Pileus Git - ~andy/linux/blob - fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/jbd2.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/parser.h>
  28 #include <linux/smp_lock.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/log2.h>
  38 #include <linux/crc16.h>
  39 #include <asm/uaccess.h>
  40
  41 #include "ext4.h"
  42 #include "ext4_jbd2.h"
  43 #include "xattr.h"
  44 #include "acl.h"
  45 #include "namei.h"
  46 #include "group.h"
  47
  48 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  49                              unsigned long journal_devnum);
  50 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
  51                                unsigned int);
  52 static void ext4_commit_super (struct super_block * sb,
  53                                struct ext4_super_block * es,
  54                                int sync);
  55 static void ext4_mark_recovery_complete(struct super_block * sb,
  56                                         struct ext4_super_block * es);
  57 static void ext4_clear_journal_err(struct super_block * sb,
  58                                    struct ext4_super_block * es);
  59 static int ext4_sync_fs(struct super_block *sb, int wait);
  60 static const char *ext4_decode_error(struct super_block * sb, int errno,
  61                                      char nbuf[16]);
  62 static int ext4_remount (struct super_block * sb, int * flags, char * data);
  63 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf);
  64 static void ext4_unlockfs(struct super_block *sb);
  65 static void ext4_write_super (struct super_block * sb);
  66 static void ext4_write_super_lockfs(struct super_block *sb);
  67
  68
  69 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
  70                                struct ext4_group_desc *bg)
  71 {
  72         return le32_to_cpu(bg->bg_block_bitmap_lo) |
  73                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  74                 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
  75 }
  76
  77 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
  78                                struct ext4_group_desc *bg)
  79 {
  80         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
  81                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  82                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
  83 }
  84
  85 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
  86                               struct ext4_group_desc *bg)
  87 {
  88         return le32_to_cpu(bg->bg_inode_table_lo) |
  89                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  90                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
  91 }
  92
  93 void ext4_block_bitmap_set(struct super_block *sb,
  94                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
  95 {
  96         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
  97         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
  98                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
  99 }
 100
 101 void ext4_inode_bitmap_set(struct super_block *sb,
 102                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 103 {
 104         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 105         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 106                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 107 }
 108
 109 void ext4_inode_table_set(struct super_block *sb,
 110                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 111 {
 112         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 113         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 114                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 115 }
 116
 117 /*
 118  * Wrappers for jbd2_journal_start/end.
 119  *
 120  * The only special thing we need to do here is to make sure that all
 121  * journal_end calls result in the superblock being marked dirty, so
 122  * that sync() will call the filesystem's write_super callback if
 123  * appropriate.
 124  */
 125 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 126 {
 127         journal_t *journal;
 128
 129         if (sb->s_flags & MS_RDONLY)
 130                 return ERR_PTR(-EROFS);
 131
 132         /* Special case here: if the journal has aborted behind our
 133          * backs (eg. EIO in the commit thread), then we still need to
 134          * take the FS itself readonly cleanly. */
 135         journal = EXT4_SB(sb)->s_journal;
 136         if (is_journal_aborted(journal)) {
 137                 ext4_abort(sb, __func__,
 138                            "Detected aborted journal");
 139                 return ERR_PTR(-EROFS);
 140         }
 141
 142         return jbd2_journal_start(journal, nblocks);
 143 }
 144
 145 /*
 146  * The only special thing we need to do here is to make sure that all
 147  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 148  * that sync() will call the filesystem's write_super callback if
 149  * appropriate.
 150  */
 151 int __ext4_journal_stop(const char *where, handle_t *handle)
 152 {
 153         struct super_block *sb;
 154         int err;
 155         int rc;
 156
 157         sb = handle->h_transaction->t_journal->j_private;
 158         err = handle->h_err;
 159         rc = jbd2_journal_stop(handle);
 160
 161         if (!err)
 162                 err = rc;
 163         if (err)
 164                 __ext4_std_error(sb, where, err);
 165         return err;
 166 }
 167
 168 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 169                 struct buffer_head *bh, handle_t *handle, int err)
 170 {
 171         char nbuf[16];
 172         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 173
 174         if (bh)
 175                 BUFFER_TRACE(bh, "abort");
 176
 177         if (!handle->h_err)
 178                 handle->h_err = err;
 179
 180         if (is_handle_aborted(handle))
 181                 return;
 182
 183         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
 184                caller, errstr, err_fn);
 185
 186         jbd2_journal_abort_handle(handle);
 187 }
 188
 189 /* Deal with the reporting of failure conditions on a filesystem such as
 190  * inconsistencies detected or read IO failures.
 191  *
 192  * On ext2, we can store the error state of the filesystem in the
 193  * superblock.  That is not possible on ext4, because we may have other
 194  * write ordering constraints on the superblock which prevent us from
 195  * writing it out straight away; and given that the journal is about to
 196  * be aborted, we can't rely on the current, or future, transactions to
 197  * write out the superblock safely.
 198  *
 199  * We'll just use the jbd2_journal_abort() error code to record an error in
 200  * the journal instead.  On recovery, the journal will compain about
 201  * that error until we've noted it down and cleared it.
 202  */
 203
 204 static void ext4_handle_error(struct super_block *sb)
 205 {
 206         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 207
 208         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 209         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 210
 211         if (sb->s_flags & MS_RDONLY)
 212                 return;
 213
 214         if (!test_opt (sb, ERRORS_CONT)) {
 215                 journal_t *journal = EXT4_SB(sb)->s_journal;
 216
 217                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 218                 if (journal)
 219                         jbd2_journal_abort(journal, -EIO);
 220         }
 221         if (test_opt (sb, ERRORS_RO)) {
 222                 printk (KERN_CRIT "Remounting filesystem read-only\n");
 223                 sb->s_flags |= MS_RDONLY;
 224         }
 225         ext4_commit_super(sb, es, 1);
 226         if (test_opt(sb, ERRORS_PANIC))
 227                 panic("EXT4-fs (device %s): panic forced after error\n",
 228                         sb->s_id);
 229 }
 230
 231 void ext4_error (struct super_block * sb, const char * function,
 232                  const char * fmt, ...)
 233 {
 234         va_list args;
 235
 236         va_start(args, fmt);
 237         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 238         vprintk(fmt, args);
 239         printk("\n");
 240         va_end(args);
 241
 242         ext4_handle_error(sb);
 243 }
 244
 245 static const char *ext4_decode_error(struct super_block * sb, int errno,
 246                                      char nbuf[16])
 247 {
 248         char *errstr = NULL;
 249
 250         switch (errno) {
 251         case -EIO:
 252                 errstr = "IO failure";
 253                 break;
 254         case -ENOMEM:
 255                 errstr = "Out of memory";
 256                 break;
 257         case -EROFS:
 258                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
 259                         errstr = "Journal has aborted";
 260                 else
 261                         errstr = "Readonly filesystem";
 262                 break;
 263         default:
 264                 /* If the caller passed in an extra buffer for unknown
 265                  * errors, textualise them now.  Else we just return
 266                  * NULL. */
 267                 if (nbuf) {
 268                         /* Check for truncated error codes... */
 269                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 270                                 errstr = nbuf;
 271                 }
 272                 break;
 273         }
 274
 275         return errstr;
 276 }
 277
 278 /* __ext4_std_error decodes expected errors from journaling functions
 279  * automatically and invokes the appropriate error response.  */
 280
 281 void __ext4_std_error (struct super_block * sb, const char * function,
 282                        int errno)
 283 {
 284         char nbuf[16];
 285         const char *errstr;
 286
 287         /* Special case: if the error is EROFS, and we're not already
 288          * inside a transaction, then there's really no point in logging
 289          * an error. */
 290         if (errno == -EROFS && journal_current_handle() == NULL &&
 291             (sb->s_flags & MS_RDONLY))
 292                 return;
 293
 294         errstr = ext4_decode_error(sb, errno, nbuf);
 295         printk (KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
 296                 sb->s_id, function, errstr);
 297
 298         ext4_handle_error(sb);
 299 }
 300
 301 /*
 302  * ext4_abort is a much stronger failure handler than ext4_error.  The
 303  * abort function may be used to deal with unrecoverable failures such
 304  * as journal IO errors or ENOMEM at a critical moment in log management.
 305  *
 306  * We unconditionally force the filesystem into an ABORT|READONLY state,
 307  * unless the error response on the fs has been set to panic in which
 308  * case we take the easy way out and panic immediately.
 309  */
 310
 311 void ext4_abort (struct super_block * sb, const char * function,
 312                  const char * fmt, ...)
 313 {
 314         va_list args;
 315
 316         printk (KERN_CRIT "ext4_abort called.\n");
 317
 318         va_start(args, fmt);
 319         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 320         vprintk(fmt, args);
 321         printk("\n");
 322         va_end(args);
 323
 324         if (test_opt(sb, ERRORS_PANIC))
 325                 panic("EXT4-fs panic from previous error\n");
 326
 327         if (sb->s_flags & MS_RDONLY)
 328                 return;
 329
 330         printk(KERN_CRIT "Remounting filesystem read-only\n");
 331         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 332         sb->s_flags |= MS_RDONLY;
 333         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 334         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 335 }
 336
 337 void ext4_warning (struct super_block * sb, const char * function,
 338                    const char * fmt, ...)
 339 {
 340         va_list args;
 341
 342         va_start(args, fmt);
 343         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
 344                sb->s_id, function);
 345         vprintk(fmt, args);
 346         printk("\n");
 347         va_end(args);
 348 }
 349
 350 void ext4_update_dynamic_rev(struct super_block *sb)
 351 {
 352         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 353
 354         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 355                 return;
 356
 357         ext4_warning(sb, __func__,
 358                      "updating to rev %d because of new feature flag, "
 359                      "running e2fsck is recommended",
 360                      EXT4_DYNAMIC_REV);
 361
 362         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 363         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 364         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 365         /* leave es->s_feature_*compat flags alone */
 366         /* es->s_uuid will be set by e2fsck if empty */
 367
 368         /*
 369          * The rest of the superblock fields should be zero, and if not it
 370          * means they are likely already in use, so leave them alone.  We
 371          * can leave it up to e2fsck to clean up any inconsistencies there.
 372          */
 373 }
 374
 375 int ext4_update_compat_feature(handle_t *handle,
 376                                         struct super_block *sb, __u32 compat)
 377 {
 378         int err = 0;
 379         if (!EXT4_HAS_COMPAT_FEATURE(sb, compat)) {
 380                 err = ext4_journal_get_write_access(handle,
 381                                 EXT4_SB(sb)->s_sbh);
 382                 if (err)
 383                         return err;
 384                 EXT4_SET_COMPAT_FEATURE(sb, compat);
 385                 sb->s_dirt = 1;
 386                 handle->h_sync = 1;
 387                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 388                                         "call ext4_journal_dirty_met adata");
 389                 err = ext4_journal_dirty_metadata(handle,
 390                                 EXT4_SB(sb)->s_sbh);
 391         }
 392         return err;
 393 }
 394
 395 int ext4_update_rocompat_feature(handle_t *handle,
 396                                         struct super_block *sb, __u32 rocompat)
 397 {
 398         int err = 0;
 399         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, rocompat)) {
 400                 err = ext4_journal_get_write_access(handle,
 401                                 EXT4_SB(sb)->s_sbh);
 402                 if (err)
 403                         return err;
 404                 EXT4_SET_RO_COMPAT_FEATURE(sb, rocompat);
 405                 sb->s_dirt = 1;
 406                 handle->h_sync = 1;
 407                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 408                                         "call ext4_journal_dirty_met adata");
 409                 err = ext4_journal_dirty_metadata(handle,
 410                                 EXT4_SB(sb)->s_sbh);
 411         }
 412         return err;
 413 }
 414
 415 int ext4_update_incompat_feature(handle_t *handle,
 416                                         struct super_block *sb, __u32 incompat)
 417 {
 418         int err = 0;
 419         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, incompat)) {
 420                 err = ext4_journal_get_write_access(handle,
 421                                 EXT4_SB(sb)->s_sbh);
 422                 if (err)
 423                         return err;
 424                 EXT4_SET_INCOMPAT_FEATURE(sb, incompat);
 425                 sb->s_dirt = 1;
 426                 handle->h_sync = 1;
 427                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 428                                         "call ext4_journal_dirty_met adata");
 429                 err = ext4_journal_dirty_metadata(handle,
 430                                 EXT4_SB(sb)->s_sbh);
 431         }
 432         return err;
 433 }
 434
 435 /*
 436  * Open the external journal device
 437  */
 438 static struct block_device *ext4_blkdev_get(dev_t dev)
 439 {
 440         struct block_device *bdev;
 441         char b[BDEVNAME_SIZE];
 442
 443         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 444         if (IS_ERR(bdev))
 445                 goto fail;
 446         return bdev;
 447
 448 fail:
 449         printk(KERN_ERR "EXT4: failed to open journal device %s: %ld\n",
 450                         __bdevname(dev, b), PTR_ERR(bdev));
 451         return NULL;
 452 }
 453
 454 /*
 455  * Release the journal device
 456  */
 457 static int ext4_blkdev_put(struct block_device *bdev)
 458 {
 459         bd_release(bdev);
 460         return blkdev_put(bdev);
 461 }
 462
 463 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 464 {
 465         struct block_device *bdev;
 466         int ret = -ENODEV;
 467
 468         bdev = sbi->journal_bdev;
 469         if (bdev) {
 470                 ret = ext4_blkdev_put(bdev);
 471                 sbi->journal_bdev = NULL;
 472         }
 473         return ret;
 474 }
 475
 476 static inline struct inode *orphan_list_entry(struct list_head *l)
 477 {
 478         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 479 }
 480
 481 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 482 {
 483         struct list_head *l;
 484
 485         printk(KERN_ERR "sb orphan head is %d\n",
 486                le32_to_cpu(sbi->s_es->s_last_orphan));
 487
 488         printk(KERN_ERR "sb_info orphan list:\n");
 489         list_for_each(l, &sbi->s_orphan) {
 490                 struct inode *inode = orphan_list_entry(l);
 491                 printk(KERN_ERR "  "
 492                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 493                        inode->i_sb->s_id, inode->i_ino, inode,
 494                        inode->i_mode, inode->i_nlink,
 495                        NEXT_ORPHAN(inode));
 496         }
 497 }
 498
 499 static void ext4_put_super (struct super_block * sb)
 500 {
 501         struct ext4_sb_info *sbi = EXT4_SB(sb);
 502         struct ext4_super_block *es = sbi->s_es;
 503         int i;
 504
 505         ext4_mb_release(sb);
 506         ext4_ext_release(sb);
 507         ext4_xattr_put_super(sb);
 508         jbd2_journal_destroy(sbi->s_journal);
 509         if (!(sb->s_flags & MS_RDONLY)) {
 510                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 511                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 512                 BUFFER_TRACE(sbi->s_sbh, "marking dirty");
 513                 mark_buffer_dirty(sbi->s_sbh);
 514                 ext4_commit_super(sb, es, 1);
 515         }
 516
 517         for (i = 0; i < sbi->s_gdb_count; i++)
 518                 brelse(sbi->s_group_desc[i]);
 519         kfree(sbi->s_group_desc);
 520         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 521         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 522         percpu_counter_destroy(&sbi->s_dirs_counter);
 523         brelse(sbi->s_sbh);
 524 #ifdef CONFIG_QUOTA
 525         for (i = 0; i < MAXQUOTAS; i++)
 526                 kfree(sbi->s_qf_names[i]);
 527 #endif
 528
 529         /* Debugging code just in case the in-memory inode orphan list
 530          * isn't empty.  The on-disk one can be non-empty if we've
 531          * detected an error and taken the fs readonly, but the
 532          * in-memory list had better be clean by this point. */
 533         if (!list_empty(&sbi->s_orphan))
 534                 dump_orphan_list(sb, sbi);
 535         J_ASSERT(list_empty(&sbi->s_orphan));
 536
 537         invalidate_bdev(sb->s_bdev);
 538         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 539                 /*
 540                  * Invalidate the journal device's buffers.  We don't want them
 541                  * floating about in memory - the physical journal device may
 542                  * hotswapped, and it breaks the `ro-after' testing code.
