summaryrefslogtreecommitdiffstats
path: root/fs/xfs/xfs_attr_list.c
blob: 25e76cd6c0533654f36dfe579145322a4f571cd9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * Copyright (c) 2013 Red Hat, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_mount.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_attr.h"
#include "xfs_attr_sf.h"
#include "xfs_attr_remote.h"
#include "xfs_attr_leaf.h"
#include "xfs_error.h"
#include "xfs_trace.h"
#include "xfs_buf_item.h"
#include "xfs_cksum.h"
#include "xfs_dir2.h"

STATIC int
xfs_attr_shortform_compare(const void *a, const void *b)
{
	xfs_attr_sf_sort_t *sa, *sb;

	sa = (xfs_attr_sf_sort_t *)a;
	sb = (xfs_attr_sf_sort_t *)b;
	if (sa->hash < sb->hash) {
		return -1;
	} else if (sa->hash > sb->hash) {
		return 1;
	} else {
		return sa->entno - sb->entno;
	}
}

#define XFS_ISRESET_CURSOR(cursor) \
	(!((cursor)->initted) && !((cursor)->hashval) && \
	 !((cursor)->blkno) && !((cursor)->offset))
/*
 * Copy out entries of shortform attribute lists for attr_list().
 * Shortform attribute lists are not stored in hashval sorted order.
 * If the output buffer is not large enough to hold them all, then we
 * we have to calculate each entries' hashvalue and sort them before
 * we can begin returning them to the user.
 */
static int
xfs_attr_shortform_list(xfs_attr_list_context_t *context)
{
	attrlist_cursor_kern_t *cursor;
	xfs_attr_sf_sort_t *sbuf, *sbp;
	xfs_attr_shortform_t *sf;
	xfs_attr_sf_entry_t *sfe;
	xfs_inode_t *dp;
	int sbsize, nsbuf, count, i;
	int error;

	ASSERT(context != NULL);
	dp = context->dp;
	ASSERT(dp != NULL);
	ASSERT(dp->i_afp != NULL);
	sf = (xfs_attr_shortform_t *)dp->i_afp->if_u1.if_data;
	ASSERT(sf != NULL);
	if (!sf->hdr.count)
		return 0;
	cursor = context->cursor;
	ASSERT(cursor != NULL);

	trace_xfs_attr_list_sf(context);

	/*
	 * If the buffer is large enough and the cursor is at the start,
	 * do not bother with sorting since we will return everything in
	 * one buffer and another call using the cursor won't need to be
	 * made.
	 * Note the generous fudge factor of 16 overhead bytes per entry.
	 * If bufsize is zero then put_listent must be a search function
	 * and can just scan through what we have.
	 */
	if (context->bufsize == 0 ||
	    (XFS_ISRESET_CURSOR(cursor) &&
             (dp->i_afp->if_bytes + sf->hdr.count * 16) < context->bufsize)) {
		for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
			error = context->put_listent(context,
					   sfe->flags,
					   sfe->nameval,
					   (int)sfe->namelen,
					   (int)sfe->valuelen);
			if (error)
				return error;
			/*
			 * Either search callback finished early or
			 * didn't fit it all in the buffer after all.
			 */
			if (context->seen_enough)
				break;
			sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
		}
		trace_xfs_attr_list_sf_all(context);
		return 0;
	}

	/* do no more for a search callback */
	if (context->bufsize == 0)
		return 0;

	/*
	 * It didn't all fit, so we have to sort everything on hashval.
	 */
	sbsize = sf->hdr.count * sizeof(*sbuf);
	sbp = sbuf = kmem_alloc(sbsize, KM_SLEEP | KM_NOFS);

	/*
	 * Scan the attribute list for the rest of the entries, storing
	 * the relevant info from only those that match into a buffer.
	 */
	nsbuf = 0;
	for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
		if (unlikely(
		    ((char *)sfe < (char *)sf) ||
		    ((char *)sfe >= ((char *)sf + dp->i_afp->if_bytes)))) {
			XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
					     XFS_ERRLEVEL_LOW,
					     context->dp->i_mount, sfe);
			kmem_free(sbuf);
			return -EFSCORRUPTED;
		}

		sbp->entno = i;
		sbp->hash = xfs_da_hashname(sfe->nameval, sfe->namelen);
		sbp->name = sfe->nameval;
		sbp->namelen = sfe->namelen;
		/* These are bytes, and both on-disk, don't endian-flip */
		sbp->valuelen = sfe->valuelen;
		sbp->flags = sfe->flags;
		sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
		sbp++;
		nsbuf++;
	}

	/*
	 * Sort the entries on hash then entno.
	 */
	xfs_sort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);

