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 dentry *ext4_get_dentry(struct super_block *sb, void *vobjp)
 690 {
 691         __u32 *objp = vobjp;
 692         unsigned long ino = objp[0];
 693         __u32 generation = objp[1];
 694         struct inode *inode;
 695         struct dentry *result;
 696
 697         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 698                 return ERR_PTR(-ESTALE);
 699         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 700                 return ERR_PTR(-ESTALE);
 701
 702         /* iget isn't really right if the inode is currently unallocated!!
 703          *
 704          * ext4_read_inode will return a bad_inode if the inode had been
 705          * deleted, so we should be safe.
 706          *
 707          * Currently we don't know the generation for parent directory, so
 708          * a generation of 0 means "accept any"
 709          */
 710         inode = iget(sb, ino);
 711         if (inode == NULL)
 712                 return ERR_PTR(-ENOMEM);
 713         if (is_bad_inode(inode) ||
 714             (generation && inode->i_generation != generation)) {
 715                 iput(inode);
 716                 return ERR_PTR(-ESTALE);
 717         }
 718         /* now to find a dentry.
 719          * If possible, get a well-connected one
 720          */
 721         result = d_alloc_anon(inode);
 722         if (!result) {
 723                 iput(inode);
 724                 return ERR_PTR(-ENOMEM);
 725         }
 726         return result;
 727 }
 728
 729 #ifdef CONFIG_QUOTA
 730 #define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
 731 #define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 732
 733 static int ext4_dquot_initialize(struct inode *inode, int type);
 734 static int ext4_dquot_drop(struct inode *inode);
 735 static int ext4_write_dquot(struct dquot *dquot);
 736 static int ext4_acquire_dquot(struct dquot *dquot);
 737 static int ext4_release_dquot(struct dquot *dquot);
 738 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 739 static int ext4_write_info(struct super_block *sb, int type);
 740 static int ext4_quota_on(struct super_block *sb, int type, int format_id, char *path);
 741 static int ext4_quota_on_mount(struct super_block *sb, int type);
 742 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 743                                size_t len, loff_t off);
 744 static ssize_t ext4_quota_write(struct super_block *sb, int type,
 745                                 const char *data, size_t len, loff_t off);
 746
 747 static struct dquot_operations ext4_quota_operations = {
 748         .initialize     = ext4_dquot_initialize,
 749         .drop           = ext4_dquot_drop,
 750         .alloc_space    = dquot_alloc_space,
 751         .alloc_inode    = dquot_alloc_inode,
 752         .free_space     = dquot_free_space,
 753         .free_inode     = dquot_free_inode,
 754         .transfer       = dquot_transfer,
 755         .write_dquot    = ext4_write_dquot,
 756         .acquire_dquot  = ext4_acquire_dquot,
 757         .release_dquot  = ext4_release_dquot,
 758         .mark_dirty     = ext4_mark_dquot_dirty,
 759         .write_info     = ext4_write_info
 760 };
 761
 762 static struct quotactl_ops ext4_qctl_operations = {
 763         .quota_on       = ext4_quota_on,
 764         .quota_off      = vfs_quota_off,
 765         .quota_sync     = vfs_quota_sync,
 766         .get_info       = vfs_get_dqinfo,
 767         .set_info       = vfs_set_dqinfo,
 768         .get_dqblk      = vfs_get_dqblk,
 769         .set_dqblk      = vfs_set_dqblk
 770 };
 771 #endif
 772
 773 static const struct super_operations ext4_sops = {
 774         .alloc_inode    = ext4_alloc_inode,
 775         .destroy_inode  = ext4_destroy_inode,
 776         .read_inode     = ext4_read_inode,
 777         .write_inode    = ext4_write_inode,
 778         .dirty_inode    = ext4_dirty_inode,
 779         .delete_inode   = ext4_delete_inode,
 780         .put_super      = ext4_put_super,
 781         .write_super    = ext4_write_super,
 782         .sync_fs        = ext4_sync_fs,
 783         .write_super_lockfs = ext4_write_super_lockfs,
 784         .unlockfs       = ext4_unlockfs,
 785         .statfs         = ext4_statfs,
 786         .remount_fs     = ext4_remount,
 787         .clear_inode    = ext4_clear_inode,
 788         .show_options   = ext4_show_options,
 789 #ifdef CONFIG_QUOTA
 790         .quota_read     = ext4_quota_read,
 791         .quota_write    = ext4_quota_write,
 792 #endif
 793 };
 794
 795 static struct export_operations ext4_export_ops = {
 796         .get_parent = ext4_get_parent,
 797         .get_dentry = ext4_get_dentry,
 798 };
 799
 800 enum {
 801         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 802         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
 803         Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov,
 804         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
 805         Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
 806         Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
 807         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
 808         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 809         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
 810         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
 811         Opt_grpquota, Opt_extents, Opt_noextents,
 812 };
 813
 814 static match_table_t tokens = {
 815         {Opt_bsd_df, "bsddf"},
 816         {Opt_minix_df, "minixdf"},
 817         {Opt_grpid, "grpid"},
 818         {Opt_grpid, "bsdgroups"},
 819         {Opt_nogrpid, "nogrpid"},
 820         {Opt_nogrpid, "sysvgroups"},
 821         {Opt_resgid, "resgid=%u"},
 822         {Opt_resuid, "resuid=%u"},
 823         {Opt_sb, "sb=%u"},
 824         {Opt_err_cont, "errors=continue"},
 825         {Opt_err_panic, "errors=panic"},
 826         {Opt_err_ro, "errors=remount-ro"},
 827         {Opt_nouid32, "nouid32"},
 828         {Opt_nocheck, "nocheck"},
 829         {Opt_nocheck, "check=none"},
 830         {Opt_debug, "debug"},
 831         {Opt_oldalloc, "oldalloc"},
 832         {Opt_orlov, "orlov"},
 833         {Opt_user_xattr, "user_xattr"},
 834         {Opt_nouser_xattr, "nouser_xattr"},
 835         {Opt_acl, "acl"},
 836         {Opt_noacl, "noacl"},
 837         {Opt_reservation, "reservation"},
 838         {Opt_noreservation, "noreservation"},
 839         {Opt_noload, "noload"},
 840         {Opt_nobh, "nobh"},
 841         {Opt_bh, "bh"},
 842         {Opt_commit, "commit=%u"},
 843         {Opt_journal_update, "journal=update"},
 844         {Opt_journal_inum, "journal=%u"},
 845         {Opt_journal_dev, "journal_dev=%u"},
 846         {Opt_abort, "abort"},
 847         {Opt_data_journal, "data=journal"},
 848         {Opt_data_ordered, "data=ordered"},
 849         {Opt_data_writeback, "data=writeback"},
 850         {Opt_offusrjquota, "usrjquota="},
 851         {Opt_usrjquota, "usrjquota=%s"},
 852         {Opt_offgrpjquota, "grpjquota="},
 853         {Opt_grpjquota, "grpjquota=%s"},
 854         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
 855         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
 856         {Opt_grpquota, "grpquota"},
 857         {Opt_noquota, "noquota"},
 858         {Opt_quota, "quota"},
 859         {Opt_usrquota, "usrquota"},
 860         {Opt_barrier, "barrier=%u"},
 861         {Opt_extents, "extents"},
 862         {Opt_noextents, "noextents"},
 863         {Opt_err, NULL},
 864         {Opt_resize, "resize"},
 865 };
 866
 867 static ext4_fsblk_t get_sb_block(void **data)
 868 {
 869         ext4_fsblk_t    sb_block;
 870         char            *options = (char *) *data;
 871
 872         if (!options || strncmp(options, "sb=", 3) != 0)
 873                 return 1;       /* Default location */
 874         options += 3;
 875         /*todo: use simple_strtoll with >32bit ext4 */
 876         sb_block = simple_strtoul(options, &options, 0);
 877         if (*options && *options != ',') {
 878                 printk("EXT4-fs: Invalid sb specification: %s\n",
 879                        (char *) *data);
 880                 return 1;
 881         }
 882         if (*options == ',')
 883                 options++;
 884         *data = (void *) options;
 885         return sb_block;
 886 }
 887
 888 static int parse_options (char *options, struct super_block *sb,
 889                           unsigned int *inum, unsigned long *journal_devnum,
 890                           ext4_fsblk_t *n_blocks_count, int is_remount)
 891 {
 892         struct ext4_sb_info *sbi = EXT4_SB(sb);
 893         char * p;
 894         substring_t args[MAX_OPT_ARGS];
 895         int data_opt = 0;
 896         int option;
 897 #ifdef CONFIG_QUOTA
 898         int qtype;
 899         char *qname;
 900 #endif
 901
 902         if (!options)
 903                 return 1;
 904
 905         while ((p = strsep (&options, ",")) != NULL) {
 906                 int token;
 907                 if (!*p)
 908                         continue;
 909
 910                 token = match_token(p, tokens, args);
 911                 switch (token) {
 912                 case Opt_bsd_df:
 913                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 914                         break;
 915                 case Opt_minix_df:
 916                         set_opt (sbi->s_mount_opt, MINIX_DF);
 917                         break;
 918                 case Opt_grpid:
 919                         set_opt (sbi->s_mount_opt, GRPID);
 920                         break;
 921                 case Opt_nogrpid:
 922                         clear_opt (sbi->s_mount_opt, GRPID);
 923                         break;
 924                 case Opt_resuid:
 925                         if (match_int(&args[0], &option))
 926                                 return 0;
 927                         sbi->s_resuid = option;
 928                         break;
 929                 case Opt_resgid:
 930                         if (match_int(&args[0], &option))
 931                                 return 0;
 932                         sbi->s_resgid = option;
 933                         break;
 934                 case Opt_sb:
 935                         /* handled by get_sb_block() instead of here */
 936                         /* *sb_block = match_int(&args[0]); */
 937                         break;
 938                 case Opt_err_panic:
 939                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 940                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 941                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 942                         break;
 943                 case Opt_err_ro:
 944                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 945                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 946                         set_opt (sbi->s_mount_opt, ERRORS_RO);
 947                         break;
 948                 case Opt_err_cont:
 949                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 950                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 951                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
 952                         break;
 953                 case Opt_nouid32:
 954                         set_opt (sbi->s_mount_opt, NO_UID32);
 955                         break;
 956                 case Opt_nocheck:
 957                         clear_opt (sbi->s_mount_opt, CHECK);
 958                         break;
 959                 case Opt_debug:
 960                         set_opt (sbi->s_mount_opt, DEBUG);
 961                         break;
 962                 case Opt_oldalloc:
 963                         set_opt (sbi->s_mount_opt, OLDALLOC);
 964                         break;
 965                 case Opt_orlov:
 966                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 967                         break;
 968 #ifdef CONFIG_EXT4DEV_FS_XATTR
 969                 case Opt_user_xattr:
 970                         set_opt (sbi->s_mount_opt, XATTR_USER);
 971                         break;
 972                 case Opt_nouser_xattr:
 973                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 974                         break;
 975 #else
 976                 case Opt_user_xattr:
 977                 case Opt_nouser_xattr:
 978                         printk("EXT4 (no)user_xattr options not supported\n");
 979                         break;
 980 #endif
 981 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 982                 case Opt_acl:
 983                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 984                         break;
 985                 case Opt_noacl:
 986                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 987                         break;
 988 #else
 989                 case Opt_acl:
 990                 case Opt_noacl:
 991                         printk("EXT4 (no)acl options not supported\n");
 992                         break;
 993 #endif
 994                 case Opt_reservation:
 995                         set_opt(sbi->s_mount_opt, RESERVATION);
