fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/jbd2.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/parser.h>
  28 #include <linux/smp_lock.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/log2.h>
  38 #include <linux/crc16.h>
  39 #include <asm/uaccess.h>
  40
  41 #include "ext4.h"
  42 #include "ext4_jbd2.h"
  43 #include "xattr.h"
  44 #include "acl.h"
  45 #include "namei.h"
  46 #include "group.h"
  47
  48 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  49                              unsigned long journal_devnum);
  50 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
  51                                unsigned int);
  52 static void ext4_commit_super (struct super_block * sb,
  53                                struct ext4_super_block * es,
  54                                int sync);
  55 static void ext4_mark_recovery_complete(struct super_block * sb,
  56                                         struct ext4_super_block * es);
  57 static void ext4_clear_journal_err(struct super_block * sb,
  58                                    struct ext4_super_block * es);
  59 static int ext4_sync_fs(struct super_block *sb, int wait);
  60 static const char *ext4_decode_error(struct super_block * sb, int errno,
  61                                      char nbuf[16]);
  62 static int ext4_remount (struct super_block * sb, int * flags, char * data);
  63 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf);
  64 static void ext4_unlockfs(struct super_block *sb);
  65 static void ext4_write_super (struct super_block * sb);
  66 static void ext4_write_super_lockfs(struct super_block *sb);
  67
  68
  69 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
  70                                struct ext4_group_desc *bg)
  71 {
  72         return le32_to_cpu(bg->bg_block_bitmap_lo) |
  73                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  74                 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
  75 }
  76
  77 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
  78                                struct ext4_group_desc *bg)
  79 {
  80         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
  81                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  82                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
  83 }
  84
  85 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
  86                               struct ext4_group_desc *bg)
  87 {
  88         return le32_to_cpu(bg->bg_inode_table_lo) |
  89                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  90                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
  91 }
  92
  93 void ext4_block_bitmap_set(struct super_block *sb,
  94                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
  95 {
  96         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
  97         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
  98                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
  99 }
 100
 101 void ext4_inode_bitmap_set(struct super_block *sb,
 102                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 103 {
 104         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 105         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 106                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 107 }
 108
 109 void ext4_inode_table_set(struct super_block *sb,
 110                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 111 {
 112         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 113         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 114                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 115 }
 116
 117 /*
 118  * Wrappers for jbd2_journal_start/end.
 119  *
 120  * The only special thing we need to do here is to make sure that all
 121  * journal_end calls result in the superblock being marked dirty, so
 122  * that sync() will call the filesystem's write_super callback if
 123  * appropriate.
 124  */
 125 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 126 {
 127         journal_t *journal;
 128
 129         if (sb->s_flags & MS_RDONLY)
 130                 return ERR_PTR(-EROFS);
 131
 132         /* Special case here: if the journal has aborted behind our
 133          * backs (eg. EIO in the commit thread), then we still need to
 134          * take the FS itself readonly cleanly. */
 135         journal = EXT4_SB(sb)->s_journal;
 136         if (is_journal_aborted(journal)) {
 137                 ext4_abort(sb, __func__,
 138                            "Detected aborted journal");
 139                 return ERR_PTR(-EROFS);
 140         }
 141
 142         return jbd2_journal_start(journal, nblocks);
 143 }
 144
 145 /*
 146  * The only special thing we need to do here is to make sure that all
 147  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 148  * that sync() will call the filesystem's write_super callback if
 149  * appropriate.
 150  */
 151 int __ext4_journal_stop(const char *where, handle_t *handle)
 152 {
 153         struct super_block *sb;
 154         int err;
 155         int rc;
 156
 157         sb = handle->h_transaction->t_journal->j_private;
 158         err = handle->h_err;
 159         rc = jbd2_journal_stop(handle);
 160
 161         if (!err)
 162                 err = rc;
 163         if (err)
 164                 __ext4_std_error(sb, where, err);
 165         return err;
 166 }
 167
 168 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 169                 struct buffer_head *bh, handle_t *handle, int err)
 170 {
 171         char nbuf[16];
 172         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 173
 174         if (bh)
 175                 BUFFER_TRACE(bh, "abort");
 176
 177         if (!handle->h_err)
 178                 handle->h_err = err;
 179
 180         if (is_handle_aborted(handle))
 181                 return;
 182
 183         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
 184                caller, errstr, err_fn);
 185
 186         jbd2_journal_abort_handle(handle);
 187 }
 188
 189 /* Deal with the reporting of failure conditions on a filesystem such as
 190  * inconsistencies detected or read IO failures.
 191  *
 192  * On ext2, we can store the error state of the filesystem in the
 193  * superblock.  That is not possible on ext4, because we may have other
 194  * write ordering constraints on the superblock which prevent us from
 195  * writing it out straight away; and given that the journal is about to
 196  * be aborted, we can't rely on the current, or future, transactions to
 197  * write out the superblock safely.
 198  *
 199  * We'll just use the jbd2_journal_abort() error code to record an error in
 200  * the journal instead.  On recovery, the journal will compain about
 201  * that error until we've noted it down and cleared it.
 202  */
 203
 204 static void ext4_handle_error(struct super_block *sb)
 205 {
 206         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 207
 208         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 209         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 210
 211         if (sb->s_flags & MS_RDONLY)
 212                 return;
 213
 214         if (!test_opt (sb, ERRORS_CONT)) {
 215                 journal_t *journal = EXT4_SB(sb)->s_journal;
 216
 217                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 218                 if (journal)
 219                         jbd2_journal_abort(journal, -EIO);
 220         }
 221         if (test_opt (sb, ERRORS_RO)) {
 222                 printk (KERN_CRIT "Remounting filesystem read-only\n");
 223                 sb->s_flags |= MS_RDONLY;
 224         }
 225         ext4_commit_super(sb, es, 1);
 226         if (test_opt(sb, ERRORS_PANIC))
 227                 panic("EXT4-fs (device %s): panic forced after error\n",
 228                         sb->s_id);
 229 }
 230
 231 void ext4_error (struct super_block * sb, const char * function,
 232                  const char * fmt, ...)
 233 {
 234         va_list args;
 235
 236         va_start(args, fmt);
 237         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 238         vprintk(fmt, args);
 239         printk("\n");
 240         va_end(args);
 241
 242         ext4_handle_error(sb);
 243 }
 244
 245 static const char *ext4_decode_error(struct super_block * sb, int errno,
 246                                      char nbuf[16])
 247 {
 248         char *errstr = NULL;
 249
 250         switch (errno) {
 251         case -EIO:
 252                 errstr = "IO failure";
 253                 break;
 254         case -ENOMEM:
 255                 errstr = "Out of memory";
 256                 break;
 257         case -EROFS:
 258                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
 259                         errstr = "Journal has aborted";
 260                 else
 261                         errstr = "Readonly filesystem";
 262                 break;
 263         default:
 264                 /* If the caller passed in an extra buffer for unknown
 265                  * errors, textualise them now.  Else we just return
 266                  * NULL. */
 267                 if (nbuf) {
 268                         /* Check for truncated error codes... */
 269                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 270                                 errstr = nbuf;
 271                 }
 272                 break;
 273         }
 274
 275         return errstr;
 276 }
 277
 278 /* __ext4_std_error decodes expected errors from journaling functions
 279  * automatically and invokes the appropriate error response.  */
 280
 281 void __ext4_std_error (struct super_block * sb, const char * function,
 282                        int errno)
 283 {
 284         char nbuf[16];
 285         const char *errstr;
 286
 287         /* Special case: if the error is EROFS, and we're not already
 288          * inside a transaction, then there's really no point in logging
 289          * an error. */
 290         if (errno == -EROFS && journal_current_handle() == NULL &&
 291             (sb->s_flags & MS_RDONLY))
 292                 return;
 293
 294         errstr = ext4_decode_error(sb, errno, nbuf);
 295         printk (KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
 296                 sb->s_id, function, errstr);
 297
 298         ext4_handle_error(sb);
 299 }
 300
 301 /*
 302  * ext4_abort is a much stronger failure handler than ext4_error.  The
 303  * abort function may be used to deal with unrecoverable failures such
 304  * as journal IO errors or ENOMEM at a critical moment in log management.
 305  *
 306  * We unconditionally force the filesystem into an ABORT|READONLY state,
 307  * unless the error response on the fs has been set to panic in which
 308  * case we take the easy way out and panic immediately.
 309  */
 310
 311 void ext4_abort (struct super_block * sb, const char * function,
 312                  const char * fmt, ...)
 313 {
 314         va_list args;
 315
 316         printk (KERN_CRIT "ext4_abort called.\n");
 317
 318         va_start(args, fmt);
 319         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 320         vprintk(fmt, args);
 321         printk("\n");
 322         va_end(args);
 323
 324         if (test_opt(sb, ERRORS_PANIC))
 325                 panic("EXT4-fs panic from previous error\n");
 326
 327         if (sb->s_flags & MS_RDONLY)
 328                 return;
 329
 330         printk(KERN_CRIT "Remounting filesystem read-only\n");
 331         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 332         sb->s_flags |= MS_RDONLY;
 333         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 334         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 335 }
 336
 337 void ext4_warning (struct super_block * sb, const char * function,
 338                    const char * fmt, ...)
 339 {
 340         va_list args;
 341
 342         va_start(args, fmt);
 343         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
 344                sb->s_id, function);
 345         vprintk(fmt, args);
 346         printk("\n");
 347         va_end(args);
 348 }
 349
 350 void ext4_update_dynamic_rev(struct super_block *sb)
 351 {
 352         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 353
 354         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 355                 return;
 356
 357         ext4_warning(sb, __func__,
 358                      "updating to rev %d because of new feature flag, "
 359                      "running e2fsck is recommended",
 360                      EXT4_DYNAMIC_REV);
 361
 362         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 363         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 364         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 365         /* leave es->s_feature_*compat flags alone */
 366         /* es->s_uuid will be set by e2fsck if empty */
 367
 368         /*
 369          * The rest of the superblock fields should be zero, and if not it
 370          * means they are likely already in use, so leave them alone.  We
 371          * can leave it up to e2fsck to clean up any inconsistencies there.
 372          */
 373 }
 374
 375 int ext4_update_compat_feature(handle_t *handle,
 376                                         struct super_block *sb, __u32 compat)
 377 {
 378         int err = 0;
 379         if (!EXT4_HAS_COMPAT_FEATURE(sb, compat)) {
 380                 err = ext4_journal_get_write_access(handle,
 381                                 EXT4_SB(sb)->s_sbh);
 382                 if (err)
 383                         return err;
 384                 EXT4_SET_COMPAT_FEATURE(sb, compat);
 385                 sb->s_dirt = 1;
 386                 handle->h_sync = 1;
 387                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 388                                         "call ext4_journal_dirty_met adata");
 389                 err = ext4_journal_dirty_metadata(handle,
 390                                 EXT4_SB(sb)->s_sbh);
 391         }
 392         return err;
 393 }
 394
 395 int ext4_update_rocompat_feature(handle_t *handle,
 396                                         struct super_block *sb, __u32 rocompat)
 397 {
 398         int err = 0;
 399         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, rocompat)) {
 400                 err = ext4_journal_get_write_access(handle,
 401                                 EXT4_SB(sb)->s_sbh);
 402                 if (err)
 403                         return err;
 404                 EXT4_SET_RO_COMPAT_FEATURE(sb, rocompat);
 405                 sb->s_dirt = 1;
 406                 handle->h_sync = 1;
 407                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 408                                         "call ext4_journal_dirty_met adata");
 409                 err = ext4_journal_dirty_metadata(handle,
 410                                 EXT4_SB(sb)->s_sbh);
 411         }
 412         return err;
 413 }
 414
 415 int ext4_update_incompat_feature(handle_t *handle,
 416                                         struct super_block *sb, __u32 incompat)
 417 {
 418         int err = 0;
 419         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, incompat)) {
 420                 err = ext4_journal_get_write_access(handle,
 421                                 EXT4_SB(sb)->s_sbh);
 422                 if (err)
 423                         return err;
 424                 EXT4_SET_INCOMPAT_FEATURE(sb, incompat);
 425                 sb->s_dirt = 1;
 426                 handle->h_sync = 1;
 427                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 428                                         "call ext4_journal_dirty_met adata");
 429                 err = ext4_journal_dirty_metadata(handle,
 430                                 EXT4_SB(sb)->s_sbh);
 431         }
 432         return err;
 433 }
 434
 435 /*
 436  * Open the external journal device
 437  */
 438 static struct block_device *ext4_blkdev_get(dev_t dev)
 439 {
 440         struct block_device *bdev;
 441         char b[BDEVNAME_SIZE];
 442
 443         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 444         if (IS_ERR(bdev))
 445                 goto fail;
 446         return bdev;
 447
 448 fail:
 449         printk(KERN_ERR "EXT4: failed to open journal device %s: %ld\n",
 450                         __bdevname(dev, b), PTR_ERR(bdev));
 451         return NULL;
 452 }
 453
 454 /*
 455  * Release the journal device
 456  */
 457 static int ext4_blkdev_put(struct block_device *bdev)
 458 {
 459         bd_release(bdev);
 460         return blkdev_put(bdev);
 461 }
 462
 463 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 464 {
 465         struct block_device *bdev;
 466         int ret = -ENODEV;
 467
 468         bdev = sbi->journal_bdev;
 469         if (bdev) {
 470                 ret = ext4_blkdev_put(bdev);
 471                 sbi->journal_bdev = NULL;
 472         }
 473         return ret;
 474 }
 475
 476 static inline struct inode *orphan_list_entry(struct list_head *l)
 477 {
 478         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 479 }
 480
 481 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 482 {
 483         struct list_head *l;
 484
 485         printk(KERN_ERR "sb orphan head is %d\n",
 486                le32_to_cpu(sbi->s_es->s_last_orphan));
 487
 488         printk(KERN_ERR "sb_info orphan list:\n");
 489         list_for_each(l, &sbi->s_orphan) {
 490                 struct inode *inode = orphan_list_entry(l);
 491                 printk(KERN_ERR "  "
 492                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 493                        inode->i_sb->s_id, inode->i_ino, inode,
 494                        inode->i_mode, inode->i_nlink,
 495                        NEXT_ORPHAN(inode));
 496         }
 497 }
 498
 499 static void ext4_put_super (struct super_block * sb)
 500 {
 501         struct ext4_sb_info *sbi = EXT4_SB(sb);
 502         struct ext4_super_block *es = sbi->s_es;
 503         int i;
 504
 505         ext4_mb_release(sb);
 506         ext4_ext_release(sb);
 507         ext4_xattr_put_super(sb);
 508         jbd2_journal_destroy(sbi->s_journal);
 509         sbi->s_journal = NULL;
 510         if (!(sb->s_flags & MS_RDONLY)) {
 511                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 512                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 513                 BUFFER_TRACE(sbi->s_sbh, "marking dirty");
 514                 mark_buffer_dirty(sbi->s_sbh);
 515                 ext4_commit_super(sb, es, 1);
 516         }
 517
 518         for (i = 0; i < sbi->s_gdb_count; i++)
 519                 brelse(sbi->s_group_desc[i]);
 520         kfree(sbi->s_group_desc);
 521         kfree(sbi->s_flex_groups);
 522         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 523         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 524         percpu_counter_destroy(&sbi->s_dirs_counter);
 525         brelse(sbi->s_sbh);
 526 #ifdef CONFIG_QUOTA
 527         for (i = 0; i < MAXQUOTAS; i++)
 528                 kfree(sbi->s_qf_names[i]);
 529 #endif
 530
 531         /* Debugging code just in case the in-memory inode orphan list
 532          * isn't empty.  The on-disk one can be non-empty if we've
 533          * detected an error and taken the fs readonly, but the
 534          * in-memory list had better be clean by this point. */
 535         if (!list_empty(&sbi->s_orphan))
 536                 dump_orphan_list(sb, sbi);
 537         J_ASSERT(list_empty(&sbi->s_orphan));
 538
 539         invalidate_bdev(sb->s_bdev);
 540         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 541                 /*
 542                  * Invalidate the journal device's buffers.  We don't want them
 543                  * floating about in memory - the physical journal device may
 544                  * hotswapped, and it breaks the `ro-after' testing code.
