fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/jbd2.h>
  24 #include <linux/ext4_fs.h>
  25 #include <linux/ext4_jbd2.h>
  26 #include <linux/slab.h>
  27 #include <linux/init.h>
  28 #include <linux/blkdev.h>
  29 #include <linux/parser.h>
  30 #include <linux/smp_lock.h>
  31 #include <linux/buffer_head.h>
  32 #include <linux/exportfs.h>
  33 #include <linux/vfs.h>
  34 #include <linux/random.h>
  35 #include <linux/mount.h>
  36 #include <linux/namei.h>
  37 #include <linux/quotaops.h>
  38 #include <linux/seq_file.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41
  42 #include <asm/uaccess.h>
  43
  44 #include "xattr.h"
  45 #include "acl.h"
  46 #include "namei.h"
  47 #include "group.h"
  48
  49 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  50                              unsigned long journal_devnum);
  51 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
  52                                unsigned int);
  53 static void ext4_commit_super (struct super_block * sb,
  54                                struct ext4_super_block * es,
  55                                int sync);
  56 static void ext4_mark_recovery_complete(struct super_block * sb,
  57                                         struct ext4_super_block * es);
  58 static void ext4_clear_journal_err(struct super_block * sb,
  59                                    struct ext4_super_block * es);
  60 static int ext4_sync_fs(struct super_block *sb, int wait);
  61 static const char *ext4_decode_error(struct super_block * sb, int errno,
  62                                      char nbuf[16]);
  63 static int ext4_remount (struct super_block * sb, int * flags, char * data);
  64 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf);
  65 static void ext4_unlockfs(struct super_block *sb);
  66 static void ext4_write_super (struct super_block * sb);
  67 static void ext4_write_super_lockfs(struct super_block *sb);
  68
  69
  70 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
  71                                struct ext4_group_desc *bg)
  72 {
  73         return le32_to_cpu(bg->bg_block_bitmap_lo) |
  74                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  75                 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
  76 }
  77
  78 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
  79                                struct ext4_group_desc *bg)
  80 {
  81         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
  82                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  83                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
  84 }
  85
  86 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
  87                               struct ext4_group_desc *bg)
  88 {
  89         return le32_to_cpu(bg->bg_inode_table_lo) |
  90                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  91                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
  92 }
  93
  94 void ext4_block_bitmap_set(struct super_block *sb,
  95                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
  96 {
  97         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
  98         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
  99                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 100 }
 101
 102 void ext4_inode_bitmap_set(struct super_block *sb,
 103                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 104 {
 105         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 106         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 107                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 108 }
 109
 110 void ext4_inode_table_set(struct super_block *sb,
 111                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 112 {
 113         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 114         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 115                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 116 }
 117
 118 /*
 119  * Wrappers for jbd2_journal_start/end.
 120  *
 121  * The only special thing we need to do here is to make sure that all
 122  * journal_end calls result in the superblock being marked dirty, so
 123  * that sync() will call the filesystem's write_super callback if
 124  * appropriate.
 125  */
 126 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 127 {
 128         journal_t *journal;
 129
 130         if (sb->s_flags & MS_RDONLY)
 131                 return ERR_PTR(-EROFS);
 132
 133         /* Special case here: if the journal has aborted behind our
 134          * backs (eg. EIO in the commit thread), then we still need to
 135          * take the FS itself readonly cleanly. */
 136         journal = EXT4_SB(sb)->s_journal;
 137         if (is_journal_aborted(journal)) {
 138                 ext4_abort(sb, __FUNCTION__,
 139                            "Detected aborted journal");
 140                 return ERR_PTR(-EROFS);
 141         }
 142
 143         return jbd2_journal_start(journal, nblocks);
 144 }
 145
 146 /*
 147  * The only special thing we need to do here is to make sure that all
 148  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 149  * that sync() will call the filesystem's write_super callback if
 150  * appropriate.
 151  */
 152 int __ext4_journal_stop(const char *where, handle_t *handle)
 153 {
 154         struct super_block *sb;
 155         int err;
 156         int rc;
 157
 158         sb = handle->h_transaction->t_journal->j_private;
 159         err = handle->h_err;
 160         rc = jbd2_journal_stop(handle);
 161
 162         if (!err)
 163                 err = rc;
 164         if (err)
 165                 __ext4_std_error(sb, where, err);
 166         return err;
 167 }
 168
 169 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 170                 struct buffer_head *bh, handle_t *handle, int err)
 171 {
 172         char nbuf[16];
 173         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 174
 175         if (bh)
 176                 BUFFER_TRACE(bh, "abort");
 177
 178         if (!handle->h_err)
 179                 handle->h_err = err;
 180
 181         if (is_handle_aborted(handle))
 182                 return;
 183
 184         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
 185                caller, errstr, err_fn);
 186
 187         jbd2_journal_abort_handle(handle);
 188 }
 189
 190 /* Deal with the reporting of failure conditions on a filesystem such as
 191  * inconsistencies detected or read IO failures.
 192  *
 193  * On ext2, we can store the error state of the filesystem in the
 194  * superblock.  That is not possible on ext4, because we may have other
 195  * write ordering constraints on the superblock which prevent us from
 196  * writing it out straight away; and given that the journal is about to
 197  * be aborted, we can't rely on the current, or future, transactions to
 198  * write out the superblock safely.
 199  *
 200  * We'll just use the jbd2_journal_abort() error code to record an error in
 201  * the journal instead.  On recovery, the journal will compain about
 202  * that error until we've noted it down and cleared it.
 203  */
 204
 205 static void ext4_handle_error(struct super_block *sb)
 206 {
 207         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 208
 209         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 210         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 211
 212         if (sb->s_flags & MS_RDONLY)
 213                 return;
 214
 215         if (!test_opt (sb, ERRORS_CONT)) {
 216                 journal_t *journal = EXT4_SB(sb)->s_journal;
 217
 218                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 219                 if (journal)
 220                         jbd2_journal_abort(journal, -EIO);
 221         }
 222         if (test_opt (sb, ERRORS_RO)) {
 223                 printk (KERN_CRIT "Remounting filesystem read-only\n");
 224                 sb->s_flags |= MS_RDONLY;
 225         }
 226         ext4_commit_super(sb, es, 1);
 227         if (test_opt(sb, ERRORS_PANIC))
 228                 panic("EXT4-fs (device %s): panic forced after error\n",
 229                         sb->s_id);
 230 }
 231
 232 void ext4_error (struct super_block * sb, const char * function,
 233                  const char * fmt, ...)
 234 {
 235         va_list args;
 236
 237         va_start(args, fmt);
 238         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 239         vprintk(fmt, args);
 240         printk("\n");
 241         va_end(args);
 242
 243         ext4_handle_error(sb);
 244 }
 245
 246 static const char *ext4_decode_error(struct super_block * sb, int errno,
 247                                      char nbuf[16])
 248 {
 249         char *errstr = NULL;
 250
 251         switch (errno) {
 252         case -EIO:
 253                 errstr = "IO failure";
 254                 break;
 255         case -ENOMEM:
 256                 errstr = "Out of memory";
 257                 break;
 258         case -EROFS:
 259                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
 260                         errstr = "Journal has aborted";
 261                 else
 262                         errstr = "Readonly filesystem";
 263                 break;
 264         default:
 265                 /* If the caller passed in an extra buffer for unknown
 266                  * errors, textualise them now.  Else we just return
 267                  * NULL. */
 268                 if (nbuf) {
 269                         /* Check for truncated error codes... */
 270                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 271                                 errstr = nbuf;
 272                 }
 273                 break;
 274         }
 275
 276         return errstr;
 277 }
 278
 279 /* __ext4_std_error decodes expected errors from journaling functions
 280  * automatically and invokes the appropriate error response.  */
 281
 282 void __ext4_std_error (struct super_block * sb, const char * function,
 283                        int errno)
 284 {
 285         char nbuf[16];
 286         const char *errstr;
 287
 288         /* Special case: if the error is EROFS, and we're not already
 289          * inside a transaction, then there's really no point in logging
 290          * an error. */
 291         if (errno == -EROFS && journal_current_handle() == NULL &&
 292             (sb->s_flags & MS_RDONLY))
 293                 return;
 294
 295         errstr = ext4_decode_error(sb, errno, nbuf);
 296         printk (KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
 297                 sb->s_id, function, errstr);
 298
 299         ext4_handle_error(sb);
 300 }
 301
 302 /*
 303  * ext4_abort is a much stronger failure handler than ext4_error.  The
 304  * abort function may be used to deal with unrecoverable failures such
 305  * as journal IO errors or ENOMEM at a critical moment in log management.
 306  *
 307  * We unconditionally force the filesystem into an ABORT|READONLY state,
 308  * unless the error response on the fs has been set to panic in which
 309  * case we take the easy way out and panic immediately.
 310  */
 311
 312 void ext4_abort (struct super_block * sb, const char * function,
 313                  const char * fmt, ...)
 314 {
 315         va_list args;
 316
 317         printk (KERN_CRIT "ext4_abort called.\n");
 318
 319         va_start(args, fmt);
 320         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 321         vprintk(fmt, args);
 322         printk("\n");
 323         va_end(args);
 324
 325         if (test_opt(sb, ERRORS_PANIC))
 326                 panic("EXT4-fs panic from previous error\n");
 327
 328         if (sb->s_flags & MS_RDONLY)
 329                 return;
 330
 331         printk(KERN_CRIT "Remounting filesystem read-only\n");
 332         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 333         sb->s_flags |= MS_RDONLY;
 334         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 335         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 336 }
 337
 338 void ext4_warning (struct super_block * sb, const char * function,
 339                    const char * fmt, ...)
 340 {
 341         va_list args;
 342
 343         va_start(args, fmt);
 344         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
 345                sb->s_id, function);
 346         vprintk(fmt, args);
 347         printk("\n");
 348         va_end(args);
 349 }
 350
 351 void ext4_update_dynamic_rev(struct super_block *sb)
 352 {
 353         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 354
 355         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 356                 return;
 357
 358         ext4_warning(sb, __FUNCTION__,
 359                      "updating to rev %d because of new feature flag, "
 360                      "running e2fsck is recommended",
 361                      EXT4_DYNAMIC_REV);
 362
 363         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 364         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 365         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 366         /* leave es->s_feature_*compat flags alone */
 367         /* es->s_uuid will be set by e2fsck if empty */
 368
 369         /*
 370          * The rest of the superblock fields should be zero, and if not it
 371          * means they are likely already in use, so leave them alone.  We
 372          * can leave it up to e2fsck to clean up any inconsistencies there.
 373          */
 374 }
 375
 376 /*
 377  * Open the external journal device
 378  */
 379 static struct block_device *ext4_blkdev_get(dev_t dev)
 380 {
 381         struct block_device *bdev;
 382         char b[BDEVNAME_SIZE];
 383
 384         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 385         if (IS_ERR(bdev))
 386                 goto fail;
 387         return bdev;
 388
 389 fail:
 390         printk(KERN_ERR "EXT4: failed to open journal device %s: %ld\n",
 391                         __bdevname(dev, b), PTR_ERR(bdev));
 392         return NULL;
 393 }
 394
 395 /*
 396  * Release the journal device
 397  */
 398 static int ext4_blkdev_put(struct block_device *bdev)
 399 {
 400         bd_release(bdev);
 401         return blkdev_put(bdev);
 402 }
 403
 404 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 405 {
 406         struct block_device *bdev;
 407         int ret = -ENODEV;
 408
 409         bdev = sbi->journal_bdev;
 410         if (bdev) {
 411                 ret = ext4_blkdev_put(bdev);
 412                 sbi->journal_bdev = NULL;
 413         }
 414         return ret;
 415 }
 416
 417 static inline struct inode *orphan_list_entry(struct list_head *l)
 418 {
 419         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 420 }
 421
 422 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 423 {
 424         struct list_head *l;
 425
 426         printk(KERN_ERR "sb orphan head is %d\n",
 427                le32_to_cpu(sbi->s_es->s_last_orphan));
 428
 429         printk(KERN_ERR "sb_info orphan list:\n");
 430         list_for_each(l, &sbi->s_orphan) {
 431                 struct inode *inode = orphan_list_entry(l);
 432                 printk(KERN_ERR "  "
 433                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 434                        inode->i_sb->s_id, inode->i_ino, inode,
 435                        inode->i_mode, inode->i_nlink,
 436                        NEXT_ORPHAN(inode));
 437         }
 438 }
 439
 440 static void ext4_put_super (struct super_block * sb)
 441 {
 442         struct ext4_sb_info *sbi = EXT4_SB(sb);
 443         struct ext4_super_block *es = sbi->s_es;
 444         int i;
 445
 446         ext4_ext_release(sb);
 447         ext4_xattr_put_super(sb);
 448         jbd2_journal_destroy(sbi->s_journal);
 449         if (!(sb->s_flags & MS_RDONLY)) {
 450                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 451                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 452                 BUFFER_TRACE(sbi->s_sbh, "marking dirty");
 453                 mark_buffer_dirty(sbi->s_sbh);
 454                 ext4_commit_super(sb, es, 1);
 455         }
 456
 457         for (i = 0; i < sbi->s_gdb_count; i++)
 458                 brelse(sbi->s_group_desc[i]);
 459         kfree(sbi->s_group_desc);
 460         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 461         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 462         percpu_counter_destroy(&sbi->s_dirs_counter);
 463         brelse(sbi->s_sbh);
 464 #ifdef CONFIG_QUOTA
 465         for (i = 0; i < MAXQUOTAS; i++)
 466                 kfree(sbi->s_qf_names[i]);
 467 #endif
 468
 469         /* Debugging code just in case the in-memory inode orphan list
 470          * isn't empty.  The on-disk one can be non-empty if we've
 471          * detected an error and taken the fs readonly, but the
 472          * in-memory list had better be clean by this point. */
 473         if (!list_empty(&sbi->s_orphan))
 474                 dump_orphan_list(sb, sbi);
 475         J_ASSERT(list_empty(&sbi->s_orphan));
 476
 477         invalidate_bdev(sb->s_bdev);
 478         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 479                 /*
 480                  * Invalidate the journal device's buffers.  We don't want them
 481                  * floating about in memory - the physical journal device may
 482                  * hotswapped, and it breaks the `ro-after' testing code.
