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         vfs_check_frozen(sb, SB_FREEZE_TRANS);
 231         /* Special case here: if the journal has aborted behind our
 232          * backs (eg. EIO in the commit thread), then we still need to
 233          * take the FS itself readonly cleanly. */
 234         journal = EXT4_SB(sb)->s_journal;
 235         if (journal) {
 236                 if (is_journal_aborted(journal)) {
 237                         ext4_abort(sb, __func__, "Detected aborted journal");
 238                         return ERR_PTR(-EROFS);
 239                 }
 240                 return jbd2_journal_start(journal, nblocks);
 241         }
 242         return ext4_get_nojournal();
 243 }
 244
 245 /*
 246  * The only special thing we need to do here is to make sure that all
 247  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 248  * that sync() will call the filesystem's write_super callback if
 249  * appropriate.
 250  */
 251 int __ext4_journal_stop(const char *where, handle_t *handle)
 252 {
 253         struct super_block *sb;
 254         int err;
 255         int rc;
 256
 257         if (!ext4_handle_valid(handle)) {
 258                 ext4_put_nojournal(handle);
 259                 return 0;
 260         }
 261         sb = handle->h_transaction->t_journal->j_private;
 262         err = handle->h_err;
 263         rc = jbd2_journal_stop(handle);
 264
 265         if (!err)
 266                 err = rc;
 267         if (err)
 268                 __ext4_std_error(sb, where, err);
 269         return err;
 270 }
 271
 272 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 273                 struct buffer_head *bh, handle_t *handle, int err)
 274 {
 275         char nbuf[16];
 276         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 277
 278         BUG_ON(!ext4_handle_valid(handle));
 279
 280         if (bh)
 281                 BUFFER_TRACE(bh, "abort");
 282
 283         if (!handle->h_err)
 284                 handle->h_err = err;
 285
 286         if (is_handle_aborted(handle))
 287                 return;
 288
 289         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
 290                caller, errstr, err_fn);
 291
 292         jbd2_journal_abort_handle(handle);
 293 }
 294
 295 /* Deal with the reporting of failure conditions on a filesystem such as
 296  * inconsistencies detected or read IO failures.
 297  *
 298  * On ext2, we can store the error state of the filesystem in the
 299  * superblock.  That is not possible on ext4, because we may have other
 300  * write ordering constraints on the superblock which prevent us from
 301  * writing it out straight away; and given that the journal is about to
 302  * be aborted, we can't rely on the current, or future, transactions to
 303  * write out the superblock safely.
 304  *
 305  * We'll just use the jbd2_journal_abort() error code to record an error in
 306  * the journal instead.  On recovery, the journal will compain about
 307  * that error until we've noted it down and cleared it.
 308  */
 309
 310 static void ext4_handle_error(struct super_block *sb)
 311 {
 312         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 313
 314         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 315         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 316
 317         if (sb->s_flags & MS_RDONLY)
 318                 return;
 319
 320         if (!test_opt(sb, ERRORS_CONT)) {
 321                 journal_t *journal = EXT4_SB(sb)->s_journal;
 322
 323                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 324                 if (journal)
 325                         jbd2_journal_abort(journal, -EIO);
 326         }
 327         if (test_opt(sb, ERRORS_RO)) {
 328                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 329                 sb->s_flags |= MS_RDONLY;
 330         }
 331         ext4_commit_super(sb, 1);
 332         if (test_opt(sb, ERRORS_PANIC))
 333                 panic("EXT4-fs (device %s): panic forced after error\n",
 334                         sb->s_id);
 335 }
 336
 337 void ext4_error(struct super_block *sb, const char *function,
 338                 const char *fmt, ...)
 339 {
 340         va_list args;
 341
 342         va_start(args, fmt);
 343         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 344         vprintk(fmt, args);
 345         printk("\n");
 346         va_end(args);
 347
 348         ext4_handle_error(sb);
 349 }
 350
 351 static const char *ext4_decode_error(struct super_block *sb, int errno,
 352                                      char nbuf[16])
 353 {
 354         char *errstr = NULL;
 355
 356         switch (errno) {
 357         case -EIO:
 358                 errstr = "IO failure";
 359                 break;
 360         case -ENOMEM:
 361                 errstr = "Out of memory";
 362                 break;
 363         case -EROFS:
 364                 if (!sb || (EXT4_SB(sb)->s_journal &&
 365                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 366                         errstr = "Journal has aborted";
 367                 else
 368                         errstr = "Readonly filesystem";
 369                 break;
 370         default:
 371                 /* If the caller passed in an extra buffer for unknown
 372                  * errors, textualise them now.  Else we just return
 373                  * NULL. */
 374                 if (nbuf) {
 375                         /* Check for truncated error codes... */
 376                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 377                                 errstr = nbuf;
 378                 }
 379                 break;
 380         }
 381
 382         return errstr;
 383 }
 384
 385 /* __ext4_std_error decodes expected errors from journaling functions
 386  * automatically and invokes the appropriate error response.  */
 387
 388 void __ext4_std_error(struct super_block *sb, const char *function, int errno)
 389 {
 390         char nbuf[16];
 391         const char *errstr;
 392
 393         /* Special case: if the error is EROFS, and we're not already
 394          * inside a transaction, then there's really no point in logging
 395          * an error. */
 396         if (errno == -EROFS && journal_current_handle() == NULL &&
 397             (sb->s_flags & MS_RDONLY))
 398                 return;
 399
 400         errstr = ext4_decode_error(sb, errno, nbuf);
 401         printk(KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
 402                sb->s_id, function, errstr);
 403
 404         ext4_handle_error(sb);
 405 }
 406
 407 /*
 408  * ext4_abort is a much stronger failure handler than ext4_error.  The
 409  * abort function may be used to deal with unrecoverable failures such
 410  * as journal IO errors or ENOMEM at a critical moment in log management.
