orphan.c

   1 /*
   2  * Ext4 orphan inode handling
   3  */
   4 #include <linux/fs.h>
   5 #include <linux/quotaops.h>
   6 #include <linux/buffer_head.h>
   7
   8 #include "ext4.h"
   9 #include "ext4_jbd2.h"
  10
  11 static int ext4_orphan_file_add(handle_t *handle, struct inode *inode)
  12 {
  13         int i, j, start;
  14         struct ext4_orphan_info *oi = &EXT4_SB(inode->i_sb)->s_orphan_info;
  15         int ret = 0;
  16         bool found = false;
  17         __le32 *bdata;
  18         int inodes_per_ob = ext4_inodes_per_orphan_block(inode->i_sb);
  19         int looped = 0;
  20
  21         /*
  22          * Find block with free orphan entry. Use CPU number for a naive hash
  23          * for a search start in the orphan file
  24          */
  25         start = raw_smp_processor_id()*13 % oi->of_blocks;
  26         i = start;
  27         do {
  28                 if (atomic_dec_if_positive(&oi->of_binfo[i].ob_free_entries)
  29                     >= 0) {
  30                         found = true;
  31                         break;
  32                 }
  33                 if (++i >= oi->of_blocks)
  34                         i = 0;
  35         } while (i != start);
  36
  37         if (!found) {
  38                 /*
  39                  * For now we don't grow or shrink orphan file. We just use
  40                  * whatever was allocated at mke2fs time. The additional
  41                  * credits we would have to reserve for each orphan inode
  42                  * operation just don't seem worth it.
  43                  */
  44                 return -ENOSPC;
  45         }
  46
  47         ret = ext4_journal_get_write_access(handle, inode->i_sb,
  48                                 oi->of_binfo[i].ob_bh, EXT4_JTR_ORPHAN_FILE);
  49         if (ret) {
  50                 atomic_inc(&oi->of_binfo[i].ob_free_entries);
  51                 return ret;
  52         }
  53
  54         bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
  55         /* Find empty slot in a block */
  56         j = 0;
  57         do {
  58                 if (looped) {
  59                         /*
  60                          * Did we walk through the block several times without
  61                          * finding free entry? It is theoretically possible
  62                          * if entries get constantly allocated and freed or
  63                          * if the block is corrupted. Avoid indefinite looping
  64                          * and bail. We'll use orphan list instead.
  65                          */
  66                         if (looped > 3) {
  67                                 atomic_inc(&oi->of_binfo[i].ob_free_entries);
  68                                 return -ENOSPC;
  69                         }
  70                         cond_resched();
  71                 }
  72                 while (bdata[j]) {
  73                         if (++j >= inodes_per_ob) {
  74                                 j = 0;
  75                                 looped++;
  76                         }
  77                 }
  78         } while (cmpxchg(&bdata[j], (__le32)0, cpu_to_le32(inode->i_ino)) !=
  79                  (__le32)0);
  80
  81         EXT4_I(inode)->i_orphan_idx = i * inodes_per_ob + j;
  82         ext4_set_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
  83
  84         return ext4_handle_dirty_metadata(handle, NULL, oi->of_binfo[i].ob_bh);
  85 }
  86
  87 /*
  88  * ext4_orphan_add() links an unlinked or truncated inode into a list of
  89  * such inodes, starting at the superblock, in case we crash before the
  90  * file is closed/deleted, or in case the inode truncate spans multiple
  91  * transactions and the last transaction is not recovered after a crash.
  92  *
  93  * At filesystem recovery time, we walk this list deleting unlinked
  94  * inodes and truncating linked inodes in ext4_orphan_cleanup().
  95  *
  96  * Orphan list manipulation functions must be called under i_rwsem unless
  97  * we are just creating the inode or deleting it.
  98  */
  99 int ext4_orphan_add(handle_t *handle, struct inode *inode)
 100 {
 101         struct super_block *sb = inode->i_sb;
 102         struct ext4_sb_info *sbi = EXT4_SB(sb);
 103         struct ext4_iloc iloc;
 104         int err = 0, rc;
 105         bool dirty = false;
 106
 107         if (!sbi->s_journal || is_bad_inode(inode))
 108                 return 0;
 109
 110         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
 111                      !inode_is_locked(inode));
 112         /*
 113          * Inode orphaned in orphan file or in orphan list?