 545                  */
 546                 sync_blockdev(sbi->journal_bdev);
 547                 invalidate_bdev(sbi->journal_bdev);
 548                 ext4_blkdev_remove(sbi);
 549         }
 550         sb->s_fs_info = NULL;
 551         kfree(sbi);
 552         return;
 553 }
 554
 555 static struct kmem_cache *ext4_inode_cachep;
 556
 557 /*
 558  * Called inside transaction, so use GFP_NOFS
 559  */
 560 static struct inode *ext4_alloc_inode(struct super_block *sb)
 561 {
 562         struct ext4_inode_info *ei;
 563
 564         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 565         if (!ei)
 566                 return NULL;
 567 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 568         ei->i_acl = EXT4_ACL_NOT_CACHED;
 569         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 570 #endif
 571         ei->i_block_alloc_info = NULL;
 572         ei->vfs_inode.i_version = 1;
 573         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 574         INIT_LIST_HEAD(&ei->i_prealloc_list);
 575         spin_lock_init(&ei->i_prealloc_lock);
 576         return &ei->vfs_inode;
 577 }
 578
 579 static void ext4_destroy_inode(struct inode *inode)
 580 {
 581         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 582                 printk("EXT4 Inode %p: orphan list check failed!\n",
 583                         EXT4_I(inode));
 584                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 585                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 586                                 true);
 587                 dump_stack();
 588         }
 589         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 590 }
 591
 592 static void init_once(struct kmem_cache *cachep, void *foo)
 593 {
 594         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 595
 596         INIT_LIST_HEAD(&ei->i_orphan);
 597 #ifdef CONFIG_EXT4DEV_FS_XATTR
 598         init_rwsem(&ei->xattr_sem);
 599 #endif
 600         init_rwsem(&ei->i_data_sem);
 601         inode_init_once(&ei->vfs_inode);
 602 }
 603
 604 static int init_inodecache(void)
 605 {
 606         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 607                                              sizeof(struct ext4_inode_info),
 608                                              0, (SLAB_RECLAIM_ACCOUNT|
 609                                                 SLAB_MEM_SPREAD),
 610                                              init_once);
 611         if (ext4_inode_cachep == NULL)
 612                 return -ENOMEM;
 613         return 0;
 614 }
 615
 616 static void destroy_inodecache(void)
 617 {
 618         kmem_cache_destroy(ext4_inode_cachep);
 619 }
 620
 621 static void ext4_clear_inode(struct inode *inode)
 622 {
 623         struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
 624 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 625         if (EXT4_I(inode)->i_acl &&
 626                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
 627                 posix_acl_release(EXT4_I(inode)->i_acl);
 628                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
 629         }
 630         if (EXT4_I(inode)->i_default_acl &&
 631                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
 632                 posix_acl_release(EXT4_I(inode)->i_default_acl);
 633                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
 634         }
 635 #endif
 636         ext4_discard_reservation(inode);
 637         EXT4_I(inode)->i_block_alloc_info = NULL;
 638         if (unlikely(rsv))
 639                 kfree(rsv);
 640 }
 641
 642 static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
 643 {
 644 #if defined(CONFIG_QUOTA)
 645         struct ext4_sb_info *sbi = EXT4_SB(sb);
 646
 647         if (sbi->s_jquota_fmt)
 648                 seq_printf(seq, ",jqfmt=%s",
 649                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold": "vfsv0");
 650
 651         if (sbi->s_qf_names[USRQUOTA])
 652                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 653
 654         if (sbi->s_qf_names[GRPQUOTA])
 655                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 656
 657         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
 658                 seq_puts(seq, ",usrquota");
 659
 660         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
 661                 seq_puts(seq, ",grpquota");
 662 #endif
 663 }
 664
 665 /*
 666  * Show an option if
 667  *  - it's set to a non-default value OR
 668  *  - if the per-sb default is different from the global default
 669  */
 670 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 671 {
 672         int def_errors;
 673         unsigned long def_mount_opts;
 674         struct super_block *sb = vfs->mnt_sb;
 675         struct ext4_sb_info *sbi = EXT4_SB(sb);
 676         struct ext4_super_block *es = sbi->s_es;
 677
 678         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 679         def_errors     = le16_to_cpu(es->s_errors);
 680
 681         if (sbi->s_sb_block != 1)
 682                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 683         if (test_opt(sb, MINIX_DF))
 684                 seq_puts(seq, ",minixdf");
 685         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
 686                 seq_puts(seq, ",grpid");
 687         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 688                 seq_puts(seq, ",nogrpid");
 689         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 690             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 691                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 692         }
 693         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 694             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 695                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 696         }
 697         if (test_opt(sb, ERRORS_RO)) {
 698                 if (def_errors == EXT4_ERRORS_PANIC ||
 699                     def_errors == EXT4_ERRORS_CONTINUE) {
 700                         seq_puts(seq, ",errors=remount-ro");
 701                 }
 702         }
 703         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
 704                 seq_puts(seq, ",errors=continue");
 705         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
 706                 seq_puts(seq, ",errors=panic");
 707         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
 708                 seq_puts(seq, ",nouid32");
 709         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
 710                 seq_puts(seq, ",debug");
 711         if (test_opt(sb, OLDALLOC))
 712                 seq_puts(seq, ",oldalloc");
 713 #ifdef CONFIG_EXT4DEV_FS_XATTR
 714         if (test_opt(sb, XATTR_USER) &&
 715                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
 716                 seq_puts(seq, ",user_xattr");
 717         if (!test_opt(sb, XATTR_USER) &&
 718             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 719                 seq_puts(seq, ",nouser_xattr");
 720         }
 721 #endif
 722 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 723         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
 724                 seq_puts(seq, ",acl");
 725         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 726                 seq_puts(seq, ",noacl");
 727 #endif
 728         if (!test_opt(sb, RESERVATION))
 729                 seq_puts(seq, ",noreservation");
 730         if (sbi->s_commit_interval) {
 731                 seq_printf(seq, ",commit=%u",
 732                            (unsigned) (sbi->s_commit_interval / HZ));
 733         }
 734         /*
 735          * We're changing the default of barrier mount option, so
 736          * let's always display its mount state so it's clear what its
 737          * status is.
 738          */
 739         seq_puts(seq, ",barrier=");
 740         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
 741         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
 742                 seq_puts(seq, ",journal_async_commit");
 743         if (test_opt(sb, NOBH))
 744                 seq_puts(seq, ",nobh");
 745         if (!test_opt(sb, EXTENTS))
 746                 seq_puts(seq, ",noextents");
 747         if (!test_opt(sb, MBALLOC))
 748                 seq_puts(seq, ",nomballoc");
 749         if (test_opt(sb, I_VERSION))
 750                 seq_puts(seq, ",i_version");
 751
 752         if (sbi->s_stripe)
 753                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
 754         /*
 755          * journal mode get enabled in different ways
 756          * So just print the value even if we didn't specify it
 757          */
 758         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 759                 seq_puts(seq, ",data=journal");
 760         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 761                 seq_puts(seq, ",data=ordered");
 762         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 763                 seq_puts(seq, ",data=writeback");
 764
 765         ext4_show_quota_options(seq, sb);
 766         return 0;
 767 }
 768
 769
 770 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 771                 u64 ino, u32 generation)
 772 {
 773         struct inode *inode;
 774
 775         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 776                 return ERR_PTR(-ESTALE);
 777         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 778                 return ERR_PTR(-ESTALE);
 779
 780         /* iget isn't really right if the inode is currently unallocated!!
 781          *
 782          * ext4_read_inode will return a bad_inode if the inode had been
 783          * deleted, so we should be safe.
 784          *
 785          * Currently we don't know the generation for parent directory, so
 786          * a generation of 0 means "accept any"
 787          */
 788         inode = ext4_iget(sb, ino);
 789         if (IS_ERR(inode))
 790                 return ERR_CAST(inode);
 791         if (generation && inode->i_generation != generation) {
 792                 iput(inode);
 793                 return ERR_PTR(-ESTALE);
 794         }
 795
 796         return inode;
 797 }
 798
 799 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 800                 int fh_len, int fh_type)
 801 {
 802         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 803                                     ext4_nfs_get_inode);
 804 }
 805
 806 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 807                 int fh_len, int fh_type)
 808 {
 809         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 810                                     ext4_nfs_get_inode);
 811 }
 812
 813 #ifdef CONFIG_QUOTA
 814 #define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
 815 #define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 816
 817 static int ext4_dquot_initialize(struct inode *inode, int type);
 818 static int ext4_dquot_drop(struct inode *inode);
 819 static int ext4_write_dquot(struct dquot *dquot);
 820 static int ext4_acquire_dquot(struct dquot *dquot);
 821 static int ext4_release_dquot(struct dquot *dquot);
 822 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 823 static int ext4_write_info(struct super_block *sb, int type);
 824 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 825                                 char *path, int remount);
 826 static int ext4_quota_on_mount(struct super_block *sb, int type);
 827 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 828                                size_t len, loff_t off);
 829 static ssize_t ext4_quota_write(struct super_block *sb, int type,
 830                                 const char *data, size_t len, loff_t off);
 831
 832 static struct dquot_operations ext4_quota_operations = {
 833         .initialize     = ext4_dquot_initialize,
 834         .drop           = ext4_dquot_drop,
 835         .alloc_space    = dquot_alloc_space,
 836         .alloc_inode    = dquot_alloc_inode,
 837         .free_space     = dquot_free_space,
 838         .free_inode     = dquot_free_inode,
 839         .transfer       = dquot_transfer,
 840         .write_dquot    = ext4_write_dquot,
 841         .acquire_dquot  = ext4_acquire_dquot,
 842         .release_dquot  = ext4_release_dquot,
 843         .mark_dirty     = ext4_mark_dquot_dirty,
 844         .write_info     = ext4_write_info
 845 };
 846
 847 static struct quotactl_ops ext4_qctl_operations = {
 848         .quota_on       = ext4_quota_on,
 849         .quota_off      = vfs_quota_off,
 850         .quota_sync     = vfs_quota_sync,
 851         .get_info       = vfs_get_dqinfo,
 852         .set_info       = vfs_set_dqinfo,
 853         .get_dqblk      = vfs_get_dqblk,
 854         .set_dqblk      = vfs_set_dqblk
 855 };
 856 #endif
 857
 858 static const struct super_operations ext4_sops = {
 859         .alloc_inode    = ext4_alloc_inode,
 860         .destroy_inode  = ext4_destroy_inode,
 861         .write_inode    = ext4_write_inode,
 862         .dirty_inode    = ext4_dirty_inode,
 863         .delete_inode   = ext4_delete_inode,
 864         .put_super      = ext4_put_super,
 865         .write_super    = ext4_write_super,
 866         .sync_fs        = ext4_sync_fs,
 867         .write_super_lockfs = ext4_write_super_lockfs,
 868         .unlockfs       = ext4_unlockfs,
 869         .statfs         = ext4_statfs,
 870         .remount_fs     = ext4_remount,
 871         .clear_inode    = ext4_clear_inode,
 872         .show_options   = ext4_show_options,
 873 #ifdef CONFIG_QUOTA
 874         .quota_read     = ext4_quota_read,
 875         .quota_write    = ext4_quota_write,
 876 #endif
 877 };
 878
 879 static const struct export_operations ext4_export_ops = {
 880         .fh_to_dentry = ext4_fh_to_dentry,
 881         .fh_to_parent = ext4_fh_to_parent,
 882         .get_parent = ext4_get_parent,
 883 };
 884
 885 enum {
 886         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 887         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
 888         Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov,
 889         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
 890         Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
 891         Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
 892         Opt_journal_checksum, Opt_journal_async_commit,
 893         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
 894         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 895         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
 896         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
 897         Opt_grpquota, Opt_extents, Opt_noextents, Opt_i_version,
 898         Opt_mballoc, Opt_nomballoc, Opt_stripe,
 899 };
 900
 901 static match_table_t tokens = {
 902         {Opt_bsd_df, "bsddf"},
 903         {Opt_minix_df, "minixdf"},
 904         {Opt_grpid, "grpid"},
 905         {Opt_grpid, "bsdgroups"},
 906         {Opt_nogrpid, "nogrpid"},
 907         {Opt_nogrpid, "sysvgroups"},
 908         {Opt_resgid, "resgid=%u"},
 909         {Opt_resuid, "resuid=%u"},
 910         {Opt_sb, "sb=%u"},
 911         {Opt_err_cont, "errors=continue"},
 912         {Opt_err_panic, "errors=panic"},
 913         {Opt_err_ro, "errors=remount-ro"},
 914         {Opt_nouid32, "nouid32"},
 915         {Opt_nocheck, "nocheck"},
 916         {Opt_nocheck, "check=none"},
 917         {Opt_debug, "debug"},
 918         {Opt_oldalloc, "oldalloc"},
 919         {Opt_orlov, "orlov"},
 920         {Opt_user_xattr, "user_xattr"},
 921         {Opt_nouser_xattr, "nouser_xattr"},
 922         {Opt_acl, "acl"},
 923         {Opt_noacl, "noacl"},
 924         {Opt_reservation, "reservation"},
 925         {Opt_noreservation, "noreservation"},
 926         {Opt_noload, "noload"},
 927         {Opt_nobh, "nobh"},
 928         {Opt_bh, "bh"},
 929         {Opt_commit, "commit=%u"},
 930         {Opt_journal_update, "journal=update"},
 931         {Opt_journal_inum, "journal=%u"},
 932         {Opt_journal_dev, "journal_dev=%u"},
 933         {Opt_journal_checksum, "journal_checksum"},
 934         {Opt_journal_async_commit, "journal_async_commit"},
 935         {Opt_abort, "abort"},
 936         {Opt_data_journal, "data=journal"},
 937         {Opt_data_ordered, "data=ordered"},
 938         {Opt_data_writeback, "data=writeback"},
 939         {Opt_offusrjquota, "usrjquota="},
 940         {Opt_usrjquota, "usrjquota=%s"},
 941         {Opt_offgrpjquota, "grpjquota="},
 942         {Opt_grpjquota, "grpjquota=%s"},
 943         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
 944         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
 945         {Opt_grpquota, "grpquota"},
 946         {Opt_noquota, "noquota"},
 947         {Opt_quota, "quota"},
 948         {Opt_usrquota, "usrquota"},
 949         {Opt_barrier, "barrier=%u"},
 950         {Opt_extents, "extents"},
 951         {Opt_noextents, "noextents"},
 952         {Opt_i_version, "i_version"},
 953         {Opt_mballoc, "mballoc"},
 954         {Opt_nomballoc, "nomballoc"},
 955         {Opt_stripe, "stripe=%u"},
 956         {Opt_resize, "resize"},
 957         {Opt_err, NULL},
 958 };
 959
 960 static ext4_fsblk_t get_sb_block(void **data)
 961 {
 962         ext4_fsblk_t    sb_block;
 963         char            *options = (char *) *data;
 964
 965         if (!options || strncmp(options, "sb=", 3) != 0)
 966                 return 1;       /* Default location */
 967         options += 3;