 543                  */
 544                 sync_blockdev(sbi->journal_bdev);
 545                 invalidate_bdev(sbi->journal_bdev);
 546                 ext4_blkdev_remove(sbi);
 547         }
 548         sb->s_fs_info = NULL;
 549         kfree(sbi);
 550         return;
 551 }
 552
 553 static struct kmem_cache *ext4_inode_cachep;
 554
 555 /*
 556  * Called inside transaction, so use GFP_NOFS
 557  */
 558 static struct inode *ext4_alloc_inode(struct super_block *sb)
 559 {
 560         struct ext4_inode_info *ei;
 561
 562         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 563         if (!ei)
 564                 return NULL;
 565 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 566         ei->i_acl = EXT4_ACL_NOT_CACHED;
 567         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 568 #endif
 569         ei->i_block_alloc_info = NULL;
 570         ei->vfs_inode.i_version = 1;
 571         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 572         INIT_LIST_HEAD(&ei->i_prealloc_list);
 573         spin_lock_init(&ei->i_prealloc_lock);
 574         return &ei->vfs_inode;
 575 }
 576
 577 static void ext4_destroy_inode(struct inode *inode)
 578 {
 579         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 580                 printk("EXT4 Inode %p: orphan list check failed!\n",
 581                         EXT4_I(inode));
 582                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 583                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 584                                 true);
 585                 dump_stack();
 586         }
 587         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 588 }
 589
 590 static void init_once(struct kmem_cache *cachep, void *foo)
 591 {
 592         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 593
 594         INIT_LIST_HEAD(&ei->i_orphan);
 595 #ifdef CONFIG_EXT4DEV_FS_XATTR
 596         init_rwsem(&ei->xattr_sem);
 597 #endif
 598         init_rwsem(&ei->i_data_sem);
 599         inode_init_once(&ei->vfs_inode);
 600 }
 601
 602 static int init_inodecache(void)
 603 {
 604         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 605                                              sizeof(struct ext4_inode_info),
 606                                              0, (SLAB_RECLAIM_ACCOUNT|
 607                                                 SLAB_MEM_SPREAD),
 608                                              init_once);
 609         if (ext4_inode_cachep == NULL)
 610                 return -ENOMEM;
 611         return 0;
 612 }
 613
 614 static void destroy_inodecache(void)
 615 {
 616         kmem_cache_destroy(ext4_inode_cachep);
 617 }
 618
 619 static void ext4_clear_inode(struct inode *inode)
 620 {
 621         struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
 622 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 623         if (EXT4_I(inode)->i_acl &&
 624                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
 625                 posix_acl_release(EXT4_I(inode)->i_acl);
 626                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
 627         }
 628         if (EXT4_I(inode)->i_default_acl &&
 629                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
 630                 posix_acl_release(EXT4_I(inode)->i_default_acl);
 631                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
 632         }
 633 #endif
 634         ext4_discard_reservation(inode);
 635         EXT4_I(inode)->i_block_alloc_info = NULL;
 636         if (unlikely(rsv))
 637                 kfree(rsv);
 638 }
 639
 640 static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
 641 {
 642 #if defined(CONFIG_QUOTA)
 643         struct ext4_sb_info *sbi = EXT4_SB(sb);
 644
 645         if (sbi->s_jquota_fmt)
 646                 seq_printf(seq, ",jqfmt=%s",
 647                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold": "vfsv0");
 648
 649         if (sbi->s_qf_names[USRQUOTA])
 650                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 651
 652         if (sbi->s_qf_names[GRPQUOTA])
 653                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 654
 655         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
 656                 seq_puts(seq, ",usrquota");
 657
 658         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
 659                 seq_puts(seq, ",grpquota");
 660 #endif
 661 }
 662
 663 /*
 664  * Show an option if
 665  *  - it's set to a non-default value OR
 666  *  - if the per-sb default is different from the global default
 667  */
 668 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 669 {
 670         int def_errors;
 671         unsigned long def_mount_opts;
 672         struct super_block *sb = vfs->mnt_sb;
 673         struct ext4_sb_info *sbi = EXT4_SB(sb);
 674         struct ext4_super_block *es = sbi->s_es;
 675
 676         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 677         def_errors     = le16_to_cpu(es->s_errors);
 678
 679         if (sbi->s_sb_block != 1)
 680                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 681         if (test_opt(sb, MINIX_DF))
 682                 seq_puts(seq, ",minixdf");
 683         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
 684                 seq_puts(seq, ",grpid");
 685         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 686                 seq_puts(seq, ",nogrpid");
 687         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 688             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 689                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 690         }
 691         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 692             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 693                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 694         }
 695         if (test_opt(sb, ERRORS_RO)) {
 696                 if (def_errors == EXT4_ERRORS_PANIC ||
 697                     def_errors == EXT4_ERRORS_CONTINUE) {
 698                         seq_puts(seq, ",errors=remount-ro");
 699                 }
 700         }
 701         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
 702                 seq_puts(seq, ",errors=continue");
 703         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
 704                 seq_puts(seq, ",errors=panic");
 705         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
 706                 seq_puts(seq, ",nouid32");
 707         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
 708                 seq_puts(seq, ",debug");
 709         if (test_opt(sb, OLDALLOC))
 710                 seq_puts(seq, ",oldalloc");
 711 #ifdef CONFIG_EXT4DEV_FS_XATTR
 712         if (test_opt(sb, XATTR_USER) &&
 713                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
 714                 seq_puts(seq, ",user_xattr");
 715         if (!test_opt(sb, XATTR_USER) &&
 716             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 717                 seq_puts(seq, ",nouser_xattr");
 718         }
 719 #endif
 720 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 721         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
 722                 seq_puts(seq, ",acl");
 723         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 724                 seq_puts(seq, ",noacl");
 725 #endif
 726         if (!test_opt(sb, RESERVATION))
 727                 seq_puts(seq, ",noreservation");
 728         if (sbi->s_commit_interval) {
 729                 seq_printf(seq, ",commit=%u",
 730                            (unsigned) (sbi->s_commit_interval / HZ));
 731         }
 732         /*
 733          * We're changing the default of barrier mount option, so
 734          * let's always display its mount state so it's clear what its
 735          * status is.
 736          */
 737         seq_puts(seq, ",barrier=");
 738         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
 739         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
 740                 seq_puts(seq, ",journal_async_commit");
 741         if (test_opt(sb, NOBH))
 742                 seq_puts(seq, ",nobh");
 743         if (!test_opt(sb, EXTENTS))
 744                 seq_puts(seq, ",noextents");
 745         if (!test_opt(sb, MBALLOC))
 746                 seq_puts(seq, ",nomballoc");
 747         if (test_opt(sb, I_VERSION))
 748                 seq_puts(seq, ",i_version");
 749
 750         if (sbi->s_stripe)
 751                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
 752         /*
 753          * journal mode get enabled in different ways
 754          * So just print the value even if we didn't specify it
 755          */
 756         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 757                 seq_puts(seq, ",data=journal");
 758         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 759                 seq_puts(seq, ",data=ordered");
 760         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 761                 seq_puts(seq, ",data=writeback");
 762
 763         ext4_show_quota_options(seq, sb);
 764         return 0;
 765 }
 766
 767
 768 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 769                 u64 ino, u32 generation)
 770 {
 771         struct inode *inode;
 772
 773         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 774                 return ERR_PTR(-ESTALE);
 775         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 776                 return ERR_PTR(-ESTALE);
 777
 778         /* iget isn't really right if the inode is currently unallocated!!
 779          *
 780          * ext4_read_inode will return a bad_inode if the inode had been
 781          * deleted, so we should be safe.
