1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
4  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
5  */
6 
7 #include <linux/module.h>
8 #include <linux/slab.h>
9 #include <linux/spinlock.h>
10 #include <linux/completion.h>
11 #include <linux/buffer_head.h>
12 #include <linux/gfs2_ondisk.h>
13 #include <linux/crc32.h>
14 #include <linux/crc32c.h>
15 #include <linux/ktime.h>
16 
17 #include "gfs2.h"
18 #include "incore.h"
19 #include "bmap.h"
20 #include "glock.h"
21 #include "glops.h"
22 #include "log.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 
gfs2_replay_read_block(struct gfs2_jdesc * jd,unsigned int blk,struct buffer_head ** bh)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 	u64 dblock;
38 	u32 extlen;
39 	int error;
40 
41 	extlen = 32;
42 	error = gfs2_get_extent(&ip->i_inode, blk, &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 
gfs2_revoke_add(struct gfs2_jdesc * jd,u64 blkno,unsigned int where)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 
gfs2_revoke_check(struct gfs2_jdesc * jd,u64 blkno,unsigned int where)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 
gfs2_revoke_clean(struct gfs2_jdesc * jd)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_first_entry(head, struct gfs2_revoke_replay, rr_list);
115 		list_del(&rr->rr_list);
116 		kfree(rr);
117 	}
118 }
119 
__get_log_header(struct gfs2_sbd * sdp,const struct gfs2_log_header * lh,unsigned int blkno,struct gfs2_log_header_host * head)120 int __get_log_header(struct gfs2_sbd *sdp, const struct gfs2_log_header *lh,
121 		     unsigned int blkno, struct gfs2_log_header_host *head)
122 {
123 	u32 hash, crc;
124 
125 	if (lh->lh_header.mh_magic != cpu_to_be32(GFS2_MAGIC) ||
126 	    lh->lh_header.mh_type != cpu_to_be32(GFS2_METATYPE_LH) ||
127 	    (blkno && be32_to_cpu(lh->lh_blkno) != blkno))
128 		return 1;
129 
130 	hash = crc32(~0, lh, LH_V1_SIZE - 4);
131 	hash = ~crc32_le_shift(hash, 4); /* assume lh_hash is zero */
132 
133 	if (be32_to_cpu(lh->lh_hash) != hash)
134 		return 1;
135 
136 	crc = crc32c(~0, (void *)lh + LH_V1_SIZE + 4,
137 		     sdp->sd_sb.sb_bsize - LH_V1_SIZE - 4);
138 
139 	if ((lh->lh_crc != 0 && be32_to_cpu(lh->lh_crc) != crc))
140 		return 1;
141 
142 	head->lh_sequence = be64_to_cpu(lh->lh_sequence);
143 	head->lh_flags = be32_to_cpu(lh->lh_flags);
144 	head->lh_tail = be32_to_cpu(lh->lh_tail);
145 	head->lh_blkno = be32_to_cpu(lh->lh_blkno);
146 
147 	head->lh_local_total = be64_to_cpu(lh->lh_local_total);
148 	head->lh_local_free = be64_to_cpu(lh->lh_local_free);
149 	head->lh_local_dinodes = be64_to_cpu(lh->lh_local_dinodes);
150 
151 	return 0;
152 }
153 /**
154  * get_log_header - read the log header for a given segment
155  * @jd: the journal
156  * @blk: the block to look at
157  * @head: the log header to return
158  *
159  * Read the log header for a given segement in a given journal.  Do a few
160  * sanity checks on it.
161  *
162  * Returns: 0 on success,
163  *          1 if the header was invalid or incomplete,
164  *          errno on error
165  */
166 
get_log_header(struct gfs2_jdesc * jd,unsigned int blk,struct gfs2_log_header_host * head)167 static int get_log_header(struct gfs2_jdesc *jd, unsigned int blk,
168 			  struct gfs2_log_header_host *head)
169 {
170 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
171 	struct buffer_head *bh;
172 	int error;
173 
174 	error = gfs2_replay_read_block(jd, blk, &bh);
175 	if (error)
176 		return error;
177 
178 	error = __get_log_header(sdp, (const struct gfs2_log_header *)bh->b_data,
179 				 blk, head);
180 	brelse(bh);
181 
182 	return error;
183 }
184 
185 /**
186  * foreach_descriptor - go through the active part of the log
187  * @jd: the journal
188  * @start: the first log header in the active region
189  * @end: the last log header (don't process the contents of this entry))
190  * @pass: iteration number (foreach_descriptor() is called in a for() loop)
191  *
192  * Call a given function once for every log descriptor in the active
193  * portion of the log.
