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
  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 struct workqueue_struct *gfs_recovery_wq;
  31
  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         int new = 0;
  38         u64 dblock;
  39         u32 extlen;
  40         int error;
  41
  42         error = gfs2_extent_map(&ip->i_inode, blk, &new, &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
  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
  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
 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_entry(head->next, struct gfs2_revoke_replay, rr_list);
 115                 list_del(&rr->rr_list);
 116                 kfree(rr);
 117         }
 118 }
 119
 120 static int gfs2_log_header_in(struct gfs2_log_header_host *lh, const void *buf)
 121 {
 122         const struct gfs2_log_header *str = buf;
 123
 124         if (str->lh_header.mh_magic != cpu_to_be32(GFS2_MAGIC) ||
 125             str->lh_header.mh_type != cpu_to_be32(GFS2_METATYPE_LH))
 126                 return 1;
 127
 128         lh->lh_sequence = be64_to_cpu(str->lh_sequence);
 129         lh->lh_flags = be32_to_cpu(str->lh_flags);
 130         lh->lh_tail = be32_to_cpu(str->lh_tail);
 131         lh->lh_blkno = be32_to_cpu(str->lh_blkno);
 132         lh->lh_hash = be32_to_cpu(str->lh_hash);
 133         return 0;
 134 }
 135
 136 /**
 137  * get_log_header - read the log header for a given segment
 138  * @jd: the journal
 139  * @blk: the block to look at
 140  * @lh: the log header to return
 141  *
 142  * Read the log header for a given segement in a given journal.  Do a few
 143  * sanity checks on it.
 144  *
 145  * Returns: 0 on success,
 146  *          1 if the header was invalid or incomplete,
 147  *          errno on error
 148  */
 149
 150 static int get_log_header(struct gfs2_jdesc *jd, unsigned int blk,
 151                           struct gfs2_log_header_host *head)
 152 {
 153         struct buffer_head *bh;
 154         struct gfs2_log_header_host uninitialized_var(lh);
 155         const u32 nothing = 0;
 156         u32 hash;
 157         int error;
 158
 159         error = gfs2_replay_read_block(jd, blk, &bh);
 160         if (error)
 161                 return error;
 162
 163         hash = crc32_le((u32)~0, bh->b_data, sizeof(struct gfs2_log_header) -
 164                                              sizeof(u32));
 165         hash = crc32_le(hash, (unsigned char const *)&nothing, sizeof(nothing));
 166         hash ^= (u32)~0;
 167         error = gfs2_log_header_in(&lh, bh->b_data);
 168         brelse(bh);
 169
 170         if (error || lh.lh_blkno != blk || lh.lh_hash != hash)
 171                 return 1;
 172
 173         *head = lh;
 174
 175         return 0;
 176 }
 177
 178 /**
 179  * find_good_lh - find a good log header
 180  * @jd: the journal
 181  * @blk: the segment to start searching from
 182  * @lh: the log header to fill in
 183  * @forward: if true search forward in the log, else search backward
 184  *
 185  * Call get_log_header() to get a log header for a segment, but if the
 186  * segment is bad, either scan forward or backward until we find a good one.
 187  *
 188  * Returns: errno
 189  */
 190
 191 static int find_good_lh(struct gfs2_jdesc *jd, unsigned int *blk,
 192                         struct gfs2_log_header_host *head)
 193 {
 194         unsigned int orig_blk = *blk;
 195         int error;
 196
 197         for (;;) {
 198                 error = get_log_header(jd, *blk, head);
 199                 if (error <= 0)
 200                         return error;
 201
 202                 if (++*blk == jd->jd_blocks)
 203                         *blk = 0;
 204
 205                 if (*blk == orig_blk) {
 206                         gfs2_consist_inode(GFS2_I(jd->jd_inode));
 207                         return -EIO;
 208                 }
 209         }
 210 }
 211
 212 /**
 213  * jhead_scan - make sure we've found the head of the log
 214  * @jd: the journal
 215  * @head: this is filled in with the log descriptor of the head
 216  *
 217  * At this point, seg and lh should be either the head of the log or just
 218  * before.  Scan forward until we find the head.
