fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/jbd2.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/parser.h>
  28 #include <linux/smp_lock.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/log2.h>
  38 #include <linux/crc16.h>
  39 #include <asm/uaccess.h>
  40
  41 #include "ext4.h"
  42 #include "ext4_jbd2.h"
  43 #include "xattr.h"
  44 #include "acl.h"
  45 #include "namei.h"
  46 #include "group.h"
  47
  48 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  49                              unsigned long journal_devnum);
  50 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
  51                                unsigned int);
  52 static void ext4_commit_super (struct super_block * sb,
  53                                struct ext4_super_block * es,
  54                                int sync);
  55 static void ext4_mark_recovery_complete(struct super_block * sb,
  56                                         struct ext4_super_block * es);
  57 static void ext4_clear_journal_err(struct super_block * sb,
  58                                    struct ext4_super_block * es);
  59 static int ext4_sync_fs(struct super_block *sb, int wait);
  60 static const char *ext4_decode_error(struct super_block * sb, int errno,
  61                                      char nbuf[16]);
  62 static int ext4_remount (struct super_block * sb, int * flags, char * data);
  63 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf);
  64 static void ext4_unlockfs(struct super_block *sb);
  65 static void ext4_write_super (struct super_block * sb);
  66 static void ext4_write_super_lockfs(struct super_block *sb);
  67
  68
  69 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
  70                                struct ext4_group_desc *bg)
  71 {
  72         return le32_to_cpu(bg->bg_block_bitmap_lo) |
  73                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  74                 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
  75 }
  76
  77 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
  78                                struct ext4_group_desc *bg)
  79 {
  80         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
  81                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  82                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
  83 }
  84
  85 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
  86                               struct ext4_group_desc *bg)
  87 {
  88         return le32_to_cpu(bg->bg_inode_table_lo) |
  89                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  90                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
  91 }
  92
  93 void ext4_block_bitmap_set(struct super_block *sb,
  94                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
  95 {
  96         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
  97         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
  98                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
  99 }
 100
 101 void ext4_inode_bitmap_set(struct super_block *sb,
 102                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 103 {
 104         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 105         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 106                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 107 }
 108
 109 void ext4_inode_table_set(struct super_block *sb,
 110                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 111 {
 112         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 113         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 114                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 115 }
 116
 117 /*
 118  * Wrappers for jbd2_journal_start/end.
 119  *
 120  * The only special thing we need to do here is to make sure that all
 121  * journal_end calls result in the superblock being marked dirty, so
 122  * that sync() will call the filesystem's write_super callback if
 123  * appropriate.
 124  */
 125 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 126 {
 127         journal_t *journal;
 128
 129         if (sb->s_flags & MS_RDONLY)
 130                 return ERR_PTR(-EROFS);
 131
 132         /* Special case here: if the journal has aborted behind our
 133          * backs (eg. EIO in the commit thread), then we still need to
 134          * take the FS itself readonly cleanly. */
 135         journal = EXT4_SB(sb)->s_journal;
 136         if (is_journal_aborted(journal)) {
 137                 ext4_abort(sb, __func__,
 138                            "Detected aborted journal");
 139                 return ERR_PTR(-EROFS);
 140         }
 141
 142         return jbd2_journal_start(journal, nblocks);
 143 }
 144
 145 /*
 146  * The only special thing we need to do here is to make sure that all
 147  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 148  * that sync() will call the filesystem's write_super callback if
 149  * appropriate.
 150  */
 151 int __ext4_journal_stop(const char *where, handle_t *handle)
 152 {
 153         struct super_block *sb;
 154         int err;
 155         int rc;
 156
 157         sb = handle->h_transaction->t_journal->j_private;
 158         err = handle->h_err;
 159         rc = jbd2_journal_stop(handle);
 160
 161         if (!err)
 162                 err = rc;
 163         if (err)
 164                 __ext4_std_error(sb, where, err);
 165         return err;
 166 }
 167
 168 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 169                 struct buffer_head *bh, handle_t *handle, int err)
 170 {
 171         char nbuf[16];
 172         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 173
 174         if (bh)
 175                 BUFFER_TRACE(bh, "abort");
 176
 177         if (!handle->h_err)
 178                 handle->h_err = err;
 179
 180         if (is_handle_aborted(handle))
 181                 return;
 182
 183         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
 184                caller, errstr, err_fn);
 185
 186         jbd2_journal_abort_handle(handle);
 187 }
 188
 189 /* Deal with the reporting of failure conditions on a filesystem such as
 190  * inconsistencies detected or read IO failures.
 191  *
 192  * On ext2, we can store the error state of the filesystem in the
 193  * superblock.  That is not possible on ext4, because we may have other
 194  * write ordering constraints on the superblock which prevent us from
 195  * writing it out straight away; and given that the journal is about to
 196  * be aborted, we can't rely on the current, or future, transactions to
 197  * write out the superblock safely.
 198  *
 199  * We'll just use the jbd2_journal_abort() error code to record an error in
 200  * the journal instead.  On recovery, the journal will compain about
 201  * that error until we've noted it down and cleared it.
 202  */
 203
 204 static void ext4_handle_error(struct super_block *sb)
 205 {
 206         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 207
 208         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 209         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 210
 211         if (sb->s_flags & MS_RDONLY)
 212                 return;
 213
 214         if (!test_opt (sb, ERRORS_CONT)) {
 215                 journal_t *journal = EXT4_SB(sb)->s_journal;
 216
 217                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 218                 if (journal)
 219                         jbd2_journal_abort(journal, -EIO);
 220         }
 221         if (test_opt (sb, ERRORS_RO)) {
 222                 printk (KERN_CRIT "Remounting filesystem read-only\n");
 223                 sb->s_flags |= MS_RDONLY;
 224         }
 225         ext4_commit_super(sb, es, 1);
 226         if (test_opt(sb, ERRORS_PANIC))
 227                 panic("EXT4-fs (device %s): panic forced after error\n",
 228                         sb->s_id);
 229 }
 230
 231 void ext4_error (struct super_block * sb, const char * function,
 232                  const char * fmt, ...)
 233 {
 234         va_list args;
 235
 236         va_start(args, fmt);
 237         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 238         vprintk(fmt, args);
 239         printk("\n");
 240         va_end(args);
 241
 242         ext4_handle_error(sb);
 243 }
 244
 245 static const char *ext4_decode_error(struct super_block * sb, int errno,
 246                                      char nbuf[16])
 247 {
 248         char *errstr = NULL;
 249
 250         switch (errno) {
 251         case -EIO:
 252                 errstr = "IO failure";
 253                 break;
 254         case -ENOMEM:
 255                 errstr = "Out of memory";
 256                 break;
 257         case -EROFS:
 258                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
 259                         errstr = "Journal has aborted";
 260                 else
 261                         errstr = "Readonly filesystem";
 262                 break;
 263         default:
 264                 /* If the caller passed in an extra buffer for unknown
 265                  * errors, textualise them now.  Else we just return
 266                  * NULL. */
 267                 if (nbuf) {
 268                         /* Check for truncated error codes... */
 269                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 270                                 errstr = nbuf;
 271                 }
 272                 break;
 273         }
 274
 275         return errstr;
 276 }
 277
 278 /* __ext4_std_error decodes expected errors from journaling functions
 279  * automatically and invokes the appropriate error response.  */
 280
 281 void __ext4_std_error (struct super_block * sb, const char * function,
 282                        int errno)
 283 {
 284         char nbuf[16];
 285         const char *errstr;
 286
 287         /* Special case: if the error is EROFS, and we're not already
 288          * inside a transaction, then there's really no point in logging
 289          * an error. */
 290         if (errno == -EROFS && journal_current_handle() == NULL &&
 291             (sb->s_flags & MS_RDONLY))
 292                 return;
 293
 294         errstr = ext4_decode_error(sb, errno, nbuf);
 295         printk (KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
 296                 sb->s_id, function, errstr);
 297
 298         ext4_handle_error(sb);
 299 }
 300
 301 /*
 302  * ext4_abort is a much stronger failure handler than ext4_error.  The
 303  * abort function may be used to deal with unrecoverable failures such
 304  * as journal IO errors or ENOMEM at a critical moment in log management.
 305  *
 306  * We unconditionally force the filesystem into an ABORT|READONLY state,
 307  * unless the error response on the fs has been set to panic in which
 308  * case we take the easy way out and panic immediately.
 309  */
 310
 311 void ext4_abort (struct super_block * sb, const char * function,
 312                  const char * fmt, ...)
 313 {
 314         va_list args;
 315
 316         printk (KERN_CRIT "ext4_abort called.\n");
 317
 318         va_start(args, fmt);
 319         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 320         vprintk(fmt, args);
 321         printk("\n");
 322         va_end(args);
 323
 324         if (test_opt(sb, ERRORS_PANIC))
 325                 panic("EXT4-fs panic from previous error\n");
 326
 327         if (sb->s_flags & MS_RDONLY)
 328                 return;
 329
 330         printk(KERN_CRIT "Remounting filesystem read-only\n");
 331         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 332         sb->s_flags |= MS_RDONLY;
 333         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 334         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 335 }
 336
 337 void ext4_warning (struct super_block * sb, const char * function,
 338                    const char * fmt, ...)
 339 {
 340         va_list args;
 341
 342         va_start(args, fmt);
 343         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
 344                sb->s_id, function);
 345         vprintk(fmt, args);
 346         printk("\n");
 347         va_end(args);
 348 }
 349
 350 void ext4_update_dynamic_rev(struct super_block *sb)
 351 {
 352         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 353
 354         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 355                 return;
 356
 357         ext4_warning(sb, __func__,
 358                      "updating to rev %d because of new feature flag, "
 359                      "running e2fsck is recommended",
 360                      EXT4_DYNAMIC_REV);
 361
 362         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 363         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 364         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 365         /* leave es->s_feature_*compat flags alone */
 366         /* es->s_uuid will be set by e2fsck if empty */
 367
 368         /*
 369          * The rest of the superblock fields should be zero, and if not it
 370          * means they are likely already in use, so leave them alone.  We
 371          * can leave it up to e2fsck to clean up any inconsistencies there.
