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/ext4_fs.h>
  25 #include <linux/ext4_jbd2.h>
  26 #include <linux/slab.h>
  27 #include <linux/init.h>
  28 #include <linux/blkdev.h>
  29 #include <linux/parser.h>
  30 #include <linux/smp_lock.h>
  31 #include <linux/buffer_head.h>
  32 #include <linux/vfs.h>
  33 #include <linux/random.h>
  34 #include <linux/mount.h>
  35 #include <linux/namei.h>
  36 #include <linux/quotaops.h>
  37 #include <linux/seq_file.h>
  38
  39 #include <asm/uaccess.h>
  40
  41 #include "xattr.h"
  42 #include "acl.h"
  43 #include "namei.h"
  44
  45 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  46                              unsigned long journal_devnum);
  47 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
  48                                unsigned int);
  49 static void ext4_commit_super (struct super_block * sb,
  50                                struct ext4_super_block * es,
  51                                int sync);
  52 static void ext4_mark_recovery_complete(struct super_block * sb,
  53                                         struct ext4_super_block * es);
  54 static void ext4_clear_journal_err(struct super_block * sb,
  55                                    struct ext4_super_block * es);
  56 static int ext4_sync_fs(struct super_block *sb, int wait);
  57 static const char *ext4_decode_error(struct super_block * sb, int errno,
  58                                      char nbuf[16]);
  59 static int ext4_remount (struct super_block * sb, int * flags, char * data);
  60 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf);
  61 static void ext4_unlockfs(struct super_block *sb);
  62 static void ext4_write_super (struct super_block * sb);
  63 static void ext4_write_super_lockfs(struct super_block *sb);
  64
  65
  66 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
  67                                struct ext4_group_desc *bg)
  68 {
  69         return le32_to_cpu(bg->bg_block_bitmap) |
  70                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  71                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
  72 }
  73
  74 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
  75                                struct ext4_group_desc *bg)
  76 {
  77         return le32_to_cpu(bg->bg_inode_bitmap) |
  78                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  79                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
  80 }
  81
  82 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
  83                               struct ext4_group_desc *bg)
  84 {
  85         return le32_to_cpu(bg->bg_inode_table) |
  86                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  87                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
  88 }
  89
  90 void ext4_block_bitmap_set(struct super_block *sb,
  91                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
  92 {
  93         bg->bg_block_bitmap = cpu_to_le32((u32)blk);
  94         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
  95                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
  96 }
  97
  98 void ext4_inode_bitmap_set(struct super_block *sb,
  99                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 100 {
 101         bg->bg_inode_bitmap  = cpu_to_le32((u32)blk);
 102         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 103                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 104 }
 105
 106 void ext4_inode_table_set(struct super_block *sb,
 107                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 108 {
 109         bg->bg_inode_table = cpu_to_le32((u32)blk);
 110         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 111                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 112 }
 113
 114 /*
 115  * Wrappers for jbd2_journal_start/end.
 116  *
 117  * The only special thing we need to do here is to make sure that all
 118  * journal_end calls result in the superblock being marked dirty, so
 119  * that sync() will call the filesystem's write_super callback if
 120  * appropriate.
 121  */
 122 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 123 {
 124         journal_t *journal;
 125
 126         if (sb->s_flags & MS_RDONLY)
 127                 return ERR_PTR(-EROFS);
 128
 129         /* Special case here: if the journal has aborted behind our
 130          * backs (eg. EIO in the commit thread), then we still need to
 131          * take the FS itself readonly cleanly. */
 132         journal = EXT4_SB(sb)->s_journal;
 133         if (is_journal_aborted(journal)) {
 134                 ext4_abort(sb, __FUNCTION__,
 135                            "Detected aborted journal");
 136                 return ERR_PTR(-EROFS);
 137         }
 138
 139         return jbd2_journal_start(journal, nblocks);
 140 }
 141
 142 /*
 143  * The only special thing we need to do here is to make sure that all
 144  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 145  * that sync() will call the filesystem's write_super callback if
 146  * appropriate.
 147  */
 148 int __ext4_journal_stop(const char *where, handle_t *handle)
 149 {
 150         struct super_block *sb;
 151         int err;
 152         int rc;
 153
 154         sb = handle->h_transaction->t_journal->j_private;
 155         err = handle->h_err;
 156         rc = jbd2_journal_stop(handle);
 157
 158         if (!err)
 159                 err = rc;
 160         if (err)
 161                 __ext4_std_error(sb, where, err);
 162         return err;
 163 }
 164
 165 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 166                 struct buffer_head *bh, handle_t *handle, int err)
 167 {
 168         char nbuf[16];
 169         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 170
 171         if (bh)
 172                 BUFFER_TRACE(bh, "abort");
 173
 174         if (!handle->h_err)
 175                 handle->h_err = err;
 176
 177         if (is_handle_aborted(handle))
 178                 return;
 179
 180         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
 181                caller, errstr, err_fn);
 182
 183         jbd2_journal_abort_handle(handle);
 184 }
 185
 186 /* Deal with the reporting of failure conditions on a filesystem such as
 187  * inconsistencies detected or read IO failures.
 188  *
 189  * On ext2, we can store the error state of the filesystem in the
 190  * superblock.  That is not possible on ext4, because we may have other
 191  * write ordering constraints on the superblock which prevent us from
 192  * writing it out straight away; and given that the journal is about to
 193  * be aborted, we can't rely on the current, or future, transactions to
 194  * write out the superblock safely.
 195  *
 196  * We'll just use the jbd2_journal_abort() error code to record an error in
 197  * the journal instead.  On recovery, the journal will compain about
 198  * that error until we've noted it down and cleared it.
 199  */
 200
 201 static void ext4_handle_error(struct super_block *sb)
 202 {
 203         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 204
 205         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 206         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 207
 208         if (sb->s_flags & MS_RDONLY)
 209                 return;
 210
 211         if (!test_opt (sb, ERRORS_CONT)) {
 212                 journal_t *journal = EXT4_SB(sb)->s_journal;
 213
 214                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 215                 if (journal)
 216                         jbd2_journal_abort(journal, -EIO);
 217         }
 218         if (test_opt (sb, ERRORS_RO)) {
 219                 printk (KERN_CRIT "Remounting filesystem read-only\n");
 220                 sb->s_flags |= MS_RDONLY;
 221         }
 222         ext4_commit_super(sb, es, 1);
 223         if (test_opt(sb, ERRORS_PANIC))
 224                 panic("EXT4-fs (device %s): panic forced after error\n",
 225                         sb->s_id);
 226 }
 227
 228 void ext4_error (struct super_block * sb, const char * function,
 229                  const char * fmt, ...)
 230 {
 231         va_list args;
 232
 233         va_start(args, fmt);
 234         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 235         vprintk(fmt, args);
 236         printk("\n");
 237         va_end(args);
 238
 239         ext4_handle_error(sb);
 240 }
 241
 242 static const char *ext4_decode_error(struct super_block * sb, int errno,
 243                                      char nbuf[16])
 244 {
 245         char *errstr = NULL;
 246
 247         switch (errno) {
 248         case -EIO:
 249                 errstr = "IO failure";
 250                 break;
 251         case -ENOMEM:
 252                 errstr = "Out of memory";
 253                 break;
 254         case -EROFS:
 255                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
 256                         errstr = "Journal has aborted";
 257                 else
 258                         errstr = "Readonly filesystem";
 259                 break;
 260         default:
 261                 /* If the caller passed in an extra buffer for unknown
 262                  * errors, textualise them now.  Else we just return
 263                  * NULL. */
 264                 if (nbuf) {
 265                         /* Check for truncated error codes... */
 266                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 267                                 errstr = nbuf;
 268                 }
 269                 break;
 270         }
 271
 272         return errstr;
 273 }
 274
 275 /* __ext4_std_error decodes expected errors from journaling functions
 276  * automatically and invokes the appropriate error response.  */
 277
 278 void __ext4_std_error (struct super_block * sb, const char * function,
 279                        int errno)
 280 {
 281         char nbuf[16];
 282         const char *errstr;
 283
 284         /* Special case: if the error is EROFS, and we're not already
 285          * inside a transaction, then there's really no point in logging
 286          * an error. */
 287         if (errno == -EROFS && journal_current_handle() == NULL &&
 288             (sb->s_flags & MS_RDONLY))
 289                 return;
 290
 291         errstr = ext4_decode_error(sb, errno, nbuf);
 292         printk (KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
 293                 sb->s_id, function, errstr);
 294
 295         ext4_handle_error(sb);
 296 }
 297
 298 /*
 299  * ext4_abort is a much stronger failure handler than ext4_error.  The
 300  * abort function may be used to deal with unrecoverable failures such
 301  * as journal IO errors or ENOMEM at a critical moment in log management.
 302  *
 303  * We unconditionally force the filesystem into an ABORT|READONLY state,
 304  * unless the error response on the fs has been set to panic in which
 305  * case we take the easy way out and panic immediately.
 306  */
 307
 308 void ext4_abort (struct super_block * sb, const char * function,
 309                  const char * fmt, ...)
 310 {
 311         va_list args;
 312
 313         printk (KERN_CRIT "ext4_abort called.\n");
 314
 315         va_start(args, fmt);
 316         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 317         vprintk(fmt, args);
 318         printk("\n");
 319         va_end(args);
 320
 321         if (test_opt(sb, ERRORS_PANIC))
 322                 panic("EXT4-fs panic from previous error\n");
 323
 324         if (sb->s_flags & MS_RDONLY)
 325                 return;
 326
 327         printk(KERN_CRIT "Remounting filesystem read-only\n");
 328         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 329         sb->s_flags |= MS_RDONLY;
 330         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 331         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 332 }
 333
 334 void ext4_warning (struct super_block * sb, const char * function,
 335                    const char * fmt, ...)
 336 {
 337         va_list args;
 338
 339         va_start(args, fmt);
 340         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
 341                sb->s_id, function);
 342         vprintk(fmt, args);
 343         printk("\n");
 344         va_end(args);
 345 }
 346
 347 void ext4_update_dynamic_rev(struct super_block *sb)
 348 {
 349         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 350
 351         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 352                 return;
 353
 354         ext4_warning(sb, __FUNCTION__,
 355                      "updating to rev %d because of new feature flag, "
 356                      "running e2fsck is recommended",
 357                      EXT4_DYNAMIC_REV);
 358
 359         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 360         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 361         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 362         /* leave es->s_feature_*compat flags alone */
 363         /* es->s_uuid will be set by e2fsck if empty */
 364
 365         /*
 366          * The rest of the superblock fields should be zero, and if not it
 367          * means they are likely already in use, so leave them alone.  We
 368          * can leave it up to e2fsck to clean up any inconsistencies there.
