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  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
 26STATIC int
 27xfs_attr_shortform_compare(const void *a, const void *b)
 28{
 29	xfs_attr_sf_sort_t *sa, *sb;
 30
 31	sa = (xfs_attr_sf_sort_t *)a;
 32	sb = (xfs_attr_sf_sort_t *)b;
 33	if (sa->hash < sb->hash) {
 34		return -1;
 35	} else if (sa->hash > sb->hash) {
 36		return 1;
 37	} else {
 38		return sa->entno - sb->entno;
 39	}
 40}
 41
 42#define XFS_ISRESET_CURSOR(cursor) \
 43	(!((cursor)->initted) && !((cursor)->hashval) && \
 44	 !((cursor)->blkno) && !((cursor)->offset))
 45/*
 46 * Copy out entries of shortform attribute lists for attr_list().
 47 * Shortform attribute lists are not stored in hashval sorted order.
 48 * If the output buffer is not large enough to hold them all, then
 49 * we have to calculate each entries' hashvalue and sort them before
 50 * we can begin returning them to the user.
 51 */
 52static int
 53xfs_attr_shortform_list(
 54	struct xfs_attr_list_context	*context)
 55{
 56	struct xfs_attrlist_cursor_kern	*cursor = &context->cursor;
 57	struct xfs_inode		*dp = context->dp;
 58	struct xfs_attr_sf_sort		*sbuf, *sbp;
 59	struct xfs_attr_shortform	*sf;
 60	struct xfs_attr_sf_entry	*sfe;
 61	int				sbsize, nsbuf, count, i;
 62	int				error = 0;
 63
 64	sf = (struct xfs_attr_shortform *)dp->i_af.if_u1.if_data;
 65	ASSERT(sf != NULL);
 66	if (!sf->hdr.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->hdr.count * 16) < context->bufsize)) {
 83		for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
 84			if (XFS_IS_CORRUPT(context->dp->i_mount,
 85					   !xfs_attr_namecheck(sfe->nameval,
 86							       sfe->namelen)))
 87				return -EFSCORRUPTED;
 88			context->put_listent(context,
 89					     sfe->flags,
 90					     sfe->nameval,
 91					     (int)sfe->namelen,
 92					     (int)sfe->valuelen);
 93			/*
 94			 * Either search callback finished early or
 95			 * didn't fit it all in the buffer after all.
 96			 */
 97			if (context->seen_enough)
 98				break;
 99			sfe = xfs_attr_sf_nextentry(sfe);
100		}
101		trace_xfs_attr_list_sf_all(context);
102		return 0;
103	}
104
105	/* do no more for a search callback */
106	if (context->bufsize == 0)
107		return 0;
108
109	/*
110	 * It didn't all fit, so we have to sort everything on hashval.
111	 */
112	sbsize = sf->hdr.count * sizeof(*sbuf);
113	sbp = sbuf = kmem_alloc(sbsize, KM_NOFS);
114
115	/*
116	 * Scan the attribute list for the rest of the entries, storing
117	 * the relevant info from only those that match into a buffer.
118	 */
119	nsbuf = 0;
120	for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
121		if (unlikely(
122		    ((char *)sfe < (char *)sf) ||
123		    ((char *)sfe >= ((char *)sf + dp->i_af.if_bytes)))) {
124			XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
125					     XFS_ERRLEVEL_LOW,
126					     context->dp->i_mount, sfe,
127					     sizeof(*sfe));
128			kmem_free(sbuf);
129			return -EFSCORRUPTED;
130		}
131
132		sbp->entno = i;
133		sbp->hash = xfs_da_hashname(sfe->nameval, sfe->namelen);
134		sbp->name = sfe->nameval;
135		sbp->namelen = sfe->namelen;
136		/* These are bytes, and both on-disk, don't endian-flip */
137		sbp->valuelen = sfe->valuelen;
138		sbp->flags = sfe->flags;
139		sfe = xfs_attr_sf_nextentry(sfe);
140		sbp++;
141		nsbuf++;
142	}
143
144	/*
145	 * Sort the entries on hash then entno.
146	 */
147	xfs_sort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);
148
149	/*
150	 * Re-find our place IN THE SORTED LIST.
