fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/jbd2.h>
  24 #include <linux/ext4_fs.h>
  25 #include <linux/ext4_jbd2.h>
  26 #include <linux/slab.h>
  27 #include <linux/init.h>
  28 #include <linux/blkdev.h>
  29 #include <linux/parser.h>
  30 #include <linux/smp_lock.h>
  31 #include <linux/buffer_head.h>
  32 #include <linux/exportfs.h>
  33 #include <linux/vfs.h>
  34 #include <linux/random.h>
  35 #include <linux/mount.h>
  36 #include <linux/namei.h>
  37 #include <linux/quotaops.h>
  38 #include <linux/seq_file.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41
  42 #include <asm/uaccess.h>
  43
  44 #include "xattr.h"
  45 #include "acl.h"
  46 #include "namei.h"
  47 #include "group.h"
  48
  49 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  50                              unsigned long journal_devnum);
  51 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
  52                                unsigned int);
  53 static void ext4_commit_super (struct super_block * sb,
  54                                struct ext4_super_block * es,
  55                                int sync);
  56 static void ext4_mark_recovery_complete(struct super_block * sb,
  57                                         struct ext4_super_block * es);
  58 static void ext4_clear_journal_err(struct super_block * sb,
  59                                    struct ext4_super_block * es);
  60 static int ext4_sync_fs(struct super_block *sb, int wait);
  61 static const char *ext4_decode_error(struct super_block * sb, int errno,
  62                                      char nbuf[16]);
  63 static int ext4_remount (struct super_block * sb, int * flags, char * data);
  64 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf);
  65 static void ext4_unlockfs(struct super_block *sb);
  66 static void ext4_write_super (struct super_block * sb);
  67 static void ext4_write_super_lockfs(struct super_block *sb);
  68
  69
  70 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
  71                                struct ext4_group_desc *bg)
  72 {
  73         return le32_to_cpu(bg->bg_block_bitmap_lo) |
  74                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  75                 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
  76 }
  77
  78 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
  79                                struct ext4_group_desc *bg)
  80 {
  81         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
  82                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  83                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
  84 }
  85
  86 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
  87                               struct ext4_group_desc *bg)
  88 {
  89         return le32_to_cpu(bg->bg_inode_table_lo) |
  90                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  91                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
  92 }
  93
  94 void ext4_block_bitmap_set(struct super_block *sb,
  95                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
  96 {
  97         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
  98         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
  99                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 100 }
 101
 102 void ext4_inode_bitmap_set(struct super_block *sb,
 103                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 104 {
 105         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 106         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 107                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 108 }
 109
 110 void ext4_inode_table_set(struct super_block *sb,
 111                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 112 {
 113         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 114         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 115                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 116 }
 117
 118 /*
 119  * Wrappers for jbd2_journal_start/end.
 120  *
 121  * The only special thing we need to do here is to make sure that all
 122  * journal_end calls result in the superblock being marked dirty, so
 123  * that sync() will call the filesystem's write_super callback if
 124  * appropriate.
 125  */
 126 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 127 {
 128         journal_t *journal;
 129
 130         if (sb->s_flags & MS_RDONLY)
 131                 return ERR_PTR(-EROFS);
 132
 133         /* Special case here: if the journal has aborted behind our
 134          * backs (eg. EIO in the commit thread), then we still need to
 135          * take the FS itself readonly cleanly. */
 136         journal = EXT4_SB(sb)->s_journal;
 137         if (is_journal_aborted(journal)) {
 138                 ext4_abort(sb, __FUNCTION__,
 139                            "Detected aborted journal");
 140                 return ERR_PTR(-EROFS);
 141         }
 142
 143         return jbd2_journal_start(journal, nblocks);
 144 }
 145
 146 /*
 147  * The only special thing we need to do here is to make sure that all
 148  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 149  * that sync() will call the filesystem's write_super callback if
 150  * appropriate.
 151  */
 152 int __ext4_journal_stop(const char *where, handle_t *handle)
 153 {
 154         struct super_block *sb;
 155         int err;
 156         int rc;
 157
 158         sb = handle->h_transaction->t_journal->j_private;
 159         err = handle->h_err;
 160         rc = jbd2_journal_stop(handle);
 161
 162         if (!err)
 163                 err = rc;
 164         if (err)
 165                 __ext4_std_error(sb, where, err);
 166         return err;
 167 }
 168
 169 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 170                 struct buffer_head *bh, handle_t *handle, int err)
 171 {
 172         char nbuf[16];
 173         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 174
 175         if (bh)
 176                 BUFFER_TRACE(bh, "abort");
 177
 178         if (!handle->h_err)
 179                 handle->h_err = err;
 180
 181         if (is_handle_aborted(handle))
 182                 return;
 183
 184         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
 185                caller, errstr, err_fn);
 186
 187         jbd2_journal_abort_handle(handle);
 188 }
 189
 190 /* Deal with the reporting of failure conditions on a filesystem such as
 191  * inconsistencies detected or read IO failures.
 192  *
 193  * On ext2, we can store the error state of the filesystem in the
 194  * superblock.  That is not possible on ext4, because we may have other
 195  * write ordering constraints on the superblock which prevent us from
 196  * writing it out straight away; and given that the journal is about to
 197  * be aborted, we can't rely on the current, or future, transactions to
 198  * write out the superblock safely.
 199  *
 200  * We'll just use the jbd2_journal_abort() error code to record an error in
 201  * the journal instead.  On recovery, the journal will compain about
 202  * that error until we've noted it down and cleared it.
 203  */
 204
 205 static void ext4_handle_error(struct super_block *sb)
 206 {
 207         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 208
 209         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 210         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 211
 212         if (sb->s_flags & MS_RDONLY)
 213                 return;
 214
 215         if (!test_opt (sb, ERRORS_CONT)) {
 216                 journal_t *journal = EXT4_SB(sb)->s_journal;
 217
 218                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 219                 if (journal)
 220                         jbd2_journal_abort(journal, -EIO);
 221         }
 222         if (test_opt (sb, ERRORS_RO)) {
 223                 printk (KERN_CRIT "Remounting filesystem read-only\n");
 224                 sb->s_flags |= MS_RDONLY;
 225         }
 226         ext4_commit_super(sb, es, 1);
 227         if (test_opt(sb, ERRORS_PANIC))
 228                 panic("EXT4-fs (device %s): panic forced after error\n",
 229                         sb->s_id);
 230 }
 231
 232 void ext4_error (struct super_block * sb, const char * function,
 233                  const char * fmt, ...)
 234 {
 235         va_list args;
 236
 237         va_start(args, fmt);
 238         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 239         vprintk(fmt, args);
 240         printk("\n");
 241         va_end(args);
 242
 243         ext4_handle_error(sb);
 244 }
 245
 246 static const char *ext4_decode_error(struct super_block * sb, int errno,
 247                                      char nbuf[16])
 248 {
 249         char *errstr = NULL;
 250
 251         switch (errno) {
 252         case -EIO:
 253                 errstr = "IO failure";
 254                 break;
 255         case -ENOMEM:
 256                 errstr = "Out of memory";
 257                 break;
 258         case -EROFS:
 259                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
 260                         errstr = "Journal has aborted";
 261                 else
 262                         errstr = "Readonly filesystem";
 263                 break;
 264         default:
 265                 /* If the caller passed in an extra buffer for unknown
 266                  * errors, textualise them now.  Else we just return
 267                  * NULL. */
 268                 if (nbuf) {
 269                         /* Check for truncated error codes... */
 270                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 271                                 errstr = nbuf;
 272                 }
 273                 break;
 274         }
 275
 276         return errstr;
 277 }
 278
 279 /* __ext4_std_error decodes expected errors from journaling functions
 280  * automatically and invokes the appropriate error response.  */
 281
 282 void __ext4_std_error (struct super_block * sb, const char * function,
 283                        int errno)
 284 {
 285         char nbuf[16];
 286         const char *errstr;
 287
 288         /* Special case: if the error is EROFS, and we're not already
 289          * inside a transaction, then there's really no point in logging
 290          * an error. */
 291         if (errno == -EROFS && journal_current_handle() == NULL &&
 292             (sb->s_flags & MS_RDONLY))
 293                 return;
 294
 295         errstr = ext4_decode_error(sb, errno, nbuf);
 296         printk (KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
 297                 sb->s_id, function, errstr);
 298
 299         ext4_handle_error(sb);
 300 }
 301
 302 /*
 303  * ext4_abort is a much stronger failure handler than ext4_error.  The
 304  * abort function may be used to deal with unrecoverable failures such
 305  * as journal IO errors or ENOMEM at a critical moment in log management.
 306  *
 307  * We unconditionally force the filesystem into an ABORT|READONLY state,
 308  * unless the error response on the fs has been set to panic in which
 309  * case we take the easy way out and panic immediately.
 310  */
 311
 312 void ext4_abort (struct super_block * sb, const char * function,
 313                  const char * fmt, ...)
 314 {
 315         va_list args;
 316
 317         printk (KERN_CRIT "ext4_abort called.\n");
 318
 319         va_start(args, fmt);
 320         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
 321         vprintk(fmt, args);
 322         printk("\n");
 323         va_end(args);
 324
 325         if (test_opt(sb, ERRORS_PANIC))
 326                 panic("EXT4-fs panic from previous error\n");
 327
 328         if (sb->s_flags & MS_RDONLY)
 329                 return;
 330
 331         printk(KERN_CRIT "Remounting filesystem read-only\n");
 332         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 333         sb->s_flags |= MS_RDONLY;
 334         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 335         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 336 }
 337
 338 void ext4_warning (struct super_block * sb, const char * function,
 339                    const char * fmt, ...)
 340 {
 341         va_list args;
 342
 343         va_start(args, fmt);
 344         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
 345                sb->s_id, function);
 346         vprintk(fmt, args);
 347         printk("\n");
 348         va_end(args);
 349 }
 350
 351 void ext4_update_dynamic_rev(struct super_block *sb)
 352 {
 353         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 354
 355         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 356                 return;
 357
 358         ext4_warning(sb, __FUNCTION__,
 359                      "updating to rev %d because of new feature flag, "
 360                      "running e2fsck is recommended",
 361                      EXT4_DYNAMIC_REV);
 362
 363         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 364         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 365         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 366         /* leave es->s_feature_*compat flags alone */
 367         /* es->s_uuid will be set by e2fsck if empty */
 368
 369         /*
 370          * The rest of the superblock fields should be zero, and if not it
 371          * means they are likely already in use, so leave them alone.  We
 372          * can leave it up to e2fsck to clean up any inconsistencies there.
 373          */
 374 }
 375
 376 int ext4_update_compat_feature(handle_t *handle,
 377                                         struct super_block *sb, __u32 compat)
 378 {
 379         int err = 0;
 380         if (!EXT4_HAS_COMPAT_FEATURE(sb, compat)) {
 381                 err = ext4_journal_get_write_access(handle,
 382                                 EXT4_SB(sb)->s_sbh);
 383                 if (err)
 384                         return err;
 385                 EXT4_SET_COMPAT_FEATURE(sb, compat);
 386                 sb->s_dirt = 1;
 387                 handle->h_sync = 1;
 388                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 389                                         "call ext4_journal_dirty_met adata");
 390                 err = ext4_journal_dirty_metadata(handle,
 391                                 EXT4_SB(sb)->s_sbh);
 392         }
 393         return err;
 394 }
 395
 396 int ext4_update_rocompat_feature(handle_t *handle,
 397                                         struct super_block *sb, __u32 rocompat)
 398 {
 399         int err = 0;
 400         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, rocompat)) {
 401                 err = ext4_journal_get_write_access(handle,
 402                                 EXT4_SB(sb)->s_sbh);
 403                 if (err)
 404                         return err;
 405                 EXT4_SET_RO_COMPAT_FEATURE(sb, rocompat);
 406                 sb->s_dirt = 1;
 407                 handle->h_sync = 1;
 408                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 409                                         "call ext4_journal_dirty_met adata");
 410                 err = ext4_journal_dirty_metadata(handle,
 411                                 EXT4_SB(sb)->s_sbh);
 412         }
 413         return err;
 414 }
 415
 416 int ext4_update_incompat_feature(handle_t *handle,
 417                                         struct super_block *sb, __u32 incompat)
 418 {
 419         int err = 0;
 420         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, incompat)) {
 421                 err = ext4_journal_get_write_access(handle,
 422                                 EXT4_SB(sb)->s_sbh);
 423                 if (err)
 424                         return err;
 425                 EXT4_SET_INCOMPAT_FEATURE(sb, incompat);
 426                 sb->s_dirt = 1;
 427                 handle->h_sync = 1;
 428                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 429                                         "call ext4_journal_dirty_met adata");
 430                 err = ext4_journal_dirty_metadata(handle,
 431                                 EXT4_SB(sb)->s_sbh);
 432         }
 433         return err;
 434 }
 435
 436 /*
 437  * Open the external journal device
 438  */
 439 static struct block_device *ext4_blkdev_get(dev_t dev)
 440 {
 441         struct block_device *bdev;
 442         char b[BDEVNAME_SIZE];
 443
 444         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 445         if (IS_ERR(bdev))
 446                 goto fail;
 447         return bdev;
 448
 449 fail:
 450         printk(KERN_ERR "EXT4: failed to open journal device %s: %ld\n",
 451                         __bdevname(dev, b), PTR_ERR(bdev));
 452         return NULL;
 453 }
 454
 455 /*
 456  * Release the journal device
 457  */
 458 static int ext4_blkdev_put(struct block_device *bdev)
 459 {
 460         bd_release(bdev);
 461         return blkdev_put(bdev);
 462 }
 463
 464 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 465 {
 466         struct block_device *bdev;
 467         int ret = -ENODEV;
 468
 469         bdev = sbi->journal_bdev;
 470         if (bdev) {
 471                 ret = ext4_blkdev_put(bdev);
 472                 sbi->journal_bdev = NULL;
 473         }
 474         return ret;
 475 }
 476
 477 static inline struct inode *orphan_list_entry(struct list_head *l)
 478 {
 479         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 480 }
 481
 482 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 483 {
 484         struct list_head *l;
 485
 486         printk(KERN_ERR "sb orphan head is %d\n",
 487                le32_to_cpu(sbi->s_es->s_last_orphan));
 488
 489         printk(KERN_ERR "sb_info orphan list:\n");
 490         list_for_each(l, &sbi->s_orphan) {
 491                 struct inode *inode = orphan_list_entry(l);
 492                 printk(KERN_ERR "  "
 493                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 494                        inode->i_sb->s_id, inode->i_ino, inode,
 495                        inode->i_mode, inode->i_nlink,
 496                        NEXT_ORPHAN(inode));
 497         }
 498 }
 499
 500 static void ext4_put_super (struct super_block * sb)
 501 {
 502         struct ext4_sb_info *sbi = EXT4_SB(sb);
 503         struct ext4_super_block *es = sbi->s_es;
 504         int i;
 505
 506         ext4_mb_release(sb);
 507         ext4_ext_release(sb);
 508         ext4_xattr_put_super(sb);
 509         jbd2_journal_destroy(sbi->s_journal);
 510         if (!(sb->s_flags & MS_RDONLY)) {
 511                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 512                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 513                 BUFFER_TRACE(sbi->s_sbh, "marking dirty");
 514                 mark_buffer_dirty(sbi->s_sbh);
 515                 ext4_commit_super(sb, es, 1);
 516         }
 517
 518         for (i = 0; i < sbi->s_gdb_count; i++)
 519                 brelse(sbi->s_group_desc[i]);
 520         kfree(sbi->s_group_desc);
 521         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 522         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 523         percpu_counter_destroy(&sbi->s_dirs_counter);
 524         brelse(sbi->s_sbh);
 525 #ifdef CONFIG_QUOTA
 526         for (i = 0; i < MAXQUOTAS; i++)
 527                 kfree(sbi->s_qf_names[i]);
 528 #endif
 529
 530         /* Debugging code just in case the in-memory inode orphan list
 531          * isn't empty.  The on-disk one can be non-empty if we've
 532          * detected an error and taken the fs readonly, but the
 533          * in-memory list had better be clean by this point. */
 534         if (!list_empty(&sbi->s_orphan))
 535                 dump_orphan_list(sb, sbi);
 536         J_ASSERT(list_empty(&sbi->s_orphan));
 537
 538         invalidate_bdev(sb->s_bdev);
 539         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 540                 /*
 541                  * Invalidate the journal device's buffers.  We don't want them
 542                  * floating about in memory - the physical journal device may
 543                  * hotswapped, and it breaks the `ro-after' testing code.
