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 <asm/semaphore.h>
  16
  17 #include "gfs2.h"
  18 #include "bmap.h"
  19 #include "glock.h"
  20 #include "glops.h"
  21 #include "lm.h"
  22 #include "lops.h"
  23 #include "meta_io.h"
  24 #include "recovery.h"
  25 #include "super.h"
  26
  27 int gfs2_replay_read_block(struct gfs2_jdesc *jd, unsigned int blk,
  28                            struct buffer_head **bh)
  29 {
  30         struct gfs2_glock *gl = jd->jd_inode->i_gl;
  31         int new = 0;
  32         uint64_t dblock;
  33         uint32_t extlen;
  34         int error;
  35
  36         error = gfs2_block_map(jd->jd_inode, blk, &new, &dblock, &extlen);
  37         if (error)
  38                 return error;
  39         if (!dblock) {
  40                 gfs2_consist_inode(jd->jd_inode);
  41                 return -EIO;
  42         }
  43
  44         gfs2_meta_ra(gl, dblock, extlen);
  45         error = gfs2_meta_read(gl, dblock, DIO_START | DIO_WAIT, bh);
  46
  47         return error;
  48 }
  49
  50 int gfs2_revoke_add(struct gfs2_sbd *sdp, uint64_t blkno, unsigned int where)
  51 {
  52         struct list_head *head = &sdp->sd_revoke_list;
  53         struct gfs2_revoke_replay *rr;
  54         int found = 0;
  55
  56         list_for_each_entry(rr, head, rr_list) {
  57                 if (rr->rr_blkno == blkno) {
  58                         found = 1;
  59                         break;
  60                 }
  61         }
  62
  63         if (found) {
  64                 rr->rr_where = where;
  65                 return 0;
  66         }
  67
  68         rr = kmalloc(sizeof(struct gfs2_revoke_replay), GFP_KERNEL);
  69         if (!rr)
  70                 return -ENOMEM;
  71
  72         rr->rr_blkno = blkno;
  73         rr->rr_where = where;
  74         list_add(&rr->rr_list, head);
  75
  76         return 1;
  77 }
  78
  79 int gfs2_revoke_check(struct gfs2_sbd *sdp, uint64_t blkno, unsigned int where)
  80 {
  81         struct gfs2_revoke_replay *rr;
  82         int wrap, a, b, revoke;
  83         int found = 0;
  84
  85         list_for_each_entry(rr, &sdp->sd_revoke_list, rr_list) {
  86                 if (rr->rr_blkno == blkno) {
  87                         found = 1;
  88                         break;
  89                 }
  90         }
  91
  92         if (!found)
  93                 return 0;
  94
  95         wrap = (rr->rr_where < sdp->sd_replay_tail);
  96         a = (sdp->sd_replay_tail < where);
  97         b = (where < rr->rr_where);
  98         revoke = (wrap) ? (a || b) : (a && b);
  99
 100         return revoke;
 101 }
 102
 103 void gfs2_revoke_clean(struct gfs2_sbd *sdp)
 104 {
 105         struct list_head *head = &sdp->sd_revoke_list;
 106         struct gfs2_revoke_replay *rr;
 107
 108         while (!list_empty(head)) {
 109                 rr = list_entry(head->next, struct gfs2_revoke_replay, rr_list);
 110                 list_del(&rr->rr_list);
 111                 kfree(rr);
 112         }
 113 }
 114
 115 /**
 116  * get_log_header - read the log header for a given segment
 117  * @jd: the journal
 118  * @blk: the block to look at
 119  * @lh: the log header to return
 120  *
 121  * Read the log header for a given segement in a given journal.  Do a few
 122  * sanity checks on it.
 123  *
 124  * Returns: 0 on success,
 125  *          1 if the header was invalid or incomplete,
 126  *          errno on error
 127  */
 128
 129 static int get_log_header(struct gfs2_jdesc *jd, unsigned int blk,
 130                           struct gfs2_log_header *head)
 131 {
 132         struct buffer_head *bh;
 133         struct gfs2_log_header lh;
 134         uint32_t hash;
 135         int error;
 136
 137         error = gfs2_replay_read_block(jd, blk, &bh);
 138         if (error)
 139                 return error;
 140
 141         memcpy(&lh, bh->b_data, sizeof(struct gfs2_log_header));
 142         lh.lh_hash = 0;
 143         hash = gfs2_disk_hash((char *)&lh, sizeof(struct gfs2_log_header));
 144         gfs2_log_header_in(&lh, bh->b_data);
 145
 146         brelse(bh);
 147
 148         if (lh.lh_header.mh_magic != GFS2_MAGIC ||
 149             lh.lh_header.mh_type != GFS2_METATYPE_LH ||
 150             lh.lh_blkno != blk ||
 151             lh.lh_hash != hash)
 152                 return 1;
 153
 154         *head = lh;
 155
 156         return 0;
 157 }
 158
 159 /**
 160  * find_good_lh - find a good log header
 161  * @jd: the journal
 162  * @blk: the segment to start searching from
 163  * @lh: the log header to fill in
 164  * @forward: if true search forward in the log, else search backward
 165  *
 166  * Call get_log_header() to get a log header for a segment, but if the
 167  * segment is bad, either scan forward or backward until we find a good one.