 114          */
 115         if (ext4_test_inode_state(inode, EXT4_STATE_ORPHAN_FILE) ||
 116             !list_empty(&EXT4_I(inode)->i_orphan))
 117                 return 0;
 118
 119         /*
 120          * Orphan handling is only valid for files with data blocks
 121          * being truncated, or files being unlinked. Note that we either
 122          * hold i_rwsem, or the inode can not be referenced from outside,
 123          * so i_nlink should not be bumped due to race
 124          */
 125         ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 126                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
 127
 128         if (sbi->s_orphan_info.of_blocks) {
 129                 err = ext4_orphan_file_add(handle, inode);
 130                 /*
 131                  * Fallback to normal orphan list of orphan file is
 132                  * out of space
 133                  */
 134                 if (err != -ENOSPC)
 135                         return err;
 136         }
 137
 138         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
 139         err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
 140                                             EXT4_JTR_NONE);
 141         if (err)
 142                 goto out;
 143
 144         err = ext4_reserve_inode_write(handle, inode, &iloc);
 145         if (err)
 146                 goto out;
 147
 148         mutex_lock(&sbi->s_orphan_lock);
 149         /*
 150          * Due to previous errors inode may be already a part of on-disk
 151          * orphan list. If so skip on-disk list modification.
 152          */
 153         if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
 154             (le32_to_cpu(sbi->s_es->s_inodes_count))) {
 155                 /* Insert this inode at the head of the on-disk orphan list */
 156                 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
 157                 lock_buffer(sbi->s_sbh);
 158                 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
 159                 ext4_superblock_csum_set(sb);
 160                 unlock_buffer(sbi->s_sbh);
 161                 dirty = true;
 162         }
 163         list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
 164         mutex_unlock(&sbi->s_orphan_lock);
 165
 166         if (dirty) {
 167                 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
 168                 rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
 169                 if (!err)
 170                         err = rc;
 171                 if (err) {
 172                         /*
 173                          * We have to remove inode from in-memory list if
 174                          * addition to on disk orphan list failed. Stray orphan
 175                          * list entries can cause panics at unmount time.
 176                          */
 177                         mutex_lock(&sbi->s_orphan_lock);
 178                         list_del_init(&EXT4_I(inode)->i_orphan);
 179                         mutex_unlock(&sbi->s_orphan_lock);
 180                 }
 181         } else
 182                 brelse(iloc.bh);
 183
 184         ext4_debug("superblock will point to %lu\n", inode->i_ino);
 185         ext4_debug("orphan inode %lu will point to %d\n",
 186                         inode->i_ino, NEXT_ORPHAN(inode));
 187 out:
 188         ext4_std_error(sb, err);
 189         return err;
 190 }
 191
 192 static int ext4_orphan_file_del(handle_t *handle, struct inode *inode)
 193 {
 194         struct ext4_orphan_info *oi = &EXT4_SB(inode->i_sb)->s_orphan_info;
 195         __le32 *bdata;
 196         int blk, off;
 197         int inodes_per_ob = ext4_inodes_per_orphan_block(inode->i_sb);
 198         int ret = 0;
 199
 200         if (!handle)
 201                 goto out;
 202         blk = EXT4_I(inode)->i_orphan_idx / inodes_per_ob;
 203         off = EXT4_I(inode)->i_orphan_idx % inodes_per_ob;
 204         if (WARN_ON_ONCE(blk >= oi->of_blocks))
 205                 goto out;
 206
 207         ret = ext4_journal_get_write_access(handle, inode->i_sb,
 208                                 oi->of_binfo[blk].ob_bh, EXT4_JTR_ORPHAN_FILE);
 209         if (ret)
 210                 goto out;
 211
 212         bdata = (__le32 *)(oi->of_binfo[blk].ob_bh->b_data);
 213         bdata[off] = 0;
 214         atomic_inc(&oi->of_binfo[blk].ob_free_entries);
 215         ret = ext4_handle_dirty_metadata(handle, NULL, oi->of_binfo[blk].ob_bh);
 216 out:
 217         ext4_clear_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
 218         INIT_LIST_HEAD(&EXT4_I(inode)->i_orphan);
 219
 220         return ret;
 221 }
 222
 223 /*
 224  * ext4_orphan_del() removes an unlinked or truncated inode from the list
 225  * of such inodes stored on disk, because it is finally being cleaned up.
