fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/jbd2.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/parser.h>
  28 #include <linux/smp_lock.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/log2.h>
  38 #include <linux/crc16.h>
  39 #include <asm/uaccess.h>
  40
  41 #include "ext4.h"
  42 #include "ext4_jbd2.h"
  43 #include "xattr.h"
  44 #include "acl.h"
  45 #include "namei.h"
  46 #include "group.h"
  47
  48 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  49                              unsigned long journal_devnum);
  50 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
  51                                unsigned int);
  52 static void ext4_commit_super(struct super_block *sb,
  53                               struct ext4_super_block *es, int sync);
  54 static void ext4_mark_recovery_complete(struct super_block *sb,
  55                                         struct ext4_super_block *es);
  56 static void ext4_clear_journal_err(struct super_block *sb,
  57                                    struct ext4_super_block *es);
  58 static int ext4_sync_fs(struct super_block *sb, int wait);
  59 static const char *ext4_decode_error(struct super_block *sb, int errno,
  60                                      char nbuf[16]);
  61 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  62 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  63 static void ext4_unlockfs(struct super_block *sb);
  64 static void ext4_write_super(struct super_block *sb);
  65 static void ext4_write_super_lockfs(struct super_block *sb);
  66
  67
  68 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
  69                                struct ext4_group_desc *bg)
  70 {
  71         return le32_to_cpu(bg->bg_block_bitmap_lo) |
  72                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  73                 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
  74 }
  75
  76 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
  77                                struct ext4_group_desc *bg)
  78 {
  79         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
  80                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  81                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
  82 }
  83
  84 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
  85                               struct ext4_group_desc *bg)
  86 {
  87         return le32_to_cpu(bg->bg_inode_table_lo) |
  88                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  89                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
  90 }
  91
  92 void ext4_block_bitmap_set(struct super_block *sb,
  93                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
  94 {
  95         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
  96         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
  97                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
  98 }
  99
 100 void ext4_inode_bitmap_set(struct super_block *sb,
 101                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 102 {
 103         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 104         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 105                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 106 }
 107
 108 void ext4_inode_table_set(struct super_block *sb,
 109                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 110 {
 111         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 112         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 113                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 114 }
 115
 116 /*
 117  * Wrappers for jbd2_journal_start/end.
 118  *
 119  * The only special thing we need to do here is to make sure that all
 120  * journal_end calls result in the superblock being marked dirty, so
 121  * that sync() will call the filesystem's write_super callback if
 122  * appropriate.
 123  */
 124 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 125 {
 126         journal_t *journal;
 127
 128         if (sb->s_flags & MS_RDONLY)
 129                 return ERR_PTR(-EROFS);
 130
 131         /* Special case here: if the journal has aborted behind our
 132          * backs (eg. EIO in the commit thread), then we still need to
 133          * take the FS itself readonly cleanly. */
 134         journal = EXT4_SB(sb)->s_journal;
 135         if (is_journal_aborted(journal)) {
 136                 ext4_abort(sb, __func__,
 137                            "Detected aborted journal");
 138                 return ERR_PTR(-EROFS);
 139         }
 140
 141         return jbd2_journal_start(journal, nblocks);
 142 }
 143
 144 /*
 145  * The only special thing we need to do here is to make sure that all
 146  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 147  * that sync() will call the filesystem's write_super callback if
 148  * appropriate.
 149  */
 150 int __ext4_journal_stop(const char *where, handle_t *handle)
 151 {
 152         struct super_block *sb;
 153         int err;
 154         int rc;
 155
 156         sb = handle->h_transaction->t_journal->j_private;
 157         err = handle->h_err;
 158         rc = jbd2_journal_stop(handle);
 159
 160         if (!err)
 161                 err = rc;
 162         if (err)
 163                 __ext4_std_error(sb, where, err);
 164         return err;
 165 }
 166
 167 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 168                 struct buffer_head *bh, handle_t *handle, int err)
 169 {
 170         char nbuf[16];
 171         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 172
 173         if (bh)
 174                 BUFFER_TRACE(bh, "abort");
 175
 176         if (!handle->h_err)
 177                 handle->h_err = err;
 178
 179         if (is_handle_aborted(handle))
 180                 return;
 181
 182         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
 183                caller, errstr, err_fn);
 184
 185         jbd2_journal_abort_handle(handle);
 186 }
 187
 188 /* Deal with the reporting of failure conditions on a filesystem such as
 189  * inconsistencies detected or read IO failures.
 190  *
 191  * On ext2, we can store the error state of the filesystem in the
 192  * superblock.  That is not possible on ext4, because we may have other
 193  * write ordering constraints on the superblock which prevent us from
 194  * writing it out straight away; and given that the journal is about to
 195  * be aborted, we can't rely on the current, or future, transactions to
 196  * write out the superblock safely.
 197  *
 198  * We'll just use the jbd2_journal_abort() error code to record an error in
 199  * the journal instead.  On recovery, the journal will compain about
 200  * that error until we've noted it down and cleared it.
 201  */
 202
 203 static void ext4_handle_error(struct super_block *sb)
 204 {
 205         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 206
 207         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 208         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 209
 210         if (sb->s_flags & MS_RDONLY)
 211                 return;
 212
 213         if (!test_opt(sb, ERRORS_CONT)) {
 214                 journal_t *journal = EXT4_SB(sb)->s_journal;
 215
 216                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 217                 if (journal)
 218                         jbd2_journal_abort(journal, -EIO);
 219         }
 220         if (test_opt(sb, ERRORS_RO)) {
 221                 printk(KERN_CRIT "Remounting filesystem read-only\n");
 222                 sb->s_flags |= MS_RDONLY;
 223         }
 224         ext4_commit_super(sb, es, 1);
 225         if (test_opt(sb, ERRORS_PANIC))
 226                 panic("EXT4-fs (device %s): panic forced after error\n",
 227                         sb->s_id);
 228 }
 229
 230 void ext4_error(struct super_block *sb, const char *function,
 231                 const char *fmt, ...)
 232 {
 233         va_list args;
 234
 235         va_start(args, fmt);
 236         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 237         vprintk(fmt, args);
 238         printk("\n");
 239         va_end(args);
 240
 241         ext4_handle_error(sb);
 242 }
 243
 244 static const char *ext4_decode_error(struct super_block *sb, int errno,
 245                                      char nbuf[16])
 246 {
 247         char *errstr = NULL;
 248
 249         switch (errno) {
 250         case -EIO:
 251                 errstr = "IO failure";
 252                 break;
 253         case -ENOMEM:
 254                 errstr = "Out of memory";
 255                 break;
 256         case -EROFS:
 257                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
 258                         errstr = "Journal has aborted";
 259                 else
 260                         errstr = "Readonly filesystem";
 261                 break;
 262         default:
 263                 /* If the caller passed in an extra buffer for unknown
 264                  * errors, textualise them now.  Else we just return
 265                  * NULL. */
 266                 if (nbuf) {
 267                         /* Check for truncated error codes... */
 268                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 269                                 errstr = nbuf;
 270                 }
 271                 break;
 272         }
 273
 274         return errstr;
 275 }
 276
 277 /* __ext4_std_error decodes expected errors from journaling functions
 278  * automatically and invokes the appropriate error response.  */
 279
 280 void __ext4_std_error(struct super_block *sb, const char *function, int errno)
 281 {
 282         char nbuf[16];
 283         const char *errstr;
 284
 285         /* Special case: if the error is EROFS, and we're not already
 286          * inside a transaction, then there's really no point in logging
 287          * an error. */
 288         if (errno == -EROFS && journal_current_handle() == NULL &&
 289             (sb->s_flags & MS_RDONLY))
 290                 return;
 291
 292         errstr = ext4_decode_error(sb, errno, nbuf);
 293         printk(KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
 294                sb->s_id, function, errstr);
 295
 296         ext4_handle_error(sb);
 297 }
 298
 299 /*
 300  * ext4_abort is a much stronger failure handler than ext4_error.  The
 301  * abort function may be used to deal with unrecoverable failures such
 302  * as journal IO errors or ENOMEM at a critical moment in log management.
 303  *
 304  * We unconditionally force the filesystem into an ABORT|READONLY state,
 305  * unless the error response on the fs has been set to panic in which
 306  * case we take the easy way out and panic immediately.
 307  */
 308
 309 void ext4_abort(struct super_block *sb, const char *function,
 310                 const char *fmt, ...)
 311 {
 312         va_list args;
 313
 314         printk(KERN_CRIT "ext4_abort called.\n");
 315
 316         va_start(args, fmt);
 317         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 318         vprintk(fmt, args);
 319         printk("\n");
 320         va_end(args);
 321
 322         if (test_opt(sb, ERRORS_PANIC))
 323                 panic("EXT4-fs panic from previous error\n");
 324
 325         if (sb->s_flags & MS_RDONLY)
 326                 return;
 327
 328         printk(KERN_CRIT "Remounting filesystem read-only\n");
 329         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 330         sb->s_flags |= MS_RDONLY;
 331         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 332         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 333 }
 334
 335 void ext4_warning(struct super_block *sb, const char *function,
 336                   const char *fmt, ...)
 337 {
 338         va_list args;
 339
 340         va_start(args, fmt);
 341         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
 342                sb->s_id, function);
 343         vprintk(fmt, args);
 344         printk("\n");
 345         va_end(args);
 346 }
 347
 348 void ext4_update_dynamic_rev(struct super_block *sb)
 349 {
 350         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 351
 352         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 353                 return;
 354
 355         ext4_warning(sb, __func__,
 356                      "updating to rev %d because of new feature flag, "
 357                      "running e2fsck is recommended",
 358                      EXT4_DYNAMIC_REV);
 359
 360         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 361         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 362         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 363         /* leave es->s_feature_*compat flags alone */
 364         /* es->s_uuid will be set by e2fsck if empty */
 365
 366         /*
 367          * The rest of the superblock fields should be zero, and if not it
 368          * means they are likely already in use, so leave them alone.  We
 369          * can leave it up to e2fsck to clean up any inconsistencies there.
 370          */
 371 }
 372
 373 int ext4_update_compat_feature(handle_t *handle,
 374                                         struct super_block *sb, __u32 compat)
 375 {
 376         int err = 0;
 377         if (!EXT4_HAS_COMPAT_FEATURE(sb, compat)) {
 378                 err = ext4_journal_get_write_access(handle,
 379                                 EXT4_SB(sb)->s_sbh);
 380                 if (err)
 381                         return err;
 382                 EXT4_SET_COMPAT_FEATURE(sb, compat);
 383                 sb->s_dirt = 1;
 384                 handle->h_sync = 1;
 385                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 386                                         "call ext4_journal_dirty_met adata");
 387                 err = ext4_journal_dirty_metadata(handle,
 388                                 EXT4_SB(sb)->s_sbh);
 389         }
 390         return err;
 391 }
 392
 393 int ext4_update_rocompat_feature(handle_t *handle,
 394                                         struct super_block *sb, __u32 rocompat)
 395 {
 396         int err = 0;
 397         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, rocompat)) {
 398                 err = ext4_journal_get_write_access(handle,
 399                                 EXT4_SB(sb)->s_sbh);
 400                 if (err)
 401                         return err;
 402                 EXT4_SET_RO_COMPAT_FEATURE(sb, rocompat);
 403                 sb->s_dirt = 1;
 404                 handle->h_sync = 1;
 405                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 406                                         "call ext4_journal_dirty_met adata");
 407                 err = ext4_journal_dirty_metadata(handle,
 408                                 EXT4_SB(sb)->s_sbh);
 409         }
 410         return err;
 411 }
 412
 413 int ext4_update_incompat_feature(handle_t *handle,
 414                                         struct super_block *sb, __u32 incompat)
 415 {
 416         int err = 0;
 417         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, incompat)) {
 418                 err = ext4_journal_get_write_access(handle,
 419                                 EXT4_SB(sb)->s_sbh);
 420                 if (err)
 421                         return err;
 422                 EXT4_SET_INCOMPAT_FEATURE(sb, incompat);
 423                 sb->s_dirt = 1;
 424                 handle->h_sync = 1;
 425                 BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
 426                                         "call ext4_journal_dirty_met adata");
 427                 err = ext4_journal_dirty_metadata(handle,
 428                                 EXT4_SB(sb)->s_sbh);
 429         }
 430         return err;
 431 }
 432
 433 /*
 434  * Open the external journal device
 435  */
 436 static struct block_device *ext4_blkdev_get(dev_t dev)
 437 {
 438         struct block_device *bdev;
 439         char b[BDEVNAME_SIZE];
 440
 441         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 442         if (IS_ERR(bdev))
 443                 goto fail;
 444         return bdev;
 445
 446 fail:
 447         printk(KERN_ERR "EXT4: failed to open journal device %s: %ld\n",
 448                         __bdevname(dev, b), PTR_ERR(bdev));
 449         return NULL;
 450 }
 451
 452 /*
 453  * Release the journal device
 454  */
 455 static int ext4_blkdev_put(struct block_device *bdev)
 456 {
 457         bd_release(bdev);
 458         return blkdev_put(bdev);
 459 }
 460
 461 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 462 {
 463         struct block_device *bdev;
 464         int ret = -ENODEV;
 465
 466         bdev = sbi->journal_bdev;
 467         if (bdev) {
 468                 ret = ext4_blkdev_put(bdev);
 469                 sbi->journal_bdev = NULL;
 470         }
 471         return ret;
 472 }
 473
 474 static inline struct inode *orphan_list_entry(struct list_head *l)
 475 {
 476         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 477 }
 478
 479 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 480 {
 481         struct list_head *l;
 482
 483         printk(KERN_ERR "sb orphan head is %d\n",
 484                le32_to_cpu(sbi->s_es->s_last_orphan));
 485
 486         printk(KERN_ERR "sb_info orphan list:\n");
 487         list_for_each(l, &sbi->s_orphan) {
 488                 struct inode *inode = orphan_list_entry(l);
 489                 printk(KERN_ERR "  "
 490                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 491                        inode->i_sb->s_id, inode->i_ino, inode,
 492                        inode->i_mode, inode->i_nlink,
 493                        NEXT_ORPHAN(inode));
 494         }
 495 }
 496
 497 static void ext4_put_super(struct super_block *sb)
 498 {
 499         struct ext4_sb_info *sbi = EXT4_SB(sb);
 500         struct ext4_super_block *es = sbi->s_es;
 501         int i;
 502
 503         ext4_mb_release(sb);
 504         ext4_ext_release(sb);
 505         ext4_xattr_put_super(sb);
 506         jbd2_journal_destroy(sbi->s_journal);
 507         sbi->s_journal = NULL;
 508         if (!(sb->s_flags & MS_RDONLY)) {
 509                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 510                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 511                 BUFFER_TRACE(sbi->s_sbh, "marking dirty");