 483                  */
 484                 sync_blockdev(sbi->journal_bdev);
 485                 invalidate_bdev(sbi->journal_bdev);
 486                 ext4_blkdev_remove(sbi);
 487         }
 488         sb->s_fs_info = NULL;
 489         kfree(sbi);
 490         return;
 491 }
 492
 493 static struct kmem_cache *ext4_inode_cachep;
 494
 495 /*
 496  * Called inside transaction, so use GFP_NOFS
 497  */
 498 static struct inode *ext4_alloc_inode(struct super_block *sb)
 499 {
 500         struct ext4_inode_info *ei;
 501
 502         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 503         if (!ei)
 504                 return NULL;
 505 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 506         ei->i_acl = EXT4_ACL_NOT_CACHED;
 507         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 508 #endif
 509         ei->i_block_alloc_info = NULL;
 510         ei->vfs_inode.i_version = 1;
 511         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 512         return &ei->vfs_inode;
 513 }
 514
 515 static void ext4_destroy_inode(struct inode *inode)
 516 {
 517         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 518                 printk("EXT4 Inode %p: orphan list check failed!\n",
 519                         EXT4_I(inode));
 520                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 521                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 522                                 true);
 523                 dump_stack();
 524         }
 525         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 526 }
 527
 528 static void init_once(struct kmem_cache *cachep, void *foo)
 529 {
 530         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 531
 532         INIT_LIST_HEAD(&ei->i_orphan);
 533 #ifdef CONFIG_EXT4DEV_FS_XATTR
 534         init_rwsem(&ei->xattr_sem);
 535 #endif
 536         mutex_init(&ei->truncate_mutex);
 537         inode_init_once(&ei->vfs_inode);
 538 }
 539
 540 static int init_inodecache(void)
 541 {
 542         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 543                                              sizeof(struct ext4_inode_info),
 544                                              0, (SLAB_RECLAIM_ACCOUNT|
 545                                                 SLAB_MEM_SPREAD),
 546                                              init_once);
 547         if (ext4_inode_cachep == NULL)
 548                 return -ENOMEM;
 549         return 0;
 550 }
 551
 552 static void destroy_inodecache(void)
 553 {
 554         kmem_cache_destroy(ext4_inode_cachep);
 555 }
 556
 557 static void ext4_clear_inode(struct inode *inode)
 558 {
 559         struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
 560 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 561         if (EXT4_I(inode)->i_acl &&
 562                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
 563                 posix_acl_release(EXT4_I(inode)->i_acl);
 564                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
 565         }
 566         if (EXT4_I(inode)->i_default_acl &&
 567                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
 568                 posix_acl_release(EXT4_I(inode)->i_default_acl);
 569                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
 570         }
 571 #endif
 572         ext4_discard_reservation(inode);
 573         EXT4_I(inode)->i_block_alloc_info = NULL;
 574         if (unlikely(rsv))
 575                 kfree(rsv);
 576 }
 577
 578 static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
 579 {
 580 #if defined(CONFIG_QUOTA)
 581         struct ext4_sb_info *sbi = EXT4_SB(sb);
 582
 583         if (sbi->s_jquota_fmt)
 584                 seq_printf(seq, ",jqfmt=%s",
 585                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold": "vfsv0");
 586
 587         if (sbi->s_qf_names[USRQUOTA])
 588                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 589
 590         if (sbi->s_qf_names[GRPQUOTA])
 591                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 592
 593         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
 594                 seq_puts(seq, ",usrquota");
 595
 596         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
 597                 seq_puts(seq, ",grpquota");
 598 #endif
 599 }
 600
 601 /*
 602  * Show an option if
 603  *  - it's set to a non-default value OR
 604  *  - if the per-sb default is different from the global default
 605  */
 606 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 607 {
 608         struct super_block *sb = vfs->mnt_sb;
 609         struct ext4_sb_info *sbi = EXT4_SB(sb);
 610         struct ext4_super_block *es = sbi->s_es;
 611         unsigned long def_mount_opts;
 612
 613         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 614
 615         if (sbi->s_sb_block != 1)
 616                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 617         if (test_opt(sb, MINIX_DF))
 618                 seq_puts(seq, ",minixdf");
 619         if (test_opt(sb, GRPID))
 620                 seq_puts(seq, ",grpid");
 621         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 622                 seq_puts(seq, ",nogrpid");
 623         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 624             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 625                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 626         }
 627         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 628             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 629                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 630         }
 631         if (test_opt(sb, ERRORS_CONT)) {
 632                 int def_errors = le16_to_cpu(es->s_errors);
 633
 634                 if (def_errors == EXT4_ERRORS_PANIC ||
 635                     def_errors == EXT4_ERRORS_RO) {
 636                         seq_puts(seq, ",errors=continue");
 637                 }
 638         }
 639         if (test_opt(sb, ERRORS_RO))
 640                 seq_puts(seq, ",errors=remount-ro");
 641         if (test_opt(sb, ERRORS_PANIC))
 642                 seq_puts(seq, ",errors=panic");
 643         if (test_opt(sb, NO_UID32))
 644                 seq_puts(seq, ",nouid32");
 645         if (test_opt(sb, DEBUG))
 646                 seq_puts(seq, ",debug");
 647         if (test_opt(sb, OLDALLOC))
 648                 seq_puts(seq, ",oldalloc");
 649 #ifdef CONFIG_EXT4_FS_XATTR
 650         if (test_opt(sb, XATTR_USER))
 651                 seq_puts(seq, ",user_xattr");
 652         if (!test_opt(sb, XATTR_USER) &&
 653             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 654                 seq_puts(seq, ",nouser_xattr");
 655         }
 656 #endif
 657 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 658         if (test_opt(sb, POSIX_ACL))
 659                 seq_puts(seq, ",acl");
 660         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 661                 seq_puts(seq, ",noacl");
 662 #endif
 663         if (!test_opt(sb, RESERVATION))
 664                 seq_puts(seq, ",noreservation");
 665         if (sbi->s_commit_interval) {
 666                 seq_printf(seq, ",commit=%u",
 667                            (unsigned) (sbi->s_commit_interval / HZ));
 668         }
 669         if (test_opt(sb, BARRIER))
 670                 seq_puts(seq, ",barrier=1");
 671         if (test_opt(sb, NOBH))
 672                 seq_puts(seq, ",nobh");
 673         if (!test_opt(sb, EXTENTS))
 674                 seq_puts(seq, ",noextents");
 675
 676         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 677                 seq_puts(seq, ",data=journal");
 678         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 679                 seq_puts(seq, ",data=ordered");
 680         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 681                 seq_puts(seq, ",data=writeback");
 682
 683         ext4_show_quota_options(seq, sb);
 684
 685         return 0;
 686 }
 687
 688
 689 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 690                 u64 ino, u32 generation)
 691 {
 692         struct inode *inode;
 693
 694         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 695                 return ERR_PTR(-ESTALE);
 696         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 697                 return ERR_PTR(-ESTALE);
 698
 699         /* iget isn't really right if the inode is currently unallocated!!
 700          *
 701          * ext4_read_inode will return a bad_inode if the inode had been
 702          * deleted, so we should be safe.
