[GFS2] Allow bmap to allocate extents
[linux-2.6.git] / fs / gfs2 / recovery.c
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/slab.h>
11 #include <linux/spinlock.h>
12 #include <linux/completion.h>
13 #include <linux/buffer_head.h>
14 #include <linux/gfs2_ondisk.h>
15 #include <linux/crc32.h>
16 #include <linux/lm_interface.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 int gfs2_replay_read_block(struct gfs2_jdesc *jd, unsigned int blk,
31                            struct buffer_head **bh)
32 {
33         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
34         struct gfs2_glock *gl = ip->i_gl;
35         int new = 0;
36         u64 dblock;
37         u32 extlen;
38         int error;
39
40         error = gfs2_extent_map(&ip->i_inode, blk, &new, &dblock, &extlen);
41         if (error)
42                 return error;
43         if (!dblock) {
44                 gfs2_consist_inode(ip);
45                 return -EIO;
46         }
47
48         *bh = gfs2_meta_ra(gl, dblock, extlen);
49
50         return error;
51 }
52
53 int gfs2_revoke_add(struct gfs2_sbd *sdp, u64 blkno, unsigned int where)
54 {
55         struct list_head *head = &sdp->sd_revoke_list;
56         struct gfs2_revoke_replay *rr;
57         int found = 0;
58
59         list_for_each_entry(rr, head, rr_list) {
60                 if (rr->rr_blkno == blkno) {
61                         found = 1;
62                         break;
63                 }
64         }
65
66         if (found) {
67                 rr->rr_where = where;
68                 return 0;
69         }
70
71         rr = kmalloc(sizeof(struct gfs2_revoke_replay), GFP_KERNEL);
72         if (!rr)
73                 return -ENOMEM;
74
75         rr->rr_blkno = blkno;
76         rr->rr_where = where;
77         list_add(&rr->rr_list, head);
78
79         return 1;
80 }
81
82 int gfs2_revoke_check(struct gfs2_sbd *sdp, u64 blkno, unsigned int where)
83 {
84         struct gfs2_revoke_replay *rr;
85         int wrap, a, b, revoke;
86         int found = 0;
87
88         list_for_each_entry(rr, &sdp->sd_revoke_list, rr_list) {
89                 if (rr->rr_blkno == blkno) {
90                         found = 1;
91                         break;
92                 }
93         }
94
95         if (!found)
96                 return 0;
97
98         wrap = (rr->rr_where < sdp->sd_replay_tail);
99         a = (sdp->sd_replay_tail < where);
100         b = (where < rr->rr_where);
101         revoke = (wrap) ? (a || b) : (a && b);
102
103         return revoke;
104 }
105
106 void gfs2_revoke_clean(struct gfs2_sbd *sdp)
107 {
108         struct list_head *head = &sdp->sd_revoke_list;
109         struct gfs2_revoke_replay *rr;
110
111         while (!list_empty(head)) {
112                 rr = list_entry(head->next, struct gfs2_revoke_replay, rr_list);
113                 list_del(&rr->rr_list);
114                 kfree(rr);
115         }
116 }
117
118 static int gfs2_log_header_in(struct gfs2_log_header_host *lh, const void *buf)
119 {
120         const struct gfs2_log_header *str = buf;
121
122         if (str->lh_header.mh_magic != cpu_to_be32(GFS2_MAGIC) ||
123             str->lh_header.mh_type != cpu_to_be32(GFS2_METATYPE_LH))
124                 return 1;
125
126         lh->lh_sequence = be64_to_cpu(str->lh_sequence);
127         lh->lh_flags = be32_to_cpu(str->lh_flags);
128         lh->lh_tail = be32_to_cpu(str->lh_tail);
129         lh->lh_blkno = be32_to_cpu(str->lh_blkno);
130         lh->lh_hash = be32_to_cpu(str->lh_hash);
131         return 0;
132 }
133
134 /**
135  * get_log_header - read the log header for a given segment
136  * @jd: the journal
137  * @blk: the block to look at
138  * @lh: the log header to return
139  *
140  * Read the log header for a given segement in a given journal.  Do a few
141  * sanity checks on it.
