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