151	 */
152	count = 0;
153	cursor->initted = 1;
154	cursor->blkno = 0;
155	for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
156		if (sbp->hash == cursor->hashval) {
157			if (cursor->offset == count) {
158				break;
159			}
160			count++;
161		} else if (sbp->hash > cursor->hashval) {
162			break;
163		}
164	}
165	if (i == nsbuf)
166		goto out;
167
168	/*
169	 * Loop putting entries into the user buffer.
170	 */
171	for ( ; i < nsbuf; i++, sbp++) {
172		if (cursor->hashval != sbp->hash) {
173			cursor->hashval = sbp->hash;
174			cursor->offset = 0;
175		}
176		if (XFS_IS_CORRUPT(context->dp->i_mount,
177				   !xfs_attr_namecheck(sbp->name,
178						       sbp->namelen))) {
179			error = -EFSCORRUPTED;
180			goto out;
181		}
182		context->put_listent(context,
183				     sbp->flags,
184				     sbp->name,
185				     sbp->namelen,
186				     sbp->valuelen);
187		if (context->seen_enough)
188			break;
189		cursor->offset++;
190	}
191out:
192	kmem_free(sbuf);
193	return error;
194}
195
196/*
197 * We didn't find the block & hash mentioned in the cursor state, so
198 * walk down the attr btree looking for the hash.
199 */
200STATIC int
201xfs_attr_node_list_lookup(
202	struct xfs_attr_list_context	*context,
203	struct xfs_attrlist_cursor_kern	*cursor,
204	struct xfs_buf			**pbp)
205{
206	struct xfs_da3_icnode_hdr	nodehdr;
207	struct xfs_da_intnode		*node;
208	struct xfs_da_node_entry	*btree;
209	struct xfs_inode		*dp = context->dp;
210	struct xfs_mount		*mp = dp->i_mount;
211	struct xfs_trans		*tp = context->tp;
212	struct xfs_buf			*bp;
213	int				i;
214	int				error = 0;
215	unsigned int			expected_level = 0;
216	uint16_t			magic;
217
218	ASSERT(*pbp == NULL);
219	cursor->blkno = 0;
220	for (;;) {
221		error = xfs_da3_node_read(tp, dp, cursor->blkno, &bp,
222				XFS_ATTR_FORK);
223		if (error)
224			return error;
225		node = bp->b_addr;
226		magic = be16_to_cpu(node->hdr.info.magic);
227		if (magic == XFS_ATTR_LEAF_MAGIC ||
228		    magic == XFS_ATTR3_LEAF_MAGIC)
229			break;
230		if (magic != XFS_DA_NODE_MAGIC &&
231		    magic != XFS_DA3_NODE_MAGIC) {
232			XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
233					node, sizeof(*node));
234			goto out_corruptbuf;
235		}
236
237		xfs_da3_node_hdr_from_disk(mp, &nodehdr, node);
238
239		/* Tree taller than we can handle; bail out! */
240		if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH)
241			goto out_corruptbuf;
242
243		/* Check the level from the root node. */
244		if (cursor->blkno == 0)
245			expected_level = nodehdr.level - 1;
246		else if (expected_level != nodehdr.level)
247			goto out_corruptbuf;
248		else
249			expected_level--;
250
251		btree = nodehdr.btree;
252		for (i = 0; i < nodehdr.count; btree++, i++) {
253			if (cursor->hashval <= be32_to_cpu(btree->hashval)) {
254				cursor->blkno = be32_to_cpu(btree->before);
255				trace_xfs_attr_list_node_descend(context,
256						btree);
257				break;
258			}
259		}
260		xfs_trans_brelse(tp, bp);
261
262		if (i == nodehdr.count)
263			return 0;
264
265		/* We can't point back to the root. */
266		if (XFS_IS_CORRUPT(mp, cursor->blkno == 0))
267			return -EFSCORRUPTED;
268	}
269
270	if (expected_level != 0)
271		goto out_corruptbuf;
272
273	*pbp = bp;
274	return 0;
275
276out_corruptbuf:
277	xfs_buf_mark_corrupt(bp);
278	xfs_trans_brelse(tp, bp);
279	return -EFSCORRUPTED;
280}
281
282STATIC int
283xfs_attr_node_list(
284	struct xfs_attr_list_context	*context)
285{
286	struct xfs_attrlist_cursor_kern	*cursor = &context->cursor;
287	struct xfs_attr3_icleaf_hdr	leafhdr;
288	struct xfs_attr_leafblock	*leaf;
289	struct xfs_da_intnode		*node;
290	struct xfs_buf			*bp;
291	struct xfs_inode		*dp = context->dp;
292	struct xfs_mount		*mp = dp->i_mount;
293	int				error = 0;
294
295	trace_xfs_attr_node_list(context);
296
297	cursor->initted = 1;
298
299	/*
300	 * Do all sorts of validation on the passed-in cursor structure.
