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/vmalloc.h>
  24 #include <linux/jbd2.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/parser.h>
  29 #include <linux/smp_lock.h>
  30 #include <linux/buffer_head.h>
  31 #include <linux/exportfs.h>
  32 #include <linux/vfs.h>
  33 #include <linux/random.h>
  34 #include <linux/mount.h>
  35 #include <linux/namei.h>
  36 #include <linux/quotaops.h>
  37 #include <linux/seq_file.h>
  38 #include <linux/proc_fs.h>
  39 #include <linux/ctype.h>
  40 #include <linux/log2.h>
  41 #include <linux/crc16.h>
  42 #include <asm/uaccess.h>
  43
  44 #include "ext4.h"
  45 #include "ext4_jbd2.h"
  46 #include "xattr.h"
  47 #include "acl.h"
  48 #include "mballoc.h"
  49
  50 #define CREATE_TRACE_POINTS
  51 #include <trace/events/ext4.h>
  52
  53 struct proc_dir_entry *ext4_proc_root;
  54 static struct kset *ext4_kset;
  55
  56 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  57                              unsigned long journal_devnum);
  58 static int ext4_commit_super(struct super_block *sb, int sync);
  59 static void ext4_mark_recovery_complete(struct super_block *sb,
  60                                         struct ext4_super_block *es);
  61 static void ext4_clear_journal_err(struct super_block *sb,
  62                                    struct ext4_super_block *es);
  63 static int ext4_sync_fs(struct super_block *sb, int wait);
  64 static const char *ext4_decode_error(struct super_block *sb, int errno,
  65                                      char nbuf[16]);
  66 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  67 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  68 static int ext4_unfreeze(struct super_block *sb);
  69 static void ext4_write_super(struct super_block *sb);
  70 static int ext4_freeze(struct super_block *sb);
  71
  72
  73 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
  74                                struct ext4_group_desc *bg)
  75 {
  76         return le32_to_cpu(bg->bg_block_bitmap_lo) |
  77                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  78                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
  79 }
  80
  81 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
  82                                struct ext4_group_desc *bg)
  83 {
  84         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
  85                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  86                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
  87 }
  88
  89 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
  90                               struct ext4_group_desc *bg)
  91 {
  92         return le32_to_cpu(bg->bg_inode_table_lo) |
  93                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  94                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
  95 }
  96
  97 __u32 ext4_free_blks_count(struct super_block *sb,
  98                               struct ext4_group_desc *bg)
  99 {
 100         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 101                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 102                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 103 }
 104
 105 __u32 ext4_free_inodes_count(struct super_block *sb,
 106                               struct ext4_group_desc *bg)
 107 {
 108         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 109                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 110                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 111 }
 112
 113 __u32 ext4_used_dirs_count(struct super_block *sb,
 114                               struct ext4_group_desc *bg)
 115 {
 116         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 117                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 118                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 119 }
 120
 121 __u32 ext4_itable_unused_count(struct super_block *sb,
 122                               struct ext4_group_desc *bg)
 123 {
 124         return le16_to_cpu(bg->bg_itable_unused_lo) |
 125                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 126                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 127 }
 128
 129 void ext4_block_bitmap_set(struct super_block *sb,
 130                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 131 {
 132         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 133         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 134                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 135 }
 136
 137 void ext4_inode_bitmap_set(struct super_block *sb,
 138                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 139 {
 140         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 141         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 142                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 143 }
 144
 145 void ext4_inode_table_set(struct super_block *sb,
 146                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 147 {
 148         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 149         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 150                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 151 }
 152
 153 void ext4_free_blks_set(struct super_block *sb,
 154                           struct ext4_group_desc *bg, __u32 count)
 155 {
 156         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 157         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 158                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 159 }
 160
 161 void ext4_free_inodes_set(struct super_block *sb,
 162                           struct ext4_group_desc *bg, __u32 count)
 163 {
 164         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 165         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 166                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 167 }
 168
 169 void ext4_used_dirs_set(struct super_block *sb,
 170                           struct ext4_group_desc *bg, __u32 count)
 171 {
 172         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 173         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 174                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 175 }
 176
 177 void ext4_itable_unused_set(struct super_block *sb,
 178                           struct ext4_group_desc *bg, __u32 count)
 179 {
 180         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 181         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 182                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 183 }
 184
 185
 186 /* Just increment the non-pointer handle value */
 187 static handle_t *ext4_get_nojournal(void)
 188 {
 189         handle_t *handle = current->journal_info;
 190         unsigned long ref_cnt = (unsigned long)handle;
 191
 192         BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
 193
 194         ref_cnt++;
 195         handle = (handle_t *)ref_cnt;
 196
 197         current->journal_info = handle;
 198         return handle;
 199 }
 200
 201
 202 /* Decrement the non-pointer handle value */
 203 static void ext4_put_nojournal(handle_t *handle)
 204 {
 205         unsigned long ref_cnt = (unsigned long)handle;
 206
 207         BUG_ON(ref_cnt == 0);
 208
 209         ref_cnt--;
 210         handle = (handle_t *)ref_cnt;
 211
 212         current->journal_info = handle;
 213 }
 214
 215 /*
 216  * Wrappers for jbd2_journal_start/end.
 217  *
 218  * The only special thing we need to do here is to make sure that all
 219  * journal_end calls result in the superblock being marked dirty, so
 220  * that sync() will call the filesystem's write_super callback if
 221  * appropriate.
 222  */
 223 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 224 {
 225         journal_t *journal;
 226
 227         if (sb->s_flags & MS_RDONLY)
 228                 return ERR_PTR(-EROFS);
 229
 230         /* Special case here: if the journal has aborted behind our
 231          * backs (eg. EIO in the commit thread), then we still need to
 232          * take the FS itself readonly cleanly. */
 233         journal = EXT4_SB(sb)->s_journal;
 234         if (journal) {
 235                 if (is_journal_aborted(journal)) {
 236                         ext4_abort(sb, __func__, "Detected aborted journal");
 237                         return ERR_PTR(-EROFS);
 238                 }
 239                 return jbd2_journal_start(journal, nblocks);
 240         }
 241         return ext4_get_nojournal();
 242 }
 243
 244 /*
 245  * The only special thing we need to do here is to make sure that all
 246  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 247  * that sync() will call the filesystem's write_super callback if
 248  * appropriate.
 249  */
 250 int __ext4_journal_stop(const char *where, handle_t *handle)
 251 {
 252         struct super_block *sb;
 253         int err;
 254         int rc;
 255
 256         if (!ext4_handle_valid(handle)) {
 257                 ext4_put_nojournal(handle);
 258                 return 0;
 259         }
 260         sb = handle->h_transaction->t_journal->j_private;
 261         err = handle->h_err;
 262         rc = jbd2_journal_stop(handle);
 263
 264         if (!err)
 265                 err = rc;
 266         if (err)
 267                 __ext4_std_error(sb, where, err);
 268         return err;
 269 }
 270
 271 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 272                 struct buffer_head *bh, handle_t *handle, int err)
 273 {
 274         char nbuf[16];
 275         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 276
 277         BUG_ON(!ext4_handle_valid(handle));
 278
 279         if (bh)
 280                 BUFFER_TRACE(bh, "abort");
 281
 282         if (!handle->h_err)
 283                 handle->h_err = err;
 284
 285         if (is_handle_aborted(handle))
 286                 return;
 287
 288         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
 289                caller, errstr, err_fn);
 290
 291         jbd2_journal_abort_handle(handle);
 292 }
 293
 294 /* Deal with the reporting of failure conditions on a filesystem such as
 295  * inconsistencies detected or read IO failures.
 296  *
 297  * On ext2, we can store the error state of the filesystem in the
 298  * superblock.  That is not possible on ext4, because we may have other
 299  * write ordering constraints on the superblock which prevent us from
 300  * writing it out straight away; and given that the journal is about to
 301  * be aborted, we can't rely on the current, or future, transactions to
 302  * write out the superblock safely.
 303  *
 304  * We'll just use the jbd2_journal_abort() error code to record an error in
 305  * the journal instead.  On recovery, the journal will compain about
 306  * that error until we've noted it down and cleared it.
 307  */
 308
 309 static void ext4_handle_error(struct super_block *sb)
 310 {
 311         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 312
 313         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 314         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 315
 316         if (sb->s_flags & MS_RDONLY)
 317                 return;
 318
 319         if (!test_opt(sb, ERRORS_CONT)) {
 320                 journal_t *journal = EXT4_SB(sb)->s_journal;
 321
 322                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 323                 if (journal)
 324                         jbd2_journal_abort(journal, -EIO);
 325         }
 326         if (test_opt(sb, ERRORS_RO)) {
 327                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 328                 sb->s_flags |= MS_RDONLY;
 329         }
 330         ext4_commit_super(sb, 1);
 331         if (test_opt(sb, ERRORS_PANIC))
 332                 panic("EXT4-fs (device %s): panic forced after error\n",
 333                         sb->s_id);
 334 }
 335
 336 void ext4_error(struct super_block *sb, const char *function,
 337                 const char *fmt, ...)
 338 {
 339         va_list args;
 340
 341         va_start(args, fmt);
 342         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 343         vprintk(fmt, args);
 344         printk("\n");
 345         va_end(args);
 346
 347         ext4_handle_error(sb);
 348 }
 349
 350 static const char *ext4_decode_error(struct super_block *sb, int errno,
 351                                      char nbuf[16])
 352 {
 353         char *errstr = NULL;
 354
 355         switch (errno) {
 356         case -EIO:
 357                 errstr = "IO failure";
 358                 break;
 359         case -ENOMEM:
 360                 errstr = "Out of memory";
 361                 break;
 362         case -EROFS:
 363                 if (!sb || (EXT4_SB(sb)->s_journal &&
 364                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 365                         errstr = "Journal has aborted";
 366                 else
 367                         errstr = "Readonly filesystem";
 368                 break;
 369         default:
 370                 /* If the caller passed in an extra buffer for unknown
 371                  * errors, textualise them now.  Else we just return
 372                  * NULL. */
 373                 if (nbuf) {
 374                         /* Check for truncated error codes... */
 375                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 376                                 errstr = nbuf;
 377                 }
 378                 break;
 379         }
 380
 381         return errstr;
 382 }
 383
 384 /* __ext4_std_error decodes expected errors from journaling functions
 385  * automatically and invokes the appropriate error response.  */
 386
 387 void __ext4_std_error(struct super_block *sb, const char *function, int errno)
 388 {
 389         char nbuf[16];
 390         const char *errstr;
 391
 392         /* Special case: if the error is EROFS, and we're not already
 393          * inside a transaction, then there's really no point in logging
 394          * an error. */
 395         if (errno == -EROFS && journal_current_handle() == NULL &&
 396             (sb->s_flags & MS_RDONLY))
 397                 return;
 398
 399         errstr = ext4_decode_error(sb, errno, nbuf);
 400         printk(KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
 401                sb->s_id, function, errstr);
 402
 403         ext4_handle_error(sb);
 404 }
 405
 406 /*
 407  * ext4_abort is a much stronger failure handler than ext4_error.  The
 408  * abort function may be used to deal with unrecoverable failures such
 409  * as journal IO errors or ENOMEM at a critical moment in log management.
 410  *
 411  * We unconditionally force the filesystem into an ABORT|READONLY state,
 412  * unless the error response on the fs has been set to panic in which
 413  * case we take the easy way out and panic immediately.
 414  */
 415
 416 void ext4_abort(struct super_block *sb, const char *function,
 417                 const char *fmt, ...)
 418 {
 419         va_list args;
 420
 421         va_start(args, fmt);
 422         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 423         vprintk(fmt, args);
 424         printk("\n");
 425         va_end(args);
 426
 427         if (test_opt(sb, ERRORS_PANIC))
 428                 panic("EXT4-fs panic from previous error\n");
 429
 430         if (sb->s_flags & MS_RDONLY)
 431                 return;
 432
 433         ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 434         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 435         sb->s_flags |= MS_RDONLY;
 436         EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 437         if (EXT4_SB(sb)->s_journal)
 438                 jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 439 }
 440
 441 void ext4_msg (struct super_block * sb, const char *prefix,
 442                    const char *fmt, ...)
 443 {
 444         va_list args;
 445
 446         va_start(args, fmt);
 447         printk("%sEXT4-fs (%s): ", prefix, sb->s_id);
 448         vprintk(fmt, args);
 449         printk("\n");
 450         va_end(args);
 451 }
 452
 453 void ext4_warning(struct super_block *sb, const char *function,
 454                   const char *fmt, ...)
 455 {
 456         va_list args;
 457
 458         va_start(args, fmt);
 459         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
 460                sb->s_id, function);
 461         vprintk(fmt, args);
 462         printk("\n");
 463         va_end(args);
 464 }
 465
 466 void ext4_grp_locked_error(struct super_block *sb, ext4_group_t grp,
 467                            const char *function, const char *fmt, ...)
 468 __releases(bitlock)
 469 __acquires(bitlock)
 470 {
 471         va_list args;
 472         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 473
 474         va_start(args, fmt);
 475         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 476         vprintk(fmt, args);
 477         printk("\n");
 478         va_end(args);
 479
 480         if (test_opt(sb, ERRORS_CONT)) {
 481                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 482                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 483                 ext4_commit_super(sb, 0);
 484                 return;
 485         }
 486         ext4_unlock_group(sb, grp);
 487         ext4_handle_error(sb);
 488         /*
 489          * We only get here in the ERRORS_RO case; relocking the group
 490          * may be dangerous, but nothing bad will happen since the
 491          * filesystem will have already been marked read/only and the
 492          * journal has been aborted.  We return 1 as a hint to callers
 493          * who might what to use the return value from
 494          * ext4_grp_locked_error() to distinguish beween the
 495          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 496          * aggressively from the ext4 function in question, with a
 497          * more appropriate error code.
 498          */
 499         ext4_lock_group(sb, grp);
 500         return;
 501 }
 502
 503 void ext4_update_dynamic_rev(struct super_block *sb)
 504 {
 505         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 506
 507         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 508                 return;
 509
 510         ext4_warning(sb, __func__,
 511                      "updating to rev %d because of new feature flag, "
 512                      "running e2fsck is recommended",
 513                      EXT4_DYNAMIC_REV);
 514
 515         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 516         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 517         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 518         /* leave es->s_feature_*compat flags alone */
 519         /* es->s_uuid will be set by e2fsck if empty */
 520
 521         /*
 522          * The rest of the superblock fields should be zero, and if not it
 523          * means they are likely already in use, so leave them alone.  We
 524          * can leave it up to e2fsck to clean up any inconsistencies there.