 219  *
 220  * Returns: errno
 221  */
 222
 223 static int jhead_scan(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
 224 {
 225         unsigned int blk = head->lh_blkno;
 226         struct gfs2_log_header_host lh;
 227         int error;
 228
 229         for (;;) {
 230                 if (++blk == jd->jd_blocks)
 231                         blk = 0;
 232
 233                 error = get_log_header(jd, blk, &lh);
 234                 if (error < 0)
 235                         return error;
 236                 if (error == 1)
 237                         continue;
 238
 239                 if (lh.lh_sequence == head->lh_sequence) {
 240                         gfs2_consist_inode(GFS2_I(jd->jd_inode));
 241                         return -EIO;
 242                 }
 243                 if (lh.lh_sequence < head->lh_sequence)
 244                         break;
 245
 246                 *head = lh;
 247         }
 248
 249         return 0;
 250 }
 251
 252 /**
 253  * gfs2_find_jhead - find the head of a log
 254  * @jd: the journal
 255  * @head: the log descriptor for the head of the log is returned here
 256  *
 257  * Do a binary search of a journal and find the valid log entry with the
 258  * highest sequence number.  (i.e. the log head)
 259  *
 260  * Returns: errno
 261  */
 262
 263 int gfs2_find_jhead(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
 264 {
 265         struct gfs2_log_header_host lh_1, lh_m;
 266         u32 blk_1, blk_2, blk_m;
 267         int error;
 268
 269         blk_1 = 0;
 270         blk_2 = jd->jd_blocks - 1;
 271
 272         for (;;) {
 273                 blk_m = (blk_1 + blk_2) / 2;
 274
 275                 error = find_good_lh(jd, &blk_1, &lh_1);
 276                 if (error)
 277                         return error;
 278
 279                 error = find_good_lh(jd, &blk_m, &lh_m);
 280                 if (error)
 281                         return error;
 282
 283                 if (blk_1 == blk_m || blk_m == blk_2)
 284                         break;
 285
 286                 if (lh_1.lh_sequence <= lh_m.lh_sequence)
 287                         blk_1 = blk_m;
 288                 else
 289                         blk_2 = blk_m;
 290         }
 291
 292         error = jhead_scan(jd, &lh_1);
 293         if (error)
 294                 return error;
 295
 296         *head = lh_1;
 297
 298         return error;
 299 }
 300
 301 /**
 302  * foreach_descriptor - go through the active part of the log
 303  * @jd: the journal
 304  * @start: the first log header in the active region
 305  * @end: the last log header (don't process the contents of this entry))
 306  *
 307  * Call a given function once for every log descriptor in the active
 308  * portion of the log.
 309  *
 310  * Returns: errno
 311  */
 312
 313 static int foreach_descriptor(struct gfs2_jdesc *jd, unsigned int start,
 314                               unsigned int end, int pass)
 315 {
 316         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
 317         struct buffer_head *bh;
 318         struct gfs2_log_descriptor *ld;
 319         int error = 0;
 320         u32 length;
 321         __be64 *ptr;
 322         unsigned int offset = sizeof(struct gfs2_log_descriptor);
 323         offset += sizeof(__be64) - 1;
 324         offset &= ~(sizeof(__be64) - 1);
 325
 326         while (start != end) {
 327                 error = gfs2_replay_read_block(jd, start, &bh);
 328                 if (error)
 329                         return error;
 330                 if (gfs2_meta_check(sdp, bh)) {
 331                         brelse(bh);
 332                         return -EIO;
 333                 }
 334                 ld = (struct gfs2_log_descriptor *)bh->b_data;
 335                 length = be32_to_cpu(ld->ld_length);
 336
 337                 if (be32_to_cpu(ld->ld_header.mh_type) == GFS2_METATYPE_LH) {
 338                         struct gfs2_log_header_host lh;
 339                         error = get_log_header(jd, start, &lh);
 340                         if (!error) {
 341                                 gfs2_replay_incr_blk(jd, &start);
 342                                 brelse(bh);
 343                                 continue;
 344                         }
 345                         if (error == 1) {
 346                                 gfs2_consist_inode(GFS2_I(jd->jd_inode));
 347                                 error = -EIO;
 348                         }
 349                         brelse(bh);
 350                         return error;
 351                 } else if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LD)) {
 352                         brelse(bh);
 353                         return -EIO;
 354                 }
 355                 ptr = (__be64 *)(bh->b_data + offset);
 356                 error = lops_scan_elements(jd, start, ld, ptr, pass);
 357                 if (error) {
 358                         brelse(bh);
 359                         return error;