	/*
	 * Re-find our place IN THE SORTED LIST.
	 */
	count = 0;
	cursor->initted = 1;
	cursor->blkno = 0;
	for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
		if (sbp->hash == cursor->hashval) {
			if (cursor->offset == count) {
				break;
			}
			count++;
		} else if (sbp->hash > cursor->hashval) {
			break;
		}
	}
	if (i == nsbuf) {
		kmem_free(sbuf);
		return 0;
	}

	/*
	 * Loop putting entries into the user buffer.
	 */
	for ( ; i < nsbuf; i++, sbp++) {
		if (cursor->hashval != sbp->hash) {
			cursor->hashval = sbp->hash;
			cursor->offset = 0;
		}
		error = context->put_listent(context,
					sbp->flags,
					sbp->name,
					sbp->namelen,
					sbp->valuelen);
		if (error) {
			kmem_free(sbuf);
			return error;
		}
		if (context->seen_enough)
			break;
		cursor->offset++;
	}

	kmem_free(sbuf);
	return 0;
}

STATIC int
xfs_attr_node_list(xfs_attr_list_context_t *context)
{
	attrlist_cursor_kern_t *cursor;
	xfs_attr_leafblock_t *leaf;
	xfs_da_intnode_t *node;
	struct xfs_attr3_icleaf_hdr leafhdr;
	struct xfs_da3_icnode_hdr nodehdr;
	struct xfs_da_node_entry *btree;
	int error, i;
	struct xfs_buf *bp;
	struct xfs_inode	*dp = context->dp;
	struct xfs_mount	*mp = dp->i_mount;

	trace_xfs_attr_node_list(context);

	cursor = context->cursor;
	cursor->initted = 1;

	/*
	 * Do all sorts of validation on the passed-in cursor structure.
	 * If anything is amiss, ignore the cursor and look up the hashval
	 * starting from the btree root.
	 */
	bp = NULL;
	if (cursor->blkno > 0) {
		error = xfs_da3_node_read(NULL, dp, cursor->blkno, -1,
					      &bp, XFS_ATTR_FORK);
		if ((error != 0) && (error != -EFSCORRUPTED))
			return error;
		if (bp) {
			struct xfs_attr_leaf_entry *entries;

			node = bp->b_addr;
			switch (be16_to_cpu(node->hdr.info.magic)) {
			case XFS_DA_NODE_MAGIC:
			case XFS_DA3_NODE_MAGIC:
				trace_xfs_attr_list_wrong_blk(context);
				xfs_trans_brelse(NULL, bp);
				bp = NULL;
				break;
			case XFS_ATTR_LEAF_MAGIC:
			case XFS_ATTR3_LEAF_MAGIC:
				leaf = bp->b_addr;
				xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo,
							     &leafhdr, leaf);
				entries = xfs_attr3_leaf_entryp(leaf);
				if (cursor->hashval > be32_to_cpu(
						entries[leafhdr.count - 1].hashval)) {
					trace_xfs_attr_list_wrong_blk(context);
					xfs_trans_brelse(NULL, bp);
					bp = NULL;
				} else if (cursor->hashval <= be32_to_cpu(
						entries[0].hashval)) {
					trace_xfs_attr_list_wrong_blk(context);
					xfs_trans_brelse(NULL, bp);
					bp = NULL;
				}
				break;
			default:
				trace_xfs_attr_list_wrong_blk(context);
				xfs_trans_brelse(NULL, bp);
				bp = NULL;
			}
		}
	}

	/*
	 * We did not find what we expected given the cursor's contents,
	 * so we start from the top and work down based on the hash value.
	 * Note that start of node block is same as start of leaf block.
	 */
	if (bp == NULL) {
		cursor->blkno = 0;
		for (;;) {
			__uint16_t magic;

			error = xfs_da3_node_read(NULL, dp,
						      cursor->blkno, -1, &bp,
						      XFS_ATTR_FORK);
			if (error)
				return error;
			node = bp->b_addr;
			magic = be16_to_cpu(node->hdr.info.magic);
			if (magic == XFS_ATTR_LEAF_MAGIC ||
			    magic == XFS_ATTR3_LEAF_MAGIC)
				break;
			if (magic != XFS_DA_NODE_MAGIC &&
			    magic != XFS_DA3_NODE_MAGIC) {
				XFS_CORRUPTION_ERROR("xfs_attr_node_list(3)",
						     XFS_ERRLEVEL_LOW,
						     context->dp->i_mount,
						     node);
				xfs_trans_brelse(NULL, bp);
				return -EFSCORRUPTED;
			}

			dp->d_ops->node_hdr_from_disk(&nodehdr, node);
			btree = dp->d_ops->node_tree_p(node);
			for (i = 0; i < nodehdr.count; btree++, i++) {
				if (cursor->hashval
						<= be32_to_cpu(btree->hashval)) {
					cursor->blkno = be32_to_cpu(btree->before);
					trace_xfs_attr_list_node_descend(context,
									 btree);
					break;
				}
			}
			if (i == nodehdr.count) {
				xfs_trans_brelse(NULL, bp);
				return 0;
			}
			xfs_trans_brelse(NULL, bp);
		}
	}
	ASSERT(bp != NULL);