 369          */
 370 }
 371
 372 /*
 373  * Open the external journal device
 374  */
 375 static struct block_device *ext4_blkdev_get(dev_t dev)
 376 {
 377         struct block_device *bdev;
 378         char b[BDEVNAME_SIZE];
 379
 380         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 381         if (IS_ERR(bdev))
 382                 goto fail;
 383         return bdev;
 384
 385 fail:
 386         printk(KERN_ERR "EXT4: failed to open journal device %s: %ld\n",
 387                         __bdevname(dev, b), PTR_ERR(bdev));
 388         return NULL;
 389 }
 390
 391 /*
 392  * Release the journal device
 393  */
 394 static int ext4_blkdev_put(struct block_device *bdev)
 395 {
 396         bd_release(bdev);
 397         return blkdev_put(bdev);
 398 }
 399
 400 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 401 {
 402         struct block_device *bdev;
 403         int ret = -ENODEV;
 404
 405         bdev = sbi->journal_bdev;
 406         if (bdev) {
 407                 ret = ext4_blkdev_put(bdev);
 408                 sbi->journal_bdev = NULL;
 409         }
 410         return ret;
 411 }
 412
 413 static inline struct inode *orphan_list_entry(struct list_head *l)
 414 {
 415         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 416 }
 417
 418 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 419 {
 420         struct list_head *l;
 421
 422         printk(KERN_ERR "sb orphan head is %d\n",
 423                le32_to_cpu(sbi->s_es->s_last_orphan));
 424
 425         printk(KERN_ERR "sb_info orphan list:\n");
 426         list_for_each(l, &sbi->s_orphan) {
 427                 struct inode *inode = orphan_list_entry(l);
 428                 printk(KERN_ERR "  "
 429                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 430                        inode->i_sb->s_id, inode->i_ino, inode,
 431                        inode->i_mode, inode->i_nlink,
 432                        NEXT_ORPHAN(inode));
 433         }
 434 }
 435
 436 static void ext4_put_super (struct super_block * sb)
 437 {
 438         struct ext4_sb_info *sbi = EXT4_SB(sb);
 439         struct ext4_super_block *es = sbi->s_es;
 440         int i;
 441
 442         ext4_ext_release(sb);
 443         ext4_xattr_put_super(sb);
 444         jbd2_journal_destroy(sbi->s_journal);
 445         if (!(sb->s_flags & MS_RDONLY)) {
 446                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 447                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 448                 BUFFER_TRACE(sbi->s_sbh, "marking dirty");
 449                 mark_buffer_dirty(sbi->s_sbh);
 450                 ext4_commit_super(sb, es, 1);
 451         }
 452
 453         for (i = 0; i < sbi->s_gdb_count; i++)
 454                 brelse(sbi->s_group_desc[i]);
 455         kfree(sbi->s_group_desc);
 456         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 457         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 458         percpu_counter_destroy(&sbi->s_dirs_counter);
 459         brelse(sbi->s_sbh);
 460 #ifdef CONFIG_QUOTA
 461         for (i = 0; i < MAXQUOTAS; i++)
 462                 kfree(sbi->s_qf_names[i]);
 463 #endif
 464
 465         /* Debugging code just in case the in-memory inode orphan list
 466          * isn't empty.  The on-disk one can be non-empty if we've
 467          * detected an error and taken the fs readonly, but the
 468          * in-memory list had better be clean by this point. */
 469         if (!list_empty(&sbi->s_orphan))
 470                 dump_orphan_list(sb, sbi);
 471         J_ASSERT(list_empty(&sbi->s_orphan));
 472
 473         invalidate_bdev(sb->s_bdev);
 474         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 475                 /*
 476                  * Invalidate the journal device's buffers.  We don't want them
 477                  * floating about in memory - the physical journal device may
 478                  * hotswapped, and it breaks the `ro-after' testing code.
 479                  */
 480                 sync_blockdev(sbi->journal_bdev);
 481                 invalidate_bdev(sbi->journal_bdev);
 482                 ext4_blkdev_remove(sbi);
 483         }
 484         sb->s_fs_info = NULL;
 485         kfree(sbi);
 486         return;
 487 }
 488
 489 static struct kmem_cache *ext4_inode_cachep;
 490
 491 /*
 492  * Called inside transaction, so use GFP_NOFS
 493  */
 494 static struct inode *ext4_alloc_inode(struct super_block *sb)
 495 {
 496         struct ext4_inode_info *ei;
 497
 498         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 499         if (!ei)
 500                 return NULL;
 501 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 502         ei->i_acl = EXT4_ACL_NOT_CACHED;
 503         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 504 #endif
 505         ei->i_block_alloc_info = NULL;
 506         ei->vfs_inode.i_version = 1;
 507         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 508         return &ei->vfs_inode;
 509 }
 510
 511 static void ext4_destroy_inode(struct inode *inode)
 512 {
 513         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 514                 printk("EXT4 Inode %p: orphan list check failed!\n",
 515                         EXT4_I(inode));
 516                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 517                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 518                                 true);
 519                 dump_stack();
 520         }
 521         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 522 }
 523
 524 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
 525 {
 526         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 527
 528         INIT_LIST_HEAD(&ei->i_orphan);
 529 #ifdef CONFIG_EXT4DEV_FS_XATTR
 530         init_rwsem(&ei->xattr_sem);
 531 #endif
 532         mutex_init(&ei->truncate_mutex);
 533         inode_init_once(&ei->vfs_inode);
 534 }
 535
 536 static int init_inodecache(void)
 537 {
 538         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 539                                              sizeof(struct ext4_inode_info),
 540                                              0, (SLAB_RECLAIM_ACCOUNT|
 541                                                 SLAB_MEM_SPREAD),
 542                                              init_once, NULL);
 543         if (ext4_inode_cachep == NULL)
 544                 return -ENOMEM;
 545         return 0;
 546 }
 547
 548 static void destroy_inodecache(void)
 549 {
 550         kmem_cache_destroy(ext4_inode_cachep);
 551 }
 552
 553 static void ext4_clear_inode(struct inode *inode)
 554 {
 555         struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
 556 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 557         if (EXT4_I(inode)->i_acl &&
 558                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
 559                 posix_acl_release(EXT4_I(inode)->i_acl);
 560                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
 561         }
 562         if (EXT4_I(inode)->i_default_acl &&
 563                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
 564                 posix_acl_release(EXT4_I(inode)->i_default_acl);
 565                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
 566         }
 567 #endif
 568         ext4_discard_reservation(inode);
 569         EXT4_I(inode)->i_block_alloc_info = NULL;
 570         if (unlikely(rsv))
 571                 kfree(rsv);
 572 }
 573
 574 static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
 575 {
 576 #if defined(CONFIG_QUOTA)
 577         struct ext4_sb_info *sbi = EXT4_SB(sb);
 578
 579         if (sbi->s_jquota_fmt)
 580                 seq_printf(seq, ",jqfmt=%s",
 581                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold": "vfsv0");
 582
 583         if (sbi->s_qf_names[USRQUOTA])
 584                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 585
 586         if (sbi->s_qf_names[GRPQUOTA])
 587                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 588
 589         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
 590                 seq_puts(seq, ",usrquota");
 591
 592         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
 593                 seq_puts(seq, ",grpquota");
 594 #endif
 595 }
 596
 597 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 598 {
 599         struct super_block *sb = vfs->mnt_sb;
 600
 601         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 602                 seq_puts(seq, ",data=journal");
 603         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 604                 seq_puts(seq, ",data=ordered");
 605         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 606                 seq_puts(seq, ",data=writeback");
 607
 608         ext4_show_quota_options(seq, sb);
 609
 610         return 0;
 611 }
 612
 613
 614 static struct dentry *ext4_get_dentry(struct super_block *sb, void *vobjp)
 615 {
 616         __u32 *objp = vobjp;
 617         unsigned long ino = objp[0];
 618         __u32 generation = objp[1];
 619         struct inode *inode;
 620         struct dentry *result;
 621
 622         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 623                 return ERR_PTR(-ESTALE);
 624         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 625                 return ERR_PTR(-ESTALE);
 626
 627         /* iget isn't really right if the inode is currently unallocated!!
 628          *
 629          * ext4_read_inode will return a bad_inode if the inode had been
 630          * deleted, so we should be safe.
 631          *
 632          * Currently we don't know the generation for parent directory, so
 633          * a generation of 0 means "accept any"
 634          */
 635         inode = iget(sb, ino);
 636         if (inode == NULL)
 637                 return ERR_PTR(-ENOMEM);
 638         if (is_bad_inode(inode) ||
 639             (generation && inode->i_generation != generation)) {
 640                 iput(inode);
 641                 return ERR_PTR(-ESTALE);
 642         }
 643         /* now to find a dentry.
 644          * If possible, get a well-connected one
 645          */
 646         result = d_alloc_anon(inode);
 647         if (!result) {
 648                 iput(inode);
 649                 return ERR_PTR(-ENOMEM);
 650         }
 651         return result;
 652 }
 653
 654 #ifdef CONFIG_QUOTA
 655 #define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
 656 #define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 657
 658 static int ext4_dquot_initialize(struct inode *inode, int type);
 659 static int ext4_dquot_drop(struct inode *inode);
 660 static int ext4_write_dquot(struct dquot *dquot);
 661 static int ext4_acquire_dquot(struct dquot *dquot);
 662 static int ext4_release_dquot(struct dquot *dquot);
 663 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 664 static int ext4_write_info(struct super_block *sb, int type);
 665 static int ext4_quota_on(struct super_block *sb, int type, int format_id, char *path);
 666 static int ext4_quota_on_mount(struct super_block *sb, int type);
 667 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 668                                size_t len, loff_t off);
 669 static ssize_t ext4_quota_write(struct super_block *sb, int type,
 670                                 const char *data, size_t len, loff_t off);
 671
 672 static struct dquot_operations ext4_quota_operations = {
 673         .initialize     = ext4_dquot_initialize,
 674         .drop           = ext4_dquot_drop,
 675         .alloc_space    = dquot_alloc_space,
 676         .alloc_inode    = dquot_alloc_inode,
 677         .free_space     = dquot_free_space,
 678         .free_inode     = dquot_free_inode,
 679         .transfer       = dquot_transfer,
 680         .write_dquot    = ext4_write_dquot,
 681         .acquire_dquot  = ext4_acquire_dquot,
 682         .release_dquot  = ext4_release_dquot,
 683         .mark_dirty     = ext4_mark_dquot_dirty,
 684         .write_info     = ext4_write_info
 685 };
 686
 687 static struct quotactl_ops ext4_qctl_operations = {
 688         .quota_on       = ext4_quota_on,
 689         .quota_off      = vfs_quota_off,
 690         .quota_sync     = vfs_quota_sync,
 691         .get_info       = vfs_get_dqinfo,
 692         .set_info       = vfs_set_dqinfo,
 693         .get_dqblk      = vfs_get_dqblk,
 694         .set_dqblk      = vfs_set_dqblk
 695 };
 696 #endif
 697
 698 static const struct super_operations ext4_sops = {
 699         .alloc_inode    = ext4_alloc_inode,
 700         .destroy_inode  = ext4_destroy_inode,
 701         .read_inode     = ext4_read_inode,
 702         .write_inode    = ext4_write_inode,
 703         .dirty_inode    = ext4_dirty_inode,
 704         .delete_inode   = ext4_delete_inode,
 705         .put_super      = ext4_put_super,
 706         .write_super    = ext4_write_super,
 707         .sync_fs        = ext4_sync_fs,
 708         .write_super_lockfs = ext4_write_super_lockfs,
 709         .unlockfs       = ext4_unlockfs,
 710         .statfs         = ext4_statfs,
 711         .remount_fs     = ext4_remount,
 712         .clear_inode    = ext4_clear_inode,
 713         .show_options   = ext4_show_options,
 714 #ifdef CONFIG_QUOTA
 715         .quota_read     = ext4_quota_read,
 716         .quota_write    = ext4_quota_write,
 717 #endif
 718 };
 719
 720 static struct export_operations ext4_export_ops = {
 721         .get_parent = ext4_get_parent,
 722         .get_dentry = ext4_get_dentry,
 723 };
 724
 725 enum {
 726         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 727         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
 728         Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov,
 729         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
 730         Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
 731         Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
 732         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
 733         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 734         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
 735         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
 736         Opt_grpquota, Opt_extents,
 737 };
 738
 739 static match_table_t tokens = {
 740         {Opt_bsd_df, "bsddf"},
 741         {Opt_minix_df, "minixdf"},
 742         {Opt_grpid, "grpid"},
 743         {Opt_grpid, "bsdgroups"},
 744         {Opt_nogrpid, "nogrpid"},
 745         {Opt_nogrpid, "sysvgroups"},
 746         {Opt_resgid, "resgid=%u"},
 747         {Opt_resuid, "resuid=%u"},
 748         {Opt_sb, "sb=%u"},
 749         {Opt_err_cont, "errors=continue"},
 750         {Opt_err_panic, "errors=panic"},
 751         {Opt_err_ro, "errors=remount-ro"},
 752         {Opt_nouid32, "nouid32"},
 753         {Opt_nocheck, "nocheck"},
 754         {Opt_nocheck, "check=none"},
 755         {Opt_debug, "debug"},
 756         {Opt_oldalloc, "oldalloc"},
 757         {Opt_orlov, "orlov"},
 758         {Opt_user_xattr, "user_xattr"},
 759         {Opt_nouser_xattr, "nouser_xattr"},
 760         {Opt_acl, "acl"},
 761         {Opt_noacl, "noacl"},
 762         {Opt_reservation, "reservation"},
 763         {Opt_noreservation, "noreservation"},
 764         {Opt_noload, "noload"},
 765         {Opt_nobh, "nobh"},