301	 * If anything is amiss, ignore the cursor and look up the hashval
302	 * starting from the btree root.
303	 */
304	bp = NULL;
305	if (cursor->blkno > 0) {
306		error = xfs_da3_node_read(context->tp, dp, cursor->blkno, &bp,
307				XFS_ATTR_FORK);
308		if ((error != 0) && (error != -EFSCORRUPTED))
309			return error;
310		if (bp) {
311			struct xfs_attr_leaf_entry *entries;
312
313			node = bp->b_addr;
314			switch (be16_to_cpu(node->hdr.info.magic)) {
315			case XFS_DA_NODE_MAGIC:
316			case XFS_DA3_NODE_MAGIC:
317				trace_xfs_attr_list_wrong_blk(context);
318				xfs_trans_brelse(context->tp, bp);
319				bp = NULL;
320				break;
321			case XFS_ATTR_LEAF_MAGIC:
322			case XFS_ATTR3_LEAF_MAGIC:
323				leaf = bp->b_addr;
324				xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo,
325							     &leafhdr, leaf);
326				entries = xfs_attr3_leaf_entryp(leaf);
327				if (cursor->hashval > be32_to_cpu(
328						entries[leafhdr.count - 1].hashval)) {
329					trace_xfs_attr_list_wrong_blk(context);
330					xfs_trans_brelse(context->tp, bp);
331					bp = NULL;
332				} else if (cursor->hashval <= be32_to_cpu(
333						entries[0].hashval)) {
334					trace_xfs_attr_list_wrong_blk(context);
335					xfs_trans_brelse(context->tp, bp);
336					bp = NULL;
337				}
338				break;
339			default:
340				trace_xfs_attr_list_wrong_blk(context);
341				xfs_trans_brelse(context->tp, bp);
342				bp = NULL;
343			}
344		}
345	}
346
347	/*
348	 * We did not find what we expected given the cursor's contents,
349	 * so we start from the top and work down based on the hash value.
350	 * Note that start of node block is same as start of leaf block.
351	 */
352	if (bp == NULL) {
353		error = xfs_attr_node_list_lookup(context, cursor, &bp);
354		if (error || !bp)
355			return error;
356	}
357	ASSERT(bp != NULL);
358
359	/*
360	 * Roll upward through the blocks, processing each leaf block in
361	 * order.  As long as there is space in the result buffer, keep
362	 * adding the information.
363	 */
364	for (;;) {
365		leaf = bp->b_addr;
366		error = xfs_attr3_leaf_list_int(bp, context);
367		if (error)
368			break;
369		xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
370		if (context->seen_enough || leafhdr.forw == 0)
371			break;
372		cursor->blkno = leafhdr.forw;
373		xfs_trans_brelse(context->tp, bp);
374		error = xfs_attr3_leaf_read(context->tp, dp, cursor->blkno,
375					    &bp);
376		if (error)
377			return error;
378	}
379	xfs_trans_brelse(context->tp, bp);
380	return error;
381}
382
383/*
384 * Copy out attribute list entries for attr_list(), for leaf attribute lists.
385 */
386int
387xfs_attr3_leaf_list_int(
388	struct xfs_buf			*bp,
389	struct xfs_attr_list_context	*context)
390{
391	struct xfs_attrlist_cursor_kern	*cursor = &context->cursor;
392	struct xfs_attr_leafblock	*leaf;
393	struct xfs_attr3_icleaf_hdr	ichdr;
394	struct xfs_attr_leaf_entry	*entries;
395	struct xfs_attr_leaf_entry	*entry;
396	int				i;
397	struct xfs_mount		*mp = context->dp->i_mount;
398
399	trace_xfs_attr_list_leaf(context);
400
401	leaf = bp->b_addr;
402	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
403	entries = xfs_attr3_leaf_entryp(leaf);
404
405	cursor->initted = 1;
406
407	/*
408	 * Re-find our place in the leaf block if this is a new syscall.