	/*
	 * Roll upward through the blocks, processing each leaf block in
	 * order.  As long as there is space in the result buffer, keep
	 * adding the information.
	 */
	for (;;) {
		leaf = bp->b_addr;
		error = xfs_attr3_leaf_list_int(bp, context);
		if (error) {
			xfs_trans_brelse(NULL, bp);
			return error;
		}
		xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
		if (context->seen_enough || leafhdr.forw == 0)
			break;
		cursor->blkno = leafhdr.forw;
		xfs_trans_brelse(NULL, bp);
		error = xfs_attr3_leaf_read(NULL, dp, cursor->blkno, -1, &bp);
		if (error)
			return error;
	}
	xfs_trans_brelse(NULL, bp);
	return 0;
}

/*
 * Copy out attribute list entries for attr_list(), for leaf attribute lists.
 */
int
xfs_attr3_leaf_list_int(
	struct xfs_buf			*bp,
	struct xfs_attr_list_context	*context)
{
	struct attrlist_cursor_kern	*cursor;
	struct xfs_attr_leafblock	*leaf;
	struct xfs_attr3_icleaf_hdr	ichdr;
	struct xfs_attr_leaf_entry	*entries;
	struct xfs_attr_leaf_entry	*entry;
	int				retval;
	int				i;
	struct xfs_mount		*mp = context->dp->i_mount;

	trace_xfs_attr_list_leaf(context);

	leaf = bp->b_addr;
	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
	entries = xfs_attr3_leaf_entryp(leaf);

	cursor = context->cursor;
	cursor->initted = 1;

	/*
	 * Re-find our place in the leaf block if this is a new syscall.
	 */
	if (context->resynch) {
		entry = &entries[0];
		for (i = 0; i < ichdr.count; entry++, i++) {
			if (be32_to_cpu(entry->hashval) == cursor->hashval) {
				if (cursor->offset == context->dupcnt) {
					context->dupcnt = 0;
					break;
				}
				context->dupcnt++;
			} else if (be32_to_cpu(entry->hashval) >
					cursor->hashval) {
				context->dupcnt = 0;
				break;
			}
		}
		if (i == ichdr.count) {
			trace_xfs_attr_list_notfound(context);
			return 0;
		}
	} else {
		entry = &entries[0];
		i = 0;
	}
	context->resynch = 0;

	/*
	 * We have found our place, start copying out the new attributes.
	 */
	retval = 0;
	for (; i < ichdr.count; entry++, i++) {
		char *name;
		int namelen, valuelen;

		if (be32_to_cpu(entry->hashval) != cursor->hashval) {
			cursor->hashval = be32_to_cpu(entry->hashval);
			cursor->offset = 0;
		}

		if (entry->flags & XFS_ATTR_INCOMPLETE)
			continue;		/* skip incomplete entries */

		if (entry->flags & XFS_ATTR_LOCAL) {
			xfs_attr_leaf_name_local_t *name_loc;

			name_loc = xfs_attr3_leaf_name_local(leaf, i);
			name = name_loc->nameval;
			namelen = name_loc->namelen;
			valuelen = be16_to_cpu(name_loc->valuelen);
		} else {
			xfs_attr_leaf_name_remote_t *name_rmt;

			name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
			name = name_rmt->name;
			namelen = name_rmt->namelen;
			valuelen = be32_to_cpu(name_rmt->valuelen);
		}

		retval = context->put_listent(context, entry->flags,
					      name, namelen, valuelen);
		if (retval)
			break;
		if (context->seen_enough)
			break;
		cursor->offset++;
	}
	trace_xfs_attr_list_leaf_end(context);
	return retval;
}

/*
 * Copy out attribute entries for attr_list(), for leaf attribute lists.
 */
STATIC int
xfs_attr_leaf_list(xfs_attr_list_context_t *context)
{
	int error;
	struct xfs_buf *bp;

	trace_xfs_attr_leaf_list(context);

	context->cursor->blkno = 0;
	error = xfs_attr3_leaf_read(NULL, context->dp, 0, -1, &bp);
	if (error)
		return error;

	error = xfs_attr3_leaf_list_int(bp, context);
	xfs_trans_brelse(NULL, bp);
	return error;
}

int
xfs_attr_list_int(
	xfs_attr_list_context_t *context)
{
	int error;
	xfs_inode_t *dp = context->dp;
	uint		lock_mode;