 411  *
 412  * We unconditionally force the filesystem into an ABORT|READONLY state,
 413  * unless the error response on the fs has been set to panic in which
 414  * case we take the easy way out and panic immediately.
 415  */
 416
 417 void ext4_abort(struct super_block *sb, const char *function,
 418                 const char *fmt, ...)
 419 {
 420         va_list args;
 421
 422         va_start(args, fmt);
 423         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 424         vprintk(fmt, args);
 425         printk("\n");
 426         va_end(args);
 427
 428         if (test_opt(sb, ERRORS_PANIC))
 429                 panic("EXT4-fs panic from previous error\n");
 430
 431         if (sb->s_flags & MS_RDONLY)
 432                 return;
 433
 434         ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 435         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 436         sb->s_flags |= MS_RDONLY;
 437         EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 438         if (EXT4_SB(sb)->s_journal)
 439                 jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 440 }
 441
 442 void ext4_msg (struct super_block * sb, const char *prefix,
 443                    const char *fmt, ...)
 444 {
 445         va_list args;
 446
 447         va_start(args, fmt);
 448         printk("%sEXT4-fs (%s): ", prefix, sb->s_id);
 449         vprintk(fmt, args);
 450         printk("\n");
 451         va_end(args);
 452 }
 453
 454 void ext4_warning(struct super_block *sb, const char *function,
 455                   const char *fmt, ...)
 456 {
 457         va_list args;
 458
 459         va_start(args, fmt);
 460         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
 461                sb->s_id, function);
 462         vprintk(fmt, args);
 463         printk("\n");
 464         va_end(args);
 465 }
 466
 467 void ext4_grp_locked_error(struct super_block *sb, ext4_group_t grp,
 468                            const char *function, const char *fmt, ...)
 469 __releases(bitlock)
 470 __acquires(bitlock)
 471 {
 472         va_list args;
 473         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 474
 475         va_start(args, fmt);
 476         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 477         vprintk(fmt, args);
 478         printk("\n");
 479         va_end(args);
 480
 481         if (test_opt(sb, ERRORS_CONT)) {
 482                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 483                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 484                 ext4_commit_super(sb, 0);
 485                 return;
 486         }
 487         ext4_unlock_group(sb, grp);
 488         ext4_handle_error(sb);
 489         /*
 490          * We only get here in the ERRORS_RO case; relocking the group
 491          * may be dangerous, but nothing bad will happen since the
 492          * filesystem will have already been marked read/only and the
 493          * journal has been aborted.  We return 1 as a hint to callers
 494          * who might what to use the return value from
 495          * ext4_grp_locked_error() to distinguish beween the
 496          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 497          * aggressively from the ext4 function in question, with a
 498          * more appropriate error code.
 499          */
 500         ext4_lock_group(sb, grp);
 501         return;
 502 }
 503
 504 void ext4_update_dynamic_rev(struct super_block *sb)
 505 {
 506         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 507
 508         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 509                 return;
 510
 511         ext4_warning(sb, __func__,
 512                      "updating to rev %d because of new feature flag, "
 513                      "running e2fsck is recommended",
 514                      EXT4_DYNAMIC_REV);
 515
 516         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 517         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 518         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 519         /* leave es->s_feature_*compat flags alone */
 520         /* es->s_uuid will be set by e2fsck if empty */
 521
 522         /*
 523          * The rest of the superblock fields should be zero, and if not it
 524          * means they are likely already in use, so leave them alone.  We
 525          * can leave it up to e2fsck to clean up any inconsistencies there.
 526          */
 527 }
 528
 529 /*
 530  * Open the external journal device
 531  */
 532 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 533 {
 534         struct block_device *bdev;
 535         char b[BDEVNAME_SIZE];
 536
 537         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 538         if (IS_ERR(bdev))
 539                 goto fail;
 540         return bdev;
 541
 542 fail:
 543         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 544                         __bdevname(dev, b), PTR_ERR(bdev));
 545         return NULL;
 546 }
 547
 548 /*
 549  * Release the journal device
 550  */
 551 static int ext4_blkdev_put(struct block_device *bdev)
 552 {
 553         bd_release(bdev);
 554         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
 555 }
 556
 557 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 558 {
 559         struct block_device *bdev;
 560         int ret = -ENODEV;
 561
 562         bdev = sbi->journal_bdev;
 563         if (bdev) {
 564                 ret = ext4_blkdev_put(bdev);
 565                 sbi->journal_bdev = NULL;
 566         }
 567         return ret;
 568 }
 569
 570 static inline struct inode *orphan_list_entry(struct list_head *l)
 571 {
 572         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 573 }
 574
 575 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 576 {
 577         struct list_head *l;
 578
 579         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 580                  le32_to_cpu(sbi->s_es->s_last_orphan));
 581
 582         printk(KERN_ERR "sb_info orphan list:\n");
 583         list_for_each(l, &sbi->s_orphan) {
 584                 struct inode *inode = orphan_list_entry(l);
 585                 printk(KERN_ERR "  "
 586                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 587                        inode->i_sb->s_id, inode->i_ino, inode,
 588                        inode->i_mode, inode->i_nlink,
 589                        NEXT_ORPHAN(inode));
 590         }
 591 }
 592
 593 static void ext4_put_super(struct super_block *sb)
 594 {
 595         struct ext4_sb_info *sbi = EXT4_SB(sb);
 596         struct ext4_super_block *es = sbi->s_es;
 597         int i, err;
 598
 599         flush_workqueue(sbi->dio_unwritten_wq);
 600         destroy_workqueue(sbi->dio_unwritten_wq);
 601
 602         lock_super(sb);
 603         lock_kernel();
