fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/jbd2.h>
  24 #include <linux/ext4_fs.h>
  25 #include <linux/ext4_jbd2.h>
  26 #include <linux/slab.h>
  27 #include <linux/init.h>
  28 #include <linux/blkdev.h>
  29 #include <linux/parser.h>
  30 #include <linux/smp_lock.h>
  31 #include <linux/buffer_head.h>
  32 #include <linux/exportfs.h>
  33 #include <linux/vfs.h>
  34 #include <linux/random.h>
  35 #include <linux/mount.h>
  36 #include <linux/namei.h>
  37 #include <linux/quotaops.h>
  38 #include <linux/seq_file.h>
  39 #include <linux/log2.h>
  40
  41 #include <asm/uaccess.h>
  42
  43 #include "xattr.h"
  44 #include "acl.h"
  45 #include "namei.h"
  46
  47 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  48                              unsigned long journal_devnum);
  49 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
  50                                unsigned int);
  51 static void ext4_commit_super (struct super_block * sb,
  52                                struct ext4_super_block * es,
  53                                int sync);
  54 static void ext4_mark_recovery_complete(struct super_block * sb,
  55                                         struct ext4_super_block * es);
  56 static void ext4_clear_journal_err(struct super_block * sb,
  57                                    struct ext4_super_block * es);
  58 static int ext4_sync_fs(struct super_block *sb, int wait);
  59 static const char *ext4_decode_error(struct super_block * sb, int errno,
  60                                      char nbuf[16]);
  61 static int ext4_remount (struct super_block * sb, int * flags, char * data);
  62 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf);
  63 static void ext4_unlockfs(struct super_block *sb);
  64 static void ext4_write_super (struct super_block * sb);
  65 static void ext4_write_super_lockfs(struct super_block *sb);
  66
  67
  68 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
  69                                struct ext4_group_desc *bg)
  70 {
  71         return le32_to_cpu(bg->bg_block_bitmap) |
  72                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  73                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
  74 }
  75
  76 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
  77                                struct ext4_group_desc *bg)
  78 {
  79         return le32_to_cpu(bg->bg_inode_bitmap) |
  80                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  81                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
  82 }
  83
  84 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
  85                               struct ext4_group_desc *bg)
  86 {
  87         return le32_to_cpu(bg->bg_inode_table) |
  88                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  89                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
  90 }
  91
  92 void ext4_block_bitmap_set(struct super_block *sb,
  93                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
  94 {
  95         bg->bg_block_bitmap = cpu_to_le32((u32)blk);
  96         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
  97                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
  98 }
  99
 100 void ext4_inode_bitmap_set(struct super_block *sb,
 101                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 102 {
 103         bg->bg_inode_bitmap  = cpu_to_le32((u32)blk);
 104         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 105                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 106 }
 107
 108 void ext4_inode_table_set(struct super_block *sb,
 109                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 110 {
 111         bg->bg_inode_table = cpu_to_le32((u32)blk);
 112         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 113                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 114 }
 115
 116 /*
 117  * Wrappers for jbd2_journal_start/end.
 118  *
 119  * The only special thing we need to do here is to make sure that all
 120  * journal_end calls result in the superblock being marked dirty, so
 121  * that sync() will call the filesystem's write_super callback if
 122  * appropriate.
 123  */
 124 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 125 {
 126         journal_t *journal;
 127
 128         if (sb->s_flags & MS_RDONLY)
 129                 return ERR_PTR(-EROFS);
 130
 131         /* Special case here: if the journal has aborted behind our
 132          * backs (eg. EIO in the commit thread), then we still need to
 133          * take the FS itself readonly cleanly. */
 134         journal = EXT4_SB(sb)->s_journal;
 135         if (is_journal_aborted(journal)) {
 136                 ext4_abort(sb, __FUNCTION__,
 137                            "Detected aborted journal");
 138                 return ERR_PTR(-EROFS);
 139         }
 140
 141         return jbd2_journal_start(journal, nblocks);
 142 }
 143
 144 /*
 145  * The only special thing we need to do here is to make sure that all
 146  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 147  * that sync() will call the filesystem's write_super callback if
 148  * appropriate.
 149  */
 150 int __ext4_journal_stop(const char *where, handle_t *handle)
 151 {
 152         struct super_block *sb;
 153         int err;
 154         int rc;
 155
 156         sb = handle->h_transaction->t_journal->j_private;
 157         err = handle->h_err;
 158         rc = jbd2_journal_stop(handle);
 159
 160         if (!err)
 161                 err = rc;
 162         if (err)
 163                 __ext4_std_error(sb, where, err);
 164         return err;
 165 }
 166
 167 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 168                 struct buffer_head *bh, handle_t *handle, int err)
 169 {
 170         char nbuf[16];
 171         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 172
 173         if (bh)
 174                 BUFFER_TRACE(bh, "abort");
 175
 176         if (!handle->h_err)
 177                 handle->h_err = err;
 178
 179         if (is_handle_aborted(handle))
 180                 return;
 181
 182         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
 183                caller, errstr, err_fn);
 184
 185         jbd2_journal_abort_handle(handle);
 186 }
 187
 188 /* Deal with the reporting of failure conditions on a filesystem such as
 189  * inconsistencies detected or read IO failures.
 190  *
 191  * On ext2, we can store the error state of the filesystem in the
 192  * superblock.  That is not possible on ext4, because we may have other
 193  * write ordering constraints on the superblock which prevent us from
 194  * writing it out straight away; and given that the journal is about to
 195  * be aborted, we can't rely on the current, or future, transactions to
 196  * write out the superblock safely.
 197  *
 198  * We'll just use the jbd2_journal_abort() error code to record an error in
 199  * the journal instead.  On recovery, the journal will compain about
 200  * that error until we've noted it down and cleared it.
 201  */
 202
 203 static void ext4_handle_error(struct super_block *sb)
 204 {
 205         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 206
 207         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 208         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 209
 210         if (sb->s_flags & MS_RDONLY)
 211                 return;
 212
 213         if (!test_opt (sb, ERRORS_CONT)) {
 214                 journal_t *journal = EXT4_SB(sb)->s_journal;
 215
 216                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 217                 if (journal)
 218                         jbd2_journal_abort(journal, -EIO);
 219         }
 220         if (test_opt (sb, ERRORS_RO)) {
 221                 printk (KERN_CRIT "Remounting filesystem read-only\n");
 222                 sb->s_flags |= MS_RDONLY;
 223         }
 224         ext4_commit_super(sb, es, 1);
 225         if (test_opt(sb, ERRORS_PANIC))
 226                 panic("EXT4-fs (device %s): panic forced after error\n",
 227                         sb->s_id);
 228 }
 229
 230 void ext4_error (struct super_block * sb, const char * function,
 231                  const char * fmt, ...)
 232 {
 233         va_list args;
 234
 235         va_start(args, fmt);
 236         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 237         vprintk(fmt, args);
 238         printk("\n");
 239         va_end(args);
 240
 241         ext4_handle_error(sb);
 242 }
 243
 244 static const char *ext4_decode_error(struct super_block * sb, int errno,
 245                                      char nbuf[16])
 246 {
 247         char *errstr = NULL;
 248
 249         switch (errno) {
 250         case -EIO:
 251                 errstr = "IO failure";
 252                 break;
 253         case -ENOMEM:
 254                 errstr = "Out of memory";
 255                 break;
 256         case -EROFS:
 257                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
 258                         errstr = "Journal has aborted";
 259                 else
 260                         errstr = "Readonly filesystem";
 261                 break;
 262         default:
 263                 /* If the caller passed in an extra buffer for unknown
 264                  * errors, textualise them now.  Else we just return
 265                  * NULL. */
 266                 if (nbuf) {
 267                         /* Check for truncated error codes... */
 268                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 269                                 errstr = nbuf;
 270                 }
 271                 break;
 272         }
 273
 274         return errstr;
 275 }
 276
 277 /* __ext4_std_error decodes expected errors from journaling functions
 278  * automatically and invokes the appropriate error response.  */
 279
 280 void __ext4_std_error (struct super_block * sb, const char * function,
 281                        int errno)
 282 {
 283         char nbuf[16];
 284         const char *errstr;
 285
 286         /* Special case: if the error is EROFS, and we're not already
 287          * inside a transaction, then there's really no point in logging
 288          * an error. */
 289         if (errno == -EROFS && journal_current_handle() == NULL &&
 290             (sb->s_flags & MS_RDONLY))
 291                 return;
 292
 293         errstr = ext4_decode_error(sb, errno, nbuf);
 294         printk (KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
 295                 sb->s_id, function, errstr);
 296
 297         ext4_handle_error(sb);
 298 }
 299
 300 /*
 301  * ext4_abort is a much stronger failure handler than ext4_error.  The
 302  * abort function may be used to deal with unrecoverable failures such
 303  * as journal IO errors or ENOMEM at a critical moment in log management.
 304  *
 305  * We unconditionally force the filesystem into an ABORT|READONLY state,
 306  * unless the error response on the fs has been set to panic in which
 307  * case we take the easy way out and panic immediately.
 308  */
 309
 310 void ext4_abort (struct super_block * sb, const char * function,
 311                  const char * fmt, ...)
 312 {
 313         va_list args;
 314
 315         printk (KERN_CRIT "ext4_abort called.\n");
 316
 317         va_start(args, fmt);
 318         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 319         vprintk(fmt, args);
 320         printk("\n");
 321         va_end(args);
 322
 323         if (test_opt(sb, ERRORS_PANIC))
 324                 panic("EXT4-fs panic from previous error\n");
 325
 326         if (sb->s_flags & MS_RDONLY)
 327                 return;
 328
 329         printk(KERN_CRIT "Remounting filesystem read-only\n");
 330         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 331         sb->s_flags |= MS_RDONLY;
 332         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 333         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 334 }
 335
 336 void ext4_warning (struct super_block * sb, const char * function,
 337                    const char * fmt, ...)
 338 {
 339         va_list args;
 340
 341         va_start(args, fmt);
 342         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
 343                sb->s_id, function);
 344         vprintk(fmt, args);
 345         printk("\n");
 346         va_end(args);
 347 }
 348
 349 void ext4_update_dynamic_rev(struct super_block *sb)
 350 {
 351         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 352
 353         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 354                 return;
 355
 356         ext4_warning(sb, __FUNCTION__,
 357                      "updating to rev %d because of new feature flag, "
 358                      "running e2fsck is recommended",
 359                      EXT4_DYNAMIC_REV);
 360
 361         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 362         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 363         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 364         /* leave es->s_feature_*compat flags alone */
 365         /* es->s_uuid will be set by e2fsck if empty */
 366
 367         /*
 368          * The rest of the superblock fields should be zero, and if not it
 369          * means they are likely already in use, so leave them alone.  We
 370          * can leave it up to e2fsck to clean up any inconsistencies there.