 782          *
 783          * Currently we don't know the generation for parent directory, so
 784          * a generation of 0 means "accept any"
 785          */
 786         inode = ext4_iget(sb, ino);
 787         if (IS_ERR(inode))
 788                 return ERR_CAST(inode);
 789         if (generation && inode->i_generation != generation) {
 790                 iput(inode);
 791                 return ERR_PTR(-ESTALE);
 792         }
 793
 794         return inode;
 795 }
 796
 797 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 798                 int fh_len, int fh_type)
 799 {
 800         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 801                                     ext4_nfs_get_inode);
 802 }
 803
 804 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 805                 int fh_len, int fh_type)
 806 {
 807         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 808                                     ext4_nfs_get_inode);
 809 }
 810
 811 #ifdef CONFIG_QUOTA
 812 #define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
 813 #define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 814
 815 static int ext4_dquot_initialize(struct inode *inode, int type);
 816 static int ext4_dquot_drop(struct inode *inode);
 817 static int ext4_write_dquot(struct dquot *dquot);
 818 static int ext4_acquire_dquot(struct dquot *dquot);
 819 static int ext4_release_dquot(struct dquot *dquot);
 820 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 821 static int ext4_write_info(struct super_block *sb, int type);
 822 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 823                                 char *path, int remount);
 824 static int ext4_quota_on_mount(struct super_block *sb, int type);
 825 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 826                                size_t len, loff_t off);
 827 static ssize_t ext4_quota_write(struct super_block *sb, int type,
 828                                 const char *data, size_t len, loff_t off);
 829
 830 static struct dquot_operations ext4_quota_operations = {
 831         .initialize     = ext4_dquot_initialize,
 832         .drop           = ext4_dquot_drop,
 833         .alloc_space    = dquot_alloc_space,
 834         .alloc_inode    = dquot_alloc_inode,
 835         .free_space     = dquot_free_space,
 836         .free_inode     = dquot_free_inode,
 837         .transfer       = dquot_transfer,
 838         .write_dquot    = ext4_write_dquot,
 839         .acquire_dquot  = ext4_acquire_dquot,
 840         .release_dquot  = ext4_release_dquot,
 841         .mark_dirty     = ext4_mark_dquot_dirty,
 842         .write_info     = ext4_write_info
 843 };
 844
 845 static struct quotactl_ops ext4_qctl_operations = {
 846         .quota_on       = ext4_quota_on,
 847         .quota_off      = vfs_quota_off,
 848         .quota_sync     = vfs_quota_sync,
 849         .get_info       = vfs_get_dqinfo,
 850         .set_info       = vfs_set_dqinfo,
 851         .get_dqblk      = vfs_get_dqblk,
 852         .set_dqblk      = vfs_set_dqblk
 853 };
 854 #endif
 855
 856 static const struct super_operations ext4_sops = {
 857         .alloc_inode    = ext4_alloc_inode,
 858         .destroy_inode  = ext4_destroy_inode,
 859         .write_inode    = ext4_write_inode,
 860         .dirty_inode    = ext4_dirty_inode,
 861         .delete_inode   = ext4_delete_inode,
 862         .put_super      = ext4_put_super,
 863         .write_super    = ext4_write_super,
 864         .sync_fs        = ext4_sync_fs,
 865         .write_super_lockfs = ext4_write_super_lockfs,
 866         .unlockfs       = ext4_unlockfs,
 867         .statfs         = ext4_statfs,
 868         .remount_fs     = ext4_remount,
 869         .clear_inode    = ext4_clear_inode,
 870         .show_options   = ext4_show_options,
 871 #ifdef CONFIG_QUOTA
 872         .quota_read     = ext4_quota_read,
 873         .quota_write    = ext4_quota_write,
 874 #endif
 875 };
 876
 877 static const struct export_operations ext4_export_ops = {
 878         .fh_to_dentry = ext4_fh_to_dentry,
 879         .fh_to_parent = ext4_fh_to_parent,
 880         .get_parent = ext4_get_parent,
 881 };
 882
 883 enum {
 884         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 885         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
 886         Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov,
 887         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
 888         Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
 889         Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
 890         Opt_journal_checksum, Opt_journal_async_commit,
 891         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
 892         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 893         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
 894         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
 895         Opt_grpquota, Opt_extents, Opt_noextents, Opt_i_version,
 896         Opt_mballoc, Opt_nomballoc, Opt_stripe,
 897 };
 898
 899 static match_table_t tokens = {
 900         {Opt_bsd_df, "bsddf"},
 901         {Opt_minix_df, "minixdf"},
 902         {Opt_grpid, "grpid"},
 903         {Opt_grpid, "bsdgroups"},
 904         {Opt_nogrpid, "nogrpid"},
 905         {Opt_nogrpid, "sysvgroups"},
 906         {Opt_resgid, "resgid=%u"},
 907         {Opt_resuid, "resuid=%u"},
 908         {Opt_sb, "sb=%u"},
 909         {Opt_err_cont, "errors=continue"},
 910         {Opt_err_panic, "errors=panic"},
 911         {Opt_err_ro, "errors=remount-ro"},
 912         {Opt_nouid32, "nouid32"},
 913         {Opt_nocheck, "nocheck"},
 914         {Opt_nocheck, "check=none"},
 915         {Opt_debug, "debug"},
 916         {Opt_oldalloc, "oldalloc"},
 917         {Opt_orlov, "orlov"},
 918         {Opt_user_xattr, "user_xattr"},
 919         {Opt_nouser_xattr, "nouser_xattr"},
 920         {Opt_acl, "acl"},
 921         {Opt_noacl, "noacl"},
 922         {Opt_reservation, "reservation"},
 923         {Opt_noreservation, "noreservation"},
 924         {Opt_noload, "noload"},
 925         {Opt_nobh, "nobh"},
 926         {Opt_bh, "bh"},
 927         {Opt_commit, "commit=%u"},
 928         {Opt_journal_update, "journal=update"},
 929         {Opt_journal_inum, "journal=%u"},
 930         {Opt_journal_dev, "journal_dev=%u"},
 931         {Opt_journal_checksum, "journal_checksum"},
 932         {Opt_journal_async_commit, "journal_async_commit"},
 933         {Opt_abort, "abort"},
 934         {Opt_data_journal, "data=journal"},
 935         {Opt_data_ordered, "data=ordered"},
 936         {Opt_data_writeback, "data=writeback"},
 937         {Opt_offusrjquota, "usrjquota="},
 938         {Opt_usrjquota, "usrjquota=%s"},
 939         {Opt_offgrpjquota, "grpjquota="},
 940         {Opt_grpjquota, "grpjquota=%s"},
 941         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
 942         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
 943         {Opt_grpquota, "grpquota"},
 944         {Opt_noquota, "noquota"},
 945         {Opt_quota, "quota"},
 946         {Opt_usrquota, "usrquota"},
 947         {Opt_barrier, "barrier=%u"},
 948         {Opt_extents, "extents"},
 949         {Opt_noextents, "noextents"},
 950         {Opt_i_version, "i_version"},
 951         {Opt_mballoc, "mballoc"},
 952         {Opt_nomballoc, "nomballoc"},
 953         {Opt_stripe, "stripe=%u"},
 954         {Opt_resize, "resize"},
 955         {Opt_err, NULL},
 956 };
 957
 958 static ext4_fsblk_t get_sb_block(void **data)
 959 {
 960         ext4_fsblk_t    sb_block;
 961         char            *options = (char *) *data;
 962
 963         if (!options || strncmp(options, "sb=", 3) != 0)
 964                 return 1;       /* Default location */
 965         options += 3;
 966         /*todo: use simple_strtoll with >32bit ext4 */
 967         sb_block = simple_strtoul(options, &options, 0);
 968         if (*options && *options != ',') {
 969                 printk("EXT4-fs: Invalid sb specification: %s\n",
 970                        (char *) *data);
 971                 return 1;
 972         }
 973         if (*options == ',')
 974                 options++;
 975         *data = (void *) options;
 976         return sb_block;
 977 }
 978
 979 static int parse_options (char *options, struct super_block *sb,
 980                           unsigned int *inum, unsigned long *journal_devnum,
 981                           ext4_fsblk_t *n_blocks_count, int is_remount)
 982 {
 983         struct ext4_sb_info *sbi = EXT4_SB(sb);
 984         char * p;
 985         substring_t args[MAX_OPT_ARGS];
 986         int data_opt = 0;
 987         int option;
 988 #ifdef CONFIG_QUOTA
 989         int qtype, qfmt;
 990         char *qname;
 991 #endif
 992
 993         if (!options)
 994                 return 1;
 995
 996         while ((p = strsep (&options, ",")) != NULL) {
 997                 int token;
 998                 if (!*p)
 999                         continue;
1000
1001                 token = match_token(p, tokens, args);
1002                 switch (token) {
1003                 case Opt_bsd_df:
1004                         clear_opt (sbi->s_mount_opt, MINIX_DF);
1005                         break;
1006                 case Opt_minix_df:
1007                         set_opt (sbi->s_mount_opt, MINIX_DF);
1008                         break;
1009                 case Opt_grpid:
1010                         set_opt (sbi->s_mount_opt, GRPID);
1011                         break;
1012                 case Opt_nogrpid:
1013                         clear_opt (sbi->s_mount_opt, GRPID);
1014                         break;
1015                 case Opt_resuid:
1016                         if (match_int(&args[0], &option))
1017                                 return 0;
1018                         sbi->s_resuid = option;
1019                         break;
1020                 case Opt_resgid:
1021                         if (match_int(&args[0], &option))
1022                                 return 0;
1023                         sbi->s_resgid = option;
1024                         break;
1025                 case Opt_sb:
1026                         /* handled by get_sb_block() instead of here */
1027                         /* *sb_block = match_int(&args[0]); */
1028                         break;
1029                 case Opt_err_panic:
1030                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
1031                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
1032                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
1033                         break;
1034                 case Opt_err_ro:
1035                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
1036                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
1037                         set_opt (sbi->s_mount_opt, ERRORS_RO);
1038                         break;
1039                 case Opt_err_cont:
1040                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
1041                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
1042                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
1043                         break;
1044                 case Opt_nouid32:
1045                         set_opt (sbi->s_mount_opt, NO_UID32);
1046                         break;
1047                 case Opt_nocheck:
1048                         clear_opt (sbi->s_mount_opt, CHECK);
1049                         break;
1050                 case Opt_debug:
1051                         set_opt (sbi->s_mount_opt, DEBUG);
1052                         break;
1053                 case Opt_oldalloc:
1054                         set_opt (sbi->s_mount_opt, OLDALLOC);
1055                         break;
1056                 case Opt_orlov:
1057                         clear_opt (sbi->s_mount_opt, OLDALLOC);
1058                         break;
1059 #ifdef CONFIG_EXT4DEV_FS_XATTR
1060                 case Opt_user_xattr:
1061                         set_opt (sbi->s_mount_opt, XATTR_USER);
1062                         break;
1063                 case Opt_nouser_xattr:
1064                         clear_opt (sbi->s_mount_opt, XATTR_USER);
1065                         break;
1066 #else
1067                 case Opt_user_xattr:
1068                 case Opt_nouser_xattr:
1069                         printk("EXT4 (no)user_xattr options not supported\n");
1070                         break;
1071 #endif
1072 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1073                 case Opt_acl:
1074                         set_opt(sbi->s_mount_opt, POSIX_ACL);
1075                         break;
1076                 case Opt_noacl:
1077                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
1078                         break;
1079 #else
1080                 case Opt_acl:
1081                 case Opt_noacl:
1082                         printk("EXT4 (no)acl options not supported\n");
1083                         break;
1084 #endif
1085                 case Opt_reservation:
1086                         set_opt(sbi->s_mount_opt, RESERVATION);
1087                         break;
1088                 case Opt_noreservation:
1089                         clear_opt(sbi->s_mount_opt, RESERVATION);
1090                         break;
1091                 case Opt_journal_update:
1092                         /* @@@ FIXME */
1093                         /* Eventually we will want to be able to create
1094                            a journal file here.  For now, only allow the
1095                            user to specify an existing inode to be the
1096                            journal file. */
1097                         if (is_remount) {
1098                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1099                                        "journal on remount\n");
1100                                 return 0;
1101                         }
1102                         set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
1103                         break;
1104                 case Opt_journal_inum:
1105                         if (is_remount) {
1106                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1107                                        "journal on remount\n");
1108                                 return 0;
1109                         }
1110                         if (match_int(&args[0], &option))
1111                                 return 0;
1112                         *inum = option;
1113                         break;
1114                 case Opt_journal_dev:
1115                         if (is_remount) {
1116                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1117                                        "journal on remount\n");
1118                                 return 0;
1119                         }
1120                         if (match_int(&args[0], &option))
1121                                 return 0;
1122                         *journal_devnum = option;
1123                         break;
1124                 case Opt_journal_checksum:
1125                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1126                         break;
1127                 case Opt_journal_async_commit:
1128                         set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1129                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1130                         break;
1131                 case Opt_noload:
1132                         set_opt (sbi->s_mount_opt, NOLOAD);
1133                         break;
1134                 case Opt_commit:
1135                         if (match_int(&args[0], &option))
1136                                 return 0;
1137                         if (option < 0)
1138                                 return 0;
1139                         if (option == 0)
1140                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1141                         sbi->s_commit_interval = HZ * option;
1142                         break;
1143                 case Opt_data_journal:
1144                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1145                         goto datacheck;
1146                 case Opt_data_ordered:
1147                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1148                         goto datacheck;
1149                 case Opt_data_writeback:
1150                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1151                 datacheck:
1152                         if (is_remount) {
1153                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1154                                                 != data_opt) {
1155                                         printk(KERN_ERR
1156                                                 "EXT4-fs: cannot change data "
1157                                                 "mode on remount\n");
1158                                         return 0;
1159                                 }
1160                         } else {
1161                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1162                                 sbi->s_mount_opt |= data_opt;
1163                         }
1164                         break;
1165 #ifdef CONFIG_QUOTA
1166                 case Opt_usrjquota:
1167                         qtype = USRQUOTA;
1168                         goto set_qf_name;
1169                 case Opt_grpjquota:
1170                         qtype = GRPQUOTA;
1171 set_qf_name:
1172                         if ((sb_any_quota_enabled(sb) ||
1173                              sb_any_quota_suspended(sb)) &&
1174                             !sbi->s_qf_names[qtype]) {
1175                                 printk(KERN_ERR
1176                                         "EXT4-fs: Cannot change journaled "
1177                                         "quota options when quota turned on.\n");
1178                                 return 0;
1179                         }
1180                         qname = match_strdup(&args[0]);
1181                         if (!qname) {
1182                                 printk(KERN_ERR
1183                                         "EXT4-fs: not enough memory for "
1184                                         "storing quotafile name.\n");
1185                                 return 0;
1186                         }
1187                         if (sbi->s_qf_names[qtype] &&
1188                             strcmp(sbi->s_qf_names[qtype], qname)) {
1189                                 printk(KERN_ERR
1190                                         "EXT4-fs: %s quota file already "
1191                                         "specified.\n", QTYPE2NAME(qtype));
1192                                 kfree(qname);
1193                                 return 0;
1194                         }
1195                         sbi->s_qf_names[qtype] = qname;
1196                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1197                                 printk(KERN_ERR
1198                                         "EXT4-fs: quotafile must be on "
1199                                         "filesystem root.\n");
1200                                 kfree(sbi->s_qf_names[qtype]);
1201                                 sbi->s_qf_names[qtype] = NULL;
1202                                 return 0;
1203                         }
1204                         set_opt(sbi->s_mount_opt, QUOTA);
1205                         break;
1206                 case Opt_offusrjquota:
1207                         qtype = USRQUOTA;
1208                         goto clear_qf_name;
1209                 case Opt_offgrpjquota:
1210                         qtype = GRPQUOTA;
1211 clear_qf_name:
1212                         if ((sb_any_quota_enabled(sb) ||
1213                              sb_any_quota_suspended(sb)) &&
1214                             sbi->s_qf_names[qtype]) {
1215                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1216                                         "journaled quota options when "
1217                                         "quota turned on.\n");
1218                                 return 0;
1219                         }
1220                         /*
1221                          * The space will be released later when all options
1222                          * are confirmed to be correct
1223                          */
1224                         sbi->s_qf_names[qtype] = NULL;
1225                         break;
1226                 case Opt_jqfmt_vfsold:
1227                         qfmt = QFMT_VFS_OLD;