 766         {Opt_bh, "bh"},
 767         {Opt_commit, "commit=%u"},
 768         {Opt_journal_update, "journal=update"},
 769         {Opt_journal_inum, "journal=%u"},
 770         {Opt_journal_dev, "journal_dev=%u"},
 771         {Opt_abort, "abort"},
 772         {Opt_data_journal, "data=journal"},
 773         {Opt_data_ordered, "data=ordered"},
 774         {Opt_data_writeback, "data=writeback"},
 775         {Opt_offusrjquota, "usrjquota="},
 776         {Opt_usrjquota, "usrjquota=%s"},
 777         {Opt_offgrpjquota, "grpjquota="},
 778         {Opt_grpjquota, "grpjquota=%s"},
 779         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
 780         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
 781         {Opt_grpquota, "grpquota"},
 782         {Opt_noquota, "noquota"},
 783         {Opt_quota, "quota"},
 784         {Opt_usrquota, "usrquota"},
 785         {Opt_barrier, "barrier=%u"},
 786         {Opt_extents, "extents"},
 787         {Opt_err, NULL},
 788         {Opt_resize, "resize"},
 789 };
 790
 791 static ext4_fsblk_t get_sb_block(void **data)
 792 {
 793         ext4_fsblk_t    sb_block;
 794         char            *options = (char *) *data;
 795
 796         if (!options || strncmp(options, "sb=", 3) != 0)
 797                 return 1;       /* Default location */
 798         options += 3;
 799         /*todo: use simple_strtoll with >32bit ext4 */
 800         sb_block = simple_strtoul(options, &options, 0);
 801         if (*options && *options != ',') {
 802                 printk("EXT4-fs: Invalid sb specification: %s\n",
 803                        (char *) *data);
 804                 return 1;
 805         }
 806         if (*options == ',')
 807                 options++;
 808         *data = (void *) options;
 809         return sb_block;
 810 }
 811
 812 static int parse_options (char *options, struct super_block *sb,
 813                           unsigned int *inum, unsigned long *journal_devnum,
 814                           ext4_fsblk_t *n_blocks_count, int is_remount)
 815 {
 816         struct ext4_sb_info *sbi = EXT4_SB(sb);
 817         char * p;
 818         substring_t args[MAX_OPT_ARGS];
 819         int data_opt = 0;
 820         int option;
 821 #ifdef CONFIG_QUOTA
 822         int qtype;
 823         char *qname;
 824 #endif
 825
 826         if (!options)
 827                 return 1;
 828
 829         while ((p = strsep (&options, ",")) != NULL) {
 830                 int token;
 831                 if (!*p)
 832                         continue;
 833
 834                 token = match_token(p, tokens, args);
 835                 switch (token) {
 836                 case Opt_bsd_df:
 837                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 838                         break;
 839                 case Opt_minix_df:
 840                         set_opt (sbi->s_mount_opt, MINIX_DF);
 841                         break;
 842                 case Opt_grpid:
 843                         set_opt (sbi->s_mount_opt, GRPID);
 844                         break;
 845                 case Opt_nogrpid:
 846                         clear_opt (sbi->s_mount_opt, GRPID);
 847                         break;
 848                 case Opt_resuid:
 849                         if (match_int(&args[0], &option))
 850                                 return 0;
 851                         sbi->s_resuid = option;
 852                         break;
 853                 case Opt_resgid:
 854                         if (match_int(&args[0], &option))
 855                                 return 0;
 856                         sbi->s_resgid = option;
 857                         break;
 858                 case Opt_sb:
 859                         /* handled by get_sb_block() instead of here */
 860                         /* *sb_block = match_int(&args[0]); */
 861                         break;
 862                 case Opt_err_panic:
 863                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 864                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 865                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 866                         break;
 867                 case Opt_err_ro:
 868                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 869                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 870                         set_opt (sbi->s_mount_opt, ERRORS_RO);
 871                         break;
 872                 case Opt_err_cont:
 873                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 874                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 875                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
 876                         break;
 877                 case Opt_nouid32:
 878                         set_opt (sbi->s_mount_opt, NO_UID32);
 879                         break;
 880                 case Opt_nocheck:
 881                         clear_opt (sbi->s_mount_opt, CHECK);
 882                         break;
 883                 case Opt_debug:
 884                         set_opt (sbi->s_mount_opt, DEBUG);
 885                         break;
 886                 case Opt_oldalloc:
 887                         set_opt (sbi->s_mount_opt, OLDALLOC);
 888                         break;
 889                 case Opt_orlov:
 890                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 891                         break;
 892 #ifdef CONFIG_EXT4DEV_FS_XATTR
 893                 case Opt_user_xattr:
 894                         set_opt (sbi->s_mount_opt, XATTR_USER);
 895                         break;
 896                 case Opt_nouser_xattr:
 897                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 898                         break;
 899 #else
 900                 case Opt_user_xattr:
 901                 case Opt_nouser_xattr:
 902                         printk("EXT4 (no)user_xattr options not supported\n");
 903                         break;
 904 #endif
 905 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 906                 case Opt_acl:
 907                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 908                         break;
 909                 case Opt_noacl:
 910                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 911                         break;
 912 #else
 913                 case Opt_acl:
 914                 case Opt_noacl:
 915                         printk("EXT4 (no)acl options not supported\n");
 916                         break;
 917 #endif
 918                 case Opt_reservation:
 919                         set_opt(sbi->s_mount_opt, RESERVATION);
 920                         break;
 921                 case Opt_noreservation:
 922                         clear_opt(sbi->s_mount_opt, RESERVATION);
 923                         break;
 924                 case Opt_journal_update:
 925                         /* @@@ FIXME */
 926                         /* Eventually we will want to be able to create
 927                            a journal file here.  For now, only allow the
 928                            user to specify an existing inode to be the
 929                            journal file. */
 930                         if (is_remount) {
 931                                 printk(KERN_ERR "EXT4-fs: cannot specify "
 932                                        "journal on remount\n");
 933                                 return 0;
 934                         }
 935                         set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
 936                         break;
 937                 case Opt_journal_inum:
 938                         if (is_remount) {
 939                                 printk(KERN_ERR "EXT4-fs: cannot specify "
 940                                        "journal on remount\n");
 941                                 return 0;
 942                         }
 943                         if (match_int(&args[0], &option))
 944                                 return 0;
 945                         *inum = option;
 946                         break;
 947                 case Opt_journal_dev:
 948                         if (is_remount) {
 949                                 printk(KERN_ERR "EXT4-fs: cannot specify "
 950                                        "journal on remount\n");
 951                                 return 0;
 952                         }
 953                         if (match_int(&args[0], &option))
 954                                 return 0;
 955                         *journal_devnum = option;
 956                         break;
 957                 case Opt_noload:
 958                         set_opt (sbi->s_mount_opt, NOLOAD);
 959                         break;
 960                 case Opt_commit:
 961                         if (match_int(&args[0], &option))
 962                                 return 0;
 963                         if (option < 0)
 964                                 return 0;
 965                         if (option == 0)
 966                                 option = JBD_DEFAULT_MAX_COMMIT_AGE;
 967                         sbi->s_commit_interval = HZ * option;
 968                         break;
 969                 case Opt_data_journal:
 970                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
 971                         goto datacheck;
 972                 case Opt_data_ordered:
 973                         data_opt = EXT4_MOUNT_ORDERED_DATA;
 974                         goto datacheck;
 975                 case Opt_data_writeback:
 976                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
 977                 datacheck:
 978                         if (is_remount) {
 979                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
 980                                                 != data_opt) {
 981                                         printk(KERN_ERR
 982                                                 "EXT4-fs: cannot change data "
 983                                                 "mode on remount\n");
 984                                         return 0;
 985                                 }
 986                         } else {
 987                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
 988                                 sbi->s_mount_opt |= data_opt;
 989                         }
 990                         break;
 991 #ifdef CONFIG_QUOTA
 992                 case Opt_usrjquota:
 993                         qtype = USRQUOTA;
 994                         goto set_qf_name;
 995                 case Opt_grpjquota:
 996                         qtype = GRPQUOTA;
 997 set_qf_name:
 998                         if (sb_any_quota_enabled(sb)) {
 999                                 printk(KERN_ERR
1000                                         "EXT4-fs: Cannot change journalled "
1001                                         "quota options when quota turned on.\n");
1002                                 return 0;
1003                         }
1004                         qname = match_strdup(&args[0]);
1005                         if (!qname) {
1006                                 printk(KERN_ERR
1007                                         "EXT4-fs: not enough memory for "
1008                                         "storing quotafile name.\n");
1009                                 return 0;
1010                         }
1011                         if (sbi->s_qf_names[qtype] &&
1012                             strcmp(sbi->s_qf_names[qtype], qname)) {
1013                                 printk(KERN_ERR
1014                                         "EXT4-fs: %s quota file already "
1015                                         "specified.\n", QTYPE2NAME(qtype));
1016                                 kfree(qname);
1017                                 return 0;
1018                         }
1019                         sbi->s_qf_names[qtype] = qname;
1020                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1021                                 printk(KERN_ERR
1022                                         "EXT4-fs: quotafile must be on "
1023                                         "filesystem root.\n");
1024                                 kfree(sbi->s_qf_names[qtype]);
1025                                 sbi->s_qf_names[qtype] = NULL;
1026                                 return 0;
1027                         }
1028                         set_opt(sbi->s_mount_opt, QUOTA);
1029                         break;
1030                 case Opt_offusrjquota:
1031                         qtype = USRQUOTA;
1032                         goto clear_qf_name;
1033                 case Opt_offgrpjquota:
1034                         qtype = GRPQUOTA;
1035 clear_qf_name:
1036                         if (sb_any_quota_enabled(sb)) {
1037                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1038                                         "journalled quota options when "
1039                                         "quota turned on.\n");
1040                                 return 0;
1041                         }
1042                         /*
1043                          * The space will be released later when all options
1044                          * are confirmed to be correct
1045                          */
1046                         sbi->s_qf_names[qtype] = NULL;
1047                         break;
1048                 case Opt_jqfmt_vfsold:
1049                         sbi->s_jquota_fmt = QFMT_VFS_OLD;
1050                         break;
1051                 case Opt_jqfmt_vfsv0:
1052                         sbi->s_jquota_fmt = QFMT_VFS_V0;
1053                         break;
1054                 case Opt_quota:
1055                 case Opt_usrquota:
1056                         set_opt(sbi->s_mount_opt, QUOTA);
1057                         set_opt(sbi->s_mount_opt, USRQUOTA);
1058                         break;
1059                 case Opt_grpquota:
1060                         set_opt(sbi->s_mount_opt, QUOTA);
1061                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1062                         break;
1063                 case Opt_noquota:
1064                         if (sb_any_quota_enabled(sb)) {
1065                                 printk(KERN_ERR "EXT4-fs: Cannot change quota "
1066                                         "options when quota turned on.\n");
1067                                 return 0;
1068                         }
1069                         clear_opt(sbi->s_mount_opt, QUOTA);
1070                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1071                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1072                         break;
1073 #else
1074                 case Opt_quota:
1075                 case Opt_usrquota:
1076                 case Opt_grpquota:
1077                 case Opt_usrjquota:
1078                 case Opt_grpjquota:
1079                 case Opt_offusrjquota:
1080                 case Opt_offgrpjquota:
1081                 case Opt_jqfmt_vfsold:
1082                 case Opt_jqfmt_vfsv0:
1083                         printk(KERN_ERR
1084                                 "EXT4-fs: journalled quota options not "
1085                                 "supported.\n");
1086                         break;
