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 complain 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_da_metadata_calc_len = 0;
 706         ei->i_delalloc_reserved_flag = 0;
 707         spin_lock_init(&(ei->i_block_reservation_lock));
 708 #ifdef CONFIG_QUOTA
 709         ei->i_reserved_quota = 0;
 710 #endif
 711         INIT_LIST_HEAD(&ei->i_aio_dio_complete_list);
 712         ei->cur_aio_dio = NULL;
 713         ei->i_sync_tid = 0;
 714         ei->i_datasync_tid = 0;
 715
 716         return &ei->vfs_inode;
 717 }
 718
 719 static void ext4_destroy_inode(struct inode *inode)
 720 {
 721         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 722                 ext4_msg(inode->i_sb, KERN_ERR,
 723                          "Inode %lu (%p): orphan list check failed!",
 724                          inode->i_ino, EXT4_I(inode));
 725                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 726                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 727                                 true);
 728                 dump_stack();
 729         }
 730         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 731 }
 732
 733 static void init_once(void *foo)
 734 {
 735         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 736
 737         INIT_LIST_HEAD(&ei->i_orphan);
 738 #ifdef CONFIG_EXT4_FS_XATTR
 739         init_rwsem(&ei->xattr_sem);
 740 #endif
 741         init_rwsem(&ei->i_data_sem);
 742         inode_init_once(&ei->vfs_inode);
 743 }
 744
 745 static int init_inodecache(void)
 746 {
 747         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 748                                              sizeof(struct ext4_inode_info),
 749                                              0, (SLAB_RECLAIM_ACCOUNT|
 750                                                 SLAB_MEM_SPREAD),
 751                                              init_once);
 752         if (ext4_inode_cachep == NULL)
 753                 return -ENOMEM;
 754         return 0;
 755 }
 756
 757 static void destroy_inodecache(void)
 758 {
 759         kmem_cache_destroy(ext4_inode_cachep);
 760 }
 761
 762 static void ext4_clear_inode(struct inode *inode)
 763 {
 764         ext4_discard_preallocations(inode);
 765         if (EXT4_JOURNAL(inode))
 766                 jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
 767                                        &EXT4_I(inode)->jinode);
 768 }
 769
 770 static inline void ext4_show_quota_options(struct seq_file *seq,
 771                                            struct super_block *sb)
 772 {
 773 #if defined(CONFIG_QUOTA)
 774         struct ext4_sb_info *sbi = EXT4_SB(sb);
 775
 776         if (sbi->s_jquota_fmt) {
 777                 char *fmtname = "";
 778
 779                 switch (sbi->s_jquota_fmt) {
 780                 case QFMT_VFS_OLD:
 781                         fmtname = "vfsold";
 782                         break;
 783                 case QFMT_VFS_V0:
 784                         fmtname = "vfsv0";
 785                         break;
 786                 case QFMT_VFS_V1:
 787                         fmtname = "vfsv1";
 788                         break;
 789                 }
 790                 seq_printf(seq, ",jqfmt=%s", fmtname);
 791         }
 792
 793         if (sbi->s_qf_names[USRQUOTA])
 794                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 795
 796         if (sbi->s_qf_names[GRPQUOTA])
 797                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 798
 799         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
 800                 seq_puts(seq, ",usrquota");
 801
 802         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
 803                 seq_puts(seq, ",grpquota");
 804 #endif
 805 }
 806
 807 /*
 808  * Show an option if
 809  *  - it's set to a non-default value OR
 810  *  - if the per-sb default is different from the global default
 811  */
 812 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 813 {
 814         int def_errors;
 815         unsigned long def_mount_opts;
 816         struct super_block *sb = vfs->mnt_sb;
 817         struct ext4_sb_info *sbi = EXT4_SB(sb);
 818         struct ext4_super_block *es = sbi->s_es;
 819
 820         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 821         def_errors     = le16_to_cpu(es->s_errors);
 822
 823         if (sbi->s_sb_block != 1)
 824                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 825         if (test_opt(sb, MINIX_DF))
 826                 seq_puts(seq, ",minixdf");
 827         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
 828                 seq_puts(seq, ",grpid");
 829         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 830                 seq_puts(seq, ",nogrpid");
 831         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 832             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 833                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 834         }
 835         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 836             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 837                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 838         }
 839         if (test_opt(sb, ERRORS_RO)) {
 840                 if (def_errors == EXT4_ERRORS_PANIC ||
 841                     def_errors == EXT4_ERRORS_CONTINUE) {
 842                         seq_puts(seq, ",errors=remount-ro");
 843                 }
 844         }
 845         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
 846                 seq_puts(seq, ",errors=continue");
 847         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
 848                 seq_puts(seq, ",errors=panic");
 849         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
 850                 seq_puts(seq, ",nouid32");
 851         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
 852                 seq_puts(seq, ",debug");
 853         if (test_opt(sb, OLDALLOC))
 854                 seq_puts(seq, ",oldalloc");
 855 #ifdef CONFIG_EXT4_FS_XATTR
 856         if (test_opt(sb, XATTR_USER) &&
 857                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
 858                 seq_puts(seq, ",user_xattr");
 859         if (!test_opt(sb, XATTR_USER) &&
 860             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 861                 seq_puts(seq, ",nouser_xattr");
 862         }
 863 #endif
 864 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 865         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
 866                 seq_puts(seq, ",acl");
 867         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 868                 seq_puts(seq, ",noacl");
 869 #endif
 870         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
 871                 seq_printf(seq, ",commit=%u",
 872                            (unsigned) (sbi->s_commit_interval / HZ));
 873         }
 874         if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
 875                 seq_printf(seq, ",min_batch_time=%u",
 876                            (unsigned) sbi->s_min_batch_time);
 877         }
 878         if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
 879                 seq_printf(seq, ",max_batch_time=%u",
 880                            (unsigned) sbi->s_min_batch_time);
 881         }
 882
 883         /*
 884          * We're changing the default of barrier mount option, so
 885          * let's always display its mount state so it's clear what its
 886          * status is.
 887          */
 888         seq_puts(seq, ",barrier=");
 889         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
 890         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
 891                 seq_puts(seq, ",journal_async_commit");
 892         if (test_opt(sb, NOBH))
 893                 seq_puts(seq, ",nobh");
 894         if (test_opt(sb, I_VERSION))
 895                 seq_puts(seq, ",i_version");
 896         if (!test_opt(sb, DELALLOC))
 897                 seq_puts(seq, ",nodelalloc");
 898
 899
 900         if (sbi->s_stripe)
 901                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
 902         /*
 903          * journal mode get enabled in different ways
 904          * So just print the value even if we didn't specify it
 905          */
 906         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 907                 seq_puts(seq, ",data=journal");
 908         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 909                 seq_puts(seq, ",data=ordered");
 910         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 911                 seq_puts(seq, ",data=writeback");
 912
 913         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
 914                 seq_printf(seq, ",inode_readahead_blks=%u",
 915                            sbi->s_inode_readahead_blks);
 916
 917         if (test_opt(sb, DATA_ERR_ABORT))
 918                 seq_puts(seq, ",data_err=abort");
 919
 920         if (test_opt(sb, NO_AUTO_DA_ALLOC))
 921                 seq_puts(seq, ",noauto_da_alloc");
 922
 923         if (test_opt(sb, DISCARD))
 924                 seq_puts(seq, ",discard");
 925
 926         if (test_opt(sb, NOLOAD))
 927                 seq_puts(seq, ",norecovery");
 928
 929         ext4_show_quota_options(seq, sb);
 930
 931         return 0;
 932 }
 933
 934 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 935                                         u64 ino, u32 generation)
 936 {
 937         struct inode *inode;
 938
 939         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 940                 return ERR_PTR(-ESTALE);
 941         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 942                 return ERR_PTR(-ESTALE);
 943
 944         /* iget isn't really right if the inode is currently unallocated!!
 945          *
 946          * ext4_read_inode will return a bad_inode if the inode had been
 947          * deleted, so we should be safe.
 948          *
 949          * Currently we don't know the generation for parent directory, so
 950          * a generation of 0 means "accept any"
 951          */
 952         inode = ext4_iget(sb, ino);
 953         if (IS_ERR(inode))
 954                 return ERR_CAST(inode);
 955         if (generation && inode->i_generation != generation) {
 956                 iput(inode);
 957                 return ERR_PTR(-ESTALE);
 958         }
 959
 960         return inode;
 961 }
 962
 963 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 964                                         int fh_len, int fh_type)
 965 {
 966         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 967                                     ext4_nfs_get_inode);
 968 }
 969
 970 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 971                                         int fh_len, int fh_type)
 972 {
 973         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 974                                     ext4_nfs_get_inode);
 975 }
 976
 977 /*
 978  * Try to release metadata pages (indirect blocks, directories) which are
 979  * mapped via the block device.  Since these pages could have journal heads
 980  * which would prevent try_to_free_buffers() from freeing them, we must use
 981  * jbd2 layer's try_to_free_buffers() function to release them.
 982  */
 983 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
 984                                  gfp_t wait)
 985 {
 986         journal_t *journal = EXT4_SB(sb)->s_journal;
 987
 988         WARN_ON(PageChecked(page));
 989         if (!page_has_buffers(page))
 990                 return 0;
 991         if (journal)
 992                 return jbd2_journal_try_to_free_buffers(journal, page,
 993                                                         wait & ~__GFP_WAIT);
 994         return try_to_free_buffers(page);
 995 }
 996
 997 #ifdef CONFIG_QUOTA
 998 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
 999 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1000
1001 static int ext4_write_dquot(struct dquot *dquot);
1002 static int ext4_acquire_dquot(struct dquot *dquot);
1003 static int ext4_release_dquot(struct dquot *dquot);
1004 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1005 static int ext4_write_info(struct super_block *sb, int type);
1006 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1007                                 char *path, int remount);
1008 static int ext4_quota_on_mount(struct super_block *sb, int type);
1009 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1010                                size_t len, loff_t off);
1011 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1012                                 const char *data, size_t len, loff_t off);
1013
1014 static const struct dquot_operations ext4_quota_operations = {
1015         .initialize     = dquot_initialize,
1016         .drop           = dquot_drop,
1017         .alloc_space    = dquot_alloc_space,
1018         .reserve_space  = dquot_reserve_space,
1019         .claim_space    = dquot_claim_space,
1020         .release_rsv    = dquot_release_reserved_space,
1021 #ifdef CONFIG_QUOTA
1022         .get_reserved_space = ext4_get_reserved_space,
1023 #endif
1024         .alloc_inode    = dquot_alloc_inode,
1025         .free_space     = dquot_free_space,
1026         .free_inode     = dquot_free_inode,
1027         .transfer       = dquot_transfer,
1028         .write_dquot    = ext4_write_dquot,
1029         .acquire_dquot  = ext4_acquire_dquot,
1030         .release_dquot  = ext4_release_dquot,
1031         .mark_dirty     = ext4_mark_dquot_dirty,
1032         .write_info     = ext4_write_info,
1033         .alloc_dquot    = dquot_alloc,
1034         .destroy_dquot  = dquot_destroy,
1035 };
1036
1037 static const struct quotactl_ops ext4_qctl_operations = {
1038         .quota_on       = ext4_quota_on,
1039         .quota_off      = vfs_quota_off,
1040         .quota_sync     = vfs_quota_sync,
1041         .get_info       = vfs_get_dqinfo,
1042         .set_info       = vfs_set_dqinfo,
1043         .get_dqblk      = vfs_get_dqblk,
1044         .set_dqblk      = vfs_set_dqblk
1045 };
1046 #endif
1047
1048 static const struct super_operations ext4_sops = {
1049         .alloc_inode    = ext4_alloc_inode,
1050         .destroy_inode  = ext4_destroy_inode,
1051         .write_inode    = ext4_write_inode,
1052         .dirty_inode    = ext4_dirty_inode,
1053         .delete_inode   = ext4_delete_inode,
1054         .put_super      = ext4_put_super,
1055         .sync_fs        = ext4_sync_fs,
1056         .freeze_fs      = ext4_freeze,
1057         .unfreeze_fs    = ext4_unfreeze,
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 super_operations ext4_nojournal_sops = {
1070         .alloc_inode    = ext4_alloc_inode,
1071         .destroy_inode  = ext4_destroy_inode,
1072         .write_inode    = ext4_write_inode,
1073         .dirty_inode    = ext4_dirty_inode,
1074         .delete_inode   = ext4_delete_inode,
1075         .write_super    = ext4_write_super,
1076         .put_super      = ext4_put_super,
1077         .statfs         = ext4_statfs,
1078         .remount_fs     = ext4_remount,
1079         .clear_inode    = ext4_clear_inode,
1080         .show_options   = ext4_show_options,
1081 #ifdef CONFIG_QUOTA
1082         .quota_read     = ext4_quota_read,
1083         .quota_write    = ext4_quota_write,
1084 #endif
1085         .bdev_try_to_free_page = bdev_try_to_free_page,
1086 };
1087
1088 static const struct export_operations ext4_export_ops = {
1089         .fh_to_dentry = ext4_fh_to_dentry,
1090         .fh_to_parent = ext4_fh_to_parent,
1091         .get_parent = ext4_get_parent,
1092 };
1093
1094 enum {
1095         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1096         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1097         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1098         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1099         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1100         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1101         Opt_journal_update, Opt_journal_dev,
1102         Opt_journal_checksum, Opt_journal_async_commit,
1103         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1104         Opt_data_err_abort, Opt_data_err_ignore,
1105         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1106         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1107         Opt_noquota, Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err,
1108         Opt_resize, Opt_usrquota, Opt_grpquota, Opt_i_version,
1109         Opt_stripe, Opt_delalloc, Opt_nodelalloc,
1110         Opt_block_validity, Opt_noblock_validity,
1111         Opt_inode_readahead_blks, Opt_journal_ioprio,
1112         Opt_discard, Opt_nodiscard,
1113 };
1114
1115 static const match_table_t tokens = {
1116         {Opt_bsd_df, "bsddf"},
1117         {Opt_minix_df, "minixdf"},
1118         {Opt_grpid, "grpid"},
1119         {Opt_grpid, "bsdgroups"},
1120         {Opt_nogrpid, "nogrpid"},
1121         {Opt_nogrpid, "sysvgroups"},
1122         {Opt_resgid, "resgid=%u"},
1123         {Opt_resuid, "resuid=%u"},
1124         {Opt_sb, "sb=%u"},
1125         {Opt_err_cont, "errors=continue"},
1126         {Opt_err_panic, "errors=panic"},
1127         {Opt_err_ro, "errors=remount-ro"},
1128         {Opt_nouid32, "nouid32"},
1129         {Opt_debug, "debug"},
1130         {Opt_oldalloc, "oldalloc"},
1131         {Opt_orlov, "orlov"},
1132         {Opt_user_xattr, "user_xattr"},
1133         {Opt_nouser_xattr, "nouser_xattr"},
1134         {Opt_acl, "acl"},
1135         {Opt_noacl, "noacl"},
1136         {Opt_noload, "noload"},
1137         {Opt_noload, "norecovery"},
1138         {Opt_nobh, "nobh"},
1139         {Opt_bh, "bh"},
1140         {Opt_commit, "commit=%u"},