194  *
195  * Returns: errno
196  */
197 
foreach_descriptor(struct gfs2_jdesc * jd,u32 start,unsigned int end,int pass)198 static int foreach_descriptor(struct gfs2_jdesc *jd, u32 start,
199 			      unsigned int end, int pass)
200 {
201 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
202 	struct buffer_head *bh;
203 	struct gfs2_log_descriptor *ld;
204 	int error = 0;
205 	u32 length;
206 	__be64 *ptr;
207 	unsigned int offset = sizeof(struct gfs2_log_descriptor);
208 	offset += sizeof(__be64) - 1;
209 	offset &= ~(sizeof(__be64) - 1);
210 
211 	while (start != end) {
212 		error = gfs2_replay_read_block(jd, start, &bh);
213 		if (error)
214 			return error;
215 		if (gfs2_meta_check(sdp, bh)) {
216 			brelse(bh);
217 			return -EIO;
218 		}
219 		ld = (struct gfs2_log_descriptor *)bh->b_data;
220 		length = be32_to_cpu(ld->ld_length);
221 
222 		if (be32_to_cpu(ld->ld_header.mh_type) == GFS2_METATYPE_LH) {
223 			struct gfs2_log_header_host lh;
224 			error = get_log_header(jd, start, &lh);
225 			if (!error) {
226 				gfs2_replay_incr_blk(jd, &start);
227 				brelse(bh);
228 				continue;
229 			}
230 			if (error == 1) {
231 				gfs2_consist_inode(GFS2_I(jd->jd_inode));
232 				error = -EIO;
233 			}
234 			brelse(bh);
235 			return error;
236 		} else if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LD)) {
237 			brelse(bh);
238 			return -EIO;
239 		}
240 		ptr = (__be64 *)(bh->b_data + offset);
241 		error = lops_scan_elements(jd, start, ld, ptr, pass);
242 		if (error) {
243 			brelse(bh);
244 			return error;
245 		}
246 
247 		while (length--)
248 			gfs2_replay_incr_blk(jd, &start);
249 
250 		brelse(bh);
251 	}
252 
253 	return 0;
254 }
255 
256 /**
257  * clean_journal - mark a dirty journal as being clean
258  * @jd: the journal
259  * @head: the head journal to start from
260  *
261  * Returns: errno
262  */
263 
clean_journal(struct gfs2_jdesc * jd,struct gfs2_log_header_host * head)264 static void clean_journal(struct gfs2_jdesc *jd,
265 			  struct gfs2_log_header_host *head)
266 {
267 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
268 	u32 lblock = head->lh_blkno;
269 
270 	gfs2_replay_incr_blk(jd, &lblock);
271 	gfs2_write_log_header(sdp, jd, head->lh_sequence + 1, 0, lblock,
272 			      GFS2_LOG_HEAD_UNMOUNT | GFS2_LOG_HEAD_RECOVERY,
273 			      REQ_PREFLUSH | REQ_FUA | REQ_META | REQ_SYNC);
274 	if (jd->jd_jid == sdp->sd_lockstruct.ls_jid) {
275 		sdp->sd_log_flush_head = lblock;
276 		gfs2_log_incr_head(sdp);
277 	}
278 }
279 
280 
gfs2_recovery_done(struct gfs2_sbd * sdp,unsigned int jid,unsigned int message)281 static void gfs2_recovery_done(struct gfs2_sbd *sdp, unsigned int jid,
282                                unsigned int message)
283 {
284 	char env_jid[20];
285 	char env_status[20];
286 	char *envp[] = { env_jid, env_status, NULL };
287 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
288 
289         ls->ls_recover_jid_done = jid;
290         ls->ls_recover_jid_status = message;
291 	sprintf(env_jid, "JID=%u", jid);
292 	sprintf(env_status, "RECOVERY=%s",
293 		message == LM_RD_SUCCESS ? "Done" : "Failed");
294         kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
295 
296 	if (sdp->sd_lockstruct.ls_ops->lm_recovery_result)
297 		sdp->sd_lockstruct.ls_ops->lm_recovery_result(sdp, jid, message);
298 }
299 
300 /**
301  * update_statfs_inode - Update the master statfs inode or zero out the local
302  *			 statfs inode for a given journal.