 544                  */
 545                 sync_blockdev(sbi->journal_bdev);
 546                 invalidate_bdev(sbi->journal_bdev);
 547                 ext4_blkdev_remove(sbi);
 548         }
 549         sb->s_fs_info = NULL;
 550         kfree(sbi);
 551         return;
 552 }
 553
 554 static struct kmem_cache *ext4_inode_cachep;
 555
 556 /*
 557  * Called inside transaction, so use GFP_NOFS
 558  */
 559 static struct inode *ext4_alloc_inode(struct super_block *sb)
 560 {
 561         struct ext4_inode_info *ei;
 562
 563         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 564         if (!ei)
 565                 return NULL;
 566 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 567         ei->i_acl = EXT4_ACL_NOT_CACHED;
 568         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 569 #endif
 570         ei->i_block_alloc_info = NULL;
 571         ei->vfs_inode.i_version = 1;
 572         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 573         INIT_LIST_HEAD(&ei->i_prealloc_list);
 574         spin_lock_init(&ei->i_prealloc_lock);
 575         return &ei->vfs_inode;
 576 }
 577
 578 static void ext4_destroy_inode(struct inode *inode)
 579 {
 580         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 581                 printk("EXT4 Inode %p: orphan list check failed!\n",
 582                         EXT4_I(inode));
 583                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 584                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 585                                 true);
 586                 dump_stack();
 587         }
 588         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 589 }
 590
 591 static void init_once(struct kmem_cache *cachep, void *foo)
 592 {
 593         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 594
 595         INIT_LIST_HEAD(&ei->i_orphan);
 596 #ifdef CONFIG_EXT4DEV_FS_XATTR
 597         init_rwsem(&ei->xattr_sem);
 598 #endif
 599         init_rwsem(&ei->i_data_sem);
 600         inode_init_once(&ei->vfs_inode);
 601 }
 602
 603 static int init_inodecache(void)
 604 {
 605         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 606                                              sizeof(struct ext4_inode_info),
 607                                              0, (SLAB_RECLAIM_ACCOUNT|
 608                                                 SLAB_MEM_SPREAD),
 609                                              init_once);
 610         if (ext4_inode_cachep == NULL)
 611                 return -ENOMEM;
 612         return 0;
 613 }
 614
 615 static void destroy_inodecache(void)
 616 {
 617         kmem_cache_destroy(ext4_inode_cachep);
 618 }
 619
 620 static void ext4_clear_inode(struct inode *inode)
 621 {
 622         struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
 623 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 624         if (EXT4_I(inode)->i_acl &&
 625                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
 626                 posix_acl_release(EXT4_I(inode)->i_acl);
 627                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
 628         }
 629         if (EXT4_I(inode)->i_default_acl &&
 630                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
 631                 posix_acl_release(EXT4_I(inode)->i_default_acl);
 632                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
 633         }
 634 #endif
 635         ext4_discard_reservation(inode);
 636         EXT4_I(inode)->i_block_alloc_info = NULL;
 637         if (unlikely(rsv))
 638                 kfree(rsv);
 639 }
 640
 641 static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
 642 {
 643 #if defined(CONFIG_QUOTA)
 644         struct ext4_sb_info *sbi = EXT4_SB(sb);
 645
 646         if (sbi->s_jquota_fmt)
 647                 seq_printf(seq, ",jqfmt=%s",
 648                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold": "vfsv0");
 649
 650         if (sbi->s_qf_names[USRQUOTA])
 651                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 652
 653         if (sbi->s_qf_names[GRPQUOTA])
 654                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 655
 656         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
 657                 seq_puts(seq, ",usrquota");
 658
 659         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
 660                 seq_puts(seq, ",grpquota");
 661 #endif
 662 }
 663
 664 /*
 665  * Show an option if
 666  *  - it's set to a non-default value OR
 667  *  - if the per-sb default is different from the global default
 668  */
 669 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 670 {
 671         int def_errors;
 672         unsigned long def_mount_opts;
 673         struct super_block *sb = vfs->mnt_sb;
 674         struct ext4_sb_info *sbi = EXT4_SB(sb);
 675         struct ext4_super_block *es = sbi->s_es;
 676
 677         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 678         def_errors     = le16_to_cpu(es->s_errors);
 679
 680         if (sbi->s_sb_block != 1)
 681                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 682         if (test_opt(sb, MINIX_DF))
 683                 seq_puts(seq, ",minixdf");
 684         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
 685                 seq_puts(seq, ",grpid");
 686         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 687                 seq_puts(seq, ",nogrpid");
 688         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 689             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 690                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 691         }
 692         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 693             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 694                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 695         }
 696         if (test_opt(sb, ERRORS_RO)) {
 697                 if (def_errors == EXT4_ERRORS_PANIC ||
 698                     def_errors == EXT4_ERRORS_CONTINUE) {
 699                         seq_puts(seq, ",errors=remount-ro");
 700                 }
 701         }
 702         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
 703                 seq_puts(seq, ",errors=continue");
 704         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
 705                 seq_puts(seq, ",errors=panic");
 706         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
 707                 seq_puts(seq, ",nouid32");
 708         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
 709                 seq_puts(seq, ",debug");
 710         if (test_opt(sb, OLDALLOC))
 711                 seq_puts(seq, ",oldalloc");
 712 #ifdef CONFIG_EXT4DEV_FS_XATTR
 713         if (test_opt(sb, XATTR_USER) &&
 714                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
 715                 seq_puts(seq, ",user_xattr");
 716         if (!test_opt(sb, XATTR_USER) &&
 717             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 718                 seq_puts(seq, ",nouser_xattr");
 719         }
 720 #endif
 721 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 722         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
 723                 seq_puts(seq, ",acl");
 724         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 725                 seq_puts(seq, ",noacl");
 726 #endif
 727         if (!test_opt(sb, RESERVATION))
 728                 seq_puts(seq, ",noreservation");
 729         if (sbi->s_commit_interval) {
 730                 seq_printf(seq, ",commit=%u",
 731                            (unsigned) (sbi->s_commit_interval / HZ));
 732         }
 733         if (test_opt(sb, BARRIER))
 734                 seq_puts(seq, ",barrier=1");
 735         if (test_opt(sb, NOBH))
 736                 seq_puts(seq, ",nobh");
 737         if (!test_opt(sb, EXTENTS))
 738                 seq_puts(seq, ",noextents");
 739         if (!test_opt(sb, MBALLOC))
 740                 seq_puts(seq, ",nomballoc");
 741         if (test_opt(sb, I_VERSION))
 742                 seq_puts(seq, ",i_version");
 743
 744         if (sbi->s_stripe)
 745                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
 746         /*
 747          * journal mode get enabled in different ways
 748          * So just print the value even if we didn't specify it
 749          */
 750         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 751                 seq_puts(seq, ",data=journal");
 752         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 753                 seq_puts(seq, ",data=ordered");
 754         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 755                 seq_puts(seq, ",data=writeback");
 756
 757         ext4_show_quota_options(seq, sb);
 758         return 0;
 759 }
 760
 761
 762 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 763                 u64 ino, u32 generation)
 764 {
 765         struct inode *inode;
 766
 767         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 768                 return ERR_PTR(-ESTALE);
 769         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 770                 return ERR_PTR(-ESTALE);
 771
 772         /* iget isn't really right if the inode is currently unallocated!!
 773          *
 774          * ext4_read_inode will return a bad_inode if the inode had been
 775          * deleted, so we should be safe.
