git.oblomov.eu Git - linux-2.6/blob - fs/gfs2/recovery.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2005 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 v.2.
   8  */
   9
  10 #include <linux/sched.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 <asm/semaphore.h>
  18
  19 #include "gfs2.h"
  20 #include "lm_interface.h"
  21 #include "incore.h"
  22 #include "bmap.h"
  23 #include "glock.h"
  24 #include "glops.h"
  25 #include "lm.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 int gfs2_replay_read_block(struct gfs2_jdesc *jd, unsigned int blk,
  34                            struct buffer_head **bh)
  35 {
  36         struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
  37         struct gfs2_glock *gl = ip->i_gl;
  38         int new = 0;
  39         uint64_t dblock;
  40         uint32_t extlen;
  41         int error;
  42
  43         error = gfs2_block_map(ip, blk, &new, &dblock,
  44                                &extlen);
  45         if (error)
  46                 return error;
  47         if (!dblock) {
  48                 gfs2_consist_inode(ip);
  49                 return -EIO;
  50         }
  51
  52         gfs2_meta_ra(gl, dblock, extlen);
  53         error = gfs2_meta_read(gl, dblock, DIO_START | DIO_WAIT, bh);
  54
  55         return error;
  56 }
  57
  58 int gfs2_revoke_add(struct gfs2_sbd *sdp, uint64_t blkno, unsigned int where)
  59 {
  60         struct list_head *head = &sdp->sd_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_KERNEL);
  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_sbd *sdp, uint64_t 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, &sdp->sd_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 < sdp->sd_replay_tail);
 104         a = (sdp->sd_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_sbd *sdp)
 112 {
 113         struct list_head *head = &sdp->sd_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 *head)
 139 {
 140         struct buffer_head *bh;
 141         struct gfs2_log_header lh;
 142         uint32_t hash;
 143         int error;
 144
 145         error = gfs2_replay_read_block(jd, blk, &bh);
 146         if (error)
 147                 return error;
 148
 149         memcpy(&lh, bh->b_data, sizeof(struct gfs2_log_header));
 150         lh.lh_hash = 0;
 151         hash = gfs2_disk_hash((char *)&lh, sizeof(struct gfs2_log_header));
 152         gfs2_log_header_in(&lh, bh->b_data);
 153
 154         brelse(bh);
 155
 156         if (lh.lh_header.mh_magic != GFS2_MAGIC ||
 157             lh.lh_header.mh_type != GFS2_METATYPE_LH ||
 158             lh.lh_blkno != blk ||
 159             lh.lh_hash != hash)
 160                 return 1;
 161
 162         *head = lh;
 163
 164         return 0;
 165 }
 166
 167 /**
 168  * find_good_lh - find a good log header
 169  * @jd: the journal
 170  * @blk: the segment to start searching from
 171  * @lh: the log header to fill in
 172  * @forward: if true search forward in the log, else search backward
 173  *
 174  * Call get_log_header() to get a log header for a segment, but if the
 175  * segment is bad, either scan forward or backward until we find a good one.
 176  *
 177  * Returns: errno
 178  */
 179
 180 static int find_good_lh(struct gfs2_jdesc *jd, unsigned int *blk,
 181                         struct gfs2_log_header *head)
 182 {
 183         unsigned int orig_blk = *blk;
 184         int error;
 185
 186         for (;;) {
 187                 error = get_log_header(jd, *blk, head);
 188                 if (error <= 0)
 189                         return error;
 190
 191                 if (++*blk == jd->jd_blocks)
 192                         *blk = 0;
 193
 194                 if (*blk == orig_blk) {
 195                         gfs2_consist_inode(jd->jd_inode->u.generic_ip);
 196                         return -EIO;
 197                 }
 198         }
 199 }
 200
 201 /**
 202  * jhead_scan - make sure we've found the head of the log
 203  * @jd: the journal
 204  * @head: this is filled in with the log descriptor of the head
 205  *
 206  * At this point, seg and lh should be either the head of the log or just
 207  * before.  Scan forward until we find the head.
