fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/jbd2.h>
  24 #include <linux/ext4_fs.h>
  25 #include <linux/ext4_jbd2.h>
  26 #include <linux/slab.h>
  27 #include <linux/init.h>
  28 #include <linux/blkdev.h>
  29 #include <linux/parser.h>
  30 #include <linux/smp_lock.h>
  31 #include <linux/buffer_head.h>
  32 #include <linux/exportfs.h>
  33 #include <linux/vfs.h>
  34 #include <linux/random.h>
  35 #include <linux/mount.h>
  36 #include <linux/namei.h>
  37 #include <linux/quotaops.h>
  38 #include <linux/seq_file.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41
  42 #include <asm/uaccess.h>
  43
  44 #include "xattr.h"
  45 #include "acl.h"
  46 #include "namei.h"
  47 #include "group.h"
  48
  49 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  50                              unsigned long journal_devnum);
  51 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
  52                                unsigned int);
  53 static void ext4_commit_super (struct super_block * sb,
  54                                struct ext4_super_block * es,
  55                                int sync);
  56 static void ext4_mark_recovery_complete(struct super_block * sb,
  57                                         struct ext4_super_block * es);
  58 static void ext4_clear_journal_err(struct super_block * sb,
  59                                    struct ext4_super_block * es);
  60 static int ext4_sync_fs(struct super_block *sb, int wait);
  61 static const char *ext4_decode_error(struct super_block * sb, int errno,
  62                                      char nbuf[16]);
  63 static int ext4_remount (struct super_block * sb, int * flags, char * data);
  64 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf);
  65 static void ext4_unlockfs(struct super_block *sb);
  66 static void ext4_write_super (struct super_block * sb);
  67 static void ext4_write_super_lockfs(struct super_block *sb);
  68
  69
  70 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
  71                                struct ext4_group_desc *bg)
  72 {
  73         return le32_to_cpu(bg->bg_block_bitmap_lo) |
  74                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  75                 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
  76 }
  77
  78 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
  79                                struct ext4_group_desc *bg)
  80 {
  81         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
  82                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  83                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
  84 }
  85
  86 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
  87                               struct ext4_group_desc *bg)
  88 {
  89         return le32_to_cpu(bg->bg_inode_table_lo) |
  90                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  91                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
  92 }
  93
  94 void ext4_block_bitmap_set(struct super_block *sb,
  95                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
  96 {
  97         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
  98         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
  99                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 100 }
 101
 102 void ext4_inode_bitmap_set(struct super_block *sb,
 103                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 104 {
 105         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 106         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 107                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 108 }
 109
 110 void ext4_inode_table_set(struct super_block *sb,
 111                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 112 {
 113         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 114         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 115                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 116 }
 117
 118 /*
 119  * Wrappers for jbd2_journal_start/end.
 120  *
 121  * The only special thing we need to do here is to make sure that all
 122  * journal_end calls result in the superblock being marked dirty, so
 123  * that sync() will call the filesystem's write_super callback if
 124  * appropriate.
 125  */
 126 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 127 {
 128         journal_t *journal;
 129
 130         if (sb->s_flags & MS_RDONLY)
 131                 return ERR_PTR(-EROFS);
 132
 133         /* Special case here: if the journal has aborted behind our
 134          * backs (eg. EIO in the commit thread), then we still need to
 135          * take the FS itself readonly cleanly. */
 136         journal = EXT4_SB(sb)->s_journal;
 137         if (is_journal_aborted(journal)) {
 138                 ext4_abort(sb, __FUNCTION__,
 139                            "Detected aborted journal");
 140                 return ERR_PTR(-EROFS);
 141         }
 142
 143         return jbd2_journal_start(journal, nblocks);
 144 }
 145
 146 /*
 147  * The only special thing we need to do here is to make sure that all
 148  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 149  * that sync() will call the filesystem's write_super callback if
 150  * appropriate.
 151  */
 152 int __ext4_journal_stop(const char *where, handle_t *handle)
 153 {
 154         struct super_block *sb;
 155         int err;
 156         int rc;
 157
 158         sb = handle->h_transaction->t_journal->j_private;
 159         err = handle->h_err;
 160         rc = jbd2_journal_stop(handle);
 161
 162         if (!err)
 163                 err = rc;
 164         if (err)
 165                 __ext4_std_error(sb, where, err);
 166         return err;
 167 }
 168
 169 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 170                 struct buffer_head *bh, handle_t *handle, int err)
 171 {
 172         char nbuf[16];
 173         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 174
 175         if (bh)
 176                 BUFFER_TRACE(bh, "abort");
 177
 178         if (!handle->h_err)
 179                 handle->h_err = err;
 180
 181         if (is_handle_aborted(handle))
 182                 return;
 183
 184         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
 185                caller, errstr, err_fn);
 186
 187         jbd2_journal_abort_handle(handle);
 188 }
 189
 190 /* Deal with the reporting of failure conditions on a filesystem such as
 191  * inconsistencies detected or read IO failures.
 192  *
 193  * On ext2, we can store the error state of the filesystem in the
 194  * superblock.  That is not possible on ext4, because we may have other
 195  * write ordering constraints on the superblock which prevent us from
 196  * writing it out straight away; and given that the journal is about to
 197  * be aborted, we can't rely on the current, or future, transactions to
 198  * write out the superblock safely.
 199  *
 200  * We'll just use the jbd2_journal_abort() error code to record an error in
 201  * the journal instead.  On recovery, the journal will compain about
 202  * that error until we've noted it down and cleared it.
 203  */
 204
 205 static void ext4_handle_error(struct super_block *sb)
 206 {
 207         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 208
 209         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 210         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 211
 212         if (sb->s_flags & MS_RDONLY)
 213                 return;
 214
 215         if (!test_opt (sb, ERRORS_CONT)) {
 216                 journal_t *journal = EXT4_SB(sb)->s_journal;
 217
 218                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 219                 if (journal)
 220                         jbd2_journal_abort(journal, -EIO);
 221         }
 222         if (test_opt (sb, ERRORS_RO)) {
 223                 printk (KERN_CRIT "Remounting filesystem read-only\n");
 224                 sb->s_flags |= MS_RDONLY;
 225         }
 226         ext4_commit_super(sb, es, 1);
 227         if (test_opt(sb, ERRORS_PANIC))
 228                 panic("EXT4-fs (device %s): panic forced after error\n",
 229                         sb->s_id);
 230 }
 231
 232 void ext4_error (struct super_block * sb, const char * function,
 233                  const char * fmt, ...)
 234 {
 235         va_list args;
 236
 237         va_start(args, fmt);
 238         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 239         vprintk(fmt, args);
 240         printk("\n");
 241         va_end(args);
 242
 243         ext4_handle_error(sb);
 244 }
 245
 246 static const char *ext4_decode_error(struct super_block * sb, int errno,
 247                                      char nbuf[16])
 248 {
 249         char *errstr = NULL;
 250
 251         switch (errno) {
 252         case -EIO:
 253                 errstr = "IO failure";
 254                 break;
 255         case -ENOMEM:
 256                 errstr = "Out of memory";
 257                 break;
 258         case -EROFS:
 259                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
 260                         errstr = "Journal has aborted";
 261                 else
 262                         errstr = "Readonly filesystem";
 263                 break;
 264         default:
 265                 /* If the caller passed in an extra buffer for unknown
 266                  * errors, textualise them now.  Else we just return
 267                  * NULL. */
 268                 if (nbuf) {
 269                         /* Check for truncated error codes... */
 270                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 271                                 errstr = nbuf;
 272                 }
 273                 break;
 274         }
 275
 276         return errstr;
 277 }
 278
 279 /* __ext4_std_error decodes expected errors from journaling functions
 280  * automatically and invokes the appropriate error response.  */
 281
 282 void __ext4_std_error (struct super_block * sb, const char * function,
 283                        int errno)
 284 {
 285         char nbuf[16];
 286         const char *errstr;
 287
 288         /* Special case: if the error is EROFS, and we're not already
 289          * inside a transaction, then there's really no point in logging
 290          * an error. */
 291         if (errno == -EROFS && journal_current_handle() == NULL &&
 292             (sb->s_flags & MS_RDONLY))
 293                 return;
 294
 295         errstr = ext4_decode_error(sb, errno, nbuf);
 296         printk (KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
 297                 sb->s_id, function, errstr);
 298
 299         ext4_handle_error(sb);
 300 }
 301
 302 /*
 303  * ext4_abort is a much stronger failure handler than ext4_error.  The
 304  * abort function may be used to deal with unrecoverable failures such
 305  * as journal IO errors or ENOMEM at a critical moment in log management.
 306  *
 307  * We unconditionally force the filesystem into an ABORT|READONLY state,
 308  * unless the error response on the fs has been set to panic in which
 309  * case we take the easy way out and panic immediately.
 310  */
 311
 312 void ext4_abort (struct super_block * sb, const char * function,
 313                  const char * fmt, ...)
 314 {
 315         va_list args;
 316
 317         printk (KERN_CRIT "ext4_abort called.\n");
 318
 319         va_start(args, fmt);
 320         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 321         vprintk(fmt, args);
 322         printk("\n");
 323         va_end(args);
 324
 325         if (test_opt(sb, ERRORS_PANIC))
 326                 panic("EXT4-fs panic from previous error\n");
 327
 328         if (sb->s_flags & MS_RDONLY)
 329                 return;
 330
 331         printk(KERN_CRIT "Remounting filesystem read-only\n");
 332         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 333         sb->s_flags |= MS_RDONLY;
 334         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 335         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 336 }
 337
 338 void ext4_warning (struct super_block * sb, const char * function,
 339                    const char * fmt, ...)
 340 {
 341         va_list args;
 342
 343         va_start(args, fmt);
 344         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
 345                sb->s_id, function);
 346         vprintk(fmt, args);
 347         printk("\n");
 348         va_end(args);
 349 }
 350
 351 void ext4_update_dynamic_rev(struct super_block *sb)
 352 {
 353         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 354
 355         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 356                 return;
 357
 358         ext4_warning(sb, __FUNCTION__,
 359                      "updating to rev %d because of new feature flag, "
 360                      "running e2fsck is recommended",
 361                      EXT4_DYNAMIC_REV);
 362
 363         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 364         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 365         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 366         /* leave es->s_feature_*compat flags alone */
 367         /* es->s_uuid will be set by e2fsck if empty */
 368
 369         /*
 370          * The rest of the superblock fields should be zero, and if not it
 371          * means they are likely already in use, so leave them alone.  We
 372          * can leave it up to e2fsck to clean up any inconsistencies there.
 373          */
 374 }
 375
 376 int ext4_update_compat_feature(handle_t *handle,
 377                                         struct super_block *sb, __u32 compat)
 378 {
 379         int err = 0;
 380         if (!EXT4_HAS_COMPAT_FEATURE(sb, compat)) {
 381                 err = ext4_journal_get_write_access(handle,
 382                                 EXT4_SB(sb)->s_sbh);
 383                 if (err)
 384                         return err;
 385                 EXT4_SET_COMPAT_FEATURE(sb, compat);
 386                 sb->s_dirt = 1;
 387                 handle->h_sync = 1;
 388                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 389                                         "call ext4_journal_dirty_met adata");
 390                 err = ext4_journal_dirty_metadata(handle,
 391                                 EXT4_SB(sb)->s_sbh);
 392         }
 393         return err;
 394 }
 395
 396 int ext4_update_rocompat_feature(handle_t *handle,
 397                                         struct super_block *sb, __u32 rocompat)
 398 {
 399         int err = 0;
 400         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, rocompat)) {
 401                 err = ext4_journal_get_write_access(handle,
 402                                 EXT4_SB(sb)->s_sbh);
 403                 if (err)
 404                         return err;
 405                 EXT4_SET_RO_COMPAT_FEATURE(sb, rocompat);
 406                 sb->s_dirt = 1;
 407                 handle->h_sync = 1;
 408                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 409                                         "call ext4_journal_dirty_met adata");
 410                 err = ext4_journal_dirty_metadata(handle,
 411                                 EXT4_SB(sb)->s_sbh);
 412         }
 413         return err;
 414 }
 415
 416 int ext4_update_incompat_feature(handle_t *handle,
 417                                         struct super_block *sb, __u32 incompat)
 418 {
 419         int err = 0;
 420         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, incompat)) {
 421                 err = ext4_journal_get_write_access(handle,
 422                                 EXT4_SB(sb)->s_sbh);
 423                 if (err)
 424                         return err;
 425                 EXT4_SET_INCOMPAT_FEATURE(sb, incompat);
 426                 sb->s_dirt = 1;
 427                 handle->h_sync = 1;
 428                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 429                                         "call ext4_journal_dirty_met adata");
 430                 err = ext4_journal_dirty_metadata(handle,
 431                                 EXT4_SB(sb)->s_sbh);
 432         }
 433         return err;
 434 }
 435
 436 /*
 437  * Open the external journal device
 438  */
 439 static struct block_device *ext4_blkdev_get(dev_t dev)
 440 {
 441         struct block_device *bdev;
 442         char b[BDEVNAME_SIZE];
 443
 444         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 445         if (IS_ERR(bdev))
 446                 goto fail;
 447         return bdev;
 448
 449 fail:
 450         printk(KERN_ERR "EXT4: failed to open journal device %s: %ld\n",
 451                         __bdevname(dev, b), PTR_ERR(bdev));
 452         return NULL;
 453 }
 454
 455 /*
 456  * Release the journal device
 457  */
 458 static int ext4_blkdev_put(struct block_device *bdev)
 459 {
 460         bd_release(bdev);
 461         return blkdev_put(bdev);
 462 }
 463
 464 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 465 {
 466         struct block_device *bdev;
 467         int ret = -ENODEV;
 468
 469         bdev = sbi->journal_bdev;
 470         if (bdev) {
 471                 ret = ext4_blkdev_put(bdev);
 472                 sbi->journal_bdev = NULL;
 473         }
 474         return ret;
 475 }
 476
 477 static inline struct inode *orphan_list_entry(struct list_head *l)
 478 {
 479         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 480 }
 481
 482 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 483 {
 484         struct list_head *l;
 485
 486         printk(KERN_ERR "sb orphan head is %d\n",
 487                le32_to_cpu(sbi->s_es->s_last_orphan));
 488
 489         printk(KERN_ERR "sb_info orphan list:\n");
 490         list_for_each(l, &sbi->s_orphan) {
 491                 struct inode *inode = orphan_list_entry(l);
 492                 printk(KERN_ERR "  "
 493                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 494                        inode->i_sb->s_id, inode->i_ino, inode,
 495                        inode->i_mode, inode->i_nlink,
 496                        NEXT_ORPHAN(inode));
 497         }
 498 }
 499
 500 static void ext4_put_super (struct super_block * sb)
 501 {
 502         struct ext4_sb_info *sbi = EXT4_SB(sb);
 503         struct ext4_super_block *es = sbi->s_es;
 504         int i;
 505
 506         ext4_mb_release(sb);
 507         ext4_ext_release(sb);
 508         ext4_xattr_put_super(sb);
 509         jbd2_journal_destroy(sbi->s_journal);
 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         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 522         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 523         percpu_counter_destroy(&sbi->s_dirs_counter);
 524         brelse(sbi->s_sbh);
 525 #ifdef CONFIG_QUOTA
 526         for (i = 0; i < MAXQUOTAS; i++)
 527                 kfree(sbi->s_qf_names[i]);
 528 #endif
 529
 530         /* Debugging code just in case the in-memory inode orphan list
 531          * isn't empty.  The on-disk one can be non-empty if we've
 532          * detected an error and taken the fs readonly, but the
 533          * in-memory list had better be clean by this point. */
 534         if (!list_empty(&sbi->s_orphan))
 535                 dump_orphan_list(sb, sbi);
 536         J_ASSERT(list_empty(&sbi->s_orphan));
 537
 538         invalidate_bdev(sb->s_bdev);
 539         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 540                 /*
 541                  * Invalidate the journal device's buffers.  We don't want them
 542                  * floating about in memory - the physical journal device may
 543                  * hotswapped, and it breaks the `ro-after' testing code.