 776          *
 777          * Currently we don't know the generation for parent directory, so
 778          * a generation of 0 means "accept any"
 779          */
 780         inode = iget(sb, ino);
 781         if (inode == NULL)
 782                 return ERR_PTR(-ENOMEM);
 783         if (is_bad_inode(inode) ||
 784             (generation && inode->i_generation != generation)) {
 785                 iput(inode);
 786                 return ERR_PTR(-ESTALE);
 787         }
 788
 789         return inode;
 790 }
 791
 792 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 793                 int fh_len, int fh_type)
 794 {
 795         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 796                                     ext4_nfs_get_inode);
 797 }
 798
 799 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 800                 int fh_len, int fh_type)
 801 {
 802         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 803                                     ext4_nfs_get_inode);
 804 }
 805
 806 #ifdef CONFIG_QUOTA
 807 #define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
 808 #define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 809
 810 static int ext4_dquot_initialize(struct inode *inode, int type);
 811 static int ext4_dquot_drop(struct inode *inode);
 812 static int ext4_write_dquot(struct dquot *dquot);
 813 static int ext4_acquire_dquot(struct dquot *dquot);
 814 static int ext4_release_dquot(struct dquot *dquot);
 815 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 816 static int ext4_write_info(struct super_block *sb, int type);
 817 static int ext4_quota_on(struct super_block *sb, int type, int format_id, char *path);
 818 static int ext4_quota_on_mount(struct super_block *sb, int type);
 819 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 820                                size_t len, loff_t off);
 821 static ssize_t ext4_quota_write(struct super_block *sb, int type,
 822                                 const char *data, size_t len, loff_t off);
 823
 824 static struct dquot_operations ext4_quota_operations = {
 825         .initialize     = ext4_dquot_initialize,
 826         .drop           = ext4_dquot_drop,
 827         .alloc_space    = dquot_alloc_space,
 828         .alloc_inode    = dquot_alloc_inode,
 829         .free_space     = dquot_free_space,
 830         .free_inode     = dquot_free_inode,
 831         .transfer       = dquot_transfer,
 832         .write_dquot    = ext4_write_dquot,
 833         .acquire_dquot  = ext4_acquire_dquot,
 834         .release_dquot  = ext4_release_dquot,
 835         .mark_dirty     = ext4_mark_dquot_dirty,
 836         .write_info     = ext4_write_info
 837 };
 838
 839 static struct quotactl_ops ext4_qctl_operations = {
 840         .quota_on       = ext4_quota_on,
 841         .quota_off      = vfs_quota_off,
 842         .quota_sync     = vfs_quota_sync,
 843         .get_info       = vfs_get_dqinfo,
 844         .set_info       = vfs_set_dqinfo,
 845         .get_dqblk      = vfs_get_dqblk,
 846         .set_dqblk      = vfs_set_dqblk
 847 };
 848 #endif
 849
 850 static const struct super_operations ext4_sops = {
 851         .alloc_inode    = ext4_alloc_inode,
 852         .destroy_inode  = ext4_destroy_inode,
 853         .read_inode     = ext4_read_inode,
 854         .write_inode    = ext4_write_inode,
 855         .dirty_inode    = ext4_dirty_inode,
 856         .delete_inode   = ext4_delete_inode,
 857         .put_super      = ext4_put_super,
 858         .write_super    = ext4_write_super,
 859         .sync_fs        = ext4_sync_fs,
 860         .write_super_lockfs = ext4_write_super_lockfs,
 861         .unlockfs       = ext4_unlockfs,
 862         .statfs         = ext4_statfs,
 863         .remount_fs     = ext4_remount,
 864         .clear_inode    = ext4_clear_inode,
 865         .show_options   = ext4_show_options,
 866 #ifdef CONFIG_QUOTA
 867         .quota_read     = ext4_quota_read,
 868         .quota_write    = ext4_quota_write,
 869 #endif
 870 };
 871
 872 static const struct export_operations ext4_export_ops = {
 873         .fh_to_dentry = ext4_fh_to_dentry,
 874         .fh_to_parent = ext4_fh_to_parent,
 875         .get_parent = ext4_get_parent,
 876 };
 877
 878 enum {
 879         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 880         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
 881         Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov,
 882         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
 883         Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
 884         Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
 885         Opt_journal_checksum, Opt_journal_async_commit,
 886         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
 887         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 888         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
 889         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
 890         Opt_grpquota, Opt_extents, Opt_noextents, Opt_i_version,
 891         Opt_mballoc, Opt_nomballoc, Opt_stripe,
 892 };
 893
 894 static match_table_t tokens = {
 895         {Opt_bsd_df, "bsddf"},
 896         {Opt_minix_df, "minixdf"},
 897         {Opt_grpid, "grpid"},
 898         {Opt_grpid, "bsdgroups"},
 899         {Opt_nogrpid, "nogrpid"},
 900         {Opt_nogrpid, "sysvgroups"},
 901         {Opt_resgid, "resgid=%u"},
 902         {Opt_resuid, "resuid=%u"},
 903         {Opt_sb, "sb=%u"},
 904         {Opt_err_cont, "errors=continue"},
 905         {Opt_err_panic, "errors=panic"},
 906         {Opt_err_ro, "errors=remount-ro"},
 907         {Opt_nouid32, "nouid32"},
 908         {Opt_nocheck, "nocheck"},
 909         {Opt_nocheck, "check=none"},
 910         {Opt_debug, "debug"},
 911         {Opt_oldalloc, "oldalloc"},
 912         {Opt_orlov, "orlov"},
 913         {Opt_user_xattr, "user_xattr"},
 914         {Opt_nouser_xattr, "nouser_xattr"},
 915         {Opt_acl, "acl"},
 916         {Opt_noacl, "noacl"},
 917         {Opt_reservation, "reservation"},
 918         {Opt_noreservation, "noreservation"},
 919         {Opt_noload, "noload"},
 920         {Opt_nobh, "nobh"},
 921         {Opt_bh, "bh"},
 922         {Opt_commit, "commit=%u"},
 923         {Opt_journal_update, "journal=update"},
 924         {Opt_journal_inum, "journal=%u"},
 925         {Opt_journal_dev, "journal_dev=%u"},
 926         {Opt_journal_checksum, "journal_checksum"},
 927         {Opt_journal_async_commit, "journal_async_commit"},
 928         {Opt_abort, "abort"},
 929         {Opt_data_journal, "data=journal"},
 930         {Opt_data_ordered, "data=ordered"},
 931         {Opt_data_writeback, "data=writeback"},
 932         {Opt_offusrjquota, "usrjquota="},
 933         {Opt_usrjquota, "usrjquota=%s"},
 934         {Opt_offgrpjquota, "grpjquota="},
 935         {Opt_grpjquota, "grpjquota=%s"},
 936         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
 937         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
 938         {Opt_grpquota, "grpquota"},
 939         {Opt_noquota, "noquota"},
 940         {Opt_quota, "quota"},
 941         {Opt_usrquota, "usrquota"},
 942         {Opt_barrier, "barrier=%u"},
 943         {Opt_extents, "extents"},
 944         {Opt_noextents, "noextents"},
 945         {Opt_i_version, "i_version"},
 946         {Opt_mballoc, "mballoc"},
 947         {Opt_nomballoc, "nomballoc"},
 948         {Opt_stripe, "stripe=%u"},
 949         {Opt_err, NULL},
 950         {Opt_resize, "resize"},
 951 };
 952
 953 static ext4_fsblk_t get_sb_block(void **data)
 954 {
 955         ext4_fsblk_t    sb_block;
 956         char            *options = (char *) *data;
 957
 958         if (!options || strncmp(options, "sb=", 3) != 0)
 959                 return 1;       /* Default location */
 960         options += 3;
 961         /*todo: use simple_strtoll with >32bit ext4 */
 962         sb_block = simple_strtoul(options, &options, 0);
 963         if (*options && *options != ',') {
 964                 printk("EXT4-fs: Invalid sb specification: %s\n",
 965                        (char *) *data);
 966                 return 1;
 967         }
 968         if (*options == ',')
 969                 options++;
 970         *data = (void *) options;
 971         return sb_block;
 972 }
 973
 974 static int parse_options (char *options, struct super_block *sb,
 975                           unsigned int *inum, unsigned long *journal_devnum,
 976                           ext4_fsblk_t *n_blocks_count, int is_remount)
 977 {
 978         struct ext4_sb_info *sbi = EXT4_SB(sb);
 979         char * p;
 980         substring_t args[MAX_OPT_ARGS];
 981         int data_opt = 0;
 982         int option;
 983 #ifdef CONFIG_QUOTA
 984         int qtype;
 985         char *qname;
 986 #endif
 987
 988         if (!options)
 989                 return 1;
 990
 991         while ((p = strsep (&options, ",")) != NULL) {
 992                 int token;
 993                 if (!*p)
 994                         continue;
 995
 996                 token = match_token(p, tokens, args);
 997                 switch (token) {
 998                 case Opt_bsd_df:
 999                         clear_opt (sbi->s_mount_opt, MINIX_DF);
1000                         break;
1001                 case Opt_minix_df:
1002                         set_opt (sbi->s_mount_opt, MINIX_DF);
1003                         break;
1004                 case Opt_grpid:
1005                         set_opt (sbi->s_mount_opt, GRPID);
1006                         break;
1007                 case Opt_nogrpid:
1008                         clear_opt (sbi->s_mount_opt, GRPID);
1009                         break;
1010                 case Opt_resuid:
1011                         if (match_int(&args[0], &option))
1012                                 return 0;
1013                         sbi->s_resuid = option;
1014                         break;
1015                 case Opt_resgid:
1016                         if (match_int(&args[0], &option))
1017                                 return 0;
1018                         sbi->s_resgid = option;
1019                         break;
1020                 case Opt_sb:
1021                         /* handled by get_sb_block() instead of here */
1022                         /* *sb_block = match_int(&args[0]); */
1023                         break;
1024                 case Opt_err_panic:
1025                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
1026                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
1027                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
1028                         break;
1029                 case Opt_err_ro:
1030                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
1031                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
1032                         set_opt (sbi->s_mount_opt, ERRORS_RO);
1033                         break;
1034                 case Opt_err_cont:
1035                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
1036                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
1037                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
1038                         break;
1039                 case Opt_nouid32:
1040                         set_opt (sbi->s_mount_opt, NO_UID32);
1041                         break;
1042                 case Opt_nocheck:
1043                         clear_opt (sbi->s_mount_opt, CHECK);
1044                         break;
1045                 case Opt_debug:
1046                         set_opt (sbi->s_mount_opt, DEBUG);
1047                         break;
1048                 case Opt_oldalloc:
1049                         set_opt (sbi->s_mount_opt, OLDALLOC);
1050                         break;
1051                 case Opt_orlov:
1052                         clear_opt (sbi->s_mount_opt, OLDALLOC);
1053                         break;
1054 #ifdef CONFIG_EXT4DEV_FS_XATTR
1055                 case Opt_user_xattr:
1056                         set_opt (sbi->s_mount_opt, XATTR_USER);
1057                         break;
1058                 case Opt_nouser_xattr:
1059                         clear_opt (sbi->s_mount_opt, XATTR_USER);
1060                         break;
1061 #else
1062                 case Opt_user_xattr:
1063                 case Opt_nouser_xattr:
1064                         printk("EXT4 (no)user_xattr options not supported\n");
1065                         break;
1066 #endif
1067 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1068                 case Opt_acl:
1069                         set_opt(sbi->s_mount_opt, POSIX_ACL);
1070                         break;
1071                 case Opt_noacl:
1072                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
1073                         break;
1074 #else
1075                 case Opt_acl:
1076                 case Opt_noacl:
1077                         printk("EXT4 (no)acl options not supported\n");
1078                         break;
1079 #endif
1080                 case Opt_reservation:
1081                         set_opt(sbi->s_mount_opt, RESERVATION);
1082                         break;
1083                 case Opt_noreservation:
1084                         clear_opt(sbi->s_mount_opt, RESERVATION);
1085                         break;
1086                 case Opt_journal_update:
1087                         /* @@@ FIXME */
1088                         /* Eventually we will want to be able to create
1089                            a journal file here.  For now, only allow the
1090                            user to specify an existing inode to be the
1091                            journal file. */
1092                         if (is_remount) {
1093                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1094                                        "journal on remount\n");
1095                                 return 0;
1096                         }
1097                         set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
1098                         break;
1099                 case Opt_journal_inum:
1100                         if (is_remount) {
1101                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1102                                        "journal on remount\n");
1103                                 return 0;
1104                         }
1105                         if (match_int(&args[0], &option))
1106                                 return 0;
1107                         *inum = option;
1108                         break;
1109                 case Opt_journal_dev:
1110                         if (is_remount) {
1111                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1112                                        "journal on remount\n");
1113                                 return 0;
1114                         }
1115                         if (match_int(&args[0], &option))
1116                                 return 0;
1117                         *journal_devnum = option;
1118                         break;
1119                 case Opt_journal_checksum:
1120                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1121                         break;
1122                 case Opt_journal_async_commit:
1123                         set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1124                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1125                         break;
1126                 case Opt_noload:
1127                         set_opt (sbi->s_mount_opt, NOLOAD);
1128                         break;
1129                 case Opt_commit:
1130                         if (match_int(&args[0], &option))
1131                                 return 0;
1132                         if (option < 0)
1133                                 return 0;
1134                         if (option == 0)
1135                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1136                         sbi->s_commit_interval = HZ * option;
1137                         break;
1138                 case Opt_data_journal:
1139                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1140                         goto datacheck;
1141                 case Opt_data_ordered:
1142                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1143                         goto datacheck;
1144                 case Opt_data_writeback:
1145                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1146                 datacheck:
1147                         if (is_remount) {
1148                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1149                                                 != data_opt) {
1150                                         printk(KERN_ERR
1151                                                 "EXT4-fs: cannot change data "
1152                                                 "mode on remount\n");
1153                                         return 0;
1154                                 }
1155                         } else {
1156                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1157                                 sbi->s_mount_opt |= data_opt;
1158                         }
1159                         break;
1160 #ifdef CONFIG_QUOTA
1161                 case Opt_usrjquota:
1162                         qtype = USRQUOTA;
1163                         goto set_qf_name;
1164                 case Opt_grpjquota:
1165                         qtype = GRPQUOTA;
1166 set_qf_name:
1167                         if (sb_any_quota_enabled(sb)) {
1168                                 printk(KERN_ERR
1169                                         "EXT4-fs: Cannot change journalled "
1170                                         "quota options when quota turned on.\n");
1171                                 return 0;
1172                         }
1173                         qname = match_strdup(&args[0]);
1174                         if (!qname) {
1175                                 printk(KERN_ERR
1176                                         "EXT4-fs: not enough memory for "
1177                                         "storing quotafile name.\n");
1178                                 return 0;
1179                         }
1180                         if (sbi->s_qf_names[qtype] &&
1181                             strcmp(sbi->s_qf_names[qtype], qname)) {
1182                                 printk(KERN_ERR
1183                                         "EXT4-fs: %s quota file already "
1184                                         "specified.\n", QTYPE2NAME(qtype));
1185                                 kfree(qname);
1186                                 return 0;
1187                         }
1188                         sbi->s_qf_names[qtype] = qname;
1189                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1190                                 printk(KERN_ERR
1191                                         "EXT4-fs: quotafile must be on "
1192                                         "filesystem root.\n");
1193                                 kfree(sbi->s_qf_names[qtype]);
1194                                 sbi->s_qf_names[qtype] = NULL;
1195                                 return 0;
1196                         }
1197                         set_opt(sbi->s_mount_opt, QUOTA);
1198                         break;
1199                 case Opt_offusrjquota:
1200                         qtype = USRQUOTA;
1201                         goto clear_qf_name;
1202                 case Opt_offgrpjquota:
1203                         qtype = GRPQUOTA;
1204 clear_qf_name:
1205                         if (sb_any_quota_enabled(sb)) {
1206                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1207                                         "journalled quota options when "
1208                                         "quota turned on.\n");
1209                                 return 0;
1210                         }
1211                         /*
1212                          * The space will be released later when all options