303  * @jd: The journal
304  * @head: If NULL, @inode is the local statfs inode and we need to zero it out.
305  *	  Otherwise, it @head contains the statfs change info that needs to be
306  *	  synced to the master statfs inode (pointed to by @inode).
307  * @inode: statfs inode to update.
308  */
update_statfs_inode(struct gfs2_jdesc * jd,struct gfs2_log_header_host * head,struct inode * inode)309 static int update_statfs_inode(struct gfs2_jdesc *jd,
310 			       struct gfs2_log_header_host *head,
311 			       struct inode *inode)
312 {
313 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
314 	struct gfs2_inode *ip;
315 	struct buffer_head *bh;
316 	struct gfs2_statfs_change_host sc;
317 	int error = 0;
318 
319 	BUG_ON(!inode);
320 	ip = GFS2_I(inode);
321 
322 	error = gfs2_meta_inode_buffer(ip, &bh);
323 	if (error)
324 		goto out;
325 
326 	spin_lock(&sdp->sd_statfs_spin);
327 
328 	if (head) { /* Update the master statfs inode */
329 		gfs2_statfs_change_in(&sc, bh->b_data + sizeof(struct gfs2_dinode));
330 		sc.sc_total += head->lh_local_total;
331 		sc.sc_free += head->lh_local_free;
332 		sc.sc_dinodes += head->lh_local_dinodes;
333 		gfs2_statfs_change_out(&sc, bh->b_data + sizeof(struct gfs2_dinode));
334 
335 		fs_info(sdp, "jid=%u: Updated master statfs Total:%lld, "
336 			"Free:%lld, Dinodes:%lld after change "
337 			"[%+lld,%+lld,%+lld]\n", jd->jd_jid, sc.sc_total,
338 			sc.sc_free, sc.sc_dinodes, head->lh_local_total,
339 			head->lh_local_free, head->lh_local_dinodes);
340 	} else { /* Zero out the local statfs inode */
341 		memset(bh->b_data + sizeof(struct gfs2_dinode), 0,
342 		       sizeof(struct gfs2_statfs_change));
343 		/* If it's our own journal, reset any in-memory changes too */
344 		if (jd->jd_jid == sdp->sd_lockstruct.ls_jid) {
345 			memset(&sdp->sd_statfs_local, 0,
346 			       sizeof(struct gfs2_statfs_change_host));
347 		}
348 	}
349 	spin_unlock(&sdp->sd_statfs_spin);
350 
351 	mark_buffer_dirty(bh);
352 	brelse(bh);
353 	gfs2_inode_metasync(ip->i_gl);
354 
355 out:
356 	return error;
357 }
358 
359 /**
360  * recover_local_statfs - Update the master and local statfs changes for this
361  *			  journal.
362  *
363  * Previously, statfs updates would be read in from the local statfs inode and
364  * synced to the master statfs inode during recovery.
365  *
366  * We now use the statfs updates in the journal head to update the master statfs
367  * inode instead of reading in from the local statfs inode. To preserve backward
368  * compatibility with kernels that can't do this, we still need to keep the
369  * local statfs inode up to date by writing changes to it. At some point in the
370  * future, we can do away with the local statfs inodes altogether and keep the
371  * statfs changes solely in the journal.
