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) 2004-2006 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 "lm.h"
  24 #include "lops.h"
  25 #include "meta_io.h"
  26 #include "recovery.h"
  27 #include "super.h"
  28 #include "util.h"
  29 #include "dir.h"
  30
  31 int gfs2_replay_read_block(struct gfs2_jdesc *jd, unsigned int blk,
  32                            struct buffer_head **bh)
  33 {
  34         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
  35         struct gfs2_glock *gl = ip->i_gl;
  36         int new = 0;
  37         u64 dblock;
  38         u32 extlen;
  39         int error;
  40
  41         error = gfs2_extent_map(&ip->i_inode, blk, &new, &dblock, &extlen);
  42         if (error)
  43                 return error;
  44         if (!dblock) {
  45                 gfs2_consist_inode(ip);
  46                 return -EIO;
  47         }
  48
  49         *bh = gfs2_meta_ra(gl, dblock, extlen);
  50
  51         return error;
  52 }
  53
  54 int gfs2_revoke_add(struct gfs2_sbd *sdp, u64 blkno, unsigned int where)
  55 {
  56         struct list_head *head = &sdp->sd_revoke_list;
  57         struct gfs2_revoke_replay *rr;
  58         int found = 0;
  59
  60         list_for_each_entry(rr, head, rr_list) {
  61                 if (rr->rr_blkno == blkno) {
  62                         found = 1;
  63                         break;
  64                 }
  65         }
  66
  67         if (found) {
  68                 rr->rr_where = where;
  69                 return 0;
  70         }
  71
  72         rr = kmalloc(sizeof(struct gfs2_revoke_replay), GFP_KERNEL);
  73         if (!rr)
  74                 return -ENOMEM;
  75
  76         rr->rr_blkno = blkno;
  77         rr->rr_where = where;
  78         list_add(&rr->rr_list, head);
  79
  80         return 1;
  81 }
  82
  83 int gfs2_revoke_check(struct gfs2_sbd *sdp, u64 blkno, unsigned int where)
  84 {
  85         struct gfs2_revoke_replay *rr;
  86         int wrap, a, b, revoke;
  87         int found = 0;
  88
  89         list_for_each_entry(rr, &sdp->sd_revoke_list, rr_list) {
  90                 if (rr->rr_blkno == blkno) {
  91                         found = 1;
  92                         break;
  93                 }
  94         }
  95
  96         if (!found)
  97                 return 0;
  98
  99         wrap = (rr->rr_where < sdp->sd_replay_tail);
 100         a = (sdp->sd_replay_tail < where);
 101         b = (where < rr->rr_where);
 102         revoke = (wrap) ? (a || b) : (a && b);
 103
 104         return revoke;
 105 }
 106
 107 void gfs2_revoke_clean(struct gfs2_sbd *sdp)
 108 {
 109         struct list_head *head = &sdp->sd_revoke_list;
 110         struct gfs2_revoke_replay *rr;
 111
 112         while (!list_empty(head)) {
 113                 rr = list_entry(head->next, struct gfs2_revoke_replay, rr_list);
 114                 list_del(&rr->rr_list);
 115                 kfree(rr);
 116         }
 117 }
 118
 119 static int gfs2_log_header_in(struct gfs2_log_header_host *lh, const void *buf)
 120 {
 121         const struct gfs2_log_header *str = buf;
 122
 123         if (str->lh_header.mh_magic != cpu_to_be32(GFS2_MAGIC) ||
 124             str->lh_header.mh_type != cpu_to_be32(GFS2_METATYPE_LH))
 125                 return 1;
 126
 127         lh->lh_sequence = be64_to_cpu(str->lh_sequence);
 128         lh->lh_flags = be32_to_cpu(str->lh_flags);
 129         lh->lh_tail = be32_to_cpu(str->lh_tail);
 130         lh->lh_blkno = be32_to_cpu(str->lh_blkno);
 131         lh->lh_hash = be32_to_cpu(str->lh_hash);
 132         return 0;
 133 }
 134
 135 /**
 136  * get_log_header - read the log header for a given segment
 137  * @jd: the journal
 138  * @blk: the block to look at
 139  * @lh: the log header to return
 140  *
 141  * Read the log header for a given segement in a given journal.  Do a few
 142  * sanity checks on it.