1213                          * are confirmed to be correct
1214                          */
1215                         sbi->s_qf_names[qtype] = NULL;
1216                         break;
1217                 case Opt_jqfmt_vfsold:
1218                         sbi->s_jquota_fmt = QFMT_VFS_OLD;
1219                         break;
1220                 case Opt_jqfmt_vfsv0:
1221                         sbi->s_jquota_fmt = QFMT_VFS_V0;
1222                         break;
1223                 case Opt_quota:
1224                 case Opt_usrquota:
1225                         set_opt(sbi->s_mount_opt, QUOTA);
1226                         set_opt(sbi->s_mount_opt, USRQUOTA);
1227                         break;
1228                 case Opt_grpquota:
1229                         set_opt(sbi->s_mount_opt, QUOTA);
1230                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1231                         break;
1232                 case Opt_noquota:
1233                         if (sb_any_quota_enabled(sb)) {
1234                                 printk(KERN_ERR "EXT4-fs: Cannot change quota "
1235                                         "options when quota turned on.\n");
1236                                 return 0;
1237                         }
1238                         clear_opt(sbi->s_mount_opt, QUOTA);
1239                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1240                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1241                         break;
1242 #else
1243                 case Opt_quota:
1244                 case Opt_usrquota:
1245                 case Opt_grpquota:
1246                 case Opt_usrjquota:
1247                 case Opt_grpjquota:
1248                 case Opt_offusrjquota:
1249                 case Opt_offgrpjquota:
1250                 case Opt_jqfmt_vfsold:
1251                 case Opt_jqfmt_vfsv0:
1252                         printk(KERN_ERR
1253                                 "EXT4-fs: journalled quota options not "
1254                                 "supported.\n");
1255                         break;
1256                 case Opt_noquota:
1257                         break;
1258 #endif
1259                 case Opt_abort:
1260                         set_opt(sbi->s_mount_opt, ABORT);
1261                         break;
1262                 case Opt_barrier:
1263                         if (match_int(&args[0], &option))
1264                                 return 0;
1265                         if (option)
1266                                 set_opt(sbi->s_mount_opt, BARRIER);
1267                         else
1268                                 clear_opt(sbi->s_mount_opt, BARRIER);
1269                         break;
1270                 case Opt_ignore:
1271                         break;
1272                 case Opt_resize:
1273                         if (!is_remount) {
1274                                 printk("EXT4-fs: resize option only available "
1275                                         "for remount\n");
1276                                 return 0;
1277                         }
1278                         if (match_int(&args[0], &option) != 0)
1279                                 return 0;
1280                         *n_blocks_count = option;
1281                         break;
1282                 case Opt_nobh:
1283                         set_opt(sbi->s_mount_opt, NOBH);
1284                         break;
1285                 case Opt_bh:
1286                         clear_opt(sbi->s_mount_opt, NOBH);
1287                         break;
1288                 case Opt_extents:
1289                         set_opt (sbi->s_mount_opt, EXTENTS);
1290                         break;
1291                 case Opt_noextents:
1292                         clear_opt (sbi->s_mount_opt, EXTENTS);
1293                         break;
1294                 case Opt_i_version:
1295                         set_opt(sbi->s_mount_opt, I_VERSION);
1296                         sb->s_flags |= MS_I_VERSION;
1297                         break;
1298                 case Opt_mballoc:
1299                         set_opt(sbi->s_mount_opt, MBALLOC);
1300                         break;
1301                 case Opt_nomballoc:
1302                         clear_opt(sbi->s_mount_opt, MBALLOC);
1303                         break;
1304                 case Opt_stripe:
1305                         if (match_int(&args[0], &option))
1306                                 return 0;
1307                         if (option < 0)
1308                                 return 0;
1309                         sbi->s_stripe = option;
1310                         break;
1311                 default:
1312                         printk (KERN_ERR
1313                                 "EXT4-fs: Unrecognized mount option \"%s\" "
1314                                 "or missing value\n", p);
1315                         return 0;
1316                 }
1317         }
1318 #ifdef CONFIG_QUOTA
1319         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1320                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1321                      sbi->s_qf_names[USRQUOTA])
1322                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1323
1324                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1325                      sbi->s_qf_names[GRPQUOTA])
1326                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1327
1328                 if ((sbi->s_qf_names[USRQUOTA] &&
1329                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1330                     (sbi->s_qf_names[GRPQUOTA] &&
1331                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1332                         printk(KERN_ERR "EXT4-fs: old and new quota "
1333                                         "format mixing.\n");
1334                         return 0;
1335                 }
1336
1337                 if (!sbi->s_jquota_fmt) {
1338                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1339                                         "not specified.\n");
1340                         return 0;
1341                 }
1342         } else {
1343                 if (sbi->s_jquota_fmt) {
1344                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1345                                         "specified with no journalling "
1346                                         "enabled.\n");
1347                         return 0;
1348                 }
1349         }
1350 #endif
1351         return 1;
1352 }
1353
1354 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1355                             int read_only)
1356 {
1357         struct ext4_sb_info *sbi = EXT4_SB(sb);
1358         int res = 0;
1359
1360         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1361                 printk (KERN_ERR "EXT4-fs warning: revision level too high, "
1362                         "forcing read-only mode\n");
1363                 res = MS_RDONLY;
1364         }
1365         if (read_only)
1366                 return res;
1367         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1368                 printk (KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1369                         "running e2fsck is recommended\n");
1370         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1371                 printk (KERN_WARNING
1372                         "EXT4-fs warning: mounting fs with errors, "
1373                         "running e2fsck is recommended\n");
1374         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1375                  le16_to_cpu(es->s_mnt_count) >=
1376                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1377                 printk (KERN_WARNING
1378                         "EXT4-fs warning: maximal mount count reached, "
1379                         "running e2fsck is recommended\n");
1380         else if (le32_to_cpu(es->s_checkinterval) &&
1381                 (le32_to_cpu(es->s_lastcheck) +
1382                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1383                 printk (KERN_WARNING
1384                         "EXT4-fs warning: checktime reached, "
1385                         "running e2fsck is recommended\n");
1386 #if 0
1387                 /* @@@ We _will_ want to clear the valid bit if we find
1388                  * inconsistencies, to force a fsck at reboot.  But for
1389                  * a plain journaled filesystem we can keep it set as
1390                  * valid forever! :)
1391                  */
1392         es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT4_VALID_FS);
1393 #endif
1394         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1395                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1396         es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
1397         es->s_mtime = cpu_to_le32(get_seconds());
1398         ext4_update_dynamic_rev(sb);
1399         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1400
1401         ext4_commit_super(sb, es, 1);
1402         if (test_opt(sb, DEBUG))
1403                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%lu, "
1404                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1405                         sb->s_blocksize,
1406                         sbi->s_groups_count,
1407                         EXT4_BLOCKS_PER_GROUP(sb),
1408                         EXT4_INODES_PER_GROUP(sb),
1409                         sbi->s_mount_opt);
1410
1411         printk(KERN_INFO "EXT4 FS on %s, ", sb->s_id);
1412         if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
1413                 char b[BDEVNAME_SIZE];
1414
1415                 printk("external journal on %s\n",
1416                         bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
1417         } else {
1418                 printk("internal journal\n");
1419         }
1420         return res;
1421 }
1422
1423 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1424                             struct ext4_group_desc *gdp)
1425 {
1426         __u16 crc = 0;
1427
1428         if (sbi->s_es->s_feature_ro_compat &
1429             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1430                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1431                 __le32 le_group = cpu_to_le32(block_group);
1432
1433                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1434                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1435                 crc = crc16(crc, (__u8 *)gdp, offset);
1436                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1437                 /* for checksum of struct ext4_group_desc do the rest...*/
1438                 if ((sbi->s_es->s_feature_incompat &
1439                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1440                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1441                         crc = crc16(crc, (__u8 *)gdp + offset,
1442                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1443                                         offset);
1444         }
1445
1446         return cpu_to_le16(crc);
1447 }
1448
1449 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1450                                 struct ext4_group_desc *gdp)
1451 {
1452         if ((sbi->s_es->s_feature_ro_compat &
1453              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1454             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1455                 return 0;
1456
1457         return 1;
1458 }
1459
1460 /* Called at mount-time, super-block is locked */
1461 static int ext4_check_descriptors(struct super_block *sb)
1462 {
1463         struct ext4_sb_info *sbi = EXT4_SB(sb);
1464         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1465         ext4_fsblk_t last_block;
1466         ext4_fsblk_t block_bitmap;
1467         ext4_fsblk_t inode_bitmap;
1468         ext4_fsblk_t inode_table;
1469         int flexbg_flag = 0;
1470         ext4_group_t i;
1471
1472         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1473                 flexbg_flag = 1;
1474
1475         ext4_debug ("Checking group descriptors");
1476
1477         for (i = 0; i < sbi->s_groups_count; i++) {
1478                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1479
1480                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1481                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1482                 else
1483                         last_block = first_block +
1484                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1485
1486                 block_bitmap = ext4_block_bitmap(sb, gdp);
1487                 if (block_bitmap < first_block || block_bitmap > last_block)
1488                 {
1489                         ext4_error (sb, "ext4_check_descriptors",
1490                                     "Block bitmap for group %lu"
1491                                     " not in group (block %llu)!",
1492                                     i, block_bitmap);
1493                         return 0;
1494                 }
1495                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1496                 if (inode_bitmap < first_block || inode_bitmap > last_block)
1497                 {
1498                         ext4_error (sb, "ext4_check_descriptors",
1499                                     "Inode bitmap for group %lu"
1500                                     " not in group (block %llu)!",
1501                                     i, inode_bitmap);
1502                         return 0;
1503                 }
1504                 inode_table = ext4_inode_table(sb, gdp);
1505                 if (inode_table < first_block ||
1506                     inode_table + sbi->s_itb_per_group - 1 > last_block)
1507                 {
1508                         ext4_error (sb, "ext4_check_descriptors",
1509                                     "Inode table for group %lu"
1510                                     " not in group (block %llu)!",
1511                                     i, inode_table);
1512                         return 0;
1513                 }
1514                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1515                         ext4_error(sb, __FUNCTION__,
1516                                    "Checksum for group %lu failed (%u!=%u)\n",
1517                                     i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1518                                     gdp)), le16_to_cpu(gdp->bg_checksum));
1519                         return 0;
1520                 }
1521                 if (!flexbg_flag)
1522                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1523         }
1524
1525         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1526         sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
1527         return 1;
1528 }
1529
1530 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1531  * the superblock) which were deleted from all directories, but held open by
1532  * a process at the time of a crash.  We walk the list and try to delete these
1533  * inodes at recovery time (only with a read-write filesystem).
1534  *
1535  * In order to keep the orphan inode chain consistent during traversal (in
1536  * case of crash during recovery), we link each inode into the superblock
1537  * orphan list_head and handle it the same way as an inode deletion during
1538  * normal operation (which journals the operations for us).
1539  *
1540  * We only do an iget() and an iput() on each inode, which is very safe if we
1541  * accidentally point at an in-use or already deleted inode.  The worst that
1542  * can happen in this case is that we get a "bit already cleared" message from
1543  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1544  * e2fsck was run on this filesystem, and it must have already done the orphan
1545  * inode cleanup for us, so we can safely abort without any further action.
1546  */
1547 static void ext4_orphan_cleanup (struct super_block * sb,
1548                                  struct ext4_super_block * es)
1549 {
1550         unsigned int s_flags = sb->s_flags;
1551         int nr_orphans = 0, nr_truncates = 0;
1552 #ifdef CONFIG_QUOTA
1553         int i;
1554 #endif
1555         if (!es->s_last_orphan) {
1556                 jbd_debug(4, "no orphan inodes to clean up\n");
1557                 return;
1558         }
1559
1560         if (bdev_read_only(sb->s_bdev)) {
1561                 printk(KERN_ERR "EXT4-fs: write access "
1562                         "unavailable, skipping orphan cleanup.\n");
1563                 return;
1564         }
1565
1566         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1567                 if (es->s_last_orphan)
1568                         jbd_debug(1, "Errors on filesystem, "
1569                                   "clearing orphan list.\n");
1570                 es->s_last_orphan = 0;
1571                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1572                 return;
1573         }
1574
1575         if (s_flags & MS_RDONLY) {
1576                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1577                        sb->s_id);
1578                 sb->s_flags &= ~MS_RDONLY;
1579         }
1580 #ifdef CONFIG_QUOTA
1581         /* Needed for iput() to work correctly and not trash data */
1582         sb->s_flags |= MS_ACTIVE;
1583         /* Turn on quotas so that they are updated correctly */
1584         for (i = 0; i < MAXQUOTAS; i++) {
1585                 if (EXT4_SB(sb)->s_qf_names[i]) {
1586                         int ret = ext4_quota_on_mount(sb, i);
1587                         if (ret < 0)
1588                                 printk(KERN_ERR
1589                                         "EXT4-fs: Cannot turn on journalled "
1590                                         "quota: error %d\n", ret);
1591                 }
1592         }
1593 #endif
1594
1595         while (es->s_last_orphan) {
1596                 struct inode *inode;
1597
1598                 if (!(inode =
1599                       ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan)))) {
1600                         es->s_last_orphan = 0;
1601                         break;
1602                 }
1603
1604                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1605                 DQUOT_INIT(inode);
1606                 if (inode->i_nlink) {
1607                         printk(KERN_DEBUG
1608                                 "%s: truncating inode %lu to %Ld bytes\n",
1609                                 __FUNCTION__, inode->i_ino, inode->i_size);
1610                         jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
1611                                   inode->i_ino, inode->i_size);
1612                         ext4_truncate(inode);
1613                         nr_truncates++;
1614                 } else {
1615                         printk(KERN_DEBUG
1616                                 "%s: deleting unreferenced inode %lu\n",
1617                                 __FUNCTION__, inode->i_ino);
1618                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1619                                   inode->i_ino);
1620                         nr_orphans++;
1621                 }
1622                 iput(inode);  /* The delete magic happens here! */
1623         }
1624
1625 #define PLURAL(x) (x), ((x)==1) ? "" : "s"
1626
1627         if (nr_orphans)
1628                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1629                        sb->s_id, PLURAL(nr_orphans));
1630         if (nr_truncates)
1631                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1632                        sb->s_id, PLURAL(nr_truncates));
1633 #ifdef CONFIG_QUOTA
1634         /* Turn quotas off */
1635         for (i = 0; i < MAXQUOTAS; i++) {
1636                 if (sb_dqopt(sb)->files[i])
1637                         vfs_quota_off(sb, i);
1638         }
1639 #endif
1640         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1641 }
1642 /*
1643  * Maximal extent format file size.