 544                  */
 545                 sync_blockdev(sbi->journal_bdev);
 546                 invalidate_bdev(sbi->journal_bdev);
 547                 ext4_blkdev_remove(sbi);
 548         }
 549         sb->s_fs_info = NULL;
 550         kfree(sbi);
 551         return;
 552 }
 553
 554 static struct kmem_cache *ext4_inode_cachep;
 555
 556 /*
 557  * Called inside transaction, so use GFP_NOFS
 558  */
 559 static struct inode *ext4_alloc_inode(struct super_block *sb)
 560 {
 561         struct ext4_inode_info *ei;
 562
 563         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 564         if (!ei)
 565                 return NULL;
 566 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 567         ei->i_acl = EXT4_ACL_NOT_CACHED;
 568         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 569 #endif
 570         ei->i_block_alloc_info = NULL;
 571         ei->vfs_inode.i_version = 1;
 572         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 573         INIT_LIST_HEAD(&ei->i_prealloc_list);
 574         spin_lock_init(&ei->i_prealloc_lock);
 575         return &ei->vfs_inode;
 576 }
 577
 578 static void ext4_destroy_inode(struct inode *inode)
 579 {
 580         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 581                 printk("EXT4 Inode %p: orphan list check failed!\n",
 582                         EXT4_I(inode));
 583                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 584                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 585                                 true);
 586                 dump_stack();
 587         }
 588         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 589 }
 590
 591 static void init_once(struct kmem_cache *cachep, void *foo)
 592 {
 593         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 594
 595         INIT_LIST_HEAD(&ei->i_orphan);
 596 #ifdef CONFIG_EXT4DEV_FS_XATTR
 597         init_rwsem(&ei->xattr_sem);
 598 #endif
 599         init_rwsem(&ei->i_data_sem);
 600         inode_init_once(&ei->vfs_inode);
 601 }
 602
 603 static int init_inodecache(void)
 604 {
 605         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 606                                              sizeof(struct ext4_inode_info),
 607                                              0, (SLAB_RECLAIM_ACCOUNT|
 608                                                 SLAB_MEM_SPREAD),
 609                                              init_once);
 610         if (ext4_inode_cachep == NULL)
 611                 return -ENOMEM;
 612         return 0;
 613 }
 614
 615 static void destroy_inodecache(void)
 616 {
 617         kmem_cache_destroy(ext4_inode_cachep);
 618 }
 619
 620 static void ext4_clear_inode(struct inode *inode)
 621 {
 622         struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
 623 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 624         if (EXT4_I(inode)->i_acl &&
 625                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
 626                 posix_acl_release(EXT4_I(inode)->i_acl);
 627                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
 628         }
 629         if (EXT4_I(inode)->i_default_acl &&
 630                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
 631                 posix_acl_release(EXT4_I(inode)->i_default_acl);
 632                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
 633         }
 634 #endif
 635         ext4_discard_reservation(inode);
 636         EXT4_I(inode)->i_block_alloc_info = NULL;
 637         if (unlikely(rsv))
 638                 kfree(rsv);
 639 }
 640
 641 static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
 642 {
 643 #if defined(CONFIG_QUOTA)
 644         struct ext4_sb_info *sbi = EXT4_SB(sb);
 645
 646         if (sbi->s_jquota_fmt)
 647                 seq_printf(seq, ",jqfmt=%s",
 648                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold": "vfsv0");
 649
 650         if (sbi->s_qf_names[USRQUOTA])
 651                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 652
 653         if (sbi->s_qf_names[GRPQUOTA])
 654                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 655
 656         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
 657                 seq_puts(seq, ",usrquota");
 658
 659         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
 660                 seq_puts(seq, ",grpquota");
 661 #endif
 662 }
 663
 664 /*
 665  * Show an option if
 666  *  - it's set to a non-default value OR
 667  *  - if the per-sb default is different from the global default
 668  */
 669 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 670 {
 671         int def_errors;
 672         unsigned long def_mount_opts;
 673         struct super_block *sb = vfs->mnt_sb;
 674         struct ext4_sb_info *sbi = EXT4_SB(sb);
 675         struct ext4_super_block *es = sbi->s_es;
 676
 677         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 678         def_errors     = le16_to_cpu(es->s_errors);
 679
 680         if (sbi->s_sb_block != 1)
 681                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 682         if (test_opt(sb, MINIX_DF))
 683                 seq_puts(seq, ",minixdf");
 684         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
 685                 seq_puts(seq, ",grpid");
 686         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 687                 seq_puts(seq, ",nogrpid");
 688         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 689             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 690                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 691         }
 692         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 693             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 694                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 695         }
 696         if (test_opt(sb, ERRORS_RO)) {
 697                 if (def_errors == EXT4_ERRORS_PANIC ||
 698                     def_errors == EXT4_ERRORS_CONTINUE) {
 699                         seq_puts(seq, ",errors=remount-ro");
 700                 }
 701         }
 702         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
 703                 seq_puts(seq, ",errors=continue");
 704         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
 705                 seq_puts(seq, ",errors=panic");
 706         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
 707                 seq_puts(seq, ",nouid32");
 708         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
 709                 seq_puts(seq, ",debug");
 710         if (test_opt(sb, OLDALLOC))
 711                 seq_puts(seq, ",oldalloc");
 712 #ifdef CONFIG_EXT4DEV_FS_XATTR
 713         if (test_opt(sb, XATTR_USER) &&
 714                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
 715                 seq_puts(seq, ",user_xattr");
 716         if (!test_opt(sb, XATTR_USER) &&
 717             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 718                 seq_puts(seq, ",nouser_xattr");
 719         }
 720 #endif
 721 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 722         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
 723                 seq_puts(seq, ",acl");
 724         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 725                 seq_puts(seq, ",noacl");
 726 #endif
 727         if (!test_opt(sb, RESERVATION))
 728                 seq_puts(seq, ",noreservation");
 729         if (sbi->s_commit_interval) {
 730                 seq_printf(seq, ",commit=%u",
 731                            (unsigned) (sbi->s_commit_interval / HZ));
 732         }
 733         if (test_opt(sb, BARRIER))
 734                 seq_puts(seq, ",barrier=1");
 735         if (test_opt(sb, NOBH))
 736                 seq_puts(seq, ",nobh");
 737         if (!test_opt(sb, EXTENTS))
 738                 seq_puts(seq, ",noextents");
 739         if (!test_opt(sb, MBALLOC))
 740                 seq_puts(seq, ",nomballoc");
 741         if (test_opt(sb, I_VERSION))
 742                 seq_puts(seq, ",i_version");
 743
 744         if (sbi->s_stripe)
 745                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
 746         /*
 747          * journal mode get enabled in different ways
 748          * So just print the value even if we didn't specify it
 749          */
 750         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 751                 seq_puts(seq, ",data=journal");
 752         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 753                 seq_puts(seq, ",data=ordered");
 754         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 755                 seq_puts(seq, ",data=writeback");
 756
 757         ext4_show_quota_options(seq, sb);
 758         return 0;
 759 }
 760
 761
 762 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 763                 u64 ino, u32 generation)
 764 {
 765         struct inode *inode;
 766
 767         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 768                 return ERR_PTR(-ESTALE);
 769         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 770                 return ERR_PTR(-ESTALE);
 771
 772         /* iget isn't really right if the inode is currently unallocated!!
 773          *
 774          * ext4_read_inode will return a bad_inode if the inode had been
 775          * deleted, so we should be safe.