 371          */
 372 }
 373
 374 /*
 375  * Open the external journal device
 376  */
 377 static struct block_device *ext4_blkdev_get(dev_t dev)
 378 {
 379         struct block_device *bdev;
 380         char b[BDEVNAME_SIZE];
 381
 382         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 383         if (IS_ERR(bdev))
 384                 goto fail;
 385         return bdev;
 386
 387 fail:
 388         printk(KERN_ERR "EXT4: failed to open journal device %s: %ld\n",
 389                         __bdevname(dev, b), PTR_ERR(bdev));
 390         return NULL;
 391 }
 392
 393 /*
 394  * Release the journal device
 395  */
 396 static int ext4_blkdev_put(struct block_device *bdev)
 397 {
 398         bd_release(bdev);
 399         return blkdev_put(bdev);
 400 }
 401
 402 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 403 {
 404         struct block_device *bdev;
 405         int ret = -ENODEV;
 406
 407         bdev = sbi->journal_bdev;
 408         if (bdev) {
 409                 ret = ext4_blkdev_put(bdev);
 410                 sbi->journal_bdev = NULL;
 411         }
 412         return ret;
 413 }
 414
 415 static inline struct inode *orphan_list_entry(struct list_head *l)
 416 {
 417         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 418 }
 419
 420 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 421 {
 422         struct list_head *l;
 423
 424         printk(KERN_ERR "sb orphan head is %d\n",
 425                le32_to_cpu(sbi->s_es->s_last_orphan));
 426
 427         printk(KERN_ERR "sb_info orphan list:\n");
 428         list_for_each(l, &sbi->s_orphan) {
 429                 struct inode *inode = orphan_list_entry(l);
 430                 printk(KERN_ERR "  "
 431                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 432                        inode->i_sb->s_id, inode->i_ino, inode,
 433                        inode->i_mode, inode->i_nlink,
 434                        NEXT_ORPHAN(inode));
 435         }
 436 }
 437
 438 static void ext4_put_super (struct super_block * sb)
 439 {
 440         struct ext4_sb_info *sbi = EXT4_SB(sb);
 441         struct ext4_super_block *es = sbi->s_es;
 442         int i;
 443
 444         ext4_ext_release(sb);
 445         ext4_xattr_put_super(sb);
 446         jbd2_journal_destroy(sbi->s_journal);
 447         if (!(sb->s_flags & MS_RDONLY)) {
 448                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 449                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 450                 BUFFER_TRACE(sbi->s_sbh, "marking dirty");
 451                 mark_buffer_dirty(sbi->s_sbh);
 452                 ext4_commit_super(sb, es, 1);
 453         }
 454
 455         for (i = 0; i < sbi->s_gdb_count; i++)
 456                 brelse(sbi->s_group_desc[i]);
 457         kfree(sbi->s_group_desc);
 458         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 459         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 460         percpu_counter_destroy(&sbi->s_dirs_counter);
 461         brelse(sbi->s_sbh);
 462 #ifdef CONFIG_QUOTA
 463         for (i = 0; i < MAXQUOTAS; i++)
 464                 kfree(sbi->s_qf_names[i]);
 465 #endif
 466
 467         /* Debugging code just in case the in-memory inode orphan list
 468          * isn't empty.  The on-disk one can be non-empty if we've
 469          * detected an error and taken the fs readonly, but the
 470          * in-memory list had better be clean by this point. */
 471         if (!list_empty(&sbi->s_orphan))
 472                 dump_orphan_list(sb, sbi);
 473         J_ASSERT(list_empty(&sbi->s_orphan));
 474
 475         invalidate_bdev(sb->s_bdev);
 476         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 477                 /*
 478                  * Invalidate the journal device's buffers.  We don't want them
 479                  * floating about in memory - the physical journal device may
 480                  * hotswapped, and it breaks the `ro-after' testing code.
 481                  */
 482                 sync_blockdev(sbi->journal_bdev);
 483                 invalidate_bdev(sbi->journal_bdev);
 484                 ext4_blkdev_remove(sbi);
 485         }
 486         sb->s_fs_info = NULL;
 487         kfree(sbi);
 488         return;
 489 }
 490
 491 static struct kmem_cache *ext4_inode_cachep;
 492
 493 /*
 494  * Called inside transaction, so use GFP_NOFS
 495  */
 496 static struct inode *ext4_alloc_inode(struct super_block *sb)
 497 {
 498         struct ext4_inode_info *ei;
 499
 500         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 501         if (!ei)
 502                 return NULL;
 503 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 504         ei->i_acl = EXT4_ACL_NOT_CACHED;
 505         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 506 #endif
 507         ei->i_block_alloc_info = NULL;
 508         ei->vfs_inode.i_version = 1;
 509         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 510         return &ei->vfs_inode;
 511 }
 512
 513 static void ext4_destroy_inode(struct inode *inode)
 514 {
 515         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 516                 printk("EXT4 Inode %p: orphan list check failed!\n",
 517                         EXT4_I(inode));
 518                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 519                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 520                                 true);
 521                 dump_stack();
 522         }
 523         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 524 }
 525
 526 static void init_once(struct kmem_cache *cachep, void *foo)
 527 {
 528         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 529
 530         INIT_LIST_HEAD(&ei->i_orphan);
 531 #ifdef CONFIG_EXT4DEV_FS_XATTR
 532         init_rwsem(&ei->xattr_sem);
 533 #endif
 534         mutex_init(&ei->truncate_mutex);
 535         inode_init_once(&ei->vfs_inode);
 536 }
 537
 538 static int init_inodecache(void)
 539 {
 540         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 541                                              sizeof(struct ext4_inode_info),
 542                                              0, (SLAB_RECLAIM_ACCOUNT|
 543                                                 SLAB_MEM_SPREAD),
 544                                              init_once);
 545         if (ext4_inode_cachep == NULL)
 546                 return -ENOMEM;
 547         return 0;
 548 }
 549
 550 static void destroy_inodecache(void)
 551 {
 552         kmem_cache_destroy(ext4_inode_cachep);
 553 }
 554
 555 static void ext4_clear_inode(struct inode *inode)
 556 {
 557         struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
 558 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 559         if (EXT4_I(inode)->i_acl &&
 560                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
 561                 posix_acl_release(EXT4_I(inode)->i_acl);
 562                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
 563         }
 564         if (EXT4_I(inode)->i_default_acl &&
 565                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
 566                 posix_acl_release(EXT4_I(inode)->i_default_acl);
 567                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
 568         }
 569 #endif
 570         ext4_discard_reservation(inode);
 571         EXT4_I(inode)->i_block_alloc_info = NULL;
 572         if (unlikely(rsv))
 573                 kfree(rsv);
 574 }
 575
 576 static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
 577 {
 578 #if defined(CONFIG_QUOTA)
 579         struct ext4_sb_info *sbi = EXT4_SB(sb);
 580
 581         if (sbi->s_jquota_fmt)
 582                 seq_printf(seq, ",jqfmt=%s",
 583                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold": "vfsv0");
 584
 585         if (sbi->s_qf_names[USRQUOTA])
 586                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 587
 588         if (sbi->s_qf_names[GRPQUOTA])
 589                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 590
 591         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
 592                 seq_puts(seq, ",usrquota");
 593
 594         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
 595                 seq_puts(seq, ",grpquota");
 596 #endif
 597 }
 598
 599 /*
 600  * Show an option if
 601  *  - it's set to a non-default value OR
 602  *  - if the per-sb default is different from the global default
 603  */
 604 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 605 {
 606         struct super_block *sb = vfs->mnt_sb;
 607         struct ext4_sb_info *sbi = EXT4_SB(sb);
 608         struct ext4_super_block *es = sbi->s_es;
 609         unsigned long def_mount_opts;
 610
 611         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 612
 613         if (sbi->s_sb_block != 1)
 614                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 615         if (test_opt(sb, MINIX_DF))
 616                 seq_puts(seq, ",minixdf");
 617         if (test_opt(sb, GRPID))
 618                 seq_puts(seq, ",grpid");
 619         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 620                 seq_puts(seq, ",nogrpid");
 621         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 622             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 623                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 624         }
 625         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 626             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 627                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 628         }
 629         if (test_opt(sb, ERRORS_CONT)) {
 630                 int def_errors = le16_to_cpu(es->s_errors);
 631
 632                 if (def_errors == EXT4_ERRORS_PANIC ||
 633                     def_errors == EXT4_ERRORS_RO) {
 634                         seq_puts(seq, ",errors=continue");
 635                 }
 636         }
 637         if (test_opt(sb, ERRORS_RO))
 638                 seq_puts(seq, ",errors=remount-ro");
 639         if (test_opt(sb, ERRORS_PANIC))
 640                 seq_puts(seq, ",errors=panic");
 641         if (test_opt(sb, NO_UID32))
 642                 seq_puts(seq, ",nouid32");
 643         if (test_opt(sb, DEBUG))
 644                 seq_puts(seq, ",debug");
 645         if (test_opt(sb, OLDALLOC))
 646                 seq_puts(seq, ",oldalloc");
 647 #ifdef CONFIG_EXT4_FS_XATTR
 648         if (test_opt(sb, XATTR_USER))
 649                 seq_puts(seq, ",user_xattr");
 650         if (!test_opt(sb, XATTR_USER) &&
 651             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 652                 seq_puts(seq, ",nouser_xattr");
 653         }
 654 #endif
 655 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 656         if (test_opt(sb, POSIX_ACL))
 657                 seq_puts(seq, ",acl");
 658         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 659                 seq_puts(seq, ",noacl");
 660 #endif
 661         if (!test_opt(sb, RESERVATION))
 662                 seq_puts(seq, ",noreservation");
 663         if (sbi->s_commit_interval) {
 664                 seq_printf(seq, ",commit=%u",
 665                            (unsigned) (sbi->s_commit_interval / HZ));
 666         }
 667         if (test_opt(sb, BARRIER))
 668                 seq_puts(seq, ",barrier=1");
 669         if (test_opt(sb, NOBH))
 670                 seq_puts(seq, ",nobh");
 671         if (!test_opt(sb, EXTENTS))
 672                 seq_puts(seq, ",noextents");
 673
 674         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 675                 seq_puts(seq, ",data=journal");
 676         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 677                 seq_puts(seq, ",data=ordered");
 678         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 679                 seq_puts(seq, ",data=writeback");
 680
 681         ext4_show_quota_options(seq, sb);
 682
 683         return 0;
 684 }
 685
 686
 687 static struct dentry *ext4_get_dentry(struct super_block *sb, void *vobjp)
 688 {
 689         __u32 *objp = vobjp;
 690         unsigned long ino = objp[0];
 691         __u32 generation = objp[1];
 692         struct inode *inode;
 693         struct dentry *result;
 694
 695         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 696                 return ERR_PTR(-ESTALE);
 697         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 698                 return ERR_PTR(-ESTALE);
 699
 700         /* iget isn't really right if the inode is currently unallocated!!
 701          *
 702          * ext4_read_inode will return a bad_inode if the inode had been
 703          * deleted, so we should be safe.
 704          *
 705          * Currently we don't know the generation for parent directory, so
 706          * a generation of 0 means "accept any"
 707          */
 708         inode = iget(sb, ino);
 709         if (inode == NULL)
 710                 return ERR_PTR(-ENOMEM);
 711         if (is_bad_inode(inode) ||
 712             (generation && inode->i_generation != generation)) {
 713                 iput(inode);
 714                 return ERR_PTR(-ESTALE);
 715         }
 716         /* now to find a dentry.