 168  *
 169  * Returns: errno
 170  */
 171
 172 static int find_good_lh(struct gfs2_jdesc *jd, unsigned int *blk,
 173                         struct gfs2_log_header *head)
 174 {
 175         unsigned int orig_blk = *blk;
 176         int error;
 177
 178         for (;;) {
 179                 error = get_log_header(jd, *blk, head);
 180                 if (error <= 0)
 181                         return error;
 182
 183                 if (++*blk == jd->jd_blocks)
 184                         *blk = 0;
 185
 186                 if (*blk == orig_blk) {
 187                         gfs2_consist_inode(jd->jd_inode);
 188                         return -EIO;
 189                 }
 190         }
 191 }
 192
 193 /**
 194  * jhead_scan - make sure we've found the head of the log
 195  * @jd: the journal
 196  * @head: this is filled in with the log descriptor of the head
 197  *
 198  * At this point, seg and lh should be either the head of the log or just
 199  * before.  Scan forward until we find the head.
 200  *
 201  * Returns: errno
 202  */
 203
 204 static int jhead_scan(struct gfs2_jdesc *jd, struct gfs2_log_header *head)
 205 {
 206         unsigned int blk = head->lh_blkno;
 207         struct gfs2_log_header lh;
 208         int error;
 209
 210         for (;;) {
 211                 if (++blk == jd->jd_blocks)
 212                         blk = 0;
 213
 214                 error = get_log_header(jd, blk, &lh);
 215                 if (error < 0)
 216                         return error;
 217                 if (error == 1)
 218                         continue;
 219
 220                 if (lh.lh_sequence == head->lh_sequence) {
 221                         gfs2_consist_inode(jd->jd_inode);
 222                         return -EIO;
 223                 }
 224                 if (lh.lh_sequence < head->lh_sequence)
 225                         break;
 226
 227                 *head = lh;
 228         }
 229
 230         return 0;
 231 }
 232
 233 /**
 234  * gfs2_find_jhead - find the head of a log
 235  * @jd: the journal
 236  * @head: the log descriptor for the head of the log is returned here
 237  *
 238  * Do a binary search of a journal and find the valid log entry with the
 239  * highest sequence number.  (i.e. the log head)
 240  *
 241  * Returns: errno
 242  */
 243
 244 int gfs2_find_jhead(struct gfs2_jdesc *jd, struct gfs2_log_header *head)
 245 {
 246         struct gfs2_log_header lh_1, lh_m;
 247         uint32_t blk_1, blk_2, blk_m;
 248         int error;
 249
 250         blk_1 = 0;
 251         blk_2 = jd->jd_blocks - 1;
 252
 253         for (;;) {
 254                 blk_m = (blk_1 + blk_2) / 2;
 255
 256                 error = find_good_lh(jd, &blk_1, &lh_1);
 257                 if (error)
 258                         return error;
 259
 260                 error = find_good_lh(jd, &blk_m, &lh_m);
 261                 if (error)
 262                         return error;
 263
 264                 if (blk_1 == blk_m || blk_m == blk_2)
 265                         break;
 266
 267                 if (lh_1.lh_sequence <= lh_m.lh_sequence)
 268                         blk_1 = blk_m;
 269                 else
 270                         blk_2 = blk_m;
 271         }
 272
 273         error = jhead_scan(jd, &lh_1);
 274         if (error)
 275                 return error;
 276
 277         *head = lh_1;
 278
 279         return error;
 280 }
 281
 282 /**
 283  * foreach_descriptor - go through the active part of the log
 284  * @jd: the journal
 285  * @start: the first log header in the active region
 286  * @end: the last log header (don't process the contents of this entry))
 287  *
 288  * Call a given function once for every log descriptor in the active
 289  * portion of the log.