1141         {Opt_min_batch_time, "min_batch_time=%u"},
1142         {Opt_max_batch_time, "max_batch_time=%u"},
1143         {Opt_journal_update, "journal=update"},
1144         {Opt_journal_dev, "journal_dev=%u"},
1145         {Opt_journal_checksum, "journal_checksum"},
1146         {Opt_journal_async_commit, "journal_async_commit"},
1147         {Opt_abort, "abort"},
1148         {Opt_data_journal, "data=journal"},
1149         {Opt_data_ordered, "data=ordered"},
1150         {Opt_data_writeback, "data=writeback"},
1151         {Opt_data_err_abort, "data_err=abort"},
1152         {Opt_data_err_ignore, "data_err=ignore"},
1153         {Opt_offusrjquota, "usrjquota="},
1154         {Opt_usrjquota, "usrjquota=%s"},
1155         {Opt_offgrpjquota, "grpjquota="},
1156         {Opt_grpjquota, "grpjquota=%s"},
1157         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1158         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1159         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1160         {Opt_grpquota, "grpquota"},
1161         {Opt_noquota, "noquota"},
1162         {Opt_quota, "quota"},
1163         {Opt_usrquota, "usrquota"},
1164         {Opt_barrier, "barrier=%u"},
1165         {Opt_barrier, "barrier"},
1166         {Opt_nobarrier, "nobarrier"},
1167         {Opt_i_version, "i_version"},
1168         {Opt_stripe, "stripe=%u"},
1169         {Opt_resize, "resize"},
1170         {Opt_delalloc, "delalloc"},
1171         {Opt_nodelalloc, "nodelalloc"},
1172         {Opt_block_validity, "block_validity"},
1173         {Opt_noblock_validity, "noblock_validity"},
1174         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1175         {Opt_journal_ioprio, "journal_ioprio=%u"},
1176         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1177         {Opt_auto_da_alloc, "auto_da_alloc"},
1178         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1179         {Opt_discard, "discard"},
1180         {Opt_nodiscard, "nodiscard"},
1181         {Opt_err, NULL},
1182 };
1183
1184 static ext4_fsblk_t get_sb_block(void **data)
1185 {
1186         ext4_fsblk_t    sb_block;
1187         char            *options = (char *) *data;
1188
1189         if (!options || strncmp(options, "sb=", 3) != 0)
1190                 return 1;       /* Default location */
1191
1192         options += 3;
1193         /* TODO: use simple_strtoll with >32bit ext4 */
1194         sb_block = simple_strtoul(options, &options, 0);
1195         if (*options && *options != ',') {
1196                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1197                        (char *) *data);
1198                 return 1;
1199         }
1200         if (*options == ',')
1201                 options++;
1202         *data = (void *) options;
1203
1204         return sb_block;
1205 }
1206
1207 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1208
1209 static int parse_options(char *options, struct super_block *sb,
1210                          unsigned long *journal_devnum,
1211                          unsigned int *journal_ioprio,
1212                          ext4_fsblk_t *n_blocks_count, int is_remount)
1213 {
1214         struct ext4_sb_info *sbi = EXT4_SB(sb);
1215         char *p;
1216         substring_t args[MAX_OPT_ARGS];
1217         int data_opt = 0;
1218         int option;
1219 #ifdef CONFIG_QUOTA
1220         int qtype, qfmt;
1221         char *qname;
1222 #endif
1223
1224         if (!options)
1225                 return 1;
1226
1227         while ((p = strsep(&options, ",")) != NULL) {
1228                 int token;
1229                 if (!*p)
1230                         continue;
1231
1232                 token = match_token(p, tokens, args);
1233                 switch (token) {
1234                 case Opt_bsd_df:
1235                         clear_opt(sbi->s_mount_opt, MINIX_DF);
1236                         break;
1237                 case Opt_minix_df:
1238                         set_opt(sbi->s_mount_opt, MINIX_DF);
1239                         break;
1240                 case Opt_grpid:
1241                         set_opt(sbi->s_mount_opt, GRPID);
1242                         break;
1243                 case Opt_nogrpid:
1244                         clear_opt(sbi->s_mount_opt, GRPID);
1245                         break;
1246                 case Opt_resuid:
1247                         if (match_int(&args[0], &option))
1248                                 return 0;
1249                         sbi->s_resuid = option;
1250                         break;
1251                 case Opt_resgid:
1252                         if (match_int(&args[0], &option))
1253                                 return 0;
1254                         sbi->s_resgid = option;
1255                         break;
1256                 case Opt_sb:
1257                         /* handled by get_sb_block() instead of here */
1258                         /* *sb_block = match_int(&args[0]); */
1259                         break;
1260                 case Opt_err_panic:
1261                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1262                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1263                         set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1264                         break;
1265                 case Opt_err_ro:
1266                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1267                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1268                         set_opt(sbi->s_mount_opt, ERRORS_RO);
1269                         break;
1270                 case Opt_err_cont:
1271                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1272                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1273                         set_opt(sbi->s_mount_opt, ERRORS_CONT);
1274                         break;
1275                 case Opt_nouid32:
1276                         set_opt(sbi->s_mount_opt, NO_UID32);
1277                         break;
1278                 case Opt_debug:
1279                         set_opt(sbi->s_mount_opt, DEBUG);
1280                         break;
1281                 case Opt_oldalloc:
1282                         set_opt(sbi->s_mount_opt, OLDALLOC);
1283                         break;
1284                 case Opt_orlov:
1285                         clear_opt(sbi->s_mount_opt, OLDALLOC);
1286                         break;
1287 #ifdef CONFIG_EXT4_FS_XATTR
1288                 case Opt_user_xattr:
1289                         set_opt(sbi->s_mount_opt, XATTR_USER);
1290                         break;
1291                 case Opt_nouser_xattr:
1292                         clear_opt(sbi->s_mount_opt, XATTR_USER);
1293                         break;
1294 #else
1295                 case Opt_user_xattr:
1296                 case Opt_nouser_xattr:
1297                         ext4_msg(sb, KERN_ERR, "(no)user_xattr options not supported");
1298                         break;
1299 #endif
1300 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1301                 case Opt_acl:
1302                         set_opt(sbi->s_mount_opt, POSIX_ACL);
1303                         break;
1304                 case Opt_noacl:
1305                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
1306                         break;
1307 #else
1308                 case Opt_acl:
1309                 case Opt_noacl:
1310                         ext4_msg(sb, KERN_ERR, "(no)acl options not supported");
1311                         break;
1312 #endif
1313                 case Opt_journal_update:
1314                         /* @@@ FIXME */
1315                         /* Eventually we will want to be able to create
1316                            a journal file here.  For now, only allow the
1317                            user to specify an existing inode to be the
1318                            journal file. */
1319                         if (is_remount) {
1320                                 ext4_msg(sb, KERN_ERR,
1321                                          "Cannot specify journal on remount");
1322                                 return 0;
1323                         }
1324                         set_opt(sbi->s_mount_opt, UPDATE_JOURNAL);
1325                         break;
1326                 case Opt_journal_dev:
1327                         if (is_remount) {
1328                                 ext4_msg(sb, KERN_ERR,
1329                                         "Cannot specify journal on remount");
1330                                 return 0;
1331                         }
1332                         if (match_int(&args[0], &option))
1333                                 return 0;
1334                         *journal_devnum = option;
1335                         break;
1336                 case Opt_journal_checksum:
1337                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1338                         break;
1339                 case Opt_journal_async_commit:
1340                         set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1341                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1342                         break;
1343                 case Opt_noload:
1344                         set_opt(sbi->s_mount_opt, NOLOAD);
1345                         break;
1346                 case Opt_commit:
1347                         if (match_int(&args[0], &option))
1348                                 return 0;
1349                         if (option < 0)
1350                                 return 0;
1351                         if (option == 0)
1352                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1353                         sbi->s_commit_interval = HZ * option;
1354                         break;
1355                 case Opt_max_batch_time:
1356                         if (match_int(&args[0], &option))
1357                                 return 0;
1358                         if (option < 0)
1359                                 return 0;
1360                         if (option == 0)
1361                                 option = EXT4_DEF_MAX_BATCH_TIME;
1362                         sbi->s_max_batch_time = option;
1363                         break;
1364                 case Opt_min_batch_time:
1365                         if (match_int(&args[0], &option))
1366                                 return 0;
1367                         if (option < 0)
1368                                 return 0;
1369                         sbi->s_min_batch_time = option;
1370                         break;
1371                 case Opt_data_journal:
1372                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1373                         goto datacheck;
1374                 case Opt_data_ordered:
1375                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1376                         goto datacheck;
1377                 case Opt_data_writeback:
1378                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1379                 datacheck:
1380                         if (is_remount) {
1381                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1382                                                 != data_opt) {
1383                                         ext4_msg(sb, KERN_ERR,
1384                                                 "Cannot change data mode on remount");
1385                                         return 0;
1386                                 }
1387                         } else {
1388                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1389                                 sbi->s_mount_opt |= data_opt;
1390                         }
1391                         break;
1392                 case Opt_data_err_abort:
1393                         set_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1394                         break;
1395                 case Opt_data_err_ignore:
1396                         clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1397                         break;
1398 #ifdef CONFIG_QUOTA
1399                 case Opt_usrjquota:
1400                         qtype = USRQUOTA;
1401                         goto set_qf_name;
1402                 case Opt_grpjquota:
1403                         qtype = GRPQUOTA;
1404 set_qf_name:
1405                         if (sb_any_quota_loaded(sb) &&
1406                             !sbi->s_qf_names[qtype]) {
1407                                 ext4_msg(sb, KERN_ERR,
1408                                        "Cannot change journaled "
1409                                        "quota options when quota turned on");
1410                                 return 0;
1411                         }
1412                         qname = match_strdup(&args[0]);
1413                         if (!qname) {
1414                                 ext4_msg(sb, KERN_ERR,
1415                                         "Not enough memory for "
1416                                         "storing quotafile name");
1417                                 return 0;
1418                         }
1419                         if (sbi->s_qf_names[qtype] &&
1420                             strcmp(sbi->s_qf_names[qtype], qname)) {
1421                                 ext4_msg(sb, KERN_ERR,
1422                                         "%s quota file already "
1423                                         "specified", QTYPE2NAME(qtype));
1424                                 kfree(qname);
1425                                 return 0;
1426                         }
1427                         sbi->s_qf_names[qtype] = qname;
1428                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1429                                 ext4_msg(sb, KERN_ERR,
1430                                         "quotafile must be on "
1431                                         "filesystem root");
1432                                 kfree(sbi->s_qf_names[qtype]);
1433                                 sbi->s_qf_names[qtype] = NULL;
1434                                 return 0;
1435                         }
1436                         set_opt(sbi->s_mount_opt, QUOTA);
1437                         break;
1438                 case Opt_offusrjquota:
1439                         qtype = USRQUOTA;
1440                         goto clear_qf_name;
1441                 case Opt_offgrpjquota:
1442                         qtype = GRPQUOTA;
1443 clear_qf_name:
1444                         if (sb_any_quota_loaded(sb) &&
1445                             sbi->s_qf_names[qtype]) {
1446                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1447                                         "journaled quota options when "
1448                                         "quota turned on");
1449                                 return 0;
1450                         }
1451                         /*
1452                          * The space will be released later when all options
1453                          * are confirmed to be correct
1454                          */
1455                         sbi->s_qf_names[qtype] = NULL;
1456                         break;
1457                 case Opt_jqfmt_vfsold:
1458                         qfmt = QFMT_VFS_OLD;
1459                         goto set_qf_format;
1460                 case Opt_jqfmt_vfsv0:
1461                         qfmt = QFMT_VFS_V0;
1462                         goto set_qf_format;
1463                 case Opt_jqfmt_vfsv1:
1464                         qfmt = QFMT_VFS_V1;
1465 set_qf_format:
1466                         if (sb_any_quota_loaded(sb) &&
1467                             sbi->s_jquota_fmt != qfmt) {
1468                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1469                                         "journaled quota options when "
1470                                         "quota turned on");
1471                                 return 0;
1472                         }
1473                         sbi->s_jquota_fmt = qfmt;
1474                         break;
1475                 case Opt_quota:
1476                 case Opt_usrquota:
1477                         set_opt(sbi->s_mount_opt, QUOTA);
1478                         set_opt(sbi->s_mount_opt, USRQUOTA);
1479                         break;
1480                 case Opt_grpquota:
1481                         set_opt(sbi->s_mount_opt, QUOTA);
1482                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1483                         break;
1484                 case Opt_noquota:
1485                         if (sb_any_quota_loaded(sb)) {
1486                                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1487                                         "options when quota turned on");
1488                                 return 0;
1489                         }
1490                         clear_opt(sbi->s_mount_opt, QUOTA);
1491                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1492                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1493                         break;
1494 #else
1495                 case Opt_quota:
1496                 case Opt_usrquota:
1497                 case Opt_grpquota:
1498                         ext4_msg(sb, KERN_ERR,
1499                                 "quota options not supported");
1500                         break;
1501                 case Opt_usrjquota:
1502                 case Opt_grpjquota:
1503                 case Opt_offusrjquota:
1504                 case Opt_offgrpjquota:
1505                 case Opt_jqfmt_vfsold:
1506                 case Opt_jqfmt_vfsv0:
1507                 case Opt_jqfmt_vfsv1:
1508                         ext4_msg(sb, KERN_ERR,
1509                                 "journaled quota options not supported");
1510                         break;
1511                 case Opt_noquota:
1512                         break;