 604         if (sb->s_dirt)
 605                 ext4_commit_super(sb, 1);
 606
 607         if (sbi->s_journal) {
 608                 err = jbd2_journal_destroy(sbi->s_journal);
 609                 sbi->s_journal = NULL;
 610                 if (err < 0)
 611                         ext4_abort(sb, __func__,
 612                                    "Couldn't clean up the journal");
 613         }
 614
 615         ext4_release_system_zone(sb);
 616         ext4_mb_release(sb);
 617         ext4_ext_release(sb);
 618         ext4_xattr_put_super(sb);
 619
 620         if (!(sb->s_flags & MS_RDONLY)) {
 621                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 622                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 623                 ext4_commit_super(sb, 1);
 624         }
 625         if (sbi->s_proc) {
 626                 remove_proc_entry(sb->s_id, ext4_proc_root);
 627         }
 628         kobject_del(&sbi->s_kobj);
 629
 630         for (i = 0; i < sbi->s_gdb_count; i++)
 631                 brelse(sbi->s_group_desc[i]);
 632         kfree(sbi->s_group_desc);
 633         if (is_vmalloc_addr(sbi->s_flex_groups))
 634                 vfree(sbi->s_flex_groups);
 635         else
 636                 kfree(sbi->s_flex_groups);
 637         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 638         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 639         percpu_counter_destroy(&sbi->s_dirs_counter);
 640         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
 641         brelse(sbi->s_sbh);
 642 #ifdef CONFIG_QUOTA
 643         for (i = 0; i < MAXQUOTAS; i++)
 644                 kfree(sbi->s_qf_names[i]);
 645 #endif
 646
 647         /* Debugging code just in case the in-memory inode orphan list
 648          * isn't empty.  The on-disk one can be non-empty if we've
 649          * detected an error and taken the fs readonly, but the
 650          * in-memory list had better be clean by this point. */
 651         if (!list_empty(&sbi->s_orphan))
 652                 dump_orphan_list(sb, sbi);
 653         J_ASSERT(list_empty(&sbi->s_orphan));
 654
 655         invalidate_bdev(sb->s_bdev);
 656         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 657                 /*
 658                  * Invalidate the journal device's buffers.  We don't want them
 659                  * floating about in memory - the physical journal device may
 660                  * hotswapped, and it breaks the `ro-after' testing code.
 661                  */
 662                 sync_blockdev(sbi->journal_bdev);
 663                 invalidate_bdev(sbi->journal_bdev);
 664                 ext4_blkdev_remove(sbi);
 665         }
 666         sb->s_fs_info = NULL;
 667         /*
 668          * Now that we are completely done shutting down the
 669          * superblock, we need to actually destroy the kobject.
 670          */
 671         unlock_kernel();
 672         unlock_super(sb);
 673         kobject_put(&sbi->s_kobj);
 674         wait_for_completion(&sbi->s_kobj_unregister);
 675         kfree(sbi->s_blockgroup_lock);
 676         kfree(sbi);
 677 }
 678
 679 static struct kmem_cache *ext4_inode_cachep;
 680
 681 /*
 682  * Called inside transaction, so use GFP_NOFS
 683  */
 684 static struct inode *ext4_alloc_inode(struct super_block *sb)
 685 {
 686         struct ext4_inode_info *ei;
 687
 688         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 689         if (!ei)
 690                 return NULL;
 691
 692         ei->vfs_inode.i_version = 1;
 693         ei->vfs_inode.i_data.writeback_index = 0;
 694         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 695         INIT_LIST_HEAD(&ei->i_prealloc_list);
 696         spin_lock_init(&ei->i_prealloc_lock);
 697         /*
 698          * Note:  We can be called before EXT4_SB(sb)->s_journal is set,
 699          * therefore it can be null here.  Don't check it, just initialize
 700          * jinode.
 701          */
 702         jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
 703         ei->i_reserved_data_blocks = 0;
 704         ei->i_reserved_meta_blocks = 0;
 705         ei->i_allocated_meta_blocks = 0;
 706         ei->i_da_metadata_calc_len = 0;
 707         ei->i_delalloc_reserved_flag = 0;
 708         spin_lock_init(&(ei->i_block_reservation_lock));
 709 #ifdef CONFIG_QUOTA
 710         ei->i_reserved_quota = 0;
 711 #endif
 712         INIT_LIST_HEAD(&ei->i_aio_dio_complete_list);
 713         ei->cur_aio_dio = NULL;
 714         ei->i_sync_tid = 0;
 715         ei->i_datasync_tid = 0;
 716
 717         return &ei->vfs_inode;
 718 }
 719
 720 static void ext4_destroy_inode(struct inode *inode)
 721 {
 722         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 723                 ext4_msg(inode->i_sb, KERN_ERR,
 724                          "Inode %lu (%p): orphan list check failed!",
 725                          inode->i_ino, EXT4_I(inode));
 726                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 727                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 728                                 true);
 729                 dump_stack();
 730         }
 731         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 732 }
 733
 734 static void init_once(void *foo)
 735 {
 736         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 737
 738         INIT_LIST_HEAD(&ei->i_orphan);
 739 #ifdef CONFIG_EXT4_FS_XATTR
 740         init_rwsem(&ei->xattr_sem);
 741 #endif
 742         init_rwsem(&ei->i_data_sem);
 743         inode_init_once(&ei->vfs_inode);
 744 }
 745
 746 static int init_inodecache(void)
 747 {
 748         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 749                                              sizeof(struct ext4_inode_info),
 750                                              0, (SLAB_RECLAIM_ACCOUNT|
 751                                                 SLAB_MEM_SPREAD),
 752                                              init_once);
 753         if (ext4_inode_cachep == NULL)
 754                 return -ENOMEM;
 755         return 0;
 756 }
 757
 758 static void destroy_inodecache(void)
 759 {
 760         kmem_cache_destroy(ext4_inode_cachep);
 761 }
 762
 763 static void ext4_clear_inode(struct inode *inode)
 764 {
 765         ext4_discard_preallocations(inode);
 766         if (EXT4_JOURNAL(inode))
 767                 jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
 768                                        &EXT4_I(inode)->jinode);
 769 }
 770
 771 static inline void ext4_show_quota_options(struct seq_file *seq,
 772                                            struct super_block *sb)
 773 {
 774 #if defined(CONFIG_QUOTA)
 775         struct ext4_sb_info *sbi = EXT4_SB(sb);
 776
 777         if (sbi->s_jquota_fmt)