 525          */
 526 }
 527
 528 /*
 529  * Open the external journal device
 530  */
 531 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 532 {
 533         struct block_device *bdev;
 534         char b[BDEVNAME_SIZE];
 535
 536         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 537         if (IS_ERR(bdev))
 538                 goto fail;
 539         return bdev;
 540
 541 fail:
 542         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 543                         __bdevname(dev, b), PTR_ERR(bdev));
 544         return NULL;
 545 }
 546
 547 /*
 548  * Release the journal device
 549  */
 550 static int ext4_blkdev_put(struct block_device *bdev)
 551 {
 552         bd_release(bdev);
 553         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
 554 }
 555
 556 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 557 {
 558         struct block_device *bdev;
 559         int ret = -ENODEV;
 560
 561         bdev = sbi->journal_bdev;
 562         if (bdev) {
 563                 ret = ext4_blkdev_put(bdev);
 564                 sbi->journal_bdev = NULL;
 565         }
 566         return ret;
 567 }
 568
 569 static inline struct inode *orphan_list_entry(struct list_head *l)
 570 {
 571         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 572 }
 573
 574 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 575 {
 576         struct list_head *l;
 577
 578         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 579                  le32_to_cpu(sbi->s_es->s_last_orphan));
 580
 581         printk(KERN_ERR "sb_info orphan list:\n");
 582         list_for_each(l, &sbi->s_orphan) {
 583                 struct inode *inode = orphan_list_entry(l);
 584                 printk(KERN_ERR "  "
 585                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 586                        inode->i_sb->s_id, inode->i_ino, inode,
 587                        inode->i_mode, inode->i_nlink,
 588                        NEXT_ORPHAN(inode));
 589         }
 590 }
 591
 592 static void ext4_put_super(struct super_block *sb)
 593 {
 594         struct ext4_sb_info *sbi = EXT4_SB(sb);
 595         struct ext4_super_block *es = sbi->s_es;
 596         int i, err;
 597
 598         flush_workqueue(sbi->dio_unwritten_wq);
 599         destroy_workqueue(sbi->dio_unwritten_wq);
 600
 601         lock_super(sb);
 602         lock_kernel();
 603         if (sb->s_dirt)
 604                 ext4_commit_super(sb, 1);
 605
 606         if (sbi->s_journal) {
 607                 err = jbd2_journal_destroy(sbi->s_journal);
 608                 sbi->s_journal = NULL;
 609                 if (err < 0)
 610                         ext4_abort(sb, __func__,
 611                                    "Couldn't clean up the journal");
 612         }
 613
 614         ext4_release_system_zone(sb);
 615         ext4_mb_release(sb);
 616         ext4_ext_release(sb);
 617         ext4_xattr_put_super(sb);
 618
 619         if (!(sb->s_flags & MS_RDONLY)) {
 620                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 621                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 622                 ext4_commit_super(sb, 1);
 623         }
 624         if (sbi->s_proc) {
 625                 remove_proc_entry(sb->s_id, ext4_proc_root);
 626         }
 627         kobject_del(&sbi->s_kobj);
 628
 629         for (i = 0; i < sbi->s_gdb_count; i++)
 630                 brelse(sbi->s_group_desc[i]);
 631         kfree(sbi->s_group_desc);
 632         if (is_vmalloc_addr(sbi->s_flex_groups))
 633                 vfree(sbi->s_flex_groups);
 634         else
 635                 kfree(sbi->s_flex_groups);
 636         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 637         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 638         percpu_counter_destroy(&sbi->s_dirs_counter);
 639         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
 640         brelse(sbi->s_sbh);
 641 #ifdef CONFIG_QUOTA
 642         for (i = 0; i < MAXQUOTAS; i++)
 643                 kfree(sbi->s_qf_names[i]);
 644 #endif
 645
 646         /* Debugging code just in case the in-memory inode orphan list
 647          * isn't empty.  The on-disk one can be non-empty if we've
 648          * detected an error and taken the fs readonly, but the
 649          * in-memory list had better be clean by this point. */
 650         if (!list_empty(&sbi->s_orphan))
 651                 dump_orphan_list(sb, sbi);
 652         J_ASSERT(list_empty(&sbi->s_orphan));
 653
 654         invalidate_bdev(sb->s_bdev);
 655         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 656                 /*
 657                  * Invalidate the journal device's buffers.  We don't want them
 658                  * floating about in memory - the physical journal device may
 659                  * hotswapped, and it breaks the `ro-after' testing code.
 660                  */
 661                 sync_blockdev(sbi->journal_bdev);
 662                 invalidate_bdev(sbi->journal_bdev);
 663                 ext4_blkdev_remove(sbi);
 664         }
 665         sb->s_fs_info = NULL;
 666         /*
 667          * Now that we are completely done shutting down the
 668          * superblock, we need to actually destroy the kobject.
 669          */
 670         unlock_kernel();
 671         unlock_super(sb);
 672         kobject_put(&sbi->s_kobj);
 673         wait_for_completion(&sbi->s_kobj_unregister);
 674         kfree(sbi->s_blockgroup_lock);
 675         kfree(sbi);
 676 }
 677
 678 static struct kmem_cache *ext4_inode_cachep;
 679
 680 /*
 681  * Called inside transaction, so use GFP_NOFS
 682  */
 683 static struct inode *ext4_alloc_inode(struct super_block *sb)
 684 {
 685         struct ext4_inode_info *ei;
 686
 687         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 688         if (!ei)
 689                 return NULL;
 690
 691         ei->vfs_inode.i_version = 1;
 692         ei->vfs_inode.i_data.writeback_index = 0;
 693         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 694         INIT_LIST_HEAD(&ei->i_prealloc_list);
 695         spin_lock_init(&ei->i_prealloc_lock);
 696         /*
 697          * Note:  We can be called before EXT4_SB(sb)->s_journal is set,
 698          * therefore it can be null here.  Don't check it, just initialize
 699          * jinode.
 700          */
 701         jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
 702         ei->i_reserved_data_blocks = 0;
 703         ei->i_reserved_meta_blocks = 0;
 704         ei->i_allocated_meta_blocks = 0;
 705         ei->i_delalloc_reserved_flag = 0;
 706         spin_lock_init(&(ei->i_block_reservation_lock));
 707         INIT_LIST_HEAD(&ei->i_aio_dio_complete_list);
 708         ei->cur_aio_dio = NULL;
 709         ei->i_sync_tid = 0;
 710         ei->i_datasync_tid = 0;
 711
 712         return &ei->vfs_inode;
 713 }
 714
 715 static void ext4_destroy_inode(struct inode *inode)
 716 {
 717         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 718                 ext4_msg(inode->i_sb, KERN_ERR,
 719                          "Inode %lu (%p): orphan list check failed!",
 720                          inode->i_ino, EXT4_I(inode));
 721                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 722                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 723                                 true);
 724                 dump_stack();
 725         }
 726         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 727 }
 728
 729 static void init_once(void *foo)
 730 {
 731         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 732
 733         INIT_LIST_HEAD(&ei->i_orphan);
 734 #ifdef CONFIG_EXT4_FS_XATTR
 735         init_rwsem(&ei->xattr_sem);
 736 #endif
 737         init_rwsem(&ei->i_data_sem);
 738         inode_init_once(&ei->vfs_inode);
 739 }
 740
 741 static int init_inodecache(void)
 742 {
 743         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 744                                              sizeof(struct ext4_inode_info),
 745                                              0, (SLAB_RECLAIM_ACCOUNT|
 746                                                 SLAB_MEM_SPREAD),
 747                                              init_once);
 748         if (ext4_inode_cachep == NULL)
 749                 return -ENOMEM;
 750         return 0;
 751 }
 752
 753 static void destroy_inodecache(void)
 754 {
 755         kmem_cache_destroy(ext4_inode_cachep);
 756 }
 757
 758 static void ext4_clear_inode(struct inode *inode)
 759 {
 760         ext4_discard_preallocations(inode);
 761         if (EXT4_JOURNAL(inode))
 762                 jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
 763                                        &EXT4_I(inode)->jinode);
 764 }
 765
 766 static inline void ext4_show_quota_options(struct seq_file *seq,
 767                                            struct super_block *sb)
 768 {
 769 #if defined(CONFIG_QUOTA)
 770         struct ext4_sb_info *sbi = EXT4_SB(sb);
 771
 772         if (sbi->s_jquota_fmt)
 773                 seq_printf(seq, ",jqfmt=%s",
 774                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold" : "vfsv0");
 775
 776         if (sbi->s_qf_names[USRQUOTA])
 777                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 778
 779         if (sbi->s_qf_names[GRPQUOTA])
 780                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 781
 782         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
 783                 seq_puts(seq, ",usrquota");
 784
 785         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
 786                 seq_puts(seq, ",grpquota");
 787 #endif
 788 }
 789
 790 /*
 791  * Show an option if
 792  *  - it's set to a non-default value OR
 793  *  - if the per-sb default is different from the global default
 794  */
 795 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 796 {
 797         int def_errors;
 798         unsigned long def_mount_opts;
 799         struct super_block *sb = vfs->mnt_sb;
 800         struct ext4_sb_info *sbi = EXT4_SB(sb);
 801         struct ext4_super_block *es = sbi->s_es;
 802
 803         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 804         def_errors     = le16_to_cpu(es->s_errors);
 805
 806         if (sbi->s_sb_block != 1)
 807                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 808         if (test_opt(sb, MINIX_DF))
 809                 seq_puts(seq, ",minixdf");
 810         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
 811                 seq_puts(seq, ",grpid");
 812         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 813                 seq_puts(seq, ",nogrpid");
 814         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 815             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 816                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 817         }
 818         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 819             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 820                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 821         }
 822         if (test_opt(sb, ERRORS_RO)) {
 823                 if (def_errors == EXT4_ERRORS_PANIC ||
 824                     def_errors == EXT4_ERRORS_CONTINUE) {
 825                         seq_puts(seq, ",errors=remount-ro");
 826                 }
 827         }
 828         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
 829                 seq_puts(seq, ",errors=continue");
 830         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
 831                 seq_puts(seq, ",errors=panic");
 832         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
 833                 seq_puts(seq, ",nouid32");
 834         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
 835                 seq_puts(seq, ",debug");
 836         if (test_opt(sb, OLDALLOC))
 837                 seq_puts(seq, ",oldalloc");
 838 #ifdef CONFIG_EXT4_FS_XATTR
 839         if (test_opt(sb, XATTR_USER) &&
 840                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
 841                 seq_puts(seq, ",user_xattr");
 842         if (!test_opt(sb, XATTR_USER) &&
 843             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 844                 seq_puts(seq, ",nouser_xattr");
 845         }
 846 #endif
 847 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 848         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
 849                 seq_puts(seq, ",acl");
 850         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 851                 seq_puts(seq, ",noacl");
 852 #endif
 853         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
 854                 seq_printf(seq, ",commit=%u",
 855                            (unsigned) (sbi->s_commit_interval / HZ));
 856         }
 857         if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
 858                 seq_printf(seq, ",min_batch_time=%u",
 859                            (unsigned) sbi->s_min_batch_time);
 860         }
 861         if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
 862                 seq_printf(seq, ",max_batch_time=%u",
 863                            (unsigned) sbi->s_min_batch_time);
 864         }
 865
 866         /*
 867          * We're changing the default of barrier mount option, so
 868          * let's always display its mount state so it's clear what its
 869          * status is.
 870          */
 871         seq_puts(seq, ",barrier=");
 872         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
 873         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
 874                 seq_puts(seq, ",journal_async_commit");
 875         if (test_opt(sb, NOBH))
 876                 seq_puts(seq, ",nobh");
 877         if (test_opt(sb, I_VERSION))
 878                 seq_puts(seq, ",i_version");
 879         if (!test_opt(sb, DELALLOC))
 880                 seq_puts(seq, ",nodelalloc");
 881
 882
 883         if (sbi->s_stripe)
 884                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
 885         /*
 886          * journal mode get enabled in different ways
 887          * So just print the value even if we didn't specify it
 888          */
 889         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 890                 seq_puts(seq, ",data=journal");
 891         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 892                 seq_puts(seq, ",data=ordered");
 893         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 894                 seq_puts(seq, ",data=writeback");
 895
 896         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
 897                 seq_printf(seq, ",inode_readahead_blks=%u",
 898                            sbi->s_inode_readahead_blks);
 899
 900         if (test_opt(sb, DATA_ERR_ABORT))
 901                 seq_puts(seq, ",data_err=abort");
 902
 903         if (test_opt(sb, NO_AUTO_DA_ALLOC))
 904                 seq_puts(seq, ",noauto_da_alloc");
 905
 906         if (test_opt(sb, DISCARD))
 907                 seq_puts(seq, ",discard");
 908
 909         if (test_opt(sb, NOLOAD))
 910                 seq_puts(seq, ",norecovery");
 911
 912         ext4_show_quota_options(seq, sb);
 913
 914         return 0;
 915 }
 916
 917 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 918                                         u64 ino, u32 generation)
 919 {
 920         struct inode *inode;
 921
 922         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 923                 return ERR_PTR(-ESTALE);
 924         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 925                 return ERR_PTR(-ESTALE);
 926
 927         /* iget isn't really right if the inode is currently unallocated!!
 928          *
 929          * ext4_read_inode will return a bad_inode if the inode had been
 930          * deleted, so we should be safe.
 931          *
 932          * Currently we don't know the generation for parent directory, so
 933          * a generation of 0 means "accept any"
 934          */
 935         inode = ext4_iget(sb, ino);
 936         if (IS_ERR(inode))
 937                 return ERR_CAST(inode);
 938         if (generation && inode->i_generation != generation) {
 939                 iput(inode);
 940                 return ERR_PTR(-ESTALE);
 941         }
 942
 943         return inode;
 944 }
 945
 946 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 947                                         int fh_len, int fh_type)
 948 {
 949         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 950                                     ext4_nfs_get_inode);
 951 }
 952
 953 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 954                                         int fh_len, int fh_type)
 955 {
 956         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 957                                     ext4_nfs_get_inode);
 958 }
 959
 960 /*
 961  * Try to release metadata pages (indirect blocks, directories) which are
 962  * mapped via the block device.  Since these pages could have journal heads
 963  * which would prevent try_to_free_buffers() from freeing them, we must use
 964  * jbd2 layer's try_to_free_buffers() function to release them.