 143  *
 144  * Returns: 0 on success,
 145  *          1 if the header was invalid or incomplete,
 146  *          errno on error
 147  */
 148
 149 static int get_log_header(struct gfs2_jdesc *jd, unsigned int blk,
 150                           struct gfs2_log_header_host *head)
 151 {
 152         struct buffer_head *bh;
 153         struct gfs2_log_header_host lh;
 154         const u32 nothing = 0;
 155         u32 hash;
 156         int error;
 157
 158         error = gfs2_replay_read_block(jd, blk, &bh);
 159         if (error)
 160                 return error;
 161
 162         hash = crc32_le((u32)~0, bh->b_data, sizeof(struct gfs2_log_header) -
 163                                              sizeof(u32));
 164         hash = crc32_le(hash, (unsigned char const *)&nothing, sizeof(nothing));
 165         hash ^= (u32)~0;
 166         error = gfs2_log_header_in(&lh, bh->b_data);
 167         brelse(bh);
 168
 169         if (error || lh.lh_blkno != blk || lh.lh_hash != hash)
 170                 return 1;
 171
 172         *head = lh;
 173
 174         return 0;
 175 }
 176
 177 /**
 178  * find_good_lh - find a good log header
 179  * @jd: the journal
 180  * @blk: the segment to start searching from
 181  * @lh: the log header to fill in
 182  * @forward: if true search forward in the log, else search backward
 183  *
 184  * Call get_log_header() to get a log header for a segment, but if the
 185  * segment is bad, either scan forward or backward until we find a good one.
 186  *
 187  * Returns: errno
 188  */
 189
 190 static int find_good_lh(struct gfs2_jdesc *jd, unsigned int *blk,
 191                         struct gfs2_log_header_host *head)
 192 {
 193         unsigned int orig_blk = *blk;
 194         int error;
 195
 196         for (;;) {
 197                 error = get_log_header(jd, *blk, head);
 198                 if (error <= 0)
 199                         return error;
 200
 201                 if (++*blk == jd->jd_blocks)
 202                         *blk = 0;
 203
 204                 if (*blk == orig_blk) {
 205                         gfs2_consist_inode(GFS2_I(jd->jd_inode));
 206                         return -EIO;
 207                 }
 208         }
 209 }
 210
 211 /**
 212  * jhead_scan - make sure we've found the head of the log
 213  * @jd: the journal
 214  * @head: this is filled in with the log descriptor of the head
 215  *
 216  * At this point, seg and lh should be either the head of the log or just
 217  * before.  Scan forward until we find the head.
 218  *
 219  * Returns: errno
 220  */
 221
 222 static int jhead_scan(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
 223 {
 224         unsigned int blk = head->lh_blkno;
 225         struct gfs2_log_header_host lh;
 226         int error;
 227
 228         for (;;) {
 229                 if (++blk == jd->jd_blocks)
 230                         blk = 0;
 231
 232                 error = get_log_header(jd, blk, &lh);
 233                 if (error < 0)
 234                         return error;
 235                 if (error == 1)
 236                         continue;
 237
 238                 if (lh.lh_sequence == head->lh_sequence) {
 239                         gfs2_consist_inode(GFS2_I(jd->jd_inode));
 240                         return -EIO;
 241                 }
 242                 if (lh.lh_sequence < head->lh_sequence)
 243                         break;
 244
 245                 *head = lh;
 246         }
 247
 248         return 0;
 249 }
 250
 251 /**
 252  * gfs2_find_jhead - find the head of a log
 253  * @jd: the journal
 254  * @head: the log descriptor for the head of the log is returned here
 255  *
 256  * Do a binary search of a journal and find the valid log entry with the
 257  * highest sequence number.  (i.e. the log head)
 258  *
 259  * Returns: errno
 260  */
 261
 262 int gfs2_find_jhead(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
 263 {
 264         struct gfs2_log_header_host lh_1, lh_m;
 265         u32 blk_1, blk_2, blk_m;
 266         int error;
 267
 268         blk_1 = 0;
 269         blk_2 = jd->jd_blocks - 1;
 270
 271         for (;;) {
 272                 blk_m = (blk_1 + blk_2) / 2;
 273
 274                 error = find_good_lh(jd, &blk_1, &lh_1);
 275                 if (error)
 276                         return error;
 277
 278                 error = find_good_lh(jd, &blk_m, &lh_m);
 279                 if (error)
 280                         return error;
 281
 282                 if (blk_1 == blk_m || blk_m == blk_2)
 283                         break;
 284
 285                 if (lh_1.lh_sequence <= lh_m.lh_sequence)
 286                         blk_1 = blk_m;
 287                 else
 288                         blk_2 = blk_m;
 289         }
 290
 291         error = jhead_scan(jd, &lh_1);
 292         if (error)
 293                 return error;
 294
 295         *head = lh_1;
 296
 297         return error;
 298 }
 299
 300 /**
 301  * foreach_descriptor - go through the active part of the log
 302  * @jd: the journal
 303  * @start: the first log header in the active region
 304  * @end: the last log header (don't process the contents of this entry))
 305  *
 306  * Call a given function once for every log descriptor in the active
 307  * portion of the log.