 776          *
 777          * Currently we don't know the generation for parent directory, so
 778          * a generation of 0 means "accept any"
 779          */
 780         inode = ext4_iget(sb, ino);
 781         if (IS_ERR(inode))
 782                 return ERR_CAST(inode);
 783         if (generation && inode->i_generation != generation) {
 784                 iput(inode);
 785                 return ERR_PTR(-ESTALE);
 786         }
 787
 788         return inode;
 789 }
 790
 791 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 792                 int fh_len, int fh_type)
 793 {
 794         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 795                                     ext4_nfs_get_inode);
 796 }
 797
 798 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 799                 int fh_len, int fh_type)
 800 {
 801         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 802                                     ext4_nfs_get_inode);
 803 }
 804
 805 #ifdef CONFIG_QUOTA
 806 #define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
 807 #define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 808
 809 static int ext4_dquot_initialize(struct inode *inode, int type);
 810 static int ext4_dquot_drop(struct inode *inode);
 811 static int ext4_write_dquot(struct dquot *dquot);
 812 static int ext4_acquire_dquot(struct dquot *dquot);
 813 static int ext4_release_dquot(struct dquot *dquot);
 814 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 815 static int ext4_write_info(struct super_block *sb, int type);
 816 static int ext4_quota_on(struct super_block *sb, int type, int format_id, char *path);
 817 static int ext4_quota_on_mount(struct super_block *sb, int type);
 818 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 819                                size_t len, loff_t off);
 820 static ssize_t ext4_quota_write(struct super_block *sb, int type,
 821                                 const char *data, size_t len, loff_t off);
 822
 823 static struct dquot_operations ext4_quota_operations = {
 824         .initialize     = ext4_dquot_initialize,
 825         .drop           = ext4_dquot_drop,
 826         .alloc_space    = dquot_alloc_space,
 827         .alloc_inode    = dquot_alloc_inode,
 828         .free_space     = dquot_free_space,
 829         .free_inode     = dquot_free_inode,
 830         .transfer       = dquot_transfer,
 831         .write_dquot    = ext4_write_dquot,
 832         .acquire_dquot  = ext4_acquire_dquot,
 833         .release_dquot  = ext4_release_dquot,
 834         .mark_dirty     = ext4_mark_dquot_dirty,
 835         .write_info     = ext4_write_info
 836 };
 837
 838 static struct quotactl_ops ext4_qctl_operations = {
 839         .quota_on       = ext4_quota_on,
 840         .quota_off      = vfs_quota_off,
 841         .quota_sync     = vfs_quota_sync,
 842         .get_info       = vfs_get_dqinfo,
 843         .set_info       = vfs_set_dqinfo,
 844         .get_dqblk      = vfs_get_dqblk,
 845         .set_dqblk      = vfs_set_dqblk
 846 };
 847 #endif
 848
 849 static const struct super_operations ext4_sops = {
 850         .alloc_inode    = ext4_alloc_inode,
 851         .destroy_inode  = ext4_destroy_inode,
 852         .write_inode    = ext4_write_inode,
 853         .dirty_inode    = ext4_dirty_inode,
 854         .delete_inode   = ext4_delete_inode,
 855         .put_super      = ext4_put_super,
 856         .write_super    = ext4_write_super,
 857         .sync_fs        = ext4_sync_fs,
 858         .write_super_lockfs = ext4_write_super_lockfs,
 859         .unlockfs       = ext4_unlockfs,
 860         .statfs         = ext4_statfs,
 861         .remount_fs     = ext4_remount,
 862         .clear_inode    = ext4_clear_inode,
 863         .show_options   = ext4_show_options,
 864 #ifdef CONFIG_QUOTA
 865         .quota_read     = ext4_quota_read,
 866         .quota_write    = ext4_quota_write,
 867 #endif
 868 };
 869
 870 static const struct export_operations ext4_export_ops = {
 871         .fh_to_dentry = ext4_fh_to_dentry,
 872         .fh_to_parent = ext4_fh_to_parent,
 873         .get_parent = ext4_get_parent,
 874 };
 875
 876 enum {
 877         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 878         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
 879         Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov,
 880         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
 881         Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
 882         Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
 883         Opt_journal_checksum, Opt_journal_async_commit,
 884         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
 885         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 886         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
 887         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
 888         Opt_grpquota, Opt_extents, Opt_noextents, Opt_i_version,
 889         Opt_mballoc, Opt_nomballoc, Opt_stripe,
 890 };
 891
 892 static match_table_t tokens = {
 893         {Opt_bsd_df, "bsddf"},
 894         {Opt_minix_df, "minixdf"},
 895         {Opt_grpid, "grpid"},
 896         {Opt_grpid, "bsdgroups"},
 897         {Opt_nogrpid, "nogrpid"},
 898         {Opt_nogrpid, "sysvgroups"},
 899         {Opt_resgid, "resgid=%u"},
 900         {Opt_resuid, "resuid=%u"},
 901         {Opt_sb, "sb=%u"},
 902         {Opt_err_cont, "errors=continue"},
 903         {Opt_err_panic, "errors=panic"},
 904         {Opt_err_ro, "errors=remount-ro"},
 905         {Opt_nouid32, "nouid32"},
 906         {Opt_nocheck, "nocheck"},
 907         {Opt_nocheck, "check=none"},
 908         {Opt_debug, "debug"},
 909         {Opt_oldalloc, "oldalloc"},
 910         {Opt_orlov, "orlov"},
 911         {Opt_user_xattr, "user_xattr"},
 912         {Opt_nouser_xattr, "nouser_xattr"},
 913         {Opt_acl, "acl"},
 914         {Opt_noacl, "noacl"},
 915         {Opt_reservation, "reservation"},
 916         {Opt_noreservation, "noreservation"},
 917         {Opt_noload, "noload"},
 918         {Opt_nobh, "nobh"},
 919         {Opt_bh, "bh"},
 920         {Opt_commit, "commit=%u"},
 921         {Opt_journal_update, "journal=update"},
 922         {Opt_journal_inum, "journal=%u"},
 923         {Opt_journal_dev, "journal_dev=%u"},
 924         {Opt_journal_checksum, "journal_checksum"},
 925         {Opt_journal_async_commit, "journal_async_commit"},
 926         {Opt_abort, "abort"},
 927         {Opt_data_journal, "data=journal"},
 928         {Opt_data_ordered, "data=ordered"},
 929         {Opt_data_writeback, "data=writeback"},
 930         {Opt_offusrjquota, "usrjquota="},
 931         {Opt_usrjquota, "usrjquota=%s"},
 932         {Opt_offgrpjquota, "grpjquota="},
 933         {Opt_grpjquota, "grpjquota=%s"},
 934         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
 935         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
 936         {Opt_grpquota, "grpquota"},
 937         {Opt_noquota, "noquota"},
 938         {Opt_quota, "quota"},
 939         {Opt_usrquota, "usrquota"},
 940         {Opt_barrier, "barrier=%u"},
 941         {Opt_extents, "extents"},
 942         {Opt_noextents, "noextents"},
 943         {Opt_i_version, "i_version"},
 944         {Opt_mballoc, "mballoc"},
 945         {Opt_nomballoc, "nomballoc"},
 946         {Opt_stripe, "stripe=%u"},
 947         {Opt_err, NULL},
 948         {Opt_resize, "resize"},
 949 };
 950
 951 static ext4_fsblk_t get_sb_block(void **data)
 952 {
 953         ext4_fsblk_t    sb_block;
 954         char            *options = (char *) *data;
 955
 956         if (!options || strncmp(options, "sb=", 3) != 0)
 957                 return 1;       /* Default location */
 958         options += 3;
 959         /*todo: use simple_strtoll with >32bit ext4 */
 960         sb_block = simple_strtoul(options, &options, 0);
 961         if (*options && *options != ',') {
 962                 printk("EXT4-fs: Invalid sb specification: %s\n",
 963                        (char *) *data);
 964                 return 1;
 965         }
 966         if (*options == ',')
 967                 options++;
 968         *data = (void *) options;
 969         return sb_block;
 970 }
 971
 972 static int parse_options (char *options, struct super_block *sb,
 973                           unsigned int *inum, unsigned long *journal_devnum,
 974                           ext4_fsblk_t *n_blocks_count, int is_remount)
 975 {
 976         struct ext4_sb_info *sbi = EXT4_SB(sb);
 977         char * p;
 978         substring_t args[MAX_OPT_ARGS];
 979         int data_opt = 0;
 980         int option;
 981 #ifdef CONFIG_QUOTA
 982         int qtype;
 983         char *qname;
 984 #endif
 985
 986         if (!options)
 987                 return 1;
 988
 989         while ((p = strsep (&options, ",")) != NULL) {
 990                 int token;
 991                 if (!*p)
 992                         continue;
 993
 994                 token = match_token(p, tokens, args);
 995                 switch (token) {
 996                 case Opt_bsd_df:
 997                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 998                         break;
 999                 case Opt_minix_df:
1000                         set_opt (sbi->s_mount_opt, MINIX_DF);
1001                         break;
1002                 case Opt_grpid:
1003                         set_opt (sbi->s_mount_opt, GRPID);
1004                         break;
1005                 case Opt_nogrpid:
1006                         clear_opt (sbi->s_mount_opt, GRPID);
1007                         break;
1008                 case Opt_resuid:
1009                         if (match_int(&args[0], &option))
1010                                 return 0;
1011                         sbi->s_resuid = option;
1012                         break;
1013                 case Opt_resgid:
1014                         if (match_int(&args[0], &option))
1015                                 return 0;
1016                         sbi->s_resgid = option;
1017                         break;
1018                 case Opt_sb:
1019                         /* handled by get_sb_block() instead of here */
1020                         /* *sb_block = match_int(&args[0]); */
1021                         break;
1022                 case Opt_err_panic:
1023                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
1024                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
1025                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
1026                         break;
1027                 case Opt_err_ro:
1028                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
1029                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
1030                         set_opt (sbi->s_mount_opt, ERRORS_RO);
1031                         break;
1032                 case Opt_err_cont:
1033                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
1034                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
1035                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
1036                         break;
1037                 case Opt_nouid32:
1038                         set_opt (sbi->s_mount_opt, NO_UID32);
1039                         break;
1040                 case Opt_nocheck:
1041                         clear_opt (sbi->s_mount_opt, CHECK);
1042                         break;
1043                 case Opt_debug:
1044                         set_opt (sbi->s_mount_opt, DEBUG);
1045                         break;
1046                 case Opt_oldalloc:
1047                         set_opt (sbi->s_mount_opt, OLDALLOC);
1048                         break;
1049                 case Opt_orlov:
1050                         clear_opt (sbi->s_mount_opt, OLDALLOC);
1051                         break;
1052 #ifdef CONFIG_EXT4DEV_FS_XATTR
1053                 case Opt_user_xattr:
1054                         set_opt (sbi->s_mount_opt, XATTR_USER);
1055                         break;
1056                 case Opt_nouser_xattr:
1057                         clear_opt (sbi->s_mount_opt, XATTR_USER);
1058                         break;
1059 #else
1060                 case Opt_user_xattr:
1061                 case Opt_nouser_xattr:
1062                         printk("EXT4 (no)user_xattr options not supported\n");
1063                         break;
1064 #endif
1065 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1066                 case Opt_acl:
1067                         set_opt(sbi->s_mount_opt, POSIX_ACL);
1068                         break;
1069                 case Opt_noacl:
1070                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
1071                         break;
1072 #else
1073                 case Opt_acl:
1074                 case Opt_noacl:
1075                         printk("EXT4 (no)acl options not supported\n");
1076                         break;
1077 #endif
1078                 case Opt_reservation:
1079                         set_opt(sbi->s_mount_opt, RESERVATION);
1080                         break;
1081                 case Opt_noreservation:
1082                         clear_opt(sbi->s_mount_opt, RESERVATION);
1083                         break;
1084                 case Opt_journal_update:
1085                         /* @@@ FIXME */
1086                         /* Eventually we will want to be able to create
1087                            a journal file here.  For now, only allow the
1088                            user to specify an existing inode to be the
1089                            journal file. */
1090                         if (is_remount) {
1091                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1092                                        "journal on remount\n");
1093                                 return 0;
1094                         }
1095                         set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
1096                         break;
1097                 case Opt_journal_inum:
1098                         if (is_remount) {
1099                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1100                                        "journal on remount\n");
1101                                 return 0;
1102                         }
1103                         if (match_int(&args[0], &option))
1104                                 return 0;
1105                         *inum = option;
1106                         break;
1107                 case Opt_journal_dev:
1108                         if (is_remount) {
1109                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1110                                        "journal on remount\n");
1111                                 return 0;
1112                         }
1113                         if (match_int(&args[0], &option))
1114                                 return 0;
1115                         *journal_devnum = option;
1116                         break;
1117                 case Opt_journal_checksum:
1118                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1119                         break;
1120                 case Opt_journal_async_commit:
1121                         set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1122                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1123                         break;
1124                 case Opt_noload:
1125                         set_opt (sbi->s_mount_opt, NOLOAD);
1126                         break;
1127                 case Opt_commit:
1128                         if (match_int(&args[0], &option))
1129                                 return 0;
1130                         if (option < 0)
1131                                 return 0;
1132                         if (option == 0)
1133                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1134                         sbi->s_commit_interval = HZ * option;
1135                         break;
1136                 case Opt_data_journal:
1137                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1138                         goto datacheck;
1139                 case Opt_data_ordered:
1140                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1141                         goto datacheck;
1142                 case Opt_data_writeback:
1143                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1144                 datacheck:
1145                         if (is_remount) {
1146                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1147                                                 != data_opt) {
1148                                         printk(KERN_ERR
1149                                                 "EXT4-fs: cannot change data "
1150                                                 "mode on remount\n");
1151                                         return 0;
1152                                 }
1153                         } else {
1154                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1155                                 sbi->s_mount_opt |= data_opt;
1156                         }
1157                         break;
1158 #ifdef CONFIG_QUOTA
1159                 case Opt_usrjquota:
1160                         qtype = USRQUOTA;
1161                         goto set_qf_name;
1162                 case Opt_grpjquota:
1163                         qtype = GRPQUOTA;
1164 set_qf_name:
1165                         if (sb_any_quota_enabled(sb)) {
1166                                 printk(KERN_ERR
1167                                         "EXT4-fs: Cannot change journalled "
1168                                         "quota options when quota turned on.\n");
1169                                 return 0;
1170                         }
1171                         qname = match_strdup(&args[0]);
1172                         if (!qname) {
1173                                 printk(KERN_ERR
1174                                         "EXT4-fs: not enough memory for "
1175                                         "storing quotafile name.\n");
1176                                 return 0;
1177                         }
1178                         if (sbi->s_qf_names[qtype] &&
1179                             strcmp(sbi->s_qf_names[qtype], qname)) {
1180                                 printk(KERN_ERR
1181                                         "EXT4-fs: %s quota file already "
1182                                         "specified.\n", QTYPE2NAME(qtype));
1183                                 kfree(qname);
1184                                 return 0;
1185                         }
1186                         sbi->s_qf_names[qtype] = qname;
1187                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1188                                 printk(KERN_ERR
1189                                         "EXT4-fs: quotafile must be on "
1190                                         "filesystem root.\n");
1191                                 kfree(sbi->s_qf_names[qtype]);
1192                                 sbi->s_qf_names[qtype] = NULL;
1193                                 return 0;
1194                         }
1195                         set_opt(sbi->s_mount_opt, QUOTA);
1196                         break;
1197                 case Opt_offusrjquota:
1198                         qtype = USRQUOTA;
1199                         goto clear_qf_name;
1200                 case Opt_offgrpjquota:
1201                         qtype = GRPQUOTA;
1202 clear_qf_name:
1203                         if (sb_any_quota_enabled(sb)) {
1204                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1205                                         "journalled quota options when "
1206                                         "quota turned on.\n");
1207                                 return 0;
1208                         }
1209                         /*
1210                          * The space will be released later when all options
1211                          * are confirmed to be correct