1087                 case Opt_noquota:
1088                         break;
1089 #endif
1090                 case Opt_abort:
1091                         set_opt(sbi->s_mount_opt, ABORT);
1092                         break;
1093                 case Opt_barrier:
1094                         if (match_int(&args[0], &option))
1095                                 return 0;
1096                         if (option)
1097                                 set_opt(sbi->s_mount_opt, BARRIER);
1098                         else
1099                                 clear_opt(sbi->s_mount_opt, BARRIER);
1100                         break;
1101                 case Opt_ignore:
1102                         break;
1103                 case Opt_resize:
1104                         if (!is_remount) {
1105                                 printk("EXT4-fs: resize option only available "
1106                                         "for remount\n");
1107                                 return 0;
1108                         }
1109                         if (match_int(&args[0], &option) != 0)
1110                                 return 0;
1111                         *n_blocks_count = option;
1112                         break;
1113                 case Opt_nobh:
1114                         set_opt(sbi->s_mount_opt, NOBH);
1115                         break;
1116                 case Opt_bh:
1117                         clear_opt(sbi->s_mount_opt, NOBH);
1118                         break;
1119                 case Opt_extents:
1120                         set_opt (sbi->s_mount_opt, EXTENTS);
1121                         break;
1122                 default:
1123                         printk (KERN_ERR
1124                                 "EXT4-fs: Unrecognized mount option \"%s\" "
1125                                 "or missing value\n", p);
1126                         return 0;
1127                 }
1128         }
1129 #ifdef CONFIG_QUOTA
1130         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1131                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1132                      sbi->s_qf_names[USRQUOTA])
1133                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1134
1135                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1136                      sbi->s_qf_names[GRPQUOTA])
1137                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1138
1139                 if ((sbi->s_qf_names[USRQUOTA] &&
1140                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1141                     (sbi->s_qf_names[GRPQUOTA] &&
1142                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1143                         printk(KERN_ERR "EXT4-fs: old and new quota "
1144                                         "format mixing.\n");
1145                         return 0;
1146                 }
1147
1148                 if (!sbi->s_jquota_fmt) {
1149                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1150                                         "not specified.\n");
1151                         return 0;
1152                 }
1153         } else {
1154                 if (sbi->s_jquota_fmt) {
1155                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1156                                         "specified with no journalling "
1157                                         "enabled.\n");
1158                         return 0;
1159                 }
1160         }
1161 #endif
1162         return 1;
1163 }
1164
1165 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1166                             int read_only)
1167 {
1168         struct ext4_sb_info *sbi = EXT4_SB(sb);
1169         int res = 0;
1170
1171         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1172                 printk (KERN_ERR "EXT4-fs warning: revision level too high, "
1173                         "forcing read-only mode\n");
1174                 res = MS_RDONLY;
1175         }
1176         if (read_only)
1177                 return res;
1178         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1179                 printk (KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1180                         "running e2fsck is recommended\n");
1181         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1182                 printk (KERN_WARNING
1183                         "EXT4-fs warning: mounting fs with errors, "
1184                         "running e2fsck is recommended\n");
1185         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1186                  le16_to_cpu(es->s_mnt_count) >=
1187                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1188                 printk (KERN_WARNING
1189                         "EXT4-fs warning: maximal mount count reached, "
1190                         "running e2fsck is recommended\n");
1191         else if (le32_to_cpu(es->s_checkinterval) &&
1192                 (le32_to_cpu(es->s_lastcheck) +
1193                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1194                 printk (KERN_WARNING
1195                         "EXT4-fs warning: checktime reached, "
1196                         "running e2fsck is recommended\n");
1197 #if 0
1198                 /* @@@ We _will_ want to clear the valid bit if we find
1199                  * inconsistencies, to force a fsck at reboot.  But for
1200                  * a plain journaled filesystem we can keep it set as
1201                  * valid forever! :)
1202                  */
1203         es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT4_VALID_FS);
1204 #endif
1205         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1206                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1207         es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
1208         es->s_mtime = cpu_to_le32(get_seconds());
1209         ext4_update_dynamic_rev(sb);
1210         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1211
1212         ext4_commit_super(sb, es, 1);
1213         if (test_opt(sb, DEBUG))
1214                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%lu, "
1215                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1216                         sb->s_blocksize,
1217                         sbi->s_groups_count,
1218                         EXT4_BLOCKS_PER_GROUP(sb),
1219                         EXT4_INODES_PER_GROUP(sb),
1220                         sbi->s_mount_opt);
1221
1222         printk(KERN_INFO "EXT4 FS on %s, ", sb->s_id);
1223         if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
1224                 char b[BDEVNAME_SIZE];
1225
1226                 printk("external journal on %s\n",
1227                         bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
1228         } else {
1229                 printk("internal journal\n");
1230         }
1231         return res;
1232 }
1233
1234 /* Called at mount-time, super-block is locked */
1235 static int ext4_check_descriptors (struct super_block * sb)
1236 {
1237         struct ext4_sb_info *sbi = EXT4_SB(sb);
1238         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1239         ext4_fsblk_t last_block;
1240         ext4_fsblk_t block_bitmap;
1241         ext4_fsblk_t inode_bitmap;
1242         ext4_fsblk_t inode_table;
1243         struct ext4_group_desc * gdp = NULL;
1244         int desc_block = 0;
1245         int i;
1246
1247         ext4_debug ("Checking group descriptors");
1248
1249         for (i = 0; i < sbi->s_groups_count; i++)
1250         {
1251                 if (i == sbi->s_groups_count - 1)
1252                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1253                 else
1254                         last_block = first_block +
1255                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1256
1257                 if ((i % EXT4_DESC_PER_BLOCK(sb)) == 0)
1258                         gdp = (struct ext4_group_desc *)
1259                                         sbi->s_group_desc[desc_block++]->b_data;
1260                 block_bitmap = ext4_block_bitmap(sb, gdp);
1261                 if (block_bitmap < first_block || block_bitmap > last_block)
1262                 {
1263                         ext4_error (sb, "ext4_check_descriptors",
1264                                     "Block bitmap for group %d"
1265                                     " not in group (block %llu)!",
1266                                     i, block_bitmap);
1267                         return 0;
1268                 }
1269                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1270                 if (inode_bitmap < first_block || inode_bitmap > last_block)
1271                 {
1272                         ext4_error (sb, "ext4_check_descriptors",
1273                                     "Inode bitmap for group %d"
1274                                     " not in group (block %llu)!",
1275                                     i, inode_bitmap);
1276                         return 0;
1277                 }
1278                 inode_table = ext4_inode_table(sb, gdp);
1279                 if (inode_table < first_block ||
1280                     inode_table + sbi->s_itb_per_group > last_block)
1281                 {
1282                         ext4_error (sb, "ext4_check_descriptors",
1283                                     "Inode table for group %d"
1284                                     " not in group (block %llu)!",
1285                                     i, inode_table);
1286                         return 0;
1287                 }
1288                 first_block += EXT4_BLOCKS_PER_GROUP(sb);
1289                 gdp = (struct ext4_group_desc *)
1290                         ((__u8 *)gdp + EXT4_DESC_SIZE(sb));
1291         }
1292
1293         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1294         sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
1295         return 1;
1296 }
1297
1298
1299 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1300  * the superblock) which were deleted from all directories, but held open by
1301  * a process at the time of a crash.  We walk the list and try to delete these
1302  * inodes at recovery time (only with a read-write filesystem).
1303  *
1304  * In order to keep the orphan inode chain consistent during traversal (in
1305  * case of crash during recovery), we link each inode into the superblock
1306  * orphan list_head and handle it the same way as an inode deletion during
1307  * normal operation (which journals the operations for us).
1308  *
1309  * We only do an iget() and an iput() on each inode, which is very safe if we
1310  * accidentally point at an in-use or already deleted inode.  The worst that
1311  * can happen in this case is that we get a "bit already cleared" message from
1312  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1313  * e2fsck was run on this filesystem, and it must have already done the orphan
1314  * inode cleanup for us, so we can safely abort without any further action.
1315  */
1316 static void ext4_orphan_cleanup (struct super_block * sb,
1317                                  struct ext4_super_block * es)
1318 {
1319         unsigned int s_flags = sb->s_flags;
1320         int nr_orphans = 0, nr_truncates = 0;
1321 #ifdef CONFIG_QUOTA
1322         int i;
1323 #endif
1324         if (!es->s_last_orphan) {
1325                 jbd_debug(4, "no orphan inodes to clean up\n");
1326                 return;
1327         }
1328
1329         if (bdev_read_only(sb->s_bdev)) {
1330                 printk(KERN_ERR "EXT4-fs: write access "
1331                         "unavailable, skipping orphan cleanup.\n");
1332                 return;
1333         }
1334
1335         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1336                 if (es->s_last_orphan)
1337                         jbd_debug(1, "Errors on filesystem, "
1338                                   "clearing orphan list.\n");
1339                 es->s_last_orphan = 0;
1340                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1341                 return;
1342         }
1343
1344         if (s_flags & MS_RDONLY) {
1345                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1346                        sb->s_id);
1347                 sb->s_flags &= ~MS_RDONLY;
1348         }
1349 #ifdef CONFIG_QUOTA
1350         /* Needed for iput() to work correctly and not trash data */
1351         sb->s_flags |= MS_ACTIVE;
1352         /* Turn on quotas so that they are updated correctly */
1353         for (i = 0; i < MAXQUOTAS; i++) {
1354                 if (EXT4_SB(sb)->s_qf_names[i]) {
1355                         int ret = ext4_quota_on_mount(sb, i);
1356                         if (ret < 0)
1357                                 printk(KERN_ERR
1358                                         "EXT4-fs: Cannot turn on journalled "
1359                                         "quota: error %d\n", ret);
1360                 }
1361         }
1362 #endif
1363
1364         while (es->s_last_orphan) {
1365                 struct inode *inode;
1366
1367                 if (!(inode =
1368                       ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan)))) {
1369                         es->s_last_orphan = 0;
1370                         break;
1371                 }
1372
1373                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1374                 DQUOT_INIT(inode);
1375                 if (inode->i_nlink) {
1376                         printk(KERN_DEBUG
1377                                 "%s: truncating inode %lu to %Ld bytes\n",
1378                                 __FUNCTION__, inode->i_ino, inode->i_size);
1379                         jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
1380                                   inode->i_ino, inode->i_size);
1381                         ext4_truncate(inode);
1382                         nr_truncates++;
1383                 } else {
1384                         printk(KERN_DEBUG
1385                                 "%s: deleting unreferenced inode %lu\n",
1386                                 __FUNCTION__, inode->i_ino);
1387                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1388                                   inode->i_ino);
1389                         nr_orphans++;
1390                 }
1391                 iput(inode);  /* The delete magic happens here! */
1392         }
1393
1394 #define PLURAL(x) (x), ((x)==1) ? "" : "s"
1395
1396         if (nr_orphans)
1397                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1398                        sb->s_id, PLURAL(nr_orphans));
1399         if (nr_truncates)
1400                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1401                        sb->s_id, PLURAL(nr_truncates));
1402 #ifdef CONFIG_QUOTA
1403         /* Turn quotas off */
1404         for (i = 0; i < MAXQUOTAS; i++) {
1405                 if (sb_dqopt(sb)->files[i])
1406                         vfs_quota_off(sb, i);
1407         }
1408 #endif
1409         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1410 }
1411
1412 #define log2(n) ffz(~(n))
1413
1414 /*
1415  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
1416  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
1417  * We need to be 1 filesystem block less than the 2^32 sector limit.