1228                         goto set_qf_format;
1229                 case Opt_jqfmt_vfsv0:
1230                         qfmt = QFMT_VFS_V0;
1231 set_qf_format:
1232                         if ((sb_any_quota_enabled(sb) ||
1233                              sb_any_quota_suspended(sb)) &&
1234                             sbi->s_jquota_fmt != qfmt) {
1235                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1236                                         "journaled quota options when "
1237                                         "quota turned on.\n");
1238                                 return 0;
1239                         }
1240                         sbi->s_jquota_fmt = qfmt;
1241                         break;
1242                 case Opt_quota:
1243                 case Opt_usrquota:
1244                         set_opt(sbi->s_mount_opt, QUOTA);
1245                         set_opt(sbi->s_mount_opt, USRQUOTA);
1246                         break;
1247                 case Opt_grpquota:
1248                         set_opt(sbi->s_mount_opt, QUOTA);
1249                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1250                         break;
1251                 case Opt_noquota:
1252                         if (sb_any_quota_enabled(sb)) {
1253                                 printk(KERN_ERR "EXT4-fs: Cannot change quota "
1254                                         "options when quota turned on.\n");
1255                                 return 0;
1256                         }
1257                         clear_opt(sbi->s_mount_opt, QUOTA);
1258                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1259                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1260                         break;
1261 #else
1262                 case Opt_quota:
1263                 case Opt_usrquota:
1264                 case Opt_grpquota:
1265                         printk(KERN_ERR
1266                                 "EXT4-fs: quota options not supported.\n");
1267                         break;
1268                 case Opt_usrjquota:
1269                 case Opt_grpjquota:
1270                 case Opt_offusrjquota:
1271                 case Opt_offgrpjquota:
1272                 case Opt_jqfmt_vfsold:
1273                 case Opt_jqfmt_vfsv0:
1274                         printk(KERN_ERR
1275                                 "EXT4-fs: journaled quota options not "
1276                                 "supported.\n");
1277                         break;
1278                 case Opt_noquota:
1279                         break;
1280 #endif
1281                 case Opt_abort:
1282                         set_opt(sbi->s_mount_opt, ABORT);
1283                         break;
1284                 case Opt_barrier:
1285                         if (match_int(&args[0], &option))
1286                                 return 0;
1287                         if (option)
1288                                 set_opt(sbi->s_mount_opt, BARRIER);
1289                         else
1290                                 clear_opt(sbi->s_mount_opt, BARRIER);
1291                         break;
1292                 case Opt_ignore:
1293                         break;
1294                 case Opt_resize:
1295                         if (!is_remount) {
1296                                 printk("EXT4-fs: resize option only available "
1297                                         "for remount\n");
1298                                 return 0;
1299                         }
1300                         if (match_int(&args[0], &option) != 0)
1301                                 return 0;
1302                         *n_blocks_count = option;
1303                         break;
1304                 case Opt_nobh:
1305                         set_opt(sbi->s_mount_opt, NOBH);
1306                         break;
1307                 case Opt_bh:
1308                         clear_opt(sbi->s_mount_opt, NOBH);
1309                         break;
1310                 case Opt_extents:
1311                         set_opt (sbi->s_mount_opt, EXTENTS);
1312                         break;
1313                 case Opt_noextents:
1314                         clear_opt (sbi->s_mount_opt, EXTENTS);
1315                         break;
1316                 case Opt_i_version:
1317                         set_opt(sbi->s_mount_opt, I_VERSION);
1318                         sb->s_flags |= MS_I_VERSION;
1319                         break;
1320                 case Opt_mballoc:
1321                         set_opt(sbi->s_mount_opt, MBALLOC);
1322                         break;
1323                 case Opt_nomballoc:
1324                         clear_opt(sbi->s_mount_opt, MBALLOC);
1325                         break;
1326                 case Opt_stripe:
1327                         if (match_int(&args[0], &option))
1328                                 return 0;
1329                         if (option < 0)
1330                                 return 0;
1331                         sbi->s_stripe = option;
1332                         break;
1333                 default:
1334                         printk (KERN_ERR
1335                                 "EXT4-fs: Unrecognized mount option \"%s\" "
1336                                 "or missing value\n", p);
1337                         return 0;
1338                 }
1339         }
1340 #ifdef CONFIG_QUOTA
1341         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1342                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1343                      sbi->s_qf_names[USRQUOTA])
1344                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1345
1346                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1347                      sbi->s_qf_names[GRPQUOTA])
1348                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1349
1350                 if ((sbi->s_qf_names[USRQUOTA] &&
1351                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1352                     (sbi->s_qf_names[GRPQUOTA] &&
1353                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1354                         printk(KERN_ERR "EXT4-fs: old and new quota "
1355                                         "format mixing.\n");
1356                         return 0;
1357                 }
1358
1359                 if (!sbi->s_jquota_fmt) {
1360                         printk(KERN_ERR "EXT4-fs: journaled quota format "
1361                                         "not specified.\n");
1362                         return 0;
1363                 }
1364         } else {
1365                 if (sbi->s_jquota_fmt) {
1366                         printk(KERN_ERR "EXT4-fs: journaled quota format "
1367                                         "specified with no journaling "
1368                                         "enabled.\n");
1369                         return 0;
1370                 }
1371         }
1372 #endif
1373         return 1;
1374 }
1375
1376 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1377                             int read_only)
1378 {
1379         struct ext4_sb_info *sbi = EXT4_SB(sb);
1380         int res = 0;
1381
1382         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1383                 printk (KERN_ERR "EXT4-fs warning: revision level too high, "
1384                         "forcing read-only mode\n");
1385                 res = MS_RDONLY;
1386         }
1387         if (read_only)
1388                 return res;
1389         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1390                 printk (KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1391                         "running e2fsck is recommended\n");
1392         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1393                 printk (KERN_WARNING
1394                         "EXT4-fs warning: mounting fs with errors, "
1395                         "running e2fsck is recommended\n");
1396         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1397                  le16_to_cpu(es->s_mnt_count) >=
1398                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1399                 printk (KERN_WARNING
1400                         "EXT4-fs warning: maximal mount count reached, "
1401                         "running e2fsck is recommended\n");
1402         else if (le32_to_cpu(es->s_checkinterval) &&
1403                 (le32_to_cpu(es->s_lastcheck) +
1404                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1405                 printk (KERN_WARNING
1406                         "EXT4-fs warning: checktime reached, "
1407                         "running e2fsck is recommended\n");
1408 #if 0
1409                 /* @@@ We _will_ want to clear the valid bit if we find
1410                  * inconsistencies, to force a fsck at reboot.  But for
1411                  * a plain journaled filesystem we can keep it set as
1412                  * valid forever! :)
1413                  */
1414         es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1415 #endif
1416         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1417                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1418         le16_add_cpu(&es->s_mnt_count, 1);
1419         es->s_mtime = cpu_to_le32(get_seconds());
1420         ext4_update_dynamic_rev(sb);
1421         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1422
1423         ext4_commit_super(sb, es, 1);
1424         if (test_opt(sb, DEBUG))
1425                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%lu, "
1426                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1427                         sb->s_blocksize,
1428                         sbi->s_groups_count,
1429                         EXT4_BLOCKS_PER_GROUP(sb),
1430                         EXT4_INODES_PER_GROUP(sb),
1431                         sbi->s_mount_opt);
1432
1433         printk(KERN_INFO "EXT4 FS on %s, ", sb->s_id);
1434         if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
1435                 char b[BDEVNAME_SIZE];
1436
1437                 printk("external journal on %s\n",
1438                         bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
1439         } else {
1440                 printk("internal journal\n");
1441         }
1442         return res;
1443 }
1444
1445 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1446                             struct ext4_group_desc *gdp)
1447 {
1448         __u16 crc = 0;
1449
1450         if (sbi->s_es->s_feature_ro_compat &
1451             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1452                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1453                 __le32 le_group = cpu_to_le32(block_group);
1454
1455                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1456                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1457                 crc = crc16(crc, (__u8 *)gdp, offset);
1458                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1459                 /* for checksum of struct ext4_group_desc do the rest...*/
1460                 if ((sbi->s_es->s_feature_incompat &
1461                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1462                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1463                         crc = crc16(crc, (__u8 *)gdp + offset,
1464                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1465                                         offset);
1466         }
1467
1468         return cpu_to_le16(crc);
1469 }
1470
1471 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1472                                 struct ext4_group_desc *gdp)
1473 {
1474         if ((sbi->s_es->s_feature_ro_compat &
1475              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1476             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1477                 return 0;
1478
1479         return 1;
1480 }
1481
1482 /* Called at mount-time, super-block is locked */
1483 static int ext4_check_descriptors(struct super_block *sb)
1484 {
1485         struct ext4_sb_info *sbi = EXT4_SB(sb);
1486         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1487         ext4_fsblk_t last_block;
1488         ext4_fsblk_t block_bitmap;
1489         ext4_fsblk_t inode_bitmap;
1490         ext4_fsblk_t inode_table;
1491         int flexbg_flag = 0;
1492         ext4_group_t i;
1493
1494         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1495                 flexbg_flag = 1;
1496
1497         ext4_debug ("Checking group descriptors");
1498
1499         for (i = 0; i < sbi->s_groups_count; i++) {
1500                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1501
1502                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1503                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1504                 else
1505                         last_block = first_block +
1506                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1507
1508                 block_bitmap = ext4_block_bitmap(sb, gdp);
1509                 if (block_bitmap < first_block || block_bitmap > last_block)
1510                 {
1511                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1512                                "Block bitmap for group %lu not in group "
1513                                "(block %llu)!", i, block_bitmap);
1514                         return 0;
1515                 }
1516                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1517                 if (inode_bitmap < first_block || inode_bitmap > last_block)
1518                 {
1519                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1520                                "Inode bitmap for group %lu not in group "
1521                                "(block %llu)!", i, inode_bitmap);
1522                         return 0;
1523                 }
1524                 inode_table = ext4_inode_table(sb, gdp);
1525                 if (inode_table < first_block ||
1526                     inode_table + sbi->s_itb_per_group - 1 > last_block)
1527                 {
1528                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1529                                "Inode table for group %lu not in group "
1530                                "(block %llu)!", i, inode_table);
1531                         return 0;
1532                 }
1533                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1534                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1535                                "Checksum for group %lu failed (%u!=%u)\n",
1536                                i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1537                                gdp)), le16_to_cpu(gdp->bg_checksum));
1538                         return 0;
1539                 }
1540                 if (!flexbg_flag)
1541                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1542         }
1543
1544         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1545         sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
1546         return 1;
1547 }
1548
1549 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1550  * the superblock) which were deleted from all directories, but held open by
1551  * a process at the time of a crash.  We walk the list and try to delete these
1552  * inodes at recovery time (only with a read-write filesystem).
1553  *
1554  * In order to keep the orphan inode chain consistent during traversal (in
1555  * case of crash during recovery), we link each inode into the superblock
1556  * orphan list_head and handle it the same way as an inode deletion during
1557  * normal operation (which journals the operations for us).
1558  *
1559  * We only do an iget() and an iput() on each inode, which is very safe if we
1560  * accidentally point at an in-use or already deleted inode.  The worst that
1561  * can happen in this case is that we get a "bit already cleared" message from
1562  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1563  * e2fsck was run on this filesystem, and it must have already done the orphan
1564  * inode cleanup for us, so we can safely abort without any further action.
1565  */
1566 static void ext4_orphan_cleanup (struct super_block * sb,
1567                                  struct ext4_super_block * es)
1568 {
1569         unsigned int s_flags = sb->s_flags;
1570         int nr_orphans = 0, nr_truncates = 0;
1571 #ifdef CONFIG_QUOTA
1572         int i;
1573 #endif
1574         if (!es->s_last_orphan) {
1575                 jbd_debug(4, "no orphan inodes to clean up\n");
1576                 return;
1577         }
1578
1579         if (bdev_read_only(sb->s_bdev)) {
1580                 printk(KERN_ERR "EXT4-fs: write access "
1581                         "unavailable, skipping orphan cleanup.\n");
1582                 return;
1583         }
1584
1585         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1586                 if (es->s_last_orphan)
1587                         jbd_debug(1, "Errors on filesystem, "
1588                                   "clearing orphan list.\n");
1589                 es->s_last_orphan = 0;
1590                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1591                 return;
1592         }
1593
1594         if (s_flags & MS_RDONLY) {
1595                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1596                        sb->s_id);
1597                 sb->s_flags &= ~MS_RDONLY;
1598         }
1599 #ifdef CONFIG_QUOTA
1600         /* Needed for iput() to work correctly and not trash data */
1601         sb->s_flags |= MS_ACTIVE;
1602         /* Turn on quotas so that they are updated correctly */
1603         for (i = 0; i < MAXQUOTAS; i++) {
1604                 if (EXT4_SB(sb)->s_qf_names[i]) {
1605                         int ret = ext4_quota_on_mount(sb, i);
1606                         if (ret < 0)
1607                                 printk(KERN_ERR
1608                                         "EXT4-fs: Cannot turn on journaled "
1609                                         "quota: error %d\n", ret);
1610                 }
1611         }
1612 #endif
1613
1614         while (es->s_last_orphan) {
1615                 struct inode *inode;
1616
1617                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
1618                 if (IS_ERR(inode)) {
1619                         es->s_last_orphan = 0;
1620                         break;
1621                 }
1622
1623                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1624                 DQUOT_INIT(inode);
1625                 if (inode->i_nlink) {
1626                         printk(KERN_DEBUG
1627                                 "%s: truncating inode %lu to %Ld bytes\n",
1628                                 __func__, inode->i_ino, inode->i_size);
1629                         jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
1630                                   inode->i_ino, inode->i_size);
1631                         ext4_truncate(inode);
1632                         nr_truncates++;
1633                 } else {
1634                         printk(KERN_DEBUG
1635                                 "%s: deleting unreferenced inode %lu\n",
1636                                 __func__, inode->i_ino);
1637                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1638                                   inode->i_ino);
1639                         nr_orphans++;
1640                 }
1641                 iput(inode);  /* The delete magic happens here! */
1642         }
1643
1644 #define PLURAL(x) (x), ((x)==1) ? "" : "s"
1645
1646         if (nr_orphans)
1647                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1648                        sb->s_id, PLURAL(nr_orphans));
1649         if (nr_truncates)
1650                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1651                        sb->s_id, PLURAL(nr_truncates));
1652 #ifdef CONFIG_QUOTA
1653         /* Turn quotas off */
1654         for (i = 0; i < MAXQUOTAS; i++) {
1655                 if (sb_dqopt(sb)->files[i])
1656                         vfs_quota_off(sb, i, 0);
1657         }
1658 #endif
1659         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1660 }
1661 /*
1662  * Maximal extent format file size.
1663  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1664  * extent format containers, within a sector_t, and within i_blocks
1665  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1666  * so that won't be a limiting factor.