 512                 mark_buffer_dirty(sbi->s_sbh);
 513                 ext4_commit_super(sb, es, 1);
 514         }
 515
 516         for (i = 0; i < sbi->s_gdb_count; i++)
 517                 brelse(sbi->s_group_desc[i]);
 518         kfree(sbi->s_group_desc);
 519         kfree(sbi->s_flex_groups);
 520         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 521         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 522         percpu_counter_destroy(&sbi->s_dirs_counter);
 523         percpu_counter_destroy(&sbi->s_dirtyblocks_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         ei->vfs_inode.i_data.writeback_index = 0;
 573         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 574         INIT_LIST_HEAD(&ei->i_prealloc_list);
 575         spin_lock_init(&ei->i_prealloc_lock);
 576         jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
 577         ei->i_reserved_data_blocks = 0;
 578         ei->i_reserved_meta_blocks = 0;
 579         ei->i_allocated_meta_blocks = 0;
 580         ei->i_delalloc_reserved_flag = 0;
 581         spin_lock_init(&(ei->i_block_reservation_lock));
 582         return &ei->vfs_inode;
 583 }
 584
 585 static void ext4_destroy_inode(struct inode *inode)
 586 {
 587         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 588                 printk("EXT4 Inode %p: orphan list check failed!\n",
 589                         EXT4_I(inode));
 590                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 591                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 592                                 true);
 593                 dump_stack();
 594         }
 595         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 596 }
 597
 598 static void init_once(void *foo)
 599 {
 600         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 601
 602         INIT_LIST_HEAD(&ei->i_orphan);
 603 #ifdef CONFIG_EXT4DEV_FS_XATTR
 604         init_rwsem(&ei->xattr_sem);
 605 #endif
 606         init_rwsem(&ei->i_data_sem);
 607         inode_init_once(&ei->vfs_inode);
 608 }
 609
 610 static int init_inodecache(void)
 611 {
 612         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 613                                              sizeof(struct ext4_inode_info),
 614                                              0, (SLAB_RECLAIM_ACCOUNT|
 615                                                 SLAB_MEM_SPREAD),
 616                                              init_once);
 617         if (ext4_inode_cachep == NULL)
 618                 return -ENOMEM;
 619         return 0;
 620 }
 621
 622 static void destroy_inodecache(void)
 623 {
 624         kmem_cache_destroy(ext4_inode_cachep);
 625 }
 626
 627 static void ext4_clear_inode(struct inode *inode)
 628 {
 629         struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
 630 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 631         if (EXT4_I(inode)->i_acl &&
 632                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
 633                 posix_acl_release(EXT4_I(inode)->i_acl);
 634                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
 635         }
 636         if (EXT4_I(inode)->i_default_acl &&
 637                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
 638                 posix_acl_release(EXT4_I(inode)->i_default_acl);
 639                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
 640         }
 641 #endif
 642         ext4_discard_reservation(inode);
 643         EXT4_I(inode)->i_block_alloc_info = NULL;
 644         if (unlikely(rsv))
 645                 kfree(rsv);
 646         jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
 647                                        &EXT4_I(inode)->jinode);
 648 }
 649
 650 static inline void ext4_show_quota_options(struct seq_file *seq,
 651                                            struct super_block *sb)
 652 {
 653 #if defined(CONFIG_QUOTA)
 654         struct ext4_sb_info *sbi = EXT4_SB(sb);
 655
 656         if (sbi->s_jquota_fmt)
 657                 seq_printf(seq, ",jqfmt=%s",
 658                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold" : "vfsv0");
 659
 660         if (sbi->s_qf_names[USRQUOTA])
 661                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 662
 663         if (sbi->s_qf_names[GRPQUOTA])
 664                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 665
 666         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
 667                 seq_puts(seq, ",usrquota");
 668
 669         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
 670                 seq_puts(seq, ",grpquota");
 671 #endif
 672 }
 673
 674 /*
 675  * Show an option if
 676  *  - it's set to a non-default value OR
 677  *  - if the per-sb default is different from the global default
 678  */
 679 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 680 {
 681         int def_errors;
 682         unsigned long def_mount_opts;
 683         struct super_block *sb = vfs->mnt_sb;
 684         struct ext4_sb_info *sbi = EXT4_SB(sb);
 685         struct ext4_super_block *es = sbi->s_es;
 686
 687         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 688         def_errors     = le16_to_cpu(es->s_errors);
 689
 690         if (sbi->s_sb_block != 1)
 691                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 692         if (test_opt(sb, MINIX_DF))
 693                 seq_puts(seq, ",minixdf");
 694         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
 695                 seq_puts(seq, ",grpid");
 696         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 697                 seq_puts(seq, ",nogrpid");
 698         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 699             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 700                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 701         }
 702         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 703             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 704                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 705         }
 706         if (test_opt(sb, ERRORS_RO)) {
 707                 if (def_errors == EXT4_ERRORS_PANIC ||
 708                     def_errors == EXT4_ERRORS_CONTINUE) {
 709                         seq_puts(seq, ",errors=remount-ro");
 710                 }
 711         }
 712         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
 713                 seq_puts(seq, ",errors=continue");
 714         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
 715                 seq_puts(seq, ",errors=panic");
 716         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
 717                 seq_puts(seq, ",nouid32");
 718         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
 719                 seq_puts(seq, ",debug");
 720         if (test_opt(sb, OLDALLOC))
 721                 seq_puts(seq, ",oldalloc");
 722 #ifdef CONFIG_EXT4DEV_FS_XATTR
 723         if (test_opt(sb, XATTR_USER) &&
 724                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
 725                 seq_puts(seq, ",user_xattr");
 726         if (!test_opt(sb, XATTR_USER) &&
 727             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 728                 seq_puts(seq, ",nouser_xattr");
 729         }
 730 #endif
 731 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 732         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
 733                 seq_puts(seq, ",acl");
 734         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 735                 seq_puts(seq, ",noacl");
 736 #endif
 737         if (!test_opt(sb, RESERVATION))
 738                 seq_puts(seq, ",noreservation");
 739         if (sbi->s_commit_interval) {
 740                 seq_printf(seq, ",commit=%u",
 741                            (unsigned) (sbi->s_commit_interval / HZ));
 742         }
 743         /*
 744          * We're changing the default of barrier mount option, so
 745          * let's always display its mount state so it's clear what its
 746          * status is.
 747          */
 748         seq_puts(seq, ",barrier=");
 749         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
 750         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
 751                 seq_puts(seq, ",journal_async_commit");
 752         if (test_opt(sb, NOBH))
 753                 seq_puts(seq, ",nobh");
 754         if (!test_opt(sb, EXTENTS))
 755                 seq_puts(seq, ",noextents");
 756         if (!test_opt(sb, MBALLOC))
 757                 seq_puts(seq, ",nomballoc");
 758         if (test_opt(sb, I_VERSION))
 759                 seq_puts(seq, ",i_version");
 760         if (!test_opt(sb, DELALLOC))
 761                 seq_puts(seq, ",nodelalloc");
 762
 763
 764         if (sbi->s_stripe)
 765                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
 766         /*
 767          * journal mode get enabled in different ways
 768          * So just print the value even if we didn't specify it
 769          */
 770         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 771                 seq_puts(seq, ",data=journal");
 772         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 773                 seq_puts(seq, ",data=ordered");
 774         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 775                 seq_puts(seq, ",data=writeback");
 776
 777         ext4_show_quota_options(seq, sb);
 778         return 0;
 779 }
 780
 781
 782 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 783                 u64 ino, u32 generation)
 784 {
 785         struct inode *inode;
 786
 787         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 788                 return ERR_PTR(-ESTALE);
 789         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 790                 return ERR_PTR(-ESTALE);
 791
 792         /* iget isn't really right if the inode is currently unallocated!!
 793          *
 794          * ext4_read_inode will return a bad_inode if the inode had been
 795          * deleted, so we should be safe.
 796          *
 797          * Currently we don't know the generation for parent directory, so
 798          * a generation of 0 means "accept any"
 799          */
 800         inode = ext4_iget(sb, ino);
 801         if (IS_ERR(inode))
 802                 return ERR_CAST(inode);
 803         if (generation && inode->i_generation != generation) {
 804                 iput(inode);
 805                 return ERR_PTR(-ESTALE);
 806         }
 807
 808         return inode;
 809 }
 810
 811 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 812                 int fh_len, int fh_type)
 813 {
 814         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 815                                     ext4_nfs_get_inode);
 816 }
 817
 818 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 819                 int fh_len, int fh_type)
 820 {
 821         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 822                                     ext4_nfs_get_inode);
 823 }
 824
 825 #ifdef CONFIG_QUOTA
 826 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
 827 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 828
 829 static int ext4_dquot_initialize(struct inode *inode, int type);
 830 static int ext4_dquot_drop(struct inode *inode);
 831 static int ext4_write_dquot(struct dquot *dquot);
 832 static int ext4_acquire_dquot(struct dquot *dquot);
 833 static int ext4_release_dquot(struct dquot *dquot);
 834 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 835 static int ext4_write_info(struct super_block *sb, int type);
 836 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 837                                 char *path, int remount);
 838 static int ext4_quota_on_mount(struct super_block *sb, int type);
 839 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 840                                size_t len, loff_t off);
 841 static ssize_t ext4_quota_write(struct super_block *sb, int type,
 842                                 const char *data, size_t len, loff_t off);
 843
 844 static struct dquot_operations ext4_quota_operations = {
 845         .initialize     = ext4_dquot_initialize,
 846         .drop           = ext4_dquot_drop,
 847         .alloc_space    = dquot_alloc_space,
 848         .alloc_inode    = dquot_alloc_inode,
 849         .free_space     = dquot_free_space,
 850         .free_inode     = dquot_free_inode,
 851         .transfer       = dquot_transfer,
 852         .write_dquot    = ext4_write_dquot,
 853         .acquire_dquot  = ext4_acquire_dquot,
 854         .release_dquot  = ext4_release_dquot,
 855         .mark_dirty     = ext4_mark_dquot_dirty,
 856         .write_info     = ext4_write_info
 857 };
 858
 859 static struct quotactl_ops ext4_qctl_operations = {
 860         .quota_on       = ext4_quota_on,
 861         .quota_off      = vfs_quota_off,
 862         .quota_sync     = vfs_quota_sync,
 863         .get_info       = vfs_get_dqinfo,
 864         .set_info       = vfs_set_dqinfo,
 865         .get_dqblk      = vfs_get_dqblk,
 866         .set_dqblk      = vfs_set_dqblk
 867 };
 868 #endif
 869
 870 static const struct super_operations ext4_sops = {
 871         .alloc_inode    = ext4_alloc_inode,
 872         .destroy_inode  = ext4_destroy_inode,
 873         .write_inode    = ext4_write_inode,
 874         .dirty_inode    = ext4_dirty_inode,
 875         .delete_inode   = ext4_delete_inode,
 876         .put_super      = ext4_put_super,
 877         .write_super    = ext4_write_super,
 878         .sync_fs        = ext4_sync_fs,
 879         .write_super_lockfs = ext4_write_super_lockfs,
 880         .unlockfs       = ext4_unlockfs,
 881         .statfs         = ext4_statfs,
 882         .remount_fs     = ext4_remount,
 883         .clear_inode    = ext4_clear_inode,
 884         .show_options   = ext4_show_options,
 885 #ifdef CONFIG_QUOTA
 886         .quota_read     = ext4_quota_read,
 887         .quota_write    = ext4_quota_write,
 888 #endif
 889 };
 890
 891 static const struct export_operations ext4_export_ops = {
 892         .fh_to_dentry = ext4_fh_to_dentry,
 893         .fh_to_parent = ext4_fh_to_parent,
 894         .get_parent = ext4_get_parent,
 895 };
 896
 897 enum {
 898         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 899         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
 900         Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov,
 901         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
 902         Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
 903         Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
 904         Opt_journal_checksum, Opt_journal_async_commit,
 905         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
 906         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 907         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
 908         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
 909         Opt_grpquota, Opt_extents, Opt_noextents, Opt_i_version,
 910         Opt_mballoc, Opt_nomballoc, Opt_stripe, Opt_delalloc, Opt_nodelalloc,
 911 };
 912
 913 static match_table_t tokens = {
 914         {Opt_bsd_df, "bsddf"},
 915         {Opt_minix_df, "minixdf"},
 916         {Opt_grpid, "grpid"},
 917         {Opt_grpid, "bsdgroups"},
 918         {Opt_nogrpid, "nogrpid"},
 919         {Opt_nogrpid, "sysvgroups"},
 920         {Opt_resgid, "resgid=%u"},
 921         {Opt_resuid, "resuid=%u"},
 922         {Opt_sb, "sb=%u"},
 923         {Opt_err_cont, "errors=continue"},
 924         {Opt_err_panic, "errors=panic"},
 925         {Opt_err_ro, "errors=remount-ro"},
 926         {Opt_nouid32, "nouid32"},
 927         {Opt_nocheck, "nocheck"},
 928         {Opt_nocheck, "check=none"},
 929         {Opt_debug, "debug"},
 930         {Opt_oldalloc, "oldalloc"},
 931         {Opt_orlov, "orlov"},
 932         {Opt_user_xattr, "user_xattr"},
 933         {Opt_nouser_xattr, "nouser_xattr"},
 934         {Opt_acl, "acl"},
 935         {Opt_noacl, "noacl"},
 936         {Opt_reservation, "reservation"},
 937         {Opt_noreservation, "noreservation"},
 938         {Opt_noload, "noload"},
 939         {Opt_nobh, "nobh"},
 940         {Opt_bh, "bh"},
 941         {Opt_commit, "commit=%u"},
 942         {Opt_journal_update, "journal=update"},
 943         {Opt_journal_inum, "journal=%u"},
 944         {Opt_journal_dev, "journal_dev=%u"},
 945         {Opt_journal_checksum, "journal_checksum"},
 946         {Opt_journal_async_commit, "journal_async_commit"},
 947         {Opt_abort, "abort"},
 948         {Opt_data_journal, "data=journal"},
 949         {Opt_data_ordered, "data=ordered"},
 950         {Opt_data_writeback, "data=writeback"},
 951         {Opt_offusrjquota, "usrjquota="},
 952         {Opt_usrjquota, "usrjquota=%s"},
 953         {Opt_offgrpjquota, "grpjquota="},
 954         {Opt_grpjquota, "grpjquota=%s"},
 955         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
 956         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
 957         {Opt_grpquota, "grpquota"},
 958         {Opt_noquota, "noquota"},
 959         {Opt_quota, "quota"},
 960         {Opt_usrquota, "usrquota"},
 961         {Opt_barrier, "barrier=%u"},
 962         {Opt_extents, "extents"},
 963         {Opt_noextents, "noextents"},
 964         {Opt_i_version, "i_version"},
 965         {Opt_mballoc, "mballoc"},
 966         {Opt_nomballoc, "nomballoc"},
 967         {Opt_stripe, "stripe=%u"},
 968         {Opt_resize, "resize"},
 969         {Opt_delalloc, "delalloc"},
 970         {Opt_nodelalloc, "nodelalloc"},
 971         {Opt_err, NULL},
 972 };
 973
 974 static ext4_fsblk_t get_sb_block(void **data)
 975 {
 976         ext4_fsblk_t    sb_block;
 977         char            *options = (char *) *data;
 978
 979         if (!options || strncmp(options, "sb=", 3) != 0)
 980                 return 1;       /* Default location */
 981         options += 3;
 982         /*todo: use simple_strtoll with >32bit ext4 */
 983         sb_block = simple_strtoul(options, &options, 0);
 984         if (*options && *options != ',') {
 985                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
 986                        (char *) *data);
 987                 return 1;
 988         }
 989         if (*options == ',')
 990                 options++;
 991         *data = (void *) options;
 992         return sb_block;
