fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/jbd2.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/parser.h>
  28 #include <linux/smp_lock.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/ctype.h>
  39 #include <linux/marker.h>
  40 #include <linux/log2.h>
  41 #include <linux/crc16.h>
  42 #include <asm/uaccess.h>
  43
  44 #include "ext4.h"
  45 #include "ext4_jbd2.h"
  46 #include "xattr.h"
  47 #include "acl.h"
  48 #include "namei.h"
  49 #include "group.h"
  50
  51 struct proc_dir_entry *ext4_proc_root;
  52 static struct kset *ext4_kset;
  53
  54 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  55                              unsigned long journal_devnum);
  56 static int ext4_commit_super(struct super_block *sb,
  57                               struct ext4_super_block *es, int sync);
  58 static void ext4_mark_recovery_complete(struct super_block *sb,
  59                                         struct ext4_super_block *es);
  60 static void ext4_clear_journal_err(struct super_block *sb,
  61                                    struct ext4_super_block *es);
  62 static int ext4_sync_fs(struct super_block *sb, int wait);
  63 static const char *ext4_decode_error(struct super_block *sb, int errno,
  64                                      char nbuf[16]);
  65 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  66 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  67 static int ext4_unfreeze(struct super_block *sb);
  68 static void ext4_write_super(struct super_block *sb);
  69 static int ext4_freeze(struct super_block *sb);
  70
  71
  72 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
  73                                struct ext4_group_desc *bg)
  74 {
  75         return le32_to_cpu(bg->bg_block_bitmap_lo) |
  76                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  77                 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
  78 }
  79
  80 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
  81                                struct ext4_group_desc *bg)
  82 {
  83         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
  84                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  85                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
  86 }
  87
  88 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
  89                               struct ext4_group_desc *bg)
  90 {
  91         return le32_to_cpu(bg->bg_inode_table_lo) |
  92                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  93                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
  94 }
  95
  96 __u32 ext4_free_blks_count(struct super_block *sb,
  97                               struct ext4_group_desc *bg)
  98 {
  99         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 100                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 101                 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 102 }
 103
 104 __u32 ext4_free_inodes_count(struct super_block *sb,
 105                               struct ext4_group_desc *bg)
 106 {
 107         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 108                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 109                 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 110 }
 111
 112 __u32 ext4_used_dirs_count(struct super_block *sb,
 113                               struct ext4_group_desc *bg)
 114 {
 115         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 116                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 117                 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 118 }
 119
 120 __u32 ext4_itable_unused_count(struct super_block *sb,
 121                               struct ext4_group_desc *bg)
 122 {
 123         return le16_to_cpu(bg->bg_itable_unused_lo) |
 124                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 125                 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 126 }
 127
 128 void ext4_block_bitmap_set(struct super_block *sb,
 129                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 130 {
 131         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 132         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 133                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 134 }
 135
 136 void ext4_inode_bitmap_set(struct super_block *sb,
 137                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 138 {
 139         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 140         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 141                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 142 }
 143
 144 void ext4_inode_table_set(struct super_block *sb,
 145                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 146 {
 147         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 148         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 149                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 150 }
 151
 152 void ext4_free_blks_set(struct super_block *sb,
 153                           struct ext4_group_desc *bg, __u32 count)
 154 {
 155         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 156         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 157                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 158 }
 159
 160 void ext4_free_inodes_set(struct super_block *sb,
 161                           struct ext4_group_desc *bg, __u32 count)
 162 {
 163         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 164         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 165                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 166 }
 167
 168 void ext4_used_dirs_set(struct super_block *sb,
 169                           struct ext4_group_desc *bg, __u32 count)
 170 {
 171         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 172         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 173                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 174 }
 175
 176 void ext4_itable_unused_set(struct super_block *sb,
 177                           struct ext4_group_desc *bg, __u32 count)
 178 {
 179         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 180         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 181                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 182 }
 183
 184 /*
 185  * Wrappers for jbd2_journal_start/end.
 186  *
 187  * The only special thing we need to do here is to make sure that all
 188  * journal_end calls result in the superblock being marked dirty, so
 189  * that sync() will call the filesystem's write_super callback if
 190  * appropriate.
 191  */
 192 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 193 {
 194         journal_t *journal;
 195
 196         if (sb->s_flags & MS_RDONLY)
 197                 return ERR_PTR(-EROFS);
 198
 199         /* Special case here: if the journal has aborted behind our
 200          * backs (eg. EIO in the commit thread), then we still need to
 201          * take the FS itself readonly cleanly. */
 202         journal = EXT4_SB(sb)->s_journal;
 203         if (journal) {
 204                 if (is_journal_aborted(journal)) {
 205                         ext4_abort(sb, __func__,
 206                                    "Detected aborted journal");
 207                         return ERR_PTR(-EROFS);
 208                 }
 209                 return jbd2_journal_start(journal, nblocks);
 210         }
 211         /*
 212          * We're not journaling, return the appropriate indication.
 213          */
 214         current->journal_info = EXT4_NOJOURNAL_HANDLE;
 215         return current->journal_info;
 216 }
 217
 218 /*
 219  * The only special thing we need to do here is to make sure that all
 220  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 221  * that sync() will call the filesystem's write_super callback if
 222  * appropriate.
 223  */
 224 int __ext4_journal_stop(const char *where, handle_t *handle)
 225 {
 226         struct super_block *sb;
 227         int err;
 228         int rc;
 229
 230         if (!ext4_handle_valid(handle)) {
 231                 /*
 232                  * Do this here since we don't call jbd2_journal_stop() in
 233                  * no-journal mode.
 234                  */
 235                 current->journal_info = NULL;
 236                 return 0;
 237         }
 238         sb = handle->h_transaction->t_journal->j_private;
 239         err = handle->h_err;
 240         rc = jbd2_journal_stop(handle);
 241
 242         if (!err)
 243                 err = rc;
 244         if (err)
 245                 __ext4_std_error(sb, where, err);
 246         return err;
 247 }
 248
 249 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 250                 struct buffer_head *bh, handle_t *handle, int err)
 251 {
 252         char nbuf[16];
 253         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 254
 255         BUG_ON(!ext4_handle_valid(handle));
 256
 257         if (bh)
 258                 BUFFER_TRACE(bh, "abort");
 259
 260         if (!handle->h_err)
 261                 handle->h_err = err;
 262
 263         if (is_handle_aborted(handle))
 264                 return;
 265
 266         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
 267                caller, errstr, err_fn);
 268
 269         jbd2_journal_abort_handle(handle);
 270 }
 271
 272 /* Deal with the reporting of failure conditions on a filesystem such as
 273  * inconsistencies detected or read IO failures.
 274  *
 275  * On ext2, we can store the error state of the filesystem in the
 276  * superblock.  That is not possible on ext4, because we may have other
 277  * write ordering constraints on the superblock which prevent us from
 278  * writing it out straight away; and given that the journal is about to
 279  * be aborted, we can't rely on the current, or future, transactions to
 280  * write out the superblock safely.
 281  *
 282  * We'll just use the jbd2_journal_abort() error code to record an error in
 283  * the journal instead.  On recovery, the journal will compain about
 284  * that error until we've noted it down and cleared it.
 285  */
 286
 287 static void ext4_handle_error(struct super_block *sb)
 288 {
 289         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 290
 291         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 292         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 293
 294         if (sb->s_flags & MS_RDONLY)
 295                 return;
 296
 297         if (!test_opt(sb, ERRORS_CONT)) {
 298                 journal_t *journal = EXT4_SB(sb)->s_journal;
 299
 300                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 301                 if (journal)
 302                         jbd2_journal_abort(journal, -EIO);
 303         }
 304         if (test_opt(sb, ERRORS_RO)) {
 305                 printk(KERN_CRIT "Remounting filesystem read-only\n");
 306                 sb->s_flags |= MS_RDONLY;
 307         }
 308         ext4_commit_super(sb, es, 1);
 309         if (test_opt(sb, ERRORS_PANIC))
 310                 panic("EXT4-fs (device %s): panic forced after error\n",
 311                         sb->s_id);
 312 }
 313
 314 void ext4_error(struct super_block *sb, const char *function,
 315                 const char *fmt, ...)
 316 {
 317         va_list args;
 318
 319         va_start(args, fmt);
 320         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 321         vprintk(fmt, args);
 322         printk("\n");
 323         va_end(args);
 324
 325         ext4_handle_error(sb);
 326 }
 327
 328 static const char *ext4_decode_error(struct super_block *sb, int errno,
 329                                      char nbuf[16])
 330 {
 331         char *errstr = NULL;
 332
 333         switch (errno) {
 334         case -EIO:
 335                 errstr = "IO failure";
 336                 break;
 337         case -ENOMEM:
 338                 errstr = "Out of memory";
 339                 break;
 340         case -EROFS:
 341                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
 342                         errstr = "Journal has aborted";
 343                 else
 344                         errstr = "Readonly filesystem";
 345                 break;
 346         default:
 347                 /* If the caller passed in an extra buffer for unknown
 348                  * errors, textualise them now.  Else we just return
 349                  * NULL. */
 350                 if (nbuf) {
 351                         /* Check for truncated error codes... */
 352                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 353                                 errstr = nbuf;
 354                 }
 355                 break;
 356         }
 357
 358         return errstr;
 359 }
 360
 361 /* __ext4_std_error decodes expected errors from journaling functions
 362  * automatically and invokes the appropriate error response.  */
 363
 364 void __ext4_std_error(struct super_block *sb, const char *function, int errno)
 365 {
 366         char nbuf[16];
 367         const char *errstr;
 368
 369         /* Special case: if the error is EROFS, and we're not already
 370          * inside a transaction, then there's really no point in logging
 371          * an error. */
 372         if (errno == -EROFS && journal_current_handle() == NULL &&
 373             (sb->s_flags & MS_RDONLY))
 374                 return;
 375
 376         errstr = ext4_decode_error(sb, errno, nbuf);
 377         printk(KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
 378                sb->s_id, function, errstr);
 379
 380         ext4_handle_error(sb);
 381 }
 382
 383 /*
 384  * ext4_abort is a much stronger failure handler than ext4_error.  The
 385  * abort function may be used to deal with unrecoverable failures such
 386  * as journal IO errors or ENOMEM at a critical moment in log management.
 387  *
 388  * We unconditionally force the filesystem into an ABORT|READONLY state,
 389  * unless the error response on the fs has been set to panic in which
 390  * case we take the easy way out and panic immediately.
 391  */
 392
 393 void ext4_abort(struct super_block *sb, const char *function,
 394                 const char *fmt, ...)
 395 {
 396         va_list args;
 397
 398         printk(KERN_CRIT "ext4_abort called.\n");
 399
 400         va_start(args, fmt);
 401         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 402         vprintk(fmt, args);
 403         printk("\n");
 404         va_end(args);
 405
 406         if (test_opt(sb, ERRORS_PANIC))
 407                 panic("EXT4-fs panic from previous error\n");
 408
 409         if (sb->s_flags & MS_RDONLY)
 410                 return;
 411
 412         printk(KERN_CRIT "Remounting filesystem read-only\n");
 413         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 414         sb->s_flags |= MS_RDONLY;
 415         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 416         if (EXT4_SB(sb)->s_journal)
 417                 jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 418 }
 419
 420 void ext4_warning(struct super_block *sb, const char *function,
 421                   const char *fmt, ...)
 422 {
 423         va_list args;
 424
 425         va_start(args, fmt);
 426         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
 427                sb->s_id, function);
 428         vprintk(fmt, args);
 429         printk("\n");
 430         va_end(args);
 431 }
 432
 433 void ext4_grp_locked_error(struct super_block *sb, ext4_group_t grp,
 434                                 const char *function, const char *fmt, ...)
 435 __releases(bitlock)
 436 __acquires(bitlock)
 437 {
 438         va_list args;
 439         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 440
 441         va_start(args, fmt);
 442         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 443         vprintk(fmt, args);
 444         printk("\n");
 445         va_end(args);
 446
 447         if (test_opt(sb, ERRORS_CONT)) {
 448                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 449                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 450                 ext4_commit_super(sb, es, 0);
 451                 return;
 452         }
 453         ext4_unlock_group(sb, grp);
 454         ext4_handle_error(sb);
 455         /*
 456          * We only get here in the ERRORS_RO case; relocking the group
 457          * may be dangerous, but nothing bad will happen since the
 458          * filesystem will have already been marked read/only and the
 459          * journal has been aborted.  We return 1 as a hint to callers
 460          * who might what to use the return value from
 461          * ext4_grp_locked_error() to distinguish beween the
 462          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 463          * aggressively from the ext4 function in question, with a
 464          * more appropriate error code.
 465          */
 466         ext4_lock_group(sb, grp);
 467         return;
 468 }
 469
 470
 471 void ext4_update_dynamic_rev(struct super_block *sb)
 472 {
 473         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 474
 475         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 476                 return;
 477
 478         ext4_warning(sb, __func__,
 479                      "updating to rev %d because of new feature flag, "
 480                      "running e2fsck is recommended",
 481                      EXT4_DYNAMIC_REV);
 482
 483         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 484         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 485         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 486         /* leave es->s_feature_*compat flags alone */
 487         /* es->s_uuid will be set by e2fsck if empty */
 488
 489         /*
 490          * The rest of the superblock fields should be zero, and if not it
 491          * means they are likely already in use, so leave them alone.  We
 492          * can leave it up to e2fsck to clean up any inconsistencies there.
 493          */
 494 }
 495
 496 /*
 497  * Open the external journal device
 498  */
 499 static struct block_device *ext4_blkdev_get(dev_t dev)
 500 {
 501         struct block_device *bdev;
 502         char b[BDEVNAME_SIZE];
 503
 504         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 505         if (IS_ERR(bdev))
 506                 goto fail;
 507         return bdev;
 508
 509 fail:
 510         printk(KERN_ERR "EXT4-fs: failed to open journal device %s: %ld\n",
 511                         __bdevname(dev, b), PTR_ERR(bdev));
 512         return NULL;
 513 }
 514
 515 /*
 516  * Release the journal device
 517  */
 518 static int ext4_blkdev_put(struct block_device *bdev)
 519 {
 520         bd_release(bdev);
 521         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
 522 }
 523
 524 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 525 {
 526         struct block_device *bdev;
 527         int ret = -ENODEV;
 528
 529         bdev = sbi->journal_bdev;
 530         if (bdev) {
 531                 ret = ext4_blkdev_put(bdev);
 532                 sbi->journal_bdev = NULL;
 533         }
 534         return ret;
 535 }
 536
 537 static inline struct inode *orphan_list_entry(struct list_head *l)
 538 {
 539         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 540 }
 541
 542 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 543 {
 544         struct list_head *l;
 545
 546         printk(KERN_ERR "sb orphan head is %d\n",
 547                le32_to_cpu(sbi->s_es->s_last_orphan));
 548
 549         printk(KERN_ERR "sb_info orphan list:\n");
 550         list_for_each(l, &sbi->s_orphan) {
 551                 struct inode *inode = orphan_list_entry(l);
 552                 printk(KERN_ERR "  "
 553                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 554                        inode->i_sb->s_id, inode->i_ino, inode,
 555                        inode->i_mode, inode->i_nlink,
 556                        NEXT_ORPHAN(inode));
 557         }
 558 }
 559
 560 static void ext4_put_super(struct super_block *sb)
 561 {
 562         struct ext4_sb_info *sbi = EXT4_SB(sb);
 563         struct ext4_super_block *es = sbi->s_es;
 564         int i, err;
 565
 566         ext4_mb_release(sb);
 567         ext4_ext_release(sb);
 568         ext4_xattr_put_super(sb);
 569         if (sbi->s_journal) {
 570                 err = jbd2_journal_destroy(sbi->s_journal);
 571                 sbi->s_journal = NULL;
 572                 if (err < 0)
 573                         ext4_abort(sb, __func__,
 574                                    "Couldn't clean up the journal");
 575         }
 576         if (!(sb->s_flags & MS_RDONLY)) {
 577                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 578                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 579                 ext4_commit_super(sb, es, 1);
 580         }
 581         if (sbi->s_proc) {
 582                 remove_proc_entry(sb->s_id, ext4_proc_root);
 583         }
 584         kobject_del(&sbi->s_kobj);
 585
 586         for (i = 0; i < sbi->s_gdb_count; i++)
 587                 brelse(sbi->s_group_desc[i]);
 588         kfree(sbi->s_group_desc);
 589         kfree(sbi->s_flex_groups);
 590         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 591         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 592         percpu_counter_destroy(&sbi->s_dirs_counter);
 593         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
 594         brelse(sbi->s_sbh);
 595 #ifdef CONFIG_QUOTA
 596         for (i = 0; i < MAXQUOTAS; i++)
 597                 kfree(sbi->s_qf_names[i]);
 598 #endif
 599
 600         /* Debugging code just in case the in-memory inode orphan list
 601          * isn't empty.  The on-disk one can be non-empty if we've
 602          * detected an error and taken the fs readonly, but the
 603          * in-memory list had better be clean by this point. */
 604         if (!list_empty(&sbi->s_orphan))
 605                 dump_orphan_list(sb, sbi);
 606         J_ASSERT(list_empty(&sbi->s_orphan));
 607
 608         invalidate_bdev(sb->s_bdev);
 609         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 610                 /*
 611                  * Invalidate the journal device's buffers.  We don't want them
 612                  * floating about in memory - the physical journal device may
 613                  * hotswapped, and it breaks the `ro-after' testing code.