1513 #endif
1514                 case Opt_abort:
1515                         sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1516                         break;
1517                 case Opt_nobarrier:
1518                         clear_opt(sbi->s_mount_opt, BARRIER);
1519                         break;
1520                 case Opt_barrier:
1521                         if (match_int(&args[0], &option)) {
1522                                 set_opt(sbi->s_mount_opt, BARRIER);
1523                                 break;
1524                         }
1525                         if (option)
1526                                 set_opt(sbi->s_mount_opt, BARRIER);
1527                         else
1528                                 clear_opt(sbi->s_mount_opt, BARRIER);
1529                         break;
1530                 case Opt_ignore:
1531                         break;
1532                 case Opt_resize:
1533                         if (!is_remount) {
1534                                 ext4_msg(sb, KERN_ERR,
1535                                         "resize option only available "
1536                                         "for remount");
1537                                 return 0;
1538                         }
1539                         if (match_int(&args[0], &option) != 0)
1540                                 return 0;
1541                         *n_blocks_count = option;
1542                         break;
1543                 case Opt_nobh:
1544                         set_opt(sbi->s_mount_opt, NOBH);
1545                         break;
1546                 case Opt_bh:
1547                         clear_opt(sbi->s_mount_opt, NOBH);
1548                         break;
1549                 case Opt_i_version:
1550                         set_opt(sbi->s_mount_opt, I_VERSION);
1551                         sb->s_flags |= MS_I_VERSION;
1552                         break;
1553                 case Opt_nodelalloc:
1554                         clear_opt(sbi->s_mount_opt, DELALLOC);
1555                         break;
1556                 case Opt_stripe:
1557                         if (match_int(&args[0], &option))
1558                                 return 0;
1559                         if (option < 0)
1560                                 return 0;
1561                         sbi->s_stripe = option;
1562                         break;
1563                 case Opt_delalloc:
1564                         set_opt(sbi->s_mount_opt, DELALLOC);
1565                         break;
1566                 case Opt_block_validity:
1567                         set_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1568                         break;
1569                 case Opt_noblock_validity:
1570                         clear_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1571                         break;
1572                 case Opt_inode_readahead_blks:
1573                         if (match_int(&args[0], &option))
1574                                 return 0;
1575                         if (option < 0 || option > (1 << 30))
1576                                 return 0;
1577                         if (!is_power_of_2(option)) {
1578                                 ext4_msg(sb, KERN_ERR,
1579                                          "EXT4-fs: inode_readahead_blks"
1580                                          " must be a power of 2");
1581                                 return 0;
1582                         }
1583                         sbi->s_inode_readahead_blks = option;
1584                         break;
1585                 case Opt_journal_ioprio:
1586                         if (match_int(&args[0], &option))
1587                                 return 0;
1588                         if (option < 0 || option > 7)
1589                                 break;
1590                         *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1591                                                             option);
1592                         break;
1593                 case Opt_noauto_da_alloc:
1594                         set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1595                         break;
1596                 case Opt_auto_da_alloc:
1597                         if (match_int(&args[0], &option)) {
1598                                 clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1599                                 break;
1600                         }
1601                         if (option)
1602                                 clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1603                         else
1604                                 set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1605                         break;
1606                 case Opt_discard:
1607                         set_opt(sbi->s_mount_opt, DISCARD);
1608                         break;
1609                 case Opt_nodiscard:
1610                         clear_opt(sbi->s_mount_opt, DISCARD);
1611                         break;
1612                 default:
1613                         ext4_msg(sb, KERN_ERR,
1614                                "Unrecognized mount option \"%s\" "
1615                                "or missing value", p);
1616                         return 0;
1617                 }
1618         }
1619 #ifdef CONFIG_QUOTA
1620         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1621                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1622                      sbi->s_qf_names[USRQUOTA])
1623                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1624
1625                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1626                      sbi->s_qf_names[GRPQUOTA])
1627                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1628
1629                 if ((sbi->s_qf_names[USRQUOTA] &&
1630                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1631                     (sbi->s_qf_names[GRPQUOTA] &&
1632                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1633                         ext4_msg(sb, KERN_ERR, "old and new quota "
1634                                         "format mixing");
1635                         return 0;
1636                 }
1637
1638                 if (!sbi->s_jquota_fmt) {
1639                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1640                                         "not specified");
1641                         return 0;
1642                 }
1643         } else {
1644                 if (sbi->s_jquota_fmt) {
1645                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1646                                         "specified with no journaling "
1647                                         "enabled");
1648                         return 0;
1649                 }
1650         }
1651 #endif
1652         return 1;
1653 }
1654
1655 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1656                             int read_only)
1657 {
1658         struct ext4_sb_info *sbi = EXT4_SB(sb);
1659         int res = 0;
1660
1661         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1662                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1663                          "forcing read-only mode");
1664                 res = MS_RDONLY;
1665         }
1666         if (read_only)
1667                 return res;
1668         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1669                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1670                          "running e2fsck is recommended");
1671         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1672                 ext4_msg(sb, KERN_WARNING,
1673                          "warning: mounting fs with errors, "
1674                          "running e2fsck is recommended");
1675         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1676                  le16_to_cpu(es->s_mnt_count) >=
1677                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1678                 ext4_msg(sb, KERN_WARNING,
1679                          "warning: maximal mount count reached, "
1680                          "running e2fsck is recommended");
1681         else if (le32_to_cpu(es->s_checkinterval) &&
1682                 (le32_to_cpu(es->s_lastcheck) +
1683                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1684                 ext4_msg(sb, KERN_WARNING,
1685                          "warning: checktime reached, "
1686                          "running e2fsck is recommended");
1687         if (!sbi->s_journal)
1688                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1689         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1690                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1691         le16_add_cpu(&es->s_mnt_count, 1);
1692         es->s_mtime = cpu_to_le32(get_seconds());
1693         ext4_update_dynamic_rev(sb);
1694         if (sbi->s_journal)
1695                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1696
1697         ext4_commit_super(sb, 1);
1698         if (test_opt(sb, DEBUG))
1699                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1700                                 "bpg=%lu, ipg=%lu, mo=%04x]\n",
1701                         sb->s_blocksize,
1702                         sbi->s_groups_count,
1703                         EXT4_BLOCKS_PER_GROUP(sb),
1704                         EXT4_INODES_PER_GROUP(sb),
1705                         sbi->s_mount_opt);
1706
1707         return res;
1708 }
1709
1710 static int ext4_fill_flex_info(struct super_block *sb)
1711 {
1712         struct ext4_sb_info *sbi = EXT4_SB(sb);
1713         struct ext4_group_desc *gdp = NULL;
1714         ext4_group_t flex_group_count;
1715         ext4_group_t flex_group;
1716         int groups_per_flex = 0;
1717         size_t size;
1718         int i;
1719
1720         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1721         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1722
1723         if (groups_per_flex < 2) {
1724                 sbi->s_log_groups_per_flex = 0;
1725                 return 1;
1726         }
1727
1728         /* We allocate both existing and potentially added groups */
1729         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1730                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1731                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1732         size = flex_group_count * sizeof(struct flex_groups);
1733         sbi->s_flex_groups = kzalloc(size, GFP_KERNEL);
1734         if (sbi->s_flex_groups == NULL) {
1735                 sbi->s_flex_groups = vmalloc(size);
1736                 if (sbi->s_flex_groups)
1737                         memset(sbi->s_flex_groups, 0, size);
1738         }
1739         if (sbi->s_flex_groups == NULL) {
1740                 ext4_msg(sb, KERN_ERR, "not enough memory for "
1741                                 "%u flex groups", flex_group_count);
1742                 goto failed;
1743         }
1744
1745         for (i = 0; i < sbi->s_groups_count; i++) {
1746                 gdp = ext4_get_group_desc(sb, i, NULL);
1747
1748                 flex_group = ext4_flex_group(sbi, i);
1749                 atomic_add(ext4_free_inodes_count(sb, gdp),
1750                            &sbi->s_flex_groups[flex_group].free_inodes);
1751                 atomic_add(ext4_free_blks_count(sb, gdp),
1752                            &sbi->s_flex_groups[flex_group].free_blocks);
1753                 atomic_add(ext4_used_dirs_count(sb, gdp),
1754                            &sbi->s_flex_groups[flex_group].used_dirs);
1755         }
1756
1757         return 1;
1758 failed:
1759         return 0;
1760 }
1761
1762 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1763                             struct ext4_group_desc *gdp)
1764 {
1765         __u16 crc = 0;
1766
1767         if (sbi->s_es->s_feature_ro_compat &
1768             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1769                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1770                 __le32 le_group = cpu_to_le32(block_group);
1771
1772                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1773                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1774                 crc = crc16(crc, (__u8 *)gdp, offset);
1775                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1776                 /* for checksum of struct ext4_group_desc do the rest...*/
1777                 if ((sbi->s_es->s_feature_incompat &
1778                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1779                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1780                         crc = crc16(crc, (__u8 *)gdp + offset,
1781                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1782                                         offset);
1783         }
1784
1785         return cpu_to_le16(crc);
1786 }
1787
1788 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1789                                 struct ext4_group_desc *gdp)
1790 {
1791         if ((sbi->s_es->s_feature_ro_compat &
1792              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1793             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1794                 return 0;
1795
1796         return 1;
1797 }
1798
1799 /* Called at mount-time, super-block is locked */
1800 static int ext4_check_descriptors(struct super_block *sb)
1801 {
1802         struct ext4_sb_info *sbi = EXT4_SB(sb);
1803         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1804         ext4_fsblk_t last_block;
1805         ext4_fsblk_t block_bitmap;
1806         ext4_fsblk_t inode_bitmap;
1807         ext4_fsblk_t inode_table;
1808         int flexbg_flag = 0;
1809         ext4_group_t i;
1810
1811         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1812                 flexbg_flag = 1;
1813
1814         ext4_debug("Checking group descriptors");
1815
1816         for (i = 0; i < sbi->s_groups_count; i++) {
1817                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1818
1819                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1820                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1821                 else
1822                         last_block = first_block +
1823                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1824
1825                 block_bitmap = ext4_block_bitmap(sb, gdp);
1826                 if (block_bitmap < first_block || block_bitmap > last_block) {
1827                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1828                                "Block bitmap for group %u not in group "
1829                                "(block %llu)!", i, block_bitmap);
1830                         return 0;
1831                 }
1832                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1833                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
1834                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1835                                "Inode bitmap for group %u not in group "
1836                                "(block %llu)!", i, inode_bitmap);
1837                         return 0;
1838                 }
1839                 inode_table = ext4_inode_table(sb, gdp);
1840                 if (inode_table < first_block ||
1841                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
1842                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1843                                "Inode table for group %u not in group "
1844                                "(block %llu)!", i, inode_table);
1845                         return 0;
1846                 }
1847                 ext4_lock_group(sb, i);
1848                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1849                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1850                                  "Checksum for group %u failed (%u!=%u)",
1851                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1852                                      gdp)), le16_to_cpu(gdp->bg_checksum));
1853                         if (!(sb->s_flags & MS_RDONLY)) {
1854                                 ext4_unlock_group(sb, i);
1855                                 return 0;
1856                         }
1857                 }
1858                 ext4_unlock_group(sb, i);
1859                 if (!flexbg_flag)
1860                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1861         }
1862
1863         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1864         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
1865         return 1;
1866 }
1867
1868 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1869  * the superblock) which were deleted from all directories, but held open by
1870  * a process at the time of a crash.  We walk the list and try to delete these
1871  * inodes at recovery time (only with a read-write filesystem).
1872  *
1873  * In order to keep the orphan inode chain consistent during traversal (in
1874  * case of crash during recovery), we link each inode into the superblock
1875  * orphan list_head and handle it the same way as an inode deletion during
1876  * normal operation (which journals the operations for us).
1877  *
1878  * We only do an iget() and an iput() on each inode, which is very safe if we
1879  * accidentally point at an in-use or already deleted inode.  The worst that
1880  * can happen in this case is that we get a "bit already cleared" message from
1881  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1882  * e2fsck was run on this filesystem, and it must have already done the orphan
1883  * inode cleanup for us, so we can safely abort without any further action.
