summaryrefslogtreecommitdiff
path: root/fs/xfs/scrub/dabtree.c
blob: e56786f0a13c8492a80e2181be6e0119d14c7e2a (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
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2017 Oracle.  All Rights Reserved.
 * Author: Darrick J. Wong <darrick.wong@oracle.com>
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_log_format.h"
#include "xfs_trans.h"
#include "xfs_inode.h"
#include "xfs_dir2.h"
#include "xfs_dir2_priv.h"
#include "xfs_attr_leaf.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/trace.h"
#include "scrub/dabtree.h"

/* Directory/Attribute Btree */

/*
 * Check for da btree operation errors.  See the section about handling
 * operational errors in common.c.
 */
bool
xchk_da_process_error(
	struct xchk_da_btree	*ds,
	int			level,
	int			*error)
{
	struct xfs_scrub	*sc = ds->sc;

	if (*error == 0)
		return true;

	switch (*error) {
	case -EDEADLOCK:
		/* Used to restart an op with deadlock avoidance. */
		trace_xchk_deadlock_retry(sc->ip, sc->sm, *error);
		break;
	case -EFSBADCRC:
	case -EFSCORRUPTED:
		/* Note the badness but don't abort. */
		sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
		*error = 0;
		/* fall through */
	default:
		trace_xchk_file_op_error(sc, ds->dargs.whichfork,
				xfs_dir2_da_to_db(ds->dargs.geo,
					ds->state->path.blk[level].blkno),
				*error, __return_address);
		break;
	}
	return false;
}

/*
 * Check for da btree corruption.  See the section about handling
 * operational errors in common.c.
 */
void
xchk_da_set_corrupt(
	struct xchk_da_btree	*ds,
	int			level)
{
	struct xfs_scrub	*sc = ds->sc;

	sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;

	trace_xchk_fblock_error(sc, ds->dargs.whichfork,
			xfs_dir2_da_to_db(ds->dargs.geo,
				ds->state->path.blk[level].blkno),
			__return_address);
}

static struct xfs_da_node_entry *
xchk_da_btree_node_entry(
	struct xchk_da_btree		*ds,
	int				level)
{
	struct xfs_da_state_blk		*blk = &ds->state->path.blk[level];
	struct xfs_da3_icnode_hdr	hdr;

	ASSERT(blk->magic == XFS_DA_NODE_MAGIC);

	xfs_da3_node_hdr_from_disk(ds->sc->mp, &hdr, blk->bp->b_addr);
	return hdr.btree + blk->index;
}

/* Scrub a da btree hash (key). */
int
xchk_da_btree_hash(
	struct xchk_da_btree		*ds,
	int				level,
	__be32				*hashp)
{
	struct xfs_da_node_entry	*entry;
	xfs_dahash_t			hash;
	xfs_dahash_t			parent_hash;

	/* Is this hash in order? */
	hash = be32_to_cpu(*hashp);
	if (hash < ds->hashes[level])
		xchk_da_set_corrupt(ds, level);
	ds->hashes[level] = hash;

	if (level == 0)
		return 0;

	/* Is this hash no larger than the parent hash? */
	entry = xchk_da_btree_node_entry(ds, level - 1);
	parent_hash = be32_to_cpu(entry->hashval);
	if (parent_hash < hash)
		xchk_da_set_corrupt(ds, level);

	return 0;
}

/*
 * Check a da btree pointer.  Returns true if it's ok to use this
 * pointer.
 */
STATIC bool
xchk_da_btree_ptr_ok(
	struct xchk_da_btree	*ds,
	int			level,
	xfs_dablk_t		blkno)
{
	if (blkno < ds->lowest || (ds->highest != 0 && blkno >= ds->highest)) {
		xchk_da_set_corrupt(ds, level);
		return false;
	}

	return true;
}

/*
 * The da btree scrubber can handle leaf1 blocks as a degenerate
 * form of leafn blocks.  Since the regular da code doesn't handle
 * leaf1, we must multiplex the verifiers.
 */
static void
xchk_da_btree_read_verify(
	struct xfs_buf		*bp)
{
	struct xfs_da_blkinfo	*info = bp->b_addr;

	switch (be16_to_cpu(info->magic)) {
	case XFS_DIR2_LEAF1_MAGIC:
	case XFS_DIR3_LEAF1_MAGIC:
		bp->b_ops = &xfs_dir3_leaf1_buf_ops;
		bp->b_ops->verify_read(bp);
		return;
	default:
		/*
		 * xfs_da3_node_buf_ops already know how to handle
		 * DA*_NODE, ATTR*_LEAF, and DIR*_LEAFN blocks.
		 */
		bp->b_ops = &xfs_da3_node_buf_ops;
		bp->b_ops->verify_read(bp);
		return;
	}
}
static void
xchk_da_btree_write_verify(
	struct xfs_buf		*bp)
{
	struct xfs_da_blkinfo	*info = bp->b_addr;