142  *
143  * Returns: 0 on success,
144  *          1 if the header was invalid or incomplete,
145  *          errno on error
146  */
147
148 static int get_log_header(struct gfs2_jdesc *jd, unsigned int blk,
149                           struct gfs2_log_header_host *head)
150 {
151         struct buffer_head *bh;
152         struct gfs2_log_header_host lh;
153         const u32 nothing = 0;
154         u32 hash;
155         int error;
156
157         error = gfs2_replay_read_block(jd, blk, &bh);
158         if (error)
159                 return error;
160
161         hash = crc32_le((u32)~0, bh->b_data, sizeof(struct gfs2_log_header) -
162                                              sizeof(u32));
163         hash = crc32_le(hash, (unsigned char const *)&nothing, sizeof(nothing));
164         hash ^= (u32)~0;
165         error = gfs2_log_header_in(&lh, bh->b_data);
166         brelse(bh);
167
168         if (error || lh.lh_blkno != blk || lh.lh_hash != hash)
169                 return 1;
170
171         *head = lh;
172
173         return 0;
174 }
175
176 /**
177  * find_good_lh - find a good log header
178  * @jd: the journal
179  * @blk: the segment to start searching from
180  * @lh: the log header to fill in
181  * @forward: if true search forward in the log, else search backward
182  *
183  * Call get_log_header() to get a log header for a segment, but if the
184  * segment is bad, either scan forward or backward until we find a good one.
185  *
186  * Returns: errno
187  */
188
189 static int find_good_lh(struct gfs2_jdesc *jd, unsigned int *blk,
190                         struct gfs2_log_header_host *head)
191 {
192         unsigned int orig_blk = *blk;
193         int error;
194
195         for (;;) {
196                 error = get_log_header(jd, *blk, head);
197                 if (error <= 0)
198                         return error;
199
200                 if (++*blk == jd->jd_blocks)
201                         *blk = 0;
202
203                 if (*blk == orig_blk) {
204                         gfs2_consist_inode(GFS2_I(jd->jd_inode));
205                         return -EIO;
206                 }
207         }
208 }
209
210 /**
211  * jhead_scan - make sure we've found the head of the log
212  * @jd: the journal
213  * @head: this is filled in with the log descriptor of the head
214  *
215  * At this point, seg and lh should be either the head of the log or just
216  * before.  Scan forward until we find the head.
217  *
218  * Returns: errno
219  */
220
221 static int jhead_scan(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
222 {
223         unsigned int blk = head->lh_blkno;
224         struct gfs2_log_header_host lh;
225         int error;
226
227         for (;;) {
228                 if (++blk == jd->jd_blocks)
229                         blk = 0;
230
231                 error = get_log_header(jd, blk, &lh);
232                 if (error < 0)
233                         return error;
234                 if (error == 1)
235                         continue;
236
237                 if (lh.lh_sequence == head->lh_sequence) {
238                         gfs2_consist_inode(GFS2_I(jd->jd_inode));
239                         return -EIO;
240                 }
241                 if (lh.lh_sequence < head->lh_sequence)
242                         break;
243
244                 *head = lh;
245         }
246
247         return 0;
248 }
249
250 /**
251  * gfs2_find_jhead - find the head of a log
252  * @jd: the journal
253  * @head: the log descriptor for the head of the log is returned here
254  *
255  * Do a binary search of a journal and find the valid log entry with the
256  * highest sequence number.  (i.e. the log head)
257  *
258  * Returns: errno
259  */
260
261 int gfs2_find_jhead(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
262 {
263         struct gfs2_log_header_host lh_1, lh_m;
264         u32 blk_1, blk_2, blk_m;
265         int error;
266
267         blk_1 = 0;
268         blk_2 = jd->jd_blocks - 1;
269
270         for (;;) {
271                 blk_m = (blk_1 + blk_2) / 2;
272
273                 error = find_good_lh(jd, &blk_1, &lh_1);
274                 if (error)
275                         return error;
276
277                 error = find_good_lh(jd, &blk_m, &lh_m);
278                 if (error)
279                         return error;
280
281                 if (blk_1 == blk_m || blk_m == blk_2)
282                         break;
283
284                 if (lh_1.lh_sequence <= lh_m.lh_sequence)
285                         blk_1 = blk_m;
286                 else
287                         blk_2 = blk_m;
288         }
289
290         error = jhead_scan(jd, &lh_1);
291         if (error)
292                 return error;
293
294         *head = lh_1;
295
296         return error;
297 }
298
299 /**
300  * foreach_descriptor - go through the active part of the log
301  * @jd: the journal
302  * @start: the first log header in the active region
303  * @end: the last log header (don't process the contents of this entry))
304  *
305  * Call a given function once for every log descriptor in the active
306  * portion of the log.