 965  */
 966 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
 967                                  gfp_t wait)
 968 {
 969         journal_t *journal = EXT4_SB(sb)->s_journal;
 970
 971         WARN_ON(PageChecked(page));
 972         if (!page_has_buffers(page))
 973                 return 0;
 974         if (journal)
 975                 return jbd2_journal_try_to_free_buffers(journal, page,
 976                                                         wait & ~__GFP_WAIT);
 977         return try_to_free_buffers(page);
 978 }
 979
 980 #ifdef CONFIG_QUOTA
 981 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
 982 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 983
 984 static int ext4_write_dquot(struct dquot *dquot);
 985 static int ext4_acquire_dquot(struct dquot *dquot);
 986 static int ext4_release_dquot(struct dquot *dquot);
 987 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 988 static int ext4_write_info(struct super_block *sb, int type);
 989 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 990                                 char *path, int remount);
 991 static int ext4_quota_on_mount(struct super_block *sb, int type);
 992 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 993                                size_t len, loff_t off);
 994 static ssize_t ext4_quota_write(struct super_block *sb, int type,
 995                                 const char *data, size_t len, loff_t off);
 996
 997 static const struct dquot_operations ext4_quota_operations = {
 998         .initialize     = dquot_initialize,
 999         .drop           = dquot_drop,
1000         .alloc_space    = dquot_alloc_space,
1001         .reserve_space  = dquot_reserve_space,
1002         .claim_space    = dquot_claim_space,
1003         .release_rsv    = dquot_release_reserved_space,
1004         .get_reserved_space = ext4_get_reserved_space,
1005         .alloc_inode    = dquot_alloc_inode,
1006         .free_space     = dquot_free_space,
1007         .free_inode     = dquot_free_inode,
1008         .transfer       = dquot_transfer,
1009         .write_dquot    = ext4_write_dquot,
1010         .acquire_dquot  = ext4_acquire_dquot,
1011         .release_dquot  = ext4_release_dquot,
1012         .mark_dirty     = ext4_mark_dquot_dirty,
1013         .write_info     = ext4_write_info,
1014         .alloc_dquot    = dquot_alloc,
1015         .destroy_dquot  = dquot_destroy,
1016 };
1017
1018 static const struct quotactl_ops ext4_qctl_operations = {
1019         .quota_on       = ext4_quota_on,
1020         .quota_off      = vfs_quota_off,
1021         .quota_sync     = vfs_quota_sync,
1022         .get_info       = vfs_get_dqinfo,
1023         .set_info       = vfs_set_dqinfo,
1024         .get_dqblk      = vfs_get_dqblk,
1025         .set_dqblk      = vfs_set_dqblk
1026 };
1027 #endif
1028
1029 static const struct super_operations ext4_sops = {
1030         .alloc_inode    = ext4_alloc_inode,
1031         .destroy_inode  = ext4_destroy_inode,
1032         .write_inode    = ext4_write_inode,
1033         .dirty_inode    = ext4_dirty_inode,
1034         .delete_inode   = ext4_delete_inode,
1035         .put_super      = ext4_put_super,
1036         .sync_fs        = ext4_sync_fs,
1037         .freeze_fs      = ext4_freeze,
1038         .unfreeze_fs    = ext4_unfreeze,
1039         .statfs         = ext4_statfs,
1040         .remount_fs     = ext4_remount,
1041         .clear_inode    = ext4_clear_inode,
1042         .show_options   = ext4_show_options,
1043 #ifdef CONFIG_QUOTA
1044         .quota_read     = ext4_quota_read,
1045         .quota_write    = ext4_quota_write,
1046 #endif
1047         .bdev_try_to_free_page = bdev_try_to_free_page,
1048 };
1049
1050 static const struct super_operations ext4_nojournal_sops = {
1051         .alloc_inode    = ext4_alloc_inode,
1052         .destroy_inode  = ext4_destroy_inode,
1053         .write_inode    = ext4_write_inode,
1054         .dirty_inode    = ext4_dirty_inode,
1055         .delete_inode   = ext4_delete_inode,
1056         .write_super    = ext4_write_super,
1057         .put_super      = ext4_put_super,
1058         .statfs         = ext4_statfs,
1059         .remount_fs     = ext4_remount,
1060         .clear_inode    = ext4_clear_inode,
1061         .show_options   = ext4_show_options,
1062 #ifdef CONFIG_QUOTA
1063         .quota_read     = ext4_quota_read,
1064         .quota_write    = ext4_quota_write,
1065 #endif
1066         .bdev_try_to_free_page = bdev_try_to_free_page,
1067 };
1068
1069 static const struct export_operations ext4_export_ops = {
1070         .fh_to_dentry = ext4_fh_to_dentry,
1071         .fh_to_parent = ext4_fh_to_parent,
1072         .get_parent = ext4_get_parent,
1073 };
1074
1075 enum {
1076         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1077         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1078         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1079         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1080         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1081         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1082         Opt_journal_update, Opt_journal_dev,
1083         Opt_journal_checksum, Opt_journal_async_commit,
1084         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1085         Opt_data_err_abort, Opt_data_err_ignore,
1086         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1087         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
1088         Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err, Opt_resize,
1089         Opt_usrquota, Opt_grpquota, Opt_i_version,
1090         Opt_stripe, Opt_delalloc, Opt_nodelalloc,
1091         Opt_block_validity, Opt_noblock_validity,
1092         Opt_inode_readahead_blks, Opt_journal_ioprio,
1093         Opt_discard, Opt_nodiscard,
1094 };
1095
1096 static const match_table_t tokens = {
1097         {Opt_bsd_df, "bsddf"},
1098         {Opt_minix_df, "minixdf"},
1099         {Opt_grpid, "grpid"},
1100         {Opt_grpid, "bsdgroups"},
1101         {Opt_nogrpid, "nogrpid"},
1102         {Opt_nogrpid, "sysvgroups"},
1103         {Opt_resgid, "resgid=%u"},
1104         {Opt_resuid, "resuid=%u"},
1105         {Opt_sb, "sb=%u"},
1106         {Opt_err_cont, "errors=continue"},
1107         {Opt_err_panic, "errors=panic"},
1108         {Opt_err_ro, "errors=remount-ro"},
1109         {Opt_nouid32, "nouid32"},
1110         {Opt_debug, "debug"},
1111         {Opt_oldalloc, "oldalloc"},
1112         {Opt_orlov, "orlov"},
1113         {Opt_user_xattr, "user_xattr"},
1114         {Opt_nouser_xattr, "nouser_xattr"},
1115         {Opt_acl, "acl"},
1116         {Opt_noacl, "noacl"},
1117         {Opt_noload, "noload"},
1118         {Opt_noload, "norecovery"},
1119         {Opt_nobh, "nobh"},
1120         {Opt_bh, "bh"},
1121         {Opt_commit, "commit=%u"},
1122         {Opt_min_batch_time, "min_batch_time=%u"},
1123         {Opt_max_batch_time, "max_batch_time=%u"},
1124         {Opt_journal_update, "journal=update"},
1125         {Opt_journal_dev, "journal_dev=%u"},
1126         {Opt_journal_checksum, "journal_checksum"},
1127         {Opt_journal_async_commit, "journal_async_commit"},
1128         {Opt_abort, "abort"},
1129         {Opt_data_journal, "data=journal"},
1130         {Opt_data_ordered, "data=ordered"},
1131         {Opt_data_writeback, "data=writeback"},
1132         {Opt_data_err_abort, "data_err=abort"},
1133         {Opt_data_err_ignore, "data_err=ignore"},
1134         {Opt_offusrjquota, "usrjquota="},
1135         {Opt_usrjquota, "usrjquota=%s"},
1136         {Opt_offgrpjquota, "grpjquota="},
1137         {Opt_grpjquota, "grpjquota=%s"},
1138         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1139         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1140         {Opt_grpquota, "grpquota"},
1141         {Opt_noquota, "noquota"},
1142         {Opt_quota, "quota"},
1143         {Opt_usrquota, "usrquota"},
1144         {Opt_barrier, "barrier=%u"},
1145         {Opt_barrier, "barrier"},
1146         {Opt_nobarrier, "nobarrier"},
1147         {Opt_i_version, "i_version"},
1148         {Opt_stripe, "stripe=%u"},
1149         {Opt_resize, "resize"},
1150         {Opt_delalloc, "delalloc"},
1151         {Opt_nodelalloc, "nodelalloc"},
1152         {Opt_block_validity, "block_validity"},
1153         {Opt_noblock_validity, "noblock_validity"},
1154         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1155         {Opt_journal_ioprio, "journal_ioprio=%u"},
1156         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1157         {Opt_auto_da_alloc, "auto_da_alloc"},
1158         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1159         {Opt_discard, "discard"},
1160         {Opt_nodiscard, "nodiscard"},
1161         {Opt_err, NULL},
1162 };
1163
1164 static ext4_fsblk_t get_sb_block(void **data)
1165 {
1166         ext4_fsblk_t    sb_block;
1167         char            *options = (char *) *data;
1168
1169         if (!options || strncmp(options, "sb=", 3) != 0)
1170                 return 1;       /* Default location */
1171
1172         options += 3;
1173         /* TODO: use simple_strtoll with >32bit ext4 */
1174         sb_block = simple_strtoul(options, &options, 0);
1175         if (*options && *options != ',') {
1176                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1177                        (char *) *data);
1178                 return 1;
1179         }
1180         if (*options == ',')
1181                 options++;
1182         *data = (void *) options;
1183
1184         return sb_block;
1185 }
1186
1187 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1188
1189 static int parse_options(char *options, struct super_block *sb,
1190                          unsigned long *journal_devnum,
1191                          unsigned int *journal_ioprio,
1192                          ext4_fsblk_t *n_blocks_count, int is_remount)
1193 {
1194         struct ext4_sb_info *sbi = EXT4_SB(sb);
1195         char *p;
1196         substring_t args[MAX_OPT_ARGS];
1197         int data_opt = 0;
1198         int option;
1199 #ifdef CONFIG_QUOTA
1200         int qtype, qfmt;
1201         char *qname;
1202 #endif
1203
1204         if (!options)
1205                 return 1;
1206
1207         while ((p = strsep(&options, ",")) != NULL) {
1208                 int token;
1209                 if (!*p)
1210                         continue;
1211
1212                 token = match_token(p, tokens, args);
1213                 switch (token) {
1214                 case Opt_bsd_df:
1215                         clear_opt(sbi->s_mount_opt, MINIX_DF);
1216                         break;
1217                 case Opt_minix_df:
1218                         set_opt(sbi->s_mount_opt, MINIX_DF);
1219                         break;
1220                 case Opt_grpid:
1221                         set_opt(sbi->s_mount_opt, GRPID);
1222                         break;
1223                 case Opt_nogrpid:
1224                         clear_opt(sbi->s_mount_opt, GRPID);
1225                         break;
1226                 case Opt_resuid:
1227                         if (match_int(&args[0], &option))
1228                                 return 0;
1229                         sbi->s_resuid = option;
1230                         break;
1231                 case Opt_resgid:
1232                         if (match_int(&args[0], &option))
1233                                 return 0;
1234                         sbi->s_resgid = option;
1235                         break;
1236                 case Opt_sb:
1237                         /* handled by get_sb_block() instead of here */
1238                         /* *sb_block = match_int(&args[0]); */
1239                         break;
1240                 case Opt_err_panic:
1241                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1242                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1243                         set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1244                         break;
1245                 case Opt_err_ro:
1246                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1247                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1248                         set_opt(sbi->s_mount_opt, ERRORS_RO);
1249                         break;
1250                 case Opt_err_cont:
1251                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1252                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1253                         set_opt(sbi->s_mount_opt, ERRORS_CONT);
1254                         break;
1255                 case Opt_nouid32:
1256                         set_opt(sbi->s_mount_opt, NO_UID32);
1257                         break;
1258                 case Opt_debug:
1259                         set_opt(sbi->s_mount_opt, DEBUG);
1260                         break;
1261                 case Opt_oldalloc:
1262                         set_opt(sbi->s_mount_opt, OLDALLOC);
1263                         break;
1264                 case Opt_orlov:
1265                         clear_opt(sbi->s_mount_opt, OLDALLOC);
1266                         break;
1267 #ifdef CONFIG_EXT4_FS_XATTR
1268                 case Opt_user_xattr:
1269                         set_opt(sbi->s_mount_opt, XATTR_USER);
1270                         break;
1271                 case Opt_nouser_xattr:
1272                         clear_opt(sbi->s_mount_opt, XATTR_USER);
1273                         break;
1274 #else
1275                 case Opt_user_xattr:
1276                 case Opt_nouser_xattr:
1277                         ext4_msg(sb, KERN_ERR, "(no)user_xattr options not supported");
1278                         break;
1279 #endif
1280 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1281                 case Opt_acl:
1282                         set_opt(sbi->s_mount_opt, POSIX_ACL);
1283                         break;
1284                 case Opt_noacl:
1285                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
1286                         break;
1287 #else
1288                 case Opt_acl:
1289                 case Opt_noacl:
1290                         ext4_msg(sb, KERN_ERR, "(no)acl options not supported");
1291                         break;
1292 #endif
1293                 case Opt_journal_update:
1294                         /* @@@ FIXME */
1295                         /* Eventually we will want to be able to create
1296                            a journal file here.  For now, only allow the
1297                            user to specify an existing inode to be the
1298                            journal file. */
1299                         if (is_remount) {
1300                                 ext4_msg(sb, KERN_ERR,
1301                                          "Cannot specify journal on remount");
1302                                 return 0;
1303                         }
1304                         set_opt(sbi->s_mount_opt, UPDATE_JOURNAL);
1305                         break;
1306                 case Opt_journal_dev:
1307                         if (is_remount) {
1308                                 ext4_msg(sb, KERN_ERR,
1309                                         "Cannot specify journal on remount");
1310                                 return 0;
1311                         }
1312                         if (match_int(&args[0], &option))
1313                                 return 0;
1314                         *journal_devnum = option;
1315                         break;
1316                 case Opt_journal_checksum:
1317                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1318                         break;
1319                 case Opt_journal_async_commit:
1320                         set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1321                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1322                         break;
1323                 case Opt_noload:
1324                         set_opt(sbi->s_mount_opt, NOLOAD);
1325                         break;
1326                 case Opt_commit:
1327                         if (match_int(&args[0], &option))
1328                                 return 0;
1329                         if (option < 0)
1330                                 return 0;
1331                         if (option == 0)
1332                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1333                         sbi->s_commit_interval = HZ * option;
1334                         break;
1335                 case Opt_max_batch_time:
1336                         if (match_int(&args[0], &option))
1337                                 return 0;
1338                         if (option < 0)
1339                                 return 0;
1340                         if (option == 0)
1341                                 option = EXT4_DEF_MAX_BATCH_TIME;
1342                         sbi->s_max_batch_time = option;
1343                         break;
1344                 case Opt_min_batch_time:
1345                         if (match_int(&args[0], &option))
1346                                 return 0;
1347                         if (option < 0)
1348                                 return 0;
1349                         sbi->s_min_batch_time = option;
1350                         break;
1351                 case Opt_data_journal:
1352                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1353                         goto datacheck;
1354                 case Opt_data_ordered:
1355                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1356                         goto datacheck;
1357                 case Opt_data_writeback:
1358                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1359                 datacheck:
1360                         if (is_remount) {
1361                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1362                                                 != data_opt) {
1363                                         ext4_msg(sb, KERN_ERR,
1364                                                 "Cannot change data mode on remount");
1365                                         return 0;
1366                                 }
1367                         } else {
1368                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1369                                 sbi->s_mount_opt |= data_opt;
1370                         }
1371                         break;
1372                 case Opt_data_err_abort:
1373                         set_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1374                         break;
1375                 case Opt_data_err_ignore:
1376                         clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1377                         break;
1378 #ifdef CONFIG_QUOTA
1379                 case Opt_usrjquota:
1380                         qtype = USRQUOTA;
1381                         goto set_qf_name;
1382                 case Opt_grpjquota:
1383                         qtype = GRPQUOTA;
1384 set_qf_name:
1385                         if (sb_any_quota_loaded(sb) &&
1386                             !sbi->s_qf_names[qtype]) {
1387                                 ext4_msg(sb, KERN_ERR,
1388                                        "Cannot change journaled "
1389                                        "quota options when quota turned on");
1390                                 return 0;
1391                         }
1392                         qname = match_strdup(&args[0]);
1393                         if (!qname) {
1394                                 ext4_msg(sb, KERN_ERR,
1395                                         "Not enough memory for "
1396                                         "storing quotafile name");
1397                                 return 0;
1398                         }
1399                         if (sbi->s_qf_names[qtype] &&
1400                             strcmp(sbi->s_qf_names[qtype], qname)) {
1401                                 ext4_msg(sb, KERN_ERR,
1402                                         "%s quota file already "
1403                                         "specified", QTYPE2NAME(qtype));
1404                                 kfree(qname);
1405                                 return 0;
1406                         }
1407                         sbi->s_qf_names[qtype] = qname;
1408                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1409                                 ext4_msg(sb, KERN_ERR,
1410                                         "quotafile must be on "
1411                                         "filesystem root");
1412                                 kfree(sbi->s_qf_names[qtype]);
1413                                 sbi->s_qf_names[qtype] = NULL;
1414                                 return 0;
1415                         }
1416                         set_opt(sbi->s_mount_opt, QUOTA);
1417                         break;
1418                 case Opt_offusrjquota:
1419                         qtype = USRQUOTA;
1420                         goto clear_qf_name;
1421                 case Opt_offgrpjquota:
1422                         qtype = GRPQUOTA;
1423 clear_qf_name:
1424                         if (sb_any_quota_loaded(sb) &&
1425                             sbi->s_qf_names[qtype]) {
1426                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1427                                         "journaled quota options when "
1428                                         "quota turned on");
1429                                 return 0;
1430                         }
1431                         /*
1432                          * The space will be released later when all options
1433                          * are confirmed to be correct
1434                          */
1435                         sbi->s_qf_names[qtype] = NULL;
1436                         break;
1437                 case Opt_jqfmt_vfsold:
1438                         qfmt = QFMT_VFS_OLD;
1439                         goto set_qf_format;
1440                 case Opt_jqfmt_vfsv0:
1441                         qfmt = QFMT_VFS_V0;
1442 set_qf_format:
1443                         if (sb_any_quota_loaded(sb) &&
1444                             sbi->s_jquota_fmt != qfmt) {
1445                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1446                                         "journaled quota options when "
1447                                         "quota turned on");
1448                                 return 0;
1449                         }
1450                         sbi->s_jquota_fmt = qfmt;
1451                         break;
1452                 case Opt_quota:
1453                 case Opt_usrquota:
1454                         set_opt(sbi->s_mount_opt, QUOTA);
1455                         set_opt(sbi->s_mount_opt, USRQUOTA);
1456                         break;
1457                 case Opt_grpquota:
1458                         set_opt(sbi->s_mount_opt, QUOTA);
1459                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1460                         break;
1461                 case Opt_noquota:
1462                         if (sb_any_quota_loaded(sb)) {
1463                                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1464                                         "options when quota turned on");
1465                                 return 0;
1466                         }
1467                         clear_opt(sbi->s_mount_opt, QUOTA);
1468                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1469                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1470                         break;
1471 #else
1472                 case Opt_quota:
1473                 case Opt_usrquota:
1474                 case Opt_grpquota:
1475                         ext4_msg(sb, KERN_ERR,
1476                                 "quota options not supported");
1477                         break;