 993 }
 994
 995 static int parse_options(char *options, struct super_block *sb,
 996                          unsigned int *inum, unsigned long *journal_devnum,
 997                          ext4_fsblk_t *n_blocks_count, int is_remount)
 998 {
 999         struct ext4_sb_info *sbi = EXT4_SB(sb);
1000         char *p;
1001         substring_t args[MAX_OPT_ARGS];
1002         int data_opt = 0;
1003         int option;
1004 #ifdef CONFIG_QUOTA
1005         int qtype, qfmt;
1006         char *qname;
1007 #endif
1008         ext4_fsblk_t last_block;
1009
1010         if (!options)
1011                 return 1;
1012
1013         while ((p = strsep(&options, ",")) != NULL) {
1014                 int token;
1015                 if (!*p)
1016                         continue;
1017
1018                 token = match_token(p, tokens, args);
1019                 switch (token) {
1020                 case Opt_bsd_df:
1021                         clear_opt(sbi->s_mount_opt, MINIX_DF);
1022                         break;
1023                 case Opt_minix_df:
1024                         set_opt(sbi->s_mount_opt, MINIX_DF);
1025                         break;
1026                 case Opt_grpid:
1027                         set_opt(sbi->s_mount_opt, GRPID);
1028                         break;
1029                 case Opt_nogrpid:
1030                         clear_opt(sbi->s_mount_opt, GRPID);
1031                         break;
1032                 case Opt_resuid:
1033                         if (match_int(&args[0], &option))
1034                                 return 0;
1035                         sbi->s_resuid = option;
1036                         break;
1037                 case Opt_resgid:
1038                         if (match_int(&args[0], &option))
1039                                 return 0;
1040                         sbi->s_resgid = option;
1041                         break;
1042                 case Opt_sb:
1043                         /* handled by get_sb_block() instead of here */
1044                         /* *sb_block = match_int(&args[0]); */
1045                         break;
1046                 case Opt_err_panic:
1047                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1048                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1049                         set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1050                         break;
1051                 case Opt_err_ro:
1052                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1053                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1054                         set_opt(sbi->s_mount_opt, ERRORS_RO);
1055                         break;
1056                 case Opt_err_cont:
1057                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1058                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1059                         set_opt(sbi->s_mount_opt, ERRORS_CONT);
1060                         break;
1061                 case Opt_nouid32:
1062                         set_opt(sbi->s_mount_opt, NO_UID32);
1063                         break;
1064                 case Opt_nocheck:
1065                         clear_opt(sbi->s_mount_opt, CHECK);
1066                         break;
1067                 case Opt_debug:
1068                         set_opt(sbi->s_mount_opt, DEBUG);
1069                         break;
1070                 case Opt_oldalloc:
1071                         set_opt(sbi->s_mount_opt, OLDALLOC);
1072                         break;
1073                 case Opt_orlov:
1074                         clear_opt(sbi->s_mount_opt, OLDALLOC);
1075                         break;
1076 #ifdef CONFIG_EXT4DEV_FS_XATTR
1077                 case Opt_user_xattr:
1078                         set_opt(sbi->s_mount_opt, XATTR_USER);
1079                         break;
1080                 case Opt_nouser_xattr:
1081                         clear_opt(sbi->s_mount_opt, XATTR_USER);
1082                         break;
1083 #else
1084                 case Opt_user_xattr:
1085                 case Opt_nouser_xattr:
1086                         printk(KERN_ERR "EXT4 (no)user_xattr options "
1087                                "not supported\n");
1088                         break;
1089 #endif
1090 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1091                 case Opt_acl:
1092                         set_opt(sbi->s_mount_opt, POSIX_ACL);
1093                         break;
1094                 case Opt_noacl:
1095                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
1096                         break;
1097 #else
1098                 case Opt_acl:
1099                 case Opt_noacl:
1100                         printk(KERN_ERR "EXT4 (no)acl options "
1101                                "not supported\n");
1102                         break;
1103 #endif
1104                 case Opt_reservation:
1105                         set_opt(sbi->s_mount_opt, RESERVATION);
1106                         break;
1107                 case Opt_noreservation:
1108                         clear_opt(sbi->s_mount_opt, RESERVATION);
1109                         break;
1110                 case Opt_journal_update:
1111                         /* @@@ FIXME */
1112                         /* Eventually we will want to be able to create
1113                            a journal file here.  For now, only allow the
1114                            user to specify an existing inode to be the
1115                            journal file. */
1116                         if (is_remount) {
1117                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1118                                        "journal on remount\n");
1119                                 return 0;
1120                         }
1121                         set_opt(sbi->s_mount_opt, UPDATE_JOURNAL);
1122                         break;
1123                 case Opt_journal_inum:
1124                         if (is_remount) {
1125                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1126                                        "journal on remount\n");
1127                                 return 0;
1128                         }
1129                         if (match_int(&args[0], &option))
1130                                 return 0;
1131                         *inum = option;
1132                         break;
1133                 case Opt_journal_dev:
1134                         if (is_remount) {
1135                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1136                                        "journal on remount\n");
1137                                 return 0;
1138                         }
1139                         if (match_int(&args[0], &option))
1140                                 return 0;
1141                         *journal_devnum = option;
1142                         break;
1143                 case Opt_journal_checksum:
1144                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1145                         break;
1146                 case Opt_journal_async_commit:
1147                         set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1148                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1149                         break;
1150                 case Opt_noload:
1151                         set_opt(sbi->s_mount_opt, NOLOAD);
1152                         break;
1153                 case Opt_commit:
1154                         if (match_int(&args[0], &option))
1155                                 return 0;
1156                         if (option < 0)
1157                                 return 0;
1158                         if (option == 0)
1159                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1160                         sbi->s_commit_interval = HZ * option;
1161                         break;
1162                 case Opt_data_journal:
1163                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1164                         goto datacheck;
1165                 case Opt_data_ordered:
1166                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1167                         goto datacheck;
1168                 case Opt_data_writeback:
1169                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1170                 datacheck:
1171                         if (is_remount) {
1172                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1173                                                 != data_opt) {
1174                                         printk(KERN_ERR
1175                                                 "EXT4-fs: cannot change data "
1176                                                 "mode on remount\n");
1177                                         return 0;
1178                                 }
1179                         } else {
1180                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1181                                 sbi->s_mount_opt |= data_opt;
1182                         }
1183                         break;
1184 #ifdef CONFIG_QUOTA
1185                 case Opt_usrjquota:
1186                         qtype = USRQUOTA;
1187                         goto set_qf_name;
1188                 case Opt_grpjquota:
1189                         qtype = GRPQUOTA;
1190 set_qf_name:
1191                         if ((sb_any_quota_enabled(sb) ||
1192                              sb_any_quota_suspended(sb)) &&
1193                             !sbi->s_qf_names[qtype]) {
1194                                 printk(KERN_ERR
1195                                        "EXT4-fs: Cannot change journaled "
1196                                        "quota options when quota turned on.\n");
1197                                 return 0;
1198                         }
1199                         qname = match_strdup(&args[0]);
1200                         if (!qname) {
1201                                 printk(KERN_ERR
1202                                         "EXT4-fs: not enough memory for "
1203                                         "storing quotafile name.\n");
1204                                 return 0;
1205                         }
1206                         if (sbi->s_qf_names[qtype] &&
1207                             strcmp(sbi->s_qf_names[qtype], qname)) {
1208                                 printk(KERN_ERR
1209                                         "EXT4-fs: %s quota file already "
1210                                         "specified.\n", QTYPE2NAME(qtype));
1211                                 kfree(qname);
1212                                 return 0;
1213                         }
1214                         sbi->s_qf_names[qtype] = qname;
1215                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1216                                 printk(KERN_ERR
1217                                         "EXT4-fs: quotafile must be on "
1218                                         "filesystem root.\n");
1219                                 kfree(sbi->s_qf_names[qtype]);
1220                                 sbi->s_qf_names[qtype] = NULL;
1221                                 return 0;
1222                         }
1223                         set_opt(sbi->s_mount_opt, QUOTA);
1224                         break;
1225                 case Opt_offusrjquota:
1226                         qtype = USRQUOTA;
1227                         goto clear_qf_name;
1228                 case Opt_offgrpjquota:
1229                         qtype = GRPQUOTA;
1230 clear_qf_name:
1231                         if ((sb_any_quota_enabled(sb) ||
1232                              sb_any_quota_suspended(sb)) &&
1233                             sbi->s_qf_names[qtype]) {
1234                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1235                                         "journaled quota options when "
1236                                         "quota turned on.\n");
1237                                 return 0;
1238                         }
1239                         /*
1240                          * The space will be released later when all options
1241                          * are confirmed to be correct
1242                          */
1243                         sbi->s_qf_names[qtype] = NULL;
1244                         break;
1245                 case Opt_jqfmt_vfsold:
1246                         qfmt = QFMT_VFS_OLD;
1247                         goto set_qf_format;
1248                 case Opt_jqfmt_vfsv0:
1249                         qfmt = QFMT_VFS_V0;
1250 set_qf_format:
1251                         if ((sb_any_quota_enabled(sb) ||
1252                              sb_any_quota_suspended(sb)) &&
1253                             sbi->s_jquota_fmt != qfmt) {
1254                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1255                                         "journaled quota options when "
1256                                         "quota turned on.\n");
1257                                 return 0;
1258                         }
1259                         sbi->s_jquota_fmt = qfmt;
1260                         break;
1261                 case Opt_quota:
1262                 case Opt_usrquota:
1263                         set_opt(sbi->s_mount_opt, QUOTA);
1264                         set_opt(sbi->s_mount_opt, USRQUOTA);
1265                         break;
1266                 case Opt_grpquota:
1267                         set_opt(sbi->s_mount_opt, QUOTA);
1268                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1269                         break;
1270                 case Opt_noquota:
1271                         if (sb_any_quota_enabled(sb)) {
1272                                 printk(KERN_ERR "EXT4-fs: Cannot change quota "
1273                                         "options when quota turned on.\n");
1274                                 return 0;
1275                         }
1276                         clear_opt(sbi->s_mount_opt, QUOTA);
1277                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1278                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1279                         break;
1280 #else
1281                 case Opt_quota:
1282                 case Opt_usrquota:
1283                 case Opt_grpquota:
1284                         printk(KERN_ERR
1285                                 "EXT4-fs: quota options not supported.\n");
1286                         break;
1287                 case Opt_usrjquota:
1288                 case Opt_grpjquota:
1289                 case Opt_offusrjquota:
1290                 case Opt_offgrpjquota:
1291                 case Opt_jqfmt_vfsold:
1292                 case Opt_jqfmt_vfsv0:
1293                         printk(KERN_ERR
1294                                 "EXT4-fs: journaled quota options not "
1295                                 "supported.\n");
1296                         break;
1297                 case Opt_noquota:
1298                         break;
1299 #endif
1300                 case Opt_abort:
1301                         set_opt(sbi->s_mount_opt, ABORT);
1302                         break;
1303                 case Opt_barrier:
1304                         if (match_int(&args[0], &option))
1305                                 return 0;
1306                         if (option)
1307                                 set_opt(sbi->s_mount_opt, BARRIER);
1308                         else
1309                                 clear_opt(sbi->s_mount_opt, BARRIER);
1310                         break;
1311                 case Opt_ignore:
1312                         break;
1313                 case Opt_resize:
1314                         if (!is_remount) {
1315                                 printk("EXT4-fs: resize option only available "
1316                                         "for remount\n");
1317                                 return 0;
1318                         }
1319                         if (match_int(&args[0], &option) != 0)
1320                                 return 0;
1321                         *n_blocks_count = option;
1322                         break;
1323                 case Opt_nobh:
1324                         set_opt(sbi->s_mount_opt, NOBH);
1325                         break;
1326                 case Opt_bh:
1327                         clear_opt(sbi->s_mount_opt, NOBH);
1328                         break;
1329                 case Opt_extents:
1330                         if (!EXT4_HAS_INCOMPAT_FEATURE(sb,
1331                                         EXT4_FEATURE_INCOMPAT_EXTENTS)) {
1332                                 ext4_warning(sb, __func__,
1333                                         "extents feature not enabled "
1334                                         "on this filesystem, use tune2fs\n");
1335                                 return 0;
1336                         }
1337                         set_opt(sbi->s_mount_opt, EXTENTS);
1338                         break;
1339                 case Opt_noextents:
1340                         /*
1341                          * When e2fsprogs support resizing an already existing
1342                          * ext3 file system to greater than 2**32 we need to
1343                          * add support to block allocator to handle growing
1344                          * already existing block  mapped inode so that blocks
1345                          * allocated for them fall within 2**32
1346                          */
1347                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1348                         if (last_block  > 0xffffffffULL) {
1349                                 printk(KERN_ERR "EXT4-fs: Filesystem too "
1350                                                 "large to mount with "
1351                                                 "-o noextents options\n");
1352                                 return 0;
1353                         }
1354                         clear_opt(sbi->s_mount_opt, EXTENTS);
1355                         break;
1356                 case Opt_i_version:
1357                         set_opt(sbi->s_mount_opt, I_VERSION);
1358                         sb->s_flags |= MS_I_VERSION;
1359                         break;
1360                 case Opt_nodelalloc:
1361                         clear_opt(sbi->s_mount_opt, DELALLOC);
1362                         break;