 703          *
 704          * Currently we don't know the generation for parent directory, so
 705          * a generation of 0 means "accept any"
 706          */
 707         inode = iget(sb, ino);
 708         if (inode == NULL)
 709                 return ERR_PTR(-ENOMEM);
 710         if (is_bad_inode(inode) ||
 711             (generation && inode->i_generation != generation)) {
 712                 iput(inode);
 713                 return ERR_PTR(-ESTALE);
 714         }
 715
 716         return inode;
 717 }
 718
 719 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 720                 int fh_len, int fh_type)
 721 {
 722         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 723                                     ext4_nfs_get_inode);
 724 }
 725
 726 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 727                 int fh_len, int fh_type)
 728 {
 729         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 730                                     ext4_nfs_get_inode);
 731 }
 732
 733 #ifdef CONFIG_QUOTA
 734 #define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
 735 #define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 736
 737 static int ext4_dquot_initialize(struct inode *inode, int type);
 738 static int ext4_dquot_drop(struct inode *inode);
 739 static int ext4_write_dquot(struct dquot *dquot);
 740 static int ext4_acquire_dquot(struct dquot *dquot);
 741 static int ext4_release_dquot(struct dquot *dquot);
 742 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 743 static int ext4_write_info(struct super_block *sb, int type);
 744 static int ext4_quota_on(struct super_block *sb, int type, int format_id, char *path);
 745 static int ext4_quota_on_mount(struct super_block *sb, int type);
 746 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 747                                size_t len, loff_t off);
 748 static ssize_t ext4_quota_write(struct super_block *sb, int type,
 749                                 const char *data, size_t len, loff_t off);
 750
 751 static struct dquot_operations ext4_quota_operations = {
 752         .initialize     = ext4_dquot_initialize,
 753         .drop           = ext4_dquot_drop,
 754         .alloc_space    = dquot_alloc_space,
 755         .alloc_inode    = dquot_alloc_inode,
 756         .free_space     = dquot_free_space,
 757         .free_inode     = dquot_free_inode,
 758         .transfer       = dquot_transfer,
 759         .write_dquot    = ext4_write_dquot,
 760         .acquire_dquot  = ext4_acquire_dquot,
 761         .release_dquot  = ext4_release_dquot,
 762         .mark_dirty     = ext4_mark_dquot_dirty,
 763         .write_info     = ext4_write_info
 764 };
 765
 766 static struct quotactl_ops ext4_qctl_operations = {
 767         .quota_on       = ext4_quota_on,
 768         .quota_off      = vfs_quota_off,
 769         .quota_sync     = vfs_quota_sync,
 770         .get_info       = vfs_get_dqinfo,
 771         .set_info       = vfs_set_dqinfo,
 772         .get_dqblk      = vfs_get_dqblk,
 773         .set_dqblk      = vfs_set_dqblk
 774 };
 775 #endif
 776
 777 static const struct super_operations ext4_sops = {
 778         .alloc_inode    = ext4_alloc_inode,
 779         .destroy_inode  = ext4_destroy_inode,
 780         .read_inode     = ext4_read_inode,
 781         .write_inode    = ext4_write_inode,
 782         .dirty_inode    = ext4_dirty_inode,
 783         .delete_inode   = ext4_delete_inode,
 784         .put_super      = ext4_put_super,
 785         .write_super    = ext4_write_super,
 786         .sync_fs        = ext4_sync_fs,
 787         .write_super_lockfs = ext4_write_super_lockfs,
 788         .unlockfs       = ext4_unlockfs,
 789         .statfs         = ext4_statfs,
 790         .remount_fs     = ext4_remount,
 791         .clear_inode    = ext4_clear_inode,
 792         .show_options   = ext4_show_options,
 793 #ifdef CONFIG_QUOTA
 794         .quota_read     = ext4_quota_read,
 795         .quota_write    = ext4_quota_write,
 796 #endif
 797 };
 798
 799 static const struct export_operations ext4_export_ops = {
 800         .fh_to_dentry = ext4_fh_to_dentry,
 801         .fh_to_parent = ext4_fh_to_parent,
 802         .get_parent = ext4_get_parent,
 803 };
 804
 805 enum {
 806         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 807         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
 808         Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov,
 809         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
 810         Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
 811         Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
 812         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
 813         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 814         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
 815         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
 816         Opt_grpquota, Opt_extents, Opt_noextents,
 817 };
 818
 819 static match_table_t tokens = {
 820         {Opt_bsd_df, "bsddf"},
 821         {Opt_minix_df, "minixdf"},
 822         {Opt_grpid, "grpid"},
 823         {Opt_grpid, "bsdgroups"},
 824         {Opt_nogrpid, "nogrpid"},
 825         {Opt_nogrpid, "sysvgroups"},
 826         {Opt_resgid, "resgid=%u"},
 827         {Opt_resuid, "resuid=%u"},
 828         {Opt_sb, "sb=%u"},
 829         {Opt_err_cont, "errors=continue"},
 830         {Opt_err_panic, "errors=panic"},
 831         {Opt_err_ro, "errors=remount-ro"},
 832         {Opt_nouid32, "nouid32"},
 833         {Opt_nocheck, "nocheck"},
 834         {Opt_nocheck, "check=none"},
 835         {Opt_debug, "debug"},
 836         {Opt_oldalloc, "oldalloc"},
 837         {Opt_orlov, "orlov"},
 838         {Opt_user_xattr, "user_xattr"},
 839         {Opt_nouser_xattr, "nouser_xattr"},
 840         {Opt_acl, "acl"},
 841         {Opt_noacl, "noacl"},
 842         {Opt_reservation, "reservation"},
 843         {Opt_noreservation, "noreservation"},
 844         {Opt_noload, "noload"},
 845         {Opt_nobh, "nobh"},
 846         {Opt_bh, "bh"},
 847         {Opt_commit, "commit=%u"},
 848         {Opt_journal_update, "journal=update"},
 849         {Opt_journal_inum, "journal=%u"},
 850         {Opt_journal_dev, "journal_dev=%u"},
 851         {Opt_abort, "abort"},
 852         {Opt_data_journal, "data=journal"},
 853         {Opt_data_ordered, "data=ordered"},
 854         {Opt_data_writeback, "data=writeback"},
 855         {Opt_offusrjquota, "usrjquota="},
 856         {Opt_usrjquota, "usrjquota=%s"},
 857         {Opt_offgrpjquota, "grpjquota="},
 858         {Opt_grpjquota, "grpjquota=%s"},
 859         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
 860         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
 861         {Opt_grpquota, "grpquota"},
 862         {Opt_noquota, "noquota"},
 863         {Opt_quota, "quota"},
 864         {Opt_usrquota, "usrquota"},
 865         {Opt_barrier, "barrier=%u"},
 866         {Opt_extents, "extents"},
 867         {Opt_noextents, "noextents"},
 868         {Opt_err, NULL},
 869         {Opt_resize, "resize"},
 870 };
 871
 872 static ext4_fsblk_t get_sb_block(void **data)
 873 {
 874         ext4_fsblk_t    sb_block;
 875         char            *options = (char *) *data;
 876
 877         if (!options || strncmp(options, "sb=", 3) != 0)
 878                 return 1;       /* Default location */
 879         options += 3;
 880         /*todo: use simple_strtoll with >32bit ext4 */
 881         sb_block = simple_strtoul(options, &options, 0);
 882         if (*options && *options != ',') {
 883                 printk("EXT4-fs: Invalid sb specification: %s\n",
 884                        (char *) *data);
 885                 return 1;
 886         }
 887         if (*options == ',')
 888                 options++;
 889         *data = (void *) options;
 890         return sb_block;
 891 }
 892
 893 static int parse_options (char *options, struct super_block *sb,
 894                           unsigned int *inum, unsigned long *journal_devnum,
 895                           ext4_fsblk_t *n_blocks_count, int is_remount)
 896 {
 897         struct ext4_sb_info *sbi = EXT4_SB(sb);
 898         char * p;
 899         substring_t args[MAX_OPT_ARGS];
 900         int data_opt = 0;
 901         int option;
 902 #ifdef CONFIG_QUOTA
 903         int qtype;
 904         char *qname;
 905 #endif
 906
 907         if (!options)
 908                 return 1;
 909
 910         while ((p = strsep (&options, ",")) != NULL) {
 911                 int token;
 912                 if (!*p)
 913                         continue;
 914
 915                 token = match_token(p, tokens, args);
 916                 switch (token) {
 917                 case Opt_bsd_df:
 918                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 919                         break;
 920                 case Opt_minix_df:
 921                         set_opt (sbi->s_mount_opt, MINIX_DF);
 922                         break;
 923                 case Opt_grpid:
 924                         set_opt (sbi->s_mount_opt, GRPID);
 925                         break;
 926                 case Opt_nogrpid:
 927                         clear_opt (sbi->s_mount_opt, GRPID);
 928                         break;
 929                 case Opt_resuid:
 930                         if (match_int(&args[0], &option))
 931                                 return 0;
 932                         sbi->s_resuid = option;
 933                         break;
 934                 case Opt_resgid:
 935                         if (match_int(&args[0], &option))
 936                                 return 0;
 937                         sbi->s_resgid = option;
 938                         break;
 939                 case Opt_sb:
 940                         /* handled by get_sb_block() instead of here */
 941                         /* *sb_block = match_int(&args[0]); */
 942                         break;
 943                 case Opt_err_panic:
 944                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 945                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 946                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 947                         break;
 948                 case Opt_err_ro:
 949                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 950                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 951                         set_opt (sbi->s_mount_opt, ERRORS_RO);
 952                         break;
 953                 case Opt_err_cont:
 954                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 955                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 956                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
 957                         break;
 958                 case Opt_nouid32:
 959                         set_opt (sbi->s_mount_opt, NO_UID32);
 960                         break;
 961                 case Opt_nocheck:
 962                         clear_opt (sbi->s_mount_opt, CHECK);
 963                         break;
 964                 case Opt_debug:
 965                         set_opt (sbi->s_mount_opt, DEBUG);
 966                         break;
 967                 case Opt_oldalloc:
 968                         set_opt (sbi->s_mount_opt, OLDALLOC);
 969                         break;
 970                 case Opt_orlov:
 971                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 972                         break;
 973 #ifdef CONFIG_EXT4DEV_FS_XATTR
 974                 case Opt_user_xattr:
 975                         set_opt (sbi->s_mount_opt, XATTR_USER);
 976                         break;
 977                 case Opt_nouser_xattr:
 978                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 979                         break;
 980 #else
 981                 case Opt_user_xattr:
 982                 case Opt_nouser_xattr:
 983                         printk("EXT4 (no)user_xattr options not supported\n");
 984                         break;
 985 #endif
 986 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 987                 case Opt_acl:
 988                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 989                         break;
 990                 case Opt_noacl:
 991                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 992                         break;
 993 #else
 994                 case Opt_acl:
 995                 case Opt_noacl:
 996                         printk("EXT4 (no)acl options not supported\n");
 997                         break;
 998 #endif
 999                 case Opt_reservation:
1000                         set_opt(sbi->s_mount_opt, RESERVATION);
1001                         break;
1002                 case Opt_noreservation:
1003                         clear_opt(sbi->s_mount_opt, RESERVATION);
1004                         break;
1005                 case Opt_journal_update:
1006                         /* @@@ FIXME */
1007                         /* Eventually we will want to be able to create
1008                            a journal file here.  For now, only allow the
1009                            user to specify an existing inode to be the
1010                            journal file. */
1011                         if (is_remount) {
1012                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1013                                        "journal on remount\n");
1014                                 return 0;
1015                         }
1016                         set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
1017                         break;
1018                 case Opt_journal_inum:
1019                         if (is_remount) {
1020                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1021                                        "journal on remount\n");
1022                                 return 0;
1023                         }
1024                         if (match_int(&args[0], &option))
1025                                 return 0;
1026                         *inum = option;
1027                         break;
1028                 case Opt_journal_dev:
1029                         if (is_remount) {
1030                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1031                                        "journal on remount\n");
1032                                 return 0;
1033                         }
1034                         if (match_int(&args[0], &option))
1035                                 return 0;
1036                         *journal_devnum = option;
1037                         break;
1038                 case Opt_noload:
1039                         set_opt (sbi->s_mount_opt, NOLOAD);
1040                         break;
1041                 case Opt_commit:
1042                         if (match_int(&args[0], &option))
1043                                 return 0;
1044                         if (option < 0)
1045                                 return 0;
1046                         if (option == 0)
1047                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1048                         sbi->s_commit_interval = HZ * option;
1049                         break;
1050                 case Opt_data_journal:
1051                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1052                         goto datacheck;
1053                 case Opt_data_ordered:
1054                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1055                         goto datacheck;
1056                 case Opt_data_writeback:
1057                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1058                 datacheck:
1059                         if (is_remount) {
1060                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1061                                                 != data_opt) {
1062                                         printk(KERN_ERR
1063                                                 "EXT4-fs: cannot change data "
1064                                                 "mode on remount\n");
1065                                         return 0;
1066                                 }
1067                         } else {
1068                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1069                                 sbi->s_mount_opt |= data_opt;
1070                         }
1071                         break;
1072 #ifdef CONFIG_QUOTA
1073                 case Opt_usrjquota:
1074                         qtype = USRQUOTA;
1075                         goto set_qf_name;
1076                 case Opt_grpjquota:
1077                         qtype = GRPQUOTA;
1078 set_qf_name:
1079                         if (sb_any_quota_enabled(sb)) {
1080                                 printk(KERN_ERR
1081                                         "EXT4-fs: Cannot change journalled "
1082                                         "quota options when quota turned on.\n");
1083                                 return 0;
1084                         }
1085                         qname = match_strdup(&args[0]);
1086                         if (!qname) {
1087                                 printk(KERN_ERR
1088                                         "EXT4-fs: not enough memory for "
1089                                         "storing quotafile name.\n");
1090                                 return 0;
1091                         }
1092                         if (sbi->s_qf_names[qtype] &&
1093                             strcmp(sbi->s_qf_names[qtype], qname)) {
1094                                 printk(KERN_ERR
1095                                         "EXT4-fs: %s quota file already "
1096                                         "specified.\n", QTYPE2NAME(qtype));
1097                                 kfree(qname);
1098                                 return 0;
1099                         }
1100                         sbi->s_qf_names[qtype] = qname;
1101                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1102                                 printk(KERN_ERR
1103                                         "EXT4-fs: quotafile must be on "
1104                                         "filesystem root.\n");
1105                                 kfree(sbi->s_qf_names[qtype]);
1106                                 sbi->s_qf_names[qtype] = NULL;
1107                                 return 0;
1108                         }
1109                         set_opt(sbi->s_mount_opt, QUOTA);
1110                         break;
1111                 case Opt_offusrjquota:
1112                         qtype = USRQUOTA;
1113                         goto clear_qf_name;
1114                 case Opt_offgrpjquota:
1115                         qtype = GRPQUOTA;
1116 clear_qf_name:
1117                         if (sb_any_quota_enabled(sb)) {
1118                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1119                                         "journalled quota options when "
1120                                         "quota turned on.\n");
1121                                 return 0;
1122                         }
1123                         /*
1124                          * The space will be released later when all options
1125                          * are confirmed to be correct
1126                          */
1127                         sbi->s_qf_names[qtype] = NULL;
1128                         break;
1129                 case Opt_jqfmt_vfsold:
1130                         sbi->s_jquota_fmt = QFMT_VFS_OLD;