1478                 case Opt_usrjquota:
1479                 case Opt_grpjquota:
1480                 case Opt_offusrjquota:
1481                 case Opt_offgrpjquota:
1482                 case Opt_jqfmt_vfsold:
1483                 case Opt_jqfmt_vfsv0:
1484                         ext4_msg(sb, KERN_ERR,
1485                                 "journaled quota options not supported");
1486                         break;
1487                 case Opt_noquota:
1488                         break;
1489 #endif
1490                 case Opt_abort:
1491                         sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1492                         break;
1493                 case Opt_nobarrier:
1494                         clear_opt(sbi->s_mount_opt, BARRIER);
1495                         break;
1496                 case Opt_barrier:
1497                         if (match_int(&args[0], &option)) {
1498                                 set_opt(sbi->s_mount_opt, BARRIER);
1499                                 break;
1500                         }
1501                         if (option)
1502                                 set_opt(sbi->s_mount_opt, BARRIER);
1503                         else
1504                                 clear_opt(sbi->s_mount_opt, BARRIER);
1505                         break;
1506                 case Opt_ignore:
1507                         break;
1508                 case Opt_resize:
1509                         if (!is_remount) {
1510                                 ext4_msg(sb, KERN_ERR,
1511                                         "resize option only available "
1512                                         "for remount");
1513                                 return 0;
1514                         }
1515                         if (match_int(&args[0], &option) != 0)
1516                                 return 0;
1517                         *n_blocks_count = option;
1518                         break;
1519                 case Opt_nobh:
1520                         set_opt(sbi->s_mount_opt, NOBH);
1521                         break;
1522                 case Opt_bh:
1523                         clear_opt(sbi->s_mount_opt, NOBH);
1524                         break;
1525                 case Opt_i_version:
1526                         set_opt(sbi->s_mount_opt, I_VERSION);
1527                         sb->s_flags |= MS_I_VERSION;
1528                         break;
1529                 case Opt_nodelalloc:
1530                         clear_opt(sbi->s_mount_opt, DELALLOC);
1531                         break;
1532                 case Opt_stripe:
1533                         if (match_int(&args[0], &option))
1534                                 return 0;
1535                         if (option < 0)
1536                                 return 0;
1537                         sbi->s_stripe = option;
1538                         break;
1539                 case Opt_delalloc:
1540                         set_opt(sbi->s_mount_opt, DELALLOC);
1541                         break;
1542                 case Opt_block_validity:
1543                         set_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1544                         break;
1545                 case Opt_noblock_validity:
1546                         clear_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1547                         break;
1548                 case Opt_inode_readahead_blks:
1549                         if (match_int(&args[0], &option))
1550                                 return 0;
1551                         if (option < 0 || option > (1 << 30))
1552                                 return 0;
1553                         if (!is_power_of_2(option)) {
1554                                 ext4_msg(sb, KERN_ERR,
1555                                          "EXT4-fs: inode_readahead_blks"
1556                                          " must be a power of 2");
1557                                 return 0;
1558                         }
1559                         sbi->s_inode_readahead_blks = option;
1560                         break;
1561                 case Opt_journal_ioprio:
1562                         if (match_int(&args[0], &option))
1563                                 return 0;
1564                         if (option < 0 || option > 7)
1565                                 break;
1566                         *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1567                                                             option);
1568                         break;
1569                 case Opt_noauto_da_alloc:
1570                         set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1571                         break;
1572                 case Opt_auto_da_alloc:
1573                         if (match_int(&args[0], &option)) {
1574                                 clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1575                                 break;
1576                         }
1577                         if (option)
1578                                 clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1579                         else
1580                                 set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1581                         break;
1582                 case Opt_discard:
1583                         set_opt(sbi->s_mount_opt, DISCARD);
1584                         break;
1585                 case Opt_nodiscard:
1586                         clear_opt(sbi->s_mount_opt, DISCARD);
1587                         break;
1588                 default:
1589                         ext4_msg(sb, KERN_ERR,
1590                                "Unrecognized mount option \"%s\" "
1591                                "or missing value", p);
1592                         return 0;
1593                 }
1594         }
1595 #ifdef CONFIG_QUOTA
1596         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1597                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1598                      sbi->s_qf_names[USRQUOTA])
1599                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1600
1601                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1602                      sbi->s_qf_names[GRPQUOTA])
1603                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1604
1605                 if ((sbi->s_qf_names[USRQUOTA] &&
1606                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1607                     (sbi->s_qf_names[GRPQUOTA] &&
1608                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1609                         ext4_msg(sb, KERN_ERR, "old and new quota "
1610                                         "format mixing");
1611                         return 0;
1612                 }
1613
1614                 if (!sbi->s_jquota_fmt) {
1615                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1616                                         "not specified");
1617                         return 0;
1618                 }
1619         } else {
1620                 if (sbi->s_jquota_fmt) {
1621                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1622                                         "specified with no journaling "
1623                                         "enabled");
1624                         return 0;
1625                 }
1626         }
1627 #endif
1628         return 1;
1629 }
1630
1631 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1632                             int read_only)
1633 {
1634         struct ext4_sb_info *sbi = EXT4_SB(sb);
1635         int res = 0;
1636
1637         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1638                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1639                          "forcing read-only mode");
1640                 res = MS_RDONLY;
1641         }
1642         if (read_only)
1643                 return res;
1644         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1645                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1646                          "running e2fsck is recommended");
1647         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1648                 ext4_msg(sb, KERN_WARNING,
1649                          "warning: mounting fs with errors, "
1650                          "running e2fsck is recommended");
1651         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1652                  le16_to_cpu(es->s_mnt_count) >=
1653                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1654                 ext4_msg(sb, KERN_WARNING,
1655                          "warning: maximal mount count reached, "
1656                          "running e2fsck is recommended");
1657         else if (le32_to_cpu(es->s_checkinterval) &&
1658                 (le32_to_cpu(es->s_lastcheck) +
1659                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1660                 ext4_msg(sb, KERN_WARNING,
1661                          "warning: checktime reached, "
1662                          "running e2fsck is recommended");
1663         if (!sbi->s_journal)
1664                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1665         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1666                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1667         le16_add_cpu(&es->s_mnt_count, 1);
1668         es->s_mtime = cpu_to_le32(get_seconds());
1669         ext4_update_dynamic_rev(sb);
1670         if (sbi->s_journal)
1671                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1672
1673         ext4_commit_super(sb, 1);
1674         if (test_opt(sb, DEBUG))
1675                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1676                                 "bpg=%lu, ipg=%lu, mo=%04x]\n",
1677                         sb->s_blocksize,
1678                         sbi->s_groups_count,
1679                         EXT4_BLOCKS_PER_GROUP(sb),
1680                         EXT4_INODES_PER_GROUP(sb),
1681                         sbi->s_mount_opt);
1682
1683         return res;
1684 }
1685
1686 static int ext4_fill_flex_info(struct super_block *sb)
1687 {
1688         struct ext4_sb_info *sbi = EXT4_SB(sb);
1689         struct ext4_group_desc *gdp = NULL;
1690         ext4_group_t flex_group_count;
1691         ext4_group_t flex_group;
1692         int groups_per_flex = 0;
1693         size_t size;
1694         int i;
1695
1696         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1697         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1698
1699         if (groups_per_flex < 2) {
1700                 sbi->s_log_groups_per_flex = 0;
1701                 return 1;
1702         }
1703
1704         /* We allocate both existing and potentially added groups */
1705         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1706                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1707                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1708         size = flex_group_count * sizeof(struct flex_groups);
1709         sbi->s_flex_groups = kzalloc(size, GFP_KERNEL);
1710         if (sbi->s_flex_groups == NULL) {
1711                 sbi->s_flex_groups = vmalloc(size);
1712                 if (sbi->s_flex_groups)
1713                         memset(sbi->s_flex_groups, 0, size);
1714         }
1715         if (sbi->s_flex_groups == NULL) {
1716                 ext4_msg(sb, KERN_ERR, "not enough memory for "
1717                                 "%u flex groups", flex_group_count);
1718                 goto failed;
1719         }
1720
1721         for (i = 0; i < sbi->s_groups_count; i++) {
1722                 gdp = ext4_get_group_desc(sb, i, NULL);
1723
1724                 flex_group = ext4_flex_group(sbi, i);
1725                 atomic_add(ext4_free_inodes_count(sb, gdp),
1726                            &sbi->s_flex_groups[flex_group].free_inodes);
1727                 atomic_add(ext4_free_blks_count(sb, gdp),
1728                            &sbi->s_flex_groups[flex_group].free_blocks);
1729                 atomic_add(ext4_used_dirs_count(sb, gdp),
1730                            &sbi->s_flex_groups[flex_group].used_dirs);
1731         }
1732
1733         return 1;
1734 failed:
1735         return 0;
1736 }
1737
1738 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1739                             struct ext4_group_desc *gdp)
1740 {
1741         __u16 crc = 0;
1742
1743         if (sbi->s_es->s_feature_ro_compat &
1744             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1745                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1746                 __le32 le_group = cpu_to_le32(block_group);
1747
1748                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1749                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1750                 crc = crc16(crc, (__u8 *)gdp, offset);
1751                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1752                 /* for checksum of struct ext4_group_desc do the rest...*/
1753                 if ((sbi->s_es->s_feature_incompat &
1754                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1755                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1756                         crc = crc16(crc, (__u8 *)gdp + offset,
1757                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1758                                         offset);
1759         }
1760
1761         return cpu_to_le16(crc);
1762 }
1763
1764 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1765                                 struct ext4_group_desc *gdp)
1766 {
1767         if ((sbi->s_es->s_feature_ro_compat &
1768              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1769             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1770                 return 0;
1771
1772         return 1;
1773 }
1774
1775 /* Called at mount-time, super-block is locked */
1776 static int ext4_check_descriptors(struct super_block *sb)
1777 {
1778         struct ext4_sb_info *sbi = EXT4_SB(sb);
1779         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1780         ext4_fsblk_t last_block;
1781         ext4_fsblk_t block_bitmap;
1782         ext4_fsblk_t inode_bitmap;
1783         ext4_fsblk_t inode_table;
1784         int flexbg_flag = 0;
1785         ext4_group_t i;
1786
1787         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1788                 flexbg_flag = 1;
1789
1790         ext4_debug("Checking group descriptors");
1791
1792         for (i = 0; i < sbi->s_groups_count; i++) {
1793                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1794
1795                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1796                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1797                 else
1798                         last_block = first_block +
1799                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1800
1801                 block_bitmap = ext4_block_bitmap(sb, gdp);
1802                 if (block_bitmap < first_block || block_bitmap > last_block) {
1803                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1804                                "Block bitmap for group %u not in group "
1805                                "(block %llu)!", i, block_bitmap);
1806                         return 0;
1807                 }
1808                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1809                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
1810                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1811                                "Inode bitmap for group %u not in group "
1812                                "(block %llu)!", i, inode_bitmap);
1813                         return 0;
1814                 }
1815                 inode_table = ext4_inode_table(sb, gdp);
1816                 if (inode_table < first_block ||
1817                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
1818                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1819                                "Inode table for group %u not in group "
1820                                "(block %llu)!", i, inode_table);
1821                         return 0;
1822                 }
1823                 ext4_lock_group(sb, i);
1824                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1825                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1826                                  "Checksum for group %u failed (%u!=%u)",
1827                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1828                                      gdp)), le16_to_cpu(gdp->bg_checksum));
1829                         if (!(sb->s_flags & MS_RDONLY)) {
1830                                 ext4_unlock_group(sb, i);
1831                                 return 0;
1832                         }
1833                 }
1834                 ext4_unlock_group(sb, i);
1835                 if (!flexbg_flag)
1836                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1837         }
1838
1839         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1840         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
1841         return 1;
1842 }
1843
1844 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1845  * the superblock) which were deleted from all directories, but held open by
1846  * a process at the time of a crash.  We walk the list and try to delete these
1847  * inodes at recovery time (only with a read-write filesystem).
1848  *
1849  * In order to keep the orphan inode chain consistent during traversal (in
1850  * case of crash during recovery), we link each inode into the superblock
1851  * orphan list_head and handle it the same way as an inode deletion during
1852  * normal operation (which journals the operations for us).
1853  *
1854  * We only do an iget() and an iput() on each inode, which is very safe if we
1855  * accidentally point at an in-use or already deleted inode.  The worst that
1856  * can happen in this case is that we get a "bit already cleared" message from
1857  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1858  * e2fsck was run on this filesystem, and it must have already done the orphan
1859  * inode cleanup for us, so we can safely abort without any further action.
1860  */
1861 static void ext4_orphan_cleanup(struct super_block *sb,
1862                                 struct ext4_super_block *es)
1863 {
1864         unsigned int s_flags = sb->s_flags;
1865         int nr_orphans = 0, nr_truncates = 0;
1866 #ifdef CONFIG_QUOTA
1867         int i;
1868 #endif
1869         if (!es->s_last_orphan) {
1870                 jbd_debug(4, "no orphan inodes to clean up\n");
1871                 return;
1872         }
1873
1874         if (bdev_read_only(sb->s_bdev)) {
1875                 ext4_msg(sb, KERN_ERR, "write access "
1876                         "unavailable, skipping orphan cleanup");
1877                 return;
1878         }
1879
1880         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1881                 if (es->s_last_orphan)
1882                         jbd_debug(1, "Errors on filesystem, "
1883                                   "clearing orphan list.\n");
1884                 es->s_last_orphan = 0;
1885                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1886                 return;
1887         }
1888
1889         if (s_flags & MS_RDONLY) {
1890                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
1891                 sb->s_flags &= ~MS_RDONLY;
1892         }
1893 #ifdef CONFIG_QUOTA
1894         /* Needed for iput() to work correctly and not trash data */
1895         sb->s_flags |= MS_ACTIVE;
1896         /* Turn on quotas so that they are updated correctly */
1897         for (i = 0; i < MAXQUOTAS; i++) {
1898                 if (EXT4_SB(sb)->s_qf_names[i]) {
1899                         int ret = ext4_quota_on_mount(sb, i);
1900                         if (ret < 0)
1901                                 ext4_msg(sb, KERN_ERR,
1902                                         "Cannot turn on journaled "
1903                                         "quota: error %d", ret);
1904                 }
1905         }
1906 #endif
1907
1908         while (es->s_last_orphan) {
1909                 struct inode *inode;
1910
1911                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
1912                 if (IS_ERR(inode)) {
1913                         es->s_last_orphan = 0;
1914                         break;
1915                 }
1916
1917                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1918                 vfs_dq_init(inode);
1919                 if (inode->i_nlink) {
1920                         ext4_msg(sb, KERN_DEBUG,
1921                                 "%s: truncating inode %lu to %lld bytes",
1922                                 __func__, inode->i_ino, inode->i_size);
1923                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
1924                                   inode->i_ino, inode->i_size);
1925                         ext4_truncate(inode);
1926                         nr_truncates++;
1927                 } else {
1928                         ext4_msg(sb, KERN_DEBUG,
1929                                 "%s: deleting unreferenced inode %lu",
1930                                 __func__, inode->i_ino);
1931                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1932                                   inode->i_ino);
1933                         nr_orphans++;
1934                 }
1935                 iput(inode);  /* The delete magic happens here! */
1936         }
1937
1938 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
1939
1940         if (nr_orphans)
1941                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
1942                        PLURAL(nr_orphans));
1943         if (nr_truncates)
1944                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
1945                        PLURAL(nr_truncates));
1946 #ifdef CONFIG_QUOTA
1947         /* Turn quotas off */
1948         for (i = 0; i < MAXQUOTAS; i++) {
1949                 if (sb_dqopt(sb)->files[i])
1950                         vfs_quota_off(sb, i, 0);
1951         }
1952 #endif
1953         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1954 }
1955
1956 /*
1957  * Maximal extent format file size.
1958  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1959  * extent format containers, within a sector_t, and within i_blocks
1960  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1961  * so that won't be a limiting factor.
1962  *
1963  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1964  */
1965 static loff_t ext4_max_size(int blkbits, int has_huge_files)
1966 {
1967         loff_t res;
1968         loff_t upper_limit = MAX_LFS_FILESIZE;
1969
1970         /* small i_blocks in vfs inode? */
1971         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1972                 /*
1973                  * CONFIG_LBDAF is not enabled implies the inode
1974                  * i_block represent total blocks in 512 bytes
1975                  * 32 == size of vfs inode i_blocks * 8
1976                  */
1977                 upper_limit = (1LL << 32) - 1;
1978
1979                 /* total blocks in file system block size */
1980                 upper_limit >>= (blkbits - 9);
1981                 upper_limit <<= blkbits;
1982         }
1983
1984         /* 32-bit extent-start container, ee_block */
1985         res = 1LL << 32;
1986         res <<= blkbits;
1987         res -= 1;
1988
1989         /* Sanity check against vm- & vfs- imposed limits */
1990         if (res > upper_limit)
1991                 res = upper_limit;
1992
1993         return res;
1994 }
1995
1996 /*
1997  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
1998  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
1999  * We need to be 1 filesystem block less than the 2^48 sector limit.