 996                         break;
 997                 case Opt_noreservation:
 998                         clear_opt(sbi->s_mount_opt, RESERVATION);
 999                         break;
1000                 case Opt_journal_update:
1001                         /* @@@ FIXME */
1002                         /* Eventually we will want to be able to create
1003                            a journal file here.  For now, only allow the
1004                            user to specify an existing inode to be the
1005                            journal file. */
1006                         if (is_remount) {
1007                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1008                                        "journal on remount\n");
1009                                 return 0;
1010                         }
1011                         set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
1012                         break;
1013                 case Opt_journal_inum:
1014                         if (is_remount) {
1015                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1016                                        "journal on remount\n");
1017                                 return 0;
1018                         }
1019                         if (match_int(&args[0], &option))
1020                                 return 0;
1021                         *inum = option;
1022                         break;
1023                 case Opt_journal_dev:
1024                         if (is_remount) {
1025                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1026                                        "journal on remount\n");
1027                                 return 0;
1028                         }
1029                         if (match_int(&args[0], &option))
1030                                 return 0;
1031                         *journal_devnum = option;
1032                         break;
1033                 case Opt_noload:
1034                         set_opt (sbi->s_mount_opt, NOLOAD);
1035                         break;
1036                 case Opt_commit:
1037                         if (match_int(&args[0], &option))
1038                                 return 0;
1039                         if (option < 0)
1040                                 return 0;
1041                         if (option == 0)
1042                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1043                         sbi->s_commit_interval = HZ * option;
1044                         break;
1045                 case Opt_data_journal:
1046                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1047                         goto datacheck;
1048                 case Opt_data_ordered:
1049                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1050                         goto datacheck;
1051                 case Opt_data_writeback:
1052                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1053                 datacheck:
1054                         if (is_remount) {
1055                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1056                                                 != data_opt) {
1057                                         printk(KERN_ERR
1058                                                 "EXT4-fs: cannot change data "
1059                                                 "mode on remount\n");
1060                                         return 0;
1061                                 }
1062                         } else {
1063                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1064                                 sbi->s_mount_opt |= data_opt;
1065                         }
1066                         break;
1067 #ifdef CONFIG_QUOTA
1068                 case Opt_usrjquota:
1069                         qtype = USRQUOTA;
1070                         goto set_qf_name;
1071                 case Opt_grpjquota:
1072                         qtype = GRPQUOTA;
1073 set_qf_name:
1074                         if (sb_any_quota_enabled(sb)) {
1075                                 printk(KERN_ERR
1076                                         "EXT4-fs: Cannot change journalled "
1077                                         "quota options when quota turned on.\n");
1078                                 return 0;
1079                         }
1080                         qname = match_strdup(&args[0]);
1081                         if (!qname) {
1082                                 printk(KERN_ERR
1083                                         "EXT4-fs: not enough memory for "
1084                                         "storing quotafile name.\n");
1085                                 return 0;
1086                         }
1087                         if (sbi->s_qf_names[qtype] &&
1088                             strcmp(sbi->s_qf_names[qtype], qname)) {
1089                                 printk(KERN_ERR
1090                                         "EXT4-fs: %s quota file already "
1091                                         "specified.\n", QTYPE2NAME(qtype));
1092                                 kfree(qname);
1093                                 return 0;
1094                         }
1095                         sbi->s_qf_names[qtype] = qname;
1096                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1097                                 printk(KERN_ERR
1098                                         "EXT4-fs: quotafile must be on "
1099                                         "filesystem root.\n");
1100                                 kfree(sbi->s_qf_names[qtype]);
1101                                 sbi->s_qf_names[qtype] = NULL;
1102                                 return 0;
1103                         }
1104                         set_opt(sbi->s_mount_opt, QUOTA);
1105                         break;
1106                 case Opt_offusrjquota:
1107                         qtype = USRQUOTA;
1108                         goto clear_qf_name;
1109                 case Opt_offgrpjquota:
1110                         qtype = GRPQUOTA;
1111 clear_qf_name:
1112                         if (sb_any_quota_enabled(sb)) {
1113                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1114                                         "journalled quota options when "
1115                                         "quota turned on.\n");
1116                                 return 0;
1117                         }
1118                         /*
1119                          * The space will be released later when all options
1120                          * are confirmed to be correct
1121                          */
1122                         sbi->s_qf_names[qtype] = NULL;
1123                         break;
1124                 case Opt_jqfmt_vfsold:
1125                         sbi->s_jquota_fmt = QFMT_VFS_OLD;
1126                         break;
1127                 case Opt_jqfmt_vfsv0:
1128                         sbi->s_jquota_fmt = QFMT_VFS_V0;
1129                         break;
1130                 case Opt_quota:
1131                 case Opt_usrquota:
1132                         set_opt(sbi->s_mount_opt, QUOTA);
1133                         set_opt(sbi->s_mount_opt, USRQUOTA);
1134                         break;
1135                 case Opt_grpquota:
1136                         set_opt(sbi->s_mount_opt, QUOTA);
1137                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1138                         break;
1139                 case Opt_noquota:
1140                         if (sb_any_quota_enabled(sb)) {
1141                                 printk(KERN_ERR "EXT4-fs: Cannot change quota "
1142                                         "options when quota turned on.\n");
1143                                 return 0;
1144                         }
1145                         clear_opt(sbi->s_mount_opt, QUOTA);
1146                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1147                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1148                         break;
1149 #else
1150                 case Opt_quota:
1151                 case Opt_usrquota:
1152                 case Opt_grpquota:
1153                 case Opt_usrjquota:
1154                 case Opt_grpjquota:
1155                 case Opt_offusrjquota:
1156                 case Opt_offgrpjquota:
1157                 case Opt_jqfmt_vfsold:
1158                 case Opt_jqfmt_vfsv0:
1159                         printk(KERN_ERR
1160                                 "EXT4-fs: journalled quota options not "
1161                                 "supported.\n");
1162                         break;
1163                 case Opt_noquota:
1164                         break;
1165 #endif
1166                 case Opt_abort:
1167                         set_opt(sbi->s_mount_opt, ABORT);
1168                         break;
1169                 case Opt_barrier:
1170                         if (match_int(&args[0], &option))
1171                                 return 0;
1172                         if (option)
1173                                 set_opt(sbi->s_mount_opt, BARRIER);
1174                         else
1175                                 clear_opt(sbi->s_mount_opt, BARRIER);
1176                         break;
1177                 case Opt_ignore:
1178                         break;
1179                 case Opt_resize:
1180                         if (!is_remount) {
1181                                 printk("EXT4-fs: resize option only available "
1182                                         "for remount\n");
1183                                 return 0;
1184                         }
1185                         if (match_int(&args[0], &option) != 0)
1186                                 return 0;
1187                         *n_blocks_count = option;
1188                         break;
1189                 case Opt_nobh:
1190                         set_opt(sbi->s_mount_opt, NOBH);
1191                         break;
1192                 case Opt_bh:
1193                         clear_opt(sbi->s_mount_opt, NOBH);
1194                         break;
1195                 case Opt_extents:
1196                         set_opt (sbi->s_mount_opt, EXTENTS);
1197                         break;
1198                 case Opt_noextents:
1199                         clear_opt (sbi->s_mount_opt, EXTENTS);
1200                         break;
1201                 default:
1202                         printk (KERN_ERR
1203                                 "EXT4-fs: Unrecognized mount option \"%s\" "
1204                                 "or missing value\n", p);
1205                         return 0;
1206                 }
1207         }
1208 #ifdef CONFIG_QUOTA
1209         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1210                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1211                      sbi->s_qf_names[USRQUOTA])
1212                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1213
1214                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1215                      sbi->s_qf_names[GRPQUOTA])
1216                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1217
1218                 if ((sbi->s_qf_names[USRQUOTA] &&
1219                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1220                     (sbi->s_qf_names[GRPQUOTA] &&
1221                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1222                         printk(KERN_ERR "EXT4-fs: old and new quota "
1223                                         "format mixing.\n");
1224                         return 0;
1225                 }
1226
1227                 if (!sbi->s_jquota_fmt) {
1228                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1229                                         "not specified.\n");
1230                         return 0;
1231                 }
1232         } else {
1233                 if (sbi->s_jquota_fmt) {
1234                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1235                                         "specified with no journalling "
1236                                         "enabled.\n");
1237                         return 0;
1238                 }
1239         }
1240 #endif
1241         return 1;
1242 }
1243
1244 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1245                             int read_only)
1246 {
1247         struct ext4_sb_info *sbi = EXT4_SB(sb);
1248         int res = 0;
1249
1250         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1251                 printk (KERN_ERR "EXT4-fs warning: revision level too high, "
1252                         "forcing read-only mode\n");
1253                 res = MS_RDONLY;
1254         }
1255         if (read_only)
1256                 return res;
1257         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1258                 printk (KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1259                         "running e2fsck is recommended\n");
1260         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1261                 printk (KERN_WARNING
1262                         "EXT4-fs warning: mounting fs with errors, "