1363                 case Opt_mballoc:
1364                         set_opt(sbi->s_mount_opt, MBALLOC);
1365                         break;
1366                 case Opt_nomballoc:
1367                         clear_opt(sbi->s_mount_opt, MBALLOC);
1368                         break;
1369                 case Opt_stripe:
1370                         if (match_int(&args[0], &option))
1371                                 return 0;
1372                         if (option < 0)
1373                                 return 0;
1374                         sbi->s_stripe = option;
1375                         break;
1376                 case Opt_delalloc:
1377                         set_opt(sbi->s_mount_opt, DELALLOC);
1378                         break;
1379                 default:
1380                         printk(KERN_ERR
1381                                "EXT4-fs: Unrecognized mount option \"%s\" "
1382                                "or missing value\n", p);
1383                         return 0;
1384                 }
1385         }
1386 #ifdef CONFIG_QUOTA
1387         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1388                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1389                      sbi->s_qf_names[USRQUOTA])
1390                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1391
1392                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1393                      sbi->s_qf_names[GRPQUOTA])
1394                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1395
1396                 if ((sbi->s_qf_names[USRQUOTA] &&
1397                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1398                     (sbi->s_qf_names[GRPQUOTA] &&
1399                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1400                         printk(KERN_ERR "EXT4-fs: old and new quota "
1401                                         "format mixing.\n");
1402                         return 0;
1403                 }
1404
1405                 if (!sbi->s_jquota_fmt) {
1406                         printk(KERN_ERR "EXT4-fs: journaled quota format "
1407                                         "not specified.\n");
1408                         return 0;
1409                 }
1410         } else {
1411                 if (sbi->s_jquota_fmt) {
1412                         printk(KERN_ERR "EXT4-fs: journaled quota format "
1413                                         "specified with no journaling "
1414                                         "enabled.\n");
1415                         return 0;
1416                 }
1417         }
1418 #endif
1419         return 1;
1420 }
1421
1422 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1423                             int read_only)
1424 {
1425         struct ext4_sb_info *sbi = EXT4_SB(sb);
1426         int res = 0;
1427
1428         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1429                 printk(KERN_ERR "EXT4-fs warning: revision level too high, "
1430                        "forcing read-only mode\n");
1431                 res = MS_RDONLY;
1432         }
1433         if (read_only)
1434                 return res;
1435         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1436                 printk(KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1437                        "running e2fsck is recommended\n");
1438         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1439                 printk(KERN_WARNING
1440                        "EXT4-fs warning: mounting fs with errors, "
1441                        "running e2fsck is recommended\n");
1442         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1443                  le16_to_cpu(es->s_mnt_count) >=
1444                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1445                 printk(KERN_WARNING
1446                        "EXT4-fs warning: maximal mount count reached, "
1447                        "running e2fsck is recommended\n");
1448         else if (le32_to_cpu(es->s_checkinterval) &&
1449                 (le32_to_cpu(es->s_lastcheck) +
1450                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1451                 printk(KERN_WARNING
1452                        "EXT4-fs warning: checktime reached, "
1453                        "running e2fsck is recommended\n");
1454 #if 0
1455                 /* @@@ We _will_ want to clear the valid bit if we find
1456                  * inconsistencies, to force a fsck at reboot.  But for
1457                  * a plain journaled filesystem we can keep it set as
1458                  * valid forever! :)
1459                  */
1460         es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1461 #endif
1462         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1463                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1464         le16_add_cpu(&es->s_mnt_count, 1);
1465         es->s_mtime = cpu_to_le32(get_seconds());
1466         ext4_update_dynamic_rev(sb);
1467         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1468
1469         ext4_commit_super(sb, es, 1);
1470         if (test_opt(sb, DEBUG))
1471                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%lu, "
1472                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1473                         sb->s_blocksize,
1474                         sbi->s_groups_count,
1475                         EXT4_BLOCKS_PER_GROUP(sb),
1476                         EXT4_INODES_PER_GROUP(sb),
1477                         sbi->s_mount_opt);
1478
1479         if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
1480                 char b[BDEVNAME_SIZE];
1481
1482                 printk(KERN_INFO "EXT4 FS on %s, external journal on %s\n",
1483                        sb->s_id, bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
1484         } else {
1485                 printk(KERN_INFO "EXT4 FS on %s, internal journal\n",
1486                        sb->s_id);
1487         }
1488         return res;
1489 }
1490
1491 static int ext4_fill_flex_info(struct super_block *sb)
1492 {
1493         struct ext4_sb_info *sbi = EXT4_SB(sb);
1494         struct ext4_group_desc *gdp = NULL;
1495         struct buffer_head *bh;
1496         ext4_group_t flex_group_count;
1497         ext4_group_t flex_group;
1498         int groups_per_flex = 0;
1499         __u64 block_bitmap = 0;
1500         int i;
1501
1502         if (!sbi->s_es->s_log_groups_per_flex) {
1503                 sbi->s_log_groups_per_flex = 0;
1504                 return 1;
1505         }
1506
1507         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1508         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1509
1510         /* We allocate both existing and potentially added groups */
1511         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1512                             ((sbi->s_es->s_reserved_gdt_blocks +1 ) <<
1513                               EXT4_DESC_PER_BLOCK_BITS(sb))) /
1514                            groups_per_flex;
1515         sbi->s_flex_groups = kzalloc(flex_group_count *
1516                                      sizeof(struct flex_groups), GFP_KERNEL);
1517         if (sbi->s_flex_groups == NULL) {
1518                 printk(KERN_ERR "EXT4-fs: not enough memory for "
1519                                 "%lu flex groups\n", flex_group_count);
1520                 goto failed;
1521         }
1522
1523         gdp = ext4_get_group_desc(sb, 1, &bh);
1524         block_bitmap = ext4_block_bitmap(sb, gdp) - 1;
1525
1526         for (i = 0; i < sbi->s_groups_count; i++) {
1527                 gdp = ext4_get_group_desc(sb, i, &bh);
1528
1529                 flex_group = ext4_flex_group(sbi, i);
1530                 sbi->s_flex_groups[flex_group].free_inodes +=
1531                         le16_to_cpu(gdp->bg_free_inodes_count);
1532                 sbi->s_flex_groups[flex_group].free_blocks +=
1533                         le16_to_cpu(gdp->bg_free_blocks_count);
1534         }
1535
1536         return 1;
1537 failed:
1538         return 0;
1539 }
1540
1541 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1542                             struct ext4_group_desc *gdp)
1543 {
1544         __u16 crc = 0;
1545
1546         if (sbi->s_es->s_feature_ro_compat &
1547             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1548                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1549                 __le32 le_group = cpu_to_le32(block_group);
1550
1551                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1552                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1553                 crc = crc16(crc, (__u8 *)gdp, offset);
1554                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1555                 /* for checksum of struct ext4_group_desc do the rest...*/
1556                 if ((sbi->s_es->s_feature_incompat &
1557                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1558                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1559                         crc = crc16(crc, (__u8 *)gdp + offset,
1560                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1561                                         offset);
1562         }
1563
1564         return cpu_to_le16(crc);
1565 }
1566
1567 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1568                                 struct ext4_group_desc *gdp)
1569 {
1570         if ((sbi->s_es->s_feature_ro_compat &
1571              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1572             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1573                 return 0;
1574
1575         return 1;
1576 }
1577
1578 /* Called at mount-time, super-block is locked */
1579 static int ext4_check_descriptors(struct super_block *sb)
1580 {
1581         struct ext4_sb_info *sbi = EXT4_SB(sb);
1582         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1583         ext4_fsblk_t last_block;
1584         ext4_fsblk_t block_bitmap;
1585         ext4_fsblk_t inode_bitmap;
1586         ext4_fsblk_t inode_table;
1587         int flexbg_flag = 0;
1588         ext4_group_t i;
1589
1590         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1591                 flexbg_flag = 1;
1592
1593         ext4_debug("Checking group descriptors");
1594
1595         for (i = 0; i < sbi->s_groups_count; i++) {
1596                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1597
1598                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1599                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1600                 else
1601                         last_block = first_block +
1602                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1603
1604                 block_bitmap = ext4_block_bitmap(sb, gdp);
1605                 if (block_bitmap < first_block || block_bitmap > last_block) {
1606                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1607                                "Block bitmap for group %lu not in group "
1608                                "(block %llu)!", i, block_bitmap);
1609                         return 0;
1610                 }
1611                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1612                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
1613                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1614                                "Inode bitmap for group %lu not in group "
1615                                "(block %llu)!", i, inode_bitmap);
1616                         return 0;
1617                 }
1618                 inode_table = ext4_inode_table(sb, gdp);
1619                 if (inode_table < first_block ||
1620                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
1621                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1622                                "Inode table for group %lu not in group "
1623                                "(block %llu)!", i, inode_table);
1624                         return 0;
1625                 }
1626                 spin_lock(sb_bgl_lock(sbi, i));
1627                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1628                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1629                                "Checksum for group %lu failed (%u!=%u)\n",
1630                                i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1631                                gdp)), le16_to_cpu(gdp->bg_checksum));
1632                         if (!(sb->s_flags & MS_RDONLY))
1633                                 return 0;
1634                 }
1635                 spin_unlock(sb_bgl_lock(sbi, i));
1636                 if (!flexbg_flag)
1637                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1638         }
1639
1640         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1641         sbi->s_es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
1642         return 1;
1643 }
1644
1645 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1646  * the superblock) which were deleted from all directories, but held open by
1647  * a process at the time of a crash.  We walk the list and try to delete these
1648  * inodes at recovery time (only with a read-write filesystem).
1649  *
1650  * In order to keep the orphan inode chain consistent during traversal (in
1651  * case of crash during recovery), we link each inode into the superblock
1652  * orphan list_head and handle it the same way as an inode deletion during
1653  * normal operation (which journals the operations for us).
1654  *
1655  * We only do an iget() and an iput() on each inode, which is very safe if we
1656  * accidentally point at an in-use or already deleted inode.  The worst that
1657  * can happen in this case is that we get a "bit already cleared" message from
1658  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1659  * e2fsck was run on this filesystem, and it must have already done the orphan
1660  * inode cleanup for us, so we can safely abort without any further action.
1661  */
1662 static void ext4_orphan_cleanup(struct super_block *sb,
1663                                 struct ext4_super_block *es)
1664 {
1665         unsigned int s_flags = sb->s_flags;
1666         int nr_orphans = 0, nr_truncates = 0;
1667 #ifdef CONFIG_QUOTA
1668         int i;
1669 #endif
1670         if (!es->s_last_orphan) {
1671                 jbd_debug(4, "no orphan inodes to clean up\n");
1672                 return;
1673         }
1674
1675         if (bdev_read_only(sb->s_bdev)) {
1676                 printk(KERN_ERR "EXT4-fs: write access "
1677                         "unavailable, skipping orphan cleanup.\n");
1678                 return;
1679         }
1680
1681         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1682                 if (es->s_last_orphan)
1683                         jbd_debug(1, "Errors on filesystem, "
1684                                   "clearing orphan list.\n");
1685                 es->s_last_orphan = 0;
1686                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1687                 return;
1688         }
1689
1690         if (s_flags & MS_RDONLY) {
1691                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1692                        sb->s_id);
1693                 sb->s_flags &= ~MS_RDONLY;
1694         }
1695 #ifdef CONFIG_QUOTA
1696         /* Needed for iput() to work correctly and not trash data */
1697         sb->s_flags |= MS_ACTIVE;
1698         /* Turn on quotas so that they are updated correctly */
1699         for (i = 0; i < MAXQUOTAS; i++) {
1700                 if (EXT4_SB(sb)->s_qf_names[i]) {
1701                         int ret = ext4_quota_on_mount(sb, i);
1702                         if (ret < 0)
1703                                 printk(KERN_ERR
1704                                         "EXT4-fs: Cannot turn on journaled "
1705                                         "quota: error %d\n", ret);
1706                 }
1707         }
1708 #endif
1709
1710         while (es->s_last_orphan) {
1711                 struct inode *inode;
1712
1713                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
1714                 if (IS_ERR(inode)) {
1715                         es->s_last_orphan = 0;
1716                         break;
1717                 }
1718
1719                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1720                 DQUOT_INIT(inode);
1721                 if (inode->i_nlink) {
1722                         printk(KERN_DEBUG
1723                                 "%s: truncating inode %lu to %lld bytes\n",
1724                                 __func__, inode->i_ino, inode->i_size);
1725                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
1726                                   inode->i_ino, inode->i_size);
1727                         ext4_truncate(inode);
1728                         nr_truncates++;
1729                 } else {
1730                         printk(KERN_DEBUG
1731                                 "%s: deleting unreferenced inode %lu\n",
1732                                 __func__, inode->i_ino);
1733                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1734                                   inode->i_ino);
1735                         nr_orphans++;
1736                 }
1737                 iput(inode);  /* The delete magic happens here! */
1738         }
1739
1740 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
1741
1742         if (nr_orphans)
1743                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1744                        sb->s_id, PLURAL(nr_orphans));
1745         if (nr_truncates)
1746                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1747                        sb->s_id, PLURAL(nr_truncates));
1748 #ifdef CONFIG_QUOTA
1749         /* Turn quotas off */
1750         for (i = 0; i < MAXQUOTAS; i++) {
1751                 if (sb_dqopt(sb)->files[i])
1752                         vfs_quota_off(sb, i, 0);
1753         }
1754 #endif
1755         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1756 }
1757 /*
1758  * Maximal extent format file size.
1759  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1760  * extent format containers, within a sector_t, and within i_blocks
1761  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1762  * so that won't be a limiting factor.