1131                         break;
1132                 case Opt_jqfmt_vfsv0:
1133                         sbi->s_jquota_fmt = QFMT_VFS_V0;
1134                         break;
1135                 case Opt_quota:
1136                 case Opt_usrquota:
1137                         set_opt(sbi->s_mount_opt, QUOTA);
1138                         set_opt(sbi->s_mount_opt, USRQUOTA);
1139                         break;
1140                 case Opt_grpquota:
1141                         set_opt(sbi->s_mount_opt, QUOTA);
1142                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1143                         break;
1144                 case Opt_noquota:
1145                         if (sb_any_quota_enabled(sb)) {
1146                                 printk(KERN_ERR "EXT4-fs: Cannot change quota "
1147                                         "options when quota turned on.\n");
1148                                 return 0;
1149                         }
1150                         clear_opt(sbi->s_mount_opt, QUOTA);
1151                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1152                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1153                         break;
1154 #else
1155                 case Opt_quota:
1156                 case Opt_usrquota:
1157                 case Opt_grpquota:
1158                 case Opt_usrjquota:
1159                 case Opt_grpjquota:
1160                 case Opt_offusrjquota:
1161                 case Opt_offgrpjquota:
1162                 case Opt_jqfmt_vfsold:
1163                 case Opt_jqfmt_vfsv0:
1164                         printk(KERN_ERR
1165                                 "EXT4-fs: journalled quota options not "
1166                                 "supported.\n");
1167                         break;
1168                 case Opt_noquota:
1169                         break;
1170 #endif
1171                 case Opt_abort:
1172                         set_opt(sbi->s_mount_opt, ABORT);
1173                         break;
1174                 case Opt_barrier:
1175                         if (match_int(&args[0], &option))
1176                                 return 0;
1177                         if (option)
1178                                 set_opt(sbi->s_mount_opt, BARRIER);
1179                         else
1180                                 clear_opt(sbi->s_mount_opt, BARRIER);
1181                         break;
1182                 case Opt_ignore:
1183                         break;
1184                 case Opt_resize:
1185                         if (!is_remount) {
1186                                 printk("EXT4-fs: resize option only available "
1187                                         "for remount\n");
1188                                 return 0;
1189                         }
1190                         if (match_int(&args[0], &option) != 0)
1191                                 return 0;
1192                         *n_blocks_count = option;
1193                         break;
1194                 case Opt_nobh:
1195                         set_opt(sbi->s_mount_opt, NOBH);
1196                         break;
1197                 case Opt_bh:
1198                         clear_opt(sbi->s_mount_opt, NOBH);
1199                         break;
1200                 case Opt_extents:
1201                         set_opt (sbi->s_mount_opt, EXTENTS);
1202                         break;
1203                 case Opt_noextents:
1204                         clear_opt (sbi->s_mount_opt, EXTENTS);
1205                         break;
1206                 default:
1207                         printk (KERN_ERR
1208                                 "EXT4-fs: Unrecognized mount option \"%s\" "
1209                                 "or missing value\n", p);
1210                         return 0;
1211                 }
1212         }
1213 #ifdef CONFIG_QUOTA
1214         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1215                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1216                      sbi->s_qf_names[USRQUOTA])
1217                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1218
1219                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1220                      sbi->s_qf_names[GRPQUOTA])
1221                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1222
1223                 if ((sbi->s_qf_names[USRQUOTA] &&
1224                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1225                     (sbi->s_qf_names[GRPQUOTA] &&
1226                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1227                         printk(KERN_ERR "EXT4-fs: old and new quota "
1228                                         "format mixing.\n");
1229                         return 0;
1230                 }
1231
1232                 if (!sbi->s_jquota_fmt) {
1233                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1234                                         "not specified.\n");
1235                         return 0;
1236                 }
1237         } else {
1238                 if (sbi->s_jquota_fmt) {
1239                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1240                                         "specified with no journalling "
1241                                         "enabled.\n");
1242                         return 0;
1243                 }
1244         }
1245 #endif
1246         return 1;
1247 }
1248
1249 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1250                             int read_only)
1251 {
1252         struct ext4_sb_info *sbi = EXT4_SB(sb);
1253         int res = 0;
1254
1255         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1256                 printk (KERN_ERR "EXT4-fs warning: revision level too high, "
1257                         "forcing read-only mode\n");
1258                 res = MS_RDONLY;
1259         }
1260         if (read_only)
1261                 return res;
1262         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1263                 printk (KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1264                         "running e2fsck is recommended\n");
1265         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1266                 printk (KERN_WARNING
1267                         "EXT4-fs warning: mounting fs with errors, "
1268                         "running e2fsck is recommended\n");
1269         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1270                  le16_to_cpu(es->s_mnt_count) >=
1271                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1272                 printk (KERN_WARNING
1273                         "EXT4-fs warning: maximal mount count reached, "
1274                         "running e2fsck is recommended\n");
1275         else if (le32_to_cpu(es->s_checkinterval) &&
1276                 (le32_to_cpu(es->s_lastcheck) +
1277                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1278                 printk (KERN_WARNING
1279                         "EXT4-fs warning: checktime reached, "
1280                         "running e2fsck is recommended\n");
1281 #if 0
1282                 /* @@@ We _will_ want to clear the valid bit if we find
1283                  * inconsistencies, to force a fsck at reboot.  But for
1284                  * a plain journaled filesystem we can keep it set as
1285                  * valid forever! :)
1286                  */
1287         es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT4_VALID_FS);
1288 #endif
1289         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1290                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1291         es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
1292         es->s_mtime = cpu_to_le32(get_seconds());
1293         ext4_update_dynamic_rev(sb);
1294         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1295
1296         ext4_commit_super(sb, es, 1);
1297         if (test_opt(sb, DEBUG))
1298                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%lu, "
1299                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1300                         sb->s_blocksize,
1301                         sbi->s_groups_count,
1302                         EXT4_BLOCKS_PER_GROUP(sb),
1303                         EXT4_INODES_PER_GROUP(sb),
1304                         sbi->s_mount_opt);
1305
1306         printk(KERN_INFO "EXT4 FS on %s, ", sb->s_id);
1307         if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
1308                 char b[BDEVNAME_SIZE];
1309
1310                 printk("external journal on %s\n",
1311                         bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
1312         } else {
1313                 printk("internal journal\n");
1314         }
1315         return res;
1316 }
1317
1318 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1319                             struct ext4_group_desc *gdp)
1320 {
1321         __u16 crc = 0;
1322
1323         if (sbi->s_es->s_feature_ro_compat &
1324             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1325                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1326                 __le32 le_group = cpu_to_le32(block_group);
1327
1328                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1329                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1330                 crc = crc16(crc, (__u8 *)gdp, offset);
1331                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1332                 /* for checksum of struct ext4_group_desc do the rest...*/
1333                 if ((sbi->s_es->s_feature_incompat &
1334                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1335                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1336                         crc = crc16(crc, (__u8 *)gdp + offset,
1337                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1338                                         offset);
1339         }
1340
1341         return cpu_to_le16(crc);
1342 }
1343
1344 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1345                                 struct ext4_group_desc *gdp)
1346 {
1347         if ((sbi->s_es->s_feature_ro_compat &
1348              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1349             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1350                 return 0;
1351
1352         return 1;
1353 }
1354
1355 /* Called at mount-time, super-block is locked */
1356 static int ext4_check_descriptors (struct super_block * sb)
1357 {
1358         struct ext4_sb_info *sbi = EXT4_SB(sb);
1359         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1360         ext4_fsblk_t last_block;
1361         ext4_fsblk_t block_bitmap;
1362         ext4_fsblk_t inode_bitmap;
1363         ext4_fsblk_t inode_table;
1364         struct ext4_group_desc * gdp = NULL;
1365         int desc_block = 0;
1366         int flexbg_flag = 0;
1367         int i;
1368
1369         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1370                 flexbg_flag = 1;
1371
1372         ext4_debug ("Checking group descriptors");
1373
1374         for (i = 0; i < sbi->s_groups_count; i++)
1375         {
1376                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1377                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1378                 else
1379                         last_block = first_block +
1380                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1381
1382                 if ((i % EXT4_DESC_PER_BLOCK(sb)) == 0)
1383                         gdp = (struct ext4_group_desc *)
1384                                         sbi->s_group_desc[desc_block++]->b_data;
1385                 block_bitmap = ext4_block_bitmap(sb, gdp);
1386                 if (block_bitmap < first_block || block_bitmap > last_block)
1387                 {
1388                         ext4_error (sb, "ext4_check_descriptors",
1389                                     "Block bitmap for group %d"
1390                                     " not in group (block %llu)!",
1391                                     i, block_bitmap);
1392                         return 0;
1393                 }
1394                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1395                 if (inode_bitmap < first_block || inode_bitmap > last_block)
1396                 {
1397                         ext4_error (sb, "ext4_check_descriptors",
1398                                     "Inode bitmap for group %d"
1399                                     " not in group (block %llu)!",
1400                                     i, inode_bitmap);
1401                         return 0;
1402                 }
1403                 inode_table = ext4_inode_table(sb, gdp);
1404                 if (inode_table < first_block ||
1405                     inode_table + sbi->s_itb_per_group - 1 > last_block)
1406                 {
1407                         ext4_error (sb, "ext4_check_descriptors",
1408                                     "Inode table for group %d"
1409                                     " not in group (block %llu)!",
1410                                     i, inode_table);
1411                         return 0;
1412                 }
1413                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1414                         ext4_error(sb, __FUNCTION__,
1415                                    "Checksum for group %d failed (%u!=%u)\n", i,
1416                                    le16_to_cpu(ext4_group_desc_csum(sbi, i,
1417                                                                     gdp)),
1418                                    le16_to_cpu(gdp->bg_checksum));
1419                         return 0;
1420                 }
1421                 if (!flexbg_flag)
1422                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1423                 gdp = (struct ext4_group_desc *)
1424                         ((__u8 *)gdp + EXT4_DESC_SIZE(sb));
1425         }
1426
1427         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1428         sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
1429         return 1;
1430 }
1431
1432
1433 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1434  * the superblock) which were deleted from all directories, but held open by
1435  * a process at the time of a crash.  We walk the list and try to delete these
1436  * inodes at recovery time (only with a read-write filesystem).
1437  *
1438  * In order to keep the orphan inode chain consistent during traversal (in
1439  * case of crash during recovery), we link each inode into the superblock
1440  * orphan list_head and handle it the same way as an inode deletion during
1441  * normal operation (which journals the operations for us).
1442  *
1443  * We only do an iget() and an iput() on each inode, which is very safe if we
1444  * accidentally point at an in-use or already deleted inode.  The worst that
1445  * can happen in this case is that we get a "bit already cleared" message from
1446  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1447  * e2fsck was run on this filesystem, and it must have already done the orphan
1448  * inode cleanup for us, so we can safely abort without any further action.
1449  */
1450 static void ext4_orphan_cleanup (struct super_block * sb,
1451                                  struct ext4_super_block * es)
1452 {
1453         unsigned int s_flags = sb->s_flags;
1454         int nr_orphans = 0, nr_truncates = 0;
1455 #ifdef CONFIG_QUOTA
1456         int i;
1457 #endif
1458         if (!es->s_last_orphan) {
1459                 jbd_debug(4, "no orphan inodes to clean up\n");
1460                 return;
1461         }
1462
1463         if (bdev_read_only(sb->s_bdev)) {
1464                 printk(KERN_ERR "EXT4-fs: write access "
1465                         "unavailable, skipping orphan cleanup.\n");
1466                 return;
1467         }
1468
1469         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1470                 if (es->s_last_orphan)
1471                         jbd_debug(1, "Errors on filesystem, "
1472                                   "clearing orphan list.\n");
1473                 es->s_last_orphan = 0;
1474                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1475                 return;
1476         }
1477
1478         if (s_flags & MS_RDONLY) {
1479                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1480                        sb->s_id);
1481                 sb->s_flags &= ~MS_RDONLY;
1482         }
1483 #ifdef CONFIG_QUOTA
1484         /* Needed for iput() to work correctly and not trash data */
1485         sb->s_flags |= MS_ACTIVE;
1486         /* Turn on quotas so that they are updated correctly */
1487         for (i = 0; i < MAXQUOTAS; i++) {
1488                 if (EXT4_SB(sb)->s_qf_names[i]) {
1489                         int ret = ext4_quota_on_mount(sb, i);
1490                         if (ret < 0)
1491                                 printk(KERN_ERR
1492                                         "EXT4-fs: Cannot turn on journalled "
1493                                         "quota: error %d\n", ret);
1494                 }
1495         }
1496 #endif
1497
1498         while (es->s_last_orphan) {
1499                 struct inode *inode;
1500
1501                 if (!(inode =
1502                       ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan)))) {
1503                         es->s_last_orphan = 0;
1504                         break;
1505                 }
1506
1507                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1508                 DQUOT_INIT(inode);
1509                 if (inode->i_nlink) {
1510                         printk(KERN_DEBUG
1511                                 "%s: truncating inode %lu to %Ld bytes\n",
1512                                 __FUNCTION__, inode->i_ino, inode->i_size);
1513                         jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
1514                                   inode->i_ino, inode->i_size);
1515                         ext4_truncate(inode);
1516                         nr_truncates++;
1517                 } else {
1518                         printk(KERN_DEBUG
1519                                 "%s: deleting unreferenced inode %lu\n",
1520                                 __FUNCTION__, inode->i_ino);
1521                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1522                                   inode->i_ino);
1523                         nr_orphans++;
1524                 }
1525                 iput(inode);  /* The delete magic happens here! */
1526         }
1527
1528 #define PLURAL(x) (x), ((x)==1) ? "" : "s"
1529
1530         if (nr_orphans)
1531                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1532                        sb->s_id, PLURAL(nr_orphans));
1533         if (nr_truncates)
1534                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1535                        sb->s_id, PLURAL(nr_truncates));
1536 #ifdef CONFIG_QUOTA
1537         /* Turn quotas off */
1538         for (i = 0; i < MAXQUOTAS; i++) {
1539                 if (sb_dqopt(sb)->files[i])
1540                         vfs_quota_off(sb, i);
1541         }
1542 #endif
1543         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1544 }
1545
1546 /*
1547  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
1548  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
1549  * We need to be 1 filesystem block less than the 2^32 sector limit.
