xref: /linux/fs/xfs/xfs_attr_list.c (revision d3426a6ed9d8398bfee2a1c5cd0ae50f2f4494a8)
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
xfs_attr_shortform_compare(const void * a,const void * b)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
xfs_attr_shortform_list(struct xfs_attr_list_context * context)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, GFP_KERNEL | __GFP_NOFAIL);
118 
119 	/*
120 	 * Scan the attribute list for the rest of the entries, storing
121 	 * the relevant info from only those that match into a buffer.
122 	 */
123 	nsbuf = 0;
124 	for (i = 0, sfe = xfs_attr_sf_firstentry(sf); i < sf->count; i++) {
125 		if (unlikely(
126 		    ((char *)sfe < (char *)sf) ||
127 		    ((char *)sfe >= ((char *)sf + dp->i_af.if_bytes)) ||
128 		    !xfs_attr_check_namespace(sfe->flags))) {
129 			XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
130 					     XFS_ERRLEVEL_LOW,
131 					     context->dp->i_mount, sfe,
132 					     sizeof(*sfe));
133 			kfree(sbuf);
134 			xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
135 			return -EFSCORRUPTED;
136 		}
137 
138 		sbp->entno = i;
139 		sbp->name = sfe->nameval;
140 		sbp->namelen = sfe->namelen;
141 		/* These are bytes, and both on-disk, don't endian-flip */
142 		sbp->value = &sfe->nameval[sfe->namelen];
143 		sbp->valuelen = sfe->valuelen;
144 		sbp->flags = sfe->flags;
145 		sbp->hash = xfs_attr_hashval(dp->i_mount, sfe->flags,
146 					     sfe->nameval, sfe->namelen,
147 					     sfe->nameval + sfe->namelen,
148 					     sfe->valuelen);
149 		sfe = xfs_attr_sf_nextentry(sfe);
150 		sbp++;
151 		nsbuf++;
152 	}
153 
154 	/*
155 	 * Sort the entries on hash then entno.
156 	 */
157 	xfs_sort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);
158 
159 	/*
160 	 * Re-find our place IN THE SORTED LIST.
161 	 */
162 	count = 0;
163 	cursor->initted = 1;
164 	cursor->blkno = 0;
165 	for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
166 		if (sbp->hash == cursor->hashval) {
167 			if (cursor->offset == count) {
168 				break;
169 			}
170 			count++;
171 		} else if (sbp->hash > cursor->hashval) {
172 			break;
173 		}
174 	}
175 	if (i == nsbuf)
176 		goto out;
177 
178 	/*
179 	 * Loop putting entries into the user buffer.
180 	 */
181 	for ( ; i < nsbuf; i++, sbp++) {
182 		if (cursor->hashval != sbp->hash) {
183 			cursor->hashval = sbp->hash;
184 			cursor->offset = 0;
185 		}
186 		if (XFS_IS_CORRUPT(context->dp->i_mount,
187 				   !xfs_attr_namecheck(sbp->flags, sbp->name,
188 						       sbp->namelen))) {
189 			xfs_dirattr_mark_sick(context->dp, XFS_ATTR_FORK);
190 			error = -EFSCORRUPTED;
191 			goto out;
192 		}
193 		context->put_listent(context,
194 				     sbp->flags,
195 				     sbp->name,
196 				     sbp->namelen,
197 				     sbp->value,
198 				     sbp->valuelen);
199 		if (context->seen_enough)
200 			break;
201 		cursor->offset++;
202 	}
203 out:
204 	kfree(sbuf);
205 	return error;
206 }
207 
208 /*
209  * We didn't find the block & hash mentioned in the cursor state, so
210  * walk down the attr btree looking for the hash.