 226  */
 227 int ext4_orphan_del(handle_t *handle, struct inode *inode)
 228 {
 229         struct list_head *prev;
 230         struct ext4_inode_info *ei = EXT4_I(inode);
 231         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 232         __u32 ino_next;
 233         struct ext4_iloc iloc;
 234         int err = 0;
 235
 236         if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
 237                 return 0;
 238
 239         WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
 240                      !inode_is_locked(inode));
 241         if (ext4_test_inode_state(inode, EXT4_STATE_ORPHAN_FILE))
 242                 return ext4_orphan_file_del(handle, inode);
 243
 244         /* Do this quick check before taking global s_orphan_lock. */
 245         if (list_empty(&ei->i_orphan))
 246                 return 0;
 247
 248         if (handle) {
 249                 /* Grab inode buffer early before taking global s_orphan_lock */
 250                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 251         }
 252
 253         mutex_lock(&sbi->s_orphan_lock);
 254         ext4_debug("remove inode %lu from orphan list\n", inode->i_ino);
 255
 256         prev = ei->i_orphan.prev;
 257         list_del_init(&ei->i_orphan);
 258
 259         /* If we're on an error path, we may not have a valid
 260          * transaction handle with which to update the orphan list on
 261          * disk, but we still need to remove the inode from the linked
 262          * list in memory. */
 263         if (!handle || err) {
 264                 mutex_unlock(&sbi->s_orphan_lock);
 265                 goto out_err;
 266         }
 267
 268         ino_next = NEXT_ORPHAN(inode);
 269         if (prev == &sbi->s_orphan) {
 270                 ext4_debug("superblock will point to %u\n", ino_next);
 271                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
 272                 err = ext4_journal_get_write_access(handle, inode->i_sb,
 273                                                     sbi->s_sbh, EXT4_JTR_NONE);
 274                 if (err) {
 275                         mutex_unlock(&sbi->s_orphan_lock);
 276                         goto out_brelse;
 277                 }
 278                 lock_buffer(sbi->s_sbh);
 279                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
 280                 ext4_superblock_csum_set(inode->i_sb);
 281                 unlock_buffer(sbi->s_sbh);
 282                 mutex_unlock(&sbi->s_orphan_lock);
 283                 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
 284         } else {
 285                 struct ext4_iloc iloc2;
 286                 struct inode *i_prev =
 287                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
 288
 289                 ext4_debug("orphan inode %lu will point to %u\n",
 290                           i_prev->i_ino, ino_next);
 291                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
 292                 if (err) {
 293                         mutex_unlock(&sbi->s_orphan_lock);
 294                         goto out_brelse;
 295                 }
 296                 NEXT_ORPHAN(i_prev) = ino_next;
 297                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
 298                 mutex_unlock(&sbi->s_orphan_lock);
 299         }
 300         if (err)
 301                 goto out_brelse;
 302         NEXT_ORPHAN(inode) = 0;
 303         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 304 out_err:
 305         ext4_std_error(inode->i_sb, err);
 306         return err;
 307
 308 out_brelse:
 309         brelse(iloc.bh);
 310         goto out_err;
 311 }
 312
 313 #ifdef CONFIG_QUOTA
 314 static int ext4_quota_on_mount(struct super_block *sb, int type)
 315 {
 316         return dquot_quota_on_mount(sb,
 317                 rcu_dereference_protected(EXT4_SB(sb)->s_qf_names[type],
 318                                           lockdep_is_held(&sb->s_umount)),
 319                 EXT4_SB(sb)->s_jquota_fmt, type);
 320 }
 321 #endif
 322
 323 static void ext4_process_orphan(struct inode *inode,
 324                                 int *nr_truncates, int *nr_orphans)
 325 {
 326         struct super_block *sb = inode->i_sb;
 327         int ret;
 328
 329         dquot_initialize(inode);
 330         if (inode->i_nlink) {
 331                 if (test_opt(sb, DEBUG))
 332                         ext4_msg(sb, KERN_DEBUG,
 333                                 "%s: truncating inode %lu to %lld bytes",
 334                                 __func__, inode->i_ino, inode->i_size);
 335                 ext4_debug("truncating inode %lu to %lld bytes\n",
 336                            inode->i_ino, inode->i_size);
 337                 inode_lock(inode);
 338                 truncate_inode_pages(inode->i_mapping, inode->i_size);
 339                 ret = ext4_truncate(inode);
 340                 if (ret) {
 341                         /*
 342                          * We need to clean up the in-core orphan list
 343                          * manually if ext4_truncate() failed to get a
 344                          * transaction handle.