 778                 seq_printf(seq, ",jqfmt=%s",
 779                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold" : "vfsv0");
 780
 781         if (sbi->s_qf_names[USRQUOTA])
 782                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 783
 784         if (sbi->s_qf_names[GRPQUOTA])
 785                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 786
 787         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
 788                 seq_puts(seq, ",usrquota");
 789
 790         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
 791                 seq_puts(seq, ",grpquota");
 792 #endif
 793 }
 794
 795 /*
 796  * Show an option if
 797  *  - it's set to a non-default value OR
 798  *  - if the per-sb default is different from the global default
 799  */
 800 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 801 {
 802         int def_errors;
 803         unsigned long def_mount_opts;
 804         struct super_block *sb = vfs->mnt_sb;
 805         struct ext4_sb_info *sbi = EXT4_SB(sb);
 806         struct ext4_super_block *es = sbi->s_es;
 807
 808         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 809         def_errors     = le16_to_cpu(es->s_errors);
 810
 811         if (sbi->s_sb_block != 1)
 812                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 813         if (test_opt(sb, MINIX_DF))
 814                 seq_puts(seq, ",minixdf");
 815         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
 816                 seq_puts(seq, ",grpid");
 817         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 818                 seq_puts(seq, ",nogrpid");
 819         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 820             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 821                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 822         }
 823         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 824             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 825                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 826         }
 827         if (test_opt(sb, ERRORS_RO)) {
 828                 if (def_errors == EXT4_ERRORS_PANIC ||
 829                     def_errors == EXT4_ERRORS_CONTINUE) {
 830                         seq_puts(seq, ",errors=remount-ro");
 831                 }
 832         }
 833         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
 834                 seq_puts(seq, ",errors=continue");
 835         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
 836                 seq_puts(seq, ",errors=panic");
 837         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
 838                 seq_puts(seq, ",nouid32");
 839         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
 840                 seq_puts(seq, ",debug");
 841         if (test_opt(sb, OLDALLOC))
 842                 seq_puts(seq, ",oldalloc");
 843 #ifdef CONFIG_EXT4_FS_XATTR
 844         if (test_opt(sb, XATTR_USER) &&
 845                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
 846                 seq_puts(seq, ",user_xattr");
 847         if (!test_opt(sb, XATTR_USER) &&
 848             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 849                 seq_puts(seq, ",nouser_xattr");
 850         }
 851 #endif
 852 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 853         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
 854                 seq_puts(seq, ",acl");
 855         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 856                 seq_puts(seq, ",noacl");
 857 #endif
 858         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
 859                 seq_printf(seq, ",commit=%u",
 860                            (unsigned) (sbi->s_commit_interval / HZ));
 861         }
 862         if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
 863                 seq_printf(seq, ",min_batch_time=%u",
 864                            (unsigned) sbi->s_min_batch_time);
 865         }
 866         if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
 867                 seq_printf(seq, ",max_batch_time=%u",
 868                            (unsigned) sbi->s_min_batch_time);
 869         }
 870
 871         /*
 872          * We're changing the default of barrier mount option, so
 873          * let's always display its mount state so it's clear what its
 874          * status is.
 875          */
 876         seq_puts(seq, ",barrier=");
 877         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
 878         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
 879                 seq_puts(seq, ",journal_async_commit");
 880         else if (test_opt(sb, JOURNAL_CHECKSUM))
 881                 seq_puts(seq, ",journal_checksum");
 882         if (test_opt(sb, NOBH))
 883                 seq_puts(seq, ",nobh");
 884         if (test_opt(sb, I_VERSION))
 885                 seq_puts(seq, ",i_version");
 886         if (!test_opt(sb, DELALLOC))
 887                 seq_puts(seq, ",nodelalloc");
 888
 889
 890         if (sbi->s_stripe)
 891                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
 892         /*
 893          * journal mode get enabled in different ways
 894          * So just print the value even if we didn't specify it
 895          */
 896         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 897                 seq_puts(seq, ",data=journal");
 898         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 899                 seq_puts(seq, ",data=ordered");
 900         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 901                 seq_puts(seq, ",data=writeback");
 902
 903         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
 904                 seq_printf(seq, ",inode_readahead_blks=%u",
 905                            sbi->s_inode_readahead_blks);
 906
 907         if (test_opt(sb, DATA_ERR_ABORT))
 908                 seq_puts(seq, ",data_err=abort");
 909
 910         if (test_opt(sb, NO_AUTO_DA_ALLOC))
 911                 seq_puts(seq, ",noauto_da_alloc");
 912
 913         if (test_opt(sb, DISCARD))
 914                 seq_puts(seq, ",discard");
 915
 916         if (test_opt(sb, NOLOAD))
 917                 seq_puts(seq, ",norecovery");
 918
 919         ext4_show_quota_options(seq, sb);
 920
 921         return 0;
 922 }
 923
 924 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 925                                         u64 ino, u32 generation)
 926 {
 927         struct inode *inode;
 928
 929         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 930                 return ERR_PTR(-ESTALE);
 931         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 932                 return ERR_PTR(-ESTALE);
 933
 934         /* iget isn't really right if the inode is currently unallocated!!