1263                         "running e2fsck is recommended\n");
1264         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1265                  le16_to_cpu(es->s_mnt_count) >=
1266                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1267                 printk (KERN_WARNING
1268                         "EXT4-fs warning: maximal mount count reached, "
1269                         "running e2fsck is recommended\n");
1270         else if (le32_to_cpu(es->s_checkinterval) &&
1271                 (le32_to_cpu(es->s_lastcheck) +
1272                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1273                 printk (KERN_WARNING
1274                         "EXT4-fs warning: checktime reached, "
1275                         "running e2fsck is recommended\n");
1276 #if 0
1277                 /* @@@ We _will_ want to clear the valid bit if we find
1278                  * inconsistencies, to force a fsck at reboot.  But for
1279                  * a plain journaled filesystem we can keep it set as
1280                  * valid forever! :)
1281                  */
1282         es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT4_VALID_FS);
1283 #endif
1284         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1285                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1286         es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
1287         es->s_mtime = cpu_to_le32(get_seconds());
1288         ext4_update_dynamic_rev(sb);
1289         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1290
1291         ext4_commit_super(sb, es, 1);
1292         if (test_opt(sb, DEBUG))
1293                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%lu, "
1294                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1295                         sb->s_blocksize,
1296                         sbi->s_groups_count,
1297                         EXT4_BLOCKS_PER_GROUP(sb),
1298                         EXT4_INODES_PER_GROUP(sb),
1299                         sbi->s_mount_opt);
1300
1301         printk(KERN_INFO "EXT4 FS on %s, ", sb->s_id);
1302         if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
1303                 char b[BDEVNAME_SIZE];
1304
1305                 printk("external journal on %s\n",
1306                         bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
1307         } else {
1308                 printk("internal journal\n");
1309         }
1310         return res;
1311 }
1312
1313 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1314                             struct ext4_group_desc *gdp)
1315 {
1316         __u16 crc = 0;
1317
1318         if (sbi->s_es->s_feature_ro_compat &
1319             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1320                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1321                 __le32 le_group = cpu_to_le32(block_group);
1322
1323                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1324                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1325                 crc = crc16(crc, (__u8 *)gdp, offset);
1326                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1327                 /* for checksum of struct ext4_group_desc do the rest...*/
1328                 if ((sbi->s_es->s_feature_incompat &
1329                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1330                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1331                         crc = crc16(crc, (__u8 *)gdp + offset,
1332                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1333                                         offset);
1334         }
1335
1336         return cpu_to_le16(crc);
1337 }
1338
1339 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1340                                 struct ext4_group_desc *gdp)
1341 {
1342         if ((sbi->s_es->s_feature_ro_compat &
1343              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1344             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1345                 return 0;
1346
1347         return 1;
1348 }
1349
1350 /* Called at mount-time, super-block is locked */
1351 static int ext4_check_descriptors (struct super_block * sb)
1352 {
1353         struct ext4_sb_info *sbi = EXT4_SB(sb);
1354         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1355         ext4_fsblk_t last_block;
1356         ext4_fsblk_t block_bitmap;
1357         ext4_fsblk_t inode_bitmap;
1358         ext4_fsblk_t inode_table;
1359         struct ext4_group_desc * gdp = NULL;
1360         int desc_block = 0;
1361         int flexbg_flag = 0;
1362         int i;
1363
1364         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1365                 flexbg_flag = 1;
1366
1367         ext4_debug ("Checking group descriptors");
1368
1369         for (i = 0; i < sbi->s_groups_count; i++)
1370         {
1371                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1372                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1373                 else
1374                         last_block = first_block +
1375                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1376
1377                 if ((i % EXT4_DESC_PER_BLOCK(sb)) == 0)
1378                         gdp = (struct ext4_group_desc *)
1379                                         sbi->s_group_desc[desc_block++]->b_data;
1380                 block_bitmap = ext4_block_bitmap(sb, gdp);
1381                 if (block_bitmap < first_block || block_bitmap > last_block)
1382                 {
1383                         ext4_error (sb, "ext4_check_descriptors",
1384                                     "Block bitmap for group %d"
1385                                     " not in group (block %llu)!",
1386                                     i, block_bitmap);
1387                         return 0;
1388                 }
1389                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1390                 if (inode_bitmap < first_block || inode_bitmap > last_block)
1391                 {
1392                         ext4_error (sb, "ext4_check_descriptors",
1393                                     "Inode bitmap for group %d"
1394                                     " not in group (block %llu)!",
1395                                     i, inode_bitmap);
1396                         return 0;
1397                 }
1398                 inode_table = ext4_inode_table(sb, gdp);
1399                 if (inode_table < first_block ||
1400                     inode_table + sbi->s_itb_per_group - 1 > last_block)
1401                 {
1402                         ext4_error (sb, "ext4_check_descriptors",
1403                                     "Inode table for group %d"
1404                                     " not in group (block %llu)!",
1405                                     i, inode_table);
1406                         return 0;
1407                 }
1408                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1409                         ext4_error(sb, __FUNCTION__,
1410                                    "Checksum for group %d failed (%u!=%u)\n", i,
1411                                    le16_to_cpu(ext4_group_desc_csum(sbi, i,
1412                                                                     gdp)),
1413                                    le16_to_cpu(gdp->bg_checksum));
1414                         return 0;
1415                 }
1416                 if (!flexbg_flag)
1417                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1418                 gdp = (struct ext4_group_desc *)
1419                         ((__u8 *)gdp + EXT4_DESC_SIZE(sb));
1420         }
1421
1422         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1423         sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
1424         return 1;
1425 }
1426
1427
1428 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1429  * the superblock) which were deleted from all directories, but held open by
1430  * a process at the time of a crash.  We walk the list and try to delete these
1431  * inodes at recovery time (only with a read-write filesystem).
1432  *
1433  * In order to keep the orphan inode chain consistent during traversal (in
1434  * case of crash during recovery), we link each inode into the superblock
1435  * orphan list_head and handle it the same way as an inode deletion during
1436  * normal operation (which journals the operations for us).
1437  *
1438  * We only do an iget() and an iput() on each inode, which is very safe if we
1439  * accidentally point at an in-use or already deleted inode.  The worst that
1440  * can happen in this case is that we get a "bit already cleared" message from
1441  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1442  * e2fsck was run on this filesystem, and it must have already done the orphan
1443  * inode cleanup for us, so we can safely abort without any further action.
1444  */
1445 static void ext4_orphan_cleanup (struct super_block * sb,
1446                                  struct ext4_super_block * es)
1447 {
1448         unsigned int s_flags = sb->s_flags;
1449         int nr_orphans = 0, nr_truncates = 0;
1450 #ifdef CONFIG_QUOTA
1451         int i;
1452 #endif
1453         if (!es->s_last_orphan) {
1454                 jbd_debug(4, "no orphan inodes to clean up\n");
1455                 return;
1456         }
1457
1458         if (bdev_read_only(sb->s_bdev)) {
1459                 printk(KERN_ERR "EXT4-fs: write access "
1460                         "unavailable, skipping orphan cleanup.\n");
1461                 return;
1462         }
1463
1464         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1465                 if (es->s_last_orphan)
1466                         jbd_debug(1, "Errors on filesystem, "
1467                                   "clearing orphan list.\n");
1468                 es->s_last_orphan = 0;
1469                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1470                 return;
1471         }
1472
1473         if (s_flags & MS_RDONLY) {
1474                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1475                        sb->s_id);
1476                 sb->s_flags &= ~MS_RDONLY;
1477         }
1478 #ifdef CONFIG_QUOTA
1479         /* Needed for iput() to work correctly and not trash data */
1480         sb->s_flags |= MS_ACTIVE;
1481         /* Turn on quotas so that they are updated correctly */
1482         for (i = 0; i < MAXQUOTAS; i++) {
1483                 if (EXT4_SB(sb)->s_qf_names[i]) {
1484                         int ret = ext4_quota_on_mount(sb, i);
1485                         if (ret < 0)
1486                                 printk(KERN_ERR
1487                                         "EXT4-fs: Cannot turn on journalled "
1488                                         "quota: error %d\n", ret);
1489                 }
1490         }
1491 #endif
1492
1493         while (es->s_last_orphan) {
1494                 struct inode *inode;
1495
1496                 if (!(inode =
1497                       ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan)))) {
1498                         es->s_last_orphan = 0;
1499                         break;
1500                 }
1501
1502                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1503                 DQUOT_INIT(inode);
1504                 if (inode->i_nlink) {
1505                         printk(KERN_DEBUG
1506                                 "%s: truncating inode %lu to %Ld bytes\n",
1507                                 __FUNCTION__, inode->i_ino, inode->i_size);
1508                         jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
1509                                   inode->i_ino, inode->i_size);
1510                         ext4_truncate(inode);
1511                         nr_truncates++;
1512                 } else {
1513                         printk(KERN_DEBUG
1514                                 "%s: deleting unreferenced inode %lu\n",
1515                                 __FUNCTION__, inode->i_ino);
1516                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1517                                   inode->i_ino);
1518                         nr_orphans++;
1519                 }
1520                 iput(inode);  /* The delete magic happens here! */
1521         }
1522
1523 #define PLURAL(x) (x), ((x)==1) ? "" : "s"
1524
1525         if (nr_orphans)
1526                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1527                        sb->s_id, PLURAL(nr_orphans));
1528         if (nr_truncates)
1529                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1530                        sb->s_id, PLURAL(nr_truncates));
1531 #ifdef CONFIG_QUOTA
1532         /* Turn quotas off */
1533         for (i = 0; i < MAXQUOTAS; i++) {
1534                 if (sb_dqopt(sb)->files[i])
1535                         vfs_quota_off(sb, i);
1536         }
1537 #endif
1538         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1539 }
1540
1541 /*
1542  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
1543  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
1544  * We need to be 1 filesystem block less than the 2^32 sector limit.
