xref: /openbmc/linux/fs/xfs/xfs_buf_item_recover.c (revision 22ed903e)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
4  * All Rights Reserved.
5  */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_log_format.h"
11 #include "xfs_trans_resv.h"
12 #include "xfs_bit.h"
13 #include "xfs_mount.h"
14 #include "xfs_trans.h"
15 #include "xfs_buf_item.h"
16 #include "xfs_trans_priv.h"
17 #include "xfs_trace.h"
18 #include "xfs_log.h"
19 #include "xfs_log_priv.h"
20 #include "xfs_log_recover.h"
21 #include "xfs_error.h"
22 #include "xfs_inode.h"
23 #include "xfs_dir2.h"
24 #include "xfs_quota.h"
25 
26 /*
27  * This is the number of entries in the l_buf_cancel_table used during
28  * recovery.
29  */
30 #define	XLOG_BC_TABLE_SIZE	64
31 
32 #define XLOG_BUF_CANCEL_BUCKET(log, blkno) \
33 	((log)->l_buf_cancel_table + ((uint64_t)blkno % XLOG_BC_TABLE_SIZE))
34 
35 /*
36  * This structure is used during recovery to record the buf log items which
37  * have been canceled and should not be replayed.
38  */
39 struct xfs_buf_cancel {
40 	xfs_daddr_t		bc_blkno;
41 	uint			bc_len;
42 	int			bc_refcount;
43 	struct list_head	bc_list;
44 };
45 
46 static struct xfs_buf_cancel *
xlog_find_buffer_cancelled(struct xlog * log,xfs_daddr_t blkno,uint len)47 xlog_find_buffer_cancelled(
48 	struct xlog		*log,
49 	xfs_daddr_t		blkno,
50 	uint			len)
51 {
52 	struct list_head	*bucket;
53 	struct xfs_buf_cancel	*bcp;
54 
55 	if (!log->l_buf_cancel_table)
56 		return NULL;
57 
58 	bucket = XLOG_BUF_CANCEL_BUCKET(log, blkno);
59 	list_for_each_entry(bcp, bucket, bc_list) {
60 		if (bcp->bc_blkno == blkno && bcp->bc_len == len)
61 			return bcp;
62 	}
63 
64 	return NULL;
65 }
66 
67 static bool
xlog_add_buffer_cancelled(struct xlog * log,xfs_daddr_t blkno,uint len)68 xlog_add_buffer_cancelled(
69 	struct xlog		*log,
70 	xfs_daddr_t		blkno,
71 	uint			len)
72 {
73 	struct xfs_buf_cancel	*bcp;
74 
75 	/*
76 	 * If we find an existing cancel record, this indicates that the buffer
77 	 * was cancelled multiple times.  To ensure that during pass 2 we keep
78 	 * the record in the table until we reach its last occurrence in the
79 	 * log, a reference count is kept to tell how many times we expect to
80 	 * see this record during the second pass.
81 	 */
82 	bcp = xlog_find_buffer_cancelled(log, blkno, len);
83 	if (bcp) {
84 		bcp->bc_refcount++;
85 		return false;
86 	}
87 
88 	bcp = kmem_alloc(sizeof(struct xfs_buf_cancel), 0);
89 	bcp->bc_blkno = blkno;
90 	bcp->bc_len = len;
91 	bcp->bc_refcount = 1;
92 	list_add_tail(&bcp->bc_list, XLOG_BUF_CANCEL_BUCKET(log, blkno));
93 	return true;
94 }
95 
96 /*
97  * Check if there is and entry for blkno, len in the buffer cancel record table.
98  */
99 bool
xlog_is_buffer_cancelled(struct xlog * log,xfs_daddr_t blkno,uint len)100 xlog_is_buffer_cancelled(
101 	struct xlog		*log,
102 	xfs_daddr_t		blkno,
103 	uint			len)
104 {
105 	return xlog_find_buffer_cancelled(log, blkno, len) != NULL;
106 }
107 
108 /*
109  * Check if there is and entry for blkno, len in the buffer cancel record table,
110  * and decremented the reference count on it if there is one.
111  *
112  * Remove the cancel record once the refcount hits zero, so that if the same
113  * buffer is re-used again after its last cancellation we actually replay the
114  * changes made at that point.
115  */
116 static bool
xlog_put_buffer_cancelled(struct xlog * log,xfs_daddr_t blkno,uint len)117 xlog_put_buffer_cancelled(
118 	struct xlog		*log,
119 	xfs_daddr_t		blkno,
120 	uint			len)
121 {
122 	struct xfs_buf_cancel	*bcp;
123 
124 	bcp = xlog_find_buffer_cancelled(log, blkno, len);
125 	if (!bcp) {
126 		ASSERT(0);
127 		return false;
128 	}
129 
130 	if (--bcp->bc_refcount == 0) {
131 		list_del(&bcp->bc_list);
132 		kmem_free(bcp);
133 	}
134 	return true;
135 }
136 
137 /* log buffer item recovery */
138 
139 /*
140  * Sort buffer items for log recovery.  Most buffer items should end up on the
141  * buffer list and are recovered first, with the following exceptions:
142  *
143  * 1. XFS_BLF_CANCEL buffers must be processed last because some log items
144  *    might depend on the incor ecancellation record, and replaying a cancelled
145  *    buffer item can remove the incore record.
146  *
147  * 2. XFS_BLF_INODE_BUF buffers are handled after most regular items so that
148  *    we replay di_next_unlinked only after flushing the inode 'free' state
149  *    to the inode buffer.
150  *
151  * See xlog_recover_reorder_trans for more details.