 208  *
 209  * Returns: errno
 210  */
 211
 212 static int jhead_scan(struct gfs2_jdesc *jd, struct gfs2_log_header *head)
 213 {
 214         unsigned int blk = head->lh_blkno;
 215         struct gfs2_log_header lh;
 216         int error;
 217
 218         for (;;) {
 219                 if (++blk == jd->jd_blocks)
 220                         blk = 0;
 221
 222                 error = get_log_header(jd, blk, &lh);
 223                 if (error < 0)
 224                         return error;
 225                 if (error == 1)
 226                         continue;
 227
 228                 if (lh.lh_sequence == head->lh_sequence) {
 229                         gfs2_consist_inode(jd->jd_inode->u.generic_ip);
 230                         return -EIO;
 231                 }
 232                 if (lh.lh_sequence < head->lh_sequence)
 233                         break;
 234
 235                 *head = lh;
 236         }
 237
 238         return 0;
 239 }
 240
 241 /**
 242  * gfs2_find_jhead - find the head of a log
 243  * @jd: the journal
 244  * @head: the log descriptor for the head of the log is returned here
 245  *
 246  * Do a binary search of a journal and find the valid log entry with the
 247  * highest sequence number.  (i.e. the log head)
 248  *
 249  * Returns: errno
 250  */
 251
 252 int gfs2_find_jhead(struct gfs2_jdesc *jd, struct gfs2_log_header *head)
 253 {
 254         struct gfs2_log_header lh_1, lh_m;
 255         uint32_t blk_1, blk_2, blk_m;
 256         int error;
 257
 258         blk_1 = 0;
 259         blk_2 = jd->jd_blocks - 1;
 260
 261         for (;;) {
 262                 blk_m = (blk_1 + blk_2) / 2;
 263
 264                 error = find_good_lh(jd, &blk_1, &lh_1);
 265                 if (error)
 266                         return error;
 267
 268                 error = find_good_lh(jd, &blk_m, &lh_m);
 269                 if (error)
 270                         return error;
 271
 272                 if (blk_1 == blk_m || blk_m == blk_2)
 273                         break;
 274
 275                 if (lh_1.lh_sequence <= lh_m.lh_sequence)
 276                         blk_1 = blk_m;
 277                 else
 278                         blk_2 = blk_m;
 279         }
 280
 281         error = jhead_scan(jd, &lh_1);
 282         if (error)
 283                 return error;
 284
 285         *head = lh_1;
 286
 287         return error;
 288 }
 289
 290 /**
 291  * foreach_descriptor - go through the active part of the log
 292  * @jd: the journal
 293  * @start: the first log header in the active region
 294  * @end: the last log header (don't process the contents of this entry))
 295  *
 296  * Call a given function once for every log descriptor in the active
 297  * portion of the log.
 298  *
 299  * Returns: errno
 300  */
 301
 302 static int foreach_descriptor(struct gfs2_jdesc *jd, unsigned int start,
 303                               unsigned int end, int pass)
 304 {
 305         struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
 306         struct gfs2_sbd *sdp = ip->i_sbd;
 307         struct buffer_head *bh;
 308         struct gfs2_log_descriptor *ld;
 309         int error = 0;
 310         u32 length;
 311         __be64 *ptr;
 312         unsigned int offset = sizeof(struct gfs2_log_descriptor);
 313         offset += (sizeof(__be64)-1);
 314         offset &= ~(sizeof(__be64)-1);
 315
 316         while (start != end) {
 317                 error = gfs2_replay_read_block(jd, start, &bh);
 318                 if (error)
 319                         return error;
 320                 if (gfs2_meta_check(sdp, bh)) {
 321                         brelse(bh);
 322                         return -EIO;
 323                 }
 324                 ld = (struct gfs2_log_descriptor *)bh->b_data;
