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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_sf_hdr		*sf = dp->i_af.if_data;
 60	struct xfs_attr_sf_entry	*sfe;
 61	int				sbsize, nsbuf, count, i;
 62	int				error = 0;
 63
 64	ASSERT(sf != NULL);
 65	if (!sf->count)
 66		return 0;
 67
 68	trace_xfs_attr_list_sf(context);
 69
 70	/*
 71	 * If the buffer is large enough and the cursor is at the start,
 72	 * do not bother with sorting since we will return everything in
 73	 * one buffer and another call using the cursor won't need to be
 74	 * made.
 75	 * Note the generous fudge factor of 16 overhead bytes per entry.
 76	 * If bufsize is zero then put_listent must be a search function
 77	 * and can just scan through what we have.
 78	 */
 79	if (context->bufsize == 0 ||
 80	    (XFS_ISRESET_CURSOR(cursor) &&
 81	     (dp->i_af.if_bytes + sf->count * 16) < context->bufsize)) {
 82		for (i = 0, sfe = xfs_attr_sf_firstentry(sf); i < sf->count; i++) {
 83			if (XFS_IS_CORRUPT(context->dp->i_mount,
 84					   !xfs_attr_namecheck(sfe->nameval,
 85							       sfe->namelen)))
 86				return -EFSCORRUPTED;
 87			context->put_listent(context,
 88					     sfe->flags,
 89					     sfe->nameval,
 90					     (int)sfe->namelen,
 91					     (int)sfe->valuelen);
 92			/*
 93			 * Either search callback finished early or
 94			 * didn't fit it all in the buffer after all.
 95			 */
 96			if (context->seen_enough)
 97				break;
 98			sfe = xfs_attr_sf_nextentry(sfe);
 99		}
100		trace_xfs_attr_list_sf_all(context);
101		return 0;
102	}
103
104	/* do no more for a search callback */
105	if (context->bufsize == 0)
106		return 0;
107
108	/*
109	 * It didn't all fit, so we have to sort everything on hashval.
110	 */
111	sbsize = sf->count * sizeof(*sbuf);
112	sbp = sbuf = kmem_alloc(sbsize, KM_NOFS);
113
114	/*
115	 * Scan the attribute list for the rest of the entries, storing
116	 * the relevant info from only those that match into a buffer.
117	 */
118	nsbuf = 0;
119	for (i = 0, sfe = xfs_attr_sf_firstentry(sf); i < sf->count; i++) {
120		if (unlikely(
121		    ((char *)sfe < (char *)sf) ||
122		    ((char *)sfe >= ((char *)sf + dp->i_af.if_bytes)))) {
123			XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
124					     XFS_ERRLEVEL_LOW,
125					     context->dp->i_mount, sfe,
126					     sizeof(*sfe));
127			kmem_free(sbuf);
128			return -EFSCORRUPTED;
129		}
130
131		sbp->entno = i;
132		sbp->hash = xfs_da_hashname(sfe->nameval, sfe->namelen);
133		sbp->name = sfe->nameval;
134		sbp->namelen = sfe->namelen;
135		/* These are bytes, and both on-disk, don't endian-flip */
136		sbp->valuelen = sfe->valuelen;
137		sbp->flags = sfe->flags;
138		sfe = xfs_attr_sf_nextentry(sfe);
139		sbp++;
140		nsbuf++;
141	}
142
143	/*
144	 * Sort the entries on hash then entno.
145	 */
146	xfs_sort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);
147
148	/*
149	 * Re-find our place IN THE SORTED LIST.
150	 */
151	count = 0;
152	cursor->initted = 1;
153	cursor->blkno = 0;
154	for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
155		if (sbp->hash == cursor->hashval) {
156			if (cursor->offset == count) {
157				break;
158			}
159			count++;
160		} else if (sbp->hash > cursor->hashval) {
161			break;
162		}
163	}
164	if (i == nsbuf)
165		goto out;
166
167	/*
168	 * Loop putting entries into the user buffer.