 614                  */
 615                 sync_blockdev(sbi->journal_bdev);
 616                 invalidate_bdev(sbi->journal_bdev);
 617                 ext4_blkdev_remove(sbi);
 618         }
 619         sb->s_fs_info = NULL;
 620         /*
 621          * Now that we are completely done shutting down the
 622          * superblock, we need to actually destroy the kobject.
 623          */
 624         unlock_kernel();
 625         unlock_super(sb);
 626         kobject_put(&sbi->s_kobj);
 627         wait_for_completion(&sbi->s_kobj_unregister);
 628         lock_super(sb);
 629         lock_kernel();
 630         kfree(sbi->s_blockgroup_lock);
 631         kfree(sbi);
 632         return;
 633 }
 634
 635 static struct kmem_cache *ext4_inode_cachep;
 636
 637 /*
 638  * Called inside transaction, so use GFP_NOFS
 639  */
 640 static struct inode *ext4_alloc_inode(struct super_block *sb)
 641 {
 642         struct ext4_inode_info *ei;
 643
 644         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 645         if (!ei)
 646                 return NULL;
 647 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 648         ei->i_acl = EXT4_ACL_NOT_CACHED;
 649         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 650 #endif
 651         ei->vfs_inode.i_version = 1;
 652         ei->vfs_inode.i_data.writeback_index = 0;
 653         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 654         INIT_LIST_HEAD(&ei->i_prealloc_list);
 655         spin_lock_init(&ei->i_prealloc_lock);
 656         /*
 657          * Note:  We can be called before EXT4_SB(sb)->s_journal is set,
 658          * therefore it can be null here.  Don't check it, just initialize
 659          * jinode.
 660          */
 661         jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
 662         ei->i_reserved_data_blocks = 0;
 663         ei->i_reserved_meta_blocks = 0;
 664         ei->i_allocated_meta_blocks = 0;
 665         ei->i_delalloc_reserved_flag = 0;
 666         spin_lock_init(&(ei->i_block_reservation_lock));
 667         return &ei->vfs_inode;
 668 }
 669
 670 static void ext4_destroy_inode(struct inode *inode)
 671 {
 672         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 673                 printk("EXT4 Inode %p: orphan list check failed!\n",
 674                         EXT4_I(inode));
 675                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 676                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 677                                 true);
 678                 dump_stack();
 679         }
 680         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 681 }
 682
 683 static void init_once(void *foo)
 684 {
 685         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 686
 687         INIT_LIST_HEAD(&ei->i_orphan);
 688 #ifdef CONFIG_EXT4_FS_XATTR
 689         init_rwsem(&ei->xattr_sem);
 690 #endif
 691         init_rwsem(&ei->i_data_sem);
 692         inode_init_once(&ei->vfs_inode);
 693 }
 694
 695 static int init_inodecache(void)
 696 {
 697         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 698                                              sizeof(struct ext4_inode_info),
 699                                              0, (SLAB_RECLAIM_ACCOUNT|
 700                                                 SLAB_MEM_SPREAD),
 701                                              init_once);
 702         if (ext4_inode_cachep == NULL)
 703                 return -ENOMEM;
 704         return 0;
 705 }
 706
 707 static void destroy_inodecache(void)
 708 {
 709         kmem_cache_destroy(ext4_inode_cachep);
 710 }
 711
 712 static void ext4_clear_inode(struct inode *inode)
 713 {
 714 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 715         if (EXT4_I(inode)->i_acl &&
 716                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
 717                 posix_acl_release(EXT4_I(inode)->i_acl);
 718                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
 719         }
 720         if (EXT4_I(inode)->i_default_acl &&
 721                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
 722                 posix_acl_release(EXT4_I(inode)->i_default_acl);
 723                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
 724         }
 725 #endif
 726         ext4_discard_preallocations(inode);
 727         if (EXT4_JOURNAL(inode))
 728                 jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
 729                                        &EXT4_I(inode)->jinode);
 730 }
 731
 732 static inline void ext4_show_quota_options(struct seq_file *seq,
 733                                            struct super_block *sb)
 734 {
 735 #if defined(CONFIG_QUOTA)
 736         struct ext4_sb_info *sbi = EXT4_SB(sb);
 737
 738         if (sbi->s_jquota_fmt)
 739                 seq_printf(seq, ",jqfmt=%s",
 740                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold" : "vfsv0");
 741
 742         if (sbi->s_qf_names[USRQUOTA])
 743                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 744
 745         if (sbi->s_qf_names[GRPQUOTA])
 746                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 747
 748         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
 749                 seq_puts(seq, ",usrquota");
 750
 751         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
 752                 seq_puts(seq, ",grpquota");
 753 #endif
 754 }
 755
 756 /*
 757  * Show an option if
 758  *  - it's set to a non-default value OR
 759  *  - if the per-sb default is different from the global default
 760  */
 761 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 762 {
 763         int def_errors;
 764         unsigned long def_mount_opts;
 765         struct super_block *sb = vfs->mnt_sb;
 766         struct ext4_sb_info *sbi = EXT4_SB(sb);
 767         struct ext4_super_block *es = sbi->s_es;
 768
 769         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 770         def_errors     = le16_to_cpu(es->s_errors);
 771
 772         if (sbi->s_sb_block != 1)
 773                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 774         if (test_opt(sb, MINIX_DF))
 775                 seq_puts(seq, ",minixdf");
 776         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
 777                 seq_puts(seq, ",grpid");
 778         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 779                 seq_puts(seq, ",nogrpid");
 780         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 781             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 782                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 783         }
 784         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 785             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 786                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 787         }
 788         if (test_opt(sb, ERRORS_RO)) {
 789                 if (def_errors == EXT4_ERRORS_PANIC ||
 790                     def_errors == EXT4_ERRORS_CONTINUE) {
 791                         seq_puts(seq, ",errors=remount-ro");
 792                 }
 793         }
 794         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
 795                 seq_puts(seq, ",errors=continue");
 796         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
 797                 seq_puts(seq, ",errors=panic");
 798         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
 799                 seq_puts(seq, ",nouid32");
 800         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
 801                 seq_puts(seq, ",debug");
 802         if (test_opt(sb, OLDALLOC))
 803                 seq_puts(seq, ",oldalloc");
 804 #ifdef CONFIG_EXT4_FS_XATTR
 805         if (test_opt(sb, XATTR_USER) &&
 806                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
 807                 seq_puts(seq, ",user_xattr");
 808         if (!test_opt(sb, XATTR_USER) &&
 809             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 810                 seq_puts(seq, ",nouser_xattr");
 811         }
 812 #endif
 813 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 814         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
 815                 seq_puts(seq, ",acl");
 816         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 817                 seq_puts(seq, ",noacl");
 818 #endif
 819         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
 820                 seq_printf(seq, ",commit=%u",
 821                            (unsigned) (sbi->s_commit_interval / HZ));
 822         }
 823         if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
 824                 seq_printf(seq, ",min_batch_time=%u",
 825                            (unsigned) sbi->s_min_batch_time);
 826         }
 827         if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
 828                 seq_printf(seq, ",max_batch_time=%u",
 829                            (unsigned) sbi->s_min_batch_time);
 830         }
 831
 832         /*
 833          * We're changing the default of barrier mount option, so
 834          * let's always display its mount state so it's clear what its
 835          * status is.
 836          */
 837         seq_puts(seq, ",barrier=");
 838         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
 839         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
 840                 seq_puts(seq, ",journal_async_commit");
 841         if (test_opt(sb, NOBH))
 842                 seq_puts(seq, ",nobh");
 843         if (test_opt(sb, I_VERSION))
 844                 seq_puts(seq, ",i_version");
 845         if (!test_opt(sb, DELALLOC))
 846                 seq_puts(seq, ",nodelalloc");
 847
 848
 849         if (sbi->s_stripe)
 850                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
 851         /*
 852          * journal mode get enabled in different ways
 853          * So just print the value even if we didn't specify it
 854          */
 855         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 856                 seq_puts(seq, ",data=journal");
 857         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 858                 seq_puts(seq, ",data=ordered");
 859         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 860                 seq_puts(seq, ",data=writeback");
 861
 862         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
 863                 seq_printf(seq, ",inode_readahead_blks=%u",
 864                            sbi->s_inode_readahead_blks);
 865
 866         if (test_opt(sb, DATA_ERR_ABORT))
 867                 seq_puts(seq, ",data_err=abort");
 868
 869         if (test_opt(sb, NO_AUTO_DA_ALLOC))
 870                 seq_puts(seq, ",noauto_da_alloc");
 871
 872         ext4_show_quota_options(seq, sb);
 873         return 0;
 874 }
 875
 876
 877 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 878                 u64 ino, u32 generation)
 879 {
 880         struct inode *inode;
 881
 882         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 883                 return ERR_PTR(-ESTALE);
 884         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 885                 return ERR_PTR(-ESTALE);
 886
 887         /* iget isn't really right if the inode is currently unallocated!!
 888          *
 889          * ext4_read_inode will return a bad_inode if the inode had been
 890          * deleted, so we should be safe.
 891          *
 892          * Currently we don't know the generation for parent directory, so
 893          * a generation of 0 means "accept any"
 894          */
 895         inode = ext4_iget(sb, ino);
 896         if (IS_ERR(inode))
 897                 return ERR_CAST(inode);
 898         if (generation && inode->i_generation != generation) {
 899                 iput(inode);
 900                 return ERR_PTR(-ESTALE);
 901         }
 902
 903         return inode;
 904 }
 905
 906 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 907                 int fh_len, int fh_type)
 908 {
 909         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 910                                     ext4_nfs_get_inode);
 911 }
 912
 913 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 914                 int fh_len, int fh_type)
 915 {
 916         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 917                                     ext4_nfs_get_inode);
 918 }
 919
 920 /*
 921  * Try to release metadata pages (indirect blocks, directories) which are
 922  * mapped via the block device.  Since these pages could have journal heads
 923  * which would prevent try_to_free_buffers() from freeing them, we must use
 924  * jbd2 layer's try_to_free_buffers() function to release them.
 925  */
 926 static int bdev_try_to_free_page(struct super_block *sb, struct page *page, gfp_t wait)
 927 {
 928         journal_t *journal = EXT4_SB(sb)->s_journal;
 929
 930         WARN_ON(PageChecked(page));
 931         if (!page_has_buffers(page))
 932                 return 0;
 933         if (journal)
 934                 return jbd2_journal_try_to_free_buffers(journal, page,
 935                                                         wait & ~__GFP_WAIT);
 936         return try_to_free_buffers(page);
 937 }
 938
 939 #ifdef CONFIG_QUOTA
 940 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
 941 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 942
 943 static int ext4_write_dquot(struct dquot *dquot);
 944 static int ext4_acquire_dquot(struct dquot *dquot);
 945 static int ext4_release_dquot(struct dquot *dquot);
 946 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 947 static int ext4_write_info(struct super_block *sb, int type);
 948 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 949                                 char *path, int remount);
 950 static int ext4_quota_on_mount(struct super_block *sb, int type);
 951 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 952                                size_t len, loff_t off);
 953 static ssize_t ext4_quota_write(struct super_block *sb, int type,
 954                                 const char *data, size_t len, loff_t off);
 955
 956 static struct dquot_operations ext4_quota_operations = {
 957         .initialize     = dquot_initialize,
 958         .drop           = dquot_drop,
 959         .alloc_space    = dquot_alloc_space,
 960         .reserve_space  = dquot_reserve_space,
 961         .claim_space    = dquot_claim_space,
 962         .release_rsv    = dquot_release_reserved_space,
 963         .get_reserved_space = ext4_get_reserved_space,
 964         .alloc_inode    = dquot_alloc_inode,
 965         .free_space     = dquot_free_space,
 966         .free_inode     = dquot_free_inode,
 967         .transfer       = dquot_transfer,
 968         .write_dquot    = ext4_write_dquot,
 969         .acquire_dquot  = ext4_acquire_dquot,
 970         .release_dquot  = ext4_release_dquot,
 971         .mark_dirty     = ext4_mark_dquot_dirty,
 972         .write_info     = ext4_write_info,
 973         .alloc_dquot    = dquot_alloc,
 974         .destroy_dquot  = dquot_destroy,
 975 };
 976
 977 static struct quotactl_ops ext4_qctl_operations = {
 978         .quota_on       = ext4_quota_on,
 979         .quota_off      = vfs_quota_off,
 980         .quota_sync     = vfs_quota_sync,
 981         .get_info       = vfs_get_dqinfo,
 982         .set_info       = vfs_set_dqinfo,
 983         .get_dqblk      = vfs_get_dqblk,
 984         .set_dqblk      = vfs_set_dqblk
 985 };
 986 #endif
 987
 988 static const struct super_operations ext4_sops = {
 989         .alloc_inode    = ext4_alloc_inode,
 990         .destroy_inode  = ext4_destroy_inode,
 991         .write_inode    = ext4_write_inode,
 992         .dirty_inode    = ext4_dirty_inode,
 993         .delete_inode   = ext4_delete_inode,
 994         .put_super      = ext4_put_super,
 995         .write_super    = ext4_write_super,
 996         .sync_fs        = ext4_sync_fs,
 997         .freeze_fs      = ext4_freeze,
 998         .unfreeze_fs    = ext4_unfreeze,
 999         .statfs         = ext4_statfs,
1000         .remount_fs     = ext4_remount,
1001         .clear_inode    = ext4_clear_inode,
1002         .show_options   = ext4_show_options,
1003 #ifdef CONFIG_QUOTA
1004         .quota_read     = ext4_quota_read,
1005         .quota_write    = ext4_quota_write,
1006 #endif
1007         .bdev_try_to_free_page = bdev_try_to_free_page,
1008 };
1009
1010 static const struct export_operations ext4_export_ops = {
1011         .fh_to_dentry = ext4_fh_to_dentry,
1012         .fh_to_parent = ext4_fh_to_parent,
1013         .get_parent = ext4_get_parent,
1014 };
1015
1016 enum {
1017         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1018         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1019         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1020         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1021         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1022         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1023         Opt_journal_update, Opt_journal_dev,
1024         Opt_journal_checksum, Opt_journal_async_commit,
1025         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1026         Opt_data_err_abort, Opt_data_err_ignore,
1027         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1028         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
1029         Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err, Opt_resize,
1030         Opt_usrquota, Opt_grpquota, Opt_i_version,
1031         Opt_stripe, Opt_delalloc, Opt_nodelalloc,
1032         Opt_inode_readahead_blks, Opt_journal_ioprio
1033 };
1034
1035 static const match_table_t tokens = {
1036         {Opt_bsd_df, "bsddf"},
1037         {Opt_minix_df, "minixdf"},
1038         {Opt_grpid, "grpid"},
1039         {Opt_grpid, "bsdgroups"},
1040         {Opt_nogrpid, "nogrpid"},
1041         {Opt_nogrpid, "sysvgroups"},
1042         {Opt_resgid, "resgid=%u"},
1043         {Opt_resuid, "resuid=%u"},
1044         {Opt_sb, "sb=%u"},
1045         {Opt_err_cont, "errors=continue"},
1046         {Opt_err_panic, "errors=panic"},
1047         {Opt_err_ro, "errors=remount-ro"},
1048         {Opt_nouid32, "nouid32"},
1049         {Opt_debug, "debug"},
1050         {Opt_oldalloc, "oldalloc"},
1051         {Opt_orlov, "orlov"},
1052         {Opt_user_xattr, "user_xattr"},
1053         {Opt_nouser_xattr, "nouser_xattr"},
1054         {Opt_acl, "acl"},
1055         {Opt_noacl, "noacl"},
1056         {Opt_noload, "noload"},
1057         {Opt_nobh, "nobh"},
1058         {Opt_bh, "bh"},
1059         {Opt_commit, "commit=%u"},
1060         {Opt_min_batch_time, "min_batch_time=%u"},
1061         {Opt_max_batch_time, "max_batch_time=%u"},
1062         {Opt_journal_update, "journal=update"},
1063         {Opt_journal_dev, "journal_dev=%u"},
1064         {Opt_journal_checksum, "journal_checksum"},
1065         {Opt_journal_async_commit, "journal_async_commit"},
1066         {Opt_abort, "abort"},
1067         {Opt_data_journal, "data=journal"},
1068         {Opt_data_ordered, "data=ordered"},
1069         {Opt_data_writeback, "data=writeback"},
1070         {Opt_data_err_abort, "data_err=abort"},
1071         {Opt_data_err_ignore, "data_err=ignore"},
1072         {Opt_offusrjquota, "usrjquota="},
1073         {Opt_usrjquota, "usrjquota=%s"},
1074         {Opt_offgrpjquota, "grpjquota="},
1075         {Opt_grpjquota, "grpjquota=%s"},
1076         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1077         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1078         {Opt_grpquota, "grpquota"},
1079         {Opt_noquota, "noquota"},
1080         {Opt_quota, "quota"},
1081         {Opt_usrquota, "usrquota"},
1082         {Opt_barrier, "barrier=%u"},
1083         {Opt_barrier, "barrier"},
1084         {Opt_nobarrier, "nobarrier"},
1085         {Opt_i_version, "i_version"},
1086         {Opt_stripe, "stripe=%u"},
1087         {Opt_resize, "resize"},
1088         {Opt_delalloc, "delalloc"},
1089         {Opt_nodelalloc, "nodelalloc"},
1090         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1091         {Opt_journal_ioprio, "journal_ioprio=%u"},
1092         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1093         {Opt_auto_da_alloc, "auto_da_alloc"},
1094         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1095         {Opt_err, NULL},
1096 };
1097
1098 static ext4_fsblk_t get_sb_block(void **data)
1099 {
1100         ext4_fsblk_t    sb_block;
1101         char            *options = (char *) *data;
1102
1103         if (!options || strncmp(options, "sb=", 3) != 0)
1104                 return 1;       /* Default location */
1105         options += 3;
1106         /*todo: use simple_strtoll with >32bit ext4 */