152  */
153 STATIC enum xlog_recover_reorder
xlog_recover_buf_reorder(struct xlog_recover_item * item)154 xlog_recover_buf_reorder(
155 	struct xlog_recover_item	*item)
156 {
157 	struct xfs_buf_log_format	*buf_f = item->ri_buf[0].i_addr;
158 
159 	if (buf_f->blf_flags & XFS_BLF_CANCEL)
160 		return XLOG_REORDER_CANCEL_LIST;
161 	if (buf_f->blf_flags & XFS_BLF_INODE_BUF)
162 		return XLOG_REORDER_INODE_BUFFER_LIST;
163 	return XLOG_REORDER_BUFFER_LIST;
164 }
165 
166 STATIC void
xlog_recover_buf_ra_pass2(struct xlog * log,struct xlog_recover_item * item)167 xlog_recover_buf_ra_pass2(
168 	struct xlog                     *log,
169 	struct xlog_recover_item        *item)
170 {
171 	struct xfs_buf_log_format	*buf_f = item->ri_buf[0].i_addr;
172 
173 	xlog_buf_readahead(log, buf_f->blf_blkno, buf_f->blf_len, NULL);
174 }
175 
176 /*
177  * Build up the table of buf cancel records so that we don't replay cancelled
178  * data in the second pass.
179  */
180 static int
xlog_recover_buf_commit_pass1(struct xlog * log,struct xlog_recover_item * item)181 xlog_recover_buf_commit_pass1(
182 	struct xlog			*log,
183 	struct xlog_recover_item	*item)
184 {
185 	struct xfs_buf_log_format	*bf = item->ri_buf[0].i_addr;
186 
187 	if (!xfs_buf_log_check_iovec(&item->ri_buf[0])) {
188 		xfs_err(log->l_mp, "bad buffer log item size (%d)",
189 				item->ri_buf[0].i_len);
190 		return -EFSCORRUPTED;
191 	}
192 
193 	if (!(bf->blf_flags & XFS_BLF_CANCEL))
194 		trace_xfs_log_recover_buf_not_cancel(log, bf);
195 	else if (xlog_add_buffer_cancelled(log, bf->blf_blkno, bf->blf_len))
196 		trace_xfs_log_recover_buf_cancel_add(log, bf);
197 	else
198 		trace_xfs_log_recover_buf_cancel_ref_inc(log, bf);
199 	return 0;
200 }
201 
202 /*
203  * Validate the recovered buffer is of the correct type and attach the
204  * appropriate buffer operations to them for writeback. Magic numbers are in a
205  * few places:
206  *	the first 16 bits of the buffer (inode buffer, dquot buffer),
207  *	the first 32 bits of the buffer (most blocks),
208  *	inside a struct xfs_da_blkinfo at the start of the buffer.
209  */
210 static void
xlog_recover_validate_buf_type(struct xfs_mount * mp,struct xfs_buf * bp,struct xfs_buf_log_format * buf_f,xfs_lsn_t current_lsn)211 xlog_recover_validate_buf_type(
212 	struct xfs_mount		*mp,
213 	struct xfs_buf			*bp,
214 	struct xfs_buf_log_format	*buf_f,
215 	xfs_lsn_t			current_lsn)
216 {
217 	struct xfs_da_blkinfo		*info = bp->b_addr;
218 	uint32_t			magic32;
219 	uint16_t			magic16;
220 	uint16_t			magicda;
221 	char				*warnmsg = NULL;
222 
223 	/*
224 	 * We can only do post recovery validation on items on CRC enabled
225 	 * fielsystems as we need to know when the buffer was written to be able
226 	 * to determine if we should have replayed the item. If we replay old
227 	 * metadata over a newer buffer, then it will enter a temporarily
228 	 * inconsistent state resulting in verification failures. Hence for now
229 	 * just avoid the verification stage for non-crc filesystems
230 	 */
231 	if (!xfs_has_crc(mp))
232 		return;
233 
234 	magic32 = be32_to_cpu(*(__be32 *)bp->b_addr);
235 	magic16 = be16_to_cpu(*(__be16*)bp->b_addr);
236 	magicda = be16_to_cpu(info->magic);
237 	switch (xfs_blft_from_flags(buf_f)) {
238 	case XFS_BLFT_BTREE_BUF:
239 		switch (magic32) {
240 		case XFS_ABTB_CRC_MAGIC:
241 		case XFS_ABTB_MAGIC:
242 			bp->b_ops = &xfs_bnobt_buf_ops;
243 			break;
244 		case XFS_ABTC_CRC_MAGIC:
245 		case XFS_ABTC_MAGIC:
246 			bp->b_ops = &xfs_cntbt_buf_ops;
247 			break;
248 		case XFS_IBT_CRC_MAGIC:
249 		case XFS_IBT_MAGIC:
250 			bp->b_ops = &xfs_inobt_buf_ops;
251 			break;
252 		case XFS_FIBT_CRC_MAGIC:
253 		case XFS_FIBT_MAGIC:
254 			bp->b_ops = &xfs_finobt_buf_ops;
255 			break;
256 		case XFS_BMAP_CRC_MAGIC:
257 		case XFS_BMAP_MAGIC:
258 			bp->b_ops = &xfs_bmbt_buf_ops;
259 			break;
260 		case XFS_RMAP_CRC_MAGIC:
261 			bp->b_ops = &xfs_rmapbt_buf_ops;
262 			break;
263 		case XFS_REFC_CRC_MAGIC:
264 			bp->b_ops = &xfs_refcountbt_buf_ops;
265 			break;
266 		default:
267 			warnmsg = "Bad btree block magic!";
268 			break;
269 		}
270 		break;
271 	case XFS_BLFT_AGF_BUF:
272 		if (magic32 != XFS_AGF_MAGIC) {
273 			warnmsg = "Bad AGF block magic!";
274 			break;
275 		}