1545  */
1546 static loff_t ext4_max_size(int bits)
1547 {
1548         loff_t res = EXT4_NDIR_BLOCKS;
1549         /* This constant is calculated to be the largest file size for a
1550          * dense, 4k-blocksize file such that the total number of
1551          * sectors in the file, including data and all indirect blocks,
1552          * does not exceed 2^32. */
1553         const loff_t upper_limit = 0x1ff7fffd000LL;
1554
1555         res += 1LL << (bits-2);
1556         res += 1LL << (2*(bits-2));
1557         res += 1LL << (3*(bits-2));
1558         res <<= bits;
1559         if (res > upper_limit)
1560                 res = upper_limit;
1561         return res;
1562 }
1563
1564 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1565                                 ext4_fsblk_t logical_sb_block, int nr)
1566 {
1567         struct ext4_sb_info *sbi = EXT4_SB(sb);
1568         unsigned long bg, first_meta_bg;
1569         int has_super = 0;
1570
1571         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1572
1573         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1574             nr < first_meta_bg)
1575                 return logical_sb_block + nr + 1;
1576         bg = sbi->s_desc_per_block * nr;
1577         if (ext4_bg_has_super(sb, bg))
1578                 has_super = 1;
1579         return (has_super + ext4_group_first_block_no(sb, bg));
1580 }
1581
1582
1583 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
1584 {
1585         struct buffer_head * bh;
1586         struct ext4_super_block *es = NULL;
1587         struct ext4_sb_info *sbi;
1588         ext4_fsblk_t block;
1589         ext4_fsblk_t sb_block = get_sb_block(&data);
1590         ext4_fsblk_t logical_sb_block;
1591         unsigned long offset = 0;
1592         unsigned int journal_inum = 0;
1593         unsigned long journal_devnum = 0;
1594         unsigned long def_mount_opts;
1595         struct inode *root;
1596         int blocksize;
1597         int hblock;
1598         int db_count;
1599         int i;
1600         int needs_recovery;
1601         __le32 features;
1602         __u64 blocks_count;
1603         int err;
1604
1605         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1606         if (!sbi)
1607                 return -ENOMEM;
1608         sb->s_fs_info = sbi;
1609         sbi->s_mount_opt = 0;
1610         sbi->s_resuid = EXT4_DEF_RESUID;
1611         sbi->s_resgid = EXT4_DEF_RESGID;
1612         sbi->s_sb_block = sb_block;
1613
1614         unlock_kernel();
1615
1616         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1617         if (!blocksize) {
1618                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1619                 goto out_fail;
1620         }
1621
1622         /*
1623          * The ext4 superblock will not be buffer aligned for other than 1kB
1624          * block sizes.  We need to calculate the offset from buffer start.
1625          */
1626         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1627                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1628                 offset = do_div(logical_sb_block, blocksize);
1629         } else {
1630                 logical_sb_block = sb_block;
1631         }
1632
1633         if (!(bh = sb_bread(sb, logical_sb_block))) {
1634                 printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
1635                 goto out_fail;
1636         }
1637         /*
1638          * Note: s_es must be initialized as soon as possible because
1639          *       some ext4 macro-instructions depend on its value
1640          */
1641         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1642         sbi->s_es = es;
1643         sb->s_magic = le16_to_cpu(es->s_magic);
1644         if (sb->s_magic != EXT4_SUPER_MAGIC)
1645                 goto cantfind_ext4;
1646
1647         /* Set defaults before we parse the mount options */
1648         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1649         if (def_mount_opts & EXT4_DEFM_DEBUG)
1650                 set_opt(sbi->s_mount_opt, DEBUG);
1651         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1652                 set_opt(sbi->s_mount_opt, GRPID);
1653         if (def_mount_opts & EXT4_DEFM_UID16)
1654                 set_opt(sbi->s_mount_opt, NO_UID32);
1655 #ifdef CONFIG_EXT4DEV_FS_XATTR
1656         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1657                 set_opt(sbi->s_mount_opt, XATTR_USER);
1658 #endif
1659 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1660         if (def_mount_opts & EXT4_DEFM_ACL)
1661                 set_opt(sbi->s_mount_opt, POSIX_ACL);
1662 #endif
1663         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1664                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1665         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1666                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1667         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1668                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1669
1670         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1671                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1672         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_RO)
1673                 set_opt(sbi->s_mount_opt, ERRORS_RO);
1674         else
1675                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
1676
1677         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1678         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1679
1680         set_opt(sbi->s_mount_opt, RESERVATION);
1681
1682         /*
1683          * turn on extents feature by default in ext4 filesystem
1684          * User -o noextents to turn it off
1685          */
1686         set_opt(sbi->s_mount_opt, EXTENTS);
1687
1688         if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
1689                             NULL, 0))
1690                 goto failed_mount;
1691
1692         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1693                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1694
1695         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1696             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1697              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1698              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1699                 printk(KERN_WARNING
1700                        "EXT4-fs warning: feature flags set on rev 0 fs, "
1701                        "running e2fsck is recommended\n");
1702         /*
1703          * Check feature flags regardless of the revision level, since we
1704          * previously didn't change the revision level when setting the flags,
1705          * so there is a chance incompat flags are set on a rev 0 filesystem.
1706          */
1707         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
1708         if (features) {
1709                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
1710                        "unsupported optional features (%x).\n",
1711                        sb->s_id, le32_to_cpu(features));
1712                 goto failed_mount;
1713         }
1714         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
1715         if (!(sb->s_flags & MS_RDONLY) && features) {
1716                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
1717                        "unsupported optional features (%x).\n",
1718                        sb->s_id, le32_to_cpu(features));
1719                 goto failed_mount;
1720         }
1721         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
1722
1723         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
1724             blocksize > EXT4_MAX_BLOCK_SIZE) {
1725                 printk(KERN_ERR
1726                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
1727                        blocksize, sb->s_id);
1728                 goto failed_mount;
1729         }
1730
1731         hblock = bdev_hardsect_size(sb->s_bdev);
1732         if (sb->s_blocksize != blocksize) {
1733                 /*
1734                  * Make sure the blocksize for the filesystem is larger
1735                  * than the hardware sectorsize for the machine.
1736                  */
1737                 if (blocksize < hblock) {
1738                         printk(KERN_ERR "EXT4-fs: blocksize %d too small for "
1739                                "device blocksize %d.\n", blocksize, hblock);
1740                         goto failed_mount;
1741                 }
1742
1743                 brelse (bh);
1744                 sb_set_blocksize(sb, blocksize);
1745                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1746                 offset = do_div(logical_sb_block, blocksize);
1747                 bh = sb_bread(sb, logical_sb_block);
1748                 if (!bh) {
1749                         printk(KERN_ERR
1750                                "EXT4-fs: Can't read superblock on 2nd try.\n");
1751                         goto failed_mount;
1752                 }
1753                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
1754                 sbi->s_es = es;
1755                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
1756                         printk (KERN_ERR
1757                                 "EXT4-fs: Magic mismatch, very weird !\n");
1758                         goto failed_mount;
1759                 }
1760         }
1761
1762         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
1763
1764         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
1765                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
1766                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
1767         } else {
1768                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1769                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1770                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
1771                     (!is_power_of_2(sbi->s_inode_size)) ||
1772                     (sbi->s_inode_size > blocksize)) {
1773                         printk (KERN_ERR
1774                                 "EXT4-fs: unsupported inode size: %d\n",
1775                                 sbi->s_inode_size);
1776                         goto failed_mount;
1777                 }
1778                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
1779                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
1780         }
1781         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
1782         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
1783                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
1784                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
1785                     !is_power_of_2(sbi->s_desc_size)) {
1786                         printk(KERN_ERR
1787                                "EXT4-fs: unsupported descriptor size %lu\n",
1788                                sbi->s_desc_size);
1789                         goto failed_mount;
1790                 }
1791         } else
1792                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
1793         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1794         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1795         if (EXT4_INODE_SIZE(sb) == 0)
1796                 goto cantfind_ext4;
1797         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
1798         if (sbi->s_inodes_per_block == 0)
1799                 goto cantfind_ext4;
1800         sbi->s_itb_per_group = sbi->s_inodes_per_group /
1801                                         sbi->s_inodes_per_block;
1802         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
1803         sbi->s_sbh = bh;
1804         sbi->s_mount_state = le16_to_cpu(es->s_state);
1805         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
1806         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
1807         for (i=0; i < 4; i++)
1808                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
1809         sbi->s_def_hash_version = es->s_def_hash_version;
1810
1811         if (sbi->s_blocks_per_group > blocksize * 8) {