1107         sb_block = simple_strtoul(options, &options, 0);
1108         if (*options && *options != ',') {
1109                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1110                        (char *) *data);
1111                 return 1;
1112         }
1113         if (*options == ',')
1114                 options++;
1115         *data = (void *) options;
1116         return sb_block;
1117 }
1118
1119 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1120
1121 static int parse_options(char *options, struct super_block *sb,
1122                          unsigned long *journal_devnum,
1123                          unsigned int *journal_ioprio,
1124                          ext4_fsblk_t *n_blocks_count, int is_remount)
1125 {
1126         struct ext4_sb_info *sbi = EXT4_SB(sb);
1127         char *p;
1128         substring_t args[MAX_OPT_ARGS];
1129         int data_opt = 0;
1130         int option;
1131 #ifdef CONFIG_QUOTA
1132         int qtype, qfmt;
1133         char *qname;
1134 #endif
1135
1136         if (!options)
1137                 return 1;
1138
1139         while ((p = strsep(&options, ",")) != NULL) {
1140                 int token;
1141                 if (!*p)
1142                         continue;
1143
1144                 token = match_token(p, tokens, args);
1145                 switch (token) {
1146                 case Opt_bsd_df:
1147                         clear_opt(sbi->s_mount_opt, MINIX_DF);
1148                         break;
1149                 case Opt_minix_df:
1150                         set_opt(sbi->s_mount_opt, MINIX_DF);
1151                         break;
1152                 case Opt_grpid:
1153                         set_opt(sbi->s_mount_opt, GRPID);
1154                         break;
1155                 case Opt_nogrpid:
1156                         clear_opt(sbi->s_mount_opt, GRPID);
1157                         break;
1158                 case Opt_resuid:
1159                         if (match_int(&args[0], &option))
1160                                 return 0;
1161                         sbi->s_resuid = option;
1162                         break;
1163                 case Opt_resgid:
1164                         if (match_int(&args[0], &option))
1165                                 return 0;
1166                         sbi->s_resgid = option;
1167                         break;
1168                 case Opt_sb:
1169                         /* handled by get_sb_block() instead of here */
1170                         /* *sb_block = match_int(&args[0]); */
1171                         break;
1172                 case Opt_err_panic:
1173                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1174                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1175                         set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1176                         break;
1177                 case Opt_err_ro:
1178                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1179                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1180                         set_opt(sbi->s_mount_opt, ERRORS_RO);
1181                         break;
1182                 case Opt_err_cont:
1183                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1184                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1185                         set_opt(sbi->s_mount_opt, ERRORS_CONT);
1186                         break;
1187                 case Opt_nouid32:
1188                         set_opt(sbi->s_mount_opt, NO_UID32);
1189                         break;
1190                 case Opt_debug:
1191                         set_opt(sbi->s_mount_opt, DEBUG);
1192                         break;
1193                 case Opt_oldalloc:
1194                         set_opt(sbi->s_mount_opt, OLDALLOC);
1195                         break;
1196                 case Opt_orlov:
1197                         clear_opt(sbi->s_mount_opt, OLDALLOC);
1198                         break;
1199 #ifdef CONFIG_EXT4_FS_XATTR
1200                 case Opt_user_xattr:
1201                         set_opt(sbi->s_mount_opt, XATTR_USER);
1202                         break;
1203                 case Opt_nouser_xattr:
1204                         clear_opt(sbi->s_mount_opt, XATTR_USER);
1205                         break;
1206 #else
1207                 case Opt_user_xattr:
1208                 case Opt_nouser_xattr:
1209                         printk(KERN_ERR "EXT4 (no)user_xattr options "
1210                                "not supported\n");
1211                         break;
1212 #endif
1213 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1214                 case Opt_acl:
1215                         set_opt(sbi->s_mount_opt, POSIX_ACL);
1216                         break;
1217                 case Opt_noacl:
1218                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
1219                         break;
1220 #else
1221                 case Opt_acl:
1222                 case Opt_noacl:
1223                         printk(KERN_ERR "EXT4 (no)acl options "
1224                                "not supported\n");
1225                         break;
1226 #endif
1227                 case Opt_journal_update:
1228                         /* @@@ FIXME */
1229                         /* Eventually we will want to be able to create
1230                            a journal file here.  For now, only allow the
1231                            user to specify an existing inode to be the
1232                            journal file. */
1233                         if (is_remount) {
1234                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1235                                        "journal on remount\n");
1236                                 return 0;
1237                         }
1238                         set_opt(sbi->s_mount_opt, UPDATE_JOURNAL);
1239                         break;
1240                 case Opt_journal_dev:
1241                         if (is_remount) {
1242                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1243                                        "journal on remount\n");
1244                                 return 0;
1245                         }
1246                         if (match_int(&args[0], &option))
1247                                 return 0;
1248                         *journal_devnum = option;
1249                         break;
1250                 case Opt_journal_checksum:
1251                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1252                         break;
1253                 case Opt_journal_async_commit:
1254                         set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1255                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1256                         break;
1257                 case Opt_noload:
1258                         set_opt(sbi->s_mount_opt, NOLOAD);
1259                         break;
1260                 case Opt_commit:
1261                         if (match_int(&args[0], &option))
1262                                 return 0;
1263                         if (option < 0)
1264                                 return 0;
1265                         if (option == 0)
1266                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1267                         sbi->s_commit_interval = HZ * option;
1268                         break;
1269                 case Opt_max_batch_time:
1270                         if (match_int(&args[0], &option))
1271                                 return 0;
1272                         if (option < 0)
1273                                 return 0;
1274                         if (option == 0)
1275                                 option = EXT4_DEF_MAX_BATCH_TIME;
1276                         sbi->s_max_batch_time = option;
1277                         break;
1278                 case Opt_min_batch_time:
1279                         if (match_int(&args[0], &option))
1280                                 return 0;
1281                         if (option < 0)
1282                                 return 0;
1283                         sbi->s_min_batch_time = option;
1284                         break;
1285                 case Opt_data_journal:
1286                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1287                         goto datacheck;
1288                 case Opt_data_ordered:
1289                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1290                         goto datacheck;
1291                 case Opt_data_writeback:
1292                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1293                 datacheck:
1294                         if (is_remount) {
1295                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1296                                                 != data_opt) {
1297                                         printk(KERN_ERR
1298                                                 "EXT4-fs: cannot change data "
1299                                                 "mode on remount\n");
1300                                         return 0;
1301                                 }
1302                         } else {
1303                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1304                                 sbi->s_mount_opt |= data_opt;
1305                         }
1306                         break;
1307                 case Opt_data_err_abort:
1308                         set_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1309                         break;
1310                 case Opt_data_err_ignore:
1311                         clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1312                         break;
1313 #ifdef CONFIG_QUOTA
1314                 case Opt_usrjquota:
1315                         qtype = USRQUOTA;
1316                         goto set_qf_name;
1317                 case Opt_grpjquota:
1318                         qtype = GRPQUOTA;
1319 set_qf_name:
1320                         if (sb_any_quota_loaded(sb) &&
1321                             !sbi->s_qf_names[qtype]) {
1322                                 printk(KERN_ERR
1323                                        "EXT4-fs: Cannot change journaled "
1324                                        "quota options when quota turned on.\n");
1325                                 return 0;
1326                         }
1327                         qname = match_strdup(&args[0]);
1328                         if (!qname) {
1329                                 printk(KERN_ERR
1330                                         "EXT4-fs: not enough memory for "
1331                                         "storing quotafile name.\n");
1332                                 return 0;
1333                         }
1334                         if (sbi->s_qf_names[qtype] &&
1335                             strcmp(sbi->s_qf_names[qtype], qname)) {
1336                                 printk(KERN_ERR
1337                                         "EXT4-fs: %s quota file already "
1338                                         "specified.\n", QTYPE2NAME(qtype));
1339                                 kfree(qname);
1340                                 return 0;
1341                         }
1342                         sbi->s_qf_names[qtype] = qname;
1343                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1344                                 printk(KERN_ERR
1345                                         "EXT4-fs: quotafile must be on "
1346                                         "filesystem root.\n");
1347                                 kfree(sbi->s_qf_names[qtype]);
1348                                 sbi->s_qf_names[qtype] = NULL;
1349                                 return 0;
1350                         }
1351                         set_opt(sbi->s_mount_opt, QUOTA);
1352                         break;
1353                 case Opt_offusrjquota:
1354                         qtype = USRQUOTA;
1355                         goto clear_qf_name;
1356                 case Opt_offgrpjquota:
1357                         qtype = GRPQUOTA;
1358 clear_qf_name:
1359                         if (sb_any_quota_loaded(sb) &&
1360                             sbi->s_qf_names[qtype]) {
1361                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1362                                         "journaled quota options when "
1363                                         "quota turned on.\n");
1364                                 return 0;
1365                         }
1366                         /*
1367                          * The space will be released later when all options
1368                          * are confirmed to be correct
1369                          */
1370                         sbi->s_qf_names[qtype] = NULL;
1371                         break;
1372                 case Opt_jqfmt_vfsold:
1373                         qfmt = QFMT_VFS_OLD;
1374                         goto set_qf_format;
1375                 case Opt_jqfmt_vfsv0:
1376                         qfmt = QFMT_VFS_V0;
1377 set_qf_format:
1378                         if (sb_any_quota_loaded(sb) &&
1379                             sbi->s_jquota_fmt != qfmt) {
1380                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1381                                         "journaled quota options when "
1382                                         "quota turned on.\n");
1383                                 return 0;
1384                         }
1385                         sbi->s_jquota_fmt = qfmt;
1386                         break;
1387                 case Opt_quota:
1388                 case Opt_usrquota:
1389                         set_opt(sbi->s_mount_opt, QUOTA);
1390                         set_opt(sbi->s_mount_opt, USRQUOTA);
1391                         break;
1392                 case Opt_grpquota:
1393                         set_opt(sbi->s_mount_opt, QUOTA);
1394                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1395                         break;
1396                 case Opt_noquota:
1397                         if (sb_any_quota_loaded(sb)) {
1398                                 printk(KERN_ERR "EXT4-fs: Cannot change quota "
1399                                         "options when quota turned on.\n");
1400                                 return 0;
1401                         }
1402                         clear_opt(sbi->s_mount_opt, QUOTA);
1403                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1404                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1405                         break;
1406 #else
1407                 case Opt_quota:
1408                 case Opt_usrquota:
1409                 case Opt_grpquota:
1410                         printk(KERN_ERR
1411                                 "EXT4-fs: quota options not supported.\n");
1412                         break;
1413                 case Opt_usrjquota:
1414                 case Opt_grpjquota:
1415                 case Opt_offusrjquota:
1416                 case Opt_offgrpjquota:
1417                 case Opt_jqfmt_vfsold:
1418                 case Opt_jqfmt_vfsv0:
1419                         printk(KERN_ERR
1420                                 "EXT4-fs: journaled quota options not "
1421                                 "supported.\n");
1422                         break;
1423                 case Opt_noquota:
1424                         break;
1425 #endif
1426                 case Opt_abort:
1427                         set_opt(sbi->s_mount_opt, ABORT);
1428                         break;
1429                 case Opt_nobarrier:
1430                         clear_opt(sbi->s_mount_opt, BARRIER);
1431                         break;
1432                 case Opt_barrier:
1433                         if (match_int(&args[0], &option)) {
1434                                 set_opt(sbi->s_mount_opt, BARRIER);
1435                                 break;
1436                         }
1437                         if (option)
1438                                 set_opt(sbi->s_mount_opt, BARRIER);
1439                         else
1440                                 clear_opt(sbi->s_mount_opt, BARRIER);
1441                         break;
1442                 case Opt_ignore:
1443                         break;
1444                 case Opt_resize:
1445                         if (!is_remount) {
1446                                 printk("EXT4-fs: resize option only available "
1447                                         "for remount\n");
1448                                 return 0;
1449                         }
1450                         if (match_int(&args[0], &option) != 0)
1451                                 return 0;
1452                         *n_blocks_count = option;
1453                         break;
1454                 case Opt_nobh:
1455                         set_opt(sbi->s_mount_opt, NOBH);
1456                         break;
1457                 case Opt_bh:
1458                         clear_opt(sbi->s_mount_opt, NOBH);
1459                         break;
1460                 case Opt_i_version:
1461                         set_opt(sbi->s_mount_opt, I_VERSION);
1462                         sb->s_flags |= MS_I_VERSION;
1463                         break;
1464                 case Opt_nodelalloc:
1465                         clear_opt(sbi->s_mount_opt, DELALLOC);
1466                         break;
1467                 case Opt_stripe:
1468                         if (match_int(&args[0], &option))
1469                                 return 0;
1470                         if (option < 0)
1471                                 return 0;
1472                         sbi->s_stripe = option;
1473                         break;
1474                 case Opt_delalloc:
1475                         set_opt(sbi->s_mount_opt, DELALLOC);
1476                         break;
1477                 case Opt_inode_readahead_blks:
1478                         if (match_int(&args[0], &option))
1479                                 return 0;
1480                         if (option < 0 || option > (1 << 30))
1481                                 return 0;
1482                         if (option & (option - 1)) {
1483                                 printk(KERN_ERR "EXT4-fs: inode_readahead_blks"
1484                                        " must be a power of 2\n");
1485                                 return 0;
1486                         }
1487                         sbi->s_inode_readahead_blks = option;
1488                         break;
1489                 case Opt_journal_ioprio:
1490                         if (match_int(&args[0], &option))
1491                                 return 0;
1492                         if (option < 0 || option > 7)
1493                                 break;
1494                         *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1495                                                             option);
1496                         break;
1497                 case Opt_noauto_da_alloc:
1498                         set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1499                         break;
1500                 case Opt_auto_da_alloc:
1501                         if (match_int(&args[0], &option)) {
1502                                 clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1503                                 break;
1504                         }
1505                         if (option)
1506                                 clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1507                         else
1508                                 set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1509                         break;
1510                 default:
1511                         printk(KERN_ERR
1512                                "EXT4-fs: Unrecognized mount option \"%s\" "
1513                                "or missing value\n", p);
1514                         return 0;
1515                 }
1516         }
1517 #ifdef CONFIG_QUOTA
1518         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1519                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1520                      sbi->s_qf_names[USRQUOTA])
1521                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1522
1523                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1524                      sbi->s_qf_names[GRPQUOTA])
1525                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1526
1527                 if ((sbi->s_qf_names[USRQUOTA] &&
1528                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1529                     (sbi->s_qf_names[GRPQUOTA] &&