409	 */
410	if (context->resynch) {
411		entry = &entries[0];
412		for (i = 0; i < ichdr.count; entry++, i++) {
413			if (be32_to_cpu(entry->hashval) == cursor->hashval) {
414				if (cursor->offset == context->dupcnt) {
415					context->dupcnt = 0;
416					break;
417				}
418				context->dupcnt++;
419			} else if (be32_to_cpu(entry->hashval) >
420					cursor->hashval) {
421				context->dupcnt = 0;
422				break;
423			}
424		}
425		if (i == ichdr.count) {
426			trace_xfs_attr_list_notfound(context);
427			return 0;
428		}
429	} else {
430		entry = &entries[0];
431		i = 0;
432	}
433	context->resynch = 0;
434
435	/*
436	 * We have found our place, start copying out the new attributes.
437	 */
438	for (; i < ichdr.count; entry++, i++) {
439		char *name;
440		int namelen, valuelen;
441
442		if (be32_to_cpu(entry->hashval) != cursor->hashval) {
443			cursor->hashval = be32_to_cpu(entry->hashval);
444			cursor->offset = 0;
445		}
446
447		if ((entry->flags & XFS_ATTR_INCOMPLETE) &&
448		    !context->allow_incomplete)
449			continue;
450
451		if (entry->flags & XFS_ATTR_LOCAL) {
452			xfs_attr_leaf_name_local_t *name_loc;
453
454			name_loc = xfs_attr3_leaf_name_local(leaf, i);
455			name = name_loc->nameval;
456			namelen = name_loc->namelen;
457			valuelen = be16_to_cpu(name_loc->valuelen);
458		} else {
459			xfs_attr_leaf_name_remote_t *name_rmt;
460
461			name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
462			name = name_rmt->name;
463			namelen = name_rmt->namelen;
464			valuelen = be32_to_cpu(name_rmt->valuelen);
465		}
466
467		if (XFS_IS_CORRUPT(context->dp->i_mount,
468				   !xfs_attr_namecheck(name, namelen)))
469			return -EFSCORRUPTED;
470		context->put_listent(context, entry->flags,
471					      name, namelen, valuelen);
472		if (context->seen_enough)
473			break;
474		cursor->offset++;
475	}
476	trace_xfs_attr_list_leaf_end(context);
477	return 0;
478}
479
480/*
481 * Copy out attribute entries for attr_list(), for leaf attribute lists.
482 */
483STATIC int
484xfs_attr_leaf_list(
485	struct xfs_attr_list_context	*context)
486{
487	struct xfs_buf			*bp;
488	int				error;
489
490	trace_xfs_attr_leaf_list(context);
491
492	context->cursor.blkno = 0;
493	error = xfs_attr3_leaf_read(context->tp, context->dp, 0, &bp);
494	if (error)
495		return error;
496
497	error = xfs_attr3_leaf_list_int(bp, context);
498	xfs_trans_brelse(context->tp, bp);
499	return error;
500}
501
502int
503xfs_attr_list_ilocked(
504	struct xfs_attr_list_context	*context)
505{
506	struct xfs_inode		*dp = context->dp;
507
508	ASSERT(xfs_isilocked(dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
509
510	/*
511	 * Decide on what work routines to call based on the inode size.
512	 */
513	if (!xfs_inode_hasattr(dp))
514		return 0;
515	if (dp->i_af.if_format == XFS_DINODE_FMT_LOCAL)
516		return xfs_attr_shortform_list(context);
517	if (xfs_attr_is_leaf(dp))
518		return xfs_attr_leaf_list(context);
519	return xfs_attr_node_list(context);
520}
521
522int
523xfs_attr_list(
524	struct xfs_attr_list_context	*context)
525{
526	struct xfs_inode		*dp = context->dp;
527	uint				lock_mode;
528	int				error;
529
530	XFS_STATS_INC(dp->i_mount, xs_attr_list);
531
532	if (xfs_is_shutdown(dp->i_mount))
533		return -EIO;
534
535	lock_mode = xfs_ilock_attr_map_shared(dp);
536	error = xfs_attr_list_ilocked(context);
537	xfs_iunlock(dp, lock_mode);
538	return error;
539}