1550  */
1551 static loff_t ext4_max_size(int bits)
1552 {
1553         loff_t res = EXT4_NDIR_BLOCKS;
1554         /* This constant is calculated to be the largest file size for a
1555          * dense, 4k-blocksize file such that the total number of
1556          * sectors in the file, including data and all indirect blocks,
1557          * does not exceed 2^32. */
1558         const loff_t upper_limit = 0x1ff7fffd000LL;
1559
1560         res += 1LL << (bits-2);
1561         res += 1LL << (2*(bits-2));
1562         res += 1LL << (3*(bits-2));
1563         res <<= bits;
1564         if (res > upper_limit)
1565                 res = upper_limit;
1566         return res;
1567 }
1568
1569 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1570                                 ext4_fsblk_t logical_sb_block, int nr)
1571 {
1572         struct ext4_sb_info *sbi = EXT4_SB(sb);
1573         unsigned long bg, first_meta_bg;
1574         int has_super = 0;
1575
1576         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1577
1578         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1579             nr < first_meta_bg)
1580                 return logical_sb_block + nr + 1;
1581         bg = sbi->s_desc_per_block * nr;
1582         if (ext4_bg_has_super(sb, bg))
1583                 has_super = 1;
1584         return (has_super + ext4_group_first_block_no(sb, bg));
1585 }
1586
1587
1588 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
1589 {
1590         struct buffer_head * bh;
1591         struct ext4_super_block *es = NULL;
1592         struct ext4_sb_info *sbi;
1593         ext4_fsblk_t block;
1594         ext4_fsblk_t sb_block = get_sb_block(&data);
1595         ext4_fsblk_t logical_sb_block;
1596         unsigned long offset = 0;
1597         unsigned int journal_inum = 0;
1598         unsigned long journal_devnum = 0;
1599         unsigned long def_mount_opts;
1600         struct inode *root;
1601         int blocksize;
1602         int hblock;
1603         int db_count;
1604         int i;
1605         int needs_recovery;
1606         __le32 features;
1607         __u64 blocks_count;
1608         int err;
1609
1610         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1611         if (!sbi)
1612                 return -ENOMEM;
1613         sb->s_fs_info = sbi;
1614         sbi->s_mount_opt = 0;
1615         sbi->s_resuid = EXT4_DEF_RESUID;
1616         sbi->s_resgid = EXT4_DEF_RESGID;
1617         sbi->s_sb_block = sb_block;
1618
1619         unlock_kernel();
1620
1621         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1622         if (!blocksize) {
1623                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1624                 goto out_fail;
1625         }
1626
1627         if (!sb_set_blocksize(sb, blocksize)) {
1628                 printk(KERN_ERR "EXT4-fs: bad blocksize %d.\n", blocksize);
1629                 goto out_fail;
1630         }
1631
1632         /*
1633          * The ext4 superblock will not be buffer aligned for other than 1kB
1634          * block sizes.  We need to calculate the offset from buffer start.
1635          */
1636         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1637                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1638                 offset = do_div(logical_sb_block, blocksize);
1639         } else {
1640                 logical_sb_block = sb_block;
1641         }
1642
1643         if (!(bh = sb_bread(sb, logical_sb_block))) {
1644                 printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
1645                 goto out_fail;
1646         }
1647         /*
1648          * Note: s_es must be initialized as soon as possible because
1649          *       some ext4 macro-instructions depend on its value
1650          */
1651         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1652         sbi->s_es = es;
1653         sb->s_magic = le16_to_cpu(es->s_magic);
1654         if (sb->s_magic != EXT4_SUPER_MAGIC)
1655                 goto cantfind_ext4;
1656
1657         /* Set defaults before we parse the mount options */
1658         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1659         if (def_mount_opts & EXT4_DEFM_DEBUG)
1660                 set_opt(sbi->s_mount_opt, DEBUG);
1661         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1662                 set_opt(sbi->s_mount_opt, GRPID);
1663         if (def_mount_opts & EXT4_DEFM_UID16)
1664                 set_opt(sbi->s_mount_opt, NO_UID32);
1665 #ifdef CONFIG_EXT4DEV_FS_XATTR
1666         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1667                 set_opt(sbi->s_mount_opt, XATTR_USER);
1668 #endif
1669 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1670         if (def_mount_opts & EXT4_DEFM_ACL)
1671                 set_opt(sbi->s_mount_opt, POSIX_ACL);
1672 #endif
1673         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1674                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1675         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1676                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1677         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1678                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1679
1680         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1681                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1682         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_RO)
1683                 set_opt(sbi->s_mount_opt, ERRORS_RO);
1684         else
1685                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
1686
1687         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1688         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1689
1690         set_opt(sbi->s_mount_opt, RESERVATION);
1691
1692         /*
1693          * turn on extents feature by default in ext4 filesystem
1694          * User -o noextents to turn it off
1695          */
1696         set_opt(sbi->s_mount_opt, EXTENTS);
1697
1698         if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
1699                             NULL, 0))
1700                 goto failed_mount;
1701
1702         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1703                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1704
1705         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1706             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1707              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1708              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1709                 printk(KERN_WARNING
1710                        "EXT4-fs warning: feature flags set on rev 0 fs, "
1711                        "running e2fsck is recommended\n");
1712         /*
1713          * Check feature flags regardless of the revision level, since we
1714          * previously didn't change the revision level when setting the flags,
1715          * so there is a chance incompat flags are set on a rev 0 filesystem.
1716          */
1717         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
1718         if (features) {
1719                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
1720                        "unsupported optional features (%x).\n",
1721                        sb->s_id, le32_to_cpu(features));
1722                 goto failed_mount;
1723         }
1724         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
1725         if (!(sb->s_flags & MS_RDONLY) && features) {
1726                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
1727                        "unsupported optional features (%x).\n",
1728                        sb->s_id, le32_to_cpu(features));
1729                 goto failed_mount;
1730         }
1731         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
1732
1733         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
1734             blocksize > EXT4_MAX_BLOCK_SIZE) {
1735                 printk(KERN_ERR
1736                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
1737                        blocksize, sb->s_id);
1738                 goto failed_mount;
1739         }
1740
1741         hblock = bdev_hardsect_size(sb->s_bdev);
1742         if (sb->s_blocksize != blocksize) {
1743                 /*
1744                  * Make sure the blocksize for the filesystem is larger
1745                  * than the hardware sectorsize for the machine.
1746                  */
1747                 if (blocksize < hblock) {
1748                         printk(KERN_ERR "EXT4-fs: blocksize %d too small for "
1749                                "device blocksize %d.\n", blocksize, hblock);
1750                         goto failed_mount;
1751                 }
1752
1753                 brelse (bh);
1754                 sb_set_blocksize(sb, blocksize);
1755                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1756                 offset = do_div(logical_sb_block, blocksize);
1757                 bh = sb_bread(sb, logical_sb_block);
1758                 if (!bh) {
1759                         printk(KERN_ERR
1760                                "EXT4-fs: Can't read superblock on 2nd try.\n");
1761                         goto failed_mount;
1762                 }
1763                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
1764                 sbi->s_es = es;
1765                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
1766                         printk (KERN_ERR
1767                                 "EXT4-fs: Magic mismatch, very weird !\n");
1768                         goto failed_mount;
1769                 }
1770         }
1771
1772         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
1773
1774         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
1775                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
1776                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
1777         } else {
1778                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1779                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1780                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
1781                     (!is_power_of_2(sbi->s_inode_size)) ||
1782                     (sbi->s_inode_size > blocksize)) {
1783                         printk (KERN_ERR
1784                                 "EXT4-fs: unsupported inode size: %d\n",
1785                                 sbi->s_inode_size);
1786                         goto failed_mount;
1787                 }
1788                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
1789                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
1790         }
1791         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
1792         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
1793                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
1794                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
1795                     !is_power_of_2(sbi->s_desc_size)) {
1796                         printk(KERN_ERR
1797                                "EXT4-fs: unsupported descriptor size %lu\n",
1798                                sbi->s_desc_size);
1799                         goto failed_mount;
1800                 }
1801         } else
1802                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
1803         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1804         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1805         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
1806                 goto cantfind_ext4;
1807         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
1808         if (sbi->s_inodes_per_block == 0)
1809                 goto cantfind_ext4;
1810         sbi->s_itb_per_group = sbi->s_inodes_per_group /
1811                                         sbi->s_inodes_per_block;
1812         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
1813         sbi->s_sbh = bh;
1814         sbi->s_mount_state = le16_to_cpu(es->s_state);
1815         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
1816         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
1817         for (i=0; i < 4; i++)
1818                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
1819         sbi->s_def_hash_version = es->s_def_hash_version;
1820
1821         if (sbi->s_blocks_per_group > blocksize * 8) {
1822                 printk (KERN_ERR
1823                         "EXT4-fs: #blocks per group too big: %lu\n",
1824                         sbi->s_blocks_per_group);
1825                 goto failed_mount;
1826         }
1827         if (sbi->s_inodes_per_group > blocksize * 8) {
1828                 printk (KERN_ERR
1829                         "EXT4-fs: #inodes per group too big: %lu\n",
1830                         sbi->s_inodes_per_group);
1831                 goto failed_mount;
1832         }
1833
1834         if (ext4_blocks_count(es) >
1835                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1836                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
1837                         " too large to mount safely\n", sb->s_id);
1838                 if (sizeof(sector_t) < 8)
1839                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
1840                                         "enabled\n");
1841                 goto failed_mount;
1842         }
1843
1844         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
1845                 goto cantfind_ext4;
1846         blocks_count = (ext4_blocks_count(es) -
1847                         le32_to_cpu(es->s_first_data_block) +
1848                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
1849         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
1850         sbi->s_groups_count = blocks_count;
1851         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
1852                    EXT4_DESC_PER_BLOCK(sb);
1853         sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
1854                                     GFP_KERNEL);
1855         if (sbi->s_group_desc == NULL) {
1856                 printk (KERN_ERR "EXT4-fs: not enough memory\n");
1857                 goto failed_mount;
1858         }
1859
1860         bgl_lock_init(&sbi->s_blockgroup_lock);
1861
1862         for (i = 0; i < db_count; i++) {
1863                 block = descriptor_loc(sb, logical_sb_block, i);
1864                 sbi->s_group_desc[i] = sb_bread(sb, block);
1865                 if (!sbi->s_group_desc[i]) {
1866                         printk (KERN_ERR "EXT4-fs: "
1867                                 "can't read group descriptor %d\n", i);
1868                         db_count = i;
1869                         goto failed_mount2;
1870                 }
1871         }
1872         if (!ext4_check_descriptors (sb)) {
1873                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
1874                 goto failed_mount2;
1875         }
1876         sbi->s_gdb_count = db_count;
1877         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1878         spin_lock_init(&sbi->s_next_gen_lock);
1879
1880         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1881                         ext4_count_free_blocks(sb));
1882         if (!err) {
1883                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1884                                 ext4_count_free_inodes(sb));
1885         }
1886         if (!err) {
1887                 err = percpu_counter_init(&sbi->s_dirs_counter,
1888                                 ext4_count_dirs(sb));
1889         }
1890         if (err) {
1891                 printk(KERN_ERR "EXT4-fs: insufficient memory\n");
1892                 goto failed_mount3;
1893         }
1894
1895         /* per fileystem reservation list head & lock */
1896         spin_lock_init(&sbi->s_rsv_window_lock);
1897         sbi->s_rsv_window_root = RB_ROOT;
1898         /* Add a single, static dummy reservation to the start of the
1899          * reservation window list --- it gives us a placeholder for
1900          * append-at-start-of-list which makes the allocation logic
1901          * _much_ simpler. */
1902         sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1903         sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1904         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1905         sbi->s_rsv_window_head.rsv_goal_size = 0;
1906         ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
1907
1908         /*
1909          * set up enough so that it can read an inode
1910          */
1911         sb->s_op = &ext4_sops;
1912         sb->s_export_op = &ext4_export_ops;
1913         sb->s_xattr = ext4_xattr_handlers;
1914 #ifdef CONFIG_QUOTA
1915         sb->s_qcop = &ext4_qctl_operations;
1916         sb->dq_op = &ext4_quota_operations;
1917 #endif
1918         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
1919
1920         sb->s_root = NULL;
1921
1922         needs_recovery = (es->s_last_orphan != 0 ||
1923                           EXT4_HAS_INCOMPAT_FEATURE(sb,
1924                                     EXT4_FEATURE_INCOMPAT_RECOVER));
1925
1926         /*
1927          * The first inode we look at is the journal inode.  Don't try
1928          * root first: it may be modified in the journal!