 308  *
 309  * Returns: errno
 310  */
 311
 312 static int foreach_descriptor(struct gfs2_jdesc *jd, unsigned int start,
 313                               unsigned int end, int pass)
 314 {
 315         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
 316         struct buffer_head *bh;
 317         struct gfs2_log_descriptor *ld;
 318         int error = 0;
 319         u32 length;
 320         __be64 *ptr;
 321         unsigned int offset = sizeof(struct gfs2_log_descriptor);
 322         offset += sizeof(__be64) - 1;
 323         offset &= ~(sizeof(__be64) - 1);
 324
 325         while (start != end) {
 326                 error = gfs2_replay_read_block(jd, start, &bh);
 327                 if (error)
 328                         return error;
 329                 if (gfs2_meta_check(sdp, bh)) {
 330                         brelse(bh);
 331                         return -EIO;
 332                 }
 333                 ld = (struct gfs2_log_descriptor *)bh->b_data;
 334                 length = be32_to_cpu(ld->ld_length);
 335
 336                 if (be32_to_cpu(ld->ld_header.mh_type) == GFS2_METATYPE_LH) {
 337                         struct gfs2_log_header_host lh;
 338                         error = get_log_header(jd, start, &lh);
 339                         if (!error) {
 340                                 gfs2_replay_incr_blk(sdp, &start);
 341                                 brelse(bh);
 342                                 continue;
 343                         }
 344                         if (error == 1) {
 345                                 gfs2_consist_inode(GFS2_I(jd->jd_inode));
 346                                 error = -EIO;
 347                         }
 348                         brelse(bh);
 349                         return error;
 350                 } else if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LD)) {
 351                         brelse(bh);
 352                         return -EIO;
 353                 }
 354                 ptr = (__be64 *)(bh->b_data + offset);
 355                 error = lops_scan_elements(jd, start, ld, ptr, pass);
 356                 if (error) {
 357                         brelse(bh);
 358                         return error;
 359                 }
 360
 361                 while (length--)
 362                         gfs2_replay_incr_blk(sdp, &start);
 363
 364                 brelse(bh);
 365         }
 366
 367         return 0;
 368 }
 369
 370 /**
 371  * clean_journal - mark a dirty journal as being clean
 372  * @sdp: the filesystem
 373  * @jd: the journal
 374  * @gl: the journal's glock
 375  * @head: the head journal to start from
 376  *
 377  * Returns: errno
 378  */
 379
 380 static int clean_journal(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
 381 {
 382         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
 383         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
 384         unsigned int lblock;
 385         struct gfs2_log_header *lh;
 386         u32 hash;
 387         struct buffer_head *bh;
 388         int error;
 389         struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
 390
 391         lblock = head->lh_blkno;
 392         gfs2_replay_incr_blk(sdp, &lblock);
 393         bh_map.b_size = 1 << ip->i_inode.i_blkbits;
 394         error = gfs2_block_map(&ip->i_inode, lblock, 0, &bh_map);
 395         if (error)
 396                 return error;
 397         if (!bh_map.b_blocknr) {
 398                 gfs2_consist_inode(ip);
 399                 return -EIO;
 400         }
 401
 402         bh = sb_getblk(sdp->sd_vfs, bh_map.b_blocknr);
 403         lock_buffer(bh);
 404         memset(bh->b_data, 0, bh->b_size);
 405         set_buffer_uptodate(bh);
 406         clear_buffer_dirty(bh);
 407         unlock_buffer(bh);
 408
 409         lh = (struct gfs2_log_header *)bh->b_data;
 410         memset(lh, 0, sizeof(struct gfs2_log_header));
 411         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 412         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
 413         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
 414         lh->lh_sequence = cpu_to_be64(head->lh_sequence + 1);
 415         lh->lh_flags = cpu_to_be32(GFS2_LOG_HEAD_UNMOUNT);
 416         lh->lh_blkno = cpu_to_be32(lblock);
 417         hash = gfs2_disk_hash((const char *)lh, sizeof(struct gfs2_log_header));
 418         lh->lh_hash = cpu_to_be32(hash);
 419
 420         set_buffer_dirty(bh);
 421         if (sync_dirty_buffer(bh))
 422                 gfs2_io_error_bh(sdp, bh);
 423         brelse(bh);
 424
 425         return error;
 426 }
 427
 428 /**
 429  * gfs2_recover_journal - recovery a given journal
 430  * @jd: the struct gfs2_jdesc describing the journal
 431  *
 432  * Acquire the journal's lock, check to see if the journal is clean, and
 433  * do recovery if necessary.