 325                 length = be32_to_cpu(ld->ld_length);
 326
 327                 if (be16_to_cpu(ld->ld_header.mh_type) == GFS2_METATYPE_LH) {
 328                         struct gfs2_log_header lh;
 329                         error = get_log_header(jd, start, &lh);
 330                         if (!error) {
 331                                 gfs2_replay_incr_blk(sdp, &start);
 332                                 continue;
 333                         }
 334                         if (error == 1) {
 335                                 gfs2_consist_inode(jd->jd_inode->u.generic_ip);
 336                                 error = -EIO;
 337                         }
 338                         brelse(bh);
 339                         return error;
 340                 } else if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LD)) {
 341                         brelse(bh);
 342                         return -EIO;
 343                 }
 344                 ptr = (__be64 *)(bh->b_data + offset);
 345                 error = lops_scan_elements(jd, start, ld, ptr, pass);
 346                 if (error) {
 347                         brelse(bh);
 348                         return error;
 349                 }
 350
 351                 while (length--)
 352                         gfs2_replay_incr_blk(sdp, &start);
 353
 354                 brelse(bh);
 355         }
 356
 357         return 0;
 358 }
 359
 360 /**
 361  * clean_journal - mark a dirty journal as being clean
 362  * @sdp: the filesystem
 363  * @jd: the journal
 364  * @gl: the journal's glock
 365  * @head: the head journal to start from
 366  *
 367  * Returns: errno
 368  */
 369
 370 static int clean_journal(struct gfs2_jdesc *jd, struct gfs2_log_header *head)
 371 {
 372         struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
 373         struct gfs2_sbd *sdp = ip->i_sbd;
 374         unsigned int lblock;
 375         int new = 0;
 376         uint64_t dblock;
 377         struct gfs2_log_header *lh;
 378         uint32_t hash;
 379         struct buffer_head *bh;
 380         int error;
 381
 382         lblock = head->lh_blkno;
 383         gfs2_replay_incr_blk(sdp, &lblock);
 384         error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
 385         if (error)
 386                 return error;
 387         if (!dblock) {
 388                 gfs2_consist_inode(ip);
 389                 return -EIO;
 390         }
 391
 392         bh = sb_getblk(sdp->sd_vfs, dblock);
 393         lock_buffer(bh);
 394         memset(bh->b_data, 0, bh->b_size);
 395         set_buffer_uptodate(bh);
 396         clear_buffer_dirty(bh);
 397         unlock_buffer(bh);
 398
 399         lh = (struct gfs2_log_header *)bh->b_data;
 400         memset(lh, 0, sizeof(struct gfs2_log_header));
 401         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 402         lh->lh_header.mh_type = cpu_to_be16(GFS2_METATYPE_LH);
 403         lh->lh_header.mh_format = cpu_to_be16(GFS2_FORMAT_LH);
 404         lh->lh_sequence = cpu_to_be64(head->lh_sequence + 1);
 405         lh->lh_flags = cpu_to_be32(GFS2_LOG_HEAD_UNMOUNT);
 406         lh->lh_blkno = cpu_to_be32(lblock);
 407         hash = gfs2_disk_hash((const char *)lh, sizeof(struct gfs2_log_header));
 408         lh->lh_hash = cpu_to_be32(hash);
 409
 410         set_buffer_dirty(bh);
 411         if (sync_dirty_buffer(bh))
 412                 gfs2_io_error_bh(sdp, bh);
 413         brelse(bh);
 414
 415         return error;
 416 }
 417
 418 /**
 419  * gfs2_recover_journal - recovery a given journal
 420  * @jd: the struct gfs2_jdesc describing the journal
 421  * @wait: Don't return until the journal is clean (or an error is encountered)
 422  *
 423  * Acquire the journal's lock, check to see if the journal is clean, and
 424  * do recovery if necessary.