 717          * If possible, get a well-connected one
 718          */
 719         result = d_alloc_anon(inode);
 720         if (!result) {
 721                 iput(inode);
 722                 return ERR_PTR(-ENOMEM);
 723         }
 724         return result;
 725 }
 726
 727 #ifdef CONFIG_QUOTA
 728 #define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
 729 #define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 730
 731 static int ext4_dquot_initialize(struct inode *inode, int type);
 732 static int ext4_dquot_drop(struct inode *inode);
 733 static int ext4_write_dquot(struct dquot *dquot);
 734 static int ext4_acquire_dquot(struct dquot *dquot);
 735 static int ext4_release_dquot(struct dquot *dquot);
 736 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 737 static int ext4_write_info(struct super_block *sb, int type);
 738 static int ext4_quota_on(struct super_block *sb, int type, int format_id, char *path);
 739 static int ext4_quota_on_mount(struct super_block *sb, int type);
 740 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 741                                size_t len, loff_t off);
 742 static ssize_t ext4_quota_write(struct super_block *sb, int type,
 743                                 const char *data, size_t len, loff_t off);
 744
 745 static struct dquot_operations ext4_quota_operations = {
 746         .initialize     = ext4_dquot_initialize,
 747         .drop           = ext4_dquot_drop,
 748         .alloc_space    = dquot_alloc_space,
 749         .alloc_inode    = dquot_alloc_inode,
 750         .free_space     = dquot_free_space,
 751         .free_inode     = dquot_free_inode,
 752         .transfer       = dquot_transfer,
 753         .write_dquot    = ext4_write_dquot,
 754         .acquire_dquot  = ext4_acquire_dquot,
 755         .release_dquot  = ext4_release_dquot,
 756         .mark_dirty     = ext4_mark_dquot_dirty,
 757         .write_info     = ext4_write_info
 758 };
 759
 760 static struct quotactl_ops ext4_qctl_operations = {
 761         .quota_on       = ext4_quota_on,
 762         .quota_off      = vfs_quota_off,
 763         .quota_sync     = vfs_quota_sync,
 764         .get_info       = vfs_get_dqinfo,
 765         .set_info       = vfs_set_dqinfo,
 766         .get_dqblk      = vfs_get_dqblk,
 767         .set_dqblk      = vfs_set_dqblk
 768 };
 769 #endif
 770
 771 static const struct super_operations ext4_sops = {
 772         .alloc_inode    = ext4_alloc_inode,
 773         .destroy_inode  = ext4_destroy_inode,
 774         .read_inode     = ext4_read_inode,
 775         .write_inode    = ext4_write_inode,
 776         .dirty_inode    = ext4_dirty_inode,
 777         .delete_inode   = ext4_delete_inode,
 778         .put_super      = ext4_put_super,
 779         .write_super    = ext4_write_super,
 780         .sync_fs        = ext4_sync_fs,
 781         .write_super_lockfs = ext4_write_super_lockfs,
 782         .unlockfs       = ext4_unlockfs,
 783         .statfs         = ext4_statfs,
 784         .remount_fs     = ext4_remount,
 785         .clear_inode    = ext4_clear_inode,
 786         .show_options   = ext4_show_options,
 787 #ifdef CONFIG_QUOTA
 788         .quota_read     = ext4_quota_read,
 789         .quota_write    = ext4_quota_write,
 790 #endif
 791 };
 792
 793 static struct export_operations ext4_export_ops = {
 794         .get_parent = ext4_get_parent,
 795         .get_dentry = ext4_get_dentry,
 796 };
 797
 798 enum {
 799         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 800         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
 801         Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov,
 802         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
 803         Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
 804         Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
 805         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
 806         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 807         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
 808         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
 809         Opt_grpquota, Opt_extents, Opt_noextents,
 810 };
 811
 812 static match_table_t tokens = {
 813         {Opt_bsd_df, "bsddf"},
 814         {Opt_minix_df, "minixdf"},
 815         {Opt_grpid, "grpid"},
 816         {Opt_grpid, "bsdgroups"},
 817         {Opt_nogrpid, "nogrpid"},
 818         {Opt_nogrpid, "sysvgroups"},
 819         {Opt_resgid, "resgid=%u"},
 820         {Opt_resuid, "resuid=%u"},
 821         {Opt_sb, "sb=%u"},
 822         {Opt_err_cont, "errors=continue"},
 823         {Opt_err_panic, "errors=panic"},
 824         {Opt_err_ro, "errors=remount-ro"},
 825         {Opt_nouid32, "nouid32"},
 826         {Opt_nocheck, "nocheck"},
 827         {Opt_nocheck, "check=none"},
 828         {Opt_debug, "debug"},
 829         {Opt_oldalloc, "oldalloc"},
 830         {Opt_orlov, "orlov"},
 831         {Opt_user_xattr, "user_xattr"},
 832         {Opt_nouser_xattr, "nouser_xattr"},
 833         {Opt_acl, "acl"},
 834         {Opt_noacl, "noacl"},
 835         {Opt_reservation, "reservation"},
 836         {Opt_noreservation, "noreservation"},
 837         {Opt_noload, "noload"},
 838         {Opt_nobh, "nobh"},
 839         {Opt_bh, "bh"},
 840         {Opt_commit, "commit=%u"},
 841         {Opt_journal_update, "journal=update"},
 842         {Opt_journal_inum, "journal=%u"},
 843         {Opt_journal_dev, "journal_dev=%u"},
 844         {Opt_abort, "abort"},
 845         {Opt_data_journal, "data=journal"},
 846         {Opt_data_ordered, "data=ordered"},
 847         {Opt_data_writeback, "data=writeback"},
 848         {Opt_offusrjquota, "usrjquota="},
 849         {Opt_usrjquota, "usrjquota=%s"},
 850         {Opt_offgrpjquota, "grpjquota="},
 851         {Opt_grpjquota, "grpjquota=%s"},
 852         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
 853         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
 854         {Opt_grpquota, "grpquota"},
 855         {Opt_noquota, "noquota"},
 856         {Opt_quota, "quota"},
 857         {Opt_usrquota, "usrquota"},
 858         {Opt_barrier, "barrier=%u"},
 859         {Opt_extents, "extents"},
 860         {Opt_noextents, "noextents"},
 861         {Opt_err, NULL},
 862         {Opt_resize, "resize"},
 863 };
 864
 865 static ext4_fsblk_t get_sb_block(void **data)
 866 {
 867         ext4_fsblk_t    sb_block;
 868         char            *options = (char *) *data;
 869
 870         if (!options || strncmp(options, "sb=", 3) != 0)
 871                 return 1;       /* Default location */
 872         options += 3;
 873         /*todo: use simple_strtoll with >32bit ext4 */
 874         sb_block = simple_strtoul(options, &options, 0);
 875         if (*options && *options != ',') {
 876                 printk("EXT4-fs: Invalid sb specification: %s\n",
 877                        (char *) *data);
 878                 return 1;
 879         }
 880         if (*options == ',')
 881                 options++;
 882         *data = (void *) options;
 883         return sb_block;
 884 }
 885
 886 static int parse_options (char *options, struct super_block *sb,
 887                           unsigned int *inum, unsigned long *journal_devnum,
 888                           ext4_fsblk_t *n_blocks_count, int is_remount)
 889 {
 890         struct ext4_sb_info *sbi = EXT4_SB(sb);
 891         char * p;
 892         substring_t args[MAX_OPT_ARGS];
 893         int data_opt = 0;
 894         int option;
 895 #ifdef CONFIG_QUOTA
 896         int qtype;
 897         char *qname;
 898 #endif
 899
 900         if (!options)
 901                 return 1;
 902
 903         while ((p = strsep (&options, ",")) != NULL) {
 904                 int token;
 905                 if (!*p)
 906                         continue;
 907
 908                 token = match_token(p, tokens, args);
 909                 switch (token) {
 910                 case Opt_bsd_df:
 911                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 912                         break;
 913                 case Opt_minix_df:
 914                         set_opt (sbi->s_mount_opt, MINIX_DF);
 915                         break;
 916                 case Opt_grpid:
 917                         set_opt (sbi->s_mount_opt, GRPID);
 918                         break;
 919                 case Opt_nogrpid:
 920                         clear_opt (sbi->s_mount_opt, GRPID);
 921                         break;
 922                 case Opt_resuid:
 923                         if (match_int(&args[0], &option))
 924                                 return 0;
 925                         sbi->s_resuid = option;
 926                         break;
 927                 case Opt_resgid:
 928                         if (match_int(&args[0], &option))
 929                                 return 0;
 930                         sbi->s_resgid = option;
 931                         break;
 932                 case Opt_sb:
 933                         /* handled by get_sb_block() instead of here */
 934                         /* *sb_block = match_int(&args[0]); */
 935                         break;
 936                 case Opt_err_panic:
 937                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 938                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 939                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 940                         break;
 941                 case Opt_err_ro:
 942                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 943                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 944                         set_opt (sbi->s_mount_opt, ERRORS_RO);
 945                         break;
 946                 case Opt_err_cont:
 947                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 948                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 949                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
 950                         break;
 951                 case Opt_nouid32:
 952                         set_opt (sbi->s_mount_opt, NO_UID32);
 953                         break;
 954                 case Opt_nocheck:
 955                         clear_opt (sbi->s_mount_opt, CHECK);
 956                         break;
 957                 case Opt_debug:
 958                         set_opt (sbi->s_mount_opt, DEBUG);
 959                         break;
 960                 case Opt_oldalloc:
 961                         set_opt (sbi->s_mount_opt, OLDALLOC);
 962                         break;
 963                 case Opt_orlov:
 964                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 965                         break;
 966 #ifdef CONFIG_EXT4DEV_FS_XATTR
 967                 case Opt_user_xattr:
 968                         set_opt (sbi->s_mount_opt, XATTR_USER);
 969                         break;
 970                 case Opt_nouser_xattr:
 971                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 972                         break;
 973 #else
 974                 case Opt_user_xattr:
 975                 case Opt_nouser_xattr:
 976                         printk("EXT4 (no)user_xattr options not supported\n");
 977                         break;
 978 #endif
 979 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 980                 case Opt_acl:
 981                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 982                         break;
 983                 case Opt_noacl:
 984                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 985                         break;
 986 #else
 987                 case Opt_acl:
 988                 case Opt_noacl:
 989                         printk("EXT4 (no)acl options not supported\n");
 990                         break;
 991 #endif
 992                 case Opt_reservation:
 993                         set_opt(sbi->s_mount_opt, RESERVATION);
 994                         break;
 995                 case Opt_noreservation:
 996                         clear_opt(sbi->s_mount_opt, RESERVATION);
 997                         break;
 998                 case Opt_journal_update:
 999                         /* @@@ FIXME */
1000                         /* Eventually we will want to be able to create
1001                            a journal file here.  For now, only allow the
1002                            user to specify an existing inode to be the
1003                            journal file. */
1004                         if (is_remount) {
1005                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1006                                        "journal on remount\n");
1007                                 return 0;
1008                         }
1009                         set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
1010                         break;
1011                 case Opt_journal_inum:
1012                         if (is_remount) {
1013                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1014                                        "journal on remount\n");
1015                                 return 0;
1016                         }
1017                         if (match_int(&args[0], &option))
1018                                 return 0;
1019                         *inum = option;
1020                         break;
1021                 case Opt_journal_dev:
1022                         if (is_remount) {
1023                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1024                                        "journal on remount\n");
1025                                 return 0;
1026                         }
1027                         if (match_int(&args[0], &option))
1028                                 return 0;
1029                         *journal_devnum = option;
1030                         break;
1031                 case Opt_noload:
1032                         set_opt (sbi->s_mount_opt, NOLOAD);
1033                         break;
1034                 case Opt_commit:
1035                         if (match_int(&args[0], &option))
1036                                 return 0;
1037                         if (option < 0)
1038                                 return 0;
1039                         if (option == 0)
1040                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1041                         sbi->s_commit_interval = HZ * option;
1042                         break;
1043                 case Opt_data_journal:
1044                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1045                         goto datacheck;
1046                 case Opt_data_ordered:
1047                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1048                         goto datacheck;
1049                 case Opt_data_writeback:
1050                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1051                 datacheck:
1052                         if (is_remount) {
1053                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1054                                                 != data_opt) {
1055                                         printk(KERN_ERR
1056                                                 "EXT4-fs: cannot change data "
1057                                                 "mode on remount\n");
1058                                         return 0;
1059                                 }
1060                         } else {
1061                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1062                                 sbi->s_mount_opt |= data_opt;
1063                         }
1064                         break;
1065 #ifdef CONFIG_QUOTA
1066                 case Opt_usrjquota:
1067                         qtype = USRQUOTA;
1068                         goto set_qf_name;
1069                 case Opt_grpjquota:
1070                         qtype = GRPQUOTA;
1071 set_qf_name:
1072                         if (sb_any_quota_enabled(sb)) {
1073                                 printk(KERN_ERR
1074                                         "EXT4-fs: Cannot change journalled "
1075                                         "quota options when quota turned on.\n");
1076                                 return 0;
1077                         }
1078                         qname = match_strdup(&args[0]);
1079                         if (!qname) {
1080                                 printk(KERN_ERR
1081                                         "EXT4-fs: not enough memory for "
1082                                         "storing quotafile name.\n");
1083                                 return 0;
1084                         }
1085                         if (sbi->s_qf_names[qtype] &&
1086                             strcmp(sbi->s_qf_names[qtype], qname)) {
1087                                 printk(KERN_ERR
1088                                         "EXT4-fs: %s quota file already "
1089                                         "specified.\n", QTYPE2NAME(qtype));
1090                                 kfree(qname);
1091                                 return 0;
1092                         }
1093                         sbi->s_qf_names[qtype] = qname;
1094                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1095                                 printk(KERN_ERR
1096                                         "EXT4-fs: quotafile must be on "
1097                                         "filesystem root.\n");
1098                                 kfree(sbi->s_qf_names[qtype]);
1099                                 sbi->s_qf_names[qtype] = NULL;
1100                                 return 0;
1101                         }
1102                         set_opt(sbi->s_mount_opt, QUOTA);
1103                         break;
1104                 case Opt_offusrjquota:
1105                         qtype = USRQUOTA;
1106                         goto clear_qf_name;
1107                 case Opt_offgrpjquota:
1108                         qtype = GRPQUOTA;