1763  *
1764  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1765  */
1766 static loff_t ext4_max_size(int blkbits)
1767 {
1768         loff_t res;
1769         loff_t upper_limit = MAX_LFS_FILESIZE;
1770
1771         /* small i_blocks in vfs inode? */
1772         if (sizeof(blkcnt_t) < sizeof(u64)) {
1773                 /*
1774                  * CONFIG_LSF is not enabled implies the inode
1775                  * i_block represent total blocks in 512 bytes
1776                  * 32 == size of vfs inode i_blocks * 8
1777                  */
1778                 upper_limit = (1LL << 32) - 1;
1779
1780                 /* total blocks in file system block size */
1781                 upper_limit >>= (blkbits - 9);
1782                 upper_limit <<= blkbits;
1783         }
1784
1785         /* 32-bit extent-start container, ee_block */
1786         res = 1LL << 32;
1787         res <<= blkbits;
1788         res -= 1;
1789
1790         /* Sanity check against vm- & vfs- imposed limits */
1791         if (res > upper_limit)
1792                 res = upper_limit;
1793
1794         return res;
1795 }
1796
1797 /*
1798  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
1799  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
1800  * We need to be 1 filesystem block less than the 2^48 sector limit.
1801  */
1802 static loff_t ext4_max_bitmap_size(int bits)
1803 {
1804         loff_t res = EXT4_NDIR_BLOCKS;
1805         int meta_blocks;
1806         loff_t upper_limit;
1807         /* This is calculated to be the largest file size for a
1808          * dense, bitmapped file such that the total number of
1809          * sectors in the file, including data and all indirect blocks,
1810          * does not exceed 2^48 -1
1811          * __u32 i_blocks_lo and _u16 i_blocks_high representing the
1812          * total number of  512 bytes blocks of the file
1813          */
1814
1815         if (sizeof(blkcnt_t) < sizeof(u64)) {
1816                 /*
1817                  * CONFIG_LSF is not enabled implies the inode
1818                  * i_block represent total blocks in 512 bytes
1819                  * 32 == size of vfs inode i_blocks * 8
1820                  */
1821                 upper_limit = (1LL << 32) - 1;
1822
1823                 /* total blocks in file system block size */
1824                 upper_limit >>= (bits - 9);
1825
1826         } else {
1827                 /*
1828                  * We use 48 bit ext4_inode i_blocks
1829                  * With EXT4_HUGE_FILE_FL set the i_blocks
1830                  * represent total number of blocks in
1831                  * file system block size
1832                  */
1833                 upper_limit = (1LL << 48) - 1;
1834
1835         }
1836
1837         /* indirect blocks */
1838         meta_blocks = 1;
1839         /* double indirect blocks */
1840         meta_blocks += 1 + (1LL << (bits-2));
1841         /* tripple indirect blocks */
1842         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
1843
1844         upper_limit -= meta_blocks;
1845         upper_limit <<= bits;
1846
1847         res += 1LL << (bits-2);
1848         res += 1LL << (2*(bits-2));
1849         res += 1LL << (3*(bits-2));
1850         res <<= bits;
1851         if (res > upper_limit)
1852                 res = upper_limit;
1853
1854         if (res > MAX_LFS_FILESIZE)
1855                 res = MAX_LFS_FILESIZE;
1856
1857         return res;
1858 }
1859
1860 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1861                                 ext4_fsblk_t logical_sb_block, int nr)
1862 {
1863         struct ext4_sb_info *sbi = EXT4_SB(sb);
1864         ext4_group_t bg, first_meta_bg;
1865         int has_super = 0;
1866
1867         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1868
1869         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1870             nr < first_meta_bg)
1871                 return logical_sb_block + nr + 1;
1872         bg = sbi->s_desc_per_block * nr;
1873         if (ext4_bg_has_super(sb, bg))
1874                 has_super = 1;
1875         return (has_super + ext4_group_first_block_no(sb, bg));
1876 }
1877
1878 /**
1879  * ext4_get_stripe_size: Get the stripe size.
1880  * @sbi: In memory super block info
1881  *
1882  * If we have specified it via mount option, then
1883  * use the mount option value. If the value specified at mount time is
1884  * greater than the blocks per group use the super block value.
1885  * If the super block value is greater than blocks per group return 0.
1886  * Allocator needs it be less than blocks per group.
1887  *
1888  */
1889 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
1890 {
1891         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
1892         unsigned long stripe_width =
1893                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
1894
1895         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
1896                 return sbi->s_stripe;
1897
1898         if (stripe_width <= sbi->s_blocks_per_group)
1899                 return stripe_width;
1900
1901         if (stride <= sbi->s_blocks_per_group)
1902                 return stride;
1903
1904         return 0;
1905 }
1906
1907 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
1908                                 __releases(kernel_lock)
1909                                 __acquires(kernel_lock)
1910
1911 {
1912         struct buffer_head *bh;
1913         struct ext4_super_block *es = NULL;
1914         struct ext4_sb_info *sbi;
1915         ext4_fsblk_t block;
1916         ext4_fsblk_t sb_block = get_sb_block(&data);
1917         ext4_fsblk_t logical_sb_block;
1918         unsigned long offset = 0;
1919         unsigned int journal_inum = 0;
1920         unsigned long journal_devnum = 0;
1921         unsigned long def_mount_opts;
1922         struct inode *root;
1923         int ret = -EINVAL;
1924         int blocksize;
1925         int db_count;
1926         int i;
1927         int needs_recovery;
1928         __le32 features;
1929         __u64 blocks_count;
1930         int err;
1931
1932         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1933         if (!sbi)
1934                 return -ENOMEM;
1935         sb->s_fs_info = sbi;
1936         sbi->s_mount_opt = 0;
1937         sbi->s_resuid = EXT4_DEF_RESUID;
1938         sbi->s_resgid = EXT4_DEF_RESGID;
1939         sbi->s_sb_block = sb_block;
1940
1941         unlock_kernel();
1942
1943         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1944         if (!blocksize) {
1945                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1946                 goto out_fail;
1947         }
1948
1949         /*
1950          * The ext4 superblock will not be buffer aligned for other than 1kB
1951          * block sizes.  We need to calculate the offset from buffer start.
1952          */
1953         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1954                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1955                 offset = do_div(logical_sb_block, blocksize);
1956         } else {
1957                 logical_sb_block = sb_block;
1958         }
1959
1960         if (!(bh = sb_bread(sb, logical_sb_block))) {
1961                 printk(KERN_ERR "EXT4-fs: unable to read superblock\n");
1962                 goto out_fail;
1963         }
1964         /*
1965          * Note: s_es must be initialized as soon as possible because
1966          *       some ext4 macro-instructions depend on its value
1967          */
1968         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1969         sbi->s_es = es;
1970         sb->s_magic = le16_to_cpu(es->s_magic);
1971         if (sb->s_magic != EXT4_SUPER_MAGIC)
1972                 goto cantfind_ext4;
1973
1974         /* Set defaults before we parse the mount options */
1975         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1976         if (def_mount_opts & EXT4_DEFM_DEBUG)
1977                 set_opt(sbi->s_mount_opt, DEBUG);
1978         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1979                 set_opt(sbi->s_mount_opt, GRPID);
1980         if (def_mount_opts & EXT4_DEFM_UID16)
1981                 set_opt(sbi->s_mount_opt, NO_UID32);
1982 #ifdef CONFIG_EXT4DEV_FS_XATTR
1983         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1984                 set_opt(sbi->s_mount_opt, XATTR_USER);
1985 #endif
1986 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1987         if (def_mount_opts & EXT4_DEFM_ACL)
1988                 set_opt(sbi->s_mount_opt, POSIX_ACL);
1989 #endif
1990         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1991                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1992         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1993                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1994         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1995                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1996
1997         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1998                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1999         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
2000                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
2001         else
2002                 set_opt(sbi->s_mount_opt, ERRORS_RO);
2003
2004         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
2005         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
2006
2007         set_opt(sbi->s_mount_opt, RESERVATION);
2008         set_opt(sbi->s_mount_opt, BARRIER);
2009
2010         /*
2011          * turn on extents feature by default in ext4 filesystem
2012          * only if feature flag already set by mkfs or tune2fs.
2013          * Use -o noextents to turn it off
2014          */
2015         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
2016                 set_opt(sbi->s_mount_opt, EXTENTS);
2017         else
2018                 ext4_warning(sb, __func__,
2019                         "extents feature not enabled on this filesystem, "
2020                         "use tune2fs.\n");
2021         /*
2022          * turn on mballoc code by default in ext4 filesystem
2023          * Use -o nomballoc to turn it off
2024          */
2025         set_opt(sbi->s_mount_opt, MBALLOC);
2026
2027         /*
2028          * enable delayed allocation by default
2029          * Use -o nodelalloc to turn it off
2030          */
2031         set_opt(sbi->s_mount_opt, DELALLOC);
2032
2033
2034         if (!parse_options((char *) data, sb, &journal_inum, &journal_devnum,
2035                            NULL, 0))
2036                 goto failed_mount;
2037
2038         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2039                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2040
2041         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
2042             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
2043              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
2044              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
2045                 printk(KERN_WARNING
2046                        "EXT4-fs warning: feature flags set on rev 0 fs, "
2047                        "running e2fsck is recommended\n");
2048
2049         /*
2050          * Since ext4 is still considered development code, we require
2051          * that the TEST_FILESYS flag in s->flags be set.
2052          */
2053         if (!(le32_to_cpu(es->s_flags) & EXT2_FLAGS_TEST_FILESYS)) {
2054                 printk(KERN_WARNING "EXT4-fs: %s: not marked "
2055                        "OK to use with test code.\n", sb->s_id);
2056                 goto failed_mount;
2057         }
2058
2059         /*
2060          * Check feature flags regardless of the revision level, since we
2061          * previously didn't change the revision level when setting the flags,
2062          * so there is a chance incompat flags are set on a rev 0 filesystem.
2063          */
2064         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
2065         if (features) {
2066                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
2067                        "unsupported optional features (%x).\n",
2068                        sb->s_id, le32_to_cpu(features));
2069                 goto failed_mount;
2070         }
2071         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
2072         if (!(sb->s_flags & MS_RDONLY) && features) {
2073                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
2074                        "unsupported optional features (%x).\n",
2075                        sb->s_id, le32_to_cpu(features));
2076                 goto failed_mount;
2077         }
2078         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2079                 /*
2080                  * Large file size enabled file system can only be
2081                  * mount if kernel is build with CONFIG_LSF
2082                  */
2083                 if (sizeof(root->i_blocks) < sizeof(u64) &&
2084                                 !(sb->s_flags & MS_RDONLY)) {
2085                         printk(KERN_ERR "EXT4-fs: %s: Filesystem with huge "
2086                                         "files cannot be mounted read-write "
2087                                         "without CONFIG_LSF.\n", sb->s_id);
2088                         goto failed_mount;
2089                 }
2090         }
2091         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
2092
2093         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
2094             blocksize > EXT4_MAX_BLOCK_SIZE) {
2095                 printk(KERN_ERR
2096                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
2097                        blocksize, sb->s_id);
2098                 goto failed_mount;
2099         }
2100
2101         if (sb->s_blocksize != blocksize) {
2102
2103                 /* Validate the filesystem blocksize */
2104                 if (!sb_set_blocksize(sb, blocksize)) {
2105                         printk(KERN_ERR "EXT4-fs: bad block size %d.\n",
2106                                         blocksize);
2107                         goto failed_mount;
2108                 }
2109
2110                 brelse(bh);
2111                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2112                 offset = do_div(logical_sb_block, blocksize);
2113                 bh = sb_bread(sb, logical_sb_block);
2114                 if (!bh) {
2115                         printk(KERN_ERR
2116                                "EXT4-fs: Can't read superblock on 2nd try.\n");
2117                         goto failed_mount;
2118                 }
2119                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
2120                 sbi->s_es = es;
2121                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
2122                         printk(KERN_ERR
2123                                "EXT4-fs: Magic mismatch, very weird !\n");
2124                         goto failed_mount;
2125                 }
2126         }
2127
2128         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits);
2129         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
2130
2131         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2132                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2133                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2134         } else {
2135                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2136                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2137                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2138                     (!is_power_of_2(sbi->s_inode_size)) ||
2139                     (sbi->s_inode_size > blocksize)) {
2140                         printk(KERN_ERR
2141                                "EXT4-fs: unsupported inode size: %d\n",
2142                                sbi->s_inode_size);
2143                         goto failed_mount;
2144                 }
2145                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2146                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2147         }
2148         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2149         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2150                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2151                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2152                     !is_power_of_2(sbi->s_desc_size)) {
2153                         printk(KERN_ERR
2154                                "EXT4-fs: unsupported descriptor size %lu\n",
2155                                sbi->s_desc_size);
2156                         goto failed_mount;
2157                 }
2158         } else
2159                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2160         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2161         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2162         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2163                 goto cantfind_ext4;
2164         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2165         if (sbi->s_inodes_per_block == 0)
2166                 goto cantfind_ext4;
2167         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2168                                         sbi->s_inodes_per_block;
2169         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2170         sbi->s_sbh = bh;
2171         sbi->s_mount_state = le16_to_cpu(es->s_state);
2172         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2173         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2174         for (i = 0; i < 4; i++)
2175                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2176         sbi->s_def_hash_version = es->s_def_hash_version;
2177
2178         if (sbi->s_blocks_per_group > blocksize * 8) {
2179                 printk(KERN_ERR
2180                        "EXT4-fs: #blocks per group too big: %lu\n",
2181                        sbi->s_blocks_per_group);
2182                 goto failed_mount;
2183         }
2184         if (sbi->s_inodes_per_group > blocksize * 8) {
2185                 printk(KERN_ERR
2186                        "EXT4-fs: #inodes per group too big: %lu\n",
2187                        sbi->s_inodes_per_group);
2188                 goto failed_mount;
2189         }
2190
2191         if (ext4_blocks_count(es) >
2192                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
2193                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
2194                         " too large to mount safely\n", sb->s_id);
2195                 if (sizeof(sector_t) < 8)
2196                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
2197                                         "enabled\n");
2198                 goto failed_mount;
2199         }
2200
2201         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2202                 goto cantfind_ext4;
2203
2204         /* ensure blocks_count calculation below doesn't sign-extend */
2205         if (ext4_blocks_count(es) + EXT4_BLOCKS_PER_GROUP(sb) <
2206             le32_to_cpu(es->s_first_data_block) + 1) {
2207                 printk(KERN_WARNING "EXT4-fs: bad geometry: block count %llu, "
2208                        "first data block %u, blocks per group %lu\n",
2209                         ext4_blocks_count(es),
2210                         le32_to_cpu(es->s_first_data_block),
2211                         EXT4_BLOCKS_PER_GROUP(sb));
2212                 goto failed_mount;
2213         }
2214         blocks_count = (ext4_blocks_count(es) -
2215                         le32_to_cpu(es->s_first_data_block) +
2216                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2217         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2218         sbi->s_groups_count = blocks_count;
2219         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2220                    EXT4_DESC_PER_BLOCK(sb);
2221         sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
2222                                     GFP_KERNEL);
2223         if (sbi->s_group_desc == NULL) {
2224                 printk(KERN_ERR "EXT4-fs: not enough memory\n");
2225                 goto failed_mount;
2226         }
2227
2228         bgl_lock_init(&sbi->s_blockgroup_lock);
2229
2230         for (i = 0; i < db_count; i++) {
2231                 block = descriptor_loc(sb, logical_sb_block, i);
2232                 sbi->s_group_desc[i] = sb_bread(sb, block);
2233                 if (!sbi->s_group_desc[i]) {
2234                         printk(KERN_ERR "EXT4-fs: "
2235                                "can't read group descriptor %d\n", i);
2236                         db_count = i;
2237                         goto failed_mount2;
2238                 }
2239         }
2240         if (!ext4_check_descriptors(sb)) {
2241                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
2242                 goto failed_mount2;
2243         }
2244         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2245                 if (!ext4_fill_flex_info(sb)) {
2246                         printk(KERN_ERR
2247                                "EXT4-fs: unable to initialize "
2248                                "flex_bg meta info!\n");
2249                         goto failed_mount2;
2250                 }
2251
2252         sbi->s_gdb_count = db_count;
2253         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2254         spin_lock_init(&sbi->s_next_gen_lock);
2255
2256         err = percpu_counter_init(&sbi->s_freeblocks_counter,
2257                         ext4_count_free_blocks(sb));
2258         if (!err) {
2259                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
2260                                 ext4_count_free_inodes(sb));
2261         }
2262         if (!err) {
2263                 err = percpu_counter_init(&sbi->s_dirs_counter,
2264                                 ext4_count_dirs(sb));
2265         }
2266         if (!err) {
2267                 err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
2268         }
2269         if (err) {
2270                 printk(KERN_ERR "EXT4-fs: insufficient memory\n");
2271                 goto failed_mount3;
2272         }
2273
2274         /* per fileystem reservation list head & lock */
2275         spin_lock_init(&sbi->s_rsv_window_lock);
2276         sbi->s_rsv_window_root = RB_ROOT;
2277         /* Add a single, static dummy reservation to the start of the
2278          * reservation window list --- it gives us a placeholder for
2279          * append-at-start-of-list which makes the allocation logic
2280          * _much_ simpler. */
2281         sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
2282         sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
2283         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
2284         sbi->s_rsv_window_head.rsv_goal_size = 0;
2285         ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
2286
2287         sbi->s_stripe = ext4_get_stripe_size(sbi);
2288
2289         /*
2290          * set up enough so that it can read an inode
2291          */
2292         sb->s_op = &ext4_sops;
2293         sb->s_export_op = &ext4_export_ops;
2294         sb->s_xattr = ext4_xattr_handlers;
2295 #ifdef CONFIG_QUOTA
2296         sb->s_qcop = &ext4_qctl_operations;
2297         sb->dq_op = &ext4_quota_operations;
2298 #endif
2299         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2300
2301         sb->s_root = NULL;
2302
2303         needs_recovery = (es->s_last_orphan != 0 ||
2304                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2305                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2306
2307         /*
2308          * The first inode we look at is the journal inode.  Don't try
2309          * root first: it may be modified in the journal!