1530                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1531                         printk(KERN_ERR "EXT4-fs: old and new quota "
1532                                         "format mixing.\n");
1533                         return 0;
1534                 }
1535
1536                 if (!sbi->s_jquota_fmt) {
1537                         printk(KERN_ERR "EXT4-fs: journaled quota format "
1538                                         "not specified.\n");
1539                         return 0;
1540                 }
1541         } else {
1542                 if (sbi->s_jquota_fmt) {
1543                         printk(KERN_ERR "EXT4-fs: journaled quota format "
1544                                         "specified with no journaling "
1545                                         "enabled.\n");
1546                         return 0;
1547                 }
1548         }
1549 #endif
1550         return 1;
1551 }
1552
1553 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1554                             int read_only)
1555 {
1556         struct ext4_sb_info *sbi = EXT4_SB(sb);
1557         int res = 0;
1558
1559         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1560                 printk(KERN_ERR "EXT4-fs warning: revision level too high, "
1561                        "forcing read-only mode\n");
1562                 res = MS_RDONLY;
1563         }
1564         if (read_only)
1565                 return res;
1566         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1567                 printk(KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1568                        "running e2fsck is recommended\n");
1569         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1570                 printk(KERN_WARNING
1571                        "EXT4-fs warning: mounting fs with errors, "
1572                        "running e2fsck is recommended\n");
1573         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1574                  le16_to_cpu(es->s_mnt_count) >=
1575                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1576                 printk(KERN_WARNING
1577                        "EXT4-fs warning: maximal mount count reached, "
1578                        "running e2fsck is recommended\n");
1579         else if (le32_to_cpu(es->s_checkinterval) &&
1580                 (le32_to_cpu(es->s_lastcheck) +
1581                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1582                 printk(KERN_WARNING
1583                        "EXT4-fs warning: checktime reached, "
1584                        "running e2fsck is recommended\n");
1585         if (!sbi->s_journal)
1586                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1587         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1588                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1589         le16_add_cpu(&es->s_mnt_count, 1);
1590         es->s_mtime = cpu_to_le32(get_seconds());
1591         ext4_update_dynamic_rev(sb);
1592         if (sbi->s_journal)
1593                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1594
1595         ext4_commit_super(sb, es, 1);
1596         if (test_opt(sb, DEBUG))
1597                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1598                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1599                         sb->s_blocksize,
1600                         sbi->s_groups_count,
1601                         EXT4_BLOCKS_PER_GROUP(sb),
1602                         EXT4_INODES_PER_GROUP(sb),
1603                         sbi->s_mount_opt);
1604
1605         if (EXT4_SB(sb)->s_journal) {
1606                 printk(KERN_INFO "EXT4 FS on %s, %s journal on %s\n",
1607                        sb->s_id, EXT4_SB(sb)->s_journal->j_inode ? "internal" :
1608                        "external", EXT4_SB(sb)->s_journal->j_devname);
1609         } else {
1610                 printk(KERN_INFO "EXT4 FS on %s, no journal\n", sb->s_id);
1611         }
1612         return res;
1613 }
1614
1615 static int ext4_fill_flex_info(struct super_block *sb)
1616 {
1617         struct ext4_sb_info *sbi = EXT4_SB(sb);
1618         struct ext4_group_desc *gdp = NULL;
1619         struct buffer_head *bh;
1620         ext4_group_t flex_group_count;
1621         ext4_group_t flex_group;
1622         int groups_per_flex = 0;
1623         int i;
1624
1625         if (!sbi->s_es->s_log_groups_per_flex) {
1626                 sbi->s_log_groups_per_flex = 0;
1627                 return 1;
1628         }
1629
1630         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1631         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1632
1633         /* We allocate both existing and potentially added groups */
1634         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1635                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1636                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1637         sbi->s_flex_groups = kzalloc(flex_group_count *
1638                                      sizeof(struct flex_groups), GFP_KERNEL);
1639         if (sbi->s_flex_groups == NULL) {
1640                 printk(KERN_ERR "EXT4-fs: not enough memory for "
1641                                 "%u flex groups\n", flex_group_count);
1642                 goto failed;
1643         }
1644
1645         for (i = 0; i < sbi->s_groups_count; i++) {
1646                 gdp = ext4_get_group_desc(sb, i, &bh);
1647
1648                 flex_group = ext4_flex_group(sbi, i);
1649                 atomic_set(&sbi->s_flex_groups[flex_group].free_inodes,
1650                            ext4_free_inodes_count(sb, gdp));
1651                 atomic_set(&sbi->s_flex_groups[flex_group].free_blocks,
1652                            ext4_free_blks_count(sb, gdp));
1653                 atomic_set(&sbi->s_flex_groups[flex_group].used_dirs,
1654                            ext4_used_dirs_count(sb, gdp));
1655         }
1656
1657         return 1;
1658 failed:
1659         return 0;
1660 }
1661
1662 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1663                             struct ext4_group_desc *gdp)
1664 {
1665         __u16 crc = 0;
1666
1667         if (sbi->s_es->s_feature_ro_compat &
1668             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1669                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1670                 __le32 le_group = cpu_to_le32(block_group);
1671
1672                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1673                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1674                 crc = crc16(crc, (__u8 *)gdp, offset);
1675                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1676                 /* for checksum of struct ext4_group_desc do the rest...*/
1677                 if ((sbi->s_es->s_feature_incompat &
1678                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1679                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1680                         crc = crc16(crc, (__u8 *)gdp + offset,
1681                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1682                                         offset);
1683         }
1684
1685         return cpu_to_le16(crc);
1686 }
1687
1688 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1689                                 struct ext4_group_desc *gdp)
1690 {
1691         if ((sbi->s_es->s_feature_ro_compat &
1692              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1693             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1694                 return 0;
1695
1696         return 1;
1697 }
1698
1699 /* Called at mount-time, super-block is locked */
1700 static int ext4_check_descriptors(struct super_block *sb)
1701 {
1702         struct ext4_sb_info *sbi = EXT4_SB(sb);
1703         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1704         ext4_fsblk_t last_block;
1705         ext4_fsblk_t block_bitmap;
1706         ext4_fsblk_t inode_bitmap;
1707         ext4_fsblk_t inode_table;
1708         int flexbg_flag = 0;
1709         ext4_group_t i;
1710
1711         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1712                 flexbg_flag = 1;
1713
1714         ext4_debug("Checking group descriptors");
1715
1716         for (i = 0; i < sbi->s_groups_count; i++) {
1717                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1718
1719                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1720                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1721                 else
1722                         last_block = first_block +
1723                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1724
1725                 block_bitmap = ext4_block_bitmap(sb, gdp);
1726                 if (block_bitmap < first_block || block_bitmap > last_block) {
1727                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1728                                "Block bitmap for group %u not in group "
1729                                "(block %llu)!\n", i, block_bitmap);
1730                         return 0;
1731                 }
1732                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1733                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
1734                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1735                                "Inode bitmap for group %u not in group "
1736                                "(block %llu)!\n", i, inode_bitmap);
1737                         return 0;
1738                 }
1739                 inode_table = ext4_inode_table(sb, gdp);
1740                 if (inode_table < first_block ||
1741                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
1742                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1743                                "Inode table for group %u not in group "
1744                                "(block %llu)!\n", i, inode_table);
1745                         return 0;
1746                 }
1747                 spin_lock(sb_bgl_lock(sbi, i));
1748                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1749                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1750                                "Checksum for group %u failed (%u!=%u)\n",
1751                                i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1752                                gdp)), le16_to_cpu(gdp->bg_checksum));
1753                         if (!(sb->s_flags & MS_RDONLY)) {
1754                                 spin_unlock(sb_bgl_lock(sbi, i));
1755                                 return 0;
1756                         }
1757                 }
1758                 spin_unlock(sb_bgl_lock(sbi, i));
1759                 if (!flexbg_flag)
1760                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1761         }
1762
1763         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1764         sbi->s_es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
1765         return 1;
1766 }
1767
1768 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1769  * the superblock) which were deleted from all directories, but held open by
1770  * a process at the time of a crash.  We walk the list and try to delete these
1771  * inodes at recovery time (only with a read-write filesystem).
1772  *
1773  * In order to keep the orphan inode chain consistent during traversal (in
1774  * case of crash during recovery), we link each inode into the superblock
1775  * orphan list_head and handle it the same way as an inode deletion during
1776  * normal operation (which journals the operations for us).
1777  *
1778  * We only do an iget() and an iput() on each inode, which is very safe if we
1779  * accidentally point at an in-use or already deleted inode.  The worst that
1780  * can happen in this case is that we get a "bit already cleared" message from
1781  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1782  * e2fsck was run on this filesystem, and it must have already done the orphan
1783  * inode cleanup for us, so we can safely abort without any further action.
1784  */
1785 static void ext4_orphan_cleanup(struct super_block *sb,
1786                                 struct ext4_super_block *es)
1787 {
1788         unsigned int s_flags = sb->s_flags;
1789         int nr_orphans = 0, nr_truncates = 0;
1790 #ifdef CONFIG_QUOTA
1791         int i;
1792 #endif
1793         if (!es->s_last_orphan) {
1794                 jbd_debug(4, "no orphan inodes to clean up\n");
1795                 return;
1796         }
1797
1798         if (bdev_read_only(sb->s_bdev)) {
1799                 printk(KERN_ERR "EXT4-fs: write access "
1800                         "unavailable, skipping orphan cleanup.\n");
1801                 return;
1802         }
1803
1804         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1805                 if (es->s_last_orphan)
1806                         jbd_debug(1, "Errors on filesystem, "
1807                                   "clearing orphan list.\n");
1808                 es->s_last_orphan = 0;
1809                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1810                 return;
1811         }
1812
1813         if (s_flags & MS_RDONLY) {
1814                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1815                        sb->s_id);
1816                 sb->s_flags &= ~MS_RDONLY;
1817         }
1818 #ifdef CONFIG_QUOTA
1819         /* Needed for iput() to work correctly and not trash data */
1820         sb->s_flags |= MS_ACTIVE;
1821         /* Turn on quotas so that they are updated correctly */
1822         for (i = 0; i < MAXQUOTAS; i++) {
1823                 if (EXT4_SB(sb)->s_qf_names[i]) {
1824                         int ret = ext4_quota_on_mount(sb, i);
1825                         if (ret < 0)
1826                                 printk(KERN_ERR
1827                                         "EXT4-fs: Cannot turn on journaled "
1828                                         "quota: error %d\n", ret);
1829                 }
1830         }
1831 #endif
1832
1833         while (es->s_last_orphan) {
1834                 struct inode *inode;
1835
1836                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
1837                 if (IS_ERR(inode)) {
1838                         es->s_last_orphan = 0;
1839                         break;
1840                 }
1841
1842                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1843                 vfs_dq_init(inode);
1844                 if (inode->i_nlink) {
1845                         printk(KERN_DEBUG
1846                                 "%s: truncating inode %lu to %lld bytes\n",
1847                                 __func__, inode->i_ino, inode->i_size);
1848                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
1849                                   inode->i_ino, inode->i_size);
1850                         ext4_truncate(inode);
1851                         nr_truncates++;
1852                 } else {
1853                         printk(KERN_DEBUG
1854                                 "%s: deleting unreferenced inode %lu\n",
1855                                 __func__, inode->i_ino);
1856                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1857                                   inode->i_ino);
1858                         nr_orphans++;
1859                 }
1860                 iput(inode);  /* The delete magic happens here! */
1861         }
1862
1863 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
1864
1865         if (nr_orphans)
1866                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1867                        sb->s_id, PLURAL(nr_orphans));
1868         if (nr_truncates)
1869                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1870                        sb->s_id, PLURAL(nr_truncates));
1871 #ifdef CONFIG_QUOTA
1872         /* Turn quotas off */
1873         for (i = 0; i < MAXQUOTAS; i++) {
1874                 if (sb_dqopt(sb)->files[i])
1875                         vfs_quota_off(sb, i, 0);
1876         }
1877 #endif
1878         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1879 }
1880 /*
1881  * Maximal extent format file size.
1882  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1883  * extent format containers, within a sector_t, and within i_blocks
1884  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1885  * so that won't be a limiting factor.
1886  *
1887  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1888  */
1889 static loff_t ext4_max_size(int blkbits, int has_huge_files)
1890 {
1891         loff_t res;
1892         loff_t upper_limit = MAX_LFS_FILESIZE;
1893
1894         /* small i_blocks in vfs inode? */
1895         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1896                 /*
1897                  * CONFIG_LBD is not enabled implies the inode
1898                  * i_block represent total blocks in 512 bytes
1899                  * 32 == size of vfs inode i_blocks * 8
1900                  */
1901                 upper_limit = (1LL << 32) - 1;
1902
1903                 /* total blocks in file system block size */
1904                 upper_limit >>= (blkbits - 9);
1905                 upper_limit <<= blkbits;
1906         }
1907
1908         /* 32-bit extent-start container, ee_block */
1909         res = 1LL << 32;
1910         res <<= blkbits;
1911         res -= 1;
1912
1913         /* Sanity check against vm- & vfs- imposed limits */
1914         if (res > upper_limit)
1915                 res = upper_limit;
1916
1917         return res;
1918 }
1919
1920 /*
1921  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
1922  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
1923  * We need to be 1 filesystem block less than the 2^48 sector limit.
1924  */
1925 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
1926 {
1927         loff_t res = EXT4_NDIR_BLOCKS;
1928         int meta_blocks;
1929         loff_t upper_limit;
1930         /* This is calculated to be the largest file size for a
1931          * dense, bitmapped file such that the total number of
1932          * sectors in the file, including data and all indirect blocks,
1933          * does not exceed 2^48 -1
1934          * __u32 i_blocks_lo and _u16 i_blocks_high representing the
1935          * total number of  512 bytes blocks of the file
1936          */
1937
1938         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1939                 /*
1940                  * !has_huge_files or CONFIG_LBD is not enabled
1941                  * implies the inode i_block represent total blocks in
1942                  * 512 bytes 32 == size of vfs inode i_blocks * 8
1943                  */
1944                 upper_limit = (1LL << 32) - 1;
1945
1946                 /* total blocks in file system block size */
1947                 upper_limit >>= (bits - 9);
1948
1949         } else {
1950                 /*
1951                  * We use 48 bit ext4_inode i_blocks
1952                  * With EXT4_HUGE_FILE_FL set the i_blocks
1953                  * represent total number of blocks in
1954                  * file system block size
1955                  */
1956                 upper_limit = (1LL << 48) - 1;
1957
1958         }
1959
1960         /* indirect blocks */
1961         meta_blocks = 1;
1962         /* double indirect blocks */
1963         meta_blocks += 1 + (1LL << (bits-2));
1964         /* tripple indirect blocks */
1965         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
1966
1967         upper_limit -= meta_blocks;
1968         upper_limit <<= bits;
1969
1970         res += 1LL << (bits-2);
1971         res += 1LL << (2*(bits-2));
1972         res += 1LL << (3*(bits-2));
1973         res <<= bits;
1974         if (res > upper_limit)
1975                 res = upper_limit;
1976
1977         if (res > MAX_LFS_FILESIZE)
1978                 res = MAX_LFS_FILESIZE;
1979
1980         return res;
1981 }
1982
1983 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1984                                 ext4_fsblk_t logical_sb_block, int nr)
1985 {
1986         struct ext4_sb_info *sbi = EXT4_SB(sb);
1987         ext4_group_t bg, first_meta_bg;
1988         int has_super = 0;
1989
1990         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1991
1992         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1993             nr < first_meta_bg)
1994                 return logical_sb_block + nr + 1;
1995         bg = sbi->s_desc_per_block * nr;
1996         if (ext4_bg_has_super(sb, bg))
1997                 has_super = 1;
1998         return (has_super + ext4_group_first_block_no(sb, bg));
1999 }
2000
2001 /**
2002  * ext4_get_stripe_size: Get the stripe size.