1884  */
1885 static void ext4_orphan_cleanup(struct super_block *sb,
1886                                 struct ext4_super_block *es)
1887 {
1888         unsigned int s_flags = sb->s_flags;
1889         int nr_orphans = 0, nr_truncates = 0;
1890 #ifdef CONFIG_QUOTA
1891         int i;
1892 #endif
1893         if (!es->s_last_orphan) {
1894                 jbd_debug(4, "no orphan inodes to clean up\n");
1895                 return;
1896         }
1897
1898         if (bdev_read_only(sb->s_bdev)) {
1899                 ext4_msg(sb, KERN_ERR, "write access "
1900                         "unavailable, skipping orphan cleanup");
1901                 return;
1902         }
1903
1904         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1905                 if (es->s_last_orphan)
1906                         jbd_debug(1, "Errors on filesystem, "
1907                                   "clearing orphan list.\n");
1908                 es->s_last_orphan = 0;
1909                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1910                 return;
1911         }
1912
1913         if (s_flags & MS_RDONLY) {
1914                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
1915                 sb->s_flags &= ~MS_RDONLY;
1916         }
1917 #ifdef CONFIG_QUOTA
1918         /* Needed for iput() to work correctly and not trash data */
1919         sb->s_flags |= MS_ACTIVE;
1920         /* Turn on quotas so that they are updated correctly */
1921         for (i = 0; i < MAXQUOTAS; i++) {
1922                 if (EXT4_SB(sb)->s_qf_names[i]) {
1923                         int ret = ext4_quota_on_mount(sb, i);
1924                         if (ret < 0)
1925                                 ext4_msg(sb, KERN_ERR,
1926                                         "Cannot turn on journaled "
1927                                         "quota: error %d", ret);
1928                 }
1929         }
1930 #endif
1931
1932         while (es->s_last_orphan) {
1933                 struct inode *inode;
1934
1935                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
1936                 if (IS_ERR(inode)) {
1937                         es->s_last_orphan = 0;
1938                         break;
1939                 }
1940
1941                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1942                 vfs_dq_init(inode);
1943                 if (inode->i_nlink) {
1944                         ext4_msg(sb, KERN_DEBUG,
1945                                 "%s: truncating inode %lu to %lld bytes",
1946                                 __func__, inode->i_ino, inode->i_size);
1947                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
1948                                   inode->i_ino, inode->i_size);
1949                         ext4_truncate(inode);
1950                         nr_truncates++;
1951                 } else {
1952                         ext4_msg(sb, KERN_DEBUG,
1953                                 "%s: deleting unreferenced inode %lu",
1954                                 __func__, inode->i_ino);
1955                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1956                                   inode->i_ino);
1957                         nr_orphans++;
1958                 }
1959                 iput(inode);  /* The delete magic happens here! */
1960         }
1961
1962 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
1963
1964         if (nr_orphans)
1965                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
1966                        PLURAL(nr_orphans));
1967         if (nr_truncates)
1968                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
1969                        PLURAL(nr_truncates));
1970 #ifdef CONFIG_QUOTA
1971         /* Turn quotas off */
1972         for (i = 0; i < MAXQUOTAS; i++) {
1973                 if (sb_dqopt(sb)->files[i])
1974                         vfs_quota_off(sb, i, 0);
1975         }
1976 #endif
1977         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1978 }
1979
1980 /*
1981  * Maximal extent format file size.
1982  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1983  * extent format containers, within a sector_t, and within i_blocks
1984  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1985  * so that won't be a limiting factor.
1986  *
1987  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1988  */
1989 static loff_t ext4_max_size(int blkbits, int has_huge_files)
1990 {
1991         loff_t res;
1992         loff_t upper_limit = MAX_LFS_FILESIZE;
1993
1994         /* small i_blocks in vfs inode? */
1995         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1996                 /*
1997                  * CONFIG_LBDAF is not enabled implies the inode
1998                  * i_block represent total blocks in 512 bytes
1999                  * 32 == size of vfs inode i_blocks * 8
2000                  */
2001                 upper_limit = (1LL << 32) - 1;
2002
2003                 /* total blocks in file system block size */
2004                 upper_limit >>= (blkbits - 9);
2005                 upper_limit <<= blkbits;
2006         }
2007
2008         /* 32-bit extent-start container, ee_block */
2009         res = 1LL << 32;
2010         res <<= blkbits;
2011         res -= 1;
2012
2013         /* Sanity check against vm- & vfs- imposed limits */
2014         if (res > upper_limit)
2015                 res = upper_limit;
2016
2017         return res;
2018 }
2019
2020 /*
2021  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2022  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2023  * We need to be 1 filesystem block less than the 2^48 sector limit.
2024  */
2025 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2026 {
2027         loff_t res = EXT4_NDIR_BLOCKS;
2028         int meta_blocks;
2029         loff_t upper_limit;
2030         /* This is calculated to be the largest file size for a dense, block
2031          * mapped file such that the file's total number of 512-byte sectors,
2032          * including data and all indirect blocks, does not exceed (2^48 - 1).
2033          *
2034          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2035          * number of 512-byte sectors of the file.
2036          */
2037
2038         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2039                 /*
2040                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2041                  * the inode i_block field represents total file blocks in
2042                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2043                  */
2044                 upper_limit = (1LL << 32) - 1;
2045
2046                 /* total blocks in file system block size */
2047                 upper_limit >>= (bits - 9);
2048
2049         } else {
2050                 /*
2051                  * We use 48 bit ext4_inode i_blocks
2052                  * With EXT4_HUGE_FILE_FL set the i_blocks
2053                  * represent total number of blocks in
2054                  * file system block size
2055                  */
2056                 upper_limit = (1LL << 48) - 1;
2057
2058         }
2059
2060         /* indirect blocks */
2061         meta_blocks = 1;
2062         /* double indirect blocks */
2063         meta_blocks += 1 + (1LL << (bits-2));
2064         /* tripple indirect blocks */
2065         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2066
2067         upper_limit -= meta_blocks;
2068         upper_limit <<= bits;
2069
2070         res += 1LL << (bits-2);
2071         res += 1LL << (2*(bits-2));
2072         res += 1LL << (3*(bits-2));
2073         res <<= bits;
2074         if (res > upper_limit)
2075                 res = upper_limit;
2076
2077         if (res > MAX_LFS_FILESIZE)
2078                 res = MAX_LFS_FILESIZE;
2079
2080         return res;
2081 }
2082
2083 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2084                                    ext4_fsblk_t logical_sb_block, int nr)
2085 {
2086         struct ext4_sb_info *sbi = EXT4_SB(sb);
2087         ext4_group_t bg, first_meta_bg;
2088         int has_super = 0;
2089
2090         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2091
2092         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2093             nr < first_meta_bg)
2094                 return logical_sb_block + nr + 1;
2095         bg = sbi->s_desc_per_block * nr;
2096         if (ext4_bg_has_super(sb, bg))
2097                 has_super = 1;
2098
2099         return (has_super + ext4_group_first_block_no(sb, bg));
2100 }
2101
2102 /**
2103  * ext4_get_stripe_size: Get the stripe size.
2104  * @sbi: In memory super block info
2105  *
2106  * If we have specified it via mount option, then
2107  * use the mount option value. If the value specified at mount time is
2108  * greater than the blocks per group use the super block value.
2109  * If the super block value is greater than blocks per group return 0.
2110  * Allocator needs it be less than blocks per group.
2111  *
2112  */
2113 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2114 {
2115         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2116         unsigned long stripe_width =
2117                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2118
2119         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2120                 return sbi->s_stripe;
2121
2122         if (stripe_width <= sbi->s_blocks_per_group)
2123                 return stripe_width;
2124
2125         if (stride <= sbi->s_blocks_per_group)
2126                 return stride;
2127
2128         return 0;
2129 }
2130
2131 /* sysfs supprt */
2132
2133 struct ext4_attr {
2134         struct attribute attr;
2135         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2136         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2137                          const char *, size_t);
2138         int offset;
2139 };
2140
2141 static int parse_strtoul(const char *buf,
2142                 unsigned long max, unsigned long *value)
2143 {
2144         char *endp;
2145
2146         *value = simple_strtoul(skip_spaces(buf), &endp, 0);
2147         endp = skip_spaces(endp);
2148         if (*endp || *value > max)
2149                 return -EINVAL;
2150
2151         return 0;
2152 }
2153
2154 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2155                                               struct ext4_sb_info *sbi,
2156                                               char *buf)
2157 {
2158         return snprintf(buf, PAGE_SIZE, "%llu\n",
2159                         (s64) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2160 }
2161
2162 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2163                                          struct ext4_sb_info *sbi, char *buf)
2164 {
2165         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2166
2167         return snprintf(buf, PAGE_SIZE, "%lu\n",
2168                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2169                          sbi->s_sectors_written_start) >> 1);
2170 }
2171
2172 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2173                                           struct ext4_sb_info *sbi, char *buf)
2174 {
2175         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2176
2177         return snprintf(buf, PAGE_SIZE, "%llu\n",
2178                         (unsigned long long)(sbi->s_kbytes_written +
2179                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2180                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2181 }
2182
2183 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2184                                           struct ext4_sb_info *sbi,
2185                                           const char *buf, size_t count)
2186 {
2187         unsigned long t;
2188
2189         if (parse_strtoul(buf, 0x40000000, &t))
2190                 return -EINVAL;
2191
2192         if (!is_power_of_2(t))
2193                 return -EINVAL;
2194
2195         sbi->s_inode_readahead_blks = t;
2196         return count;
2197 }
2198
2199 static ssize_t sbi_ui_show(struct ext4_attr *a,
2200                            struct ext4_sb_info *sbi, char *buf)
2201 {
2202         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2203
2204         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2205 }
2206
2207 static ssize_t sbi_ui_store(struct ext4_attr *a,
2208                             struct ext4_sb_info *sbi,
2209                             const char *buf, size_t count)
2210 {
2211         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2212         unsigned long t;
2213
2214         if (parse_strtoul(buf, 0xffffffff, &t))
2215                 return -EINVAL;
2216         *ui = t;
2217         return count;
2218 }
2219
2220 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2221 static struct ext4_attr ext4_attr_##_name = {                   \
2222         .attr = {.name = __stringify(_name), .mode = _mode },   \
2223         .show   = _show,                                        \
2224         .store  = _store,                                       \
2225         .offset = offsetof(struct ext4_sb_info, _elname),       \
2226 }
2227 #define EXT4_ATTR(name, mode, show, store) \
2228 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2229
2230 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2231 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2232 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2233         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2234 #define ATTR_LIST(name) &ext4_attr_##name.attr
2235
2236 EXT4_RO_ATTR(delayed_allocation_blocks);
2237 EXT4_RO_ATTR(session_write_kbytes);
2238 EXT4_RO_ATTR(lifetime_write_kbytes);
2239 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2240                  inode_readahead_blks_store, s_inode_readahead_blks);
2241 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2242 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2243 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2244 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2245 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2246 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2247 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2248 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2249
2250 static struct attribute *ext4_attrs[] = {
2251         ATTR_LIST(delayed_allocation_blocks),
2252         ATTR_LIST(session_write_kbytes),
2253         ATTR_LIST(lifetime_write_kbytes),
2254         ATTR_LIST(inode_readahead_blks),
2255         ATTR_LIST(inode_goal),
2256         ATTR_LIST(mb_stats),
2257         ATTR_LIST(mb_max_to_scan),
2258         ATTR_LIST(mb_min_to_scan),
2259         ATTR_LIST(mb_order2_req),
2260         ATTR_LIST(mb_stream_req),
2261         ATTR_LIST(mb_group_prealloc),
2262         ATTR_LIST(max_writeback_mb_bump),
2263         NULL,
2264 };
2265
2266 static ssize_t ext4_attr_show(struct kobject *kobj,
2267                               struct attribute *attr, char *buf)
2268 {
2269         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2270                                                 s_kobj);
2271         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2272
2273         return a->show ? a->show(a, sbi, buf) : 0;
2274 }
2275
2276 static ssize_t ext4_attr_store(struct kobject *kobj,
2277                                struct attribute *attr,
2278                                const char *buf, size_t len)
2279 {
2280         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2281                                                 s_kobj);
2282         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2283
2284         return a->store ? a->store(a, sbi, buf, len) : 0;
2285 }
2286
2287 static void ext4_sb_release(struct kobject *kobj)
2288 {
2289         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2290                                                 s_kobj);
2291         complete(&sbi->s_kobj_unregister);
2292 }
2293
2294
2295 static struct sysfs_ops ext4_attr_ops = {
2296         .show   = ext4_attr_show,
2297         .store  = ext4_attr_store,
2298 };
2299
2300 static struct kobj_type ext4_ktype = {
2301         .default_attrs  = ext4_attrs,
2302         .sysfs_ops      = &ext4_attr_ops,
2303         .release        = ext4_sb_release,
2304 };
2305
2306 /*
2307  * Check whether this filesystem can be mounted based on
2308  * the features present and the RDONLY/RDWR mount requested.
2309  * Returns 1 if this filesystem can be mounted as requested,
2310  * 0 if it cannot be.
2311  */
2312 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2313 {
2314         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2315                 ext4_msg(sb, KERN_ERR,
2316                         "Couldn't mount because of "
2317                         "unsupported optional features (%x)",
2318                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2319                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2320                 return 0;
2321         }
2322
2323         if (readonly)
2324                 return 1;
2325
2326         /* Check that feature set is OK for a read-write mount */
2327         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2328                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2329                          "unsupported optional features (%x)",
2330                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2331                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2332                 return 0;
2333         }
2334         /*
2335          * Large file size enabled file system can only be mounted
2336          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2337          */
2338         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2339                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2340                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2341                                  "cannot be mounted RDWR without "
2342                                  "CONFIG_LBDAF");
2343                         return 0;
2344                 }
2345         }
2346         return 1;
2347 }
2348
2349 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
2350                                 __releases(kernel_lock)
2351                                 __acquires(kernel_lock)
2352 {
2353         struct buffer_head *bh;
2354         struct ext4_super_block *es = NULL;
2355         struct ext4_sb_info *sbi;
2356         ext4_fsblk_t block;
2357         ext4_fsblk_t sb_block = get_sb_block(&data);
2358         ext4_fsblk_t logical_sb_block;
2359         unsigned long offset = 0;
2360         unsigned long journal_devnum = 0;
2361         unsigned long def_mount_opts;
2362         struct inode *root;
2363         char *cp;
2364         const char *descr;
2365         int ret = -EINVAL;
2366         int blocksize;
2367         unsigned int db_count;
2368         unsigned int i;
2369         int needs_recovery, has_huge_files;
2370         __u64 blocks_count;
2371         int err;
2372         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
2373
2374         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
2375         if (!sbi)
2376                 return -ENOMEM;
2377
2378         sbi->s_blockgroup_lock =
2379                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
2380         if (!sbi->s_blockgroup_lock) {
2381                 kfree(sbi);
2382                 return -ENOMEM;
2383         }
2384         sb->s_fs_info = sbi;
2385         sbi->s_mount_opt = 0;
2386         sbi->s_resuid = EXT4_DEF_RESUID;
2387         sbi->s_resgid = EXT4_DEF_RESGID;
2388         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
2389         sbi->s_sb_block = sb_block;
2390         sbi->s_sectors_written_start = part_stat_read(sb->s_bdev->bd_part,
2391                                                       sectors[1]);
2392
2393         unlock_kernel();
2394
2395         /* Cleanup superblock name */
2396         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
2397                 *cp = '!';
2398
2399         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
2400         if (!blocksize) {
2401                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
2402                 goto out_fail;
2403         }
2404
2405         /*
2406          * The ext4 superblock will not be buffer aligned for other than 1kB
2407          * block sizes.  We need to calculate the offset from buffer start.