276 		bp->b_ops = &xfs_agf_buf_ops;
277 		break;
278 	case XFS_BLFT_AGFL_BUF:
279 		if (magic32 != XFS_AGFL_MAGIC) {
280 			warnmsg = "Bad AGFL block magic!";
281 			break;
282 		}
283 		bp->b_ops = &xfs_agfl_buf_ops;
284 		break;
285 	case XFS_BLFT_AGI_BUF:
286 		if (magic32 != XFS_AGI_MAGIC) {
287 			warnmsg = "Bad AGI block magic!";
288 			break;
289 		}
290 		bp->b_ops = &xfs_agi_buf_ops;
291 		break;
292 	case XFS_BLFT_UDQUOT_BUF:
293 	case XFS_BLFT_PDQUOT_BUF:
294 	case XFS_BLFT_GDQUOT_BUF:
295 #ifdef CONFIG_XFS_QUOTA
296 		if (magic16 != XFS_DQUOT_MAGIC) {
297 			warnmsg = "Bad DQUOT block magic!";
298 			break;
299 		}
300 		bp->b_ops = &xfs_dquot_buf_ops;
301 #else
302 		xfs_alert(mp,
303 	"Trying to recover dquots without QUOTA support built in!");
304 		ASSERT(0);
305 #endif
306 		break;
307 	case XFS_BLFT_DINO_BUF:
308 		if (magic16 != XFS_DINODE_MAGIC) {
309 			warnmsg = "Bad INODE block magic!";
310 			break;
311 		}
312 		bp->b_ops = &xfs_inode_buf_ops;
313 		break;
314 	case XFS_BLFT_SYMLINK_BUF:
315 		if (magic32 != XFS_SYMLINK_MAGIC) {
316 			warnmsg = "Bad symlink block magic!";
317 			break;
318 		}
319 		bp->b_ops = &xfs_symlink_buf_ops;
320 		break;
321 	case XFS_BLFT_DIR_BLOCK_BUF:
322 		if (magic32 != XFS_DIR2_BLOCK_MAGIC &&
323 		    magic32 != XFS_DIR3_BLOCK_MAGIC) {
324 			warnmsg = "Bad dir block magic!";
325 			break;
326 		}
327 		bp->b_ops = &xfs_dir3_block_buf_ops;
328 		break;
329 	case XFS_BLFT_DIR_DATA_BUF:
330 		if (magic32 != XFS_DIR2_DATA_MAGIC &&
331 		    magic32 != XFS_DIR3_DATA_MAGIC) {
332 			warnmsg = "Bad dir data magic!";
333 			break;
334 		}
335 		bp->b_ops = &xfs_dir3_data_buf_ops;
336 		break;
337 	case XFS_BLFT_DIR_FREE_BUF:
338 		if (magic32 != XFS_DIR2_FREE_MAGIC &&
339 		    magic32 != XFS_DIR3_FREE_MAGIC) {
340 			warnmsg = "Bad dir3 free magic!";
341 			break;
342 		}
343 		bp->b_ops = &xfs_dir3_free_buf_ops;
344 		break;
345 	case XFS_BLFT_DIR_LEAF1_BUF:
346 		if (magicda != XFS_DIR2_LEAF1_MAGIC &&
347 		    magicda != XFS_DIR3_LEAF1_MAGIC) {
348 			warnmsg = "Bad dir leaf1 magic!";
349 			break;
350 		}
351 		bp->b_ops = &xfs_dir3_leaf1_buf_ops;
352 		break;
353 	case XFS_BLFT_DIR_LEAFN_BUF:
354 		if (magicda != XFS_DIR2_LEAFN_MAGIC &&
355 		    magicda != XFS_DIR3_LEAFN_MAGIC) {
356 			warnmsg = "Bad dir leafn magic!";
357 			break;
358 		}
359 		bp->b_ops = &xfs_dir3_leafn_buf_ops;
360 		break;
361 	case XFS_BLFT_DA_NODE_BUF:
362 		if (magicda != XFS_DA_NODE_MAGIC &&
363 		    magicda != XFS_DA3_NODE_MAGIC) {
364 			warnmsg = "Bad da node magic!";
365 			break;
366 		}
367 		bp->b_ops = &xfs_da3_node_buf_ops;
368 		break;
369 	case XFS_BLFT_ATTR_LEAF_BUF:
370 		if (magicda != XFS_ATTR_LEAF_MAGIC &&
371 		    magicda != XFS_ATTR3_LEAF_MAGIC) {
372 			warnmsg = "Bad attr leaf magic!";
373 			break;
374 		}
375 		bp->b_ops = &xfs_attr3_leaf_buf_ops;
376 		break;
377 	case XFS_BLFT_ATTR_RMT_BUF:
378 		if (magic32 != XFS_ATTR3_RMT_MAGIC) {
379 			warnmsg = "Bad attr remote magic!";
380 			break;
381 		}
382 		bp->b_ops = &xfs_attr3_rmt_buf_ops;
383 		break;
384 	case XFS_BLFT_SB_BUF:
385 		if (magic32 != XFS_SB_MAGIC) {
386 			warnmsg = "Bad SB block magic!";
387 			break;
388 		}
389 		bp->b_ops = &xfs_sb_buf_ops;
390 		break;
391 #ifdef CONFIG_XFS_RT
392 	case XFS_BLFT_RTBITMAP_BUF:
393 	case XFS_BLFT_RTSUMMARY_BUF:
394 		/* no magic numbers for verification of RT buffers */
395 		bp->b_ops = &xfs_rtbuf_ops;
396 		break;
397 #endif /* CONFIG_XFS_RT */
398 	default:
399 		xfs_warn(mp, "Unknown buffer type %d!",
400 			 xfs_blft_from_flags(buf_f));
401 		break;
402 	}
403 
404 	/*
405 	 * Nothing else to do in the case of a NULL current LSN as this means
406 	 * the buffer is more recent than the change in the log and will be
407 	 * skipped.
408 	 */
409 	if (current_lsn == NULLCOMMITLSN)
410 		return;
411 
412 	if (warnmsg) {
413 		xfs_warn(mp, warnmsg);
414 		ASSERT(0);
415 	}
416 
417 	/*
418 	 * We must update the metadata LSN of the buffer as it is written out to
419 	 * ensure that older transactions never replay over this one and corrupt
420 	 * the buffer. This can occur if log recovery is interrupted at some
421 	 * point after the current transaction completes, at which point a
422 	 * subsequent mount starts recovery from the beginning.