1929          */
1930         if (!test_opt(sb, NOLOAD) &&
1931             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
1932                 if (ext4_load_journal(sb, es, journal_devnum))
1933                         goto failed_mount3;
1934         } else if (journal_inum) {
1935                 if (ext4_create_journal(sb, es, journal_inum))
1936                         goto failed_mount3;
1937         } else {
1938                 if (!silent)
1939                         printk (KERN_ERR
1940                                 "ext4: No journal on filesystem on %s\n",
1941                                 sb->s_id);
1942                 goto failed_mount3;
1943         }
1944
1945         if (ext4_blocks_count(es) > 0xffffffffULL &&
1946             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
1947                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
1948                 printk(KERN_ERR "ext4: Failed to set 64-bit journal feature\n");
1949                 goto failed_mount4;
1950         }
1951
1952         /* We have now updated the journal if required, so we can
1953          * validate the data journaling mode. */
1954         switch (test_opt(sb, DATA_FLAGS)) {
1955         case 0:
1956                 /* No mode set, assume a default based on the journal
1957                  * capabilities: ORDERED_DATA if the journal can
1958                  * cope, else JOURNAL_DATA
1959                  */
1960                 if (jbd2_journal_check_available_features
1961                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
1962                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
1963                 else
1964                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
1965                 break;
1966
1967         case EXT4_MOUNT_ORDERED_DATA:
1968         case EXT4_MOUNT_WRITEBACK_DATA:
1969                 if (!jbd2_journal_check_available_features
1970                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
1971                         printk(KERN_ERR "EXT4-fs: Journal does not support "
1972                                "requested data journaling mode\n");
1973                         goto failed_mount4;
1974                 }
1975         default:
1976                 break;
1977         }
1978
1979         if (test_opt(sb, NOBH)) {
1980                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
1981                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
1982                                 "its supported only with writeback mode\n");
1983                         clear_opt(sbi->s_mount_opt, NOBH);
1984                 }
1985         }
1986         /*
1987          * The jbd2_journal_load will have done any necessary log recovery,
1988          * so we can safely mount the rest of the filesystem now.
1989          */
1990
1991         root = iget(sb, EXT4_ROOT_INO);
1992         sb->s_root = d_alloc_root(root);
1993         if (!sb->s_root) {
1994                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
1995                 iput(root);
1996                 goto failed_mount4;
1997         }
1998         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1999                 dput(sb->s_root);
2000                 sb->s_root = NULL;
2001                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
2002                 goto failed_mount4;
2003         }
2004
2005         ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
2006
2007         /* determine the minimum size of new large inodes, if present */
2008         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2009                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2010                                                      EXT4_GOOD_OLD_INODE_SIZE;
2011                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2012                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2013                         if (sbi->s_want_extra_isize <
2014                             le16_to_cpu(es->s_want_extra_isize))
2015                                 sbi->s_want_extra_isize =
2016                                         le16_to_cpu(es->s_want_extra_isize);
2017                         if (sbi->s_want_extra_isize <
2018                             le16_to_cpu(es->s_min_extra_isize))
2019                                 sbi->s_want_extra_isize =
2020                                         le16_to_cpu(es->s_min_extra_isize);
2021                 }
2022         }
2023         /* Check if enough inode space is available */
2024         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2025                                                         sbi->s_inode_size) {
2026                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2027                                                        EXT4_GOOD_OLD_INODE_SIZE;
2028                 printk(KERN_INFO "EXT4-fs: required extra inode space not"
2029                         "available.\n");
2030         }
2031
2032         /*
2033          * akpm: core read_super() calls in here with the superblock locked.
2034          * That deadlocks, because orphan cleanup needs to lock the superblock
2035          * in numerous places.  Here we just pop the lock - it's relatively
2036          * harmless, because we are now ready to accept write_super() requests,
2037          * and aviro says that's the only reason for hanging onto the
2038          * superblock lock.
2039          */
2040         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2041         ext4_orphan_cleanup(sb, es);
2042         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2043         if (needs_recovery)
2044                 printk (KERN_INFO "EXT4-fs: recovery complete.\n");
2045         ext4_mark_recovery_complete(sb, es);
2046         printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
2047                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
2048                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
2049                 "writeback");
2050
2051         ext4_ext_init(sb);
2052
2053         lock_kernel();
2054         return 0;
2055
2056 cantfind_ext4:
2057         if (!silent)
2058                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
2059                        sb->s_id);
2060         goto failed_mount;
2061
2062 failed_mount4:
2063         jbd2_journal_destroy(sbi->s_journal);
2064 failed_mount3:
2065         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2066         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2067         percpu_counter_destroy(&sbi->s_dirs_counter);
2068 failed_mount2:
2069         for (i = 0; i < db_count; i++)
2070                 brelse(sbi->s_group_desc[i]);
2071         kfree(sbi->s_group_desc);
2072 failed_mount:
2073 #ifdef CONFIG_QUOTA
2074         for (i = 0; i < MAXQUOTAS; i++)
2075                 kfree(sbi->s_qf_names[i]);
2076 #endif
2077         ext4_blkdev_remove(sbi);
2078         brelse(bh);
2079 out_fail:
2080         sb->s_fs_info = NULL;
2081         kfree(sbi);
2082         lock_kernel();
2083         return -EINVAL;
2084 }
2085
2086 /*
2087  * Setup any per-fs journal parameters now.  We'll do this both on
2088  * initial mount, once the journal has been initialised but before we've
2089  * done any recovery; and again on any subsequent remount.
2090  */
2091 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2092 {
2093         struct ext4_sb_info *sbi = EXT4_SB(sb);
2094
2095         if (sbi->s_commit_interval)
2096                 journal->j_commit_interval = sbi->s_commit_interval;
2097         /* We could also set up an ext4-specific default for the commit
2098          * interval here, but for now we'll just fall back to the jbd
2099          * default. */
2100
2101         spin_lock(&journal->j_state_lock);
2102         if (test_opt(sb, BARRIER))
2103                 journal->j_flags |= JBD2_BARRIER;
2104         else
2105                 journal->j_flags &= ~JBD2_BARRIER;
2106         spin_unlock(&journal->j_state_lock);
2107 }
2108
2109 static journal_t *ext4_get_journal(struct super_block *sb,
2110                                    unsigned int journal_inum)
2111 {
2112         struct inode *journal_inode;
2113         journal_t *journal;
2114
2115         /* First, test for the existence of a valid inode on disk.  Bad
2116          * things happen if we iget() an unused inode, as the subsequent
2117          * iput() will try to delete it. */
2118
2119         journal_inode = iget(sb, journal_inum);
2120         if (!journal_inode) {
2121                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
2122                 return NULL;
2123         }
2124         if (!journal_inode->i_nlink) {
2125                 make_bad_inode(journal_inode);
2126                 iput(journal_inode);
2127                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
2128                 return NULL;
2129         }
2130
2131         jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
2132                   journal_inode, journal_inode->i_size);
2133         if (is_bad_inode(journal_inode) || !S_ISREG(journal_inode->i_mode)) {
2134                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
2135                 iput(journal_inode);
2136                 return NULL;
2137         }
2138
2139         journal = jbd2_journal_init_inode(journal_inode);
2140         if (!journal) {
2141                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
2142                 iput(journal_inode);
2143                 return NULL;
2144         }
2145         journal->j_private = sb;
2146         ext4_init_journal_params(sb, journal);
2147         return journal;
2148 }
2149
2150 static journal_t *ext4_get_dev_journal(struct super_block *sb,
2151                                        dev_t j_dev)
2152 {
2153         struct buffer_head * bh;
2154         journal_t *journal;
2155         ext4_fsblk_t start;
2156         ext4_fsblk_t len;
2157         int hblock, blocksize;
2158         ext4_fsblk_t sb_block;
2159         unsigned long offset;
2160         struct ext4_super_block * es;
2161         struct block_device *bdev;
2162
2163         bdev = ext4_blkdev_get(j_dev);
2164         if (bdev == NULL)
2165                 return NULL;
2166
2167         if (bd_claim(bdev, sb)) {
2168                 printk(KERN_ERR
2169                         "EXT4: failed to claim external journal device.\n");
2170                 blkdev_put(bdev);
2171                 return NULL;
2172         }
2173
2174         blocksize = sb->s_blocksize;
2175         hblock = bdev_hardsect_size(bdev);
2176         if (blocksize < hblock) {
2177                 printk(KERN_ERR
2178                         "EXT4-fs: blocksize too small for journal device.\n");
2179                 goto out_bdev;
2180         }
2181
2182         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2183         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2184         set_blocksize(bdev, blocksize);
2185         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2186                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2187                        "external journal\n");
2188                 goto out_bdev;
2189         }
2190
2191         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2192         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2193             !(le32_to_cpu(es->s_feature_incompat) &
2194               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2195                 printk(KERN_ERR "EXT4-fs: external journal has "
2196                                         "bad superblock\n");
2197                 brelse(bh);
2198                 goto out_bdev;
2199         }
2200
2201         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2202                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2203                 brelse(bh);
2204                 goto out_bdev;
2205         }
2206
2207         len = ext4_blocks_count(es);
2208         start = sb_block + 1;
2209         brelse(bh);     /* we're done with the superblock */
2210
2211         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2212                                         start, len, blocksize);
2213         if (!journal) {
2214                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2215                 goto out_bdev;
2216         }
2217         journal->j_private = sb;
2218         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2219         wait_on_buffer(journal->j_sb_buffer);
2220         if (!buffer_uptodate(journal->j_sb_buffer)) {
2221                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2222                 goto out_journal;
2223         }
2224         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2225                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2226                                         "user (unsupported) - %d\n",
2227                         be32_to_cpu(journal->j_superblock->s_nr_users));
2228                 goto out_journal;
2229         }
2230         EXT4_SB(sb)->journal_bdev = bdev;
2231         ext4_init_journal_params(sb, journal);
2232         return journal;
2233 out_journal:
2234         jbd2_journal_destroy(journal);
2235 out_bdev:
2236         ext4_blkdev_put(bdev);
2237         return NULL;
2238 }
2239
2240 static int ext4_load_journal(struct super_block *sb,
2241                              struct ext4_super_block *es,
2242                              unsigned long journal_devnum)
2243 {
2244         journal_t *journal;
2245         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2246         dev_t journal_dev;
2247         int err = 0;
2248         int really_read_only;
2249
2250         if (journal_devnum &&
2251             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2252                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2253                         "numbers have changed\n");
2254                 journal_dev = new_decode_dev(journal_devnum);
2255         } else
2256                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2257
2258         really_read_only = bdev_read_only(sb->s_bdev);
2259
2260         /*
2261          * Are we loading a blank journal or performing recovery after a
2262          * crash?  For recovery, we need to check in advance whether we
2263          * can get read-write access to the device.