2408          */
2409         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
2410                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2411                 offset = do_div(logical_sb_block, blocksize);
2412         } else {
2413                 logical_sb_block = sb_block;
2414         }
2415
2416         if (!(bh = sb_bread(sb, logical_sb_block))) {
2417                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
2418                 goto out_fail;
2419         }
2420         /*
2421          * Note: s_es must be initialized as soon as possible because
2422          *       some ext4 macro-instructions depend on its value
2423          */
2424         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2425         sbi->s_es = es;
2426         sb->s_magic = le16_to_cpu(es->s_magic);
2427         if (sb->s_magic != EXT4_SUPER_MAGIC)
2428                 goto cantfind_ext4;
2429         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
2430
2431         /* Set defaults before we parse the mount options */
2432         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
2433         if (def_mount_opts & EXT4_DEFM_DEBUG)
2434                 set_opt(sbi->s_mount_opt, DEBUG);
2435         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
2436                 set_opt(sbi->s_mount_opt, GRPID);
2437         if (def_mount_opts & EXT4_DEFM_UID16)
2438                 set_opt(sbi->s_mount_opt, NO_UID32);
2439 #ifdef CONFIG_EXT4_FS_XATTR
2440         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
2441                 set_opt(sbi->s_mount_opt, XATTR_USER);
2442 #endif
2443 #ifdef CONFIG_EXT4_FS_POSIX_ACL
2444         if (def_mount_opts & EXT4_DEFM_ACL)
2445                 set_opt(sbi->s_mount_opt, POSIX_ACL);
2446 #endif
2447         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
2448                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
2449         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
2450                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
2451         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
2452                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
2453
2454         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
2455                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
2456         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
2457                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
2458         else
2459                 set_opt(sbi->s_mount_opt, ERRORS_RO);
2460
2461         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
2462         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
2463         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
2464         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
2465         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
2466
2467         set_opt(sbi->s_mount_opt, BARRIER);
2468
2469         /*
2470          * enable delayed allocation by default
2471          * Use -o nodelalloc to turn it off
2472          */
2473         set_opt(sbi->s_mount_opt, DELALLOC);
2474
2475         if (!parse_options((char *) data, sb, &journal_devnum,
2476                            &journal_ioprio, NULL, 0))
2477                 goto failed_mount;
2478
2479         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2480                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2481
2482         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
2483             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
2484              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
2485              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
2486                 ext4_msg(sb, KERN_WARNING,
2487                        "feature flags set on rev 0 fs, "
2488                        "running e2fsck is recommended");
2489
2490         /*
2491          * Check feature flags regardless of the revision level, since we
2492          * previously didn't change the revision level when setting the flags,
2493          * so there is a chance incompat flags are set on a rev 0 filesystem.
2494          */
2495         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
2496                 goto failed_mount;
2497
2498         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
2499
2500         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
2501             blocksize > EXT4_MAX_BLOCK_SIZE) {
2502                 ext4_msg(sb, KERN_ERR,
2503                        "Unsupported filesystem blocksize %d", blocksize);
2504                 goto failed_mount;
2505         }
2506
2507         if (sb->s_blocksize != blocksize) {
2508                 /* Validate the filesystem blocksize */
2509                 if (!sb_set_blocksize(sb, blocksize)) {
2510                         ext4_msg(sb, KERN_ERR, "bad block size %d",
2511                                         blocksize);
2512                         goto failed_mount;
2513                 }
2514
2515                 brelse(bh);
2516                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2517                 offset = do_div(logical_sb_block, blocksize);
2518                 bh = sb_bread(sb, logical_sb_block);
2519                 if (!bh) {
2520                         ext4_msg(sb, KERN_ERR,
2521                                "Can't read superblock on 2nd try");
2522                         goto failed_mount;
2523                 }
2524                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
2525                 sbi->s_es = es;
2526                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
2527                         ext4_msg(sb, KERN_ERR,
2528                                "Magic mismatch, very weird!");
2529                         goto failed_mount;
2530                 }
2531         }
2532
2533         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2534                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
2535         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
2536                                                       has_huge_files);
2537         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
2538
2539         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2540                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2541                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2542         } else {
2543                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2544                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2545                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2546                     (!is_power_of_2(sbi->s_inode_size)) ||
2547                     (sbi->s_inode_size > blocksize)) {
2548                         ext4_msg(sb, KERN_ERR,
2549                                "unsupported inode size: %d",
2550                                sbi->s_inode_size);
2551                         goto failed_mount;
2552                 }
2553                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2554                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2555         }
2556
2557         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2558         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2559                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2560                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2561                     !is_power_of_2(sbi->s_desc_size)) {
2562                         ext4_msg(sb, KERN_ERR,
2563                                "unsupported descriptor size %lu",
2564                                sbi->s_desc_size);
2565                         goto failed_mount;
2566                 }
2567         } else
2568                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2569
2570         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2571         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2572         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2573                 goto cantfind_ext4;
2574
2575         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2576         if (sbi->s_inodes_per_block == 0)
2577                 goto cantfind_ext4;
2578         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2579                                         sbi->s_inodes_per_block;
2580         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2581         sbi->s_sbh = bh;
2582         sbi->s_mount_state = le16_to_cpu(es->s_state);
2583         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2584         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2585
2586         for (i = 0; i < 4; i++)
2587                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2588         sbi->s_def_hash_version = es->s_def_hash_version;
2589         i = le32_to_cpu(es->s_flags);
2590         if (i & EXT2_FLAGS_UNSIGNED_HASH)
2591                 sbi->s_hash_unsigned = 3;
2592         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
2593 #ifdef __CHAR_UNSIGNED__
2594                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
2595                 sbi->s_hash_unsigned = 3;
2596 #else
2597                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
2598 #endif
2599                 sb->s_dirt = 1;
2600         }
2601
2602         if (sbi->s_blocks_per_group > blocksize * 8) {
2603                 ext4_msg(sb, KERN_ERR,
2604                        "#blocks per group too big: %lu",
2605                        sbi->s_blocks_per_group);
2606                 goto failed_mount;
2607         }
2608         if (sbi->s_inodes_per_group > blocksize * 8) {
2609                 ext4_msg(sb, KERN_ERR,
2610                        "#inodes per group too big: %lu",
2611                        sbi->s_inodes_per_group);
2612                 goto failed_mount;
2613         }
2614
2615         /*
2616          * Test whether we have more sectors than will fit in sector_t,
2617          * and whether the max offset is addressable by the page cache.
2618          */
2619         if ((ext4_blocks_count(es) >
2620              (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) ||
2621             (ext4_blocks_count(es) >
2622              (pgoff_t)(~0ULL) >> (PAGE_CACHE_SHIFT - sb->s_blocksize_bits))) {
2623                 ext4_msg(sb, KERN_ERR, "filesystem"
2624                          " too large to mount safely on this system");
2625                 if (sizeof(sector_t) < 8)
2626                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
2627                 ret = -EFBIG;
2628                 goto failed_mount;
2629         }
2630
2631         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2632                 goto cantfind_ext4;
2633
2634         /* check blocks count against device size */
2635         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
2636         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
2637                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
2638                        "exceeds size of device (%llu blocks)",
2639                        ext4_blocks_count(es), blocks_count);
2640                 goto failed_mount;
2641         }
2642
2643         /*
2644          * It makes no sense for the first data block to be beyond the end
2645          * of the filesystem.
2646          */
2647         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
2648                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data"
2649                          "block %u is beyond end of filesystem (%llu)",
2650                          le32_to_cpu(es->s_first_data_block),
2651                          ext4_blocks_count(es));
2652                 goto failed_mount;
2653         }
2654         blocks_count = (ext4_blocks_count(es) -
2655                         le32_to_cpu(es->s_first_data_block) +
2656                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2657         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2658         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
2659                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
2660                        "(block count %llu, first data block %u, "
2661                        "blocks per group %lu)", sbi->s_groups_count,
2662                        ext4_blocks_count(es),
2663                        le32_to_cpu(es->s_first_data_block),
2664                        EXT4_BLOCKS_PER_GROUP(sb));
2665                 goto failed_mount;
2666         }
2667         sbi->s_groups_count = blocks_count;
2668         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
2669                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
2670         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2671                    EXT4_DESC_PER_BLOCK(sb);
2672         sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
2673                                     GFP_KERNEL);
2674         if (sbi->s_group_desc == NULL) {
2675                 ext4_msg(sb, KERN_ERR, "not enough memory");
2676                 goto failed_mount;
2677         }
2678
2679 #ifdef CONFIG_PROC_FS
2680         if (ext4_proc_root)
2681                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
2682 #endif
2683
2684         bgl_lock_init(sbi->s_blockgroup_lock);
2685
2686         for (i = 0; i < db_count; i++) {
2687                 block = descriptor_loc(sb, logical_sb_block, i);
2688                 sbi->s_group_desc[i] = sb_bread(sb, block);
2689                 if (!sbi->s_group_desc[i]) {
2690                         ext4_msg(sb, KERN_ERR,
2691                                "can't read group descriptor %d", i);
2692                         db_count = i;
2693                         goto failed_mount2;
2694                 }
2695         }
2696         if (!ext4_check_descriptors(sb)) {
2697                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
2698                 goto failed_mount2;
2699         }
2700         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2701                 if (!ext4_fill_flex_info(sb)) {
2702                         ext4_msg(sb, KERN_ERR,
2703                                "unable to initialize "
2704                                "flex_bg meta info!");
2705                         goto failed_mount2;
2706                 }
2707
2708         sbi->s_gdb_count = db_count;
2709         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2710         spin_lock_init(&sbi->s_next_gen_lock);
2711
2712         err = percpu_counter_init(&sbi->s_freeblocks_counter,
2713                         ext4_count_free_blocks(sb));
2714         if (!err) {
2715                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
2716                                 ext4_count_free_inodes(sb));
2717         }
2718         if (!err) {
2719                 err = percpu_counter_init(&sbi->s_dirs_counter,
2720                                 ext4_count_dirs(sb));
2721         }
2722         if (!err) {
2723                 err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
2724         }
2725         if (err) {
2726                 ext4_msg(sb, KERN_ERR, "insufficient memory");
2727                 goto failed_mount3;
2728         }
2729
2730         sbi->s_stripe = ext4_get_stripe_size(sbi);
2731         sbi->s_max_writeback_mb_bump = 128;
2732
2733         /*
2734          * set up enough so that it can read an inode
2735          */
2736         if (!test_opt(sb, NOLOAD) &&
2737             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
2738                 sb->s_op = &ext4_sops;
2739         else
2740                 sb->s_op = &ext4_nojournal_sops;
2741         sb->s_export_op = &ext4_export_ops;
2742         sb->s_xattr = ext4_xattr_handlers;
2743 #ifdef CONFIG_QUOTA
2744         sb->s_qcop = &ext4_qctl_operations;
2745         sb->dq_op = &ext4_quota_operations;
2746 #endif
2747         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2748         mutex_init(&sbi->s_orphan_lock);
2749         mutex_init(&sbi->s_resize_lock);
2750
2751         sb->s_root = NULL;
2752
2753         needs_recovery = (es->s_last_orphan != 0 ||
2754                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2755                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2756
2757         /*
2758          * The first inode we look at is the journal inode.  Don't try
2759          * root first: it may be modified in the journal!
2760          */
2761         if (!test_opt(sb, NOLOAD) &&
2762             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2763                 if (ext4_load_journal(sb, es, journal_devnum))
2764                         goto failed_mount3;
2765         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
2766               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2767                 ext4_msg(sb, KERN_ERR, "required journal recovery "
2768                        "suppressed and not mounted read-only");
2769                 goto failed_mount4;
2770         } else {
2771                 clear_opt(sbi->s_mount_opt, DATA_FLAGS);
2772                 set_opt(sbi->s_mount_opt, WRITEBACK_DATA);
2773                 sbi->s_journal = NULL;
2774                 needs_recovery = 0;
2775                 goto no_journal;
2776         }
2777
2778         if (ext4_blocks_count(es) > 0xffffffffULL &&
2779             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2780                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2781                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
2782                 goto failed_mount4;
2783         }
2784
2785         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2786                 jbd2_journal_set_features(sbi->s_journal,
2787                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2788                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2789         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2790                 jbd2_journal_set_features(sbi->s_journal,
2791                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2792                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2793                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2794         } else {
2795                 jbd2_journal_clear_features(sbi->s_journal,
2796                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2797                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2798         }
2799
2800         /* We have now updated the journal if required, so we can
2801          * validate the data journaling mode. */
2802         switch (test_opt(sb, DATA_FLAGS)) {
2803         case 0:
2804                 /* No mode set, assume a default based on the journal
2805                  * capabilities: ORDERED_DATA if the journal can
2806                  * cope, else JOURNAL_DATA
2807                  */
2808                 if (jbd2_journal_check_available_features
2809                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2810                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
2811                 else
2812                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2813                 break;
2814
2815         case EXT4_MOUNT_ORDERED_DATA:
2816         case EXT4_MOUNT_WRITEBACK_DATA:
2817                 if (!jbd2_journal_check_available_features
2818                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2819                         ext4_msg(sb, KERN_ERR, "Journal does not support "
2820                                "requested data journaling mode");
2821                         goto failed_mount4;
2822                 }
2823         default:
2824                 break;
2825         }
2826         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
2827
2828 no_journal:
2829
2830         if (test_opt(sb, NOBH)) {
2831                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2832                         ext4_msg(sb, KERN_WARNING, "Ignoring nobh option - "
2833                                 "its supported only with writeback mode");
2834                         clear_opt(sbi->s_mount_opt, NOBH);
2835                 }
2836         }
2837         EXT4_SB(sb)->dio_unwritten_wq = create_workqueue("ext4-dio-unwritten");
2838         if (!EXT4_SB(sb)->dio_unwritten_wq) {
2839                 printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
2840                 goto failed_mount_wq;
2841         }
2842
2843         /*
2844          * The jbd2_journal_load will have done any necessary log recovery,
2845          * so we can safely mount the rest of the filesystem now.
