xref: /openbmc/linux/fs/gfs2/recovery.c (revision afb46f79)
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License version 2.
8  */
9 
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/gfs2_ondisk.h>
16 #include <linux/crc32.h>
17 
18 #include "gfs2.h"
19 #include "incore.h"
20 #include "bmap.h"
21 #include "glock.h"
22 #include "glops.h"
23 #include "lops.h"
24 #include "meta_io.h"
25 #include "recovery.h"
26 #include "super.h"
27 #include "util.h"
28 #include "dir.h"
29 
30 struct workqueue_struct *gfs_recovery_wq;
31 
32 int gfs2_replay_read_block(struct gfs2_jdesc *jd, unsigned int blk,
33 			   struct buffer_head **bh)
34 {
35 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
36 	struct gfs2_glock *gl = ip->i_gl;
37 	int new = 0;
38 	u64 dblock;
39 	u32 extlen;
40 	int error;
41 
42 	error = gfs2_extent_map(&ip->i_inode, blk, &new, &dblock, &extlen);
43 	if (error)
44 		return error;
45 	if (!dblock) {
46 		gfs2_consist_inode(ip);
47 		return -EIO;
48 	}
49 
50 	*bh = gfs2_meta_ra(gl, dblock, extlen);
51 
52 	return error;
53 }
54 
55 int gfs2_revoke_add(struct gfs2_jdesc *jd, u64 blkno, unsigned int where)
56 {
57 	struct list_head *head = &jd->jd_revoke_list;
58 	struct gfs2_revoke_replay *rr;
59 	int found = 0;
60 
61 	list_for_each_entry(rr, head, rr_list) {
62 		if (rr->rr_blkno == blkno) {
63 			found = 1;
64 			break;
65 		}
66 	}
67 
68 	if (found) {
69 		rr->rr_where = where;
70 		return 0;
71 	}
72 
73 	rr = kmalloc(sizeof(struct gfs2_revoke_replay), GFP_NOFS);
74 	if (!rr)
75 		return -ENOMEM;
76 
77 	rr->rr_blkno = blkno;
78 	rr->rr_where = where;
79 	list_add(&rr->rr_list, head);
80 
81 	return 1;
82 }
83 
84 int gfs2_revoke_check(struct gfs2_jdesc *jd, u64 blkno, unsigned int where)
85 {
86 	struct gfs2_revoke_replay *rr;
87 	int wrap, a, b, revoke;
88 	int found = 0;
89 
90 	list_for_each_entry(rr, &jd->jd_revoke_list, rr_list) {
91 		if (rr->rr_blkno == blkno) {
92 			found = 1;
93 			break;
94 		}
95 	}
96 
97 	if (!found)
98 		return 0;
99 
100 	wrap = (rr->rr_where < jd->jd_replay_tail);
101 	a = (jd->jd_replay_tail < where);
102 	b = (where < rr->rr_where);
103 	revoke = (wrap) ? (a || b) : (a && b);
104 
105 	return revoke;
106 }
107 
108 void gfs2_revoke_clean(struct gfs2_jdesc *jd)
109 {
110 	struct list_head *head = &jd->jd_revoke_list;
111 	struct gfs2_revoke_replay *rr;
112 
113 	while (!list_empty(head)) {
114 		rr = list_entry(head->next, struct gfs2_revoke_replay, rr_list);
115 		list_del(&rr->rr_list);
116 		kfree(rr);
117 	}
118 }
119 
120 static int gfs2_log_header_in(struct gfs2_log_header_host *lh, const void *buf)
121 {
122 	const struct gfs2_log_header *str = buf;
123 
124 	if (str->lh_header.mh_magic != cpu_to_be32(GFS2_MAGIC) ||
125 	    str->lh_header.mh_type != cpu_to_be32(GFS2_METATYPE_LH))
126 		return 1;
127 
128 	lh->lh_sequence = be64_to_cpu(str->lh_sequence);
129 	lh->lh_flags = be32_to_cpu(str->lh_flags);
130 	lh->lh_tail = be32_to_cpu(str->lh_tail);
131 	lh->lh_blkno = be32_to_cpu(str->lh_blkno);
132 	lh->lh_hash = be32_to_cpu(str->lh_hash);
133 	return 0;
134 }
135 
136 /**
137  * get_log_header - read the log header for a given segment
138  * @jd: the journal
139  * @blk: the block to look at
140  * @lh: the log header to return
141  *
142  * Read the log header for a given segement in a given journal.  Do a few
143  * sanity checks on it.