1667  *
1668  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1669  */
1670 static loff_t ext4_max_size(int blkbits)
1671 {
1672         loff_t res;
1673         loff_t upper_limit = MAX_LFS_FILESIZE;
1674
1675         /* small i_blocks in vfs inode? */
1676         if (sizeof(blkcnt_t) < sizeof(u64)) {
1677                 /*
1678                  * CONFIG_LSF is not enabled implies the inode
1679                  * i_block represent total blocks in 512 bytes
1680                  * 32 == size of vfs inode i_blocks * 8
1681                  */
1682                 upper_limit = (1LL << 32) - 1;
1683
1684                 /* total blocks in file system block size */
1685                 upper_limit >>= (blkbits - 9);
1686                 upper_limit <<= blkbits;
1687         }
1688
1689         /* 32-bit extent-start container, ee_block */
1690         res = 1LL << 32;
1691         res <<= blkbits;
1692         res -= 1;
1693
1694         /* Sanity check against vm- & vfs- imposed limits */
1695         if (res > upper_limit)
1696                 res = upper_limit;
1697
1698         return res;
1699 }
1700
1701 /*
1702  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
1703  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
1704  * We need to be 1 filesystem block less than the 2^48 sector limit.
1705  */
1706 static loff_t ext4_max_bitmap_size(int bits)
1707 {
1708         loff_t res = EXT4_NDIR_BLOCKS;
1709         int meta_blocks;
1710         loff_t upper_limit;
1711         /* This is calculated to be the largest file size for a
1712          * dense, bitmapped file such that the total number of
1713          * sectors in the file, including data and all indirect blocks,
1714          * does not exceed 2^48 -1
1715          * __u32 i_blocks_lo and _u16 i_blocks_high representing the
1716          * total number of  512 bytes blocks of the file
1717          */
1718
1719         if (sizeof(blkcnt_t) < sizeof(u64)) {
1720                 /*
1721                  * CONFIG_LSF is not enabled implies the inode
1722                  * i_block represent total blocks in 512 bytes
1723                  * 32 == size of vfs inode i_blocks * 8
1724                  */
1725                 upper_limit = (1LL << 32) - 1;
1726
1727                 /* total blocks in file system block size */
1728                 upper_limit >>= (bits - 9);
1729
1730         } else {
1731                 /*
1732                  * We use 48 bit ext4_inode i_blocks
1733                  * With EXT4_HUGE_FILE_FL set the i_blocks
1734                  * represent total number of blocks in
1735                  * file system block size
1736                  */
1737                 upper_limit = (1LL << 48) - 1;
1738
1739         }
1740
1741         /* indirect blocks */
1742         meta_blocks = 1;
1743         /* double indirect blocks */
1744         meta_blocks += 1 + (1LL << (bits-2));
1745         /* tripple indirect blocks */
1746         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
1747
1748         upper_limit -= meta_blocks;
1749         upper_limit <<= bits;
1750
1751         res += 1LL << (bits-2);
1752         res += 1LL << (2*(bits-2));
1753         res += 1LL << (3*(bits-2));
1754         res <<= bits;
1755         if (res > upper_limit)
1756                 res = upper_limit;
1757
1758         if (res > MAX_LFS_FILESIZE)
1759                 res = MAX_LFS_FILESIZE;
1760
1761         return res;
1762 }
1763
1764 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1765                                 ext4_fsblk_t logical_sb_block, int nr)
1766 {
1767         struct ext4_sb_info *sbi = EXT4_SB(sb);
1768         ext4_group_t bg, first_meta_bg;
1769         int has_super = 0;
1770
1771         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1772
1773         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1774             nr < first_meta_bg)
1775                 return logical_sb_block + nr + 1;
1776         bg = sbi->s_desc_per_block * nr;
1777         if (ext4_bg_has_super(sb, bg))
1778                 has_super = 1;
1779         return (has_super + ext4_group_first_block_no(sb, bg));
1780 }
1781
1782 /**
1783  * ext4_get_stripe_size: Get the stripe size.
1784  * @sbi: In memory super block info
1785  *
1786  * If we have specified it via mount option, then
1787  * use the mount option value. If the value specified at mount time is
1788  * greater than the blocks per group use the super block value.
1789  * If the super block value is greater than blocks per group return 0.
1790  * Allocator needs it be less than blocks per group.
1791  *
1792  */
1793 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
1794 {
1795         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
1796         unsigned long stripe_width =
1797                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
1798
1799         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
1800                 return sbi->s_stripe;
1801
1802         if (stripe_width <= sbi->s_blocks_per_group)
1803                 return stripe_width;
1804
1805         if (stride <= sbi->s_blocks_per_group)
1806                 return stride;
1807
1808         return 0;
1809 }
1810
1811 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
1812                                 __releases(kernel_sem)
1813                                 __acquires(kernel_sem)
1814
1815 {
1816         struct buffer_head * bh;
1817         struct ext4_super_block *es = NULL;
1818         struct ext4_sb_info *sbi;
1819         ext4_fsblk_t block;
1820         ext4_fsblk_t sb_block = get_sb_block(&data);
1821         ext4_fsblk_t logical_sb_block;
1822         unsigned long offset = 0;
1823         unsigned int journal_inum = 0;
1824         unsigned long journal_devnum = 0;
1825         unsigned long def_mount_opts;
1826         struct inode *root;
1827         int ret = -EINVAL;
1828         int blocksize;
1829         int db_count;
1830         int i;
1831         int needs_recovery;
1832         __le32 features;
1833         __u64 blocks_count;
1834         int err;
1835
1836         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1837         if (!sbi)
1838                 return -ENOMEM;
1839         sb->s_fs_info = sbi;
1840         sbi->s_mount_opt = 0;
1841         sbi->s_resuid = EXT4_DEF_RESUID;
1842         sbi->s_resgid = EXT4_DEF_RESGID;
1843         sbi->s_sb_block = sb_block;
1844
1845         unlock_kernel();
1846
1847         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1848         if (!blocksize) {
1849                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1850                 goto out_fail;
1851         }
1852
1853         if (!sb_set_blocksize(sb, blocksize)) {
1854                 printk(KERN_ERR "EXT4-fs: bad blocksize %d.\n", blocksize);
1855                 goto out_fail;
1856         }
1857
1858         /*
1859          * The ext4 superblock will not be buffer aligned for other than 1kB
1860          * block sizes.  We need to calculate the offset from buffer start.
1861          */
1862         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1863                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1864                 offset = do_div(logical_sb_block, blocksize);
1865         } else {
1866                 logical_sb_block = sb_block;
1867         }
1868
1869         if (!(bh = sb_bread(sb, logical_sb_block))) {
1870                 printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
1871                 goto out_fail;
1872         }
1873         /*
1874          * Note: s_es must be initialized as soon as possible because
1875          *       some ext4 macro-instructions depend on its value
1876          */
1877         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1878         sbi->s_es = es;
1879         sb->s_magic = le16_to_cpu(es->s_magic);
1880         if (sb->s_magic != EXT4_SUPER_MAGIC)
1881                 goto cantfind_ext4;
1882
1883         /* Set defaults before we parse the mount options */
1884         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1885         if (def_mount_opts & EXT4_DEFM_DEBUG)
1886                 set_opt(sbi->s_mount_opt, DEBUG);
1887         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1888                 set_opt(sbi->s_mount_opt, GRPID);
1889         if (def_mount_opts & EXT4_DEFM_UID16)
1890                 set_opt(sbi->s_mount_opt, NO_UID32);
1891 #ifdef CONFIG_EXT4DEV_FS_XATTR
1892         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1893                 set_opt(sbi->s_mount_opt, XATTR_USER);
1894 #endif
1895 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1896         if (def_mount_opts & EXT4_DEFM_ACL)
1897                 set_opt(sbi->s_mount_opt, POSIX_ACL);
1898 #endif
1899         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1900                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1901         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1902                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1903         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1904                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1905
1906         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1907                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1908         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
1909                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
1910         else
1911                 set_opt(sbi->s_mount_opt, ERRORS_RO);
1912
1913         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1914         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1915
1916         set_opt(sbi->s_mount_opt, RESERVATION);
1917         set_opt(sbi->s_mount_opt, BARRIER);
1918
1919         /*
1920          * turn on extents feature by default in ext4 filesystem
1921          * User -o noextents to turn it off
1922          */
1923         set_opt(sbi->s_mount_opt, EXTENTS);
1924         /*
1925          * turn on mballoc feature by default in ext4 filesystem
1926          * User -o nomballoc to turn it off
1927          */
1928         set_opt(sbi->s_mount_opt, MBALLOC);
1929
1930         if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
1931                             NULL, 0))
1932                 goto failed_mount;
1933
1934         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1935                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1936
1937         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1938             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1939              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1940              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1941                 printk(KERN_WARNING
1942                        "EXT4-fs warning: feature flags set on rev 0 fs, "
1943                        "running e2fsck is recommended\n");
1944
1945         /*
1946          * Since ext4 is still considered development code, we require
1947          * that the TEST_FILESYS flag in s->flags be set.
1948          */
1949         if (!(le32_to_cpu(es->s_flags) & EXT2_FLAGS_TEST_FILESYS)) {
1950                 printk(KERN_WARNING "EXT4-fs: %s: not marked "
1951                        "OK to use with test code.\n", sb->s_id);
1952                 goto failed_mount;
1953         }
1954
1955         /*
1956          * Check feature flags regardless of the revision level, since we
1957          * previously didn't change the revision level when setting the flags,
1958          * so there is a chance incompat flags are set on a rev 0 filesystem.
1959          */
1960         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
1961         if (features) {
1962                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
1963                        "unsupported optional features (%x).\n",
1964                        sb->s_id, le32_to_cpu(features));
1965                 goto failed_mount;
1966         }
1967         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
1968         if (!(sb->s_flags & MS_RDONLY) && features) {
1969                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
1970                        "unsupported optional features (%x).\n",
1971                        sb->s_id, le32_to_cpu(features));
1972                 goto failed_mount;
1973         }
1974         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
1975                 /*
1976                  * Large file size enabled file system can only be
1977                  * mount if kernel is build with CONFIG_LSF
1978                  */
1979                 if (sizeof(root->i_blocks) < sizeof(u64) &&
1980                                 !(sb->s_flags & MS_RDONLY)) {
1981                         printk(KERN_ERR "EXT4-fs: %s: Filesystem with huge "
1982                                         "files cannot be mounted read-write "
1983                                         "without CONFIG_LSF.\n", sb->s_id);
1984                         goto failed_mount;
1985                 }
1986         }
1987         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
1988
1989         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
1990             blocksize > EXT4_MAX_BLOCK_SIZE) {
1991                 printk(KERN_ERR
1992                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
1993                        blocksize, sb->s_id);
1994                 goto failed_mount;
1995         }
1996
1997         if (sb->s_blocksize != blocksize) {
1998
1999                 /* Validate the filesystem blocksize */
2000                 if (!sb_set_blocksize(sb, blocksize)) {
2001                         printk(KERN_ERR "EXT4-fs: bad block size %d.\n",
2002                                         blocksize);
2003                         goto failed_mount;
2004                 }
2005
2006                 brelse (bh);
2007                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2008                 offset = do_div(logical_sb_block, blocksize);
2009                 bh = sb_bread(sb, logical_sb_block);
2010                 if (!bh) {
2011                         printk(KERN_ERR
2012                                "EXT4-fs: Can't read superblock on 2nd try.\n");
2013                         goto failed_mount;
2014                 }
2015                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
2016                 sbi->s_es = es;
2017                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
2018                         printk (KERN_ERR
2019                                 "EXT4-fs: Magic mismatch, very weird !\n");
2020                         goto failed_mount;
2021                 }
2022         }
2023
2024         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits);
2025         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
2026
2027         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2028                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2029                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2030         } else {
2031                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2032                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2033                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2034                     (!is_power_of_2(sbi->s_inode_size)) ||
2035                     (sbi->s_inode_size > blocksize)) {
2036                         printk (KERN_ERR
2037                                 "EXT4-fs: unsupported inode size: %d\n",
2038                                 sbi->s_inode_size);
2039                         goto failed_mount;
2040                 }
2041                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2042                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2043         }
2044         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2045         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2046                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2047                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2048                     !is_power_of_2(sbi->s_desc_size)) {
2049                         printk(KERN_ERR
2050                                "EXT4-fs: unsupported descriptor size %lu\n",
2051                                sbi->s_desc_size);
2052                         goto failed_mount;
2053                 }
2054         } else
2055                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2056         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2057         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2058         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2059                 goto cantfind_ext4;
2060         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2061         if (sbi->s_inodes_per_block == 0)
2062                 goto cantfind_ext4;
2063         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2064                                         sbi->s_inodes_per_block;
2065         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2066         sbi->s_sbh = bh;
2067         sbi->s_mount_state = le16_to_cpu(es->s_state);
2068         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2069         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2070         for (i=0; i < 4; i++)
2071                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2072         sbi->s_def_hash_version = es->s_def_hash_version;
2073
2074         if (sbi->s_blocks_per_group > blocksize * 8) {
2075                 printk (KERN_ERR
2076                         "EXT4-fs: #blocks per group too big: %lu\n",
2077                         sbi->s_blocks_per_group);
2078                 goto failed_mount;
2079         }
2080         if (sbi->s_inodes_per_group > blocksize * 8) {
2081                 printk (KERN_ERR
2082                         "EXT4-fs: #inodes per group too big: %lu\n",
2083                         sbi->s_inodes_per_group);
2084                 goto failed_mount;
2085         }
2086
2087         if (ext4_blocks_count(es) >
2088                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
2089                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
2090                         " too large to mount safely\n", sb->s_id);
2091                 if (sizeof(sector_t) < 8)
2092                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
2093                                         "enabled\n");
2094                 goto failed_mount;
2095         }
2096
2097         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2098                 goto cantfind_ext4;
2099
2100         /* ensure blocks_count calculation below doesn't sign-extend */
2101         if (ext4_blocks_count(es) + EXT4_BLOCKS_PER_GROUP(sb) <
2102             le32_to_cpu(es->s_first_data_block) + 1) {
2103                 printk(KERN_WARNING "EXT4-fs: bad geometry: block count %llu, "
2104                        "first data block %u, blocks per group %lu\n",
2105                         ext4_blocks_count(es),
2106                         le32_to_cpu(es->s_first_data_block),
2107                         EXT4_BLOCKS_PER_GROUP(sb));
2108                 goto failed_mount;
2109         }
2110         blocks_count = (ext4_blocks_count(es) -
2111                         le32_to_cpu(es->s_first_data_block) +
2112                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2113         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2114         sbi->s_groups_count = blocks_count;
2115         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2116                    EXT4_DESC_PER_BLOCK(sb);
2117         sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
2118                                     GFP_KERNEL);
2119         if (sbi->s_group_desc == NULL) {
2120                 printk (KERN_ERR "EXT4-fs: not enough memory\n");
2121                 goto failed_mount;
2122         }
2123
2124         bgl_lock_init(&sbi->s_blockgroup_lock);
2125
2126         for (i = 0; i < db_count; i++) {
2127                 block = descriptor_loc(sb, logical_sb_block, i);
2128                 sbi->s_group_desc[i] = sb_bread(sb, block);
2129                 if (!sbi->s_group_desc[i]) {
2130                         printk (KERN_ERR "EXT4-fs: "
2131                                 "can't read group descriptor %d\n", i);
2132                         db_count = i;
2133                         goto failed_mount2;
2134                 }
2135         }
2136         if (!ext4_check_descriptors (sb)) {
2137                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
2138                 goto failed_mount2;
2139         }
2140         sbi->s_gdb_count = db_count;
2141         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2142         spin_lock_init(&sbi->s_next_gen_lock);
2143
2144         err = percpu_counter_init(&sbi->s_freeblocks_counter,
2145                         ext4_count_free_blocks(sb));
2146         if (!err) {
2147                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
2148                                 ext4_count_free_inodes(sb));
2149         }
2150         if (!err) {
2151                 err = percpu_counter_init(&sbi->s_dirs_counter,
2152                                 ext4_count_dirs(sb));
2153         }
2154         if (err) {
2155                 printk(KERN_ERR "EXT4-fs: insufficient memory\n");
2156                 goto failed_mount3;
2157         }
2158
2159         /* per fileystem reservation list head & lock */
2160         spin_lock_init(&sbi->s_rsv_window_lock);
2161         sbi->s_rsv_window_root = RB_ROOT;
2162         /* Add a single, static dummy reservation to the start of the
2163          * reservation window list --- it gives us a placeholder for
2164          * append-at-start-of-list which makes the allocation logic
2165          * _much_ simpler. */
2166         sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
2167         sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
2168         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
2169         sbi->s_rsv_window_head.rsv_goal_size = 0;
2170         ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
2171
2172         sbi->s_stripe = ext4_get_stripe_size(sbi);
2173
2174         /*
2175          * set up enough so that it can read an inode
2176          */
2177         sb->s_op = &ext4_sops;
2178         sb->s_export_op = &ext4_export_ops;
2179         sb->s_xattr = ext4_xattr_handlers;
2180 #ifdef CONFIG_QUOTA
2181         sb->s_qcop = &ext4_qctl_operations;
2182         sb->dq_op = &ext4_quota_operations;
2183 #endif
2184         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2185
2186         sb->s_root = NULL;
2187
2188         needs_recovery = (es->s_last_orphan != 0 ||
2189                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2190                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2191
2192         /*
2193          * The first inode we look at is the journal inode.  Don't try
2194          * root first: it may be modified in the journal!