2264          */
2265
2266         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2267                 if (sb->s_flags & MS_RDONLY) {
2268                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2269                                         "required on readonly filesystem.\n");
2270                         if (really_read_only) {
2271                                 printk(KERN_ERR "EXT4-fs: write access "
2272                                         "unavailable, cannot proceed.\n");
2273                                 return -EROFS;
2274                         }
2275                         printk (KERN_INFO "EXT4-fs: write access will "
2276                                         "be enabled during recovery.\n");
2277                 }
2278         }
2279
2280         if (journal_inum && journal_dev) {
2281                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2282                        "and inode journals!\n");
2283                 return -EINVAL;
2284         }
2285
2286         if (journal_inum) {
2287                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2288                         return -EINVAL;
2289         } else {
2290                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2291                         return -EINVAL;
2292         }
2293
2294         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2295                 err = jbd2_journal_update_format(journal);
2296                 if (err)  {
2297                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2298                         jbd2_journal_destroy(journal);
2299                         return err;
2300                 }
2301         }
2302
2303         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2304                 err = jbd2_journal_wipe(journal, !really_read_only);
2305         if (!err)
2306                 err = jbd2_journal_load(journal);
2307
2308         if (err) {
2309                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2310                 jbd2_journal_destroy(journal);
2311                 return err;
2312         }
2313
2314         EXT4_SB(sb)->s_journal = journal;
2315         ext4_clear_journal_err(sb, es);
2316
2317         if (journal_devnum &&
2318             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2319                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2320                 sb->s_dirt = 1;
2321
2322                 /* Make sure we flush the recovery flag to disk. */
2323                 ext4_commit_super(sb, es, 1);
2324         }
2325
2326         return 0;
2327 }
2328
2329 static int ext4_create_journal(struct super_block * sb,
2330                                struct ext4_super_block * es,
2331                                unsigned int journal_inum)
2332 {
2333         journal_t *journal;
2334         int err;
2335
2336         if (sb->s_flags & MS_RDONLY) {
2337                 printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2338                                 "create journal.\n");
2339                 return -EROFS;
2340         }
2341
2342         journal = ext4_get_journal(sb, journal_inum);
2343         if (!journal)
2344                 return -EINVAL;
2345
2346         printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2347                journal_inum);
2348
2349         err = jbd2_journal_create(journal);
2350         if (err) {
2351                 printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2352                 jbd2_journal_destroy(journal);
2353                 return -EIO;
2354         }
2355
2356         EXT4_SB(sb)->s_journal = journal;
2357
2358         ext4_update_dynamic_rev(sb);
2359         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2360         EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2361
2362         es->s_journal_inum = cpu_to_le32(journal_inum);
2363         sb->s_dirt = 1;
2364
2365         /* Make sure we flush the recovery flag to disk. */
2366         ext4_commit_super(sb, es, 1);
2367
2368         return 0;
2369 }
2370
2371 static void ext4_commit_super (struct super_block * sb,
2372                                struct ext4_super_block * es,
2373                                int sync)
2374 {
2375         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2376
2377         if (!sbh)
2378                 return;
2379         es->s_wtime = cpu_to_le32(get_seconds());
2380         ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2381         es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2382         BUFFER_TRACE(sbh, "marking dirty");
2383         mark_buffer_dirty(sbh);
2384         if (sync)
2385                 sync_dirty_buffer(sbh);
2386 }
2387
2388
2389 /*
2390  * Have we just finished recovery?  If so, and if we are mounting (or
2391  * remounting) the filesystem readonly, then we will end up with a
2392  * consistent fs on disk.  Record that fact.
2393  */
2394 static void ext4_mark_recovery_complete(struct super_block * sb,
2395                                         struct ext4_super_block * es)
2396 {
2397         journal_t *journal = EXT4_SB(sb)->s_journal;
2398
2399         jbd2_journal_lock_updates(journal);
2400         jbd2_journal_flush(journal);
2401         lock_super(sb);
2402         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2403             sb->s_flags & MS_RDONLY) {
2404                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2405                 sb->s_dirt = 0;
2406                 ext4_commit_super(sb, es, 1);
2407         }
2408         unlock_super(sb);
2409         jbd2_journal_unlock_updates(journal);
2410 }
2411
2412 /*
2413  * If we are mounting (or read-write remounting) a filesystem whose journal
2414  * has recorded an error from a previous lifetime, move that error to the
2415  * main filesystem now.
2416  */
2417 static void ext4_clear_journal_err(struct super_block * sb,
2418                                    struct ext4_super_block * es)
2419 {
2420         journal_t *journal;
2421         int j_errno;
2422         const char *errstr;
2423
2424         journal = EXT4_SB(sb)->s_journal;
2425
2426         /*
2427          * Now check for any error status which may have been recorded in the
2428          * journal by a prior ext4_error() or ext4_abort()
2429          */
2430
2431         j_errno = jbd2_journal_errno(journal);
2432         if (j_errno) {
2433                 char nbuf[16];
2434
2435                 errstr = ext4_decode_error(sb, j_errno, nbuf);
2436                 ext4_warning(sb, __FUNCTION__, "Filesystem error recorded "
2437                              "from previous mount: %s", errstr);
2438                 ext4_warning(sb, __FUNCTION__, "Marking fs in need of "
2439                              "filesystem check.");
2440
2441                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2442                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2443                 ext4_commit_super (sb, es, 1);
2444
2445                 jbd2_journal_clear_err(journal);
2446         }
2447 }
2448
2449 /*
2450  * Force the running and committing transactions to commit,
2451  * and wait on the commit.
2452  */
2453 int ext4_force_commit(struct super_block *sb)
2454 {
2455         journal_t *journal;
2456         int ret;
2457
2458         if (sb->s_flags & MS_RDONLY)
2459                 return 0;
2460
2461         journal = EXT4_SB(sb)->s_journal;
2462         sb->s_dirt = 0;
2463         ret = ext4_journal_force_commit(journal);
2464         return ret;
2465 }
2466
2467 /*
2468  * Ext4 always journals updates to the superblock itself, so we don't
2469  * have to propagate any other updates to the superblock on disk at this
2470  * point.  Just start an async writeback to get the buffers on their way
2471  * to the disk.
2472  *
2473  * This implicitly triggers the writebehind on sync().
2474  */
2475
2476 static void ext4_write_super (struct super_block * sb)
2477 {
2478         if (mutex_trylock(&sb->s_lock) != 0)
2479                 BUG();
2480         sb->s_dirt = 0;
2481 }
2482
2483 static int ext4_sync_fs(struct super_block *sb, int wait)
2484 {
2485         tid_t target;
2486
2487         sb->s_dirt = 0;
2488         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2489                 if (wait)
2490                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2491         }
2492         return 0;
2493 }
2494
2495 /*
2496  * LVM calls this function before a (read-only) snapshot is created.  This
2497  * gives us a chance to flush the journal completely and mark the fs clean.
2498  */
2499 static void ext4_write_super_lockfs(struct super_block *sb)
2500 {
2501         sb->s_dirt = 0;
2502
2503         if (!(sb->s_flags & MS_RDONLY)) {
2504                 journal_t *journal = EXT4_SB(sb)->s_journal;
2505
2506                 /* Now we set up the journal barrier. */
2507                 jbd2_journal_lock_updates(journal);
2508                 jbd2_journal_flush(journal);
2509
2510                 /* Journal blocked and flushed, clear needs_recovery flag. */
2511                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2512                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2513         }
2514 }
2515
2516 /*
2517  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2518  * flag here, even though the filesystem is not technically dirty yet.
2519  */
2520 static void ext4_unlockfs(struct super_block *sb)
2521 {
2522         if (!(sb->s_flags & MS_RDONLY)) {
2523                 lock_super(sb);
2524                 /* Reser the needs_recovery flag before the fs is unlocked. */
2525                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2526                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2527                 unlock_super(sb);
2528                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2529         }
2530 }
2531
2532 static int ext4_remount (struct super_block * sb, int * flags, char * data)
2533 {
2534         struct ext4_super_block * es;
2535         struct ext4_sb_info *sbi = EXT4_SB(sb);
2536         ext4_fsblk_t n_blocks_count = 0;
2537         unsigned long old_sb_flags;
2538         struct ext4_mount_options old_opts;
2539         int err;
2540 #ifdef CONFIG_QUOTA
2541         int i;
2542 #endif
2543
2544         /* Store the original options */
2545         old_sb_flags = sb->s_flags;
2546         old_opts.s_mount_opt = sbi->s_mount_opt;
2547         old_opts.s_resuid = sbi->s_resuid;
2548         old_opts.s_resgid = sbi->s_resgid;
2549         old_opts.s_commit_interval = sbi->s_commit_interval;
2550 #ifdef CONFIG_QUOTA
2551         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2552         for (i = 0; i < MAXQUOTAS; i++)
2553                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2554 #endif
2555
2556         /*
2557          * Allow the "check" option to be passed as a remount option.
2558          */
2559         if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2560                 err = -EINVAL;
2561                 goto restore_opts;
2562         }
2563
2564         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2565                 ext4_abort(sb, __FUNCTION__, "Abort forced by user");
2566
2567         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2568                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2569
2570         es = sbi->s_es;
2571
2572         ext4_init_journal_params(sb, sbi->s_journal);
2573
2574         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2575                 n_blocks_count > ext4_blocks_count(es)) {
2576                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
2577                         err = -EROFS;
2578                         goto restore_opts;
2579                 }
2580
2581                 if (*flags & MS_RDONLY) {
2582                         /*
2583                          * First of all, the unconditional stuff we have to do
2584                          * to disable replay of the journal when we next remount
2585                          */
2586                         sb->s_flags |= MS_RDONLY;
2587
2588                         /*
2589                          * OK, test if we are remounting a valid rw partition
2590                          * readonly, and if so set the rdonly flag and then
2591                          * mark the partition as valid again.
2592                          */
2593                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
2594                             (sbi->s_mount_state & EXT4_VALID_FS))
2595                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
2596
2597                         /*
2598                          * We have to unlock super so that we can wait for
2599                          * transactions.
2600                          */
2601                         unlock_super(sb);
2602                         ext4_mark_recovery_complete(sb, es);
2603                         lock_super(sb);
2604                 } else {
2605                         __le32 ret;
2606                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2607                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
2608                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2609                                        "remount RDWR because of unsupported "
2610                                        "optional features (%x).\n",
2611                                        sb->s_id, le32_to_cpu(ret));
2612                                 err = -EROFS;
2613                                 goto restore_opts;
2614                         }
2615
2616                         /*
2617                          * If we have an unprocessed orphan list hanging
2618                          * around from a previously readonly bdev mount,
2619                          * require a full umount/remount for now.
2620                          */
2621                         if (es->s_last_orphan) {
2622                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2623                                        "remount RDWR because of unprocessed "
2624                                        "orphan inode list.  Please "
2625                                        "umount/remount instead.\n",
2626                                        sb->s_id);
2627                                 err = -EINVAL;
2628                                 goto restore_opts;
2629                         }
2630
2631                         /*
2632                          * Mounting a RDONLY partition read-write, so reread
2633                          * and store the current valid flag.  (It may have
2634                          * been changed by e2fsck since we originally mounted
2635                          * the partition.)
2636                          */
2637                         ext4_clear_journal_err(sb, es);
2638                         sbi->s_mount_state = le16_to_cpu(es->s_state);
2639                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
2640                                 goto restore_opts;
2641                         if (!ext4_setup_super (sb, es, 0))
2642                                 sb->s_flags &= ~MS_RDONLY;
2643                 }
2644         }
2645 #ifdef CONFIG_QUOTA
2646         /* Release old quota file names */
2647         for (i = 0; i < MAXQUOTAS; i++)
2648                 if (old_opts.s_qf_names[i] &&
2649                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2650                         kfree(old_opts.s_qf_names[i]);
2651 #endif
2652         return 0;
2653 restore_opts:
2654         sb->s_flags = old_sb_flags;
2655         sbi->s_mount_opt = old_opts.s_mount_opt;
2656         sbi->s_resuid = old_opts.s_resuid;
2657         sbi->s_resgid = old_opts.s_resgid;
2658         sbi->s_commit_interval = old_opts.s_commit_interval;
2659 #ifdef CONFIG_QUOTA
2660         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
2661         for (i = 0; i < MAXQUOTAS; i++) {
2662                 if (sbi->s_qf_names[i] &&
2663                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2664                         kfree(sbi->s_qf_names[i]);
2665                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
2666         }
2667 #endif
2668         return err;
2669 }
2670
2671 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
2672 {
2673         struct super_block *sb = dentry->d_sb;
2674         struct ext4_sb_info *sbi = EXT4_SB(sb);
2675         struct ext4_super_block *es = sbi->s_es;
2676         u64 fsid;
2677
2678         if (test_opt(sb, MINIX_DF)) {
2679                 sbi->s_overhead_last = 0;
2680         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
2681                 unsigned long ngroups = sbi->s_groups_count, i;
2682                 ext4_fsblk_t overhead = 0;
2683                 smp_rmb();
2684
2685                 /*
2686                  * Compute the overhead (FS structures).  This is constant
2687                  * for a given filesystem unless the number of block groups
2688                  * changes so we cache the previous value until it does.