144  *
145  * Returns: 0 on success,
146  *          1 if the header was invalid or incomplete,
147  *          errno on error
148  */
149 
150 static int get_log_header(struct gfs2_jdesc *jd, unsigned int blk,
151 			  struct gfs2_log_header_host *head)
152 {
153 	struct buffer_head *bh;
154 	struct gfs2_log_header_host uninitialized_var(lh);
155 	const u32 nothing = 0;
156 	u32 hash;
157 	int error;
158 
159 	error = gfs2_replay_read_block(jd, blk, &bh);
160 	if (error)
161 		return error;
162 
163 	hash = crc32_le((u32)~0, bh->b_data, sizeof(struct gfs2_log_header) -
164 					     sizeof(u32));
165 	hash = crc32_le(hash, (unsigned char const *)&nothing, sizeof(nothing));
166 	hash ^= (u32)~0;
167 	error = gfs2_log_header_in(&lh, bh->b_data);
168 	brelse(bh);
169 
170 	if (error || lh.lh_blkno != blk || lh.lh_hash != hash)
171 		return 1;
172 
173 	*head = lh;
174 
175 	return 0;
176 }
177 
178 /**
179  * find_good_lh - find a good log header
180  * @jd: the journal
181  * @blk: the segment to start searching from
182  * @lh: the log header to fill in
183  * @forward: if true search forward in the log, else search backward
184  *
185  * Call get_log_header() to get a log header for a segment, but if the
186  * segment is bad, either scan forward or backward until we find a good one.
187  *
188  * Returns: errno
189  */
190 
191 static int find_good_lh(struct gfs2_jdesc *jd, unsigned int *blk,
192 			struct gfs2_log_header_host *head)
193 {
194 	unsigned int orig_blk = *blk;
195 	int error;
196 
197 	for (;;) {
198 		error = get_log_header(jd, *blk, head);
199 		if (error <= 0)
200 			return error;
201 
202 		if (++*blk == jd->jd_blocks)
203 			*blk = 0;
204 
205 		if (*blk == orig_blk) {
206 			gfs2_consist_inode(GFS2_I(jd->jd_inode));
207 			return -EIO;
208 		}
209 	}
210 }
211 
212 /**
213  * jhead_scan - make sure we've found the head of the log
214  * @jd: the journal
215  * @head: this is filled in with the log descriptor of the head
216  *
217  * At this point, seg and lh should be either the head of the log or just
218  * before.  Scan forward until we find the head.
219  *
220  * Returns: errno
221  */
222 
223 static int jhead_scan(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
224 {
225 	unsigned int blk = head->lh_blkno;
226 	struct gfs2_log_header_host lh;
227 	int error;
228 
229 	for (;;) {
230 		if (++blk == jd->jd_blocks)
231 			blk = 0;
232 
233 		error = get_log_header(jd, blk, &lh);
234 		if (error < 0)
235 			return error;
236 		if (error == 1)
237 			continue;
238 
239 		if (lh.lh_sequence == head->lh_sequence) {
240 			gfs2_consist_inode(GFS2_I(jd->jd_inode));
241 			return -EIO;
242 		}
243 		if (lh.lh_sequence < head->lh_sequence)
244 			break;
245 
246 		*head = lh;
247 	}
248 
249 	return 0;
250 }
251 
252 /**
253  * gfs2_find_jhead - find the head of a log
254  * @jd: the journal
255  * @head: the log descriptor for the head of the log is returned here
256  *
257  * Do a binary search of a journal and find the valid log entry with the
258  * highest sequence number.  (i.e. the log head)
259  *
260  * Returns: errno
261  */
262 
263 int gfs2_find_jhead(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
264 {
265 	struct gfs2_log_header_host lh_1, lh_m;
266 	u32 blk_1, blk_2, blk_m;
267 	int error;
268 
269 	blk_1 = 0;
