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/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 #include <linux/crc32c.h>
  18 #include <linux/ktime.h>
  19
  20 #include "gfs2.h"
  21 #include "incore.h"
  22 #include "bmap.h"
  23 #include "glock.h"
  24 #include "glops.h"
  25 #include "log.h"
  26 #include "lops.h"
  27 #include "meta_io.h"
  28 #include "recovery.h"
  29 #include "super.h"
  30 #include "util.h"
  31 #include "dir.h"
  32
  33 struct workqueue_struct *gfs_recovery_wq;
  34
  35 int gfs2_replay_read_block(struct gfs2_jdesc *jd, unsigned int blk,
  36                            struct buffer_head **bh)
  37 {
  38         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
  39         struct gfs2_glock *gl = ip->i_gl;
  40         int new = 0;
  41         u64 dblock;
  42         u32 extlen;
  43         int error;
  44
  45         error = gfs2_extent_map(&ip->i_inode, blk, &new, &dblock, &extlen);
  46         if (error)
  47                 return error;
  48         if (!dblock) {
  49                 gfs2_consist_inode(ip);
  50                 return -EIO;
  51         }
  52
  53         *bh = gfs2_meta_ra(gl, dblock, extlen);
  54
  55         return error;
  56 }
  57
  58 int gfs2_revoke_add(struct gfs2_jdesc *jd, u64 blkno, unsigned int where)
  59 {
  60         struct list_head *head = &jd->jd_revoke_list;
  61         struct gfs2_revoke_replay *rr;
  62         int found = 0;
  63
  64         list_for_each_entry(rr, head, rr_list) {
  65                 if (rr->rr_blkno == blkno) {
  66                         found = 1;
  67                         break;
  68                 }
  69         }
  70
  71         if (found) {
  72                 rr->rr_where = where;
  73                 return 0;
  74         }
  75
  76         rr = kmalloc(sizeof(struct gfs2_revoke_replay), GFP_NOFS);
  77         if (!rr)
  78                 return -ENOMEM;
  79
  80         rr->rr_blkno = blkno;
  81         rr->rr_where = where;
  82         list_add(&rr->rr_list, head);
  83
  84         return 1;
  85 }
  86
  87 int gfs2_revoke_check(struct gfs2_jdesc *jd, u64 blkno, unsigned int where)
  88 {
  89         struct gfs2_revoke_replay *rr;
  90         int wrap, a, b, revoke;
  91         int found = 0;
  92
  93         list_for_each_entry(rr, &jd->jd_revoke_list, rr_list) {
  94                 if (rr->rr_blkno == blkno) {
  95                         found = 1;
  96                         break;
  97                 }
  98         }
  99
 100         if (!found)
 101                 return 0;
 102
 103         wrap = (rr->rr_where < jd->jd_replay_tail);
 104         a = (jd->jd_replay_tail < where);
 105         b = (where < rr->rr_where);
 106         revoke = (wrap) ? (a || b) : (a && b);
 107
 108         return revoke;
 109 }
 110
 111 void gfs2_revoke_clean(struct gfs2_jdesc *jd)
 112 {
 113         struct list_head *head = &jd->jd_revoke_list;
 114         struct gfs2_revoke_replay *rr;
 115
 116         while (!list_empty(head)) {
 117                 rr = list_entry(head->next, struct gfs2_revoke_replay, rr_list);
 118                 list_del(&rr->rr_list);
 119                 kfree(rr);
 120         }
 121 }
 122
 123 /**
 124  * get_log_header - read the log header for a given segment
 125  * @jd: the journal
 126  * @blk: the block to look at
 127  * @lh: the log header to return
 128  *
 129  * Read the log header for a given segement in a given journal.  Do a few
 130  * sanity checks on it.