307  *
308  * Returns: errno
309  */
310
311 static int foreach_descriptor(struct gfs2_jdesc *jd, unsigned int start,
312                               unsigned int end, int pass)
313 {
314         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
315         struct buffer_head *bh;
316         struct gfs2_log_descriptor *ld;
317         int error = 0;
318         u32 length;
319         __be64 *ptr;
320         unsigned int offset = sizeof(struct gfs2_log_descriptor);
321         offset += sizeof(__be64) - 1;
322         offset &= ~(sizeof(__be64) - 1);
323
324         while (start != end) {
325                 error = gfs2_replay_read_block(jd, start, &bh);
326                 if (error)
327                         return error;
328                 if (gfs2_meta_check(sdp, bh)) {
329                         brelse(bh);
330                         return -EIO;
331                 }
332                 ld = (struct gfs2_log_descriptor *)bh->b_data;
333                 length = be32_to_cpu(ld->ld_length);
334
335                 if (be32_to_cpu(ld->ld_header.mh_type) == GFS2_METATYPE_LH) {
336                         struct gfs2_log_header_host lh;
337                         error = get_log_header(jd, start, &lh);
338                         if (!error) {
339                                 gfs2_replay_incr_blk(sdp, &start);
340                                 brelse(bh);
341                                 continue;
342                         }
343                         if (error == 1) {
344                                 gfs2_consist_inode(GFS2_I(jd->jd_inode));
345                                 error = -EIO;
346                         }
347                         brelse(bh);
348                         return error;
349                 } else if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LD)) {
350                         brelse(bh);
351                         return -EIO;
352                 }
353                 ptr = (__be64 *)(bh->b_data + offset);
354                 error = lops_scan_elements(jd, start, ld, ptr, pass);
355                 if (error) {
356                         brelse(bh);
357                         return error;
358                 }
359
360                 while (length--)
361                         gfs2_replay_incr_blk(sdp, &start);
362
363                 brelse(bh);
364         }
365
366         return 0;
367 }
368
369 /**
370  * clean_journal - mark a dirty journal as being clean
371  * @sdp: the filesystem
372  * @jd: the journal
373  * @gl: the journal's glock
374  * @head: the head journal to start from
375  *
376  * Returns: errno
377  */
378
379 static int clean_journal(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
380 {
381         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
382         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
383         unsigned int lblock;
384         struct gfs2_log_header *lh;
385         u32 hash;
386         struct buffer_head *bh;
387         int error;
388         struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
389
390         lblock = head->lh_blkno;
391         gfs2_replay_incr_blk(sdp, &lblock);
392         bh_map.b_size = 1 << ip->i_inode.i_blkbits;
393         error = gfs2_block_map(&ip->i_inode, lblock, &bh_map, 0);
394         if (error)
395                 return error;
396         if (!bh_map.b_blocknr) {
397                 gfs2_consist_inode(ip);
398                 return -EIO;
399         }
400
401         bh = sb_getblk(sdp->sd_vfs, bh_map.b_blocknr);
402         lock_buffer(bh);
403         memset(bh->b_data, 0, bh->b_size);
404         set_buffer_uptodate(bh);
405         clear_buffer_dirty(bh);
406         unlock_buffer(bh);
407
408         lh = (struct gfs2_log_header *)bh->b_data;
409         memset(lh, 0, sizeof(struct gfs2_log_header));
410         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
411         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
412         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
413         lh->lh_sequence = cpu_to_be64(head->lh_sequence + 1);
414         lh->lh_flags = cpu_to_be32(GFS2_LOG_HEAD_UNMOUNT);
415         lh->lh_blkno = cpu_to_be32(lblock);
416         hash = gfs2_disk_hash((const char *)lh, sizeof(struct gfs2_log_header));
417         lh->lh_hash = cpu_to_be32(hash);
418
419         set_buffer_dirty(bh);
420         if (sync_dirty_buffer(bh))
421                 gfs2_io_error_bh(sdp, bh);
422         brelse(bh);
423
424         return error;
425 }
426
427
428 static void gfs2_lm_recovery_done(struct gfs2_sbd *sdp, unsigned int jid,
429                                   unsigned int message)
430 {
431         if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
432                 sdp->sd_lockstruct.ls_ops->lm_recovery_done(
433                         sdp->sd_lockstruct.ls_lockspace, jid, message);
434 }
435
436
437 /**
438  * gfs2_recover_journal - recovery a given journal
439  * @jd: the struct gfs2_jdesc describing the journal
440  *
441  * Acquire the journal's lock, check to see if the journal is clean, and
442  * do recovery if necessary.