 345                          */
 346                         ext4_orphan_del(NULL, inode);
 347                         ext4_std_error(inode->i_sb, ret);
 348                 }
 349                 inode_unlock(inode);
 350                 (*nr_truncates)++;
 351         } else {
 352                 if (test_opt(sb, DEBUG))
 353                         ext4_msg(sb, KERN_DEBUG,
 354                                 "%s: deleting unreferenced inode %lu",
 355                                 __func__, inode->i_ino);
 356                 ext4_debug("deleting unreferenced inode %lu\n",
 357                            inode->i_ino);
 358                 (*nr_orphans)++;
 359         }
 360         iput(inode);  /* The delete magic happens here! */
 361 }
 362
 363 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
 364  * the superblock) which were deleted from all directories, but held open by
 365  * a process at the time of a crash.  We walk the list and try to delete these
 366  * inodes at recovery time (only with a read-write filesystem).
 367  *
 368  * In order to keep the orphan inode chain consistent during traversal (in
 369  * case of crash during recovery), we link each inode into the superblock
 370  * orphan list_head and handle it the same way as an inode deletion during
 371  * normal operation (which journals the operations for us).
 372  *
 373  * We only do an iget() and an iput() on each inode, which is very safe if we
 374  * accidentally point at an in-use or already deleted inode.  The worst that
 375  * can happen in this case is that we get a "bit already cleared" message from
 376  * ext4_free_inode().  The only reason we would point at a wrong inode is if
 377  * e2fsck was run on this filesystem, and it must have already done the orphan
 378  * inode cleanup for us, so we can safely abort without any further action.
 379  */
 380 void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 381 {
 382         unsigned int s_flags = sb->s_flags;
 383         int nr_orphans = 0, nr_truncates = 0;
 384         struct inode *inode;
 385         int i, j;
 386 #ifdef CONFIG_QUOTA
 387         int quota_update = 0;
 388 #endif
 389         __le32 *bdata;
 390         struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
 391         int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
 392
 393         if (!es->s_last_orphan && !oi->of_blocks) {
 394                 ext4_debug("no orphan inodes to clean up\n");
 395                 return;
 396         }
 397
 398         if (bdev_read_only(sb->s_bdev)) {
 399                 ext4_msg(sb, KERN_ERR, "write access "
 400                         "unavailable, skipping orphan cleanup");
 401                 return;
 402         }
 403
 404         /* Check if feature set would not allow a r/w mount */
 405         if (!ext4_feature_set_ok(sb, 0)) {
 406                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
 407                          "unknown ROCOMPAT features");
 408                 return;
 409         }
 410
 411         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
 412                 /* don't clear list on RO mount w/ errors */
 413                 if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
 414                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
 415                                   "clearing orphan list.");
 416                         es->s_last_orphan = 0;
 417                 }
 418                 ext4_debug("Skipping orphan recovery on fs with errors.\n");
 419                 return;
 420         }
 421
 422         if (s_flags & SB_RDONLY) {
 423                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
 424                 sb->s_flags &= ~SB_RDONLY;
 425         }
 426 #ifdef CONFIG_QUOTA
 427         /*
 428          * Turn on quotas which were not enabled for read-only mounts if
 429          * filesystem has quota feature, so that they are updated correctly.