 935          *
 936          * ext4_read_inode will return a bad_inode if the inode had been
 937          * deleted, so we should be safe.
 938          *
 939          * Currently we don't know the generation for parent directory, so
 940          * a generation of 0 means "accept any"
 941          */
 942         inode = ext4_iget(sb, ino);
 943         if (IS_ERR(inode))
 944                 return ERR_CAST(inode);
 945         if (generation && inode->i_generation != generation) {
 946                 iput(inode);
 947                 return ERR_PTR(-ESTALE);
 948         }
 949
 950         return inode;
 951 }
 952
 953 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 954                                         int fh_len, int fh_type)
 955 {
 956         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 957                                     ext4_nfs_get_inode);
 958 }
 959
 960 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 961                                         int fh_len, int fh_type)
 962 {
 963         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 964                                     ext4_nfs_get_inode);
 965 }
 966
 967 /*
 968  * Try to release metadata pages (indirect blocks, directories) which are
 969  * mapped via the block device.  Since these pages could have journal heads
 970  * which would prevent try_to_free_buffers() from freeing them, we must use
 971  * jbd2 layer's try_to_free_buffers() function to release them.
 972  */
 973 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
 974                                  gfp_t wait)
 975 {
 976         journal_t *journal = EXT4_SB(sb)->s_journal;
 977
 978         WARN_ON(PageChecked(page));
 979         if (!page_has_buffers(page))
 980                 return 0;
 981         if (journal)
 982                 return jbd2_journal_try_to_free_buffers(journal, page,
 983                                                         wait & ~__GFP_WAIT);
 984         return try_to_free_buffers(page);
 985 }
 986
 987 #ifdef CONFIG_QUOTA
 988 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
 989 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 990
 991 static int ext4_write_dquot(struct dquot *dquot);
 992 static int ext4_acquire_dquot(struct dquot *dquot);
 993 static int ext4_release_dquot(struct dquot *dquot);
 994 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 995 static int ext4_write_info(struct super_block *sb, int type);
 996 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 997                                 char *path, int remount);
 998 static int ext4_quota_on_mount(struct super_block *sb, int type);
 999 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1000                                size_t len, loff_t off);
1001 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1002                                 const char *data, size_t len, loff_t off);
1003
1004 static const struct dquot_operations ext4_quota_operations = {
1005         .initialize     = dquot_initialize,
1006         .drop           = dquot_drop,
1007         .alloc_space    = dquot_alloc_space,
1008         .reserve_space  = dquot_reserve_space,
1009         .claim_space    = dquot_claim_space,
1010         .release_rsv    = dquot_release_reserved_space,
1011 #ifdef CONFIG_QUOTA
1012         .get_reserved_space = ext4_get_reserved_space,
1013 #endif
1014         .alloc_inode    = dquot_alloc_inode,
1015         .free_space     = dquot_free_space,
1016         .free_inode     = dquot_free_inode,
1017         .transfer       = dquot_transfer,
1018         .write_dquot    = ext4_write_dquot,
1019         .acquire_dquot  = ext4_acquire_dquot,
1020         .release_dquot  = ext4_release_dquot,
1021         .mark_dirty     = ext4_mark_dquot_dirty,
1022         .write_info     = ext4_write_info,
1023         .alloc_dquot    = dquot_alloc,
1024         .destroy_dquot  = dquot_destroy,
1025 };
1026
1027 static const struct quotactl_ops ext4_qctl_operations = {
1028         .quota_on       = ext4_quota_on,
1029         .quota_off      = vfs_quota_off,
1030         .quota_sync     = vfs_quota_sync,
1031         .get_info       = vfs_get_dqinfo,
1032         .set_info       = vfs_set_dqinfo,
1033         .get_dqblk      = vfs_get_dqblk,
1034         .set_dqblk      = vfs_set_dqblk
1035 };
1036 #endif
1037
1038 static const struct super_operations ext4_sops = {
1039         .alloc_inode    = ext4_alloc_inode,
1040         .destroy_inode  = ext4_destroy_inode,
1041         .write_inode    = ext4_write_inode,
1042         .dirty_inode    = ext4_dirty_inode,
1043         .delete_inode   = ext4_delete_inode,
1044         .put_super      = ext4_put_super,
1045         .sync_fs        = ext4_sync_fs,
1046         .freeze_fs      = ext4_freeze,
1047         .unfreeze_fs    = ext4_unfreeze,
1048         .statfs         = ext4_statfs,
1049         .remount_fs     = ext4_remount,
1050         .clear_inode    = ext4_clear_inode,
1051         .show_options   = ext4_show_options,
1052 #ifdef CONFIG_QUOTA
1053         .quota_read     = ext4_quota_read,
1054         .quota_write    = ext4_quota_write,
1055 #endif
1056         .bdev_try_to_free_page = bdev_try_to_free_page,
1057 };
1058
1059 static const struct super_operations ext4_nojournal_sops = {
1060         .alloc_inode    = ext4_alloc_inode,
1061         .destroy_inode  = ext4_destroy_inode,
1062         .write_inode    = ext4_write_inode,
1063         .dirty_inode    = ext4_dirty_inode,
1064         .delete_inode   = ext4_delete_inode,
1065         .write_super    = ext4_write_super,
1066         .put_super      = ext4_put_super,
1067         .statfs         = ext4_statfs,
1068         .remount_fs     = ext4_remount,
1069         .clear_inode    = ext4_clear_inode,
1070         .show_options   = ext4_show_options,
1071 #ifdef CONFIG_QUOTA
1072         .quota_read     = ext4_quota_read,
1073         .quota_write    = ext4_quota_write,
1074 #endif
1075         .bdev_try_to_free_page = bdev_try_to_free_page,
1076 };
1077
1078 static const struct export_operations ext4_export_ops = {