1109 clear_qf_name:
1110                         if (sb_any_quota_enabled(sb)) {
1111                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1112                                         "journalled quota options when "
1113                                         "quota turned on.\n");
1114                                 return 0;
1115                         }
1116                         /*
1117                          * The space will be released later when all options
1118                          * are confirmed to be correct
1119                          */
1120                         sbi->s_qf_names[qtype] = NULL;
1121                         break;
1122                 case Opt_jqfmt_vfsold:
1123                         sbi->s_jquota_fmt = QFMT_VFS_OLD;
1124                         break;
1125                 case Opt_jqfmt_vfsv0:
1126                         sbi->s_jquota_fmt = QFMT_VFS_V0;
1127                         break;
1128                 case Opt_quota:
1129                 case Opt_usrquota:
1130                         set_opt(sbi->s_mount_opt, QUOTA);
1131                         set_opt(sbi->s_mount_opt, USRQUOTA);
1132                         break;
1133                 case Opt_grpquota:
1134                         set_opt(sbi->s_mount_opt, QUOTA);
1135                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1136                         break;
1137                 case Opt_noquota:
1138                         if (sb_any_quota_enabled(sb)) {
1139                                 printk(KERN_ERR "EXT4-fs: Cannot change quota "
1140                                         "options when quota turned on.\n");
1141                                 return 0;
1142                         }
1143                         clear_opt(sbi->s_mount_opt, QUOTA);
1144                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1145                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1146                         break;
1147 #else
1148                 case Opt_quota:
1149                 case Opt_usrquota:
1150                 case Opt_grpquota:
1151                 case Opt_usrjquota:
1152                 case Opt_grpjquota:
1153                 case Opt_offusrjquota:
1154                 case Opt_offgrpjquota:
1155                 case Opt_jqfmt_vfsold:
1156                 case Opt_jqfmt_vfsv0:
1157                         printk(KERN_ERR
1158                                 "EXT4-fs: journalled quota options not "
1159                                 "supported.\n");
1160                         break;
1161                 case Opt_noquota:
1162                         break;
1163 #endif
1164                 case Opt_abort:
1165                         set_opt(sbi->s_mount_opt, ABORT);
1166                         break;
1167                 case Opt_barrier:
1168                         if (match_int(&args[0], &option))
1169                                 return 0;
1170                         if (option)
1171                                 set_opt(sbi->s_mount_opt, BARRIER);
1172                         else
1173                                 clear_opt(sbi->s_mount_opt, BARRIER);
1174                         break;
1175                 case Opt_ignore:
1176                         break;
1177                 case Opt_resize:
1178                         if (!is_remount) {
1179                                 printk("EXT4-fs: resize option only available "
1180                                         "for remount\n");
1181                                 return 0;
1182                         }
1183                         if (match_int(&args[0], &option) != 0)
1184                                 return 0;
1185                         *n_blocks_count = option;
1186                         break;
1187                 case Opt_nobh:
1188                         set_opt(sbi->s_mount_opt, NOBH);
1189                         break;
1190                 case Opt_bh:
1191                         clear_opt(sbi->s_mount_opt, NOBH);
1192                         break;
1193                 case Opt_extents:
1194                         set_opt (sbi->s_mount_opt, EXTENTS);
1195                         break;
1196                 case Opt_noextents:
1197                         clear_opt (sbi->s_mount_opt, EXTENTS);
1198                         break;
1199                 default:
1200                         printk (KERN_ERR
1201                                 "EXT4-fs: Unrecognized mount option \"%s\" "
1202                                 "or missing value\n", p);
1203                         return 0;
1204                 }
1205         }
1206 #ifdef CONFIG_QUOTA
1207         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1208                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1209                      sbi->s_qf_names[USRQUOTA])
1210                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1211
1212                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1213                      sbi->s_qf_names[GRPQUOTA])
1214                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1215
1216                 if ((sbi->s_qf_names[USRQUOTA] &&
1217                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1218                     (sbi->s_qf_names[GRPQUOTA] &&
1219                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1220                         printk(KERN_ERR "EXT4-fs: old and new quota "
1221                                         "format mixing.\n");
1222                         return 0;
1223                 }
1224
1225                 if (!sbi->s_jquota_fmt) {
1226                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1227                                         "not specified.\n");
1228                         return 0;
1229                 }
1230         } else {
1231                 if (sbi->s_jquota_fmt) {
1232                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1233                                         "specified with no journalling "
1234                                         "enabled.\n");
1235                         return 0;
1236                 }
1237         }
1238 #endif
1239         return 1;
1240 }
1241
1242 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1243                             int read_only)
1244 {
1245         struct ext4_sb_info *sbi = EXT4_SB(sb);
1246         int res = 0;
1247
1248         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1249                 printk (KERN_ERR "EXT4-fs warning: revision level too high, "
1250                         "forcing read-only mode\n");
1251                 res = MS_RDONLY;
1252         }
1253         if (read_only)
1254                 return res;
1255         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1256                 printk (KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1257                         "running e2fsck is recommended\n");
1258         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1259                 printk (KERN_WARNING
1260                         "EXT4-fs warning: mounting fs with errors, "
1261                         "running e2fsck is recommended\n");
1262         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1263                  le16_to_cpu(es->s_mnt_count) >=
1264                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1265                 printk (KERN_WARNING
1266                         "EXT4-fs warning: maximal mount count reached, "
1267                         "running e2fsck is recommended\n");
1268         else if (le32_to_cpu(es->s_checkinterval) &&
1269                 (le32_to_cpu(es->s_lastcheck) +
1270                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1271                 printk (KERN_WARNING
1272                         "EXT4-fs warning: checktime reached, "
1273                         "running e2fsck is recommended\n");
1274 #if 0
1275                 /* @@@ We _will_ want to clear the valid bit if we find
1276                  * inconsistencies, to force a fsck at reboot.  But for
1277                  * a plain journaled filesystem we can keep it set as
1278                  * valid forever! :)
1279                  */
1280         es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT4_VALID_FS);
1281 #endif
1282         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1283                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1284         es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
1285         es->s_mtime = cpu_to_le32(get_seconds());
1286         ext4_update_dynamic_rev(sb);
1287         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1288
1289         ext4_commit_super(sb, es, 1);
1290         if (test_opt(sb, DEBUG))
1291                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%lu, "
1292                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1293                         sb->s_blocksize,
1294                         sbi->s_groups_count,
1295                         EXT4_BLOCKS_PER_GROUP(sb),
1296                         EXT4_INODES_PER_GROUP(sb),
1297                         sbi->s_mount_opt);
1298
1299         printk(KERN_INFO "EXT4 FS on %s, ", sb->s_id);
1300         if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
1301                 char b[BDEVNAME_SIZE];
1302
1303                 printk("external journal on %s\n",
1304                         bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
1305         } else {
1306                 printk("internal journal\n");
1307         }
1308         return res;
1309 }
1310
1311 /* Called at mount-time, super-block is locked */
1312 static int ext4_check_descriptors (struct super_block * sb)
1313 {
1314         struct ext4_sb_info *sbi = EXT4_SB(sb);
1315         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1316         ext4_fsblk_t last_block;
1317         ext4_fsblk_t block_bitmap;
1318         ext4_fsblk_t inode_bitmap;
1319         ext4_fsblk_t inode_table;
1320         struct ext4_group_desc * gdp = NULL;
1321         int desc_block = 0;
1322         int i;
1323
1324         ext4_debug ("Checking group descriptors");
1325
1326         for (i = 0; i < sbi->s_groups_count; i++)
1327         {
1328                 if (i == sbi->s_groups_count - 1)
1329                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1330                 else
1331                         last_block = first_block +
1332                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1333
1334                 if ((i % EXT4_DESC_PER_BLOCK(sb)) == 0)
1335                         gdp = (struct ext4_group_desc *)
1336                                         sbi->s_group_desc[desc_block++]->b_data;
1337                 block_bitmap = ext4_block_bitmap(sb, gdp);
1338                 if (block_bitmap < first_block || block_bitmap > last_block)
1339                 {
1340                         ext4_error (sb, "ext4_check_descriptors",
1341                                     "Block bitmap for group %d"
1342                                     " not in group (block %llu)!",
1343                                     i, block_bitmap);
1344                         return 0;
1345                 }
1346                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1347                 if (inode_bitmap < first_block || inode_bitmap > last_block)
1348                 {
1349                         ext4_error (sb, "ext4_check_descriptors",
1350                                     "Inode bitmap for group %d"
1351                                     " not in group (block %llu)!",
1352                                     i, inode_bitmap);
1353                         return 0;
1354                 }
1355                 inode_table = ext4_inode_table(sb, gdp);
1356                 if (inode_table < first_block ||
1357                     inode_table + sbi->s_itb_per_group - 1 > last_block)
1358                 {
1359                         ext4_error (sb, "ext4_check_descriptors",
1360                                     "Inode table for group %d"
1361                                     " not in group (block %llu)!",
1362                                     i, inode_table);
1363                         return 0;
1364                 }
1365                 first_block += EXT4_BLOCKS_PER_GROUP(sb);
1366                 gdp = (struct ext4_group_desc *)
1367                         ((__u8 *)gdp + EXT4_DESC_SIZE(sb));
1368         }
1369
1370         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1371         sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
1372         return 1;
1373 }
1374
1375
1376 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1377  * the superblock) which were deleted from all directories, but held open by
1378  * a process at the time of a crash.  We walk the list and try to delete these
1379  * inodes at recovery time (only with a read-write filesystem).
1380  *
1381  * In order to keep the orphan inode chain consistent during traversal (in
1382  * case of crash during recovery), we link each inode into the superblock
1383  * orphan list_head and handle it the same way as an inode deletion during
1384  * normal operation (which journals the operations for us).
1385  *
1386  * We only do an iget() and an iput() on each inode, which is very safe if we
1387  * accidentally point at an in-use or already deleted inode.  The worst that
1388  * can happen in this case is that we get a "bit already cleared" message from
1389  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1390  * e2fsck was run on this filesystem, and it must have already done the orphan
1391  * inode cleanup for us, so we can safely abort without any further action.
1392  */
1393 static void ext4_orphan_cleanup (struct super_block * sb,
1394                                  struct ext4_super_block * es)
1395 {
1396         unsigned int s_flags = sb->s_flags;
1397         int nr_orphans = 0, nr_truncates = 0;
1398 #ifdef CONFIG_QUOTA
1399         int i;
1400 #endif
1401         if (!es->s_last_orphan) {
1402                 jbd_debug(4, "no orphan inodes to clean up\n");
1403                 return;
1404         }
1405
1406         if (bdev_read_only(sb->s_bdev)) {
1407                 printk(KERN_ERR "EXT4-fs: write access "
1408                         "unavailable, skipping orphan cleanup.\n");
1409                 return;
1410         }
1411
1412         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1413                 if (es->s_last_orphan)
1414                         jbd_debug(1, "Errors on filesystem, "
1415                                   "clearing orphan list.\n");
1416                 es->s_last_orphan = 0;
1417                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1418                 return;
1419         }
1420
1421         if (s_flags & MS_RDONLY) {
1422                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1423                        sb->s_id);
1424                 sb->s_flags &= ~MS_RDONLY;
1425         }
1426 #ifdef CONFIG_QUOTA
1427         /* Needed for iput() to work correctly and not trash data */
1428         sb->s_flags |= MS_ACTIVE;
1429         /* Turn on quotas so that they are updated correctly */
1430         for (i = 0; i < MAXQUOTAS; i++) {
1431                 if (EXT4_SB(sb)->s_qf_names[i]) {
1432                         int ret = ext4_quota_on_mount(sb, i);
1433                         if (ret < 0)
1434                                 printk(KERN_ERR
1435                                         "EXT4-fs: Cannot turn on journalled "
1436                                         "quota: error %d\n", ret);
1437                 }
1438         }
1439 #endif
1440
1441         while (es->s_last_orphan) {
1442                 struct inode *inode;
1443
1444                 if (!(inode =
1445                       ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan)))) {
1446                         es->s_last_orphan = 0;
1447                         break;
1448                 }
1449
1450                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1451                 DQUOT_INIT(inode);
1452                 if (inode->i_nlink) {
1453                         printk(KERN_DEBUG
1454                                 "%s: truncating inode %lu to %Ld bytes\n",
1455                                 __FUNCTION__, inode->i_ino, inode->i_size);
1456                         jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
1457                                   inode->i_ino, inode->i_size);
1458                         ext4_truncate(inode);
1459                         nr_truncates++;
1460                 } else {
1461                         printk(KERN_DEBUG
1462                                 "%s: deleting unreferenced inode %lu\n",
1463                                 __FUNCTION__, inode->i_ino);
1464                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1465                                   inode->i_ino);
1466                         nr_orphans++;
1467                 }
1468                 iput(inode);  /* The delete magic happens here! */
1469         }
1470
1471 #define PLURAL(x) (x), ((x)==1) ? "" : "s"
1472
1473         if (nr_orphans)
1474                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1475                        sb->s_id, PLURAL(nr_orphans));
1476         if (nr_truncates)
1477                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1478                        sb->s_id, PLURAL(nr_truncates));
1479 #ifdef CONFIG_QUOTA
1480         /* Turn quotas off */
1481         for (i = 0; i < MAXQUOTAS; i++) {
1482                 if (sb_dqopt(sb)->files[i])
1483                         vfs_quota_off(sb, i);
1484         }
1485 #endif
1486         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1487 }
1488
1489 /*
1490  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
1491  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
1492  * We need to be 1 filesystem block less than the 2^32 sector limit.