169	 */
170	for ( ; i < nsbuf; i++, sbp++) {
171		if (cursor->hashval != sbp->hash) {
172			cursor->hashval = sbp->hash;
173			cursor->offset = 0;
174		}
175		if (XFS_IS_CORRUPT(context->dp->i_mount,
176				   !xfs_attr_namecheck(sbp->name,
177						       sbp->namelen))) {
178			error = -EFSCORRUPTED;
179			goto out;
180		}
181		context->put_listent(context,
182				     sbp->flags,
183				     sbp->name,
184				     sbp->namelen,
185				     sbp->valuelen);
186		if (context->seen_enough)
187			break;
188		cursor->offset++;
189	}
190out:
191	kmem_free(sbuf);
192	return error;
193}
194
195/*
196 * We didn't find the block & hash mentioned in the cursor state, so
197 * walk down the attr btree looking for the hash.
198 */
199STATIC int
200xfs_attr_node_list_lookup(
201	struct xfs_attr_list_context	*context,
202	struct xfs_attrlist_cursor_kern	*cursor,
203	struct xfs_buf			**pbp)
204{
205	struct xfs_da3_icnode_hdr	nodehdr;
206	struct xfs_da_intnode		*node;
207	struct xfs_da_node_entry	*btree;
208	struct xfs_inode		*dp = context->dp;
209	struct xfs_mount		*mp = dp->i_mount;
210	struct xfs_trans		*tp = context->tp;
211	struct xfs_buf			*bp;
212	int				i;
213	int				error = 0;
214	unsigned int			expected_level = 0;
215	uint16_t			magic;
216
217	ASSERT(*pbp == NULL);
218	cursor->blkno = 0;
219	for (;;) {
220		error = xfs_da3_node_read(tp, dp, cursor->blkno, &bp,
221				XFS_ATTR_FORK);
222		if (error)
223			return error;
224		node = bp->b_addr;
225		magic = be16_to_cpu(node->hdr.info.magic);
226		if (magic == XFS_ATTR_LEAF_MAGIC ||
227		    magic == XFS_ATTR3_LEAF_MAGIC)
228			break;
229		if (magic != XFS_DA_NODE_MAGIC &&
230		    magic != XFS_DA3_NODE_MAGIC) {
231			XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
232					node, sizeof(*node));
233			goto out_corruptbuf;
234		}
235
236		xfs_da3_node_hdr_from_disk(mp, &nodehdr, node);
237
238		/* Tree taller than we can handle; bail out! */
239		if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH)
240			goto out_corruptbuf;
241
242		/* Check the level from the root node. */
243		if (cursor->blkno == 0)
244			expected_level = nodehdr.level - 1;
245		else if (expected_level != nodehdr.level)
246			goto out_corruptbuf;
247		else
248			expected_level--;
249
250		btree = nodehdr.btree;
251		for (i = 0; i < nodehdr.count; btree++, i++) {
252			if (cursor->hashval <= be32_to_cpu(btree->hashval)) {
253				cursor->blkno = be32_to_cpu(btree->before);
254				trace_xfs_attr_list_node_descend(context,
255						btree);
256				break;
257			}
258		}
259		xfs_trans_brelse(tp, bp);
260
261		if (i == nodehdr.count)
262			return 0;
263
264		/* We can't point back to the root. */
265		if (XFS_IS_CORRUPT(mp, cursor->blkno == 0))
266			return -EFSCORRUPTED;
267	}
268
269	if (expected_level != 0)
270		goto out_corruptbuf;
271
272	*pbp = bp;
273	return 0;
274
275out_corruptbuf:
276	xfs_buf_mark_corrupt(bp);
277	xfs_trans_brelse(tp, bp);
278	return -EFSCORRUPTED;
279}
280
281STATIC int
282xfs_attr_node_list(
283	struct xfs_attr_list_context	*context)
284{
285	struct xfs_attrlist_cursor_kern	*cursor = &context->cursor;
286	struct xfs_attr3_icleaf_hdr	leafhdr;
287	struct xfs_attr_leafblock	*leaf;
288	struct xfs_da_intnode		*node;
289	struct xfs_buf			*bp;
290	struct xfs_inode		*dp = context->dp;
291	struct xfs_mount		*mp = dp->i_mount;
292	int				error = 0;
293
294	trace_xfs_attr_node_list(context);
295
296	cursor->initted = 1;
297
298	/*
299	 * Do all sorts of validation on the passed-in cursor structure.