270 	blk_2 = jd->jd_blocks - 1;
271 
272 	for (;;) {
273 		blk_m = (blk_1 + blk_2) / 2;
274 
275 		error = find_good_lh(jd, &blk_1, &lh_1);
276 		if (error)
277 			return error;
278 
279 		error = find_good_lh(jd, &blk_m, &lh_m);
280 		if (error)
281 			return error;
282 
283 		if (blk_1 == blk_m || blk_m == blk_2)
284 			break;
285 
286 		if (lh_1.lh_sequence <= lh_m.lh_sequence)
287 			blk_1 = blk_m;
288 		else
289 			blk_2 = blk_m;
290 	}
291 
292 	error = jhead_scan(jd, &lh_1);
293 	if (error)
294 		return error;
295 
296 	*head = lh_1;
297 
298 	return error;
299 }
300 
301 /**
302  * foreach_descriptor - go through the active part of the log
303  * @jd: the journal
304  * @start: the first log header in the active region
305  * @end: the last log header (don't process the contents of this entry))
306  *
307  * Call a given function once for every log descriptor in the active
308  * portion of the log.
309  *
310  * Returns: errno
311  */
312 
313 static int foreach_descriptor(struct gfs2_jdesc *jd, unsigned int start,
314 			      unsigned int end, int pass)
315 {
316 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
317 	struct buffer_head *bh;
318 	struct gfs2_log_descriptor *ld;
319 	int error = 0;
320 	u32 length;
321 	__be64 *ptr;
322 	unsigned int offset = sizeof(struct gfs2_log_descriptor);
323 	offset += sizeof(__be64) - 1;
324 	offset &= ~(sizeof(__be64) - 1);
325 
326 	while (start != end) {
327 		error = gfs2_replay_read_block(jd, start, &bh);
328 		if (error)
329 			return error;
330 		if (gfs2_meta_check(sdp, bh)) {
331 			brelse(bh);
332 			return -EIO;
333 		}
334 		ld = (struct gfs2_log_descriptor *)bh->b_data;
335 		length = be32_to_cpu(ld->ld_length);
336 
337 		if (be32_to_cpu(ld->ld_header.mh_type) == GFS2_METATYPE_LH) {
338 			struct gfs2_log_header_host lh;
339 			error = get_log_header(jd, start, &lh);
340 			if (!error) {
341 				gfs2_replay_incr_blk(sdp, &start);
342 				brelse(bh);
343 				continue;
344 			}
345 			if (error == 1) {
346 				gfs2_consist_inode(GFS2_I(jd->jd_inode));
347 				error = -EIO;
348 			}
349 			brelse(bh);
350 			return error;
351 		} else if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LD)) {
352 			brelse(bh);
353 			return -EIO;
354 		}
355 		ptr = (__be64 *)(bh->b_data + offset);
356 		error = lops_scan_elements(jd, start, ld, ptr, pass);
357 		if (error) {
358 			brelse(bh);
359 			return error;
360 		}
361 
362 		while (length--)
363 			gfs2_replay_incr_blk(sdp, &start);
364 
365 		brelse(bh);
366 	}
367 
368 	return 0;
369 }
370 
371 /**
372  * clean_journal - mark a dirty journal as being clean
373  * @sdp: the filesystem
374  * @jd: the journal
375  * @gl: the journal's glock
376  * @head: the head journal to start from
377  *
378  * Returns: errno
379  */
380 
381 static int clean_journal(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
382 {
383 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
384 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
385 	unsigned int lblock;
386 	struct gfs2_log_header *lh;
387 	u32 hash;
388 	struct buffer_head *bh;
389 	int error;
390 	struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
391 
392 	lblock = head->lh_blkno;
393 	gfs2_replay_incr_blk(sdp, &lblock);
394 	bh_map.b_size = 1 << ip->i_inode.i_blkbits;
395 	error = gfs2_block_map(&ip->i_inode, lblock, &bh_map, 0);