1212                          */
1213                         sbi->s_qf_names[qtype] = NULL;
1214                         break;
1215                 case Opt_jqfmt_vfsold:
1216                         sbi->s_jquota_fmt = QFMT_VFS_OLD;
1217                         break;
1218                 case Opt_jqfmt_vfsv0:
1219                         sbi->s_jquota_fmt = QFMT_VFS_V0;
1220                         break;
1221                 case Opt_quota:
1222                 case Opt_usrquota:
1223                         set_opt(sbi->s_mount_opt, QUOTA);
1224                         set_opt(sbi->s_mount_opt, USRQUOTA);
1225                         break;
1226                 case Opt_grpquota:
1227                         set_opt(sbi->s_mount_opt, QUOTA);
1228                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1229                         break;
1230                 case Opt_noquota:
1231                         if (sb_any_quota_enabled(sb)) {
1232                                 printk(KERN_ERR "EXT4-fs: Cannot change quota "
1233                                         "options when quota turned on.\n");
1234                                 return 0;
1235                         }
1236                         clear_opt(sbi->s_mount_opt, QUOTA);
1237                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1238                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1239                         break;
1240 #else
1241                 case Opt_quota:
1242                 case Opt_usrquota:
1243                 case Opt_grpquota:
1244                 case Opt_usrjquota:
1245                 case Opt_grpjquota:
1246                 case Opt_offusrjquota:
1247                 case Opt_offgrpjquota:
1248                 case Opt_jqfmt_vfsold:
1249                 case Opt_jqfmt_vfsv0:
1250                         printk(KERN_ERR
1251                                 "EXT4-fs: journalled quota options not "
1252                                 "supported.\n");
1253                         break;
1254                 case Opt_noquota:
1255                         break;
1256 #endif
1257                 case Opt_abort:
1258                         set_opt(sbi->s_mount_opt, ABORT);
1259                         break;
1260                 case Opt_barrier:
1261                         if (match_int(&args[0], &option))
1262                                 return 0;
1263                         if (option)
1264                                 set_opt(sbi->s_mount_opt, BARRIER);
1265                         else
1266                                 clear_opt(sbi->s_mount_opt, BARRIER);
1267                         break;
1268                 case Opt_ignore:
1269                         break;
1270                 case Opt_resize:
1271                         if (!is_remount) {
1272                                 printk("EXT4-fs: resize option only available "
1273                                         "for remount\n");
1274                                 return 0;
1275                         }
1276                         if (match_int(&args[0], &option) != 0)
1277                                 return 0;
1278                         *n_blocks_count = option;
1279                         break;
1280                 case Opt_nobh:
1281                         set_opt(sbi->s_mount_opt, NOBH);
1282                         break;
1283                 case Opt_bh:
1284                         clear_opt(sbi->s_mount_opt, NOBH);
1285                         break;
1286                 case Opt_extents:
1287                         set_opt (sbi->s_mount_opt, EXTENTS);
1288                         break;
1289                 case Opt_noextents:
1290                         clear_opt (sbi->s_mount_opt, EXTENTS);
1291                         break;
1292                 case Opt_i_version:
1293                         set_opt(sbi->s_mount_opt, I_VERSION);
1294                         sb->s_flags |= MS_I_VERSION;
1295                         break;
1296                 case Opt_mballoc:
1297                         set_opt(sbi->s_mount_opt, MBALLOC);
1298                         break;
1299                 case Opt_nomballoc:
1300                         clear_opt(sbi->s_mount_opt, MBALLOC);
1301                         break;
1302                 case Opt_stripe:
1303                         if (match_int(&args[0], &option))
1304                                 return 0;
1305                         if (option < 0)
1306                                 return 0;
1307                         sbi->s_stripe = option;
1308                         break;
1309                 default:
1310                         printk (KERN_ERR
1311                                 "EXT4-fs: Unrecognized mount option \"%s\" "
1312                                 "or missing value\n", p);
1313                         return 0;
1314                 }
1315         }
1316 #ifdef CONFIG_QUOTA
1317         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1318                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1319                      sbi->s_qf_names[USRQUOTA])
1320                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1321
1322                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1323                      sbi->s_qf_names[GRPQUOTA])
1324                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1325
1326                 if ((sbi->s_qf_names[USRQUOTA] &&
1327                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1328                     (sbi->s_qf_names[GRPQUOTA] &&
1329                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1330                         printk(KERN_ERR "EXT4-fs: old and new quota "
1331                                         "format mixing.\n");
1332                         return 0;
1333                 }
1334
1335                 if (!sbi->s_jquota_fmt) {
1336                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1337                                         "not specified.\n");
1338                         return 0;
1339                 }
1340         } else {
1341                 if (sbi->s_jquota_fmt) {
1342                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1343                                         "specified with no journalling "
1344                                         "enabled.\n");
1345                         return 0;
1346                 }
1347         }
1348 #endif
1349         return 1;
1350 }
1351
1352 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1353                             int read_only)
1354 {
1355         struct ext4_sb_info *sbi = EXT4_SB(sb);
1356         int res = 0;
1357
1358         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1359                 printk (KERN_ERR "EXT4-fs warning: revision level too high, "
1360                         "forcing read-only mode\n");
1361                 res = MS_RDONLY;
1362         }
1363         if (read_only)
1364                 return res;
1365         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1366                 printk (KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1367                         "running e2fsck is recommended\n");
1368         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1369                 printk (KERN_WARNING
1370                         "EXT4-fs warning: mounting fs with errors, "
1371                         "running e2fsck is recommended\n");
1372         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1373                  le16_to_cpu(es->s_mnt_count) >=
1374                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1375                 printk (KERN_WARNING
1376                         "EXT4-fs warning: maximal mount count reached, "
1377                         "running e2fsck is recommended\n");
1378         else if (le32_to_cpu(es->s_checkinterval) &&
1379                 (le32_to_cpu(es->s_lastcheck) +
1380                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1381                 printk (KERN_WARNING
1382                         "EXT4-fs warning: checktime reached, "
1383                         "running e2fsck is recommended\n");
1384 #if 0
1385                 /* @@@ We _will_ want to clear the valid bit if we find
1386                  * inconsistencies, to force a fsck at reboot.  But for
1387                  * a plain journaled filesystem we can keep it set as
1388                  * valid forever! :)
1389                  */
1390         es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT4_VALID_FS);
1391 #endif
1392         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1393                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1394         es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
1395         es->s_mtime = cpu_to_le32(get_seconds());
1396         ext4_update_dynamic_rev(sb);
1397         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1398
1399         ext4_commit_super(sb, es, 1);
1400         if (test_opt(sb, DEBUG))
1401                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%lu, "
1402                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1403                         sb->s_blocksize,
1404                         sbi->s_groups_count,
1405                         EXT4_BLOCKS_PER_GROUP(sb),
1406                         EXT4_INODES_PER_GROUP(sb),
1407                         sbi->s_mount_opt);
1408
1409         printk(KERN_INFO "EXT4 FS on %s, ", sb->s_id);
1410         if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
1411                 char b[BDEVNAME_SIZE];
1412
1413                 printk("external journal on %s\n",
1414                         bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
1415         } else {
1416                 printk("internal journal\n");
1417         }
1418         return res;
1419 }
1420
1421 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1422                             struct ext4_group_desc *gdp)
1423 {
1424         __u16 crc = 0;
1425
1426         if (sbi->s_es->s_feature_ro_compat &
1427             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1428                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1429                 __le32 le_group = cpu_to_le32(block_group);
1430
1431                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1432                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1433                 crc = crc16(crc, (__u8 *)gdp, offset);
1434                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1435                 /* for checksum of struct ext4_group_desc do the rest...*/
1436                 if ((sbi->s_es->s_feature_incompat &
1437                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1438                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1439                         crc = crc16(crc, (__u8 *)gdp + offset,
1440                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1441                                         offset);
1442         }
1443
1444         return cpu_to_le16(crc);
1445 }
1446
1447 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1448                                 struct ext4_group_desc *gdp)
1449 {
1450         if ((sbi->s_es->s_feature_ro_compat &
1451              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1452             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1453                 return 0;
1454
1455         return 1;
1456 }
1457
1458 /* Called at mount-time, super-block is locked */
1459 static int ext4_check_descriptors(struct super_block *sb)
1460 {
1461         struct ext4_sb_info *sbi = EXT4_SB(sb);
1462         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1463         ext4_fsblk_t last_block;
1464         ext4_fsblk_t block_bitmap;
1465         ext4_fsblk_t inode_bitmap;
1466         ext4_fsblk_t inode_table;
1467         int flexbg_flag = 0;
1468         ext4_group_t i;
1469
1470         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1471                 flexbg_flag = 1;
1472
1473         ext4_debug ("Checking group descriptors");
1474
1475         for (i = 0; i < sbi->s_groups_count; i++) {
1476                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1477
1478                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1479                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1480                 else
1481                         last_block = first_block +
1482                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1483
1484                 block_bitmap = ext4_block_bitmap(sb, gdp);
1485                 if (block_bitmap < first_block || block_bitmap > last_block)
1486                 {
1487                         ext4_error (sb, "ext4_check_descriptors",
1488                                     "Block bitmap for group %lu"
1489                                     " not in group (block %llu)!",
1490                                     i, block_bitmap);
1491                         return 0;
1492                 }
1493                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1494                 if (inode_bitmap < first_block || inode_bitmap > last_block)
1495                 {
1496                         ext4_error (sb, "ext4_check_descriptors",
1497                                     "Inode bitmap for group %lu"
1498                                     " not in group (block %llu)!",
1499                                     i, inode_bitmap);
1500                         return 0;
1501                 }
1502                 inode_table = ext4_inode_table(sb, gdp);
1503                 if (inode_table < first_block ||
1504                     inode_table + sbi->s_itb_per_group - 1 > last_block)
1505                 {
1506                         ext4_error (sb, "ext4_check_descriptors",
1507                                     "Inode table for group %lu"
1508                                     " not in group (block %llu)!",
1509                                     i, inode_table);
1510                         return 0;
1511                 }
1512                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1513                         ext4_error(sb, __FUNCTION__,
1514                                    "Checksum for group %lu failed (%u!=%u)\n",
1515                                     i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1516                                     gdp)), le16_to_cpu(gdp->bg_checksum));
1517                         return 0;
1518                 }
1519                 if (!flexbg_flag)
1520                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1521         }
1522
1523         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1524         sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
1525         return 1;
1526 }
1527
1528 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1529  * the superblock) which were deleted from all directories, but held open by
1530  * a process at the time of a crash.  We walk the list and try to delete these
1531  * inodes at recovery time (only with a read-write filesystem).
1532  *
1533  * In order to keep the orphan inode chain consistent during traversal (in
1534  * case of crash during recovery), we link each inode into the superblock
1535  * orphan list_head and handle it the same way as an inode deletion during
1536  * normal operation (which journals the operations for us).
1537  *
1538  * We only do an iget() and an iput() on each inode, which is very safe if we
1539  * accidentally point at an in-use or already deleted inode.  The worst that
1540  * can happen in this case is that we get a "bit already cleared" message from
1541  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1542  * e2fsck was run on this filesystem, and it must have already done the orphan
1543  * inode cleanup for us, so we can safely abort without any further action.
1544  */
1545 static void ext4_orphan_cleanup (struct super_block * sb,
1546                                  struct ext4_super_block * es)
1547 {
1548         unsigned int s_flags = sb->s_flags;
1549         int nr_orphans = 0, nr_truncates = 0;
1550 #ifdef CONFIG_QUOTA
1551         int i;
1552 #endif
1553         if (!es->s_last_orphan) {
1554                 jbd_debug(4, "no orphan inodes to clean up\n");
1555                 return;
1556         }
1557
1558         if (bdev_read_only(sb->s_bdev)) {
1559                 printk(KERN_ERR "EXT4-fs: write access "
1560                         "unavailable, skipping orphan cleanup.\n");
1561                 return;
1562         }
1563
1564         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1565                 if (es->s_last_orphan)
1566                         jbd_debug(1, "Errors on filesystem, "
1567                                   "clearing orphan list.\n");
1568                 es->s_last_orphan = 0;
1569                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1570                 return;
1571         }
1572
1573         if (s_flags & MS_RDONLY) {
1574                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1575                        sb->s_id);
1576                 sb->s_flags &= ~MS_RDONLY;
1577         }
1578 #ifdef CONFIG_QUOTA
1579         /* Needed for iput() to work correctly and not trash data */
1580         sb->s_flags |= MS_ACTIVE;
1581         /* Turn on quotas so that they are updated correctly */
1582         for (i = 0; i < MAXQUOTAS; i++) {
1583                 if (EXT4_SB(sb)->s_qf_names[i]) {
1584                         int ret = ext4_quota_on_mount(sb, i);
1585                         if (ret < 0)
1586                                 printk(KERN_ERR
1587                                         "EXT4-fs: Cannot turn on journalled "
1588                                         "quota: error %d\n", ret);
1589                 }
1590         }
1591 #endif
1592
1593         while (es->s_last_orphan) {
1594                 struct inode *inode;
1595
1596                 if (!(inode =
1597                       ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan)))) {
1598                         es->s_last_orphan = 0;
1599                         break;
1600                 }
1601
1602                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1603                 DQUOT_INIT(inode);
1604                 if (inode->i_nlink) {
1605                         printk(KERN_DEBUG
1606                                 "%s: truncating inode %lu to %Ld bytes\n",
1607                                 __FUNCTION__, inode->i_ino, inode->i_size);
1608                         jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
1609                                   inode->i_ino, inode->i_size);
1610                         ext4_truncate(inode);
1611                         nr_truncates++;
1612                 } else {
1613                         printk(KERN_DEBUG
1614                                 "%s: deleting unreferenced inode %lu\n",
1615                                 __FUNCTION__, inode->i_ino);
1616                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1617                                   inode->i_ino);
1618                         nr_orphans++;
1619                 }
1620                 iput(inode);  /* The delete magic happens here! */
1621         }
1622
1623 #define PLURAL(x) (x), ((x)==1) ? "" : "s"
1624
1625         if (nr_orphans)
1626                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1627                        sb->s_id, PLURAL(nr_orphans));
1628         if (nr_truncates)
1629                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1630                        sb->s_id, PLURAL(nr_truncates));
1631 #ifdef CONFIG_QUOTA
1632         /* Turn quotas off */
1633         for (i = 0; i < MAXQUOTAS; i++) {
1634                 if (sb_dqopt(sb)->files[i])
1635                         vfs_quota_off(sb, i);
1636         }
1637 #endif
1638         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1639 }
1640 /*
1641  * Maximal extent format file size.