 968         /*todo: use simple_strtoll with >32bit ext4 */
 969         sb_block = simple_strtoul(options, &options, 0);
 970         if (*options && *options != ',') {
 971                 printk("EXT4-fs: Invalid sb specification: %s\n",
 972                        (char *) *data);
 973                 return 1;
 974         }
 975         if (*options == ',')
 976                 options++;
 977         *data = (void *) options;
 978         return sb_block;
 979 }
 980
 981 static int parse_options (char *options, struct super_block *sb,
 982                           unsigned int *inum, unsigned long *journal_devnum,
 983                           ext4_fsblk_t *n_blocks_count, int is_remount)
 984 {
 985         struct ext4_sb_info *sbi = EXT4_SB(sb);
 986         char * p;
 987         substring_t args[MAX_OPT_ARGS];
 988         int data_opt = 0;
 989         int option;
 990 #ifdef CONFIG_QUOTA
 991         int qtype, qfmt;
 992         char *qname;
 993 #endif
 994
 995         if (!options)
 996                 return 1;
 997
 998         while ((p = strsep (&options, ",")) != NULL) {
 999                 int token;
1000                 if (!*p)
1001                         continue;
1002
1003                 token = match_token(p, tokens, args);
1004                 switch (token) {
1005                 case Opt_bsd_df:
1006                         clear_opt (sbi->s_mount_opt, MINIX_DF);
1007                         break;
1008                 case Opt_minix_df:
1009                         set_opt (sbi->s_mount_opt, MINIX_DF);
1010                         break;
1011                 case Opt_grpid:
1012                         set_opt (sbi->s_mount_opt, GRPID);
1013                         break;
1014                 case Opt_nogrpid:
1015                         clear_opt (sbi->s_mount_opt, GRPID);
1016                         break;
1017                 case Opt_resuid:
1018                         if (match_int(&args[0], &option))
1019                                 return 0;
1020                         sbi->s_resuid = option;
1021                         break;
1022                 case Opt_resgid:
1023                         if (match_int(&args[0], &option))
1024                                 return 0;
1025                         sbi->s_resgid = option;
1026                         break;
1027                 case Opt_sb:
1028                         /* handled by get_sb_block() instead of here */
1029                         /* *sb_block = match_int(&args[0]); */
1030                         break;
1031                 case Opt_err_panic:
1032                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
1033                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
1034                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
1035                         break;
1036                 case Opt_err_ro:
1037                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
1038                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
1039                         set_opt (sbi->s_mount_opt, ERRORS_RO);
1040                         break;
1041                 case Opt_err_cont:
1042                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
1043                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
1044                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
1045                         break;
1046                 case Opt_nouid32:
1047                         set_opt (sbi->s_mount_opt, NO_UID32);
1048                         break;
1049                 case Opt_nocheck:
1050                         clear_opt (sbi->s_mount_opt, CHECK);
1051                         break;
1052                 case Opt_debug:
1053                         set_opt (sbi->s_mount_opt, DEBUG);
1054                         break;
1055                 case Opt_oldalloc:
1056                         set_opt (sbi->s_mount_opt, OLDALLOC);
1057                         break;
1058                 case Opt_orlov:
1059                         clear_opt (sbi->s_mount_opt, OLDALLOC);
1060                         break;
1061 #ifdef CONFIG_EXT4DEV_FS_XATTR
1062                 case Opt_user_xattr:
1063                         set_opt (sbi->s_mount_opt, XATTR_USER);
1064                         break;
1065                 case Opt_nouser_xattr:
1066                         clear_opt (sbi->s_mount_opt, XATTR_USER);
1067                         break;
1068 #else
1069                 case Opt_user_xattr:
1070                 case Opt_nouser_xattr:
1071                         printk("EXT4 (no)user_xattr options not supported\n");
1072                         break;
1073 #endif
1074 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1075                 case Opt_acl:
1076                         set_opt(sbi->s_mount_opt, POSIX_ACL);
1077                         break;
1078                 case Opt_noacl:
1079                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
1080                         break;
1081 #else
1082                 case Opt_acl:
1083                 case Opt_noacl:
1084                         printk("EXT4 (no)acl options not supported\n");
1085                         break;
1086 #endif
1087                 case Opt_reservation:
1088                         set_opt(sbi->s_mount_opt, RESERVATION);
1089                         break;
1090                 case Opt_noreservation:
1091                         clear_opt(sbi->s_mount_opt, RESERVATION);
1092                         break;
1093                 case Opt_journal_update:
1094                         /* @@@ FIXME */
1095                         /* Eventually we will want to be able to create
1096                            a journal file here.  For now, only allow the
1097                            user to specify an existing inode to be the
1098                            journal file. */
1099                         if (is_remount) {
1100                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1101                                        "journal on remount\n");
1102                                 return 0;
1103                         }
1104                         set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
1105                         break;
1106                 case Opt_journal_inum:
1107                         if (is_remount) {
1108                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1109                                        "journal on remount\n");
1110                                 return 0;
1111                         }
1112                         if (match_int(&args[0], &option))
1113                                 return 0;
1114                         *inum = option;
1115                         break;
1116                 case Opt_journal_dev:
1117                         if (is_remount) {
1118                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1119                                        "journal on remount\n");
1120                                 return 0;
1121                         }
1122                         if (match_int(&args[0], &option))
1123                                 return 0;
1124                         *journal_devnum = option;
1125                         break;
1126                 case Opt_journal_checksum:
1127                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1128                         break;
1129                 case Opt_journal_async_commit:
1130                         set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1131                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1132                         break;
1133                 case Opt_noload:
1134                         set_opt (sbi->s_mount_opt, NOLOAD);
1135                         break;
1136                 case Opt_commit:
1137                         if (match_int(&args[0], &option))
1138                                 return 0;
1139                         if (option < 0)
1140                                 return 0;
1141                         if (option == 0)
1142                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1143                         sbi->s_commit_interval = HZ * option;
1144                         break;
1145                 case Opt_data_journal:
1146                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1147                         goto datacheck;
1148                 case Opt_data_ordered:
1149                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1150                         goto datacheck;
1151                 case Opt_data_writeback:
1152                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1153                 datacheck:
1154                         if (is_remount) {
1155                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1156                                                 != data_opt) {
1157                                         printk(KERN_ERR
1158                                                 "EXT4-fs: cannot change data "
1159                                                 "mode on remount\n");
1160                                         return 0;
1161                                 }
1162                         } else {
1163                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1164                                 sbi->s_mount_opt |= data_opt;
1165                         }
1166                         break;
1167 #ifdef CONFIG_QUOTA
1168                 case Opt_usrjquota:
1169                         qtype = USRQUOTA;
1170                         goto set_qf_name;
1171                 case Opt_grpjquota:
1172                         qtype = GRPQUOTA;
1173 set_qf_name:
1174                         if ((sb_any_quota_enabled(sb) ||
1175                              sb_any_quota_suspended(sb)) &&
1176                             !sbi->s_qf_names[qtype]) {
1177                                 printk(KERN_ERR
1178                                         "EXT4-fs: Cannot change journaled "
1179                                         "quota options when quota turned on.\n");
1180                                 return 0;
1181                         }
1182                         qname = match_strdup(&args[0]);
1183                         if (!qname) {
1184                                 printk(KERN_ERR
1185                                         "EXT4-fs: not enough memory for "
1186                                         "storing quotafile name.\n");
1187                                 return 0;
1188                         }
1189                         if (sbi->s_qf_names[qtype] &&
1190                             strcmp(sbi->s_qf_names[qtype], qname)) {
1191                                 printk(KERN_ERR
1192                                         "EXT4-fs: %s quota file already "
1193                                         "specified.\n", QTYPE2NAME(qtype));
1194                                 kfree(qname);
1195                                 return 0;
1196                         }
1197                         sbi->s_qf_names[qtype] = qname;
1198                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1199                                 printk(KERN_ERR
1200                                         "EXT4-fs: quotafile must be on "
1201                                         "filesystem root.\n");
1202                                 kfree(sbi->s_qf_names[qtype]);
1203                                 sbi->s_qf_names[qtype] = NULL;
1204                                 return 0;
1205                         }
1206                         set_opt(sbi->s_mount_opt, QUOTA);
1207                         break;
1208                 case Opt_offusrjquota:
1209                         qtype = USRQUOTA;
1210                         goto clear_qf_name;
1211                 case Opt_offgrpjquota:
1212                         qtype = GRPQUOTA;
1213 clear_qf_name:
1214                         if ((sb_any_quota_enabled(sb) ||
1215                              sb_any_quota_suspended(sb)) &&
1216                             sbi->s_qf_names[qtype]) {
1217                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1218                                         "journaled quota options when "
1219                                         "quota turned on.\n");
1220                                 return 0;
1221                         }
1222                         /*
1223                          * The space will be released later when all options
1224                          * are confirmed to be correct
1225                          */
1226                         sbi->s_qf_names[qtype] = NULL;
1227                         break;
1228                 case Opt_jqfmt_vfsold:
1229                         qfmt = QFMT_VFS_OLD;
1230                         goto set_qf_format;
1231                 case Opt_jqfmt_vfsv0:
1232                         qfmt = QFMT_VFS_V0;
1233 set_qf_format:
1234                         if ((sb_any_quota_enabled(sb) ||
1235                              sb_any_quota_suspended(sb)) &&
1236                             sbi->s_jquota_fmt != qfmt) {
1237                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1238                                         "journaled quota options when "
1239                                         "quota turned on.\n");
1240                                 return 0;
1241                         }
1242                         sbi->s_jquota_fmt = qfmt;
1243                         break;
1244                 case Opt_quota:
1245                 case Opt_usrquota:
1246                         set_opt(sbi->s_mount_opt, QUOTA);
1247                         set_opt(sbi->s_mount_opt, USRQUOTA);
1248                         break;
1249                 case Opt_grpquota:
1250                         set_opt(sbi->s_mount_opt, QUOTA);
1251                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1252                         break;
1253                 case Opt_noquota:
1254                         if (sb_any_quota_enabled(sb)) {
1255                                 printk(KERN_ERR "EXT4-fs: Cannot change quota "
1256                                         "options when quota turned on.\n");
1257                                 return 0;
1258                         }
1259                         clear_opt(sbi->s_mount_opt, QUOTA);
1260                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1261                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1262                         break;
1263 #else
1264                 case Opt_quota:
1265                 case Opt_usrquota:
1266                 case Opt_grpquota:
1267                         printk(KERN_ERR
1268                                 "EXT4-fs: quota options not supported.\n");
1269                         break;
1270                 case Opt_usrjquota:
1271                 case Opt_grpjquota:
1272                 case Opt_offusrjquota:
1273                 case Opt_offgrpjquota:
1274                 case Opt_jqfmt_vfsold:
1275                 case Opt_jqfmt_vfsv0:
1276                         printk(KERN_ERR
1277                                 "EXT4-fs: journaled quota options not "
1278                                 "supported.\n");
1279                         break;
1280                 case Opt_noquota:
1281                         break;
1282 #endif
1283                 case Opt_abort:
1284                         set_opt(sbi->s_mount_opt, ABORT);
1285                         break;
1286                 case Opt_barrier:
1287                         if (match_int(&args[0], &option))
1288                                 return 0;
1289                         if (option)
1290                                 set_opt(sbi->s_mount_opt, BARRIER);
1291                         else
1292                                 clear_opt(sbi->s_mount_opt, BARRIER);
1293                         break;
1294                 case Opt_ignore:
1295                         break;
1296                 case Opt_resize:
1297                         if (!is_remount) {
1298                                 printk("EXT4-fs: resize option only available "
1299                                         "for remount\n");
1300                                 return 0;
1301                         }
1302                         if (match_int(&args[0], &option) != 0)
1303                                 return 0;
1304                         *n_blocks_count = option;
1305                         break;
1306                 case Opt_nobh:
1307                         set_opt(sbi->s_mount_opt, NOBH);
1308                         break;
1309                 case Opt_bh:
1310                         clear_opt(sbi->s_mount_opt, NOBH);
1311                         break;
1312                 case Opt_extents:
1313                         set_opt (sbi->s_mount_opt, EXTENTS);
1314                         break;
1315                 case Opt_noextents:
1316                         clear_opt (sbi->s_mount_opt, EXTENTS);
1317                         break;
1318                 case Opt_i_version:
1319                         set_opt(sbi->s_mount_opt, I_VERSION);
1320                         sb->s_flags |= MS_I_VERSION;
1321                         break;
1322                 case Opt_mballoc:
1323                         set_opt(sbi->s_mount_opt, MBALLOC);
1324                         break;
1325                 case Opt_nomballoc:
1326                         clear_opt(sbi->s_mount_opt, MBALLOC);