 372          */
 373 }
 374
 375 int ext4_update_compat_feature(handle_t *handle,
 376                                         struct super_block *sb, __u32 compat)
 377 {
 378         int err = 0;
 379         if (!EXT4_HAS_COMPAT_FEATURE(sb, compat)) {
 380                 err = ext4_journal_get_write_access(handle,
 381                                 EXT4_SB(sb)->s_sbh);
 382                 if (err)
 383                         return err;
 384                 EXT4_SET_COMPAT_FEATURE(sb, compat);
 385                 sb->s_dirt = 1;
 386                 handle->h_sync = 1;
 387                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 388                                         "call ext4_journal_dirty_met adata");
 389                 err = ext4_journal_dirty_metadata(handle,
 390                                 EXT4_SB(sb)->s_sbh);
 391         }
 392         return err;
 393 }
 394
 395 int ext4_update_rocompat_feature(handle_t *handle,
 396                                         struct super_block *sb, __u32 rocompat)
 397 {
 398         int err = 0;
 399         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, rocompat)) {
 400                 err = ext4_journal_get_write_access(handle,
 401                                 EXT4_SB(sb)->s_sbh);
 402                 if (err)
 403                         return err;
 404                 EXT4_SET_RO_COMPAT_FEATURE(sb, rocompat);
 405                 sb->s_dirt = 1;
 406                 handle->h_sync = 1;
 407                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 408                                         "call ext4_journal_dirty_met adata");
 409                 err = ext4_journal_dirty_metadata(handle,
 410                                 EXT4_SB(sb)->s_sbh);
 411         }
 412         return err;
 413 }
 414
 415 int ext4_update_incompat_feature(handle_t *handle,
 416                                         struct super_block *sb, __u32 incompat)
 417 {
 418         int err = 0;
 419         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, incompat)) {
 420                 err = ext4_journal_get_write_access(handle,
 421                                 EXT4_SB(sb)->s_sbh);
 422                 if (err)
 423                         return err;
 424                 EXT4_SET_INCOMPAT_FEATURE(sb, incompat);
 425                 sb->s_dirt = 1;
 426                 handle->h_sync = 1;
 427                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 428                                         "call ext4_journal_dirty_met adata");
 429                 err = ext4_journal_dirty_metadata(handle,
 430                                 EXT4_SB(sb)->s_sbh);
 431         }
 432         return err;
 433 }
 434
 435 /*
 436  * Open the external journal device
 437  */
 438 static struct block_device *ext4_blkdev_get(dev_t dev)
 439 {
 440         struct block_device *bdev;
 441         char b[BDEVNAME_SIZE];
 442
 443         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 444         if (IS_ERR(bdev))
 445                 goto fail;
 446         return bdev;
 447
 448 fail:
 449         printk(KERN_ERR "EXT4: failed to open journal device %s: %ld\n",
 450                         __bdevname(dev, b), PTR_ERR(bdev));
 451         return NULL;
 452 }
 453
 454 /*
 455  * Release the journal device
 456  */
 457 static int ext4_blkdev_put(struct block_device *bdev)
 458 {
 459         bd_release(bdev);
 460         return blkdev_put(bdev);
 461 }
 462
 463 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 464 {
 465         struct block_device *bdev;
 466         int ret = -ENODEV;
 467
 468         bdev = sbi->journal_bdev;
 469         if (bdev) {
 470                 ret = ext4_blkdev_put(bdev);
 471                 sbi->journal_bdev = NULL;
 472         }
 473         return ret;
 474 }
 475
 476 static inline struct inode *orphan_list_entry(struct list_head *l)
 477 {
 478         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 479 }
 480
 481 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 482 {
 483         struct list_head *l;
 484
 485         printk(KERN_ERR "sb orphan head is %d\n",
 486                le32_to_cpu(sbi->s_es->s_last_orphan));
 487
 488         printk(KERN_ERR "sb_info orphan list:\n");
 489         list_for_each(l, &sbi->s_orphan) {
 490                 struct inode *inode = orphan_list_entry(l);
 491                 printk(KERN_ERR "  "
 492                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 493                        inode->i_sb->s_id, inode->i_ino, inode,
 494                        inode->i_mode, inode->i_nlink,
 495                        NEXT_ORPHAN(inode));
 496         }
 497 }
 498
 499 static void ext4_put_super (struct super_block * sb)
 500 {
 501         struct ext4_sb_info *sbi = EXT4_SB(sb);
 502         struct ext4_super_block *es = sbi->s_es;
 503         int i;
 504
 505         ext4_mb_release(sb);
 506         ext4_ext_release(sb);
 507         ext4_xattr_put_super(sb);
 508         jbd2_journal_destroy(sbi->s_journal);
 509         if (!(sb->s_flags & MS_RDONLY)) {
 510                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 511                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 512                 BUFFER_TRACE(sbi->s_sbh, "marking dirty");
 513                 mark_buffer_dirty(sbi->s_sbh);
 514                 ext4_commit_super(sb, es, 1);
 515         }
 516
 517         for (i = 0; i < sbi->s_gdb_count; i++)
 518                 brelse(sbi->s_group_desc[i]);
 519         kfree(sbi->s_group_desc);
 520         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 521         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 522         percpu_counter_destroy(&sbi->s_dirs_counter);
 523         brelse(sbi->s_sbh);
 524 #ifdef CONFIG_QUOTA
 525         for (i = 0; i < MAXQUOTAS; i++)
 526                 kfree(sbi->s_qf_names[i]);
 527 #endif
 528
 529         /* Debugging code just in case the in-memory inode orphan list
 530          * isn't empty.  The on-disk one can be non-empty if we've
 531          * detected an error and taken the fs readonly, but the
 532          * in-memory list had better be clean by this point. */
 533         if (!list_empty(&sbi->s_orphan))
 534                 dump_orphan_list(sb, sbi);
 535         J_ASSERT(list_empty(&sbi->s_orphan));
 536
 537         invalidate_bdev(sb->s_bdev);
 538         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 539                 /*
 540                  * Invalidate the journal device's buffers.  We don't want them
 541                  * floating about in memory - the physical journal device may
 542                  * hotswapped, and it breaks the `ro-after' testing code.
 543                  */
 544                 sync_blockdev(sbi->journal_bdev);
 545                 invalidate_bdev(sbi->journal_bdev);
 546                 ext4_blkdev_remove(sbi);
 547         }
 548         sb->s_fs_info = NULL;
 549         kfree(sbi);
 550         return;
 551 }
 552
 553 static struct kmem_cache *ext4_inode_cachep;
 554
 555 /*
 556  * Called inside transaction, so use GFP_NOFS
 557  */
 558 static struct inode *ext4_alloc_inode(struct super_block *sb)
 559 {
 560         struct ext4_inode_info *ei;
 561
 562         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 563         if (!ei)
 564                 return NULL;
 565 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 566         ei->i_acl = EXT4_ACL_NOT_CACHED;
 567         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 568 #endif
 569         ei->i_block_alloc_info = NULL;
 570         ei->vfs_inode.i_version = 1;
 571         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 572         INIT_LIST_HEAD(&ei->i_prealloc_list);
 573         spin_lock_init(&ei->i_prealloc_lock);
 574         return &ei->vfs_inode;
 575 }
 576
 577 static void ext4_destroy_inode(struct inode *inode)
 578 {
 579         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 580                 printk("EXT4 Inode %p: orphan list check failed!\n",
 581                         EXT4_I(inode));
 582                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 583                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 584                                 true);
 585                 dump_stack();
 586         }
 587         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 588 }
 589
 590 static void init_once(struct kmem_cache *cachep, void *foo)
 591 {
 592         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 593
 594         INIT_LIST_HEAD(&ei->i_orphan);
 595 #ifdef CONFIG_EXT4DEV_FS_XATTR
 596         init_rwsem(&ei->xattr_sem);
 597 #endif
 598         init_rwsem(&ei->i_data_sem);
 599         inode_init_once(&ei->vfs_inode);
 600 }
 601
 602 static int init_inodecache(void)
 603 {
 604         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 605                                              sizeof(struct ext4_inode_info),
 606                                              0, (SLAB_RECLAIM_ACCOUNT|
 607                                                 SLAB_MEM_SPREAD),
 608                                              init_once);
 609         if (ext4_inode_cachep == NULL)
 610                 return -ENOMEM;
 611         return 0;
 612 }
 613
 614 static void destroy_inodecache(void)
 615 {
 616         kmem_cache_destroy(ext4_inode_cachep);
 617 }
 618
 619 static void ext4_clear_inode(struct inode *inode)
 620 {
 621         struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
 622 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 623         if (EXT4_I(inode)->i_acl &&
 624                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
 625                 posix_acl_release(EXT4_I(inode)->i_acl);
 626                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
 627         }
 628         if (EXT4_I(inode)->i_default_acl &&
 629                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
 630                 posix_acl_release(EXT4_I(inode)->i_default_acl);
 631                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
 632         }
 633 #endif
 634         ext4_discard_reservation(inode);
 635         EXT4_I(inode)->i_block_alloc_info = NULL;
 636         if (unlikely(rsv))
 637                 kfree(rsv);
 638 }
 639
 640 static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
 641 {
 642 #if defined(CONFIG_QUOTA)
 643         struct ext4_sb_info *sbi = EXT4_SB(sb);
 644
 645         if (sbi->s_jquota_fmt)
 646                 seq_printf(seq, ",jqfmt=%s",
 647                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold": "vfsv0");
 648
 649         if (sbi->s_qf_names[USRQUOTA])
 650                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 651
 652         if (sbi->s_qf_names[GRPQUOTA])
 653                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 654
 655         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
 656                 seq_puts(seq, ",usrquota");
 657
 658         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
 659                 seq_puts(seq, ",grpquota");
 660 #endif
 661 }
 662
 663 /*
 664  * Show an option if
 665  *  - it's set to a non-default value OR
 666  *  - if the per-sb default is different from the global default
 667  */
 668 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 669 {
 670         int def_errors;
 671         unsigned long def_mount_opts;
 672         struct super_block *sb = vfs->mnt_sb;
 673         struct ext4_sb_info *sbi = EXT4_SB(sb);
 674         struct ext4_super_block *es = sbi->s_es;
 675
 676         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 677         def_errors     = le16_to_cpu(es->s_errors);
 678
 679         if (sbi->s_sb_block != 1)
 680                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 681         if (test_opt(sb, MINIX_DF))
 682                 seq_puts(seq, ",minixdf");
 683         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
 684                 seq_puts(seq, ",grpid");
 685         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 686                 seq_puts(seq, ",nogrpid");
 687         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 688             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 689                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 690         }
 691         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 692             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 693                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 694         }
 695         if (test_opt(sb, ERRORS_RO)) {
 696                 if (def_errors == EXT4_ERRORS_PANIC ||
 697                     def_errors == EXT4_ERRORS_CONTINUE) {
 698                         seq_puts(seq, ",errors=remount-ro");
 699                 }
 700         }
 701         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
 702                 seq_puts(seq, ",errors=continue");
 703         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
 704                 seq_puts(seq, ",errors=panic");
 705         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
 706                 seq_puts(seq, ",nouid32");
 707         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
 708                 seq_puts(seq, ",debug");
 709         if (test_opt(sb, OLDALLOC))
 710                 seq_puts(seq, ",oldalloc");
 711 #ifdef CONFIG_EXT4DEV_FS_XATTR
 712         if (test_opt(sb, XATTR_USER) &&
 713                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
 714                 seq_puts(seq, ",user_xattr");
 715         if (!test_opt(sb, XATTR_USER) &&
 716             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 717                 seq_puts(seq, ",nouser_xattr");
 718         }
 719 #endif
 720 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 721         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
 722                 seq_puts(seq, ",acl");
 723         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 724                 seq_puts(seq, ",noacl");
 725 #endif
 726         if (!test_opt(sb, RESERVATION))
 727                 seq_puts(seq, ",noreservation");
 728         if (sbi->s_commit_interval) {
 729                 seq_printf(seq, ",commit=%u",
 730                            (unsigned) (sbi->s_commit_interval / HZ));
 731         }
 732         if (test_opt(sb, BARRIER))
 733                 seq_puts(seq, ",barrier=1");
 734         if (test_opt(sb, NOBH))
 735                 seq_puts(seq, ",nobh");
 736         if (!test_opt(sb, EXTENTS))
 737                 seq_puts(seq, ",noextents");
 738         if (!test_opt(sb, MBALLOC))
 739                 seq_puts(seq, ",nomballoc");
 740         if (test_opt(sb, I_VERSION))
 741                 seq_puts(seq, ",i_version");
 742
 743         if (sbi->s_stripe)
 744                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
 745         /*
 746          * journal mode get enabled in different ways
 747          * So just print the value even if we didn't specify it
 748          */
 749         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 750                 seq_puts(seq, ",data=journal");
 751         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 752                 seq_puts(seq, ",data=ordered");
 753         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 754                 seq_puts(seq, ",data=writeback");
 755
 756         ext4_show_quota_options(seq, sb);
 757         return 0;
 758 }
 759
 760
 761 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 762                 u64 ino, u32 generation)
 763 {
 764         struct inode *inode;
 765
 766         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 767                 return ERR_PTR(-ESTALE);
 768         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 769                 return ERR_PTR(-ESTALE);
 770
 771         /* iget isn't really right if the inode is currently unallocated!!