2689                  */
2690
2691                 /*
2692                  * All of the blocks before first_data_block are
2693                  * overhead
2694                  */
2695                 overhead = le32_to_cpu(es->s_first_data_block);
2696
2697                 /*
2698                  * Add the overhead attributed to the superblock and
2699                  * block group descriptors.  If the sparse superblocks
2700                  * feature is turned on, then not all groups have this.
2701                  */
2702                 for (i = 0; i < ngroups; i++) {
2703                         overhead += ext4_bg_has_super(sb, i) +
2704                                 ext4_bg_num_gdb(sb, i);
2705                         cond_resched();
2706                 }
2707
2708                 /*
2709                  * Every block group has an inode bitmap, a block
2710                  * bitmap, and an inode table.
2711                  */
2712                 overhead += ngroups * (2 + sbi->s_itb_per_group);
2713                 sbi->s_overhead_last = overhead;
2714                 smp_wmb();
2715                 sbi->s_blocks_last = ext4_blocks_count(es);
2716         }
2717
2718         buf->f_type = EXT4_SUPER_MAGIC;
2719         buf->f_bsize = sb->s_blocksize;
2720         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
2721         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter);
2722         ext4_free_blocks_count_set(es, buf->f_bfree);
2723         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
2724         if (buf->f_bfree < ext4_r_blocks_count(es))
2725                 buf->f_bavail = 0;
2726         buf->f_files = le32_to_cpu(es->s_inodes_count);
2727         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
2728         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
2729         buf->f_namelen = EXT4_NAME_LEN;
2730         fsid = le64_to_cpup((void *)es->s_uuid) ^
2731                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
2732         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
2733         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
2734         return 0;
2735 }
2736
2737 /* Helper function for writing quotas on sync - we need to start transaction before quota file
2738  * is locked for write. Otherwise the are possible deadlocks:
2739  * Process 1                         Process 2
2740  * ext4_create()                     quota_sync()
2741  *   jbd2_journal_start()                   write_dquot()
2742  *   DQUOT_INIT()                        down(dqio_mutex)
2743  *     down(dqio_mutex)                    jbd2_journal_start()
2744  *
2745  */
2746
2747 #ifdef CONFIG_QUOTA
2748
2749 static inline struct inode *dquot_to_inode(struct dquot *dquot)
2750 {
2751         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
2752 }
2753
2754 static int ext4_dquot_initialize(struct inode *inode, int type)
2755 {
2756         handle_t *handle;
2757         int ret, err;
2758
2759         /* We may create quota structure so we need to reserve enough blocks */
2760         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
2761         if (IS_ERR(handle))
2762                 return PTR_ERR(handle);
2763         ret = dquot_initialize(inode, type);
2764         err = ext4_journal_stop(handle);
2765         if (!ret)
2766                 ret = err;
2767         return ret;
2768 }
2769
2770 static int ext4_dquot_drop(struct inode *inode)
2771 {
2772         handle_t *handle;
2773         int ret, err;
2774
2775         /* We may delete quota structure so we need to reserve enough blocks */
2776         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
2777         if (IS_ERR(handle))
2778                 return PTR_ERR(handle);
2779         ret = dquot_drop(inode);
2780         err = ext4_journal_stop(handle);
2781         if (!ret)
2782                 ret = err;
2783         return ret;
2784 }
2785
2786 static int ext4_write_dquot(struct dquot *dquot)
2787 {
2788         int ret, err;
2789         handle_t *handle;
2790         struct inode *inode;
2791
2792         inode = dquot_to_inode(dquot);
2793         handle = ext4_journal_start(inode,
2794                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
2795         if (IS_ERR(handle))
2796                 return PTR_ERR(handle);
2797         ret = dquot_commit(dquot);
2798         err = ext4_journal_stop(handle);
2799         if (!ret)
2800                 ret = err;
2801         return ret;
2802 }
2803
2804 static int ext4_acquire_dquot(struct dquot *dquot)
2805 {
2806         int ret, err;
2807         handle_t *handle;
2808
2809         handle = ext4_journal_start(dquot_to_inode(dquot),
2810                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
2811         if (IS_ERR(handle))
2812                 return PTR_ERR(handle);
2813         ret = dquot_acquire(dquot);
2814         err = ext4_journal_stop(handle);
2815         if (!ret)
2816                 ret = err;
2817         return ret;
2818 }
2819
2820 static int ext4_release_dquot(struct dquot *dquot)
2821 {
2822         int ret, err;
2823         handle_t *handle;
2824
2825         handle = ext4_journal_start(dquot_to_inode(dquot),
2826                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
2827         if (IS_ERR(handle)) {
2828                 /* Release dquot anyway to avoid endless cycle in dqput() */
2829                 dquot_release(dquot);
2830                 return PTR_ERR(handle);
2831         }
2832         ret = dquot_release(dquot);
2833         err = ext4_journal_stop(handle);
2834         if (!ret)
2835                 ret = err;
2836         return ret;
2837 }
2838
2839 static int ext4_mark_dquot_dirty(struct dquot *dquot)
2840 {
2841         /* Are we journalling quotas? */
2842         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
2843             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
2844                 dquot_mark_dquot_dirty(dquot);
2845                 return ext4_write_dquot(dquot);
2846         } else {
2847                 return dquot_mark_dquot_dirty(dquot);
2848         }
2849 }
2850
2851 static int ext4_write_info(struct super_block *sb, int type)
2852 {
2853         int ret, err;
2854         handle_t *handle;
2855
2856         /* Data block + inode block */
2857         handle = ext4_journal_start(sb->s_root->d_inode, 2);
2858         if (IS_ERR(handle))
2859                 return PTR_ERR(handle);
2860         ret = dquot_commit_info(sb, type);
2861         err = ext4_journal_stop(handle);
2862         if (!ret)
2863                 ret = err;
2864         return ret;
2865 }
2866
2867 /*
2868  * Turn on quotas during mount time - we need to find
2869  * the quota file and such...
2870  */
2871 static int ext4_quota_on_mount(struct super_block *sb, int type)
2872 {
2873         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
2874                         EXT4_SB(sb)->s_jquota_fmt, type);
2875 }
2876
2877 /*
2878  * Standard function to be called on quota_on
2879  */
2880 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
2881                          char *path)
2882 {
2883         int err;
2884         struct nameidata nd;
2885
2886         if (!test_opt(sb, QUOTA))
2887                 return -EINVAL;
2888         /* Not journalling quota? */
2889         if (!EXT4_SB(sb)->s_qf_names[USRQUOTA] &&
2890             !EXT4_SB(sb)->s_qf_names[GRPQUOTA])
2891                 return vfs_quota_on(sb, type, format_id, path);
2892         err = path_lookup(path, LOOKUP_FOLLOW, &nd);
2893         if (err)
2894                 return err;
2895         /* Quotafile not on the same filesystem? */
2896         if (nd.mnt->mnt_sb != sb) {
2897                 path_release(&nd);
2898                 return -EXDEV;
2899         }
2900         /* Quotafile not of fs root? */
2901         if (nd.dentry->d_parent->d_inode != sb->s_root->d_inode)
2902                 printk(KERN_WARNING
2903                         "EXT4-fs: Quota file not on filesystem root. "
2904                         "Journalled quota will not work.\n");
2905         path_release(&nd);
2906         return vfs_quota_on(sb, type, format_id, path);
2907 }
2908
2909 /* Read data from quotafile - avoid pagecache and such because we cannot afford
2910  * acquiring the locks... As quota files are never truncated and quota code
2911  * itself serializes the operations (and noone else should touch the files)
2912  * we don't have to be afraid of races */
2913 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
2914                                size_t len, loff_t off)
2915 {
2916         struct inode *inode = sb_dqopt(sb)->files[type];
2917         sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2918         int err = 0;
2919         int offset = off & (sb->s_blocksize - 1);
2920         int tocopy;
2921         size_t toread;
2922         struct buffer_head *bh;
2923         loff_t i_size = i_size_read(inode);
2924
2925         if (off > i_size)
2926                 return 0;
2927         if (off+len > i_size)
2928                 len = i_size-off;
2929         toread = len;
2930         while (toread > 0) {
2931                 tocopy = sb->s_blocksize - offset < toread ?
2932                                 sb->s_blocksize - offset : toread;
2933                 bh = ext4_bread(NULL, inode, blk, 0, &err);
2934                 if (err)
2935                         return err;
2936                 if (!bh)        /* A hole? */
2937                         memset(data, 0, tocopy);
2938                 else
2939                         memcpy(data, bh->b_data+offset, tocopy);
2940                 brelse(bh);
2941                 offset = 0;
2942                 toread -= tocopy;
2943                 data += tocopy;
2944                 blk++;
2945         }
2946         return len;
2947 }
2948
2949 /* Write to quotafile (we know the transaction is already started and has
2950  * enough credits) */
2951 static ssize_t ext4_quota_write(struct super_block *sb, int type,
2952                                 const char *data, size_t len, loff_t off)
2953 {
2954         struct inode *inode = sb_dqopt(sb)->files[type];
2955         sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2956         int err = 0;
2957         int offset = off & (sb->s_blocksize - 1);
2958         int tocopy;
2959         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
2960         size_t towrite = len;
2961         struct buffer_head *bh;
2962         handle_t *handle = journal_current_handle();
2963
2964         if (!handle) {
2965                 printk(KERN_WARNING "EXT4-fs: Quota write (off=%Lu, len=%Lu)"
2966                         " cancelled because transaction is not started.\n",
2967                         (unsigned long long)off, (unsigned long long)len);
2968                 return -EIO;
2969         }
2970         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2971         while (towrite > 0) {
2972                 tocopy = sb->s_blocksize - offset < towrite ?
2973                                 sb->s_blocksize - offset : towrite;
2974                 bh = ext4_bread(handle, inode, blk, 1, &err);
2975                 if (!bh)
2976                         goto out;
2977                 if (journal_quota) {
2978                         err = ext4_journal_get_write_access(handle, bh);
2979                         if (err) {
2980                                 brelse(bh);
2981                                 goto out;
2982                         }
2983                 }
2984                 lock_buffer(bh);
2985                 memcpy(bh->b_data+offset, data, tocopy);
2986                 flush_dcache_page(bh->b_page);
2987                 unlock_buffer(bh);
2988                 if (journal_quota)
2989                         err = ext4_journal_dirty_metadata(handle, bh);
2990                 else {
2991                         /* Always do at least ordered writes for quotas */
2992                         err = ext4_journal_dirty_data(handle, bh);
2993                         mark_buffer_dirty(bh);
2994                 }
2995                 brelse(bh);
2996                 if (err)
2997                         goto out;
2998                 offset = 0;
2999                 towrite -= tocopy;
3000                 data += tocopy;
3001                 blk++;
3002         }
3003 out:
3004         if (len == towrite)
3005                 return err;
3006         if (inode->i_size < off+len-towrite) {
3007                 i_size_write(inode, off+len-towrite);
3008                 EXT4_I(inode)->i_disksize = inode->i_size;
3009         }
3010         inode->i_version++;
3011         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3012         ext4_mark_inode_dirty(handle, inode);
3013         mutex_unlock(&inode->i_mutex);
3014         return len - towrite;
3015 }
3016
3017 #endif
3018
3019 static int ext4_get_sb(struct file_system_type *fs_type,
3020         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3021 {
3022         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3023 }
3024
3025 static struct file_system_type ext4dev_fs_type = {
3026         .owner          = THIS_MODULE,
3027         .name           = "ext4dev",
3028         .get_sb         = ext4_get_sb,
3029         .kill_sb        = kill_block_super,
3030         .fs_flags       = FS_REQUIRES_DEV,
3031 };
3032
3033 static int __init init_ext4_fs(void)
3034 {
3035         int err = init_ext4_xattr();
3036         if (err)
3037                 return err;
3038         err = init_inodecache();
3039         if (err)
3040                 goto out1;
3041         err = register_filesystem(&ext4dev_fs_type);
3042         if (err)
3043                 goto out;
3044         return 0;
3045 out:
3046         destroy_inodecache();
3047 out1:
3048         exit_ext4_xattr();
3049         return err;
3050 }
3051
3052 static void __exit exit_ext4_fs(void)
3053 {
3054         unregister_filesystem(&ext4dev_fs_type);
3055         destroy_inodecache();
3056         exit_ext4_xattr();
3057 }
3058
3059 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
3060 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
3061 MODULE_LICENSE("GPL");
3062 module_init(init_ext4_fs)
3063 module_exit(exit_ext4_fs)