1327                         break;
1328                 case Opt_stripe:
1329                         if (match_int(&args[0], &option))
1330                                 return 0;
1331                         if (option < 0)
1332                                 return 0;
1333                         sbi->s_stripe = option;
1334                         break;
1335                 default:
1336                         printk (KERN_ERR
1337                                 "EXT4-fs: Unrecognized mount option \"%s\" "
1338                                 "or missing value\n", p);
1339                         return 0;
1340                 }
1341         }
1342 #ifdef CONFIG_QUOTA
1343         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1344                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1345                      sbi->s_qf_names[USRQUOTA])
1346                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1347
1348                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1349                      sbi->s_qf_names[GRPQUOTA])
1350                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1351
1352                 if ((sbi->s_qf_names[USRQUOTA] &&
1353                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1354                     (sbi->s_qf_names[GRPQUOTA] &&
1355                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1356                         printk(KERN_ERR "EXT4-fs: old and new quota "
1357                                         "format mixing.\n");
1358                         return 0;
1359                 }
1360
1361                 if (!sbi->s_jquota_fmt) {
1362                         printk(KERN_ERR "EXT4-fs: journaled quota format "
1363                                         "not specified.\n");
1364                         return 0;
1365                 }
1366         } else {
1367                 if (sbi->s_jquota_fmt) {
1368                         printk(KERN_ERR "EXT4-fs: journaled quota format "
1369                                         "specified with no journaling "
1370                                         "enabled.\n");
1371                         return 0;
1372                 }
1373         }
1374 #endif
1375         return 1;
1376 }
1377
1378 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1379                             int read_only)
1380 {
1381         struct ext4_sb_info *sbi = EXT4_SB(sb);
1382         int res = 0;
1383
1384         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1385                 printk (KERN_ERR "EXT4-fs warning: revision level too high, "
1386                         "forcing read-only mode\n");
1387                 res = MS_RDONLY;
1388         }
1389         if (read_only)
1390                 return res;
1391         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1392                 printk (KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1393                         "running e2fsck is recommended\n");
1394         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1395                 printk (KERN_WARNING
1396                         "EXT4-fs warning: mounting fs with errors, "
1397                         "running e2fsck is recommended\n");
1398         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1399                  le16_to_cpu(es->s_mnt_count) >=
1400                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1401                 printk (KERN_WARNING
1402                         "EXT4-fs warning: maximal mount count reached, "
1403                         "running e2fsck is recommended\n");
1404         else if (le32_to_cpu(es->s_checkinterval) &&
1405                 (le32_to_cpu(es->s_lastcheck) +
1406                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1407                 printk (KERN_WARNING
1408                         "EXT4-fs warning: checktime reached, "
1409                         "running e2fsck is recommended\n");
1410 #if 0
1411                 /* @@@ We _will_ want to clear the valid bit if we find
1412                  * inconsistencies, to force a fsck at reboot.  But for
1413                  * a plain journaled filesystem we can keep it set as
1414                  * valid forever! :)
1415                  */
1416         es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1417 #endif
1418         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1419                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1420         le16_add_cpu(&es->s_mnt_count, 1);
1421         es->s_mtime = cpu_to_le32(get_seconds());
1422         ext4_update_dynamic_rev(sb);
1423         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1424
1425         ext4_commit_super(sb, es, 1);
1426         if (test_opt(sb, DEBUG))
1427                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%lu, "
1428                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1429                         sb->s_blocksize,
1430                         sbi->s_groups_count,
1431                         EXT4_BLOCKS_PER_GROUP(sb),
1432                         EXT4_INODES_PER_GROUP(sb),
1433                         sbi->s_mount_opt);
1434
1435         printk(KERN_INFO "EXT4 FS on %s, ", sb->s_id);
1436         if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
1437                 char b[BDEVNAME_SIZE];
1438
1439                 printk("external journal on %s\n",
1440                         bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
1441         } else {
1442                 printk("internal journal\n");
1443         }
1444         return res;
1445 }
1446
1447 static int ext4_fill_flex_info(struct super_block *sb)
1448 {
1449         struct ext4_sb_info *sbi = EXT4_SB(sb);
1450         struct ext4_group_desc *gdp = NULL;
1451         struct buffer_head *bh;
1452         ext4_group_t flex_group_count;
1453         ext4_group_t flex_group;
1454         int groups_per_flex = 0;
1455         __u64 block_bitmap = 0;
1456         int i;
1457
1458         if (!sbi->s_es->s_log_groups_per_flex) {
1459                 sbi->s_log_groups_per_flex = 0;
1460                 return 1;
1461         }
1462
1463         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1464         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1465
1466         flex_group_count = (sbi->s_groups_count + groups_per_flex - 1) /
1467                 groups_per_flex;
1468         sbi->s_flex_groups = kmalloc(flex_group_count *
1469                                      sizeof(struct flex_groups), GFP_KERNEL);
1470         if (sbi->s_flex_groups == NULL) {
1471                 printk(KERN_ERR "EXT4-fs: not enough memory\n");
1472                 goto failed;
1473         }
1474         memset(sbi->s_flex_groups, 0, flex_group_count *
1475                sizeof(struct flex_groups));
1476
1477         gdp = ext4_get_group_desc(sb, 1, &bh);
1478         block_bitmap = ext4_block_bitmap(sb, gdp) - 1;
1479
1480         for (i = 0; i < sbi->s_groups_count; i++) {
1481                 gdp = ext4_get_group_desc(sb, i, &bh);
1482
1483                 flex_group = ext4_flex_group(sbi, i);
1484                 sbi->s_flex_groups[flex_group].free_inodes +=
1485                         le16_to_cpu(gdp->bg_free_inodes_count);
1486                 sbi->s_flex_groups[flex_group].free_blocks +=
1487                         le16_to_cpu(gdp->bg_free_blocks_count);
1488         }
1489
1490         return 1;
1491 failed:
1492         return 0;
1493 }
1494
1495 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1496                             struct ext4_group_desc *gdp)
1497 {
1498         __u16 crc = 0;
1499
1500         if (sbi->s_es->s_feature_ro_compat &
1501             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1502                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1503                 __le32 le_group = cpu_to_le32(block_group);
1504
1505                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1506                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1507                 crc = crc16(crc, (__u8 *)gdp, offset);
1508                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1509                 /* for checksum of struct ext4_group_desc do the rest...*/
1510                 if ((sbi->s_es->s_feature_incompat &
1511                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1512                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1513                         crc = crc16(crc, (__u8 *)gdp + offset,
1514                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1515                                         offset);
1516         }
1517
1518         return cpu_to_le16(crc);
1519 }
1520
1521 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1522                                 struct ext4_group_desc *gdp)
1523 {
1524         if ((sbi->s_es->s_feature_ro_compat &
1525              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1526             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1527                 return 0;
1528
1529         return 1;
1530 }
1531
1532 /* Called at mount-time, super-block is locked */
1533 static int ext4_check_descriptors(struct super_block *sb)
1534 {
1535         struct ext4_sb_info *sbi = EXT4_SB(sb);
1536         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1537         ext4_fsblk_t last_block;
1538         ext4_fsblk_t block_bitmap;
1539         ext4_fsblk_t inode_bitmap;
1540         ext4_fsblk_t inode_table;
1541         int flexbg_flag = 0;
1542         ext4_group_t i;
1543
1544         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1545                 flexbg_flag = 1;
1546
1547         ext4_debug ("Checking group descriptors");
1548
1549         for (i = 0; i < sbi->s_groups_count; i++) {
1550                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1551
1552                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1553                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1554                 else
1555                         last_block = first_block +
1556                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1557
1558                 block_bitmap = ext4_block_bitmap(sb, gdp);
1559                 if (block_bitmap < first_block || block_bitmap > last_block)
1560                 {
1561                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1562                                "Block bitmap for group %lu not in group "
1563                                "(block %llu)!", i, block_bitmap);
1564                         return 0;
1565                 }
1566                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1567                 if (inode_bitmap < first_block || inode_bitmap > last_block)
1568                 {
1569                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1570                                "Inode bitmap for group %lu not in group "
1571                                "(block %llu)!", i, inode_bitmap);
1572                         return 0;
1573                 }
1574                 inode_table = ext4_inode_table(sb, gdp);
1575                 if (inode_table < first_block ||
1576                     inode_table + sbi->s_itb_per_group - 1 > last_block)
1577                 {
1578                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1579                                "Inode table for group %lu not in group "
1580                                "(block %llu)!", i, inode_table);
1581                         return 0;
1582                 }
1583                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1584                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1585                                "Checksum for group %lu failed (%u!=%u)\n",
1586                                i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1587                                gdp)), le16_to_cpu(gdp->bg_checksum));
1588                         return 0;
1589                 }
1590                 if (!flexbg_flag)
1591                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1592         }
1593
1594         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1595         sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
1596         return 1;
1597 }
1598
1599 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1600  * the superblock) which were deleted from all directories, but held open by
1601  * a process at the time of a crash.  We walk the list and try to delete these
1602  * inodes at recovery time (only with a read-write filesystem).
1603  *
1604  * In order to keep the orphan inode chain consistent during traversal (in
1605  * case of crash during recovery), we link each inode into the superblock
1606  * orphan list_head and handle it the same way as an inode deletion during
1607  * normal operation (which journals the operations for us).
1608  *
1609  * We only do an iget() and an iput() on each inode, which is very safe if we
1610  * accidentally point at an in-use or already deleted inode.  The worst that
1611  * can happen in this case is that we get a "bit already cleared" message from
1612  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1613  * e2fsck was run on this filesystem, and it must have already done the orphan
1614  * inode cleanup for us, so we can safely abort without any further action.
1615  */
1616 static void ext4_orphan_cleanup (struct super_block * sb,
1617                                  struct ext4_super_block * es)
1618 {
1619         unsigned int s_flags = sb->s_flags;
1620         int nr_orphans = 0, nr_truncates = 0;
1621 #ifdef CONFIG_QUOTA
1622         int i;
1623 #endif
1624         if (!es->s_last_orphan) {
1625                 jbd_debug(4, "no orphan inodes to clean up\n");
1626                 return;
1627         }
1628
1629         if (bdev_read_only(sb->s_bdev)) {
1630                 printk(KERN_ERR "EXT4-fs: write access "
1631                         "unavailable, skipping orphan cleanup.\n");
1632                 return;
1633         }
1634
1635         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1636                 if (es->s_last_orphan)
1637                         jbd_debug(1, "Errors on filesystem, "
1638                                   "clearing orphan list.\n");
1639                 es->s_last_orphan = 0;
1640                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1641                 return;
1642         }
1643
1644         if (s_flags & MS_RDONLY) {
1645                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1646                        sb->s_id);
1647                 sb->s_flags &= ~MS_RDONLY;
1648         }
1649 #ifdef CONFIG_QUOTA
1650         /* Needed for iput() to work correctly and not trash data */
1651         sb->s_flags |= MS_ACTIVE;
1652         /* Turn on quotas so that they are updated correctly */
1653         for (i = 0; i < MAXQUOTAS; i++) {
1654                 if (EXT4_SB(sb)->s_qf_names[i]) {
1655                         int ret = ext4_quota_on_mount(sb, i);
1656                         if (ret < 0)
1657                                 printk(KERN_ERR
1658                                         "EXT4-fs: Cannot turn on journaled "
1659                                         "quota: error %d\n", ret);
1660                 }
1661         }
1662 #endif
1663
1664         while (es->s_last_orphan) {
1665                 struct inode *inode;
1666
1667                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
1668                 if (IS_ERR(inode)) {
1669                         es->s_last_orphan = 0;
1670                         break;
1671                 }
1672
1673                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1674                 DQUOT_INIT(inode);
1675                 if (inode->i_nlink) {
1676                         printk(KERN_DEBUG
1677                                 "%s: truncating inode %lu to %Ld bytes\n",
1678                                 __func__, inode->i_ino, inode->i_size);
1679                         jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
1680                                   inode->i_ino, inode->i_size);
1681                         ext4_truncate(inode);
1682                         nr_truncates++;
1683                 } else {
1684                         printk(KERN_DEBUG
1685                                 "%s: deleting unreferenced inode %lu\n",
1686                                 __func__, inode->i_ino);
1687                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1688                                   inode->i_ino);
1689                         nr_orphans++;
1690                 }
1691                 iput(inode);  /* The delete magic happens here! */
1692         }
1693
1694 #define PLURAL(x) (x), ((x)==1) ? "" : "s"
1695
1696         if (nr_orphans)
1697                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1698                        sb->s_id, PLURAL(nr_orphans));
1699         if (nr_truncates)
1700                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1701                        sb->s_id, PLURAL(nr_truncates));
1702 #ifdef CONFIG_QUOTA
1703         /* Turn quotas off */
1704         for (i = 0; i < MAXQUOTAS; i++) {
1705                 if (sb_dqopt(sb)->files[i])
1706                         vfs_quota_off(sb, i, 0);
1707         }
1708 #endif
1709         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1710 }
1711 /*
1712  * Maximal extent format file size.