1812                 printk (KERN_ERR
1813                         "EXT4-fs: #blocks per group too big: %lu\n",
1814                         sbi->s_blocks_per_group);
1815                 goto failed_mount;
1816         }
1817         if (sbi->s_inodes_per_group > blocksize * 8) {
1818                 printk (KERN_ERR
1819                         "EXT4-fs: #inodes per group too big: %lu\n",
1820                         sbi->s_inodes_per_group);
1821                 goto failed_mount;
1822         }
1823
1824         if (ext4_blocks_count(es) >
1825                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1826                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
1827                         " too large to mount safely\n", sb->s_id);
1828                 if (sizeof(sector_t) < 8)
1829                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
1830                                         "enabled\n");
1831                 goto failed_mount;
1832         }
1833
1834         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
1835                 goto cantfind_ext4;
1836         blocks_count = (ext4_blocks_count(es) -
1837                         le32_to_cpu(es->s_first_data_block) +
1838                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
1839         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
1840         sbi->s_groups_count = blocks_count;
1841         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
1842                    EXT4_DESC_PER_BLOCK(sb);
1843         sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
1844                                     GFP_KERNEL);
1845         if (sbi->s_group_desc == NULL) {
1846                 printk (KERN_ERR "EXT4-fs: not enough memory\n");
1847                 goto failed_mount;
1848         }
1849
1850         bgl_lock_init(&sbi->s_blockgroup_lock);
1851
1852         for (i = 0; i < db_count; i++) {
1853                 block = descriptor_loc(sb, logical_sb_block, i);
1854                 sbi->s_group_desc[i] = sb_bread(sb, block);
1855                 if (!sbi->s_group_desc[i]) {
1856                         printk (KERN_ERR "EXT4-fs: "
1857                                 "can't read group descriptor %d\n", i);
1858                         db_count = i;
1859                         goto failed_mount2;
1860                 }
1861         }
1862         if (!ext4_check_descriptors (sb)) {
1863                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
1864                 goto failed_mount2;
1865         }
1866         sbi->s_gdb_count = db_count;
1867         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1868         spin_lock_init(&sbi->s_next_gen_lock);
1869
1870         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1871                         ext4_count_free_blocks(sb));
1872         if (!err) {
1873                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1874                                 ext4_count_free_inodes(sb));
1875         }
1876         if (!err) {
1877                 err = percpu_counter_init(&sbi->s_dirs_counter,
1878                                 ext4_count_dirs(sb));
1879         }
1880         if (err) {
1881                 printk(KERN_ERR "EXT4-fs: insufficient memory\n");
1882                 goto failed_mount3;
1883         }
1884
1885         /* per fileystem reservation list head & lock */
1886         spin_lock_init(&sbi->s_rsv_window_lock);
1887         sbi->s_rsv_window_root = RB_ROOT;
1888         /* Add a single, static dummy reservation to the start of the
1889          * reservation window list --- it gives us a placeholder for
1890          * append-at-start-of-list which makes the allocation logic
1891          * _much_ simpler. */
1892         sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1893         sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1894         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1895         sbi->s_rsv_window_head.rsv_goal_size = 0;
1896         ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
1897
1898         /*
1899          * set up enough so that it can read an inode
1900          */
1901         sb->s_op = &ext4_sops;
1902         sb->s_export_op = &ext4_export_ops;
1903         sb->s_xattr = ext4_xattr_handlers;
1904 #ifdef CONFIG_QUOTA
1905         sb->s_qcop = &ext4_qctl_operations;
1906         sb->dq_op = &ext4_quota_operations;
1907 #endif
1908         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
1909
1910         sb->s_root = NULL;
1911
1912         needs_recovery = (es->s_last_orphan != 0 ||
1913                           EXT4_HAS_INCOMPAT_FEATURE(sb,
1914                                     EXT4_FEATURE_INCOMPAT_RECOVER));
1915
1916         /*
1917          * The first inode we look at is the journal inode.  Don't try
1918          * root first: it may be modified in the journal!
1919          */
1920         if (!test_opt(sb, NOLOAD) &&
1921             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
1922                 if (ext4_load_journal(sb, es, journal_devnum))
1923                         goto failed_mount3;
1924         } else if (journal_inum) {
1925                 if (ext4_create_journal(sb, es, journal_inum))
1926                         goto failed_mount3;
1927         } else {
1928                 if (!silent)
1929                         printk (KERN_ERR
1930                                 "ext4: No journal on filesystem on %s\n",
1931                                 sb->s_id);
1932                 goto failed_mount3;
1933         }
1934
1935         if (ext4_blocks_count(es) > 0xffffffffULL &&
1936             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
1937                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
1938                 printk(KERN_ERR "ext4: Failed to set 64-bit journal feature\n");
1939                 goto failed_mount4;
1940         }
1941
1942         /* We have now updated the journal if required, so we can
1943          * validate the data journaling mode. */
1944         switch (test_opt(sb, DATA_FLAGS)) {
1945         case 0:
1946                 /* No mode set, assume a default based on the journal
1947                  * capabilities: ORDERED_DATA if the journal can
1948                  * cope, else JOURNAL_DATA
1949                  */
1950                 if (jbd2_journal_check_available_features
1951                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
1952                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
1953                 else
1954                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
1955                 break;
1956
1957         case EXT4_MOUNT_ORDERED_DATA:
1958         case EXT4_MOUNT_WRITEBACK_DATA:
1959                 if (!jbd2_journal_check_available_features
1960                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
1961                         printk(KERN_ERR "EXT4-fs: Journal does not support "
1962                                "requested data journaling mode\n");
1963                         goto failed_mount4;
1964                 }
1965         default:
1966                 break;
1967         }
1968
1969         if (test_opt(sb, NOBH)) {
1970                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
1971                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
1972                                 "its supported only with writeback mode\n");
1973                         clear_opt(sbi->s_mount_opt, NOBH);
1974                 }
1975         }
1976         /*
1977          * The jbd2_journal_load will have done any necessary log recovery,
1978          * so we can safely mount the rest of the filesystem now.
1979          */
1980
1981         root = iget(sb, EXT4_ROOT_INO);
1982         sb->s_root = d_alloc_root(root);
1983         if (!sb->s_root) {
1984                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
1985                 iput(root);
1986                 goto failed_mount4;
1987         }
1988         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1989                 dput(sb->s_root);
1990                 sb->s_root = NULL;
1991                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
1992                 goto failed_mount4;
1993         }
1994
1995         ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1996
1997         /* determine the minimum size of new large inodes, if present */
1998         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
1999                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2000                                                      EXT4_GOOD_OLD_INODE_SIZE;
2001                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2002                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2003                         if (sbi->s_want_extra_isize <
2004                             le16_to_cpu(es->s_want_extra_isize))
2005                                 sbi->s_want_extra_isize =
2006                                         le16_to_cpu(es->s_want_extra_isize);
2007                         if (sbi->s_want_extra_isize <
2008                             le16_to_cpu(es->s_min_extra_isize))
2009                                 sbi->s_want_extra_isize =
2010                                         le16_to_cpu(es->s_min_extra_isize);
2011                 }
2012         }
2013         /* Check if enough inode space is available */
2014         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2015                                                         sbi->s_inode_size) {
2016                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2017                                                        EXT4_GOOD_OLD_INODE_SIZE;
2018                 printk(KERN_INFO "EXT4-fs: required extra inode space not"
2019                         "available.\n");
2020         }
2021
2022         /*
2023          * akpm: core read_super() calls in here with the superblock locked.
2024          * That deadlocks, because orphan cleanup needs to lock the superblock
2025          * in numerous places.  Here we just pop the lock - it's relatively
2026          * harmless, because we are now ready to accept write_super() requests,
2027          * and aviro says that's the only reason for hanging onto the
2028          * superblock lock.
2029          */
2030         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2031         ext4_orphan_cleanup(sb, es);
2032         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2033         if (needs_recovery)
2034                 printk (KERN_INFO "EXT4-fs: recovery complete.\n");
2035         ext4_mark_recovery_complete(sb, es);
2036         printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
2037                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
2038                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
2039                 "writeback");
2040
2041         ext4_ext_init(sb);
2042
2043         lock_kernel();
2044         return 0;
2045
2046 cantfind_ext4:
2047         if (!silent)
2048                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
2049                        sb->s_id);
2050         goto failed_mount;
2051
2052 failed_mount4:
2053         jbd2_journal_destroy(sbi->s_journal);
2054 failed_mount3:
2055         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2056         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2057         percpu_counter_destroy(&sbi->s_dirs_counter);
2058 failed_mount2:
2059         for (i = 0; i < db_count; i++)
2060                 brelse(sbi->s_group_desc[i]);
2061         kfree(sbi->s_group_desc);
2062 failed_mount:
2063 #ifdef CONFIG_QUOTA
2064         for (i = 0; i < MAXQUOTAS; i++)
2065                 kfree(sbi->s_qf_names[i]);
2066 #endif
2067         ext4_blkdev_remove(sbi);
2068         brelse(bh);
2069 out_fail:
2070         sb->s_fs_info = NULL;
2071         kfree(sbi);
2072         lock_kernel();
2073         return -EINVAL;
2074 }
2075
2076 /*
2077  * Setup any per-fs journal parameters now.  We'll do this both on
2078  * initial mount, once the journal has been initialised but before we've
2079  * done any recovery; and again on any subsequent remount.