300	 * If anything is amiss, ignore the cursor and look up the hashval
301	 * starting from the btree root.
302	 */
303	bp = NULL;
304	if (cursor->blkno > 0) {
305		error = xfs_da3_node_read(context->tp, dp, cursor->blkno, &bp,
306				XFS_ATTR_FORK);
307		if ((error != 0) && (error != -EFSCORRUPTED))
308			return error;
309		if (bp) {
310			struct xfs_attr_leaf_entry *entries;
311
312			node = bp->b_addr;
313			switch (be16_to_cpu(node->hdr.info.magic)) {
314			case XFS_DA_NODE_MAGIC:
315			case XFS_DA3_NODE_MAGIC:
316				trace_xfs_attr_list_wrong_blk(context);
317				xfs_trans_brelse(context->tp, bp);
318				bp = NULL;
319				break;
320			case XFS_ATTR_LEAF_MAGIC:
321			case XFS_ATTR3_LEAF_MAGIC:
322				leaf = bp->b_addr;
323				xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo,
324							     &leafhdr, leaf);
325				entries = xfs_attr3_leaf_entryp(leaf);
326				if (cursor->hashval > be32_to_cpu(
327						entries[leafhdr.count - 1].hashval)) {
328					trace_xfs_attr_list_wrong_blk(context);
329					xfs_trans_brelse(context->tp, bp);
330					bp = NULL;
331				} else if (cursor->hashval <= be32_to_cpu(
332						entries[0].hashval)) {
333					trace_xfs_attr_list_wrong_blk(context);
334					xfs_trans_brelse(context->tp, bp);
335					bp = NULL;
336				}
337				break;
338			default:
339				trace_xfs_attr_list_wrong_blk(context);
340				xfs_trans_brelse(context->tp, bp);
341				bp = NULL;
342			}
343		}
344	}
345
346	/*
347	 * We did not find what we expected given the cursor's contents,
348	 * so we start from the top and work down based on the hash value.
349	 * Note that start of node block is same as start of leaf block.
350	 */
351	if (bp == NULL) {
352		error = xfs_attr_node_list_lookup(context, cursor, &bp);
353		if (error || !bp)
354			return error;
355	}
356	ASSERT(bp != NULL);
357
358	/*
359	 * Roll upward through the blocks, processing each leaf block in
360	 * order.  As long as there is space in the result buffer, keep
361	 * adding the information.
362	 */
363	for (;;) {
364		leaf = bp->b_addr;
365		error = xfs_attr3_leaf_list_int(bp, context);
366		if (error)
367			break;
368		xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
369		if (context->seen_enough || leafhdr.forw == 0)
370			break;
371		cursor->blkno = leafhdr.forw;
372		xfs_trans_brelse(context->tp, bp);
373		error = xfs_attr3_leaf_read(context->tp, dp, cursor->blkno,
374					    &bp);
375		if (error)
376			return error;
377	}
378	xfs_trans_brelse(context->tp, bp);
379	return error;
380}
381
382/*
383 * Copy out attribute list entries for attr_list(), for leaf attribute lists.
384 */
385int
386xfs_attr3_leaf_list_int(
387	struct xfs_buf			*bp,
388	struct xfs_attr_list_context	*context)
389{
390	struct xfs_attrlist_cursor_kern	*cursor = &context->cursor;
391	struct xfs_attr_leafblock	*leaf;
392	struct xfs_attr3_icleaf_hdr	ichdr;
393	struct xfs_attr_leaf_entry	*entries;
394	struct xfs_attr_leaf_entry	*entry;
395	int				i;
396	struct xfs_mount		*mp = context->dp->i_mount;
397
398	trace_xfs_attr_list_leaf(context);
399
400	leaf = bp->b_addr;
401	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
402	entries = xfs_attr3_leaf_entryp(leaf);
403
404	cursor->initted = 1;
405
406	/*
407	 * Re-find our place in the leaf block if this is a new syscall.
