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/slow-work.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_recovery_done(struct gfs2_sbd *sdp, unsigned int jid,
 429                                unsigned int message)
 430 {
 431         char env_jid[20];
 432         char env_status[20];
 433         char *envp[] = { env_jid, env_status, NULL };
 434         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 435         ls->ls_recover_jid_done = jid;
 436         ls->ls_recover_jid_status = message;
 437         sprintf(env_jid, "JID=%d", jid);
 438         sprintf(env_status, "RECOVERY=%s",
 439                 message == LM_RD_SUCCESS ? "Done" : "Failed");
 440         kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
 441 }
 442
 443 static int gfs2_recover_get_ref(struct slow_work *work)
 444 {
 445         struct gfs2_jdesc *jd = container_of(work, struct gfs2_jdesc, jd_work);
 446         if (test_and_set_bit(JDF_RECOVERY, &jd->jd_flags))
 447                 return -EBUSY;
 448         return 0;
 449 }
 450
 451 static void gfs2_recover_put_ref(struct slow_work *work)
 452 {
 453         struct gfs2_jdesc *jd = container_of(work, struct gfs2_jdesc, jd_work);
 454         clear_bit(JDF_RECOVERY, &jd->jd_flags);
 455         smp_mb__after_clear_bit();
 456         wake_up_bit(&jd->jd_flags, JDF_RECOVERY);
 457 }
 458
 459 static void gfs2_recover_work(struct slow_work *work)
 460 {
 461         struct gfs2_jdesc *jd = container_of(work, struct gfs2_jdesc, jd_work);
 462         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
 463         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
 464         struct gfs2_log_header_host head;
 465         struct gfs2_holder j_gh, ji_gh, t_gh;
 466         unsigned long t;
 467         int ro = 0;
 468         unsigned int pass;
 469         int error;
 470
 471         if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
 472                 fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n",
 473                         jd->jd_jid);
 474
 475                 /* Acquire the journal lock so we can do recovery */
 476
 477                 error = gfs2_glock_nq_num(sdp, jd->jd_jid, &gfs2_journal_glops,
 478                                           LM_ST_EXCLUSIVE,
 479                                           LM_FLAG_NOEXP | LM_FLAG_TRY | GL_NOCACHE,
 480                                           &j_gh);
 481                 switch (error) {
 482                 case 0:
 483                         break;
 484
 485                 case GLR_TRYFAILED:
 486                         fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
 487                         error = 0;
 488
 489                 default:
 490                         goto fail;
 491                 };
 492
 493                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
 494                                            LM_FLAG_NOEXP | GL_NOCACHE, &ji_gh);
 495                 if (error)
 496                         goto fail_gunlock_j;
 497         } else {
 498                 fs_info(sdp, "jid=%u, already locked for use\n", jd->jd_jid);
 499         }
 500
 501         fs_info(sdp, "jid=%u: Looking at journal...\n", jd->jd_jid);
 502
 503         error = gfs2_jdesc_check(jd);
 504         if (error)
 505                 goto fail_gunlock_ji;
 506
 507         error = gfs2_find_jhead(jd, &head);
 508         if (error)
 509                 goto fail_gunlock_ji;
 510
 511         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 512                 fs_info(sdp, "jid=%u: Acquiring the transaction lock...\n",
 513                         jd->jd_jid);
 514
 515                 t = jiffies;
 516
 517                 /* Acquire a shared hold on the transaction lock */
 518
 519                 error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED,
 520                                            LM_FLAG_NOEXP | LM_FLAG_PRIORITY |
 521                                            GL_NOCACHE, &t_gh);
 522                 if (error)
 523                         goto fail_gunlock_ji;
 524
 525                 if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
 526                         if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
 527                                 ro = 1;
 528                 } else {
 529                         if (sdp->sd_vfs->s_flags & MS_RDONLY) {
 530                                 /* check if device itself is read-only */
 531                                 ro = bdev_read_only(sdp->sd_vfs->s_bdev);
 532                                 if (!ro) {
 533                                         fs_info(sdp, "recovery required on "
 534                                                 "read-only filesystem.\n");
 535                                         fs_info(sdp, "write access will be "
 536                                                 "enabled during recovery.\n");
 537                                 }
 538                         }
 539                 }
 540
 541                 if (ro) {
 542                         fs_warn(sdp, "jid=%u: Can't replay: read-only block "
 543                                 "device\n", jd->jd_jid);
 544                         error = -EROFS;
 545                         goto fail_gunlock_tr;
 546                 }
 547
 548                 fs_info(sdp, "jid=%u: Replaying journal...\n", jd->jd_jid);
 549
 550                 for (pass = 0; pass < 2; pass++) {
 551                         lops_before_scan(jd, &head, pass);
 552                         error = foreach_descriptor(jd, head.lh_tail,
 553                                                    head.lh_blkno, pass);
 554                         lops_after_scan(jd, error, pass);
 555                         if (error)
 556                                 goto fail_gunlock_tr;
 557                 }
 558
 559                 error = clean_journal(jd, &head);
 560                 if (error)
 561                         goto fail_gunlock_tr;
 562
 563                 gfs2_glock_dq_uninit(&t_gh);
 564                 t = DIV_ROUND_UP(jiffies - t, HZ);
 565                 fs_info(sdp, "jid=%u: Journal replayed in %lus\n",
 566                         jd->jd_jid, t);
 567         }
 568
 569         if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
 570                 gfs2_glock_dq_uninit(&ji_gh);
 571
 572         gfs2_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
 573
 574         if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
 575                 gfs2_glock_dq_uninit(&j_gh);
 576
 577         fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
 578         return;
 579
 580 fail_gunlock_tr:
 581         gfs2_glock_dq_uninit(&t_gh);
 582 fail_gunlock_ji:
 583         if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
 584                 gfs2_glock_dq_uninit(&ji_gh);
 585 fail_gunlock_j:
 586                 gfs2_glock_dq_uninit(&j_gh);
 587         }
 588
 589         fs_info(sdp, "jid=%u: %s\n", jd->jd_jid, (error) ? "Failed" : "Done");
 590
 591 fail:
 592         gfs2_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
 593 }
 594
 595 struct slow_work_ops gfs2_recover_ops = {
 596         .get_ref = gfs2_recover_get_ref,
 597         .put_ref = gfs2_recover_put_ref,
 598         .execute = gfs2_recover_work,
 599 };
 600
 601
 602 static int gfs2_recovery_wait(void *word)
 603 {
 604         schedule();
 605         return 0;
 606 }
 607
 608 int gfs2_recover_journal(struct gfs2_jdesc *jd)
 609 {
 610         int rv;
 611         rv = slow_work_enqueue(&jd->jd_work);
 612         if (rv)
 613                 return rv;
 614         wait_on_bit(&jd->jd_flags, JDF_RECOVERY, gfs2_recovery_wait, TASK_UNINTERRUPTIBLE);
 615         return 0;
 616 }
 617