211  */
212 STATIC int
xfs_attr_node_list_lookup(struct xfs_attr_list_context * context,struct xfs_attrlist_cursor_kern * cursor,struct xfs_buf ** pbp)213 xfs_attr_node_list_lookup(
214 	struct xfs_attr_list_context	*context,
215 	struct xfs_attrlist_cursor_kern	*cursor,
216 	struct xfs_buf			**pbp)
217 {
218 	struct xfs_da3_icnode_hdr	nodehdr;
219 	struct xfs_da_intnode		*node;
220 	struct xfs_da_node_entry	*btree;
221 	struct xfs_inode		*dp = context->dp;
222 	struct xfs_mount		*mp = dp->i_mount;
223 	struct xfs_trans		*tp = context->tp;
224 	struct xfs_buf			*bp;
225 	xfs_failaddr_t			fa;
226 	int				i;
227 	int				error = 0;
228 	unsigned int			expected_level = 0;
229 	uint16_t			magic;
230 
231 	ASSERT(*pbp == NULL);
232 	cursor->blkno = 0;
233 	for (;;) {
234 		error = xfs_da3_node_read(tp, dp, cursor->blkno, &bp,
235 				XFS_ATTR_FORK);
236 		if (error)
237 			return error;
238 		node = bp->b_addr;
239 		magic = be16_to_cpu(node->hdr.info.magic);
240 		if (magic == XFS_ATTR_LEAF_MAGIC ||
241 		    magic == XFS_ATTR3_LEAF_MAGIC)
242 			break;
243 		if (magic != XFS_DA_NODE_MAGIC &&
244 		    magic != XFS_DA3_NODE_MAGIC) {
245 			XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
246 					node, sizeof(*node));
247 			goto out_corruptbuf;
248 		}
249 
250 		fa = xfs_da3_node_header_check(bp, dp->i_ino);
251 		if (fa)
252 			goto out_corruptbuf;
253 
254 		xfs_da3_node_hdr_from_disk(mp, &nodehdr, node);
255 
256 		/* Tree taller than we can handle; bail out! */
257 		if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH)
258 			goto out_corruptbuf;
259 
260 		/* Check the level from the root node. */
261 		if (cursor->blkno == 0)
262 			expected_level = nodehdr.level - 1;
263 		else if (expected_level != nodehdr.level)
264 			goto out_corruptbuf;
265 		else
266 			expected_level--;
267 
268 		btree = nodehdr.btree;
269 		for (i = 0; i < nodehdr.count; btree++, i++) {
270 			if (cursor->hashval <= be32_to_cpu(btree->hashval)) {
271 				cursor->blkno = be32_to_cpu(btree->before);
272 				trace_xfs_attr_list_node_descend(context,
273 						btree);
274 				break;
275 			}
276 		}
277 		xfs_trans_brelse(tp, bp);
278 
279 		if (i == nodehdr.count)
280 			return 0;
281 
282 		/* We can't point back to the root. */
283 		if (XFS_IS_CORRUPT(mp, cursor->blkno == 0)) {
284 			xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
285 			return -EFSCORRUPTED;
286 		}
287 	}
288 
289 	fa = xfs_attr3_leaf_header_check(bp, dp->i_ino);
290 	if (fa) {
291 		__xfs_buf_mark_corrupt(bp, fa);
292 		goto out_releasebuf;
293 	}
294 
295 	if (expected_level != 0)
296 		goto out_corruptbuf;
297 
298 	*pbp = bp;
299 	return 0;
300 
301 out_corruptbuf:
302 	xfs_buf_mark_corrupt(bp);
303 out_releasebuf:
304 	xfs_trans_brelse(tp, bp);
305 	xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
306 	return -EFSCORRUPTED;
307 }
308 
309 STATIC int
xfs_attr_node_list(struct xfs_attr_list_context * context)310 xfs_attr_node_list(
311 	struct xfs_attr_list_context	*context)
312 {
313 	struct xfs_attrlist_cursor_kern	*cursor = &context->cursor;
314 	struct xfs_attr3_icleaf_hdr	leafhdr;
315 	struct xfs_attr_leafblock	*leaf;
316 	struct xfs_da_intnode		*node;
317 	struct xfs_buf			*bp;
318 	struct xfs_inode		*dp = context->dp;
319 	struct xfs_mount		*mp = dp->i_mount;
320 	xfs_failaddr_t			fa;
321 	int				error = 0;
322 
323 	trace_xfs_attr_node_list(context);
324 
325 	cursor->initted = 1;
326 
327 	/*
328 	 * Do all sorts of validation on the passed-in cursor structure.
329 	 * If anything is amiss, ignore the cursor and look up the hashval
330 	 * starting from the btree root.