2000  */
2001 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2002 {
2003         loff_t res = EXT4_NDIR_BLOCKS;
2004         int meta_blocks;
2005         loff_t upper_limit;
2006         /* This is calculated to be the largest file size for a dense, block
2007          * mapped file such that the file's total number of 512-byte sectors,
2008          * including data and all indirect blocks, does not exceed (2^48 - 1).
2009          *
2010          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2011          * number of 512-byte sectors of the file.
2012          */
2013
2014         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2015                 /*
2016                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2017                  * the inode i_block field represents total file blocks in
2018                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2019                  */
2020                 upper_limit = (1LL << 32) - 1;
2021
2022                 /* total blocks in file system block size */
2023                 upper_limit >>= (bits - 9);
2024
2025         } else {
2026                 /*
2027                  * We use 48 bit ext4_inode i_blocks
2028                  * With EXT4_HUGE_FILE_FL set the i_blocks
2029                  * represent total number of blocks in
2030                  * file system block size
2031                  */
2032                 upper_limit = (1LL << 48) - 1;
2033
2034         }
2035
2036         /* indirect blocks */
2037         meta_blocks = 1;
2038         /* double indirect blocks */
2039         meta_blocks += 1 + (1LL << (bits-2));
2040         /* tripple indirect blocks */
2041         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2042
2043         upper_limit -= meta_blocks;
2044         upper_limit <<= bits;
2045
2046         res += 1LL << (bits-2);
2047         res += 1LL << (2*(bits-2));
2048         res += 1LL << (3*(bits-2));
2049         res <<= bits;
2050         if (res > upper_limit)
2051                 res = upper_limit;
2052
2053         if (res > MAX_LFS_FILESIZE)
2054                 res = MAX_LFS_FILESIZE;
2055
2056         return res;
2057 }
2058
2059 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2060                                    ext4_fsblk_t logical_sb_block, int nr)
2061 {
2062         struct ext4_sb_info *sbi = EXT4_SB(sb);
2063         ext4_group_t bg, first_meta_bg;
2064         int has_super = 0;
2065
2066         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2067
2068         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2069             nr < first_meta_bg)
2070                 return logical_sb_block + nr + 1;
2071         bg = sbi->s_desc_per_block * nr;
2072         if (ext4_bg_has_super(sb, bg))
2073                 has_super = 1;
2074
2075         return (has_super + ext4_group_first_block_no(sb, bg));
2076 }
2077
2078 /**
2079  * ext4_get_stripe_size: Get the stripe size.
2080  * @sbi: In memory super block info
2081  *
2082  * If we have specified it via mount option, then
2083  * use the mount option value. If the value specified at mount time is
2084  * greater than the blocks per group use the super block value.
2085  * If the super block value is greater than blocks per group return 0.
2086  * Allocator needs it be less than blocks per group.
2087  *
2088  */
2089 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2090 {
2091         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2092         unsigned long stripe_width =
2093                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2094
2095         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2096                 return sbi->s_stripe;
2097
2098         if (stripe_width <= sbi->s_blocks_per_group)
2099                 return stripe_width;
2100
2101         if (stride <= sbi->s_blocks_per_group)
2102                 return stride;
2103
2104         return 0;
2105 }
2106
2107 /* sysfs supprt */
2108
2109 struct ext4_attr {
2110         struct attribute attr;
2111         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2112         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2113                          const char *, size_t);
2114         int offset;
2115 };
2116
2117 static int parse_strtoul(const char *buf,
2118                 unsigned long max, unsigned long *value)
2119 {
2120         char *endp;
2121
2122         while (*buf && isspace(*buf))
2123                 buf++;
2124         *value = simple_strtoul(buf, &endp, 0);
2125         while (*endp && isspace(*endp))
2126                 endp++;
2127         if (*endp || *value > max)
2128                 return -EINVAL;
2129
2130         return 0;
2131 }
2132
2133 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2134                                               struct ext4_sb_info *sbi,
2135                                               char *buf)
2136 {
2137         return snprintf(buf, PAGE_SIZE, "%llu\n",
2138                         (s64) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2139 }
2140
2141 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2142                                          struct ext4_sb_info *sbi, char *buf)
2143 {
2144         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2145
2146         return snprintf(buf, PAGE_SIZE, "%lu\n",
2147                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2148                          sbi->s_sectors_written_start) >> 1);
2149 }
2150
2151 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2152                                           struct ext4_sb_info *sbi, char *buf)
2153 {
2154         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2155
2156         return snprintf(buf, PAGE_SIZE, "%llu\n",
2157                         sbi->s_kbytes_written +
2158                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2159                           EXT4_SB(sb)->s_sectors_written_start) >> 1));
2160 }
2161
2162 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2163                                           struct ext4_sb_info *sbi,
2164                                           const char *buf, size_t count)
2165 {
2166         unsigned long t;
2167
2168         if (parse_strtoul(buf, 0x40000000, &t))
2169                 return -EINVAL;
2170
2171         if (!is_power_of_2(t))
2172                 return -EINVAL;
2173
2174         sbi->s_inode_readahead_blks = t;
2175         return count;
2176 }
2177
2178 static ssize_t sbi_ui_show(struct ext4_attr *a,
2179                            struct ext4_sb_info *sbi, char *buf)
2180 {
2181         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2182
2183         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2184 }
2185
2186 static ssize_t sbi_ui_store(struct ext4_attr *a,
2187                             struct ext4_sb_info *sbi,
2188                             const char *buf, size_t count)
2189 {
2190         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2191         unsigned long t;
2192
2193         if (parse_strtoul(buf, 0xffffffff, &t))
2194                 return -EINVAL;
2195         *ui = t;
2196         return count;
2197 }
2198
2199 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2200 static struct ext4_attr ext4_attr_##_name = {                   \
2201         .attr = {.name = __stringify(_name), .mode = _mode },   \
2202         .show   = _show,                                        \
2203         .store  = _store,                                       \
2204         .offset = offsetof(struct ext4_sb_info, _elname),       \
2205 }
2206 #define EXT4_ATTR(name, mode, show, store) \
2207 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2208
2209 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2210 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2211 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2212         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2213 #define ATTR_LIST(name) &ext4_attr_##name.attr
2214
2215 EXT4_RO_ATTR(delayed_allocation_blocks);
2216 EXT4_RO_ATTR(session_write_kbytes);
2217 EXT4_RO_ATTR(lifetime_write_kbytes);
2218 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2219                  inode_readahead_blks_store, s_inode_readahead_blks);
2220 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2221 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2222 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2223 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2224 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2225 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2226 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2227 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2228
2229 static struct attribute *ext4_attrs[] = {
2230         ATTR_LIST(delayed_allocation_blocks),
2231         ATTR_LIST(session_write_kbytes),
2232         ATTR_LIST(lifetime_write_kbytes),
2233         ATTR_LIST(inode_readahead_blks),
2234         ATTR_LIST(inode_goal),
2235         ATTR_LIST(mb_stats),
2236         ATTR_LIST(mb_max_to_scan),
2237         ATTR_LIST(mb_min_to_scan),
2238         ATTR_LIST(mb_order2_req),
2239         ATTR_LIST(mb_stream_req),
2240         ATTR_LIST(mb_group_prealloc),
2241         ATTR_LIST(max_writeback_mb_bump),
2242         NULL,
2243 };
2244
2245 static ssize_t ext4_attr_show(struct kobject *kobj,
2246                               struct attribute *attr, char *buf)
2247 {
2248         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2249                                                 s_kobj);
2250         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2251
2252         return a->show ? a->show(a, sbi, buf) : 0;
2253 }
2254
2255 static ssize_t ext4_attr_store(struct kobject *kobj,
2256                                struct attribute *attr,
2257                                const char *buf, size_t len)
2258 {
2259         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2260                                                 s_kobj);
2261         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2262
2263         return a->store ? a->store(a, sbi, buf, len) : 0;
2264 }
2265
2266 static void ext4_sb_release(struct kobject *kobj)
2267 {
2268         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2269                                                 s_kobj);
2270         complete(&sbi->s_kobj_unregister);
2271 }
2272
2273
2274 static struct sysfs_ops ext4_attr_ops = {
2275         .show   = ext4_attr_show,
2276         .store  = ext4_attr_store,
2277 };
2278
2279 static struct kobj_type ext4_ktype = {
2280         .default_attrs  = ext4_attrs,
2281         .sysfs_ops      = &ext4_attr_ops,
2282         .release        = ext4_sb_release,
2283 };
2284
2285 /*
2286  * Check whether this filesystem can be mounted based on
2287  * the features present and the RDONLY/RDWR mount requested.
2288  * Returns 1 if this filesystem can be mounted as requested,
2289  * 0 if it cannot be.
2290  */
2291 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2292 {
2293         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2294                 ext4_msg(sb, KERN_ERR,
2295                         "Couldn't mount because of "
2296                         "unsupported optional features (%x)",
2297                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2298                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2299                 return 0;
2300         }
2301
2302         if (readonly)
2303                 return 1;
2304
2305         /* Check that feature set is OK for a read-write mount */
2306         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2307                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2308                          "unsupported optional features (%x)",
2309                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2310                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2311                 return 0;
2312         }
2313         /*
2314          * Large file size enabled file system can only be mounted
2315          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2316          */
2317         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2318                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2319                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2320                                  "cannot be mounted RDWR without "
2321                                  "CONFIG_LBDAF");
2322                         return 0;
2323                 }
2324         }
2325         return 1;
2326 }
2327
2328 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
2329                                 __releases(kernel_lock)
2330                                 __acquires(kernel_lock)
2331 {
2332         struct buffer_head *bh;
2333         struct ext4_super_block *es = NULL;
2334         struct ext4_sb_info *sbi;
2335         ext4_fsblk_t block;
2336         ext4_fsblk_t sb_block = get_sb_block(&data);
2337         ext4_fsblk_t logical_sb_block;
2338         unsigned long offset = 0;
2339         unsigned long journal_devnum = 0;
2340         unsigned long def_mount_opts;
2341         struct inode *root;
2342         char *cp;
2343         const char *descr;
2344         int ret = -EINVAL;
2345         int blocksize;
2346         unsigned int db_count;
2347         unsigned int i;
2348         int needs_recovery, has_huge_files;
2349         __u64 blocks_count;
2350         int err;
2351         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
2352
2353         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
2354         if (!sbi)
2355                 return -ENOMEM;
2356
2357         sbi->s_blockgroup_lock =
2358                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
2359         if (!sbi->s_blockgroup_lock) {
2360                 kfree(sbi);
2361                 return -ENOMEM;
2362         }
2363         sb->s_fs_info = sbi;
2364         sbi->s_mount_opt = 0;
2365         sbi->s_resuid = EXT4_DEF_RESUID;
2366         sbi->s_resgid = EXT4_DEF_RESGID;
2367         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
2368         sbi->s_sb_block = sb_block;
2369         sbi->s_sectors_written_start = part_stat_read(sb->s_bdev->bd_part,
2370                                                       sectors[1]);
2371
2372         unlock_kernel();
2373
2374         /* Cleanup superblock name */
2375         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
2376                 *cp = '!';
2377
2378         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
2379         if (!blocksize) {
2380                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
2381                 goto out_fail;
2382         }
2383
2384         /*
2385          * The ext4 superblock will not be buffer aligned for other than 1kB
2386          * block sizes.  We need to calculate the offset from buffer start.
2387          */
2388         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
2389                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2390                 offset = do_div(logical_sb_block, blocksize);
2391         } else {
2392                 logical_sb_block = sb_block;
2393         }
2394
2395         if (!(bh = sb_bread(sb, logical_sb_block))) {
2396                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
2397                 goto out_fail;
2398         }
2399         /*
2400          * Note: s_es must be initialized as soon as possible because
2401          *       some ext4 macro-instructions depend on its value
2402          */
2403         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2404         sbi->s_es = es;
2405         sb->s_magic = le16_to_cpu(es->s_magic);
2406         if (sb->s_magic != EXT4_SUPER_MAGIC)
2407                 goto cantfind_ext4;
2408         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
2409
2410         /* Set defaults before we parse the mount options */
2411         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
2412         if (def_mount_opts & EXT4_DEFM_DEBUG)
2413                 set_opt(sbi->s_mount_opt, DEBUG);
2414         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
2415                 set_opt(sbi->s_mount_opt, GRPID);
2416         if (def_mount_opts & EXT4_DEFM_UID16)
2417                 set_opt(sbi->s_mount_opt, NO_UID32);
2418 #ifdef CONFIG_EXT4_FS_XATTR
2419         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
2420                 set_opt(sbi->s_mount_opt, XATTR_USER);
2421 #endif
2422 #ifdef CONFIG_EXT4_FS_POSIX_ACL
2423         if (def_mount_opts & EXT4_DEFM_ACL)
2424                 set_opt(sbi->s_mount_opt, POSIX_ACL);
2425 #endif
2426         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
2427                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
2428         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
2429                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
2430         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
2431                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
2432
2433         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
2434                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
2435         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
2436                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
2437         else
2438                 set_opt(sbi->s_mount_opt, ERRORS_RO);
2439
2440         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
2441         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
2442         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
2443         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
2444         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
2445
2446         set_opt(sbi->s_mount_opt, BARRIER);
2447
2448         /*
2449          * enable delayed allocation by default
2450          * Use -o nodelalloc to turn it off
2451          */
2452         set_opt(sbi->s_mount_opt, DELALLOC);
2453
2454         if (!parse_options((char *) data, sb, &journal_devnum,
2455                            &journal_ioprio, NULL, 0))
2456                 goto failed_mount;
2457
2458         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2459                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2460
2461         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
2462             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
2463              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
2464              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
2465                 ext4_msg(sb, KERN_WARNING,
2466                        "feature flags set on rev 0 fs, "
2467                        "running e2fsck is recommended");
2468
2469         /*
2470          * Check feature flags regardless of the revision level, since we
2471          * previously didn't change the revision level when setting the flags,
2472          * so there is a chance incompat flags are set on a rev 0 filesystem.
2473          */
2474         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
2475                 goto failed_mount;
2476
2477         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
2478
2479         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
2480             blocksize > EXT4_MAX_BLOCK_SIZE) {
2481                 ext4_msg(sb, KERN_ERR,
2482                        "Unsupported filesystem blocksize %d", blocksize);
2483                 goto failed_mount;
2484         }
2485
2486         if (sb->s_blocksize != blocksize) {
2487                 /* Validate the filesystem blocksize */
2488                 if (!sb_set_blocksize(sb, blocksize)) {
2489                         ext4_msg(sb, KERN_ERR, "bad block size %d",
2490                                         blocksize);
2491                         goto failed_mount;
2492                 }
2493
2494                 brelse(bh);
2495                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2496                 offset = do_div(logical_sb_block, blocksize);
2497                 bh = sb_bread(sb, logical_sb_block);
2498                 if (!bh) {
2499                         ext4_msg(sb, KERN_ERR,
2500                                "Can't read superblock on 2nd try");
2501                         goto failed_mount;
2502                 }
2503                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
2504                 sbi->s_es = es;
2505                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
2506                         ext4_msg(sb, KERN_ERR,
2507                                "Magic mismatch, very weird!");
2508                         goto failed_mount;
2509                 }
2510         }
2511
2512         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2513                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
2514         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
2515                                                       has_huge_files);
2516         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
2517
2518         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2519                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2520                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2521         } else {
2522                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2523                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2524                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2525                     (!is_power_of_2(sbi->s_inode_size)) ||
2526                     (sbi->s_inode_size > blocksize)) {
2527                         ext4_msg(sb, KERN_ERR,
2528                                "unsupported inode size: %d",
2529                                sbi->s_inode_size);
2530                         goto failed_mount;
2531                 }
2532                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2533                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2534         }
2535
2536         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2537         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2538                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2539                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2540                     !is_power_of_2(sbi->s_desc_size)) {
2541                         ext4_msg(sb, KERN_ERR,
2542                                "unsupported descriptor size %lu",
2543                                sbi->s_desc_size);
2544                         goto failed_mount;
2545                 }
2546         } else
2547                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2548
2549         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2550         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2551         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2552                 goto cantfind_ext4;
2553
2554         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2555         if (sbi->s_inodes_per_block == 0)
2556                 goto cantfind_ext4;
2557         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2558                                         sbi->s_inodes_per_block;
2559         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2560         sbi->s_sbh = bh;
2561         sbi->s_mount_state = le16_to_cpu(es->s_state);
2562         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2563         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2564
2565         for (i = 0; i < 4; i++)
2566                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2567         sbi->s_def_hash_version = es->s_def_hash_version;
2568         i = le32_to_cpu(es->s_flags);
2569         if (i & EXT2_FLAGS_UNSIGNED_HASH)
2570                 sbi->s_hash_unsigned = 3;
2571         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
2572 #ifdef __CHAR_UNSIGNED__
2573                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
2574                 sbi->s_hash_unsigned = 3;
2575 #else
2576                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
2577 #endif
2578                 sb->s_dirt = 1;
2579         }
2580
2581         if (sbi->s_blocks_per_group > blocksize * 8) {
2582                 ext4_msg(sb, KERN_ERR,
2583                        "#blocks per group too big: %lu",
2584                        sbi->s_blocks_per_group);
2585                 goto failed_mount;
2586         }
2587         if (sbi->s_inodes_per_group > blocksize * 8) {
2588                 ext4_msg(sb, KERN_ERR,
2589                        "#inodes per group too big: %lu",
2590                        sbi->s_inodes_per_group);
2591                 goto failed_mount;
2592         }
2593
2594         /*
2595          * Test whether we have more sectors than will fit in sector_t,
2596          * and whether the max offset is addressable by the page cache.