1713  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1714  * extent format containers, within a sector_t, and within i_blocks
1715  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1716  * so that won't be a limiting factor.
1717  *
1718  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1719  */
1720 static loff_t ext4_max_size(int blkbits)
1721 {
1722         loff_t res;
1723         loff_t upper_limit = MAX_LFS_FILESIZE;
1724
1725         /* small i_blocks in vfs inode? */
1726         if (sizeof(blkcnt_t) < sizeof(u64)) {
1727                 /*
1728                  * CONFIG_LSF is not enabled implies the inode
1729                  * i_block represent total blocks in 512 bytes
1730                  * 32 == size of vfs inode i_blocks * 8
1731                  */
1732                 upper_limit = (1LL << 32) - 1;
1733
1734                 /* total blocks in file system block size */
1735                 upper_limit >>= (blkbits - 9);
1736                 upper_limit <<= blkbits;
1737         }
1738
1739         /* 32-bit extent-start container, ee_block */
1740         res = 1LL << 32;
1741         res <<= blkbits;
1742         res -= 1;
1743
1744         /* Sanity check against vm- & vfs- imposed limits */
1745         if (res > upper_limit)
1746                 res = upper_limit;
1747
1748         return res;
1749 }
1750
1751 /*
1752  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
1753  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
1754  * We need to be 1 filesystem block less than the 2^48 sector limit.
1755  */
1756 static loff_t ext4_max_bitmap_size(int bits)
1757 {
1758         loff_t res = EXT4_NDIR_BLOCKS;
1759         int meta_blocks;
1760         loff_t upper_limit;
1761         /* This is calculated to be the largest file size for a
1762          * dense, bitmapped file such that the total number of
1763          * sectors in the file, including data and all indirect blocks,
1764          * does not exceed 2^48 -1
1765          * __u32 i_blocks_lo and _u16 i_blocks_high representing the
1766          * total number of  512 bytes blocks of the file
1767          */
1768
1769         if (sizeof(blkcnt_t) < sizeof(u64)) {
1770                 /*
1771                  * CONFIG_LSF is not enabled implies the inode
1772                  * i_block represent total blocks in 512 bytes
1773                  * 32 == size of vfs inode i_blocks * 8
1774                  */
1775                 upper_limit = (1LL << 32) - 1;
1776
1777                 /* total blocks in file system block size */
1778                 upper_limit >>= (bits - 9);
1779
1780         } else {
1781                 /*
1782                  * We use 48 bit ext4_inode i_blocks
1783                  * With EXT4_HUGE_FILE_FL set the i_blocks
1784                  * represent total number of blocks in
1785                  * file system block size
1786                  */
1787                 upper_limit = (1LL << 48) - 1;
1788
1789         }
1790
1791         /* indirect blocks */
1792         meta_blocks = 1;
1793         /* double indirect blocks */
1794         meta_blocks += 1 + (1LL << (bits-2));
1795         /* tripple indirect blocks */
1796         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
1797
1798         upper_limit -= meta_blocks;
1799         upper_limit <<= bits;
1800
1801         res += 1LL << (bits-2);
1802         res += 1LL << (2*(bits-2));
1803         res += 1LL << (3*(bits-2));
1804         res <<= bits;
1805         if (res > upper_limit)
1806                 res = upper_limit;
1807
1808         if (res > MAX_LFS_FILESIZE)
1809                 res = MAX_LFS_FILESIZE;
1810
1811         return res;
1812 }
1813
1814 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1815                                 ext4_fsblk_t logical_sb_block, int nr)
1816 {
1817         struct ext4_sb_info *sbi = EXT4_SB(sb);
1818         ext4_group_t bg, first_meta_bg;
1819         int has_super = 0;
1820
1821         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1822
1823         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1824             nr < first_meta_bg)
1825                 return logical_sb_block + nr + 1;
1826         bg = sbi->s_desc_per_block * nr;
1827         if (ext4_bg_has_super(sb, bg))
1828                 has_super = 1;
1829         return (has_super + ext4_group_first_block_no(sb, bg));
1830 }
1831
1832 /**
1833  * ext4_get_stripe_size: Get the stripe size.
1834  * @sbi: In memory super block info
1835  *
1836  * If we have specified it via mount option, then
1837  * use the mount option value. If the value specified at mount time is
1838  * greater than the blocks per group use the super block value.
1839  * If the super block value is greater than blocks per group return 0.
1840  * Allocator needs it be less than blocks per group.
1841  *
1842  */
1843 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
1844 {
1845         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
1846         unsigned long stripe_width =
1847                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
1848
1849         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
1850                 return sbi->s_stripe;
1851
1852         if (stripe_width <= sbi->s_blocks_per_group)
1853                 return stripe_width;
1854
1855         if (stride <= sbi->s_blocks_per_group)
1856                 return stride;
1857
1858         return 0;
1859 }
1860
1861 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
1862                                 __releases(kernel_lock)
1863                                 __acquires(kernel_lock)
1864
1865 {
1866         struct buffer_head * bh;
1867         struct ext4_super_block *es = NULL;
1868         struct ext4_sb_info *sbi;
1869         ext4_fsblk_t block;
1870         ext4_fsblk_t sb_block = get_sb_block(&data);
1871         ext4_fsblk_t logical_sb_block;
1872         unsigned long offset = 0;
1873         unsigned int journal_inum = 0;
1874         unsigned long journal_devnum = 0;
1875         unsigned long def_mount_opts;
1876         struct inode *root;
1877         int ret = -EINVAL;
1878         int blocksize;
1879         int db_count;
1880         int i;
1881         int needs_recovery;
1882         __le32 features;
1883         __u64 blocks_count;
1884         int err;
1885
1886         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1887         if (!sbi)
1888                 return -ENOMEM;
1889         sb->s_fs_info = sbi;
1890         sbi->s_mount_opt = 0;
1891         sbi->s_resuid = EXT4_DEF_RESUID;
1892         sbi->s_resgid = EXT4_DEF_RESGID;
1893         sbi->s_sb_block = sb_block;
1894
1895         unlock_kernel();
1896
1897         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1898         if (!blocksize) {
1899                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1900                 goto out_fail;
1901         }
1902
1903         /*
1904          * The ext4 superblock will not be buffer aligned for other than 1kB
1905          * block sizes.  We need to calculate the offset from buffer start.
1906          */
1907         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1908                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1909                 offset = do_div(logical_sb_block, blocksize);
1910         } else {
1911                 logical_sb_block = sb_block;
1912         }
1913
1914         if (!(bh = sb_bread(sb, logical_sb_block))) {
1915                 printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
1916                 goto out_fail;
1917         }
1918         /*
1919          * Note: s_es must be initialized as soon as possible because
1920          *       some ext4 macro-instructions depend on its value
1921          */
1922         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1923         sbi->s_es = es;
1924         sb->s_magic = le16_to_cpu(es->s_magic);
1925         if (sb->s_magic != EXT4_SUPER_MAGIC)
1926                 goto cantfind_ext4;
1927
1928         /* Set defaults before we parse the mount options */
1929         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1930         if (def_mount_opts & EXT4_DEFM_DEBUG)
1931                 set_opt(sbi->s_mount_opt, DEBUG);
1932         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1933                 set_opt(sbi->s_mount_opt, GRPID);
1934         if (def_mount_opts & EXT4_DEFM_UID16)
1935                 set_opt(sbi->s_mount_opt, NO_UID32);
1936 #ifdef CONFIG_EXT4DEV_FS_XATTR
1937         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1938                 set_opt(sbi->s_mount_opt, XATTR_USER);
1939 #endif
1940 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1941         if (def_mount_opts & EXT4_DEFM_ACL)
1942                 set_opt(sbi->s_mount_opt, POSIX_ACL);
1943 #endif
1944         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1945                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1946         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1947                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1948         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1949                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1950
1951         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1952                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1953         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
1954                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
1955         else
1956                 set_opt(sbi->s_mount_opt, ERRORS_RO);
1957
1958         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1959         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1960
1961         set_opt(sbi->s_mount_opt, RESERVATION);
1962         set_opt(sbi->s_mount_opt, BARRIER);
1963
1964         /*
1965          * turn on extents feature by default in ext4 filesystem
1966          * User -o noextents to turn it off
1967          */
1968         set_opt(sbi->s_mount_opt, EXTENTS);
1969         /*
1970          * turn on mballoc feature by default in ext4 filesystem
1971          * User -o nomballoc to turn it off
1972          */
1973         set_opt(sbi->s_mount_opt, MBALLOC);
1974
1975         if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
1976                             NULL, 0))
1977                 goto failed_mount;
1978
1979         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1980                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1981
1982         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1983             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1984              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1985              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1986                 printk(KERN_WARNING
1987                        "EXT4-fs warning: feature flags set on rev 0 fs, "
1988                        "running e2fsck is recommended\n");
1989
1990         /*
1991          * Since ext4 is still considered development code, we require
1992          * that the TEST_FILESYS flag in s->flags be set.
1993          */
1994         if (!(le32_to_cpu(es->s_flags) & EXT2_FLAGS_TEST_FILESYS)) {
1995                 printk(KERN_WARNING "EXT4-fs: %s: not marked "
1996                        "OK to use with test code.\n", sb->s_id);
1997                 goto failed_mount;
1998         }
1999
2000         /*
2001          * Check feature flags regardless of the revision level, since we
2002          * previously didn't change the revision level when setting the flags,
2003          * so there is a chance incompat flags are set on a rev 0 filesystem.
2004          */
2005         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
2006         if (features) {
2007                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
2008                        "unsupported optional features (%x).\n",
2009                        sb->s_id, le32_to_cpu(features));
2010                 goto failed_mount;
2011         }
2012         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
2013         if (!(sb->s_flags & MS_RDONLY) && features) {
2014                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
2015                        "unsupported optional features (%x).\n",
2016                        sb->s_id, le32_to_cpu(features));
2017                 goto failed_mount;
2018         }
2019         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2020                 /*
2021                  * Large file size enabled file system can only be
2022                  * mount if kernel is build with CONFIG_LSF
2023                  */
2024                 if (sizeof(root->i_blocks) < sizeof(u64) &&
2025                                 !(sb->s_flags & MS_RDONLY)) {
2026                         printk(KERN_ERR "EXT4-fs: %s: Filesystem with huge "
2027                                         "files cannot be mounted read-write "
2028                                         "without CONFIG_LSF.\n", sb->s_id);
2029                         goto failed_mount;
2030                 }
2031         }
2032         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
2033
2034         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
2035             blocksize > EXT4_MAX_BLOCK_SIZE) {
2036                 printk(KERN_ERR
2037                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
2038                        blocksize, sb->s_id);
2039                 goto failed_mount;
2040         }
2041
2042         if (sb->s_blocksize != blocksize) {
2043
2044                 /* Validate the filesystem blocksize */
2045                 if (!sb_set_blocksize(sb, blocksize)) {
2046                         printk(KERN_ERR "EXT4-fs: bad block size %d.\n",
2047                                         blocksize);
2048                         goto failed_mount;
2049                 }
2050
2051                 brelse (bh);
2052                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2053                 offset = do_div(logical_sb_block, blocksize);
2054                 bh = sb_bread(sb, logical_sb_block);
2055                 if (!bh) {
2056                         printk(KERN_ERR
2057                                "EXT4-fs: Can't read superblock on 2nd try.\n");
2058                         goto failed_mount;
2059                 }
2060                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
2061                 sbi->s_es = es;
2062                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
2063                         printk (KERN_ERR
2064                                 "EXT4-fs: Magic mismatch, very weird !\n");
2065                         goto failed_mount;
2066                 }
2067         }
2068
2069         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits);
2070         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
2071
2072         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2073                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2074                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2075         } else {
2076                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2077                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2078                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2079                     (!is_power_of_2(sbi->s_inode_size)) ||
2080                     (sbi->s_inode_size > blocksize)) {
2081                         printk (KERN_ERR
2082                                 "EXT4-fs: unsupported inode size: %d\n",
2083                                 sbi->s_inode_size);
2084                         goto failed_mount;
2085                 }
2086                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2087                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2088         }
2089         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2090         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2091                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2092                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2093                     !is_power_of_2(sbi->s_desc_size)) {
2094                         printk(KERN_ERR
2095                                "EXT4-fs: unsupported descriptor size %lu\n",
2096                                sbi->s_desc_size);
2097                         goto failed_mount;
2098                 }
2099         } else
2100                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2101         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2102         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2103         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2104                 goto cantfind_ext4;
2105         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2106         if (sbi->s_inodes_per_block == 0)
2107                 goto cantfind_ext4;
2108         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2109                                         sbi->s_inodes_per_block;
2110         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2111         sbi->s_sbh = bh;
2112         sbi->s_mount_state = le16_to_cpu(es->s_state);
2113         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2114         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2115         for (i=0; i < 4; i++)
2116                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2117         sbi->s_def_hash_version = es->s_def_hash_version;
2118
2119         if (sbi->s_blocks_per_group > blocksize * 8) {
2120                 printk (KERN_ERR
2121                         "EXT4-fs: #blocks per group too big: %lu\n",
2122                         sbi->s_blocks_per_group);
2123                 goto failed_mount;
2124         }
2125         if (sbi->s_inodes_per_group > blocksize * 8) {
2126                 printk (KERN_ERR
2127                         "EXT4-fs: #inodes per group too big: %lu\n",
2128                         sbi->s_inodes_per_group);
2129                 goto failed_mount;
2130         }
2131
2132         if (ext4_blocks_count(es) >
2133                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
2134                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
2135                         " too large to mount safely\n", sb->s_id);
2136                 if (sizeof(sector_t) < 8)
2137                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
2138                                         "enabled\n");
2139                 goto failed_mount;
2140         }
2141
2142         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2143                 goto cantfind_ext4;
2144
2145         /* ensure blocks_count calculation below doesn't sign-extend */
2146         if (ext4_blocks_count(es) + EXT4_BLOCKS_PER_GROUP(sb) <
2147             le32_to_cpu(es->s_first_data_block) + 1) {
2148                 printk(KERN_WARNING "EXT4-fs: bad geometry: block count %llu, "
2149                        "first data block %u, blocks per group %lu\n",
2150                         ext4_blocks_count(es),
2151                         le32_to_cpu(es->s_first_data_block),
2152                         EXT4_BLOCKS_PER_GROUP(sb));
2153                 goto failed_mount;
2154         }
2155         blocks_count = (ext4_blocks_count(es) -
2156                         le32_to_cpu(es->s_first_data_block) +
2157                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2158         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2159         sbi->s_groups_count = blocks_count;
2160         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2161                    EXT4_DESC_PER_BLOCK(sb);
2162         sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
2163                                     GFP_KERNEL);
2164         if (sbi->s_group_desc == NULL) {
2165                 printk (KERN_ERR "EXT4-fs: not enough memory\n");
2166                 goto failed_mount;
2167         }
2168
2169         bgl_lock_init(&sbi->s_blockgroup_lock);
2170
2171         for (i = 0; i < db_count; i++) {
2172                 block = descriptor_loc(sb, logical_sb_block, i);
2173                 sbi->s_group_desc[i] = sb_bread(sb, block);
2174                 if (!sbi->s_group_desc[i]) {
2175                         printk (KERN_ERR "EXT4-fs: "
2176                                 "can't read group descriptor %d\n", i);
2177                         db_count = i;
2178                         goto failed_mount2;
2179                 }
2180         }
2181         if (!ext4_check_descriptors (sb)) {
2182                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
2183                 goto failed_mount2;
2184         }
2185         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2186                 if (!ext4_fill_flex_info(sb)) {
2187                         printk(KERN_ERR
2188                                "EXT4-fs: unable to initialize "
2189                                "flex_bg meta info!\n");
2190                         goto failed_mount2;
2191                 }
2192
2193         sbi->s_gdb_count = db_count;
2194         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2195         spin_lock_init(&sbi->s_next_gen_lock);
2196
2197         err = percpu_counter_init(&sbi->s_freeblocks_counter,
2198                         ext4_count_free_blocks(sb));
2199         if (!err) {
2200                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
2201                                 ext4_count_free_inodes(sb));
2202         }
2203         if (!err) {
2204                 err = percpu_counter_init(&sbi->s_dirs_counter,
2205                                 ext4_count_dirs(sb));
2206         }
2207         if (err) {
2208                 printk(KERN_ERR "EXT4-fs: insufficient memory\n");
2209                 goto failed_mount3;
2210         }
2211
2212         /* per fileystem reservation list head & lock */
2213         spin_lock_init(&sbi->s_rsv_window_lock);
2214         sbi->s_rsv_window_root = RB_ROOT;
2215         /* Add a single, static dummy reservation to the start of the
2216          * reservation window list --- it gives us a placeholder for
2217          * append-at-start-of-list which makes the allocation logic
2218          * _much_ simpler. */
2219         sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
2220         sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
2221         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
2222         sbi->s_rsv_window_head.rsv_goal_size = 0;
2223         ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
2224
2225         sbi->s_stripe = ext4_get_stripe_size(sbi);
2226
2227         /*
2228          * set up enough so that it can read an inode
2229          */
2230         sb->s_op = &ext4_sops;
2231         sb->s_export_op = &ext4_export_ops;
2232         sb->s_xattr = ext4_xattr_handlers;
2233 #ifdef CONFIG_QUOTA
2234         sb->s_qcop = &ext4_qctl_operations;
2235         sb->dq_op = &ext4_quota_operations;
2236 #endif
2237         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2238
2239         sb->s_root = NULL;
2240
2241         needs_recovery = (es->s_last_orphan != 0 ||
2242                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2243                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2244
2245         /*
2246          * The first inode we look at is the journal inode.  Don't try
2247          * root first: it may be modified in the journal!