	XFS_STATS_INC(dp->i_mount, xs_attr_list);

	if (XFS_FORCED_SHUTDOWN(dp->i_mount))
		return -EIO;

	/*
	 * Decide on what work routines to call based on the inode size.
	 */
	lock_mode = xfs_ilock_attr_map_shared(dp);
	if (!xfs_inode_hasattr(dp)) {
		error = 0;
	} else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
		error = xfs_attr_shortform_list(context);
	} else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
		error = xfs_attr_leaf_list(context);
	} else {
		error = xfs_attr_node_list(context);
	}
	xfs_iunlock(dp, lock_mode);
	return error;
}

#define	ATTR_ENTBASESIZE		/* minimum bytes used by an attr */ \
	(((struct attrlist_ent *) 0)->a_name - (char *) 0)
#define	ATTR_ENTSIZE(namelen)		/* actual bytes used by an attr */ \
	((ATTR_ENTBASESIZE + (namelen) + 1 + sizeof(u_int32_t)-1) \
	 & ~(sizeof(u_int32_t)-1))

/*
 * Format an attribute and copy it out to the user's buffer.
 * Take care to check values and protect against them changing later,
 * we may be reading them directly out of a user buffer.
 */
STATIC int
xfs_attr_put_listent(
	xfs_attr_list_context_t *context,
	int		flags,
	unsigned char	*name,
	int		namelen,
	int		valuelen)
{
	struct attrlist *alist = (struct attrlist *)context->alist;
	attrlist_ent_t *aep;
	int arraytop;

	ASSERT(!(context->flags & ATTR_KERNOVAL));
	ASSERT(context->count >= 0);
	ASSERT(context->count < (ATTR_MAX_VALUELEN/8));
	ASSERT(context->firstu >= sizeof(*alist));
	ASSERT(context->firstu <= context->bufsize);

	/*
	 * Only list entries in the right namespace.
	 */
	if (((context->flags & ATTR_SECURE) == 0) !=
	    ((flags & XFS_ATTR_SECURE) == 0))
		return 0;
	if (((context->flags & ATTR_ROOT) == 0) !=
	    ((flags & XFS_ATTR_ROOT) == 0))
		return 0;

	arraytop = sizeof(*alist) +
			context->count * sizeof(alist->al_offset[0]);
	context->firstu -= ATTR_ENTSIZE(namelen);
	if (context->firstu < arraytop) {
		trace_xfs_attr_list_full(context);
		alist->al_more = 1;
		context->seen_enough = 1;
		return 0;
	}

	aep = (attrlist_ent_t *)&context->alist[context->firstu];
	aep->a_valuelen = valuelen;
	memcpy(aep->a_name, name, namelen);
	aep->a_name[namelen] = 0;
	alist->al_offset[context->count++] = context->firstu;
	alist->al_count = context->count;
	trace_xfs_attr_list_add(context);
	return 0;
}

/*
 * Generate a list of extended attribute names and optionally
 * also value lengths.  Positive return value follows the XFS
 * convention of being an error, zero or negative return code
 * is the length of the buffer returned (negated), indicating
 * success.
 */
int
xfs_attr_list(
	xfs_inode_t	*dp,
	char		*buffer,
	int		bufsize,
	int		flags,
	attrlist_cursor_kern_t *cursor)
{
	xfs_attr_list_context_t context;
	struct attrlist *alist;
	int error;

	/*
	 * Validate the cursor.
	 */
	if (cursor->pad1 || cursor->pad2)
		return -EINVAL;
	if ((cursor->initted == 0) &&
	    (cursor->hashval || cursor->blkno || cursor->offset))
		return -EINVAL;

	/*
	 * Check for a properly aligned buffer.
	 */
	if (((long)buffer) & (sizeof(int)-1))
		return -EFAULT;
	if (flags & ATTR_KERNOVAL)
		bufsize = 0;

	/*
	 * Initialize the output buffer.
	 */
	memset(&context, 0, sizeof(context));
	context.dp = dp;
	context.cursor = cursor;
	context.resynch = 1;
	context.flags = flags;
	context.alist = buffer;
	context.bufsize = (bufsize & ~(sizeof(int)-1));  /* align */
	context.firstu = context.bufsize;
	context.put_listent = xfs_attr_put_listent;

	alist = (struct attrlist *)context.alist;
	alist->al_count = 0;
	alist->al_more = 0;
	alist->al_offset[0] = context.bufsize;

	error = xfs_attr_list_int(&context);
	ASSERT(error <= 0);
	return error;
}
OpenPOWER on IntegriCloud