1642  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1643  * extent format containers, within a sector_t, and within i_blocks
1644  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1645  * so that won't be a limiting factor.
1646  *
1647  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1648  */
1649 static loff_t ext4_max_size(int blkbits)
1650 {
1651         loff_t res;
1652         loff_t upper_limit = MAX_LFS_FILESIZE;
1653
1654         /* small i_blocks in vfs inode? */
1655         if (sizeof(blkcnt_t) < sizeof(u64)) {
1656                 /*
1657                  * CONFIG_LSF is not enabled implies the inode
1658                  * i_block represent total blocks in 512 bytes
1659                  * 32 == size of vfs inode i_blocks * 8
1660                  */
1661                 upper_limit = (1LL << 32) - 1;
1662
1663                 /* total blocks in file system block size */
1664                 upper_limit >>= (blkbits - 9);
1665                 upper_limit <<= blkbits;
1666         }
1667
1668         /* 32-bit extent-start container, ee_block */
1669         res = 1LL << 32;
1670         res <<= blkbits;
1671         res -= 1;
1672
1673         /* Sanity check against vm- & vfs- imposed limits */
1674         if (res > upper_limit)
1675                 res = upper_limit;
1676
1677         return res;
1678 }
1679
1680 /*
1681  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
1682  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
1683  * We need to be 1 filesystem block less than the 2^48 sector limit.
1684  */
1685 static loff_t ext4_max_bitmap_size(int bits)
1686 {
1687         loff_t res = EXT4_NDIR_BLOCKS;
1688         int meta_blocks;
1689         loff_t upper_limit;
1690         /* This is calculated to be the largest file size for a
1691          * dense, bitmapped file such that the total number of
1692          * sectors in the file, including data and all indirect blocks,
1693          * does not exceed 2^48 -1
1694          * __u32 i_blocks_lo and _u16 i_blocks_high representing the
1695          * total number of  512 bytes blocks of the file
1696          */
1697
1698         if (sizeof(blkcnt_t) < sizeof(u64)) {
1699                 /*
1700                  * CONFIG_LSF is not enabled implies the inode
1701                  * i_block represent total blocks in 512 bytes
1702                  * 32 == size of vfs inode i_blocks * 8
1703                  */
1704                 upper_limit = (1LL << 32) - 1;
1705
1706                 /* total blocks in file system block size */
1707                 upper_limit >>= (bits - 9);
1708
1709         } else {
1710                 /*
1711                  * We use 48 bit ext4_inode i_blocks
1712                  * With EXT4_HUGE_FILE_FL set the i_blocks
1713                  * represent total number of blocks in
1714                  * file system block size
1715                  */
1716                 upper_limit = (1LL << 48) - 1;
1717
1718         }
1719
1720         /* indirect blocks */
1721         meta_blocks = 1;
1722         /* double indirect blocks */
1723         meta_blocks += 1 + (1LL << (bits-2));
1724         /* tripple indirect blocks */
1725         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
1726
1727         upper_limit -= meta_blocks;
1728         upper_limit <<= bits;
1729
1730         res += 1LL << (bits-2);
1731         res += 1LL << (2*(bits-2));
1732         res += 1LL << (3*(bits-2));
1733         res <<= bits;
1734         if (res > upper_limit)
1735                 res = upper_limit;
1736
1737         if (res > MAX_LFS_FILESIZE)
1738                 res = MAX_LFS_FILESIZE;
1739
1740         return res;
1741 }
1742
1743 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1744                                 ext4_fsblk_t logical_sb_block, int nr)
1745 {
1746         struct ext4_sb_info *sbi = EXT4_SB(sb);
1747         ext4_group_t bg, first_meta_bg;
1748         int has_super = 0;
1749
1750         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1751
1752         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1753             nr < first_meta_bg)
1754                 return logical_sb_block + nr + 1;
1755         bg = sbi->s_desc_per_block * nr;
1756         if (ext4_bg_has_super(sb, bg))
1757                 has_super = 1;
1758         return (has_super + ext4_group_first_block_no(sb, bg));
1759 }
1760
1761 /**
1762  * ext4_get_stripe_size: Get the stripe size.
1763  * @sbi: In memory super block info
1764  *
1765  * If we have specified it via mount option, then
1766  * use the mount option value. If the value specified at mount time is
1767  * greater than the blocks per group use the super block value.
1768  * If the super block value is greater than blocks per group return 0.
1769  * Allocator needs it be less than blocks per group.
1770  *
1771  */
1772 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
1773 {
1774         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
1775         unsigned long stripe_width =
1776                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
1777
1778         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
1779                 return sbi->s_stripe;
1780
1781         if (stripe_width <= sbi->s_blocks_per_group)
1782                 return stripe_width;
1783
1784         if (stride <= sbi->s_blocks_per_group)
1785                 return stride;
1786
1787         return 0;
1788 }
1789
1790 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
1791                                 __releases(kernel_sem)
1792                                 __acquires(kernel_sem)
1793
1794 {
1795         struct buffer_head * bh;
1796         struct ext4_super_block *es = NULL;
1797         struct ext4_sb_info *sbi;
1798         ext4_fsblk_t block;
1799         ext4_fsblk_t sb_block = get_sb_block(&data);
1800         ext4_fsblk_t logical_sb_block;
1801         unsigned long offset = 0;
1802         unsigned int journal_inum = 0;
1803         unsigned long journal_devnum = 0;
1804         unsigned long def_mount_opts;
1805         struct inode *root;
1806         int ret = -EINVAL;
1807         int blocksize;
1808         int db_count;
1809         int i;
1810         int needs_recovery;
1811         __le32 features;
1812         __u64 blocks_count;
1813         int err;
1814
1815         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1816         if (!sbi)
1817                 return -ENOMEM;
1818         sb->s_fs_info = sbi;
1819         sbi->s_mount_opt = 0;
1820         sbi->s_resuid = EXT4_DEF_RESUID;
1821         sbi->s_resgid = EXT4_DEF_RESGID;
1822         sbi->s_sb_block = sb_block;
1823
1824         unlock_kernel();
1825
1826         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1827         if (!blocksize) {
1828                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1829                 goto out_fail;
1830         }
1831
1832         if (!sb_set_blocksize(sb, blocksize)) {
1833                 printk(KERN_ERR "EXT4-fs: bad blocksize %d.\n", blocksize);
1834                 goto out_fail;
1835         }
1836
1837         /*
1838          * The ext4 superblock will not be buffer aligned for other than 1kB
1839          * block sizes.  We need to calculate the offset from buffer start.
1840          */
1841         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1842                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1843                 offset = do_div(logical_sb_block, blocksize);
1844         } else {
1845                 logical_sb_block = sb_block;
1846         }
1847
1848         if (!(bh = sb_bread(sb, logical_sb_block))) {
1849                 printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
1850                 goto out_fail;
1851         }
1852         /*
1853          * Note: s_es must be initialized as soon as possible because
1854          *       some ext4 macro-instructions depend on its value
1855          */
1856         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1857         sbi->s_es = es;
1858         sb->s_magic = le16_to_cpu(es->s_magic);
1859         if (sb->s_magic != EXT4_SUPER_MAGIC)
1860                 goto cantfind_ext4;
1861
1862         /* Set defaults before we parse the mount options */
1863         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1864         if (def_mount_opts & EXT4_DEFM_DEBUG)
1865                 set_opt(sbi->s_mount_opt, DEBUG);
1866         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1867                 set_opt(sbi->s_mount_opt, GRPID);
1868         if (def_mount_opts & EXT4_DEFM_UID16)
1869                 set_opt(sbi->s_mount_opt, NO_UID32);
1870 #ifdef CONFIG_EXT4DEV_FS_XATTR
1871         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1872                 set_opt(sbi->s_mount_opt, XATTR_USER);
1873 #endif
1874 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1875         if (def_mount_opts & EXT4_DEFM_ACL)
1876                 set_opt(sbi->s_mount_opt, POSIX_ACL);
1877 #endif
1878         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1879                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1880         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1881                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1882         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1883                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1884
1885         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1886                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1887         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
1888                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
1889         else
1890                 set_opt(sbi->s_mount_opt, ERRORS_RO);
1891
1892         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1893         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1894
1895         set_opt(sbi->s_mount_opt, RESERVATION);
1896
1897         /*
1898          * turn on extents feature by default in ext4 filesystem
1899          * User -o noextents to turn it off
1900          */
1901         set_opt(sbi->s_mount_opt, EXTENTS);
1902         /*
1903          * turn on mballoc feature by default in ext4 filesystem
1904          * User -o nomballoc to turn it off
1905          */
1906         set_opt(sbi->s_mount_opt, MBALLOC);
1907
1908         if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
1909                             NULL, 0))
1910                 goto failed_mount;
1911
1912         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1913                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1914
1915         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1916             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1917              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1918              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1919                 printk(KERN_WARNING
1920                        "EXT4-fs warning: feature flags set on rev 0 fs, "
1921                        "running e2fsck is recommended\n");
1922         /*
1923          * Check feature flags regardless of the revision level, since we
1924          * previously didn't change the revision level when setting the flags,
1925          * so there is a chance incompat flags are set on a rev 0 filesystem.
1926          */
1927         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
1928         if (features) {
1929                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
1930                        "unsupported optional features (%x).\n",
1931                        sb->s_id, le32_to_cpu(features));
1932                 goto failed_mount;
1933         }
1934         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
1935         if (!(sb->s_flags & MS_RDONLY) && features) {
1936                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
1937                        "unsupported optional features (%x).\n",
1938                        sb->s_id, le32_to_cpu(features));
1939                 goto failed_mount;
1940         }
1941         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
1942                 /*
1943                  * Large file size enabled file system can only be
1944                  * mount if kernel is build with CONFIG_LSF
1945                  */
1946                 if (sizeof(root->i_blocks) < sizeof(u64) &&
1947                                 !(sb->s_flags & MS_RDONLY)) {
1948                         printk(KERN_ERR "EXT4-fs: %s: Filesystem with huge "
1949                                         "files cannot be mounted read-write "
1950                                         "without CONFIG_LSF.\n", sb->s_id);
1951                         goto failed_mount;
1952                 }
1953         }
1954         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
1955
1956         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
1957             blocksize > EXT4_MAX_BLOCK_SIZE) {
1958                 printk(KERN_ERR
1959                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
1960                        blocksize, sb->s_id);
1961                 goto failed_mount;
1962         }
1963
1964         if (sb->s_blocksize != blocksize) {
1965
1966                 /* Validate the filesystem blocksize */
1967                 if (!sb_set_blocksize(sb, blocksize)) {
1968                         printk(KERN_ERR "EXT4-fs: bad block size %d.\n",
1969                                         blocksize);
1970                         goto failed_mount;
1971                 }
1972
1973                 brelse (bh);
1974                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1975                 offset = do_div(logical_sb_block, blocksize);
1976                 bh = sb_bread(sb, logical_sb_block);
1977                 if (!bh) {
1978                         printk(KERN_ERR
1979                                "EXT4-fs: Can't read superblock on 2nd try.\n");
1980                         goto failed_mount;
1981                 }
1982                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
1983                 sbi->s_es = es;
1984                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
1985                         printk (KERN_ERR
1986                                 "EXT4-fs: Magic mismatch, very weird !\n");
1987                         goto failed_mount;
1988                 }
1989         }
1990
1991         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits);
1992         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
1993
1994         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
1995                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
1996                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
1997         } else {
1998                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1999                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2000                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2001                     (!is_power_of_2(sbi->s_inode_size)) ||
2002                     (sbi->s_inode_size > blocksize)) {
2003                         printk (KERN_ERR
2004                                 "EXT4-fs: unsupported inode size: %d\n",
2005                                 sbi->s_inode_size);
2006                         goto failed_mount;
2007                 }
2008                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2009                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2010         }
2011         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2012         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2013                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2014                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2015                     !is_power_of_2(sbi->s_desc_size)) {
2016                         printk(KERN_ERR
2017                                "EXT4-fs: unsupported descriptor size %lu\n",
2018                                sbi->s_desc_size);
2019                         goto failed_mount;
2020                 }
2021         } else
2022                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2023         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2024         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2025         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2026                 goto cantfind_ext4;
2027         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2028         if (sbi->s_inodes_per_block == 0)
2029                 goto cantfind_ext4;
2030         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2031                                         sbi->s_inodes_per_block;
2032         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2033         sbi->s_sbh = bh;
2034         sbi->s_mount_state = le16_to_cpu(es->s_state);
2035         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2036         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2037         for (i=0; i < 4; i++)
2038                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2039         sbi->s_def_hash_version = es->s_def_hash_version;
2040
2041         if (sbi->s_blocks_per_group > blocksize * 8) {
2042                 printk (KERN_ERR
2043                         "EXT4-fs: #blocks per group too big: %lu\n",
2044                         sbi->s_blocks_per_group);
2045                 goto failed_mount;
2046         }
2047         if (sbi->s_inodes_per_group > blocksize * 8) {
2048                 printk (KERN_ERR
2049                         "EXT4-fs: #inodes per group too big: %lu\n",
2050                         sbi->s_inodes_per_group);
2051                 goto failed_mount;
2052         }
2053
2054         if (ext4_blocks_count(es) >
2055                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
2056                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
2057                         " too large to mount safely\n", sb->s_id);
2058                 if (sizeof(sector_t) < 8)
2059                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
2060                                         "enabled\n");
2061                 goto failed_mount;
2062         }
2063
2064         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2065                 goto cantfind_ext4;
2066
2067         /* ensure blocks_count calculation below doesn't sign-extend */
2068         if (ext4_blocks_count(es) + EXT4_BLOCKS_PER_GROUP(sb) <
2069             le32_to_cpu(es->s_first_data_block) + 1) {
2070                 printk(KERN_WARNING "EXT4-fs: bad geometry: block count %llu, "
2071                        "first data block %u, blocks per group %lu\n",
2072                         ext4_blocks_count(es),
2073                         le32_to_cpu(es->s_first_data_block),
2074                         EXT4_BLOCKS_PER_GROUP(sb));
2075                 goto failed_mount;
2076         }
2077         blocks_count = (ext4_blocks_count(es) -
2078                         le32_to_cpu(es->s_first_data_block) +
2079                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2080         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2081         sbi->s_groups_count = blocks_count;
2082         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2083                    EXT4_DESC_PER_BLOCK(sb);
2084         sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
2085                                     GFP_KERNEL);
2086         if (sbi->s_group_desc == NULL) {
2087                 printk (KERN_ERR "EXT4-fs: not enough memory\n");
2088                 goto failed_mount;
2089         }
2090
2091         bgl_lock_init(&sbi->s_blockgroup_lock);
2092
2093         for (i = 0; i < db_count; i++) {
2094                 block = descriptor_loc(sb, logical_sb_block, i);
2095                 sbi->s_group_desc[i] = sb_bread(sb, block);
2096                 if (!sbi->s_group_desc[i]) {
2097                         printk (KERN_ERR "EXT4-fs: "
2098                                 "can't read group descriptor %d\n", i);
2099                         db_count = i;
2100                         goto failed_mount2;
2101                 }
2102         }
2103         if (!ext4_check_descriptors (sb)) {
2104                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
2105                 goto failed_mount2;
2106         }
2107         sbi->s_gdb_count = db_count;
2108         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2109         spin_lock_init(&sbi->s_next_gen_lock);
2110
2111         err = percpu_counter_init(&sbi->s_freeblocks_counter,
2112                         ext4_count_free_blocks(sb));
2113         if (!err) {
2114                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
2115                                 ext4_count_free_inodes(sb));
2116         }
2117         if (!err) {
2118                 err = percpu_counter_init(&sbi->s_dirs_counter,
2119                                 ext4_count_dirs(sb));
2120         }
2121         if (err) {
2122                 printk(KERN_ERR "EXT4-fs: insufficient memory\n");
2123                 goto failed_mount3;
2124         }
2125
2126         /* per fileystem reservation list head & lock */
2127         spin_lock_init(&sbi->s_rsv_window_lock);
2128         sbi->s_rsv_window_root = RB_ROOT;
2129         /* Add a single, static dummy reservation to the start of the
2130          * reservation window list --- it gives us a placeholder for
2131          * append-at-start-of-list which makes the allocation logic
2132          * _much_ simpler. */
2133         sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
2134         sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
2135         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
2136         sbi->s_rsv_window_head.rsv_goal_size = 0;
2137         ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
2138
2139         sbi->s_stripe = ext4_get_stripe_size(sbi);
2140
2141         /*
2142          * set up enough so that it can read an inode
2143          */
2144         sb->s_op = &ext4_sops;
2145         sb->s_export_op = &ext4_export_ops;
2146         sb->s_xattr = ext4_xattr_handlers;
2147 #ifdef CONFIG_QUOTA
2148         sb->s_qcop = &ext4_qctl_operations;
2149         sb->dq_op = &ext4_quota_operations;
2150 #endif
2151         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2152
2153         sb->s_root = NULL;
2154
2155         needs_recovery = (es->s_last_orphan != 0 ||
2156                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2157                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2158
2159         /*
2160          * The first inode we look at is the journal inode.  Don't try
2161          * root first: it may be modified in the journal!
