fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/jbd2.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/parser.h>
  28 #include <linux/smp_lock.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/marker.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <asm/uaccess.h>
  42
  43 #include "ext4.h"
  44 #include "ext4_jbd2.h"
  45 #include "xattr.h"
  46 #include "acl.h"
  47 #include "namei.h"
  48 #include "group.h"
  49
  50 struct proc_dir_entry *ext4_proc_root;
  51
  52 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  53                              unsigned long journal_devnum);
  54 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
  55                                unsigned int);
  56 static void ext4_commit_super(struct super_block *sb,
  57                               struct ext4_super_block *es, int sync);
  58 static void ext4_mark_recovery_complete(struct super_block *sb,
  59                                         struct ext4_super_block *es);
  60 static void ext4_clear_journal_err(struct super_block *sb,
  61                                    struct ext4_super_block *es);
  62 static int ext4_sync_fs(struct super_block *sb, int wait);
  63 static const char *ext4_decode_error(struct super_block *sb, int errno,
  64                                      char nbuf[16]);
  65 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  66 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  67 static void ext4_unlockfs(struct super_block *sb);
  68 static void ext4_write_super(struct super_block *sb);
  69 static void ext4_write_super_lockfs(struct super_block *sb);
  70
  71
  72 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
  73                                struct ext4_group_desc *bg)
  74 {
  75         return le32_to_cpu(bg->bg_block_bitmap_lo) |
  76                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  77                 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
  78 }
  79
  80 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
  81                                struct ext4_group_desc *bg)
  82 {
  83         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
  84                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  85                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
  86 }
  87
  88 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
  89                               struct ext4_group_desc *bg)
  90 {
  91         return le32_to_cpu(bg->bg_inode_table_lo) |
  92                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  93                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
  94 }
  95
  96 void ext4_block_bitmap_set(struct super_block *sb,
  97                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
  98 {
  99         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 100         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 101                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 102 }
 103
 104 void ext4_inode_bitmap_set(struct super_block *sb,
 105                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 106 {
 107         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 108         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 109                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 110 }
 111
 112 void ext4_inode_table_set(struct super_block *sb,
 113                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 114 {
 115         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 116         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 117                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 118 }
 119
 120 /*
 121  * Wrappers for jbd2_journal_start/end.
 122  *
 123  * The only special thing we need to do here is to make sure that all
 124  * journal_end calls result in the superblock being marked dirty, so
 125  * that sync() will call the filesystem's write_super callback if
 126  * appropriate.
 127  */
 128 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 129 {
 130         journal_t *journal;
 131
 132         if (sb->s_flags & MS_RDONLY)
 133                 return ERR_PTR(-EROFS);
 134
 135         /* Special case here: if the journal has aborted behind our
 136          * backs (eg. EIO in the commit thread), then we still need to
 137          * take the FS itself readonly cleanly. */
 138         journal = EXT4_SB(sb)->s_journal;
 139         if (is_journal_aborted(journal)) {
 140                 ext4_abort(sb, __func__,
 141                            "Detected aborted journal");
 142                 return ERR_PTR(-EROFS);
 143         }
 144
 145         return jbd2_journal_start(journal, nblocks);
 146 }
 147
 148 /*
 149  * The only special thing we need to do here is to make sure that all
 150  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 151  * that sync() will call the filesystem's write_super callback if
 152  * appropriate.
 153  */
 154 int __ext4_journal_stop(const char *where, handle_t *handle)
 155 {
 156         struct super_block *sb;
 157         int err;
 158         int rc;
 159
 160         sb = handle->h_transaction->t_journal->j_private;
 161         err = handle->h_err;
 162         rc = jbd2_journal_stop(handle);
 163
 164         if (!err)
 165                 err = rc;
 166         if (err)
 167                 __ext4_std_error(sb, where, err);
 168         return err;
 169 }
 170
 171 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 172                 struct buffer_head *bh, handle_t *handle, int err)
 173 {
 174         char nbuf[16];
 175         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 176
 177         if (bh)
 178                 BUFFER_TRACE(bh, "abort");
 179
 180         if (!handle->h_err)
 181                 handle->h_err = err;
 182
 183         if (is_handle_aborted(handle))
 184                 return;
 185
 186         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
 187                caller, errstr, err_fn);
 188
 189         jbd2_journal_abort_handle(handle);
 190 }
 191
 192 /* Deal with the reporting of failure conditions on a filesystem such as
 193  * inconsistencies detected or read IO failures.
 194  *
 195  * On ext2, we can store the error state of the filesystem in the
 196  * superblock.  That is not possible on ext4, because we may have other
 197  * write ordering constraints on the superblock which prevent us from
 198  * writing it out straight away; and given that the journal is about to
 199  * be aborted, we can't rely on the current, or future, transactions to
 200  * write out the superblock safely.
 201  *
 202  * We'll just use the jbd2_journal_abort() error code to record an error in
 203  * the journal instead.  On recovery, the journal will compain about
 204  * that error until we've noted it down and cleared it.
 205  */
 206
 207 static void ext4_handle_error(struct super_block *sb)
 208 {
 209         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 210
 211         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 212         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 213
 214         if (sb->s_flags & MS_RDONLY)
 215                 return;
 216
 217         if (!test_opt(sb, ERRORS_CONT)) {
 218                 journal_t *journal = EXT4_SB(sb)->s_journal;
 219
 220                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 221                 if (journal)
 222                         jbd2_journal_abort(journal, -EIO);
 223         }
 224         if (test_opt(sb, ERRORS_RO)) {
 225                 printk(KERN_CRIT "Remounting filesystem read-only\n");
 226                 sb->s_flags |= MS_RDONLY;
 227         }
 228         ext4_commit_super(sb, es, 1);
 229         if (test_opt(sb, ERRORS_PANIC))
 230                 panic("EXT4-fs (device %s): panic forced after error\n",
 231                         sb->s_id);
 232 }
 233
 234 void ext4_error(struct super_block *sb, const char *function,
 235                 const char *fmt, ...)
 236 {
 237         va_list args;
 238
 239         va_start(args, fmt);
 240         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 241         vprintk(fmt, args);
 242         printk("\n");
 243         va_end(args);
 244
 245         ext4_handle_error(sb);
 246 }
 247
 248 static const char *ext4_decode_error(struct super_block *sb, int errno,
 249                                      char nbuf[16])
 250 {
 251         char *errstr = NULL;
 252
 253         switch (errno) {
 254         case -EIO:
 255                 errstr = "IO failure";
 256                 break;
 257         case -ENOMEM:
 258                 errstr = "Out of memory";
 259                 break;
 260         case -EROFS:
 261                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
 262                         errstr = "Journal has aborted";
 263                 else
 264                         errstr = "Readonly filesystem";
 265                 break;
 266         default:
 267                 /* If the caller passed in an extra buffer for unknown
 268                  * errors, textualise them now.  Else we just return
 269                  * NULL. */
 270                 if (nbuf) {
 271                         /* Check for truncated error codes... */
 272                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 273                                 errstr = nbuf;
 274                 }
 275                 break;
 276         }
 277
 278         return errstr;
 279 }
 280
 281 /* __ext4_std_error decodes expected errors from journaling functions
 282  * automatically and invokes the appropriate error response.  */
 283
 284 void __ext4_std_error(struct super_block *sb, const char *function, int errno)
 285 {
 286         char nbuf[16];
 287         const char *errstr;
 288
 289         /* Special case: if the error is EROFS, and we're not already
 290          * inside a transaction, then there's really no point in logging
 291          * an error. */
 292         if (errno == -EROFS && journal_current_handle() == NULL &&
 293             (sb->s_flags & MS_RDONLY))
 294                 return;
 295
 296         errstr = ext4_decode_error(sb, errno, nbuf);
 297         printk(KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
 298                sb->s_id, function, errstr);
 299
 300         ext4_handle_error(sb);
 301 }
 302
 303 /*
 304  * ext4_abort is a much stronger failure handler than ext4_error.  The
 305  * abort function may be used to deal with unrecoverable failures such
 306  * as journal IO errors or ENOMEM at a critical moment in log management.
 307  *
 308  * We unconditionally force the filesystem into an ABORT|READONLY state,
 309  * unless the error response on the fs has been set to panic in which
 310  * case we take the easy way out and panic immediately.
 311  */
 312
 313 void ext4_abort(struct super_block *sb, const char *function,
 314                 const char *fmt, ...)
 315 {
 316         va_list args;
 317
 318         printk(KERN_CRIT "ext4_abort called.\n");
 319
 320         va_start(args, fmt);
 321         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 322         vprintk(fmt, args);
 323         printk("\n");
 324         va_end(args);
 325
 326         if (test_opt(sb, ERRORS_PANIC))
 327                 panic("EXT4-fs panic from previous error\n");
 328
 329         if (sb->s_flags & MS_RDONLY)
 330                 return;
 331
 332         printk(KERN_CRIT "Remounting filesystem read-only\n");
 333         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 334         sb->s_flags |= MS_RDONLY;
 335         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 336         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 337 }
 338
 339 void ext4_warning(struct super_block *sb, const char *function,
 340                   const char *fmt, ...)
 341 {
 342         va_list args;
 343
 344         va_start(args, fmt);
 345         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
 346                sb->s_id, function);
 347         vprintk(fmt, args);
 348         printk("\n");
 349         va_end(args);
 350 }
 351
 352 void ext4_update_dynamic_rev(struct super_block *sb)
 353 {
 354         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 355
 356         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 357                 return;
 358
 359         ext4_warning(sb, __func__,
 360                      "updating to rev %d because of new feature flag, "
 361                      "running e2fsck is recommended",
 362                      EXT4_DYNAMIC_REV);
 363
 364         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 365         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 366         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 367         /* leave es->s_feature_*compat flags alone */
 368         /* es->s_uuid will be set by e2fsck if empty */
 369
 370         /*
 371          * The rest of the superblock fields should be zero, and if not it
 372          * means they are likely already in use, so leave them alone.  We
 373          * can leave it up to e2fsck to clean up any inconsistencies there.
 374          */
 375 }
 376
 377 /*
 378  * Open the external journal device
 379  */
 380 static struct block_device *ext4_blkdev_get(dev_t dev)
 381 {
 382         struct block_device *bdev;
 383         char b[BDEVNAME_SIZE];
 384
 385         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 386         if (IS_ERR(bdev))
 387                 goto fail;
 388         return bdev;
 389
 390 fail:
 391         printk(KERN_ERR "EXT4: failed to open journal device %s: %ld\n",
 392                         __bdevname(dev, b), PTR_ERR(bdev));
 393         return NULL;
 394 }
 395
 396 /*
 397  * Release the journal device
 398  */
 399 static int ext4_blkdev_put(struct block_device *bdev)
 400 {
 401         bd_release(bdev);
 402         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
 403 }
 404
 405 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 406 {
 407         struct block_device *bdev;
 408         int ret = -ENODEV;
 409
 410         bdev = sbi->journal_bdev;
 411         if (bdev) {
 412                 ret = ext4_blkdev_put(bdev);
 413                 sbi->journal_bdev = NULL;
 414         }
 415         return ret;
 416 }
 417
 418 static inline struct inode *orphan_list_entry(struct list_head *l)
 419 {
 420         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 421 }
 422
 423 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 424 {
 425         struct list_head *l;
 426
 427         printk(KERN_ERR "sb orphan head is %d\n",
 428                le32_to_cpu(sbi->s_es->s_last_orphan));
 429
 430         printk(KERN_ERR "sb_info orphan list:\n");
 431         list_for_each(l, &sbi->s_orphan) {
 432                 struct inode *inode = orphan_list_entry(l);
 433                 printk(KERN_ERR "  "
 434                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 435                        inode->i_sb->s_id, inode->i_ino, inode,
 436                        inode->i_mode, inode->i_nlink,
 437                        NEXT_ORPHAN(inode));
 438         }
 439 }
 440
 441 static void ext4_put_super(struct super_block *sb)
 442 {
 443         struct ext4_sb_info *sbi = EXT4_SB(sb);
 444         struct ext4_super_block *es = sbi->s_es;
 445         int i;
 446
 447         ext4_mb_release(sb);
 448         ext4_ext_release(sb);
 449         ext4_xattr_put_super(sb);
 450         if (jbd2_journal_destroy(sbi->s_journal) < 0)
 451                 ext4_abort(sb, __func__, "Couldn't clean up the journal");
 452         sbi->s_journal = NULL;
 453         if (!(sb->s_flags & MS_RDONLY)) {
 454                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 455                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 456                 ext4_commit_super(sb, es, 1);
 457         }
 458         if (sbi->s_proc) {
 459                 remove_proc_entry("inode_readahead_blks", sbi->s_proc);
 460                 remove_proc_entry(sb->s_id, ext4_proc_root);
 461         }
 462
 463         for (i = 0; i < sbi->s_gdb_count; i++)
 464                 brelse(sbi->s_group_desc[i]);
 465         kfree(sbi->s_group_desc);
 466         kfree(sbi->s_flex_groups);
 467         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 468         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 469         percpu_counter_destroy(&sbi->s_dirs_counter);
 470         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
 471         brelse(sbi->s_sbh);
 472 #ifdef CONFIG_QUOTA
 473         for (i = 0; i < MAXQUOTAS; i++)
 474                 kfree(sbi->s_qf_names[i]);
 475 #endif
 476
 477         /* Debugging code just in case the in-memory inode orphan list
 478          * isn't empty.  The on-disk one can be non-empty if we've
 479          * detected an error and taken the fs readonly, but the
 480          * in-memory list had better be clean by this point. */
 481         if (!list_empty(&sbi->s_orphan))
 482                 dump_orphan_list(sb, sbi);
 483         J_ASSERT(list_empty(&sbi->s_orphan));
 484
 485         invalidate_bdev(sb->s_bdev);
 486         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 487                 /*
 488                  * Invalidate the journal device's buffers.  We don't want them
 489                  * floating about in memory - the physical journal device may
 490                  * hotswapped, and it breaks the `ro-after' testing code.
