode		*dp = context->dp;
320 	struct xfs_mount		*mp = dp->i_mount;
321 	xfs_failaddr_t			fa;
322 	int				error = 0;
323 
324 	trace_xfs_attr_node_list(context);
325 
326 	cursor->initted = 1;
327 
328 	/*
329 	 * Do all sorts of validation on the passed-in cursor structure.
330 	 * If anything is amiss, ignore the cursor and look up the hashval
331 	 * starting from the btree root.
332 	 */
333 	bp = NULL;
334 	if (cursor->blkno > 0) {
335 		struct xfs_attr_leaf_entry *entries;
336 
337 		error = xfs_da3_node_read(context->tp, dp, cursor->blkno, &bp,
338 				XFS_ATTR_FORK);
339 		if (xfs_metadata_is_sick(error))
340 			xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
341 		if (error != 0 && error != -EFSCORRUPTED)
342 			return error;
343 		if (!bp)
344 			goto need_lookup;
345 
346 		node = bp->b_addr;
347 		switch (be16_to_cpu(node->hdr.info.magic)) {
348 		case XFS_DA_NODE_MAGIC:
349 		case XFS_DA3_NODE_MAGIC:
350 			trace_xfs_attr_list_wrong_blk(context);
351 			fa = xfs_da3_node_header_check(bp, dp->i_ino);
352 			if (fa) {
353 				__xfs_buf_mark_corrupt(bp, fa);
354 				xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
355 			}
356 			xfs_trans_brelse(context->tp, bp);
357 			bp = NULL;
358 			break;
359 		case XFS_ATTR_LEAF_MAGIC:
360 		case XFS_ATTR3_LEAF_MAGIC:
361 			leaf = bp->b_addr;
362 			fa = xfs_attr3_leaf_header_check(bp, dp->i_ino);
363 			if (fa) {
364 				__xfs_buf_mark_corrupt(bp, fa);
365 				xfs_trans_brelse(context->tp, bp);
366 				xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
367 				bp = NULL;
368 				break;
369 			}
370 			xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo,
371 						     &leafhdr, leaf);
372 			entries = xfs_attr3_leaf_entryp(leaf);
373 			if (cursor->hashval > be32_to_cpu(
374 					entries[leafhdr.count - 1].hashval)) {
375 				trace_xfs_attr_list_wrong_blk(context);
376 				xfs_trans_brelse(context->tp, bp);
377 				bp = NULL;
378 			} else if (cursor->hashval <= be32_to_cpu(
379 					entries[0].hashval)) {
380 				trace_xfs_attr_list_wrong_blk(context);
381 				xfs_trans_brelse(context->tp, bp);
382 				bp = NULL;
383 			}
384 			break;
385 		default:
386 			trace_xfs_attr_list_wrong_blk(context);
387 			xfs_trans_brelse(context->tp, bp);
388 			bp = NULL;
389 		}
390 	}
391 
392 	/*
393 	 * We did not find what we expected given the cursor's contents,
394 	 * so we start from the top and work down based on the hash value.
395 	 * Note that start of node block is same as start of leaf block.
396 	 */
397 	if (bp == NULL) {
398 need_lookup:
399 		error = xfs_attr_node_list_lookup(context, cursor, &bp);
400 		if (error || !bp)
401 			return error;
402 	}
403 	ASSERT(bp != NULL);
404 
405 	/*
406 	 * Roll upward through the blocks, processing each leaf block in
407 	 * order.  As long as there is space in the result buffer, keep
408 	 * adding the information.
409 	 */
410 	for (;;) {
411 		leaf = bp->b_addr;
412 		error = xfs_attr3_leaf_list_int(bp, context);
413 		if (error)
414 			break;
415 		xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
416 		if (context->seen_enough || leafhdr.forw == 0)
417 			break;
418 		cursor->blkno = leafhdr.forw;
419 		xfs_trans_brelse(context->tp, bp);
420 		error = xfs_attr3_leaf_read(context->tp, dp, dp->i_ino,
421 				cursor->blkno, &bp);
422 		if (error)
423 			return error;
424 	}
425 	xfs_trans_brelse(context->tp, bp);
426 	return error;
427 }
428 
429 /*
430  * Copy out attribute list entries for attr_list(), for leaf attribute lists.
431  */
432 int
433 xfs_attr3_leaf_list_int(
434 	struct xfs_buf			*bp,
435 	struct xfs_attr_list_context	*context)
436 {
437 	struct xfs_attrlist_cursor_kern	*cursor = &context->cursor;
438 	struct xfs_attr_leafblock	*leaf;
439 	struct xfs_attr3_icleaf_hdr	ichdr;
440 	struct xfs_attr_leaf_entry	*entries;
441 	struct xfs_attr_leaf_entry	*entry;
442 	int				i;
443 	struct xfs_mount		*mp = context->dp->i_mount;
444 
445 	trace_xfs_attr_list_leaf(context);
446 
447 	leaf = bp->b_addr;
448 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
449 	entries = xfs_attr3_leaf_entryp(leaf);
450 
451 	cursor->initted = 1;
452 
453 	/*
454 	 * Re-find our place in the leaf block if this is a new syscall.