2003  * @sbi: In memory super block info
2004  *
2005  * If we have specified it via mount option, then
2006  * use the mount option value. If the value specified at mount time is
2007  * greater than the blocks per group use the super block value.
2008  * If the super block value is greater than blocks per group return 0.
2009  * Allocator needs it be less than blocks per group.
2010  *
2011  */
2012 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2013 {
2014         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2015         unsigned long stripe_width =
2016                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2017
2018         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2019                 return sbi->s_stripe;
2020
2021         if (stripe_width <= sbi->s_blocks_per_group)
2022                 return stripe_width;
2023
2024         if (stride <= sbi->s_blocks_per_group)
2025                 return stride;
2026
2027         return 0;
2028 }
2029
2030 /* sysfs supprt */
2031
2032 struct ext4_attr {
2033         struct attribute attr;
2034         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2035         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2036                          const char *, size_t);
2037         int offset;
2038 };
2039
2040 static int parse_strtoul(const char *buf,
2041                 unsigned long max, unsigned long *value)
2042 {
2043         char *endp;
2044
2045         while (*buf && isspace(*buf))
2046                 buf++;
2047         *value = simple_strtoul(buf, &endp, 0);
2048         while (*endp && isspace(*endp))
2049                 endp++;
2050         if (*endp || *value > max)
2051                 return -EINVAL;
2052
2053         return 0;
2054 }
2055
2056 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2057                                               struct ext4_sb_info *sbi,
2058                                               char *buf)
2059 {
2060         return snprintf(buf, PAGE_SIZE, "%llu\n",
2061                         (s64) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2062 }
2063
2064 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2065                                          struct ext4_sb_info *sbi, char *buf)
2066 {
2067         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2068
2069         return snprintf(buf, PAGE_SIZE, "%lu\n",
2070                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2071                          sbi->s_sectors_written_start) >> 1);
2072 }
2073
2074 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2075                                           struct ext4_sb_info *sbi, char *buf)
2076 {
2077         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2078
2079         return snprintf(buf, PAGE_SIZE, "%llu\n",
2080                         sbi->s_kbytes_written +
2081                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2082                           EXT4_SB(sb)->s_sectors_written_start) >> 1));
2083 }
2084
2085 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2086                                           struct ext4_sb_info *sbi,
2087                                           const char *buf, size_t count)
2088 {
2089         unsigned long t;
2090
2091         if (parse_strtoul(buf, 0x40000000, &t))
2092                 return -EINVAL;
2093
2094         /* inode_readahead_blks must be a power of 2 */
2095         if (t & (t-1))
2096                 return -EINVAL;
2097
2098         sbi->s_inode_readahead_blks = t;
2099         return count;
2100 }
2101
2102 static ssize_t sbi_ui_show(struct ext4_attr *a,
2103                                 struct ext4_sb_info *sbi, char *buf)
2104 {
2105         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2106
2107         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2108 }
2109
2110 static ssize_t sbi_ui_store(struct ext4_attr *a,
2111                             struct ext4_sb_info *sbi,
2112                             const char *buf, size_t count)
2113 {
2114         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2115         unsigned long t;
2116
2117         if (parse_strtoul(buf, 0xffffffff, &t))
2118                 return -EINVAL;
2119         *ui = t;
2120         return count;
2121 }
2122
2123 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2124 static struct ext4_attr ext4_attr_##_name = {                   \
2125         .attr = {.name = __stringify(_name), .mode = _mode },   \
2126         .show   = _show,                                        \
2127         .store  = _store,                                       \
2128         .offset = offsetof(struct ext4_sb_info, _elname),       \
2129 }
2130 #define EXT4_ATTR(name, mode, show, store) \
2131 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2132
2133 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2134 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2135 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2136         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2137 #define ATTR_LIST(name) &ext4_attr_##name.attr
2138
2139 EXT4_RO_ATTR(delayed_allocation_blocks);
2140 EXT4_RO_ATTR(session_write_kbytes);
2141 EXT4_RO_ATTR(lifetime_write_kbytes);
2142 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2143                  inode_readahead_blks_store, s_inode_readahead_blks);
2144 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2145 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2146 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2147 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2148 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2149 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2150
2151 static struct attribute *ext4_attrs[] = {
2152         ATTR_LIST(delayed_allocation_blocks),
2153         ATTR_LIST(session_write_kbytes),
2154         ATTR_LIST(lifetime_write_kbytes),
2155         ATTR_LIST(inode_readahead_blks),
2156         ATTR_LIST(mb_stats),
2157         ATTR_LIST(mb_max_to_scan),
2158         ATTR_LIST(mb_min_to_scan),
2159         ATTR_LIST(mb_order2_req),
2160         ATTR_LIST(mb_stream_req),
2161         ATTR_LIST(mb_group_prealloc),
2162         NULL,
2163 };
2164
2165 static ssize_t ext4_attr_show(struct kobject *kobj,
2166                               struct attribute *attr, char *buf)
2167 {
2168         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2169                                                 s_kobj);
2170         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2171
2172         return a->show ? a->show(a, sbi, buf) : 0;
2173 }
2174
2175 static ssize_t ext4_attr_store(struct kobject *kobj,
2176                                struct attribute *attr,
2177                                const char *buf, size_t len)
2178 {
2179         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2180                                                 s_kobj);
2181         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2182
2183         return a->store ? a->store(a, sbi, buf, len) : 0;
2184 }
2185
2186 static void ext4_sb_release(struct kobject *kobj)
2187 {
2188         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2189                                                 s_kobj);
2190         complete(&sbi->s_kobj_unregister);
2191 }
2192
2193
2194 static struct sysfs_ops ext4_attr_ops = {
2195         .show   = ext4_attr_show,
2196         .store  = ext4_attr_store,
2197 };
2198
2199 static struct kobj_type ext4_ktype = {
2200         .default_attrs  = ext4_attrs,
2201         .sysfs_ops      = &ext4_attr_ops,
2202         .release        = ext4_sb_release,
2203 };
2204
2205 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
2206                                 __releases(kernel_lock)
2207                                 __acquires(kernel_lock)
2208
2209 {
2210         struct buffer_head *bh;
2211         struct ext4_super_block *es = NULL;
2212         struct ext4_sb_info *sbi;
2213         ext4_fsblk_t block;
2214         ext4_fsblk_t sb_block = get_sb_block(&data);
2215         ext4_fsblk_t logical_sb_block;
2216         unsigned long offset = 0;
2217         unsigned long journal_devnum = 0;
2218         unsigned long def_mount_opts;
2219         struct inode *root;
2220         char *cp;
2221         const char *descr;
2222         int ret = -EINVAL;
2223         int blocksize;
2224         unsigned int db_count;
2225         unsigned int i;
2226         int needs_recovery, has_huge_files;
2227         int features;
2228         __u64 blocks_count;
2229         int err;
2230         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
2231
2232         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
2233         if (!sbi)
2234                 return -ENOMEM;
2235
2236         sbi->s_blockgroup_lock =
2237                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
2238         if (!sbi->s_blockgroup_lock) {
2239                 kfree(sbi);
2240                 return -ENOMEM;
2241         }
2242         sb->s_fs_info = sbi;
2243         sbi->s_mount_opt = 0;
2244         sbi->s_resuid = EXT4_DEF_RESUID;
2245         sbi->s_resgid = EXT4_DEF_RESGID;
2246         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
2247         sbi->s_sb_block = sb_block;
2248         sbi->s_sectors_written_start = part_stat_read(sb->s_bdev->bd_part,
2249                                                       sectors[1]);
2250
2251         unlock_kernel();
2252
2253         /* Cleanup superblock name */
2254         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
2255                 *cp = '!';
2256
2257         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
2258         if (!blocksize) {
2259                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
2260                 goto out_fail;
2261         }
2262
2263         /*
2264          * The ext4 superblock will not be buffer aligned for other than 1kB
2265          * block sizes.  We need to calculate the offset from buffer start.
2266          */
2267         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
2268                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2269                 offset = do_div(logical_sb_block, blocksize);
2270         } else {
2271                 logical_sb_block = sb_block;
2272         }
2273
2274         if (!(bh = sb_bread(sb, logical_sb_block))) {
2275                 printk(KERN_ERR "EXT4-fs: unable to read superblock\n");
2276                 goto out_fail;
2277         }
2278         /*
2279          * Note: s_es must be initialized as soon as possible because
2280          *       some ext4 macro-instructions depend on its value
2281          */
2282         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2283         sbi->s_es = es;
2284         sb->s_magic = le16_to_cpu(es->s_magic);
2285         if (sb->s_magic != EXT4_SUPER_MAGIC)
2286                 goto cantfind_ext4;
2287         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
2288
2289         /* Set defaults before we parse the mount options */
2290         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
2291         if (def_mount_opts & EXT4_DEFM_DEBUG)
2292                 set_opt(sbi->s_mount_opt, DEBUG);
2293         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
2294                 set_opt(sbi->s_mount_opt, GRPID);
2295         if (def_mount_opts & EXT4_DEFM_UID16)
2296                 set_opt(sbi->s_mount_opt, NO_UID32);
2297 #ifdef CONFIG_EXT4_FS_XATTR
2298         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
2299                 set_opt(sbi->s_mount_opt, XATTR_USER);
2300 #endif
2301 #ifdef CONFIG_EXT4_FS_POSIX_ACL
2302         if (def_mount_opts & EXT4_DEFM_ACL)
2303                 set_opt(sbi->s_mount_opt, POSIX_ACL);
2304 #endif
2305         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
2306                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
2307         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
2308                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
2309         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
2310                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
2311
2312         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
2313                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
2314         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
2315                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
2316         else
2317                 set_opt(sbi->s_mount_opt, ERRORS_RO);
2318
2319         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
2320         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
2321         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
2322         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
2323         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
2324
2325         set_opt(sbi->s_mount_opt, BARRIER);
2326
2327         /*
2328          * enable delayed allocation by default
2329          * Use -o nodelalloc to turn it off
2330          */
2331         set_opt(sbi->s_mount_opt, DELALLOC);
2332
2333
2334         if (!parse_options((char *) data, sb, &journal_devnum,
2335                            &journal_ioprio, NULL, 0))
2336                 goto failed_mount;
2337
2338         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2339                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2340
2341         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
2342             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
2343              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
2344              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
2345                 printk(KERN_WARNING
2346                        "EXT4-fs warning: feature flags set on rev 0 fs, "
2347                        "running e2fsck is recommended\n");
2348
2349         /*
2350          * Check feature flags regardless of the revision level, since we
2351          * previously didn't change the revision level when setting the flags,
2352          * so there is a chance incompat flags are set on a rev 0 filesystem.
2353          */
2354         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
2355         if (features) {
2356                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
2357                        "unsupported optional features (%x).\n", sb->s_id,
2358                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2359                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2360                 goto failed_mount;
2361         }
2362         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
2363         if (!(sb->s_flags & MS_RDONLY) && features) {
2364                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
2365                        "unsupported optional features (%x).\n", sb->s_id,
2366                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2367                         ~EXT4_FEATURE_RO_COMPAT_SUPP));
2368                 goto failed_mount;
2369         }
2370         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2371                                     EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
2372         if (has_huge_files) {
2373                 /*
2374                  * Large file size enabled file system can only be
2375                  * mount if kernel is build with CONFIG_LBD
2376                  */
2377                 if (sizeof(root->i_blocks) < sizeof(u64) &&
2378                                 !(sb->s_flags & MS_RDONLY)) {
2379                         printk(KERN_ERR "EXT4-fs: %s: Filesystem with huge "
2380                                         "files cannot be mounted read-write "
2381                                         "without CONFIG_LBD.\n", sb->s_id);
2382                         goto failed_mount;
2383                 }
2384         }
2385         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
2386
2387         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
2388             blocksize > EXT4_MAX_BLOCK_SIZE) {
2389                 printk(KERN_ERR
2390                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
2391                        blocksize, sb->s_id);
2392                 goto failed_mount;
2393         }
2394
2395         if (sb->s_blocksize != blocksize) {
2396
2397                 /* Validate the filesystem blocksize */
2398                 if (!sb_set_blocksize(sb, blocksize)) {
2399                         printk(KERN_ERR "EXT4-fs: bad block size %d.\n",
2400                                         blocksize);
2401                         goto failed_mount;
2402                 }
2403
2404                 brelse(bh);
2405                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2406                 offset = do_div(logical_sb_block, blocksize);
2407                 bh = sb_bread(sb, logical_sb_block);
2408                 if (!bh) {
2409                         printk(KERN_ERR
2410                                "EXT4-fs: Can't read superblock on 2nd try.\n");
2411                         goto failed_mount;
2412                 }
2413                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
2414                 sbi->s_es = es;
2415                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
2416                         printk(KERN_ERR
2417                                "EXT4-fs: Magic mismatch, very weird !\n");
2418                         goto failed_mount;
2419                 }
2420         }
2421
2422         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
2423                                                       has_huge_files);
2424         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
2425
2426         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2427                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2428                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2429         } else {
2430                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2431                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2432                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2433                     (!is_power_of_2(sbi->s_inode_size)) ||
2434                     (sbi->s_inode_size > blocksize)) {
2435                         printk(KERN_ERR
2436                                "EXT4-fs: unsupported inode size: %d\n",
2437                                sbi->s_inode_size);
2438                         goto failed_mount;
2439                 }
2440                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2441                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2442         }
2443         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2444         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2445                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2446                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2447                     !is_power_of_2(sbi->s_desc_size)) {
2448                         printk(KERN_ERR
2449                                "EXT4-fs: unsupported descriptor size %lu\n",
2450                                sbi->s_desc_size);
2451                         goto failed_mount;
2452                 }
2453         } else
2454                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2455         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2456         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2457         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2458                 goto cantfind_ext4;
2459         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2460         if (sbi->s_inodes_per_block == 0)
2461                 goto cantfind_ext4;
2462         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2463                                         sbi->s_inodes_per_block;
2464         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2465         sbi->s_sbh = bh;
2466         sbi->s_mount_state = le16_to_cpu(es->s_state);
2467         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2468         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2469         for (i = 0; i < 4; i++)
2470                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2471         sbi->s_def_hash_version = es->s_def_hash_version;
2472         i = le32_to_cpu(es->s_flags);
2473         if (i & EXT2_FLAGS_UNSIGNED_HASH)
2474                 sbi->s_hash_unsigned = 3;
2475         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
2476 #ifdef __CHAR_UNSIGNED__
2477                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
2478                 sbi->s_hash_unsigned = 3;
2479 #else
2480                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
2481 #endif
2482                 sb->s_dirt = 1;
2483         }
2484
2485         if (sbi->s_blocks_per_group > blocksize * 8) {
2486                 printk(KERN_ERR
2487                        "EXT4-fs: #blocks per group too big: %lu\n",
2488                        sbi->s_blocks_per_group);
2489                 goto failed_mount;
2490         }
2491         if (sbi->s_inodes_per_group > blocksize * 8) {
2492                 printk(KERN_ERR
2493                        "EXT4-fs: #inodes per group too big: %lu\n",
2494                        sbi->s_inodes_per_group);
2495                 goto failed_mount;
2496         }
2497
2498         if (ext4_blocks_count(es) >
2499                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
2500                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
2501                         " too large to mount safely\n", sb->s_id);
2502                 if (sizeof(sector_t) < 8)
2503                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
2504                                         "enabled\n");
2505                 goto failed_mount;
2506         }
2507
2508         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2509                 goto cantfind_ext4;
2510
2511         /*
2512          * It makes no sense for the first data block to be beyond the end
2513          * of the filesystem.