2846          */
2847
2848         root = ext4_iget(sb, EXT4_ROOT_INO);
2849         if (IS_ERR(root)) {
2850                 ext4_msg(sb, KERN_ERR, "get root inode failed");
2851                 ret = PTR_ERR(root);
2852                 goto failed_mount4;
2853         }
2854         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2855                 iput(root);
2856                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
2857                 goto failed_mount4;
2858         }
2859         sb->s_root = d_alloc_root(root);
2860         if (!sb->s_root) {
2861                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
2862                 iput(root);
2863                 ret = -ENOMEM;
2864                 goto failed_mount4;
2865         }
2866
2867         ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
2868
2869         /* determine the minimum size of new large inodes, if present */
2870         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2871                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2872                                                      EXT4_GOOD_OLD_INODE_SIZE;
2873                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2874                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2875                         if (sbi->s_want_extra_isize <
2876                             le16_to_cpu(es->s_want_extra_isize))
2877                                 sbi->s_want_extra_isize =
2878                                         le16_to_cpu(es->s_want_extra_isize);
2879                         if (sbi->s_want_extra_isize <
2880                             le16_to_cpu(es->s_min_extra_isize))
2881                                 sbi->s_want_extra_isize =
2882                                         le16_to_cpu(es->s_min_extra_isize);
2883                 }
2884         }
2885         /* Check if enough inode space is available */
2886         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2887                                                         sbi->s_inode_size) {
2888                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2889                                                        EXT4_GOOD_OLD_INODE_SIZE;
2890                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
2891                          "available");
2892         }
2893
2894         if (test_opt(sb, DELALLOC) &&
2895             (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2896                 ext4_msg(sb, KERN_WARNING, "Ignoring delalloc option - "
2897                          "requested data journaling mode");
2898                 clear_opt(sbi->s_mount_opt, DELALLOC);
2899         }
2900
2901         err = ext4_setup_system_zone(sb);
2902         if (err) {
2903                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
2904                          "zone (%d)\n", err);
2905                 goto failed_mount4;
2906         }
2907
2908         ext4_ext_init(sb);
2909         err = ext4_mb_init(sb, needs_recovery);
2910         if (err) {
2911                 ext4_msg(sb, KERN_ERR, "failed to initalize mballoc (%d)",
2912                          err);
2913                 goto failed_mount4;
2914         }
2915
2916         sbi->s_kobj.kset = ext4_kset;
2917         init_completion(&sbi->s_kobj_unregister);
2918         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
2919                                    "%s", sb->s_id);
2920         if (err) {
2921                 ext4_mb_release(sb);
2922                 ext4_ext_release(sb);
2923                 goto failed_mount4;
2924         };
2925
2926         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2927         ext4_orphan_cleanup(sb, es);
2928         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2929         if (needs_recovery) {
2930                 ext4_msg(sb, KERN_INFO, "recovery complete");
2931                 ext4_mark_recovery_complete(sb, es);
2932         }
2933         if (EXT4_SB(sb)->s_journal) {
2934                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2935                         descr = " journalled data mode";
2936                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2937                         descr = " ordered data mode";
2938                 else
2939                         descr = " writeback data mode";
2940         } else
2941                 descr = "out journal";
2942
2943         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s", descr);
2944
2945         lock_kernel();
2946         return 0;
2947
2948 cantfind_ext4:
2949         if (!silent)
2950                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
2951         goto failed_mount;
2952
2953 failed_mount4:
2954         ext4_msg(sb, KERN_ERR, "mount failed");
2955         destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
2956 failed_mount_wq:
2957         ext4_release_system_zone(sb);
2958         if (sbi->s_journal) {
2959                 jbd2_journal_destroy(sbi->s_journal);
2960                 sbi->s_journal = NULL;
2961         }
2962 failed_mount3:
2963         if (sbi->s_flex_groups) {
2964                 if (is_vmalloc_addr(sbi->s_flex_groups))
2965                         vfree(sbi->s_flex_groups);
2966                 else
2967                         kfree(sbi->s_flex_groups);
2968         }
2969         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2970         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2971         percpu_counter_destroy(&sbi->s_dirs_counter);
2972         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
2973 failed_mount2:
2974         for (i = 0; i < db_count; i++)
2975                 brelse(sbi->s_group_desc[i]);
2976         kfree(sbi->s_group_desc);
2977 failed_mount:
2978         if (sbi->s_proc) {
2979                 remove_proc_entry(sb->s_id, ext4_proc_root);
2980         }
2981 #ifdef CONFIG_QUOTA
2982         for (i = 0; i < MAXQUOTAS; i++)
2983                 kfree(sbi->s_qf_names[i]);
2984 #endif
2985         ext4_blkdev_remove(sbi);
2986         brelse(bh);
2987 out_fail:
2988         sb->s_fs_info = NULL;
2989         kfree(sbi->s_blockgroup_lock);
2990         kfree(sbi);
2991         lock_kernel();
2992         return ret;
2993 }
2994
2995 /*
2996  * Setup any per-fs journal parameters now.  We'll do this both on
2997  * initial mount, once the journal has been initialised but before we've
2998  * done any recovery; and again on any subsequent remount.
2999  */
3000 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
3001 {
3002         struct ext4_sb_info *sbi = EXT4_SB(sb);
3003
3004         journal->j_commit_interval = sbi->s_commit_interval;
3005         journal->j_min_batch_time = sbi->s_min_batch_time;
3006         journal->j_max_batch_time = sbi->s_max_batch_time;
3007
3008         spin_lock(&journal->j_state_lock);
3009         if (test_opt(sb, BARRIER))
3010                 journal->j_flags |= JBD2_BARRIER;
3011         else
3012                 journal->j_flags &= ~JBD2_BARRIER;
3013         if (test_opt(sb, DATA_ERR_ABORT))
3014                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
3015         else
3016                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
3017         spin_unlock(&journal->j_state_lock);
3018 }
3019
3020 static journal_t *ext4_get_journal(struct super_block *sb,
3021                                    unsigned int journal_inum)
3022 {
3023         struct inode *journal_inode;
3024         journal_t *journal;
3025
3026         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3027
3028         /* First, test for the existence of a valid inode on disk.  Bad
3029          * things happen if we iget() an unused inode, as the subsequent
3030          * iput() will try to delete it. */
3031
3032         journal_inode = ext4_iget(sb, journal_inum);
3033         if (IS_ERR(journal_inode)) {
3034                 ext4_msg(sb, KERN_ERR, "no journal found");
3035                 return NULL;
3036         }
3037         if (!journal_inode->i_nlink) {
3038                 make_bad_inode(journal_inode);
3039                 iput(journal_inode);
3040                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
3041                 return NULL;
3042         }
3043
3044         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
3045                   journal_inode, journal_inode->i_size);
3046         if (!S_ISREG(journal_inode->i_mode)) {
3047                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
3048                 iput(journal_inode);
3049                 return NULL;
3050         }
3051
3052         journal = jbd2_journal_init_inode(journal_inode);
3053         if (!journal) {
3054                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
3055                 iput(journal_inode);
3056                 return NULL;
3057         }
3058         journal->j_private = sb;
3059         ext4_init_journal_params(sb, journal);
3060         return journal;
3061 }
3062
3063 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3064                                        dev_t j_dev)
3065 {
3066         struct buffer_head *bh;
3067         journal_t *journal;
3068         ext4_fsblk_t start;
3069         ext4_fsblk_t len;
3070         int hblock, blocksize;
3071         ext4_fsblk_t sb_block;
3072         unsigned long offset;
3073         struct ext4_super_block *es;
3074         struct block_device *bdev;
3075
3076         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3077
3078         bdev = ext4_blkdev_get(j_dev, sb);
3079         if (bdev == NULL)
3080                 return NULL;
3081
3082         if (bd_claim(bdev, sb)) {
3083                 ext4_msg(sb, KERN_ERR,
3084                         "failed to claim external journal device");
3085                 blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
3086                 return NULL;
3087         }
3088
3089         blocksize = sb->s_blocksize;
3090         hblock = bdev_logical_block_size(bdev);
3091         if (blocksize < hblock) {
3092                 ext4_msg(sb, KERN_ERR,
3093                         "blocksize too small for journal device");
3094                 goto out_bdev;
3095         }
3096
3097         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3098         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3099         set_blocksize(bdev, blocksize);
3100         if (!(bh = __bread(bdev, sb_block, blocksize))) {
3101                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3102                        "external journal");
3103                 goto out_bdev;
3104         }
3105
3106         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3107         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3108             !(le32_to_cpu(es->s_feature_incompat) &
3109               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3110                 ext4_msg(sb, KERN_ERR, "external journal has "
3111                                         "bad superblock");
3112                 brelse(bh);
3113                 goto out_bdev;
3114         }
3115
3116         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3117                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3118                 brelse(bh);
3119                 goto out_bdev;
3120         }
3121
3122         len = ext4_blocks_count(es);
3123         start = sb_block + 1;
3124         brelse(bh);     /* we're done with the superblock */
3125
3126         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
3127                                         start, len, blocksize);
3128         if (!journal) {
3129                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
3130                 goto out_bdev;
3131         }
3132         journal->j_private = sb;
3133         ll_rw_block(READ, 1, &journal->j_sb_buffer);
3134         wait_on_buffer(journal->j_sb_buffer);
3135         if (!buffer_uptodate(journal->j_sb_buffer)) {
3136                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
3137                 goto out_journal;
3138         }
3139         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
3140                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
3141                                         "user (unsupported) - %d",
3142                         be32_to_cpu(journal->j_superblock->s_nr_users));
3143                 goto out_journal;
3144         }
3145         EXT4_SB(sb)->journal_bdev = bdev;
3146         ext4_init_journal_params(sb, journal);
3147         return journal;
3148
3149 out_journal:
3150         jbd2_journal_destroy(journal);
3151 out_bdev:
3152         ext4_blkdev_put(bdev);
3153         return NULL;
3154 }
3155
3156 static int ext4_load_journal(struct super_block *sb,
3157                              struct ext4_super_block *es,
3158                              unsigned long journal_devnum)
3159 {
3160         journal_t *journal;
3161         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
3162         dev_t journal_dev;
3163         int err = 0;
3164         int really_read_only;
3165
3166         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3167
3168         if (journal_devnum &&
3169             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3170                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
3171                         "numbers have changed");
3172                 journal_dev = new_decode_dev(journal_devnum);
3173         } else
3174                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
3175
3176         really_read_only = bdev_read_only(sb->s_bdev);
3177
3178         /*
3179          * Are we loading a blank journal or performing recovery after a
3180          * crash?  For recovery, we need to check in advance whether we
3181          * can get read-write access to the device.
3182          */
3183         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3184                 if (sb->s_flags & MS_RDONLY) {
3185                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
3186                                         "required on readonly filesystem");
3187                         if (really_read_only) {
3188                                 ext4_msg(sb, KERN_ERR, "write access "
3189                                         "unavailable, cannot proceed");
3190                                 return -EROFS;
3191                         }
3192                         ext4_msg(sb, KERN_INFO, "write access will "
3193                                "be enabled during recovery");
3194                 }
3195         }
3196
3197         if (journal_inum && journal_dev) {
3198                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
3199                        "and inode journals!");
3200                 return -EINVAL;
3201         }
3202
3203         if (journal_inum) {
3204                 if (!(journal = ext4_get_journal(sb, journal_inum)))
3205                         return -EINVAL;
3206         } else {
3207                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
3208                         return -EINVAL;
3209         }
3210
3211         if (!(journal->j_flags & JBD2_BARRIER))
3212                 ext4_msg(sb, KERN_INFO, "barriers disabled");
3213
3214         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
3215                 err = jbd2_journal_update_format(journal);
3216                 if (err)  {
3217                         ext4_msg(sb, KERN_ERR, "error updating journal");
3218                         jbd2_journal_destroy(journal);
3219                         return err;
3220                 }
3221         }
3222
3223         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
3224                 err = jbd2_journal_wipe(journal, !really_read_only);
3225         if (!err)
3226                 err = jbd2_journal_load(journal);
3227
3228         if (err) {
3229                 ext4_msg(sb, KERN_ERR, "error loading journal");
3230                 jbd2_journal_destroy(journal);
3231                 return err;
3232         }
3233
3234         EXT4_SB(sb)->s_journal = journal;
3235         ext4_clear_journal_err(sb, es);
3236
3237         if (journal_devnum &&
3238             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3239                 es->s_journal_dev = cpu_to_le32(journal_devnum);
3240
3241                 /* Make sure we flush the recovery flag to disk. */
3242                 ext4_commit_super(sb, 1);
3243         }
3244
3245         return 0;
3246 }
3247
3248 static int ext4_commit_super(struct super_block *sb, int sync)
3249 {
3250         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
3251         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
3252         int error = 0;
3253
3254         if (!sbh)
3255                 return error;
3256         if (buffer_write_io_error(sbh)) {
3257                 /*
3258                  * Oh, dear.  A previous attempt to write the
3259                  * superblock failed.  This could happen because the
3260                  * USB device was yanked out.  Or it could happen to
3261                  * be a transient write error and maybe the block will
3262                  * be remapped.  Nothing we can do but to retry the
3263                  * write and hope for the best.