2310          */
2311         if (!test_opt(sb, NOLOAD) &&
2312             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2313                 if (ext4_load_journal(sb, es, journal_devnum))
2314                         goto failed_mount3;
2315                 if (!(sb->s_flags & MS_RDONLY) &&
2316                     EXT4_SB(sb)->s_journal->j_failed_commit) {
2317                         printk(KERN_CRIT "EXT4-fs error (device %s): "
2318                                "ext4_fill_super: Journal transaction "
2319                                "%u is corrupt\n", sb->s_id,
2320                                EXT4_SB(sb)->s_journal->j_failed_commit);
2321                         if (test_opt(sb, ERRORS_RO)) {
2322                                 printk(KERN_CRIT
2323                                        "Mounting filesystem read-only\n");
2324                                 sb->s_flags |= MS_RDONLY;
2325                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2326                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2327                         }
2328                         if (test_opt(sb, ERRORS_PANIC)) {
2329                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2330                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2331                                 ext4_commit_super(sb, es, 1);
2332                                 printk(KERN_CRIT
2333                                        "EXT4-fs (device %s): mount failed\n",
2334                                       sb->s_id);
2335                                 goto failed_mount4;
2336                         }
2337                 }
2338         } else if (journal_inum) {
2339                 if (ext4_create_journal(sb, es, journal_inum))
2340                         goto failed_mount3;
2341         } else {
2342                 if (!silent)
2343                         printk(KERN_ERR
2344                                "ext4: No journal on filesystem on %s\n",
2345                                sb->s_id);
2346                 goto failed_mount3;
2347         }
2348
2349         if (ext4_blocks_count(es) > 0xffffffffULL &&
2350             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2351                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2352                 printk(KERN_ERR "ext4: Failed to set 64-bit journal feature\n");
2353                 goto failed_mount4;
2354         }
2355
2356         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2357                 jbd2_journal_set_features(sbi->s_journal,
2358                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2359                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2360         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2361                 jbd2_journal_set_features(sbi->s_journal,
2362                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2363                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2364                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2365         } else {
2366                 jbd2_journal_clear_features(sbi->s_journal,
2367                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2368                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2369         }
2370
2371         /* We have now updated the journal if required, so we can
2372          * validate the data journaling mode. */
2373         switch (test_opt(sb, DATA_FLAGS)) {
2374         case 0:
2375                 /* No mode set, assume a default based on the journal
2376                  * capabilities: ORDERED_DATA if the journal can
2377                  * cope, else JOURNAL_DATA
2378                  */
2379                 if (jbd2_journal_check_available_features
2380                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2381                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
2382                 else
2383                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2384                 break;
2385
2386         case EXT4_MOUNT_ORDERED_DATA:
2387         case EXT4_MOUNT_WRITEBACK_DATA:
2388                 if (!jbd2_journal_check_available_features
2389                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2390                         printk(KERN_ERR "EXT4-fs: Journal does not support "
2391                                "requested data journaling mode\n");
2392                         goto failed_mount4;
2393                 }
2394         default:
2395                 break;
2396         }
2397
2398         if (test_opt(sb, NOBH)) {
2399                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2400                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
2401                                 "its supported only with writeback mode\n");
2402                         clear_opt(sbi->s_mount_opt, NOBH);
2403                 }
2404         }
2405         /*
2406          * The jbd2_journal_load will have done any necessary log recovery,
2407          * so we can safely mount the rest of the filesystem now.
2408          */
2409
2410         root = ext4_iget(sb, EXT4_ROOT_INO);
2411         if (IS_ERR(root)) {
2412                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
2413                 ret = PTR_ERR(root);
2414                 goto failed_mount4;
2415         }
2416         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2417                 iput(root);
2418                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
2419                 goto failed_mount4;
2420         }
2421         sb->s_root = d_alloc_root(root);
2422         if (!sb->s_root) {
2423                 printk(KERN_ERR "EXT4-fs: get root dentry failed\n");
2424                 iput(root);
2425                 ret = -ENOMEM;
2426                 goto failed_mount4;
2427         }
2428
2429         ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
2430
2431         /* determine the minimum size of new large inodes, if present */
2432         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2433                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2434                                                      EXT4_GOOD_OLD_INODE_SIZE;
2435                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2436                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2437                         if (sbi->s_want_extra_isize <
2438                             le16_to_cpu(es->s_want_extra_isize))
2439                                 sbi->s_want_extra_isize =
2440                                         le16_to_cpu(es->s_want_extra_isize);
2441                         if (sbi->s_want_extra_isize <
2442                             le16_to_cpu(es->s_min_extra_isize))
2443                                 sbi->s_want_extra_isize =
2444                                         le16_to_cpu(es->s_min_extra_isize);
2445                 }
2446         }
2447         /* Check if enough inode space is available */
2448         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2449                                                         sbi->s_inode_size) {
2450                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2451                                                        EXT4_GOOD_OLD_INODE_SIZE;
2452                 printk(KERN_INFO "EXT4-fs: required extra inode space not"
2453                         "available.\n");
2454         }
2455
2456         /*
2457          * akpm: core read_super() calls in here with the superblock locked.
2458          * That deadlocks, because orphan cleanup needs to lock the superblock
2459          * in numerous places.  Here we just pop the lock - it's relatively
2460          * harmless, because we are now ready to accept write_super() requests,
2461          * and aviro says that's the only reason for hanging onto the
2462          * superblock lock.
2463          */
2464         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2465         ext4_orphan_cleanup(sb, es);
2466         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2467         if (needs_recovery)
2468                 printk(KERN_INFO "EXT4-fs: recovery complete.\n");
2469         ext4_mark_recovery_complete(sb, es);
2470         printk(KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
2471                test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
2472                test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
2473                "writeback");
2474
2475         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
2476                 printk(KERN_WARNING "EXT4-fs: Ignoring delalloc option - "
2477                                 "requested data journaling mode\n");
2478                 clear_opt(sbi->s_mount_opt, DELALLOC);
2479         } else if (test_opt(sb, DELALLOC))
2480                 printk(KERN_INFO "EXT4-fs: delayed allocation enabled\n");
2481
2482         ext4_ext_init(sb);
2483         ext4_mb_init(sb, needs_recovery);
2484
2485         lock_kernel();
2486         return 0;
2487
2488 cantfind_ext4:
2489         if (!silent)
2490                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
2491                        sb->s_id);
2492         goto failed_mount;
2493
2494 failed_mount4:
2495         jbd2_journal_destroy(sbi->s_journal);
2496         sbi->s_journal = NULL;
2497 failed_mount3:
2498         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2499         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2500         percpu_counter_destroy(&sbi->s_dirs_counter);
2501         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
2502 failed_mount2:
2503         for (i = 0; i < db_count; i++)
2504                 brelse(sbi->s_group_desc[i]);
2505         kfree(sbi->s_group_desc);
2506 failed_mount:
2507 #ifdef CONFIG_QUOTA
2508         for (i = 0; i < MAXQUOTAS; i++)
2509                 kfree(sbi->s_qf_names[i]);
2510 #endif
2511         ext4_blkdev_remove(sbi);
2512         brelse(bh);
2513 out_fail:
2514         sb->s_fs_info = NULL;
2515         kfree(sbi);
2516         lock_kernel();
2517         return ret;
2518 }
2519
2520 /*
2521  * Setup any per-fs journal parameters now.  We'll do this both on
2522  * initial mount, once the journal has been initialised but before we've
2523  * done any recovery; and again on any subsequent remount.
2524  */
2525 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2526 {
2527         struct ext4_sb_info *sbi = EXT4_SB(sb);
2528
2529         if (sbi->s_commit_interval)
2530                 journal->j_commit_interval = sbi->s_commit_interval;
2531         /* We could also set up an ext4-specific default for the commit
2532          * interval here, but for now we'll just fall back to the jbd
2533          * default. */
2534
2535         spin_lock(&journal->j_state_lock);
2536         if (test_opt(sb, BARRIER))
2537                 journal->j_flags |= JBD2_BARRIER;
2538         else
2539                 journal->j_flags &= ~JBD2_BARRIER;
2540         spin_unlock(&journal->j_state_lock);
2541 }
2542
2543 static journal_t *ext4_get_journal(struct super_block *sb,
2544                                    unsigned int journal_inum)
2545 {
2546         struct inode *journal_inode;
2547         journal_t *journal;
2548
2549         /* First, test for the existence of a valid inode on disk.  Bad
2550          * things happen if we iget() an unused inode, as the subsequent
2551          * iput() will try to delete it. */
2552
2553         journal_inode = ext4_iget(sb, journal_inum);
2554         if (IS_ERR(journal_inode)) {
2555                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
2556                 return NULL;
2557         }
2558         if (!journal_inode->i_nlink) {
2559                 make_bad_inode(journal_inode);
2560                 iput(journal_inode);
2561                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
2562                 return NULL;
2563         }
2564
2565         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
2566                   journal_inode, journal_inode->i_size);
2567         if (!S_ISREG(journal_inode->i_mode)) {
2568                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
2569                 iput(journal_inode);
2570                 return NULL;
2571         }
2572
2573         journal = jbd2_journal_init_inode(journal_inode);
2574         if (!journal) {
2575                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
2576                 iput(journal_inode);
2577                 return NULL;
2578         }
2579         journal->j_private = sb;
2580         ext4_init_journal_params(sb, journal);
2581         return journal;
2582 }
2583
2584 static journal_t *ext4_get_dev_journal(struct super_block *sb,
2585                                        dev_t j_dev)
2586 {
2587         struct buffer_head *bh;
2588         journal_t *journal;
2589         ext4_fsblk_t start;
2590         ext4_fsblk_t len;
2591         int hblock, blocksize;
2592         ext4_fsblk_t sb_block;
2593         unsigned long offset;
2594         struct ext4_super_block *es;
2595         struct block_device *bdev;
2596
2597         bdev = ext4_blkdev_get(j_dev);
2598         if (bdev == NULL)
2599                 return NULL;
2600
2601         if (bd_claim(bdev, sb)) {
2602                 printk(KERN_ERR
2603                         "EXT4: failed to claim external journal device.\n");
2604                 blkdev_put(bdev);
2605                 return NULL;
2606         }
2607
2608         blocksize = sb->s_blocksize;
2609         hblock = bdev_hardsect_size(bdev);
2610         if (blocksize < hblock) {
2611                 printk(KERN_ERR
2612                         "EXT4-fs: blocksize too small for journal device.\n");
2613                 goto out_bdev;
2614         }
2615
2616         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2617         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2618         set_blocksize(bdev, blocksize);
2619         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2620                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2621                        "external journal\n");
2622                 goto out_bdev;
2623         }
2624
2625         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2626         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2627             !(le32_to_cpu(es->s_feature_incompat) &
2628               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2629                 printk(KERN_ERR "EXT4-fs: external journal has "
2630                                         "bad superblock\n");
2631                 brelse(bh);
2632                 goto out_bdev;
2633         }
2634
2635         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2636                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2637                 brelse(bh);
2638                 goto out_bdev;
2639         }
2640
2641         len = ext4_blocks_count(es);
2642         start = sb_block + 1;
2643         brelse(bh);     /* we're done with the superblock */
2644
2645         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2646                                         start, len, blocksize);
2647         if (!journal) {
2648                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2649                 goto out_bdev;
2650         }
2651         journal->j_private = sb;
2652         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2653         wait_on_buffer(journal->j_sb_buffer);
2654         if (!buffer_uptodate(journal->j_sb_buffer)) {
2655                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2656                 goto out_journal;
2657         }
2658         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2659                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2660                                         "user (unsupported) - %d\n",
2661                         be32_to_cpu(journal->j_superblock->s_nr_users));
2662                 goto out_journal;
2663         }
2664         EXT4_SB(sb)->journal_bdev = bdev;
2665         ext4_init_journal_params(sb, journal);
2666         return journal;
2667 out_journal:
2668         jbd2_journal_destroy(journal);
2669 out_bdev:
2670         ext4_blkdev_put(bdev);
2671         return NULL;
2672 }
2673
2674 static int ext4_load_journal(struct super_block *sb,
2675                              struct ext4_super_block *es,
2676                              unsigned long journal_devnum)
2677 {
2678         journal_t *journal;
2679         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2680         dev_t journal_dev;
2681         int err = 0;
2682         int really_read_only;
2683
2684         if (journal_devnum &&
2685             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2686                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2687                         "numbers have changed\n");
2688                 journal_dev = new_decode_dev(journal_devnum);
2689         } else
2690                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2691
2692         really_read_only = bdev_read_only(sb->s_bdev);
2693
2694         /*
2695          * Are we loading a blank journal or performing recovery after a
2696          * crash?  For recovery, we need to check in advance whether we
2697          * can get read-write access to the device.
