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 */
39struct 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
46static struct xfs_buf_cancel *
47xlog_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
67static bool
68xlog_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 = kmalloc(sizeof(struct xfs_buf_cancel), GFP_KERNEL | __GFP_NOFAIL);
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 */
99bool
100xlog_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 */
116static bool
117xlog_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		kfree(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 */
153STATIC enum xlog_recover_reorder
154xlog_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
166STATIC void
167xlog_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 */
180static int
181xlog_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 */
210static void
211xlog_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 */
444STATIC void
445xlog_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 */
538STATIC bool
539xlog_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 */
585STATIC int
586xlog_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 */
707static xfs_lsn_t
708xlog_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
855recover_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 */
883STATIC int
884xlog_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
1000out_release:
1001	xfs_buf_relse(bp);
1002	return error;
1003cancelled:
1004	trace_xfs_log_recover_buf_cancel(log, buf_f);
1005	return 0;
1006}
1007
1008const 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
1017void
1018xlog_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
1028int
1029xlog_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
1049void
1050xlog_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			kfree(bc);
1066		}
1067	}
1068
1069	kfree(log->l_buf_cancel_table);
1070	log->l_buf_cancel_table = NULL;
1071}
1072