 290  *
 291  * Returns: errno
 292  */
 293
 294 static int foreach_descriptor(struct gfs2_jdesc *jd, unsigned int start,
 295                               unsigned int end, int pass)
 296 {
 297         struct gfs2_sbd *sdp = jd->jd_inode->i_sbd;
 298         struct buffer_head *bh;
 299         struct gfs2_log_descriptor *ld;
 300         int error = 0;
 301         u32 length;
 302         __be64 *ptr;
 303         unsigned int offset = sizeof(struct gfs2_log_descriptor);
 304         offset += (sizeof(__be64)-1);
 305         offset &= ~(sizeof(__be64)-1);
 306
 307         while (start != end) {
 308                 error = gfs2_replay_read_block(jd, start, &bh);
 309                 if (error)
 310                         return error;
 311                 if (gfs2_meta_check(sdp, bh)) {
 312                         brelse(bh);
 313                         return -EIO;
 314                 }
 315                 ld = (struct gfs2_log_descriptor *)bh->b_data;
 316                 length = be32_to_cpu(ld->ld_length);
 317
 318                 if (be16_to_cpu(ld->ld_header.mh_type) == GFS2_METATYPE_LH) {
 319                         struct gfs2_log_header lh;
 320                         error = get_log_header(jd, start, &lh);
 321                         if (!error) {
 322                                 gfs2_replay_incr_blk(sdp, &start);
 323                                 continue;
 324                         }
 325                         if (error == 1) {
 326                                 gfs2_consist_inode(jd->jd_inode);
 327                                 error = -EIO;
 328                         }
 329                         brelse(bh);
 330                         return error;
 331                 } else if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LD)) {
 332                         brelse(bh);
 333                         return -EIO;
 334                 }
 335                 ptr = (__be64 *)(bh->b_data + offset);
 336                 error = lops_scan_elements(jd, start, ld, ptr, pass);
 337                 if (error) {
 338                         brelse(bh);
 339                         return error;
 340                 }
 341
 342                 while (length--)
 343                         gfs2_replay_incr_blk(sdp, &start);
 344
 345                 brelse(bh);
 346         }
 347
 348         return 0;
 349 }
 350
 351 /**
 352  * clean_journal - mark a dirty journal as being clean
 353  * @sdp: the filesystem
 354  * @jd: the journal
 355  * @gl: the journal's glock
 356  * @head: the head journal to start from
 357  *
 358  * Returns: errno
 359  */
 360
 361 static int clean_journal(struct gfs2_jdesc *jd, struct gfs2_log_header *head)
 362 {
 363         struct gfs2_inode *ip = jd->jd_inode;
 364         struct gfs2_sbd *sdp = ip->i_sbd;
 365         unsigned int lblock;
 366         int new = 0;
 367         uint64_t dblock;
 368         struct gfs2_log_header *lh;
 369         uint32_t hash;
 370         struct buffer_head *bh;
 371         int error;
 372
 373         lblock = head->lh_blkno;
 374         gfs2_replay_incr_blk(sdp, &lblock);
 375         error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
 376         if (error)
 377                 return error;
 378         if (!dblock) {
 379                 gfs2_consist_inode(ip);
 380                 return -EIO;
 381         }
 382
 383         bh = sb_getblk(sdp->sd_vfs, dblock);
 384         lock_buffer(bh);
 385         memset(bh->b_data, 0, bh->b_size);
 386         set_buffer_uptodate(bh);
 387         clear_buffer_dirty(bh);
 388         unlock_buffer(bh);
 389
 390         lh = (struct gfs2_log_header *)bh->b_data;
 391         memset(lh, 0, sizeof(struct gfs2_log_header));
 392         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 393         lh->lh_header.mh_type = cpu_to_be16(GFS2_METATYPE_LH);
 394         lh->lh_header.mh_format = cpu_to_be16(GFS2_FORMAT_LH);
 395         lh->lh_sequence = cpu_to_be64(head->lh_sequence + 1);
 396         lh->lh_flags = cpu_to_be32(GFS2_LOG_HEAD_UNMOUNT);
 397         lh->lh_blkno = cpu_to_be32(lblock);
 398         hash = gfs2_disk_hash((const char *)lh, sizeof(struct gfs2_log_header));
 399         lh->lh_hash = cpu_to_be32(hash);
 400
 401         set_buffer_dirty(bh);
 402         if (sync_dirty_buffer(bh))
 403                 gfs2_io_error_bh(sdp, bh);
 404         brelse(bh);
 405
 406         return error;
 407 }
 408
 409 /**
 410  * gfs2_recover_journal - recovery a given journal
 411  * @jd: the struct gfs2_jdesc describing the journal
 412  * @wait: Don't return until the journal is clean (or an error is encountered)
 413  *
 414  * Acquire the journal's lock, check to see if the journal is clean, and
 415  * do recovery if necessary.