1493  */
1494 static loff_t ext4_max_size(int bits)
1495 {
1496         loff_t res = EXT4_NDIR_BLOCKS;
1497         /* This constant is calculated to be the largest file size for a
1498          * dense, 4k-blocksize file such that the total number of
1499          * sectors in the file, including data and all indirect blocks,
1500          * does not exceed 2^32. */
1501         const loff_t upper_limit = 0x1ff7fffd000LL;
1502
1503         res += 1LL << (bits-2);
1504         res += 1LL << (2*(bits-2));
1505         res += 1LL << (3*(bits-2));
1506         res <<= bits;
1507         if (res > upper_limit)
1508                 res = upper_limit;
1509         return res;
1510 }
1511
1512 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1513                                 ext4_fsblk_t logical_sb_block, int nr)
1514 {
1515         struct ext4_sb_info *sbi = EXT4_SB(sb);
1516         unsigned long bg, first_meta_bg;
1517         int has_super = 0;
1518
1519         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1520
1521         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1522             nr < first_meta_bg)
1523                 return logical_sb_block + nr + 1;
1524         bg = sbi->s_desc_per_block * nr;
1525         if (ext4_bg_has_super(sb, bg))
1526                 has_super = 1;
1527         return (has_super + ext4_group_first_block_no(sb, bg));
1528 }
1529
1530
1531 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
1532 {
1533         struct buffer_head * bh;
1534         struct ext4_super_block *es = NULL;
1535         struct ext4_sb_info *sbi;
1536         ext4_fsblk_t block;
1537         ext4_fsblk_t sb_block = get_sb_block(&data);
1538         ext4_fsblk_t logical_sb_block;
1539         unsigned long offset = 0;
1540         unsigned int journal_inum = 0;
1541         unsigned long journal_devnum = 0;
1542         unsigned long def_mount_opts;
1543         struct inode *root;
1544         int blocksize;
1545         int hblock;
1546         int db_count;
1547         int i;
1548         int needs_recovery;
1549         __le32 features;
1550         __u64 blocks_count;
1551         int err;
1552
1553         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1554         if (!sbi)
1555                 return -ENOMEM;
1556         sb->s_fs_info = sbi;
1557         sbi->s_mount_opt = 0;
1558         sbi->s_resuid = EXT4_DEF_RESUID;
1559         sbi->s_resgid = EXT4_DEF_RESGID;
1560         sbi->s_sb_block = sb_block;
1561
1562         unlock_kernel();
1563
1564         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1565         if (!blocksize) {
1566                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1567                 goto out_fail;
1568         }
1569
1570         /*
1571          * The ext4 superblock will not be buffer aligned for other than 1kB
1572          * block sizes.  We need to calculate the offset from buffer start.
1573          */
1574         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1575                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1576                 offset = do_div(logical_sb_block, blocksize);
1577         } else {
1578                 logical_sb_block = sb_block;
1579         }
1580
1581         if (!(bh = sb_bread(sb, logical_sb_block))) {
1582                 printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
1583                 goto out_fail;
1584         }
1585         /*
1586          * Note: s_es must be initialized as soon as possible because
1587          *       some ext4 macro-instructions depend on its value
1588          */
1589         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1590         sbi->s_es = es;
1591         sb->s_magic = le16_to_cpu(es->s_magic);
1592         if (sb->s_magic != EXT4_SUPER_MAGIC)
1593                 goto cantfind_ext4;
1594
1595         /* Set defaults before we parse the mount options */
1596         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1597         if (def_mount_opts & EXT4_DEFM_DEBUG)
1598                 set_opt(sbi->s_mount_opt, DEBUG);
1599         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1600                 set_opt(sbi->s_mount_opt, GRPID);
1601         if (def_mount_opts & EXT4_DEFM_UID16)
1602                 set_opt(sbi->s_mount_opt, NO_UID32);
1603 #ifdef CONFIG_EXT4DEV_FS_XATTR
1604         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1605                 set_opt(sbi->s_mount_opt, XATTR_USER);
1606 #endif
1607 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1608         if (def_mount_opts & EXT4_DEFM_ACL)
1609                 set_opt(sbi->s_mount_opt, POSIX_ACL);
1610 #endif
1611         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1612                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1613         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1614                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1615         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1616                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1617
1618         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1619                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1620         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_RO)
1621                 set_opt(sbi->s_mount_opt, ERRORS_RO);
1622         else
1623                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
1624
1625         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1626         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1627
1628         set_opt(sbi->s_mount_opt, RESERVATION);
1629
1630         /*
1631          * turn on extents feature by default in ext4 filesystem
1632          * User -o noextents to turn it off
1633          */
1634         set_opt(sbi->s_mount_opt, EXTENTS);
1635
1636         if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
1637                             NULL, 0))
1638                 goto failed_mount;
1639
1640         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1641                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1642
1643         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1644             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1645              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1646              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1647                 printk(KERN_WARNING
1648                        "EXT4-fs warning: feature flags set on rev 0 fs, "
1649                        "running e2fsck is recommended\n");
1650         /*
1651          * Check feature flags regardless of the revision level, since we
1652          * previously didn't change the revision level when setting the flags,
1653          * so there is a chance incompat flags are set on a rev 0 filesystem.
1654          */
1655         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
1656         if (features) {
1657                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
1658                        "unsupported optional features (%x).\n",
1659                        sb->s_id, le32_to_cpu(features));
1660                 goto failed_mount;
1661         }
1662         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
1663         if (!(sb->s_flags & MS_RDONLY) && features) {
1664                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
1665                        "unsupported optional features (%x).\n",
1666                        sb->s_id, le32_to_cpu(features));
1667                 goto failed_mount;
1668         }
1669         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
1670
1671         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
1672             blocksize > EXT4_MAX_BLOCK_SIZE) {
1673                 printk(KERN_ERR
1674                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
1675                        blocksize, sb->s_id);
1676                 goto failed_mount;
1677         }
1678
1679         hblock = bdev_hardsect_size(sb->s_bdev);
1680         if (sb->s_blocksize != blocksize) {
1681                 /*
1682                  * Make sure the blocksize for the filesystem is larger
1683                  * than the hardware sectorsize for the machine.
1684                  */
1685                 if (blocksize < hblock) {
1686                         printk(KERN_ERR "EXT4-fs: blocksize %d too small for "
1687                                "device blocksize %d.\n", blocksize, hblock);
1688                         goto failed_mount;
1689                 }
1690
1691                 brelse (bh);
1692                 sb_set_blocksize(sb, blocksize);
1693                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1694                 offset = do_div(logical_sb_block, blocksize);
1695                 bh = sb_bread(sb, logical_sb_block);
1696                 if (!bh) {
1697                         printk(KERN_ERR
1698                                "EXT4-fs: Can't read superblock on 2nd try.\n");
1699                         goto failed_mount;
1700                 }
1701                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
1702                 sbi->s_es = es;
1703                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
1704                         printk (KERN_ERR
1705                                 "EXT4-fs: Magic mismatch, very weird !\n");
1706                         goto failed_mount;
1707                 }
1708         }
1709
1710         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
1711
1712         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
1713                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
1714                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
1715         } else {
1716                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1717                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1718                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
1719                     (!is_power_of_2(sbi->s_inode_size)) ||
1720                     (sbi->s_inode_size > blocksize)) {
1721                         printk (KERN_ERR
1722                                 "EXT4-fs: unsupported inode size: %d\n",
1723                                 sbi->s_inode_size);
1724                         goto failed_mount;
1725                 }
1726                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
1727                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
1728         }
1729         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
1730         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
1731                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
1732                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
1733                     !is_power_of_2(sbi->s_desc_size)) {
1734                         printk(KERN_ERR
1735                                "EXT4-fs: unsupported descriptor size %lu\n",
1736                                sbi->s_desc_size);
1737                         goto failed_mount;
1738                 }
1739         } else
1740                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
1741         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1742         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1743         if (EXT4_INODE_SIZE(sb) == 0)
1744                 goto cantfind_ext4;
1745         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
1746         if (sbi->s_inodes_per_block == 0)
1747                 goto cantfind_ext4;
1748         sbi->s_itb_per_group = sbi->s_inodes_per_group /
1749                                         sbi->s_inodes_per_block;
1750         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
1751         sbi->s_sbh = bh;
1752         sbi->s_mount_state = le16_to_cpu(es->s_state);
1753         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
1754         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
1755         for (i=0; i < 4; i++)
1756                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
1757         sbi->s_def_hash_version = es->s_def_hash_version;
1758
1759         if (sbi->s_blocks_per_group > blocksize * 8) {
1760                 printk (KERN_ERR
1761                         "EXT4-fs: #blocks per group too big: %lu\n",
1762                         sbi->s_blocks_per_group);
1763                 goto failed_mount;
1764         }
1765         if (sbi->s_inodes_per_group > blocksize * 8) {
1766                 printk (KERN_ERR
1767                         "EXT4-fs: #inodes per group too big: %lu\n",
1768                         sbi->s_inodes_per_group);
1769                 goto failed_mount;
1770         }
1771
1772         if (ext4_blocks_count(es) >
1773                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1774                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
1775                         " too large to mount safely\n", sb->s_id);
1776                 if (sizeof(sector_t) < 8)
1777                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
1778                                         "enabled\n");
1779                 goto failed_mount;
1780         }
1781
1782         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
1783                 goto cantfind_ext4;
1784         blocks_count = (ext4_blocks_count(es) -
1785                         le32_to_cpu(es->s_first_data_block) +
1786                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
1787         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
1788         sbi->s_groups_count = blocks_count;
1789         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
1790                    EXT4_DESC_PER_BLOCK(sb);
1791         sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
1792                                     GFP_KERNEL);
1793         if (sbi->s_group_desc == NULL) {
1794                 printk (KERN_ERR "EXT4-fs: not enough memory\n");
1795                 goto failed_mount;
1796         }
1797
1798         bgl_lock_init(&sbi->s_blockgroup_lock);
1799
1800         for (i = 0; i < db_count; i++) {
1801                 block = descriptor_loc(sb, logical_sb_block, i);
1802                 sbi->s_group_desc[i] = sb_bread(sb, block);
1803                 if (!sbi->s_group_desc[i]) {
1804                         printk (KERN_ERR "EXT4-fs: "
1805                                 "can't read group descriptor %d\n", i);
1806                         db_count = i;
1807                         goto failed_mount2;
1808                 }
1809         }
1810         if (!ext4_check_descriptors (sb)) {
1811                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
1812                 goto failed_mount2;
1813         }
1814         sbi->s_gdb_count = db_count;
1815         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1816         spin_lock_init(&sbi->s_next_gen_lock);
1817
1818         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1819                         ext4_count_free_blocks(sb));
1820         if (!err) {
1821                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1822                                 ext4_count_free_inodes(sb));
1823         }
1824         if (!err) {
1825                 err = percpu_counter_init(&sbi->s_dirs_counter,
1826                                 ext4_count_dirs(sb));
1827         }
1828         if (err) {
1829                 printk(KERN_ERR "EXT4-fs: insufficient memory\n");
1830                 goto failed_mount3;
1831         }
1832
1833         /* per fileystem reservation list head & lock */
1834         spin_lock_init(&sbi->s_rsv_window_lock);
1835         sbi->s_rsv_window_root = RB_ROOT;
1836         /* Add a single, static dummy reservation to the start of the
1837          * reservation window list --- it gives us a placeholder for
1838          * append-at-start-of-list which makes the allocation logic
1839          * _much_ simpler. */
1840         sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1841         sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1842         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1843         sbi->s_rsv_window_head.rsv_goal_size = 0;
1844         ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
1845
1846         /*
1847          * set up enough so that it can read an inode
1848          */
1849         sb->s_op = &ext4_sops;
1850         sb->s_export_op = &ext4_export_ops;
1851         sb->s_xattr = ext4_xattr_handlers;
1852 #ifdef CONFIG_QUOTA
1853         sb->s_qcop = &ext4_qctl_operations;
1854         sb->dq_op = &ext4_quota_operations;
1855 #endif
1856         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
1857
1858         sb->s_root = NULL;
1859
1860         needs_recovery = (es->s_last_orphan != 0 ||
1861                           EXT4_HAS_INCOMPAT_FEATURE(sb,
1862                                     EXT4_FEATURE_INCOMPAT_RECOVER));
1863
1864         /*
1865          * The first inode we look at is the journal inode.  Don't try
1866          * root first: it may be modified in the journal!