2162          */
2163         if (!test_opt(sb, NOLOAD) &&
2164             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2165                 if (ext4_load_journal(sb, es, journal_devnum))
2166                         goto failed_mount3;
2167         } else if (journal_inum) {
2168                 if (ext4_create_journal(sb, es, journal_inum))
2169                         goto failed_mount3;
2170         } else {
2171                 if (!silent)
2172                         printk (KERN_ERR
2173                                 "ext4: No journal on filesystem on %s\n",
2174                                 sb->s_id);
2175                 goto failed_mount3;
2176         }
2177
2178         if (ext4_blocks_count(es) > 0xffffffffULL &&
2179             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2180                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2181                 printk(KERN_ERR "ext4: Failed to set 64-bit journal feature\n");
2182                 goto failed_mount4;
2183         }
2184
2185         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2186                 jbd2_journal_set_features(sbi->s_journal,
2187                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2188                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2189         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2190                 jbd2_journal_set_features(sbi->s_journal,
2191                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2192                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2193                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2194         } else {
2195                 jbd2_journal_clear_features(sbi->s_journal,
2196                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2197                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2198         }
2199
2200         /* We have now updated the journal if required, so we can
2201          * validate the data journaling mode. */
2202         switch (test_opt(sb, DATA_FLAGS)) {
2203         case 0:
2204                 /* No mode set, assume a default based on the journal
2205                  * capabilities: ORDERED_DATA if the journal can
2206                  * cope, else JOURNAL_DATA
2207                  */
2208                 if (jbd2_journal_check_available_features
2209                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2210                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
2211                 else
2212                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2213                 break;
2214
2215         case EXT4_MOUNT_ORDERED_DATA:
2216         case EXT4_MOUNT_WRITEBACK_DATA:
2217                 if (!jbd2_journal_check_available_features
2218                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2219                         printk(KERN_ERR "EXT4-fs: Journal does not support "
2220                                "requested data journaling mode\n");
2221                         goto failed_mount4;
2222                 }
2223         default:
2224                 break;
2225         }
2226
2227         if (test_opt(sb, NOBH)) {
2228                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2229                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
2230                                 "its supported only with writeback mode\n");
2231                         clear_opt(sbi->s_mount_opt, NOBH);
2232                 }
2233         }
2234         /*
2235          * The jbd2_journal_load will have done any necessary log recovery,
2236          * so we can safely mount the rest of the filesystem now.
2237          */
2238
2239         root = ext4_iget(sb, EXT4_ROOT_INO);
2240         if (IS_ERR(root)) {
2241                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
2242                 ret = PTR_ERR(root);
2243                 goto failed_mount4;
2244         }
2245         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2246                 iput(root);
2247                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
2248                 goto failed_mount4;
2249         }
2250         sb->s_root = d_alloc_root(root);
2251         if (!sb->s_root) {
2252                 printk(KERN_ERR "EXT4-fs: get root dentry failed\n");
2253                 iput(root);
2254                 ret = -ENOMEM;
2255                 goto failed_mount4;
2256         }
2257
2258         ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
2259
2260         /* determine the minimum size of new large inodes, if present */
2261         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2262                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2263                                                      EXT4_GOOD_OLD_INODE_SIZE;
2264                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2265                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2266                         if (sbi->s_want_extra_isize <
2267                             le16_to_cpu(es->s_want_extra_isize))
2268                                 sbi->s_want_extra_isize =
2269                                         le16_to_cpu(es->s_want_extra_isize);
2270                         if (sbi->s_want_extra_isize <
2271                             le16_to_cpu(es->s_min_extra_isize))
2272                                 sbi->s_want_extra_isize =
2273                                         le16_to_cpu(es->s_min_extra_isize);
2274                 }
2275         }
2276         /* Check if enough inode space is available */
2277         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2278                                                         sbi->s_inode_size) {
2279                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2280                                                        EXT4_GOOD_OLD_INODE_SIZE;
2281                 printk(KERN_INFO "EXT4-fs: required extra inode space not"
2282                         "available.\n");
2283         }
2284
2285         /*
2286          * akpm: core read_super() calls in here with the superblock locked.
2287          * That deadlocks, because orphan cleanup needs to lock the superblock
2288          * in numerous places.  Here we just pop the lock - it's relatively
2289          * harmless, because we are now ready to accept write_super() requests,
2290          * and aviro says that's the only reason for hanging onto the
2291          * superblock lock.
2292          */
2293         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2294         ext4_orphan_cleanup(sb, es);
2295         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2296         if (needs_recovery)
2297                 printk (KERN_INFO "EXT4-fs: recovery complete.\n");
2298         ext4_mark_recovery_complete(sb, es);
2299         printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
2300                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
2301                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
2302                 "writeback");
2303
2304         ext4_ext_init(sb);
2305         ext4_mb_init(sb, needs_recovery);
2306
2307         lock_kernel();
2308         return 0;
2309
2310 cantfind_ext4:
2311         if (!silent)
2312                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
2313                        sb->s_id);
2314         goto failed_mount;
2315
2316 failed_mount4:
2317         jbd2_journal_destroy(sbi->s_journal);
2318 failed_mount3:
2319         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2320         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2321         percpu_counter_destroy(&sbi->s_dirs_counter);
2322 failed_mount2:
2323         for (i = 0; i < db_count; i++)
2324                 brelse(sbi->s_group_desc[i]);
2325         kfree(sbi->s_group_desc);
2326 failed_mount:
2327 #ifdef CONFIG_QUOTA
2328         for (i = 0; i < MAXQUOTAS; i++)
2329                 kfree(sbi->s_qf_names[i]);
2330 #endif
2331         ext4_blkdev_remove(sbi);
2332         brelse(bh);
2333 out_fail:
2334         sb->s_fs_info = NULL;
2335         kfree(sbi);
2336         lock_kernel();
2337         return ret;
2338 }
2339
2340 /*
2341  * Setup any per-fs journal parameters now.  We'll do this both on
2342  * initial mount, once the journal has been initialised but before we've
2343  * done any recovery; and again on any subsequent remount.
2344  */
2345 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2346 {
2347         struct ext4_sb_info *sbi = EXT4_SB(sb);
2348
2349         if (sbi->s_commit_interval)
2350                 journal->j_commit_interval = sbi->s_commit_interval;
2351         /* We could also set up an ext4-specific default for the commit
2352          * interval here, but for now we'll just fall back to the jbd
2353          * default. */
2354
2355         spin_lock(&journal->j_state_lock);
2356         if (test_opt(sb, BARRIER))
2357                 journal->j_flags |= JBD2_BARRIER;
2358         else
2359                 journal->j_flags &= ~JBD2_BARRIER;
2360         spin_unlock(&journal->j_state_lock);
2361 }
2362
2363 static journal_t *ext4_get_journal(struct super_block *sb,
2364                                    unsigned int journal_inum)
2365 {
2366         struct inode *journal_inode;
2367         journal_t *journal;
2368
2369         /* First, test for the existence of a valid inode on disk.  Bad
2370          * things happen if we iget() an unused inode, as the subsequent
2371          * iput() will try to delete it. */
2372
2373         journal_inode = ext4_iget(sb, journal_inum);
2374         if (IS_ERR(journal_inode)) {
2375                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
2376                 return NULL;
2377         }
2378         if (!journal_inode->i_nlink) {
2379                 make_bad_inode(journal_inode);
2380                 iput(journal_inode);
2381                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
2382                 return NULL;
2383         }
2384
2385         jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
2386                   journal_inode, journal_inode->i_size);
2387         if (!S_ISREG(journal_inode->i_mode)) {
2388                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
2389                 iput(journal_inode);
2390                 return NULL;
2391         }
2392
2393         journal = jbd2_journal_init_inode(journal_inode);
2394         if (!journal) {
2395                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
2396                 iput(journal_inode);
2397                 return NULL;
2398         }
2399         journal->j_private = sb;
2400         ext4_init_journal_params(sb, journal);
2401         return journal;
2402 }
2403
2404 static journal_t *ext4_get_dev_journal(struct super_block *sb,
2405                                        dev_t j_dev)
2406 {
2407         struct buffer_head * bh;
2408         journal_t *journal;
2409         ext4_fsblk_t start;
2410         ext4_fsblk_t len;
2411         int hblock, blocksize;
2412         ext4_fsblk_t sb_block;
2413         unsigned long offset;
2414         struct ext4_super_block * es;
2415         struct block_device *bdev;
2416
2417         bdev = ext4_blkdev_get(j_dev);
2418         if (bdev == NULL)
2419                 return NULL;
2420
2421         if (bd_claim(bdev, sb)) {
2422                 printk(KERN_ERR
2423                         "EXT4: failed to claim external journal device.\n");
2424                 blkdev_put(bdev);
2425                 return NULL;
2426         }
2427
2428         blocksize = sb->s_blocksize;
2429         hblock = bdev_hardsect_size(bdev);
2430         if (blocksize < hblock) {
2431                 printk(KERN_ERR
2432                         "EXT4-fs: blocksize too small for journal device.\n");
2433                 goto out_bdev;
2434         }
2435
2436         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2437         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2438         set_blocksize(bdev, blocksize);
2439         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2440                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2441                        "external journal\n");
2442                 goto out_bdev;
2443         }
2444
2445         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2446         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2447             !(le32_to_cpu(es->s_feature_incompat) &
2448               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2449                 printk(KERN_ERR "EXT4-fs: external journal has "
2450                                         "bad superblock\n");
2451                 brelse(bh);
2452                 goto out_bdev;
2453         }
2454
2455         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2456                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2457                 brelse(bh);
2458                 goto out_bdev;
2459         }
2460
2461         len = ext4_blocks_count(es);
2462         start = sb_block + 1;
2463         brelse(bh);     /* we're done with the superblock */
2464
2465         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2466                                         start, len, blocksize);
2467         if (!journal) {
2468                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2469                 goto out_bdev;
2470         }
2471         journal->j_private = sb;
2472         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2473         wait_on_buffer(journal->j_sb_buffer);
2474         if (!buffer_uptodate(journal->j_sb_buffer)) {
2475                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2476                 goto out_journal;
2477         }
2478         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2479                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2480                                         "user (unsupported) - %d\n",
2481                         be32_to_cpu(journal->j_superblock->s_nr_users));
2482                 goto out_journal;
2483         }
2484         EXT4_SB(sb)->journal_bdev = bdev;
2485         ext4_init_journal_params(sb, journal);
2486         return journal;
2487 out_journal:
2488         jbd2_journal_destroy(journal);
2489 out_bdev:
2490         ext4_blkdev_put(bdev);
2491         return NULL;
2492 }
2493
2494 static int ext4_load_journal(struct super_block *sb,
2495                              struct ext4_super_block *es,
2496                              unsigned long journal_devnum)
2497 {
2498         journal_t *journal;
2499         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2500         dev_t journal_dev;
2501         int err = 0;
2502         int really_read_only;
2503
2504         if (journal_devnum &&
2505             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2506                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2507                         "numbers have changed\n");
2508                 journal_dev = new_decode_dev(journal_devnum);
2509         } else
2510                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2511
2512         really_read_only = bdev_read_only(sb->s_bdev);
2513
2514         /*
2515          * Are we loading a blank journal or performing recovery after a
2516          * crash?  For recovery, we need to check in advance whether we
2517          * can get read-write access to the device.