 772          *
 773          * ext4_read_inode will return a bad_inode if the inode had been
 774          * deleted, so we should be safe.
 775          *
 776          * Currently we don't know the generation for parent directory, so
 777          * a generation of 0 means "accept any"
 778          */
 779         inode = ext4_iget(sb, ino);
 780         if (IS_ERR(inode))
 781                 return ERR_CAST(inode);
 782         if (generation && inode->i_generation != generation) {
 783                 iput(inode);
 784                 return ERR_PTR(-ESTALE);
 785         }
 786
 787         return inode;
 788 }
 789
 790 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 791                 int fh_len, int fh_type)
 792 {
 793         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 794                                     ext4_nfs_get_inode);
 795 }
 796
 797 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 798                 int fh_len, int fh_type)
 799 {
 800         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 801                                     ext4_nfs_get_inode);
 802 }
 803
 804 #ifdef CONFIG_QUOTA
 805 #define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
 806 #define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 807
 808 static int ext4_dquot_initialize(struct inode *inode, int type);
 809 static int ext4_dquot_drop(struct inode *inode);
 810 static int ext4_write_dquot(struct dquot *dquot);
 811 static int ext4_acquire_dquot(struct dquot *dquot);
 812 static int ext4_release_dquot(struct dquot *dquot);
 813 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 814 static int ext4_write_info(struct super_block *sb, int type);
 815 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 816                                 char *path, int remount);
 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_resize, "resize"},
 948         {Opt_err, NULL},
 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(~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         le16_add_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                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1488                                "Block bitmap for group %lu not in group "
1489                                "(block %llu)!", i, block_bitmap);
1490                         return 0;
1491                 }
1492                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1493                 if (inode_bitmap < first_block || inode_bitmap > last_block)
1494                 {
1495                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1496                                "Inode bitmap for group %lu not in group "
1497                                "(block %llu)!", i, inode_bitmap);
1498                         return 0;
1499                 }
1500                 inode_table = ext4_inode_table(sb, gdp);
1501                 if (inode_table < first_block ||
1502                     inode_table + sbi->s_itb_per_group - 1 > last_block)
1503                 {
1504                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1505                                "Inode table for group %lu not in group "
1506                                "(block %llu)!", i, inode_table);
1507                         return 0;
1508                 }
1509                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1510                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1511                                "Checksum for group %lu failed (%u!=%u)\n",
1512                                i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1513                                gdp)), le16_to_cpu(gdp->bg_checksum));
1514                         return 0;
1515                 }
1516                 if (!flexbg_flag)
1517                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1518         }
1519
1520         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1521         sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
1522         return 1;
1523 }
1524
1525 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1526  * the superblock) which were deleted from all directories, but held open by
1527  * a process at the time of a crash.  We walk the list and try to delete these
1528  * inodes at recovery time (only with a read-write filesystem).
1529  *
1530  * In order to keep the orphan inode chain consistent during traversal (in
1531  * case of crash during recovery), we link each inode into the superblock
1532  * orphan list_head and handle it the same way as an inode deletion during
1533  * normal operation (which journals the operations for us).
1534  *
1535  * We only do an iget() and an iput() on each inode, which is very safe if we
1536  * accidentally point at an in-use or already deleted inode.  The worst that
1537  * can happen in this case is that we get a "bit already cleared" message from
1538  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1539  * e2fsck was run on this filesystem, and it must have already done the orphan
1540  * inode cleanup for us, so we can safely abort without any further action.
1541  */
1542 static void ext4_orphan_cleanup (struct super_block * sb,
1543                                  struct ext4_super_block * es)
1544 {
1545         unsigned int s_flags = sb->s_flags;
1546         int nr_orphans = 0, nr_truncates = 0;
1547 #ifdef CONFIG_QUOTA
1548         int i;
1549 #endif
1550         if (!es->s_last_orphan) {
1551                 jbd_debug(4, "no orphan inodes to clean up\n");
1552                 return;
1553         }
1554
1555         if (bdev_read_only(sb->s_bdev)) {
1556                 printk(KERN_ERR "EXT4-fs: write access "
1557                         "unavailable, skipping orphan cleanup.\n");
1558                 return;
1559         }
1560
1561         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1562                 if (es->s_last_orphan)
1563                         jbd_debug(1, "Errors on filesystem, "
1564                                   "clearing orphan list.\n");
1565                 es->s_last_orphan = 0;
1566                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1567                 return;
1568         }
1569
1570         if (s_flags & MS_RDONLY) {
1571                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1572                        sb->s_id);
1573                 sb->s_flags &= ~MS_RDONLY;
1574         }
1575 #ifdef CONFIG_QUOTA
1576         /* Needed for iput() to work correctly and not trash data */
1577         sb->s_flags |= MS_ACTIVE;
1578         /* Turn on quotas so that they are updated correctly */
1579         for (i = 0; i < MAXQUOTAS; i++) {
1580                 if (EXT4_SB(sb)->s_qf_names[i]) {
1581                         int ret = ext4_quota_on_mount(sb, i);
1582                         if (ret < 0)
1583                                 printk(KERN_ERR
1584                                         "EXT4-fs: Cannot turn on journalled "
1585                                         "quota: error %d\n", ret);
1586                 }
1587         }
1588 #endif
1589
1590         while (es->s_last_orphan) {
1591                 struct inode *inode;
1592
1593                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
1594                 if (IS_ERR(inode)) {
1595                         es->s_last_orphan = 0;
1596                         break;
1597                 }
1598
1599                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1600                 DQUOT_INIT(inode);
1601                 if (inode->i_nlink) {
1602                         printk(KERN_DEBUG
1603                                 "%s: truncating inode %lu to %Ld bytes\n",
1604                                 __func__, inode->i_ino, inode->i_size);
1605                         jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
1606                                   inode->i_ino, inode->i_size);
1607                         ext4_truncate(inode);
1608                         nr_truncates++;
1609                 } else {
1610                         printk(KERN_DEBUG
1611                                 "%s: deleting unreferenced inode %lu\n",
1612                                 __func__, inode->i_ino);
1613                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1614                                   inode->i_ino);
1615                         nr_orphans++;
1616                 }
1617                 iput(inode);  /* The delete magic happens here! */
1618         }
1619
1620 #define PLURAL(x) (x), ((x)==1) ? "" : "s"
1621
1622         if (nr_orphans)
1623                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1624                        sb->s_id, PLURAL(nr_orphans));
1625         if (nr_truncates)
1626                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1627                        sb->s_id, PLURAL(nr_truncates));
1628 #ifdef CONFIG_QUOTA
1629         /* Turn quotas off */
1630         for (i = 0; i < MAXQUOTAS; i++) {
1631                 if (sb_dqopt(sb)->files[i])
1632                         vfs_quota_off(sb, i, 0);
1633         }
1634 #endif
1635         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1636 }
1637 /*
1638  * Maximal extent format file size.
1639  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1640  * extent format containers, within a sector_t, and within i_blocks
1641  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1642  * so that won't be a limiting factor.
1643  *
1644  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1645  */
1646 static loff_t ext4_max_size(int blkbits)
1647 {
1648         loff_t res;
1649         loff_t upper_limit = MAX_LFS_FILESIZE;
1650
1651         /* small i_blocks in vfs inode? */
1652         if (sizeof(blkcnt_t) < sizeof(u64)) {
1653                 /*
1654                  * CONFIG_LSF is not enabled implies the inode
1655                  * i_block represent total blocks in 512 bytes
1656                  * 32 == size of vfs inode i_blocks * 8
1657                  */
1658                 upper_limit = (1LL << 32) - 1;
1659
1660                 /* total blocks in file system block size */
1661                 upper_limit >>= (blkbits - 9);
1662                 upper_limit <<= blkbits;
1663         }
1664
1665         /* 32-bit extent-start container, ee_block */
1666         res = 1LL << 32;
1667         res <<= blkbits;
1668         res -= 1;
1669
1670         /* Sanity check against vm- & vfs- imposed limits */
1671         if (res > upper_limit)
1672                 res = upper_limit;
1673
1674         return res;
1675 }
1676
1677 /*
1678  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
1679  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
1680  * We need to be 1 filesystem block less than the 2^48 sector limit.
