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_NOFS);
  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 uninitialized_var(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