2080  */
2081 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2082 {
2083         struct ext4_sb_info *sbi = EXT4_SB(sb);
2084
2085         if (sbi->s_commit_interval)
2086                 journal->j_commit_interval = sbi->s_commit_interval;
2087         /* We could also set up an ext4-specific default for the commit
2088          * interval here, but for now we'll just fall back to the jbd
2089          * default. */
2090
2091         spin_lock(&journal->j_state_lock);
2092         if (test_opt(sb, BARRIER))
2093                 journal->j_flags |= JBD2_BARRIER;
2094         else
2095                 journal->j_flags &= ~JBD2_BARRIER;
2096         spin_unlock(&journal->j_state_lock);
2097 }
2098
2099 static journal_t *ext4_get_journal(struct super_block *sb,
2100                                    unsigned int journal_inum)
2101 {
2102         struct inode *journal_inode;
2103         journal_t *journal;
2104
2105         /* First, test for the existence of a valid inode on disk.  Bad
2106          * things happen if we iget() an unused inode, as the subsequent
2107          * iput() will try to delete it. */
2108
2109         journal_inode = iget(sb, journal_inum);
2110         if (!journal_inode) {
2111                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
2112                 return NULL;
2113         }
2114         if (!journal_inode->i_nlink) {
2115                 make_bad_inode(journal_inode);
2116                 iput(journal_inode);
2117                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
2118                 return NULL;
2119         }
2120
2121         jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
2122                   journal_inode, journal_inode->i_size);
2123         if (is_bad_inode(journal_inode) || !S_ISREG(journal_inode->i_mode)) {
2124                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
2125                 iput(journal_inode);
2126                 return NULL;
2127         }
2128
2129         journal = jbd2_journal_init_inode(journal_inode);
2130         if (!journal) {
2131                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
2132                 iput(journal_inode);
2133                 return NULL;
2134         }
2135         journal->j_private = sb;
2136         ext4_init_journal_params(sb, journal);
2137         return journal;
2138 }
2139
2140 static journal_t *ext4_get_dev_journal(struct super_block *sb,
2141                                        dev_t j_dev)
2142 {
2143         struct buffer_head * bh;
2144         journal_t *journal;
2145         ext4_fsblk_t start;
2146         ext4_fsblk_t len;
2147         int hblock, blocksize;
2148         ext4_fsblk_t sb_block;
2149         unsigned long offset;
2150         struct ext4_super_block * es;
2151         struct block_device *bdev;
2152
2153         bdev = ext4_blkdev_get(j_dev);
2154         if (bdev == NULL)
2155                 return NULL;
2156
2157         if (bd_claim(bdev, sb)) {
2158                 printk(KERN_ERR
2159                         "EXT4: failed to claim external journal device.\n");
2160                 blkdev_put(bdev);
2161                 return NULL;
2162         }
2163
2164         blocksize = sb->s_blocksize;
2165         hblock = bdev_hardsect_size(bdev);
2166         if (blocksize < hblock) {
2167                 printk(KERN_ERR
2168                         "EXT4-fs: blocksize too small for journal device.\n");
2169                 goto out_bdev;
2170         }
2171
2172         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2173         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2174         set_blocksize(bdev, blocksize);
2175         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2176                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2177                        "external journal\n");
2178                 goto out_bdev;
2179         }
2180
2181         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2182         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2183             !(le32_to_cpu(es->s_feature_incompat) &
2184               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2185                 printk(KERN_ERR "EXT4-fs: external journal has "
2186                                         "bad superblock\n");
2187                 brelse(bh);
2188                 goto out_bdev;
2189         }
2190
2191         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2192                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2193                 brelse(bh);
2194                 goto out_bdev;
2195         }
2196
2197         len = ext4_blocks_count(es);
2198         start = sb_block + 1;
2199         brelse(bh);     /* we're done with the superblock */
2200
2201         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2202                                         start, len, blocksize);
2203         if (!journal) {
2204                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2205                 goto out_bdev;
2206         }
2207         journal->j_private = sb;
2208         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2209         wait_on_buffer(journal->j_sb_buffer);
2210         if (!buffer_uptodate(journal->j_sb_buffer)) {
2211                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2212                 goto out_journal;
2213         }
2214         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2215                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2216                                         "user (unsupported) - %d\n",
2217                         be32_to_cpu(journal->j_superblock->s_nr_users));
2218                 goto out_journal;
2219         }
2220         EXT4_SB(sb)->journal_bdev = bdev;
2221         ext4_init_journal_params(sb, journal);
2222         return journal;
2223 out_journal:
2224         jbd2_journal_destroy(journal);
2225 out_bdev:
2226         ext4_blkdev_put(bdev);
2227         return NULL;
2228 }
2229
2230 static int ext4_load_journal(struct super_block *sb,
2231                              struct ext4_super_block *es,
2232                              unsigned long journal_devnum)
2233 {
2234         journal_t *journal;
2235         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2236         dev_t journal_dev;
2237         int err = 0;
2238         int really_read_only;
2239
2240         if (journal_devnum &&
2241             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2242                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2243                         "numbers have changed\n");
2244                 journal_dev = new_decode_dev(journal_devnum);
2245         } else
2246                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2247
2248         really_read_only = bdev_read_only(sb->s_bdev);
2249
2250         /*
2251          * Are we loading a blank journal or performing recovery after a
2252          * crash?  For recovery, we need to check in advance whether we
2253          * can get read-write access to the device.
2254          */
2255
2256         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2257                 if (sb->s_flags & MS_RDONLY) {
2258                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2259                                         "required on readonly filesystem.\n");
2260                         if (really_read_only) {
2261                                 printk(KERN_ERR "EXT4-fs: write access "
2262                                         "unavailable, cannot proceed.\n");
2263                                 return -EROFS;
2264                         }
2265                         printk (KERN_INFO "EXT4-fs: write access will "
2266                                         "be enabled during recovery.\n");
2267                 }
2268         }
2269
2270         if (journal_inum && journal_dev) {
2271                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2272                        "and inode journals!\n");
2273                 return -EINVAL;
2274         }
2275
2276         if (journal_inum) {
2277                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2278                         return -EINVAL;
2279         } else {
2280                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2281                         return -EINVAL;
2282         }
2283
2284         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2285                 err = jbd2_journal_update_format(journal);
2286                 if (err)  {
2287                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2288                         jbd2_journal_destroy(journal);
2289                         return err;
2290                 }
2291         }
2292
2293         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2294                 err = jbd2_journal_wipe(journal, !really_read_only);
2295         if (!err)
2296                 err = jbd2_journal_load(journal);
2297
2298         if (err) {
2299                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2300                 jbd2_journal_destroy(journal);
2301                 return err;
2302         }
2303
2304         EXT4_SB(sb)->s_journal = journal;
2305         ext4_clear_journal_err(sb, es);
2306
2307         if (journal_devnum &&
2308             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2309                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2310                 sb->s_dirt = 1;
2311
2312                 /* Make sure we flush the recovery flag to disk. */
2313                 ext4_commit_super(sb, es, 1);
2314         }
2315
2316         return 0;
2317 }
2318
2319 static int ext4_create_journal(struct super_block * sb,
2320                                struct ext4_super_block * es,
2321                                unsigned int journal_inum)
2322 {
2323         journal_t *journal;
2324         int err;
2325
2326         if (sb->s_flags & MS_RDONLY) {
2327                 printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2328                                 "create journal.\n");
2329                 return -EROFS;
2330         }
2331
2332         journal = ext4_get_journal(sb, journal_inum);
2333         if (!journal)
2334                 return -EINVAL;
2335
2336         printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2337                journal_inum);
2338
2339         err = jbd2_journal_create(journal);
2340         if (err) {
2341                 printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2342                 jbd2_journal_destroy(journal);
2343                 return -EIO;
2344         }
2345
2346         EXT4_SB(sb)->s_journal = journal;
2347
2348         ext4_update_dynamic_rev(sb);
2349         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2350         EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2351
2352         es->s_journal_inum = cpu_to_le32(journal_inum);
2353         sb->s_dirt = 1;
2354
2355         /* Make sure we flush the recovery flag to disk. */
2356         ext4_commit_super(sb, es, 1);
2357
2358         return 0;
2359 }
2360
2361 static void ext4_commit_super (struct super_block * sb,
2362                                struct ext4_super_block * es,
2363                                int sync)
2364 {
2365         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2366
2367         if (!sbh)
2368                 return;
2369         es->s_wtime = cpu_to_le32(get_seconds());
2370         ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2371         es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2372         BUFFER_TRACE(sbh, "marking dirty");
2373         mark_buffer_dirty(sbh);
2374         if (sync)
2375                 sync_dirty_buffer(sbh);
2376 }
2377
2378
2379 /*
2380  * Have we just finished recovery?  If so, and if we are mounting (or
2381  * remounting) the filesystem readonly, then we will end up with a
2382  * consistent fs on disk.  Record that fact.
2383  */
2384 static void ext4_mark_recovery_complete(struct super_block * sb,
2385                                         struct ext4_super_block * es)
2386 {
2387         journal_t *journal = EXT4_SB(sb)->s_journal;
2388
2389         jbd2_journal_lock_updates(journal);
2390         jbd2_journal_flush(journal);
2391         lock_super(sb);
2392         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2393             sb->s_flags & MS_RDONLY) {
2394                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2395                 sb->s_dirt = 0;
2396                 ext4_commit_super(sb, es, 1);
2397         }
2398         unlock_super(sb);
2399         jbd2_journal_unlock_updates(journal);
2400 }
2401
2402 /*
2403  * If we are mounting (or read-write remounting) a filesystem whose journal
2404  * has recorded an error from a previous lifetime, move that error to the
2405  * main filesystem now.
2406  */
2407 static void ext4_clear_journal_err(struct super_block * sb,
2408                                    struct ext4_super_block * es)
2409 {
2410         journal_t *journal;
2411         int j_errno;
2412         const char *errstr;
2413
2414         journal = EXT4_SB(sb)->s_journal;
2415
2416         /*
2417          * Now check for any error status which may have been recorded in the
2418          * journal by a prior ext4_error() or ext4_abort()
2419          */
2420
2421         j_errno = jbd2_journal_errno(journal);
2422         if (j_errno) {
2423                 char nbuf[16];
2424
2425                 errstr = ext4_decode_error(sb, j_errno, nbuf);
2426                 ext4_warning(sb, __FUNCTION__, "Filesystem error recorded "
2427                              "from previous mount: %s", errstr);
2428                 ext4_warning(sb, __FUNCTION__, "Marking fs in need of "
2429                              "filesystem check.");
2430
2431                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2432                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2433                 ext4_commit_super (sb, es, 1);
2434
2435                 jbd2_journal_clear_err(journal);
2436         }
2437 }
2438
2439 /*
2440  * Force the running and committing transactions to commit,
2441  * and wait on the commit.
2442  */
2443 int ext4_force_commit(struct super_block *sb)
2444 {
2445         journal_t *journal;
2446         int ret;
2447
2448         if (sb->s_flags & MS_RDONLY)
2449                 return 0;
2450
2451         journal = EXT4_SB(sb)->s_journal;
2452         sb->s_dirt = 0;
2453         ret = ext4_journal_force_commit(journal);
2454         return ret;
2455 }
2456
2457 /*
2458  * Ext4 always journals updates to the superblock itself, so we don't
2459  * have to propagate any other updates to the superblock on disk at this
2460  * point.  Just start an async writeback to get the buffers on their way
2461  * to the disk.