372  *
373  * @jd: the journal
374  * @head: the journal head
375  *
376  * Returns: errno
377  */
recover_local_statfs(struct gfs2_jdesc * jd,struct gfs2_log_header_host * head)378 static void recover_local_statfs(struct gfs2_jdesc *jd,
379 				 struct gfs2_log_header_host *head)
380 {
381 	int error;
382 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
383 
384 	if (!head->lh_local_total && !head->lh_local_free
385 	    && !head->lh_local_dinodes) /* No change */
386 		goto zero_local;
387 
388 	 /* First update the master statfs inode with the changes we
389 	  * found in the journal. */
390 	error = update_statfs_inode(jd, head, sdp->sd_statfs_inode);
391 	if (error)
392 		goto out;
393 
394 zero_local:
395 	/* Zero out the local statfs inode so any changes in there
396 	 * are not re-recovered. */
397 	error = update_statfs_inode(jd, NULL,
398 				    find_local_statfs_inode(sdp, jd->jd_jid));
399 out:
400 	return;
401 }
402 
gfs2_recover_func(struct work_struct * work)403 void gfs2_recover_func(struct work_struct *work)
404 {
405 	struct gfs2_jdesc *jd = container_of(work, struct gfs2_jdesc, jd_work);
406 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
407 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
408 	struct gfs2_log_header_host head;
409 	struct gfs2_holder j_gh, ji_gh, thaw_gh;
410 	ktime_t t_start, t_jlck, t_jhd, t_tlck, t_rep;
411 	int ro = 0;
412 	unsigned int pass;
413 	int error = 0;
414 	int jlocked = 0;
415 
416 	if (gfs2_withdrawn(sdp)) {
417 		fs_err(sdp, "jid=%u: Recovery not attempted due to withdraw.\n",
418 		       jd->jd_jid);
419 		goto fail;
420 	}
421 	t_start = ktime_get();
422 	if (sdp->sd_args.ar_spectator)
423 		goto fail;
424 	if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
425 		fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n",
426 			jd->jd_jid);
427 		jlocked = 1;
428 		/* Acquire the journal lock so we can do recovery */
429 
430 		error = gfs2_glock_nq_num(sdp, jd->jd_jid, &gfs2_journal_glops,
431 					  LM_ST_EXCLUSIVE,
432 					  LM_FLAG_NOEXP | LM_FLAG_TRY | GL_NOCACHE,
433 					  &j_gh);
434 		switch (error) {
435 		case 0:
436 			break;
437 
438 		case GLR_TRYFAILED:
439 			fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
440 			error = 0;
441 			goto fail;
442 
443 		default:
444 			goto fail;
445 		}
446 
447 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
448 					   LM_FLAG_NOEXP | GL_NOCACHE, &ji_gh);
449 		if (error)
450 			goto fail_gunlock_j;
451 	} else {
452 		fs_info(sdp, "jid=%u, already locked for use\n", jd->jd_jid);
453 	}
454 
455 	t_jlck = ktime_get();
456 	fs_info(sdp, "jid=%u: Looking at journal...\n", jd->jd_jid);
457 
458 	error = gfs2_jdesc_check(jd);
459 	if (error)
460 		goto fail_gunlock_ji;
461 
462 	error = gfs2_find_jhead(jd, &head, true);
463 	if (error)
464 		goto fail_gunlock_ji;
465 	t_jhd = ktime_get();
466 	fs_info(sdp, "jid=%u: Journal head lookup took %lldms\n", jd->jd_jid,
467 		ktime_ms_delta(t_jhd, t_jlck));
468 
469 	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
470 		fs_info(sdp, "jid=%u: Acquiring the transaction lock...\n",
471 			jd->jd_jid);
472 
473 		/* Acquire a shared hold on the freeze lock */
474 
475 		error = gfs2_freeze_lock(sdp, &thaw_gh, LM_FLAG_PRIORITY);
476 		if (error)
477 			goto fail_gunlock_ji;