331 	 */
332 	bp = NULL;
333 	if (cursor->blkno > 0) {
334 		struct xfs_attr_leaf_entry *entries;
335 
336 		error = xfs_da3_node_read(context->tp, dp, cursor->blkno, &bp,
337 				XFS_ATTR_FORK);
338 		if (xfs_metadata_is_sick(error))
339 			xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
340 		if (error != 0 && error != -EFSCORRUPTED)
341 			return error;
342 		if (!bp)
343 			goto need_lookup;
344 
345 		node = bp->b_addr;
346 		switch (be16_to_cpu(node->hdr.info.magic)) {
347 		case XFS_DA_NODE_MAGIC:
348 		case XFS_DA3_NODE_MAGIC:
349 			trace_xfs_attr_list_wrong_blk(context);
350 			fa = xfs_da3_node_header_check(bp, dp->i_ino);
351 			if (fa) {
352 				__xfs_buf_mark_corrupt(bp, fa);
353 				xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
354 			}
355 			xfs_trans_brelse(context->tp, bp);
356 			bp = NULL;
357 			break;
358 		case XFS_ATTR_LEAF_MAGIC:
359 		case XFS_ATTR3_LEAF_MAGIC:
360 			leaf = bp->b_addr;
361 			fa = xfs_attr3_leaf_header_check(bp, dp->i_ino);
362 			if (fa) {
363 				__xfs_buf_mark_corrupt(bp, fa);
364 				xfs_trans_brelse(context->tp, bp);
365 				xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
366 				bp = NULL;
367 				break;
368 			}
369 			xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo,
370 						     &leafhdr, leaf);
371 			entries = xfs_attr3_leaf_entryp(leaf);
372 			if (cursor->hashval > be32_to_cpu(
373 					entries[leafhdr.count - 1].hashval)) {
374 				trace_xfs_attr_list_wrong_blk(context);
375 				xfs_trans_brelse(context->tp, bp);
376 				bp = NULL;
377 			} else if (cursor->hashval <= be32_to_cpu(
378 					entries[0].hashval)) {
379 				trace_xfs_attr_list_wrong_blk(context);
380 				xfs_trans_brelse(context->tp, bp);
381 				bp = NULL;
382 			}
383 			break;
384 		default:
385 			trace_xfs_attr_list_wrong_blk(context);
386 			xfs_trans_brelse(context->tp, bp);
387 			bp = NULL;
388 		}
389 	}
390 
391 	/*
392 	 * We did not find what we expected given the cursor's contents,
393 	 * so we start from the top and work down based on the hash value.
394 	 * Note that start of node block is same as start of leaf block.
395 	 */
396 	if (bp == NULL) {
397 need_lookup:
398 		error = xfs_attr_node_list_lookup(context, cursor, &bp);
399 		if (error || !bp)
400 			return error;
401 	}
402 	ASSERT(bp != NULL);
403 
404 	/*
405 	 * Roll upward through the blocks, processing each leaf block in
406 	 * order.  As long as there is space in the result buffer, keep
407 	 * adding the information.
408 	 */
409 	for (;;) {
410 		leaf = bp->b_addr;
411 		error = xfs_attr3_leaf_list_int(bp, context);
412 		if (error)
413 			break;
414 		xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
415 		if (context->seen_enough || leafhdr.forw == 0)
416 			break;
417 		cursor->blkno = leafhdr.forw;
418 		xfs_trans_brelse(context->tp, bp);
419 		error = xfs_attr3_leaf_read(context->tp, dp, dp->i_ino,
420 				cursor->blkno, &bp);
421 		if (error)
422 			return error;
423 	}
424 	xfs_trans_brelse(context->tp, bp);
425 	return error;
426 }
427 
428 /*
429  * Copy out attribute list entries for attr_list(), for leaf attribute lists.
430  */
431 int
xfs_attr3_leaf_list_int(struct xfs_buf * bp,struct xfs_attr_list_context * context)432 xfs_attr3_leaf_list_int(
433 	struct xfs_buf			*bp,
434 	struct xfs_attr_list_context	*context)
435 {
436 	struct xfs_attrlist_cursor_kern	*cursor = &context->cursor;
437 	struct xfs_attr_leafblock	*leaf;
438 	struct xfs_attr3_icleaf_hdr	ichdr;
439 	struct xfs_attr_leaf_entry	*entries;
440 	struct xfs_attr_leaf_entry	*entry;
441 	int				i;
442 	struct xfs_mount		*mp = context->dp->i_mount;
443 
444 	trace_xfs_attr_list_leaf(context);
445 
446 	leaf = bp->b_addr;
447 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
448 	entries = xfs_attr3_leaf_entryp(leaf);
449 
450 	cursor->initted = 1;
451 
452 	/*
453 	 * Re-find our place in the leaf block if this is a new syscall.
454 	 */
455 	if (context->resynch) {
456 		entry = &entries[0];
457 		for (i = 0; i < ichdr.count; entry++, i++) {
458 			if (be32_to_cpu(entry->hashval) == cursor->hashval) {
459 				if (cursor->offset == context->dupcnt) {
460 					context->dupcnt = 0;
461 					break;
462 				}
463 				context->dupcnt++;
464 			} else if (be32_to_cpu(entry->hashval) >
465 					cursor->hashval) {
466 				context->dupcnt = 0;
467 				break;
468 			}
469 		}
470 		if (i == ichdr.count) {
471 			trace_xfs_attr_list_notfound(context);
472 			return 0;
473 		}
474 	} else {
475 		entry = &entries[0];
476 		i = 0;
477 	}
478 	context->resynch = 0;
479 
480 	/*
481 	 * We have found our place, start copying out the new attributes.