2195          */
2196         if (!test_opt(sb, NOLOAD) &&
2197             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2198                 if (ext4_load_journal(sb, es, journal_devnum))
2199                         goto failed_mount3;
2200                 if (!(sb->s_flags & MS_RDONLY) &&
2201                     EXT4_SB(sb)->s_journal->j_failed_commit) {
2202                         printk(KERN_CRIT "EXT4-fs error (device %s): "
2203                                "ext4_fill_super: Journal transaction "
2204                                "%u is corrupt\n", sb->s_id,
2205                                EXT4_SB(sb)->s_journal->j_failed_commit);
2206                         if (test_opt (sb, ERRORS_RO)) {
2207                                 printk (KERN_CRIT
2208                                         "Mounting filesystem read-only\n");
2209                                 sb->s_flags |= MS_RDONLY;
2210                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2211                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2212                         }
2213                         if (test_opt(sb, ERRORS_PANIC)) {
2214                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2215                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2216                                 ext4_commit_super(sb, es, 1);
2217                                 printk(KERN_CRIT
2218                                        "EXT4-fs (device %s): mount failed\n",
2219                                       sb->s_id);
2220                                 goto failed_mount4;
2221                         }
2222                 }
2223         } else if (journal_inum) {
2224                 if (ext4_create_journal(sb, es, journal_inum))
2225                         goto failed_mount3;
2226         } else {
2227                 if (!silent)
2228                         printk (KERN_ERR
2229                                 "ext4: No journal on filesystem on %s\n",
2230                                 sb->s_id);
2231                 goto failed_mount3;
2232         }
2233
2234         if (ext4_blocks_count(es) > 0xffffffffULL &&
2235             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2236                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2237                 printk(KERN_ERR "ext4: Failed to set 64-bit journal feature\n");
2238                 goto failed_mount4;
2239         }
2240
2241         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2242                 jbd2_journal_set_features(sbi->s_journal,
2243                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2244                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2245         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2246                 jbd2_journal_set_features(sbi->s_journal,
2247                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2248                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2249                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2250         } else {
2251                 jbd2_journal_clear_features(sbi->s_journal,
2252                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2253                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2254         }
2255
2256         /* We have now updated the journal if required, so we can
2257          * validate the data journaling mode. */
2258         switch (test_opt(sb, DATA_FLAGS)) {
2259         case 0:
2260                 /* No mode set, assume a default based on the journal
2261                  * capabilities: ORDERED_DATA if the journal can
2262                  * cope, else JOURNAL_DATA
2263                  */
2264                 if (jbd2_journal_check_available_features
2265                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2266                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
2267                 else
2268                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2269                 break;
2270
2271         case EXT4_MOUNT_ORDERED_DATA:
2272         case EXT4_MOUNT_WRITEBACK_DATA:
2273                 if (!jbd2_journal_check_available_features
2274                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2275                         printk(KERN_ERR "EXT4-fs: Journal does not support "
2276                                "requested data journaling mode\n");
2277                         goto failed_mount4;
2278                 }
2279         default:
2280                 break;
2281         }
2282
2283         if (test_opt(sb, NOBH)) {
2284                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2285                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
2286                                 "its supported only with writeback mode\n");
2287                         clear_opt(sbi->s_mount_opt, NOBH);
2288                 }
2289         }
2290         /*
2291          * The jbd2_journal_load will have done any necessary log recovery,
2292          * so we can safely mount the rest of the filesystem now.
2293          */
2294
2295         root = ext4_iget(sb, EXT4_ROOT_INO);
2296         if (IS_ERR(root)) {
2297                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
2298                 ret = PTR_ERR(root);
2299                 goto failed_mount4;
2300         }
2301         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2302                 iput(root);
2303                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
2304                 goto failed_mount4;
2305         }
2306         sb->s_root = d_alloc_root(root);
2307         if (!sb->s_root) {
2308                 printk(KERN_ERR "EXT4-fs: get root dentry failed\n");
2309                 iput(root);
2310                 ret = -ENOMEM;
2311                 goto failed_mount4;
2312         }
2313
2314         ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
2315
2316         /* determine the minimum size of new large inodes, if present */
2317         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2318                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2319                                                      EXT4_GOOD_OLD_INODE_SIZE;
2320                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2321                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2322                         if (sbi->s_want_extra_isize <
2323                             le16_to_cpu(es->s_want_extra_isize))
2324                                 sbi->s_want_extra_isize =
2325                                         le16_to_cpu(es->s_want_extra_isize);
2326                         if (sbi->s_want_extra_isize <
2327                             le16_to_cpu(es->s_min_extra_isize))
2328                                 sbi->s_want_extra_isize =
2329                                         le16_to_cpu(es->s_min_extra_isize);
2330                 }
2331         }
2332         /* Check if enough inode space is available */
2333         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2334                                                         sbi->s_inode_size) {
2335                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2336                                                        EXT4_GOOD_OLD_INODE_SIZE;
2337                 printk(KERN_INFO "EXT4-fs: required extra inode space not"
2338                         "available.\n");
2339         }
2340
2341         /*
2342          * akpm: core read_super() calls in here with the superblock locked.
2343          * That deadlocks, because orphan cleanup needs to lock the superblock
2344          * in numerous places.  Here we just pop the lock - it's relatively
2345          * harmless, because we are now ready to accept write_super() requests,
2346          * and aviro says that's the only reason for hanging onto the
2347          * superblock lock.
2348          */
2349         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2350         ext4_orphan_cleanup(sb, es);
2351         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2352         if (needs_recovery)
2353                 printk (KERN_INFO "EXT4-fs: recovery complete.\n");
2354         ext4_mark_recovery_complete(sb, es);
2355         printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
2356                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
2357                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
2358                 "writeback");
2359
2360         ext4_ext_init(sb);
2361         ext4_mb_init(sb, needs_recovery);
2362
2363         lock_kernel();
2364         return 0;
2365
2366 cantfind_ext4:
2367         if (!silent)
2368                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
2369                        sb->s_id);
2370         goto failed_mount;
2371
2372 failed_mount4:
2373         jbd2_journal_destroy(sbi->s_journal);
2374 failed_mount3:
2375         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2376         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2377         percpu_counter_destroy(&sbi->s_dirs_counter);
2378 failed_mount2:
2379         for (i = 0; i < db_count; i++)
2380                 brelse(sbi->s_group_desc[i]);
2381         kfree(sbi->s_group_desc);
2382 failed_mount:
2383 #ifdef CONFIG_QUOTA
2384         for (i = 0; i < MAXQUOTAS; i++)
2385                 kfree(sbi->s_qf_names[i]);
2386 #endif
2387         ext4_blkdev_remove(sbi);
2388         brelse(bh);
2389 out_fail:
2390         sb->s_fs_info = NULL;
2391         kfree(sbi);
2392         lock_kernel();
2393         return ret;
2394 }
2395
2396 /*
2397  * Setup any per-fs journal parameters now.  We'll do this both on
2398  * initial mount, once the journal has been initialised but before we've
2399  * done any recovery; and again on any subsequent remount.
2400  */
2401 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2402 {
2403         struct ext4_sb_info *sbi = EXT4_SB(sb);
2404
2405         if (sbi->s_commit_interval)
2406                 journal->j_commit_interval = sbi->s_commit_interval;
2407         /* We could also set up an ext4-specific default for the commit
2408          * interval here, but for now we'll just fall back to the jbd
2409          * default. */
2410
2411         spin_lock(&journal->j_state_lock);
2412         if (test_opt(sb, BARRIER))
2413                 journal->j_flags |= JBD2_BARRIER;
2414         else
2415                 journal->j_flags &= ~JBD2_BARRIER;
2416         spin_unlock(&journal->j_state_lock);
2417 }
2418
2419 static journal_t *ext4_get_journal(struct super_block *sb,
2420                                    unsigned int journal_inum)
2421 {
2422         struct inode *journal_inode;
2423         journal_t *journal;
2424
2425         /* First, test for the existence of a valid inode on disk.  Bad
2426          * things happen if we iget() an unused inode, as the subsequent
2427          * iput() will try to delete it. */
2428
2429         journal_inode = ext4_iget(sb, journal_inum);
2430         if (IS_ERR(journal_inode)) {
2431                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
2432                 return NULL;
2433         }
2434         if (!journal_inode->i_nlink) {
2435                 make_bad_inode(journal_inode);
2436                 iput(journal_inode);
2437                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
2438                 return NULL;
2439         }
2440
2441         jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
2442                   journal_inode, journal_inode->i_size);
2443         if (!S_ISREG(journal_inode->i_mode)) {
2444                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
2445                 iput(journal_inode);
2446                 return NULL;
2447         }
2448
2449         journal = jbd2_journal_init_inode(journal_inode);
2450         if (!journal) {
2451                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
2452                 iput(journal_inode);
2453                 return NULL;
2454         }
2455         journal->j_private = sb;
2456         ext4_init_journal_params(sb, journal);
2457         return journal;
2458 }
2459
2460 static journal_t *ext4_get_dev_journal(struct super_block *sb,
2461                                        dev_t j_dev)
2462 {
2463         struct buffer_head * bh;
2464         journal_t *journal;
2465         ext4_fsblk_t start;
2466         ext4_fsblk_t len;
2467         int hblock, blocksize;
2468         ext4_fsblk_t sb_block;
2469         unsigned long offset;
2470         struct ext4_super_block * es;
2471         struct block_device *bdev;
2472
2473         bdev = ext4_blkdev_get(j_dev);
2474         if (bdev == NULL)
2475                 return NULL;
2476
2477         if (bd_claim(bdev, sb)) {
2478                 printk(KERN_ERR
2479                         "EXT4: failed to claim external journal device.\n");
2480                 blkdev_put(bdev);
2481                 return NULL;
2482         }
2483
2484         blocksize = sb->s_blocksize;
2485         hblock = bdev_hardsect_size(bdev);
2486         if (blocksize < hblock) {
2487                 printk(KERN_ERR
2488                         "EXT4-fs: blocksize too small for journal device.\n");
2489                 goto out_bdev;
2490         }
2491
2492         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2493         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2494         set_blocksize(bdev, blocksize);
2495         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2496                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2497                        "external journal\n");
2498                 goto out_bdev;
2499         }
2500
2501         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2502         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2503             !(le32_to_cpu(es->s_feature_incompat) &
2504               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2505                 printk(KERN_ERR "EXT4-fs: external journal has "
2506                                         "bad superblock\n");
2507                 brelse(bh);
2508                 goto out_bdev;
2509         }
2510
2511         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2512                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2513                 brelse(bh);
2514                 goto out_bdev;
2515         }
2516
2517         len = ext4_blocks_count(es);
2518         start = sb_block + 1;
2519         brelse(bh);     /* we're done with the superblock */
2520
2521         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2522                                         start, len, blocksize);
2523         if (!journal) {
2524                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2525                 goto out_bdev;
2526         }
2527         journal->j_private = sb;
2528         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2529         wait_on_buffer(journal->j_sb_buffer);
2530         if (!buffer_uptodate(journal->j_sb_buffer)) {
2531                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2532                 goto out_journal;
2533         }
2534         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2535                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2536                                         "user (unsupported) - %d\n",
2537                         be32_to_cpu(journal->j_superblock->s_nr_users));
2538                 goto out_journal;
2539         }
2540         EXT4_SB(sb)->journal_bdev = bdev;
2541         ext4_init_journal_params(sb, journal);
2542         return journal;
2543 out_journal:
2544         jbd2_journal_destroy(journal);
2545 out_bdev:
2546         ext4_blkdev_put(bdev);
2547         return NULL;
2548 }
2549
2550 static int ext4_load_journal(struct super_block *sb,
2551                              struct ext4_super_block *es,
2552                              unsigned long journal_devnum)
2553 {
2554         journal_t *journal;
2555         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2556         dev_t journal_dev;
2557         int err = 0;
2558         int really_read_only;
2559
2560         if (journal_devnum &&
2561             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2562                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2563                         "numbers have changed\n");
2564                 journal_dev = new_decode_dev(journal_devnum);
2565         } else
2566                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2567
2568         really_read_only = bdev_read_only(sb->s_bdev);
2569
2570         /*
2571          * Are we loading a blank journal or performing recovery after a
2572          * crash?  For recovery, we need to check in advance whether we
2573          * can get read-write access to the device.