2248          */
2249         if (!test_opt(sb, NOLOAD) &&
2250             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2251                 if (ext4_load_journal(sb, es, journal_devnum))
2252                         goto failed_mount3;
2253                 if (!(sb->s_flags & MS_RDONLY) &&
2254                     EXT4_SB(sb)->s_journal->j_failed_commit) {
2255                         printk(KERN_CRIT "EXT4-fs error (device %s): "
2256                                "ext4_fill_super: Journal transaction "
2257                                "%u is corrupt\n", sb->s_id,
2258                                EXT4_SB(sb)->s_journal->j_failed_commit);
2259                         if (test_opt (sb, ERRORS_RO)) {
2260                                 printk (KERN_CRIT
2261                                         "Mounting filesystem read-only\n");
2262                                 sb->s_flags |= MS_RDONLY;
2263                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2264                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2265                         }
2266                         if (test_opt(sb, ERRORS_PANIC)) {
2267                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2268                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2269                                 ext4_commit_super(sb, es, 1);
2270                                 printk(KERN_CRIT
2271                                        "EXT4-fs (device %s): mount failed\n",
2272                                       sb->s_id);
2273                                 goto failed_mount4;
2274                         }
2275                 }
2276         } else if (journal_inum) {
2277                 if (ext4_create_journal(sb, es, journal_inum))
2278                         goto failed_mount3;
2279         } else {
2280                 if (!silent)
2281                         printk (KERN_ERR
2282                                 "ext4: No journal on filesystem on %s\n",
2283                                 sb->s_id);
2284                 goto failed_mount3;
2285         }
2286
2287         if (ext4_blocks_count(es) > 0xffffffffULL &&
2288             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2289                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2290                 printk(KERN_ERR "ext4: Failed to set 64-bit journal feature\n");
2291                 goto failed_mount4;
2292         }
2293
2294         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2295                 jbd2_journal_set_features(sbi->s_journal,
2296                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2297                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2298         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2299                 jbd2_journal_set_features(sbi->s_journal,
2300                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2301                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2302                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2303         } else {
2304                 jbd2_journal_clear_features(sbi->s_journal,
2305                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2306                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2307         }
2308
2309         /* We have now updated the journal if required, so we can
2310          * validate the data journaling mode. */
2311         switch (test_opt(sb, DATA_FLAGS)) {
2312         case 0:
2313                 /* No mode set, assume a default based on the journal
2314                  * capabilities: ORDERED_DATA if the journal can
2315                  * cope, else JOURNAL_DATA
2316                  */
2317                 if (jbd2_journal_check_available_features
2318                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2319                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
2320                 else
2321                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2322                 break;
2323
2324         case EXT4_MOUNT_ORDERED_DATA:
2325         case EXT4_MOUNT_WRITEBACK_DATA:
2326                 if (!jbd2_journal_check_available_features
2327                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2328                         printk(KERN_ERR "EXT4-fs: Journal does not support "
2329                                "requested data journaling mode\n");
2330                         goto failed_mount4;
2331                 }
2332         default:
2333                 break;
2334         }
2335
2336         if (test_opt(sb, NOBH)) {
2337                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2338                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
2339                                 "its supported only with writeback mode\n");
2340                         clear_opt(sbi->s_mount_opt, NOBH);
2341                 }
2342         }
2343         /*
2344          * The jbd2_journal_load will have done any necessary log recovery,
2345          * so we can safely mount the rest of the filesystem now.
2346          */
2347
2348         root = ext4_iget(sb, EXT4_ROOT_INO);
2349         if (IS_ERR(root)) {
2350                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
2351                 ret = PTR_ERR(root);
2352                 goto failed_mount4;
2353         }
2354         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2355                 iput(root);
2356                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
2357                 goto failed_mount4;
2358         }
2359         sb->s_root = d_alloc_root(root);
2360         if (!sb->s_root) {
2361                 printk(KERN_ERR "EXT4-fs: get root dentry failed\n");
2362                 iput(root);
2363                 ret = -ENOMEM;
2364                 goto failed_mount4;
2365         }
2366
2367         ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
2368
2369         /* determine the minimum size of new large inodes, if present */
2370         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2371                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2372                                                      EXT4_GOOD_OLD_INODE_SIZE;
2373                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2374                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2375                         if (sbi->s_want_extra_isize <
2376                             le16_to_cpu(es->s_want_extra_isize))
2377                                 sbi->s_want_extra_isize =
2378                                         le16_to_cpu(es->s_want_extra_isize);
2379                         if (sbi->s_want_extra_isize <
2380                             le16_to_cpu(es->s_min_extra_isize))
2381                                 sbi->s_want_extra_isize =
2382                                         le16_to_cpu(es->s_min_extra_isize);
2383                 }
2384         }
2385         /* Check if enough inode space is available */
2386         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2387                                                         sbi->s_inode_size) {
2388                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2389                                                        EXT4_GOOD_OLD_INODE_SIZE;
2390                 printk(KERN_INFO "EXT4-fs: required extra inode space not"
2391                         "available.\n");
2392         }
2393
2394         /*
2395          * akpm: core read_super() calls in here with the superblock locked.
2396          * That deadlocks, because orphan cleanup needs to lock the superblock
2397          * in numerous places.  Here we just pop the lock - it's relatively
2398          * harmless, because we are now ready to accept write_super() requests,
2399          * and aviro says that's the only reason for hanging onto the
2400          * superblock lock.
2401          */
2402         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2403         ext4_orphan_cleanup(sb, es);
2404         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2405         if (needs_recovery)
2406                 printk (KERN_INFO "EXT4-fs: recovery complete.\n");
2407         ext4_mark_recovery_complete(sb, es);
2408         printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
2409                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
2410                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
2411                 "writeback");
2412
2413         ext4_ext_init(sb);
2414         ext4_mb_init(sb, needs_recovery);
2415
2416         lock_kernel();
2417         return 0;
2418
2419 cantfind_ext4:
2420         if (!silent)
2421                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
2422                        sb->s_id);
2423         goto failed_mount;
2424
2425 failed_mount4:
2426         jbd2_journal_destroy(sbi->s_journal);
2427         sbi->s_journal = NULL;
2428 failed_mount3:
2429         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2430         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2431         percpu_counter_destroy(&sbi->s_dirs_counter);
2432 failed_mount2:
2433         for (i = 0; i < db_count; i++)
2434                 brelse(sbi->s_group_desc[i]);
2435         kfree(sbi->s_group_desc);
2436 failed_mount:
2437 #ifdef CONFIG_QUOTA
2438         for (i = 0; i < MAXQUOTAS; i++)
2439                 kfree(sbi->s_qf_names[i]);
2440 #endif
2441         ext4_blkdev_remove(sbi);
2442         brelse(bh);
2443 out_fail:
2444         sb->s_fs_info = NULL;
2445         kfree(sbi);
2446         lock_kernel();
2447         return ret;
2448 }
2449
2450 /*
2451  * Setup any per-fs journal parameters now.  We'll do this both on
2452  * initial mount, once the journal has been initialised but before we've
2453  * done any recovery; and again on any subsequent remount.
2454  */
2455 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2456 {
2457         struct ext4_sb_info *sbi = EXT4_SB(sb);
2458
2459         if (sbi->s_commit_interval)
2460                 journal->j_commit_interval = sbi->s_commit_interval;
2461         /* We could also set up an ext4-specific default for the commit
2462          * interval here, but for now we'll just fall back to the jbd
2463          * default. */
2464
2465         spin_lock(&journal->j_state_lock);
2466         if (test_opt(sb, BARRIER))
2467                 journal->j_flags |= JBD2_BARRIER;
2468         else
2469                 journal->j_flags &= ~JBD2_BARRIER;
2470         spin_unlock(&journal->j_state_lock);
2471 }
2472
2473 static journal_t *ext4_get_journal(struct super_block *sb,
2474                                    unsigned int journal_inum)
2475 {
2476         struct inode *journal_inode;
2477         journal_t *journal;
2478
2479         /* First, test for the existence of a valid inode on disk.  Bad
2480          * things happen if we iget() an unused inode, as the subsequent
2481          * iput() will try to delete it. */
2482
2483         journal_inode = ext4_iget(sb, journal_inum);
2484         if (IS_ERR(journal_inode)) {
2485                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
2486                 return NULL;
2487         }
2488         if (!journal_inode->i_nlink) {
2489                 make_bad_inode(journal_inode);
2490                 iput(journal_inode);
2491                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
2492                 return NULL;
2493         }
2494
2495         jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
2496                   journal_inode, journal_inode->i_size);
2497         if (!S_ISREG(journal_inode->i_mode)) {
2498                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
2499                 iput(journal_inode);
2500                 return NULL;
2501         }
2502
2503         journal = jbd2_journal_init_inode(journal_inode);
2504         if (!journal) {
2505                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
2506                 iput(journal_inode);
2507                 return NULL;
2508         }
2509         journal->j_private = sb;
2510         ext4_init_journal_params(sb, journal);
2511         return journal;
2512 }
2513
2514 static journal_t *ext4_get_dev_journal(struct super_block *sb,
2515                                        dev_t j_dev)
2516 {
2517         struct buffer_head * bh;
2518         journal_t *journal;
2519         ext4_fsblk_t start;
2520         ext4_fsblk_t len;
2521         int hblock, blocksize;
2522         ext4_fsblk_t sb_block;
2523         unsigned long offset;
2524         struct ext4_super_block * es;
2525         struct block_device *bdev;
2526
2527         bdev = ext4_blkdev_get(j_dev);
2528         if (bdev == NULL)
2529                 return NULL;
2530
2531         if (bd_claim(bdev, sb)) {
2532                 printk(KERN_ERR
2533                         "EXT4: failed to claim external journal device.\n");
2534                 blkdev_put(bdev);
2535                 return NULL;
2536         }
2537
2538         blocksize = sb->s_blocksize;
2539         hblock = bdev_hardsect_size(bdev);
2540         if (blocksize < hblock) {
2541                 printk(KERN_ERR
2542                         "EXT4-fs: blocksize too small for journal device.\n");
2543                 goto out_bdev;
2544         }
2545
2546         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2547         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2548         set_blocksize(bdev, blocksize);
2549         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2550                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2551                        "external journal\n");
2552                 goto out_bdev;
2553         }
2554
2555         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2556         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2557             !(le32_to_cpu(es->s_feature_incompat) &
2558               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2559                 printk(KERN_ERR "EXT4-fs: external journal has "
2560                                         "bad superblock\n");
2561                 brelse(bh);
2562                 goto out_bdev;
2563         }
2564
2565         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2566                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2567                 brelse(bh);
2568                 goto out_bdev;
2569         }
2570
2571         len = ext4_blocks_count(es);
2572         start = sb_block + 1;
2573         brelse(bh);     /* we're done with the superblock */
2574
2575         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2576                                         start, len, blocksize);
2577         if (!journal) {
2578                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2579                 goto out_bdev;
2580         }
2581         journal->j_private = sb;
2582         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2583         wait_on_buffer(journal->j_sb_buffer);
2584         if (!buffer_uptodate(journal->j_sb_buffer)) {
2585                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2586                 goto out_journal;
2587         }
2588         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2589                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2590                                         "user (unsupported) - %d\n",
2591                         be32_to_cpu(journal->j_superblock->s_nr_users));
2592                 goto out_journal;
2593         }
2594         EXT4_SB(sb)->journal_bdev = bdev;
2595         ext4_init_journal_params(sb, journal);
2596         return journal;
2597 out_journal:
2598         jbd2_journal_destroy(journal);
2599 out_bdev:
2600         ext4_blkdev_put(bdev);
2601         return NULL;
2602 }
2603
2604 static int ext4_load_journal(struct super_block *sb,
2605                              struct ext4_super_block *es,
2606                              unsigned long journal_devnum)
2607 {
2608         journal_t *journal;
2609         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2610         dev_t journal_dev;
2611         int err = 0;
2612         int really_read_only;
2613
2614         if (journal_devnum &&
2615             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2616                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2617                         "numbers have changed\n");
2618                 journal_dev = new_decode_dev(journal_devnum);
2619         } else
2620                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2621
2622         really_read_only = bdev_read_only(sb->s_bdev);
2623
2624         /*
2625          * Are we loading a blank journal or performing recovery after a
2626          * crash?  For recovery, we need to check in advance whether we
2627          * can get read-write access to the device.