 360                 }
 361
 362                 while (length--)
 363                         gfs2_replay_incr_blk(jd, &start);
 364
 365                 brelse(bh);
 366         }
 367
 368         return 0;
 369 }
 370
 371 /**
 372  * clean_journal - mark a dirty journal as being clean
 373  * @sdp: the filesystem
 374  * @jd: the journal
 375  * @gl: the journal's glock
 376  * @head: the head journal to start from
 377  *
 378  * Returns: errno
 379  */
 380
 381 static int clean_journal(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
 382 {
 383         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
 384         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
 385         unsigned int lblock;
 386         struct gfs2_log_header *lh;
 387         u32 hash;
 388         struct buffer_head *bh;
 389         int error;
 390         struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
 391
 392         lblock = head->lh_blkno;
 393         gfs2_replay_incr_blk(jd, &lblock);
 394         bh_map.b_size = 1 << ip->i_inode.i_blkbits;
 395         error = gfs2_block_map(&ip->i_inode, lblock, &bh_map, 0);
 396         if (error)
 397                 return error;
 398         if (!bh_map.b_blocknr) {
 399                 gfs2_consist_inode(ip);
 400                 return -EIO;
 401         }
 402
 403         bh = sb_getblk(sdp->sd_vfs, bh_map.b_blocknr);
 404         lock_buffer(bh);
 405         memset(bh->b_data, 0, bh->b_size);
 406         set_buffer_uptodate(bh);
 407         clear_buffer_dirty(bh);
 408         unlock_buffer(bh);
 409
 410         lh = (struct gfs2_log_header *)bh->b_data;
 411         memset(lh, 0, sizeof(struct gfs2_log_header));
 412         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 413         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
 414         lh->lh_header.__pad0 = cpu_to_be64(0);
 415         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
 416         lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
 417         lh->lh_sequence = cpu_to_be64(head->lh_sequence + 1);
 418         lh->lh_flags = cpu_to_be32(GFS2_LOG_HEAD_UNMOUNT);
 419         lh->lh_blkno = cpu_to_be32(lblock);
 420         hash = gfs2_disk_hash((const char *)lh, sizeof(struct gfs2_log_header));
 421         lh->lh_hash = cpu_to_be32(hash);
 422
 423         set_buffer_dirty(bh);
 424         if (sync_dirty_buffer(bh))
 425                 gfs2_io_error_bh(sdp, bh);
 426         brelse(bh);
 427
 428         return error;
 429 }
 430
 431
 432 static void gfs2_recovery_done(struct gfs2_sbd *sdp, unsigned int jid,
 433                                unsigned int message)
 434 {
 435         char env_jid[20];
 436         char env_status[20];
 437         char *envp[] = { env_jid, env_status, NULL };
 438         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 439
 440         ls->ls_recover_jid_done = jid;
 441         ls->ls_recover_jid_status = message;
 442         sprintf(env_jid, "JID=%u", jid);
 443         sprintf(env_status, "RECOVERY=%s",
 444                 message == LM_RD_SUCCESS ? "Done" : "Failed");
 445         kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
 446
 447         if (sdp->sd_lockstruct.ls_ops->lm_recovery_result)
 448                 sdp->sd_lockstruct.ls_ops->lm_recovery_result(sdp, jid, message);
 449 }
 450
 451 void gfs2_recover_func(struct work_struct *work)
 452 {
 453         struct gfs2_jdesc *jd = container_of(work, struct gfs2_jdesc, jd_work);
 454         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
 455         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
 456         struct gfs2_log_header_host head;
 457         struct gfs2_holder j_gh, ji_gh, thaw_gh;
 458         unsigned long t;
 459         int ro = 0;
 460         unsigned int pass;
 461         int error;
 462         int jlocked = 0;
 463
 464         if (sdp->sd_args.ar_spectator ||
 465             (jd->jd_jid != sdp->sd_lockstruct.ls_jid)) {
 466                 fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n",
 467                         jd->jd_jid);
 468                 jlocked = 1;
 469                 /* Acquire the journal lock so we can do recovery */
 470
 471                 error = gfs2_glock_nq_num(sdp, jd->jd_jid, &gfs2_journal_glops,
 472                                           LM_ST_EXCLUSIVE,
 473                                           LM_FLAG_NOEXP | LM_FLAG_TRY | GL_NOCACHE,
 474                                           &j_gh);
 475                 switch (error) {
 476                 case 0:
 477                         break;
 478
 479                 case GLR_TRYFAILED:
 480                         fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
 481                         error = 0;
 482
 483                 default:
 484                         goto fail;
 485                 };
 486
 487                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