423 	 *
424 	 * Write verifiers update the metadata LSN from log items attached to
425 	 * the buffer. Therefore, initialize a bli purely to carry the LSN to
426 	 * the verifier.
427 	 */
428 	if (bp->b_ops) {
429 		struct xfs_buf_log_item	*bip;
430 
431 		bp->b_flags |= _XBF_LOGRECOVERY;
432 		xfs_buf_item_init(bp, mp);
433 		bip = bp->b_log_item;
434 		bip->bli_item.li_lsn = current_lsn;
435 	}
436 }
437 
438 /*
439  * Perform a 'normal' buffer recovery.  Each logged region of the
440  * buffer should be copied over the corresponding region in the
441  * given buffer.  The bitmap in the buf log format structure indicates
442  * where to place the logged data.
443  */
444 STATIC void
xlog_recover_do_reg_buffer(struct xfs_mount * mp,struct xlog_recover_item * item,struct xfs_buf * bp,struct xfs_buf_log_format * buf_f,xfs_lsn_t current_lsn)445 xlog_recover_do_reg_buffer(
446 	struct xfs_mount		*mp,
447 	struct xlog_recover_item	*item,
448 	struct xfs_buf			*bp,
449 	struct xfs_buf_log_format	*buf_f,
450 	xfs_lsn_t			current_lsn)
451 {
452 	int			i;
453 	int			bit;
454 	int			nbits;
455 	xfs_failaddr_t		fa;
456 	const size_t		size_disk_dquot = sizeof(struct xfs_disk_dquot);
457 
458 	trace_xfs_log_recover_buf_reg_buf(mp->m_log, buf_f);
459 
460 	bit = 0;
461 	i = 1;  /* 0 is the buf format structure */
462 	while (1) {
463 		bit = xfs_next_bit(buf_f->blf_data_map,
464 				   buf_f->blf_map_size, bit);
465 		if (bit == -1)
466 			break;
467 		nbits = xfs_contig_bits(buf_f->blf_data_map,
468 					buf_f->blf_map_size, bit);
469 		ASSERT(nbits > 0);
470 		ASSERT(item->ri_buf[i].i_addr != NULL);
471 		ASSERT(item->ri_buf[i].i_len % XFS_BLF_CHUNK == 0);
472 		ASSERT(BBTOB(bp->b_length) >=
473 		       ((uint)bit << XFS_BLF_SHIFT) + (nbits << XFS_BLF_SHIFT));
474 
475 		/*
476 		 * The dirty regions logged in the buffer, even though
477 		 * contiguous, may span multiple chunks. This is because the
478 		 * dirty region may span a physical page boundary in a buffer
479 		 * and hence be split into two separate vectors for writing into
480 		 * the log. Hence we need to trim nbits back to the length of
481 		 * the current region being copied out of the log.
482 		 */
483 		if (item->ri_buf[i].i_len < (nbits << XFS_BLF_SHIFT))
484 			nbits = item->ri_buf[i].i_len >> XFS_BLF_SHIFT;
485 
486 		/*
487 		 * Do a sanity check if this is a dquot buffer. Just checking
488 		 * the first dquot in the buffer should do. XXXThis is
489 		 * probably a good thing to do for other buf types also.
490 		 */
491 		fa = NULL;
492 		if (buf_f->blf_flags &
493 		   (XFS_BLF_UDQUOT_BUF|XFS_BLF_PDQUOT_BUF|XFS_BLF_GDQUOT_BUF)) {
494 			if (item->ri_buf[i].i_addr == NULL) {
495 				xfs_alert(mp,
496 					"XFS: NULL dquot in %s.", __func__);
497 				goto next;
498 			}
499 			if (item->ri_buf[i].i_len < size_disk_dquot) {
500 				xfs_alert(mp,
501 					"XFS: dquot too small (%d) in %s.",
502 					item->ri_buf[i].i_len, __func__);
503 				goto next;
504 			}
505 			fa = xfs_dquot_verify(mp, item->ri_buf[i].i_addr, -1);
506 			if (fa) {
507 				xfs_alert(mp,
508 	"dquot corrupt at %pS trying to replay into block 0x%llx",
509 					fa, xfs_buf_daddr(bp));
510 				goto next;
511 			}
512 		}
513 
514 		memcpy(xfs_buf_offset(bp,
515 			(uint)bit << XFS_BLF_SHIFT),	/* dest */
516 			item->ri_buf[i].i_addr,		/* source */
517 			nbits<<XFS_BLF_SHIFT);		/* length */
518  next:
519 		i++;
520 		bit += nbits;
521 	}
522 
523 	/* Shouldn't be any more regions */
524 	ASSERT(i == item->ri_total);
525 
526 	xlog_recover_validate_buf_type(mp, bp, buf_f, current_lsn);
527 }
528 
529 /*
530  * Perform a dquot buffer recovery.
531  * Simple algorithm: if we have found a QUOTAOFF log item of the same type
532  * (ie. USR or GRP), then just toss this buffer away; don't recover it.
533  * Else, treat it as a regular buffer and do recovery.
534  *
535  * Return false if the buffer was tossed and true if we recovered the buffer to
536  * indicate to the caller if the buffer needs writing.
537  */
538 STATIC bool
xlog_recover_do_dquot_buffer(struct xfs_mount * mp,struct xlog * log,struct xlog_recover_item * item,struct xfs_buf * bp,struct xfs_buf_log_format * buf_f)539 xlog_recover_do_dquot_buffer(
540 	struct xfs_mount		*mp,
541 	struct xlog			*log,
542 	struct xlog_recover_item	*item,
543 	struct xfs_buf			*bp,
544 	struct xfs_buf_log_format	*buf_f)
545 {
546 	uint			type;
547 
548 	trace_xfs_log_recover_buf_dquot_buf(log, buf_f);
549 
550 	/*
551 	 * Filesystems are required to send in quota flags at mount time.