455 	 */
456 	if (context->resynch) {
457 		entry = &entries[0];
458 		for (i = 0; i < ichdr.count; entry++, i++) {
459 			if (be32_to_cpu(entry->hashval) == cursor->hashval) {
460 				if (cursor->offset == context->dupcnt) {
461 					context->dupcnt = 0;
462 					break;
463 				}
464 				context->dupcnt++;
465 			} else if (be32_to_cpu(entry->hashval) >
466 					cursor->hashval) {
467 				context->dupcnt = 0;
468 				break;
469 			}
470 		}
471 		if (i == ichdr.count) {
472 			trace_xfs_attr_list_notfound(context);
473 			return 0;
474 		}
475 	} else {
476 		entry = &entries[0];
477 		i = 0;
478 	}
479 	context->resynch = 0;
480 
481 	/*
482 	 * We have found our place, start copying out the new attributes.
483 	 */
484 	for (; i < ichdr.count; entry++, i++) {
485 		char *name;
486 		void *value;
487 		int namelen, valuelen;
488 
489 		if (be32_to_cpu(entry->hashval) != cursor->hashval) {
490 			cursor->hashval = be32_to_cpu(entry->hashval);
491 			cursor->offset = 0;
492 		}
493 
494 		if ((entry->flags & XFS_ATTR_INCOMPLETE) &&
495 		    !context->allow_incomplete)
496 			continue;
497 
498 		if (entry->flags & XFS_ATTR_LOCAL) {
499 			xfs_attr_leaf_name_local_t *name_loc;
500 
501 			name_loc = xfs_attr3_leaf_name_local(leaf, i);
502 			name = name_loc->nameval;
503 			namelen = name_loc->namelen;
504 			value = &name_loc->nameval[name_loc->namelen];
505 			valuelen = be16_to_cpu(name_loc->valuelen);
506 		} else {
507 			xfs_attr_leaf_name_remote_t *name_rmt;
508 
509 			name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
510 			name = name_rmt->name;
511 			namelen = name_rmt->namelen;
512 			value = NULL;
513 			valuelen = be32_to_cpu(name_rmt->valuelen);
514 		}
515 
516 		if (XFS_IS_CORRUPT(context->dp->i_mount,
517 				   !xfs_attr_namecheck(entry->flags, name,
518 						       namelen))) {
519 			xfs_dirattr_mark_sick(context->dp, XFS_ATTR_FORK);
520 			return -EFSCORRUPTED;
521 		}
522 		context->put_listent(context, entry->flags,
523 					      name, namelen, value, valuelen);
524 		if (context->seen_enough)
525 			break;
526 		cursor->offset++;
527 	}
528 	trace_xfs_attr_list_leaf_end(context);
529 	return 0;
530 }
531 
532 /*
533  * Copy out attribute entries for attr_list(), for leaf attribute lists.
534  */
535 STATIC int
536 xfs_attr_leaf_list(
537 	struct xfs_attr_list_context	*context)
538 {
539 	struct xfs_buf			*bp;
540 	int				error;
541 
542 	trace_xfs_attr_leaf_list(context);
543 
544 	context->cursor.blkno = 0;
545 	error = xfs_attr3_leaf_read(context->tp, context->dp,
546 			context->dp->i_ino, 0, &bp);
547 	if (error)
548 		return error;
549 
550 	error = xfs_attr3_leaf_list_int(bp, context);
551 	xfs_trans_brelse(context->tp, bp);
552 	return error;
553 }
554 
555 int
556 xfs_attr_list_ilocked(
557 	struct xfs_attr_list_context	*context)
558 {
559 	struct xfs_inode		*dp = context->dp;
560 	int				error;
561 
562 	xfs_assert_ilocked(dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL);
563 
564 	/*
565 	 * Decide on what work routines to call based on the inode size.
566 	 */
567 	if (!xfs_inode_hasattr(dp))
568 		return 0;
569 	if (dp->i_af.if_format == XFS_DINODE_FMT_LOCAL)
570 		return xfs_attr_shortform_list(context);
571 
572 	/* Prerequisite for xfs_attr_is_leaf */
573 	error = xfs_iread_extents(NULL, dp, XFS_ATTR_FORK);
574 	if (error)
575 		return error;
576 
577 	if (xfs_attr_is_leaf(dp))
578 		return xfs_attr_leaf_list(context);
579 	return xfs_attr_node_list(context);
580 }
581 
582 int
583 xfs_attr_list(
584 	struct xfs_attr_list_context	*context)
585 {
586 	struct xfs_inode		*dp = context->dp;
587 	uint				lock_mode;
588 	int				error;
589 
590 	XFS_STATS_INC(dp->i_mount, xs_attr_list);
591 
592 	if (xfs_is_shutdown(dp->i_mount))
593 		return -EIO;
594 
595 	lock_mode = xfs_ilock_attr_map_shared(dp);
596 	error = xfs_attr_list_ilocked(context);
597 	xfs_iunlock(dp, lock_mode);
598 	return error;
599 }
600