 491                  */
 492                 sync_blockdev(sbi->journal_bdev);
 493                 invalidate_bdev(sbi->journal_bdev);
 494                 ext4_blkdev_remove(sbi);
 495         }
 496         sb->s_fs_info = NULL;
 497         kfree(sbi);
 498         return;
 499 }
 500
 501 static struct kmem_cache *ext4_inode_cachep;
 502
 503 /*
 504  * Called inside transaction, so use GFP_NOFS
 505  */
 506 static struct inode *ext4_alloc_inode(struct super_block *sb)
 507 {
 508         struct ext4_inode_info *ei;
 509
 510         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 511         if (!ei)
 512                 return NULL;
 513 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 514         ei->i_acl = EXT4_ACL_NOT_CACHED;
 515         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 516 #endif
 517         ei->vfs_inode.i_version = 1;
 518         ei->vfs_inode.i_data.writeback_index = 0;
 519         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 520         INIT_LIST_HEAD(&ei->i_prealloc_list);
 521         spin_lock_init(&ei->i_prealloc_lock);
 522         jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
 523         ei->i_reserved_data_blocks = 0;
 524         ei->i_reserved_meta_blocks = 0;
 525         ei->i_allocated_meta_blocks = 0;
 526         ei->i_delalloc_reserved_flag = 0;
 527         spin_lock_init(&(ei->i_block_reservation_lock));
 528         return &ei->vfs_inode;
 529 }
 530
 531 static void ext4_destroy_inode(struct inode *inode)
 532 {
 533         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 534                 printk("EXT4 Inode %p: orphan list check failed!\n",
 535                         EXT4_I(inode));
 536                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 537                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 538                                 true);
 539                 dump_stack();
 540         }
 541         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 542 }
 543
 544 static void init_once(void *foo)
 545 {
 546         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 547
 548         INIT_LIST_HEAD(&ei->i_orphan);
 549 #ifdef CONFIG_EXT4_FS_XATTR
 550         init_rwsem(&ei->xattr_sem);
 551 #endif
 552         init_rwsem(&ei->i_data_sem);
 553         inode_init_once(&ei->vfs_inode);
 554 }
 555
 556 static int init_inodecache(void)
 557 {
 558         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 559                                              sizeof(struct ext4_inode_info),
 560                                              0, (SLAB_RECLAIM_ACCOUNT|
 561                                                 SLAB_MEM_SPREAD),
 562                                              init_once);
 563         if (ext4_inode_cachep == NULL)
 564                 return -ENOMEM;
 565         return 0;
 566 }
 567
 568 static void destroy_inodecache(void)
 569 {
 570         kmem_cache_destroy(ext4_inode_cachep);
 571 }
 572
 573 static void ext4_clear_inode(struct inode *inode)
 574 {
 575 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 576         if (EXT4_I(inode)->i_acl &&
 577                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
 578                 posix_acl_release(EXT4_I(inode)->i_acl);
 579                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
 580         }
 581         if (EXT4_I(inode)->i_default_acl &&
 582                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
 583                 posix_acl_release(EXT4_I(inode)->i_default_acl);
 584                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
 585         }
 586 #endif
 587         ext4_discard_preallocations(inode);
 588         jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
 589                                        &EXT4_I(inode)->jinode);
 590 }
 591
 592 static inline void ext4_show_quota_options(struct seq_file *seq,
 593                                            struct super_block *sb)
 594 {
 595 #if defined(CONFIG_QUOTA)
 596         struct ext4_sb_info *sbi = EXT4_SB(sb);
 597
 598         if (sbi->s_jquota_fmt)
 599                 seq_printf(seq, ",jqfmt=%s",
 600                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold" : "vfsv0");
 601
 602         if (sbi->s_qf_names[USRQUOTA])
 603                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 604
 605         if (sbi->s_qf_names[GRPQUOTA])
 606                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 607
 608         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
 609                 seq_puts(seq, ",usrquota");
 610
 611         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
 612                 seq_puts(seq, ",grpquota");
 613 #endif
 614 }
 615
 616 /*
 617  * Show an option if
 618  *  - it's set to a non-default value OR
 619  *  - if the per-sb default is different from the global default
 620  */
 621 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 622 {
 623         int def_errors;
 624         unsigned long def_mount_opts;
 625         struct super_block *sb = vfs->mnt_sb;
 626         struct ext4_sb_info *sbi = EXT4_SB(sb);
 627         struct ext4_super_block *es = sbi->s_es;
 628
 629         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 630         def_errors     = le16_to_cpu(es->s_errors);
 631
 632         if (sbi->s_sb_block != 1)
 633                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 634         if (test_opt(sb, MINIX_DF))
 635                 seq_puts(seq, ",minixdf");
 636         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
 637                 seq_puts(seq, ",grpid");
 638         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 639                 seq_puts(seq, ",nogrpid");
 640         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 641             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 642                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 643         }
 644         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 645             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 646                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 647         }
 648         if (test_opt(sb, ERRORS_RO)) {
 649                 if (def_errors == EXT4_ERRORS_PANIC ||
 650                     def_errors == EXT4_ERRORS_CONTINUE) {
 651                         seq_puts(seq, ",errors=remount-ro");
 652                 }
 653         }
 654         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
 655                 seq_puts(seq, ",errors=continue");
 656         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
 657                 seq_puts(seq, ",errors=panic");
 658         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
 659                 seq_puts(seq, ",nouid32");
 660         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
 661                 seq_puts(seq, ",debug");
 662         if (test_opt(sb, OLDALLOC))
 663                 seq_puts(seq, ",oldalloc");
 664 #ifdef CONFIG_EXT4_FS_XATTR
 665         if (test_opt(sb, XATTR_USER) &&
 666                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
 667                 seq_puts(seq, ",user_xattr");
 668         if (!test_opt(sb, XATTR_USER) &&
 669             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 670                 seq_puts(seq, ",nouser_xattr");
 671         }
 672 #endif
 673 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 674         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
 675                 seq_puts(seq, ",acl");
 676         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 677                 seq_puts(seq, ",noacl");
 678 #endif
 679         if (!test_opt(sb, RESERVATION))
 680                 seq_puts(seq, ",noreservation");
 681         if (sbi->s_commit_interval) {
 682                 seq_printf(seq, ",commit=%u",
 683                            (unsigned) (sbi->s_commit_interval / HZ));
 684         }
 685         /*
 686          * We're changing the default of barrier mount option, so
 687          * let's always display its mount state so it's clear what its
 688          * status is.
 689          */
 690         seq_puts(seq, ",barrier=");
 691         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
 692         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
 693                 seq_puts(seq, ",journal_async_commit");
 694         if (test_opt(sb, NOBH))
 695                 seq_puts(seq, ",nobh");
 696         if (!test_opt(sb, EXTENTS))
 697                 seq_puts(seq, ",noextents");
 698         if (test_opt(sb, I_VERSION))
 699                 seq_puts(seq, ",i_version");
 700         if (!test_opt(sb, DELALLOC))
 701                 seq_puts(seq, ",nodelalloc");
 702
 703
 704         if (sbi->s_stripe)
 705                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
 706         /*
 707          * journal mode get enabled in different ways
 708          * So just print the value even if we didn't specify it
 709          */
 710         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 711                 seq_puts(seq, ",data=journal");
 712         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 713                 seq_puts(seq, ",data=ordered");
 714         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 715                 seq_puts(seq, ",data=writeback");
 716
 717         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
 718                 seq_printf(seq, ",inode_readahead_blks=%u",
 719                            sbi->s_inode_readahead_blks);
 720
 721         if (test_opt(sb, DATA_ERR_ABORT))
 722                 seq_puts(seq, ",data_err=abort");
 723
 724         ext4_show_quota_options(seq, sb);
 725         return 0;
 726 }
 727
 728
 729 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 730                 u64 ino, u32 generation)
 731 {
 732         struct inode *inode;
 733
 734         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 735                 return ERR_PTR(-ESTALE);
 736         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 737                 return ERR_PTR(-ESTALE);
 738
 739         /* iget isn't really right if the inode is currently unallocated!!
 740          *
 741          * ext4_read_inode will return a bad_inode if the inode had been
 742          * deleted, so we should be safe.
 743          *
 744          * Currently we don't know the generation for parent directory, so
 745          * a generation of 0 means "accept any"
 746          */
 747         inode = ext4_iget(sb, ino);
 748         if (IS_ERR(inode))
 749                 return ERR_CAST(inode);
 750         if (generation && inode->i_generation != generation) {
 751                 iput(inode);
 752                 return ERR_PTR(-ESTALE);
 753         }
 754
 755         return inode;
 756 }
 757
 758 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 759                 int fh_len, int fh_type)
 760 {
 761         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 762                                     ext4_nfs_get_inode);
 763 }
 764
 765 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 766                 int fh_len, int fh_type)
 767 {
 768         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 769                                     ext4_nfs_get_inode);
 770 }
 771
 772 #ifdef CONFIG_QUOTA
 773 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
 774 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 775
 776 static int ext4_dquot_initialize(struct inode *inode, int type);
 777 static int ext4_dquot_drop(struct inode *inode);
 778 static int ext4_write_dquot(struct dquot *dquot);
 779 static int ext4_acquire_dquot(struct dquot *dquot);
 780 static int ext4_release_dquot(struct dquot *dquot);
 781 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 782 static int ext4_write_info(struct super_block *sb, int type);
 783 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 784                                 char *path, int remount);
 785 static int ext4_quota_on_mount(struct super_block *sb, int type);
 786 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 787                                size_t len, loff_t off);
 788 static ssize_t ext4_quota_write(struct super_block *sb, int type,
 789                                 const char *data, size_t len, loff_t off);
 790
 791 static struct dquot_operations ext4_quota_operations = {
 792         .initialize     = ext4_dquot_initialize,
 793         .drop           = ext4_dquot_drop,
 794         .alloc_space    = dquot_alloc_space,
 795         .alloc_inode    = dquot_alloc_inode,
 796         .free_space     = dquot_free_space,
 797         .free_inode     = dquot_free_inode,
 798         .transfer       = dquot_transfer,
 799         .write_dquot    = ext4_write_dquot,
 800         .acquire_dquot  = ext4_acquire_dquot,
 801         .release_dquot  = ext4_release_dquot,
 802         .mark_dirty     = ext4_mark_dquot_dirty,
 803         .write_info     = ext4_write_info
 804 };
 805
 806 static struct quotactl_ops ext4_qctl_operations = {
 807         .quota_on       = ext4_quota_on,
 808         .quota_off      = vfs_quota_off,
 809         .quota_sync     = vfs_quota_sync,
 810         .get_info       = vfs_get_dqinfo,
 811         .set_info       = vfs_set_dqinfo,
 812         .get_dqblk      = vfs_get_dqblk,
 813         .set_dqblk      = vfs_set_dqblk
 814 };
 815 #endif
 816
 817 static const struct super_operations ext4_sops = {
 818         .alloc_inode    = ext4_alloc_inode,
 819         .destroy_inode  = ext4_destroy_inode,
 820         .write_inode    = ext4_write_inode,
 821         .dirty_inode    = ext4_dirty_inode,
 822         .delete_inode   = ext4_delete_inode,
 823         .put_super      = ext4_put_super,
 824         .write_super    = ext4_write_super,
 825         .sync_fs        = ext4_sync_fs,
 826         .write_super_lockfs = ext4_write_super_lockfs,
 827         .unlockfs       = ext4_unlockfs,
 828         .statfs         = ext4_statfs,
 829         .remount_fs     = ext4_remount,
 830         .clear_inode    = ext4_clear_inode,
 831         .show_options   = ext4_show_options,
 832 #ifdef CONFIG_QUOTA
 833         .quota_read     = ext4_quota_read,
 834         .quota_write    = ext4_quota_write,
 835 #endif
 836 };
 837
 838 static const struct export_operations ext4_export_ops = {
 839         .fh_to_dentry = ext4_fh_to_dentry,
 840         .fh_to_parent = ext4_fh_to_parent,
 841         .get_parent = ext4_get_parent,
 842 };
 843
 844 enum {
 845         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 846         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
 847         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
 848         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
 849         Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
 850         Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
 851         Opt_journal_checksum, Opt_journal_async_commit,
 852         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
 853         Opt_data_err_abort, Opt_data_err_ignore,
 854         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 855         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
 856         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
 857         Opt_grpquota, Opt_extents, Opt_noextents, Opt_i_version,
 858         Opt_stripe, Opt_delalloc, Opt_nodelalloc,
 859         Opt_inode_readahead_blks
 860 };
 861
 862 static const match_table_t tokens = {
 863         {Opt_bsd_df, "bsddf"},
 864         {Opt_minix_df, "minixdf"},
 865         {Opt_grpid, "grpid"},
 866         {Opt_grpid, "bsdgroups"},
 867         {Opt_nogrpid, "nogrpid"},
 868         {Opt_nogrpid, "sysvgroups"},
 869         {Opt_resgid, "resgid=%u"},
 870         {Opt_resuid, "resuid=%u"},
 871         {Opt_sb, "sb=%u"},
 872         {Opt_err_cont, "errors=continue"},
 873         {Opt_err_panic, "errors=panic"},
 874         {Opt_err_ro, "errors=remount-ro"},
 875         {Opt_nouid32, "nouid32"},
 876         {Opt_debug, "debug"},
 877         {Opt_oldalloc, "oldalloc"},
 878         {Opt_orlov, "orlov"},
 879         {Opt_user_xattr, "user_xattr"},
 880         {Opt_nouser_xattr, "nouser_xattr"},
 881         {Opt_acl, "acl"},
 882         {Opt_noacl, "noacl"},
 883         {Opt_reservation, "reservation"},
 884         {Opt_noreservation, "noreservation"},
 885         {Opt_noload, "noload"},
 886         {Opt_nobh, "nobh"},
 887         {Opt_bh, "bh"},
 888         {Opt_commit, "commit=%u"},
 889         {Opt_journal_update, "journal=update"},
 890         {Opt_journal_inum, "journal=%u"},
 891         {Opt_journal_dev, "journal_dev=%u"},
 892         {Opt_journal_checksum, "journal_checksum"},
 893         {Opt_journal_async_commit, "journal_async_commit"},
 894         {Opt_abort, "abort"},
 895         {Opt_data_journal, "data=journal"},
 896         {Opt_data_ordered, "data=ordered"},
 897         {Opt_data_writeback, "data=writeback"},
 898         {Opt_data_err_abort, "data_err=abort"},
 899         {Opt_data_err_ignore, "data_err=ignore"},
 900         {Opt_offusrjquota, "usrjquota="},
 901         {Opt_usrjquota, "usrjquota=%s"},
 902         {Opt_offgrpjquota, "grpjquota="},
 903         {Opt_grpjquota, "grpjquota=%s"},
 904         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
 905         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
 906         {Opt_grpquota, "grpquota"},
 907         {Opt_noquota, "noquota"},
 908         {Opt_quota, "quota"},
 909         {Opt_usrquota, "usrquota"},
 910         {Opt_barrier, "barrier=%u"},
 911         {Opt_extents, "extents"},
 912         {Opt_noextents, "noextents"},
 913         {Opt_i_version, "i_version"},
 914         {Opt_stripe, "stripe=%u"},
 915         {Opt_resize, "resize"},
 916         {Opt_delalloc, "delalloc"},
 917         {Opt_nodelalloc, "nodelalloc"},
 918         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
 919         {Opt_err, NULL},
 920 };
 921
 922 static ext4_fsblk_t get_sb_block(void **data)
 923 {
 924         ext4_fsblk_t    sb_block;
 925         char            *options = (char *) *data;
 926
 927         if (!options || strncmp(options, "sb=", 3) != 0)
 928                 return 1;       /* Default location */
 929         options += 3;
 930         /*todo: use simple_strtoll with >32bit ext4 */
 931         sb_block = simple_strtoul(options, &options, 0);
 932         if (*options && *options != ',') {
 933                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
 934                        (char *) *data);
 935                 return 1;
 936         }
 937         if (*options == ',')
 938                 options++;
 939         *data = (void *) options;
 940         return sb_block;
 941 }
 942
 943 static int parse_options(char *options, struct super_block *sb,
 944                          unsigned int *inum, unsigned long *journal_devnum,
 945                          ext4_fsblk_t *n_blocks_count, int is_remount)
 946 {
 947         struct ext4_sb_info *sbi = EXT4_SB(sb);
 948         char *p;
 949         substring_t args[MAX_OPT_ARGS];
 950         int data_opt = 0;
 951         int option;
 952 #ifdef CONFIG_QUOTA
 953         int qtype, qfmt;
 954         char *qname;
 955 #endif
 956         ext4_fsblk_t last_block;
 957
 958         if (!options)
 959                 return 1;
 960
 961         while ((p = strsep(&options, ",")) != NULL) {
 962                 int token;
 963                 if (!*p)
 964                         continue;
 965
 966                 token = match_token(p, tokens, args);
 967                 switch (token) {
 968                 case Opt_bsd_df:
 969                         clear_opt(sbi->s_mount_opt, MINIX_DF);
 970                         break;
 971                 case Opt_minix_df:
 972                         set_opt(sbi->s_mount_opt, MINIX_DF);
 973                         break;
 974                 case Opt_grpid:
 975                         set_opt(sbi->s_mount_opt, GRPID);