3264                  */
3265                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
3266                        "superblock detected");
3267                 clear_buffer_write_io_error(sbh);
3268                 set_buffer_uptodate(sbh);
3269         }
3270         /*
3271          * If the file system is mounted read-only, don't update the
3272          * superblock write time.  This avoids updating the superblock
3273          * write time when we are mounting the root file system
3274          * read/only but we need to replay the journal; at that point,
3275          * for people who are east of GMT and who make their clock
3276          * tick in localtime for Windows bug-for-bug compatibility,
3277          * the clock is set in the future, and this will cause e2fsck
3278          * to complain and force a full file system check.
3279          */
3280         if (!(sb->s_flags & MS_RDONLY))
3281                 es->s_wtime = cpu_to_le32(get_seconds());
3282         es->s_kbytes_written =
3283                 cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
3284                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
3285                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
3286         ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
3287                                         &EXT4_SB(sb)->s_freeblocks_counter));
3288         es->s_free_inodes_count = cpu_to_le32(percpu_counter_sum_positive(
3289                                         &EXT4_SB(sb)->s_freeinodes_counter));
3290         sb->s_dirt = 0;
3291         BUFFER_TRACE(sbh, "marking dirty");
3292         mark_buffer_dirty(sbh);
3293         if (sync) {
3294                 error = sync_dirty_buffer(sbh);
3295                 if (error)
3296                         return error;
3297
3298                 error = buffer_write_io_error(sbh);
3299                 if (error) {
3300                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
3301                                "superblock");
3302                         clear_buffer_write_io_error(sbh);
3303                         set_buffer_uptodate(sbh);
3304                 }
3305         }
3306         return error;
3307 }
3308
3309 /*
3310  * Have we just finished recovery?  If so, and if we are mounting (or
3311  * remounting) the filesystem readonly, then we will end up with a
3312  * consistent fs on disk.  Record that fact.
3313  */
3314 static void ext4_mark_recovery_complete(struct super_block *sb,
3315                                         struct ext4_super_block *es)
3316 {
3317         journal_t *journal = EXT4_SB(sb)->s_journal;
3318
3319         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3320                 BUG_ON(journal != NULL);
3321                 return;
3322         }
3323         jbd2_journal_lock_updates(journal);
3324         if (jbd2_journal_flush(journal) < 0)
3325                 goto out;
3326
3327         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
3328             sb->s_flags & MS_RDONLY) {
3329                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3330                 ext4_commit_super(sb, 1);
3331         }
3332
3333 out:
3334         jbd2_journal_unlock_updates(journal);
3335 }
3336
3337 /*
3338  * If we are mounting (or read-write remounting) a filesystem whose journal
3339  * has recorded an error from a previous lifetime, move that error to the
3340  * main filesystem now.
3341  */
3342 static void ext4_clear_journal_err(struct super_block *sb,
3343                                    struct ext4_super_block *es)
3344 {
3345         journal_t *journal;
3346         int j_errno;
3347         const char *errstr;
3348
3349         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3350
3351         journal = EXT4_SB(sb)->s_journal;
3352
3353         /*
3354          * Now check for any error status which may have been recorded in the
3355          * journal by a prior ext4_error() or ext4_abort()
3356          */
3357
3358         j_errno = jbd2_journal_errno(journal);
3359         if (j_errno) {
3360                 char nbuf[16];
3361
3362                 errstr = ext4_decode_error(sb, j_errno, nbuf);
3363                 ext4_warning(sb, __func__, "Filesystem error recorded "
3364                              "from previous mount: %s", errstr);
3365                 ext4_warning(sb, __func__, "Marking fs in need of "
3366                              "filesystem check.");
3367
3368                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
3369                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
3370                 ext4_commit_super(sb, 1);
3371
3372                 jbd2_journal_clear_err(journal);
3373         }
3374 }
3375
3376 /*
3377  * Force the running and committing transactions to commit,
3378  * and wait on the commit.
3379  */
3380 int ext4_force_commit(struct super_block *sb)
3381 {
3382         journal_t *journal;
3383         int ret = 0;
3384
3385         if (sb->s_flags & MS_RDONLY)
3386                 return 0;
3387
3388         journal = EXT4_SB(sb)->s_journal;
3389         if (journal)
3390                 ret = ext4_journal_force_commit(journal);
3391
3392         return ret;
3393 }
3394
3395 static void ext4_write_super(struct super_block *sb)
3396 {
3397         lock_super(sb);
3398         ext4_commit_super(sb, 1);
3399         unlock_super(sb);
3400 }
3401
3402 static int ext4_sync_fs(struct super_block *sb, int wait)
3403 {
3404         int ret = 0;
3405         tid_t target;
3406         struct ext4_sb_info *sbi = EXT4_SB(sb);
3407
3408         trace_ext4_sync_fs(sb, wait);
3409         flush_workqueue(sbi->dio_unwritten_wq);
3410         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
3411                 if (wait)
3412                         jbd2_log_wait_commit(sbi->s_journal, target);
3413         }
3414         return ret;
3415 }
3416
3417 /*
3418  * LVM calls this function before a (read-only) snapshot is created.  This
3419  * gives us a chance to flush the journal completely and mark the fs clean.
3420  */
3421 static int ext4_freeze(struct super_block *sb)
3422 {
3423         int error = 0;
3424         journal_t *journal;
3425
3426         if (sb->s_flags & MS_RDONLY)
3427                 return 0;
3428
3429         journal = EXT4_SB(sb)->s_journal;
3430
3431         /* Now we set up the journal barrier. */
3432         jbd2_journal_lock_updates(journal);
3433
3434         /*
3435          * Don't clear the needs_recovery flag if we failed to flush
3436          * the journal.
3437          */
3438         error = jbd2_journal_flush(journal);
3439         if (error < 0) {
3440         out:
3441                 jbd2_journal_unlock_updates(journal);
3442                 return error;
3443         }
3444
3445         /* Journal blocked and flushed, clear needs_recovery flag. */
3446         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3447         error = ext4_commit_super(sb, 1);
3448         if (error)
3449                 goto out;
3450         return 0;
3451 }
3452
3453 /*
3454  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
3455  * flag here, even though the filesystem is not technically dirty yet.
3456  */
3457 static int ext4_unfreeze(struct super_block *sb)
3458 {
3459         if (sb->s_flags & MS_RDONLY)
3460                 return 0;
3461
3462         lock_super(sb);
3463         /* Reset the needs_recovery flag before the fs is unlocked. */
3464         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3465         ext4_commit_super(sb, 1);
3466         unlock_super(sb);
3467         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3468         return 0;
3469 }
3470
3471 static int ext4_remount(struct super_block *sb, int *flags, char *data)
3472 {
3473         struct ext4_super_block *es;
3474         struct ext4_sb_info *sbi = EXT4_SB(sb);
3475         ext4_fsblk_t n_blocks_count = 0;
3476         unsigned long old_sb_flags;
3477         struct ext4_mount_options old_opts;
3478         ext4_group_t g;
3479         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3480         int err;
3481 #ifdef CONFIG_QUOTA
3482         int i;
3483 #endif
3484
3485         lock_kernel();
3486
3487         /* Store the original options */
3488         lock_super(sb);
3489         old_sb_flags = sb->s_flags;
3490         old_opts.s_mount_opt = sbi->s_mount_opt;
3491         old_opts.s_resuid = sbi->s_resuid;
3492         old_opts.s_resgid = sbi->s_resgid;
3493         old_opts.s_commit_interval = sbi->s_commit_interval;
3494         old_opts.s_min_batch_time = sbi->s_min_batch_time;
3495         old_opts.s_max_batch_time = sbi->s_max_batch_time;
3496 #ifdef CONFIG_QUOTA
3497         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
3498         for (i = 0; i < MAXQUOTAS; i++)
3499                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
3500 #endif
3501         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
3502                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
3503
3504         /*
3505          * Allow the "check" option to be passed as a remount option.
3506          */
3507         if (!parse_options(data, sb, NULL, &journal_ioprio,
3508                            &n_blocks_count, 1)) {
3509                 err = -EINVAL;
3510                 goto restore_opts;
3511         }
3512
3513         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
3514                 ext4_abort(sb, __func__, "Abort forced by user");
3515
3516         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3517                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
3518
3519         es = sbi->s_es;
3520
3521         if (sbi->s_journal) {
3522                 ext4_init_journal_params(sb, sbi->s_journal);
3523                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3524         }
3525
3526         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
3527                 n_blocks_count > ext4_blocks_count(es)) {
3528                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
3529                         err = -EROFS;
3530                         goto restore_opts;
3531                 }
3532
3533                 if (*flags & MS_RDONLY) {
3534                         /*
3535                          * First of all, the unconditional stuff we have to do
3536                          * to disable replay of the journal when we next remount
3537                          */
3538                         sb->s_flags |= MS_RDONLY;
3539
3540                         /*
3541                          * OK, test if we are remounting a valid rw partition
3542                          * readonly, and if so set the rdonly flag and then
3543                          * mark the partition as valid again.
3544                          */
3545                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
3546                             (sbi->s_mount_state & EXT4_VALID_FS))
3547                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
3548
3549                         if (sbi->s_journal)
3550                                 ext4_mark_recovery_complete(sb, es);
3551                 } else {
3552                         /* Make sure we can mount this feature set readwrite */
3553                         if (!ext4_feature_set_ok(sb, 0)) {
3554                                 err = -EROFS;
3555                                 goto restore_opts;
3556                         }
3557                         /*
3558                          * Make sure the group descriptor checksums
3559                          * are sane.  If they aren't, refuse to remount r/w.
3560                          */
3561                         for (g = 0; g < sbi->s_groups_count; g++) {
3562                                 struct ext4_group_desc *gdp =
3563                                         ext4_get_group_desc(sb, g, NULL);
3564
3565                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
3566                                         ext4_msg(sb, KERN_ERR,
3567                "ext4_remount: Checksum for group %u failed (%u!=%u)",
3568                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
3569                                                le16_to_cpu(gdp->bg_checksum));
3570                                         err = -EINVAL;
3571                                         goto restore_opts;
3572                                 }
3573                         }
3574
3575                         /*
3576                          * If we have an unprocessed orphan list hanging
3577                          * around from a previously readonly bdev mount,
3578                          * require a full umount/remount for now.
3579                          */
3580                         if (es->s_last_orphan) {
3581                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
3582                                        "remount RDWR because of unprocessed "
3583                                        "orphan inode list.  Please "
3584                                        "umount/remount instead");
3585                                 err = -EINVAL;
3586                                 goto restore_opts;
3587                         }
3588
3589                         /*
3590                          * Mounting a RDONLY partition read-write, so reread
3591                          * and store the current valid flag.  (It may have
3592                          * been changed by e2fsck since we originally mounted
3593                          * the partition.)
3594                          */
3595                         if (sbi->s_journal)
3596                                 ext4_clear_journal_err(sb, es);
3597                         sbi->s_mount_state = le16_to_cpu(es->s_state);
3598                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
3599                                 goto restore_opts;
3600                         if (!ext4_setup_super(sb, es, 0))
3601                                 sb->s_flags &= ~MS_RDONLY;
3602                 }
3603         }
3604         ext4_setup_system_zone(sb);
3605         if (sbi->s_journal == NULL)
3606                 ext4_commit_super(sb, 1);
3607
3608 #ifdef CONFIG_QUOTA
3609         /* Release old quota file names */
3610         for (i = 0; i < MAXQUOTAS; i++)
3611                 if (old_opts.s_qf_names[i] &&
3612                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3613                         kfree(old_opts.s_qf_names[i]);
3614 #endif
3615         unlock_super(sb);
3616         unlock_kernel();
3617         return 0;
3618
3619 restore_opts:
3620         sb->s_flags = old_sb_flags;
3621         sbi->s_mount_opt = old_opts.s_mount_opt;
3622         sbi->s_resuid = old_opts.s_resuid;
3623         sbi->s_resgid = old_opts.s_resgid;
3624         sbi->s_commit_interval = old_opts.s_commit_interval;
3625         sbi->s_min_batch_time = old_opts.s_min_batch_time;
3626         sbi->s_max_batch_time = old_opts.s_max_batch_time;
3627 #ifdef CONFIG_QUOTA
3628         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
3629         for (i = 0; i < MAXQUOTAS; i++) {
3630                 if (sbi->s_qf_names[i] &&
3631                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3632                         kfree(sbi->s_qf_names[i]);
3633                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
3634         }
3635 #endif
3636         unlock_super(sb);
3637         unlock_kernel();
3638         return err;
3639 }
3640
3641 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
3642 {
3643         struct super_block *sb = dentry->d_sb;
3644         struct ext4_sb_info *sbi = EXT4_SB(sb);
3645         struct ext4_super_block *es = sbi->s_es;
3646         u64 fsid;
3647
3648         if (test_opt(sb, MINIX_DF)) {
3649                 sbi->s_overhead_last = 0;
3650         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
3651                 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3652                 ext4_fsblk_t overhead = 0;
3653
3654                 /*
3655                  * Compute the overhead (FS structures).  This is constant
3656                  * for a given filesystem unless the number of block groups
3657                  * changes so we cache the previous value until it does.
3658                  */
3659
3660                 /*
3661                  * All of the blocks before first_data_block are
3662                  * overhead
3663                  */
3664                 overhead = le32_to_cpu(es->s_first_data_block);
3665
3666                 /*
3667                  * Add the overhead attributed to the superblock and
3668                  * block group descriptors.  If the sparse superblocks
3669                  * feature is turned on, then not all groups have this.