552 	 */
553 	if (!mp->m_qflags)
554 		return false;
555 
556 	type = 0;
557 	if (buf_f->blf_flags & XFS_BLF_UDQUOT_BUF)
558 		type |= XFS_DQTYPE_USER;
559 	if (buf_f->blf_flags & XFS_BLF_PDQUOT_BUF)
560 		type |= XFS_DQTYPE_PROJ;
561 	if (buf_f->blf_flags & XFS_BLF_GDQUOT_BUF)
562 		type |= XFS_DQTYPE_GROUP;
563 	/*
564 	 * This type of quotas was turned off, so ignore this buffer
565 	 */
566 	if (log->l_quotaoffs_flag & type)
567 		return false;
568 
569 	xlog_recover_do_reg_buffer(mp, item, bp, buf_f, NULLCOMMITLSN);
570 	return true;
571 }
572 
573 /*
574  * Perform recovery for a buffer full of inodes.  In these buffers, the only
575  * data which should be recovered is that which corresponds to the
576  * di_next_unlinked pointers in the on disk inode structures.  The rest of the
577  * data for the inodes is always logged through the inodes themselves rather
578  * than the inode buffer and is recovered in xlog_recover_inode_pass2().
579  *
580  * The only time when buffers full of inodes are fully recovered is when the
581  * buffer is full of newly allocated inodes.  In this case the buffer will
582  * not be marked as an inode buffer and so will be sent to
583  * xlog_recover_do_reg_buffer() below during recovery.
584  */
585 STATIC int
xlog_recover_do_inode_buffer(struct xfs_mount * mp,struct xlog_recover_item * item,struct xfs_buf * bp,struct xfs_buf_log_format * buf_f)586 xlog_recover_do_inode_buffer(
587 	struct xfs_mount		*mp,
588 	struct xlog_recover_item	*item,
589 	struct xfs_buf			*bp,
590 	struct xfs_buf_log_format	*buf_f)
591 {
592 	int				i;
593 	int				item_index = 0;
594 	int				bit = 0;
595 	int				nbits = 0;
596 	int				reg_buf_offset = 0;
597 	int				reg_buf_bytes = 0;
598 	int				next_unlinked_offset;
599 	int				inodes_per_buf;
600 	xfs_agino_t			*logged_nextp;
601 	xfs_agino_t			*buffer_nextp;
602 
603 	trace_xfs_log_recover_buf_inode_buf(mp->m_log, buf_f);
604 
605 	/*
606 	 * Post recovery validation only works properly on CRC enabled
607 	 * filesystems.
608 	 */
609 	if (xfs_has_crc(mp))
610 		bp->b_ops = &xfs_inode_buf_ops;
611 
612 	inodes_per_buf = BBTOB(bp->b_length) >> mp->m_sb.sb_inodelog;
613 	for (i = 0; i < inodes_per_buf; i++) {
614 		next_unlinked_offset = (i * mp->m_sb.sb_inodesize) +
615 			offsetof(struct xfs_dinode, di_next_unlinked);
616 
617 		while (next_unlinked_offset >=
618 		       (reg_buf_offset + reg_buf_bytes)) {
619 			/*
620 			 * The next di_next_unlinked field is beyond
621 			 * the current logged region.  Find the next
622 			 * logged region that contains or is beyond
623 			 * the current di_next_unlinked field.
624 			 */
625 			bit += nbits;
626 			bit = xfs_next_bit(buf_f->blf_data_map,
627 					   buf_f->blf_map_size, bit);
628 
629 			/*
630 			 * If there are no more logged regions in the
631 			 * buffer, then we're done.
632 			 */
633 			if (bit == -1)
634 				return 0;
635 
636 			nbits = xfs_contig_bits(buf_f->blf_data_map,
637 						buf_f->blf_map_size, bit);
638 			ASSERT(nbits > 0);
639 			reg_buf_offset = bit << XFS_BLF_SHIFT;
640 			reg_buf_bytes = nbits << XFS_BLF_SHIFT;
641 			item_index++;
642 		}
643 
644 		/*
645 		 * If the current logged region starts after the current
646 		 * di_next_unlinked field, then move on to the next
647 		 * di_next_unlinked field.
648 		 */
649 		if (next_unlinked_offset < reg_buf_offset)
650 			continue;
651 
652 		ASSERT(item->ri_buf[item_index].i_addr != NULL);
653 		ASSERT((item->ri_buf[item_index].i_len % XFS_BLF_CHUNK) == 0);
654 		ASSERT((reg_buf_offset + reg_buf_bytes) <= BBTOB(bp->b_length));
655 
656 		/*
657 		 * The current logged region contains a copy of the
658 		 * current di_next_unlinked field.  Extract its value
659 		 * and copy it to the buffer copy.
660 		 */
661 		logged_nextp = item->ri_buf[item_index].i_addr +
662 				next_unlinked_offset - reg_buf_offset;
663 		if (XFS_IS_CORRUPT(mp, *logged_nextp == 0)) {
664 			xfs_alert(mp,
665 		"Bad inode buffer log record (ptr = "PTR_FMT", bp = "PTR_FMT"). "
666 		"Trying to replay bad (0) inode di_next_unlinked field.",
667 				item, bp);
668 			return -EFSCORRUPTED;
669 		}
670 
671 		buffer_nextp = xfs_buf_offset(bp, next_unlinked_offset);
672 		*buffer_nextp = *logged_nextp;
673 
674 		/*
675 		 * If necessary, recalculate the CRC in the on-disk inode. We
676 		 * have to leave the inode in a consistent state for whoever
677 		 * reads it next....