2597          */
2598         if ((ext4_blocks_count(es) >
2599              (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) ||
2600             (ext4_blocks_count(es) >
2601              (pgoff_t)(~0ULL) >> (PAGE_CACHE_SHIFT - sb->s_blocksize_bits))) {
2602                 ext4_msg(sb, KERN_ERR, "filesystem"
2603                          " too large to mount safely on this system");
2604                 if (sizeof(sector_t) < 8)
2605                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
2606                 ret = -EFBIG;
2607                 goto failed_mount;
2608         }
2609
2610         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2611                 goto cantfind_ext4;
2612
2613         /* check blocks count against device size */
2614         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
2615         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
2616                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
2617                        "exceeds size of device (%llu blocks)",
2618                        ext4_blocks_count(es), blocks_count);
2619                 goto failed_mount;
2620         }
2621
2622         /*
2623          * It makes no sense for the first data block to be beyond the end
2624          * of the filesystem.
2625          */
2626         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
2627                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data"
2628                          "block %u is beyond end of filesystem (%llu)",
2629                          le32_to_cpu(es->s_first_data_block),
2630                          ext4_blocks_count(es));
2631                 goto failed_mount;
2632         }
2633         blocks_count = (ext4_blocks_count(es) -
2634                         le32_to_cpu(es->s_first_data_block) +
2635                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2636         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2637         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
2638                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
2639                        "(block count %llu, first data block %u, "
2640                        "blocks per group %lu)", sbi->s_groups_count,
2641                        ext4_blocks_count(es),
2642                        le32_to_cpu(es->s_first_data_block),
2643                        EXT4_BLOCKS_PER_GROUP(sb));
2644                 goto failed_mount;
2645         }
2646         sbi->s_groups_count = blocks_count;
2647         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
2648                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
2649         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2650                    EXT4_DESC_PER_BLOCK(sb);
2651         sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
2652                                     GFP_KERNEL);
2653         if (sbi->s_group_desc == NULL) {
2654                 ext4_msg(sb, KERN_ERR, "not enough memory");
2655                 goto failed_mount;
2656         }
2657
2658 #ifdef CONFIG_PROC_FS
2659         if (ext4_proc_root)
2660                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
2661 #endif
2662
2663         bgl_lock_init(sbi->s_blockgroup_lock);
2664
2665         for (i = 0; i < db_count; i++) {
2666                 block = descriptor_loc(sb, logical_sb_block, i);
2667                 sbi->s_group_desc[i] = sb_bread(sb, block);
2668                 if (!sbi->s_group_desc[i]) {
2669                         ext4_msg(sb, KERN_ERR,
2670                                "can't read group descriptor %d", i);
2671                         db_count = i;
2672                         goto failed_mount2;
2673                 }
2674         }
2675         if (!ext4_check_descriptors(sb)) {
2676                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
2677                 goto failed_mount2;
2678         }
2679         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2680                 if (!ext4_fill_flex_info(sb)) {
2681                         ext4_msg(sb, KERN_ERR,
2682                                "unable to initialize "
2683                                "flex_bg meta info!");
2684                         goto failed_mount2;
2685                 }
2686
2687         sbi->s_gdb_count = db_count;
2688         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2689         spin_lock_init(&sbi->s_next_gen_lock);
2690
2691         err = percpu_counter_init(&sbi->s_freeblocks_counter,
2692                         ext4_count_free_blocks(sb));
2693         if (!err) {
2694                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
2695                                 ext4_count_free_inodes(sb));
2696         }
2697         if (!err) {
2698                 err = percpu_counter_init(&sbi->s_dirs_counter,
2699                                 ext4_count_dirs(sb));
2700         }
2701         if (!err) {
2702                 err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
2703         }
2704         if (err) {
2705                 ext4_msg(sb, KERN_ERR, "insufficient memory");
2706                 goto failed_mount3;
2707         }
2708
2709         sbi->s_stripe = ext4_get_stripe_size(sbi);
2710         sbi->s_max_writeback_mb_bump = 128;
2711
2712         /*
2713          * set up enough so that it can read an inode
2714          */
2715         if (!test_opt(sb, NOLOAD) &&
2716             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
2717                 sb->s_op = &ext4_sops;
2718         else
2719                 sb->s_op = &ext4_nojournal_sops;
2720         sb->s_export_op = &ext4_export_ops;
2721         sb->s_xattr = ext4_xattr_handlers;
2722 #ifdef CONFIG_QUOTA
2723         sb->s_qcop = &ext4_qctl_operations;
2724         sb->dq_op = &ext4_quota_operations;
2725 #endif
2726         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2727         mutex_init(&sbi->s_orphan_lock);
2728         mutex_init(&sbi->s_resize_lock);
2729
2730         sb->s_root = NULL;
2731
2732         needs_recovery = (es->s_last_orphan != 0 ||
2733                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2734                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2735
2736         /*
2737          * The first inode we look at is the journal inode.  Don't try
2738          * root first: it may be modified in the journal!
2739          */
2740         if (!test_opt(sb, NOLOAD) &&
2741             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2742                 if (ext4_load_journal(sb, es, journal_devnum))
2743                         goto failed_mount3;
2744         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
2745               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2746                 ext4_msg(sb, KERN_ERR, "required journal recovery "
2747                        "suppressed and not mounted read-only");
2748                 goto failed_mount4;
2749         } else {
2750                 clear_opt(sbi->s_mount_opt, DATA_FLAGS);
2751                 set_opt(sbi->s_mount_opt, WRITEBACK_DATA);
2752                 sbi->s_journal = NULL;
2753                 needs_recovery = 0;
2754                 goto no_journal;
2755         }
2756
2757         if (ext4_blocks_count(es) > 0xffffffffULL &&
2758             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2759                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2760                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
2761                 goto failed_mount4;
2762         }
2763
2764         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2765                 jbd2_journal_set_features(sbi->s_journal,
2766                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2767                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2768         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2769                 jbd2_journal_set_features(sbi->s_journal,
2770                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2771                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2772                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2773         } else {
2774                 jbd2_journal_clear_features(sbi->s_journal,
2775                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2776                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2777         }
2778
2779         /* We have now updated the journal if required, so we can
2780          * validate the data journaling mode. */
2781         switch (test_opt(sb, DATA_FLAGS)) {
2782         case 0:
2783                 /* No mode set, assume a default based on the journal
2784                  * capabilities: ORDERED_DATA if the journal can
2785                  * cope, else JOURNAL_DATA
2786                  */
2787                 if (jbd2_journal_check_available_features
2788                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2789                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
2790                 else
2791                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2792                 break;
2793
2794         case EXT4_MOUNT_ORDERED_DATA:
2795         case EXT4_MOUNT_WRITEBACK_DATA:
2796                 if (!jbd2_journal_check_available_features
2797                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2798                         ext4_msg(sb, KERN_ERR, "Journal does not support "
2799                                "requested data journaling mode");
2800                         goto failed_mount4;
2801                 }
2802         default:
2803                 break;
2804         }
2805         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
2806
2807 no_journal:
2808
2809         if (test_opt(sb, NOBH)) {
2810                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2811                         ext4_msg(sb, KERN_WARNING, "Ignoring nobh option - "
2812                                 "its supported only with writeback mode");
2813                         clear_opt(sbi->s_mount_opt, NOBH);
2814                 }
2815         }
2816         EXT4_SB(sb)->dio_unwritten_wq = create_workqueue("ext4-dio-unwritten");
2817         if (!EXT4_SB(sb)->dio_unwritten_wq) {
2818                 printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
2819                 goto failed_mount_wq;
2820         }
2821
2822         /*
2823          * The jbd2_journal_load will have done any necessary log recovery,
2824          * so we can safely mount the rest of the filesystem now.
2825          */
2826
2827         root = ext4_iget(sb, EXT4_ROOT_INO);
2828         if (IS_ERR(root)) {
2829                 ext4_msg(sb, KERN_ERR, "get root inode failed");
2830                 ret = PTR_ERR(root);
2831                 goto failed_mount4;
2832         }
2833         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2834                 iput(root);
2835                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
2836                 goto failed_mount4;
2837         }
2838         sb->s_root = d_alloc_root(root);
2839         if (!sb->s_root) {
2840                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
2841                 iput(root);
2842                 ret = -ENOMEM;
2843                 goto failed_mount4;
2844         }
2845
2846         ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
2847
2848         /* determine the minimum size of new large inodes, if present */
2849         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2850                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2851                                                      EXT4_GOOD_OLD_INODE_SIZE;
2852                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2853                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2854                         if (sbi->s_want_extra_isize <
2855                             le16_to_cpu(es->s_want_extra_isize))
2856                                 sbi->s_want_extra_isize =
2857                                         le16_to_cpu(es->s_want_extra_isize);
2858                         if (sbi->s_want_extra_isize <
2859                             le16_to_cpu(es->s_min_extra_isize))
2860                                 sbi->s_want_extra_isize =
2861                                         le16_to_cpu(es->s_min_extra_isize);
2862                 }
2863         }
2864         /* Check if enough inode space is available */
2865         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2866                                                         sbi->s_inode_size) {
2867                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2868                                                        EXT4_GOOD_OLD_INODE_SIZE;
2869                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
2870                          "available");
2871         }
2872
2873         if (test_opt(sb, DELALLOC) &&
2874             (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2875                 ext4_msg(sb, KERN_WARNING, "Ignoring delalloc option - "
2876                          "requested data journaling mode");
2877                 clear_opt(sbi->s_mount_opt, DELALLOC);
2878         }
2879
2880         err = ext4_setup_system_zone(sb);
2881         if (err) {
2882                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
2883                          "zone (%d)\n", err);
2884                 goto failed_mount4;
2885         }
2886
2887         ext4_ext_init(sb);
2888         err = ext4_mb_init(sb, needs_recovery);
2889         if (err) {
2890                 ext4_msg(sb, KERN_ERR, "failed to initalize mballoc (%d)",
2891                          err);
2892                 goto failed_mount4;
2893         }
2894
2895         sbi->s_kobj.kset = ext4_kset;
2896         init_completion(&sbi->s_kobj_unregister);
2897         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
2898                                    "%s", sb->s_id);
2899         if (err) {
2900                 ext4_mb_release(sb);
2901                 ext4_ext_release(sb);
2902                 goto failed_mount4;
2903         };
2904
2905         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2906         ext4_orphan_cleanup(sb, es);
2907         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2908         if (needs_recovery) {
2909                 ext4_msg(sb, KERN_INFO, "recovery complete");
2910                 ext4_mark_recovery_complete(sb, es);
2911         }
2912         if (EXT4_SB(sb)->s_journal) {
2913                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2914                         descr = " journalled data mode";
2915                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2916                         descr = " ordered data mode";
2917                 else
2918                         descr = " writeback data mode";
2919         } else
2920                 descr = "out journal";
2921
2922         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s", descr);
2923
2924         lock_kernel();
2925         return 0;
2926
2927 cantfind_ext4:
2928         if (!silent)
2929                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
2930         goto failed_mount;
2931
2932 failed_mount4:
2933         ext4_msg(sb, KERN_ERR, "mount failed");
2934         destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
2935 failed_mount_wq:
2936         ext4_release_system_zone(sb);
2937         if (sbi->s_journal) {
2938                 jbd2_journal_destroy(sbi->s_journal);
2939                 sbi->s_journal = NULL;
2940         }
2941 failed_mount3:
2942         if (sbi->s_flex_groups) {
2943                 if (is_vmalloc_addr(sbi->s_flex_groups))
2944                         vfree(sbi->s_flex_groups);
2945                 else
2946                         kfree(sbi->s_flex_groups);
2947         }
2948         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2949         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2950         percpu_counter_destroy(&sbi->s_dirs_counter);
2951         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
2952 failed_mount2:
2953         for (i = 0; i < db_count; i++)
2954                 brelse(sbi->s_group_desc[i]);
2955         kfree(sbi->s_group_desc);
2956 failed_mount:
2957         if (sbi->s_proc) {
2958                 remove_proc_entry(sb->s_id, ext4_proc_root);
2959         }
2960 #ifdef CONFIG_QUOTA
2961         for (i = 0; i < MAXQUOTAS; i++)
2962                 kfree(sbi->s_qf_names[i]);
2963 #endif
2964         ext4_blkdev_remove(sbi);
2965         brelse(bh);
2966 out_fail:
2967         sb->s_fs_info = NULL;
2968         kfree(sbi->s_blockgroup_lock);
2969         kfree(sbi);
2970         lock_kernel();
2971         return ret;
2972 }
2973
2974 /*
2975  * Setup any per-fs journal parameters now.  We'll do this both on
2976  * initial mount, once the journal has been initialised but before we've
2977  * done any recovery; and again on any subsequent remount.