482 	 */
483 	for (; i < ichdr.count; entry++, i++) {
484 		char *name;
485 		void *value;
486 		int namelen, valuelen;
487 
488 		if (be32_to_cpu(entry->hashval) != cursor->hashval) {
489 			cursor->hashval = be32_to_cpu(entry->hashval);
490 			cursor->offset = 0;
491 		}
492 
493 		if ((entry->flags & XFS_ATTR_INCOMPLETE) &&
494 		    !context->allow_incomplete)
495 			continue;
496 
497 		if (entry->flags & XFS_ATTR_LOCAL) {
498 			xfs_attr_leaf_name_local_t *name_loc;
499 
500 			name_loc = xfs_attr3_leaf_name_local(leaf, i);
501 			name = name_loc->nameval;
502 			namelen = name_loc->namelen;
503 			value = &name_loc->nameval[name_loc->namelen];
504 			valuelen = be16_to_cpu(name_loc->valuelen);
505 		} else {
506 			xfs_attr_leaf_name_remote_t *name_rmt;
507 
508 			name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
509 			name = name_rmt->name;
510 			namelen = name_rmt->namelen;
511 			value = NULL;
512 			valuelen = be32_to_cpu(name_rmt->valuelen);
513 		}
514 
515 		if (XFS_IS_CORRUPT(context->dp->i_mount,
516 				   !xfs_attr_namecheck(entry->flags, name,
517 						       namelen))) {
518 			xfs_dirattr_mark_sick(context->dp, XFS_ATTR_FORK);
519 			return -EFSCORRUPTED;
520 		}
521 		context->put_listent(context, entry->flags,
522 					      name, namelen, value, valuelen);
523 		if (context->seen_enough)
524 			break;
525 		cursor->offset++;
526 	}
527 	trace_xfs_attr_list_leaf_end(context);
528 	return 0;
529 }
530 
531 /*
532  * Copy out attribute entries for attr_list(), for leaf attribute lists.
533  */
534 STATIC int
xfs_attr_leaf_list(struct xfs_attr_list_context * context)535 xfs_attr_leaf_list(
536 	struct xfs_attr_list_context	*context)
537 {
538 	struct xfs_buf			*bp;
539 	int				error;
540 
541 	trace_xfs_attr_leaf_list(context);
542 
543 	context->cursor.blkno = 0;
544 	error = xfs_attr3_leaf_read(context->tp, context->dp,
545 			context->dp->i_ino, 0, &bp);
546 	if (error)
547 		return error;
548 
549 	error = xfs_attr3_leaf_list_int(bp, context);
550 	xfs_trans_brelse(context->tp, bp);
551 	return error;
552 }
553 
554 int
xfs_attr_list_ilocked(struct xfs_attr_list_context * context)555 xfs_attr_list_ilocked(
556 	struct xfs_attr_list_context	*context)
557 {
558 	struct xfs_inode		*dp = context->dp;
559 	int				error;
560 
561 	xfs_assert_ilocked(dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL);
562 
563 	/*
564 	 * Decide on what work routines to call based on the inode size.
565 	 */
566 	if (!xfs_inode_hasattr(dp))
567 		return 0;
568 	if (dp->i_af.if_format == XFS_DINODE_FMT_LOCAL)
569 		return xfs_attr_shortform_list(context);
570 
571 	/* Prerequisite for xfs_attr_is_leaf */
572 	error = xfs_iread_extents(NULL, dp, XFS_ATTR_FORK);
573 	if (error)
574 		return error;
575 
576 	if (xfs_attr_is_leaf(dp))
577 		return xfs_attr_leaf_list(context);
578 	return xfs_attr_node_list(context);
579 }
580 
581 int
xfs_attr_list(struct xfs_attr_list_context * context)582 xfs_attr_list(
583 	struct xfs_attr_list_context	*context)
584 {
585 	struct xfs_inode		*dp = context->dp;
586 	uint				lock_mode;
587 	int				error;
588 
589 	XFS_STATS_INC(dp->i_mount, xs_attr_list);
590 
591 	if (xfs_is_shutdown(dp->i_mount))
592 		return -EIO;
593 
594 	lock_mode = xfs_ilock_attr_map_shared(dp);
595 	error = xfs_attr_list_ilocked(context);
596 	xfs_iunlock(dp, lock_mode);
597 	return error;
598 }
599