1681  */
1682 static loff_t ext4_max_bitmap_size(int bits)
1683 {
1684         loff_t res = EXT4_NDIR_BLOCKS;
1685         int meta_blocks;
1686         loff_t upper_limit;
1687         /* This is calculated to be the largest file size for a
1688          * dense, bitmapped file such that the total number of
1689          * sectors in the file, including data and all indirect blocks,
1690          * does not exceed 2^48 -1
1691          * __u32 i_blocks_lo and _u16 i_blocks_high representing the
1692          * total number of  512 bytes blocks of the file
1693          */
1694
1695         if (sizeof(blkcnt_t) < sizeof(u64)) {
1696                 /*
1697                  * CONFIG_LSF is not enabled implies the inode
1698                  * i_block represent total blocks in 512 bytes
1699                  * 32 == size of vfs inode i_blocks * 8
1700                  */
1701                 upper_limit = (1LL << 32) - 1;
1702
1703                 /* total blocks in file system block size */
1704                 upper_limit >>= (bits - 9);
1705
1706         } else {
1707                 /*
1708                  * We use 48 bit ext4_inode i_blocks
1709                  * With EXT4_HUGE_FILE_FL set the i_blocks
1710                  * represent total number of blocks in
1711                  * file system block size
1712                  */
1713                 upper_limit = (1LL << 48) - 1;
1714
1715         }
1716
1717         /* indirect blocks */
1718         meta_blocks = 1;
1719         /* double indirect blocks */
1720         meta_blocks += 1 + (1LL << (bits-2));
1721         /* tripple indirect blocks */
1722         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
1723
1724         upper_limit -= meta_blocks;
1725         upper_limit <<= bits;
1726
1727         res += 1LL << (bits-2);
1728         res += 1LL << (2*(bits-2));
1729         res += 1LL << (3*(bits-2));
1730         res <<= bits;
1731         if (res > upper_limit)
1732                 res = upper_limit;
1733
1734         if (res > MAX_LFS_FILESIZE)
1735                 res = MAX_LFS_FILESIZE;
1736
1737         return res;
1738 }
1739
1740 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1741                                 ext4_fsblk_t logical_sb_block, int nr)
1742 {
1743         struct ext4_sb_info *sbi = EXT4_SB(sb);
1744         ext4_group_t bg, first_meta_bg;
1745         int has_super = 0;
1746
1747         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1748
1749         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1750             nr < first_meta_bg)
1751                 return logical_sb_block + nr + 1;
1752         bg = sbi->s_desc_per_block * nr;
1753         if (ext4_bg_has_super(sb, bg))
1754                 has_super = 1;
1755         return (has_super + ext4_group_first_block_no(sb, bg));
1756 }
1757
1758 /**
1759  * ext4_get_stripe_size: Get the stripe size.
1760  * @sbi: In memory super block info
1761  *
1762  * If we have specified it via mount option, then
1763  * use the mount option value. If the value specified at mount time is
1764  * greater than the blocks per group use the super block value.
1765  * If the super block value is greater than blocks per group return 0.
1766  * Allocator needs it be less than blocks per group.
1767  *
1768  */
1769 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
1770 {
1771         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
1772         unsigned long stripe_width =
1773                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
1774
1775         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
1776                 return sbi->s_stripe;
1777
1778         if (stripe_width <= sbi->s_blocks_per_group)
1779                 return stripe_width;
1780
1781         if (stride <= sbi->s_blocks_per_group)
1782                 return stride;
1783
1784         return 0;
1785 }
1786
1787 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
1788                                 __releases(kernel_sem)
1789                                 __acquires(kernel_sem)
1790
1791 {
1792         struct buffer_head * bh;
1793         struct ext4_super_block *es = NULL;
1794         struct ext4_sb_info *sbi;
1795         ext4_fsblk_t block;
1796         ext4_fsblk_t sb_block = get_sb_block(&data);
1797         ext4_fsblk_t logical_sb_block;
1798         unsigned long offset = 0;
1799         unsigned int journal_inum = 0;
1800         unsigned long journal_devnum = 0;
1801         unsigned long def_mount_opts;
1802         struct inode *root;
1803         int ret = -EINVAL;
1804         int blocksize;
1805         int db_count;
1806         int i;
1807         int needs_recovery;
1808         __le32 features;
1809         __u64 blocks_count;
1810         int err;
1811
1812         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1813         if (!sbi)
1814                 return -ENOMEM;
1815         sb->s_fs_info = sbi;
1816         sbi->s_mount_opt = 0;
1817         sbi->s_resuid = EXT4_DEF_RESUID;
1818         sbi->s_resgid = EXT4_DEF_RESGID;
1819         sbi->s_sb_block = sb_block;
1820
1821         unlock_kernel();
1822
1823         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1824         if (!blocksize) {
1825                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1826                 goto out_fail;
1827         }
1828
1829         if (!sb_set_blocksize(sb, blocksize)) {
1830                 printk(KERN_ERR "EXT4-fs: bad blocksize %d.\n", blocksize);
1831                 goto out_fail;
1832         }
1833
1834         /*
1835          * The ext4 superblock will not be buffer aligned for other than 1kB
1836          * block sizes.  We need to calculate the offset from buffer start.
1837          */
1838         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1839                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1840                 offset = do_div(logical_sb_block, blocksize);
1841         } else {
1842                 logical_sb_block = sb_block;
1843         }
1844
1845         if (!(bh = sb_bread(sb, logical_sb_block))) {
1846                 printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
1847                 goto out_fail;
1848         }
1849         /*
1850          * Note: s_es must be initialized as soon as possible because
1851          *       some ext4 macro-instructions depend on its value
1852          */
1853         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1854         sbi->s_es = es;
1855         sb->s_magic = le16_to_cpu(es->s_magic);
1856         if (sb->s_magic != EXT4_SUPER_MAGIC)
1857                 goto cantfind_ext4;
1858
1859         /* Set defaults before we parse the mount options */
1860         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1861         if (def_mount_opts & EXT4_DEFM_DEBUG)
1862                 set_opt(sbi->s_mount_opt, DEBUG);
1863         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1864                 set_opt(sbi->s_mount_opt, GRPID);
1865         if (def_mount_opts & EXT4_DEFM_UID16)
1866                 set_opt(sbi->s_mount_opt, NO_UID32);
1867 #ifdef CONFIG_EXT4DEV_FS_XATTR
1868         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1869                 set_opt(sbi->s_mount_opt, XATTR_USER);
1870 #endif
1871 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1872         if (def_mount_opts & EXT4_DEFM_ACL)
1873                 set_opt(sbi->s_mount_opt, POSIX_ACL);
1874 #endif
1875         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1876                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1877         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1878                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1879         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1880                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1881
1882         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1883                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1884         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
1885                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
1886         else
1887                 set_opt(sbi->s_mount_opt, ERRORS_RO);
1888
1889         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1890         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1891
1892         set_opt(sbi->s_mount_opt, RESERVATION);
1893
1894         /*
1895          * turn on extents feature by default in ext4 filesystem
1896          * User -o noextents to turn it off
1897          */
1898         set_opt(sbi->s_mount_opt, EXTENTS);
1899         /*
1900          * turn on mballoc feature by default in ext4 filesystem
1901          * User -o nomballoc to turn it off
1902          */
1903         set_opt(sbi->s_mount_opt, MBALLOC);
1904
1905         if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
1906                             NULL, 0))
1907                 goto failed_mount;
1908
1909         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1910                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1911
1912         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1913             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1914              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1915              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1916                 printk(KERN_WARNING
1917                        "EXT4-fs warning: feature flags set on rev 0 fs, "
1918                        "running e2fsck is recommended\n");
1919
1920         /*
1921          * Since ext4 is still considered development code, we require
1922          * that the TEST_FILESYS flag in s->flags be set.
1923          */
1924         if (!(le32_to_cpu(es->s_flags) & EXT2_FLAGS_TEST_FILESYS)) {
1925                 printk(KERN_WARNING "EXT4-fs: %s: not marked "
1926                        "OK to use with test code.\n", sb->s_id);
1927                 goto failed_mount;
1928         }
1929
1930         /*
1931          * Check feature flags regardless of the revision level, since we
1932          * previously didn't change the revision level when setting the flags,
1933          * so there is a chance incompat flags are set on a rev 0 filesystem.