1644  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1645  * extent format containers, within a sector_t, and within i_blocks
1646  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1647  * so that won't be a limiting factor.
1648  *
1649  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1650  */
1651 static loff_t ext4_max_size(int blkbits)
1652 {
1653         loff_t res;
1654         loff_t upper_limit = MAX_LFS_FILESIZE;
1655
1656         /* small i_blocks in vfs inode? */
1657         if (sizeof(blkcnt_t) < sizeof(u64)) {
1658                 /*
1659                  * CONFIG_LSF is not enabled implies the inode
1660                  * i_block represent total blocks in 512 bytes
1661                  * 32 == size of vfs inode i_blocks * 8
1662                  */
1663                 upper_limit = (1LL << 32) - 1;
1664
1665                 /* total blocks in file system block size */
1666                 upper_limit >>= (blkbits - 9);
1667                 upper_limit <<= blkbits;
1668         }
1669
1670         /* 32-bit extent-start container, ee_block */
1671         res = 1LL << 32;
1672         res <<= blkbits;
1673         res -= 1;
1674
1675         /* Sanity check against vm- & vfs- imposed limits */
1676         if (res > upper_limit)
1677                 res = upper_limit;
1678
1679         return res;
1680 }
1681
1682 /*
1683  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
1684  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
1685  * We need to be 1 filesystem block less than the 2^48 sector limit.
1686  */
1687 static loff_t ext4_max_bitmap_size(int bits)
1688 {
1689         loff_t res = EXT4_NDIR_BLOCKS;
1690         int meta_blocks;
1691         loff_t upper_limit;
1692         /* This is calculated to be the largest file size for a
1693          * dense, bitmapped file such that the total number of
1694          * sectors in the file, including data and all indirect blocks,
1695          * does not exceed 2^48 -1
1696          * __u32 i_blocks_lo and _u16 i_blocks_high representing the
1697          * total number of  512 bytes blocks of the file
1698          */
1699
1700         if (sizeof(blkcnt_t) < sizeof(u64)) {
1701                 /*
1702                  * CONFIG_LSF is not enabled implies the inode
1703                  * i_block represent total blocks in 512 bytes
1704                  * 32 == size of vfs inode i_blocks * 8
1705                  */
1706                 upper_limit = (1LL << 32) - 1;
1707
1708                 /* total blocks in file system block size */
1709                 upper_limit >>= (bits - 9);
1710
1711         } else {
1712                 /*
1713                  * We use 48 bit ext4_inode i_blocks
1714                  * With EXT4_HUGE_FILE_FL set the i_blocks
1715                  * represent total number of blocks in
1716                  * file system block size
1717                  */
1718                 upper_limit = (1LL << 48) - 1;
1719
1720         }
1721
1722         /* indirect blocks */
1723         meta_blocks = 1;
1724         /* double indirect blocks */
1725         meta_blocks += 1 + (1LL << (bits-2));
1726         /* tripple indirect blocks */
1727         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
1728
1729         upper_limit -= meta_blocks;
1730         upper_limit <<= bits;
1731
1732         res += 1LL << (bits-2);
1733         res += 1LL << (2*(bits-2));
1734         res += 1LL << (3*(bits-2));
1735         res <<= bits;
1736         if (res > upper_limit)
1737                 res = upper_limit;
1738
1739         if (res > MAX_LFS_FILESIZE)
1740                 res = MAX_LFS_FILESIZE;
1741
1742         return res;
1743 }
1744
1745 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1746                                 ext4_fsblk_t logical_sb_block, int nr)
1747 {
1748         struct ext4_sb_info *sbi = EXT4_SB(sb);
1749         ext4_group_t bg, first_meta_bg;
1750         int has_super = 0;
1751
1752         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1753
1754         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1755             nr < first_meta_bg)
1756                 return logical_sb_block + nr + 1;
1757         bg = sbi->s_desc_per_block * nr;
1758         if (ext4_bg_has_super(sb, bg))
1759                 has_super = 1;
1760         return (has_super + ext4_group_first_block_no(sb, bg));
1761 }
1762
1763 /**
1764  * ext4_get_stripe_size: Get the stripe size.
1765  * @sbi: In memory super block info
1766  *
1767  * If we have specified it via mount option, then
1768  * use the mount option value. If the value specified at mount time is
1769  * greater than the blocks per group use the super block value.
1770  * If the super block value is greater than blocks per group return 0.
1771  * Allocator needs it be less than blocks per group.
1772  *
1773  */
1774 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
1775 {
1776         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
1777         unsigned long stripe_width =
1778                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
1779
1780         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
1781                 return sbi->s_stripe;
1782
1783         if (stripe_width <= sbi->s_blocks_per_group)
1784                 return stripe_width;
1785
1786         if (stride <= sbi->s_blocks_per_group)
1787                 return stride;
1788
1789         return 0;
1790 }
1791
1792 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
1793                                 __releases(kernel_sem)
1794                                 __acquires(kernel_sem)
1795
1796 {
1797         struct buffer_head * bh;
1798         struct ext4_super_block *es = NULL;
1799         struct ext4_sb_info *sbi;
1800         ext4_fsblk_t block;
1801         ext4_fsblk_t sb_block = get_sb_block(&data);
1802         ext4_fsblk_t logical_sb_block;
1803         unsigned long offset = 0;
1804         unsigned int journal_inum = 0;
1805         unsigned long journal_devnum = 0;
1806         unsigned long def_mount_opts;
1807         struct inode *root;
1808         int blocksize;
1809         int db_count;
1810         int i;
1811         int needs_recovery;
1812         __le32 features;
1813         __u64 blocks_count;
1814         int err;
1815
1816         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1817         if (!sbi)
1818                 return -ENOMEM;
1819         sb->s_fs_info = sbi;
1820         sbi->s_mount_opt = 0;
1821         sbi->s_resuid = EXT4_DEF_RESUID;
1822         sbi->s_resgid = EXT4_DEF_RESGID;
1823         sbi->s_sb_block = sb_block;
1824
1825         unlock_kernel();
1826
1827         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1828         if (!blocksize) {
1829                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1830                 goto out_fail;
1831         }
1832
1833         if (!sb_set_blocksize(sb, blocksize)) {
1834                 printk(KERN_ERR "EXT4-fs: bad blocksize %d.\n", blocksize);
1835                 goto out_fail;
1836         }
1837
1838         /*
1839          * The ext4 superblock will not be buffer aligned for other than 1kB
1840          * block sizes.  We need to calculate the offset from buffer start.
1841          */
1842         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1843                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1844                 offset = do_div(logical_sb_block, blocksize);
1845         } else {
1846                 logical_sb_block = sb_block;
1847         }
1848
1849         if (!(bh = sb_bread(sb, logical_sb_block))) {
1850                 printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
1851                 goto out_fail;
1852         }
1853         /*
1854          * Note: s_es must be initialized as soon as possible because
1855          *       some ext4 macro-instructions depend on its value
1856          */
1857         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1858         sbi->s_es = es;
1859         sb->s_magic = le16_to_cpu(es->s_magic);
1860         if (sb->s_magic != EXT4_SUPER_MAGIC)
1861                 goto cantfind_ext4;
1862
1863         /* Set defaults before we parse the mount options */
1864         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1865         if (def_mount_opts & EXT4_DEFM_DEBUG)
1866                 set_opt(sbi->s_mount_opt, DEBUG);
1867         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1868                 set_opt(sbi->s_mount_opt, GRPID);
1869         if (def_mount_opts & EXT4_DEFM_UID16)
1870                 set_opt(sbi->s_mount_opt, NO_UID32);
1871 #ifdef CONFIG_EXT4DEV_FS_XATTR
1872         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1873                 set_opt(sbi->s_mount_opt, XATTR_USER);
1874 #endif
1875 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1876         if (def_mount_opts & EXT4_DEFM_ACL)
1877                 set_opt(sbi->s_mount_opt, POSIX_ACL);
1878 #endif
1879         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1880                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1881         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1882                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1883         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1884                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1885
1886         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1887                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1888         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
1889                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
1890         else
1891                 set_opt(sbi->s_mount_opt, ERRORS_RO);
1892
1893         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1894         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1895
1896         set_opt(sbi->s_mount_opt, RESERVATION);
1897
1898         /*
1899          * turn on extents feature by default in ext4 filesystem
1900          * User -o noextents to turn it off
1901          */
1902         set_opt(sbi->s_mount_opt, EXTENTS);
1903         /*
1904          * turn on mballoc feature by default in ext4 filesystem
1905          * User -o nomballoc to turn it off
1906          */
1907         set_opt(sbi->s_mount_opt, MBALLOC);
1908
1909         if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
1910                             NULL, 0))
1911                 goto failed_mount;
1912
1913         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1914                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1915
1916         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1917             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1918              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1919              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1920                 printk(KERN_WARNING
1921                        "EXT4-fs warning: feature flags set on rev 0 fs, "
1922                        "running e2fsck is recommended\n");
1923         /*
1924          * Check feature flags regardless of the revision level, since we
1925          * previously didn't change the revision level when setting the flags,
1926          * so there is a chance incompat flags are set on a rev 0 filesystem.