	switch (be16_to_cpu(info->magic)) {
	case XFS_DIR2_LEAF1_MAGIC:
	case XFS_DIR3_LEAF1_MAGIC:
		bp->b_ops = &xfs_dir3_leaf1_buf_ops;
		bp->b_ops->verify_write(bp);
		return;
	default:
		/*
		 * xfs_da3_node_buf_ops already know how to handle
		 * DA*_NODE, ATTR*_LEAF, and DIR*_LEAFN blocks.
		 */
		bp->b_ops = &xfs_da3_node_buf_ops;
		bp->b_ops->verify_write(bp);
		return;
	}
}
static void *
xchk_da_btree_verify(
	struct xfs_buf		*bp)
{
	struct xfs_da_blkinfo	*info = bp->b_addr;

	switch (be16_to_cpu(info->magic)) {
	case XFS_DIR2_LEAF1_MAGIC:
	case XFS_DIR3_LEAF1_MAGIC:
		bp->b_ops = &xfs_dir3_leaf1_buf_ops;
		return bp->b_ops->verify_struct(bp);
	default:
		bp->b_ops = &xfs_da3_node_buf_ops;
		return bp->b_ops->verify_struct(bp);
	}
}

static const struct xfs_buf_ops xchk_da_btree_buf_ops = {
	.name = "xchk_da_btree",
	.verify_read = xchk_da_btree_read_verify,
	.verify_write = xchk_da_btree_write_verify,
	.verify_struct = xchk_da_btree_verify,
};

/* Check a block's sibling. */
STATIC int
xchk_da_btree_block_check_sibling(
	struct xchk_da_btree	*ds,
	int			level,
	int			direction,
	xfs_dablk_t		sibling)
{
	struct xfs_da_state_path *path = &ds->state->path;
	struct xfs_da_state_path *altpath = &ds->state->altpath;
	int			retval;
	int			plevel;
	int			error;

	memcpy(altpath, path, sizeof(ds->state->altpath));

	/*
	 * If the pointer is null, we shouldn't be able to move the upper
	 * level pointer anywhere.
	 */
	if (sibling == 0) {
		error = xfs_da3_path_shift(ds->state, altpath, direction,
				false, &retval);
		if (error == 0 && retval == 0)
			xchk_da_set_corrupt(ds, level);
		error = 0;
		goto out;
	}

	/* Move the alternate cursor one block in the direction given. */
	error = xfs_da3_path_shift(ds->state, altpath, direction, false,
			&retval);
	if (!xchk_da_process_error(ds, level, &error))
		goto out;
	if (retval) {
		xchk_da_set_corrupt(ds, level);
		goto out;
	}
	if (altpath->blk[level].bp)
		xchk_buffer_recheck(ds->sc, altpath->blk[level].bp);

	/* Compare upper level pointer to sibling pointer. */
	if (altpath->blk[level].blkno != sibling)
		xchk_da_set_corrupt(ds, level);

out:
	/* Free all buffers in the altpath that aren't referenced from path. */
	for (plevel = 0; plevel < altpath->active; plevel++) {
		if (altpath->blk[plevel].bp == NULL ||
		    (plevel < path->active &&
		     altpath->blk[plevel].bp == path->blk[plevel].bp))
			continue;

		xfs_trans_brelse(ds->dargs.trans, altpath->blk[plevel].bp);
		altpath->blk[plevel].bp = NULL;
	}

	return error;
}

/* Check a block's sibling pointers. */
STATIC int
xchk_da_btree_block_check_siblings(
	struct xchk_da_btree	*ds,
	int			level,
	struct xfs_da_blkinfo	*hdr)
{
	xfs_dablk_t		forw;
	xfs_dablk_t		back;
	int			error = 0;

	forw = be32_to_cpu(hdr->forw);
	back = be32_to_cpu(hdr->back);

	/* Top level blocks should not have sibling pointers. */
	if (level == 0) {
		if (forw != 0 || back != 0)
			xchk_da_set_corrupt(ds, level);
		return 0;
	}

	/*
	 * Check back (left) and forw (right) pointers.  These functions
	 * absorb error codes for us.
	 */
	error = xchk_da_btree_block_check_sibling(ds, level, 0, back);
	if (error)
		goto out;
	error = xchk_da_btree_block_check_sibling(ds, level, 1, forw);

out:
	memset(&ds->state->altpath, 0, sizeof(ds->state->altpath));
	return error;
}