 131  *
 132  * Returns: 0 on success,
 133  *          1 if the header was invalid or incomplete,
 134  *          errno on error
 135  */
 136
 137 static int get_log_header(struct gfs2_jdesc *jd, unsigned int blk,
 138                           struct gfs2_log_header_host *head)
 139 {
 140         struct gfs2_log_header *lh;
 141         struct buffer_head *bh;
 142         u32 hash, crc;
 143         int error;
 144
 145         error = gfs2_replay_read_block(jd, blk, &bh);
 146         if (error)
 147                 return error;
 148         lh = (void *)bh->b_data;
 149
 150         hash = crc32(~0, lh, LH_V1_SIZE - 4);
 151         hash = ~crc32_le_shift(hash, 4);  /* assume lh_hash is zero */
 152
 153         crc = crc32c(~0, (void *)lh + LH_V1_SIZE + 4,
 154                      bh->b_size - LH_V1_SIZE - 4);
 155
 156         error = lh->lh_header.mh_magic != cpu_to_be32(GFS2_MAGIC) ||
 157                 lh->lh_header.mh_type != cpu_to_be32(GFS2_METATYPE_LH) ||
 158                 be32_to_cpu(lh->lh_blkno) != blk ||
 159                 be32_to_cpu(lh->lh_hash) != hash ||
 160                 (lh->lh_crc != 0 && be32_to_cpu(lh->lh_crc) != crc);
 161
 162         brelse(bh);
 163
 164         if (!error) {
 165                 head->lh_sequence = be64_to_cpu(lh->lh_sequence);
 166                 head->lh_flags = be32_to_cpu(lh->lh_flags);
 167                 head->lh_tail = be32_to_cpu(lh->lh_tail);
 168                 head->lh_blkno = be32_to_cpu(lh->lh_blkno);
 169         }
 170         return error;
 171 }
 172
 173 /**
 174  * find_good_lh - find a good log header
 175  * @jd: the journal
 176  * @blk: the segment to start searching from
 177  * @lh: the log header to fill in
 178  * @forward: if true search forward in the log, else search backward
 179  *
 180  * Call get_log_header() to get a log header for a segment, but if the
 181  * segment is bad, either scan forward or backward until we find a good one.
 182  *
 183  * Returns: errno
 184  */
 185
 186 static int find_good_lh(struct gfs2_jdesc *jd, unsigned int *blk,
 187                         struct gfs2_log_header_host *head)
 188 {
 189         unsigned int orig_blk = *blk;
 190         int error;
 191
 192         for (;;) {
 193                 error = get_log_header(jd, *blk, head);
 194                 if (error <= 0)
 195                         return error;
 196
 197                 if (++*blk == jd->jd_blocks)
 198                         *blk = 0;
 199
 200                 if (*blk == orig_blk) {
 201                         gfs2_consist_inode(GFS2_I(jd->jd_inode));
 202                         return -EIO;
 203                 }
 204         }
 205 }
 206
 207 /**
 208  * jhead_scan - make sure we've found the head of the log
 209  * @jd: the journal
 210  * @head: this is filled in with the log descriptor of the head
 211  *
 212  * At this point, seg and lh should be either the head of the log or just
 213  * before.  Scan forward until we find the head.