408	 */
409	if (context->resynch) {
410		entry = &entries[0];
411		for (i = 0; i < ichdr.count; entry++, i++) {
412			if (be32_to_cpu(entry->hashval) == cursor->hashval) {
413				if (cursor->offset == context->dupcnt) {
414					context->dupcnt = 0;
415					break;
416				}
417				context->dupcnt++;
418			} else if (be32_to_cpu(entry->hashval) >
419					cursor->hashval) {
420				context->dupcnt = 0;
421				break;
422			}
423		}
424		if (i == ichdr.count) {
425			trace_xfs_attr_list_notfound(context);
426			return 0;
427		}
428	} else {
429		entry = &entries[0];
430		i = 0;
431	}
432	context->resynch = 0;
433
434	/*
435	 * We have found our place, start copying out the new attributes.
436	 */
437	for (; i < ichdr.count; entry++, i++) {
438		char *name;
439		int namelen, valuelen;
440
441		if (be32_to_cpu(entry->hashval) != cursor->hashval) {
442			cursor->hashval = be32_to_cpu(entry->hashval);
443			cursor->offset = 0;
444		}
445
446		if ((entry->flags & XFS_ATTR_INCOMPLETE) &&
447		    !context->allow_incomplete)
448			continue;
449
450		if (entry->flags & XFS_ATTR_LOCAL) {
451			xfs_attr_leaf_name_local_t *name_loc;
452
453			name_loc = xfs_attr3_leaf_name_local(leaf, i);
454			name = name_loc->nameval;
455			namelen = name_loc->namelen;
456			valuelen = be16_to_cpu(name_loc->valuelen);
457		} else {
458			xfs_attr_leaf_name_remote_t *name_rmt;
459
460			name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
461			name = name_rmt->name;
462			namelen = name_rmt->namelen;
463			valuelen = be32_to_cpu(name_rmt->valuelen);
464		}
465
466		if (XFS_IS_CORRUPT(context->dp->i_mount,
467				   !xfs_attr_namecheck(name, namelen)))
468			return -EFSCORRUPTED;
469		context->put_listent(context, entry->flags,
470					      name, namelen, valuelen);
471		if (context->seen_enough)
472			break;
473		cursor->offset++;
474	}
475	trace_xfs_attr_list_leaf_end(context);
476	return 0;
477}
478
479/*
480 * Copy out attribute entries for attr_list(), for leaf attribute lists.
481 */
482STATIC int
483xfs_attr_leaf_list(
484	struct xfs_attr_list_context	*context)
485{
486	struct xfs_buf			*bp;
487	int				error;
488
489	trace_xfs_attr_leaf_list(context);
490
491	context->cursor.blkno = 0;
492	error = xfs_attr3_leaf_read(context->tp, context->dp, 0, &bp);
493	if (error)
494		return error;
495
496	error = xfs_attr3_leaf_list_int(bp, context);
497	xfs_trans_brelse(context->tp, bp);
498	return error;
499}
500
501int
502xfs_attr_list_ilocked(
503	struct xfs_attr_list_context	*context)
504{
505	struct xfs_inode		*dp = context->dp;
506
507	ASSERT(xfs_isilocked(dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
508
509	/*
510	 * Decide on what work routines to call based on the inode size.
511	 */
512	if (!xfs_inode_hasattr(dp))
513		return 0;
514	if (dp->i_af.if_format == XFS_DINODE_FMT_LOCAL)
515		return xfs_attr_shortform_list(context);
516	if (xfs_attr_is_leaf(dp))
517		return xfs_attr_leaf_list(context);
518	return xfs_attr_node_list(context);
519}
520
521int
522xfs_attr_list(
523	struct xfs_attr_list_context	*context)
524{
525	struct xfs_inode		*dp = context->dp;
526	uint				lock_mode;
527	int				error;
528
529	XFS_STATS_INC(dp->i_mount, xs_attr_list);
530
531	if (xfs_is_shutdown(dp->i_mount))
532		return -EIO;
533
534	lock_mode = xfs_ilock_attr_map_shared(dp);
535	error = xfs_attr_list_ilocked(context);
536	xfs_iunlock(dp, lock_mode);
537	return error;
538}