2698          */
2699
2700         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2701                 if (sb->s_flags & MS_RDONLY) {
2702                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2703                                         "required on readonly filesystem.\n");
2704                         if (really_read_only) {
2705                                 printk(KERN_ERR "EXT4-fs: write access "
2706                                         "unavailable, cannot proceed.\n");
2707                                 return -EROFS;
2708                         }
2709                         printk(KERN_INFO "EXT4-fs: write access will "
2710                                "be enabled during recovery.\n");
2711                 }
2712         }
2713
2714         if (journal_inum && journal_dev) {
2715                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2716                        "and inode journals!\n");
2717                 return -EINVAL;
2718         }
2719
2720         if (journal_inum) {
2721                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2722                         return -EINVAL;
2723         } else {
2724                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2725                         return -EINVAL;
2726         }
2727
2728         if (journal->j_flags & JBD2_BARRIER)
2729                 printk(KERN_INFO "EXT4-fs: barriers enabled\n");
2730         else
2731                 printk(KERN_INFO "EXT4-fs: barriers disabled\n");
2732
2733         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2734                 err = jbd2_journal_update_format(journal);
2735                 if (err)  {
2736                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2737                         jbd2_journal_destroy(journal);
2738                         return err;
2739                 }
2740         }
2741
2742         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2743                 err = jbd2_journal_wipe(journal, !really_read_only);
2744         if (!err)
2745                 err = jbd2_journal_load(journal);
2746
2747         if (err) {
2748                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2749                 jbd2_journal_destroy(journal);
2750                 return err;
2751         }
2752
2753         EXT4_SB(sb)->s_journal = journal;
2754         ext4_clear_journal_err(sb, es);
2755
2756         if (journal_devnum &&
2757             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2758                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2759                 sb->s_dirt = 1;
2760
2761                 /* Make sure we flush the recovery flag to disk. */
2762                 ext4_commit_super(sb, es, 1);
2763         }
2764
2765         return 0;
2766 }
2767
2768 static int ext4_create_journal(struct super_block *sb,
2769                                struct ext4_super_block *es,
2770                                unsigned int journal_inum)
2771 {
2772         journal_t *journal;
2773         int err;
2774
2775         if (sb->s_flags & MS_RDONLY) {
2776                 printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2777                                 "create journal.\n");
2778                 return -EROFS;
2779         }
2780
2781         journal = ext4_get_journal(sb, journal_inum);
2782         if (!journal)
2783                 return -EINVAL;
2784
2785         printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2786                journal_inum);
2787
2788         err = jbd2_journal_create(journal);
2789         if (err) {
2790                 printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2791                 jbd2_journal_destroy(journal);
2792                 return -EIO;
2793         }
2794
2795         EXT4_SB(sb)->s_journal = journal;
2796
2797         ext4_update_dynamic_rev(sb);
2798         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2799         EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2800
2801         es->s_journal_inum = cpu_to_le32(journal_inum);
2802         sb->s_dirt = 1;
2803
2804         /* Make sure we flush the recovery flag to disk. */
2805         ext4_commit_super(sb, es, 1);
2806
2807         return 0;
2808 }
2809
2810 static void ext4_commit_super(struct super_block *sb,
2811                               struct ext4_super_block *es, int sync)
2812 {
2813         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2814
2815         if (!sbh)
2816                 return;
2817         es->s_wtime = cpu_to_le32(get_seconds());
2818         ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2819         es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2820         BUFFER_TRACE(sbh, "marking dirty");
2821         mark_buffer_dirty(sbh);
2822         if (sync)
2823                 sync_dirty_buffer(sbh);
2824 }
2825
2826
2827 /*
2828  * Have we just finished recovery?  If so, and if we are mounting (or
2829  * remounting) the filesystem readonly, then we will end up with a
2830  * consistent fs on disk.  Record that fact.
2831  */
2832 static void ext4_mark_recovery_complete(struct super_block *sb,
2833                                         struct ext4_super_block *es)
2834 {
2835         journal_t *journal = EXT4_SB(sb)->s_journal;
2836
2837         jbd2_journal_lock_updates(journal);
2838         jbd2_journal_flush(journal);
2839         lock_super(sb);
2840         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2841             sb->s_flags & MS_RDONLY) {
2842                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2843                 sb->s_dirt = 0;
2844                 ext4_commit_super(sb, es, 1);
2845         }
2846         unlock_super(sb);
2847         jbd2_journal_unlock_updates(journal);
2848 }
2849
2850 /*
2851  * If we are mounting (or read-write remounting) a filesystem whose journal
2852  * has recorded an error from a previous lifetime, move that error to the
2853  * main filesystem now.
2854  */
2855 static void ext4_clear_journal_err(struct super_block *sb,
2856                                    struct ext4_super_block *es)
2857 {
2858         journal_t *journal;
2859         int j_errno;
2860         const char *errstr;
2861
2862         journal = EXT4_SB(sb)->s_journal;
2863
2864         /*
2865          * Now check for any error status which may have been recorded in the
2866          * journal by a prior ext4_error() or ext4_abort()
2867          */
2868
2869         j_errno = jbd2_journal_errno(journal);
2870         if (j_errno) {
2871                 char nbuf[16];
2872
2873                 errstr = ext4_decode_error(sb, j_errno, nbuf);
2874                 ext4_warning(sb, __func__, "Filesystem error recorded "
2875                              "from previous mount: %s", errstr);
2876                 ext4_warning(sb, __func__, "Marking fs in need of "
2877                              "filesystem check.");
2878
2879                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2880                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2881                 ext4_commit_super(sb, es, 1);
2882
2883                 jbd2_journal_clear_err(journal);
2884         }
2885 }
2886
2887 /*
2888  * Force the running and committing transactions to commit,
2889  * and wait on the commit.
2890  */
2891 int ext4_force_commit(struct super_block *sb)
2892 {
2893         journal_t *journal;
2894         int ret;
2895
2896         if (sb->s_flags & MS_RDONLY)
2897                 return 0;
2898
2899         journal = EXT4_SB(sb)->s_journal;
2900         sb->s_dirt = 0;
2901         ret = ext4_journal_force_commit(journal);
2902         return ret;
2903 }
2904
2905 /*
2906  * Ext4 always journals updates to the superblock itself, so we don't
2907  * have to propagate any other updates to the superblock on disk at this
2908  * point.  Just start an async writeback to get the buffers on their way
2909  * to the disk.
2910  *
2911  * This implicitly triggers the writebehind on sync().
2912  */
2913
2914 static void ext4_write_super(struct super_block *sb)
2915 {
2916         if (mutex_trylock(&sb->s_lock) != 0)
2917                 BUG();
2918         sb->s_dirt = 0;
2919 }
2920
2921 static int ext4_sync_fs(struct super_block *sb, int wait)
2922 {
2923         tid_t target;
2924
2925         sb->s_dirt = 0;
2926         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2927                 if (wait)
2928                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2929         }
2930         return 0;
2931 }
2932
2933 /*
2934  * LVM calls this function before a (read-only) snapshot is created.  This
2935  * gives us a chance to flush the journal completely and mark the fs clean.
2936  */
2937 static void ext4_write_super_lockfs(struct super_block *sb)
2938 {
2939         sb->s_dirt = 0;
2940
2941         if (!(sb->s_flags & MS_RDONLY)) {
2942                 journal_t *journal = EXT4_SB(sb)->s_journal;
2943
2944                 /* Now we set up the journal barrier. */
2945                 jbd2_journal_lock_updates(journal);
2946                 jbd2_journal_flush(journal);
2947
2948                 /* Journal blocked and flushed, clear needs_recovery flag. */
2949                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2950                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2951         }
2952 }
2953
2954 /*
2955  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2956  * flag here, even though the filesystem is not technically dirty yet.
2957  */
2958 static void ext4_unlockfs(struct super_block *sb)
2959 {
2960         if (!(sb->s_flags & MS_RDONLY)) {
2961                 lock_super(sb);
2962                 /* Reser the needs_recovery flag before the fs is unlocked. */
2963                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2964                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2965                 unlock_super(sb);
2966                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2967         }
2968 }
2969
2970 static int ext4_remount(struct super_block *sb, int *flags, char *data)
2971 {
2972         struct ext4_super_block *es;
2973         struct ext4_sb_info *sbi = EXT4_SB(sb);
2974         ext4_fsblk_t n_blocks_count = 0;
2975         unsigned long old_sb_flags;
2976         struct ext4_mount_options old_opts;
2977         ext4_group_t g;
2978         int err;
2979 #ifdef CONFIG_QUOTA
2980         int i;
2981 #endif
2982
2983         /* Store the original options */
2984         old_sb_flags = sb->s_flags;
2985         old_opts.s_mount_opt = sbi->s_mount_opt;
2986         old_opts.s_resuid = sbi->s_resuid;
2987         old_opts.s_resgid = sbi->s_resgid;
2988         old_opts.s_commit_interval = sbi->s_commit_interval;
2989 #ifdef CONFIG_QUOTA
2990         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2991         for (i = 0; i < MAXQUOTAS; i++)
2992                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2993 #endif
2994
2995         /*
2996          * Allow the "check" option to be passed as a remount option.
2997          */
2998         if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2999                 err = -EINVAL;
3000                 goto restore_opts;
3001         }
3002
3003         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
3004                 ext4_abort(sb, __func__, "Abort forced by user");
3005
3006         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3007                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
3008
3009         es = sbi->s_es;
3010
3011         ext4_init_journal_params(sb, sbi->s_journal);
3012
3013         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
3014                 n_blocks_count > ext4_blocks_count(es)) {
3015                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
3016                         err = -EROFS;
3017                         goto restore_opts;
3018                 }
3019
3020                 if (*flags & MS_RDONLY) {
3021                         /*
3022                          * First of all, the unconditional stuff we have to do
3023                          * to disable replay of the journal when we next remount
3024                          */
3025                         sb->s_flags |= MS_RDONLY;
3026
3027                         /*
3028                          * OK, test if we are remounting a valid rw partition
3029                          * readonly, and if so set the rdonly flag and then
3030                          * mark the partition as valid again.
3031                          */
3032                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
3033                             (sbi->s_mount_state & EXT4_VALID_FS))
3034                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
3035
3036                         /*
3037                          * We have to unlock super so that we can wait for
3038                          * transactions.
3039                          */
3040                         unlock_super(sb);
3041                         ext4_mark_recovery_complete(sb, es);
3042                         lock_super(sb);
3043                 } else {
3044                         __le32 ret;
3045                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3046                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
3047                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
3048                                        "remount RDWR because of unsupported "
3049                                        "optional features (%x).\n",
3050                                        sb->s_id, le32_to_cpu(ret));
3051                                 err = -EROFS;
3052                                 goto restore_opts;
3053                         }
3054
3055                         /*
3056                          * Make sure the group descriptor checksums
3057                          * are sane.  If they aren't, refuse to
3058                          * remount r/w.
3059                          */
3060                         for (g = 0; g < sbi->s_groups_count; g++) {
3061                                 struct ext4_group_desc *gdp =
3062                                         ext4_get_group_desc(sb, g, NULL);
3063
3064                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
3065                                         printk(KERN_ERR
3066                "EXT4-fs: ext4_remount: "
3067                 "Checksum for group %lu failed (%u!=%u)\n",
3068                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
3069                                                le16_to_cpu(gdp->bg_checksum));
3070                                         err = -EINVAL;
3071                                         goto restore_opts;
3072                                 }
3073                         }
3074
3075                         /*
3076                          * If we have an unprocessed orphan list hanging
3077                          * around from a previously readonly bdev mount,
3078                          * require a full umount/remount for now.
3079                          */
3080                         if (es->s_last_orphan) {
3081                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
3082                                        "remount RDWR because of unprocessed "
3083                                        "orphan inode list.  Please "
3084                                        "umount/remount instead.\n",
3085                                        sb->s_id);
3086                                 err = -EINVAL;
3087                                 goto restore_opts;
3088                         }
3089
3090                         /*
3091                          * Mounting a RDONLY partition read-write, so reread
3092                          * and store the current valid flag.  (It may have
3093                          * been changed by e2fsck since we originally mounted
3094                          * the partition.)