443  *
444  * Returns: errno
445  */
446
447 int gfs2_recover_journal(struct gfs2_jdesc *jd)
448 {
449         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
450         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
451         struct gfs2_log_header_host head;
452         struct gfs2_holder j_gh, ji_gh, t_gh;
453         unsigned long t;
454         int ro = 0;
455         unsigned int pass;
456         int error;
457
458         if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
459                 fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n",
460                         jd->jd_jid);
461
462                 /* Acquire the journal lock so we can do recovery */
463
464                 error = gfs2_glock_nq_num(sdp, jd->jd_jid, &gfs2_journal_glops,
465                                           LM_ST_EXCLUSIVE,
466                                           LM_FLAG_NOEXP | LM_FLAG_TRY | GL_NOCACHE,
467                                           &j_gh);
468                 switch (error) {
469                 case 0:
470                         break;
471
472                 case GLR_TRYFAILED:
473                         fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
474                         error = 0;
475
476                 default:
477                         goto fail;
478                 };
479
480                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
481                                            LM_FLAG_NOEXP | GL_NOCACHE, &ji_gh);
482                 if (error)
483                         goto fail_gunlock_j;
484         } else {
485                 fs_info(sdp, "jid=%u, already locked for use\n", jd->jd_jid);
486         }
487
488         fs_info(sdp, "jid=%u: Looking at journal...\n", jd->jd_jid);
489
490         error = gfs2_jdesc_check(jd);
491         if (error)
492                 goto fail_gunlock_ji;
493
494         error = gfs2_find_jhead(jd, &head);
495         if (error)
496                 goto fail_gunlock_ji;
497
498         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
499                 fs_info(sdp, "jid=%u: Acquiring the transaction lock...\n",
500                         jd->jd_jid);
501
502                 t = jiffies;
503
504                 /* Acquire a shared hold on the transaction lock */
505
506                 error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED,
507                                            LM_FLAG_NOEXP | LM_FLAG_PRIORITY |
508                                            GL_NOCANCEL | GL_NOCACHE, &t_gh);
509                 if (error)
510                         goto fail_gunlock_ji;
511
512                 if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
513                         if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
514                                 ro = 1;
515                 } else {
516                         if (sdp->sd_vfs->s_flags & MS_RDONLY) {
517                                 /* check if device itself is read-only */
518                                 ro = bdev_read_only(sdp->sd_vfs->s_bdev);
519                                 if (!ro) {
520                                         fs_info(sdp, "recovery required on "
521                                                 "read-only filesystem.\n");
522                                         fs_info(sdp, "write access will be "
523                                                 "enabled during recovery.\n");
524                                 }
525                         }
526                 }
527
528                 if (ro) {
529                         fs_warn(sdp, "jid=%u: Can't replay: read-only block "
530                                 "device\n", jd->jd_jid);
531                         error = -EROFS;
532                         goto fail_gunlock_tr;
533                 }
534
535                 fs_info(sdp, "jid=%u: Replaying journal...\n", jd->jd_jid);
536
537                 for (pass = 0; pass < 2; pass++) {
538                         lops_before_scan(jd, &head, pass);
539                         error = foreach_descriptor(jd, head.lh_tail,
540                                                    head.lh_blkno, pass);
541                         lops_after_scan(jd, error, pass);
542                         if (error)
543                                 goto fail_gunlock_tr;
544                 }
545
546                 error = clean_journal(jd, &head);
547                 if (error)
548                         goto fail_gunlock_tr;
549
550                 gfs2_glock_dq_uninit(&t_gh);
551                 t = DIV_ROUND_UP(jiffies - t, HZ);
552                 fs_info(sdp, "jid=%u: Journal replayed in %lus\n",
553                         jd->jd_jid, t);
554         }
555
556         if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
557                 gfs2_glock_dq_uninit(&ji_gh);
558
559         gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
560
561         if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
562                 gfs2_glock_dq_uninit(&j_gh);
563
564         fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
565         return 0;
566
567 fail_gunlock_tr:
568         gfs2_glock_dq_uninit(&t_gh);
569 fail_gunlock_ji:
570         if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
571                 gfs2_glock_dq_uninit(&ji_gh);
572 fail_gunlock_j:
573                 gfs2_glock_dq_uninit(&j_gh);
574         }
575
576         fs_info(sdp, "jid=%u: %s\n", jd->jd_jid, (error) ? "Failed" : "Done");
577
578 fail:
579         gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
580         return error;
581 }
582
583 /**
584  * gfs2_check_journals - Recover any dirty journals
585  * @sdp: the filesystem
586  *
587  */
588
589 void gfs2_check_journals(struct gfs2_sbd *sdp)
590 {
591         struct gfs2_jdesc *jd;
592
593         for (;;) {
594                 jd = gfs2_jdesc_find_dirty(sdp);
595                 if (!jd)
596                         break;
597
598                 if (jd != sdp->sd_jdesc)
599                         gfs2_recover_journal(jd);
600         }
601 }
602