1418  */
1419 static loff_t ext4_max_size(int bits)
1420 {
1421         loff_t res = EXT4_NDIR_BLOCKS;
1422         /* This constant is calculated to be the largest file size for a
1423          * dense, 4k-blocksize file such that the total number of
1424          * sectors in the file, including data and all indirect blocks,
1425          * does not exceed 2^32. */
1426         const loff_t upper_limit = 0x1ff7fffd000LL;
1427
1428         res += 1LL << (bits-2);
1429         res += 1LL << (2*(bits-2));
1430         res += 1LL << (3*(bits-2));
1431         res <<= bits;
1432         if (res > upper_limit)
1433                 res = upper_limit;
1434         return res;
1435 }
1436
1437 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1438                                 ext4_fsblk_t logical_sb_block, int nr)
1439 {
1440         struct ext4_sb_info *sbi = EXT4_SB(sb);
1441         unsigned long bg, first_meta_bg;
1442         int has_super = 0;
1443
1444         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1445
1446         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1447             nr < first_meta_bg)
1448                 return logical_sb_block + nr + 1;
1449         bg = sbi->s_desc_per_block * nr;
1450         if (ext4_bg_has_super(sb, bg))
1451                 has_super = 1;
1452         return (has_super + ext4_group_first_block_no(sb, bg));
1453 }
1454
1455
1456 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
1457 {
1458         struct buffer_head * bh;
1459         struct ext4_super_block *es = NULL;
1460         struct ext4_sb_info *sbi;
1461         ext4_fsblk_t block;
1462         ext4_fsblk_t sb_block = get_sb_block(&data);
1463         ext4_fsblk_t logical_sb_block;
1464         unsigned long offset = 0;
1465         unsigned int journal_inum = 0;
1466         unsigned long journal_devnum = 0;
1467         unsigned long def_mount_opts;
1468         struct inode *root;
1469         int blocksize;
1470         int hblock;
1471         int db_count;
1472         int i;
1473         int needs_recovery;
1474         __le32 features;
1475         __u64 blocks_count;
1476
1477         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1478         if (!sbi)
1479                 return -ENOMEM;
1480         sb->s_fs_info = sbi;
1481         sbi->s_mount_opt = 0;
1482         sbi->s_resuid = EXT4_DEF_RESUID;
1483         sbi->s_resgid = EXT4_DEF_RESGID;
1484
1485         unlock_kernel();
1486
1487         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1488         if (!blocksize) {
1489                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1490                 goto out_fail;
1491         }
1492
1493         /*
1494          * The ext4 superblock will not be buffer aligned for other than 1kB
1495          * block sizes.  We need to calculate the offset from buffer start.
1496          */
1497         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1498                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1499                 offset = do_div(logical_sb_block, blocksize);
1500         } else {
1501                 logical_sb_block = sb_block;
1502         }
1503
1504         if (!(bh = sb_bread(sb, logical_sb_block))) {
1505                 printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
1506                 goto out_fail;
1507         }
1508         /*
1509          * Note: s_es must be initialized as soon as possible because
1510          *       some ext4 macro-instructions depend on its value
1511          */
1512         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1513         sbi->s_es = es;
1514         sb->s_magic = le16_to_cpu(es->s_magic);
1515         if (sb->s_magic != EXT4_SUPER_MAGIC)
1516                 goto cantfind_ext4;
1517
1518         /* Set defaults before we parse the mount options */
1519         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1520         if (def_mount_opts & EXT4_DEFM_DEBUG)
1521                 set_opt(sbi->s_mount_opt, DEBUG);
1522         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1523                 set_opt(sbi->s_mount_opt, GRPID);
1524         if (def_mount_opts & EXT4_DEFM_UID16)
1525                 set_opt(sbi->s_mount_opt, NO_UID32);
1526 #ifdef CONFIG_EXT4DEV_FS_XATTR
1527         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1528                 set_opt(sbi->s_mount_opt, XATTR_USER);
1529 #endif
1530 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1531         if (def_mount_opts & EXT4_DEFM_ACL)
1532                 set_opt(sbi->s_mount_opt, POSIX_ACL);
1533 #endif
1534         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1535                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1536         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1537                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1538         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1539                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1540
1541         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1542                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1543         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_RO)
1544                 set_opt(sbi->s_mount_opt, ERRORS_RO);
1545         else
1546                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
1547
1548         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1549         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1550
1551         set_opt(sbi->s_mount_opt, RESERVATION);
1552
1553         if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
1554                             NULL, 0))
1555                 goto failed_mount;
1556
1557         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1558                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1559
1560         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1561             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1562              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1563              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1564                 printk(KERN_WARNING
1565                        "EXT4-fs warning: feature flags set on rev 0 fs, "
1566                        "running e2fsck is recommended\n");
1567         /*
1568          * Check feature flags regardless of the revision level, since we
1569          * previously didn't change the revision level when setting the flags,
1570          * so there is a chance incompat flags are set on a rev 0 filesystem.
1571          */
1572         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
1573         if (features) {
1574                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
1575                        "unsupported optional features (%x).\n",
1576                        sb->s_id, le32_to_cpu(features));
1577                 goto failed_mount;
1578         }
1579         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
1580         if (!(sb->s_flags & MS_RDONLY) && features) {
1581                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
1582                        "unsupported optional features (%x).\n",
1583                        sb->s_id, le32_to_cpu(features));
1584                 goto failed_mount;
1585         }
1586         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
1587
1588         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
1589             blocksize > EXT4_MAX_BLOCK_SIZE) {
1590                 printk(KERN_ERR
1591                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
1592                        blocksize, sb->s_id);
1593                 goto failed_mount;
1594         }
1595
1596         hblock = bdev_hardsect_size(sb->s_bdev);
1597         if (sb->s_blocksize != blocksize) {
1598                 /*
1599                  * Make sure the blocksize for the filesystem is larger
1600                  * than the hardware sectorsize for the machine.
1601                  */
1602                 if (blocksize < hblock) {
1603                         printk(KERN_ERR "EXT4-fs: blocksize %d too small for "
1604                                "device blocksize %d.\n", blocksize, hblock);
1605                         goto failed_mount;
1606                 }
1607
1608                 brelse (bh);
1609                 sb_set_blocksize(sb, blocksize);
1610                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1611                 offset = do_div(logical_sb_block, blocksize);
1612                 bh = sb_bread(sb, logical_sb_block);
1613                 if (!bh) {
1614                         printk(KERN_ERR
1615                                "EXT4-fs: Can't read superblock on 2nd try.\n");
1616                         goto failed_mount;
1617                 }
1618                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
1619                 sbi->s_es = es;
1620                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
1621                         printk (KERN_ERR
1622                                 "EXT4-fs: Magic mismatch, very weird !\n");
1623                         goto failed_mount;
1624                 }
1625         }
1626
1627         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
1628
1629         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
1630                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
1631                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
1632         } else {
1633                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1634                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1635                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
1636                     (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
1637                     (sbi->s_inode_size > blocksize)) {
1638                         printk (KERN_ERR
1639                                 "EXT4-fs: unsupported inode size: %d\n",
1640                                 sbi->s_inode_size);
1641                         goto failed_mount;
1642                 }
1643         }
1644         sbi->s_frag_size = EXT4_MIN_FRAG_SIZE <<
1645                                    le32_to_cpu(es->s_log_frag_size);
1646         if (blocksize != sbi->s_frag_size) {
1647                 printk(KERN_ERR
1648                        "EXT4-fs: fragsize %lu != blocksize %u (unsupported)\n",
1649                        sbi->s_frag_size, blocksize);
1650                 goto failed_mount;
1651         }
1652         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
1653         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
1654                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
1655                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
1656                     sbi->s_desc_size & (sbi->s_desc_size - 1)) {
1657                         printk(KERN_ERR
1658                                "EXT4-fs: unsupported descriptor size %lu\n",
1659                                sbi->s_desc_size);
1660                         goto failed_mount;
1661                 }
1662         } else
1663                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
1664         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1665         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1666         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1667         if (EXT4_INODE_SIZE(sb) == 0)
1668                 goto cantfind_ext4;
1669         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
1670         if (sbi->s_inodes_per_block == 0)
1671                 goto cantfind_ext4;
1672         sbi->s_itb_per_group = sbi->s_inodes_per_group /
1673                                         sbi->s_inodes_per_block;
1674         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
1675         sbi->s_sbh = bh;
1676         sbi->s_mount_state = le16_to_cpu(es->s_state);
1677         sbi->s_addr_per_block_bits = log2(EXT4_ADDR_PER_BLOCK(sb));
1678         sbi->s_desc_per_block_bits = log2(EXT4_DESC_PER_BLOCK(sb));
1679         for (i=0; i < 4; i++)
1680                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
1681         sbi->s_def_hash_version = es->s_def_hash_version;
1682
1683         if (sbi->s_blocks_per_group > blocksize * 8) {
1684                 printk (KERN_ERR
1685                         "EXT4-fs: #blocks per group too big: %lu\n",
1686                         sbi->s_blocks_per_group);
1687                 goto failed_mount;
1688         }
1689         if (sbi->s_frags_per_group > blocksize * 8) {
1690                 printk (KERN_ERR
1691                         "EXT4-fs: #fragments per group too big: %lu\n",
1692                         sbi->s_frags_per_group);
1693                 goto failed_mount;
1694         }
1695         if (sbi->s_inodes_per_group > blocksize * 8) {
1696                 printk (KERN_ERR
1697                         "EXT4-fs: #inodes per group too big: %lu\n",
1698                         sbi->s_inodes_per_group);
1699                 goto failed_mount;
1700         }
1701
1702         if (ext4_blocks_count(es) >
1703                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1704                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
1705                         " too large to mount safely\n", sb->s_id);
1706                 if (sizeof(sector_t) < 8)
1707                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
1708                                         "enabled\n");
1709                 goto failed_mount;
1710         }
1711
1712         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
1713                 goto cantfind_ext4;
1714         blocks_count = (ext4_blocks_count(es) -
1715                         le32_to_cpu(es->s_first_data_block) +
1716                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
1717         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
1718         sbi->s_groups_count = blocks_count;
1719         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
1720                    EXT4_DESC_PER_BLOCK(sb);
1721         sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
1722                                     GFP_KERNEL);
1723         if (sbi->s_group_desc == NULL) {
1724                 printk (KERN_ERR "EXT4-fs: not enough memory\n");
1725                 goto failed_mount;
1726         }
1727
1728         bgl_lock_init(&sbi->s_blockgroup_lock);
1729
1730         for (i = 0; i < db_count; i++) {
1731                 block = descriptor_loc(sb, logical_sb_block, i);
1732                 sbi->s_group_desc[i] = sb_bread(sb, block);
1733                 if (!sbi->s_group_desc[i]) {
1734                         printk (KERN_ERR "EXT4-fs: "
1735                                 "can't read group descriptor %d\n", i);
1736                         db_count = i;
1737                         goto failed_mount2;
1738                 }
1739         }
1740         if (!ext4_check_descriptors (sb)) {
1741                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
1742                 goto failed_mount2;
1743         }
1744         sbi->s_gdb_count = db_count;
1745         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1746         spin_lock_init(&sbi->s_next_gen_lock);
1747
1748         percpu_counter_init(&sbi->s_freeblocks_counter,
1749                 ext4_count_free_blocks(sb));
1750         percpu_counter_init(&sbi->s_freeinodes_counter,
1751                 ext4_count_free_inodes(sb));
1752         percpu_counter_init(&sbi->s_dirs_counter,
1753                 ext4_count_dirs(sb));
1754
1755         /* per fileystem reservation list head & lock */
1756         spin_lock_init(&sbi->s_rsv_window_lock);
1757         sbi->s_rsv_window_root = RB_ROOT;
1758         /* Add a single, static dummy reservation to the start of the
1759          * reservation window list --- it gives us a placeholder for
1760          * append-at-start-of-list which makes the allocation logic
1761          * _much_ simpler. */
1762         sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1763         sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1764         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1765         sbi->s_rsv_window_head.rsv_goal_size = 0;
1766         ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
1767
1768         /*
1769          * set up enough so that it can read an inode
1770          */
1771         sb->s_op = &ext4_sops;
1772         sb->s_export_op = &ext4_export_ops;
1773         sb->s_xattr = ext4_xattr_handlers;
1774 #ifdef CONFIG_QUOTA
1775         sb->s_qcop = &ext4_qctl_operations;
1776         sb->dq_op = &ext4_quota_operations;
1777 #endif
1778         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
1779
1780         sb->s_root = NULL;
1781
1782         needs_recovery = (es->s_last_orphan != 0 ||
1783                           EXT4_HAS_INCOMPAT_FEATURE(sb,
1784                                     EXT4_FEATURE_INCOMPAT_RECOVER));
1785
1786         /*
1787          * The first inode we look at is the journal inode.  Don't try
1788          * root first: it may be modified in the journal!