1079         .fh_to_dentry = ext4_fh_to_dentry,
1080         .fh_to_parent = ext4_fh_to_parent,
1081         .get_parent = ext4_get_parent,
1082 };
1083
1084 enum {
1085         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1086         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1087         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1088         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1089         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1090         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1091         Opt_journal_update, Opt_journal_dev,
1092         Opt_journal_checksum, Opt_journal_async_commit,
1093         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1094         Opt_data_err_abort, Opt_data_err_ignore,
1095         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1096         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
1097         Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err, Opt_resize,
1098         Opt_usrquota, Opt_grpquota, Opt_i_version,
1099         Opt_stripe, Opt_delalloc, Opt_nodelalloc,
1100         Opt_block_validity, Opt_noblock_validity,
1101         Opt_inode_readahead_blks, Opt_journal_ioprio,
1102         Opt_discard, Opt_nodiscard,
1103 };
1104
1105 static const match_table_t tokens = {
1106         {Opt_bsd_df, "bsddf"},
1107         {Opt_minix_df, "minixdf"},
1108         {Opt_grpid, "grpid"},
1109         {Opt_grpid, "bsdgroups"},
1110         {Opt_nogrpid, "nogrpid"},
1111         {Opt_nogrpid, "sysvgroups"},
1112         {Opt_resgid, "resgid=%u"},
1113         {Opt_resuid, "resuid=%u"},
1114         {Opt_sb, "sb=%u"},
1115         {Opt_err_cont, "errors=continue"},
1116         {Opt_err_panic, "errors=panic"},
1117         {Opt_err_ro, "errors=remount-ro"},
1118         {Opt_nouid32, "nouid32"},
1119         {Opt_debug, "debug"},
1120         {Opt_oldalloc, "oldalloc"},
1121         {Opt_orlov, "orlov"},
1122         {Opt_user_xattr, "user_xattr"},
1123         {Opt_nouser_xattr, "nouser_xattr"},
1124         {Opt_acl, "acl"},
1125         {Opt_noacl, "noacl"},
1126         {Opt_noload, "noload"},
1127         {Opt_noload, "norecovery"},
1128         {Opt_nobh, "nobh"},
1129         {Opt_bh, "bh"},
1130         {Opt_commit, "commit=%u"},
1131         {Opt_min_batch_time, "min_batch_time=%u"},
1132         {Opt_max_batch_time, "max_batch_time=%u"},
1133         {Opt_journal_update, "journal=update"},
1134         {Opt_journal_dev, "journal_dev=%u"},
1135         {Opt_journal_checksum, "journal_checksum"},
1136         {Opt_journal_async_commit, "journal_async_commit"},
1137         {Opt_abort, "abort"},
1138         {Opt_data_journal, "data=journal"},
1139         {Opt_data_ordered, "data=ordered"},
1140         {Opt_data_writeback, "data=writeback"},
1141         {Opt_data_err_abort, "data_err=abort"},
1142         {Opt_data_err_ignore, "data_err=ignore"},
1143         {Opt_offusrjquota, "usrjquota="},
1144         {Opt_usrjquota, "usrjquota=%s"},
1145         {Opt_offgrpjquota, "grpjquota="},
1146         {Opt_grpjquota, "grpjquota=%s"},
1147         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1148         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1149         {Opt_grpquota, "grpquota"},
1150         {Opt_noquota, "noquota"},
1151         {Opt_quota, "quota"},
1152         {Opt_usrquota, "usrquota"},
1153         {Opt_barrier, "barrier=%u"},
1154         {Opt_barrier, "barrier"},
1155         {Opt_nobarrier, "nobarrier"},
1156         {Opt_i_version, "i_version"},
1157         {Opt_stripe, "stripe=%u"},
1158         {Opt_resize, "resize"},
1159         {Opt_delalloc, "delalloc"},
1160         {Opt_nodelalloc, "nodelalloc"},
1161         {Opt_block_validity, "block_validity"},
1162         {Opt_noblock_validity, "noblock_validity"},
1163         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1164         {Opt_journal_ioprio, "journal_ioprio=%u"},
1165         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1166         {Opt_auto_da_alloc, "auto_da_alloc"},
1167         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1168         {Opt_discard, "discard"},
1169         {Opt_nodiscard, "nodiscard"},
1170         {Opt_err, NULL},
1171 };
1172
1173 static ext4_fsblk_t get_sb_block(void **data)
1174 {
1175         ext4_fsblk_t    sb_block;
1176         char            *options = (char *) *data;
1177
1178         if (!options || strncmp(options, "sb=", 3) != 0)
1179                 return 1;       /* Default location */
1180
1181         options += 3;
1182         /* TODO: use simple_strtoll with >32bit ext4 */
1183         sb_block = simple_strtoul(options, &options, 0);
1184         if (*options && *options != ',') {
1185                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1186                        (char *) *data);
1187                 return 1;
1188         }
1189         if (*options == ',')
1190                 options++;
1191         *data = (void *) options;
1192
1193         return sb_block;
1194 }
1195
1196 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1197
1198 static int parse_options(char *options, struct super_block *sb,
1199                          unsigned long *journal_devnum,
1200                          unsigned int *journal_ioprio,
1201                          ext4_fsblk_t *n_blocks_count, int is_remount)
1202 {
1203         struct ext4_sb_info *sbi = EXT4_SB(sb);
1204         char *p;
1205         substring_t args[MAX_OPT_ARGS];
1206         int data_opt = 0;
1207         int option;
1208 #ifdef CONFIG_QUOTA
1209         int qtype, qfmt;
1210         char *qname;
1211 #endif
1212
1213         if (!options)
1214                 return 1;
1215
1216         while ((p = strsep(&options, ",")) != NULL) {
1217                 int token;
1218                 if (!*p)
1219                         continue;
1220
1221                 /*
1222                  * Initialize args struct so we know whether arg was
1223                  * found; some options take optional arguments.