 214  *
 215  * Returns: errno
 216  */
 217
 218 static int jhead_scan(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
 219 {
 220         unsigned int blk = head->lh_blkno;
 221         struct gfs2_log_header_host lh;
 222         int error;
 223
 224         for (;;) {
 225                 if (++blk == jd->jd_blocks)
 226                         blk = 0;
 227
 228                 error = get_log_header(jd, blk, &lh);
 229                 if (error < 0)
 230                         return error;
 231                 if (error == 1)
 232                         continue;
 233
 234                 if (lh.lh_sequence == head->lh_sequence) {
 235                         gfs2_consist_inode(GFS2_I(jd->jd_inode));
 236                         return -EIO;
 237                 }
 238                 if (lh.lh_sequence < head->lh_sequence)
 239                         break;
 240
 241                 *head = lh;
 242         }
 243
 244         return 0;
 245 }
 246
 247 /**
 248  * gfs2_find_jhead - find the head of a log
 249  * @jd: the journal
 250  * @head: the log descriptor for the head of the log is returned here
 251  *
 252  * Do a binary search of a journal and find the valid log entry with the
 253  * highest sequence number.  (i.e. the log head)
 254  *
 255  * Returns: errno
 256  */
 257
 258 int gfs2_find_jhead(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
 259 {
 260         struct gfs2_log_header_host lh_1, lh_m;
 261         u32 blk_1, blk_2, blk_m;
 262         int error;
 263
 264         blk_1 = 0;
 265         blk_2 = jd->jd_blocks - 1;
 266
 267         for (;;) {
 268                 blk_m = (blk_1 + blk_2) / 2;
 269
 270                 error = find_good_lh(jd, &blk_1, &lh_1);
 271                 if (error)
 272                         return error;
 273
 274                 error = find_good_lh(jd, &blk_m, &lh_m);
 275                 if (error)
 276                         return error;
 277
 278                 if (blk_1 == blk_m || blk_m == blk_2)
 279                         break;
 280
 281                 if (lh_1.lh_sequence <= lh_m.lh_sequence)
 282                         blk_1 = blk_m;
 283                 else
 284                         blk_2 = blk_m;
 285         }
 286
 287         error = jhead_scan(jd, &lh_1);
 288         if (error)
 289                 return error;
 290
 291         *head = lh_1;
 292
 293         return error;
 294 }
 295
 296 /**
 297  * foreach_descriptor - go through the active part of the log
 298  * @jd: the journal
 299  * @start: the first log header in the active region
 300  * @end: the last log header (don't process the contents of this entry))
 301  *
 302  * Call a given function once for every log descriptor in the active
 303  * portion of the log.
 304  *
 305  * Returns: errno
 306  */
 307
 308 static int foreach_descriptor(struct gfs2_jdesc *jd, unsigned int start,
 309                               unsigned int end, int pass)
 310 {
 311         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
 312         struct buffer_head *bh;
 313         struct gfs2_log_descriptor *ld;
 314         int error = 0;
 315         u32 length;
 316         __be64 *ptr;
 317         unsigned int offset = sizeof(struct gfs2_log_descriptor);
 318         offset += sizeof(__be64) - 1;
 319         offset &= ~(sizeof(__be64) - 1);
 320
 321         while (start != end) {
 322                 error = gfs2_replay_read_block(jd, start, &bh);
 323                 if (error)
 324                         return error;
 325                 if (gfs2_meta_check(sdp, bh)) {
 326                         brelse(bh);
 327                         return -EIO;
 328                 }
 329                 ld = (struct gfs2_log_descriptor *)bh->b_data;
 330                 length = be32_to_cpu(ld->ld_length);
 331
 332                 if (be32_to_cpu(ld->ld_header.mh_type) == GFS2_METATYPE_LH) {
 333                         struct gfs2_log_header_host lh;
 334                         error = get_log_header(jd, start, &lh);
 335                         if (!error) {
 336                                 gfs2_replay_incr_blk(jd, &start);
 337                                 brelse(bh);
 338                                 continue;
 339                         }
 340                         if (error == 1) {
 341                                 gfs2_consist_inode(GFS2_I(jd->jd_inode));
 342                                 error = -EIO;
 343                         }
 344                         brelse(bh);
 345                         return error;