 976                         break;
 977                 case Opt_nogrpid:
 978                         clear_opt(sbi->s_mount_opt, GRPID);
 979                         break;
 980                 case Opt_resuid:
 981                         if (match_int(&args[0], &option))
 982                                 return 0;
 983                         sbi->s_resuid = option;
 984                         break;
 985                 case Opt_resgid:
 986                         if (match_int(&args[0], &option))
 987                                 return 0;
 988                         sbi->s_resgid = option;
 989                         break;
 990                 case Opt_sb:
 991                         /* handled by get_sb_block() instead of here */
 992                         /* *sb_block = match_int(&args[0]); */
 993                         break;
 994                 case Opt_err_panic:
 995                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
 996                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
 997                         set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 998                         break;
 999                 case Opt_err_ro:
1000                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1001                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1002                         set_opt(sbi->s_mount_opt, ERRORS_RO);
1003                         break;
1004                 case Opt_err_cont:
1005                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1006                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1007                         set_opt(sbi->s_mount_opt, ERRORS_CONT);
1008                         break;
1009                 case Opt_nouid32:
1010                         set_opt(sbi->s_mount_opt, NO_UID32);
1011                         break;
1012                 case Opt_debug:
1013                         set_opt(sbi->s_mount_opt, DEBUG);
1014                         break;
1015                 case Opt_oldalloc:
1016                         set_opt(sbi->s_mount_opt, OLDALLOC);
1017                         break;
1018                 case Opt_orlov:
1019                         clear_opt(sbi->s_mount_opt, OLDALLOC);
1020                         break;
1021 #ifdef CONFIG_EXT4_FS_XATTR
1022                 case Opt_user_xattr:
1023                         set_opt(sbi->s_mount_opt, XATTR_USER);
1024                         break;
1025                 case Opt_nouser_xattr:
1026                         clear_opt(sbi->s_mount_opt, XATTR_USER);
1027                         break;
1028 #else
1029                 case Opt_user_xattr:
1030                 case Opt_nouser_xattr:
1031                         printk(KERN_ERR "EXT4 (no)user_xattr options "
1032                                "not supported\n");
1033                         break;
1034 #endif
1035 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1036                 case Opt_acl:
1037                         set_opt(sbi->s_mount_opt, POSIX_ACL);
1038                         break;
1039                 case Opt_noacl:
1040                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
1041                         break;
1042 #else
1043                 case Opt_acl:
1044                 case Opt_noacl:
1045                         printk(KERN_ERR "EXT4 (no)acl options "
1046                                "not supported\n");
1047                         break;
1048 #endif
1049                 case Opt_reservation:
1050                         set_opt(sbi->s_mount_opt, RESERVATION);
1051                         break;
1052                 case Opt_noreservation:
1053                         clear_opt(sbi->s_mount_opt, RESERVATION);
1054                         break;
1055                 case Opt_journal_update:
1056                         /* @@@ FIXME */
1057                         /* Eventually we will want to be able to create
1058                            a journal file here.  For now, only allow the
1059                            user to specify an existing inode to be the
1060                            journal file. */
1061                         if (is_remount) {
1062                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1063                                        "journal on remount\n");
1064                                 return 0;
1065                         }
1066                         set_opt(sbi->s_mount_opt, UPDATE_JOURNAL);
1067                         break;
1068                 case Opt_journal_inum:
1069                         if (is_remount) {
1070                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1071                                        "journal on remount\n");
1072                                 return 0;
1073                         }
1074                         if (match_int(&args[0], &option))
1075                                 return 0;
1076                         *inum = option;
1077                         break;
1078                 case Opt_journal_dev:
1079                         if (is_remount) {
1080                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1081                                        "journal on remount\n");
1082                                 return 0;
1083                         }
1084                         if (match_int(&args[0], &option))
1085                                 return 0;
1086                         *journal_devnum = option;
1087                         break;
1088                 case Opt_journal_checksum:
1089                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1090                         break;
1091                 case Opt_journal_async_commit:
1092                         set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1093                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1094                         break;
1095                 case Opt_noload:
1096                         set_opt(sbi->s_mount_opt, NOLOAD);
1097                         break;
1098                 case Opt_commit:
1099                         if (match_int(&args[0], &option))
1100                                 return 0;
1101                         if (option < 0)
1102                                 return 0;
1103                         if (option == 0)
1104                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1105                         sbi->s_commit_interval = HZ * option;
1106                         break;
1107                 case Opt_data_journal:
1108                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1109                         goto datacheck;
1110                 case Opt_data_ordered:
1111                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1112                         goto datacheck;
1113                 case Opt_data_writeback:
1114                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1115                 datacheck:
1116                         if (is_remount) {
1117                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1118                                                 != data_opt) {
1119                                         printk(KERN_ERR
1120                                                 "EXT4-fs: cannot change data "
1121                                                 "mode on remount\n");
1122                                         return 0;
1123                                 }
1124                         } else {
1125                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1126                                 sbi->s_mount_opt |= data_opt;
1127                         }
1128                         break;
1129                 case Opt_data_err_abort:
1130                         set_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1131                         break;
1132                 case Opt_data_err_ignore:
1133                         clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1134                         break;
1135 #ifdef CONFIG_QUOTA
1136                 case Opt_usrjquota:
1137                         qtype = USRQUOTA;
1138                         goto set_qf_name;
1139                 case Opt_grpjquota:
1140                         qtype = GRPQUOTA;
1141 set_qf_name:
1142                         if ((sb_any_quota_enabled(sb) ||
1143                              sb_any_quota_suspended(sb)) &&
1144                             !sbi->s_qf_names[qtype]) {
1145                                 printk(KERN_ERR
1146                                        "EXT4-fs: Cannot change journaled "
1147                                        "quota options when quota turned on.\n");
1148                                 return 0;
1149                         }
1150                         qname = match_strdup(&args[0]);
1151                         if (!qname) {
1152                                 printk(KERN_ERR
1153                                         "EXT4-fs: not enough memory for "
1154                                         "storing quotafile name.\n");
1155                                 return 0;
1156                         }
1157                         if (sbi->s_qf_names[qtype] &&
1158                             strcmp(sbi->s_qf_names[qtype], qname)) {
1159                                 printk(KERN_ERR
1160                                         "EXT4-fs: %s quota file already "
1161                                         "specified.\n", QTYPE2NAME(qtype));
1162                                 kfree(qname);
1163                                 return 0;
1164                         }
1165                         sbi->s_qf_names[qtype] = qname;
1166                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1167                                 printk(KERN_ERR
1168                                         "EXT4-fs: quotafile must be on "
1169                                         "filesystem root.\n");
1170                                 kfree(sbi->s_qf_names[qtype]);
1171                                 sbi->s_qf_names[qtype] = NULL;
1172                                 return 0;
1173                         }
1174                         set_opt(sbi->s_mount_opt, QUOTA);
1175                         break;
1176                 case Opt_offusrjquota:
1177                         qtype = USRQUOTA;
1178                         goto clear_qf_name;
1179                 case Opt_offgrpjquota:
1180                         qtype = GRPQUOTA;
1181 clear_qf_name:
1182                         if ((sb_any_quota_enabled(sb) ||
1183                              sb_any_quota_suspended(sb)) &&
1184                             sbi->s_qf_names[qtype]) {
1185                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1186                                         "journaled quota options when "
1187                                         "quota turned on.\n");
1188                                 return 0;
1189                         }
1190                         /*
1191                          * The space will be released later when all options
1192                          * are confirmed to be correct
1193                          */
1194                         sbi->s_qf_names[qtype] = NULL;
1195                         break;
1196                 case Opt_jqfmt_vfsold:
1197                         qfmt = QFMT_VFS_OLD;
1198                         goto set_qf_format;
1199                 case Opt_jqfmt_vfsv0:
1200                         qfmt = QFMT_VFS_V0;
1201 set_qf_format:
1202                         if ((sb_any_quota_enabled(sb) ||
1203                              sb_any_quota_suspended(sb)) &&
1204                             sbi->s_jquota_fmt != qfmt) {
1205                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1206                                         "journaled quota options when "
1207                                         "quota turned on.\n");
1208                                 return 0;
1209                         }
1210                         sbi->s_jquota_fmt = qfmt;
1211                         break;
1212                 case Opt_quota:
1213                 case Opt_usrquota:
1214                         set_opt(sbi->s_mount_opt, QUOTA);
1215                         set_opt(sbi->s_mount_opt, USRQUOTA);
1216                         break;
1217                 case Opt_grpquota:
1218                         set_opt(sbi->s_mount_opt, QUOTA);
1219                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1220                         break;
1221                 case Opt_noquota:
1222                         if (sb_any_quota_enabled(sb)) {
1223                                 printk(KERN_ERR "EXT4-fs: Cannot change quota "
1224                                         "options when quota turned on.\n");
1225                                 return 0;
1226                         }
1227                         clear_opt(sbi->s_mount_opt, QUOTA);
1228                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1229                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1230                         break;
1231 #else
1232                 case Opt_quota:
1233                 case Opt_usrquota:
1234                 case Opt_grpquota:
1235                         printk(KERN_ERR
1236                                 "EXT4-fs: quota options not supported.\n");
1237                         break;
1238                 case Opt_usrjquota:
1239                 case Opt_grpjquota:
1240                 case Opt_offusrjquota:
1241                 case Opt_offgrpjquota:
1242                 case Opt_jqfmt_vfsold:
1243                 case Opt_jqfmt_vfsv0:
1244                         printk(KERN_ERR
1245                                 "EXT4-fs: journaled quota options not "
1246                                 "supported.\n");
1247                         break;
1248                 case Opt_noquota:
1249                         break;
1250 #endif
1251                 case Opt_abort:
1252                         set_opt(sbi->s_mount_opt, ABORT);
1253                         break;
1254                 case Opt_barrier:
1255                         if (match_int(&args[0], &option))
1256                                 return 0;
1257                         if (option)
1258                                 set_opt(sbi->s_mount_opt, BARRIER);
1259                         else
1260                                 clear_opt(sbi->s_mount_opt, BARRIER);
1261                         break;
1262                 case Opt_ignore:
1263                         break;
1264                 case Opt_resize:
1265                         if (!is_remount) {
1266                                 printk("EXT4-fs: resize option only available "
1267                                         "for remount\n");
1268                                 return 0;
1269                         }
1270                         if (match_int(&args[0], &option) != 0)
1271                                 return 0;
1272                         *n_blocks_count = option;
1273                         break;
1274                 case Opt_nobh:
1275                         set_opt(sbi->s_mount_opt, NOBH);
1276                         break;
1277                 case Opt_bh:
1278                         clear_opt(sbi->s_mount_opt, NOBH);
1279                         break;
1280                 case Opt_extents:
1281                         if (!EXT4_HAS_INCOMPAT_FEATURE(sb,
1282                                         EXT4_FEATURE_INCOMPAT_EXTENTS)) {
1283                                 ext4_warning(sb, __func__,
1284                                         "extents feature not enabled "
1285                                         "on this filesystem, use tune2fs\n");
1286                                 return 0;
1287                         }
1288                         set_opt(sbi->s_mount_opt, EXTENTS);
1289                         break;
1290                 case Opt_noextents:
1291                         /*
1292                          * When e2fsprogs support resizing an already existing
1293                          * ext3 file system to greater than 2**32 we need to
1294                          * add support to block allocator to handle growing
1295                          * already existing block  mapped inode so that blocks
1296                          * allocated for them fall within 2**32
1297                          */
1298                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1299                         if (last_block  > 0xffffffffULL) {
1300                                 printk(KERN_ERR "EXT4-fs: Filesystem too "
1301                                                 "large to mount with "
1302                                                 "-o noextents options\n");
1303                                 return 0;
1304                         }
1305                         clear_opt(sbi->s_mount_opt, EXTENTS);
1306                         break;
1307                 case Opt_i_version:
1308                         set_opt(sbi->s_mount_opt, I_VERSION);
1309                         sb->s_flags |= MS_I_VERSION;
1310                         break;
1311                 case Opt_nodelalloc:
1312                         clear_opt(sbi->s_mount_opt, DELALLOC);
1313                         break;
1314                 case Opt_stripe:
1315                         if (match_int(&args[0], &option))
1316                                 return 0;
1317                         if (option < 0)
1318                                 return 0;
1319                         sbi->s_stripe = option;
1320                         break;
1321                 case Opt_delalloc:
1322                         set_opt(sbi->s_mount_opt, DELALLOC);
1323                         break;
1324                 case Opt_inode_readahead_blks:
1325                         if (match_int(&args[0], &option))
1326                                 return 0;
1327                         if (option < 0 || option > (1 << 30))
1328                                 return 0;
1329                         sbi->s_inode_readahead_blks = option;
1330                         break;
1331                 default:
1332                         printk(KERN_ERR
1333                                "EXT4-fs: Unrecognized mount option \"%s\" "
1334                                "or missing value\n", p);
1335                         return 0;
1336                 }
1337         }
1338 #ifdef CONFIG_QUOTA
1339         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1340                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1341                      sbi->s_qf_names[USRQUOTA])
1342                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1343
1344                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1345                      sbi->s_qf_names[GRPQUOTA])
1346                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1347
1348                 if ((sbi->s_qf_names[USRQUOTA] &&
1349                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1350                     (sbi->s_qf_names[GRPQUOTA] &&
1351                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1352                         printk(KERN_ERR "EXT4-fs: old and new quota "
1353                                         "format mixing.\n");
1354                         return 0;
1355                 }
1356
1357                 if (!sbi->s_jquota_fmt) {
1358                         printk(KERN_ERR "EXT4-fs: journaled quota format "
1359                                         "not specified.\n");
1360                         return 0;
1361                 }
1362         } else {
1363                 if (sbi->s_jquota_fmt) {
1364                         printk(KERN_ERR "EXT4-fs: journaled quota format "
1365                                         "specified with no journaling "
1366                                         "enabled.\n");
1367                         return 0;