1224                  */
1225                 args[0].to = args[0].from = 0;
1226                 token = match_token(p, tokens, args);
1227                 switch (token) {
1228                 case Opt_bsd_df:
1229                         clear_opt(sbi->s_mount_opt, MINIX_DF);
1230                         break;
1231                 case Opt_minix_df:
1232                         set_opt(sbi->s_mount_opt, MINIX_DF);
1233                         break;
1234                 case Opt_grpid:
1235                         set_opt(sbi->s_mount_opt, GRPID);
1236                         break;
1237                 case Opt_nogrpid:
1238                         clear_opt(sbi->s_mount_opt, GRPID);
1239                         break;
1240                 case Opt_resuid:
1241                         if (match_int(&args[0], &option))
1242                                 return 0;
1243                         sbi->s_resuid = option;
1244                         break;
1245                 case Opt_resgid:
1246                         if (match_int(&args[0], &option))
1247                                 return 0;
1248                         sbi->s_resgid = option;
1249                         break;
1250                 case Opt_sb:
1251                         /* handled by get_sb_block() instead of here */
1252                         /* *sb_block = match_int(&args[0]); */
1253                         break;
1254                 case Opt_err_panic:
1255                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1256                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1257                         set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1258                         break;
1259                 case Opt_err_ro:
1260                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1261                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1262                         set_opt(sbi->s_mount_opt, ERRORS_RO);
1263                         break;
1264                 case Opt_err_cont:
1265                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1266                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1267                         set_opt(sbi->s_mount_opt, ERRORS_CONT);
1268                         break;
1269                 case Opt_nouid32:
1270                         set_opt(sbi->s_mount_opt, NO_UID32);
1271                         break;
1272                 case Opt_debug:
1273                         set_opt(sbi->s_mount_opt, DEBUG);
1274                         break;
1275                 case Opt_oldalloc:
1276                         set_opt(sbi->s_mount_opt, OLDALLOC);
1277                         break;
1278                 case Opt_orlov:
1279                         clear_opt(sbi->s_mount_opt, OLDALLOC);
1280                         break;
1281 #ifdef CONFIG_EXT4_FS_XATTR
1282                 case Opt_user_xattr:
1283                         set_opt(sbi->s_mount_opt, XATTR_USER);
1284                         break;
1285                 case Opt_nouser_xattr:
1286                         clear_opt(sbi->s_mount_opt, XATTR_USER);
1287                         break;
1288 #else
1289                 case Opt_user_xattr:
1290                 case Opt_nouser_xattr:
1291                         ext4_msg(sb, KERN_ERR, "(no)user_xattr options not supported");
1292                         break;
1293 #endif
1294 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1295                 case Opt_acl:
1296                         set_opt(sbi->s_mount_opt, POSIX_ACL);
1297                         break;
1298                 case Opt_noacl:
1299                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
1300                         break;
1301 #else
1302                 case Opt_acl:
1303                 case Opt_noacl:
1304                         ext4_msg(sb, KERN_ERR, "(no)acl options not supported");
1305                         break;
1306 #endif
1307                 case Opt_journal_update:
1308                         /* @@@ FIXME */
1309                         /* Eventually we will want to be able to create
1310                            a journal file here.  For now, only allow the
1311                            user to specify an existing inode to be the
1312                            journal file. */
1313                         if (is_remount) {
1314                                 ext4_msg(sb, KERN_ERR,
1315                                          "Cannot specify journal on remount");
1316                                 return 0;
1317                         }
1318                         set_opt(sbi->s_mount_opt, UPDATE_JOURNAL);
1319                         break;
1320                 case Opt_journal_dev:
1321                         if (is_remount) {
1322                                 ext4_msg(sb, KERN_ERR,
1323                                         "Cannot specify journal on remount");
1324                                 return 0;
1325                         }
1326                         if (match_int(&args[0], &option))
1327                                 return 0;
1328                         *journal_devnum = option;
1329                         break;
1330                 case Opt_journal_checksum:
1331                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1332                         break;
1333                 case Opt_journal_async_commit:
1334                         set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1335                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1336                         break;
1337                 case Opt_noload:
1338                         set_opt(sbi->s_mount_opt, NOLOAD);
1339                         break;
1340                 case Opt_commit:
1341                         if (match_int(&args[0], &option))
1342                                 return 0;
1343                         if (option < 0)
1344                                 return 0;
1345                         if (option == 0)
1346                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1347                         sbi->s_commit_interval = HZ * option;
1348                         break;
1349                 case Opt_max_batch_time:
1350                         if (match_int(&args[0], &option))
1351                                 return 0;
1352                         if (option < 0)
1353                                 return 0;
1354                         if (option == 0)
1355                                 option = EXT4_DEF_MAX_BATCH_TIME;
1356                         sbi->s_max_batch_time = option;
1357                         break;
1358                 case Opt_min_batch_time:
1359                         if (match_int(&args[0], &option))
1360                                 return 0;
1361                         if (option < 0)
1362                                 return 0;
1363                         sbi->s_min_batch_time = option;
1364                         break;
1365                 case Opt_data_journal:
1366                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1367                         goto datacheck;
1368                 case Opt_data_ordered:
1369                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1370                         goto datacheck;
1371                 case Opt_data_writeback:
1372                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1373                 datacheck:
1374                         if (is_remount) {
1375                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1376                                                 != data_opt) {
1377                                         ext4_msg(sb, KERN_ERR,
1378                                                 "Cannot change data mode on remount");
1379                                         return 0;
1380                                 }
1381                         } else {
1382                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1383                                 sbi->s_mount_opt |= data_opt;