3670                  */
3671                 for (i = 0; i < ngroups; i++) {
3672                         overhead += ext4_bg_has_super(sb, i) +
3673                                 ext4_bg_num_gdb(sb, i);
3674                         cond_resched();
3675                 }
3676
3677                 /*
3678                  * Every block group has an inode bitmap, a block
3679                  * bitmap, and an inode table.
3680                  */
3681                 overhead += ngroups * (2 + sbi->s_itb_per_group);
3682                 sbi->s_overhead_last = overhead;
3683                 smp_wmb();
3684                 sbi->s_blocks_last = ext4_blocks_count(es);
3685         }
3686
3687         buf->f_type = EXT4_SUPER_MAGIC;
3688         buf->f_bsize = sb->s_blocksize;
3689         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
3690         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
3691                        percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
3692         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
3693         if (buf->f_bfree < ext4_r_blocks_count(es))
3694                 buf->f_bavail = 0;
3695         buf->f_files = le32_to_cpu(es->s_inodes_count);
3696         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
3697         buf->f_namelen = EXT4_NAME_LEN;
3698         fsid = le64_to_cpup((void *)es->s_uuid) ^
3699                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
3700         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
3701         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
3702
3703         return 0;
3704 }
3705
3706 /* Helper function for writing quotas on sync - we need to start transaction
3707  * before quota file is locked for write. Otherwise the are possible deadlocks:
3708  * Process 1                         Process 2
3709  * ext4_create()                     quota_sync()
3710  *   jbd2_journal_start()                  write_dquot()
3711  *   vfs_dq_init()                         down(dqio_mutex)
3712  *     down(dqio_mutex)                    jbd2_journal_start()
3713  *
3714  */
3715
3716 #ifdef CONFIG_QUOTA
3717
3718 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3719 {
3720         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3721 }
3722
3723 static int ext4_write_dquot(struct dquot *dquot)
3724 {
3725         int ret, err;
3726         handle_t *handle;
3727         struct inode *inode;
3728
3729         inode = dquot_to_inode(dquot);
3730         handle = ext4_journal_start(inode,
3731                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3732         if (IS_ERR(handle))
3733                 return PTR_ERR(handle);
3734         ret = dquot_commit(dquot);
3735         err = ext4_journal_stop(handle);
3736         if (!ret)
3737                 ret = err;
3738         return ret;
3739 }
3740
3741 static int ext4_acquire_dquot(struct dquot *dquot)
3742 {
3743         int ret, err;
3744         handle_t *handle;
3745
3746         handle = ext4_journal_start(dquot_to_inode(dquot),
3747                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3748         if (IS_ERR(handle))
3749                 return PTR_ERR(handle);
3750         ret = dquot_acquire(dquot);
3751         err = ext4_journal_stop(handle);
3752         if (!ret)
3753                 ret = err;
3754         return ret;
3755 }
3756
3757 static int ext4_release_dquot(struct dquot *dquot)
3758 {
3759         int ret, err;
3760         handle_t *handle;
3761
3762         handle = ext4_journal_start(dquot_to_inode(dquot),
3763                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3764         if (IS_ERR(handle)) {
3765                 /* Release dquot anyway to avoid endless cycle in dqput() */
3766                 dquot_release(dquot);
3767                 return PTR_ERR(handle);
3768         }
3769         ret = dquot_release(dquot);
3770         err = ext4_journal_stop(handle);
3771         if (!ret)
3772                 ret = err;
3773         return ret;
3774 }
3775
3776 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3777 {
3778         /* Are we journaling quotas? */
3779         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3780             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3781                 dquot_mark_dquot_dirty(dquot);
3782                 return ext4_write_dquot(dquot);
3783         } else {
3784                 return dquot_mark_dquot_dirty(dquot);
3785         }
3786 }
3787
3788 static int ext4_write_info(struct super_block *sb, int type)
3789 {
3790         int ret, err;
3791         handle_t *handle;
3792
3793         /* Data block + inode block */
3794         handle = ext4_journal_start(sb->s_root->d_inode, 2);
3795         if (IS_ERR(handle))
3796                 return PTR_ERR(handle);
3797         ret = dquot_commit_info(sb, type);
3798         err = ext4_journal_stop(handle);
3799         if (!ret)
3800                 ret = err;
3801         return ret;
3802 }
3803
3804 /*
3805  * Turn on quotas during mount time - we need to find
3806  * the quota file and such...
3807  */
3808 static int ext4_quota_on_mount(struct super_block *sb, int type)
3809 {
3810         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3811                                   EXT4_SB(sb)->s_jquota_fmt, type);
3812 }
3813
3814 /*
3815  * Standard function to be called on quota_on
3816  */
3817 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3818                          char *name, int remount)
3819 {
3820         int err;
3821         struct path path;
3822
3823         if (!test_opt(sb, QUOTA))
3824                 return -EINVAL;
3825         /* When remounting, no checks are needed and in fact, name is NULL */
3826         if (remount)
3827                 return vfs_quota_on(sb, type, format_id, name, remount);
3828
3829         err = kern_path(name, LOOKUP_FOLLOW, &path);
3830         if (err)
3831                 return err;
3832
3833         /* Quotafile not on the same filesystem? */
3834         if (path.mnt->mnt_sb != sb) {
3835                 path_put(&path);
3836                 return -EXDEV;
3837         }
3838         /* Journaling quota? */
3839         if (EXT4_SB(sb)->s_qf_names[type]) {
3840                 /* Quotafile not in fs root? */
3841                 if (path.dentry->d_parent != sb->s_root)
3842                         ext4_msg(sb, KERN_WARNING,
3843                                 "Quota file not on filesystem root. "
3844                                 "Journaled quota will not work");
3845         }
3846
3847         /*
3848          * When we journal data on quota file, we have to flush journal to see
3849          * all updates to the file when we bypass pagecache...
3850          */
3851         if (EXT4_SB(sb)->s_journal &&
3852             ext4_should_journal_data(path.dentry->d_inode)) {
3853                 /*
3854                  * We don't need to lock updates but journal_flush() could
3855                  * otherwise be livelocked...
3856                  */
3857                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
3858                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
3859                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3860                 if (err) {
3861                         path_put(&path);
3862                         return err;
3863                 }
3864         }
3865
3866         err = vfs_quota_on_path(sb, type, format_id, &path);
3867         path_put(&path);
3868         return err;
3869 }
3870
3871 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3872  * acquiring the locks... As quota files are never truncated and quota code
3873  * itself serializes the operations (and noone else should touch the files)
3874  * we don't have to be afraid of races */
3875 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3876                                size_t len, loff_t off)
3877 {
3878         struct inode *inode = sb_dqopt(sb)->files[type];
3879         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3880         int err = 0;
3881         int offset = off & (sb->s_blocksize - 1);
3882         int tocopy;
3883         size_t toread;
3884         struct buffer_head *bh;
3885         loff_t i_size = i_size_read(inode);
3886
3887         if (off > i_size)
3888                 return 0;
3889         if (off+len > i_size)
3890                 len = i_size-off;
3891         toread = len;
3892         while (toread > 0) {
3893                 tocopy = sb->s_blocksize - offset < toread ?
3894                                 sb->s_blocksize - offset : toread;
3895                 bh = ext4_bread(NULL, inode, blk, 0, &err);
3896                 if (err)
3897                         return err;
3898                 if (!bh)        /* A hole? */
3899                         memset(data, 0, tocopy);
3900                 else
3901                         memcpy(data, bh->b_data+offset, tocopy);
3902                 brelse(bh);
3903                 offset = 0;
3904                 toread -= tocopy;
3905                 data += tocopy;
3906                 blk++;
3907         }
3908         return len;
3909 }
3910
3911 /* Write to quotafile (we know the transaction is already started and has
3912  * enough credits) */
3913 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3914                                 const char *data, size_t len, loff_t off)
3915 {
3916         struct inode *inode = sb_dqopt(sb)->files[type];
3917         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3918         int err = 0;
3919         int offset = off & (sb->s_blocksize - 1);
3920         int tocopy;
3921         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3922         size_t towrite = len;
3923         struct buffer_head *bh;
3924         handle_t *handle = journal_current_handle();
3925
3926         if (EXT4_SB(sb)->s_journal && !handle) {
3927                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
3928                         " cancelled because transaction is not started",
3929                         (unsigned long long)off, (unsigned long long)len);
3930                 return -EIO;
3931         }
3932         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3933         while (towrite > 0) {
3934                 tocopy = sb->s_blocksize - offset < towrite ?
3935                                 sb->s_blocksize - offset : towrite;
3936                 bh = ext4_bread(handle, inode, blk, 1, &err);
3937                 if (!bh)
3938                         goto out;
3939                 if (journal_quota) {
3940                         err = ext4_journal_get_write_access(handle, bh);
3941                         if (err) {
3942                                 brelse(bh);
3943                                 goto out;
3944                         }
3945                 }
3946                 lock_buffer(bh);
3947                 memcpy(bh->b_data+offset, data, tocopy);
3948                 flush_dcache_page(bh->b_page);
3949                 unlock_buffer(bh);
3950                 if (journal_quota)
3951                         err = ext4_handle_dirty_metadata(handle, NULL, bh);
3952                 else {
3953                         /* Always do at least ordered writes for quotas */
3954                         err = ext4_jbd2_file_inode(handle, inode);
3955                         mark_buffer_dirty(bh);
3956                 }
3957                 brelse(bh);
3958                 if (err)
3959                         goto out;
3960                 offset = 0;
3961                 towrite -= tocopy;
3962                 data += tocopy;
3963                 blk++;
3964         }
3965 out:
3966         if (len == towrite) {
3967                 mutex_unlock(&inode->i_mutex);
3968                 return err;
3969         }
3970         if (inode->i_size < off+len-towrite) {
3971                 i_size_write(inode, off+len-towrite);
3972                 EXT4_I(inode)->i_disksize = inode->i_size;
3973         }
3974         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3975         ext4_mark_inode_dirty(handle, inode);
3976         mutex_unlock(&inode->i_mutex);
3977         return len - towrite;
3978 }
3979
3980 #endif
3981
3982 static int ext4_get_sb(struct file_system_type *fs_type, int flags,
3983                        const char *dev_name, void *data, struct vfsmount *mnt)
3984 {
3985         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super,mnt);
3986 }
3987
3988 #if !defined(CONTIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
3989 static struct file_system_type ext2_fs_type = {
3990         .owner          = THIS_MODULE,
3991         .name           = "ext2",
3992         .get_sb         = ext4_get_sb,
3993         .kill_sb        = kill_block_super,
3994         .fs_flags       = FS_REQUIRES_DEV,
3995 };
3996
3997 static inline void register_as_ext2(void)
3998 {
3999         int err = register_filesystem(&ext2_fs_type);
4000         if (err)
4001                 printk(KERN_WARNING
4002                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
4003 }
4004
4005 static inline void unregister_as_ext2(void)
4006 {
4007         unregister_filesystem(&ext2_fs_type);
4008 }
4009 MODULE_ALIAS("ext2");
4010 #else
4011 static inline void register_as_ext2(void) { }
4012 static inline void unregister_as_ext2(void) { }
4013 #endif
4014
4015 #if !defined(CONTIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4016 static struct file_system_type ext3_fs_type = {
4017         .owner          = THIS_MODULE,
4018         .name           = "ext3",
4019         .get_sb         = ext4_get_sb,
4020         .kill_sb        = kill_block_super,
4021         .fs_flags       = FS_REQUIRES_DEV,
4022 };
4023
4024 static inline void register_as_ext3(void)
4025 {
4026         int err = register_filesystem(&ext3_fs_type);
4027         if (err)
4028                 printk(KERN_WARNING
4029                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
4030 }
4031
4032 static inline void unregister_as_ext3(void)
4033 {
4034         unregister_filesystem(&ext3_fs_type);
4035 }
4036 MODULE_ALIAS("ext3");
4037 #else
4038 static inline void register_as_ext3(void) { }
4039 static inline void unregister_as_ext3(void) { }
4040 #endif
4041
4042 static struct file_system_type ext4_fs_type = {
4043         .owner          = THIS_MODULE,
4044         .name           = "ext4",
4045         .get_sb         = ext4_get_sb,
4046         .kill_sb        = kill_block_super,
4047         .fs_flags       = FS_REQUIRES_DEV,
4048 };
4049
4050 static int __init init_ext4_fs(void)
4051 {
4052         int err;
4053
4054         err = init_ext4_system_zone();
4055         if (err)
4056                 return err;
4057         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
4058         if (!ext4_kset)
4059                 goto out4;
4060         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
4061         err = init_ext4_mballoc();
4062         if (err)
4063                 goto out3;
4064
4065         err = init_ext4_xattr();
4066         if (err)
4067                 goto out2;
4068         err = init_inodecache();
4069         if (err)
4070                 goto out1;
4071         register_as_ext2();
4072         register_as_ext3();
4073         err = register_filesystem(&ext4_fs_type);
4074         if (err)
4075                 goto out;
4076         return 0;
4077 out:
4078         unregister_as_ext2();
4079         unregister_as_ext3();
4080         destroy_inodecache();
4081 out1:
4082         exit_ext4_xattr();
4083 out2:
4084         exit_ext4_mballoc();
4085 out3:
4086         remove_proc_entry("fs/ext4", NULL);
4087         kset_unregister(ext4_kset);
4088 out4:
4089         exit_ext4_system_zone();
4090         return err;
4091 }
4092
4093 static void __exit exit_ext4_fs(void)
4094 {
4095         unregister_as_ext2();
4096         unregister_as_ext3();
4097         unregister_filesystem(&ext4_fs_type);
4098         destroy_inodecache();
4099         exit_ext4_xattr();
4100         exit_ext4_mballoc();
4101         remove_proc_entry("fs/ext4", NULL);
4102         kset_unregister(ext4_kset);
4103         exit_ext4_system_zone();
4104 }
4105
4106 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
4107 MODULE_DESCRIPTION("Fourth Extended Filesystem");
4108 MODULE_LICENSE("GPL");
4109 module_init(init_ext4_fs)
4110 module_exit(exit_ext4_fs)