 434  *
 435  * Returns: errno
 436  */
 437
 438 int gfs2_recover_journal(struct gfs2_jdesc *jd)
 439 {
 440         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
 441         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
 442         struct gfs2_log_header_host head;
 443         struct gfs2_holder j_gh, ji_gh, t_gh;
 444         unsigned long t;
 445         int ro = 0;
 446         unsigned int pass;
 447         int error;
 448
 449         if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
 450                 fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n",
 451                         jd->jd_jid);
 452
 453                 /* Aquire the journal lock so we can do recovery */
 454
 455                 error = gfs2_glock_nq_num(sdp, jd->jd_jid, &gfs2_journal_glops,
 456                                           LM_ST_EXCLUSIVE,
 457                                           LM_FLAG_NOEXP | LM_FLAG_TRY | GL_NOCACHE,
 458                                           &j_gh);
 459                 switch (error) {
 460                 case 0:
 461                         break;
 462
 463                 case GLR_TRYFAILED:
 464                         fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
 465                         error = 0;
 466
 467                 default:
 468                         goto fail;
 469                 };
 470
 471                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
 472                                            LM_FLAG_NOEXP, &ji_gh);
 473                 if (error)
 474                         goto fail_gunlock_j;
 475         } else {
 476                 fs_info(sdp, "jid=%u, already locked for use\n", jd->jd_jid);
 477         }
 478
 479         fs_info(sdp, "jid=%u: Looking at journal...\n", jd->jd_jid);
 480
 481         error = gfs2_jdesc_check(jd);
 482         if (error)
 483                 goto fail_gunlock_ji;
 484
 485         error = gfs2_find_jhead(jd, &head);
 486         if (error)
 487                 goto fail_gunlock_ji;
 488
 489         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 490                 fs_info(sdp, "jid=%u: Acquiring the transaction lock...\n",
 491                         jd->jd_jid);
 492
 493                 t = jiffies;
 494
 495                 /* Acquire a shared hold on the transaction lock */
 496
 497                 error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED,
 498                                            LM_FLAG_NOEXP | LM_FLAG_PRIORITY |
 499                                            GL_NOCANCEL | GL_NOCACHE, &t_gh);
 500                 if (error)
 501                         goto fail_gunlock_ji;
 502
 503                 if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
 504                         if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
 505                                 ro = 1;
 506                 } else {
 507                         if (sdp->sd_vfs->s_flags & MS_RDONLY)
 508                                 ro = 1;
 509                 }
 510
 511                 if (ro) {
 512                         fs_warn(sdp, "jid=%u: Can't replay: read-only FS\n",
 513                                 jd->jd_jid);
 514                         error = -EROFS;
 515                         goto fail_gunlock_tr;
 516                 }
 517
 518                 fs_info(sdp, "jid=%u: Replaying journal...\n", jd->jd_jid);
 519
 520                 for (pass = 0; pass < 2; pass++) {
 521                         lops_before_scan(jd, &head, pass);
 522                         error = foreach_descriptor(jd, head.lh_tail,
 523                                                    head.lh_blkno, pass);
 524                         lops_after_scan(jd, error, pass);
 525                         if (error)
 526                                 goto fail_gunlock_tr;
 527                 }
 528
 529                 error = clean_journal(jd, &head);
 530                 if (error)
 531                         goto fail_gunlock_tr;
 532
 533                 gfs2_glock_dq_uninit(&t_gh);
 534                 t = DIV_ROUND_UP(jiffies - t, HZ);
 535                 fs_info(sdp, "jid=%u: Journal replayed in %lus\n",
 536                         jd->jd_jid, t);
 537         }
 538
 539         if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
 540                 gfs2_glock_dq_uninit(&ji_gh);
 541
 542         gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
 543
 544         if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
 545                 gfs2_glock_dq_uninit(&j_gh);
 546
 547         fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
 548         return 0;
 549
 550 fail_gunlock_tr:
 551         gfs2_glock_dq_uninit(&t_gh);
 552 fail_gunlock_ji:
 553         if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
 554                 gfs2_glock_dq_uninit(&ji_gh);
 555 fail_gunlock_j:
 556                 gfs2_glock_dq_uninit(&j_gh);
 557         }
 558
 559         fs_info(sdp, "jid=%u: %s\n", jd->jd_jid, (error) ? "Failed" : "Done");
 560
 561 fail:
 562         gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
 563         return error;
 564 }
 565
 566 /**
 567  * gfs2_check_journals - Recover any dirty journals
 568  * @sdp: the filesystem
 569  *
 570  */
 571
 572 void gfs2_check_journals(struct gfs2_sbd *sdp)
 573 {
 574         struct gfs2_jdesc *jd;
 575
 576         for (;;) {
 577                 jd = gfs2_jdesc_find_dirty(sdp);
 578                 if (!jd)
 579                         break;
 580
 581                 if (jd != sdp->sd_jdesc)
 582                         gfs2_recover_journal(jd);
 583         }
 584 }
 585