678 		 */
679 		xfs_dinode_calc_crc(mp,
680 				xfs_buf_offset(bp, i * mp->m_sb.sb_inodesize));
681 
682 	}
683 
684 	return 0;
685 }
686 
687 /*
688  * V5 filesystems know the age of the buffer on disk being recovered. We can
689  * have newer objects on disk than we are replaying, and so for these cases we
690  * don't want to replay the current change as that will make the buffer contents
691  * temporarily invalid on disk.
692  *
693  * The magic number might not match the buffer type we are going to recover
694  * (e.g. reallocated blocks), so we ignore the xfs_buf_log_format flags.  Hence
695  * extract the LSN of the existing object in the buffer based on it's current
696  * magic number.  If we don't recognise the magic number in the buffer, then
697  * return a LSN of -1 so that the caller knows it was an unrecognised block and
698  * so can recover the buffer.
699  *
700  * Note: we cannot rely solely on magic number matches to determine that the
701  * buffer has a valid LSN - we also need to verify that it belongs to this
702  * filesystem, so we need to extract the object's LSN and compare it to that
703  * which we read from the superblock. If the UUIDs don't match, then we've got a
704  * stale metadata block from an old filesystem instance that we need to recover
705  * over the top of.
706  */
707 static xfs_lsn_t
xlog_recover_get_buf_lsn(struct xfs_mount * mp,struct xfs_buf * bp,struct xfs_buf_log_format * buf_f)708 xlog_recover_get_buf_lsn(
709 	struct xfs_mount	*mp,
710 	struct xfs_buf		*bp,
711 	struct xfs_buf_log_format *buf_f)
712 {
713 	uint32_t		magic32;
714 	uint16_t		magic16;
715 	uint16_t		magicda;
716 	void			*blk = bp->b_addr;
717 	uuid_t			*uuid;
718 	xfs_lsn_t		lsn = -1;
719 	uint16_t		blft;
720 
721 	/* v4 filesystems always recover immediately */
722 	if (!xfs_has_crc(mp))
723 		goto recover_immediately;
724 
725 	/*
726 	 * realtime bitmap and summary file blocks do not have magic numbers or
727 	 * UUIDs, so we must recover them immediately.
728 	 */
729 	blft = xfs_blft_from_flags(buf_f);
730 	if (blft == XFS_BLFT_RTBITMAP_BUF || blft == XFS_BLFT_RTSUMMARY_BUF)
731 		goto recover_immediately;
732 
733 	magic32 = be32_to_cpu(*(__be32 *)blk);
734 	switch (magic32) {
735 	case XFS_ABTB_CRC_MAGIC:
736 	case XFS_ABTC_CRC_MAGIC:
737 	case XFS_ABTB_MAGIC:
738 	case XFS_ABTC_MAGIC:
739 	case XFS_RMAP_CRC_MAGIC:
740 	case XFS_REFC_CRC_MAGIC:
741 	case XFS_FIBT_CRC_MAGIC:
742 	case XFS_FIBT_MAGIC:
743 	case XFS_IBT_CRC_MAGIC:
744 	case XFS_IBT_MAGIC: {
745 		struct xfs_btree_block *btb = blk;
746 
747 		lsn = be64_to_cpu(btb->bb_u.s.bb_lsn);
748 		uuid = &btb->bb_u.s.bb_uuid;
749 		break;
750 	}
751 	case XFS_BMAP_CRC_MAGIC:
752 	case XFS_BMAP_MAGIC: {
753 		struct xfs_btree_block *btb = blk;
754 
755 		lsn = be64_to_cpu(btb->bb_u.l.bb_lsn);
756 		uuid = &btb->bb_u.l.bb_uuid;
757 		break;
758 	}
759 	case XFS_AGF_MAGIC:
760 		lsn = be64_to_cpu(((struct xfs_agf *)blk)->agf_lsn);
761 		uuid = &((struct xfs_agf *)blk)->agf_uuid;
762 		break;
763 	case XFS_AGFL_MAGIC:
764 		lsn = be64_to_cpu(((struct xfs_agfl *)blk)->agfl_lsn);
765 		uuid = &((struct xfs_agfl *)blk)->agfl_uuid;
766 		break;
767 	case XFS_AGI_MAGIC:
768 		lsn = be64_to_cpu(((struct xfs_agi *)blk)->agi_lsn);
769 		uuid = &((struct xfs_agi *)blk)->agi_uuid;
770 		break;
771 	case XFS_SYMLINK_MAGIC:
772 		lsn = be64_to_cpu(((struct xfs_dsymlink_hdr *)blk)->sl_lsn);
773 		uuid = &((struct xfs_dsymlink_hdr *)blk)->sl_uuid;
774 		break;
775 	case XFS_DIR3_BLOCK_MAGIC:
776 	case XFS_DIR3_DATA_MAGIC:
777 	case XFS_DIR3_FREE_MAGIC:
778 		lsn = be64_to_cpu(((struct xfs_dir3_blk_hdr *)blk)->lsn);
779 		uuid = &((struct xfs_dir3_blk_hdr *)blk)->uuid;
780 		break;
781 	case XFS_ATTR3_RMT_MAGIC:
782 		/*
783 		 * Remote attr blocks are written synchronously, rather than
784 		 * being logged. That means they do not contain a valid LSN
785 		 * (i.e. transactionally ordered) in them, and hence any time we
786 		 * see a buffer to replay over the top of a remote attribute
787 		 * block we should simply do so.
788 		 */
789 		goto recover_immediately;
790 	case XFS_SB_MAGIC:
791 		/*
792 		 * superblock uuids are magic. We may or may not have a
793 		 * sb_meta_uuid on disk, but it will be set in the in-core
794 		 * superblock. We set the uuid pointer for verification
795 		 * according to the superblock feature mask to ensure we check
796 		 * the relevant UUID in the superblock.