1789          */
1790         if (!test_opt(sb, NOLOAD) &&
1791             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
1792                 if (ext4_load_journal(sb, es, journal_devnum))
1793                         goto failed_mount3;
1794         } else if (journal_inum) {
1795                 if (ext4_create_journal(sb, es, journal_inum))
1796                         goto failed_mount3;
1797         } else {
1798                 if (!silent)
1799                         printk (KERN_ERR
1800                                 "ext4: No journal on filesystem on %s\n",
1801                                 sb->s_id);
1802                 goto failed_mount3;
1803         }
1804
1805         /* We have now updated the journal if required, so we can
1806          * validate the data journaling mode. */
1807         switch (test_opt(sb, DATA_FLAGS)) {
1808         case 0:
1809                 /* No mode set, assume a default based on the journal
1810                  * capabilities: ORDERED_DATA if the journal can
1811                  * cope, else JOURNAL_DATA
1812                  */
1813                 if (jbd2_journal_check_available_features
1814                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
1815                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
1816                 else
1817                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
1818                 break;
1819
1820         case EXT4_MOUNT_ORDERED_DATA:
1821         case EXT4_MOUNT_WRITEBACK_DATA:
1822                 if (!jbd2_journal_check_available_features
1823                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
1824                         printk(KERN_ERR "EXT4-fs: Journal does not support "
1825                                "requested data journaling mode\n");
1826                         goto failed_mount4;
1827                 }
1828         default:
1829                 break;
1830         }
1831
1832         if (test_opt(sb, NOBH)) {
1833                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
1834                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
1835                                 "its supported only with writeback mode\n");
1836                         clear_opt(sbi->s_mount_opt, NOBH);
1837                 }
1838         }
1839         /*
1840          * The jbd2_journal_load will have done any necessary log recovery,
1841          * so we can safely mount the rest of the filesystem now.
1842          */
1843
1844         root = iget(sb, EXT4_ROOT_INO);
1845         sb->s_root = d_alloc_root(root);
1846         if (!sb->s_root) {
1847                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
1848                 iput(root);
1849                 goto failed_mount4;
1850         }
1851         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1852                 dput(sb->s_root);
1853                 sb->s_root = NULL;
1854                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
1855                 goto failed_mount4;
1856         }
1857
1858         ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1859         /*
1860          * akpm: core read_super() calls in here with the superblock locked.
1861          * That deadlocks, because orphan cleanup needs to lock the superblock
1862          * in numerous places.  Here we just pop the lock - it's relatively
1863          * harmless, because we are now ready to accept write_super() requests,
1864          * and aviro says that's the only reason for hanging onto the
1865          * superblock lock.
1866          */
1867         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
1868         ext4_orphan_cleanup(sb, es);
1869         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
1870         if (needs_recovery)
1871                 printk (KERN_INFO "EXT4-fs: recovery complete.\n");
1872         ext4_mark_recovery_complete(sb, es);
1873         printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
1874                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
1875                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
1876                 "writeback");
1877
1878         ext4_ext_init(sb);
1879
1880         lock_kernel();
1881         return 0;
1882
1883 cantfind_ext4:
1884         if (!silent)
1885                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
1886                        sb->s_id);
1887         goto failed_mount;
1888
1889 failed_mount4:
1890         jbd2_journal_destroy(sbi->s_journal);
1891 failed_mount3:
1892         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1893         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1894         percpu_counter_destroy(&sbi->s_dirs_counter);
1895 failed_mount2:
1896         for (i = 0; i < db_count; i++)
1897                 brelse(sbi->s_group_desc[i]);
1898         kfree(sbi->s_group_desc);
1899 failed_mount:
1900 #ifdef CONFIG_QUOTA
1901         for (i = 0; i < MAXQUOTAS; i++)
1902                 kfree(sbi->s_qf_names[i]);
1903 #endif
1904         ext4_blkdev_remove(sbi);
1905         brelse(bh);
1906 out_fail:
1907         sb->s_fs_info = NULL;
1908         kfree(sbi);
1909         lock_kernel();
1910         return -EINVAL;
1911 }
1912
1913 /*
1914  * Setup any per-fs journal parameters now.  We'll do this both on
1915  * initial mount, once the journal has been initialised but before we've
1916  * done any recovery; and again on any subsequent remount.
1917  */
1918 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
1919 {
1920         struct ext4_sb_info *sbi = EXT4_SB(sb);
1921
1922         if (sbi->s_commit_interval)
1923                 journal->j_commit_interval = sbi->s_commit_interval;
1924         /* We could also set up an ext4-specific default for the commit
1925          * interval here, but for now we'll just fall back to the jbd
1926          * default. */
1927
1928         spin_lock(&journal->j_state_lock);
1929         if (test_opt(sb, BARRIER))
1930                 journal->j_flags |= JBD2_BARRIER;
1931         else
1932                 journal->j_flags &= ~JBD2_BARRIER;
1933         spin_unlock(&journal->j_state_lock);
1934 }
1935
1936 static journal_t *ext4_get_journal(struct super_block *sb,
1937                                    unsigned int journal_inum)
1938 {
1939         struct inode *journal_inode;
1940         journal_t *journal;
1941
1942         /* First, test for the existence of a valid inode on disk.  Bad
1943          * things happen if we iget() an unused inode, as the subsequent
1944          * iput() will try to delete it. */
1945
1946         journal_inode = iget(sb, journal_inum);
1947         if (!journal_inode) {
1948                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
1949                 return NULL;
1950         }
1951         if (!journal_inode->i_nlink) {
1952                 make_bad_inode(journal_inode);
1953                 iput(journal_inode);
1954                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
1955                 return NULL;
1956         }
1957
1958         jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
1959                   journal_inode, journal_inode->i_size);
1960         if (is_bad_inode(journal_inode) || !S_ISREG(journal_inode->i_mode)) {
1961                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
1962                 iput(journal_inode);
1963                 return NULL;
1964         }
1965
1966         journal = jbd2_journal_init_inode(journal_inode);
1967         if (!journal) {
1968                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
1969                 iput(journal_inode);
1970                 return NULL;
1971         }
1972         journal->j_private = sb;
1973         ext4_init_journal_params(sb, journal);
1974         return journal;
1975 }
1976
1977 static journal_t *ext4_get_dev_journal(struct super_block *sb,
1978                                        dev_t j_dev)
1979 {
1980         struct buffer_head * bh;
1981         journal_t *journal;
1982         ext4_fsblk_t start;
1983         ext4_fsblk_t len;
1984         int hblock, blocksize;
1985         ext4_fsblk_t sb_block;
1986         unsigned long offset;
1987         struct ext4_super_block * es;
1988         struct block_device *bdev;
1989
1990         bdev = ext4_blkdev_get(j_dev);
1991         if (bdev == NULL)
1992                 return NULL;
1993
1994         if (bd_claim(bdev, sb)) {
1995                 printk(KERN_ERR
1996                         "EXT4: failed to claim external journal device.\n");
1997                 blkdev_put(bdev);
1998                 return NULL;
1999         }
2000
2001         blocksize = sb->s_blocksize;
2002         hblock = bdev_hardsect_size(bdev);
2003         if (blocksize < hblock) {
2004                 printk(KERN_ERR
2005                         "EXT4-fs: blocksize too small for journal device.\n");
2006                 goto out_bdev;
2007         }
2008
2009         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2010         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2011         set_blocksize(bdev, blocksize);
2012         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2013                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2014                        "external journal\n");
2015                 goto out_bdev;
2016         }
2017
2018         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2019         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2020             !(le32_to_cpu(es->s_feature_incompat) &
2021               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2022                 printk(KERN_ERR "EXT4-fs: external journal has "
2023                                         "bad superblock\n");
2024                 brelse(bh);
2025                 goto out_bdev;
2026         }
2027
2028         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2029                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2030                 brelse(bh);
2031                 goto out_bdev;
2032         }
2033
2034         len = ext4_blocks_count(es);
2035         start = sb_block + 1;
2036         brelse(bh);     /* we're done with the superblock */
2037
2038         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2039                                         start, len, blocksize);
2040         if (!journal) {
2041                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2042                 goto out_bdev;
2043         }
2044         journal->j_private = sb;
2045         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2046         wait_on_buffer(journal->j_sb_buffer);
2047         if (!buffer_uptodate(journal->j_sb_buffer)) {
2048                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2049                 goto out_journal;
2050         }
2051         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2052                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2053                                         "user (unsupported) - %d\n",
2054                         be32_to_cpu(journal->j_superblock->s_nr_users));
2055                 goto out_journal;
2056         }
2057         EXT4_SB(sb)->journal_bdev = bdev;
2058         ext4_init_journal_params(sb, journal);
2059         return journal;
2060 out_journal:
2061         jbd2_journal_destroy(journal);
2062 out_bdev:
2063         ext4_blkdev_put(bdev);
2064         return NULL;
2065 }
2066
2067 static int ext4_load_journal(struct super_block *sb,
2068                              struct ext4_super_block *es,
2069                              unsigned long journal_devnum)
2070 {
2071         journal_t *journal;
2072         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2073         dev_t journal_dev;
2074         int err = 0;
2075         int really_read_only;
2076
2077         if (journal_devnum &&
2078             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2079                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2080                         "numbers have changed\n");
2081                 journal_dev = new_decode_dev(journal_devnum);
2082         } else
2083                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2084
2085         really_read_only = bdev_read_only(sb->s_bdev);
2086
2087         /*
2088          * Are we loading a blank journal or performing recovery after a
2089          * crash?  For recovery, we need to check in advance whether we
2090          * can get read-write access to the device.