1368                 }
1369         }
1370 #endif
1371         return 1;
1372 }
1373
1374 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1375                             int read_only)
1376 {
1377         struct ext4_sb_info *sbi = EXT4_SB(sb);
1378         int res = 0;
1379
1380         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1381                 printk(KERN_ERR "EXT4-fs warning: revision level too high, "
1382                        "forcing read-only mode\n");
1383                 res = MS_RDONLY;
1384         }
1385         if (read_only)
1386                 return res;
1387         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1388                 printk(KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1389                        "running e2fsck is recommended\n");
1390         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1391                 printk(KERN_WARNING
1392                        "EXT4-fs warning: mounting fs with errors, "
1393                        "running e2fsck is recommended\n");
1394         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1395                  le16_to_cpu(es->s_mnt_count) >=
1396                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1397                 printk(KERN_WARNING
1398                        "EXT4-fs warning: maximal mount count reached, "
1399                        "running e2fsck is recommended\n");
1400         else if (le32_to_cpu(es->s_checkinterval) &&
1401                 (le32_to_cpu(es->s_lastcheck) +
1402                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1403                 printk(KERN_WARNING
1404                        "EXT4-fs warning: checktime reached, "
1405                        "running e2fsck is recommended\n");
1406 #if 0
1407                 /* @@@ We _will_ want to clear the valid bit if we find
1408                  * inconsistencies, to force a fsck at reboot.  But for
1409                  * a plain journaled filesystem we can keep it set as
1410                  * valid forever! :)
1411                  */
1412         es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1413 #endif
1414         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1415                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1416         le16_add_cpu(&es->s_mnt_count, 1);
1417         es->s_mtime = cpu_to_le32(get_seconds());
1418         ext4_update_dynamic_rev(sb);
1419         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1420
1421         ext4_commit_super(sb, es, 1);
1422         if (test_opt(sb, DEBUG))
1423                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%lu, "
1424                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1425                         sb->s_blocksize,
1426                         sbi->s_groups_count,
1427                         EXT4_BLOCKS_PER_GROUP(sb),
1428                         EXT4_INODES_PER_GROUP(sb),
1429                         sbi->s_mount_opt);
1430
1431         printk(KERN_INFO "EXT4 FS on %s, %s journal on %s\n",
1432                sb->s_id, EXT4_SB(sb)->s_journal->j_inode ? "internal" :
1433                "external", EXT4_SB(sb)->s_journal->j_devname);
1434         return res;
1435 }
1436
1437 static int ext4_fill_flex_info(struct super_block *sb)
1438 {
1439         struct ext4_sb_info *sbi = EXT4_SB(sb);
1440         struct ext4_group_desc *gdp = NULL;
1441         struct buffer_head *bh;
1442         ext4_group_t flex_group_count;
1443         ext4_group_t flex_group;
1444         int groups_per_flex = 0;
1445         __u64 block_bitmap = 0;
1446         int i;
1447
1448         if (!sbi->s_es->s_log_groups_per_flex) {
1449                 sbi->s_log_groups_per_flex = 0;
1450                 return 1;
1451         }
1452
1453         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1454         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1455
1456         /* We allocate both existing and potentially added groups */
1457         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1458                             ((sbi->s_es->s_reserved_gdt_blocks +1 ) <<
1459                               EXT4_DESC_PER_BLOCK_BITS(sb))) /
1460                            groups_per_flex;
1461         sbi->s_flex_groups = kzalloc(flex_group_count *
1462                                      sizeof(struct flex_groups), GFP_KERNEL);
1463         if (sbi->s_flex_groups == NULL) {
1464                 printk(KERN_ERR "EXT4-fs: not enough memory for "
1465                                 "%lu flex groups\n", flex_group_count);
1466                 goto failed;
1467         }
1468
1469         gdp = ext4_get_group_desc(sb, 1, &bh);
1470         block_bitmap = ext4_block_bitmap(sb, gdp) - 1;
1471
1472         for (i = 0; i < sbi->s_groups_count; i++) {
1473                 gdp = ext4_get_group_desc(sb, i, &bh);
1474
1475                 flex_group = ext4_flex_group(sbi, i);
1476                 sbi->s_flex_groups[flex_group].free_inodes +=
1477                         le16_to_cpu(gdp->bg_free_inodes_count);
1478                 sbi->s_flex_groups[flex_group].free_blocks +=
1479                         le16_to_cpu(gdp->bg_free_blocks_count);
1480         }
1481
1482         return 1;
1483 failed:
1484         return 0;
1485 }
1486
1487 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1488                             struct ext4_group_desc *gdp)
1489 {
1490         __u16 crc = 0;
1491
1492         if (sbi->s_es->s_feature_ro_compat &
1493             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1494                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1495                 __le32 le_group = cpu_to_le32(block_group);
1496
1497                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1498                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1499                 crc = crc16(crc, (__u8 *)gdp, offset);
1500                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1501                 /* for checksum of struct ext4_group_desc do the rest...*/
1502                 if ((sbi->s_es->s_feature_incompat &
1503                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1504                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1505                         crc = crc16(crc, (__u8 *)gdp + offset,
1506                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1507                                         offset);
1508         }
1509
1510         return cpu_to_le16(crc);
1511 }
1512
1513 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1514                                 struct ext4_group_desc *gdp)
1515 {
1516         if ((sbi->s_es->s_feature_ro_compat &
1517              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1518             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1519                 return 0;
1520
1521         return 1;
1522 }
1523
1524 /* Called at mount-time, super-block is locked */
1525 static int ext4_check_descriptors(struct super_block *sb)
1526 {
1527         struct ext4_sb_info *sbi = EXT4_SB(sb);
1528         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1529         ext4_fsblk_t last_block;
1530         ext4_fsblk_t block_bitmap;
1531         ext4_fsblk_t inode_bitmap;
1532         ext4_fsblk_t inode_table;
1533         int flexbg_flag = 0;
1534         ext4_group_t i;
1535
1536         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1537                 flexbg_flag = 1;
1538
1539         ext4_debug("Checking group descriptors");
1540
1541         for (i = 0; i < sbi->s_groups_count; i++) {
1542                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1543
1544                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1545                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1546                 else
1547                         last_block = first_block +
1548                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1549
1550                 block_bitmap = ext4_block_bitmap(sb, gdp);
1551                 if (block_bitmap < first_block || block_bitmap > last_block) {
1552                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1553                                "Block bitmap for group %lu not in group "
1554                                "(block %llu)!\n", i, block_bitmap);
1555                         return 0;
1556                 }
1557                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1558                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
1559                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1560                                "Inode bitmap for group %lu not in group "
1561                                "(block %llu)!\n", i, inode_bitmap);
1562                         return 0;
1563                 }
1564                 inode_table = ext4_inode_table(sb, gdp);
1565                 if (inode_table < first_block ||
1566                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
1567                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1568                                "Inode table for group %lu not in group "
1569                                "(block %llu)!\n", i, inode_table);
1570                         return 0;
1571                 }
1572                 spin_lock(sb_bgl_lock(sbi, i));
1573                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1574                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1575                                "Checksum for group %lu failed (%u!=%u)\n",
1576                                i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1577                                gdp)), le16_to_cpu(gdp->bg_checksum));
1578                         if (!(sb->s_flags & MS_RDONLY)) {
1579                                 spin_unlock(sb_bgl_lock(sbi, i));
1580                                 return 0;
1581                         }
1582                 }
1583                 spin_unlock(sb_bgl_lock(sbi, i));
1584                 if (!flexbg_flag)
1585                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1586         }
1587
1588         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1589         sbi->s_es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
1590         return 1;
1591 }
1592
1593 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1594  * the superblock) which were deleted from all directories, but held open by
1595  * a process at the time of a crash.  We walk the list and try to delete these
1596  * inodes at recovery time (only with a read-write filesystem).
1597  *
1598  * In order to keep the orphan inode chain consistent during traversal (in
1599  * case of crash during recovery), we link each inode into the superblock
1600  * orphan list_head and handle it the same way as an inode deletion during
1601  * normal operation (which journals the operations for us).
1602  *
1603  * We only do an iget() and an iput() on each inode, which is very safe if we
1604  * accidentally point at an in-use or already deleted inode.  The worst that
1605  * can happen in this case is that we get a "bit already cleared" message from
1606  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1607  * e2fsck was run on this filesystem, and it must have already done the orphan
1608  * inode cleanup for us, so we can safely abort without any further action.
1609  */
1610 static void ext4_orphan_cleanup(struct super_block *sb,
1611                                 struct ext4_super_block *es)
1612 {
1613         unsigned int s_flags = sb->s_flags;
1614         int nr_orphans = 0, nr_truncates = 0;
1615 #ifdef CONFIG_QUOTA
1616         int i;
1617 #endif
1618         if (!es->s_last_orphan) {
1619                 jbd_debug(4, "no orphan inodes to clean up\n");
1620                 return;
1621         }
1622
1623         if (bdev_read_only(sb->s_bdev)) {
1624                 printk(KERN_ERR "EXT4-fs: write access "
1625                         "unavailable, skipping orphan cleanup.\n");
1626                 return;
1627         }
1628
1629         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1630                 if (es->s_last_orphan)
1631                         jbd_debug(1, "Errors on filesystem, "
1632                                   "clearing orphan list.\n");
1633                 es->s_last_orphan = 0;
1634                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1635                 return;
1636         }
1637
1638         if (s_flags & MS_RDONLY) {
1639                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1640                        sb->s_id);
1641                 sb->s_flags &= ~MS_RDONLY;
1642         }
1643 #ifdef CONFIG_QUOTA
1644         /* Needed for iput() to work correctly and not trash data */
1645         sb->s_flags |= MS_ACTIVE;
1646         /* Turn on quotas so that they are updated correctly */
1647         for (i = 0; i < MAXQUOTAS; i++) {
1648                 if (EXT4_SB(sb)->s_qf_names[i]) {
1649                         int ret = ext4_quota_on_mount(sb, i);
1650                         if (ret < 0)
1651                                 printk(KERN_ERR
1652                                         "EXT4-fs: Cannot turn on journaled "
1653                                         "quota: error %d\n", ret);
1654                 }
1655         }
1656 #endif
1657
1658         while (es->s_last_orphan) {
1659                 struct inode *inode;
1660
1661                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
1662                 if (IS_ERR(inode)) {
1663                         es->s_last_orphan = 0;
1664                         break;
1665                 }
1666
1667                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1668                 DQUOT_INIT(inode);
1669                 if (inode->i_nlink) {
1670                         printk(KERN_DEBUG
1671                                 "%s: truncating inode %lu to %lld bytes\n",
1672                                 __func__, inode->i_ino, inode->i_size);
1673                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
1674                                   inode->i_ino, inode->i_size);
1675                         ext4_truncate(inode);
1676                         nr_truncates++;
1677                 } else {
1678                         printk(KERN_DEBUG
1679                                 "%s: deleting unreferenced inode %lu\n",
1680                                 __func__, inode->i_ino);
1681                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1682                                   inode->i_ino);
1683                         nr_orphans++;
1684                 }
1685                 iput(inode);  /* The delete magic happens here! */
1686         }
1687
1688 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
1689
1690         if (nr_orphans)
1691                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1692                        sb->s_id, PLURAL(nr_orphans));
1693         if (nr_truncates)
1694                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1695                        sb->s_id, PLURAL(nr_truncates));
1696 #ifdef CONFIG_QUOTA
1697         /* Turn quotas off */
1698         for (i = 0; i < MAXQUOTAS; i++) {
1699                 if (sb_dqopt(sb)->files[i])
1700                         vfs_quota_off(sb, i, 0);
1701         }
1702 #endif
1703         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1704 }
1705 /*
1706  * Maximal extent format file size.
1707  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1708  * extent format containers, within a sector_t, and within i_blocks
1709  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1710  * so that won't be a limiting factor.
1711  *
1712  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1713  */
1714 static loff_t ext4_max_size(int blkbits, int has_huge_files)
1715 {
1716         loff_t res;
1717         loff_t upper_limit = MAX_LFS_FILESIZE;
1718
1719         /* small i_blocks in vfs inode? */
1720         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1721                 /*
1722                  * CONFIG_LSF is not enabled implies the inode
1723                  * i_block represent total blocks in 512 bytes
1724                  * 32 == size of vfs inode i_blocks * 8
1725                  */
1726                 upper_limit = (1LL << 32) - 1;
1727
1728                 /* total blocks in file system block size */
1729                 upper_limit >>= (blkbits - 9);
1730                 upper_limit <<= blkbits;
1731         }
1732
1733         /* 32-bit extent-start container, ee_block */
1734         res = 1LL << 32;
1735         res <<= blkbits;
1736         res -= 1;
1737
1738         /* Sanity check against vm- & vfs- imposed limits */
1739         if (res > upper_limit)
1740                 res = upper_limit;
1741
1742         return res;
1743 }
1744
1745 /*
1746  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
1747  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
1748  * We need to be 1 filesystem block less than the 2^48 sector limit.
1749  */
1750 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
1751 {
1752         loff_t res = EXT4_NDIR_BLOCKS;
1753         int meta_blocks;
1754         loff_t upper_limit;
1755         /* This is calculated to be the largest file size for a
1756          * dense, bitmapped file such that the total number of
1757          * sectors in the file, including data and all indirect blocks,
1758          * does not exceed 2^48 -1
1759          * __u32 i_blocks_lo and _u16 i_blocks_high representing the
1760          * total number of  512 bytes blocks of the file
1761          */
1762
1763         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1764                 /*
1765                  * !has_huge_files or CONFIG_LSF is not enabled
1766                  * implies the inode i_block represent total blocks in
1767                  * 512 bytes 32 == size of vfs inode i_blocks * 8
1768                  */
1769                 upper_limit = (1LL << 32) - 1;
1770
1771                 /* total blocks in file system block size */
1772                 upper_limit >>= (bits - 9);
1773
1774         } else {
1775                 /*
1776                  * We use 48 bit ext4_inode i_blocks
1777                  * With EXT4_HUGE_FILE_FL set the i_blocks
1778                  * represent total number of blocks in
1779                  * file system block size
1780                  */
1781                 upper_limit = (1LL << 48) - 1;
1782
1783         }
1784
1785         /* indirect blocks */
1786         meta_blocks = 1;
1787         /* double indirect blocks */
1788         meta_blocks += 1 + (1LL << (bits-2));
1789         /* tripple indirect blocks */
1790         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
1791
1792         upper_limit -= meta_blocks;
1793         upper_limit <<= bits;
1794
1795         res += 1LL << (bits-2);
1796         res += 1LL << (2*(bits-2));
1797         res += 1LL << (3*(bits-2));
1798         res <<= bits;
1799         if (res > upper_limit)
1800                 res = upper_limit;
1801
1802         if (res > MAX_LFS_FILESIZE)
1803                 res = MAX_LFS_FILESIZE;
1804
1805         return res;
1806 }
1807
1808 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1809                                 ext4_fsblk_t logical_sb_block, int nr)
1810 {
1811         struct ext4_sb_info *sbi = EXT4_SB(sb);
1812         ext4_group_t bg, first_meta_bg;
1813         int has_super = 0;
1814
1815         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1816
1817         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1818             nr < first_meta_bg)
1819                 return logical_sb_block + nr + 1;
1820         bg = sbi->s_desc_per_block * nr;
1821         if (ext4_bg_has_super(sb, bg))
1822                 has_super = 1;
1823         return (has_super + ext4_group_first_block_no(sb, bg));
1824 }
1825
1826 /**
1827  * ext4_get_stripe_size: Get the stripe size.