 430          */
 431         if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
 432                 int ret = ext4_enable_quotas(sb);
 433
 434                 if (!ret)
 435                         quota_update = 1;
 436                 else
 437                         ext4_msg(sb, KERN_ERR,
 438                                 "Cannot turn on quotas: error %d", ret);
 439         }
 440
 441         /* Turn on journaled quotas used for old sytle */
 442         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
 443                 if (EXT4_SB(sb)->s_qf_names[i]) {
 444                         int ret = ext4_quota_on_mount(sb, i);
 445
 446                         if (!ret)
 447                                 quota_update = 1;
 448                         else
 449                                 ext4_msg(sb, KERN_ERR,
 450                                         "Cannot turn on journaled "
 451                                         "quota: type %d: error %d", i, ret);
 452                 }
 453         }
 454 #endif
 455
 456         while (es->s_last_orphan) {
 457                 /*
 458                  * We may have encountered an error during cleanup; if
 459                  * so, skip the rest.
 460                  */
 461                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
 462                         ext4_debug("Skipping orphan recovery on fs with errors.\n");
 463                         es->s_last_orphan = 0;
 464                         break;
 465                 }
 466
 467                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
 468                 if (IS_ERR(inode)) {
 469                         es->s_last_orphan = 0;
 470                         break;
 471                 }
 472
 473                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
 474                 ext4_process_orphan(inode, &nr_truncates, &nr_orphans);
 475         }
 476
 477         for (i = 0; i < oi->of_blocks; i++) {
 478                 bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
 479                 for (j = 0; j < inodes_per_ob; j++) {
 480                         if (!bdata[j])
 481                                 continue;
 482                         inode = ext4_orphan_get(sb, le32_to_cpu(bdata[j]));
 483                         if (IS_ERR(inode))
 484                                 continue;
 485                         ext4_set_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
 486                         EXT4_I(inode)->i_orphan_idx = i * inodes_per_ob + j;
 487                         ext4_process_orphan(inode, &nr_truncates, &nr_orphans);
 488                 }
 489         }
 490
 491 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
 492
 493         if (nr_orphans)
 494                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
 495                        PLURAL(nr_orphans));
 496         if (nr_truncates)
 497                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
 498                        PLURAL(nr_truncates));
 499 #ifdef CONFIG_QUOTA
 500         /* Turn off quotas if they were enabled for orphan cleanup */
 501         if (quota_update) {
 502                 for (i = 0; i < EXT4_MAXQUOTAS; i++) {
 503                         if (sb_dqopt(sb)->files[i])
 504                                 dquot_quota_off(sb, i);
 505                 }
 506         }
 507 #endif
 508         sb->s_flags = s_flags; /* Restore SB_RDONLY status */
 509 }
 510
 511 void ext4_release_orphan_info(struct super_block *sb)
 512 {
 513         int i;
 514         struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
 515
 516         if (!oi->of_blocks)
 517                 return;
 518         for (i = 0; i < oi->of_blocks; i++)
 519                 brelse(oi->of_binfo[i].ob_bh);
 520         kfree(oi->of_binfo);
 521 }
 522
 523 static struct ext4_orphan_block_tail *ext4_orphan_block_tail(
 524                                                 struct super_block *sb,
 525                                                 struct buffer_head *bh)
 526 {
 527         return (struct ext4_orphan_block_tail *)(bh->b_data + sb->s_blocksize -
 528                                 sizeof(struct ext4_orphan_block_tail));
 529 }
 530
 531 static int ext4_orphan_file_block_csum_verify(struct super_block *sb,
 532                                               struct buffer_head *bh)
 533 {
 534         __u32 calculated;
 535         int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
 536         struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
 537         struct ext4_orphan_block_tail *ot;
 538         __le64 dsk_block_nr = cpu_to_le64(bh->b_blocknr);
 539
 540         if (!ext4_has_metadata_csum(sb))
 541                 return 1;
 542
 543         ot = ext4_orphan_block_tail(sb, bh);