2574          */
2575
2576         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2577                 if (sb->s_flags & MS_RDONLY) {
2578                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2579                                         "required on readonly filesystem.\n");
2580                         if (really_read_only) {
2581                                 printk(KERN_ERR "EXT4-fs: write access "
2582                                         "unavailable, cannot proceed.\n");
2583                                 return -EROFS;
2584                         }
2585                         printk (KERN_INFO "EXT4-fs: write access will "
2586                                         "be enabled during recovery.\n");
2587                 }
2588         }
2589
2590         if (journal_inum && journal_dev) {
2591                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2592                        "and inode journals!\n");
2593                 return -EINVAL;
2594         }
2595
2596         if (journal_inum) {
2597                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2598                         return -EINVAL;
2599         } else {
2600                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2601                         return -EINVAL;
2602         }
2603
2604         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2605                 err = jbd2_journal_update_format(journal);
2606                 if (err)  {
2607                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2608                         jbd2_journal_destroy(journal);
2609                         return err;
2610                 }
2611         }
2612
2613         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2614                 err = jbd2_journal_wipe(journal, !really_read_only);
2615         if (!err)
2616                 err = jbd2_journal_load(journal);
2617
2618         if (err) {
2619                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2620                 jbd2_journal_destroy(journal);
2621                 return err;
2622         }
2623
2624         EXT4_SB(sb)->s_journal = journal;
2625         ext4_clear_journal_err(sb, es);
2626
2627         if (journal_devnum &&
2628             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2629                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2630                 sb->s_dirt = 1;
2631
2632                 /* Make sure we flush the recovery flag to disk. */
2633                 ext4_commit_super(sb, es, 1);
2634         }
2635
2636         return 0;
2637 }
2638
2639 static int ext4_create_journal(struct super_block * sb,
2640                                struct ext4_super_block * es,
2641                                unsigned int journal_inum)
2642 {
2643         journal_t *journal;
2644         int err;
2645
2646         if (sb->s_flags & MS_RDONLY) {
2647                 printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2648                                 "create journal.\n");
2649                 return -EROFS;
2650         }
2651
2652         journal = ext4_get_journal(sb, journal_inum);
2653         if (!journal)
2654                 return -EINVAL;
2655
2656         printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2657                journal_inum);
2658
2659         err = jbd2_journal_create(journal);
2660         if (err) {
2661                 printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2662                 jbd2_journal_destroy(journal);
2663                 return -EIO;
2664         }
2665
2666         EXT4_SB(sb)->s_journal = journal;
2667
2668         ext4_update_dynamic_rev(sb);
2669         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2670         EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2671
2672         es->s_journal_inum = cpu_to_le32(journal_inum);
2673         sb->s_dirt = 1;
2674
2675         /* Make sure we flush the recovery flag to disk. */
2676         ext4_commit_super(sb, es, 1);
2677
2678         return 0;
2679 }
2680
2681 static void ext4_commit_super (struct super_block * sb,
2682                                struct ext4_super_block * es,
2683                                int sync)
2684 {
2685         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2686
2687         if (!sbh)
2688                 return;
2689         es->s_wtime = cpu_to_le32(get_seconds());
2690         ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2691         es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2692         BUFFER_TRACE(sbh, "marking dirty");
2693         mark_buffer_dirty(sbh);
2694         if (sync)
2695                 sync_dirty_buffer(sbh);
2696 }
2697
2698
2699 /*
2700  * Have we just finished recovery?  If so, and if we are mounting (or
2701  * remounting) the filesystem readonly, then we will end up with a
2702  * consistent fs on disk.  Record that fact.
2703  */
2704 static void ext4_mark_recovery_complete(struct super_block * sb,
2705                                         struct ext4_super_block * es)
2706 {
2707         journal_t *journal = EXT4_SB(sb)->s_journal;
2708
2709         jbd2_journal_lock_updates(journal);
2710         jbd2_journal_flush(journal);
2711         lock_super(sb);
2712         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2713             sb->s_flags & MS_RDONLY) {
2714                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2715                 sb->s_dirt = 0;
2716                 ext4_commit_super(sb, es, 1);
2717         }
2718         unlock_super(sb);
2719         jbd2_journal_unlock_updates(journal);
2720 }
2721
2722 /*
2723  * If we are mounting (or read-write remounting) a filesystem whose journal
2724  * has recorded an error from a previous lifetime, move that error to the
2725  * main filesystem now.
2726  */
2727 static void ext4_clear_journal_err(struct super_block * sb,
2728                                    struct ext4_super_block * es)
2729 {
2730         journal_t *journal;
2731         int j_errno;
2732         const char *errstr;
2733
2734         journal = EXT4_SB(sb)->s_journal;
2735
2736         /*
2737          * Now check for any error status which may have been recorded in the
2738          * journal by a prior ext4_error() or ext4_abort()
2739          */
2740
2741         j_errno = jbd2_journal_errno(journal);
2742         if (j_errno) {
2743                 char nbuf[16];
2744
2745                 errstr = ext4_decode_error(sb, j_errno, nbuf);
2746                 ext4_warning(sb, __func__, "Filesystem error recorded "
2747                              "from previous mount: %s", errstr);
2748                 ext4_warning(sb, __func__, "Marking fs in need of "
2749                              "filesystem check.");
2750
2751                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2752                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2753                 ext4_commit_super (sb, es, 1);
2754
2755                 jbd2_journal_clear_err(journal);
2756         }
2757 }
2758
2759 /*
2760  * Force the running and committing transactions to commit,
2761  * and wait on the commit.
2762  */
2763 int ext4_force_commit(struct super_block *sb)
2764 {
2765         journal_t *journal;
2766         int ret;
2767
2768         if (sb->s_flags & MS_RDONLY)
2769                 return 0;
2770
2771         journal = EXT4_SB(sb)->s_journal;
2772         sb->s_dirt = 0;
2773         ret = ext4_journal_force_commit(journal);
2774         return ret;
2775 }
2776
2777 /*
2778  * Ext4 always journals updates to the superblock itself, so we don't
2779  * have to propagate any other updates to the superblock on disk at this
2780  * point.  Just start an async writeback to get the buffers on their way
2781  * to the disk.
2782  *
2783  * This implicitly triggers the writebehind on sync().
2784  */
2785
2786 static void ext4_write_super (struct super_block * sb)
2787 {
2788         if (mutex_trylock(&sb->s_lock) != 0)
2789                 BUG();
2790         sb->s_dirt = 0;
2791 }
2792
2793 static int ext4_sync_fs(struct super_block *sb, int wait)
2794 {
2795         tid_t target;
2796
2797         sb->s_dirt = 0;
2798         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2799                 if (wait)
2800                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2801         }
2802         return 0;
2803 }
2804
2805 /*
2806  * LVM calls this function before a (read-only) snapshot is created.  This
2807  * gives us a chance to flush the journal completely and mark the fs clean.
2808  */
2809 static void ext4_write_super_lockfs(struct super_block *sb)
2810 {
2811         sb->s_dirt = 0;
2812
2813         if (!(sb->s_flags & MS_RDONLY)) {
2814                 journal_t *journal = EXT4_SB(sb)->s_journal;
2815
2816                 /* Now we set up the journal barrier. */
2817                 jbd2_journal_lock_updates(journal);
2818                 jbd2_journal_flush(journal);
2819
2820                 /* Journal blocked and flushed, clear needs_recovery flag. */
2821                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2822                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2823         }
2824 }
2825
2826 /*
2827  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2828  * flag here, even though the filesystem is not technically dirty yet.
2829  */
2830 static void ext4_unlockfs(struct super_block *sb)
2831 {
2832         if (!(sb->s_flags & MS_RDONLY)) {
2833                 lock_super(sb);
2834                 /* Reser the needs_recovery flag before the fs is unlocked. */
2835                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2836                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2837                 unlock_super(sb);
2838                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2839         }
2840 }
2841
2842 static int ext4_remount (struct super_block * sb, int * flags, char * data)
2843 {
2844         struct ext4_super_block * es;
2845         struct ext4_sb_info *sbi = EXT4_SB(sb);
2846         ext4_fsblk_t n_blocks_count = 0;
2847         unsigned long old_sb_flags;
2848         struct ext4_mount_options old_opts;
2849         int err;
2850 #ifdef CONFIG_QUOTA
2851         int i;
2852 #endif
2853
2854         /* Store the original options */
2855         old_sb_flags = sb->s_flags;
2856         old_opts.s_mount_opt = sbi->s_mount_opt;
2857         old_opts.s_resuid = sbi->s_resuid;
2858         old_opts.s_resgid = sbi->s_resgid;
2859         old_opts.s_commit_interval = sbi->s_commit_interval;
2860 #ifdef CONFIG_QUOTA
2861         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2862         for (i = 0; i < MAXQUOTAS; i++)
2863                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2864 #endif
2865
2866         /*
2867          * Allow the "check" option to be passed as a remount option.
2868          */
2869         if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2870                 err = -EINVAL;
2871                 goto restore_opts;
2872         }
2873
2874         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2875                 ext4_abort(sb, __func__, "Abort forced by user");
2876
2877         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2878                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2879
2880         es = sbi->s_es;
2881
2882         ext4_init_journal_params(sb, sbi->s_journal);
2883
2884         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2885                 n_blocks_count > ext4_blocks_count(es)) {
2886                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
2887                         err = -EROFS;
2888                         goto restore_opts;
2889                 }
2890
2891                 if (*flags & MS_RDONLY) {
2892                         /*
2893                          * First of all, the unconditional stuff we have to do
2894                          * to disable replay of the journal when we next remount
2895                          */
2896                         sb->s_flags |= MS_RDONLY;
2897
2898                         /*
2899                          * OK, test if we are remounting a valid rw partition
2900                          * readonly, and if so set the rdonly flag and then
2901                          * mark the partition as valid again.
2902                          */
2903                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
2904                             (sbi->s_mount_state & EXT4_VALID_FS))
2905                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
2906
2907                         /*
2908                          * We have to unlock super so that we can wait for
2909                          * transactions.
2910                          */
2911                         unlock_super(sb);
2912                         ext4_mark_recovery_complete(sb, es);
2913                         lock_super(sb);
2914                 } else {
2915                         __le32 ret;
2916                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2917                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
2918                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2919                                        "remount RDWR because of unsupported "
2920                                        "optional features (%x).\n",
2921                                        sb->s_id, le32_to_cpu(ret));
2922                                 err = -EROFS;
2923                                 goto restore_opts;
2924                         }
2925
2926                         /*
2927                          * If we have an unprocessed orphan list hanging
2928                          * around from a previously readonly bdev mount,
2929                          * require a full umount/remount for now.
2930                          */
2931                         if (es->s_last_orphan) {
2932                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2933                                        "remount RDWR because of unprocessed "
2934                                        "orphan inode list.  Please "
2935                                        "umount/remount instead.\n",
2936                                        sb->s_id);
2937                                 err = -EINVAL;
2938                                 goto restore_opts;
2939                         }
2940
2941                         /*
2942                          * Mounting a RDONLY partition read-write, so reread
2943                          * and store the current valid flag.  (It may have
2944                          * been changed by e2fsck since we originally mounted
2945                          * the partition.)
2946                          */
2947                         ext4_clear_journal_err(sb, es);
2948                         sbi->s_mount_state = le16_to_cpu(es->s_state);
2949                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
2950                                 goto restore_opts;
2951                         if (!ext4_setup_super (sb, es, 0))
2952                                 sb->s_flags &= ~MS_RDONLY;
2953                 }
2954         }
2955 #ifdef CONFIG_QUOTA
2956         /* Release old quota file names */
2957         for (i = 0; i < MAXQUOTAS; i++)
2958                 if (old_opts.s_qf_names[i] &&
2959                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2960                         kfree(old_opts.s_qf_names[i]);
2961 #endif
2962         return 0;
2963 restore_opts:
2964         sb->s_flags = old_sb_flags;
2965         sbi->s_mount_opt = old_opts.s_mount_opt;
2966         sbi->s_resuid = old_opts.s_resuid;
2967         sbi->s_resgid = old_opts.s_resgid;
2968         sbi->s_commit_interval = old_opts.s_commit_interval;
2969 #ifdef CONFIG_QUOTA
2970         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
2971         for (i = 0; i < MAXQUOTAS; i++) {
2972                 if (sbi->s_qf_names[i] &&
2973                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2974                         kfree(sbi->s_qf_names[i]);
2975                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
2976         }
2977 #endif
2978         return err;
2979 }
2980
2981 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
2982 {
2983         struct super_block *sb = dentry->d_sb;
2984         struct ext4_sb_info *sbi = EXT4_SB(sb);
2985         struct ext4_super_block *es = sbi->s_es;
2986         u64 fsid;
2987
2988         if (test_opt(sb, MINIX_DF)) {
2989                 sbi->s_overhead_last = 0;
2990         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
2991                 ext4_group_t ngroups = sbi->s_groups_count, i;
2992                 ext4_fsblk_t overhead = 0;
2993                 smp_rmb();
2994
2995                 /*
2996                  * Compute the overhead (FS structures).  This is constant
2997                  * for a given filesystem unless the number of block groups
2998                  * changes so we cache the previous value until it does.