 346                 } else if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LD)) {
 347                         brelse(bh);
 348                         return -EIO;
 349                 }
 350                 ptr = (__be64 *)(bh->b_data + offset);
 351                 error = lops_scan_elements(jd, start, ld, ptr, pass);
 352                 if (error) {
 353                         brelse(bh);
 354                         return error;
 355                 }
 356
 357                 while (length--)
 358                         gfs2_replay_incr_blk(jd, &start);
 359
 360                 brelse(bh);
 361         }
 362
 363         return 0;
 364 }
 365
 366 /**
 367  * clean_journal - mark a dirty journal as being clean
 368  * @jd: the journal
 369  * @head: the head journal to start from
 370  *
 371  * Returns: errno
 372  */
 373
 374 static void clean_journal(struct gfs2_jdesc *jd,
 375                           struct gfs2_log_header_host *head)
 376 {
 377         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
 378
 379         sdp->sd_log_flush_head = head->lh_blkno;
 380         gfs2_replay_incr_blk(jd, &sdp->sd_log_flush_head);
 381         gfs2_write_log_header(sdp, jd, head->lh_sequence + 1, 0,
 382                               GFS2_LOG_HEAD_UNMOUNT | GFS2_LOG_HEAD_RECOVERY,
 383                               REQ_PREFLUSH | REQ_FUA | REQ_META | REQ_SYNC);
 384 }
 385
 386
 387 static void gfs2_recovery_done(struct gfs2_sbd *sdp, unsigned int jid,
 388                                unsigned int message)
 389 {
 390         char env_jid[20];
 391         char env_status[20];
 392         char *envp[] = { env_jid, env_status, NULL };
 393         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 394
 395         ls->ls_recover_jid_done = jid;
 396         ls->ls_recover_jid_status = message;
 397         sprintf(env_jid, "JID=%u", jid);
 398         sprintf(env_status, "RECOVERY=%s",
 399                 message == LM_RD_SUCCESS ? "Done" : "Failed");
 400         kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
 401
 402         if (sdp->sd_lockstruct.ls_ops->lm_recovery_result)
 403                 sdp->sd_lockstruct.ls_ops->lm_recovery_result(sdp, jid, message);
 404 }
 405
 406 void gfs2_recover_func(struct work_struct *work)
 407 {
 408         struct gfs2_jdesc *jd = container_of(work, struct gfs2_jdesc, jd_work);
 409         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
 410         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
 411         struct gfs2_log_header_host head;
 412         struct gfs2_holder j_gh, ji_gh, thaw_gh;
 413         ktime_t t_start, t_jlck, t_jhd, t_tlck, t_rep;
 414         int ro = 0;
 415         unsigned int pass;
 416         int error;
 417         int jlocked = 0;
 418
 419         t_start = ktime_get();
 420         if (sdp->sd_args.ar_spectator ||
 421             (jd->jd_jid != sdp->sd_lockstruct.ls_jid)) {
 422                 fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n",
 423                         jd->jd_jid);
 424                 jlocked = 1;
 425                 /* Acquire the journal lock so we can do recovery */
 426
 427                 error = gfs2_glock_nq_num(sdp, jd->jd_jid, &gfs2_journal_glops,
 428                                           LM_ST_EXCLUSIVE,
 429                                           LM_FLAG_NOEXP | LM_FLAG_TRY | GL_NOCACHE,
 430                                           &j_gh);
 431                 switch (error) {
 432                 case 0:
 433                         break;
 434
 435                 case GLR_TRYFAILED:
 436                         fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
 437                         error = 0;
 438
 439                 default:
 440                         goto fail;
 441                 };
 442
 443                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
 444                                            LM_FLAG_NOEXP | GL_NOCACHE, &ji_gh);
 445                 if (error)
 446                         goto fail_gunlock_j;
 447         } else {
 448                 fs_info(sdp, "jid=%u, already locked for use\n", jd->jd_jid);
 449         }
 450
 451         t_jlck = ktime_get();
 452         fs_info(sdp, "jid=%u: Looking at journal...\n", jd->jd_jid);
 453
 454         error = gfs2_jdesc_check(jd);
 455         if (error)
 456                 goto fail_gunlock_ji;
 457
 458         error = gfs2_find_jhead(jd, &head);
 459         if (error)
 460                 goto fail_gunlock_ji;
 461         t_jhd = ktime_get();
 462