/* Load a dir/attribute block from a btree. */
STATIC int
xchk_da_btree_block(
	struct xchk_da_btree		*ds,
	int				level,
	xfs_dablk_t			blkno)
{
	struct xfs_da_state_blk		*blk;
	struct xfs_da_intnode		*node;
	struct xfs_da_node_entry	*btree;
	struct xfs_da3_blkinfo		*hdr3;
	struct xfs_da_args		*dargs = &ds->dargs;
	struct xfs_inode		*ip = ds->dargs.dp;
	xfs_ino_t			owner;
	int				*pmaxrecs;
	struct xfs_da3_icnode_hdr	nodehdr;
	int				error = 0;

	blk = &ds->state->path.blk[level];
	ds->state->path.active = level + 1;

	/* Release old block. */
	if (blk->bp) {
		xfs_trans_brelse(dargs->trans, blk->bp);
		blk->bp = NULL;
	}

	/* Check the pointer. */
	blk->blkno = blkno;
	if (!xchk_da_btree_ptr_ok(ds, level, blkno))
		goto out_nobuf;

	/* Read the buffer. */
	error = xfs_da_read_buf(dargs->trans, dargs->dp, blk->blkno,
			XFS_DABUF_MAP_HOLE_OK, &blk->bp, dargs->whichfork,
			&xchk_da_btree_buf_ops);
	if (!xchk_da_process_error(ds, level, &error))
		goto out_nobuf;
	if (blk->bp)
		xchk_buffer_recheck(ds->sc, blk->bp);

	/*
	 * We didn't find a dir btree root block, which means that
	 * there's no LEAF1/LEAFN tree (at least not where it's supposed
	 * to be), so jump out now.
	 */
	if (ds->dargs.whichfork == XFS_DATA_FORK && level == 0 &&
			blk->bp == NULL)
		goto out_nobuf;

	/* It's /not/ ok for attr trees not to have a da btree. */
	if (blk->bp == NULL) {
		xchk_da_set_corrupt(ds, level);
		goto out_nobuf;
	}

	hdr3 = blk->bp->b_addr;
	blk->magic = be16_to_cpu(hdr3->hdr.magic);
	pmaxrecs = &ds->maxrecs[level];

	/* We only started zeroing the header on v5 filesystems. */
	if (xfs_sb_version_hascrc(&ds->sc->mp->m_sb) && hdr3->hdr.pad)
		xchk_da_set_corrupt(ds, level);

	/* Check the owner. */
	if (xfs_sb_version_hascrc(&ip->i_mount->m_sb)) {
		owner = be64_to_cpu(hdr3->owner);
		if (owner != ip->i_ino)
			xchk_da_set_corrupt(ds, level);
	}

	/* Check the siblings. */
	error = xchk_da_btree_block_check_siblings(ds, level, &hdr3->hdr);
	if (error)
		goto out;

	/* Interpret the buffer. */
	switch (blk->magic) {
	case XFS_ATTR_LEAF_MAGIC:
	case XFS_ATTR3_LEAF_MAGIC:
		xfs_trans_buf_set_type(dargs->trans, blk->bp,
				XFS_BLFT_ATTR_LEAF_BUF);
		blk->magic = XFS_ATTR_LEAF_MAGIC;
		blk->hashval = xfs_attr_leaf_lasthash(blk->bp, pmaxrecs);
		if (ds->tree_level != 0)
			xchk_da_set_corrupt(ds, level);
		break;
	case XFS_DIR2_LEAFN_MAGIC:
	case XFS_DIR3_LEAFN_MAGIC:
		xfs_trans_buf_set_type(dargs->trans, blk->bp,
				XFS_BLFT_DIR_LEAFN_BUF);
		blk->magic = XFS_DIR2_LEAFN_MAGIC;
		blk->hashval = xfs_dir2_leaf_lasthash(ip, blk->bp, pmaxrecs);
		if (ds->tree_level != 0)
			xchk_da_set_corrupt(ds, level);
		break;
	case XFS_DIR2_LEAF1_MAGIC:
	case XFS_DIR3_LEAF1_MAGIC:
		xfs_trans_buf_set_type(dargs->trans, blk->bp,
				XFS_BLFT_DIR_LEAF1_BUF);
		blk->magic = XFS_DIR2_LEAF1_MAGIC;
		blk->hashval = xfs_dir2_leaf_lasthash(ip, blk->bp, pmaxrecs);
		if (ds->tree_level != 0)
			xchk_da_set_corrupt(ds, level);
		break;
	case XFS_DA_NODE_MAGIC:
	case XFS_DA3_NODE_MAGIC:
		xfs_trans_buf_set_type(dargs->trans, blk->bp,
				XFS_BLFT_DA_NODE_BUF);
		blk->magic = XFS_DA_NODE_MAGIC;
		node = blk->bp->b_addr;
		xfs_da3_node_hdr_from_disk(ip->i_mount, &nodehdr, node);
		btree = nodehdr.btree;
		*pmaxrecs = nodehdr.count;
		blk->hashval = be32_to_cpu(btree[*pmaxrecs - 1].hashval);
		if (level == 0) {
			if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH) {
				xchk_da_set_corrupt(ds, level);
				goto out_freebp;
			}
			ds->tree_level = nodehdr.level;
		} else {
			if (ds->tree_level != nodehdr.level) {
				xchk_da_set_corrupt(ds, level);
				goto out_freebp;
			}
		}