2091          */
2092
2093         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2094                 if (sb->s_flags & MS_RDONLY) {
2095                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2096                                         "required on readonly filesystem.\n");
2097                         if (really_read_only) {
2098                                 printk(KERN_ERR "EXT4-fs: write access "
2099                                         "unavailable, cannot proceed.\n");
2100                                 return -EROFS;
2101                         }
2102                         printk (KERN_INFO "EXT4-fs: write access will "
2103                                         "be enabled during recovery.\n");
2104                 }
2105         }
2106
2107         if (journal_inum && journal_dev) {
2108                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2109                        "and inode journals!\n");
2110                 return -EINVAL;
2111         }
2112
2113         if (journal_inum) {
2114                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2115                         return -EINVAL;
2116         } else {
2117                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2118                         return -EINVAL;
2119         }
2120
2121         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2122                 err = jbd2_journal_update_format(journal);
2123                 if (err)  {
2124                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2125                         jbd2_journal_destroy(journal);
2126                         return err;
2127                 }
2128         }
2129
2130         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2131                 err = jbd2_journal_wipe(journal, !really_read_only);
2132         if (!err)
2133                 err = jbd2_journal_load(journal);
2134
2135         if (err) {
2136                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2137                 jbd2_journal_destroy(journal);
2138                 return err;
2139         }
2140
2141         EXT4_SB(sb)->s_journal = journal;
2142         ext4_clear_journal_err(sb, es);
2143
2144         if (journal_devnum &&
2145             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2146                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2147                 sb->s_dirt = 1;
2148
2149                 /* Make sure we flush the recovery flag to disk. */
2150                 ext4_commit_super(sb, es, 1);
2151         }
2152
2153         return 0;
2154 }
2155
2156 static int ext4_create_journal(struct super_block * sb,
2157                                struct ext4_super_block * es,
2158                                unsigned int journal_inum)
2159 {
2160         journal_t *journal;
2161
2162         if (sb->s_flags & MS_RDONLY) {
2163                 printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2164                                 "create journal.\n");
2165                 return -EROFS;
2166         }
2167
2168         if (!(journal = ext4_get_journal(sb, journal_inum)))
2169                 return -EINVAL;
2170
2171         printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2172                journal_inum);
2173
2174         if (jbd2_journal_create(journal)) {
2175                 printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2176                 jbd2_journal_destroy(journal);
2177                 return -EIO;
2178         }
2179
2180         EXT4_SB(sb)->s_journal = journal;
2181
2182         ext4_update_dynamic_rev(sb);
2183         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2184         EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2185
2186         es->s_journal_inum = cpu_to_le32(journal_inum);
2187         sb->s_dirt = 1;
2188
2189         /* Make sure we flush the recovery flag to disk. */
2190         ext4_commit_super(sb, es, 1);
2191
2192         return 0;
2193 }
2194
2195 static void ext4_commit_super (struct super_block * sb,
2196                                struct ext4_super_block * es,
2197                                int sync)
2198 {
2199         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2200
2201         if (!sbh)
2202                 return;
2203         es->s_wtime = cpu_to_le32(get_seconds());
2204         ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2205         es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2206         BUFFER_TRACE(sbh, "marking dirty");
2207         mark_buffer_dirty(sbh);
2208         if (sync)
2209                 sync_dirty_buffer(sbh);
2210 }
2211
2212
2213 /*
2214  * Have we just finished recovery?  If so, and if we are mounting (or
2215  * remounting) the filesystem readonly, then we will end up with a
2216  * consistent fs on disk.  Record that fact.
2217  */
2218 static void ext4_mark_recovery_complete(struct super_block * sb,
2219                                         struct ext4_super_block * es)
2220 {
2221         journal_t *journal = EXT4_SB(sb)->s_journal;
2222
2223         jbd2_journal_lock_updates(journal);
2224         jbd2_journal_flush(journal);
2225         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2226             sb->s_flags & MS_RDONLY) {
2227                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2228                 sb->s_dirt = 0;
2229                 ext4_commit_super(sb, es, 1);
2230         }
2231         jbd2_journal_unlock_updates(journal);
2232 }
2233
2234 /*
2235  * If we are mounting (or read-write remounting) a filesystem whose journal
2236  * has recorded an error from a previous lifetime, move that error to the
2237  * main filesystem now.
2238  */
2239 static void ext4_clear_journal_err(struct super_block * sb,
2240                                    struct ext4_super_block * es)
2241 {
2242         journal_t *journal;
2243         int j_errno;
2244         const char *errstr;
2245
2246         journal = EXT4_SB(sb)->s_journal;
2247
2248         /*
2249          * Now check for any error status which may have been recorded in the
2250          * journal by a prior ext4_error() or ext4_abort()
2251          */
2252
2253         j_errno = jbd2_journal_errno(journal);
2254         if (j_errno) {
2255                 char nbuf[16];
2256
2257                 errstr = ext4_decode_error(sb, j_errno, nbuf);
2258                 ext4_warning(sb, __FUNCTION__, "Filesystem error recorded "
2259                              "from previous mount: %s", errstr);
2260                 ext4_warning(sb, __FUNCTION__, "Marking fs in need of "
2261                              "filesystem check.");
2262
2263                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2264                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2265                 ext4_commit_super (sb, es, 1);
2266
2267                 jbd2_journal_clear_err(journal);
2268         }
2269 }
2270
2271 /*
2272  * Force the running and committing transactions to commit,
2273  * and wait on the commit.
2274  */
2275 int ext4_force_commit(struct super_block *sb)
2276 {
2277         journal_t *journal;
2278         int ret;
2279
2280         if (sb->s_flags & MS_RDONLY)
2281                 return 0;
2282
2283         journal = EXT4_SB(sb)->s_journal;
2284         sb->s_dirt = 0;
2285         ret = ext4_journal_force_commit(journal);
2286         return ret;
2287 }
2288
2289 /*
2290  * Ext4 always journals updates to the superblock itself, so we don't
2291  * have to propagate any other updates to the superblock on disk at this
2292  * point.  Just start an async writeback to get the buffers on their way
2293  * to the disk.
2294  *
2295  * This implicitly triggers the writebehind on sync().
2296  */
2297
2298 static void ext4_write_super (struct super_block * sb)
2299 {
2300         if (mutex_trylock(&sb->s_lock) != 0)
2301                 BUG();
2302         sb->s_dirt = 0;
2303 }
2304
2305 static int ext4_sync_fs(struct super_block *sb, int wait)
2306 {
2307         tid_t target;
2308
2309         sb->s_dirt = 0;
2310         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2311                 if (wait)
2312                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2313         }
2314         return 0;
2315 }
2316
2317 /*
2318  * LVM calls this function before a (read-only) snapshot is created.  This
2319  * gives us a chance to flush the journal completely and mark the fs clean.
2320  */
2321 static void ext4_write_super_lockfs(struct super_block *sb)
2322 {
2323         sb->s_dirt = 0;
2324
2325         if (!(sb->s_flags & MS_RDONLY)) {
2326                 journal_t *journal = EXT4_SB(sb)->s_journal;
2327
2328                 /* Now we set up the journal barrier. */
2329                 jbd2_journal_lock_updates(journal);
2330                 jbd2_journal_flush(journal);
2331
2332                 /* Journal blocked and flushed, clear needs_recovery flag. */
2333                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2334                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2335         }
2336 }
2337
2338 /*
2339  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2340  * flag here, even though the filesystem is not technically dirty yet.
2341  */
2342 static void ext4_unlockfs(struct super_block *sb)
2343 {
2344         if (!(sb->s_flags & MS_RDONLY)) {
2345                 lock_super(sb);
2346                 /* Reser the needs_recovery flag before the fs is unlocked. */
2347                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2348                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2349                 unlock_super(sb);
2350                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2351         }
2352 }
2353
2354 static int ext4_remount (struct super_block * sb, int * flags, char * data)
2355 {
2356         struct ext4_super_block * es;
2357         struct ext4_sb_info *sbi = EXT4_SB(sb);
2358         ext4_fsblk_t n_blocks_count = 0;
2359         unsigned long old_sb_flags;
2360         struct ext4_mount_options old_opts;
2361         int err;
2362 #ifdef CONFIG_QUOTA
2363         int i;
2364 #endif
2365
2366         /* Store the original options */
2367         old_sb_flags = sb->s_flags;
2368         old_opts.s_mount_opt = sbi->s_mount_opt;
2369         old_opts.s_resuid = sbi->s_resuid;
2370         old_opts.s_resgid = sbi->s_resgid;
2371         old_opts.s_commit_interval = sbi->s_commit_interval;
2372 #ifdef CONFIG_QUOTA
2373         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2374         for (i = 0; i < MAXQUOTAS; i++)
2375                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2376 #endif
2377
2378         /*
2379          * Allow the "check" option to be passed as a remount option.
2380          */
2381         if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2382                 err = -EINVAL;
2383                 goto restore_opts;
2384         }
2385
2386         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2387                 ext4_abort(sb, __FUNCTION__, "Abort forced by user");
2388
2389         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2390                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2391
2392         es = sbi->s_es;
2393
2394         ext4_init_journal_params(sb, sbi->s_journal);
2395
2396         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2397                 n_blocks_count > ext4_blocks_count(es)) {
2398                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
2399                         err = -EROFS;
2400                         goto restore_opts;
2401                 }
2402
2403                 if (*flags & MS_RDONLY) {
2404                         /*
2405                          * First of all, the unconditional stuff we have to do
2406                          * to disable replay of the journal when we next remount
2407                          */
2408                         sb->s_flags |= MS_RDONLY;
2409
2410                         /*
2411                          * OK, test if we are remounting a valid rw partition
2412                          * readonly, and if so set the rdonly flag and then
2413                          * mark the partition as valid again.
2414                          */
2415                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
2416                             (sbi->s_mount_state & EXT4_VALID_FS))
2417                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
2418
2419                         ext4_mark_recovery_complete(sb, es);
2420                 } else {
2421                         __le32 ret;
2422                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2423                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
2424                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2425                                        "remount RDWR because of unsupported "
2426                                        "optional features (%x).\n",
2427                                        sb->s_id, le32_to_cpu(ret));
2428                                 err = -EROFS;
2429                                 goto restore_opts;
2430                         }
2431
2432                         /*
2433                          * If we have an unprocessed orphan list hanging
2434                          * around from a previously readonly bdev mount,
2435                          * require a full umount/remount for now.
2436                          */
2437                         if (es->s_last_orphan) {
2438                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2439                                        "remount RDWR because of unprocessed "
2440                                        "orphan inode list.  Please "
2441                                        "umount/remount instead.\n",
2442                                        sb->s_id);
2443                                 err = -EINVAL;
2444                                 goto restore_opts;
2445                         }
2446
2447                         /*
2448                          * Mounting a RDONLY partition read-write, so reread
2449                          * and store the current valid flag.  (It may have
2450                          * been changed by e2fsck since we originally mounted
2451                          * the partition.)
2452                          */
2453                         ext4_clear_journal_err(sb, es);
2454                         sbi->s_mount_state = le16_to_cpu(es->s_state);
2455                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
2456                                 goto restore_opts;
2457                         if (!ext4_setup_super (sb, es, 0))
2458                                 sb->s_flags &= ~MS_RDONLY;
2459                 }
2460         }
2461 #ifdef CONFIG_QUOTA
2462         /* Release old quota file names */
2463         for (i = 0; i < MAXQUOTAS; i++)
2464                 if (old_opts.s_qf_names[i] &&
2465                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2466                         kfree(old_opts.s_qf_names[i]);
2467 #endif
2468         return 0;
2469 restore_opts:
2470         sb->s_flags = old_sb_flags;
2471         sbi->s_mount_opt = old_opts.s_mount_opt;
2472         sbi->s_resuid = old_opts.s_resuid;
2473         sbi->s_resgid = old_opts.s_resgid;
2474         sbi->s_commit_interval = old_opts.s_commit_interval;
2475 #ifdef CONFIG_QUOTA
2476         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
2477         for (i = 0; i < MAXQUOTAS; i++) {
2478                 if (sbi->s_qf_names[i] &&
2479                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2480                         kfree(sbi->s_qf_names[i]);
2481                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
2482         }
2483 #endif
2484         return err;
2485 }
2486
2487 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
2488 {
2489         struct super_block *sb = dentry->d_sb;
2490         struct ext4_sb_info *sbi = EXT4_SB(sb);
2491         struct ext4_super_block *es = sbi->s_es;
2492         ext4_fsblk_t overhead;
2493         int i;
2494         u64 fsid;
2495
2496         if (test_opt (sb, MINIX_DF))
2497                 overhead = 0;
2498         else {
2499                 unsigned long ngroups;
2500                 ngroups = EXT4_SB(sb)->s_groups_count;
2501                 smp_rmb();
2502
2503                 /*
2504                  * Compute the overhead (FS structures)
2505                  */
2506
2507                 /*
2508                  * All of the blocks before first_data_block are
2509                  * overhead
2510                  */
2511                 overhead = le32_to_cpu(es->s_first_data_block);
2512
2513                 /*
2514                  * Add the overhead attributed to the superblock and
2515                  * block group descriptors.  If the sparse superblocks
2516                  * feature is turned on, then not all groups have this.