1867          */
1868         if (!test_opt(sb, NOLOAD) &&
1869             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
1870                 if (ext4_load_journal(sb, es, journal_devnum))
1871                         goto failed_mount3;
1872         } else if (journal_inum) {
1873                 if (ext4_create_journal(sb, es, journal_inum))
1874                         goto failed_mount3;
1875         } else {
1876                 if (!silent)
1877                         printk (KERN_ERR
1878                                 "ext4: No journal on filesystem on %s\n",
1879                                 sb->s_id);
1880                 goto failed_mount3;
1881         }
1882
1883         if (ext4_blocks_count(es) > 0xffffffffULL &&
1884             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
1885                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
1886                 printk(KERN_ERR "ext4: Failed to set 64-bit journal feature\n");
1887                 goto failed_mount4;
1888         }
1889
1890         /* We have now updated the journal if required, so we can
1891          * validate the data journaling mode. */
1892         switch (test_opt(sb, DATA_FLAGS)) {
1893         case 0:
1894                 /* No mode set, assume a default based on the journal
1895                  * capabilities: ORDERED_DATA if the journal can
1896                  * cope, else JOURNAL_DATA
1897                  */
1898                 if (jbd2_journal_check_available_features
1899                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
1900                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
1901                 else
1902                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
1903                 break;
1904
1905         case EXT4_MOUNT_ORDERED_DATA:
1906         case EXT4_MOUNT_WRITEBACK_DATA:
1907                 if (!jbd2_journal_check_available_features
1908                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
1909                         printk(KERN_ERR "EXT4-fs: Journal does not support "
1910                                "requested data journaling mode\n");
1911                         goto failed_mount4;
1912                 }
1913         default:
1914                 break;
1915         }
1916
1917         if (test_opt(sb, NOBH)) {
1918                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
1919                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
1920                                 "its supported only with writeback mode\n");
1921                         clear_opt(sbi->s_mount_opt, NOBH);
1922                 }
1923         }
1924         /*
1925          * The jbd2_journal_load will have done any necessary log recovery,
1926          * so we can safely mount the rest of the filesystem now.
1927          */
1928
1929         root = iget(sb, EXT4_ROOT_INO);
1930         sb->s_root = d_alloc_root(root);
1931         if (!sb->s_root) {
1932                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
1933                 iput(root);
1934                 goto failed_mount4;
1935         }
1936         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1937                 dput(sb->s_root);
1938                 sb->s_root = NULL;
1939                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
1940                 goto failed_mount4;
1941         }
1942
1943         ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1944
1945         /* determine the minimum size of new large inodes, if present */
1946         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
1947                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
1948                                                      EXT4_GOOD_OLD_INODE_SIZE;
1949                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1950                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
1951                         if (sbi->s_want_extra_isize <
1952                             le16_to_cpu(es->s_want_extra_isize))
1953                                 sbi->s_want_extra_isize =
1954                                         le16_to_cpu(es->s_want_extra_isize);
1955                         if (sbi->s_want_extra_isize <
1956                             le16_to_cpu(es->s_min_extra_isize))
1957                                 sbi->s_want_extra_isize =
1958                                         le16_to_cpu(es->s_min_extra_isize);
1959                 }
1960         }
1961         /* Check if enough inode space is available */
1962         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
1963                                                         sbi->s_inode_size) {
1964                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
1965                                                        EXT4_GOOD_OLD_INODE_SIZE;
1966                 printk(KERN_INFO "EXT4-fs: required extra inode space not"
1967                         "available.\n");
1968         }
1969
1970         /*
1971          * akpm: core read_super() calls in here with the superblock locked.
1972          * That deadlocks, because orphan cleanup needs to lock the superblock
1973          * in numerous places.  Here we just pop the lock - it's relatively
1974          * harmless, because we are now ready to accept write_super() requests,
1975          * and aviro says that's the only reason for hanging onto the
1976          * superblock lock.
1977          */
1978         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
1979         ext4_orphan_cleanup(sb, es);
1980         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
1981         if (needs_recovery)
1982                 printk (KERN_INFO "EXT4-fs: recovery complete.\n");
1983         ext4_mark_recovery_complete(sb, es);
1984         printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
1985                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
1986                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
1987                 "writeback");
1988
1989         ext4_ext_init(sb);
1990
1991         lock_kernel();
1992         return 0;
1993
1994 cantfind_ext4:
1995         if (!silent)
1996                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
1997                        sb->s_id);
1998         goto failed_mount;
1999
2000 failed_mount4:
2001         jbd2_journal_destroy(sbi->s_journal);
2002 failed_mount3:
2003         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2004         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2005         percpu_counter_destroy(&sbi->s_dirs_counter);
2006 failed_mount2:
2007         for (i = 0; i < db_count; i++)
2008                 brelse(sbi->s_group_desc[i]);
2009         kfree(sbi->s_group_desc);
2010 failed_mount:
2011 #ifdef CONFIG_QUOTA
2012         for (i = 0; i < MAXQUOTAS; i++)
2013                 kfree(sbi->s_qf_names[i]);
2014 #endif
2015         ext4_blkdev_remove(sbi);
2016         brelse(bh);
2017 out_fail:
2018         sb->s_fs_info = NULL;
2019         kfree(sbi);
2020         lock_kernel();
2021         return -EINVAL;
2022 }
2023
2024 /*
2025  * Setup any per-fs journal parameters now.  We'll do this both on
2026  * initial mount, once the journal has been initialised but before we've
2027  * done any recovery; and again on any subsequent remount.
2028  */
2029 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2030 {
2031         struct ext4_sb_info *sbi = EXT4_SB(sb);
2032
2033         if (sbi->s_commit_interval)
2034                 journal->j_commit_interval = sbi->s_commit_interval;
2035         /* We could also set up an ext4-specific default for the commit
2036          * interval here, but for now we'll just fall back to the jbd
2037          * default. */
2038
2039         spin_lock(&journal->j_state_lock);
2040         if (test_opt(sb, BARRIER))
2041                 journal->j_flags |= JBD2_BARRIER;
2042         else
2043                 journal->j_flags &= ~JBD2_BARRIER;
2044         spin_unlock(&journal->j_state_lock);
2045 }
2046
2047 static journal_t *ext4_get_journal(struct super_block *sb,
2048                                    unsigned int journal_inum)
2049 {
2050         struct inode *journal_inode;
2051         journal_t *journal;
2052
2053         /* First, test for the existence of a valid inode on disk.  Bad
2054          * things happen if we iget() an unused inode, as the subsequent
2055          * iput() will try to delete it. */
2056
2057         journal_inode = iget(sb, journal_inum);
2058         if (!journal_inode) {
2059                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
2060                 return NULL;
2061         }
2062         if (!journal_inode->i_nlink) {
2063                 make_bad_inode(journal_inode);
2064                 iput(journal_inode);
2065                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
2066                 return NULL;
2067         }
2068
2069         jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
2070                   journal_inode, journal_inode->i_size);
2071         if (is_bad_inode(journal_inode) || !S_ISREG(journal_inode->i_mode)) {
2072                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
2073                 iput(journal_inode);
2074                 return NULL;
2075         }
2076
2077         journal = jbd2_journal_init_inode(journal_inode);
2078         if (!journal) {
2079                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
2080                 iput(journal_inode);
2081                 return NULL;
2082         }
2083         journal->j_private = sb;
2084         ext4_init_journal_params(sb, journal);
2085         return journal;
2086 }
2087
2088 static journal_t *ext4_get_dev_journal(struct super_block *sb,
2089                                        dev_t j_dev)
2090 {
2091         struct buffer_head * bh;
2092         journal_t *journal;
2093         ext4_fsblk_t start;
2094         ext4_fsblk_t len;
2095         int hblock, blocksize;
2096         ext4_fsblk_t sb_block;
2097         unsigned long offset;
2098         struct ext4_super_block * es;
2099         struct block_device *bdev;
2100
2101         bdev = ext4_blkdev_get(j_dev);
2102         if (bdev == NULL)
2103                 return NULL;
2104
2105         if (bd_claim(bdev, sb)) {
2106                 printk(KERN_ERR
2107                         "EXT4: failed to claim external journal device.\n");
2108                 blkdev_put(bdev);
2109                 return NULL;
2110         }
2111
2112         blocksize = sb->s_blocksize;
2113         hblock = bdev_hardsect_size(bdev);
2114         if (blocksize < hblock) {
2115                 printk(KERN_ERR
2116                         "EXT4-fs: blocksize too small for journal device.\n");
2117                 goto out_bdev;
2118         }
2119
2120         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2121         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2122         set_blocksize(bdev, blocksize);
2123         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2124                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2125                        "external journal\n");
2126                 goto out_bdev;
2127         }
2128
2129         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2130         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2131             !(le32_to_cpu(es->s_feature_incompat) &
2132               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2133                 printk(KERN_ERR "EXT4-fs: external journal has "
2134                                         "bad superblock\n");
2135                 brelse(bh);
2136                 goto out_bdev;
2137         }
2138
2139         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2140                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2141                 brelse(bh);
2142                 goto out_bdev;
2143         }
2144
2145         len = ext4_blocks_count(es);
2146         start = sb_block + 1;
2147         brelse(bh);     /* we're done with the superblock */
2148
2149         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2150                                         start, len, blocksize);
2151         if (!journal) {
2152                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2153                 goto out_bdev;
2154         }
2155         journal->j_private = sb;
2156         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2157         wait_on_buffer(journal->j_sb_buffer);
2158         if (!buffer_uptodate(journal->j_sb_buffer)) {
2159                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2160                 goto out_journal;
2161         }
2162         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2163                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2164                                         "user (unsupported) - %d\n",
2165                         be32_to_cpu(journal->j_superblock->s_nr_users));
2166                 goto out_journal;
2167         }
2168         EXT4_SB(sb)->journal_bdev = bdev;
2169         ext4_init_journal_params(sb, journal);
2170         return journal;
2171 out_journal:
2172         jbd2_journal_destroy(journal);
2173 out_bdev:
2174         ext4_blkdev_put(bdev);
2175         return NULL;
2176 }
2177
2178 static int ext4_load_journal(struct super_block *sb,
2179                              struct ext4_super_block *es,
2180                              unsigned long journal_devnum)
2181 {
2182         journal_t *journal;
2183         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2184         dev_t journal_dev;
2185         int err = 0;
2186         int really_read_only;
2187
2188         if (journal_devnum &&
2189             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2190                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2191                         "numbers have changed\n");
2192                 journal_dev = new_decode_dev(journal_devnum);
2193         } else
2194                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2195
2196         really_read_only = bdev_read_only(sb->s_bdev);
2197
2198         /*
2199          * Are we loading a blank journal or performing recovery after a
2200          * crash?  For recovery, we need to check in advance whether we
2201          * can get read-write access to the device.