2628          */
2629
2630         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2631                 if (sb->s_flags & MS_RDONLY) {
2632                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2633                                         "required on readonly filesystem.\n");
2634                         if (really_read_only) {
2635                                 printk(KERN_ERR "EXT4-fs: write access "
2636                                         "unavailable, cannot proceed.\n");
2637                                 return -EROFS;
2638                         }
2639                         printk (KERN_INFO "EXT4-fs: write access will "
2640                                         "be enabled during recovery.\n");
2641                 }
2642         }
2643
2644         if (journal_inum && journal_dev) {
2645                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2646                        "and inode journals!\n");
2647                 return -EINVAL;
2648         }
2649
2650         if (journal_inum) {
2651                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2652                         return -EINVAL;
2653         } else {
2654                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2655                         return -EINVAL;
2656         }
2657
2658         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2659                 err = jbd2_journal_update_format(journal);
2660                 if (err)  {
2661                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2662                         jbd2_journal_destroy(journal);
2663                         return err;
2664                 }
2665         }
2666
2667         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2668                 err = jbd2_journal_wipe(journal, !really_read_only);
2669         if (!err)
2670                 err = jbd2_journal_load(journal);
2671
2672         if (err) {
2673                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2674                 jbd2_journal_destroy(journal);
2675                 return err;
2676         }
2677
2678         EXT4_SB(sb)->s_journal = journal;
2679         ext4_clear_journal_err(sb, es);
2680
2681         if (journal_devnum &&
2682             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2683                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2684                 sb->s_dirt = 1;
2685
2686                 /* Make sure we flush the recovery flag to disk. */
2687                 ext4_commit_super(sb, es, 1);
2688         }
2689
2690         return 0;
2691 }
2692
2693 static int ext4_create_journal(struct super_block * sb,
2694                                struct ext4_super_block * es,
2695                                unsigned int journal_inum)
2696 {
2697         journal_t *journal;
2698         int err;
2699
2700         if (sb->s_flags & MS_RDONLY) {
2701                 printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2702                                 "create journal.\n");
2703                 return -EROFS;
2704         }
2705
2706         journal = ext4_get_journal(sb, journal_inum);
2707         if (!journal)
2708                 return -EINVAL;
2709
2710         printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2711                journal_inum);
2712
2713         err = jbd2_journal_create(journal);
2714         if (err) {
2715                 printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2716                 jbd2_journal_destroy(journal);
2717                 return -EIO;
2718         }
2719
2720         EXT4_SB(sb)->s_journal = journal;
2721
2722         ext4_update_dynamic_rev(sb);
2723         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2724         EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2725
2726         es->s_journal_inum = cpu_to_le32(journal_inum);
2727         sb->s_dirt = 1;
2728
2729         /* Make sure we flush the recovery flag to disk. */
2730         ext4_commit_super(sb, es, 1);
2731
2732         return 0;
2733 }
2734
2735 static void ext4_commit_super (struct super_block * sb,
2736                                struct ext4_super_block * es,
2737                                int sync)
2738 {
2739         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2740
2741         if (!sbh)
2742                 return;
2743         es->s_wtime = cpu_to_le32(get_seconds());
2744         ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2745         es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2746         BUFFER_TRACE(sbh, "marking dirty");
2747         mark_buffer_dirty(sbh);
2748         if (sync)
2749                 sync_dirty_buffer(sbh);
2750 }
2751
2752
2753 /*
2754  * Have we just finished recovery?  If so, and if we are mounting (or
2755  * remounting) the filesystem readonly, then we will end up with a
2756  * consistent fs on disk.  Record that fact.
2757  */
2758 static void ext4_mark_recovery_complete(struct super_block * sb,
2759                                         struct ext4_super_block * es)
2760 {
2761         journal_t *journal = EXT4_SB(sb)->s_journal;
2762
2763         jbd2_journal_lock_updates(journal);
2764         jbd2_journal_flush(journal);
2765         lock_super(sb);
2766         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2767             sb->s_flags & MS_RDONLY) {
2768                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2769                 sb->s_dirt = 0;
2770                 ext4_commit_super(sb, es, 1);
2771         }
2772         unlock_super(sb);
2773         jbd2_journal_unlock_updates(journal);
2774 }
2775
2776 /*
2777  * If we are mounting (or read-write remounting) a filesystem whose journal
2778  * has recorded an error from a previous lifetime, move that error to the
2779  * main filesystem now.
2780  */
2781 static void ext4_clear_journal_err(struct super_block * sb,
2782                                    struct ext4_super_block * es)
2783 {
2784         journal_t *journal;
2785         int j_errno;
2786         const char *errstr;
2787
2788         journal = EXT4_SB(sb)->s_journal;
2789
2790         /*
2791          * Now check for any error status which may have been recorded in the
2792          * journal by a prior ext4_error() or ext4_abort()
2793          */
2794
2795         j_errno = jbd2_journal_errno(journal);
2796         if (j_errno) {
2797                 char nbuf[16];
2798
2799                 errstr = ext4_decode_error(sb, j_errno, nbuf);
2800                 ext4_warning(sb, __func__, "Filesystem error recorded "
2801                              "from previous mount: %s", errstr);
2802                 ext4_warning(sb, __func__, "Marking fs in need of "
2803                              "filesystem check.");
2804
2805                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2806                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2807                 ext4_commit_super (sb, es, 1);
2808
2809                 jbd2_journal_clear_err(journal);
2810         }
2811 }
2812
2813 /*
2814  * Force the running and committing transactions to commit,
2815  * and wait on the commit.
2816  */
2817 int ext4_force_commit(struct super_block *sb)
2818 {
2819         journal_t *journal;
2820         int ret;
2821
2822         if (sb->s_flags & MS_RDONLY)
2823                 return 0;
2824
2825         journal = EXT4_SB(sb)->s_journal;
2826         sb->s_dirt = 0;
2827         ret = ext4_journal_force_commit(journal);
2828         return ret;
2829 }
2830
2831 /*
2832  * Ext4 always journals updates to the superblock itself, so we don't
2833  * have to propagate any other updates to the superblock on disk at this
2834  * point.  Just start an async writeback to get the buffers on their way
2835  * to the disk.
2836  *
2837  * This implicitly triggers the writebehind on sync().
2838  */
2839
2840 static void ext4_write_super (struct super_block * sb)
2841 {
2842         if (mutex_trylock(&sb->s_lock) != 0)
2843                 BUG();
2844         sb->s_dirt = 0;
2845 }
2846
2847 static int ext4_sync_fs(struct super_block *sb, int wait)
2848 {
2849         tid_t target;
2850
2851         sb->s_dirt = 0;
2852         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2853                 if (wait)
2854                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2855         }
2856         return 0;
2857 }
2858
2859 /*
2860  * LVM calls this function before a (read-only) snapshot is created.  This
2861  * gives us a chance to flush the journal completely and mark the fs clean.
2862  */
2863 static void ext4_write_super_lockfs(struct super_block *sb)
2864 {
2865         sb->s_dirt = 0;
2866
2867         if (!(sb->s_flags & MS_RDONLY)) {
2868                 journal_t *journal = EXT4_SB(sb)->s_journal;
2869
2870                 /* Now we set up the journal barrier. */
2871                 jbd2_journal_lock_updates(journal);
2872                 jbd2_journal_flush(journal);
2873
2874                 /* Journal blocked and flushed, clear needs_recovery flag. */
2875                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2876                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2877         }
2878 }
2879
2880 /*
2881  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2882  * flag here, even though the filesystem is not technically dirty yet.
2883  */
2884 static void ext4_unlockfs(struct super_block *sb)
2885 {
2886         if (!(sb->s_flags & MS_RDONLY)) {
2887                 lock_super(sb);
2888                 /* Reser the needs_recovery flag before the fs is unlocked. */
2889                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2890                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2891                 unlock_super(sb);
2892                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2893         }
2894 }
2895
2896 static int ext4_remount (struct super_block * sb, int * flags, char * data)
2897 {
2898         struct ext4_super_block * es;
2899         struct ext4_sb_info *sbi = EXT4_SB(sb);
2900         ext4_fsblk_t n_blocks_count = 0;
2901         unsigned long old_sb_flags;
2902         struct ext4_mount_options old_opts;
2903         int err;
2904 #ifdef CONFIG_QUOTA
2905         int i;
2906 #endif
2907
2908         /* Store the original options */
2909         old_sb_flags = sb->s_flags;
2910         old_opts.s_mount_opt = sbi->s_mount_opt;
2911         old_opts.s_resuid = sbi->s_resuid;
2912         old_opts.s_resgid = sbi->s_resgid;
2913         old_opts.s_commit_interval = sbi->s_commit_interval;
2914 #ifdef CONFIG_QUOTA
2915         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2916         for (i = 0; i < MAXQUOTAS; i++)
2917                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2918 #endif
2919
2920         /*
2921          * Allow the "check" option to be passed as a remount option.
2922          */
2923         if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2924                 err = -EINVAL;
2925                 goto restore_opts;
2926         }
2927
2928         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2929                 ext4_abort(sb, __func__, "Abort forced by user");
2930
2931         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2932                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2933
2934         es = sbi->s_es;
2935
2936         ext4_init_journal_params(sb, sbi->s_journal);
2937
2938         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2939                 n_blocks_count > ext4_blocks_count(es)) {
2940                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
2941                         err = -EROFS;
2942                         goto restore_opts;
2943                 }
2944
2945                 if (*flags & MS_RDONLY) {
2946                         /*
2947                          * First of all, the unconditional stuff we have to do
2948                          * to disable replay of the journal when we next remount
2949                          */
2950                         sb->s_flags |= MS_RDONLY;
2951
2952                         /*
2953                          * OK, test if we are remounting a valid rw partition
2954                          * readonly, and if so set the rdonly flag and then
2955                          * mark the partition as valid again.
2956                          */
2957                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
2958                             (sbi->s_mount_state & EXT4_VALID_FS))
2959                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
2960
2961                         /*
2962                          * We have to unlock super so that we can wait for
2963                          * transactions.
2964                          */
2965                         unlock_super(sb);
2966                         ext4_mark_recovery_complete(sb, es);
2967                         lock_super(sb);
2968                 } else {
2969                         __le32 ret;
2970                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2971                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
2972                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2973                                        "remount RDWR because of unsupported "
2974                                        "optional features (%x).\n",
2975                                        sb->s_id, le32_to_cpu(ret));
2976                                 err = -EROFS;
2977                                 goto restore_opts;
2978                         }
2979
2980                         /*
2981                          * If we have an unprocessed orphan list hanging
2982                          * around from a previously readonly bdev mount,
2983                          * require a full umount/remount for now.
2984                          */
2985                         if (es->s_last_orphan) {
2986                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2987                                        "remount RDWR because of unprocessed "
2988                                        "orphan inode list.  Please "
2989                                        "umount/remount instead.\n",
2990                                        sb->s_id);
2991                                 err = -EINVAL;
2992                                 goto restore_opts;
2993                         }
2994
2995                         /*
2996                          * Mounting a RDONLY partition read-write, so reread
2997                          * and store the current valid flag.  (It may have
2998                          * been changed by e2fsck since we originally mounted
2999                          * the partition.)
3000                          */
3001                         ext4_clear_journal_err(sb, es);
3002                         sbi->s_mount_state = le16_to_cpu(es->s_state);
3003                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
3004                                 goto restore_opts;
3005                         if (!ext4_setup_super (sb, es, 0))
3006                                 sb->s_flags &= ~MS_RDONLY;
3007                 }
3008         }
3009 #ifdef CONFIG_QUOTA
3010         /* Release old quota file names */
3011         for (i = 0; i < MAXQUOTAS; i++)
3012                 if (old_opts.s_qf_names[i] &&
3013                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3014                         kfree(old_opts.s_qf_names[i]);
3015 #endif
3016         return 0;
3017 restore_opts:
3018         sb->s_flags = old_sb_flags;
3019         sbi->s_mount_opt = old_opts.s_mount_opt;
3020         sbi->s_resuid = old_opts.s_resuid;
3021         sbi->s_resgid = old_opts.s_resgid;
3022         sbi->s_commit_interval = old_opts.s_commit_interval;
3023 #ifdef CONFIG_QUOTA
3024         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
3025         for (i = 0; i < MAXQUOTAS; i++) {
3026                 if (sbi->s_qf_names[i] &&
3027                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3028                         kfree(sbi->s_qf_names[i]);
3029                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
3030         }
3031 #endif
3032         return err;
3033 }
3034
3035 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
3036 {
3037         struct super_block *sb = dentry->d_sb;
3038         struct ext4_sb_info *sbi = EXT4_SB(sb);
3039         struct ext4_super_block *es = sbi->s_es;
3040         u64 fsid;
3041
3042         if (test_opt(sb, MINIX_DF)) {
3043                 sbi->s_overhead_last = 0;
3044         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
3045                 ext4_group_t ngroups = sbi->s_groups_count, i;
3046                 ext4_fsblk_t overhead = 0;
3047                 smp_rmb();
3048
3049                 /*
3050                  * Compute the overhead (FS structures).  This is constant
3051                  * for a given filesystem unless the number of block groups
3052                  * changes so we cache the previous value until it does.