2514          */
2515         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
2516                 printk(KERN_WARNING "EXT4-fs: bad geometry: first data"
2517                        "block %u is beyond end of filesystem (%llu)\n",
2518                        le32_to_cpu(es->s_first_data_block),
2519                        ext4_blocks_count(es));
2520                 goto failed_mount;
2521         }
2522         blocks_count = (ext4_blocks_count(es) -
2523                         le32_to_cpu(es->s_first_data_block) +
2524                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2525         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2526         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
2527                 printk(KERN_WARNING "EXT4-fs: groups count too large: %u "
2528                        "(block count %llu, first data block %u, "
2529                        "blocks per group %lu)\n", sbi->s_groups_count,
2530                        ext4_blocks_count(es),
2531                        le32_to_cpu(es->s_first_data_block),
2532                        EXT4_BLOCKS_PER_GROUP(sb));
2533                 goto failed_mount;
2534         }
2535         sbi->s_groups_count = blocks_count;
2536         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2537                    EXT4_DESC_PER_BLOCK(sb);
2538         sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
2539                                     GFP_KERNEL);
2540         if (sbi->s_group_desc == NULL) {
2541                 printk(KERN_ERR "EXT4-fs: not enough memory\n");
2542                 goto failed_mount;
2543         }
2544
2545 #ifdef CONFIG_PROC_FS
2546         if (ext4_proc_root)
2547                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
2548 #endif
2549
2550         bgl_lock_init(sbi->s_blockgroup_lock);
2551
2552         for (i = 0; i < db_count; i++) {
2553                 block = descriptor_loc(sb, logical_sb_block, i);
2554                 sbi->s_group_desc[i] = sb_bread(sb, block);
2555                 if (!sbi->s_group_desc[i]) {
2556                         printk(KERN_ERR "EXT4-fs: "
2557                                "can't read group descriptor %d\n", i);
2558                         db_count = i;
2559                         goto failed_mount2;
2560                 }
2561         }
2562         if (!ext4_check_descriptors(sb)) {
2563                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
2564                 goto failed_mount2;
2565         }
2566         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2567                 if (!ext4_fill_flex_info(sb)) {
2568                         printk(KERN_ERR
2569                                "EXT4-fs: unable to initialize "
2570                                "flex_bg meta info!\n");
2571                         goto failed_mount2;
2572                 }
2573
2574         sbi->s_gdb_count = db_count;
2575         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2576         spin_lock_init(&sbi->s_next_gen_lock);
2577
2578         err = percpu_counter_init(&sbi->s_freeblocks_counter,
2579                         ext4_count_free_blocks(sb));
2580         if (!err) {
2581                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
2582                                 ext4_count_free_inodes(sb));
2583         }
2584         if (!err) {
2585                 err = percpu_counter_init(&sbi->s_dirs_counter,
2586                                 ext4_count_dirs(sb));
2587         }
2588         if (!err) {
2589                 err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
2590         }
2591         if (err) {
2592                 printk(KERN_ERR "EXT4-fs: insufficient memory\n");
2593                 goto failed_mount3;
2594         }
2595
2596         sbi->s_stripe = ext4_get_stripe_size(sbi);
2597
2598         /*
2599          * set up enough so that it can read an inode
2600          */
2601         sb->s_op = &ext4_sops;
2602         sb->s_export_op = &ext4_export_ops;
2603         sb->s_xattr = ext4_xattr_handlers;
2604 #ifdef CONFIG_QUOTA
2605         sb->s_qcop = &ext4_qctl_operations;
2606         sb->dq_op = &ext4_quota_operations;
2607 #endif
2608         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2609
2610         sb->s_root = NULL;
2611
2612         needs_recovery = (es->s_last_orphan != 0 ||
2613                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2614                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2615
2616         /*
2617          * The first inode we look at is the journal inode.  Don't try
2618          * root first: it may be modified in the journal!
2619          */
2620         if (!test_opt(sb, NOLOAD) &&
2621             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2622                 if (ext4_load_journal(sb, es, journal_devnum))
2623                         goto failed_mount3;
2624                 if (!(sb->s_flags & MS_RDONLY) &&
2625                     EXT4_SB(sb)->s_journal->j_failed_commit) {
2626                         printk(KERN_CRIT "EXT4-fs error (device %s): "
2627                                "ext4_fill_super: Journal transaction "
2628                                "%u is corrupt\n", sb->s_id,
2629                                EXT4_SB(sb)->s_journal->j_failed_commit);
2630                         if (test_opt(sb, ERRORS_RO)) {
2631                                 printk(KERN_CRIT
2632                                        "Mounting filesystem read-only\n");
2633                                 sb->s_flags |= MS_RDONLY;
2634                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2635                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2636                         }
2637                         if (test_opt(sb, ERRORS_PANIC)) {
2638                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2639                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2640                                 ext4_commit_super(sb, es, 1);
2641                                 goto failed_mount4;
2642                         }
2643                 }
2644         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
2645               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2646                 printk(KERN_ERR "EXT4-fs: required journal recovery "
2647                        "suppressed and not mounted read-only\n");
2648                 goto failed_mount4;
2649         } else {
2650                 clear_opt(sbi->s_mount_opt, DATA_FLAGS);
2651                 set_opt(sbi->s_mount_opt, WRITEBACK_DATA);
2652                 sbi->s_journal = NULL;
2653                 needs_recovery = 0;
2654                 goto no_journal;
2655         }
2656
2657         if (ext4_blocks_count(es) > 0xffffffffULL &&
2658             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2659                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2660                 printk(KERN_ERR "EXT4-fs: Failed to set 64-bit journal feature\n");
2661                 goto failed_mount4;
2662         }
2663
2664         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2665                 jbd2_journal_set_features(sbi->s_journal,
2666                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2667                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2668         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2669                 jbd2_journal_set_features(sbi->s_journal,
2670                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2671                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2672                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2673         } else {
2674                 jbd2_journal_clear_features(sbi->s_journal,
2675                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2676                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2677         }
2678
2679         /* We have now updated the journal if required, so we can
2680          * validate the data journaling mode. */
2681         switch (test_opt(sb, DATA_FLAGS)) {
2682         case 0:
2683                 /* No mode set, assume a default based on the journal
2684                  * capabilities: ORDERED_DATA if the journal can
2685                  * cope, else JOURNAL_DATA
2686                  */
2687                 if (jbd2_journal_check_available_features
2688                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2689                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
2690                 else
2691                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2692                 break;
2693
2694         case EXT4_MOUNT_ORDERED_DATA:
2695         case EXT4_MOUNT_WRITEBACK_DATA:
2696                 if (!jbd2_journal_check_available_features
2697                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2698                         printk(KERN_ERR "EXT4-fs: Journal does not support "
2699                                "requested data journaling mode\n");
2700                         goto failed_mount4;
2701                 }
2702         default:
2703                 break;
2704         }
2705         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
2706
2707 no_journal:
2708
2709         if (test_opt(sb, NOBH)) {
2710                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2711                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
2712                                 "its supported only with writeback mode\n");
2713                         clear_opt(sbi->s_mount_opt, NOBH);
2714                 }
2715         }
2716         /*
2717          * The jbd2_journal_load will have done any necessary log recovery,
2718          * so we can safely mount the rest of the filesystem now.
2719          */
2720
2721         root = ext4_iget(sb, EXT4_ROOT_INO);
2722         if (IS_ERR(root)) {
2723                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
2724                 ret = PTR_ERR(root);
2725                 goto failed_mount4;
2726         }
2727         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2728                 iput(root);
2729                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
2730                 goto failed_mount4;
2731         }
2732         sb->s_root = d_alloc_root(root);
2733         if (!sb->s_root) {
2734                 printk(KERN_ERR "EXT4-fs: get root dentry failed\n");
2735                 iput(root);
2736                 ret = -ENOMEM;
2737                 goto failed_mount4;
2738         }
2739
2740         ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
2741
2742         /* determine the minimum size of new large inodes, if present */
2743         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2744                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2745                                                      EXT4_GOOD_OLD_INODE_SIZE;
2746                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2747                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2748                         if (sbi->s_want_extra_isize <
2749                             le16_to_cpu(es->s_want_extra_isize))
2750                                 sbi->s_want_extra_isize =
2751                                         le16_to_cpu(es->s_want_extra_isize);
2752                         if (sbi->s_want_extra_isize <
2753                             le16_to_cpu(es->s_min_extra_isize))
2754                                 sbi->s_want_extra_isize =
2755                                         le16_to_cpu(es->s_min_extra_isize);
2756                 }
2757         }
2758         /* Check if enough inode space is available */
2759         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2760                                                         sbi->s_inode_size) {
2761                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2762                                                        EXT4_GOOD_OLD_INODE_SIZE;
2763                 printk(KERN_INFO "EXT4-fs: required extra inode space not"
2764                         "available.\n");
2765         }
2766
2767         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
2768                 printk(KERN_WARNING "EXT4-fs: Ignoring delalloc option - "
2769                                 "requested data journaling mode\n");
2770                 clear_opt(sbi->s_mount_opt, DELALLOC);
2771         } else if (test_opt(sb, DELALLOC))
2772                 printk(KERN_INFO "EXT4-fs: delayed allocation enabled\n");
2773
2774         ext4_ext_init(sb);
2775         err = ext4_mb_init(sb, needs_recovery);
2776         if (err) {
2777                 printk(KERN_ERR "EXT4-fs: failed to initalize mballoc (%d)\n",
2778                        err);
2779                 goto failed_mount4;
2780         }
2781
2782         sbi->s_kobj.kset = ext4_kset;
2783         init_completion(&sbi->s_kobj_unregister);
2784         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
2785                                    "%s", sb->s_id);
2786         if (err) {
2787                 ext4_mb_release(sb);
2788                 ext4_ext_release(sb);
2789                 goto failed_mount4;
2790         };
2791
2792         /*
2793          * akpm: core read_super() calls in here with the superblock locked.
2794          * That deadlocks, because orphan cleanup needs to lock the superblock
2795          * in numerous places.  Here we just pop the lock - it's relatively
2796          * harmless, because we are now ready to accept write_super() requests,
2797          * and aviro says that's the only reason for hanging onto the
2798          * superblock lock.
2799          */
2800         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2801         ext4_orphan_cleanup(sb, es);
2802         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2803         if (needs_recovery) {
2804                 printk(KERN_INFO "EXT4-fs: recovery complete.\n");
2805                 ext4_mark_recovery_complete(sb, es);
2806         }
2807         if (EXT4_SB(sb)->s_journal) {
2808                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2809                         descr = " journalled data mode";
2810                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2811                         descr = " ordered data mode";
2812                 else
2813                         descr = " writeback data mode";
2814         } else
2815                 descr = "out journal";
2816
2817         printk(KERN_INFO "EXT4-fs: mounted filesystem %s with%s\n",
2818                sb->s_id, descr);
2819
2820         lock_kernel();
2821         return 0;
2822
2823 cantfind_ext4:
2824         if (!silent)
2825                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
2826                        sb->s_id);
2827         goto failed_mount;
2828
2829 failed_mount4:
2830         printk(KERN_ERR "EXT4-fs (device %s): mount failed\n", sb->s_id);
2831         if (sbi->s_journal) {
2832                 jbd2_journal_destroy(sbi->s_journal);
2833                 sbi->s_journal = NULL;
2834         }
2835 failed_mount3:
2836         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2837         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2838         percpu_counter_destroy(&sbi->s_dirs_counter);
2839         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
2840 failed_mount2:
2841         for (i = 0; i < db_count; i++)
2842                 brelse(sbi->s_group_desc[i]);
2843         kfree(sbi->s_group_desc);
2844 failed_mount:
2845         if (sbi->s_proc) {
2846                 remove_proc_entry(sb->s_id, ext4_proc_root);
2847         }
2848 #ifdef CONFIG_QUOTA
2849         for (i = 0; i < MAXQUOTAS; i++)
2850                 kfree(sbi->s_qf_names[i]);
2851 #endif
2852         ext4_blkdev_remove(sbi);
2853         brelse(bh);
2854 out_fail:
2855         sb->s_fs_info = NULL;
2856         kfree(sbi);
2857         lock_kernel();
2858         return ret;
2859 }
2860
2861 /*
2862  * Setup any per-fs journal parameters now.  We'll do this both on
2863  * initial mount, once the journal has been initialised but before we've
2864  * done any recovery; and again on any subsequent remount.
2865  */
2866 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2867 {
2868         struct ext4_sb_info *sbi = EXT4_SB(sb);
2869
2870         journal->j_commit_interval = sbi->s_commit_interval;
2871         journal->j_min_batch_time = sbi->s_min_batch_time;
2872         journal->j_max_batch_time = sbi->s_max_batch_time;
2873
2874         spin_lock(&journal->j_state_lock);
2875         if (test_opt(sb, BARRIER))
2876                 journal->j_flags |= JBD2_BARRIER;
2877         else
2878                 journal->j_flags &= ~JBD2_BARRIER;
2879         if (test_opt(sb, DATA_ERR_ABORT))
2880                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
2881         else
2882                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
2883         spin_unlock(&journal->j_state_lock);
2884 }
2885
2886 static journal_t *ext4_get_journal(struct super_block *sb,
2887                                    unsigned int journal_inum)
2888 {
2889         struct inode *journal_inode;
2890         journal_t *journal;
2891
2892         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
2893
2894         /* First, test for the existence of a valid inode on disk.  Bad
2895          * things happen if we iget() an unused inode, as the subsequent
2896          * iput() will try to delete it. */
2897
2898         journal_inode = ext4_iget(sb, journal_inum);
2899         if (IS_ERR(journal_inode)) {
2900                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
2901                 return NULL;
2902         }
2903         if (!journal_inode->i_nlink) {
2904                 make_bad_inode(journal_inode);
2905                 iput(journal_inode);
2906                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
2907                 return NULL;
2908         }
2909
2910         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
2911                   journal_inode, journal_inode->i_size);
2912         if (!S_ISREG(journal_inode->i_mode)) {
2913                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
2914                 iput(journal_inode);
2915                 return NULL;
2916         }
2917
2918         journal = jbd2_journal_init_inode(journal_inode);
2919         if (!journal) {
2920                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
2921                 iput(journal_inode);
2922                 return NULL;
2923         }
2924         journal->j_private = sb;
2925         ext4_init_journal_params(sb, journal);
2926         return journal;
2927 }
2928
2929 static journal_t *ext4_get_dev_journal(struct super_block *sb,
2930                                        dev_t j_dev)
2931 {
2932         struct buffer_head *bh;
2933         journal_t *journal;
2934         ext4_fsblk_t start;
2935         ext4_fsblk_t len;
2936         int hblock, blocksize;
2937         ext4_fsblk_t sb_block;
2938         unsigned long offset;
2939         struct ext4_super_block *es;
2940         struct block_device *bdev;
2941
2942         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
2943
2944         bdev = ext4_blkdev_get(j_dev);
2945         if (bdev == NULL)
2946                 return NULL;
2947
2948         if (bd_claim(bdev, sb)) {
2949                 printk(KERN_ERR
2950                         "EXT4-fs: failed to claim external journal device.\n");
2951                 blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
2952                 return NULL;
2953         }
2954
2955         blocksize = sb->s_blocksize;
2956         hblock = bdev_hardsect_size(bdev);
2957         if (blocksize < hblock) {
2958                 printk(KERN_ERR
2959                         "EXT4-fs: blocksize too small for journal device.\n");
2960                 goto out_bdev;
2961         }
2962
2963         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2964         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2965         set_blocksize(bdev, blocksize);
2966         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2967                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2968                        "external journal\n");
2969                 goto out_bdev;
2970         }
2971
2972         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2973         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2974             !(le32_to_cpu(es->s_feature_incompat) &
2975               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2976                 printk(KERN_ERR "EXT4-fs: external journal has "
2977                                         "bad superblock\n");
2978                 brelse(bh);
2979                 goto out_bdev;
2980         }
2981
2982         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2983                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2984                 brelse(bh);
2985                 goto out_bdev;
2986         }
2987
2988         len = ext4_blocks_count(es);
2989         start = sb_block + 1;
2990         brelse(bh);     /* we're done with the superblock */
2991
2992         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2993                                         start, len, blocksize);
2994         if (!journal) {
2995                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2996                 goto out_bdev;
2997         }
2998         journal->j_private = sb;
2999         ll_rw_block(READ, 1, &journal->j_sb_buffer);
3000         wait_on_buffer(journal->j_sb_buffer);
3001         if (!buffer_uptodate(journal->j_sb_buffer)) {
3002                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
3003                 goto out_journal;
3004         }
3005         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
3006                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
3007                                         "user (unsupported) - %d\n",
3008                         be32_to_cpu(journal->j_superblock->s_nr_users));
3009                 goto out_journal;
3010         }
3011         EXT4_SB(sb)->journal_bdev = bdev;
3012         ext4_init_journal_params(sb, journal);
3013         return journal;
3014 out_journal:
3015         jbd2_journal_destroy(journal);
3016 out_bdev:
3017         ext4_blkdev_put(bdev);
3018         return NULL;
3019 }
3020
3021 static int ext4_load_journal(struct super_block *sb,
3022                              struct ext4_super_block *es,
3023                              unsigned long journal_devnum)
3024 {
3025         journal_t *journal;
3026         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
3027         dev_t journal_dev;
3028         int err = 0;
3029         int really_read_only;
3030
3031         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3032
3033         if (journal_devnum &&
3034             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3035                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
3036                         "numbers have changed\n");
3037                 journal_dev = new_decode_dev(journal_devnum);
3038         } else
3039                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
3040
3041         really_read_only = bdev_read_only(sb->s_bdev);
3042
3043         /*
3044          * Are we loading a blank journal or performing recovery after a
3045          * crash?  For recovery, we need to check in advance whether we
3046          * can get read-write access to the device.