 425  *
 426  * Returns: errno
 427  */
 428
 429 int gfs2_recover_journal(struct gfs2_jdesc *jd, int wait)
 430 {
 431         struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
 432         struct gfs2_sbd *sdp = ip->i_sbd;
 433         struct gfs2_log_header head;
 434         struct gfs2_holder j_gh, ji_gh, t_gh;
 435         unsigned long t;
 436         int ro = 0;
 437         unsigned int pass;
 438         int error;
 439
 440         fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n", jd->jd_jid);
 441
 442         /* Aquire the journal lock so we can do recovery */
 443
 444         error = gfs2_glock_nq_num(sdp,
 445                                   jd->jd_jid, &gfs2_journal_glops,
 446                                   LM_ST_EXCLUSIVE,
 447                                   LM_FLAG_NOEXP |
 448                                   ((wait) ? 0 : LM_FLAG_TRY) |
 449                                   GL_NOCACHE, &j_gh);
 450         switch (error) {
 451         case 0:
 452                 break;
 453
 454         case GLR_TRYFAILED:
 455                 fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
 456                 error = 0;
 457
 458         default:
 459                 goto fail;
 460         };
 461
 462         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
 463                                    LM_FLAG_NOEXP, &ji_gh);
 464         if (error)
 465                 goto fail_gunlock_j;
 466
 467         fs_info(sdp, "jid=%u: Looking at journal...\n", jd->jd_jid);
 468
 469         error = gfs2_jdesc_check(jd);
 470         if (error)
 471                 goto fail_gunlock_ji;
 472
 473         error = gfs2_find_jhead(jd, &head);
 474         if (error)
 475                 goto fail_gunlock_ji;
 476
 477         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 478                 fs_info(sdp, "jid=%u: Acquiring the transaction lock...\n",
 479                         jd->jd_jid);
 480
 481                 t = jiffies;
 482
 483                 /* Acquire a shared hold on the transaction lock */
 484
 485                 error = gfs2_glock_nq_init(sdp->sd_trans_gl,
 486                                            LM_ST_SHARED,
 487                                            LM_FLAG_NOEXP |
 488                                            LM_FLAG_PRIORITY |
 489                                            GL_NEVER_RECURSE |
 490                                            GL_NOCANCEL |
 491                                            GL_NOCACHE,
 492                                            &t_gh);
 493                 if (error)
 494                         goto fail_gunlock_ji;
 495
 496                 if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
 497                         if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
 498                                 ro = 1;
 499                 } else {
 500                         if (sdp->sd_vfs->s_flags & MS_RDONLY)
 501                                 ro = 1;
 502                 }
 503
 504                 if (ro) {
 505                         fs_warn(sdp, "jid=%u: Can't replay: read-only FS\n",
 506                                 jd->jd_jid);
 507                         error = -EROFS;
 508                         goto fail_gunlock_tr;
 509                 }
 510
 511                 fs_info(sdp, "jid=%u: Replaying journal...\n", jd->jd_jid);
 512
 513                 for (pass = 0; pass < 2; pass++) {
 514                         lops_before_scan(jd, &head, pass);
 515                         error = foreach_descriptor(jd, head.lh_tail,
 516                                                    head.lh_blkno, pass);
 517                         lops_after_scan(jd, error, pass);
 518                         if (error)
 519                                 goto fail_gunlock_tr;
 520                 }
 521
 522                 error = clean_journal(jd, &head);
 523                 if (error)
 524                         goto fail_gunlock_tr;
 525
 526                 gfs2_glock_dq_uninit(&t_gh);
 527
 528                 t = DIV_ROUND_UP(jiffies - t, HZ);
 529
 530                 fs_info(sdp, "jid=%u: Journal replayed in %lus\n",
 531                         jd->jd_jid, t);
 532         }
 533
 534         gfs2_glock_dq_uninit(&ji_gh);
 535
 536         gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
 537
 538         gfs2_glock_dq_uninit(&j_gh);
 539
 540         fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
 541
 542         return 0;
 543
 544  fail_gunlock_tr:
 545         gfs2_glock_dq_uninit(&t_gh);
 546
 547  fail_gunlock_ji:
 548         gfs2_glock_dq_uninit(&ji_gh);
 549
 550  fail_gunlock_j:
 551         gfs2_glock_dq_uninit(&j_gh);
 552
 553         fs_info(sdp, "jid=%u: %s\n", jd->jd_jid, (error) ? "Failed" : "Done");
 554
 555  fail:
 556         gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
 557
 558         return error;
 559 }
 560
 561 /**
 562  * gfs2_check_journals - Recover any dirty journals
 563  * @sdp: the filesystem
 564  *
 565  */
 566
 567 void gfs2_check_journals(struct gfs2_sbd *sdp)
 568 {
 569         struct gfs2_jdesc *jd;
 570
 571         for (;;) {
 572                 jd = gfs2_jdesc_find_dirty(sdp);
 573                 if (!jd)
 574                         break;
 575
 576                 if (jd != sdp->sd_jdesc)
 577                         gfs2_recover_journal(jd, NO_WAIT);
 578         }
 579 }
 580