2202          */
2203
2204         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2205                 if (sb->s_flags & MS_RDONLY) {
2206                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2207                                         "required on readonly filesystem.\n");
2208                         if (really_read_only) {
2209                                 printk(KERN_ERR "EXT4-fs: write access "
2210                                         "unavailable, cannot proceed.\n");
2211                                 return -EROFS;
2212                         }
2213                         printk (KERN_INFO "EXT4-fs: write access will "
2214                                         "be enabled during recovery.\n");
2215                 }
2216         }
2217
2218         if (journal_inum && journal_dev) {
2219                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2220                        "and inode journals!\n");
2221                 return -EINVAL;
2222         }
2223
2224         if (journal_inum) {
2225                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2226                         return -EINVAL;
2227         } else {
2228                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2229                         return -EINVAL;
2230         }
2231
2232         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2233                 err = jbd2_journal_update_format(journal);
2234                 if (err)  {
2235                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2236                         jbd2_journal_destroy(journal);
2237                         return err;
2238                 }
2239         }
2240
2241         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2242                 err = jbd2_journal_wipe(journal, !really_read_only);
2243         if (!err)
2244                 err = jbd2_journal_load(journal);
2245
2246         if (err) {
2247                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2248                 jbd2_journal_destroy(journal);
2249                 return err;
2250         }
2251
2252         EXT4_SB(sb)->s_journal = journal;
2253         ext4_clear_journal_err(sb, es);
2254
2255         if (journal_devnum &&
2256             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2257                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2258                 sb->s_dirt = 1;
2259
2260                 /* Make sure we flush the recovery flag to disk. */
2261                 ext4_commit_super(sb, es, 1);
2262         }
2263
2264         return 0;
2265 }
2266
2267 static int ext4_create_journal(struct super_block * sb,
2268                                struct ext4_super_block * es,
2269                                unsigned int journal_inum)
2270 {
2271         journal_t *journal;
2272         int err;
2273
2274         if (sb->s_flags & MS_RDONLY) {
2275                 printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2276                                 "create journal.\n");
2277                 return -EROFS;
2278         }
2279
2280         journal = ext4_get_journal(sb, journal_inum);
2281         if (!journal)
2282                 return -EINVAL;
2283
2284         printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2285                journal_inum);
2286
2287         err = jbd2_journal_create(journal);
2288         if (err) {
2289                 printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2290                 jbd2_journal_destroy(journal);
2291                 return -EIO;
2292         }
2293
2294         EXT4_SB(sb)->s_journal = journal;
2295
2296         ext4_update_dynamic_rev(sb);
2297         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2298         EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2299
2300         es->s_journal_inum = cpu_to_le32(journal_inum);
2301         sb->s_dirt = 1;
2302
2303         /* Make sure we flush the recovery flag to disk. */
2304         ext4_commit_super(sb, es, 1);
2305
2306         return 0;
2307 }
2308
2309 static void ext4_commit_super (struct super_block * sb,
2310                                struct ext4_super_block * es,
2311                                int sync)
2312 {
2313         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2314
2315         if (!sbh)
2316                 return;
2317         es->s_wtime = cpu_to_le32(get_seconds());
2318         ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2319         es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2320         BUFFER_TRACE(sbh, "marking dirty");
2321         mark_buffer_dirty(sbh);
2322         if (sync)
2323                 sync_dirty_buffer(sbh);
2324 }
2325
2326
2327 /*
2328  * Have we just finished recovery?  If so, and if we are mounting (or
2329  * remounting) the filesystem readonly, then we will end up with a
2330  * consistent fs on disk.  Record that fact.
2331  */
2332 static void ext4_mark_recovery_complete(struct super_block * sb,
2333                                         struct ext4_super_block * es)
2334 {
2335         journal_t *journal = EXT4_SB(sb)->s_journal;
2336
2337         jbd2_journal_lock_updates(journal);
2338         jbd2_journal_flush(journal);
2339         lock_super(sb);
2340         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2341             sb->s_flags & MS_RDONLY) {
2342                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2343                 sb->s_dirt = 0;
2344                 ext4_commit_super(sb, es, 1);
2345         }
2346         unlock_super(sb);
2347         jbd2_journal_unlock_updates(journal);
2348 }
2349
2350 /*
2351  * If we are mounting (or read-write remounting) a filesystem whose journal
2352  * has recorded an error from a previous lifetime, move that error to the
2353  * main filesystem now.
2354  */
2355 static void ext4_clear_journal_err(struct super_block * sb,
2356                                    struct ext4_super_block * es)
2357 {
2358         journal_t *journal;
2359         int j_errno;
2360         const char *errstr;
2361
2362         journal = EXT4_SB(sb)->s_journal;
2363
2364         /*
2365          * Now check for any error status which may have been recorded in the
2366          * journal by a prior ext4_error() or ext4_abort()
2367          */
2368
2369         j_errno = jbd2_journal_errno(journal);
2370         if (j_errno) {
2371                 char nbuf[16];
2372
2373                 errstr = ext4_decode_error(sb, j_errno, nbuf);
2374                 ext4_warning(sb, __FUNCTION__, "Filesystem error recorded "
2375                              "from previous mount: %s", errstr);
2376                 ext4_warning(sb, __FUNCTION__, "Marking fs in need of "
2377                              "filesystem check.");
2378
2379                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2380                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2381                 ext4_commit_super (sb, es, 1);
2382
2383                 jbd2_journal_clear_err(journal);
2384         }
2385 }
2386
2387 /*
2388  * Force the running and committing transactions to commit,
2389  * and wait on the commit.
2390  */
2391 int ext4_force_commit(struct super_block *sb)
2392 {
2393         journal_t *journal;
2394         int ret;
2395
2396         if (sb->s_flags & MS_RDONLY)
2397                 return 0;
2398
2399         journal = EXT4_SB(sb)->s_journal;
2400         sb->s_dirt = 0;
2401         ret = ext4_journal_force_commit(journal);
2402         return ret;
2403 }
2404
2405 /*
2406  * Ext4 always journals updates to the superblock itself, so we don't
2407  * have to propagate any other updates to the superblock on disk at this
2408  * point.  Just start an async writeback to get the buffers on their way
2409  * to the disk.
2410  *
2411  * This implicitly triggers the writebehind on sync().
2412  */
2413
2414 static void ext4_write_super (struct super_block * sb)
2415 {
2416         if (mutex_trylock(&sb->s_lock) != 0)
2417                 BUG();
2418         sb->s_dirt = 0;
2419 }
2420
2421 static int ext4_sync_fs(struct super_block *sb, int wait)
2422 {
2423         tid_t target;
2424
2425         sb->s_dirt = 0;
2426         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2427                 if (wait)
2428                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2429         }
2430         return 0;
2431 }
2432
2433 /*
2434  * LVM calls this function before a (read-only) snapshot is created.  This
2435  * gives us a chance to flush the journal completely and mark the fs clean.
2436  */
2437 static void ext4_write_super_lockfs(struct super_block *sb)
2438 {
2439         sb->s_dirt = 0;
2440
2441         if (!(sb->s_flags & MS_RDONLY)) {
2442                 journal_t *journal = EXT4_SB(sb)->s_journal;
2443
2444                 /* Now we set up the journal barrier. */
2445                 jbd2_journal_lock_updates(journal);
2446                 jbd2_journal_flush(journal);
2447
2448                 /* Journal blocked and flushed, clear needs_recovery flag. */
2449                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2450                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2451         }
2452 }
2453
2454 /*
2455  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2456  * flag here, even though the filesystem is not technically dirty yet.
2457  */
2458 static void ext4_unlockfs(struct super_block *sb)
2459 {
2460         if (!(sb->s_flags & MS_RDONLY)) {
2461                 lock_super(sb);
2462                 /* Reser the needs_recovery flag before the fs is unlocked. */
2463                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2464                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2465                 unlock_super(sb);
2466                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2467         }
2468 }
2469
2470 static int ext4_remount (struct super_block * sb, int * flags, char * data)
2471 {
2472         struct ext4_super_block * es;
2473         struct ext4_sb_info *sbi = EXT4_SB(sb);
2474         ext4_fsblk_t n_blocks_count = 0;
2475         unsigned long old_sb_flags;
2476         struct ext4_mount_options old_opts;
2477         int err;
2478 #ifdef CONFIG_QUOTA
2479         int i;
2480 #endif
2481
2482         /* Store the original options */
2483         old_sb_flags = sb->s_flags;
2484         old_opts.s_mount_opt = sbi->s_mount_opt;
2485         old_opts.s_resuid = sbi->s_resuid;
2486         old_opts.s_resgid = sbi->s_resgid;
2487         old_opts.s_commit_interval = sbi->s_commit_interval;
2488 #ifdef CONFIG_QUOTA
2489         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2490         for (i = 0; i < MAXQUOTAS; i++)
2491                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2492 #endif
2493
2494         /*
2495          * Allow the "check" option to be passed as a remount option.
2496          */
2497         if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2498                 err = -EINVAL;
2499                 goto restore_opts;
2500         }
2501
2502         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2503                 ext4_abort(sb, __FUNCTION__, "Abort forced by user");
2504
2505         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2506                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2507
2508         es = sbi->s_es;
2509
2510         ext4_init_journal_params(sb, sbi->s_journal);
2511
2512         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2513                 n_blocks_count > ext4_blocks_count(es)) {
2514                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
2515                         err = -EROFS;
2516                         goto restore_opts;
2517                 }
2518
2519                 if (*flags & MS_RDONLY) {
2520                         /*
2521                          * First of all, the unconditional stuff we have to do
2522                          * to disable replay of the journal when we next remount
2523                          */
2524                         sb->s_flags |= MS_RDONLY;
2525
2526                         /*
2527                          * OK, test if we are remounting a valid rw partition
2528                          * readonly, and if so set the rdonly flag and then
2529                          * mark the partition as valid again.
2530                          */
2531                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
2532                             (sbi->s_mount_state & EXT4_VALID_FS))
2533                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
2534
2535                         /*
2536                          * We have to unlock super so that we can wait for
2537                          * transactions.
2538                          */
2539                         unlock_super(sb);
2540                         ext4_mark_recovery_complete(sb, es);
2541                         lock_super(sb);
2542                 } else {
2543                         __le32 ret;
2544                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2545                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
2546                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2547                                        "remount RDWR because of unsupported "
2548                                        "optional features (%x).\n",
2549                                        sb->s_id, le32_to_cpu(ret));
2550                                 err = -EROFS;
2551                                 goto restore_opts;
2552                         }
2553
2554                         /*
2555                          * If we have an unprocessed orphan list hanging
2556                          * around from a previously readonly bdev mount,
2557                          * require a full umount/remount for now.
2558                          */
2559                         if (es->s_last_orphan) {
2560                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2561                                        "remount RDWR because of unprocessed "
2562                                        "orphan inode list.  Please "
2563                                        "umount/remount instead.\n",
2564                                        sb->s_id);
2565                                 err = -EINVAL;
2566                                 goto restore_opts;
2567                         }
2568
2569                         /*
2570                          * Mounting a RDONLY partition read-write, so reread
2571                          * and store the current valid flag.  (It may have
2572                          * been changed by e2fsck since we originally mounted
2573                          * the partition.)
2574                          */
2575                         ext4_clear_journal_err(sb, es);
2576                         sbi->s_mount_state = le16_to_cpu(es->s_state);
2577                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
2578                                 goto restore_opts;
2579                         if (!ext4_setup_super (sb, es, 0))
2580                                 sb->s_flags &= ~MS_RDONLY;
2581                 }
2582         }
2583 #ifdef CONFIG_QUOTA
2584         /* Release old quota file names */
2585         for (i = 0; i < MAXQUOTAS; i++)
2586                 if (old_opts.s_qf_names[i] &&
2587                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2588                         kfree(old_opts.s_qf_names[i]);
2589 #endif
2590         return 0;
2591 restore_opts:
2592         sb->s_flags = old_sb_flags;
2593         sbi->s_mount_opt = old_opts.s_mount_opt;
2594         sbi->s_resuid = old_opts.s_resuid;
2595         sbi->s_resgid = old_opts.s_resgid;
2596         sbi->s_commit_interval = old_opts.s_commit_interval;
2597 #ifdef CONFIG_QUOTA
2598         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
2599         for (i = 0; i < MAXQUOTAS; i++) {
2600                 if (sbi->s_qf_names[i] &&
2601                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2602                         kfree(sbi->s_qf_names[i]);
2603                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
2604         }
2605 #endif
2606         return err;
2607 }
2608
2609 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
2610 {
2611         struct super_block *sb = dentry->d_sb;
2612         struct ext4_sb_info *sbi = EXT4_SB(sb);
2613         struct ext4_super_block *es = sbi->s_es;
2614         u64 fsid;
2615
2616         if (test_opt(sb, MINIX_DF)) {
2617                 sbi->s_overhead_last = 0;
2618         } else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
2619                 unsigned long ngroups = sbi->s_groups_count, i;
2620                 ext4_fsblk_t overhead = 0;
2621                 smp_rmb();
2622
2623                 /*
2624                  * Compute the overhead (FS structures).  This is constant
2625                  * for a given filesystem unless the number of block groups
2626                  * changes so we cache the previous value until it does.