2462  *
2463  * This implicitly triggers the writebehind on sync().
2464  */
2465
2466 static void ext4_write_super (struct super_block * sb)
2467 {
2468         if (mutex_trylock(&sb->s_lock) != 0)
2469                 BUG();
2470         sb->s_dirt = 0;
2471 }
2472
2473 static int ext4_sync_fs(struct super_block *sb, int wait)
2474 {
2475         tid_t target;
2476
2477         sb->s_dirt = 0;
2478         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2479                 if (wait)
2480                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2481         }
2482         return 0;
2483 }
2484
2485 /*
2486  * LVM calls this function before a (read-only) snapshot is created.  This
2487  * gives us a chance to flush the journal completely and mark the fs clean.
2488  */
2489 static void ext4_write_super_lockfs(struct super_block *sb)
2490 {
2491         sb->s_dirt = 0;
2492
2493         if (!(sb->s_flags & MS_RDONLY)) {
2494                 journal_t *journal = EXT4_SB(sb)->s_journal;
2495
2496                 /* Now we set up the journal barrier. */
2497                 jbd2_journal_lock_updates(journal);
2498                 jbd2_journal_flush(journal);
2499
2500                 /* Journal blocked and flushed, clear needs_recovery flag. */
2501                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2502                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2503         }
2504 }
2505
2506 /*
2507  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2508  * flag here, even though the filesystem is not technically dirty yet.
2509  */
2510 static void ext4_unlockfs(struct super_block *sb)
2511 {
2512         if (!(sb->s_flags & MS_RDONLY)) {
2513                 lock_super(sb);
2514                 /* Reser the needs_recovery flag before the fs is unlocked. */
2515                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2516                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2517                 unlock_super(sb);
2518                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2519         }
2520 }
2521
2522 static int ext4_remount (struct super_block * sb, int * flags, char * data)
2523 {
2524         struct ext4_super_block * es;
2525         struct ext4_sb_info *sbi = EXT4_SB(sb);
2526         ext4_fsblk_t n_blocks_count = 0;
2527         unsigned long old_sb_flags;
2528         struct ext4_mount_options old_opts;
2529         int err;
2530 #ifdef CONFIG_QUOTA
2531         int i;
2532 #endif
2533
2534         /* Store the original options */
2535         old_sb_flags = sb->s_flags;
2536         old_opts.s_mount_opt = sbi->s_mount_opt;
2537         old_opts.s_resuid = sbi->s_resuid;
2538         old_opts.s_resgid = sbi->s_resgid;
2539         old_opts.s_commit_interval = sbi->s_commit_interval;
2540 #ifdef CONFIG_QUOTA
2541         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2542         for (i = 0; i < MAXQUOTAS; i++)
2543                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2544 #endif
2545
2546         /*
2547          * Allow the "check" option to be passed as a remount option.
2548          */
2549         if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2550                 err = -EINVAL;
2551                 goto restore_opts;
2552         }
2553
2554         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2555                 ext4_abort(sb, __FUNCTION__, "Abort forced by user");
2556
2557         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2558                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2559
2560         es = sbi->s_es;
2561
2562         ext4_init_journal_params(sb, sbi->s_journal);
2563
2564         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2565                 n_blocks_count > ext4_blocks_count(es)) {
2566                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
2567                         err = -EROFS;
2568                         goto restore_opts;
2569                 }
2570
2571                 if (*flags & MS_RDONLY) {
2572                         /*
2573                          * First of all, the unconditional stuff we have to do
2574                          * to disable replay of the journal when we next remount
2575                          */
2576                         sb->s_flags |= MS_RDONLY;
2577
2578                         /*
2579                          * OK, test if we are remounting a valid rw partition
2580                          * readonly, and if so set the rdonly flag and then
2581                          * mark the partition as valid again.
2582                          */
2583                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
2584                             (sbi->s_mount_state & EXT4_VALID_FS))
2585                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
2586
2587                         /*
2588                          * We have to unlock super so that we can wait for
2589                          * transactions.
2590                          */
2591                         unlock_super(sb);
2592                         ext4_mark_recovery_complete(sb, es);
2593                         lock_super(sb);
2594                 } else {
2595                         __le32 ret;
2596                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2597                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
2598                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2599                                        "remount RDWR because of unsupported "
2600                                        "optional features (%x).\n",
2601                                        sb->s_id, le32_to_cpu(ret));
2602                                 err = -EROFS;
2603                                 goto restore_opts;
2604                         }
2605
2606                         /*
2607                          * If we have an unprocessed orphan list hanging
2608                          * around from a previously readonly bdev mount,
2609                          * require a full umount/remount for now.
2610                          */
2611                         if (es->s_last_orphan) {
2612                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2613                                        "remount RDWR because of unprocessed "
2614                                        "orphan inode list.  Please "
2615                                        "umount/remount instead.\n",
2616                                        sb->s_id);
2617                                 err = -EINVAL;
2618                                 goto restore_opts;
2619                         }
2620
2621                         /*
2622                          * Mounting a RDONLY partition read-write, so reread
2623                          * and store the current valid flag.  (It may have
2624                          * been changed by e2fsck since we originally mounted
2625                          * the partition.)
2626                          */
2627                         ext4_clear_journal_err(sb, es);
2628                         sbi->s_mount_state = le16_to_cpu(es->s_state);
2629                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
2630                                 goto restore_opts;
2631                         if (!ext4_setup_super (sb, es, 0))
2632                                 sb->s_flags &= ~MS_RDONLY;
2633                 }
2634         }
2635 #ifdef CONFIG_QUOTA
2636         /* Release old quota file names */
2637         for (i = 0; i < MAXQUOTAS; i++)
2638                 if (old_opts.s_qf_names[i] &&
2639                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2640                         kfree(old_opts.s_qf_names[i]);
2641 #endif
2642         return 0;
2643 restore_opts:
2644         sb->s_flags = old_sb_flags;
2645         sbi->s_mount_opt = old_opts.s_mount_opt;
2646         sbi->s_resuid = old_opts.s_resuid;
2647         sbi->s_resgid = old_opts.s_resgid;
2648         sbi->s_commit_interval = old_opts.s_commit_interval;
2649 #ifdef CONFIG_QUOTA
2650         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
2651         for (i = 0; i < MAXQUOTAS; i++) {
2652                 if (sbi->s_qf_names[i] &&
2653                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2654                         kfree(sbi->s_qf_names[i]);
2655                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
2656         }
2657 #endif
2658         return err;
2659 }
2660
2661 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
2662 {
2663         struct super_block *sb = dentry->d_sb;
2664         struct ext4_sb_info *sbi = EXT4_SB(sb);
2665         struct ext4_super_block *es = sbi->s_es;
2666         u64 fsid;
2667
2668         if (test_opt(sb, MINIX_DF)) {
2669                 sbi->s_overhead_last = 0;
2670         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
2671                 unsigned long ngroups = sbi->s_groups_count, i;
2672                 ext4_fsblk_t overhead = 0;
2673                 smp_rmb();
2674
2675                 /*
2676                  * Compute the overhead (FS structures).  This is constant
2677                  * for a given filesystem unless the number of block groups
2678                  * changes so we cache the previous value until it does.
2679                  */
2680
2681                 /*
2682                  * All of the blocks before first_data_block are
2683                  * overhead
2684                  */
2685                 overhead = le32_to_cpu(es->s_first_data_block);
2686
2687                 /*
2688                  * Add the overhead attributed to the superblock and
2689                  * block group descriptors.  If the sparse superblocks
2690                  * feature is turned on, then not all groups have this.
2691                  */
2692                 for (i = 0; i < ngroups; i++) {
2693                         overhead += ext4_bg_has_super(sb, i) +
2694                                 ext4_bg_num_gdb(sb, i);
2695                         cond_resched();
2696                 }
2697
2698                 /*
2699                  * Every block group has an inode bitmap, a block
2700                  * bitmap, and an inode table.