 544         calculated = ext4_chksum(EXT4_SB(sb), oi->of_csum_seed,
 545                                  (__u8 *)&dsk_block_nr, sizeof(dsk_block_nr));
 546         calculated = ext4_chksum(EXT4_SB(sb), calculated, (__u8 *)bh->b_data,
 547                                  inodes_per_ob * sizeof(__u32));
 548         return le32_to_cpu(ot->ob_checksum) == calculated;
 549 }
 550
 551 /* This gets called only when checksumming is enabled */
 552 void ext4_orphan_file_block_trigger(struct jbd2_buffer_trigger_type *triggers,
 553                                     struct buffer_head *bh,
 554                                     void *data, size_t size)
 555 {
 556         struct super_block *sb = EXT4_TRIGGER(triggers)->sb;
 557         __u32 csum;
 558         int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
 559         struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
 560         struct ext4_orphan_block_tail *ot;
 561         __le64 dsk_block_nr = cpu_to_le64(bh->b_blocknr);
 562
 563         csum = ext4_chksum(EXT4_SB(sb), oi->of_csum_seed,
 564                            (__u8 *)&dsk_block_nr, sizeof(dsk_block_nr));
 565         csum = ext4_chksum(EXT4_SB(sb), csum, (__u8 *)data,
 566                            inodes_per_ob * sizeof(__u32));
 567         ot = ext4_orphan_block_tail(sb, bh);
 568         ot->ob_checksum = cpu_to_le32(csum);
 569 }
 570
 571 int ext4_init_orphan_info(struct super_block *sb)
 572 {
 573         struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
 574         struct inode *inode;
 575         int i, j;
 576         int ret;
 577         int free;
 578         __le32 *bdata;
 579         int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
 580         struct ext4_orphan_block_tail *ot;
 581         ino_t orphan_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_orphan_file_inum);
 582
 583         if (!ext4_has_feature_orphan_file(sb))
 584                 return 0;
 585
 586         inode = ext4_iget(sb, orphan_ino, EXT4_IGET_SPECIAL);
 587         if (IS_ERR(inode)) {
 588                 ext4_msg(sb, KERN_ERR, "get orphan inode failed");
 589                 return PTR_ERR(inode);
 590         }
 591         oi->of_blocks = inode->i_size >> sb->s_blocksize_bits;
 592         oi->of_csum_seed = EXT4_I(inode)->i_csum_seed;
 593         oi->of_binfo = kmalloc(oi->of_blocks*sizeof(struct ext4_orphan_block),
 594                                GFP_KERNEL);
 595         if (!oi->of_binfo) {
 596                 ret = -ENOMEM;
 597                 goto out_put;
 598         }
 599         for (i = 0; i < oi->of_blocks; i++) {
 600                 oi->of_binfo[i].ob_bh = ext4_bread(NULL, inode, i, 0);
 601                 if (IS_ERR(oi->of_binfo[i].ob_bh)) {
 602                         ret = PTR_ERR(oi->of_binfo[i].ob_bh);
 603                         goto out_free;
 604                 }
 605                 if (!oi->of_binfo[i].ob_bh) {
 606                         ret = -EIO;
 607                         goto out_free;
 608                 }
 609                 ot = ext4_orphan_block_tail(sb, oi->of_binfo[i].ob_bh);
 610                 if (le32_to_cpu(ot->ob_magic) != EXT4_ORPHAN_BLOCK_MAGIC) {
 611                         ext4_error(sb, "orphan file block %d: bad magic", i);
 612                         ret = -EIO;
 613                         goto out_free;
 614                 }
 615                 if (!ext4_orphan_file_block_csum_verify(sb,
 616                                                 oi->of_binfo[i].ob_bh)) {
 617                         ext4_error(sb, "orphan file block %d: bad checksum", i);
 618                         ret = -EIO;
 619                         goto out_free;
 620                 }
 621                 bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
 622                 free = 0;
 623                 for (j = 0; j < inodes_per_ob; j++)
 624                         if (bdata[j] == 0)
 625                                 free++;
 626                 atomic_set(&oi->of_binfo[i].ob_free_entries, free);
 627         }
 628         iput(inode);
 629         return 0;
 630 out_free:
 631         for (i--; i >= 0; i--)
 632                 brelse(oi->of_binfo[i].ob_bh);
 633         kfree(oi->of_binfo);
 634 out_put:
 635         iput(inode);
 636         return ret;
 637 }
 638
 639 int ext4_orphan_file_empty(struct super_block *sb)
 640 {
 641         struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
 642         int i;
 643         int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
 644
 645         if (!ext4_has_feature_orphan_file(sb))
 646                 return 1;
 647         for (i = 0; i < oi->of_blocks; i++)
 648                 if (atomic_read(&oi->of_binfo[i].ob_free_entries) !=
 649                     inodes_per_ob)
 650                         return 0;
 651         return 1;
 652 }