1828  * @sbi: In memory super block info
1829  *
1830  * If we have specified it via mount option, then
1831  * use the mount option value. If the value specified at mount time is
1832  * greater than the blocks per group use the super block value.
1833  * If the super block value is greater than blocks per group return 0.
1834  * Allocator needs it be less than blocks per group.
1835  *
1836  */
1837 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
1838 {
1839         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
1840         unsigned long stripe_width =
1841                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
1842
1843         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
1844                 return sbi->s_stripe;
1845
1846         if (stripe_width <= sbi->s_blocks_per_group)
1847                 return stripe_width;
1848
1849         if (stride <= sbi->s_blocks_per_group)
1850                 return stride;
1851
1852         return 0;
1853 }
1854
1855 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
1856                                 __releases(kernel_lock)
1857                                 __acquires(kernel_lock)
1858
1859 {
1860         struct buffer_head *bh;
1861         struct ext4_super_block *es = NULL;
1862         struct ext4_sb_info *sbi;
1863         ext4_fsblk_t block;
1864         ext4_fsblk_t sb_block = get_sb_block(&data);
1865         ext4_fsblk_t logical_sb_block;
1866         unsigned long offset = 0;
1867         unsigned int journal_inum = 0;
1868         unsigned long journal_devnum = 0;
1869         unsigned long def_mount_opts;
1870         struct inode *root;
1871         char *cp;
1872         int ret = -EINVAL;
1873         int blocksize;
1874         int db_count;
1875         int i;
1876         int needs_recovery, has_huge_files;
1877         __le32 features;
1878         __u64 blocks_count;
1879         int err;
1880
1881         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1882         if (!sbi)
1883                 return -ENOMEM;
1884         sb->s_fs_info = sbi;
1885         sbi->s_mount_opt = 0;
1886         sbi->s_resuid = EXT4_DEF_RESUID;
1887         sbi->s_resgid = EXT4_DEF_RESGID;
1888         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
1889         sbi->s_sb_block = sb_block;
1890
1891         unlock_kernel();
1892
1893         /* Cleanup superblock name */
1894         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
1895                 *cp = '!';
1896
1897         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1898         if (!blocksize) {
1899                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1900                 goto out_fail;
1901         }
1902
1903         /*
1904          * The ext4 superblock will not be buffer aligned for other than 1kB
1905          * block sizes.  We need to calculate the offset from buffer start.
1906          */
1907         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1908                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1909                 offset = do_div(logical_sb_block, blocksize);
1910         } else {
1911                 logical_sb_block = sb_block;
1912         }
1913
1914         if (!(bh = sb_bread(sb, logical_sb_block))) {
1915                 printk(KERN_ERR "EXT4-fs: unable to read superblock\n");
1916                 goto out_fail;
1917         }
1918         /*
1919          * Note: s_es must be initialized as soon as possible because
1920          *       some ext4 macro-instructions depend on its value
1921          */
1922         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1923         sbi->s_es = es;
1924         sb->s_magic = le16_to_cpu(es->s_magic);
1925         if (sb->s_magic != EXT4_SUPER_MAGIC)
1926                 goto cantfind_ext4;
1927
1928         /* Set defaults before we parse the mount options */
1929         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1930         if (def_mount_opts & EXT4_DEFM_DEBUG)
1931                 set_opt(sbi->s_mount_opt, DEBUG);
1932         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1933                 set_opt(sbi->s_mount_opt, GRPID);
1934         if (def_mount_opts & EXT4_DEFM_UID16)
1935                 set_opt(sbi->s_mount_opt, NO_UID32);
1936 #ifdef CONFIG_EXT4_FS_XATTR
1937         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1938                 set_opt(sbi->s_mount_opt, XATTR_USER);
1939 #endif
1940 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1941         if (def_mount_opts & EXT4_DEFM_ACL)
1942                 set_opt(sbi->s_mount_opt, POSIX_ACL);
1943 #endif
1944         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1945                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1946         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1947                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1948         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1949                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1950
1951         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1952                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1953         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
1954                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
1955         else
1956                 set_opt(sbi->s_mount_opt, ERRORS_RO);
1957
1958         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1959         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1960
1961         set_opt(sbi->s_mount_opt, RESERVATION);
1962         set_opt(sbi->s_mount_opt, BARRIER);
1963
1964         /*
1965          * turn on extents feature by default in ext4 filesystem
1966          * only if feature flag already set by mkfs or tune2fs.
1967          * Use -o noextents to turn it off
1968          */
1969         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
1970                 set_opt(sbi->s_mount_opt, EXTENTS);
1971         else
1972                 ext4_warning(sb, __func__,
1973                         "extents feature not enabled on this filesystem, "
1974                         "use tune2fs.\n");
1975
1976         /*
1977          * enable delayed allocation by default
1978          * Use -o nodelalloc to turn it off
1979          */
1980         set_opt(sbi->s_mount_opt, DELALLOC);
1981
1982
1983         if (!parse_options((char *) data, sb, &journal_inum, &journal_devnum,
1984                            NULL, 0))
1985                 goto failed_mount;
1986
1987         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1988                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1989
1990         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1991             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1992              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1993              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1994                 printk(KERN_WARNING
1995                        "EXT4-fs warning: feature flags set on rev 0 fs, "
1996                        "running e2fsck is recommended\n");
1997
1998         /*
1999          * Check feature flags regardless of the revision level, since we
2000          * previously didn't change the revision level when setting the flags,
2001          * so there is a chance incompat flags are set on a rev 0 filesystem.
2002          */
2003         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
2004         if (features) {
2005                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
2006                        "unsupported optional features (%x).\n",
2007                        sb->s_id, le32_to_cpu(features));
2008                 goto failed_mount;
2009         }
2010         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
2011         if (!(sb->s_flags & MS_RDONLY) && features) {
2012                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
2013                        "unsupported optional features (%x).\n",
2014                        sb->s_id, le32_to_cpu(features));
2015                 goto failed_mount;
2016         }
2017         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2018                                     EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
2019         if (has_huge_files) {
2020                 /*
2021                  * Large file size enabled file system can only be
2022                  * mount if kernel is build with CONFIG_LSF
2023                  */
2024                 if (sizeof(root->i_blocks) < sizeof(u64) &&
2025                                 !(sb->s_flags & MS_RDONLY)) {
2026                         printk(KERN_ERR "EXT4-fs: %s: Filesystem with huge "
2027                                         "files cannot be mounted read-write "
2028                                         "without CONFIG_LSF.\n", sb->s_id);
2029                         goto failed_mount;
2030                 }
2031         }
2032         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
2033
2034         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
2035             blocksize > EXT4_MAX_BLOCK_SIZE) {
2036                 printk(KERN_ERR
2037                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
2038                        blocksize, sb->s_id);
2039                 goto failed_mount;
2040         }
2041
2042         if (sb->s_blocksize != blocksize) {
2043
2044                 /* Validate the filesystem blocksize */
2045                 if (!sb_set_blocksize(sb, blocksize)) {
2046                         printk(KERN_ERR "EXT4-fs: bad block size %d.\n",
2047                                         blocksize);
2048                         goto failed_mount;
2049                 }
2050
2051                 brelse(bh);
2052                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2053                 offset = do_div(logical_sb_block, blocksize);
2054                 bh = sb_bread(sb, logical_sb_block);
2055                 if (!bh) {
2056                         printk(KERN_ERR
2057                                "EXT4-fs: Can't read superblock on 2nd try.\n");
2058                         goto failed_mount;
2059                 }
2060                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
2061                 sbi->s_es = es;
2062                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
2063                         printk(KERN_ERR
2064                                "EXT4-fs: Magic mismatch, very weird !\n");
2065                         goto failed_mount;
2066                 }
2067         }
2068
2069         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
2070                                                       has_huge_files);
2071         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
2072
2073         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2074                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2075                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2076         } else {
2077                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2078                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2079                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2080                     (!is_power_of_2(sbi->s_inode_size)) ||
2081                     (sbi->s_inode_size > blocksize)) {
2082                         printk(KERN_ERR
2083                                "EXT4-fs: unsupported inode size: %d\n",
2084                                sbi->s_inode_size);
2085                         goto failed_mount;
2086                 }
2087                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2088                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2089         }
2090         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2091         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2092                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2093                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2094                     !is_power_of_2(sbi->s_desc_size)) {
2095                         printk(KERN_ERR
2096                                "EXT4-fs: unsupported descriptor size %lu\n",
2097                                sbi->s_desc_size);
2098                         goto failed_mount;
2099                 }
2100         } else
2101                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2102         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2103         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2104         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2105                 goto cantfind_ext4;
2106         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2107         if (sbi->s_inodes_per_block == 0)
2108                 goto cantfind_ext4;
2109         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2110                                         sbi->s_inodes_per_block;
2111         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2112         sbi->s_sbh = bh;
2113         sbi->s_mount_state = le16_to_cpu(es->s_state);
2114         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2115         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2116         for (i = 0; i < 4; i++)
2117                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2118         sbi->s_def_hash_version = es->s_def_hash_version;
2119
2120         if (sbi->s_blocks_per_group > blocksize * 8) {
2121                 printk(KERN_ERR
2122                        "EXT4-fs: #blocks per group too big: %lu\n",
2123                        sbi->s_blocks_per_group);
2124                 goto failed_mount;
2125         }
2126         if (sbi->s_inodes_per_group > blocksize * 8) {
2127                 printk(KERN_ERR
2128                        "EXT4-fs: #inodes per group too big: %lu\n",
2129                        sbi->s_inodes_per_group);
2130                 goto failed_mount;
2131         }
2132
2133         if (ext4_blocks_count(es) >
2134                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
2135                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
2136                         " too large to mount safely\n", sb->s_id);
2137                 if (sizeof(sector_t) < 8)
2138                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
2139                                         "enabled\n");
2140                 goto failed_mount;
2141         }
2142
2143         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2144                 goto cantfind_ext4;
2145
2146         /* ensure blocks_count calculation below doesn't sign-extend */
2147         if (ext4_blocks_count(es) + EXT4_BLOCKS_PER_GROUP(sb) <
2148             le32_to_cpu(es->s_first_data_block) + 1) {
2149                 printk(KERN_WARNING "EXT4-fs: bad geometry: block count %llu, "
2150                        "first data block %u, blocks per group %lu\n",
2151                         ext4_blocks_count(es),
2152                         le32_to_cpu(es->s_first_data_block),
2153                         EXT4_BLOCKS_PER_GROUP(sb));
2154                 goto failed_mount;
2155         }
2156         blocks_count = (ext4_blocks_count(es) -
2157                         le32_to_cpu(es->s_first_data_block) +
2158                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2159         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2160         sbi->s_groups_count = blocks_count;
2161         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2162                    EXT4_DESC_PER_BLOCK(sb);
2163         sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
2164                                     GFP_KERNEL);
2165         if (sbi->s_group_desc == NULL) {
2166                 printk(KERN_ERR "EXT4-fs: not enough memory\n");
2167                 goto failed_mount;
2168         }
2169
2170 #ifdef CONFIG_PROC_FS
2171         if (ext4_proc_root)
2172                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
2173
2174         if (sbi->s_proc)
2175                 proc_create_data("inode_readahead_blks", 0644, sbi->s_proc,
2176                                  &ext4_ui_proc_fops,
2177                                  &sbi->s_inode_readahead_blks);
2178 #endif
2179
2180         bgl_lock_init(&sbi->s_blockgroup_lock);
2181
2182         for (i = 0; i < db_count; i++) {
2183                 block = descriptor_loc(sb, logical_sb_block, i);
2184                 sbi->s_group_desc[i] = sb_bread(sb, block);
2185                 if (!sbi->s_group_desc[i]) {
2186                         printk(KERN_ERR "EXT4-fs: "
2187                                "can't read group descriptor %d\n", i);
2188                         db_count = i;
2189                         goto failed_mount2;
2190                 }
2191         }
2192         if (!ext4_check_descriptors(sb)) {
2193                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
2194                 goto failed_mount2;
2195         }
2196         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2197                 if (!ext4_fill_flex_info(sb)) {
2198                         printk(KERN_ERR
2199                                "EXT4-fs: unable to initialize "
2200                                "flex_bg meta info!\n");
2201                         goto failed_mount2;
2202                 }
2203
2204         sbi->s_gdb_count = db_count;
2205         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2206         spin_lock_init(&sbi->s_next_gen_lock);
2207
2208         err = percpu_counter_init(&sbi->s_freeblocks_counter,
2209                         ext4_count_free_blocks(sb));
2210         if (!err) {
2211                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
2212                                 ext4_count_free_inodes(sb));
2213         }
2214         if (!err) {
2215                 err = percpu_counter_init(&sbi->s_dirs_counter,
2216                                 ext4_count_dirs(sb));
2217         }
2218         if (!err) {
2219                 err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
2220         }
2221         if (err) {
2222                 printk(KERN_ERR "EXT4-fs: insufficient memory\n");
2223                 goto failed_mount3;
2224         }
2225
2226         sbi->s_stripe = ext4_get_stripe_size(sbi);
2227
2228         /*
2229          * set up enough so that it can read an inode
2230          */
2231         sb->s_op = &ext4_sops;
2232         sb->s_export_op = &ext4_export_ops;
2233         sb->s_xattr = ext4_xattr_handlers;
2234 #ifdef CONFIG_QUOTA
2235         sb->s_qcop = &ext4_qctl_operations;
2236         sb->dq_op = &ext4_quota_operations;
2237 #endif
2238         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2239
2240         sb->s_root = NULL;
2241
2242         needs_recovery = (es->s_last_orphan != 0 ||
2243                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2244                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2245
2246         /*
2247          * The first inode we look at is the journal inode.  Don't try
2248          * root first: it may be modified in the journal!