1934          */
1935         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
1936         if (features) {
1937                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
1938                        "unsupported optional features (%x).\n",
1939                        sb->s_id, le32_to_cpu(features));
1940                 goto failed_mount;
1941         }
1942         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
1943         if (!(sb->s_flags & MS_RDONLY) && features) {
1944                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
1945                        "unsupported optional features (%x).\n",
1946                        sb->s_id, le32_to_cpu(features));
1947                 goto failed_mount;
1948         }
1949         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
1950                 /*
1951                  * Large file size enabled file system can only be
1952                  * mount if kernel is build with CONFIG_LSF
1953                  */
1954                 if (sizeof(root->i_blocks) < sizeof(u64) &&
1955                                 !(sb->s_flags & MS_RDONLY)) {
1956                         printk(KERN_ERR "EXT4-fs: %s: Filesystem with huge "
1957                                         "files cannot be mounted read-write "
1958                                         "without CONFIG_LSF.\n", sb->s_id);
1959                         goto failed_mount;
1960                 }
1961         }
1962         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
1963
1964         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
1965             blocksize > EXT4_MAX_BLOCK_SIZE) {
1966                 printk(KERN_ERR
1967                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
1968                        blocksize, sb->s_id);
1969                 goto failed_mount;
1970         }
1971
1972         if (sb->s_blocksize != blocksize) {
1973
1974                 /* Validate the filesystem blocksize */
1975                 if (!sb_set_blocksize(sb, blocksize)) {
1976                         printk(KERN_ERR "EXT4-fs: bad block size %d.\n",
1977                                         blocksize);
1978                         goto failed_mount;
1979                 }
1980
1981                 brelse (bh);
1982                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1983                 offset = do_div(logical_sb_block, blocksize);
1984                 bh = sb_bread(sb, logical_sb_block);
1985                 if (!bh) {
1986                         printk(KERN_ERR
1987                                "EXT4-fs: Can't read superblock on 2nd try.\n");
1988                         goto failed_mount;
1989                 }
1990                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
1991                 sbi->s_es = es;
1992                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
1993                         printk (KERN_ERR
1994                                 "EXT4-fs: Magic mismatch, very weird !\n");
1995                         goto failed_mount;
1996                 }
1997         }
1998
1999         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits);
2000         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
2001
2002         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2003                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2004                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2005         } else {
2006                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2007                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2008                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2009                     (!is_power_of_2(sbi->s_inode_size)) ||
2010                     (sbi->s_inode_size > blocksize)) {
2011                         printk (KERN_ERR
2012                                 "EXT4-fs: unsupported inode size: %d\n",
2013                                 sbi->s_inode_size);
2014                         goto failed_mount;
2015                 }
2016                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2017                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2018         }
2019         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2020         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2021                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2022                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2023                     !is_power_of_2(sbi->s_desc_size)) {
2024                         printk(KERN_ERR
2025                                "EXT4-fs: unsupported descriptor size %lu\n",
2026                                sbi->s_desc_size);
2027                         goto failed_mount;
2028                 }
2029         } else
2030                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2031         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2032         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2033         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2034                 goto cantfind_ext4;
2035         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2036         if (sbi->s_inodes_per_block == 0)
2037                 goto cantfind_ext4;
2038         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2039                                         sbi->s_inodes_per_block;
2040         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2041         sbi->s_sbh = bh;
2042         sbi->s_mount_state = le16_to_cpu(es->s_state);
2043         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2044         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2045         for (i=0; i < 4; i++)
2046                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2047         sbi->s_def_hash_version = es->s_def_hash_version;
2048
2049         if (sbi->s_blocks_per_group > blocksize * 8) {
2050                 printk (KERN_ERR
2051                         "EXT4-fs: #blocks per group too big: %lu\n",
2052                         sbi->s_blocks_per_group);
2053                 goto failed_mount;
2054         }
2055         if (sbi->s_inodes_per_group > blocksize * 8) {
2056                 printk (KERN_ERR
2057                         "EXT4-fs: #inodes per group too big: %lu\n",
2058                         sbi->s_inodes_per_group);
2059                 goto failed_mount;
2060         }
2061
2062         if (ext4_blocks_count(es) >
2063                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
2064                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
2065                         " too large to mount safely\n", sb->s_id);
2066                 if (sizeof(sector_t) < 8)
2067                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
2068                                         "enabled\n");
2069                 goto failed_mount;
2070         }
2071
2072         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2073                 goto cantfind_ext4;
2074
2075         /* ensure blocks_count calculation below doesn't sign-extend */
2076         if (ext4_blocks_count(es) + EXT4_BLOCKS_PER_GROUP(sb) <
2077             le32_to_cpu(es->s_first_data_block) + 1) {
2078                 printk(KERN_WARNING "EXT4-fs: bad geometry: block count %llu, "
2079                        "first data block %u, blocks per group %lu\n",
2080                         ext4_blocks_count(es),
2081                         le32_to_cpu(es->s_first_data_block),
2082                         EXT4_BLOCKS_PER_GROUP(sb));
2083                 goto failed_mount;
2084         }
2085         blocks_count = (ext4_blocks_count(es) -
2086                         le32_to_cpu(es->s_first_data_block) +
2087                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2088         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2089         sbi->s_groups_count = blocks_count;
2090         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2091                    EXT4_DESC_PER_BLOCK(sb);
2092         sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
2093                                     GFP_KERNEL);
2094         if (sbi->s_group_desc == NULL) {
2095                 printk (KERN_ERR "EXT4-fs: not enough memory\n");
2096                 goto failed_mount;
2097         }
2098
2099         bgl_lock_init(&sbi->s_blockgroup_lock);
2100
2101         for (i = 0; i < db_count; i++) {
2102                 block = descriptor_loc(sb, logical_sb_block, i);
2103                 sbi->s_group_desc[i] = sb_bread(sb, block);
2104                 if (!sbi->s_group_desc[i]) {
2105                         printk (KERN_ERR "EXT4-fs: "
2106                                 "can't read group descriptor %d\n", i);
2107                         db_count = i;
2108                         goto failed_mount2;
2109                 }
2110         }
2111         if (!ext4_check_descriptors (sb)) {
2112                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
2113                 goto failed_mount2;
2114         }
2115         sbi->s_gdb_count = db_count;
2116         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2117         spin_lock_init(&sbi->s_next_gen_lock);
2118
2119         err = percpu_counter_init(&sbi->s_freeblocks_counter,
2120                         ext4_count_free_blocks(sb));
2121         if (!err) {
2122                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
2123                                 ext4_count_free_inodes(sb));
2124         }
2125         if (!err) {
2126                 err = percpu_counter_init(&sbi->s_dirs_counter,
2127                                 ext4_count_dirs(sb));
2128         }
2129         if (err) {
2130                 printk(KERN_ERR "EXT4-fs: insufficient memory\n");
2131                 goto failed_mount3;
2132         }
2133
2134         /* per fileystem reservation list head & lock */
2135         spin_lock_init(&sbi->s_rsv_window_lock);
2136         sbi->s_rsv_window_root = RB_ROOT;
2137         /* Add a single, static dummy reservation to the start of the
2138          * reservation window list --- it gives us a placeholder for
2139          * append-at-start-of-list which makes the allocation logic
2140          * _much_ simpler. */
2141         sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
2142         sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
2143         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
2144         sbi->s_rsv_window_head.rsv_goal_size = 0;
2145         ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
2146
2147         sbi->s_stripe = ext4_get_stripe_size(sbi);
2148
2149         /*
2150          * set up enough so that it can read an inode
2151          */
2152         sb->s_op = &ext4_sops;
2153         sb->s_export_op = &ext4_export_ops;
2154         sb->s_xattr = ext4_xattr_handlers;
2155 #ifdef CONFIG_QUOTA
2156         sb->s_qcop = &ext4_qctl_operations;
2157         sb->dq_op = &ext4_quota_operations;
2158 #endif
2159         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2160
2161         sb->s_root = NULL;
2162
2163         needs_recovery = (es->s_last_orphan != 0 ||
2164                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2165                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2166
2167         /*
2168          * The first inode we look at is the journal inode.  Don't try
2169          * root first: it may be modified in the journal!
2170          */
2171         if (!test_opt(sb, NOLOAD) &&
2172             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2173                 if (ext4_load_journal(sb, es, journal_devnum))
2174                         goto failed_mount3;
2175         } else if (journal_inum) {
2176                 if (ext4_create_journal(sb, es, journal_inum))
2177                         goto failed_mount3;
2178         } else {
2179                 if (!silent)
2180                         printk (KERN_ERR
2181                                 "ext4: No journal on filesystem on %s\n",
2182                                 sb->s_id);
2183                 goto failed_mount3;
2184         }
2185
2186         if (ext4_blocks_count(es) > 0xffffffffULL &&
2187             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2188                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2189                 printk(KERN_ERR "ext4: Failed to set 64-bit journal feature\n");
2190                 goto failed_mount4;
2191         }
2192
2193         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2194                 jbd2_journal_set_features(sbi->s_journal,
2195                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2196                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2197         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2198                 jbd2_journal_set_features(sbi->s_journal,
2199                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2200                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2201                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2202         } else {
2203                 jbd2_journal_clear_features(sbi->s_journal,
2204                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2205                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2206         }
2207
2208         /* We have now updated the journal if required, so we can
2209          * validate the data journaling mode. */
2210         switch (test_opt(sb, DATA_FLAGS)) {
2211         case 0:
2212                 /* No mode set, assume a default based on the journal
2213                  * capabilities: ORDERED_DATA if the journal can
2214                  * cope, else JOURNAL_DATA
2215                  */
2216                 if (jbd2_journal_check_available_features
2217                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2218                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
2219                 else
2220                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2221                 break;
2222
2223         case EXT4_MOUNT_ORDERED_DATA:
2224         case EXT4_MOUNT_WRITEBACK_DATA:
2225                 if (!jbd2_journal_check_available_features
2226                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2227                         printk(KERN_ERR "EXT4-fs: Journal does not support "
2228                                "requested data journaling mode\n");
2229                         goto failed_mount4;
2230                 }
2231         default:
2232                 break;
2233         }
2234
2235         if (test_opt(sb, NOBH)) {
2236                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2237                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
2238                                 "its supported only with writeback mode\n");
2239                         clear_opt(sbi->s_mount_opt, NOBH);
2240                 }
2241         }
2242         /*
2243          * The jbd2_journal_load will have done any necessary log recovery,
2244          * so we can safely mount the rest of the filesystem now.
2245          */
2246
2247         root = ext4_iget(sb, EXT4_ROOT_INO);
2248         if (IS_ERR(root)) {
2249                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
2250                 ret = PTR_ERR(root);
2251                 goto failed_mount4;
2252         }
2253         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2254                 iput(root);
2255                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
2256                 goto failed_mount4;
2257         }
2258         sb->s_root = d_alloc_root(root);
2259         if (!sb->s_root) {
2260                 printk(KERN_ERR "EXT4-fs: get root dentry failed\n");
2261                 iput(root);
2262                 ret = -ENOMEM;
2263                 goto failed_mount4;
2264         }
2265
2266         ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
2267
2268         /* determine the minimum size of new large inodes, if present */
2269         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2270                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2271                                                      EXT4_GOOD_OLD_INODE_SIZE;
2272                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2273                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2274                         if (sbi->s_want_extra_isize <
2275                             le16_to_cpu(es->s_want_extra_isize))
2276                                 sbi->s_want_extra_isize =
2277                                         le16_to_cpu(es->s_want_extra_isize);
2278                         if (sbi->s_want_extra_isize <
2279                             le16_to_cpu(es->s_min_extra_isize))
2280                                 sbi->s_want_extra_isize =
2281                                         le16_to_cpu(es->s_min_extra_isize);
2282                 }
2283         }
2284         /* Check if enough inode space is available */
2285         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2286                                                         sbi->s_inode_size) {
2287                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2288                                                        EXT4_GOOD_OLD_INODE_SIZE;
2289                 printk(KERN_INFO "EXT4-fs: required extra inode space not"
2290                         "available.\n");
2291         }
2292
2293         /*
2294          * akpm: core read_super() calls in here with the superblock locked.
2295          * That deadlocks, because orphan cleanup needs to lock the superblock
2296          * in numerous places.  Here we just pop the lock - it's relatively
2297          * harmless, because we are now ready to accept write_super() requests,
2298          * and aviro says that's the only reason for hanging onto the
2299          * superblock lock.
2300          */
2301         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2302         ext4_orphan_cleanup(sb, es);
2303         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2304         if (needs_recovery)
2305                 printk (KERN_INFO "EXT4-fs: recovery complete.\n");
2306         ext4_mark_recovery_complete(sb, es);
2307         printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
2308                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
2309                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
2310                 "writeback");
2311
2312         ext4_ext_init(sb);
2313         ext4_mb_init(sb, needs_recovery);
2314
2315         lock_kernel();
2316         return 0;
2317
2318 cantfind_ext4:
2319         if (!silent)
2320                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
2321                        sb->s_id);
2322         goto failed_mount;
2323
2324 failed_mount4:
2325         jbd2_journal_destroy(sbi->s_journal);
2326 failed_mount3:
2327         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2328         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2329         percpu_counter_destroy(&sbi->s_dirs_counter);
2330 failed_mount2:
2331         for (i = 0; i < db_count; i++)
2332                 brelse(sbi->s_group_desc[i]);
2333         kfree(sbi->s_group_desc);
2334 failed_mount:
2335 #ifdef CONFIG_QUOTA
2336         for (i = 0; i < MAXQUOTAS; i++)
2337                 kfree(sbi->s_qf_names[i]);
2338 #endif
2339         ext4_blkdev_remove(sbi);
2340         brelse(bh);
2341 out_fail:
2342         sb->s_fs_info = NULL;
2343         kfree(sbi);
2344         lock_kernel();
2345         return ret;
2346 }
2347
2348 /*
2349  * Setup any per-fs journal parameters now.  We'll do this both on
2350  * initial mount, once the journal has been initialised but before we've
2351  * done any recovery; and again on any subsequent remount.