2701                  */
2702                 overhead += ngroups * (2 + sbi->s_itb_per_group);
2703                 sbi->s_overhead_last = overhead;
2704                 smp_wmb();
2705                 sbi->s_blocks_last = ext4_blocks_count(es);
2706         }
2707
2708         buf->f_type = EXT4_SUPER_MAGIC;
2709         buf->f_bsize = sb->s_blocksize;
2710         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
2711         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter);
2712         ext4_free_blocks_count_set(es, buf->f_bfree);
2713         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
2714         if (buf->f_bfree < ext4_r_blocks_count(es))
2715                 buf->f_bavail = 0;
2716         buf->f_files = le32_to_cpu(es->s_inodes_count);
2717         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
2718         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
2719         buf->f_namelen = EXT4_NAME_LEN;
2720         fsid = le64_to_cpup((void *)es->s_uuid) ^
2721                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
2722         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
2723         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
2724         return 0;
2725 }
2726
2727 /* Helper function for writing quotas on sync - we need to start transaction before quota file
2728  * is locked for write. Otherwise the are possible deadlocks:
2729  * Process 1                         Process 2
2730  * ext4_create()                     quota_sync()
2731  *   jbd2_journal_start()                   write_dquot()
2732  *   DQUOT_INIT()                        down(dqio_mutex)
2733  *     down(dqio_mutex)                    jbd2_journal_start()
2734  *
2735  */
2736
2737 #ifdef CONFIG_QUOTA
2738
2739 static inline struct inode *dquot_to_inode(struct dquot *dquot)
2740 {
2741         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
2742 }
2743
2744 static int ext4_dquot_initialize(struct inode *inode, int type)
2745 {
2746         handle_t *handle;
2747         int ret, err;
2748
2749         /* We may create quota structure so we need to reserve enough blocks */
2750         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
2751         if (IS_ERR(handle))
2752                 return PTR_ERR(handle);
2753         ret = dquot_initialize(inode, type);
2754         err = ext4_journal_stop(handle);
2755         if (!ret)
2756                 ret = err;
2757         return ret;
2758 }
2759
2760 static int ext4_dquot_drop(struct inode *inode)
2761 {
2762         handle_t *handle;
2763         int ret, err;
2764
2765         /* We may delete quota structure so we need to reserve enough blocks */
2766         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
2767         if (IS_ERR(handle))
2768                 return PTR_ERR(handle);
2769         ret = dquot_drop(inode);
2770         err = ext4_journal_stop(handle);
2771         if (!ret)
2772                 ret = err;
2773         return ret;
2774 }
2775
2776 static int ext4_write_dquot(struct dquot *dquot)
2777 {
2778         int ret, err;
2779         handle_t *handle;
2780         struct inode *inode;
2781
2782         inode = dquot_to_inode(dquot);
2783         handle = ext4_journal_start(inode,
2784                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
2785         if (IS_ERR(handle))
2786                 return PTR_ERR(handle);
2787         ret = dquot_commit(dquot);
2788         err = ext4_journal_stop(handle);
2789         if (!ret)
2790                 ret = err;
2791         return ret;
2792 }
2793
2794 static int ext4_acquire_dquot(struct dquot *dquot)
2795 {
2796         int ret, err;
2797         handle_t *handle;
2798
2799         handle = ext4_journal_start(dquot_to_inode(dquot),
2800                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
2801         if (IS_ERR(handle))
2802                 return PTR_ERR(handle);
2803         ret = dquot_acquire(dquot);
2804         err = ext4_journal_stop(handle);
2805         if (!ret)
2806                 ret = err;
2807         return ret;
2808 }
2809
2810 static int ext4_release_dquot(struct dquot *dquot)
2811 {
2812         int ret, err;
2813         handle_t *handle;
2814
2815         handle = ext4_journal_start(dquot_to_inode(dquot),
2816                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
2817         if (IS_ERR(handle)) {
2818                 /* Release dquot anyway to avoid endless cycle in dqput() */
2819                 dquot_release(dquot);
2820                 return PTR_ERR(handle);
2821         }
2822         ret = dquot_release(dquot);
2823         err = ext4_journal_stop(handle);
2824         if (!ret)
2825                 ret = err;
2826         return ret;
2827 }
2828
2829 static int ext4_mark_dquot_dirty(struct dquot *dquot)
2830 {
2831         /* Are we journalling quotas? */
2832         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
2833             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
2834                 dquot_mark_dquot_dirty(dquot);
2835                 return ext4_write_dquot(dquot);
2836         } else {
2837                 return dquot_mark_dquot_dirty(dquot);
2838         }
2839 }
2840
2841 static int ext4_write_info(struct super_block *sb, int type)
2842 {
2843         int ret, err;
2844         handle_t *handle;
2845
2846         /* Data block + inode block */
2847         handle = ext4_journal_start(sb->s_root->d_inode, 2);
2848         if (IS_ERR(handle))
2849                 return PTR_ERR(handle);
2850         ret = dquot_commit_info(sb, type);
2851         err = ext4_journal_stop(handle);
2852         if (!ret)
2853                 ret = err;
2854         return ret;
2855 }
2856
2857 /*
2858  * Turn on quotas during mount time - we need to find
2859  * the quota file and such...
2860  */
2861 static int ext4_quota_on_mount(struct super_block *sb, int type)
2862 {
2863         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
2864                         EXT4_SB(sb)->s_jquota_fmt, type);
2865 }
2866
2867 /*
2868  * Standard function to be called on quota_on
2869  */
2870 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
2871                          char *path)
2872 {
2873         int err;
2874         struct nameidata nd;
2875
2876         if (!test_opt(sb, QUOTA))
2877                 return -EINVAL;
2878         /* Not journalling quota? */
2879         if (!EXT4_SB(sb)->s_qf_names[USRQUOTA] &&
2880             !EXT4_SB(sb)->s_qf_names[GRPQUOTA])
2881                 return vfs_quota_on(sb, type, format_id, path);
2882         err = path_lookup(path, LOOKUP_FOLLOW, &nd);
2883         if (err)
2884                 return err;
2885         /* Quotafile not on the same filesystem? */
2886         if (nd.mnt->mnt_sb != sb) {
2887                 path_release(&nd);
2888                 return -EXDEV;
2889         }
2890         /* Quotafile not of fs root? */
2891         if (nd.dentry->d_parent->d_inode != sb->s_root->d_inode)
2892                 printk(KERN_WARNING
2893                         "EXT4-fs: Quota file not on filesystem root. "
2894                         "Journalled quota will not work.\n");
2895         path_release(&nd);
2896         return vfs_quota_on(sb, type, format_id, path);
2897 }
2898
2899 /* Read data from quotafile - avoid pagecache and such because we cannot afford
2900  * acquiring the locks... As quota files are never truncated and quota code
2901  * itself serializes the operations (and noone else should touch the files)
2902  * we don't have to be afraid of races */
2903 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
2904                                size_t len, loff_t off)
2905 {
2906         struct inode *inode = sb_dqopt(sb)->files[type];
2907         sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2908         int err = 0;
2909         int offset = off & (sb->s_blocksize - 1);
2910         int tocopy;
2911         size_t toread;
2912         struct buffer_head *bh;
2913         loff_t i_size = i_size_read(inode);
2914
2915         if (off > i_size)
2916                 return 0;
2917         if (off+len > i_size)
2918                 len = i_size-off;
2919         toread = len;
2920         while (toread > 0) {
2921                 tocopy = sb->s_blocksize - offset < toread ?
2922                                 sb->s_blocksize - offset : toread;
2923                 bh = ext4_bread(NULL, inode, blk, 0, &err);
2924                 if (err)
2925                         return err;
2926                 if (!bh)        /* A hole? */
2927                         memset(data, 0, tocopy);
2928                 else
2929                         memcpy(data, bh->b_data+offset, tocopy);
2930                 brelse(bh);
2931                 offset = 0;
2932                 toread -= tocopy;
2933                 data += tocopy;
2934                 blk++;
2935         }
2936         return len;
2937 }
2938
2939 /* Write to quotafile (we know the transaction is already started and has
2940  * enough credits) */
2941 static ssize_t ext4_quota_write(struct super_block *sb, int type,
2942                                 const char *data, size_t len, loff_t off)
2943 {
2944         struct inode *inode = sb_dqopt(sb)->files[type];
2945         sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2946         int err = 0;
2947         int offset = off & (sb->s_blocksize - 1);
2948         int tocopy;
2949         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
2950         size_t towrite = len;
2951         struct buffer_head *bh;
2952         handle_t *handle = journal_current_handle();
2953
2954         if (!handle) {
2955                 printk(KERN_WARNING "EXT4-fs: Quota write (off=%Lu, len=%Lu)"
2956                         " cancelled because transaction is not started.\n",
2957                         (unsigned long long)off, (unsigned long long)len);
2958                 return -EIO;
2959         }
2960         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2961         while (towrite > 0) {
2962                 tocopy = sb->s_blocksize - offset < towrite ?
2963                                 sb->s_blocksize - offset : towrite;
2964                 bh = ext4_bread(handle, inode, blk, 1, &err);
2965                 if (!bh)
2966                         goto out;
2967                 if (journal_quota) {
2968                         err = ext4_journal_get_write_access(handle, bh);
2969                         if (err) {
2970                                 brelse(bh);
2971                                 goto out;
2972                         }
2973                 }
2974                 lock_buffer(bh);
2975                 memcpy(bh->b_data+offset, data, tocopy);
2976                 flush_dcache_page(bh->b_page);
2977                 unlock_buffer(bh);
2978                 if (journal_quota)
2979                         err = ext4_journal_dirty_metadata(handle, bh);
2980                 else {
2981                         /* Always do at least ordered writes for quotas */
2982                         err = ext4_journal_dirty_data(handle, bh);
2983                         mark_buffer_dirty(bh);
2984                 }
2985                 brelse(bh);
2986                 if (err)
2987                         goto out;
2988                 offset = 0;
2989                 towrite -= tocopy;
2990                 data += tocopy;
2991                 blk++;
2992         }
2993 out:
2994         if (len == towrite)
2995                 return err;
2996         if (inode->i_size < off+len-towrite) {
2997                 i_size_write(inode, off+len-towrite);
2998                 EXT4_I(inode)->i_disksize = inode->i_size;
2999         }
3000         inode->i_version++;
3001         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3002         ext4_mark_inode_dirty(handle, inode);
3003         mutex_unlock(&inode->i_mutex);
3004         return len - towrite;
3005 }
3006
3007 #endif
3008
3009 static int ext4_get_sb(struct file_system_type *fs_type,
3010         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3011 {
3012         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3013 }
3014
3015 static struct file_system_type ext4dev_fs_type = {
3016         .owner          = THIS_MODULE,
3017         .name           = "ext4dev",
3018         .get_sb         = ext4_get_sb,
3019         .kill_sb        = kill_block_super,
3020         .fs_flags       = FS_REQUIRES_DEV,
3021 };
3022
3023 static int __init init_ext4_fs(void)
3024 {
3025         int err = init_ext4_xattr();
3026         if (err)
3027                 return err;
3028         err = init_inodecache();
3029         if (err)
3030                 goto out1;
3031         err = register_filesystem(&ext4dev_fs_type);
3032         if (err)
3033                 goto out;
3034         return 0;
3035 out:
3036         destroy_inodecache();
3037 out1:
3038         exit_ext4_xattr();
3039         return err;
3040 }
3041
3042 static void __exit exit_ext4_fs(void)
3043 {
3044         unregister_filesystem(&ext4dev_fs_type);
3045         destroy_inodecache();
3046         exit_ext4_xattr();
3047 }
3048
3049 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
3050 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
3051 MODULE_LICENSE("GPL");
3052 module_init(init_ext4_fs)
3053 module_exit(exit_ext4_fs)