1927          */
1928         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
1929         if (features) {
1930                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
1931                        "unsupported optional features (%x).\n",
1932                        sb->s_id, le32_to_cpu(features));
1933                 goto failed_mount;
1934         }
1935         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
1936         if (!(sb->s_flags & MS_RDONLY) && features) {
1937                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
1938                        "unsupported optional features (%x).\n",
1939                        sb->s_id, le32_to_cpu(features));
1940                 goto failed_mount;
1941         }
1942         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
1943                 /*
1944                  * Large file size enabled file system can only be
1945                  * mount if kernel is build with CONFIG_LSF
1946                  */
1947                 if (sizeof(root->i_blocks) < sizeof(u64) &&
1948                                 !(sb->s_flags & MS_RDONLY)) {
1949                         printk(KERN_ERR "EXT4-fs: %s: Filesystem with huge "
1950                                         "files cannot be mounted read-write "
1951                                         "without CONFIG_LSF.\n", sb->s_id);
1952                         goto failed_mount;
1953                 }
1954         }
1955         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
1956
1957         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
1958             blocksize > EXT4_MAX_BLOCK_SIZE) {
1959                 printk(KERN_ERR
1960                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
1961                        blocksize, sb->s_id);
1962                 goto failed_mount;
1963         }
1964
1965         if (sb->s_blocksize != blocksize) {
1966
1967                 /* Validate the filesystem blocksize */
1968                 if (!sb_set_blocksize(sb, blocksize)) {
1969                         printk(KERN_ERR "EXT4-fs: bad block size %d.\n",
1970                                         blocksize);
1971                         goto failed_mount;
1972                 }
1973
1974                 brelse (bh);
1975                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1976                 offset = do_div(logical_sb_block, blocksize);
1977                 bh = sb_bread(sb, logical_sb_block);
1978                 if (!bh) {
1979                         printk(KERN_ERR
1980                                "EXT4-fs: Can't read superblock on 2nd try.\n");
1981                         goto failed_mount;
1982                 }
1983                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
1984                 sbi->s_es = es;
1985                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
1986                         printk (KERN_ERR
1987                                 "EXT4-fs: Magic mismatch, very weird !\n");
1988                         goto failed_mount;
1989                 }
1990         }
1991
1992         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits);
1993         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
1994
1995         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
1996                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
1997                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
1998         } else {
1999                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2000                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2001                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2002                     (!is_power_of_2(sbi->s_inode_size)) ||
2003                     (sbi->s_inode_size > blocksize)) {
2004                         printk (KERN_ERR
2005                                 "EXT4-fs: unsupported inode size: %d\n",
2006                                 sbi->s_inode_size);
2007                         goto failed_mount;
2008                 }
2009                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2010                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2011         }
2012         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2013         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2014                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2015                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2016                     !is_power_of_2(sbi->s_desc_size)) {
2017                         printk(KERN_ERR
2018                                "EXT4-fs: unsupported descriptor size %lu\n",
2019                                sbi->s_desc_size);
2020                         goto failed_mount;
2021                 }
2022         } else
2023                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2024         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2025         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2026         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2027                 goto cantfind_ext4;
2028         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2029         if (sbi->s_inodes_per_block == 0)
2030                 goto cantfind_ext4;
2031         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2032                                         sbi->s_inodes_per_block;
2033         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2034         sbi->s_sbh = bh;
2035         sbi->s_mount_state = le16_to_cpu(es->s_state);
2036         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2037         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2038         for (i=0; i < 4; i++)
2039                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2040         sbi->s_def_hash_version = es->s_def_hash_version;
2041
2042         if (sbi->s_blocks_per_group > blocksize * 8) {
2043                 printk (KERN_ERR
2044                         "EXT4-fs: #blocks per group too big: %lu\n",
2045                         sbi->s_blocks_per_group);
2046                 goto failed_mount;
2047         }
2048         if (sbi->s_inodes_per_group > blocksize * 8) {
2049                 printk (KERN_ERR
2050                         "EXT4-fs: #inodes per group too big: %lu\n",
2051                         sbi->s_inodes_per_group);
2052                 goto failed_mount;
2053         }
2054
2055         if (ext4_blocks_count(es) >
2056                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
2057                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
2058                         " too large to mount safely\n", sb->s_id);
2059                 if (sizeof(sector_t) < 8)
2060                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
2061                                         "enabled\n");
2062                 goto failed_mount;
2063         }
2064
2065         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2066                 goto cantfind_ext4;
2067
2068         /* ensure blocks_count calculation below doesn't sign-extend */
2069         if (ext4_blocks_count(es) + EXT4_BLOCKS_PER_GROUP(sb) <
2070             le32_to_cpu(es->s_first_data_block) + 1) {
2071                 printk(KERN_WARNING "EXT4-fs: bad geometry: block count %llu, "
2072                        "first data block %u, blocks per group %lu\n",
2073                         ext4_blocks_count(es),
2074                         le32_to_cpu(es->s_first_data_block),
2075                         EXT4_BLOCKS_PER_GROUP(sb));
2076                 goto failed_mount;
2077         }
2078         blocks_count = (ext4_blocks_count(es) -
2079                         le32_to_cpu(es->s_first_data_block) +
2080                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2081         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2082         sbi->s_groups_count = blocks_count;
2083         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2084                    EXT4_DESC_PER_BLOCK(sb);
2085         sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
2086                                     GFP_KERNEL);
2087         if (sbi->s_group_desc == NULL) {
2088                 printk (KERN_ERR "EXT4-fs: not enough memory\n");
2089                 goto failed_mount;
2090         }
2091
2092         bgl_lock_init(&sbi->s_blockgroup_lock);
2093
2094         for (i = 0; i < db_count; i++) {
2095                 block = descriptor_loc(sb, logical_sb_block, i);
2096                 sbi->s_group_desc[i] = sb_bread(sb, block);
2097                 if (!sbi->s_group_desc[i]) {
2098                         printk (KERN_ERR "EXT4-fs: "
2099                                 "can't read group descriptor %d\n", i);
2100                         db_count = i;
2101                         goto failed_mount2;
2102                 }
2103         }
2104         if (!ext4_check_descriptors (sb)) {
2105                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
2106                 goto failed_mount2;
2107         }
2108         sbi->s_gdb_count = db_count;
2109         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2110         spin_lock_init(&sbi->s_next_gen_lock);
2111
2112         err = percpu_counter_init(&sbi->s_freeblocks_counter,
2113                         ext4_count_free_blocks(sb));
2114         if (!err) {
2115                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
2116                                 ext4_count_free_inodes(sb));
2117         }
2118         if (!err) {
2119                 err = percpu_counter_init(&sbi->s_dirs_counter,
2120                                 ext4_count_dirs(sb));
2121         }
2122         if (err) {
2123                 printk(KERN_ERR "EXT4-fs: insufficient memory\n");
2124                 goto failed_mount3;
2125         }
2126
2127         /* per fileystem reservation list head & lock */
2128         spin_lock_init(&sbi->s_rsv_window_lock);
2129         sbi->s_rsv_window_root = RB_ROOT;
2130         /* Add a single, static dummy reservation to the start of the
2131          * reservation window list --- it gives us a placeholder for
2132          * append-at-start-of-list which makes the allocation logic
2133          * _much_ simpler. */
2134         sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
2135         sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
2136         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
2137         sbi->s_rsv_window_head.rsv_goal_size = 0;
2138         ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
2139
2140         sbi->s_stripe = ext4_get_stripe_size(sbi);
2141
2142         /*
2143          * set up enough so that it can read an inode
2144          */
2145         sb->s_op = &ext4_sops;
2146         sb->s_export_op = &ext4_export_ops;
2147         sb->s_xattr = ext4_xattr_handlers;
2148 #ifdef CONFIG_QUOTA
2149         sb->s_qcop = &ext4_qctl_operations;
2150         sb->dq_op = &ext4_quota_operations;
2151 #endif
2152         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2153
2154         sb->s_root = NULL;
2155
2156         needs_recovery = (es->s_last_orphan != 0 ||
2157                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2158                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2159
2160         /*
2161          * The first inode we look at is the journal inode.  Don't try
2162          * root first: it may be modified in the journal!
2163          */
2164         if (!test_opt(sb, NOLOAD) &&
2165             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2166                 if (ext4_load_journal(sb, es, journal_devnum))
2167                         goto failed_mount3;
2168         } else if (journal_inum) {
2169                 if (ext4_create_journal(sb, es, journal_inum))
2170                         goto failed_mount3;
2171         } else {
2172                 if (!silent)
2173                         printk (KERN_ERR
2174                                 "ext4: No journal on filesystem on %s\n",
2175                                 sb->s_id);
2176                 goto failed_mount3;
2177         }
2178
2179         if (ext4_blocks_count(es) > 0xffffffffULL &&
2180             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2181                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2182                 printk(KERN_ERR "ext4: Failed to set 64-bit journal feature\n");
2183                 goto failed_mount4;
2184         }
2185
2186         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2187                 jbd2_journal_set_features(sbi->s_journal,
2188                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2189                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2190         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2191                 jbd2_journal_set_features(sbi->s_journal,
2192                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2193                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2194                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2195         } else {
2196                 jbd2_journal_clear_features(sbi->s_journal,
2197                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2198                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2199         }
2200
2201         /* We have now updated the journal if required, so we can
2202          * validate the data journaling mode. */
2203         switch (test_opt(sb, DATA_FLAGS)) {
2204         case 0:
2205                 /* No mode set, assume a default based on the journal
2206                  * capabilities: ORDERED_DATA if the journal can
2207                  * cope, else JOURNAL_DATA
2208                  */
2209                 if (jbd2_journal_check_available_features
2210                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2211                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
2212                 else
2213                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2214                 break;
2215
2216         case EXT4_MOUNT_ORDERED_DATA:
2217         case EXT4_MOUNT_WRITEBACK_DATA:
2218                 if (!jbd2_journal_check_available_features
2219                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2220                         printk(KERN_ERR "EXT4-fs: Journal does not support "
2221                                "requested data journaling mode\n");
2222                         goto failed_mount4;
2223                 }
2224         default:
2225                 break;
2226         }
2227
2228         if (test_opt(sb, NOBH)) {
2229                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2230                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
2231                                 "its supported only with writeback mode\n");
2232                         clear_opt(sbi->s_mount_opt, NOBH);
2233                 }
2234         }
2235         /*
2236          * The jbd2_journal_load will have done any necessary log recovery,
2237          * so we can safely mount the rest of the filesystem now.
2238          */
2239
2240         root = iget(sb, EXT4_ROOT_INO);
2241         sb->s_root = d_alloc_root(root);
2242         if (!sb->s_root) {
2243                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
2244                 iput(root);
2245                 goto failed_mount4;
2246         }
2247         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2248                 dput(sb->s_root);
2249                 sb->s_root = NULL;
2250                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
2251                 goto failed_mount4;
2252         }
2253
2254         ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
2255
2256         /* determine the minimum size of new large inodes, if present */
2257         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2258                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2259                                                      EXT4_GOOD_OLD_INODE_SIZE;
2260                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2261                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2262                         if (sbi->s_want_extra_isize <
2263                             le16_to_cpu(es->s_want_extra_isize))
2264                                 sbi->s_want_extra_isize =
2265                                         le16_to_cpu(es->s_want_extra_isize);
2266                         if (sbi->s_want_extra_isize <
2267                             le16_to_cpu(es->s_min_extra_isize))
2268                                 sbi->s_want_extra_isize =
2269                                         le16_to_cpu(es->s_min_extra_isize);
2270                 }
2271         }
2272         /* Check if enough inode space is available */
2273         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2274                                                         sbi->s_inode_size) {
2275                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2276                                                        EXT4_GOOD_OLD_INODE_SIZE;
2277                 printk(KERN_INFO "EXT4-fs: required extra inode space not"
2278                         "available.\n");
2279         }
2280
2281         /*
2282          * akpm: core read_super() calls in here with the superblock locked.
2283          * That deadlocks, because orphan cleanup needs to lock the superblock
2284          * in numerous places.  Here we just pop the lock - it's relatively
2285          * harmless, because we are now ready to accept write_super() requests,
2286          * and aviro says that's the only reason for hanging onto the
2287          * superblock lock.
2288          */
2289         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2290         ext4_orphan_cleanup(sb, es);
2291         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2292         if (needs_recovery)
2293                 printk (KERN_INFO "EXT4-fs: recovery complete.\n");
2294         ext4_mark_recovery_complete(sb, es);
2295         printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
2296                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
2297                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
2298                 "writeback");
2299
2300         ext4_ext_init(sb);
2301         ext4_mb_init(sb, needs_recovery);
2302
2303         lock_kernel();
2304         return 0;
2305
2306 cantfind_ext4:
2307         if (!silent)
2308                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
2309                        sb->s_id);
2310         goto failed_mount;
2311
2312 failed_mount4:
2313         jbd2_journal_destroy(sbi->s_journal);
2314 failed_mount3:
2315         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2316         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2317         percpu_counter_destroy(&sbi->s_dirs_counter);
2318 failed_mount2:
2319         for (i = 0; i < db_count; i++)
2320                 brelse(sbi->s_group_desc[i]);
2321         kfree(sbi->s_group_desc);
2322 failed_mount:
2323 #ifdef CONFIG_QUOTA
2324         for (i = 0; i < MAXQUOTAS; i++)
2325                 kfree(sbi->s_qf_names[i]);
2326 #endif
2327         ext4_blkdev_remove(sbi);
2328         brelse(bh);
2329 out_fail:
2330         sb->s_fs_info = NULL;
2331         kfree(sbi);
2332         lock_kernel();
2333         return -EINVAL;
2334 }
2335
2336 /*
2337  * Setup any per-fs journal parameters now.  We'll do this both on
2338  * initial mount, once the journal has been initialised but before we've
2339  * done any recovery; and again on any subsequent remount.
2340  */
2341 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2342 {
2343         struct ext4_sb_info *sbi = EXT4_SB(sb);
2344
2345         if (sbi->s_commit_interval)
2346                 journal->j_commit_interval = sbi->s_commit_interval;
2347         /* We could also set up an ext4-specific default for the commit
2348          * interval here, but for now we'll just fall back to the jbd
2349          * default. */
2350
2351         spin_lock(&journal->j_state_lock);
2352         if (test_opt(sb, BARRIER))
2353                 journal->j_flags |= JBD2_BARRIER;
2354         else
2355                 journal->j_flags &= ~JBD2_BARRIER;
2356         spin_unlock(&journal->j_state_lock);
2357 }
2358
2359 static journal_t *ext4_get_journal(struct super_block *sb,
2360                                    unsigned int journal_inum)
2361 {
2362         struct inode *journal_inode;
2363         journal_t *journal;
2364
2365         /* First, test for the existence of a valid inode on disk.  Bad
2366          * things happen if we iget() an unused inode, as the subsequent
2367          * iput() will try to delete it. */
2368
2369         journal_inode = iget(sb, journal_inum);
2370         if (!journal_inode) {
2371                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
2372                 return NULL;
2373         }
2374         if (!journal_inode->i_nlink) {
2375                 make_bad_inode(journal_inode);
2376                 iput(journal_inode);
2377                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
2378                 return NULL;
2379         }
2380
2381         jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
2382                   journal_inode, journal_inode->i_size);
2383         if (is_bad_inode(journal_inode) || !S_ISREG(journal_inode->i_mode)) {
2384                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
2385                 iput(journal_inode);
2386                 return NULL;
2387         }
2388
2389         journal = jbd2_journal_init_inode(journal_inode);
2390         if (!journal) {
2391                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
2392                 iput(journal_inode);
2393                 return NULL;
2394         }
2395         journal->j_private = sb;
2396         ext4_init_journal_params(sb, journal);
2397         return journal;
2398 }
2399
2400 static journal_t *ext4_get_dev_journal(struct super_block *sb,
2401                                        dev_t j_dev)
2402 {
2403         struct buffer_head * bh;
2404         journal_t *journal;
2405         ext4_fsblk_t start;
2406         ext4_fsblk_t len;
2407         int hblock, blocksize;
2408         ext4_fsblk_t sb_block;
2409         unsigned long offset;
2410         struct ext4_super_block * es;
2411         struct block_device *bdev;
2412
2413         bdev = ext4_blkdev_get(j_dev);
2414         if (bdev == NULL)
2415                 return NULL;
2416
2417         if (bd_claim(bdev, sb)) {
2418                 printk(KERN_ERR
2419                         "EXT4: failed to claim external journal device.\n");
2420                 blkdev_put(bdev);
2421                 return NULL;
2422         }
2423
2424         blocksize = sb->s_blocksize;
2425         hblock = bdev_hardsect_size(bdev);
2426         if (blocksize < hblock) {
2427                 printk(KERN_ERR
2428                         "EXT4-fs: blocksize too small for journal device.\n");
2429                 goto out_bdev;
2430         }
2431
2432         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2433         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2434         set_blocksize(bdev, blocksize);
2435         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2436                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2437                        "external journal\n");
2438                 goto out_bdev;
2439         }
2440
2441         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2442         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2443             !(le32_to_cpu(es->s_feature_incompat) &
2444               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2445                 printk(KERN_ERR "EXT4-fs: external journal has "
2446                                         "bad superblock\n");
2447                 brelse(bh);
2448                 goto out_bdev;
2449         }
2450
2451         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2452                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2453                 brelse(bh);
2454                 goto out_bdev;
2455         }
2456
2457         len = ext4_blocks_count(es);
2458         start = sb_block + 1;
2459         brelse(bh);     /* we're done with the superblock */
2460
2461         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2462                                         start, len, blocksize);
2463         if (!journal) {
2464                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2465                 goto out_bdev;
2466         }
2467         journal->j_private = sb;
2468         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2469         wait_on_buffer(journal->j_sb_buffer);
2470         if (!buffer_uptodate(journal->j_sb_buffer)) {
2471                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2472                 goto out_journal;
2473         }
2474         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2475                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2476                                         "user (unsupported) - %d\n",
2477                         be32_to_cpu(journal->j_superblock->s_nr_users));
2478                 goto out_journal;
2479         }
2480         EXT4_SB(sb)->journal_bdev = bdev;
2481         ext4_init_journal_params(sb, journal);
2482         return journal;
2483 out_journal:
2484         jbd2_journal_destroy(journal);
2485 out_bdev:
2486         ext4_blkdev_put(bdev);
2487         return NULL;
2488 }
2489
2490 static int ext4_load_journal(struct super_block *sb,
2491                              struct ext4_super_block *es,
2492                              unsigned long journal_devnum)
2493 {
2494         journal_t *journal;
2495         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2496         dev_t journal_dev;
2497         int err = 0;
2498         int really_read_only;
2499
2500         if (journal_devnum &&
2501             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2502                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2503                         "numbers have changed\n");
2504                 journal_dev = new_decode_dev(journal_devnum);
2505         } else
2506                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2507
2508         really_read_only = bdev_read_only(sb->s_bdev);
2509
2510         /*
2511          * Are we loading a blank journal or performing recovery after a
2512          * crash?  For recovery, we need to check in advance whether we
2513          * can get read-write access to the device.