797 		 */
798 		lsn = be64_to_cpu(((struct xfs_dsb *)blk)->sb_lsn);
799 		if (xfs_has_metauuid(mp))
800 			uuid = &((struct xfs_dsb *)blk)->sb_meta_uuid;
801 		else
802 			uuid = &((struct xfs_dsb *)blk)->sb_uuid;
803 		break;
804 	default:
805 		break;
806 	}
807 
808 	if (lsn != (xfs_lsn_t)-1) {
809 		if (!uuid_equal(&mp->m_sb.sb_meta_uuid, uuid))
810 			goto recover_immediately;
811 		return lsn;
812 	}
813 
814 	magicda = be16_to_cpu(((struct xfs_da_blkinfo *)blk)->magic);
815 	switch (magicda) {
816 	case XFS_DIR3_LEAF1_MAGIC:
817 	case XFS_DIR3_LEAFN_MAGIC:
818 	case XFS_ATTR3_LEAF_MAGIC:
819 	case XFS_DA3_NODE_MAGIC:
820 		lsn = be64_to_cpu(((struct xfs_da3_blkinfo *)blk)->lsn);
821 		uuid = &((struct xfs_da3_blkinfo *)blk)->uuid;
822 		break;
823 	default:
824 		break;
825 	}
826 
827 	if (lsn != (xfs_lsn_t)-1) {
828 		if (!uuid_equal(&mp->m_sb.sb_meta_uuid, uuid))
829 			goto recover_immediately;
830 		return lsn;
831 	}
832 
833 	/*
834 	 * We do individual object checks on dquot and inode buffers as they
835 	 * have their own individual LSN records. Also, we could have a stale
836 	 * buffer here, so we have to at least recognise these buffer types.
837 	 *
838 	 * A notd complexity here is inode unlinked list processing - it logs
839 	 * the inode directly in the buffer, but we don't know which inodes have
840 	 * been modified, and there is no global buffer LSN. Hence we need to
841 	 * recover all inode buffer types immediately. This problem will be
842 	 * fixed by logical logging of the unlinked list modifications.
843 	 */
844 	magic16 = be16_to_cpu(*(__be16 *)blk);
845 	switch (magic16) {
846 	case XFS_DQUOT_MAGIC:
847 	case XFS_DINODE_MAGIC:
848 		goto recover_immediately;
849 	default:
850 		break;
851 	}
852 
853 	/* unknown buffer contents, recover immediately */
854 
855 recover_immediately:
856 	return (xfs_lsn_t)-1;
857 
858 }
859 
860 /*
861  * This routine replays a modification made to a buffer at runtime.
862  * There are actually two types of buffer, regular and inode, which
863  * are handled differently.  Inode buffers are handled differently
864  * in that we only recover a specific set of data from them, namely
865  * the inode di_next_unlinked fields.  This is because all other inode
866  * data is actually logged via inode records and any data we replay
867  * here which overlaps that may be stale.
868  *
869  * When meta-data buffers are freed at run time we log a buffer item
870  * with the XFS_BLF_CANCEL bit set to indicate that previous copies
871  * of the buffer in the log should not be replayed at recovery time.
872  * This is so that if the blocks covered by the buffer are reused for
873  * file data before we crash we don't end up replaying old, freed
874  * meta-data into a user's file.
875  *
876  * To handle the cancellation of buffer log items, we make two passes
877  * over the log during recovery.  During the first we build a table of
878  * those buffers which have been cancelled, and during the second we
879  * only replay those buffers which do not have corresponding cancel
880  * records in the table.  See xlog_recover_buf_pass[1,2] above
881  * for more details on the implementation of the table of cancel records.
882  */
883 STATIC int
xlog_recover_buf_commit_pass2(struct xlog * log,struct list_head * buffer_list,struct xlog_recover_item * item,xfs_lsn_t current_lsn)884 xlog_recover_buf_commit_pass2(
885 	struct xlog			*log,
886 	struct list_head		*buffer_list,
887 	struct xlog_recover_item	*item,
888 	xfs_lsn_t			current_lsn)
889 {
890 	struct xfs_buf_log_format	*buf_f = item->ri_buf[0].i_addr;
891 	struct xfs_mount		*mp = log->l_mp;
892 	struct xfs_buf			*bp;
893 	int				error;
894 	uint				buf_flags;
895 	xfs_lsn_t			lsn;
896 
897 	/*
898 	 * In this pass we only want to recover all the buffers which have
899 	 * not been cancelled and are not cancellation buffers themselves.
900 	 */
901 	if (buf_f->blf_flags & XFS_BLF_CANCEL) {
902 		if (xlog_put_buffer_cancelled(log, buf_f->blf_blkno,
903 				buf_f->blf_len))
904 			goto cancelled;
905 	} else {
906 
907 		if (xlog_is_buffer_cancelled(log, buf_f->blf_blkno,
908 				buf_f->blf_len))
909 			goto cancelled;
910 	}
911 
912 	trace_xfs_log_recover_buf_recover(log, buf_f);
913 
914 	buf_flags = 0;
915 	if (buf_f->blf_flags & XFS_BLF_INODE_BUF)
916 		buf_flags |= XBF_UNMAPPED;
917 
918 	error = xfs_buf_read(mp->m_ddev_targp, buf_f->blf_blkno, buf_f->blf_len,
919 			  buf_flags, &bp, NULL);
920 	if (error)
921 		return error;
922 
923 	/*
924 	 * Recover the buffer only if we get an LSN from it and it's less than
925 	 * the lsn of the transaction we are replaying.
926 	 *
927 	 * Note that we have to be extremely careful of readahead here.
928 	 * Readahead does not attach verfiers to the buffers so if we don't
929 	 * actually do any replay after readahead because of the LSN we found
930 	 * in the buffer if more recent than that current transaction then we
931 	 * need to attach the verifier directly. Failure to do so can lead to
932 	 * future recovery actions (e.g. EFI and unlinked list recovery) can
933 	 * operate on the buffers and they won't get the verifier attached. This
934 	 * can lead to blocks on disk having the correct content but a stale
935 	 * CRC.
936 	 *
937 	 * It is safe to assume these clean buffers are currently up to date.