		/* XXX: Check hdr3.pad32 once we know how to fix it. */
		break;
	default:
		xchk_da_set_corrupt(ds, level);
		goto out_freebp;
	}

out:
	return error;
out_freebp:
	xfs_trans_brelse(dargs->trans, blk->bp);
	blk->bp = NULL;
out_nobuf:
	blk->blkno = 0;
	return error;
}

/* Visit all nodes and leaves of a da btree. */
int
xchk_da_btree(
	struct xfs_scrub		*sc,
	int				whichfork,
	xchk_da_btree_rec_fn		scrub_fn,
	void				*private)
{
	struct xchk_da_btree		ds = {};
	struct xfs_mount		*mp = sc->mp;
	struct xfs_da_state_blk		*blks;
	struct xfs_da_node_entry	*key;
	xfs_dablk_t			blkno;
	int				level;
	int				error;

	/* Skip short format data structures; no btree to scan. */
	if (!xfs_ifork_has_extents(XFS_IFORK_PTR(sc->ip, whichfork)))
		return 0;

	/* Set up initial da state. */
	ds.dargs.dp = sc->ip;
	ds.dargs.whichfork = whichfork;
	ds.dargs.trans = sc->tp;
	ds.dargs.op_flags = XFS_DA_OP_OKNOENT;
	ds.state = xfs_da_state_alloc(&ds.dargs);
	ds.sc = sc;
	ds.private = private;
	if (whichfork == XFS_ATTR_FORK) {
		ds.dargs.geo = mp->m_attr_geo;
		ds.lowest = 0;
		ds.highest = 0;
	} else {
		ds.dargs.geo = mp->m_dir_geo;
		ds.lowest = ds.dargs.geo->leafblk;
		ds.highest = ds.dargs.geo->freeblk;
	}
	blkno = ds.lowest;
	level = 0;

	/* Find the root of the da tree, if present. */
	blks = ds.state->path.blk;
	error = xchk_da_btree_block(&ds, level, blkno);
	if (error)
		goto out_state;
	/*
	 * We didn't find a block at ds.lowest, which means that there's
	 * no LEAF1/LEAFN tree (at least not where it's supposed to be),
	 * so jump out now.
	 */
	if (blks[level].bp == NULL)
		goto out_state;

	blks[level].index = 0;
	while (level >= 0 && level < XFS_DA_NODE_MAXDEPTH) {
		/* Handle leaf block. */
		if (blks[level].magic != XFS_DA_NODE_MAGIC) {
			/* End of leaf, pop back towards the root. */
			if (blks[level].index >= ds.maxrecs[level]) {
				if (level > 0)
					blks[level - 1].index++;
				ds.tree_level++;
				level--;
				continue;
			}

			/* Dispatch record scrubbing. */
			error = scrub_fn(&ds, level);
			if (error)
				break;
			if (xchk_should_terminate(sc, &error) ||
			    (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
				break;

			blks[level].index++;
			continue;
		}


		/* End of node, pop back towards the root. */
		if (blks[level].index >= ds.maxrecs[level]) {
			if (level > 0)
				blks[level - 1].index++;
			ds.tree_level++;
			level--;
			continue;
		}

		/* Hashes in order for scrub? */
		key = xchk_da_btree_node_entry(&ds, level);
		error = xchk_da_btree_hash(&ds, level, &key->hashval);
		if (error)
			goto out;

		/* Drill another level deeper. */
		blkno = be32_to_cpu(key->before);
		level++;
		if (level >= XFS_DA_NODE_MAXDEPTH) {
			/* Too deep! */
			xchk_da_set_corrupt(&ds, level - 1);
			break;
		}
		ds.tree_level--;
		error = xchk_da_btree_block(&ds, level, blkno);
		if (error)
			goto out;
		if (blks[level].bp == NULL)
			goto out;

		blks[level].index = 0;
	}

out:
	/* Release all the buffers we're tracking. */
	for (level = 0; level < XFS_DA_NODE_MAXDEPTH; level++) {
		if (blks[level].bp == NULL)
			continue;
		xfs_trans_brelse(sc->tp, blks[level].bp);
		blks[level].bp = NULL;
	}

out_state:
	xfs_da_state_free(ds.state);
	return error;
}