2517                  */
2518                 for (i = 0; i < ngroups; i++) {
2519                         overhead += ext4_bg_has_super(sb, i) +
2520                                 ext4_bg_num_gdb(sb, i);
2521                         cond_resched();
2522                 }
2523
2524                 /*
2525                  * Every block group has an inode bitmap, a block
2526                  * bitmap, and an inode table.
2527                  */
2528                 overhead += (ngroups * (2 + EXT4_SB(sb)->s_itb_per_group));
2529         }
2530
2531         buf->f_type = EXT4_SUPER_MAGIC;
2532         buf->f_bsize = sb->s_blocksize;
2533         buf->f_blocks = ext4_blocks_count(es) - overhead;
2534         buf->f_bfree = percpu_counter_sum(&sbi->s_freeblocks_counter);
2535         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
2536         if (buf->f_bfree < ext4_r_blocks_count(es))
2537                 buf->f_bavail = 0;
2538         buf->f_files = le32_to_cpu(es->s_inodes_count);
2539         buf->f_ffree = percpu_counter_sum(&sbi->s_freeinodes_counter);
2540         buf->f_namelen = EXT4_NAME_LEN;
2541         fsid = le64_to_cpup((void *)es->s_uuid) ^
2542                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
2543         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
2544         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
2545         return 0;
2546 }
2547
2548 /* Helper function for writing quotas on sync - we need to start transaction before quota file
2549  * is locked for write. Otherwise the are possible deadlocks:
2550  * Process 1                         Process 2
2551  * ext4_create()                     quota_sync()
2552  *   jbd2_journal_start()                   write_dquot()
2553  *   DQUOT_INIT()                        down(dqio_mutex)
2554  *     down(dqio_mutex)                    jbd2_journal_start()
2555  *
2556  */
2557
2558 #ifdef CONFIG_QUOTA
2559
2560 static inline struct inode *dquot_to_inode(struct dquot *dquot)
2561 {
2562         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
2563 }
2564
2565 static int ext4_dquot_initialize(struct inode *inode, int type)
2566 {
2567         handle_t *handle;
2568         int ret, err;
2569
2570         /* We may create quota structure so we need to reserve enough blocks */
2571         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
2572         if (IS_ERR(handle))
2573                 return PTR_ERR(handle);
2574         ret = dquot_initialize(inode, type);
2575         err = ext4_journal_stop(handle);
2576         if (!ret)
2577                 ret = err;
2578         return ret;
2579 }
2580
2581 static int ext4_dquot_drop(struct inode *inode)
2582 {
2583         handle_t *handle;
2584         int ret, err;
2585
2586         /* We may delete quota structure so we need to reserve enough blocks */
2587         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
2588         if (IS_ERR(handle))
2589                 return PTR_ERR(handle);
2590         ret = dquot_drop(inode);
2591         err = ext4_journal_stop(handle);
2592         if (!ret)
2593                 ret = err;
2594         return ret;
2595 }
2596
2597 static int ext4_write_dquot(struct dquot *dquot)
2598 {
2599         int ret, err;
2600         handle_t *handle;
2601         struct inode *inode;
2602
2603         inode = dquot_to_inode(dquot);
2604         handle = ext4_journal_start(inode,
2605                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
2606         if (IS_ERR(handle))
2607                 return PTR_ERR(handle);
2608         ret = dquot_commit(dquot);
2609         err = ext4_journal_stop(handle);
2610         if (!ret)
2611                 ret = err;
2612         return ret;
2613 }
2614
2615 static int ext4_acquire_dquot(struct dquot *dquot)
2616 {
2617         int ret, err;
2618         handle_t *handle;
2619
2620         handle = ext4_journal_start(dquot_to_inode(dquot),
2621                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
2622         if (IS_ERR(handle))
2623                 return PTR_ERR(handle);
2624         ret = dquot_acquire(dquot);
2625         err = ext4_journal_stop(handle);
2626         if (!ret)
2627                 ret = err;
2628         return ret;
2629 }
2630
2631 static int ext4_release_dquot(struct dquot *dquot)
2632 {
2633         int ret, err;
2634         handle_t *handle;
2635
2636         handle = ext4_journal_start(dquot_to_inode(dquot),
2637                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
2638         if (IS_ERR(handle))
2639                 return PTR_ERR(handle);
2640         ret = dquot_release(dquot);
2641         err = ext4_journal_stop(handle);
2642         if (!ret)
2643                 ret = err;
2644         return ret;
2645 }
2646
2647 static int ext4_mark_dquot_dirty(struct dquot *dquot)
2648 {
2649         /* Are we journalling quotas? */
2650         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
2651             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
2652                 dquot_mark_dquot_dirty(dquot);
2653                 return ext4_write_dquot(dquot);
2654         } else {
2655                 return dquot_mark_dquot_dirty(dquot);
2656         }
2657 }
2658
2659 static int ext4_write_info(struct super_block *sb, int type)
2660 {
2661         int ret, err;
2662         handle_t *handle;
2663
2664         /* Data block + inode block */
2665         handle = ext4_journal_start(sb->s_root->d_inode, 2);
2666         if (IS_ERR(handle))
2667                 return PTR_ERR(handle);
2668         ret = dquot_commit_info(sb, type);
2669         err = ext4_journal_stop(handle);
2670         if (!ret)
2671                 ret = err;
2672         return ret;
2673 }
2674
2675 /*
2676  * Turn on quotas during mount time - we need to find
2677  * the quota file and such...
2678  */
2679 static int ext4_quota_on_mount(struct super_block *sb, int type)
2680 {
2681         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
2682                         EXT4_SB(sb)->s_jquota_fmt, type);
2683 }
2684
2685 /*
2686  * Standard function to be called on quota_on
2687  */
2688 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
2689                          char *path)
2690 {
2691         int err;
2692         struct nameidata nd;
2693
2694         if (!test_opt(sb, QUOTA))
2695                 return -EINVAL;
2696         /* Not journalling quota? */
2697         if (!EXT4_SB(sb)->s_qf_names[USRQUOTA] &&
2698             !EXT4_SB(sb)->s_qf_names[GRPQUOTA])
2699                 return vfs_quota_on(sb, type, format_id, path);
2700         err = path_lookup(path, LOOKUP_FOLLOW, &nd);
2701         if (err)
2702                 return err;
2703         /* Quotafile not on the same filesystem? */
2704         if (nd.mnt->mnt_sb != sb) {
2705                 path_release(&nd);
2706                 return -EXDEV;
2707         }
2708         /* Quotafile not of fs root? */
2709         if (nd.dentry->d_parent->d_inode != sb->s_root->d_inode)
2710                 printk(KERN_WARNING
2711                         "EXT4-fs: Quota file not on filesystem root. "
2712                         "Journalled quota will not work.\n");
2713         path_release(&nd);
2714         return vfs_quota_on(sb, type, format_id, path);
2715 }
2716
2717 /* Read data from quotafile - avoid pagecache and such because we cannot afford
2718  * acquiring the locks... As quota files are never truncated and quota code
2719  * itself serializes the operations (and noone else should touch the files)
2720  * we don't have to be afraid of races */
2721 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
2722                                size_t len, loff_t off)
2723 {
2724         struct inode *inode = sb_dqopt(sb)->files[type];
2725         sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2726         int err = 0;
2727         int offset = off & (sb->s_blocksize - 1);
2728         int tocopy;
2729         size_t toread;
2730         struct buffer_head *bh;
2731         loff_t i_size = i_size_read(inode);
2732
2733         if (off > i_size)
2734                 return 0;
2735         if (off+len > i_size)
2736                 len = i_size-off;
2737         toread = len;
2738         while (toread > 0) {
2739                 tocopy = sb->s_blocksize - offset < toread ?
2740                                 sb->s_blocksize - offset : toread;
2741                 bh = ext4_bread(NULL, inode, blk, 0, &err);
2742                 if (err)
2743                         return err;
2744                 if (!bh)        /* A hole? */
2745                         memset(data, 0, tocopy);
2746                 else
2747                         memcpy(data, bh->b_data+offset, tocopy);
2748                 brelse(bh);
2749                 offset = 0;
2750                 toread -= tocopy;
2751                 data += tocopy;
2752                 blk++;
2753         }
2754         return len;
2755 }
2756
2757 /* Write to quotafile (we know the transaction is already started and has
2758  * enough credits) */
2759 static ssize_t ext4_quota_write(struct super_block *sb, int type,
2760                                 const char *data, size_t len, loff_t off)
2761 {
2762         struct inode *inode = sb_dqopt(sb)->files[type];
2763         sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2764         int err = 0;
2765         int offset = off & (sb->s_blocksize - 1);
2766         int tocopy;
2767         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
2768         size_t towrite = len;
2769         struct buffer_head *bh;
2770         handle_t *handle = journal_current_handle();
2771
2772         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2773         while (towrite > 0) {
2774                 tocopy = sb->s_blocksize - offset < towrite ?
2775                                 sb->s_blocksize - offset : towrite;
2776                 bh = ext4_bread(handle, inode, blk, 1, &err);
2777                 if (!bh)
2778                         goto out;
2779                 if (journal_quota) {
2780                         err = ext4_journal_get_write_access(handle, bh);
2781                         if (err) {
2782                                 brelse(bh);
2783                                 goto out;
2784                         }
2785                 }
2786                 lock_buffer(bh);
2787                 memcpy(bh->b_data+offset, data, tocopy);
2788                 flush_dcache_page(bh->b_page);
2789                 unlock_buffer(bh);
2790                 if (journal_quota)
2791                         err = ext4_journal_dirty_metadata(handle, bh);
2792                 else {
2793                         /* Always do at least ordered writes for quotas */
2794                         err = ext4_journal_dirty_data(handle, bh);
2795                         mark_buffer_dirty(bh);
2796                 }
2797                 brelse(bh);
2798                 if (err)
2799                         goto out;
2800                 offset = 0;
2801                 towrite -= tocopy;
2802                 data += tocopy;
2803                 blk++;
2804         }
2805 out:
2806         if (len == towrite)
2807                 return err;
2808         if (inode->i_size < off+len-towrite) {
2809                 i_size_write(inode, off+len-towrite);
2810                 EXT4_I(inode)->i_disksize = inode->i_size;
2811         }
2812         inode->i_version++;
2813         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2814         ext4_mark_inode_dirty(handle, inode);
2815         mutex_unlock(&inode->i_mutex);
2816         return len - towrite;
2817 }
2818
2819 #endif
2820
2821 static int ext4_get_sb(struct file_system_type *fs_type,
2822         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
2823 {
2824         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
2825 }
2826
2827 static struct file_system_type ext4dev_fs_type = {
2828         .owner          = THIS_MODULE,
2829         .name           = "ext4dev",
2830         .get_sb         = ext4_get_sb,
2831         .kill_sb        = kill_block_super,
2832         .fs_flags       = FS_REQUIRES_DEV,
2833 };
2834
2835 static int __init init_ext4_fs(void)
2836 {
2837         int err = init_ext4_xattr();
2838         if (err)
2839                 return err;
2840         err = init_inodecache();
2841         if (err)
2842                 goto out1;
2843         err = register_filesystem(&ext4dev_fs_type);
2844         if (err)
2845                 goto out;
2846         return 0;
2847 out:
2848         destroy_inodecache();
2849 out1:
2850         exit_ext4_xattr();
2851         return err;
2852 }
2853
2854 static void __exit exit_ext4_fs(void)
2855 {
2856         unregister_filesystem(&ext4dev_fs_type);
2857         destroy_inodecache();
2858         exit_ext4_xattr();
2859 }
2860
2861 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
2862 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
2863 MODULE_LICENSE("GPL");
2864 module_init(init_ext4_fs)
2865 module_exit(exit_ext4_fs)