2249          */
2250         if (!test_opt(sb, NOLOAD) &&
2251             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2252                 if (ext4_load_journal(sb, es, journal_devnum))
2253                         goto failed_mount3;
2254                 if (!(sb->s_flags & MS_RDONLY) &&
2255                     EXT4_SB(sb)->s_journal->j_failed_commit) {
2256                         printk(KERN_CRIT "EXT4-fs error (device %s): "
2257                                "ext4_fill_super: Journal transaction "
2258                                "%u is corrupt\n", sb->s_id,
2259                                EXT4_SB(sb)->s_journal->j_failed_commit);
2260                         if (test_opt(sb, ERRORS_RO)) {
2261                                 printk(KERN_CRIT
2262                                        "Mounting filesystem read-only\n");
2263                                 sb->s_flags |= MS_RDONLY;
2264                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2265                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2266                         }
2267                         if (test_opt(sb, ERRORS_PANIC)) {
2268                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2269                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2270                                 ext4_commit_super(sb, es, 1);
2271                                 printk(KERN_CRIT
2272                                        "EXT4-fs (device %s): mount failed\n",
2273                                       sb->s_id);
2274                                 goto failed_mount4;
2275                         }
2276                 }
2277         } else if (journal_inum) {
2278                 if (ext4_create_journal(sb, es, journal_inum))
2279                         goto failed_mount3;
2280         } else {
2281                 if (!silent)
2282                         printk(KERN_ERR
2283                                "ext4: No journal on filesystem on %s\n",
2284                                sb->s_id);
2285                 goto failed_mount3;
2286         }
2287
2288         if (ext4_blocks_count(es) > 0xffffffffULL &&
2289             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2290                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2291                 printk(KERN_ERR "ext4: Failed to set 64-bit journal feature\n");
2292                 goto failed_mount4;
2293         }
2294
2295         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2296                 jbd2_journal_set_features(sbi->s_journal,
2297                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2298                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2299         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2300                 jbd2_journal_set_features(sbi->s_journal,
2301                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2302                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2303                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2304         } else {
2305                 jbd2_journal_clear_features(sbi->s_journal,
2306                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2307                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2308         }
2309
2310         /* We have now updated the journal if required, so we can
2311          * validate the data journaling mode. */
2312         switch (test_opt(sb, DATA_FLAGS)) {
2313         case 0:
2314                 /* No mode set, assume a default based on the journal
2315                  * capabilities: ORDERED_DATA if the journal can
2316                  * cope, else JOURNAL_DATA
2317                  */
2318                 if (jbd2_journal_check_available_features
2319                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2320                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
2321                 else
2322                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2323                 break;
2324
2325         case EXT4_MOUNT_ORDERED_DATA:
2326         case EXT4_MOUNT_WRITEBACK_DATA:
2327                 if (!jbd2_journal_check_available_features
2328                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2329                         printk(KERN_ERR "EXT4-fs: Journal does not support "
2330                                "requested data journaling mode\n");
2331                         goto failed_mount4;
2332                 }
2333         default:
2334                 break;
2335         }
2336
2337         if (test_opt(sb, NOBH)) {
2338                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2339                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
2340                                 "its supported only with writeback mode\n");
2341                         clear_opt(sbi->s_mount_opt, NOBH);
2342                 }
2343         }
2344         /*
2345          * The jbd2_journal_load will have done any necessary log recovery,
2346          * so we can safely mount the rest of the filesystem now.
2347          */
2348
2349         root = ext4_iget(sb, EXT4_ROOT_INO);
2350         if (IS_ERR(root)) {
2351                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
2352                 ret = PTR_ERR(root);
2353                 goto failed_mount4;
2354         }
2355         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2356                 iput(root);
2357                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
2358                 goto failed_mount4;
2359         }
2360         sb->s_root = d_alloc_root(root);
2361         if (!sb->s_root) {
2362                 printk(KERN_ERR "EXT4-fs: get root dentry failed\n");
2363                 iput(root);
2364                 ret = -ENOMEM;
2365                 goto failed_mount4;
2366         }
2367
2368         ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
2369
2370         /* determine the minimum size of new large inodes, if present */
2371         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2372                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2373                                                      EXT4_GOOD_OLD_INODE_SIZE;
2374                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2375                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2376                         if (sbi->s_want_extra_isize <
2377                             le16_to_cpu(es->s_want_extra_isize))
2378                                 sbi->s_want_extra_isize =
2379                                         le16_to_cpu(es->s_want_extra_isize);
2380                         if (sbi->s_want_extra_isize <
2381                             le16_to_cpu(es->s_min_extra_isize))
2382                                 sbi->s_want_extra_isize =
2383                                         le16_to_cpu(es->s_min_extra_isize);
2384                 }
2385         }
2386         /* Check if enough inode space is available */
2387         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2388                                                         sbi->s_inode_size) {
2389                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2390                                                        EXT4_GOOD_OLD_INODE_SIZE;
2391                 printk(KERN_INFO "EXT4-fs: required extra inode space not"
2392                         "available.\n");
2393         }
2394
2395         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
2396                 printk(KERN_WARNING "EXT4-fs: Ignoring delalloc option - "
2397                                 "requested data journaling mode\n");
2398                 clear_opt(sbi->s_mount_opt, DELALLOC);
2399         } else if (test_opt(sb, DELALLOC))
2400                 printk(KERN_INFO "EXT4-fs: delayed allocation enabled\n");
2401
2402         ext4_ext_init(sb);
2403         err = ext4_mb_init(sb, needs_recovery);
2404         if (err) {
2405                 printk(KERN_ERR "EXT4-fs: failed to initalize mballoc (%d)\n",
2406                        err);
2407                 goto failed_mount4;
2408         }
2409
2410         /*
2411          * akpm: core read_super() calls in here with the superblock locked.
2412          * That deadlocks, because orphan cleanup needs to lock the superblock
2413          * in numerous places.  Here we just pop the lock - it's relatively
2414          * harmless, because we are now ready to accept write_super() requests,
2415          * and aviro says that's the only reason for hanging onto the
2416          * superblock lock.
2417          */
2418         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2419         ext4_orphan_cleanup(sb, es);
2420         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2421         if (needs_recovery)
2422                 printk(KERN_INFO "EXT4-fs: recovery complete.\n");
2423         ext4_mark_recovery_complete(sb, es);
2424         printk(KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
2425                test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
2426                test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
2427                "writeback");
2428
2429         lock_kernel();
2430         return 0;
2431
2432 cantfind_ext4:
2433         if (!silent)
2434                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
2435                        sb->s_id);
2436         goto failed_mount;
2437
2438 failed_mount4:
2439         jbd2_journal_destroy(sbi->s_journal);
2440         sbi->s_journal = NULL;
2441 failed_mount3:
2442         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2443         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2444         percpu_counter_destroy(&sbi->s_dirs_counter);
2445         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
2446 failed_mount2:
2447         for (i = 0; i < db_count; i++)
2448                 brelse(sbi->s_group_desc[i]);
2449         kfree(sbi->s_group_desc);
2450 failed_mount:
2451         if (sbi->s_proc) {
2452                 remove_proc_entry("inode_readahead_blks", sbi->s_proc);
2453                 remove_proc_entry(sb->s_id, ext4_proc_root);
2454         }
2455 #ifdef CONFIG_QUOTA
2456         for (i = 0; i < MAXQUOTAS; i++)
2457                 kfree(sbi->s_qf_names[i]);
2458 #endif
2459         ext4_blkdev_remove(sbi);
2460         brelse(bh);
2461 out_fail:
2462         sb->s_fs_info = NULL;
2463         kfree(sbi);
2464         lock_kernel();
2465         return ret;
2466 }
2467
2468 /*
2469  * Setup any per-fs journal parameters now.  We'll do this both on
2470  * initial mount, once the journal has been initialised but before we've
2471  * done any recovery; and again on any subsequent remount.
2472  */
2473 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2474 {
2475         struct ext4_sb_info *sbi = EXT4_SB(sb);
2476
2477         if (sbi->s_commit_interval)
2478                 journal->j_commit_interval = sbi->s_commit_interval;
2479         /* We could also set up an ext4-specific default for the commit
2480          * interval here, but for now we'll just fall back to the jbd
2481          * default. */
2482
2483         spin_lock(&journal->j_state_lock);
2484         if (test_opt(sb, BARRIER))
2485                 journal->j_flags |= JBD2_BARRIER;
2486         else
2487                 journal->j_flags &= ~JBD2_BARRIER;
2488         if (test_opt(sb, DATA_ERR_ABORT))
2489                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
2490         else
2491                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
2492         spin_unlock(&journal->j_state_lock);
2493 }
2494
2495 static journal_t *ext4_get_journal(struct super_block *sb,
2496                                    unsigned int journal_inum)
2497 {
2498         struct inode *journal_inode;
2499         journal_t *journal;
2500
2501         /* First, test for the existence of a valid inode on disk.  Bad
2502          * things happen if we iget() an unused inode, as the subsequent
2503          * iput() will try to delete it. */
2504
2505         journal_inode = ext4_iget(sb, journal_inum);
2506         if (IS_ERR(journal_inode)) {
2507                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
2508                 return NULL;
2509         }
2510         if (!journal_inode->i_nlink) {
2511                 make_bad_inode(journal_inode);
2512                 iput(journal_inode);
2513                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
2514                 return NULL;
2515         }
2516
2517         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
2518                   journal_inode, journal_inode->i_size);
2519         if (!S_ISREG(journal_inode->i_mode)) {
2520                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
2521                 iput(journal_inode);
2522                 return NULL;
2523         }
2524
2525         journal = jbd2_journal_init_inode(journal_inode);
2526         if (!journal) {
2527                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
2528                 iput(journal_inode);
2529                 return NULL;
2530         }
2531         journal->j_private = sb;
2532         ext4_init_journal_params(sb, journal);
2533         return journal;
2534 }
2535
2536 static journal_t *ext4_get_dev_journal(struct super_block *sb,
2537                                        dev_t j_dev)
2538 {
2539         struct buffer_head *bh;
2540         journal_t *journal;
2541         ext4_fsblk_t start;
2542         ext4_fsblk_t len;
2543         int hblock, blocksize;
2544         ext4_fsblk_t sb_block;
2545         unsigned long offset;
2546         struct ext4_super_block *es;
2547         struct block_device *bdev;
2548
2549         bdev = ext4_blkdev_get(j_dev);
2550         if (bdev == NULL)
2551                 return NULL;
2552
2553         if (bd_claim(bdev, sb)) {
2554                 printk(KERN_ERR
2555                         "EXT4: failed to claim external journal device.\n");
2556                 blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
2557                 return NULL;
2558         }
2559
2560         blocksize = sb->s_blocksize;
2561         hblock = bdev_hardsect_size(bdev);
2562         if (blocksize < hblock) {
2563                 printk(KERN_ERR
2564                         "EXT4-fs: blocksize too small for journal device.\n");
2565                 goto out_bdev;
2566         }
2567
2568         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2569         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2570         set_blocksize(bdev, blocksize);
2571         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2572                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2573                        "external journal\n");
2574                 goto out_bdev;
2575         }
2576
2577         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2578         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2579             !(le32_to_cpu(es->s_feature_incompat) &
2580               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2581                 printk(KERN_ERR "EXT4-fs: external journal has "
2582                                         "bad superblock\n");
2583                 brelse(bh);
2584                 goto out_bdev;
2585         }
2586
2587         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2588                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2589                 brelse(bh);
2590                 goto out_bdev;
2591         }
2592
2593         len = ext4_blocks_count(es);
2594         start = sb_block + 1;
2595         brelse(bh);     /* we're done with the superblock */
2596
2597         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2598                                         start, len, blocksize);
2599         if (!journal) {
2600                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2601                 goto out_bdev;
2602         }
2603         journal->j_private = sb;
2604         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2605         wait_on_buffer(journal->j_sb_buffer);
2606         if (!buffer_uptodate(journal->j_sb_buffer)) {
2607                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2608                 goto out_journal;
2609         }
2610         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2611                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2612                                         "user (unsupported) - %d\n",
2613                         be32_to_cpu(journal->j_superblock->s_nr_users));
2614                 goto out_journal;
2615         }
2616         EXT4_SB(sb)->journal_bdev = bdev;
2617         ext4_init_journal_params(sb, journal);
2618         return journal;
2619 out_journal:
2620         jbd2_journal_destroy(journal);
2621 out_bdev:
2622         ext4_blkdev_put(bdev);
2623         return NULL;
2624 }
2625
2626 static int ext4_load_journal(struct super_block *sb,
2627                              struct ext4_super_block *es,
2628                              unsigned long journal_devnum)
2629 {
2630         journal_t *journal;
2631         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2632         dev_t journal_dev;
2633         int err = 0;
2634         int really_read_only;
2635
2636         if (journal_devnum &&
2637             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2638                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2639                         "numbers have changed\n");
2640                 journal_dev = new_decode_dev(journal_devnum);
2641         } else
2642                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2643
2644         really_read_only = bdev_read_only(sb->s_bdev);
2645
2646         /*
2647          * Are we loading a blank journal or performing recovery after a
2648          * crash?  For recovery, we need to check in advance whether we
2649          * can get read-write access to the device.