2518          */
2519
2520         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2521                 if (sb->s_flags & MS_RDONLY) {
2522                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2523                                         "required on readonly filesystem.\n");
2524                         if (really_read_only) {
2525                                 printk(KERN_ERR "EXT4-fs: write access "
2526                                         "unavailable, cannot proceed.\n");
2527                                 return -EROFS;
2528                         }
2529                         printk (KERN_INFO "EXT4-fs: write access will "
2530                                         "be enabled during recovery.\n");
2531                 }
2532         }
2533
2534         if (journal_inum && journal_dev) {
2535                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2536                        "and inode journals!\n");
2537                 return -EINVAL;
2538         }
2539
2540         if (journal_inum) {
2541                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2542                         return -EINVAL;
2543         } else {
2544                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2545                         return -EINVAL;
2546         }
2547
2548         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2549                 err = jbd2_journal_update_format(journal);
2550                 if (err)  {
2551                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2552                         jbd2_journal_destroy(journal);
2553                         return err;
2554                 }
2555         }
2556
2557         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2558                 err = jbd2_journal_wipe(journal, !really_read_only);
2559         if (!err)
2560                 err = jbd2_journal_load(journal);
2561
2562         if (err) {
2563                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2564                 jbd2_journal_destroy(journal);
2565                 return err;
2566         }
2567
2568         EXT4_SB(sb)->s_journal = journal;
2569         ext4_clear_journal_err(sb, es);
2570
2571         if (journal_devnum &&
2572             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2573                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2574                 sb->s_dirt = 1;
2575
2576                 /* Make sure we flush the recovery flag to disk. */
2577                 ext4_commit_super(sb, es, 1);
2578         }
2579
2580         return 0;
2581 }
2582
2583 static int ext4_create_journal(struct super_block * sb,
2584                                struct ext4_super_block * es,
2585                                unsigned int journal_inum)
2586 {
2587         journal_t *journal;
2588         int err;
2589
2590         if (sb->s_flags & MS_RDONLY) {
2591                 printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2592                                 "create journal.\n");
2593                 return -EROFS;
2594         }
2595
2596         journal = ext4_get_journal(sb, journal_inum);
2597         if (!journal)
2598                 return -EINVAL;
2599
2600         printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2601                journal_inum);
2602
2603         err = jbd2_journal_create(journal);
2604         if (err) {
2605                 printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2606                 jbd2_journal_destroy(journal);
2607                 return -EIO;
2608         }
2609
2610         EXT4_SB(sb)->s_journal = journal;
2611
2612         ext4_update_dynamic_rev(sb);
2613         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2614         EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2615
2616         es->s_journal_inum = cpu_to_le32(journal_inum);
2617         sb->s_dirt = 1;
2618
2619         /* Make sure we flush the recovery flag to disk. */
2620         ext4_commit_super(sb, es, 1);
2621
2622         return 0;
2623 }
2624
2625 static void ext4_commit_super (struct super_block * sb,
2626                                struct ext4_super_block * es,
2627                                int sync)
2628 {
2629         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2630
2631         if (!sbh)
2632                 return;
2633         es->s_wtime = cpu_to_le32(get_seconds());
2634         ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2635         es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2636         BUFFER_TRACE(sbh, "marking dirty");
2637         mark_buffer_dirty(sbh);
2638         if (sync)
2639                 sync_dirty_buffer(sbh);
2640 }
2641
2642
2643 /*
2644  * Have we just finished recovery?  If so, and if we are mounting (or
2645  * remounting) the filesystem readonly, then we will end up with a
2646  * consistent fs on disk.  Record that fact.
2647  */
2648 static void ext4_mark_recovery_complete(struct super_block * sb,
2649                                         struct ext4_super_block * es)
2650 {
2651         journal_t *journal = EXT4_SB(sb)->s_journal;
2652
2653         jbd2_journal_lock_updates(journal);
2654         jbd2_journal_flush(journal);
2655         lock_super(sb);
2656         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2657             sb->s_flags & MS_RDONLY) {
2658                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2659                 sb->s_dirt = 0;
2660                 ext4_commit_super(sb, es, 1);
2661         }
2662         unlock_super(sb);
2663         jbd2_journal_unlock_updates(journal);
2664 }
2665
2666 /*
2667  * If we are mounting (or read-write remounting) a filesystem whose journal
2668  * has recorded an error from a previous lifetime, move that error to the
2669  * main filesystem now.
2670  */
2671 static void ext4_clear_journal_err(struct super_block * sb,
2672                                    struct ext4_super_block * es)
2673 {
2674         journal_t *journal;
2675         int j_errno;
2676         const char *errstr;
2677
2678         journal = EXT4_SB(sb)->s_journal;
2679
2680         /*
2681          * Now check for any error status which may have been recorded in the
2682          * journal by a prior ext4_error() or ext4_abort()
2683          */
2684
2685         j_errno = jbd2_journal_errno(journal);
2686         if (j_errno) {
2687                 char nbuf[16];
2688
2689                 errstr = ext4_decode_error(sb, j_errno, nbuf);
2690                 ext4_warning(sb, __FUNCTION__, "Filesystem error recorded "
2691                              "from previous mount: %s", errstr);
2692                 ext4_warning(sb, __FUNCTION__, "Marking fs in need of "
2693                              "filesystem check.");
2694
2695                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2696                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2697                 ext4_commit_super (sb, es, 1);
2698
2699                 jbd2_journal_clear_err(journal);
2700         }
2701 }
2702
2703 /*
2704  * Force the running and committing transactions to commit,
2705  * and wait on the commit.
2706  */
2707 int ext4_force_commit(struct super_block *sb)
2708 {
2709         journal_t *journal;
2710         int ret;
2711
2712         if (sb->s_flags & MS_RDONLY)
2713                 return 0;
2714
2715         journal = EXT4_SB(sb)->s_journal;
2716         sb->s_dirt = 0;
2717         ret = ext4_journal_force_commit(journal);
2718         return ret;
2719 }
2720
2721 /*
2722  * Ext4 always journals updates to the superblock itself, so we don't
2723  * have to propagate any other updates to the superblock on disk at this
2724  * point.  Just start an async writeback to get the buffers on their way
2725  * to the disk.
2726  *
2727  * This implicitly triggers the writebehind on sync().
2728  */
2729
2730 static void ext4_write_super (struct super_block * sb)
2731 {
2732         if (mutex_trylock(&sb->s_lock) != 0)
2733                 BUG();
2734         sb->s_dirt = 0;
2735 }
2736
2737 static int ext4_sync_fs(struct super_block *sb, int wait)
2738 {
2739         tid_t target;
2740
2741         sb->s_dirt = 0;
2742         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2743                 if (wait)
2744                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2745         }
2746         return 0;
2747 }
2748
2749 /*
2750  * LVM calls this function before a (read-only) snapshot is created.  This
2751  * gives us a chance to flush the journal completely and mark the fs clean.
2752  */
2753 static void ext4_write_super_lockfs(struct super_block *sb)
2754 {
2755         sb->s_dirt = 0;
2756
2757         if (!(sb->s_flags & MS_RDONLY)) {
2758                 journal_t *journal = EXT4_SB(sb)->s_journal;
2759
2760                 /* Now we set up the journal barrier. */
2761                 jbd2_journal_lock_updates(journal);
2762                 jbd2_journal_flush(journal);
2763
2764                 /* Journal blocked and flushed, clear needs_recovery flag. */
2765                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2766                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2767         }
2768 }
2769
2770 /*
2771  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2772  * flag here, even though the filesystem is not technically dirty yet.
2773  */
2774 static void ext4_unlockfs(struct super_block *sb)
2775 {
2776         if (!(sb->s_flags & MS_RDONLY)) {
2777                 lock_super(sb);
2778                 /* Reser the needs_recovery flag before the fs is unlocked. */
2779                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2780                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2781                 unlock_super(sb);
2782                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2783         }
2784 }
2785
2786 static int ext4_remount (struct super_block * sb, int * flags, char * data)
2787 {
2788         struct ext4_super_block * es;
2789         struct ext4_sb_info *sbi = EXT4_SB(sb);
2790         ext4_fsblk_t n_blocks_count = 0;
2791         unsigned long old_sb_flags;
2792         struct ext4_mount_options old_opts;
2793         int err;
2794 #ifdef CONFIG_QUOTA
2795         int i;
2796 #endif
2797
2798         /* Store the original options */
2799         old_sb_flags = sb->s_flags;
2800         old_opts.s_mount_opt = sbi->s_mount_opt;
2801         old_opts.s_resuid = sbi->s_resuid;
2802         old_opts.s_resgid = sbi->s_resgid;
2803         old_opts.s_commit_interval = sbi->s_commit_interval;
2804 #ifdef CONFIG_QUOTA
2805         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2806         for (i = 0; i < MAXQUOTAS; i++)
2807                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2808 #endif
2809
2810         /*
2811          * Allow the "check" option to be passed as a remount option.
2812          */
2813         if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2814                 err = -EINVAL;
2815                 goto restore_opts;
2816         }
2817
2818         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2819                 ext4_abort(sb, __FUNCTION__, "Abort forced by user");
2820
2821         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2822                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2823
2824         es = sbi->s_es;
2825
2826         ext4_init_journal_params(sb, sbi->s_journal);
2827
2828         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2829                 n_blocks_count > ext4_blocks_count(es)) {
2830                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
2831                         err = -EROFS;
2832                         goto restore_opts;
2833                 }
2834
2835                 if (*flags & MS_RDONLY) {
2836                         /*
2837                          * First of all, the unconditional stuff we have to do
2838                          * to disable replay of the journal when we next remount
2839                          */
2840                         sb->s_flags |= MS_RDONLY;
2841
2842                         /*
2843                          * OK, test if we are remounting a valid rw partition
2844                          * readonly, and if so set the rdonly flag and then
2845                          * mark the partition as valid again.
2846                          */
2847                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
2848                             (sbi->s_mount_state & EXT4_VALID_FS))
2849                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
2850
2851                         /*
2852                          * We have to unlock super so that we can wait for
2853                          * transactions.
2854                          */
2855                         unlock_super(sb);
2856                         ext4_mark_recovery_complete(sb, es);
2857                         lock_super(sb);
2858                 } else {
2859                         __le32 ret;
2860                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2861                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
2862                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2863                                        "remount RDWR because of unsupported "
2864                                        "optional features (%x).\n",
2865                                        sb->s_id, le32_to_cpu(ret));
2866                                 err = -EROFS;
2867                                 goto restore_opts;
2868                         }
2869
2870                         /*
2871                          * If we have an unprocessed orphan list hanging
2872                          * around from a previously readonly bdev mount,
2873                          * require a full umount/remount for now.
2874                          */
2875                         if (es->s_last_orphan) {
2876                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2877                                        "remount RDWR because of unprocessed "
2878                                        "orphan inode list.  Please "
2879                                        "umount/remount instead.\n",
2880                                        sb->s_id);
2881                                 err = -EINVAL;
2882                                 goto restore_opts;
2883                         }
2884
2885                         /*
2886                          * Mounting a RDONLY partition read-write, so reread
2887                          * and store the current valid flag.  (It may have
2888                          * been changed by e2fsck since we originally mounted
2889                          * the partition.)