2514          */
2515
2516         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2517                 if (sb->s_flags & MS_RDONLY) {
2518                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2519                                         "required on readonly filesystem.\n");
2520                         if (really_read_only) {
2521                                 printk(KERN_ERR "EXT4-fs: write access "
2522                                         "unavailable, cannot proceed.\n");
2523                                 return -EROFS;
2524                         }
2525                         printk (KERN_INFO "EXT4-fs: write access will "
2526                                         "be enabled during recovery.\n");
2527                 }
2528         }
2529
2530         if (journal_inum && journal_dev) {
2531                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2532                        "and inode journals!\n");
2533                 return -EINVAL;
2534         }
2535
2536         if (journal_inum) {
2537                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2538                         return -EINVAL;
2539         } else {
2540                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2541                         return -EINVAL;
2542         }
2543
2544         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2545                 err = jbd2_journal_update_format(journal);
2546                 if (err)  {
2547                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2548                         jbd2_journal_destroy(journal);
2549                         return err;
2550                 }
2551         }
2552
2553         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2554                 err = jbd2_journal_wipe(journal, !really_read_only);
2555         if (!err)
2556                 err = jbd2_journal_load(journal);
2557
2558         if (err) {
2559                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2560                 jbd2_journal_destroy(journal);
2561                 return err;
2562         }
2563
2564         EXT4_SB(sb)->s_journal = journal;
2565         ext4_clear_journal_err(sb, es);
2566
2567         if (journal_devnum &&
2568             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2569                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2570                 sb->s_dirt = 1;
2571
2572                 /* Make sure we flush the recovery flag to disk. */
2573                 ext4_commit_super(sb, es, 1);
2574         }
2575
2576         return 0;
2577 }
2578
2579 static int ext4_create_journal(struct super_block * sb,
2580                                struct ext4_super_block * es,
2581                                unsigned int journal_inum)
2582 {
2583         journal_t *journal;
2584         int err;
2585
2586         if (sb->s_flags & MS_RDONLY) {
2587                 printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2588                                 "create journal.\n");
2589                 return -EROFS;
2590         }
2591
2592         journal = ext4_get_journal(sb, journal_inum);
2593         if (!journal)
2594                 return -EINVAL;
2595
2596         printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2597                journal_inum);
2598
2599         err = jbd2_journal_create(journal);
2600         if (err) {
2601                 printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2602                 jbd2_journal_destroy(journal);
2603                 return -EIO;
2604         }
2605
2606         EXT4_SB(sb)->s_journal = journal;
2607
2608         ext4_update_dynamic_rev(sb);
2609         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2610         EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2611
2612         es->s_journal_inum = cpu_to_le32(journal_inum);
2613         sb->s_dirt = 1;
2614
2615         /* Make sure we flush the recovery flag to disk. */
2616         ext4_commit_super(sb, es, 1);
2617
2618         return 0;
2619 }
2620
2621 static void ext4_commit_super (struct super_block * sb,
2622                                struct ext4_super_block * es,
2623                                int sync)
2624 {
2625         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2626
2627         if (!sbh)
2628                 return;
2629         es->s_wtime = cpu_to_le32(get_seconds());
2630         ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2631         es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2632         BUFFER_TRACE(sbh, "marking dirty");
2633         mark_buffer_dirty(sbh);
2634         if (sync)
2635                 sync_dirty_buffer(sbh);
2636 }
2637
2638
2639 /*
2640  * Have we just finished recovery?  If so, and if we are mounting (or
2641  * remounting) the filesystem readonly, then we will end up with a
2642  * consistent fs on disk.  Record that fact.
2643  */
2644 static void ext4_mark_recovery_complete(struct super_block * sb,
2645                                         struct ext4_super_block * es)
2646 {
2647         journal_t *journal = EXT4_SB(sb)->s_journal;
2648
2649         jbd2_journal_lock_updates(journal);
2650         jbd2_journal_flush(journal);
2651         lock_super(sb);
2652         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2653             sb->s_flags & MS_RDONLY) {
2654                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2655                 sb->s_dirt = 0;
2656                 ext4_commit_super(sb, es, 1);
2657         }
2658         unlock_super(sb);
2659         jbd2_journal_unlock_updates(journal);
2660 }
2661
2662 /*
2663  * If we are mounting (or read-write remounting) a filesystem whose journal
2664  * has recorded an error from a previous lifetime, move that error to the
2665  * main filesystem now.
2666  */
2667 static void ext4_clear_journal_err(struct super_block * sb,
2668                                    struct ext4_super_block * es)
2669 {
2670         journal_t *journal;
2671         int j_errno;
2672         const char *errstr;
2673
2674         journal = EXT4_SB(sb)->s_journal;
2675
2676         /*
2677          * Now check for any error status which may have been recorded in the
2678          * journal by a prior ext4_error() or ext4_abort()
2679          */
2680
2681         j_errno = jbd2_journal_errno(journal);
2682         if (j_errno) {
2683                 char nbuf[16];
2684
2685                 errstr = ext4_decode_error(sb, j_errno, nbuf);
2686                 ext4_warning(sb, __FUNCTION__, "Filesystem error recorded "
2687                              "from previous mount: %s", errstr);
2688                 ext4_warning(sb, __FUNCTION__, "Marking fs in need of "
2689                              "filesystem check.");
2690
2691                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2692                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2693                 ext4_commit_super (sb, es, 1);
2694
2695                 jbd2_journal_clear_err(journal);
2696         }
2697 }
2698
2699 /*
2700  * Force the running and committing transactions to commit,
2701  * and wait on the commit.
2702  */
2703 int ext4_force_commit(struct super_block *sb)
2704 {
2705         journal_t *journal;
2706         int ret;
2707
2708         if (sb->s_flags & MS_RDONLY)
2709                 return 0;
2710
2711         journal = EXT4_SB(sb)->s_journal;
2712         sb->s_dirt = 0;
2713         ret = ext4_journal_force_commit(journal);
2714         return ret;
2715 }
2716
2717 /*
2718  * Ext4 always journals updates to the superblock itself, so we don't
2719  * have to propagate any other updates to the superblock on disk at this
2720  * point.  Just start an async writeback to get the buffers on their way
2721  * to the disk.
2722  *
2723  * This implicitly triggers the writebehind on sync().
2724  */
2725
2726 static void ext4_write_super (struct super_block * sb)
2727 {
2728         if (mutex_trylock(&sb->s_lock) != 0)
2729                 BUG();
2730         sb->s_dirt = 0;
2731 }
2732
2733 static int ext4_sync_fs(struct super_block *sb, int wait)
2734 {
2735         tid_t target;
2736
2737         sb->s_dirt = 0;
2738         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2739                 if (wait)
2740                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2741         }
2742         return 0;
2743 }
2744
2745 /*
2746  * LVM calls this function before a (read-only) snapshot is created.  This
2747  * gives us a chance to flush the journal completely and mark the fs clean.
2748  */
2749 static void ext4_write_super_lockfs(struct super_block *sb)
2750 {
2751         sb->s_dirt = 0;
2752
2753         if (!(sb->s_flags & MS_RDONLY)) {
2754                 journal_t *journal = EXT4_SB(sb)->s_journal;
2755
2756                 /* Now we set up the journal barrier. */
2757                 jbd2_journal_lock_updates(journal);
2758                 jbd2_journal_flush(journal);
2759
2760                 /* Journal blocked and flushed, clear needs_recovery flag. */
2761                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2762                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2763         }
2764 }
2765
2766 /*
2767  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2768  * flag here, even though the filesystem is not technically dirty yet.
2769  */
2770 static void ext4_unlockfs(struct super_block *sb)
2771 {
2772         if (!(sb->s_flags & MS_RDONLY)) {
2773                 lock_super(sb);
2774                 /* Reser the needs_recovery flag before the fs is unlocked. */
2775                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2776                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2777                 unlock_super(sb);
2778                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2779         }
2780 }
2781
2782 static int ext4_remount (struct super_block * sb, int * flags, char * data)
2783 {
2784         struct ext4_super_block * es;
2785         struct ext4_sb_info *sbi = EXT4_SB(sb);
2786         ext4_fsblk_t n_blocks_count = 0;
2787         unsigned long old_sb_flags;
2788         struct ext4_mount_options old_opts;
2789         int err;
2790 #ifdef CONFIG_QUOTA
2791         int i;
2792 #endif
2793
2794         /* Store the original options */
2795         old_sb_flags = sb->s_flags;
2796         old_opts.s_mount_opt = sbi->s_mount_opt;
2797         old_opts.s_resuid = sbi->s_resuid;
2798         old_opts.s_resgid = sbi->s_resgid;
2799         old_opts.s_commit_interval = sbi->s_commit_interval;
2800 #ifdef CONFIG_QUOTA
2801         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2802         for (i = 0; i < MAXQUOTAS; i++)
2803                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2804 #endif
2805
2806         /*
2807          * Allow the "check" option to be passed as a remount option.
2808          */
2809         if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2810                 err = -EINVAL;
2811                 goto restore_opts;
2812         }
2813
2814         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2815                 ext4_abort(sb, __FUNCTION__, "Abort forced by user");
2816
2817         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2818                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2819
2820         es = sbi->s_es;
2821
2822         ext4_init_journal_params(sb, sbi->s_journal);
2823
2824         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2825                 n_blocks_count > ext4_blocks_count(es)) {
2826                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
2827                         err = -EROFS;
2828                         goto restore_opts;
2829                 }
2830
2831                 if (*flags & MS_RDONLY) {
2832                         /*
2833                          * First of all, the unconditional stuff we have to do
2834                          * to disable replay of the journal when we next remount
2835                          */
2836                         sb->s_flags |= MS_RDONLY;
2837
2838                         /*
2839                          * OK, test if we are remounting a valid rw partition
2840                          * readonly, and if so set the rdonly flag and then
2841                          * mark the partition as valid again.
2842                          */
2843                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
2844                             (sbi->s_mount_state & EXT4_VALID_FS))
2845                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
2846
2847                         /*
2848                          * We have to unlock super so that we can wait for
2849                          * transactions.
2850                          */
2851                         unlock_super(sb);
2852                         ext4_mark_recovery_complete(sb, es);
2853                         lock_super(sb);
2854                 } else {
2855                         __le32 ret;
2856                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2857                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
2858                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2859                                        "remount RDWR because of unsupported "
2860                                        "optional features (%x).\n",
2861                                        sb->s_id, le32_to_cpu(ret));
2862                                 err = -EROFS;
2863                                 goto restore_opts;
2864                         }
2865
2866                         /*
2867                          * If we have an unprocessed orphan list hanging
2868                          * around from a previously readonly bdev mount,
2869                          * require a full umount/remount for now.
2870                          */
2871                         if (es->s_last_orphan) {
2872                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2873                                        "remount RDWR because of unprocessed "
2874                                        "orphan inode list.  Please "
2875                                        "umount/remount instead.\n",
2876                                        sb->s_id);
2877                                 err = -EINVAL;
2878                                 goto restore_opts;
2879                         }
2880
2881                         /*
2882                          * Mounting a RDONLY partition read-write, so reread
2883                          * and store the current valid flag.  (It may have
2884                          * been changed by e2fsck since we originally mounted
2885                          * the partition.)