2650          */
2651
2652         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2653                 if (sb->s_flags & MS_RDONLY) {
2654                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2655                                         "required on readonly filesystem.\n");
2656                         if (really_read_only) {
2657                                 printk(KERN_ERR "EXT4-fs: write access "
2658                                         "unavailable, cannot proceed.\n");
2659                                 return -EROFS;
2660                         }
2661                         printk(KERN_INFO "EXT4-fs: write access will "
2662                                "be enabled during recovery.\n");
2663                 }
2664         }
2665
2666         if (journal_inum && journal_dev) {
2667                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2668                        "and inode journals!\n");
2669                 return -EINVAL;
2670         }
2671
2672         if (journal_inum) {
2673                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2674                         return -EINVAL;
2675         } else {
2676                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2677                         return -EINVAL;
2678         }
2679
2680         if (journal->j_flags & JBD2_BARRIER)
2681                 printk(KERN_INFO "EXT4-fs: barriers enabled\n");
2682         else
2683                 printk(KERN_INFO "EXT4-fs: barriers disabled\n");
2684
2685         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2686                 err = jbd2_journal_update_format(journal);
2687                 if (err)  {
2688                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2689                         jbd2_journal_destroy(journal);
2690                         return err;
2691                 }
2692         }
2693
2694         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2695                 err = jbd2_journal_wipe(journal, !really_read_only);
2696         if (!err)
2697                 err = jbd2_journal_load(journal);
2698
2699         if (err) {
2700                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2701                 jbd2_journal_destroy(journal);
2702                 return err;
2703         }
2704
2705         EXT4_SB(sb)->s_journal = journal;
2706         ext4_clear_journal_err(sb, es);
2707
2708         if (journal_devnum &&
2709             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2710                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2711                 sb->s_dirt = 1;
2712
2713                 /* Make sure we flush the recovery flag to disk. */
2714                 ext4_commit_super(sb, es, 1);
2715         }
2716
2717         return 0;
2718 }
2719
2720 static int ext4_create_journal(struct super_block *sb,
2721                                struct ext4_super_block *es,
2722                                unsigned int journal_inum)
2723 {
2724         journal_t *journal;
2725         int err;
2726
2727         if (sb->s_flags & MS_RDONLY) {
2728                 printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2729                                 "create journal.\n");
2730                 return -EROFS;
2731         }
2732
2733         journal = ext4_get_journal(sb, journal_inum);
2734         if (!journal)
2735                 return -EINVAL;
2736
2737         printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2738                journal_inum);
2739
2740         err = jbd2_journal_create(journal);
2741         if (err) {
2742                 printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2743                 jbd2_journal_destroy(journal);
2744                 return -EIO;
2745         }
2746
2747         EXT4_SB(sb)->s_journal = journal;
2748
2749         ext4_update_dynamic_rev(sb);
2750         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2751         EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2752
2753         es->s_journal_inum = cpu_to_le32(journal_inum);
2754         sb->s_dirt = 1;
2755
2756         /* Make sure we flush the recovery flag to disk. */
2757         ext4_commit_super(sb, es, 1);
2758
2759         return 0;
2760 }
2761
2762 static void ext4_commit_super(struct super_block *sb,
2763                               struct ext4_super_block *es, int sync)
2764 {
2765         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2766
2767         if (!sbh)
2768                 return;
2769         if (buffer_write_io_error(sbh)) {
2770                 /*
2771                  * Oh, dear.  A previous attempt to write the
2772                  * superblock failed.  This could happen because the
2773                  * USB device was yanked out.  Or it could happen to
2774                  * be a transient write error and maybe the block will
2775                  * be remapped.  Nothing we can do but to retry the
2776                  * write and hope for the best.
2777                  */
2778                 printk(KERN_ERR "ext4: previous I/O error to "
2779                        "superblock detected for %s.\n", sb->s_id);
2780                 clear_buffer_write_io_error(sbh);
2781                 set_buffer_uptodate(sbh);
2782         }
2783         es->s_wtime = cpu_to_le32(get_seconds());
2784         ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2785         es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2786         BUFFER_TRACE(sbh, "marking dirty");
2787         mark_buffer_dirty(sbh);
2788         if (sync) {
2789                 sync_dirty_buffer(sbh);
2790                 if (buffer_write_io_error(sbh)) {
2791                         printk(KERN_ERR "ext4: I/O error while writing "
2792                                "superblock for %s.\n", sb->s_id);
2793                         clear_buffer_write_io_error(sbh);
2794                         set_buffer_uptodate(sbh);
2795                 }
2796         }
2797 }
2798
2799
2800 /*
2801  * Have we just finished recovery?  If so, and if we are mounting (or
2802  * remounting) the filesystem readonly, then we will end up with a
2803  * consistent fs on disk.  Record that fact.
2804  */
2805 static void ext4_mark_recovery_complete(struct super_block *sb,
2806                                         struct ext4_super_block *es)
2807 {
2808         journal_t *journal = EXT4_SB(sb)->s_journal;
2809
2810         jbd2_journal_lock_updates(journal);
2811         if (jbd2_journal_flush(journal) < 0)
2812                 goto out;
2813
2814         lock_super(sb);
2815         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2816             sb->s_flags & MS_RDONLY) {
2817                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2818                 sb->s_dirt = 0;
2819                 ext4_commit_super(sb, es, 1);
2820         }
2821         unlock_super(sb);
2822
2823 out:
2824         jbd2_journal_unlock_updates(journal);
2825 }
2826
2827 /*
2828  * If we are mounting (or read-write remounting) a filesystem whose journal
2829  * has recorded an error from a previous lifetime, move that error to the
2830  * main filesystem now.
2831  */
2832 static void ext4_clear_journal_err(struct super_block *sb,
2833                                    struct ext4_super_block *es)
2834 {
2835         journal_t *journal;
2836         int j_errno;
2837         const char *errstr;
2838
2839         journal = EXT4_SB(sb)->s_journal;
2840
2841         /*
2842          * Now check for any error status which may have been recorded in the
2843          * journal by a prior ext4_error() or ext4_abort()
2844          */
2845
2846         j_errno = jbd2_journal_errno(journal);
2847         if (j_errno) {
2848                 char nbuf[16];
2849
2850                 errstr = ext4_decode_error(sb, j_errno, nbuf);
2851                 ext4_warning(sb, __func__, "Filesystem error recorded "
2852                              "from previous mount: %s", errstr);
2853                 ext4_warning(sb, __func__, "Marking fs in need of "
2854                              "filesystem check.");
2855
2856                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2857                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2858                 ext4_commit_super(sb, es, 1);
2859
2860                 jbd2_journal_clear_err(journal);
2861         }
2862 }
2863
2864 /*
2865  * Force the running and committing transactions to commit,
2866  * and wait on the commit.
2867  */
2868 int ext4_force_commit(struct super_block *sb)
2869 {
2870         journal_t *journal;
2871         int ret;
2872
2873         if (sb->s_flags & MS_RDONLY)
2874                 return 0;
2875
2876         journal = EXT4_SB(sb)->s_journal;
2877         sb->s_dirt = 0;
2878         ret = ext4_journal_force_commit(journal);
2879         return ret;
2880 }
2881
2882 /*
2883  * Ext4 always journals updates to the superblock itself, so we don't
2884  * have to propagate any other updates to the superblock on disk at this
2885  * point.  Just start an async writeback to get the buffers on their way
2886  * to the disk.
2887  *
2888  * This implicitly triggers the writebehind on sync().
2889  */
2890
2891 static void ext4_write_super(struct super_block *sb)
2892 {
2893         if (mutex_trylock(&sb->s_lock) != 0)
2894                 BUG();
2895         sb->s_dirt = 0;
2896 }
2897
2898 static int ext4_sync_fs(struct super_block *sb, int wait)
2899 {
2900         tid_t target;
2901
2902         trace_mark(ext4_sync_fs, "dev %s wait %d", sb->s_id, wait);
2903         sb->s_dirt = 0;
2904         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2905                 if (wait)
2906                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2907         }
2908         return 0;
2909 }
2910
2911 /*
2912  * LVM calls this function before a (read-only) snapshot is created.  This
2913  * gives us a chance to flush the journal completely and mark the fs clean.
2914  */
2915 static void ext4_write_super_lockfs(struct super_block *sb)
2916 {
2917         sb->s_dirt = 0;
2918
2919         if (!(sb->s_flags & MS_RDONLY)) {
2920                 journal_t *journal = EXT4_SB(sb)->s_journal;
2921
2922                 /* Now we set up the journal barrier. */
2923                 jbd2_journal_lock_updates(journal);
2924
2925                 /*
2926                  * We don't want to clear needs_recovery flag when we failed
2927                  * to flush the journal.
2928                  */
2929                 if (jbd2_journal_flush(journal) < 0)
2930                         return;
2931
2932                 /* Journal blocked and flushed, clear needs_recovery flag. */
2933                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2934                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2935         }
2936 }
2937
2938 /*
2939  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2940  * flag here, even though the filesystem is not technically dirty yet.
2941  */
2942 static void ext4_unlockfs(struct super_block *sb)
2943 {
2944         if (!(sb->s_flags & MS_RDONLY)) {
2945                 lock_super(sb);
2946                 /* Reser the needs_recovery flag before the fs is unlocked. */
2947                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2948                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2949                 unlock_super(sb);
2950                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2951         }
2952 }
2953
2954 static int ext4_remount(struct super_block *sb, int *flags, char *data)
2955 {
2956         struct ext4_super_block *es;
2957         struct ext4_sb_info *sbi = EXT4_SB(sb);
2958         ext4_fsblk_t n_blocks_count = 0;
2959         unsigned long old_sb_flags;
2960         struct ext4_mount_options old_opts;
2961         ext4_group_t g;
2962         int err;
2963 #ifdef CONFIG_QUOTA
2964         int i;
2965 #endif
2966
2967         /* Store the original options */
2968         old_sb_flags = sb->s_flags;
2969         old_opts.s_mount_opt = sbi->s_mount_opt;
2970         old_opts.s_resuid = sbi->s_resuid;
2971         old_opts.s_resgid = sbi->s_resgid;
2972         old_opts.s_commit_interval = sbi->s_commit_interval;
2973 #ifdef CONFIG_QUOTA
2974         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2975         for (i = 0; i < MAXQUOTAS; i++)
2976                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2977 #endif
2978
2979         /*
2980          * Allow the "check" option to be passed as a remount option.
2981          */
2982         if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2983                 err = -EINVAL;
2984                 goto restore_opts;
2985         }
2986
2987         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2988                 ext4_abort(sb, __func__, "Abort forced by user");
2989
2990         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2991                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2992
2993         es = sbi->s_es;
2994
2995         ext4_init_journal_params(sb, sbi->s_journal);
2996
2997         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2998                 n_blocks_count > ext4_blocks_count(es)) {
2999                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
3000                         err = -EROFS;
3001                         goto restore_opts;
3002                 }
3003
3004                 if (*flags & MS_RDONLY) {
3005                         /*
3006                          * First of all, the unconditional stuff we have to do
3007                          * to disable replay of the journal when we next remount
3008                          */
3009                         sb->s_flags |= MS_RDONLY;
3010
3011                         /*
3012                          * OK, test if we are remounting a valid rw partition
3013                          * readonly, and if so set the rdonly flag and then
3014                          * mark the partition as valid again.
3015                          */
3016                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
3017                             (sbi->s_mount_state & EXT4_VALID_FS))
3018                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
3019
3020                         /*
3021                          * We have to unlock super so that we can wait for
3022                          * transactions.
3023                          */
3024                         unlock_super(sb);
3025                         ext4_mark_recovery_complete(sb, es);
3026                         lock_super(sb);
3027                 } else {
3028                         __le32 ret;
3029                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3030                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
3031                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
3032                                        "remount RDWR because of unsupported "
3033                                        "optional features (%x).\n",
3034                                        sb->s_id, le32_to_cpu(ret));
3035                                 err = -EROFS;
3036                                 goto restore_opts;
3037                         }
3038
3039                         /*
3040                          * Make sure the group descriptor checksums
3041                          * are sane.  If they aren't, refuse to
3042                          * remount r/w.
3043                          */
3044                         for (g = 0; g < sbi->s_groups_count; g++) {
3045                                 struct ext4_group_desc *gdp =
3046                                         ext4_get_group_desc(sb, g, NULL);
3047
3048                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
3049                                         printk(KERN_ERR
3050                "EXT4-fs: ext4_remount: "
3051                 "Checksum for group %lu failed (%u!=%u)\n",
3052                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
3053                                                le16_to_cpu(gdp->bg_checksum));
3054                                         err = -EINVAL;
3055                                         goto restore_opts;
3056                                 }
3057                         }
3058
3059                         /*
3060                          * If we have an unprocessed orphan list hanging
3061                          * around from a previously readonly bdev mount,
3062                          * require a full umount/remount for now.
3063                          */
3064                         if (es->s_last_orphan) {
3065                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
3066                                        "remount RDWR because of unprocessed "
3067                                        "orphan inode list.  Please "
3068                                        "umount/remount instead.\n",
3069                                        sb->s_id);
3070                                 err = -EINVAL;
3071                                 goto restore_opts;
3072                         }
3073
3074                         /*
3075                          * Mounting a RDONLY partition read-write, so reread
3076                          * and store the current valid flag.  (It may have
3077                          * been changed by e2fsck since we originally mounted
3078                          * the partition.)
3079                          */
3080                         ext4_clear_journal_err(sb, es);
3081                         sbi->s_mount_state = le16_to_cpu(es->s_state);
3082                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
3083                                 goto restore_opts;
3084                         if (!ext4_setup_super(sb, es, 0))
3085                                 sb->s_flags &= ~MS_RDONLY;
3086                 }
3087         }
3088 #ifdef CONFIG_QUOTA
3089         /* Release old quota file names */
3090         for (i = 0; i < MAXQUOTAS; i++)
3091                 if (old_opts.s_qf_names[i] &&
3092                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3093                         kfree(old_opts.s_qf_names[i]);
3094 #endif
3095         return 0;
3096 restore_opts:
3097         sb->s_flags = old_sb_flags;
3098         sbi->s_mount_opt = old_opts.s_mount_opt;
3099         sbi->s_resuid = old_opts.s_resuid;
3100         sbi->s_resgid = old_opts.s_resgid;
3101         sbi->s_commit_interval = old_opts.s_commit_interval;
3102 #ifdef CONFIG_QUOTA
3103         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
3104         for (i = 0; i < MAXQUOTAS; i++) {
3105                 if (sbi->s_qf_names[i] &&
3106                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3107                         kfree(sbi->s_qf_names[i]);
3108                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
3109         }
3110 #endif
3111         return err;
3112 }
3113
3114 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
3115 {
3116         struct super_block *sb = dentry->d_sb;
3117         struct ext4_sb_info *sbi = EXT4_SB(sb);
3118         struct ext4_super_block *es = sbi->s_es;
3119         u64 fsid;
3120
3121         if (test_opt(sb, MINIX_DF)) {
3122                 sbi->s_overhead_last = 0;
3123         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
3124                 ext4_group_t ngroups = sbi->s_groups_count, i;
3125                 ext4_fsblk_t overhead = 0;
3126                 smp_rmb();
3127
3128                 /*
3129                  * Compute the overhead (FS structures).  This is constant
3130                  * for a given filesystem unless the number of block groups
3131                  * changes so we cache the previous value until it does.
3132                  */
3133
3134                 /*
3135                  * All of the blocks before first_data_block are
3136                  * overhead
3137                  */
3138                 overhead = le32_to_cpu(es->s_first_data_block);
3139
3140                 /*
3141                  * Add the overhead attributed to the superblock and
3142                  * block group descriptors.  If the sparse superblocks
3143                  * feature is turned on, then not all groups have this.
3144                  */
3145                 for (i = 0; i < ngroups; i++) {
3146                         overhead += ext4_bg_has_super(sb, i) +
3147                                 ext4_bg_num_gdb(sb, i);
3148                         cond_resched();
3149                 }
3150
3151                 /*
3152                  * Every block group has an inode bitmap, a block
3153                  * bitmap, and an inode table.