3047          */
3048
3049         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3050                 if (sb->s_flags & MS_RDONLY) {
3051                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
3052                                         "required on readonly filesystem.\n");
3053                         if (really_read_only) {
3054                                 printk(KERN_ERR "EXT4-fs: write access "
3055                                         "unavailable, cannot proceed.\n");
3056                                 return -EROFS;
3057                         }
3058                         printk(KERN_INFO "EXT4-fs: write access will "
3059                                "be enabled during recovery.\n");
3060                 }
3061         }
3062
3063         if (journal_inum && journal_dev) {
3064                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
3065                        "and inode journals!\n");
3066                 return -EINVAL;
3067         }
3068
3069         if (journal_inum) {
3070                 if (!(journal = ext4_get_journal(sb, journal_inum)))
3071                         return -EINVAL;
3072         } else {
3073                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
3074                         return -EINVAL;
3075         }
3076
3077         if (journal->j_flags & JBD2_BARRIER)
3078                 printk(KERN_INFO "EXT4-fs: barriers enabled\n");
3079         else
3080                 printk(KERN_INFO "EXT4-fs: barriers disabled\n");
3081
3082         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
3083                 err = jbd2_journal_update_format(journal);
3084                 if (err)  {
3085                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
3086                         jbd2_journal_destroy(journal);
3087                         return err;
3088                 }
3089         }
3090
3091         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
3092                 err = jbd2_journal_wipe(journal, !really_read_only);
3093         if (!err)
3094                 err = jbd2_journal_load(journal);
3095
3096         if (err) {
3097                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
3098                 jbd2_journal_destroy(journal);
3099                 return err;
3100         }
3101
3102         EXT4_SB(sb)->s_journal = journal;
3103         ext4_clear_journal_err(sb, es);
3104
3105         if (journal_devnum &&
3106             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3107                 es->s_journal_dev = cpu_to_le32(journal_devnum);
3108                 sb->s_dirt = 1;
3109
3110                 /* Make sure we flush the recovery flag to disk. */
3111                 ext4_commit_super(sb, es, 1);
3112         }
3113
3114         return 0;
3115 }
3116
3117 static int ext4_commit_super(struct super_block *sb,
3118                               struct ext4_super_block *es, int sync)
3119 {
3120         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
3121         int error = 0;
3122
3123         if (!sbh)
3124                 return error;
3125         if (buffer_write_io_error(sbh)) {
3126                 /*
3127                  * Oh, dear.  A previous attempt to write the
3128                  * superblock failed.  This could happen because the
3129                  * USB device was yanked out.  Or it could happen to
3130                  * be a transient write error and maybe the block will
3131                  * be remapped.  Nothing we can do but to retry the
3132                  * write and hope for the best.
3133                  */
3134                 printk(KERN_ERR "EXT4-fs: previous I/O error to "
3135                        "superblock detected for %s.\n", sb->s_id);
3136                 clear_buffer_write_io_error(sbh);
3137                 set_buffer_uptodate(sbh);
3138         }
3139         es->s_wtime = cpu_to_le32(get_seconds());
3140         es->s_kbytes_written =
3141                 cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
3142                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
3143                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
3144         ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
3145                                         &EXT4_SB(sb)->s_freeblocks_counter));
3146         es->s_free_inodes_count = cpu_to_le32(percpu_counter_sum_positive(
3147                                         &EXT4_SB(sb)->s_freeinodes_counter));
3148
3149         BUFFER_TRACE(sbh, "marking dirty");
3150         mark_buffer_dirty(sbh);
3151         if (sync) {
3152                 error = sync_dirty_buffer(sbh);
3153                 if (error)
3154                         return error;
3155
3156                 error = buffer_write_io_error(sbh);
3157                 if (error) {
3158                         printk(KERN_ERR "EXT4-fs: I/O error while writing "
3159                                "superblock for %s.\n", sb->s_id);
3160                         clear_buffer_write_io_error(sbh);
3161                         set_buffer_uptodate(sbh);
3162                 }
3163         }
3164         return error;
3165 }
3166
3167
3168 /*
3169  * Have we just finished recovery?  If so, and if we are mounting (or
3170  * remounting) the filesystem readonly, then we will end up with a
3171  * consistent fs on disk.  Record that fact.
3172  */
3173 static void ext4_mark_recovery_complete(struct super_block *sb,
3174                                         struct ext4_super_block *es)
3175 {
3176         journal_t *journal = EXT4_SB(sb)->s_journal;
3177
3178         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3179                 BUG_ON(journal != NULL);
3180                 return;
3181         }
3182         jbd2_journal_lock_updates(journal);
3183         if (jbd2_journal_flush(journal) < 0)
3184                 goto out;
3185
3186         lock_super(sb);
3187         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
3188             sb->s_flags & MS_RDONLY) {
3189                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3190                 sb->s_dirt = 0;
3191                 ext4_commit_super(sb, es, 1);
3192         }
3193         unlock_super(sb);
3194
3195 out:
3196         jbd2_journal_unlock_updates(journal);
3197 }
3198
3199 /*
3200  * If we are mounting (or read-write remounting) a filesystem whose journal
3201  * has recorded an error from a previous lifetime, move that error to the
3202  * main filesystem now.
3203  */
3204 static void ext4_clear_journal_err(struct super_block *sb,
3205                                    struct ext4_super_block *es)
3206 {
3207         journal_t *journal;
3208         int j_errno;
3209         const char *errstr;
3210
3211         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3212
3213         journal = EXT4_SB(sb)->s_journal;
3214
3215         /*
3216          * Now check for any error status which may have been recorded in the
3217          * journal by a prior ext4_error() or ext4_abort()
3218          */
3219
3220         j_errno = jbd2_journal_errno(journal);
3221         if (j_errno) {
3222                 char nbuf[16];
3223
3224                 errstr = ext4_decode_error(sb, j_errno, nbuf);
3225                 ext4_warning(sb, __func__, "Filesystem error recorded "
3226                              "from previous mount: %s", errstr);
3227                 ext4_warning(sb, __func__, "Marking fs in need of "
3228                              "filesystem check.");
3229
3230                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
3231                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
3232                 ext4_commit_super(sb, es, 1);
3233
3234                 jbd2_journal_clear_err(journal);
3235         }
3236 }
3237
3238 /*
3239  * Force the running and committing transactions to commit,
3240  * and wait on the commit.
3241  */
3242 int ext4_force_commit(struct super_block *sb)
3243 {
3244         journal_t *journal;
3245         int ret = 0;
3246
3247         if (sb->s_flags & MS_RDONLY)
3248                 return 0;
3249
3250         journal = EXT4_SB(sb)->s_journal;
3251         if (journal) {
3252                 sb->s_dirt = 0;
3253                 ret = ext4_journal_force_commit(journal);
3254         }
3255
3256         return ret;
3257 }
3258
3259 /*
3260  * Ext4 always journals updates to the superblock itself, so we don't
3261  * have to propagate any other updates to the superblock on disk at this
3262  * point.  (We can probably nuke this function altogether, and remove
3263  * any mention to sb->s_dirt in all of fs/ext4; eventual cleanup...)
3264  */
3265 static void ext4_write_super(struct super_block *sb)
3266 {
3267         if (EXT4_SB(sb)->s_journal) {
3268                 if (mutex_trylock(&sb->s_lock) != 0)
3269                         BUG();
3270                 sb->s_dirt = 0;
3271         } else {
3272                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
3273         }
3274 }
3275
3276 static int ext4_sync_fs(struct super_block *sb, int wait)
3277 {
3278         int ret = 0;
3279         tid_t target;
3280
3281         trace_mark(ext4_sync_fs, "dev %s wait %d", sb->s_id, wait);
3282         sb->s_dirt = 0;
3283         if (EXT4_SB(sb)->s_journal) {
3284                 if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal,
3285                                               &target)) {
3286                         if (wait)
3287                                 jbd2_log_wait_commit(EXT4_SB(sb)->s_journal,
3288                                                      target);
3289                 }
3290         } else {
3291                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, wait);
3292         }
3293         return ret;
3294 }
3295
3296 /*
3297  * LVM calls this function before a (read-only) snapshot is created.  This
3298  * gives us a chance to flush the journal completely and mark the fs clean.
3299  */
3300 static int ext4_freeze(struct super_block *sb)
3301 {
3302         int error = 0;
3303         journal_t *journal;
3304         sb->s_dirt = 0;
3305
3306         if (!(sb->s_flags & MS_RDONLY)) {
3307                 journal = EXT4_SB(sb)->s_journal;
3308
3309                 if (journal) {
3310                         /* Now we set up the journal barrier. */
3311                         jbd2_journal_lock_updates(journal);
3312
3313                         /*
3314                          * We don't want to clear needs_recovery flag when we
3315                          * failed to flush the journal.
3316                          */
3317                         error = jbd2_journal_flush(journal);
3318                         if (error < 0)
3319                                 goto out;
3320                 }
3321
3322                 /* Journal blocked and flushed, clear needs_recovery flag. */
3323                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3324                 error = ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
3325                 if (error)
3326                         goto out;
3327         }
3328         return 0;
3329 out:
3330         jbd2_journal_unlock_updates(journal);
3331         return error;
3332 }
3333
3334 /*
3335  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
3336  * flag here, even though the filesystem is not technically dirty yet.
3337  */
3338 static int ext4_unfreeze(struct super_block *sb)
3339 {
3340         if (EXT4_SB(sb)->s_journal && !(sb->s_flags & MS_RDONLY)) {
3341                 lock_super(sb);
3342                 /* Reser the needs_recovery flag before the fs is unlocked. */
3343                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3344                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
3345                 unlock_super(sb);
3346                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3347         }
3348         return 0;
3349 }
3350
3351 static int ext4_remount(struct super_block *sb, int *flags, char *data)
3352 {
3353         struct ext4_super_block *es;
3354         struct ext4_sb_info *sbi = EXT4_SB(sb);
3355         ext4_fsblk_t n_blocks_count = 0;
3356         unsigned long old_sb_flags;
3357         struct ext4_mount_options old_opts;
3358         ext4_group_t g;
3359         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3360         int err;
3361 #ifdef CONFIG_QUOTA
3362         int i;
3363 #endif
3364
3365         /* Store the original options */
3366         old_sb_flags = sb->s_flags;
3367         old_opts.s_mount_opt = sbi->s_mount_opt;
3368         old_opts.s_resuid = sbi->s_resuid;
3369         old_opts.s_resgid = sbi->s_resgid;
3370         old_opts.s_commit_interval = sbi->s_commit_interval;
3371         old_opts.s_min_batch_time = sbi->s_min_batch_time;
3372         old_opts.s_max_batch_time = sbi->s_max_batch_time;
3373 #ifdef CONFIG_QUOTA
3374         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
3375         for (i = 0; i < MAXQUOTAS; i++)
3376                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
3377 #endif
3378         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
3379                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
3380
3381         /*
3382          * Allow the "check" option to be passed as a remount option.
3383          */
3384         if (!parse_options(data, sb, NULL, &journal_ioprio,
3385                            &n_blocks_count, 1)) {
3386                 err = -EINVAL;
3387                 goto restore_opts;
3388         }
3389
3390         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
3391                 ext4_abort(sb, __func__, "Abort forced by user");
3392
3393         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3394                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
3395
3396         es = sbi->s_es;
3397
3398         if (sbi->s_journal) {
3399                 ext4_init_journal_params(sb, sbi->s_journal);
3400                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3401         }
3402
3403         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
3404                 n_blocks_count > ext4_blocks_count(es)) {
3405                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
3406                         err = -EROFS;
3407                         goto restore_opts;
3408                 }
3409
3410                 if (*flags & MS_RDONLY) {
3411                         /*
3412                          * First of all, the unconditional stuff we have to do
3413                          * to disable replay of the journal when we next remount
3414                          */
3415                         sb->s_flags |= MS_RDONLY;
3416
3417                         /*
3418                          * OK, test if we are remounting a valid rw partition
3419                          * readonly, and if so set the rdonly flag and then
3420                          * mark the partition as valid again.
3421                          */
3422                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
3423                             (sbi->s_mount_state & EXT4_VALID_FS))
3424                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
3425
3426                         /*
3427                          * We have to unlock super so that we can wait for
3428                          * transactions.
3429                          */
3430                         if (sbi->s_journal) {
3431                                 unlock_super(sb);
3432                                 ext4_mark_recovery_complete(sb, es);
3433                                 lock_super(sb);
3434                         }
3435                 } else {
3436                         int ret;
3437                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3438                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
3439                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
3440                                        "remount RDWR because of unsupported "
3441                                        "optional features (%x).\n", sb->s_id,
3442                                 (le32_to_cpu(sbi->s_es->s_feature_ro_compat) &
3443                                         ~EXT4_FEATURE_RO_COMPAT_SUPP));
3444                                 err = -EROFS;
3445                                 goto restore_opts;
3446                         }
3447
3448                         /*
3449                          * Make sure the group descriptor checksums
3450                          * are sane.  If they aren't, refuse to
3451                          * remount r/w.
3452                          */
3453                         for (g = 0; g < sbi->s_groups_count; g++) {
3454                                 struct ext4_group_desc *gdp =
3455                                         ext4_get_group_desc(sb, g, NULL);
3456
3457                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
3458                                         printk(KERN_ERR
3459                "EXT4-fs: ext4_remount: "
3460                 "Checksum for group %u failed (%u!=%u)\n",
3461                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
3462                                                le16_to_cpu(gdp->bg_checksum));
3463                                         err = -EINVAL;
3464                                         goto restore_opts;
3465                                 }
3466                         }
3467
3468                         /*
3469                          * If we have an unprocessed orphan list hanging
3470                          * around from a previously readonly bdev mount,
3471                          * require a full umount/remount for now.