396 	if (error)
397 		return error;
398 	if (!bh_map.b_blocknr) {
399 		gfs2_consist_inode(ip);
400 		return -EIO;
401 	}
402 
403 	bh = sb_getblk(sdp->sd_vfs, bh_map.b_blocknr);
404 	lock_buffer(bh);
405 	memset(bh->b_data, 0, bh->b_size);
406 	set_buffer_uptodate(bh);
407 	clear_buffer_dirty(bh);
408 	unlock_buffer(bh);
409 
410 	lh = (struct gfs2_log_header *)bh->b_data;
411 	memset(lh, 0, sizeof(struct gfs2_log_header));
412 	lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
413 	lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
414 	lh->lh_header.__pad0 = cpu_to_be64(0);
415 	lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
416 	lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
417 	lh->lh_sequence = cpu_to_be64(head->lh_sequence + 1);
418 	lh->lh_flags = cpu_to_be32(GFS2_LOG_HEAD_UNMOUNT);
419 	lh->lh_blkno = cpu_to_be32(lblock);
420 	hash = gfs2_disk_hash((const char *)lh, sizeof(struct gfs2_log_header));
421 	lh->lh_hash = cpu_to_be32(hash);
422 
423 	set_buffer_dirty(bh);
424 	if (sync_dirty_buffer(bh))
425 		gfs2_io_error_bh(sdp, bh);
426 	brelse(bh);
427 
428 	return error;
429 }
430 
431 
432 static void gfs2_recovery_done(struct gfs2_sbd *sdp, unsigned int jid,
433                                unsigned int message)
434 {
435 	char env_jid[20];
436 	char env_status[20];
437 	char *envp[] = { env_jid, env_status, NULL };
438 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
439 
440         ls->ls_recover_jid_done = jid;
441         ls->ls_recover_jid_status = message;
442 	sprintf(env_jid, "JID=%d", jid);
443 	sprintf(env_status, "RECOVERY=%s",
444 		message == LM_RD_SUCCESS ? "Done" : "Failed");
445         kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
446 
447 	if (sdp->sd_lockstruct.ls_ops->lm_recovery_result)
448 		sdp->sd_lockstruct.ls_ops->lm_recovery_result(sdp, jid, message);
449 }
450 
451 void gfs2_recover_func(struct work_struct *work)
452 {
453 	struct gfs2_jdesc *jd = container_of(work, struct gfs2_jdesc, jd_work);
454 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
455 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
456 	struct gfs2_log_header_host head;
457 	struct gfs2_holder j_gh, ji_gh, t_gh;
458 	unsigned long t;
459 	int ro = 0;
460 	unsigned int pass;
461 	int error;
462 	int jlocked = 0;
463 
464 	if (sdp->sd_args.ar_spectator ||
465 	    (jd->jd_jid != sdp->sd_lockstruct.ls_jid)) {
466 		fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n",
467 			jd->jd_jid);
468 		jlocked = 1;
469 		/* Acquire the journal lock so we can do recovery */
470 
471 		error = gfs2_glock_nq_num(sdp, jd->jd_jid, &gfs2_journal_glops,
472 					  LM_ST_EXCLUSIVE,
473 					  LM_FLAG_NOEXP | LM_FLAG_TRY | GL_NOCACHE,
474 					  &j_gh);
475 		switch (error) {
476 		case 0:
477 			break;
478 
479 		case GLR_TRYFAILED:
480 			fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
481 			error = 0;
482 
483 		default:
484 			goto fail;
485 		};
486 
487 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
488 					   LM_FLAG_NOEXP | GL_NOCACHE, &ji_gh);
489 		if (error)
490 			goto fail_gunlock_j;
491 	} else {
492 		fs_info(sdp, "jid=%u, already locked for use\n", jd->jd_jid);
493 	}
494 
495 	fs_info(sdp, "jid=%u: Looking at journal...\n", jd->jd_jid);
496 
497 	error = gfs2_jdesc_check(jd);