2352  */
2353 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2354 {
2355         struct ext4_sb_info *sbi = EXT4_SB(sb);
2356
2357         if (sbi->s_commit_interval)
2358                 journal->j_commit_interval = sbi->s_commit_interval;
2359         /* We could also set up an ext4-specific default for the commit
2360          * interval here, but for now we'll just fall back to the jbd
2361          * default. */
2362
2363         spin_lock(&journal->j_state_lock);
2364         if (test_opt(sb, BARRIER))
2365                 journal->j_flags |= JBD2_BARRIER;
2366         else
2367                 journal->j_flags &= ~JBD2_BARRIER;
2368         spin_unlock(&journal->j_state_lock);
2369 }
2370
2371 static journal_t *ext4_get_journal(struct super_block *sb,
2372                                    unsigned int journal_inum)
2373 {
2374         struct inode *journal_inode;
2375         journal_t *journal;
2376
2377         /* First, test for the existence of a valid inode on disk.  Bad
2378          * things happen if we iget() an unused inode, as the subsequent
2379          * iput() will try to delete it. */
2380
2381         journal_inode = ext4_iget(sb, journal_inum);
2382         if (IS_ERR(journal_inode)) {
2383                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
2384                 return NULL;
2385         }
2386         if (!journal_inode->i_nlink) {
2387                 make_bad_inode(journal_inode);
2388                 iput(journal_inode);
2389                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
2390                 return NULL;
2391         }
2392
2393         jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
2394                   journal_inode, journal_inode->i_size);
2395         if (!S_ISREG(journal_inode->i_mode)) {
2396                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
2397                 iput(journal_inode);
2398                 return NULL;
2399         }
2400
2401         journal = jbd2_journal_init_inode(journal_inode);
2402         if (!journal) {
2403                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
2404                 iput(journal_inode);
2405                 return NULL;
2406         }
2407         journal->j_private = sb;
2408         ext4_init_journal_params(sb, journal);
2409         return journal;
2410 }
2411
2412 static journal_t *ext4_get_dev_journal(struct super_block *sb,
2413                                        dev_t j_dev)
2414 {
2415         struct buffer_head * bh;
2416         journal_t *journal;
2417         ext4_fsblk_t start;
2418         ext4_fsblk_t len;
2419         int hblock, blocksize;
2420         ext4_fsblk_t sb_block;
2421         unsigned long offset;
2422         struct ext4_super_block * es;
2423         struct block_device *bdev;
2424
2425         bdev = ext4_blkdev_get(j_dev);
2426         if (bdev == NULL)
2427                 return NULL;
2428
2429         if (bd_claim(bdev, sb)) {
2430                 printk(KERN_ERR
2431                         "EXT4: failed to claim external journal device.\n");
2432                 blkdev_put(bdev);
2433                 return NULL;
2434         }
2435
2436         blocksize = sb->s_blocksize;
2437         hblock = bdev_hardsect_size(bdev);
2438         if (blocksize < hblock) {
2439                 printk(KERN_ERR
2440                         "EXT4-fs: blocksize too small for journal device.\n");
2441                 goto out_bdev;
2442         }
2443
2444         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2445         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2446         set_blocksize(bdev, blocksize);
2447         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2448                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2449                        "external journal\n");
2450                 goto out_bdev;
2451         }
2452
2453         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2454         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2455             !(le32_to_cpu(es->s_feature_incompat) &
2456               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2457                 printk(KERN_ERR "EXT4-fs: external journal has "
2458                                         "bad superblock\n");
2459                 brelse(bh);
2460                 goto out_bdev;
2461         }
2462
2463         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2464                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2465                 brelse(bh);
2466                 goto out_bdev;
2467         }
2468
2469         len = ext4_blocks_count(es);
2470         start = sb_block + 1;
2471         brelse(bh);     /* we're done with the superblock */
2472
2473         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2474                                         start, len, blocksize);
2475         if (!journal) {
2476                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2477                 goto out_bdev;
2478         }
2479         journal->j_private = sb;
2480         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2481         wait_on_buffer(journal->j_sb_buffer);
2482         if (!buffer_uptodate(journal->j_sb_buffer)) {
2483                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2484                 goto out_journal;
2485         }
2486         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2487                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2488                                         "user (unsupported) - %d\n",
2489                         be32_to_cpu(journal->j_superblock->s_nr_users));
2490                 goto out_journal;
2491         }
2492         EXT4_SB(sb)->journal_bdev = bdev;
2493         ext4_init_journal_params(sb, journal);
2494         return journal;
2495 out_journal:
2496         jbd2_journal_destroy(journal);
2497 out_bdev:
2498         ext4_blkdev_put(bdev);
2499         return NULL;
2500 }
2501
2502 static int ext4_load_journal(struct super_block *sb,
2503                              struct ext4_super_block *es,
2504                              unsigned long journal_devnum)
2505 {
2506         journal_t *journal;
2507         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2508         dev_t journal_dev;
2509         int err = 0;
2510         int really_read_only;
2511
2512         if (journal_devnum &&
2513             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2514                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2515                         "numbers have changed\n");
2516                 journal_dev = new_decode_dev(journal_devnum);
2517         } else
2518                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2519
2520         really_read_only = bdev_read_only(sb->s_bdev);
2521
2522         /*
2523          * Are we loading a blank journal or performing recovery after a
2524          * crash?  For recovery, we need to check in advance whether we
2525          * can get read-write access to the device.
2526          */
2527
2528         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2529                 if (sb->s_flags & MS_RDONLY) {
2530                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2531                                         "required on readonly filesystem.\n");
2532                         if (really_read_only) {
2533                                 printk(KERN_ERR "EXT4-fs: write access "
2534                                         "unavailable, cannot proceed.\n");
2535                                 return -EROFS;
2536                         }
2537                         printk (KERN_INFO "EXT4-fs: write access will "
2538                                         "be enabled during recovery.\n");
2539                 }
2540         }
2541
2542         if (journal_inum && journal_dev) {
2543                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2544                        "and inode journals!\n");
2545                 return -EINVAL;
2546         }
2547
2548         if (journal_inum) {
2549                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2550                         return -EINVAL;
2551         } else {
2552                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2553                         return -EINVAL;
2554         }
2555
2556         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2557                 err = jbd2_journal_update_format(journal);
2558                 if (err)  {
2559                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2560                         jbd2_journal_destroy(journal);
2561                         return err;
2562                 }
2563         }
2564
2565         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2566                 err = jbd2_journal_wipe(journal, !really_read_only);
2567         if (!err)
2568                 err = jbd2_journal_load(journal);
2569
2570         if (err) {
2571                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2572                 jbd2_journal_destroy(journal);
2573                 return err;
2574         }
2575
2576         EXT4_SB(sb)->s_journal = journal;
2577         ext4_clear_journal_err(sb, es);
2578
2579         if (journal_devnum &&
2580             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2581                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2582                 sb->s_dirt = 1;
2583
2584                 /* Make sure we flush the recovery flag to disk. */
2585                 ext4_commit_super(sb, es, 1);
2586         }
2587
2588         return 0;
2589 }
2590
2591 static int ext4_create_journal(struct super_block * sb,
2592                                struct ext4_super_block * es,
2593                                unsigned int journal_inum)
2594 {
2595         journal_t *journal;
2596         int err;
2597
2598         if (sb->s_flags & MS_RDONLY) {
2599                 printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2600                                 "create journal.\n");
2601                 return -EROFS;
2602         }
2603
2604         journal = ext4_get_journal(sb, journal_inum);
2605         if (!journal)
2606                 return -EINVAL;
2607
2608         printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2609                journal_inum);
2610
2611         err = jbd2_journal_create(journal);
2612         if (err) {
2613                 printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2614                 jbd2_journal_destroy(journal);
2615                 return -EIO;
2616         }
2617
2618         EXT4_SB(sb)->s_journal = journal;
2619
2620         ext4_update_dynamic_rev(sb);
2621         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2622         EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2623
2624         es->s_journal_inum = cpu_to_le32(journal_inum);
2625         sb->s_dirt = 1;
2626
2627         /* Make sure we flush the recovery flag to disk. */
2628         ext4_commit_super(sb, es, 1);
2629
2630         return 0;
2631 }
2632
2633 static void ext4_commit_super (struct super_block * sb,
2634                                struct ext4_super_block * es,
2635                                int sync)
2636 {
2637         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2638
2639         if (!sbh)
2640                 return;
2641         es->s_wtime = cpu_to_le32(get_seconds());
2642         ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2643         es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2644         BUFFER_TRACE(sbh, "marking dirty");
2645         mark_buffer_dirty(sbh);
2646         if (sync)
2647                 sync_dirty_buffer(sbh);
2648 }
2649
2650
2651 /*
2652  * Have we just finished recovery?  If so, and if we are mounting (or
2653  * remounting) the filesystem readonly, then we will end up with a
2654  * consistent fs on disk.  Record that fact.
2655  */
2656 static void ext4_mark_recovery_complete(struct super_block * sb,
2657                                         struct ext4_super_block * es)
2658 {
2659         journal_t *journal = EXT4_SB(sb)->s_journal;
2660
2661         jbd2_journal_lock_updates(journal);
2662         jbd2_journal_flush(journal);
2663         lock_super(sb);
2664         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2665             sb->s_flags & MS_RDONLY) {
2666                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2667                 sb->s_dirt = 0;
2668                 ext4_commit_super(sb, es, 1);
2669         }
2670         unlock_super(sb);
2671         jbd2_journal_unlock_updates(journal);
2672 }
2673
2674 /*
2675  * If we are mounting (or read-write remounting) a filesystem whose journal
2676  * has recorded an error from a previous lifetime, move that error to the
2677  * main filesystem now.