3154                  */
3155                 overhead += ngroups * (2 + sbi->s_itb_per_group);
3156                 sbi->s_overhead_last = overhead;
3157                 smp_wmb();
3158                 sbi->s_blocks_last = ext4_blocks_count(es);
3159         }
3160
3161         buf->f_type = EXT4_SUPER_MAGIC;
3162         buf->f_bsize = sb->s_blocksize;
3163         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
3164         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
3165                        percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
3166         ext4_free_blocks_count_set(es, buf->f_bfree);
3167         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
3168         if (buf->f_bfree < ext4_r_blocks_count(es))
3169                 buf->f_bavail = 0;
3170         buf->f_files = le32_to_cpu(es->s_inodes_count);
3171         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
3172         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
3173         buf->f_namelen = EXT4_NAME_LEN;
3174         fsid = le64_to_cpup((void *)es->s_uuid) ^
3175                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
3176         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
3177         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
3178         return 0;
3179 }
3180
3181 /* Helper function for writing quotas on sync - we need to start transaction before quota file
3182  * is locked for write. Otherwise the are possible deadlocks:
3183  * Process 1                         Process 2
3184  * ext4_create()                     quota_sync()
3185  *   jbd2_journal_start()                   write_dquot()
3186  *   DQUOT_INIT()                        down(dqio_mutex)
3187  *     down(dqio_mutex)                    jbd2_journal_start()
3188  *
3189  */
3190
3191 #ifdef CONFIG_QUOTA
3192
3193 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3194 {
3195         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3196 }
3197
3198 static int ext4_dquot_initialize(struct inode *inode, int type)
3199 {
3200         handle_t *handle;
3201         int ret, err;
3202
3203         /* We may create quota structure so we need to reserve enough blocks */
3204         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
3205         if (IS_ERR(handle))
3206                 return PTR_ERR(handle);
3207         ret = dquot_initialize(inode, type);
3208         err = ext4_journal_stop(handle);
3209         if (!ret)
3210                 ret = err;
3211         return ret;
3212 }
3213
3214 static int ext4_dquot_drop(struct inode *inode)
3215 {
3216         handle_t *handle;
3217         int ret, err;
3218
3219         /* We may delete quota structure so we need to reserve enough blocks */
3220         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
3221         if (IS_ERR(handle)) {
3222                 /*
3223                  * We call dquot_drop() anyway to at least release references
3224                  * to quota structures so that umount does not hang.
3225                  */
3226                 dquot_drop(inode);
3227                 return PTR_ERR(handle);
3228         }
3229         ret = dquot_drop(inode);
3230         err = ext4_journal_stop(handle);
3231         if (!ret)
3232                 ret = err;
3233         return ret;
3234 }
3235
3236 static int ext4_write_dquot(struct dquot *dquot)
3237 {
3238         int ret, err;
3239         handle_t *handle;
3240         struct inode *inode;
3241
3242         inode = dquot_to_inode(dquot);
3243         handle = ext4_journal_start(inode,
3244                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3245         if (IS_ERR(handle))
3246                 return PTR_ERR(handle);
3247         ret = dquot_commit(dquot);
3248         err = ext4_journal_stop(handle);
3249         if (!ret)
3250                 ret = err;
3251         return ret;
3252 }
3253
3254 static int ext4_acquire_dquot(struct dquot *dquot)
3255 {
3256         int ret, err;
3257         handle_t *handle;
3258
3259         handle = ext4_journal_start(dquot_to_inode(dquot),
3260                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3261         if (IS_ERR(handle))
3262                 return PTR_ERR(handle);
3263         ret = dquot_acquire(dquot);
3264         err = ext4_journal_stop(handle);
3265         if (!ret)
3266                 ret = err;
3267         return ret;
3268 }
3269
3270 static int ext4_release_dquot(struct dquot *dquot)
3271 {
3272         int ret, err;
3273         handle_t *handle;
3274
3275         handle = ext4_journal_start(dquot_to_inode(dquot),
3276                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3277         if (IS_ERR(handle)) {
3278                 /* Release dquot anyway to avoid endless cycle in dqput() */
3279                 dquot_release(dquot);
3280                 return PTR_ERR(handle);
3281         }
3282         ret = dquot_release(dquot);
3283         err = ext4_journal_stop(handle);
3284         if (!ret)
3285                 ret = err;
3286         return ret;
3287 }
3288
3289 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3290 {
3291         /* Are we journaling quotas? */
3292         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3293             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3294                 dquot_mark_dquot_dirty(dquot);
3295                 return ext4_write_dquot(dquot);
3296         } else {
3297                 return dquot_mark_dquot_dirty(dquot);
3298         }
3299 }
3300
3301 static int ext4_write_info(struct super_block *sb, int type)
3302 {
3303         int ret, err;
3304         handle_t *handle;
3305
3306         /* Data block + inode block */
3307         handle = ext4_journal_start(sb->s_root->d_inode, 2);
3308         if (IS_ERR(handle))
3309                 return PTR_ERR(handle);
3310         ret = dquot_commit_info(sb, type);
3311         err = ext4_journal_stop(handle);
3312         if (!ret)
3313                 ret = err;
3314         return ret;
3315 }
3316
3317 /*
3318  * Turn on quotas during mount time - we need to find
3319  * the quota file and such...
3320  */
3321 static int ext4_quota_on_mount(struct super_block *sb, int type)
3322 {
3323         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3324                         EXT4_SB(sb)->s_jquota_fmt, type);
3325 }
3326
3327 /*
3328  * Standard function to be called on quota_on
3329  */
3330 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3331                          char *name, int remount)
3332 {
3333         int err;
3334         struct path path;
3335
3336         if (!test_opt(sb, QUOTA))
3337                 return -EINVAL;
3338         /* When remounting, no checks are needed and in fact, name is NULL */
3339         if (remount)
3340                 return vfs_quota_on(sb, type, format_id, name, remount);
3341
3342         err = kern_path(name, LOOKUP_FOLLOW, &path);
3343         if (err)
3344                 return err;
3345
3346         /* Quotafile not on the same filesystem? */
3347         if (path.mnt->mnt_sb != sb) {
3348                 path_put(&path);
3349                 return -EXDEV;
3350         }
3351         /* Journaling quota? */
3352         if (EXT4_SB(sb)->s_qf_names[type]) {
3353                 /* Quotafile not in fs root? */
3354                 if (path.dentry->d_parent != sb->s_root)
3355                         printk(KERN_WARNING
3356                                 "EXT4-fs: Quota file not on filesystem root. "
3357                                 "Journaled quota will not work.\n");
3358         }
3359
3360         /*
3361          * When we journal data on quota file, we have to flush journal to see
3362          * all updates to the file when we bypass pagecache...
3363          */
3364         if (ext4_should_journal_data(path.dentry->d_inode)) {
3365                 /*
3366                  * We don't need to lock updates but journal_flush() could
3367                  * otherwise be livelocked...
3368                  */
3369                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
3370                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
3371                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3372                 if (err) {
3373                         path_put(&path);
3374                         return err;
3375                 }
3376         }
3377
3378         err = vfs_quota_on_path(sb, type, format_id, &path);
3379         path_put(&path);
3380         return err;
3381 }
3382
3383 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3384  * acquiring the locks... As quota files are never truncated and quota code
3385  * itself serializes the operations (and noone else should touch the files)
3386  * we don't have to be afraid of races */
3387 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3388                                size_t len, loff_t off)
3389 {
3390         struct inode *inode = sb_dqopt(sb)->files[type];
3391         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3392         int err = 0;
3393         int offset = off & (sb->s_blocksize - 1);
3394         int tocopy;
3395         size_t toread;
3396         struct buffer_head *bh;
3397         loff_t i_size = i_size_read(inode);
3398
3399         if (off > i_size)
3400                 return 0;
3401         if (off+len > i_size)
3402                 len = i_size-off;
3403         toread = len;
3404         while (toread > 0) {
3405                 tocopy = sb->s_blocksize - offset < toread ?
3406                                 sb->s_blocksize - offset : toread;
3407                 bh = ext4_bread(NULL, inode, blk, 0, &err);
3408                 if (err)
3409                         return err;
3410                 if (!bh)        /* A hole? */
3411                         memset(data, 0, tocopy);
3412                 else
3413                         memcpy(data, bh->b_data+offset, tocopy);
3414                 brelse(bh);
3415                 offset = 0;
3416                 toread -= tocopy;
3417                 data += tocopy;
3418                 blk++;
3419         }
3420         return len;
3421 }
3422
3423 /* Write to quotafile (we know the transaction is already started and has
3424  * enough credits) */
3425 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3426                                 const char *data, size_t len, loff_t off)
3427 {
3428         struct inode *inode = sb_dqopt(sb)->files[type];
3429         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3430         int err = 0;
3431         int offset = off & (sb->s_blocksize - 1);
3432         int tocopy;
3433         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3434         size_t towrite = len;
3435         struct buffer_head *bh;
3436         handle_t *handle = journal_current_handle();
3437
3438         if (!handle) {
3439                 printk(KERN_WARNING "EXT4-fs: Quota write (off=%llu, len=%llu)"
3440                         " cancelled because transaction is not started.\n",
3441                         (unsigned long long)off, (unsigned long long)len);
3442                 return -EIO;
3443         }
3444         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3445         while (towrite > 0) {
3446                 tocopy = sb->s_blocksize - offset < towrite ?
3447                                 sb->s_blocksize - offset : towrite;
3448                 bh = ext4_bread(handle, inode, blk, 1, &err);
3449                 if (!bh)
3450                         goto out;
3451                 if (journal_quota) {
3452                         err = ext4_journal_get_write_access(handle, bh);
3453                         if (err) {
3454                                 brelse(bh);
3455                                 goto out;
3456                         }
3457                 }
3458                 lock_buffer(bh);
3459                 memcpy(bh->b_data+offset, data, tocopy);
3460                 flush_dcache_page(bh->b_page);
3461                 unlock_buffer(bh);
3462                 if (journal_quota)
3463                         err = ext4_journal_dirty_metadata(handle, bh);
3464                 else {
3465                         /* Always do at least ordered writes for quotas */
3466                         err = ext4_jbd2_file_inode(handle, inode);
3467                         mark_buffer_dirty(bh);
3468                 }
3469                 brelse(bh);
3470                 if (err)
3471                         goto out;
3472                 offset = 0;
3473                 towrite -= tocopy;
3474                 data += tocopy;
3475                 blk++;
3476         }
3477 out:
3478         if (len == towrite) {
3479                 mutex_unlock(&inode->i_mutex);
3480                 return err;
3481         }
3482         if (inode->i_size < off+len-towrite) {
3483                 i_size_write(inode, off+len-towrite);
3484                 EXT4_I(inode)->i_disksize = inode->i_size;
3485         }
3486         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3487         ext4_mark_inode_dirty(handle, inode);
3488         mutex_unlock(&inode->i_mutex);
3489         return len - towrite;
3490 }
3491
3492 #endif
3493
3494 static int ext4_get_sb(struct file_system_type *fs_type,
3495         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3496 {
3497         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3498 }
3499
3500 #ifdef CONFIG_PROC_FS
3501 static int ext4_ui_proc_show(struct seq_file *m, void *v)
3502 {
3503         unsigned int *p = m->private;
3504
3505         seq_printf(m, "%u\n", *p);
3506         return 0;
3507 }
3508
3509 static int ext4_ui_proc_open(struct inode *inode, struct file *file)
3510 {
3511         return single_open(file, ext4_ui_proc_show, PDE(inode)->data);
3512 }
3513
3514 static ssize_t ext4_ui_proc_write(struct file *file, const char __user *buf,
3515                                size_t cnt, loff_t *ppos)
3516 {
3517         unsigned int *p = PDE(file->f_path.dentry->d_inode)->data;
3518         char str[32];
3519         unsigned long value;
3520
3521         if (cnt >= sizeof(str))
3522                 return -EINVAL;
3523         if (copy_from_user(str, buf, cnt))
3524                 return -EFAULT;
3525         value = simple_strtol(str, NULL, 0);
3526         if (value < 0)
3527                 return -ERANGE;
3528         *p = value;
3529         return cnt;
3530 }
3531
3532 const struct file_operations ext4_ui_proc_fops = {
3533         .owner          = THIS_MODULE,
3534         .open           = ext4_ui_proc_open,
3535         .read           = seq_read,
3536         .llseek         = seq_lseek,
3537         .release        = single_release,
3538         .write          = ext4_ui_proc_write,
3539 };
3540 #endif
3541
3542 static struct file_system_type ext4_fs_type = {
3543         .owner          = THIS_MODULE,
3544         .name           = "ext4",
3545         .get_sb         = ext4_get_sb,
3546         .kill_sb        = kill_block_super,
3547         .fs_flags       = FS_REQUIRES_DEV,
3548 };
3549
3550 #ifdef CONFIG_EXT4DEV_COMPAT
3551 static int ext4dev_get_sb(struct file_system_type *fs_type,
3552         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3553 {
3554         printk(KERN_WARNING "EXT4-fs: Update your userspace programs "
3555                "to mount using ext4\n");
3556         printk(KERN_WARNING "EXT4-fs: ext4dev backwards compatibility "
3557                "will go away by 2.6.31\n");
3558         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3559 }
3560
3561 static struct file_system_type ext4dev_fs_type = {
3562         .owner          = THIS_MODULE,
3563         .name           = "ext4dev",
3564         .get_sb         = ext4dev_get_sb,
3565         .kill_sb        = kill_block_super,
3566         .fs_flags       = FS_REQUIRES_DEV,
3567 };
3568 MODULE_ALIAS("ext4dev");
3569 #endif
3570
3571 static int __init init_ext4_fs(void)
3572 {
3573         int err;
3574
3575         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
3576         err = init_ext4_mballoc();
3577         if (err)
3578                 return err;
3579
3580         err = init_ext4_xattr();
3581         if (err)
3582                 goto out2;
3583         err = init_inodecache();
3584         if (err)
3585                 goto out1;
3586         err = register_filesystem(&ext4_fs_type);
3587         if (err)
3588                 goto out;
3589 #ifdef CONFIG_EXT4DEV_COMPAT
3590         err = register_filesystem(&ext4dev_fs_type);
3591         if (err) {
3592                 unregister_filesystem(&ext4_fs_type);
3593                 goto out;
3594         }
3595 #endif
3596         return 0;
3597 out:
3598         destroy_inodecache();
3599 out1:
3600         exit_ext4_xattr();
3601 out2:
3602         exit_ext4_mballoc();
3603         return err;
3604 }
3605
3606 static void __exit exit_ext4_fs(void)
3607 {
3608         unregister_filesystem(&ext4_fs_type);
3609 #ifdef CONFIG_EXT4DEV_COMPAT
3610         unregister_filesystem(&ext4dev_fs_type);
3611 #endif
3612         destroy_inodecache();
3613         exit_ext4_xattr();
3614         exit_ext4_mballoc();
3615         remove_proc_entry("fs/ext4", NULL);
3616 }
3617
3618 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
3619 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
3620 MODULE_LICENSE("GPL");
3621 module_init(init_ext4_fs)
3622 module_exit(exit_ext4_fs)