2627                  */
2628
2629                 /*
2630                  * All of the blocks before first_data_block are
2631                  * overhead
2632                  */
2633                 overhead = le32_to_cpu(es->s_first_data_block);
2634
2635                 /*
2636                  * Add the overhead attributed to the superblock and
2637                  * block group descriptors.  If the sparse superblocks
2638                  * feature is turned on, then not all groups have this.
2639                  */
2640                 for (i = 0; i < ngroups; i++) {
2641                         overhead += ext4_bg_has_super(sb, i) +
2642                                 ext4_bg_num_gdb(sb, i);
2643                         cond_resched();
2644                 }
2645
2646                 /*
2647                  * Every block group has an inode bitmap, a block
2648                  * bitmap, and an inode table.
2649                  */
2650                 overhead += ngroups * (2 + sbi->s_itb_per_group);
2651                 sbi->s_overhead_last = overhead;
2652                 smp_wmb();
2653                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
2654         }
2655
2656         buf->f_type = EXT4_SUPER_MAGIC;
2657         buf->f_bsize = sb->s_blocksize;
2658         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
2659         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter);
2660         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
2661         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
2662         if (buf->f_bfree < ext4_r_blocks_count(es))
2663                 buf->f_bavail = 0;
2664         buf->f_files = le32_to_cpu(es->s_inodes_count);
2665         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
2666         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
2667         buf->f_namelen = EXT4_NAME_LEN;
2668         fsid = le64_to_cpup((void *)es->s_uuid) ^
2669                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
2670         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
2671         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
2672         return 0;
2673 }
2674
2675 /* Helper function for writing quotas on sync - we need to start transaction before quota file
2676  * is locked for write. Otherwise the are possible deadlocks:
2677  * Process 1                         Process 2
2678  * ext4_create()                     quota_sync()
2679  *   jbd2_journal_start()                   write_dquot()
2680  *   DQUOT_INIT()                        down(dqio_mutex)
2681  *     down(dqio_mutex)                    jbd2_journal_start()
2682  *
2683  */
2684
2685 #ifdef CONFIG_QUOTA
2686
2687 static inline struct inode *dquot_to_inode(struct dquot *dquot)
2688 {
2689         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
2690 }
2691
2692 static int ext4_dquot_initialize(struct inode *inode, int type)
2693 {
2694         handle_t *handle;
2695         int ret, err;
2696
2697         /* We may create quota structure so we need to reserve enough blocks */
2698         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
2699         if (IS_ERR(handle))
2700                 return PTR_ERR(handle);
2701         ret = dquot_initialize(inode, type);
2702         err = ext4_journal_stop(handle);
2703         if (!ret)
2704                 ret = err;
2705         return ret;
2706 }
2707
2708 static int ext4_dquot_drop(struct inode *inode)
2709 {
2710         handle_t *handle;
2711         int ret, err;
2712
2713         /* We may delete quota structure so we need to reserve enough blocks */
2714         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
2715         if (IS_ERR(handle))
2716                 return PTR_ERR(handle);
2717         ret = dquot_drop(inode);
2718         err = ext4_journal_stop(handle);
2719         if (!ret)
2720                 ret = err;
2721         return ret;
2722 }
2723
2724 static int ext4_write_dquot(struct dquot *dquot)
2725 {
2726         int ret, err;
2727         handle_t *handle;
2728         struct inode *inode;
2729
2730         inode = dquot_to_inode(dquot);
2731         handle = ext4_journal_start(inode,
2732                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
2733         if (IS_ERR(handle))
2734                 return PTR_ERR(handle);
2735         ret = dquot_commit(dquot);
2736         err = ext4_journal_stop(handle);
2737         if (!ret)
2738                 ret = err;
2739         return ret;
2740 }
2741
2742 static int ext4_acquire_dquot(struct dquot *dquot)
2743 {
2744         int ret, err;
2745         handle_t *handle;
2746
2747         handle = ext4_journal_start(dquot_to_inode(dquot),
2748                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
2749         if (IS_ERR(handle))
2750                 return PTR_ERR(handle);
2751         ret = dquot_acquire(dquot);
2752         err = ext4_journal_stop(handle);
2753         if (!ret)
2754                 ret = err;
2755         return ret;
2756 }
2757
2758 static int ext4_release_dquot(struct dquot *dquot)
2759 {
2760         int ret, err;
2761         handle_t *handle;
2762
2763         handle = ext4_journal_start(dquot_to_inode(dquot),
2764                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
2765         if (IS_ERR(handle)) {
2766                 /* Release dquot anyway to avoid endless cycle in dqput() */
2767                 dquot_release(dquot);
2768                 return PTR_ERR(handle);
2769         }
2770         ret = dquot_release(dquot);
2771         err = ext4_journal_stop(handle);
2772         if (!ret)
2773                 ret = err;
2774         return ret;
2775 }
2776
2777 static int ext4_mark_dquot_dirty(struct dquot *dquot)
2778 {
2779         /* Are we journalling quotas? */
2780         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
2781             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
2782                 dquot_mark_dquot_dirty(dquot);
2783                 return ext4_write_dquot(dquot);
2784         } else {
2785                 return dquot_mark_dquot_dirty(dquot);
2786         }
2787 }
2788
2789 static int ext4_write_info(struct super_block *sb, int type)
2790 {
2791         int ret, err;
2792         handle_t *handle;
2793
2794         /* Data block + inode block */
2795         handle = ext4_journal_start(sb->s_root->d_inode, 2);
2796         if (IS_ERR(handle))
2797                 return PTR_ERR(handle);
2798         ret = dquot_commit_info(sb, type);
2799         err = ext4_journal_stop(handle);
2800         if (!ret)
2801                 ret = err;
2802         return ret;
2803 }
2804
2805 /*
2806  * Turn on quotas during mount time - we need to find
2807  * the quota file and such...
2808  */
2809 static int ext4_quota_on_mount(struct super_block *sb, int type)
2810 {
2811         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
2812                         EXT4_SB(sb)->s_jquota_fmt, type);
2813 }
2814
2815 /*
2816  * Standard function to be called on quota_on
2817  */
2818 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
2819                          char *path)
2820 {
2821         int err;
2822         struct nameidata nd;
2823
2824         if (!test_opt(sb, QUOTA))
2825                 return -EINVAL;
2826         /* Not journalling quota? */
2827         if (!EXT4_SB(sb)->s_qf_names[USRQUOTA] &&
2828             !EXT4_SB(sb)->s_qf_names[GRPQUOTA])
2829                 return vfs_quota_on(sb, type, format_id, path);
2830         err = path_lookup(path, LOOKUP_FOLLOW, &nd);
2831         if (err)
2832                 return err;
2833         /* Quotafile not on the same filesystem? */
2834         if (nd.mnt->mnt_sb != sb) {
2835                 path_release(&nd);
2836                 return -EXDEV;
2837         }
2838         /* Quotafile not of fs root? */
2839         if (nd.dentry->d_parent->d_inode != sb->s_root->d_inode)
2840                 printk(KERN_WARNING
2841                         "EXT4-fs: Quota file not on filesystem root. "
2842                         "Journalled quota will not work.\n");
2843         path_release(&nd);
2844         return vfs_quota_on(sb, type, format_id, path);
2845 }
2846
2847 /* Read data from quotafile - avoid pagecache and such because we cannot afford
2848  * acquiring the locks... As quota files are never truncated and quota code
2849  * itself serializes the operations (and noone else should touch the files)
2850  * we don't have to be afraid of races */
2851 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
2852                                size_t len, loff_t off)
2853 {
2854         struct inode *inode = sb_dqopt(sb)->files[type];
2855         sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2856         int err = 0;
2857         int offset = off & (sb->s_blocksize - 1);
2858         int tocopy;
2859         size_t toread;
2860         struct buffer_head *bh;
2861         loff_t i_size = i_size_read(inode);
2862
2863         if (off > i_size)
2864                 return 0;
2865         if (off+len > i_size)
2866                 len = i_size-off;
2867         toread = len;
2868         while (toread > 0) {
2869                 tocopy = sb->s_blocksize - offset < toread ?
2870                                 sb->s_blocksize - offset : toread;
2871                 bh = ext4_bread(NULL, inode, blk, 0, &err);
2872                 if (err)
2873                         return err;
2874                 if (!bh)        /* A hole? */
2875                         memset(data, 0, tocopy);
2876                 else
2877                         memcpy(data, bh->b_data+offset, tocopy);
2878                 brelse(bh);
2879                 offset = 0;
2880                 toread -= tocopy;
2881                 data += tocopy;
2882                 blk++;
2883         }
2884         return len;
2885 }
2886
2887 /* Write to quotafile (we know the transaction is already started and has
2888  * enough credits) */
2889 static ssize_t ext4_quota_write(struct super_block *sb, int type,
2890                                 const char *data, size_t len, loff_t off)
2891 {
2892         struct inode *inode = sb_dqopt(sb)->files[type];
2893         sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2894         int err = 0;
2895         int offset = off & (sb->s_blocksize - 1);
2896         int tocopy;
2897         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
2898         size_t towrite = len;
2899         struct buffer_head *bh;
2900         handle_t *handle = journal_current_handle();
2901
2902         if (!handle) {
2903                 printk(KERN_WARNING "EXT4-fs: Quota write (off=%Lu, len=%Lu)"
2904                         " cancelled because transaction is not started.\n",
2905                         (unsigned long long)off, (unsigned long long)len);
2906                 return -EIO;
2907         }
2908         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2909         while (towrite > 0) {
2910                 tocopy = sb->s_blocksize - offset < towrite ?
2911                                 sb->s_blocksize - offset : towrite;
2912                 bh = ext4_bread(handle, inode, blk, 1, &err);
2913                 if (!bh)
2914                         goto out;
2915                 if (journal_quota) {
2916                         err = ext4_journal_get_write_access(handle, bh);
2917                         if (err) {
2918                                 brelse(bh);
2919                                 goto out;
2920                         }
2921                 }
2922                 lock_buffer(bh);
2923                 memcpy(bh->b_data+offset, data, tocopy);
2924                 flush_dcache_page(bh->b_page);
2925                 unlock_buffer(bh);
2926                 if (journal_quota)
2927                         err = ext4_journal_dirty_metadata(handle, bh);
2928                 else {
2929                         /* Always do at least ordered writes for quotas */
2930                         err = ext4_journal_dirty_data(handle, bh);
2931                         mark_buffer_dirty(bh);
2932                 }
2933                 brelse(bh);
2934                 if (err)
2935                         goto out;
2936                 offset = 0;
2937                 towrite -= tocopy;
2938                 data += tocopy;
2939                 blk++;
2940         }
2941 out:
2942         if (len == towrite)
2943                 return err;
2944         if (inode->i_size < off+len-towrite) {
2945                 i_size_write(inode, off+len-towrite);
2946                 EXT4_I(inode)->i_disksize = inode->i_size;
2947         }
2948         inode->i_version++;
2949         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2950         ext4_mark_inode_dirty(handle, inode);
2951         mutex_unlock(&inode->i_mutex);
2952         return len - towrite;
2953 }
2954
2955 #endif
2956
2957 static int ext4_get_sb(struct file_system_type *fs_type,
2958         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
2959 {
2960         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
2961 }
2962
2963 static struct file_system_type ext4dev_fs_type = {
2964         .owner          = THIS_MODULE,
2965         .name           = "ext4dev",
2966         .get_sb         = ext4_get_sb,
2967         .kill_sb        = kill_block_super,
2968         .fs_flags       = FS_REQUIRES_DEV,
2969 };
2970
2971 static int __init init_ext4_fs(void)
2972 {
2973         int err = init_ext4_xattr();
2974         if (err)
2975                 return err;
2976         err = init_inodecache();
2977         if (err)
2978                 goto out1;
2979         err = register_filesystem(&ext4dev_fs_type);
2980         if (err)
2981                 goto out;
2982         return 0;
2983 out:
2984         destroy_inodecache();
2985 out1:
2986         exit_ext4_xattr();
2987         return err;
2988 }
2989
2990 static void __exit exit_ext4_fs(void)
2991 {
2992         unregister_filesystem(&ext4dev_fs_type);
2993         destroy_inodecache();
2994         exit_ext4_xattr();
2995 }
2996
2997 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
2998 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
2999 MODULE_LICENSE("GPL");
3000 module_init(init_ext4_fs)
3001 module_exit(exit_ext4_fs)