938 	 * If the buffer is dirtied by a later transaction being replayed, then
939 	 * the verifier will be reset to match whatever recover turns that
940 	 * buffer into.
941 	 */
942 	lsn = xlog_recover_get_buf_lsn(mp, bp, buf_f);
943 	if (lsn && lsn != -1 && XFS_LSN_CMP(lsn, current_lsn) >= 0) {
944 		trace_xfs_log_recover_buf_skip(log, buf_f);
945 		xlog_recover_validate_buf_type(mp, bp, buf_f, NULLCOMMITLSN);
946 
947 		/*
948 		 * We're skipping replay of this buffer log item due to the log
949 		 * item LSN being behind the ondisk buffer.  Verify the buffer
950 		 * contents since we aren't going to run the write verifier.
951 		 */
952 		if (bp->b_ops) {
953 			bp->b_ops->verify_read(bp);
954 			error = bp->b_error;
955 		}
956 		goto out_release;
957 	}
958 
959 	if (buf_f->blf_flags & XFS_BLF_INODE_BUF) {
960 		error = xlog_recover_do_inode_buffer(mp, item, bp, buf_f);
961 		if (error)
962 			goto out_release;
963 	} else if (buf_f->blf_flags &
964 		  (XFS_BLF_UDQUOT_BUF|XFS_BLF_PDQUOT_BUF|XFS_BLF_GDQUOT_BUF)) {
965 		bool	dirty;
966 
967 		dirty = xlog_recover_do_dquot_buffer(mp, log, item, bp, buf_f);
968 		if (!dirty)
969 			goto out_release;
970 	} else {
971 		xlog_recover_do_reg_buffer(mp, item, bp, buf_f, current_lsn);
972 	}
973 
974 	/*
975 	 * Perform delayed write on the buffer.  Asynchronous writes will be
976 	 * slower when taking into account all the buffers to be flushed.
977 	 *
978 	 * Also make sure that only inode buffers with good sizes stay in
979 	 * the buffer cache.  The kernel moves inodes in buffers of 1 block
980 	 * or inode_cluster_size bytes, whichever is bigger.  The inode
981 	 * buffers in the log can be a different size if the log was generated
982 	 * by an older kernel using unclustered inode buffers or a newer kernel
983 	 * running with a different inode cluster size.  Regardless, if
984 	 * the inode buffer size isn't max(blocksize, inode_cluster_size)
985 	 * for *our* value of inode_cluster_size, then we need to keep
986 	 * the buffer out of the buffer cache so that the buffer won't
987 	 * overlap with future reads of those inodes.
988 	 */
989 	if (XFS_DINODE_MAGIC ==
990 	    be16_to_cpu(*((__be16 *)xfs_buf_offset(bp, 0))) &&
991 	    (BBTOB(bp->b_length) != M_IGEO(log->l_mp)->inode_cluster_size)) {
992 		xfs_buf_stale(bp);
993 		error = xfs_bwrite(bp);
994 	} else {
995 		ASSERT(bp->b_mount == mp);
996 		bp->b_flags |= _XBF_LOGRECOVERY;
997 		xfs_buf_delwri_queue(bp, buffer_list);
998 	}
999 
1000 out_release:
1001 	xfs_buf_relse(bp);
1002 	return error;
1003 cancelled:
1004 	trace_xfs_log_recover_buf_cancel(log, buf_f);
1005 	return 0;
1006 }
1007 
1008 const struct xlog_recover_item_ops xlog_buf_item_ops = {
1009 	.item_type		= XFS_LI_BUF,
1010 	.reorder		= xlog_recover_buf_reorder,
1011 	.ra_pass2		= xlog_recover_buf_ra_pass2,
1012 	.commit_pass1		= xlog_recover_buf_commit_pass1,
1013 	.commit_pass2		= xlog_recover_buf_commit_pass2,
1014 };
1015 
1016 #ifdef DEBUG
1017 void
xlog_check_buf_cancel_table(struct xlog * log)1018 xlog_check_buf_cancel_table(
1019 	struct xlog	*log)
1020 {
1021 	int		i;
1022 
1023 	for (i = 0; i < XLOG_BC_TABLE_SIZE; i++)
1024 		ASSERT(list_empty(&log->l_buf_cancel_table[i]));
1025 }
1026 #endif
1027 
1028 int
xlog_alloc_buf_cancel_table(struct xlog * log)1029 xlog_alloc_buf_cancel_table(
1030 	struct xlog	*log)
1031 {
1032 	void		*p;
1033 	int		i;
1034 
1035 	ASSERT(log->l_buf_cancel_table == NULL);
1036 
1037 	p = kmalloc_array(XLOG_BC_TABLE_SIZE, sizeof(struct list_head),
1038 			  GFP_KERNEL);
1039 	if (!p)
1040 		return -ENOMEM;
1041 
1042 	log->l_buf_cancel_table = p;
1043 	for (i = 0; i < XLOG_BC_TABLE_SIZE; i++)
1044 		INIT_LIST_HEAD(&log->l_buf_cancel_table[i]);
1045 
1046 	return 0;
1047 }
1048 
1049 void
xlog_free_buf_cancel_table(struct xlog * log)1050 xlog_free_buf_cancel_table(
1051 	struct xlog	*log)
1052 {
1053 	int		i;
1054 
1055 	if (!log->l_buf_cancel_table)
1056 		return;
1057 
1058 	for (i = 0; i < XLOG_BC_TABLE_SIZE; i++) {
1059 		struct xfs_buf_cancel	*bc;
1060 
1061 		while ((bc = list_first_entry_or_null(
1062 				&log->l_buf_cancel_table[i],
1063 				struct xfs_buf_cancel, bc_list))) {
1064 			list_del(&bc->bc_list);
1065 			kmem_free(bc);
1066 		}
1067 	}
1068 
1069 	kmem_free(log->l_buf_cancel_table);
1070 	log->l_buf_cancel_table = NULL;
1071 }
1072