2978  */
2979 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2980 {
2981         struct ext4_sb_info *sbi = EXT4_SB(sb);
2982
2983         journal->j_commit_interval = sbi->s_commit_interval;
2984         journal->j_min_batch_time = sbi->s_min_batch_time;
2985         journal->j_max_batch_time = sbi->s_max_batch_time;
2986
2987         spin_lock(&journal->j_state_lock);
2988         if (test_opt(sb, BARRIER))
2989                 journal->j_flags |= JBD2_BARRIER;
2990         else
2991                 journal->j_flags &= ~JBD2_BARRIER;
2992         if (test_opt(sb, DATA_ERR_ABORT))
2993                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
2994         else
2995                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
2996         spin_unlock(&journal->j_state_lock);
2997 }
2998
2999 static journal_t *ext4_get_journal(struct super_block *sb,
3000                                    unsigned int journal_inum)
3001 {
3002         struct inode *journal_inode;
3003         journal_t *journal;
3004
3005         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3006
3007         /* First, test for the existence of a valid inode on disk.  Bad
3008          * things happen if we iget() an unused inode, as the subsequent
3009          * iput() will try to delete it. */
3010
3011         journal_inode = ext4_iget(sb, journal_inum);
3012         if (IS_ERR(journal_inode)) {
3013                 ext4_msg(sb, KERN_ERR, "no journal found");
3014                 return NULL;
3015         }
3016         if (!journal_inode->i_nlink) {
3017                 make_bad_inode(journal_inode);
3018                 iput(journal_inode);
3019                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
3020                 return NULL;
3021         }
3022
3023         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
3024                   journal_inode, journal_inode->i_size);
3025         if (!S_ISREG(journal_inode->i_mode)) {
3026                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
3027                 iput(journal_inode);
3028                 return NULL;
3029         }
3030
3031         journal = jbd2_journal_init_inode(journal_inode);
3032         if (!journal) {
3033                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
3034                 iput(journal_inode);
3035                 return NULL;
3036         }
3037         journal->j_private = sb;
3038         ext4_init_journal_params(sb, journal);
3039         return journal;
3040 }
3041
3042 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3043                                        dev_t j_dev)
3044 {
3045         struct buffer_head *bh;
3046         journal_t *journal;
3047         ext4_fsblk_t start;
3048         ext4_fsblk_t len;
3049         int hblock, blocksize;
3050         ext4_fsblk_t sb_block;
3051         unsigned long offset;
3052         struct ext4_super_block *es;
3053         struct block_device *bdev;
3054
3055         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3056
3057         bdev = ext4_blkdev_get(j_dev, sb);
3058         if (bdev == NULL)
3059                 return NULL;
3060
3061         if (bd_claim(bdev, sb)) {
3062                 ext4_msg(sb, KERN_ERR,
3063                         "failed to claim external journal device");
3064                 blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
3065                 return NULL;
3066         }
3067
3068         blocksize = sb->s_blocksize;
3069         hblock = bdev_logical_block_size(bdev);
3070         if (blocksize < hblock) {
3071                 ext4_msg(sb, KERN_ERR,
3072                         "blocksize too small for journal device");
3073                 goto out_bdev;
3074         }
3075
3076         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3077         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3078         set_blocksize(bdev, blocksize);
3079         if (!(bh = __bread(bdev, sb_block, blocksize))) {
3080                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3081                        "external journal");
3082                 goto out_bdev;
3083         }
3084
3085         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3086         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3087             !(le32_to_cpu(es->s_feature_incompat) &
3088               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3089                 ext4_msg(sb, KERN_ERR, "external journal has "
3090                                         "bad superblock");
3091                 brelse(bh);
3092                 goto out_bdev;
3093         }
3094
3095         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3096                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3097                 brelse(bh);
3098                 goto out_bdev;
3099         }
3100
3101         len = ext4_blocks_count(es);
3102         start = sb_block + 1;
3103         brelse(bh);     /* we're done with the superblock */
3104
3105         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
3106                                         start, len, blocksize);
3107         if (!journal) {
3108                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
3109                 goto out_bdev;
3110         }
3111         journal->j_private = sb;
3112         ll_rw_block(READ, 1, &journal->j_sb_buffer);
3113         wait_on_buffer(journal->j_sb_buffer);
3114         if (!buffer_uptodate(journal->j_sb_buffer)) {
3115                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
3116                 goto out_journal;
3117         }
3118         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
3119                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
3120                                         "user (unsupported) - %d",
3121                         be32_to_cpu(journal->j_superblock->s_nr_users));
3122                 goto out_journal;
3123         }
3124         EXT4_SB(sb)->journal_bdev = bdev;
3125         ext4_init_journal_params(sb, journal);
3126         return journal;
3127
3128 out_journal:
3129         jbd2_journal_destroy(journal);
3130 out_bdev:
3131         ext4_blkdev_put(bdev);
3132         return NULL;
3133 }
3134
3135 static int ext4_load_journal(struct super_block *sb,
3136                              struct ext4_super_block *es,
3137                              unsigned long journal_devnum)
3138 {
3139         journal_t *journal;
3140         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
3141         dev_t journal_dev;
3142         int err = 0;
3143         int really_read_only;
3144
3145         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3146
3147         if (journal_devnum &&
3148             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3149                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
3150                         "numbers have changed");
3151                 journal_dev = new_decode_dev(journal_devnum);
3152         } else
3153                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
3154
3155         really_read_only = bdev_read_only(sb->s_bdev);
3156
3157         /*
3158          * Are we loading a blank journal or performing recovery after a
3159          * crash?  For recovery, we need to check in advance whether we
3160          * can get read-write access to the device.
3161          */
3162         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3163                 if (sb->s_flags & MS_RDONLY) {
3164                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
3165                                         "required on readonly filesystem");
3166                         if (really_read_only) {
3167                                 ext4_msg(sb, KERN_ERR, "write access "
3168                                         "unavailable, cannot proceed");
3169                                 return -EROFS;
3170                         }
3171                         ext4_msg(sb, KERN_INFO, "write access will "
3172                                "be enabled during recovery");
3173                 }
3174         }
3175
3176         if (journal_inum && journal_dev) {
3177                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
3178                        "and inode journals!");
3179                 return -EINVAL;
3180         }
3181
3182         if (journal_inum) {
3183                 if (!(journal = ext4_get_journal(sb, journal_inum)))
3184                         return -EINVAL;
3185         } else {
3186                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
3187                         return -EINVAL;
3188         }
3189
3190         if (!(journal->j_flags & JBD2_BARRIER))
3191                 ext4_msg(sb, KERN_INFO, "barriers disabled");
3192
3193         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
3194                 err = jbd2_journal_update_format(journal);
3195                 if (err)  {
3196                         ext4_msg(sb, KERN_ERR, "error updating journal");
3197                         jbd2_journal_destroy(journal);
3198                         return err;
3199                 }
3200         }
3201
3202         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
3203                 err = jbd2_journal_wipe(journal, !really_read_only);
3204         if (!err)
3205                 err = jbd2_journal_load(journal);
3206
3207         if (err) {
3208                 ext4_msg(sb, KERN_ERR, "error loading journal");
3209                 jbd2_journal_destroy(journal);
3210                 return err;
3211         }
3212
3213         EXT4_SB(sb)->s_journal = journal;
3214         ext4_clear_journal_err(sb, es);
3215
3216         if (journal_devnum &&
3217             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3218                 es->s_journal_dev = cpu_to_le32(journal_devnum);
3219
3220                 /* Make sure we flush the recovery flag to disk. */
3221                 ext4_commit_super(sb, 1);
3222         }
3223
3224         return 0;
3225 }
3226
3227 static int ext4_commit_super(struct super_block *sb, int sync)
3228 {
3229         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
3230         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
3231         int error = 0;
3232
3233         if (!sbh)
3234                 return error;
3235         if (buffer_write_io_error(sbh)) {
3236                 /*
3237                  * Oh, dear.  A previous attempt to write the
3238                  * superblock failed.  This could happen because the
3239                  * USB device was yanked out.  Or it could happen to
3240                  * be a transient write error and maybe the block will
3241                  * be remapped.  Nothing we can do but to retry the
3242                  * write and hope for the best.
3243                  */
3244                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
3245                        "superblock detected");
3246                 clear_buffer_write_io_error(sbh);
3247                 set_buffer_uptodate(sbh);
3248         }
3249         /*
3250          * If the file system is mounted read-only, don't update the
3251          * superblock write time.  This avoids updating the superblock
3252          * write time when we are mounting the root file system
3253          * read/only but we need to replay the journal; at that point,
3254          * for people who are east of GMT and who make their clock
3255          * tick in localtime for Windows bug-for-bug compatibility,
3256          * the clock is set in the future, and this will cause e2fsck
3257          * to complain and force a full file system check.
3258          */
3259         if (!(sb->s_flags & MS_RDONLY))
3260                 es->s_wtime = cpu_to_le32(get_seconds());
3261         es->s_kbytes_written =
3262                 cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
3263                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
3264                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
3265         ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
3266                                         &EXT4_SB(sb)->s_freeblocks_counter));
3267         es->s_free_inodes_count = cpu_to_le32(percpu_counter_sum_positive(
3268                                         &EXT4_SB(sb)->s_freeinodes_counter));
3269         sb->s_dirt = 0;
3270         BUFFER_TRACE(sbh, "marking dirty");
3271         mark_buffer_dirty(sbh);
3272         if (sync) {
3273                 error = sync_dirty_buffer(sbh);
3274                 if (error)
3275                         return error;
3276
3277                 error = buffer_write_io_error(sbh);
3278                 if (error) {
3279                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
3280                                "superblock");
3281                         clear_buffer_write_io_error(sbh);
3282                         set_buffer_uptodate(sbh);
3283                 }
3284         }
3285         return error;
3286 }
3287
3288 /*
3289  * Have we just finished recovery?  If so, and if we are mounting (or
3290  * remounting) the filesystem readonly, then we will end up with a
3291  * consistent fs on disk.  Record that fact.
3292  */
3293 static void ext4_mark_recovery_complete(struct super_block *sb,
3294                                         struct ext4_super_block *es)
3295 {
3296         journal_t *journal = EXT4_SB(sb)->s_journal;
3297
3298         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3299                 BUG_ON(journal != NULL);
3300                 return;
3301         }
3302         jbd2_journal_lock_updates(journal);
3303         if (jbd2_journal_flush(journal) < 0)
3304                 goto out;
3305
3306         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
3307             sb->s_flags & MS_RDONLY) {
3308                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3309                 ext4_commit_super(sb, 1);
3310         }
3311
3312 out:
3313         jbd2_journal_unlock_updates(journal);
3314 }
3315
3316 /*
3317  * If we are mounting (or read-write remounting) a filesystem whose journal
3318  * has recorded an error from a previous lifetime, move that error to the
3319  * main filesystem now.
3320  */
3321 static void ext4_clear_journal_err(struct super_block *sb,
3322                                    struct ext4_super_block *es)
3323 {
3324         journal_t *journal;
3325         int j_errno;
3326         const char *errstr;
3327
3328         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3329
3330         journal = EXT4_SB(sb)->s_journal;
3331
3332         /*
3333          * Now check for any error status which may have been recorded in the
3334          * journal by a prior ext4_error() or ext4_abort()
3335          */
3336
3337         j_errno = jbd2_journal_errno(journal);
3338         if (j_errno) {
3339                 char nbuf[16];
3340
3341                 errstr = ext4_decode_error(sb, j_errno, nbuf);
3342                 ext4_warning(sb, __func__, "Filesystem error recorded "
3343                              "from previous mount: %s", errstr);
3344                 ext4_warning(sb, __func__, "Marking fs in need of "
3345                              "filesystem check.");
3346
3347                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
3348                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
3349                 ext4_commit_super(sb, 1);
3350
3351                 jbd2_journal_clear_err(journal);
3352         }
3353 }
3354
3355 /*
3356  * Force the running and committing transactions to commit,
3357  * and wait on the commit.
3358  */
3359 int ext4_force_commit(struct super_block *sb)
3360 {
3361         journal_t *journal;
3362         int ret = 0;
3363
3364         if (sb->s_flags & MS_RDONLY)
3365                 return 0;
3366
3367         journal = EXT4_SB(sb)->s_journal;
3368         if (journal)
3369                 ret = ext4_journal_force_commit(journal);
3370
3371         return ret;
3372 }
3373
3374 static void ext4_write_super(struct super_block *sb)
3375 {
3376         lock_super(sb);
3377         ext4_commit_super(sb, 1);
3378         unlock_super(sb);
3379 }
3380
3381 static int ext4_sync_fs(struct super_block *sb, int wait)
3382 {
3383         int ret = 0;
3384         tid_t target;
3385         struct ext4_sb_info *sbi = EXT4_SB(sb);
3386
3387         trace_ext4_sync_fs(sb, wait);
3388         flush_workqueue(sbi->dio_unwritten_wq);
3389         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
3390                 if (wait)
3391                         jbd2_log_wait_commit(sbi->s_journal, target);
3392         }
3393         return ret;
3394 }
3395
3396 /*
3397  * LVM calls this function before a (read-only) snapshot is created.  This
3398  * gives us a chance to flush the journal completely and mark the fs clean.
3399  */
3400 static int ext4_freeze(struct super_block *sb)
3401 {
3402         int error = 0;
3403         journal_t *journal;
3404
3405         if (sb->s_flags & MS_RDONLY)
3406                 return 0;
3407
3408         journal = EXT4_SB(sb)->s_journal;
3409
3410         /* Now we set up the journal barrier. */
3411         jbd2_journal_lock_updates(journal);
3412
3413         /*
3414          * Don't clear the needs_recovery flag if we failed to flush
3415          * the journal.
3416          */
3417         error = jbd2_journal_flush(journal);
3418         if (error < 0) {
3419         out:
3420                 jbd2_journal_unlock_updates(journal);
3421                 return error;
3422         }
3423
3424         /* Journal blocked and flushed, clear needs_recovery flag. */
3425         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3426         error = ext4_commit_super(sb, 1);
3427         if (error)
3428                 goto out;
3429         return 0;
3430 }
3431
3432 /*
3433  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
3434  * flag here, even though the filesystem is not technically dirty yet.
3435  */
3436 static int ext4_unfreeze(struct super_block *sb)
3437 {
3438         if (sb->s_flags & MS_RDONLY)
3439                 return 0;
3440
3441         lock_super(sb);
3442         /* Reset the needs_recovery flag before the fs is unlocked. */
3443         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3444         ext4_commit_super(sb, 1);
3445         unlock_super(sb);
3446         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3447         return 0;
3448 }
3449
3450 static int ext4_remount(struct super_block *sb, int *flags, char *data)
3451 {
3452         struct ext4_super_block *es;
3453         struct ext4_sb_info *sbi = EXT4_SB(sb);
3454         ext4_fsblk_t n_blocks_count = 0;
3455         unsigned long old_sb_flags;
3456         struct ext4_mount_options old_opts;
3457         ext4_group_t g;
3458         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3459         int err;
3460 #ifdef CONFIG_QUOTA
3461         int i;
3462 #endif
3463
3464         lock_kernel();
3465
3466         /* Store the original options */
3467         lock_super(sb);
3468         old_sb_flags = sb->s_flags;
3469         old_opts.s_mount_opt = sbi->s_mount_opt;
3470         old_opts.s_resuid = sbi->s_resuid;
3471         old_opts.s_resgid = sbi->s_resgid;
3472         old_opts.s_commit_interval = sbi->s_commit_interval;
3473         old_opts.s_min_batch_time = sbi->s_min_batch_time;
3474         old_opts.s_max_batch_time = sbi->s_max_batch_time;
3475 #ifdef CONFIG_QUOTA
3476         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
3477         for (i = 0; i < MAXQUOTAS; i++)
3478                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
3479 #endif
3480         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
3481                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
3482
3483         /*
3484          * Allow the "check" option to be passed as a remount option.
3485          */
3486         if (!parse_options(data, sb, NULL, &journal_ioprio,
3487                            &n_blocks_count, 1)) {
3488                 err = -EINVAL;
3489                 goto restore_opts;
3490         }
3491
3492         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
3493                 ext4_abort(sb, __func__, "Abort forced by user");
3494
3495         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3496                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
3497
3498         es = sbi->s_es;
3499
3500         if (sbi->s_journal) {
3501                 ext4_init_journal_params(sb, sbi->s_journal);
3502                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3503         }
3504
3505         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
3506                 n_blocks_count > ext4_blocks_count(es)) {
3507                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
3508                         err = -EROFS;
3509                         goto restore_opts;
3510                 }
3511
3512                 if (*flags & MS_RDONLY) {
3513                         /*
3514                          * First of all, the unconditional stuff we have to do
3515                          * to disable replay of the journal when we next remount
3516                          */
3517                         sb->s_flags |= MS_RDONLY;
3518
3519                         /*
3520                          * OK, test if we are remounting a valid rw partition
3521                          * readonly, and if so set the rdonly flag and then
3522                          * mark the partition as valid again.
3523                          */
3524                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
3525                             (sbi->s_mount_state & EXT4_VALID_FS))
3526                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
3527
3528                         if (sbi->s_journal)
3529                                 ext4_mark_recovery_complete(sb, es);
3530                 } else {
3531                         /* Make sure we can mount this feature set readwrite */
3532                         if (!ext4_feature_set_ok(sb, 0)) {
3533                                 err = -EROFS;
3534                                 goto restore_opts;
3535                         }
3536                         /*
3537                          * Make sure the group descriptor checksums
3538                          * are sane.  If they aren't, refuse to remount r/w.
3539                          */
3540                         for (g = 0; g < sbi->s_groups_count; g++) {
3541                                 struct ext4_group_desc *gdp =
3542                                         ext4_get_group_desc(sb, g, NULL);
3543
3544                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
3545                                         ext4_msg(sb, KERN_ERR,
3546                "ext4_remount: Checksum for group %u failed (%u!=%u)",
3547                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
3548                                                le16_to_cpu(gdp->bg_checksum));
3549                                         err = -EINVAL;
3550                                         goto restore_opts;
3551                                 }
3552                         }
3553
3554                         /*
3555                          * If we have an unprocessed orphan list hanging
3556                          * around from a previously readonly bdev mount,
3557                          * require a full umount/remount for now.
3558                          */
3559                         if (es->s_last_orphan) {
3560                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
3561                                        "remount RDWR because of unprocessed "
3562                                        "orphan inode list.  Please "
3563                                        "umount/remount instead");
3564                                 err = -EINVAL;
3565                                 goto restore_opts;
3566                         }
3567
3568                         /*
3569                          * Mounting a RDONLY partition read-write, so reread
3570                          * and store the current valid flag.  (It may have
3571                          * been changed by e2fsck since we originally mounted
3572                          * the partition.)