2678  */
2679 static void ext4_clear_journal_err(struct super_block * sb,
2680                                    struct ext4_super_block * es)
2681 {
2682         journal_t *journal;
2683         int j_errno;
2684         const char *errstr;
2685
2686         journal = EXT4_SB(sb)->s_journal;
2687
2688         /*
2689          * Now check for any error status which may have been recorded in the
2690          * journal by a prior ext4_error() or ext4_abort()
2691          */
2692
2693         j_errno = jbd2_journal_errno(journal);
2694         if (j_errno) {
2695                 char nbuf[16];
2696
2697                 errstr = ext4_decode_error(sb, j_errno, nbuf);
2698                 ext4_warning(sb, __func__, "Filesystem error recorded "
2699                              "from previous mount: %s", errstr);
2700                 ext4_warning(sb, __func__, "Marking fs in need of "
2701                              "filesystem check.");
2702
2703                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2704                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2705                 ext4_commit_super (sb, es, 1);
2706
2707                 jbd2_journal_clear_err(journal);
2708         }
2709 }
2710
2711 /*
2712  * Force the running and committing transactions to commit,
2713  * and wait on the commit.
2714  */
2715 int ext4_force_commit(struct super_block *sb)
2716 {
2717         journal_t *journal;
2718         int ret;
2719
2720         if (sb->s_flags & MS_RDONLY)
2721                 return 0;
2722
2723         journal = EXT4_SB(sb)->s_journal;
2724         sb->s_dirt = 0;
2725         ret = ext4_journal_force_commit(journal);
2726         return ret;
2727 }
2728
2729 /*
2730  * Ext4 always journals updates to the superblock itself, so we don't
2731  * have to propagate any other updates to the superblock on disk at this
2732  * point.  Just start an async writeback to get the buffers on their way
2733  * to the disk.
2734  *
2735  * This implicitly triggers the writebehind on sync().
2736  */
2737
2738 static void ext4_write_super (struct super_block * sb)
2739 {
2740         if (mutex_trylock(&sb->s_lock) != 0)
2741                 BUG();
2742         sb->s_dirt = 0;
2743 }
2744
2745 static int ext4_sync_fs(struct super_block *sb, int wait)
2746 {
2747         tid_t target;
2748
2749         sb->s_dirt = 0;
2750         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2751                 if (wait)
2752                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2753         }
2754         return 0;
2755 }
2756
2757 /*
2758  * LVM calls this function before a (read-only) snapshot is created.  This
2759  * gives us a chance to flush the journal completely and mark the fs clean.
2760  */
2761 static void ext4_write_super_lockfs(struct super_block *sb)
2762 {
2763         sb->s_dirt = 0;
2764
2765         if (!(sb->s_flags & MS_RDONLY)) {
2766                 journal_t *journal = EXT4_SB(sb)->s_journal;
2767
2768                 /* Now we set up the journal barrier. */
2769                 jbd2_journal_lock_updates(journal);
2770                 jbd2_journal_flush(journal);
2771
2772                 /* Journal blocked and flushed, clear needs_recovery flag. */
2773                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2774                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2775         }
2776 }
2777
2778 /*
2779  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2780  * flag here, even though the filesystem is not technically dirty yet.
2781  */
2782 static void ext4_unlockfs(struct super_block *sb)
2783 {
2784         if (!(sb->s_flags & MS_RDONLY)) {
2785                 lock_super(sb);
2786                 /* Reser the needs_recovery flag before the fs is unlocked. */
2787                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2788                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2789                 unlock_super(sb);
2790                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2791         }
2792 }
2793
2794 static int ext4_remount (struct super_block * sb, int * flags, char * data)
2795 {
2796         struct ext4_super_block * es;
2797         struct ext4_sb_info *sbi = EXT4_SB(sb);
2798         ext4_fsblk_t n_blocks_count = 0;
2799         unsigned long old_sb_flags;
2800         struct ext4_mount_options old_opts;
2801         int err;
2802 #ifdef CONFIG_QUOTA
2803         int i;
2804 #endif
2805
2806         /* Store the original options */
2807         old_sb_flags = sb->s_flags;
2808         old_opts.s_mount_opt = sbi->s_mount_opt;
2809         old_opts.s_resuid = sbi->s_resuid;
2810         old_opts.s_resgid = sbi->s_resgid;
2811         old_opts.s_commit_interval = sbi->s_commit_interval;
2812 #ifdef CONFIG_QUOTA
2813         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2814         for (i = 0; i < MAXQUOTAS; i++)
2815                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2816 #endif
2817
2818         /*
2819          * Allow the "check" option to be passed as a remount option.
2820          */
2821         if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2822                 err = -EINVAL;
2823                 goto restore_opts;
2824         }
2825
2826         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2827                 ext4_abort(sb, __func__, "Abort forced by user");
2828
2829         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2830                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2831
2832         es = sbi->s_es;
2833
2834         ext4_init_journal_params(sb, sbi->s_journal);
2835
2836         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2837                 n_blocks_count > ext4_blocks_count(es)) {
2838                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
2839                         err = -EROFS;
2840                         goto restore_opts;
2841                 }
2842
2843                 if (*flags & MS_RDONLY) {
2844                         /*
2845                          * First of all, the unconditional stuff we have to do
2846                          * to disable replay of the journal when we next remount
2847                          */
2848                         sb->s_flags |= MS_RDONLY;
2849
2850                         /*
2851                          * OK, test if we are remounting a valid rw partition
2852                          * readonly, and if so set the rdonly flag and then
2853                          * mark the partition as valid again.
2854                          */
2855                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
2856                             (sbi->s_mount_state & EXT4_VALID_FS))
2857                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
2858
2859                         /*
2860                          * We have to unlock super so that we can wait for
2861                          * transactions.
2862                          */
2863                         unlock_super(sb);
2864                         ext4_mark_recovery_complete(sb, es);
2865                         lock_super(sb);
2866                 } else {
2867                         __le32 ret;
2868                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2869                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
2870                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2871                                        "remount RDWR because of unsupported "
2872                                        "optional features (%x).\n",
2873                                        sb->s_id, le32_to_cpu(ret));
2874                                 err = -EROFS;
2875                                 goto restore_opts;
2876                         }
2877
2878                         /*
2879                          * If we have an unprocessed orphan list hanging
2880                          * around from a previously readonly bdev mount,
2881                          * require a full umount/remount for now.
2882                          */
2883                         if (es->s_last_orphan) {
2884                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2885                                        "remount RDWR because of unprocessed "
2886                                        "orphan inode list.  Please "
2887                                        "umount/remount instead.\n",
2888                                        sb->s_id);
2889                                 err = -EINVAL;
2890                                 goto restore_opts;
2891                         }
2892
2893                         /*
2894                          * Mounting a RDONLY partition read-write, so reread
2895                          * and store the current valid flag.  (It may have
2896                          * been changed by e2fsck since we originally mounted
2897                          * the partition.)
2898                          */
2899                         ext4_clear_journal_err(sb, es);
2900                         sbi->s_mount_state = le16_to_cpu(es->s_state);
2901                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
2902                                 goto restore_opts;
2903                         if (!ext4_setup_super (sb, es, 0))
2904                                 sb->s_flags &= ~MS_RDONLY;
2905                 }
2906         }
2907 #ifdef CONFIG_QUOTA
2908         /* Release old quota file names */
2909         for (i = 0; i < MAXQUOTAS; i++)
2910                 if (old_opts.s_qf_names[i] &&
2911                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2912                         kfree(old_opts.s_qf_names[i]);
2913 #endif
2914         return 0;
2915 restore_opts:
2916         sb->s_flags = old_sb_flags;
2917         sbi->s_mount_opt = old_opts.s_mount_opt;
2918         sbi->s_resuid = old_opts.s_resuid;
2919         sbi->s_resgid = old_opts.s_resgid;
2920         sbi->s_commit_interval = old_opts.s_commit_interval;
2921 #ifdef CONFIG_QUOTA
2922         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
2923         for (i = 0; i < MAXQUOTAS; i++) {
2924                 if (sbi->s_qf_names[i] &&
2925                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2926                         kfree(sbi->s_qf_names[i]);
2927                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
2928         }
2929 #endif
2930         return err;
2931 }
2932
2933 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
2934 {
2935         struct super_block *sb = dentry->d_sb;
2936         struct ext4_sb_info *sbi = EXT4_SB(sb);
2937         struct ext4_super_block *es = sbi->s_es;
2938         u64 fsid;
2939
2940         if (test_opt(sb, MINIX_DF)) {
2941                 sbi->s_overhead_last = 0;
2942         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
2943                 ext4_group_t ngroups = sbi->s_groups_count, i;
2944                 ext4_fsblk_t overhead = 0;
2945                 smp_rmb();
2946
2947                 /*
2948                  * Compute the overhead (FS structures).  This is constant
2949                  * for a given filesystem unless the number of block groups
2950                  * changes so we cache the previous value until it does.
2951                  */
2952
2953                 /*
2954                  * All of the blocks before first_data_block are
2955                  * overhead
2956                  */
2957                 overhead = le32_to_cpu(es->s_first_data_block);
2958
2959                 /*
2960                  * Add the overhead attributed to the superblock and
2961                  * block group descriptors.  If the sparse superblocks
2962                  * feature is turned on, then not all groups have this.
2963                  */
2964                 for (i = 0; i < ngroups; i++) {
2965                         overhead += ext4_bg_has_super(sb, i) +
2966                                 ext4_bg_num_gdb(sb, i);
2967                         cond_resched();
2968                 }
2969
2970                 /*
2971                  * Every block group has an inode bitmap, a block
2972                  * bitmap, and an inode table.
2973                  */
2974                 overhead += ngroups * (2 + sbi->s_itb_per_group);
2975                 sbi->s_overhead_last = overhead;
2976                 smp_wmb();
2977                 sbi->s_blocks_last = ext4_blocks_count(es);
2978         }
2979
2980         buf->f_type = EXT4_SUPER_MAGIC;
2981         buf->f_bsize = sb->s_blocksize;
2982         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
2983         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter);
2984         ext4_free_blocks_count_set(es, buf->f_bfree);
2985         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
2986         if (buf->f_bfree < ext4_r_blocks_count(es))
2987                 buf->f_bavail = 0;
2988         buf->f_files = le32_to_cpu(es->s_inodes_count);
2989         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
2990         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
2991         buf->f_namelen = EXT4_NAME_LEN;
2992         fsid = le64_to_cpup((void *)es->s_uuid) ^
2993                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
2994         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
2995         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
2996         return 0;
2997 }
2998
2999 /* Helper function for writing quotas on sync - we need to start transaction before quota file
3000  * is locked for write. Otherwise the are possible deadlocks:
3001  * Process 1                         Process 2
3002  * ext4_create()                     quota_sync()
3003  *   jbd2_journal_start()                   write_dquot()
3004  *   DQUOT_INIT()                        down(dqio_mutex)
3005  *     down(dqio_mutex)                    jbd2_journal_start()
3006  *
3007  */
3008
3009 #ifdef CONFIG_QUOTA
3010
3011 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3012 {
3013         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3014 }
3015
3016 static int ext4_dquot_initialize(struct inode *inode, int type)
3017 {
3018         handle_t *handle;
3019         int ret, err;
3020
3021         /* We may create quota structure so we need to reserve enough blocks */
3022         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
3023         if (IS_ERR(handle))
3024                 return PTR_ERR(handle);
3025         ret = dquot_initialize(inode, type);
3026         err = ext4_journal_stop(handle);
3027         if (!ret)
3028                 ret = err;
3029         return ret;
3030 }
3031
3032 static int ext4_dquot_drop(struct inode *inode)
3033 {
3034         handle_t *handle;
3035         int ret, err;
3036
3037         /* We may delete quota structure so we need to reserve enough blocks */
3038         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
3039         if (IS_ERR(handle)) {
3040                 /*
3041                  * We call dquot_drop() anyway to at least release references
3042                  * to quota structures so that umount does not hang.