3053                  */
3054
3055                 /*
3056                  * All of the blocks before first_data_block are
3057                  * overhead
3058                  */
3059                 overhead = le32_to_cpu(es->s_first_data_block);
3060
3061                 /*
3062                  * Add the overhead attributed to the superblock and
3063                  * block group descriptors.  If the sparse superblocks
3064                  * feature is turned on, then not all groups have this.
3065                  */
3066                 for (i = 0; i < ngroups; i++) {
3067                         overhead += ext4_bg_has_super(sb, i) +
3068                                 ext4_bg_num_gdb(sb, i);
3069                         cond_resched();
3070                 }
3071
3072                 /*
3073                  * Every block group has an inode bitmap, a block
3074                  * bitmap, and an inode table.
3075                  */
3076                 overhead += ngroups * (2 + sbi->s_itb_per_group);
3077                 sbi->s_overhead_last = overhead;
3078                 smp_wmb();
3079                 sbi->s_blocks_last = ext4_blocks_count(es);
3080         }
3081
3082         buf->f_type = EXT4_SUPER_MAGIC;
3083         buf->f_bsize = sb->s_blocksize;
3084         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
3085         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter);
3086         ext4_free_blocks_count_set(es, buf->f_bfree);
3087         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
3088         if (buf->f_bfree < ext4_r_blocks_count(es))
3089                 buf->f_bavail = 0;
3090         buf->f_files = le32_to_cpu(es->s_inodes_count);
3091         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
3092         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
3093         buf->f_namelen = EXT4_NAME_LEN;
3094         fsid = le64_to_cpup((void *)es->s_uuid) ^
3095                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
3096         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
3097         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
3098         return 0;
3099 }
3100
3101 /* Helper function for writing quotas on sync - we need to start transaction before quota file
3102  * is locked for write. Otherwise the are possible deadlocks:
3103  * Process 1                         Process 2
3104  * ext4_create()                     quota_sync()
3105  *   jbd2_journal_start()                   write_dquot()
3106  *   DQUOT_INIT()                        down(dqio_mutex)
3107  *     down(dqio_mutex)                    jbd2_journal_start()
3108  *
3109  */
3110
3111 #ifdef CONFIG_QUOTA
3112
3113 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3114 {
3115         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3116 }
3117
3118 static int ext4_dquot_initialize(struct inode *inode, int type)
3119 {
3120         handle_t *handle;
3121         int ret, err;
3122
3123         /* We may create quota structure so we need to reserve enough blocks */
3124         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
3125         if (IS_ERR(handle))
3126                 return PTR_ERR(handle);
3127         ret = dquot_initialize(inode, type);
3128         err = ext4_journal_stop(handle);
3129         if (!ret)
3130                 ret = err;
3131         return ret;
3132 }
3133
3134 static int ext4_dquot_drop(struct inode *inode)
3135 {
3136         handle_t *handle;
3137         int ret, err;
3138
3139         /* We may delete quota structure so we need to reserve enough blocks */
3140         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
3141         if (IS_ERR(handle)) {
3142                 /*
3143                  * We call dquot_drop() anyway to at least release references
3144                  * to quota structures so that umount does not hang.
3145                  */
3146                 dquot_drop(inode);
3147                 return PTR_ERR(handle);
3148         }
3149         ret = dquot_drop(inode);
3150         err = ext4_journal_stop(handle);
3151         if (!ret)
3152                 ret = err;
3153         return ret;
3154 }
3155
3156 static int ext4_write_dquot(struct dquot *dquot)
3157 {
3158         int ret, err;
3159         handle_t *handle;
3160         struct inode *inode;
3161
3162         inode = dquot_to_inode(dquot);
3163         handle = ext4_journal_start(inode,
3164                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3165         if (IS_ERR(handle))
3166                 return PTR_ERR(handle);
3167         ret = dquot_commit(dquot);
3168         err = ext4_journal_stop(handle);
3169         if (!ret)
3170                 ret = err;
3171         return ret;
3172 }
3173
3174 static int ext4_acquire_dquot(struct dquot *dquot)
3175 {
3176         int ret, err;
3177         handle_t *handle;
3178
3179         handle = ext4_journal_start(dquot_to_inode(dquot),
3180                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3181         if (IS_ERR(handle))
3182                 return PTR_ERR(handle);
3183         ret = dquot_acquire(dquot);
3184         err = ext4_journal_stop(handle);
3185         if (!ret)
3186                 ret = err;
3187         return ret;
3188 }
3189
3190 static int ext4_release_dquot(struct dquot *dquot)
3191 {
3192         int ret, err;
3193         handle_t *handle;
3194
3195         handle = ext4_journal_start(dquot_to_inode(dquot),
3196                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3197         if (IS_ERR(handle)) {
3198                 /* Release dquot anyway to avoid endless cycle in dqput() */
3199                 dquot_release(dquot);
3200                 return PTR_ERR(handle);
3201         }
3202         ret = dquot_release(dquot);
3203         err = ext4_journal_stop(handle);
3204         if (!ret)
3205                 ret = err;
3206         return ret;
3207 }
3208
3209 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3210 {
3211         /* Are we journaling quotas? */
3212         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3213             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3214                 dquot_mark_dquot_dirty(dquot);
3215                 return ext4_write_dquot(dquot);
3216         } else {
3217                 return dquot_mark_dquot_dirty(dquot);
3218         }
3219 }
3220
3221 static int ext4_write_info(struct super_block *sb, int type)
3222 {
3223         int ret, err;
3224         handle_t *handle;
3225
3226         /* Data block + inode block */
3227         handle = ext4_journal_start(sb->s_root->d_inode, 2);
3228         if (IS_ERR(handle))
3229                 return PTR_ERR(handle);
3230         ret = dquot_commit_info(sb, type);
3231         err = ext4_journal_stop(handle);
3232         if (!ret)
3233                 ret = err;
3234         return ret;
3235 }
3236
3237 /*
3238  * Turn on quotas during mount time - we need to find
3239  * the quota file and such...
3240  */
3241 static int ext4_quota_on_mount(struct super_block *sb, int type)
3242 {
3243         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3244                         EXT4_SB(sb)->s_jquota_fmt, type);
3245 }
3246
3247 /*
3248  * Standard function to be called on quota_on
3249  */
3250 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3251                          char *path, int remount)
3252 {
3253         int err;
3254         struct nameidata nd;
3255
3256         if (!test_opt(sb, QUOTA))
3257                 return -EINVAL;
3258         /* When remounting, no checks are needed and in fact, path is NULL */
3259         if (remount)
3260                 return vfs_quota_on(sb, type, format_id, path, remount);
3261
3262         err = path_lookup(path, LOOKUP_FOLLOW, &nd);
3263         if (err)
3264                 return err;
3265
3266         /* Quotafile not on the same filesystem? */
3267         if (nd.path.mnt->mnt_sb != sb) {
3268                 path_put(&nd.path);
3269                 return -EXDEV;
3270         }
3271         /* Journaling quota? */
3272         if (EXT4_SB(sb)->s_qf_names[type]) {
3273                 /* Quotafile not of fs root? */
3274                 if (nd.path.dentry->d_parent->d_inode != sb->s_root->d_inode)
3275                         printk(KERN_WARNING
3276                                 "EXT4-fs: Quota file not on filesystem root. "
3277                                 "Journaled quota will not work.\n");
3278         }
3279
3280         /*
3281          * When we journal data on quota file, we have to flush journal to see
3282          * all updates to the file when we bypass pagecache...
3283          */
3284         if (ext4_should_journal_data(nd.path.dentry->d_inode)) {
3285                 /*
3286                  * We don't need to lock updates but journal_flush() could
3287                  * otherwise be livelocked...
3288                  */
3289                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
3290                 jbd2_journal_flush(EXT4_SB(sb)->s_journal);
3291                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3292         }
3293
3294         path_put(&nd.path);
3295         return vfs_quota_on(sb, type, format_id, path, remount);
3296 }
3297
3298 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3299  * acquiring the locks... As quota files are never truncated and quota code
3300  * itself serializes the operations (and noone else should touch the files)
3301  * we don't have to be afraid of races */
3302 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3303                                size_t len, loff_t off)
3304 {
3305         struct inode *inode = sb_dqopt(sb)->files[type];
3306         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3307         int err = 0;
3308         int offset = off & (sb->s_blocksize - 1);
3309         int tocopy;
3310         size_t toread;
3311         struct buffer_head *bh;
3312         loff_t i_size = i_size_read(inode);
3313
3314         if (off > i_size)
3315                 return 0;
3316         if (off+len > i_size)
3317                 len = i_size-off;
3318         toread = len;
3319         while (toread > 0) {
3320                 tocopy = sb->s_blocksize - offset < toread ?
3321                                 sb->s_blocksize - offset : toread;
3322                 bh = ext4_bread(NULL, inode, blk, 0, &err);
3323                 if (err)
3324                         return err;
3325                 if (!bh)        /* A hole? */
3326                         memset(data, 0, tocopy);
3327                 else
3328                         memcpy(data, bh->b_data+offset, tocopy);
3329                 brelse(bh);
3330                 offset = 0;
3331                 toread -= tocopy;
3332                 data += tocopy;
3333                 blk++;
3334         }
3335         return len;
3336 }
3337
3338 /* Write to quotafile (we know the transaction is already started and has
3339  * enough credits) */
3340 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3341                                 const char *data, size_t len, loff_t off)
3342 {
3343         struct inode *inode = sb_dqopt(sb)->files[type];
3344         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3345         int err = 0;
3346         int offset = off & (sb->s_blocksize - 1);
3347         int tocopy;
3348         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3349         size_t towrite = len;
3350         struct buffer_head *bh;
3351         handle_t *handle = journal_current_handle();
3352
3353         if (!handle) {
3354                 printk(KERN_WARNING "EXT4-fs: Quota write (off=%Lu, len=%Lu)"
3355                         " cancelled because transaction is not started.\n",
3356                         (unsigned long long)off, (unsigned long long)len);
3357                 return -EIO;
3358         }
3359         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3360         while (towrite > 0) {
3361                 tocopy = sb->s_blocksize - offset < towrite ?
3362                                 sb->s_blocksize - offset : towrite;
3363                 bh = ext4_bread(handle, inode, blk, 1, &err);
3364                 if (!bh)
3365                         goto out;
3366                 if (journal_quota) {
3367                         err = ext4_journal_get_write_access(handle, bh);
3368                         if (err) {
3369                                 brelse(bh);
3370                                 goto out;
3371                         }
3372                 }
3373                 lock_buffer(bh);
3374                 memcpy(bh->b_data+offset, data, tocopy);
3375                 flush_dcache_page(bh->b_page);
3376                 unlock_buffer(bh);
3377                 if (journal_quota)
3378                         err = ext4_journal_dirty_metadata(handle, bh);
3379                 else {
3380                         /* Always do at least ordered writes for quotas */
3381                         err = ext4_journal_dirty_data(handle, bh);
3382                         mark_buffer_dirty(bh);
3383                 }
3384                 brelse(bh);
3385                 if (err)
3386                         goto out;
3387                 offset = 0;
3388                 towrite -= tocopy;
3389                 data += tocopy;
3390                 blk++;
3391         }
3392 out:
3393         if (len == towrite) {
3394                 mutex_unlock(&inode->i_mutex);
3395                 return err;
3396         }
3397         if (inode->i_size < off+len-towrite) {
3398                 i_size_write(inode, off+len-towrite);
3399                 EXT4_I(inode)->i_disksize = inode->i_size;
3400         }
3401         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3402         ext4_mark_inode_dirty(handle, inode);
3403         mutex_unlock(&inode->i_mutex);
3404         return len - towrite;
3405 }
3406
3407 #endif
3408
3409 static int ext4_get_sb(struct file_system_type *fs_type,
3410         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3411 {
3412         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3413 }
3414
3415 static struct file_system_type ext4dev_fs_type = {
3416         .owner          = THIS_MODULE,
3417         .name           = "ext4dev",
3418         .get_sb         = ext4_get_sb,
3419         .kill_sb        = kill_block_super,
3420         .fs_flags       = FS_REQUIRES_DEV,
3421 };
3422
3423 static int __init init_ext4_fs(void)
3424 {
3425         int err;
3426
3427         err = init_ext4_mballoc();
3428         if (err)
3429                 return err;
3430
3431         err = init_ext4_xattr();
3432         if (err)
3433                 goto out2;
3434         err = init_inodecache();
3435         if (err)
3436                 goto out1;
3437         err = register_filesystem(&ext4dev_fs_type);
3438         if (err)
3439                 goto out;
3440         return 0;
3441 out:
3442         destroy_inodecache();
3443 out1:
3444         exit_ext4_xattr();
3445 out2:
3446         exit_ext4_mballoc();
3447         return err;
3448 }
3449
3450 static void __exit exit_ext4_fs(void)
3451 {
3452         unregister_filesystem(&ext4dev_fs_type);
3453         destroy_inodecache();
3454         exit_ext4_xattr();
3455         exit_ext4_mballoc();
3456 }
3457
3458 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
3459 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
3460 MODULE_LICENSE("GPL");
3461 module_init(init_ext4_fs)
3462 module_exit(exit_ext4_fs)