2890                          */
2891                         ext4_clear_journal_err(sb, es);
2892                         sbi->s_mount_state = le16_to_cpu(es->s_state);
2893                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
2894                                 goto restore_opts;
2895                         if (!ext4_setup_super (sb, es, 0))
2896                                 sb->s_flags &= ~MS_RDONLY;
2897                 }
2898         }
2899 #ifdef CONFIG_QUOTA
2900         /* Release old quota file names */
2901         for (i = 0; i < MAXQUOTAS; i++)
2902                 if (old_opts.s_qf_names[i] &&
2903                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2904                         kfree(old_opts.s_qf_names[i]);
2905 #endif
2906         return 0;
2907 restore_opts:
2908         sb->s_flags = old_sb_flags;
2909         sbi->s_mount_opt = old_opts.s_mount_opt;
2910         sbi->s_resuid = old_opts.s_resuid;
2911         sbi->s_resgid = old_opts.s_resgid;
2912         sbi->s_commit_interval = old_opts.s_commit_interval;
2913 #ifdef CONFIG_QUOTA
2914         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
2915         for (i = 0; i < MAXQUOTAS; i++) {
2916                 if (sbi->s_qf_names[i] &&
2917                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2918                         kfree(sbi->s_qf_names[i]);
2919                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
2920         }
2921 #endif
2922         return err;
2923 }
2924
2925 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
2926 {
2927         struct super_block *sb = dentry->d_sb;
2928         struct ext4_sb_info *sbi = EXT4_SB(sb);
2929         struct ext4_super_block *es = sbi->s_es;
2930         u64 fsid;
2931
2932         if (test_opt(sb, MINIX_DF)) {
2933                 sbi->s_overhead_last = 0;
2934         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
2935                 ext4_group_t ngroups = sbi->s_groups_count, i;
2936                 ext4_fsblk_t overhead = 0;
2937                 smp_rmb();
2938
2939                 /*
2940                  * Compute the overhead (FS structures).  This is constant
2941                  * for a given filesystem unless the number of block groups
2942                  * changes so we cache the previous value until it does.
2943                  */
2944
2945                 /*
2946                  * All of the blocks before first_data_block are
2947                  * overhead
2948                  */
2949                 overhead = le32_to_cpu(es->s_first_data_block);
2950
2951                 /*
2952                  * Add the overhead attributed to the superblock and
2953                  * block group descriptors.  If the sparse superblocks
2954                  * feature is turned on, then not all groups have this.
2955                  */
2956                 for (i = 0; i < ngroups; i++) {
2957                         overhead += ext4_bg_has_super(sb, i) +
2958                                 ext4_bg_num_gdb(sb, i);
2959                         cond_resched();
2960                 }
2961
2962                 /*
2963                  * Every block group has an inode bitmap, a block
2964                  * bitmap, and an inode table.
2965                  */
2966                 overhead += ngroups * (2 + sbi->s_itb_per_group);
2967                 sbi->s_overhead_last = overhead;
2968                 smp_wmb();
2969                 sbi->s_blocks_last = ext4_blocks_count(es);
2970         }
2971
2972         buf->f_type = EXT4_SUPER_MAGIC;
2973         buf->f_bsize = sb->s_blocksize;
2974         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
2975         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter);
2976         ext4_free_blocks_count_set(es, buf->f_bfree);
2977         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
2978         if (buf->f_bfree < ext4_r_blocks_count(es))
2979                 buf->f_bavail = 0;
2980         buf->f_files = le32_to_cpu(es->s_inodes_count);
2981         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
2982         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
2983         buf->f_namelen = EXT4_NAME_LEN;
2984         fsid = le64_to_cpup((void *)es->s_uuid) ^
2985                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
2986         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
2987         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
2988         return 0;
2989 }
2990
2991 /* Helper function for writing quotas on sync - we need to start transaction before quota file
2992  * is locked for write. Otherwise the are possible deadlocks:
2993  * Process 1                         Process 2
2994  * ext4_create()                     quota_sync()
2995  *   jbd2_journal_start()                   write_dquot()
2996  *   DQUOT_INIT()                        down(dqio_mutex)
2997  *     down(dqio_mutex)                    jbd2_journal_start()
2998  *
2999  */
3000
3001 #ifdef CONFIG_QUOTA
3002
3003 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3004 {
3005         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3006 }
3007
3008 static int ext4_dquot_initialize(struct inode *inode, int type)
3009 {
3010         handle_t *handle;
3011         int ret, err;
3012
3013         /* We may create quota structure so we need to reserve enough blocks */
3014         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
3015         if (IS_ERR(handle))
3016                 return PTR_ERR(handle);
3017         ret = dquot_initialize(inode, type);
3018         err = ext4_journal_stop(handle);
3019         if (!ret)
3020                 ret = err;
3021         return ret;
3022 }
3023
3024 static int ext4_dquot_drop(struct inode *inode)
3025 {
3026         handle_t *handle;
3027         int ret, err;
3028
3029         /* We may delete quota structure so we need to reserve enough blocks */
3030         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
3031         if (IS_ERR(handle))
3032                 return PTR_ERR(handle);
3033         ret = dquot_drop(inode);
3034         err = ext4_journal_stop(handle);
3035         if (!ret)
3036                 ret = err;
3037         return ret;
3038 }
3039
3040 static int ext4_write_dquot(struct dquot *dquot)
3041 {
3042         int ret, err;
3043         handle_t *handle;
3044         struct inode *inode;
3045
3046         inode = dquot_to_inode(dquot);
3047         handle = ext4_journal_start(inode,
3048                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3049         if (IS_ERR(handle))
3050                 return PTR_ERR(handle);
3051         ret = dquot_commit(dquot);
3052         err = ext4_journal_stop(handle);
3053         if (!ret)
3054                 ret = err;
3055         return ret;
3056 }
3057
3058 static int ext4_acquire_dquot(struct dquot *dquot)
3059 {
3060         int ret, err;
3061         handle_t *handle;
3062
3063         handle = ext4_journal_start(dquot_to_inode(dquot),
3064                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3065         if (IS_ERR(handle))
3066                 return PTR_ERR(handle);
3067         ret = dquot_acquire(dquot);
3068         err = ext4_journal_stop(handle);
3069         if (!ret)
3070                 ret = err;
3071         return ret;
3072 }
3073
3074 static int ext4_release_dquot(struct dquot *dquot)
3075 {
3076         int ret, err;
3077         handle_t *handle;
3078
3079         handle = ext4_journal_start(dquot_to_inode(dquot),
3080                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3081         if (IS_ERR(handle)) {
3082                 /* Release dquot anyway to avoid endless cycle in dqput() */
3083                 dquot_release(dquot);
3084                 return PTR_ERR(handle);
3085         }
3086         ret = dquot_release(dquot);
3087         err = ext4_journal_stop(handle);
3088         if (!ret)
3089                 ret = err;
3090         return ret;
3091 }
3092
3093 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3094 {
3095         /* Are we journalling quotas? */
3096         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3097             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3098                 dquot_mark_dquot_dirty(dquot);
3099                 return ext4_write_dquot(dquot);
3100         } else {
3101                 return dquot_mark_dquot_dirty(dquot);
3102         }
3103 }
3104
3105 static int ext4_write_info(struct super_block *sb, int type)
3106 {
3107         int ret, err;
3108         handle_t *handle;
3109
3110         /* Data block + inode block */
3111         handle = ext4_journal_start(sb->s_root->d_inode, 2);
3112         if (IS_ERR(handle))
3113                 return PTR_ERR(handle);
3114         ret = dquot_commit_info(sb, type);
3115         err = ext4_journal_stop(handle);
3116         if (!ret)
3117                 ret = err;
3118         return ret;
3119 }
3120
3121 /*
3122  * Turn on quotas during mount time - we need to find
3123  * the quota file and such...
3124  */
3125 static int ext4_quota_on_mount(struct super_block *sb, int type)
3126 {
3127         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3128                         EXT4_SB(sb)->s_jquota_fmt, type);
3129 }
3130
3131 /*
3132  * Standard function to be called on quota_on
3133  */
3134 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3135                          char *path)
3136 {
3137         int err;
3138         struct nameidata nd;
3139
3140         if (!test_opt(sb, QUOTA))
3141                 return -EINVAL;
3142         /* Not journalling quota? */
3143         if (!EXT4_SB(sb)->s_qf_names[USRQUOTA] &&
3144             !EXT4_SB(sb)->s_qf_names[GRPQUOTA])
3145                 return vfs_quota_on(sb, type, format_id, path);
3146         err = path_lookup(path, LOOKUP_FOLLOW, &nd);
3147         if (err)
3148                 return err;
3149         /* Quotafile not on the same filesystem? */
3150         if (nd.mnt->mnt_sb != sb) {
3151                 path_release(&nd);
3152                 return -EXDEV;
3153         }
3154         /* Quotafile not of fs root? */
3155         if (nd.dentry->d_parent->d_inode != sb->s_root->d_inode)
3156                 printk(KERN_WARNING
3157                         "EXT4-fs: Quota file not on filesystem root. "
3158                         "Journalled quota will not work.\n");
3159         path_release(&nd);
3160         return vfs_quota_on(sb, type, format_id, path);
3161 }
3162
3163 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3164  * acquiring the locks... As quota files are never truncated and quota code
3165  * itself serializes the operations (and noone else should touch the files)
3166  * we don't have to be afraid of races */
3167 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3168                                size_t len, loff_t off)
3169 {
3170         struct inode *inode = sb_dqopt(sb)->files[type];
3171         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3172         int err = 0;
3173         int offset = off & (sb->s_blocksize - 1);
3174         int tocopy;
3175         size_t toread;
3176         struct buffer_head *bh;
3177         loff_t i_size = i_size_read(inode);
3178
3179         if (off > i_size)
3180                 return 0;
3181         if (off+len > i_size)
3182                 len = i_size-off;
3183         toread = len;
3184         while (toread > 0) {
3185                 tocopy = sb->s_blocksize - offset < toread ?
3186                                 sb->s_blocksize - offset : toread;
3187                 bh = ext4_bread(NULL, inode, blk, 0, &err);
3188                 if (err)
3189                         return err;
3190                 if (!bh)        /* A hole? */
3191                         memset(data, 0, tocopy);
3192                 else
3193                         memcpy(data, bh->b_data+offset, tocopy);
3194                 brelse(bh);
3195                 offset = 0;
3196                 toread -= tocopy;
3197                 data += tocopy;
3198                 blk++;
3199         }
3200         return len;
3201 }
3202
3203 /* Write to quotafile (we know the transaction is already started and has
3204  * enough credits) */
3205 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3206                                 const char *data, size_t len, loff_t off)
3207 {
3208         struct inode *inode = sb_dqopt(sb)->files[type];
3209         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3210         int err = 0;
3211         int offset = off & (sb->s_blocksize - 1);
3212         int tocopy;
3213         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3214         size_t towrite = len;
3215         struct buffer_head *bh;
3216         handle_t *handle = journal_current_handle();
3217
3218         if (!handle) {
3219                 printk(KERN_WARNING "EXT4-fs: Quota write (off=%Lu, len=%Lu)"
3220                         " cancelled because transaction is not started.\n",
3221                         (unsigned long long)off, (unsigned long long)len);
3222                 return -EIO;
3223         }
3224         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3225         while (towrite > 0) {
3226                 tocopy = sb->s_blocksize - offset < towrite ?
3227                                 sb->s_blocksize - offset : towrite;
3228                 bh = ext4_bread(handle, inode, blk, 1, &err);
3229                 if (!bh)
3230                         goto out;
3231                 if (journal_quota) {
3232                         err = ext4_journal_get_write_access(handle, bh);
3233                         if (err) {
3234                                 brelse(bh);
3235                                 goto out;
3236                         }
3237                 }
3238                 lock_buffer(bh);
3239                 memcpy(bh->b_data+offset, data, tocopy);
3240                 flush_dcache_page(bh->b_page);
3241                 unlock_buffer(bh);
3242                 if (journal_quota)
3243                         err = ext4_journal_dirty_metadata(handle, bh);
3244                 else {
3245                         /* Always do at least ordered writes for quotas */
3246                         err = ext4_journal_dirty_data(handle, bh);
3247                         mark_buffer_dirty(bh);
3248                 }
3249                 brelse(bh);
3250                 if (err)
3251                         goto out;
3252                 offset = 0;
3253                 towrite -= tocopy;
3254                 data += tocopy;
3255                 blk++;
3256         }
3257 out:
3258         if (len == towrite)
3259                 return err;
3260         if (inode->i_size < off+len-towrite) {
3261                 i_size_write(inode, off+len-towrite);
3262                 EXT4_I(inode)->i_disksize = inode->i_size;
3263         }
3264         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3265         ext4_mark_inode_dirty(handle, inode);
3266         mutex_unlock(&inode->i_mutex);
3267         return len - towrite;
3268 }
3269
3270 #endif
3271
3272 static int ext4_get_sb(struct file_system_type *fs_type,
3273         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3274 {
3275         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3276 }
3277
3278 static struct file_system_type ext4dev_fs_type = {
3279         .owner          = THIS_MODULE,
3280         .name           = "ext4dev",
3281         .get_sb         = ext4_get_sb,
3282         .kill_sb        = kill_block_super,
3283         .fs_flags       = FS_REQUIRES_DEV,
3284 };
3285
3286 static int __init init_ext4_fs(void)
3287 {
3288         int err;
3289
3290         err = init_ext4_mballoc();
3291         if (err)
3292                 return err;
3293
3294         err = init_ext4_xattr();
3295         if (err)
3296                 goto out2;
3297         err = init_inodecache();
3298         if (err)
3299                 goto out1;
3300         err = register_filesystem(&ext4dev_fs_type);
3301         if (err)
3302                 goto out;
3303         return 0;
3304 out:
3305         destroy_inodecache();
3306 out1:
3307         exit_ext4_xattr();
3308 out2:
3309         exit_ext4_mballoc();
3310         return err;
3311 }
3312
3313 static void __exit exit_ext4_fs(void)
3314 {
3315         unregister_filesystem(&ext4dev_fs_type);
3316         destroy_inodecache();
3317         exit_ext4_xattr();
3318         exit_ext4_mballoc();
3319 }
3320
3321 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
3322 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
3323 MODULE_LICENSE("GPL");
3324 module_init(init_ext4_fs)
3325 module_exit(exit_ext4_fs)