2999                  */
3000
3001                 /*
3002                  * All of the blocks before first_data_block are
3003                  * overhead
3004                  */
3005                 overhead = le32_to_cpu(es->s_first_data_block);
3006
3007                 /*
3008                  * Add the overhead attributed to the superblock and
3009                  * block group descriptors.  If the sparse superblocks
3010                  * feature is turned on, then not all groups have this.
3011                  */
3012                 for (i = 0; i < ngroups; i++) {
3013                         overhead += ext4_bg_has_super(sb, i) +
3014                                 ext4_bg_num_gdb(sb, i);
3015                         cond_resched();
3016                 }
3017
3018                 /*
3019                  * Every block group has an inode bitmap, a block
3020                  * bitmap, and an inode table.
3021                  */
3022                 overhead += ngroups * (2 + sbi->s_itb_per_group);
3023                 sbi->s_overhead_last = overhead;
3024                 smp_wmb();
3025                 sbi->s_blocks_last = ext4_blocks_count(es);
3026         }
3027
3028         buf->f_type = EXT4_SUPER_MAGIC;
3029         buf->f_bsize = sb->s_blocksize;
3030         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
3031         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter);
3032         ext4_free_blocks_count_set(es, buf->f_bfree);
3033         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
3034         if (buf->f_bfree < ext4_r_blocks_count(es))
3035                 buf->f_bavail = 0;
3036         buf->f_files = le32_to_cpu(es->s_inodes_count);
3037         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
3038         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
3039         buf->f_namelen = EXT4_NAME_LEN;
3040         fsid = le64_to_cpup((void *)es->s_uuid) ^
3041                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
3042         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
3043         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
3044         return 0;
3045 }
3046
3047 /* Helper function for writing quotas on sync - we need to start transaction before quota file
3048  * is locked for write. Otherwise the are possible deadlocks:
3049  * Process 1                         Process 2
3050  * ext4_create()                     quota_sync()
3051  *   jbd2_journal_start()                   write_dquot()
3052  *   DQUOT_INIT()                        down(dqio_mutex)
3053  *     down(dqio_mutex)                    jbd2_journal_start()
3054  *
3055  */
3056
3057 #ifdef CONFIG_QUOTA
3058
3059 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3060 {
3061         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3062 }
3063
3064 static int ext4_dquot_initialize(struct inode *inode, int type)
3065 {
3066         handle_t *handle;
3067         int ret, err;
3068
3069         /* We may create quota structure so we need to reserve enough blocks */
3070         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
3071         if (IS_ERR(handle))
3072                 return PTR_ERR(handle);
3073         ret = dquot_initialize(inode, type);
3074         err = ext4_journal_stop(handle);
3075         if (!ret)
3076                 ret = err;
3077         return ret;
3078 }
3079
3080 static int ext4_dquot_drop(struct inode *inode)
3081 {
3082         handle_t *handle;
3083         int ret, err;
3084
3085         /* We may delete quota structure so we need to reserve enough blocks */
3086         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
3087         if (IS_ERR(handle)) {
3088                 /*
3089                  * We call dquot_drop() anyway to at least release references
3090                  * to quota structures so that umount does not hang.
3091                  */
3092                 dquot_drop(inode);
3093                 return PTR_ERR(handle);
3094         }
3095         ret = dquot_drop(inode);
3096         err = ext4_journal_stop(handle);
3097         if (!ret)
3098                 ret = err;
3099         return ret;
3100 }
3101
3102 static int ext4_write_dquot(struct dquot *dquot)
3103 {
3104         int ret, err;
3105         handle_t *handle;
3106         struct inode *inode;
3107
3108         inode = dquot_to_inode(dquot);
3109         handle = ext4_journal_start(inode,
3110                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3111         if (IS_ERR(handle))
3112                 return PTR_ERR(handle);
3113         ret = dquot_commit(dquot);
3114         err = ext4_journal_stop(handle);
3115         if (!ret)
3116                 ret = err;
3117         return ret;
3118 }
3119
3120 static int ext4_acquire_dquot(struct dquot *dquot)
3121 {
3122         int ret, err;
3123         handle_t *handle;
3124
3125         handle = ext4_journal_start(dquot_to_inode(dquot),
3126                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3127         if (IS_ERR(handle))
3128                 return PTR_ERR(handle);
3129         ret = dquot_acquire(dquot);
3130         err = ext4_journal_stop(handle);
3131         if (!ret)
3132                 ret = err;
3133         return ret;
3134 }
3135
3136 static int ext4_release_dquot(struct dquot *dquot)
3137 {
3138         int ret, err;
3139         handle_t *handle;
3140
3141         handle = ext4_journal_start(dquot_to_inode(dquot),
3142                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3143         if (IS_ERR(handle)) {
3144                 /* Release dquot anyway to avoid endless cycle in dqput() */
3145                 dquot_release(dquot);
3146                 return PTR_ERR(handle);
3147         }
3148         ret = dquot_release(dquot);
3149         err = ext4_journal_stop(handle);
3150         if (!ret)
3151                 ret = err;
3152         return ret;
3153 }
3154
3155 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3156 {
3157         /* Are we journaling quotas? */
3158         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3159             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3160                 dquot_mark_dquot_dirty(dquot);
3161                 return ext4_write_dquot(dquot);
3162         } else {
3163                 return dquot_mark_dquot_dirty(dquot);
3164         }
3165 }
3166
3167 static int ext4_write_info(struct super_block *sb, int type)
3168 {
3169         int ret, err;
3170         handle_t *handle;
3171
3172         /* Data block + inode block */
3173         handle = ext4_journal_start(sb->s_root->d_inode, 2);
3174         if (IS_ERR(handle))
3175                 return PTR_ERR(handle);
3176         ret = dquot_commit_info(sb, type);
3177         err = ext4_journal_stop(handle);
3178         if (!ret)
3179                 ret = err;
3180         return ret;
3181 }
3182
3183 /*
3184  * Turn on quotas during mount time - we need to find
3185  * the quota file and such...
3186  */
3187 static int ext4_quota_on_mount(struct super_block *sb, int type)
3188 {
3189         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3190                         EXT4_SB(sb)->s_jquota_fmt, type);
3191 }
3192
3193 /*
3194  * Standard function to be called on quota_on
3195  */
3196 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3197                          char *path, int remount)
3198 {
3199         int err;
3200         struct nameidata nd;
3201
3202         if (!test_opt(sb, QUOTA))
3203                 return -EINVAL;
3204         /* When remounting, no checks are needed and in fact, path is NULL */
3205         if (remount)
3206                 return vfs_quota_on(sb, type, format_id, path, remount);
3207
3208         err = path_lookup(path, LOOKUP_FOLLOW, &nd);
3209         if (err)
3210                 return err;
3211
3212         /* Quotafile not on the same filesystem? */
3213         if (nd.path.mnt->mnt_sb != sb) {
3214                 path_put(&nd.path);
3215                 return -EXDEV;
3216         }
3217         /* Journaling quota? */
3218         if (EXT4_SB(sb)->s_qf_names[type]) {
3219                 /* Quotafile not of fs root? */
3220                 if (nd.path.dentry->d_parent->d_inode != sb->s_root->d_inode)
3221                         printk(KERN_WARNING
3222                                 "EXT4-fs: Quota file not on filesystem root. "
3223                                 "Journaled quota will not work.\n");
3224         }
3225
3226         /*
3227          * When we journal data on quota file, we have to flush journal to see
3228          * all updates to the file when we bypass pagecache...
3229          */
3230         if (ext4_should_journal_data(nd.path.dentry->d_inode)) {
3231                 /*
3232                  * We don't need to lock updates but journal_flush() could
3233                  * otherwise be livelocked...
3234                  */
3235                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
3236                 jbd2_journal_flush(EXT4_SB(sb)->s_journal);
3237                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3238         }
3239
3240         path_put(&nd.path);
3241         return vfs_quota_on(sb, type, format_id, path, remount);
3242 }
3243
3244 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3245  * acquiring the locks... As quota files are never truncated and quota code
3246  * itself serializes the operations (and noone else should touch the files)
3247  * we don't have to be afraid of races */
3248 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3249                                size_t len, loff_t off)
3250 {
3251         struct inode *inode = sb_dqopt(sb)->files[type];
3252         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3253         int err = 0;
3254         int offset = off & (sb->s_blocksize - 1);
3255         int tocopy;
3256         size_t toread;
3257         struct buffer_head *bh;
3258         loff_t i_size = i_size_read(inode);
3259
3260         if (off > i_size)
3261                 return 0;
3262         if (off+len > i_size)
3263                 len = i_size-off;
3264         toread = len;
3265         while (toread > 0) {
3266                 tocopy = sb->s_blocksize - offset < toread ?
3267                                 sb->s_blocksize - offset : toread;
3268                 bh = ext4_bread(NULL, inode, blk, 0, &err);
3269                 if (err)
3270                         return err;
3271                 if (!bh)        /* A hole? */
3272                         memset(data, 0, tocopy);
3273                 else
3274                         memcpy(data, bh->b_data+offset, tocopy);
3275                 brelse(bh);
3276                 offset = 0;
3277                 toread -= tocopy;
3278                 data += tocopy;
3279                 blk++;
3280         }
3281         return len;
3282 }
3283
3284 /* Write to quotafile (we know the transaction is already started and has
3285  * enough credits) */
3286 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3287                                 const char *data, size_t len, loff_t off)
3288 {
3289         struct inode *inode = sb_dqopt(sb)->files[type];
3290         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3291         int err = 0;
3292         int offset = off & (sb->s_blocksize - 1);
3293         int tocopy;
3294         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3295         size_t towrite = len;
3296         struct buffer_head *bh;
3297         handle_t *handle = journal_current_handle();
3298
3299         if (!handle) {
3300                 printk(KERN_WARNING "EXT4-fs: Quota write (off=%Lu, len=%Lu)"
3301                         " cancelled because transaction is not started.\n",
3302                         (unsigned long long)off, (unsigned long long)len);
3303                 return -EIO;
3304         }
3305         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3306         while (towrite > 0) {
3307                 tocopy = sb->s_blocksize - offset < towrite ?
3308                                 sb->s_blocksize - offset : towrite;
3309                 bh = ext4_bread(handle, inode, blk, 1, &err);
3310                 if (!bh)
3311                         goto out;
3312                 if (journal_quota) {
3313                         err = ext4_journal_get_write_access(handle, bh);
3314                         if (err) {
3315                                 brelse(bh);
3316                                 goto out;
3317                         }
3318                 }
3319                 lock_buffer(bh);
3320                 memcpy(bh->b_data+offset, data, tocopy);
3321                 flush_dcache_page(bh->b_page);
3322                 unlock_buffer(bh);
3323                 if (journal_quota)
3324                         err = ext4_journal_dirty_metadata(handle, bh);
3325                 else {
3326                         /* Always do at least ordered writes for quotas */
3327                         err = ext4_journal_dirty_data(handle, bh);
3328                         mark_buffer_dirty(bh);
3329                 }
3330                 brelse(bh);
3331                 if (err)
3332                         goto out;
3333                 offset = 0;
3334                 towrite -= tocopy;
3335                 data += tocopy;
3336                 blk++;
3337         }
3338 out:
3339         if (len == towrite) {
3340                 mutex_unlock(&inode->i_mutex);
3341                 return err;
3342         }
3343         if (inode->i_size < off+len-towrite) {
3344                 i_size_write(inode, off+len-towrite);
3345                 EXT4_I(inode)->i_disksize = inode->i_size;
3346         }
3347         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3348         ext4_mark_inode_dirty(handle, inode);
3349         mutex_unlock(&inode->i_mutex);
3350         return len - towrite;
3351 }
3352
3353 #endif
3354
3355 static int ext4_get_sb(struct file_system_type *fs_type,
3356         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3357 {
3358         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3359 }
3360
3361 static struct file_system_type ext4dev_fs_type = {
3362         .owner          = THIS_MODULE,
3363         .name           = "ext4dev",
3364         .get_sb         = ext4_get_sb,
3365         .kill_sb        = kill_block_super,
3366         .fs_flags       = FS_REQUIRES_DEV,
3367 };
3368
3369 static int __init init_ext4_fs(void)
3370 {
3371         int err;
3372
3373         err = init_ext4_mballoc();
3374         if (err)
3375                 return err;
3376
3377         err = init_ext4_xattr();
3378         if (err)
3379                 goto out2;
3380         err = init_inodecache();
3381         if (err)
3382                 goto out1;
3383         err = register_filesystem(&ext4dev_fs_type);
3384         if (err)
3385                 goto out;
3386         return 0;
3387 out:
3388         destroy_inodecache();
3389 out1:
3390         exit_ext4_xattr();
3391 out2:
3392         exit_ext4_mballoc();
3393         return err;
3394 }
3395
3396 static void __exit exit_ext4_fs(void)
3397 {
3398         unregister_filesystem(&ext4dev_fs_type);
3399         destroy_inodecache();
3400         exit_ext4_xattr();
3401         exit_ext4_mballoc();
3402 }
3403
3404 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
3405 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
3406 MODULE_LICENSE("GPL");
3407 module_init(init_ext4_fs)
3408 module_exit(exit_ext4_fs)