3095                          */
3096                         ext4_clear_journal_err(sb, es);
3097                         sbi->s_mount_state = le16_to_cpu(es->s_state);
3098                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
3099                                 goto restore_opts;
3100                         if (!ext4_setup_super(sb, es, 0))
3101                                 sb->s_flags &= ~MS_RDONLY;
3102                 }
3103         }
3104 #ifdef CONFIG_QUOTA
3105         /* Release old quota file names */
3106         for (i = 0; i < MAXQUOTAS; i++)
3107                 if (old_opts.s_qf_names[i] &&
3108                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3109                         kfree(old_opts.s_qf_names[i]);
3110 #endif
3111         return 0;
3112 restore_opts:
3113         sb->s_flags = old_sb_flags;
3114         sbi->s_mount_opt = old_opts.s_mount_opt;
3115         sbi->s_resuid = old_opts.s_resuid;
3116         sbi->s_resgid = old_opts.s_resgid;
3117         sbi->s_commit_interval = old_opts.s_commit_interval;
3118 #ifdef CONFIG_QUOTA
3119         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
3120         for (i = 0; i < MAXQUOTAS; i++) {
3121                 if (sbi->s_qf_names[i] &&
3122                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3123                         kfree(sbi->s_qf_names[i]);
3124                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
3125         }
3126 #endif
3127         return err;
3128 }
3129
3130 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
3131 {
3132         struct super_block *sb = dentry->d_sb;
3133         struct ext4_sb_info *sbi = EXT4_SB(sb);
3134         struct ext4_super_block *es = sbi->s_es;
3135         u64 fsid;
3136
3137         if (test_opt(sb, MINIX_DF)) {
3138                 sbi->s_overhead_last = 0;
3139         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
3140                 ext4_group_t ngroups = sbi->s_groups_count, i;
3141                 ext4_fsblk_t overhead = 0;
3142                 smp_rmb();
3143
3144                 /*
3145                  * Compute the overhead (FS structures).  This is constant
3146                  * for a given filesystem unless the number of block groups
3147                  * changes so we cache the previous value until it does.
3148                  */
3149
3150                 /*
3151                  * All of the blocks before first_data_block are
3152                  * overhead
3153                  */
3154                 overhead = le32_to_cpu(es->s_first_data_block);
3155
3156                 /*
3157                  * Add the overhead attributed to the superblock and
3158                  * block group descriptors.  If the sparse superblocks
3159                  * feature is turned on, then not all groups have this.
3160                  */
3161                 for (i = 0; i < ngroups; i++) {
3162                         overhead += ext4_bg_has_super(sb, i) +
3163                                 ext4_bg_num_gdb(sb, i);
3164                         cond_resched();
3165                 }
3166
3167                 /*
3168                  * Every block group has an inode bitmap, a block
3169                  * bitmap, and an inode table.
3170                  */
3171                 overhead += ngroups * (2 + sbi->s_itb_per_group);
3172                 sbi->s_overhead_last = overhead;
3173                 smp_wmb();
3174                 sbi->s_blocks_last = ext4_blocks_count(es);
3175         }
3176
3177         buf->f_type = EXT4_SUPER_MAGIC;
3178         buf->f_bsize = sb->s_blocksize;
3179         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
3180         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
3181                        percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
3182         ext4_free_blocks_count_set(es, buf->f_bfree);
3183         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
3184         if (buf->f_bfree < ext4_r_blocks_count(es))
3185                 buf->f_bavail = 0;
3186         buf->f_files = le32_to_cpu(es->s_inodes_count);
3187         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
3188         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
3189         buf->f_namelen = EXT4_NAME_LEN;
3190         fsid = le64_to_cpup((void *)es->s_uuid) ^
3191                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
3192         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
3193         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
3194         return 0;
3195 }
3196
3197 /* Helper function for writing quotas on sync - we need to start transaction before quota file
3198  * is locked for write. Otherwise the are possible deadlocks:
3199  * Process 1                         Process 2
3200  * ext4_create()                     quota_sync()
3201  *   jbd2_journal_start()                   write_dquot()
3202  *   DQUOT_INIT()                        down(dqio_mutex)
3203  *     down(dqio_mutex)                    jbd2_journal_start()
3204  *
3205  */
3206
3207 #ifdef CONFIG_QUOTA
3208
3209 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3210 {
3211         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3212 }
3213
3214 static int ext4_dquot_initialize(struct inode *inode, int type)
3215 {
3216         handle_t *handle;
3217         int ret, err;
3218
3219         /* We may create quota structure so we need to reserve enough blocks */
3220         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
3221         if (IS_ERR(handle))
3222                 return PTR_ERR(handle);
3223         ret = dquot_initialize(inode, type);
3224         err = ext4_journal_stop(handle);
3225         if (!ret)
3226                 ret = err;
3227         return ret;
3228 }
3229
3230 static int ext4_dquot_drop(struct inode *inode)
3231 {
3232         handle_t *handle;
3233         int ret, err;
3234
3235         /* We may delete quota structure so we need to reserve enough blocks */
3236         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
3237         if (IS_ERR(handle)) {
3238                 /*
3239                  * We call dquot_drop() anyway to at least release references
3240                  * to quota structures so that umount does not hang.
3241                  */
3242                 dquot_drop(inode);
3243                 return PTR_ERR(handle);
3244         }
3245         ret = dquot_drop(inode);
3246         err = ext4_journal_stop(handle);
3247         if (!ret)
3248                 ret = err;
3249         return ret;
3250 }
3251
3252 static int ext4_write_dquot(struct dquot *dquot)
3253 {
3254         int ret, err;
3255         handle_t *handle;
3256         struct inode *inode;
3257
3258         inode = dquot_to_inode(dquot);
3259         handle = ext4_journal_start(inode,
3260                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3261         if (IS_ERR(handle))
3262                 return PTR_ERR(handle);
3263         ret = dquot_commit(dquot);
3264         err = ext4_journal_stop(handle);
3265         if (!ret)
3266                 ret = err;
3267         return ret;
3268 }
3269
3270 static int ext4_acquire_dquot(struct dquot *dquot)
3271 {
3272         int ret, err;
3273         handle_t *handle;
3274
3275         handle = ext4_journal_start(dquot_to_inode(dquot),
3276                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3277         if (IS_ERR(handle))
3278                 return PTR_ERR(handle);
3279         ret = dquot_acquire(dquot);
3280         err = ext4_journal_stop(handle);
3281         if (!ret)
3282                 ret = err;
3283         return ret;
3284 }
3285
3286 static int ext4_release_dquot(struct dquot *dquot)
3287 {
3288         int ret, err;
3289         handle_t *handle;
3290
3291         handle = ext4_journal_start(dquot_to_inode(dquot),
3292                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3293         if (IS_ERR(handle)) {
3294                 /* Release dquot anyway to avoid endless cycle in dqput() */
3295                 dquot_release(dquot);
3296                 return PTR_ERR(handle);
3297         }
3298         ret = dquot_release(dquot);
3299         err = ext4_journal_stop(handle);
3300         if (!ret)
3301                 ret = err;
3302         return ret;
3303 }
3304
3305 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3306 {
3307         /* Are we journaling quotas? */
3308         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3309             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3310                 dquot_mark_dquot_dirty(dquot);
3311                 return ext4_write_dquot(dquot);
3312         } else {
3313                 return dquot_mark_dquot_dirty(dquot);
3314         }
3315 }
3316
3317 static int ext4_write_info(struct super_block *sb, int type)
3318 {
3319         int ret, err;
3320         handle_t *handle;
3321
3322         /* Data block + inode block */
3323         handle = ext4_journal_start(sb->s_root->d_inode, 2);
3324         if (IS_ERR(handle))
3325                 return PTR_ERR(handle);
3326         ret = dquot_commit_info(sb, type);
3327         err = ext4_journal_stop(handle);
3328         if (!ret)
3329                 ret = err;
3330         return ret;
3331 }
3332
3333 /*
3334  * Turn on quotas during mount time - we need to find
3335  * the quota file and such...
3336  */
3337 static int ext4_quota_on_mount(struct super_block *sb, int type)
3338 {
3339         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3340                         EXT4_SB(sb)->s_jquota_fmt, type);
3341 }
3342
3343 /*
3344  * Standard function to be called on quota_on
3345  */
3346 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3347                          char *path, int remount)
3348 {
3349         int err;
3350         struct nameidata nd;
3351
3352         if (!test_opt(sb, QUOTA))
3353                 return -EINVAL;
3354         /* When remounting, no checks are needed and in fact, path is NULL */
3355         if (remount)
3356                 return vfs_quota_on(sb, type, format_id, path, remount);
3357
3358         err = path_lookup(path, LOOKUP_FOLLOW, &nd);
3359         if (err)
3360                 return err;
3361
3362         /* Quotafile not on the same filesystem? */
3363         if (nd.path.mnt->mnt_sb != sb) {
3364                 path_put(&nd.path);
3365                 return -EXDEV;
3366         }
3367         /* Journaling quota? */
3368         if (EXT4_SB(sb)->s_qf_names[type]) {
3369                 /* Quotafile not in fs root? */
3370                 if (nd.path.dentry->d_parent->d_inode != sb->s_root->d_inode)
3371                         printk(KERN_WARNING
3372                                 "EXT4-fs: Quota file not on filesystem root. "
3373                                 "Journaled quota will not work.\n");
3374         }
3375
3376         /*
3377          * When we journal data on quota file, we have to flush journal to see
3378          * all updates to the file when we bypass pagecache...
3379          */
3380         if (ext4_should_journal_data(nd.path.dentry->d_inode)) {
3381                 /*
3382                  * We don't need to lock updates but journal_flush() could
3383                  * otherwise be livelocked...
3384                  */
3385                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
3386                 jbd2_journal_flush(EXT4_SB(sb)->s_journal);
3387                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3388         }
3389
3390         err = vfs_quota_on_path(sb, type, format_id, &nd.path);
3391         path_put(&nd.path);
3392         return err;
3393 }
3394
3395 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3396  * acquiring the locks... As quota files are never truncated and quota code
3397  * itself serializes the operations (and noone else should touch the files)
3398  * we don't have to be afraid of races */
3399 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3400                                size_t len, loff_t off)
3401 {
3402         struct inode *inode = sb_dqopt(sb)->files[type];
3403         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3404         int err = 0;
3405         int offset = off & (sb->s_blocksize - 1);
3406         int tocopy;
3407         size_t toread;
3408         struct buffer_head *bh;
3409         loff_t i_size = i_size_read(inode);
3410
3411         if (off > i_size)
3412                 return 0;
3413         if (off+len > i_size)
3414                 len = i_size-off;
3415         toread = len;
3416         while (toread > 0) {
3417                 tocopy = sb->s_blocksize - offset < toread ?
3418                                 sb->s_blocksize - offset : toread;
3419                 bh = ext4_bread(NULL, inode, blk, 0, &err);
3420                 if (err)
3421                         return err;
3422                 if (!bh)        /* A hole? */
3423                         memset(data, 0, tocopy);
3424                 else
3425                         memcpy(data, bh->b_data+offset, tocopy);
3426                 brelse(bh);
3427                 offset = 0;
3428                 toread -= tocopy;
3429                 data += tocopy;
3430                 blk++;
3431         }
3432         return len;
3433 }
3434
3435 /* Write to quotafile (we know the transaction is already started and has
3436  * enough credits) */
3437 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3438                                 const char *data, size_t len, loff_t off)
3439 {
3440         struct inode *inode = sb_dqopt(sb)->files[type];
3441         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3442         int err = 0;
3443         int offset = off & (sb->s_blocksize - 1);
3444         int tocopy;
3445         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3446         size_t towrite = len;
3447         struct buffer_head *bh;
3448         handle_t *handle = journal_current_handle();
3449
3450         if (!handle) {
3451                 printk(KERN_WARNING "EXT4-fs: Quota write (off=%llu, len=%llu)"
3452                         " cancelled because transaction is not started.\n",
3453                         (unsigned long long)off, (unsigned long long)len);
3454                 return -EIO;
3455         }
3456         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3457         while (towrite > 0) {
3458                 tocopy = sb->s_blocksize - offset < towrite ?
3459                                 sb->s_blocksize - offset : towrite;
3460                 bh = ext4_bread(handle, inode, blk, 1, &err);
3461                 if (!bh)
3462                         goto out;
3463                 if (journal_quota) {
3464                         err = ext4_journal_get_write_access(handle, bh);
3465                         if (err) {
3466                                 brelse(bh);
3467                                 goto out;
3468                         }
3469                 }
3470                 lock_buffer(bh);
3471                 memcpy(bh->b_data+offset, data, tocopy);
3472                 flush_dcache_page(bh->b_page);
3473                 unlock_buffer(bh);
3474                 if (journal_quota)
3475                         err = ext4_journal_dirty_metadata(handle, bh);
3476                 else {
3477                         /* Always do at least ordered writes for quotas */
3478                         err = ext4_jbd2_file_inode(handle, inode);
3479                         mark_buffer_dirty(bh);
3480                 }
3481                 brelse(bh);
3482                 if (err)
3483                         goto out;
3484                 offset = 0;
3485                 towrite -= tocopy;
3486                 data += tocopy;
3487                 blk++;
3488         }
3489 out:
3490         if (len == towrite) {
3491                 mutex_unlock(&inode->i_mutex);
3492                 return err;
3493         }
3494         if (inode->i_size < off+len-towrite) {
3495                 i_size_write(inode, off+len-towrite);
3496                 EXT4_I(inode)->i_disksize = inode->i_size;
3497         }
3498         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3499         ext4_mark_inode_dirty(handle, inode);
3500         mutex_unlock(&inode->i_mutex);
3501         return len - towrite;
3502 }
3503
3504 #endif
3505
3506 static int ext4_get_sb(struct file_system_type *fs_type,
3507         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3508 {
3509         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3510 }
3511
3512 static struct file_system_type ext4dev_fs_type = {
3513         .owner          = THIS_MODULE,
3514         .name           = "ext4dev",
3515         .get_sb         = ext4_get_sb,
3516         .kill_sb        = kill_block_super,
3517         .fs_flags       = FS_REQUIRES_DEV,
3518 };
3519
3520 static int __init init_ext4_fs(void)
3521 {
3522         int err;
3523
3524         err = init_ext4_mballoc();
3525         if (err)
3526                 return err;
3527
3528         err = init_ext4_xattr();
3529         if (err)
3530                 goto out2;
3531         err = init_inodecache();
3532         if (err)
3533                 goto out1;
3534         err = register_filesystem(&ext4dev_fs_type);
3535         if (err)
3536                 goto out;
3537         return 0;
3538 out:
3539         destroy_inodecache();
3540 out1:
3541         exit_ext4_xattr();
3542 out2:
3543         exit_ext4_mballoc();
3544         return err;
3545 }
3546
3547 static void __exit exit_ext4_fs(void)
3548 {
3549         unregister_filesystem(&ext4dev_fs_type);
3550         destroy_inodecache();
3551         exit_ext4_xattr();
3552         exit_ext4_mballoc();
3553 }
3554
3555 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
3556 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
3557 MODULE_LICENSE("GPL");
3558 module_init(init_ext4_fs)
3559 module_exit(exit_ext4_fs)