3472                          */
3473                         if (es->s_last_orphan) {
3474                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
3475                                        "remount RDWR because of unprocessed "
3476                                        "orphan inode list.  Please "
3477                                        "umount/remount instead.\n",
3478                                        sb->s_id);
3479                                 err = -EINVAL;
3480                                 goto restore_opts;
3481                         }
3482
3483                         /*
3484                          * Mounting a RDONLY partition read-write, so reread
3485                          * and store the current valid flag.  (It may have
3486                          * been changed by e2fsck since we originally mounted
3487                          * the partition.)
3488                          */
3489                         if (sbi->s_journal)
3490                                 ext4_clear_journal_err(sb, es);
3491                         sbi->s_mount_state = le16_to_cpu(es->s_state);
3492                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
3493                                 goto restore_opts;
3494                         if (!ext4_setup_super(sb, es, 0))
3495                                 sb->s_flags &= ~MS_RDONLY;
3496                 }
3497         }
3498         if (sbi->s_journal == NULL)
3499                 ext4_commit_super(sb, es, 1);
3500
3501 #ifdef CONFIG_QUOTA
3502         /* Release old quota file names */
3503         for (i = 0; i < MAXQUOTAS; i++)
3504                 if (old_opts.s_qf_names[i] &&
3505                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3506                         kfree(old_opts.s_qf_names[i]);
3507 #endif
3508         return 0;
3509 restore_opts:
3510         sb->s_flags = old_sb_flags;
3511         sbi->s_mount_opt = old_opts.s_mount_opt;
3512         sbi->s_resuid = old_opts.s_resuid;
3513         sbi->s_resgid = old_opts.s_resgid;
3514         sbi->s_commit_interval = old_opts.s_commit_interval;
3515         sbi->s_min_batch_time = old_opts.s_min_batch_time;
3516         sbi->s_max_batch_time = old_opts.s_max_batch_time;
3517 #ifdef CONFIG_QUOTA
3518         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
3519         for (i = 0; i < MAXQUOTAS; i++) {
3520                 if (sbi->s_qf_names[i] &&
3521                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3522                         kfree(sbi->s_qf_names[i]);
3523                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
3524         }
3525 #endif
3526         return err;
3527 }
3528
3529 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
3530 {
3531         struct super_block *sb = dentry->d_sb;
3532         struct ext4_sb_info *sbi = EXT4_SB(sb);
3533         struct ext4_super_block *es = sbi->s_es;
3534         u64 fsid;
3535
3536         if (test_opt(sb, MINIX_DF)) {
3537                 sbi->s_overhead_last = 0;
3538         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
3539                 ext4_group_t ngroups = sbi->s_groups_count, i;
3540                 ext4_fsblk_t overhead = 0;
3541                 smp_rmb();
3542
3543                 /*
3544                  * Compute the overhead (FS structures).  This is constant
3545                  * for a given filesystem unless the number of block groups
3546                  * changes so we cache the previous value until it does.
3547                  */
3548
3549                 /*
3550                  * All of the blocks before first_data_block are
3551                  * overhead
3552                  */
3553                 overhead = le32_to_cpu(es->s_first_data_block);
3554
3555                 /*
3556                  * Add the overhead attributed to the superblock and
3557                  * block group descriptors.  If the sparse superblocks
3558                  * feature is turned on, then not all groups have this.
3559                  */
3560                 for (i = 0; i < ngroups; i++) {
3561                         overhead += ext4_bg_has_super(sb, i) +
3562                                 ext4_bg_num_gdb(sb, i);
3563                         cond_resched();
3564                 }
3565
3566                 /*
3567                  * Every block group has an inode bitmap, a block
3568                  * bitmap, and an inode table.
3569                  */
3570                 overhead += ngroups * (2 + sbi->s_itb_per_group);
3571                 sbi->s_overhead_last = overhead;
3572                 smp_wmb();
3573                 sbi->s_blocks_last = ext4_blocks_count(es);
3574         }
3575
3576         buf->f_type = EXT4_SUPER_MAGIC;
3577         buf->f_bsize = sb->s_blocksize;
3578         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
3579         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
3580                        percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
3581         ext4_free_blocks_count_set(es, buf->f_bfree);
3582         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
3583         if (buf->f_bfree < ext4_r_blocks_count(es))
3584                 buf->f_bavail = 0;
3585         buf->f_files = le32_to_cpu(es->s_inodes_count);
3586         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
3587         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
3588         buf->f_namelen = EXT4_NAME_LEN;
3589         fsid = le64_to_cpup((void *)es->s_uuid) ^
3590                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
3591         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
3592         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
3593         return 0;
3594 }
3595
3596 /* Helper function for writing quotas on sync - we need to start transaction before quota file
3597  * is locked for write. Otherwise the are possible deadlocks:
3598  * Process 1                         Process 2
3599  * ext4_create()                     quota_sync()
3600  *   jbd2_journal_start()                  write_dquot()
3601  *   vfs_dq_init()                         down(dqio_mutex)
3602  *     down(dqio_mutex)                    jbd2_journal_start()
3603  *
3604  */
3605
3606 #ifdef CONFIG_QUOTA
3607
3608 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3609 {
3610         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3611 }
3612
3613 static int ext4_write_dquot(struct dquot *dquot)
3614 {
3615         int ret, err;
3616         handle_t *handle;
3617         struct inode *inode;
3618
3619         inode = dquot_to_inode(dquot);
3620         handle = ext4_journal_start(inode,
3621                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3622         if (IS_ERR(handle))
3623                 return PTR_ERR(handle);
3624         ret = dquot_commit(dquot);
3625         err = ext4_journal_stop(handle);
3626         if (!ret)
3627                 ret = err;
3628         return ret;
3629 }
3630
3631 static int ext4_acquire_dquot(struct dquot *dquot)
3632 {
3633         int ret, err;
3634         handle_t *handle;
3635
3636         handle = ext4_journal_start(dquot_to_inode(dquot),
3637                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3638         if (IS_ERR(handle))
3639                 return PTR_ERR(handle);
3640         ret = dquot_acquire(dquot);
3641         err = ext4_journal_stop(handle);
3642         if (!ret)
3643                 ret = err;
3644         return ret;
3645 }
3646
3647 static int ext4_release_dquot(struct dquot *dquot)
3648 {
3649         int ret, err;
3650         handle_t *handle;
3651
3652         handle = ext4_journal_start(dquot_to_inode(dquot),
3653                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3654         if (IS_ERR(handle)) {
3655                 /* Release dquot anyway to avoid endless cycle in dqput() */
3656                 dquot_release(dquot);
3657                 return PTR_ERR(handle);
3658         }
3659         ret = dquot_release(dquot);
3660         err = ext4_journal_stop(handle);
3661         if (!ret)
3662                 ret = err;
3663         return ret;
3664 }
3665
3666 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3667 {
3668         /* Are we journaling quotas? */
3669         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3670             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3671                 dquot_mark_dquot_dirty(dquot);
3672                 return ext4_write_dquot(dquot);
3673         } else {
3674                 return dquot_mark_dquot_dirty(dquot);
3675         }
3676 }
3677
3678 static int ext4_write_info(struct super_block *sb, int type)
3679 {
3680         int ret, err;
3681         handle_t *handle;
3682
3683         /* Data block + inode block */
3684         handle = ext4_journal_start(sb->s_root->d_inode, 2);
3685         if (IS_ERR(handle))
3686                 return PTR_ERR(handle);
3687         ret = dquot_commit_info(sb, type);
3688         err = ext4_journal_stop(handle);
3689         if (!ret)
3690                 ret = err;
3691         return ret;
3692 }
3693
3694 /*
3695  * Turn on quotas during mount time - we need to find
3696  * the quota file and such...
3697  */
3698 static int ext4_quota_on_mount(struct super_block *sb, int type)
3699 {
3700         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3701                         EXT4_SB(sb)->s_jquota_fmt, type);
3702 }
3703
3704 /*
3705  * Standard function to be called on quota_on
3706  */
3707 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3708                          char *name, int remount)
3709 {
3710         int err;
3711         struct path path;
3712
3713         if (!test_opt(sb, QUOTA))
3714                 return -EINVAL;
3715         /* When remounting, no checks are needed and in fact, name is NULL */
3716         if (remount)
3717                 return vfs_quota_on(sb, type, format_id, name, remount);
3718
3719         err = kern_path(name, LOOKUP_FOLLOW, &path);
3720         if (err)
3721                 return err;
3722
3723         /* Quotafile not on the same filesystem? */
3724         if (path.mnt->mnt_sb != sb) {
3725                 path_put(&path);
3726                 return -EXDEV;
3727         }
3728         /* Journaling quota? */
3729         if (EXT4_SB(sb)->s_qf_names[type]) {
3730                 /* Quotafile not in fs root? */
3731                 if (path.dentry->d_parent != sb->s_root)
3732                         printk(KERN_WARNING
3733                                 "EXT4-fs: Quota file not on filesystem root. "
3734                                 "Journaled quota will not work.\n");
3735         }
3736
3737         /*
3738          * When we journal data on quota file, we have to flush journal to see
3739          * all updates to the file when we bypass pagecache...
3740          */
3741         if (EXT4_SB(sb)->s_journal &&
3742             ext4_should_journal_data(path.dentry->d_inode)) {
3743                 /*
3744                  * We don't need to lock updates but journal_flush() could
3745                  * otherwise be livelocked...
3746                  */
3747                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
3748                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
3749                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3750                 if (err) {
3751                         path_put(&path);
3752                         return err;
3753                 }
3754         }
3755
3756         err = vfs_quota_on_path(sb, type, format_id, &path);
3757         path_put(&path);
3758         return err;
3759 }
3760
3761 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3762  * acquiring the locks... As quota files are never truncated and quota code
3763  * itself serializes the operations (and noone else should touch the files)
3764  * we don't have to be afraid of races */
3765 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3766                                size_t len, loff_t off)
3767 {
3768         struct inode *inode = sb_dqopt(sb)->files[type];
3769         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3770         int err = 0;
3771         int offset = off & (sb->s_blocksize - 1);
3772         int tocopy;
3773         size_t toread;
3774         struct buffer_head *bh;
3775         loff_t i_size = i_size_read(inode);
3776
3777         if (off > i_size)
3778                 return 0;
3779         if (off+len > i_size)
3780                 len = i_size-off;
3781         toread = len;
3782         while (toread > 0) {
3783                 tocopy = sb->s_blocksize - offset < toread ?
3784                                 sb->s_blocksize - offset : toread;
3785                 bh = ext4_bread(NULL, inode, blk, 0, &err);
3786                 if (err)
3787                         return err;
3788                 if (!bh)        /* A hole? */
3789                         memset(data, 0, tocopy);
3790                 else
3791                         memcpy(data, bh->b_data+offset, tocopy);
3792                 brelse(bh);
3793                 offset = 0;
3794                 toread -= tocopy;
3795                 data += tocopy;
3796                 blk++;
3797         }
3798         return len;
3799 }
3800
3801 /* Write to quotafile (we know the transaction is already started and has
3802  * enough credits) */
3803 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3804                                 const char *data, size_t len, loff_t off)
3805 {
3806         struct inode *inode = sb_dqopt(sb)->files[type];
3807         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3808         int err = 0;
3809         int offset = off & (sb->s_blocksize - 1);
3810         int tocopy;
3811         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3812         size_t towrite = len;
3813         struct buffer_head *bh;
3814         handle_t *handle = journal_current_handle();
3815
3816         if (EXT4_SB(sb)->s_journal && !handle) {
3817                 printk(KERN_WARNING "EXT4-fs: Quota write (off=%llu, len=%llu)"
3818                         " cancelled because transaction is not started.\n",
3819                         (unsigned long long)off, (unsigned long long)len);
3820                 return -EIO;
3821         }
3822         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3823         while (towrite > 0) {
3824                 tocopy = sb->s_blocksize - offset < towrite ?
3825                                 sb->s_blocksize - offset : towrite;
3826                 bh = ext4_bread(handle, inode, blk, 1, &err);
3827                 if (!bh)
3828                         goto out;
3829                 if (journal_quota) {
3830                         err = ext4_journal_get_write_access(handle, bh);
3831                         if (err) {
3832                                 brelse(bh);
3833                                 goto out;
3834                         }
3835                 }
3836                 lock_buffer(bh);
3837                 memcpy(bh->b_data+offset, data, tocopy);
3838                 flush_dcache_page(bh->b_page);
3839                 unlock_buffer(bh);
3840                 if (journal_quota)
3841                         err = ext4_handle_dirty_metadata(handle, NULL, bh);
3842                 else {
3843                         /* Always do at least ordered writes for quotas */
3844                         err = ext4_jbd2_file_inode(handle, inode);
3845                         mark_buffer_dirty(bh);
3846                 }
3847                 brelse(bh);
3848                 if (err)
3849                         goto out;
3850                 offset = 0;
3851                 towrite -= tocopy;
3852                 data += tocopy;
3853                 blk++;
3854         }
3855 out:
3856         if (len == towrite) {
3857                 mutex_unlock(&inode->i_mutex);
3858                 return err;
3859         }
3860         if (inode->i_size < off+len-towrite) {
3861                 i_size_write(inode, off+len-towrite);
3862                 EXT4_I(inode)->i_disksize = inode->i_size;
3863         }
3864         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3865         ext4_mark_inode_dirty(handle, inode);
3866         mutex_unlock(&inode->i_mutex);
3867         return len - towrite;
3868 }
3869
3870 #endif
3871
3872 static int ext4_get_sb(struct file_system_type *fs_type,
3873         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3874 {
3875         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3876 }
3877
3878 static struct file_system_type ext4_fs_type = {
3879         .owner          = THIS_MODULE,
3880         .name           = "ext4",
3881         .get_sb         = ext4_get_sb,
3882         .kill_sb        = kill_block_super,
3883         .fs_flags       = FS_REQUIRES_DEV,
3884 };
3885
3886 #ifdef CONFIG_EXT4DEV_COMPAT
3887 static int ext4dev_get_sb(struct file_system_type *fs_type,
3888         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3889 {
3890         printk(KERN_WARNING "EXT4-fs: Update your userspace programs "
3891                "to mount using ext4\n");
3892         printk(KERN_WARNING "EXT4-fs: ext4dev backwards compatibility "
3893                "will go away by 2.6.31\n");
3894         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3895 }
3896
3897 static struct file_system_type ext4dev_fs_type = {
3898         .owner          = THIS_MODULE,
3899         .name           = "ext4dev",
3900         .get_sb         = ext4dev_get_sb,
3901         .kill_sb        = kill_block_super,
3902         .fs_flags       = FS_REQUIRES_DEV,
3903 };
3904 MODULE_ALIAS("ext4dev");
3905 #endif
3906
3907 static int __init init_ext4_fs(void)
3908 {
3909         int err;
3910
3911         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
3912         if (!ext4_kset)
3913                 return -ENOMEM;
3914         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
3915         err = init_ext4_mballoc();
3916         if (err)
3917                 return err;
3918
3919         err = init_ext4_xattr();
3920         if (err)
3921                 goto out2;
3922         err = init_inodecache();
3923         if (err)
3924                 goto out1;
3925         err = register_filesystem(&ext4_fs_type);
3926         if (err)
3927                 goto out;
3928 #ifdef CONFIG_EXT4DEV_COMPAT
3929         err = register_filesystem(&ext4dev_fs_type);
3930         if (err) {
3931                 unregister_filesystem(&ext4_fs_type);
3932                 goto out;
3933         }
3934 #endif
3935         return 0;
3936 out:
3937         destroy_inodecache();
3938 out1:
3939         exit_ext4_xattr();
3940 out2:
3941         exit_ext4_mballoc();
3942         return err;
3943 }
3944
3945 static void __exit exit_ext4_fs(void)
3946 {
3947         unregister_filesystem(&ext4_fs_type);
3948 #ifdef CONFIG_EXT4DEV_COMPAT
3949         unregister_filesystem(&ext4dev_fs_type);
3950 #endif
3951         destroy_inodecache();
3952         exit_ext4_xattr();
3953         exit_ext4_mballoc();
3954         remove_proc_entry("fs/ext4", NULL);
3955         kset_unregister(ext4_kset);
3956 }
3957
3958 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
3959 MODULE_DESCRIPTION("Fourth Extended Filesystem");
3960 MODULE_LICENSE("GPL");
3961 module_init(init_ext4_fs)
3962 module_exit(exit_ext4_fs)