498 	if (error)
499 		goto fail_gunlock_ji;
500 
501 	error = gfs2_find_jhead(jd, &head);
502 	if (error)
503 		goto fail_gunlock_ji;
504 
505 	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
506 		fs_info(sdp, "jid=%u: Acquiring the transaction lock...\n",
507 			jd->jd_jid);
508 
509 		t = jiffies;
510 
511 		/* Acquire a shared hold on the transaction lock */
512 
513 		error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED,
514 					   LM_FLAG_NOEXP | LM_FLAG_PRIORITY |
515 					   GL_NOCACHE, &t_gh);
516 		if (error)
517 			goto fail_gunlock_ji;
518 
519 		if (test_bit(SDF_RORECOVERY, &sdp->sd_flags)) {
520 			ro = 1;
521 		} else if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
522 			if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
523 				ro = 1;
524 		} else {
525 			if (sdp->sd_vfs->s_flags & MS_RDONLY) {
526 				/* check if device itself is read-only */
527 				ro = bdev_read_only(sdp->sd_vfs->s_bdev);
528 				if (!ro) {
529 					fs_info(sdp, "recovery required on "
530 						"read-only filesystem.\n");
531 					fs_info(sdp, "write access will be "
532 						"enabled during recovery.\n");
533 				}
534 			}
535 		}
536 
537 		if (ro) {
538 			fs_warn(sdp, "jid=%u: Can't replay: read-only block "
539 				"device\n", jd->jd_jid);
540 			error = -EROFS;
541 			goto fail_gunlock_tr;
542 		}
543 
544 		fs_info(sdp, "jid=%u: Replaying journal...\n", jd->jd_jid);
545 
546 		for (pass = 0; pass < 2; pass++) {
547 			lops_before_scan(jd, &head, pass);
548 			error = foreach_descriptor(jd, head.lh_tail,
549 						   head.lh_blkno, pass);
550 			lops_after_scan(jd, error, pass);
551 			if (error)
552 				goto fail_gunlock_tr;
553 		}
554 
555 		error = clean_journal(jd, &head);
556 		if (error)
557 			goto fail_gunlock_tr;
558 
559 		gfs2_glock_dq_uninit(&t_gh);
560 		t = DIV_ROUND_UP(jiffies - t, HZ);
561 		fs_info(sdp, "jid=%u: Journal replayed in %lus\n",
562 			jd->jd_jid, t);
563 	}
564 
565 	gfs2_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
566 
567 	if (jlocked) {
568 		gfs2_glock_dq_uninit(&ji_gh);
569 		gfs2_glock_dq_uninit(&j_gh);
570 	}
571 
572 	fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
573 	goto done;
574 
575 fail_gunlock_tr:
576 	gfs2_glock_dq_uninit(&t_gh);
577 fail_gunlock_ji:
578 	if (jlocked) {
579 		gfs2_glock_dq_uninit(&ji_gh);
580 fail_gunlock_j:
581 		gfs2_glock_dq_uninit(&j_gh);
582 	}
583 
584 	fs_info(sdp, "jid=%u: %s\n", jd->jd_jid, (error) ? "Failed" : "Done");
585 fail:
586 	jd->jd_recover_error = error;
587 	gfs2_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
588 done:
589 	clear_bit(JDF_RECOVERY, &jd->jd_flags);
590 	smp_mb__after_clear_bit();
591 	wake_up_bit(&jd->jd_flags, JDF_RECOVERY);
592 }
593 
594 static int gfs2_recovery_wait(void *word)
595 {
596 	schedule();
597 	return 0;
598 }
599 
600 int gfs2_recover_journal(struct gfs2_jdesc *jd, bool wait)
601 {
602 	int rv;
603 
604 	if (test_and_set_bit(JDF_RECOVERY, &jd->jd_flags))
605 		return -EBUSY;
606 
607 	/* we have JDF_RECOVERY, queue should always succeed */
608 	rv = queue_work(gfs_recovery_wq, &jd->jd_work);
609 	BUG_ON(!rv);
610 
611 	if (wait)
612 		wait_on_bit(&jd->jd_flags, JDF_RECOVERY, gfs2_recovery_wait,
613 			    TASK_UNINTERRUPTIBLE);
614 
615 	return wait ? jd->jd_recover_error : 0;
616 }
617 
618