 416  *
 417  * Returns: errno
 418  */
 419
 420 int gfs2_recover_journal(struct gfs2_jdesc *jd, int wait)
 421 {
 422         struct gfs2_sbd *sdp = jd->jd_inode->i_sbd;
 423         struct gfs2_log_header head;
 424         struct gfs2_holder j_gh, ji_gh, t_gh;
 425         unsigned long t;
 426         int ro = 0;
 427         unsigned int pass;
 428         int error;
 429
 430         fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n", jd->jd_jid);
 431
 432         /* Aquire the journal lock so we can do recovery */
 433
 434         error = gfs2_glock_nq_num(sdp,
 435                                   jd->jd_jid, &gfs2_journal_glops,
 436                                   LM_ST_EXCLUSIVE,
 437                                   LM_FLAG_NOEXP |
 438                                   ((wait) ? 0 : LM_FLAG_TRY) |
 439                                   GL_NOCACHE, &j_gh);
 440         switch (error) {
 441         case 0:
 442                 break;
 443
 444         case GLR_TRYFAILED:
 445                 fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
 446                 error = 0;
 447
 448         default:
 449                 goto fail;
 450         };
 451
 452         error = gfs2_glock_nq_init(jd->jd_inode->i_gl, LM_ST_SHARED,
 453                                    LM_FLAG_NOEXP, &ji_gh);
 454         if (error)
 455                 goto fail_gunlock_j;
 456
 457         fs_info(sdp, "jid=%u: Looking at journal...\n", jd->jd_jid);
 458
 459         error = gfs2_jdesc_check(jd);
 460         if (error)
 461                 goto fail_gunlock_ji;
 462
 463         error = gfs2_find_jhead(jd, &head);
 464         if (error)
 465                 goto fail_gunlock_ji;
 466
 467         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 468                 fs_info(sdp, "jid=%u: Acquiring the transaction lock...\n",
 469                         jd->jd_jid);
 470
 471                 t = jiffies;
 472
 473                 /* Acquire a shared hold on the transaction lock */
 474
 475                 error = gfs2_glock_nq_init(sdp->sd_trans_gl,
 476                                            LM_ST_SHARED,
 477                                            LM_FLAG_NOEXP |
 478                                            LM_FLAG_PRIORITY |
 479                                            GL_NEVER_RECURSE |
 480                                            GL_NOCANCEL |
 481                                            GL_NOCACHE,
 482                                            &t_gh);
 483                 if (error)
 484                         goto fail_gunlock_ji;
 485
 486                 if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
 487                         if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
 488                                 ro = 1;
 489                 } else {
 490                         if (sdp->sd_vfs->s_flags & MS_RDONLY)
 491                                 ro = 1;
 492                 }
 493
 494                 if (ro) {
 495                         fs_warn(sdp, "jid=%u: Can't replay: read-only FS\n",
 496                                 jd->jd_jid);
 497                         error = -EROFS;
 498                         goto fail_gunlock_tr;
 499                 }
 500
 501                 fs_info(sdp, "jid=%u: Replaying journal...\n", jd->jd_jid);
 502
 503                 for (pass = 0; pass < 2; pass++) {
 504                         lops_before_scan(jd, &head, pass);
 505                         error = foreach_descriptor(jd, head.lh_tail,
 506                                                    head.lh_blkno, pass);
 507                         lops_after_scan(jd, error, pass);
 508                         if (error)
 509                                 goto fail_gunlock_tr;
 510                 }
 511
 512                 error = clean_journal(jd, &head);
 513                 if (error)
 514                         goto fail_gunlock_tr;
 515
 516                 gfs2_glock_dq_uninit(&t_gh);
 517
 518                 t = DIV_RU(jiffies - t, HZ);
 519
 520                 fs_info(sdp, "jid=%u: Journal replayed in %lus\n",
 521                         jd->jd_jid, t);
 522         }
 523
 524         gfs2_glock_dq_uninit(&ji_gh);
 525
 526         gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
 527
 528         gfs2_glock_dq_uninit(&j_gh);
 529
 530         fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
 531
 532         return 0;
 533
 534  fail_gunlock_tr:
 535         gfs2_glock_dq_uninit(&t_gh);
 536
 537  fail_gunlock_ji:
 538         gfs2_glock_dq_uninit(&ji_gh);
 539
 540  fail_gunlock_j:
 541         gfs2_glock_dq_uninit(&j_gh);
 542
 543         fs_info(sdp, "jid=%u: %s\n", jd->jd_jid, (error) ? "Failed" : "Done");
 544
 545  fail:
 546         gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
 547
 548         return error;
 549 }
 550
 551 /**
 552  * gfs2_check_journals - Recover any dirty journals
 553  * @sdp: the filesystem
 554  *
 555  */
 556
 557 void gfs2_check_journals(struct gfs2_sbd *sdp)
 558 {
 559         struct gfs2_jdesc *jd;
 560
 561         for (;;) {
 562                 jd = gfs2_jdesc_find_dirty(sdp);
 563                 if (!jd)
 564                         break;
 565
 566                 if (jd != sdp->sd_jdesc)
 567                         gfs2_recover_journal(jd, NO_WAIT);
 568         }
 569 }
 570