 463         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 464                 fs_info(sdp, "jid=%u: Acquiring the transaction lock...\n",
 465                         jd->jd_jid);
 466
 467                 /* Acquire a shared hold on the freeze lock */
 468
 469                 error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED,
 470                                            LM_FLAG_NOEXP | LM_FLAG_PRIORITY,
 471                                            &thaw_gh);
 472                 if (error)
 473                         goto fail_gunlock_ji;
 474
 475                 if (test_bit(SDF_RORECOVERY, &sdp->sd_flags)) {
 476                         ro = 1;
 477                 } else if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
 478                         if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
 479                                 ro = 1;
 480                 } else {
 481                         if (sb_rdonly(sdp->sd_vfs)) {
 482                                 /* check if device itself is read-only */
 483                                 ro = bdev_read_only(sdp->sd_vfs->s_bdev);
 484                                 if (!ro) {
 485                                         fs_info(sdp, "recovery required on "
 486                                                 "read-only filesystem.\n");
 487                                         fs_info(sdp, "write access will be "
 488                                                 "enabled during recovery.\n");
 489                                 }
 490                         }
 491                 }
 492
 493                 if (ro) {
 494                         fs_warn(sdp, "jid=%u: Can't replay: read-only block "
 495                                 "device\n", jd->jd_jid);
 496                         error = -EROFS;
 497                         goto fail_gunlock_thaw;
 498                 }
 499
 500                 t_tlck = ktime_get();
 501                 fs_info(sdp, "jid=%u: Replaying journal...\n", jd->jd_jid);
 502
 503                 for (pass = 0; pass < 2; pass++) {
 504                         lops_before_scan(jd, &head, pass);
 505                         error = foreach_descriptor(jd, head.lh_tail,
 506                                                    head.lh_blkno, pass);
 507                         lops_after_scan(jd, error, pass);
 508                         if (error)
 509                                 goto fail_gunlock_thaw;
 510                 }
 511
 512                 clean_journal(jd, &head);
 513
 514                 gfs2_glock_dq_uninit(&thaw_gh);
 515                 t_rep = ktime_get();
 516                 fs_info(sdp, "jid=%u: Journal replayed in %lldms [jlck:%lldms, "
 517                         "jhead:%lldms, tlck:%lldms, replay:%lldms]\n",
 518                         jd->jd_jid, ktime_ms_delta(t_rep, t_start),
 519                         ktime_ms_delta(t_jlck, t_start),
 520                         ktime_ms_delta(t_jhd, t_jlck),
 521                         ktime_ms_delta(t_tlck, t_jhd),
 522                         ktime_ms_delta(t_rep, t_tlck));
 523         }
 524
 525         gfs2_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
 526
 527         if (jlocked) {
 528                 gfs2_glock_dq_uninit(&ji_gh);
 529                 gfs2_glock_dq_uninit(&j_gh);
 530         }
 531
 532         fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
 533         goto done;
 534
 535 fail_gunlock_thaw:
 536         gfs2_glock_dq_uninit(&thaw_gh);
 537 fail_gunlock_ji:
 538         if (jlocked) {
 539                 gfs2_glock_dq_uninit(&ji_gh);
 540 fail_gunlock_j:
 541                 gfs2_glock_dq_uninit(&j_gh);
 542         }
 543
 544         fs_info(sdp, "jid=%u: %s\n", jd->jd_jid, (error) ? "Failed" : "Done");
 545 fail:
 546         jd->jd_recover_error = error;
 547         gfs2_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
 548 done:
 549         clear_bit(JDF_RECOVERY, &jd->jd_flags);
 550         smp_mb__after_atomic();
 551         wake_up_bit(&jd->jd_flags, JDF_RECOVERY);
 552 }
 553
 554 int gfs2_recover_journal(struct gfs2_jdesc *jd, bool wait)
 555 {
 556         int rv;
 557
 558         if (test_and_set_bit(JDF_RECOVERY, &jd->jd_flags))
 559                 return -EBUSY;
 560
 561         /* we have JDF_RECOVERY, queue should always succeed */
 562         rv = queue_work(gfs_recovery_wq, &jd->jd_work);
 563         BUG_ON(!rv);
 564
 565         if (wait)
 566                 wait_on_bit(&jd->jd_flags, JDF_RECOVERY,
 567                             TASK_UNINTERRUPTIBLE);
 568
 569         return wait ? jd->jd_recover_error : 0;
 570 }
 571