 488                                            LM_FLAG_NOEXP | GL_NOCACHE, &ji_gh);
 489                 if (error)
 490                         goto fail_gunlock_j;
 491         } else {
 492                 fs_info(sdp, "jid=%u, already locked for use\n", jd->jd_jid);
 493         }
 494
 495         fs_info(sdp, "jid=%u: Looking at journal...\n", jd->jd_jid);
 496
 497         error = gfs2_jdesc_check(jd);
 498         if (error)
 499                 goto fail_gunlock_ji;
 500
 501         error = gfs2_find_jhead(jd, &head);
 502         if (error)
 503                 goto fail_gunlock_ji;
 504
 505         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 506                 fs_info(sdp, "jid=%u: Acquiring the transaction lock...\n",
 507                         jd->jd_jid);
 508
 509                 t = jiffies;
 510
 511                 /* Acquire a shared hold on the freeze lock */
 512
 513                 error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED,
 514                                            LM_FLAG_NOEXP | LM_FLAG_PRIORITY,
 515                                            &thaw_gh);
 516                 if (error)
 517                         goto fail_gunlock_ji;
 518
 519                 if (test_bit(SDF_RORECOVERY, &sdp->sd_flags)) {
 520                         ro = 1;
 521                 } else if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
 522                         if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
 523                                 ro = 1;
 524                 } else {
 525                         if (sb_rdonly(sdp->sd_vfs)) {
 526                                 /* check if device itself is read-only */
 527                                 ro = bdev_read_only(sdp->sd_vfs->s_bdev);
 528                                 if (!ro) {
 529                                         fs_info(sdp, "recovery required on "
 530                                                 "read-only filesystem.\n");
 531                                         fs_info(sdp, "write access will be "
 532                                                 "enabled during recovery.\n");
 533                                 }
 534                         }
 535                 }
 536
 537                 if (ro) {
 538                         fs_warn(sdp, "jid=%u: Can't replay: read-only block "
 539                                 "device\n", jd->jd_jid);
 540                         error = -EROFS;
 541                         goto fail_gunlock_thaw;
 542                 }
 543
 544                 fs_info(sdp, "jid=%u: Replaying journal...\n", jd->jd_jid);
 545
 546                 for (pass = 0; pass < 2; pass++) {
 547                         lops_before_scan(jd, &head, pass);
 548                         error = foreach_descriptor(jd, head.lh_tail,
 549                                                    head.lh_blkno, pass);
 550                         lops_after_scan(jd, error, pass);
 551                         if (error)
 552                                 goto fail_gunlock_thaw;
 553                 }
 554
 555                 error = clean_journal(jd, &head);
 556                 if (error)
 557                         goto fail_gunlock_thaw;
 558
 559                 gfs2_glock_dq_uninit(&thaw_gh);
 560                 t = DIV_ROUND_UP(jiffies - t, HZ);
 561                 fs_info(sdp, "jid=%u: Journal replayed in %lus\n",
 562                         jd->jd_jid, t);
 563         }
 564
 565         gfs2_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
 566
 567         if (jlocked) {
 568                 gfs2_glock_dq_uninit(&ji_gh);
 569                 gfs2_glock_dq_uninit(&j_gh);
 570         }
 571
 572         fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
 573         goto done;
 574
 575 fail_gunlock_thaw:
 576         gfs2_glock_dq_uninit(&thaw_gh);
 577 fail_gunlock_ji:
 578         if (jlocked) {
 579                 gfs2_glock_dq_uninit(&ji_gh);
 580 fail_gunlock_j:
 581                 gfs2_glock_dq_uninit(&j_gh);
 582         }
 583
 584         fs_info(sdp, "jid=%u: %s\n", jd->jd_jid, (error) ? "Failed" : "Done");
 585 fail:
 586         jd->jd_recover_error = error;
 587         gfs2_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
 588 done:
 589         clear_bit(JDF_RECOVERY, &jd->jd_flags);
 590         smp_mb__after_atomic();
 591         wake_up_bit(&jd->jd_flags, JDF_RECOVERY);
 592 }
 593
 594 int gfs2_recover_journal(struct gfs2_jdesc *jd, bool wait)
 595 {
 596         int rv;
 597
 598         if (test_and_set_bit(JDF_RECOVERY, &jd->jd_flags))
 599                 return -EBUSY;
 600
 601         /* we have JDF_RECOVERY, queue should always succeed */
 602         rv = queue_work(gfs_recovery_wq, &jd->jd_work);
 603         BUG_ON(!rv);
 604
 605         if (wait)
 606                 wait_on_bit(&jd->jd_flags, JDF_RECOVERY,
 607                             TASK_UNINTERRUPTIBLE);
 608
 609         return wait ? jd->jd_recover_error : 0;
 610 }
 611