3573                          */
3574                         if (sbi->s_journal)
3575                                 ext4_clear_journal_err(sb, es);
3576                         sbi->s_mount_state = le16_to_cpu(es->s_state);
3577                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
3578                                 goto restore_opts;
3579                         if (!ext4_setup_super(sb, es, 0))
3580                                 sb->s_flags &= ~MS_RDONLY;
3581                 }
3582         }
3583         ext4_setup_system_zone(sb);
3584         if (sbi->s_journal == NULL)
3585                 ext4_commit_super(sb, 1);
3586
3587 #ifdef CONFIG_QUOTA
3588         /* Release old quota file names */
3589         for (i = 0; i < MAXQUOTAS; i++)
3590                 if (old_opts.s_qf_names[i] &&
3591                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3592                         kfree(old_opts.s_qf_names[i]);
3593 #endif
3594         unlock_super(sb);
3595         unlock_kernel();
3596         return 0;
3597
3598 restore_opts:
3599         sb->s_flags = old_sb_flags;
3600         sbi->s_mount_opt = old_opts.s_mount_opt;
3601         sbi->s_resuid = old_opts.s_resuid;
3602         sbi->s_resgid = old_opts.s_resgid;
3603         sbi->s_commit_interval = old_opts.s_commit_interval;
3604         sbi->s_min_batch_time = old_opts.s_min_batch_time;
3605         sbi->s_max_batch_time = old_opts.s_max_batch_time;
3606 #ifdef CONFIG_QUOTA
3607         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
3608         for (i = 0; i < MAXQUOTAS; i++) {
3609                 if (sbi->s_qf_names[i] &&
3610                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3611                         kfree(sbi->s_qf_names[i]);
3612                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
3613         }
3614 #endif
3615         unlock_super(sb);
3616         unlock_kernel();
3617         return err;
3618 }
3619
3620 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
3621 {
3622         struct super_block *sb = dentry->d_sb;
3623         struct ext4_sb_info *sbi = EXT4_SB(sb);
3624         struct ext4_super_block *es = sbi->s_es;
3625         u64 fsid;
3626
3627         if (test_opt(sb, MINIX_DF)) {
3628                 sbi->s_overhead_last = 0;
3629         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
3630                 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3631                 ext4_fsblk_t overhead = 0;
3632
3633                 /*
3634                  * Compute the overhead (FS structures).  This is constant
3635                  * for a given filesystem unless the number of block groups
3636                  * changes so we cache the previous value until it does.
3637                  */
3638
3639                 /*
3640                  * All of the blocks before first_data_block are
3641                  * overhead
3642                  */
3643                 overhead = le32_to_cpu(es->s_first_data_block);
3644
3645                 /*
3646                  * Add the overhead attributed to the superblock and
3647                  * block group descriptors.  If the sparse superblocks
3648                  * feature is turned on, then not all groups have this.
3649                  */
3650                 for (i = 0; i < ngroups; i++) {
3651                         overhead += ext4_bg_has_super(sb, i) +
3652                                 ext4_bg_num_gdb(sb, i);
3653                         cond_resched();
3654                 }
3655
3656                 /*
3657                  * Every block group has an inode bitmap, a block
3658                  * bitmap, and an inode table.
3659                  */
3660                 overhead += ngroups * (2 + sbi->s_itb_per_group);
3661                 sbi->s_overhead_last = overhead;
3662                 smp_wmb();
3663                 sbi->s_blocks_last = ext4_blocks_count(es);
3664         }
3665
3666         buf->f_type = EXT4_SUPER_MAGIC;
3667         buf->f_bsize = sb->s_blocksize;
3668         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
3669         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
3670                        percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
3671         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
3672         if (buf->f_bfree < ext4_r_blocks_count(es))
3673                 buf->f_bavail = 0;
3674         buf->f_files = le32_to_cpu(es->s_inodes_count);
3675         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
3676         buf->f_namelen = EXT4_NAME_LEN;
3677         fsid = le64_to_cpup((void *)es->s_uuid) ^
3678                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
3679         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
3680         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
3681
3682         return 0;
3683 }
3684
3685 /* Helper function for writing quotas on sync - we need to start transaction
3686  * before quota file is locked for write. Otherwise the are possible deadlocks:
3687  * Process 1                         Process 2
3688  * ext4_create()                     quota_sync()
3689  *   jbd2_journal_start()                  write_dquot()
3690  *   vfs_dq_init()                         down(dqio_mutex)
3691  *     down(dqio_mutex)                    jbd2_journal_start()
3692  *
3693  */
3694
3695 #ifdef CONFIG_QUOTA
3696
3697 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3698 {
3699         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3700 }
3701
3702 static int ext4_write_dquot(struct dquot *dquot)
3703 {
3704         int ret, err;
3705         handle_t *handle;
3706         struct inode *inode;
3707
3708         inode = dquot_to_inode(dquot);
3709         handle = ext4_journal_start(inode,
3710                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3711         if (IS_ERR(handle))
3712                 return PTR_ERR(handle);
3713         ret = dquot_commit(dquot);
3714         err = ext4_journal_stop(handle);
3715         if (!ret)
3716                 ret = err;
3717         return ret;
3718 }
3719
3720 static int ext4_acquire_dquot(struct dquot *dquot)
3721 {
3722         int ret, err;
3723         handle_t *handle;
3724
3725         handle = ext4_journal_start(dquot_to_inode(dquot),
3726                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3727         if (IS_ERR(handle))
3728                 return PTR_ERR(handle);
3729         ret = dquot_acquire(dquot);
3730         err = ext4_journal_stop(handle);
3731         if (!ret)
3732                 ret = err;
3733         return ret;
3734 }
3735
3736 static int ext4_release_dquot(struct dquot *dquot)
3737 {
3738         int ret, err;
3739         handle_t *handle;
3740
3741         handle = ext4_journal_start(dquot_to_inode(dquot),
3742                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3743         if (IS_ERR(handle)) {
3744                 /* Release dquot anyway to avoid endless cycle in dqput() */
3745                 dquot_release(dquot);
3746                 return PTR_ERR(handle);
3747         }
3748         ret = dquot_release(dquot);
3749         err = ext4_journal_stop(handle);
3750         if (!ret)
3751                 ret = err;
3752         return ret;
3753 }
3754
3755 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3756 {
3757         /* Are we journaling quotas? */
3758         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3759             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3760                 dquot_mark_dquot_dirty(dquot);
3761                 return ext4_write_dquot(dquot);
3762         } else {
3763                 return dquot_mark_dquot_dirty(dquot);
3764         }
3765 }
3766
3767 static int ext4_write_info(struct super_block *sb, int type)
3768 {
3769         int ret, err;
3770         handle_t *handle;
3771
3772         /* Data block + inode block */
3773         handle = ext4_journal_start(sb->s_root->d_inode, 2);
3774         if (IS_ERR(handle))
3775                 return PTR_ERR(handle);
3776         ret = dquot_commit_info(sb, type);
3777         err = ext4_journal_stop(handle);
3778         if (!ret)
3779                 ret = err;
3780         return ret;
3781 }
3782
3783 /*
3784  * Turn on quotas during mount time - we need to find
3785  * the quota file and such...
3786  */
3787 static int ext4_quota_on_mount(struct super_block *sb, int type)
3788 {
3789         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3790                                   EXT4_SB(sb)->s_jquota_fmt, type);
3791 }
3792
3793 /*
3794  * Standard function to be called on quota_on
3795  */
3796 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3797                          char *name, int remount)
3798 {
3799         int err;
3800         struct path path;
3801
3802         if (!test_opt(sb, QUOTA))
3803                 return -EINVAL;
3804         /* When remounting, no checks are needed and in fact, name is NULL */
3805         if (remount)
3806                 return vfs_quota_on(sb, type, format_id, name, remount);
3807
3808         err = kern_path(name, LOOKUP_FOLLOW, &path);
3809         if (err)
3810                 return err;
3811
3812         /* Quotafile not on the same filesystem? */
3813         if (path.mnt->mnt_sb != sb) {
3814                 path_put(&path);
3815                 return -EXDEV;
3816         }
3817         /* Journaling quota? */
3818         if (EXT4_SB(sb)->s_qf_names[type]) {
3819                 /* Quotafile not in fs root? */
3820                 if (path.dentry->d_parent != sb->s_root)
3821                         ext4_msg(sb, KERN_WARNING,
3822                                 "Quota file not on filesystem root. "
3823                                 "Journaled quota will not work");
3824         }
3825
3826         /*
3827          * When we journal data on quota file, we have to flush journal to see
3828          * all updates to the file when we bypass pagecache...
3829          */
3830         if (EXT4_SB(sb)->s_journal &&
3831             ext4_should_journal_data(path.dentry->d_inode)) {
3832                 /*
3833                  * We don't need to lock updates but journal_flush() could
3834                  * otherwise be livelocked...
3835                  */
3836                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
3837                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
3838                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3839                 if (err) {
3840                         path_put(&path);
3841                         return err;
3842                 }
3843         }
3844
3845         err = vfs_quota_on_path(sb, type, format_id, &path);
3846         path_put(&path);
3847         return err;
3848 }
3849
3850 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3851  * acquiring the locks... As quota files are never truncated and quota code
3852  * itself serializes the operations (and noone else should touch the files)
3853  * we don't have to be afraid of races */
3854 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3855                                size_t len, loff_t off)
3856 {
3857         struct inode *inode = sb_dqopt(sb)->files[type];
3858         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3859         int err = 0;
3860         int offset = off & (sb->s_blocksize - 1);
3861         int tocopy;
3862         size_t toread;
3863         struct buffer_head *bh;
3864         loff_t i_size = i_size_read(inode);
3865
3866         if (off > i_size)
3867                 return 0;
3868         if (off+len > i_size)
3869                 len = i_size-off;
3870         toread = len;
3871         while (toread > 0) {
3872                 tocopy = sb->s_blocksize - offset < toread ?
3873                                 sb->s_blocksize - offset : toread;
3874                 bh = ext4_bread(NULL, inode, blk, 0, &err);
3875                 if (err)
3876                         return err;
3877                 if (!bh)        /* A hole? */
3878                         memset(data, 0, tocopy);
3879                 else
3880                         memcpy(data, bh->b_data+offset, tocopy);
3881                 brelse(bh);
3882                 offset = 0;
3883                 toread -= tocopy;
3884                 data += tocopy;
3885                 blk++;
3886         }
3887         return len;
3888 }
3889
3890 /* Write to quotafile (we know the transaction is already started and has
3891  * enough credits) */
3892 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3893                                 const char *data, size_t len, loff_t off)
3894 {
3895         struct inode *inode = sb_dqopt(sb)->files[type];
3896         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3897         int err = 0;
3898         int offset = off & (sb->s_blocksize - 1);
3899         int tocopy;
3900         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3901         size_t towrite = len;
3902         struct buffer_head *bh;
3903         handle_t *handle = journal_current_handle();
3904
3905         if (EXT4_SB(sb)->s_journal && !handle) {
3906                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
3907                         " cancelled because transaction is not started",
3908                         (unsigned long long)off, (unsigned long long)len);
3909                 return -EIO;
3910         }
3911         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3912         while (towrite > 0) {
3913                 tocopy = sb->s_blocksize - offset < towrite ?
3914                                 sb->s_blocksize - offset : towrite;
3915                 bh = ext4_bread(handle, inode, blk, 1, &err);
3916                 if (!bh)
3917                         goto out;
3918                 if (journal_quota) {
3919                         err = ext4_journal_get_write_access(handle, bh);
3920                         if (err) {
3921                                 brelse(bh);
3922                                 goto out;
3923                         }
3924                 }
3925                 lock_buffer(bh);
3926                 memcpy(bh->b_data+offset, data, tocopy);
3927                 flush_dcache_page(bh->b_page);
3928                 unlock_buffer(bh);
3929                 if (journal_quota)
3930                         err = ext4_handle_dirty_metadata(handle, NULL, bh);
3931                 else {
3932                         /* Always do at least ordered writes for quotas */
3933                         err = ext4_jbd2_file_inode(handle, inode);
3934                         mark_buffer_dirty(bh);
3935                 }
3936                 brelse(bh);
3937                 if (err)
3938                         goto out;
3939                 offset = 0;
3940                 towrite -= tocopy;
3941                 data += tocopy;
3942                 blk++;
3943         }
3944 out:
3945         if (len == towrite) {
3946                 mutex_unlock(&inode->i_mutex);
3947                 return err;
3948         }
3949         if (inode->i_size < off+len-towrite) {
3950                 i_size_write(inode, off+len-towrite);
3951                 EXT4_I(inode)->i_disksize = inode->i_size;
3952         }
3953         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3954         ext4_mark_inode_dirty(handle, inode);
3955         mutex_unlock(&inode->i_mutex);
3956         return len - towrite;
3957 }
3958
3959 #endif
3960
3961 static int ext4_get_sb(struct file_system_type *fs_type, int flags,
3962                        const char *dev_name, void *data, struct vfsmount *mnt)
3963 {
3964         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super,mnt);
3965 }
3966
3967 #if !defined(CONTIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
3968 static struct file_system_type ext2_fs_type = {
3969         .owner          = THIS_MODULE,
3970         .name           = "ext2",
3971         .get_sb         = ext4_get_sb,
3972         .kill_sb        = kill_block_super,
3973         .fs_flags       = FS_REQUIRES_DEV,
3974 };
3975
3976 static inline void register_as_ext2(void)
3977 {
3978         int err = register_filesystem(&ext2_fs_type);
3979         if (err)
3980                 printk(KERN_WARNING
3981                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
3982 }
3983
3984 static inline void unregister_as_ext2(void)
3985 {
3986         unregister_filesystem(&ext2_fs_type);
3987 }
3988 #else
3989 static inline void register_as_ext2(void) { }
3990 static inline void unregister_as_ext2(void) { }
3991 #endif
3992
3993 #if !defined(CONTIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
3994 static struct file_system_type ext3_fs_type = {
3995         .owner          = THIS_MODULE,
3996         .name           = "ext3",
3997         .get_sb         = ext4_get_sb,
3998         .kill_sb        = kill_block_super,
3999         .fs_flags       = FS_REQUIRES_DEV,
4000 };
4001
4002 static inline void register_as_ext3(void)
4003 {
4004         int err = register_filesystem(&ext3_fs_type);
4005         if (err)
4006                 printk(KERN_WARNING
4007                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
4008 }
4009
4010 static inline void unregister_as_ext3(void)
4011 {
4012         unregister_filesystem(&ext3_fs_type);
4013 }
4014 #else
4015 static inline void register_as_ext3(void) { }
4016 static inline void unregister_as_ext3(void) { }
4017 #endif
4018
4019 static struct file_system_type ext4_fs_type = {
4020         .owner          = THIS_MODULE,
4021         .name           = "ext4",
4022         .get_sb         = ext4_get_sb,
4023         .kill_sb        = kill_block_super,
4024         .fs_flags       = FS_REQUIRES_DEV,
4025 };
4026
4027 static int __init init_ext4_fs(void)
4028 {
4029         int err;
4030
4031         err = init_ext4_system_zone();
4032         if (err)
4033                 return err;
4034         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
4035         if (!ext4_kset)
4036                 goto out4;
4037         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
4038         err = init_ext4_mballoc();
4039         if (err)
4040                 goto out3;
4041
4042         err = init_ext4_xattr();
4043         if (err)
4044                 goto out2;
4045         err = init_inodecache();
4046         if (err)
4047                 goto out1;
4048         register_as_ext2();
4049         register_as_ext3();
4050         err = register_filesystem(&ext4_fs_type);
4051         if (err)
4052                 goto out;
4053         return 0;
4054 out:
4055         unregister_as_ext2();
4056         unregister_as_ext3();
4057         destroy_inodecache();
4058 out1:
4059         exit_ext4_xattr();
4060 out2:
4061         exit_ext4_mballoc();
4062 out3:
4063         remove_proc_entry("fs/ext4", NULL);
4064         kset_unregister(ext4_kset);
4065 out4:
4066         exit_ext4_system_zone();
4067         return err;
4068 }
4069
4070 static void __exit exit_ext4_fs(void)
4071 {
4072         unregister_as_ext2();
4073         unregister_as_ext3();
4074         unregister_filesystem(&ext4_fs_type);
4075         destroy_inodecache();
4076         exit_ext4_xattr();
4077         exit_ext4_mballoc();
4078         remove_proc_entry("fs/ext4", NULL);
4079         kset_unregister(ext4_kset);
4080         exit_ext4_system_zone();
4081 }
4082
4083 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
4084 MODULE_DESCRIPTION("Fourth Extended Filesystem");
4085 MODULE_LICENSE("GPL");
4086 module_init(init_ext4_fs)
4087 module_exit(exit_ext4_fs)