3043                  */
3044                 dquot_drop(inode);
3045                 return PTR_ERR(handle);
3046         }
3047         ret = dquot_drop(inode);
3048         err = ext4_journal_stop(handle);
3049         if (!ret)
3050                 ret = err;
3051         return ret;
3052 }
3053
3054 static int ext4_write_dquot(struct dquot *dquot)
3055 {
3056         int ret, err;
3057         handle_t *handle;
3058         struct inode *inode;
3059
3060         inode = dquot_to_inode(dquot);
3061         handle = ext4_journal_start(inode,
3062                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3063         if (IS_ERR(handle))
3064                 return PTR_ERR(handle);
3065         ret = dquot_commit(dquot);
3066         err = ext4_journal_stop(handle);
3067         if (!ret)
3068                 ret = err;
3069         return ret;
3070 }
3071
3072 static int ext4_acquire_dquot(struct dquot *dquot)
3073 {
3074         int ret, err;
3075         handle_t *handle;
3076
3077         handle = ext4_journal_start(dquot_to_inode(dquot),
3078                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3079         if (IS_ERR(handle))
3080                 return PTR_ERR(handle);
3081         ret = dquot_acquire(dquot);
3082         err = ext4_journal_stop(handle);
3083         if (!ret)
3084                 ret = err;
3085         return ret;
3086 }
3087
3088 static int ext4_release_dquot(struct dquot *dquot)
3089 {
3090         int ret, err;
3091         handle_t *handle;
3092
3093         handle = ext4_journal_start(dquot_to_inode(dquot),
3094                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3095         if (IS_ERR(handle)) {
3096                 /* Release dquot anyway to avoid endless cycle in dqput() */
3097                 dquot_release(dquot);
3098                 return PTR_ERR(handle);
3099         }
3100         ret = dquot_release(dquot);
3101         err = ext4_journal_stop(handle);
3102         if (!ret)
3103                 ret = err;
3104         return ret;
3105 }
3106
3107 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3108 {
3109         /* Are we journalling quotas? */
3110         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3111             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3112                 dquot_mark_dquot_dirty(dquot);
3113                 return ext4_write_dquot(dquot);
3114         } else {
3115                 return dquot_mark_dquot_dirty(dquot);
3116         }
3117 }
3118
3119 static int ext4_write_info(struct super_block *sb, int type)
3120 {
3121         int ret, err;
3122         handle_t *handle;
3123
3124         /* Data block + inode block */
3125         handle = ext4_journal_start(sb->s_root->d_inode, 2);
3126         if (IS_ERR(handle))
3127                 return PTR_ERR(handle);
3128         ret = dquot_commit_info(sb, type);
3129         err = ext4_journal_stop(handle);
3130         if (!ret)
3131                 ret = err;
3132         return ret;
3133 }
3134
3135 /*
3136  * Turn on quotas during mount time - we need to find
3137  * the quota file and such...
3138  */
3139 static int ext4_quota_on_mount(struct super_block *sb, int type)
3140 {
3141         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3142                         EXT4_SB(sb)->s_jquota_fmt, type);
3143 }
3144
3145 /*
3146  * Standard function to be called on quota_on
3147  */
3148 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3149                          char *path, int remount)
3150 {
3151         int err;
3152         struct nameidata nd;
3153
3154         if (!test_opt(sb, QUOTA))
3155                 return -EINVAL;
3156         /* Not journalling quota? */
3157         if ((!EXT4_SB(sb)->s_qf_names[USRQUOTA] &&
3158             !EXT4_SB(sb)->s_qf_names[GRPQUOTA]) || remount)
3159                 return vfs_quota_on(sb, type, format_id, path, remount);
3160         err = path_lookup(path, LOOKUP_FOLLOW, &nd);
3161         if (err)
3162                 return err;
3163         /* Quotafile not on the same filesystem? */
3164         if (nd.path.mnt->mnt_sb != sb) {
3165                 path_put(&nd.path);
3166                 return -EXDEV;
3167         }
3168         /* Quotafile not of fs root? */
3169         if (nd.path.dentry->d_parent->d_inode != sb->s_root->d_inode)
3170                 printk(KERN_WARNING
3171                         "EXT4-fs: Quota file not on filesystem root. "
3172                         "Journalled quota will not work.\n");
3173         path_put(&nd.path);
3174         return vfs_quota_on(sb, type, format_id, path, remount);
3175 }
3176
3177 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3178  * acquiring the locks... As quota files are never truncated and quota code
3179  * itself serializes the operations (and noone else should touch the files)
3180  * we don't have to be afraid of races */
3181 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3182                                size_t len, loff_t off)
3183 {
3184         struct inode *inode = sb_dqopt(sb)->files[type];
3185         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3186         int err = 0;
3187         int offset = off & (sb->s_blocksize - 1);
3188         int tocopy;
3189         size_t toread;
3190         struct buffer_head *bh;
3191         loff_t i_size = i_size_read(inode);
3192
3193         if (off > i_size)
3194                 return 0;
3195         if (off+len > i_size)
3196                 len = i_size-off;
3197         toread = len;
3198         while (toread > 0) {
3199                 tocopy = sb->s_blocksize - offset < toread ?
3200                                 sb->s_blocksize - offset : toread;
3201                 bh = ext4_bread(NULL, inode, blk, 0, &err);
3202                 if (err)
3203                         return err;
3204                 if (!bh)        /* A hole? */
3205                         memset(data, 0, tocopy);
3206                 else
3207                         memcpy(data, bh->b_data+offset, tocopy);
3208                 brelse(bh);
3209                 offset = 0;
3210                 toread -= tocopy;
3211                 data += tocopy;
3212                 blk++;
3213         }
3214         return len;
3215 }
3216
3217 /* Write to quotafile (we know the transaction is already started and has
3218  * enough credits) */
3219 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3220                                 const char *data, size_t len, loff_t off)
3221 {
3222         struct inode *inode = sb_dqopt(sb)->files[type];
3223         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3224         int err = 0;
3225         int offset = off & (sb->s_blocksize - 1);
3226         int tocopy;
3227         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3228         size_t towrite = len;
3229         struct buffer_head *bh;
3230         handle_t *handle = journal_current_handle();
3231
3232         if (!handle) {
3233                 printk(KERN_WARNING "EXT4-fs: Quota write (off=%Lu, len=%Lu)"
3234                         " cancelled because transaction is not started.\n",
3235                         (unsigned long long)off, (unsigned long long)len);
3236                 return -EIO;
3237         }
3238         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3239         while (towrite > 0) {
3240                 tocopy = sb->s_blocksize - offset < towrite ?
3241                                 sb->s_blocksize - offset : towrite;
3242                 bh = ext4_bread(handle, inode, blk, 1, &err);
3243                 if (!bh)
3244                         goto out;
3245                 if (journal_quota) {
3246                         err = ext4_journal_get_write_access(handle, bh);
3247                         if (err) {
3248                                 brelse(bh);
3249                                 goto out;
3250                         }
3251                 }
3252                 lock_buffer(bh);
3253                 memcpy(bh->b_data+offset, data, tocopy);
3254                 flush_dcache_page(bh->b_page);
3255                 unlock_buffer(bh);
3256                 if (journal_quota)
3257                         err = ext4_journal_dirty_metadata(handle, bh);
3258                 else {
3259                         /* Always do at least ordered writes for quotas */
3260                         err = ext4_journal_dirty_data(handle, bh);
3261                         mark_buffer_dirty(bh);
3262                 }
3263                 brelse(bh);
3264                 if (err)
3265                         goto out;
3266                 offset = 0;
3267                 towrite -= tocopy;
3268                 data += tocopy;
3269                 blk++;
3270         }
3271 out:
3272         if (len == towrite)
3273                 return err;
3274         if (inode->i_size < off+len-towrite) {
3275                 i_size_write(inode, off+len-towrite);
3276                 EXT4_I(inode)->i_disksize = inode->i_size;
3277         }
3278         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3279         ext4_mark_inode_dirty(handle, inode);
3280         mutex_unlock(&inode->i_mutex);
3281         return len - towrite;
3282 }
3283
3284 #endif
3285
3286 static int ext4_get_sb(struct file_system_type *fs_type,
3287         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3288 {
3289         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3290 }
3291
3292 static struct file_system_type ext4dev_fs_type = {
3293         .owner          = THIS_MODULE,
3294         .name           = "ext4dev",
3295         .get_sb         = ext4_get_sb,
3296         .kill_sb        = kill_block_super,
3297         .fs_flags       = FS_REQUIRES_DEV,
3298 };
3299
3300 static int __init init_ext4_fs(void)
3301 {
3302         int err;
3303
3304         err = init_ext4_mballoc();
3305         if (err)
3306                 return err;
3307
3308         err = init_ext4_xattr();
3309         if (err)
3310                 goto out2;
3311         err = init_inodecache();
3312         if (err)
3313                 goto out1;
3314         err = register_filesystem(&ext4dev_fs_type);
3315         if (err)
3316                 goto out;
3317         return 0;
3318 out:
3319         destroy_inodecache();
3320 out1:
3321         exit_ext4_xattr();
3322 out2:
3323         exit_ext4_mballoc();
3324         return err;
3325 }
3326
3327 static void __exit exit_ext4_fs(void)
3328 {
3329         unregister_filesystem(&ext4dev_fs_type);
3330         destroy_inodecache();
3331         exit_ext4_xattr();
3332         exit_ext4_mballoc();
3333 }
3334
3335 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
3336 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
3337 MODULE_LICENSE("GPL");
3338 module_init(init_ext4_fs)
3339 module_exit(exit_ext4_fs)