478 
479 		if (test_bit(SDF_RORECOVERY, &sdp->sd_flags)) {
480 			ro = 1;
481 		} else if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
482 			if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
483 				ro = 1;
484 		} else {
485 			if (sb_rdonly(sdp->sd_vfs)) {
486 				/* check if device itself is read-only */
487 				ro = bdev_read_only(sdp->sd_vfs->s_bdev);
488 				if (!ro) {
489 					fs_info(sdp, "recovery required on "
490 						"read-only filesystem.\n");
491 					fs_info(sdp, "write access will be "
492 						"enabled during recovery.\n");
493 				}
494 			}
495 		}
496 
497 		if (ro) {
498 			fs_warn(sdp, "jid=%u: Can't replay: read-only block "
499 				"device\n", jd->jd_jid);
500 			error = -EROFS;
501 			goto fail_gunlock_thaw;
502 		}
503 
504 		t_tlck = ktime_get();
505 		fs_info(sdp, "jid=%u: Replaying journal...0x%x to 0x%x\n",
506 			jd->jd_jid, head.lh_tail, head.lh_blkno);
507 
508 		/* We take the sd_log_flush_lock here primarily to prevent log
509 		 * flushes and simultaneous journal replays from stomping on
510 		 * each other wrt jd_log_bio. */
511 		down_read(&sdp->sd_log_flush_lock);
512 		for (pass = 0; pass < 2; pass++) {
513 			lops_before_scan(jd, &head, pass);
514 			error = foreach_descriptor(jd, head.lh_tail,
515 						   head.lh_blkno, pass);
516 			lops_after_scan(jd, error, pass);
517 			if (error) {
518 				up_read(&sdp->sd_log_flush_lock);
519 				goto fail_gunlock_thaw;
520 			}
521 		}
522 
523 		recover_local_statfs(jd, &head);
524 		clean_journal(jd, &head);
525 		up_read(&sdp->sd_log_flush_lock);
526 
527 		gfs2_freeze_unlock(&thaw_gh);
528 		t_rep = ktime_get();
529 		fs_info(sdp, "jid=%u: Journal replayed in %lldms [jlck:%lldms, "
530 			"jhead:%lldms, tlck:%lldms, replay:%lldms]\n",
531 			jd->jd_jid, ktime_ms_delta(t_rep, t_start),
532 			ktime_ms_delta(t_jlck, t_start),
533 			ktime_ms_delta(t_jhd, t_jlck),
534 			ktime_ms_delta(t_tlck, t_jhd),
535 			ktime_ms_delta(t_rep, t_tlck));
536 	}
537 
538 	gfs2_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
539 
540 	if (jlocked) {
541 		gfs2_glock_dq_uninit(&ji_gh);
542 		gfs2_glock_dq_uninit(&j_gh);
543 	}
544 
545 	fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
546 	goto done;
547 
548 fail_gunlock_thaw:
549 	gfs2_freeze_unlock(&thaw_gh);
550 fail_gunlock_ji:
551 	if (jlocked) {
552 		gfs2_glock_dq_uninit(&ji_gh);
553 fail_gunlock_j:
554 		gfs2_glock_dq_uninit(&j_gh);
555 	}
556 
557 	fs_info(sdp, "jid=%u: %s\n", jd->jd_jid, (error) ? "Failed" : "Done");
558 fail:
559 	jd->jd_recover_error = error;
560 	gfs2_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
561 done:
562 	clear_bit(JDF_RECOVERY, &jd->jd_flags);
563 	smp_mb__after_atomic();
564 	wake_up_bit(&jd->jd_flags, JDF_RECOVERY);
565 }
566 
gfs2_recover_journal(struct gfs2_jdesc * jd,bool wait)567 int gfs2_recover_journal(struct gfs2_jdesc *jd, bool wait)
568 {
569 	int rv;
570 
571 	if (test_and_set_bit(JDF_RECOVERY, &jd->jd_flags))
572 		return -EBUSY;
573 
574 	/* we have JDF_RECOVERY, queue should always succeed */
575 	rv = queue_work(gfs_recovery_wq, &jd->jd_work);
576 	BUG_ON(!rv);
577 
578 	if (wait)
579 		wait_on_bit(&jd->jd_flags, JDF_RECOVERY,
580 			    TASK_UNINTERRUPTIBLE);
581 
582 	return wait ? jd->jd_recover_error : 0;
583 }
584 
585