2886                          */
2887                         ext4_clear_journal_err(sb, es);
2888                         sbi->s_mount_state = le16_to_cpu(es->s_state);
2889                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
2890                                 goto restore_opts;
2891                         if (!ext4_setup_super (sb, es, 0))
2892                                 sb->s_flags &= ~MS_RDONLY;
2893                 }
2894         }
2895 #ifdef CONFIG_QUOTA
2896         /* Release old quota file names */
2897         for (i = 0; i < MAXQUOTAS; i++)
2898                 if (old_opts.s_qf_names[i] &&
2899                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2900                         kfree(old_opts.s_qf_names[i]);
2901 #endif
2902         return 0;
2903 restore_opts:
2904         sb->s_flags = old_sb_flags;
2905         sbi->s_mount_opt = old_opts.s_mount_opt;
2906         sbi->s_resuid = old_opts.s_resuid;
2907         sbi->s_resgid = old_opts.s_resgid;
2908         sbi->s_commit_interval = old_opts.s_commit_interval;
2909 #ifdef CONFIG_QUOTA
2910         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
2911         for (i = 0; i < MAXQUOTAS; i++) {
2912                 if (sbi->s_qf_names[i] &&
2913                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2914                         kfree(sbi->s_qf_names[i]);
2915                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
2916         }
2917 #endif
2918         return err;
2919 }
2920
2921 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
2922 {
2923         struct super_block *sb = dentry->d_sb;
2924         struct ext4_sb_info *sbi = EXT4_SB(sb);
2925         struct ext4_super_block *es = sbi->s_es;
2926         u64 fsid;
2927
2928         if (test_opt(sb, MINIX_DF)) {
2929                 sbi->s_overhead_last = 0;
2930         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
2931                 ext4_group_t ngroups = sbi->s_groups_count, i;
2932                 ext4_fsblk_t overhead = 0;
2933                 smp_rmb();
2934
2935                 /*
2936                  * Compute the overhead (FS structures).  This is constant
2937                  * for a given filesystem unless the number of block groups
2938                  * changes so we cache the previous value until it does.
2939                  */
2940
2941                 /*
2942                  * All of the blocks before first_data_block are
2943                  * overhead
2944                  */
2945                 overhead = le32_to_cpu(es->s_first_data_block);
2946
2947                 /*
2948                  * Add the overhead attributed to the superblock and
2949                  * block group descriptors.  If the sparse superblocks
2950                  * feature is turned on, then not all groups have this.
2951                  */
2952                 for (i = 0; i < ngroups; i++) {
2953                         overhead += ext4_bg_has_super(sb, i) +
2954                                 ext4_bg_num_gdb(sb, i);
2955                         cond_resched();
2956                 }
2957
2958                 /*
2959                  * Every block group has an inode bitmap, a block
2960                  * bitmap, and an inode table.
2961                  */
2962                 overhead += ngroups * (2 + sbi->s_itb_per_group);
2963                 sbi->s_overhead_last = overhead;
2964                 smp_wmb();
2965                 sbi->s_blocks_last = ext4_blocks_count(es);
2966         }
2967
2968         buf->f_type = EXT4_SUPER_MAGIC;
2969         buf->f_bsize = sb->s_blocksize;
2970         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
2971         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter);
2972         ext4_free_blocks_count_set(es, buf->f_bfree);
2973         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
2974         if (buf->f_bfree < ext4_r_blocks_count(es))
2975                 buf->f_bavail = 0;
2976         buf->f_files = le32_to_cpu(es->s_inodes_count);
2977         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
2978         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
2979         buf->f_namelen = EXT4_NAME_LEN;
2980         fsid = le64_to_cpup((void *)es->s_uuid) ^
2981                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
2982         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
2983         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
2984         return 0;
2985 }
2986
2987 /* Helper function for writing quotas on sync - we need to start transaction before quota file
2988  * is locked for write. Otherwise the are possible deadlocks:
2989  * Process 1                         Process 2
2990  * ext4_create()                     quota_sync()
2991  *   jbd2_journal_start()                   write_dquot()
2992  *   DQUOT_INIT()                        down(dqio_mutex)
2993  *     down(dqio_mutex)                    jbd2_journal_start()
2994  *
2995  */
2996
2997 #ifdef CONFIG_QUOTA
2998
2999 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3000 {
3001         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3002 }
3003
3004 static int ext4_dquot_initialize(struct inode *inode, int type)
3005 {
3006         handle_t *handle;
3007         int ret, err;
3008
3009         /* We may create quota structure so we need to reserve enough blocks */
3010         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
3011         if (IS_ERR(handle))
3012                 return PTR_ERR(handle);
3013         ret = dquot_initialize(inode, type);
3014         err = ext4_journal_stop(handle);
3015         if (!ret)
3016                 ret = err;
3017         return ret;
3018 }
3019
3020 static int ext4_dquot_drop(struct inode *inode)
3021 {
3022         handle_t *handle;
3023         int ret, err;
3024
3025         /* We may delete quota structure so we need to reserve enough blocks */
3026         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
3027         if (IS_ERR(handle))
3028                 return PTR_ERR(handle);
3029         ret = dquot_drop(inode);
3030         err = ext4_journal_stop(handle);
3031         if (!ret)
3032                 ret = err;
3033         return ret;
3034 }
3035
3036 static int ext4_write_dquot(struct dquot *dquot)
3037 {
3038         int ret, err;
3039         handle_t *handle;
3040         struct inode *inode;
3041
3042         inode = dquot_to_inode(dquot);
3043         handle = ext4_journal_start(inode,
3044                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3045         if (IS_ERR(handle))
3046                 return PTR_ERR(handle);
3047         ret = dquot_commit(dquot);
3048         err = ext4_journal_stop(handle);
3049         if (!ret)
3050                 ret = err;
3051         return ret;
3052 }
3053
3054 static int ext4_acquire_dquot(struct dquot *dquot)
3055 {
3056         int ret, err;
3057         handle_t *handle;
3058
3059         handle = ext4_journal_start(dquot_to_inode(dquot),
3060                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3061         if (IS_ERR(handle))
3062                 return PTR_ERR(handle);
3063         ret = dquot_acquire(dquot);
3064         err = ext4_journal_stop(handle);
3065         if (!ret)
3066                 ret = err;
3067         return ret;
3068 }
3069
3070 static int ext4_release_dquot(struct dquot *dquot)
3071 {
3072         int ret, err;
3073         handle_t *handle;
3074
3075         handle = ext4_journal_start(dquot_to_inode(dquot),
3076                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3077         if (IS_ERR(handle)) {
3078                 /* Release dquot anyway to avoid endless cycle in dqput() */
3079                 dquot_release(dquot);
3080                 return PTR_ERR(handle);
3081         }
3082         ret = dquot_release(dquot);
3083         err = ext4_journal_stop(handle);
3084         if (!ret)
3085                 ret = err;
3086         return ret;
3087 }
3088
3089 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3090 {
3091         /* Are we journalling quotas? */
3092         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3093             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3094                 dquot_mark_dquot_dirty(dquot);
3095                 return ext4_write_dquot(dquot);
3096         } else {
3097                 return dquot_mark_dquot_dirty(dquot);
3098         }
3099 }
3100
3101 static int ext4_write_info(struct super_block *sb, int type)
3102 {
3103         int ret, err;
3104         handle_t *handle;
3105
3106         /* Data block + inode block */
3107         handle = ext4_journal_start(sb->s_root->d_inode, 2);
3108         if (IS_ERR(handle))
3109                 return PTR_ERR(handle);
3110         ret = dquot_commit_info(sb, type);
3111         err = ext4_journal_stop(handle);
3112         if (!ret)
3113                 ret = err;
3114         return ret;
3115 }
3116
3117 /*
3118  * Turn on quotas during mount time - we need to find
3119  * the quota file and such...
3120  */
3121 static int ext4_quota_on_mount(struct super_block *sb, int type)
3122 {
3123         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3124                         EXT4_SB(sb)->s_jquota_fmt, type);
3125 }
3126
3127 /*
3128  * Standard function to be called on quota_on
3129  */
3130 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3131                          char *path)
3132 {
3133         int err;
3134         struct nameidata nd;
3135
3136         if (!test_opt(sb, QUOTA))
3137                 return -EINVAL;
3138         /* Not journalling quota? */
3139         if (!EXT4_SB(sb)->s_qf_names[USRQUOTA] &&
3140             !EXT4_SB(sb)->s_qf_names[GRPQUOTA])
3141                 return vfs_quota_on(sb, type, format_id, path);
3142         err = path_lookup(path, LOOKUP_FOLLOW, &nd);
3143         if (err)
3144                 return err;
3145         /* Quotafile not on the same filesystem? */
3146         if (nd.mnt->mnt_sb != sb) {
3147                 path_release(&nd);
3148                 return -EXDEV;
3149         }
3150         /* Quotafile not of fs root? */
3151         if (nd.dentry->d_parent->d_inode != sb->s_root->d_inode)
3152                 printk(KERN_WARNING
3153                         "EXT4-fs: Quota file not on filesystem root. "
3154                         "Journalled quota will not work.\n");
3155         path_release(&nd);
3156         return vfs_quota_on(sb, type, format_id, path);
3157 }
3158
3159 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3160  * acquiring the locks... As quota files are never truncated and quota code
3161  * itself serializes the operations (and noone else should touch the files)
3162  * we don't have to be afraid of races */
3163 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3164                                size_t len, loff_t off)
3165 {
3166         struct inode *inode = sb_dqopt(sb)->files[type];
3167         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3168         int err = 0;
3169         int offset = off & (sb->s_blocksize - 1);
3170         int tocopy;
3171         size_t toread;
3172         struct buffer_head *bh;
3173         loff_t i_size = i_size_read(inode);
3174
3175         if (off > i_size)
3176                 return 0;
3177         if (off+len > i_size)
3178                 len = i_size-off;
3179         toread = len;
3180         while (toread > 0) {
3181                 tocopy = sb->s_blocksize - offset < toread ?
3182                                 sb->s_blocksize - offset : toread;
3183                 bh = ext4_bread(NULL, inode, blk, 0, &err);
3184                 if (err)
3185                         return err;
3186                 if (!bh)        /* A hole? */
3187                         memset(data, 0, tocopy);
3188                 else
3189                         memcpy(data, bh->b_data+offset, tocopy);
3190                 brelse(bh);
3191                 offset = 0;
3192                 toread -= tocopy;
3193                 data += tocopy;
3194                 blk++;
3195         }
3196         return len;
3197 }
3198
3199 /* Write to quotafile (we know the transaction is already started and has
3200  * enough credits) */
3201 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3202                                 const char *data, size_t len, loff_t off)
3203 {
3204         struct inode *inode = sb_dqopt(sb)->files[type];
3205         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3206         int err = 0;
3207         int offset = off & (sb->s_blocksize - 1);
3208         int tocopy;
3209         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3210         size_t towrite = len;
3211         struct buffer_head *bh;
3212         handle_t *handle = journal_current_handle();
3213
3214         if (!handle) {
3215                 printk(KERN_WARNING "EXT4-fs: Quota write (off=%Lu, len=%Lu)"
3216                         " cancelled because transaction is not started.\n",
3217                         (unsigned long long)off, (unsigned long long)len);
3218                 return -EIO;
3219         }
3220         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3221         while (towrite > 0) {
3222                 tocopy = sb->s_blocksize - offset < towrite ?
3223                                 sb->s_blocksize - offset : towrite;
3224                 bh = ext4_bread(handle, inode, blk, 1, &err);
3225                 if (!bh)
3226                         goto out;
3227                 if (journal_quota) {
3228                         err = ext4_journal_get_write_access(handle, bh);
3229                         if (err) {
3230                                 brelse(bh);
3231                                 goto out;
3232                         }
3233                 }
3234                 lock_buffer(bh);
3235                 memcpy(bh->b_data+offset, data, tocopy);
3236                 flush_dcache_page(bh->b_page);
3237                 unlock_buffer(bh);
3238                 if (journal_quota)
3239                         err = ext4_journal_dirty_metadata(handle, bh);
3240                 else {
3241                         /* Always do at least ordered writes for quotas */
3242                         err = ext4_journal_dirty_data(handle, bh);
3243                         mark_buffer_dirty(bh);
3244                 }
3245                 brelse(bh);
3246                 if (err)
3247                         goto out;
3248                 offset = 0;
3249                 towrite -= tocopy;
3250                 data += tocopy;
3251                 blk++;
3252         }
3253 out:
3254         if (len == towrite)
3255                 return err;
3256         if (inode->i_size < off+len-towrite) {
3257                 i_size_write(inode, off+len-towrite);
3258                 EXT4_I(inode)->i_disksize = inode->i_size;
3259         }
3260         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3261         ext4_mark_inode_dirty(handle, inode);
3262         mutex_unlock(&inode->i_mutex);
3263         return len - towrite;
3264 }
3265
3266 #endif
3267
3268 static int ext4_get_sb(struct file_system_type *fs_type,
3269         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3270 {
3271         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3272 }
3273
3274 static struct file_system_type ext4dev_fs_type = {
3275         .owner          = THIS_MODULE,
3276         .name           = "ext4dev",
3277         .get_sb         = ext4_get_sb,
3278         .kill_sb        = kill_block_super,
3279         .fs_flags       = FS_REQUIRES_DEV,
3280 };
3281
3282 static int __init init_ext4_fs(void)
3283 {
3284         int err;
3285
3286         err = init_ext4_mballoc();
3287         if (err)
3288                 return err;
3289
3290         err = init_ext4_xattr();
3291         if (err)
3292                 goto out2;
3293         err = init_inodecache();
3294         if (err)
3295                 goto out1;
3296         err = register_filesystem(&ext4dev_fs_type);
3297         if (err)
3298                 goto out;
3299         return 0;
3300 out:
3301         destroy_inodecache();
3302 out1:
3303         exit_ext4_xattr();
3304 out2:
3305         exit_ext4_mballoc();
3306         return err;
3307 }
3308
3309 static void __exit exit_ext4_fs(void)
3310 {
3311         unregister_filesystem(&ext4dev_fs_type);
3312         destroy_inodecache();
3313         exit_ext4_xattr();
3314         exit_ext4_mballoc();
3315 }
3316
3317 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
3318 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
3319 MODULE_LICENSE("GPL");
3320 module_init(init_ext4_fs)
3321 module_exit(exit_ext4_fs)