1384                         }
1385                         break;
1386                 case Opt_data_err_abort:
1387                         set_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1388                         break;
1389                 case Opt_data_err_ignore:
1390                         clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1391                         break;
1392 #ifdef CONFIG_QUOTA
1393                 case Opt_usrjquota:
1394                         qtype = USRQUOTA;
1395                         goto set_qf_name;
1396                 case Opt_grpjquota:
1397                         qtype = GRPQUOTA;
1398 set_qf_name:
1399                         if (sb_any_quota_loaded(sb) &&
1400                             !sbi->s_qf_names[qtype]) {
1401                                 ext4_msg(sb, KERN_ERR,
1402                                        "Cannot change journaled "
1403                                        "quota options when quota turned on");
1404                                 return 0;
1405                         }
1406                         qname = match_strdup(&args[0]);
1407                         if (!qname) {
1408                                 ext4_msg(sb, KERN_ERR,
1409                                         "Not enough memory for "
1410                                         "storing quotafile name");
1411                                 return 0;
1412                         }
1413                         if (sbi->s_qf_names[qtype] &&
1414                             strcmp(sbi->s_qf_names[qtype], qname)) {
1415                                 ext4_msg(sb, KERN_ERR,
1416                                         "%s quota file already "
1417                                         "specified", QTYPE2NAME(qtype));
1418                                 kfree(qname);
1419                                 return 0;
1420                         }
1421                         sbi->s_qf_names[qtype] = qname;
1422                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1423                                 ext4_msg(sb, KERN_ERR,
1424                                         "quotafile must be on "
1425                                         "filesystem root");
1426                                 kfree(sbi->s_qf_names[qtype]);
1427                                 sbi->s_qf_names[qtype] = NULL;
1428                                 return 0;
1429                         }
1430                         set_opt(sbi->s_mount_opt, QUOTA);
1431                         break;
1432                 case Opt_offusrjquota:
1433                         qtype = USRQUOTA;
1434                         goto clear_qf_name;
1435                 case Opt_offgrpjquota:
1436                         qtype = GRPQUOTA;
1437 clear_qf_name:
1438                         if (sb_any_quota_loaded(sb) &&
1439                             sbi->s_qf_names[qtype]) {
1440                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1441                                         "journaled quota options when "
1442                                         "quota turned on");
1443                                 return 0;
1444                         }
1445                         /*
1446                          * The space will be released later when all options
1447                          * are confirmed to be correct
1448                          */
1449                         sbi->s_qf_names[qtype] = NULL;
1450                         break;
1451                 case Opt_jqfmt_vfsold:
1452                         qfmt = QFMT_VFS_OLD;
1453                         goto set_qf_format;
1454                 case Opt_jqfmt_vfsv0:
1455                         qfmt = QFMT_VFS_V0;
1456 set_qf_format:
1457                         if (sb_any_quota_loaded(sb) &&
1458                             sbi->s_jquota_fmt != qfmt) {
1459                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1460                                         "journaled quota options when "
1461                                         "quota turned on");
1462                                 return 0;
1463                         }
1464                         sbi->s_jquota_fmt = qfmt;
1465                         break;
1466                 case Opt_quota:
1467                 case Opt_usrquota:
1468                         set_opt(sbi->s_mount_opt, QUOTA);
1469                         set_opt(sbi->s_mount_opt, USRQUOTA);
1470                         break;
1471                 case Opt_grpquota:
1472                         set_opt(sbi->s_mount_opt, QUOTA);
1473                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1474                         break;
1475                 case Opt_noquota:
1476                         if (sb_any_quota_loaded(sb)) {
1477                                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1478                                         "options when quota turned on");
1479                                 return 0;
1480                         }
1481                         clear_opt(sbi->s_mount_opt, QUOTA);
1482                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1483                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1484                         break;
1485 #else
1486                 case Opt_quota:
1487                 case Opt_usrquota:
1488                 case Opt_grpquota:
1489                         ext4_msg(sb, KERN_ERR,
1490                                 "quota options not supported");
1491                         break;
1492                 case Opt_usrjquota:
1493                 case Opt_grpjquota:
1494                 case Opt_offusrjquota:
1495                 case Opt_offgrpjquota:
1496                 case Opt_jqfmt_vfsold:
1497                 case Opt_jqfmt_vfsv0:
1498                         ext4_msg(sb, KERN_ERR,
1499                                 "journaled quota options not supported");
1500                         break;
1501                 case Opt_noquota:
1502                         break;
1503 #endif
1504                 case Opt_abort:
1505                         sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1506                         break;
1507                 case Opt_nobarrier:
1508                         clear_opt(sbi->s_mount_opt, BARRIER);
1509                         break;
1510                 case Opt_barrier:
1511                         if (args[0].from) {
1512                                 if (match_int(&args[0], &option))
1513                                         return 0;
1514                         } else
1515                                 option = 1;     /* No argument, default to 1 */
1516                         if (option)
1517                                 set_opt(sbi->s_mount_opt, BARRIER);
1518                         else
1519                                 clear_opt(sbi->s_mount_opt, BARRIER);
1520                         break;
1521                 case Opt_ignore:
1522                         break;
1523                 case Opt_resize:
1524                         if (!is_remount) {
1525                                 ext4_msg(sb, KERN_ERR,
1526                                         "resize option only available "
1527                                         "for remount");
1528                                 return 0;
1529                         }
1530                         if (match_int(&args[0], &option) != 0)
1531                                 return 0;
1532                         *n_blocks_count = option;
1533                         break;
1534                 case Opt_nobh:
1535                         set_opt(sbi->s_mount_opt, NOBH);
1536                         break;
1537                 case Opt_bh:
1538                         clear_opt(sbi->s_mount_opt, NOBH);
1539                         break;
1540                 case Opt_i_version:
1541                         set_opt(sbi->s_mount_opt, I_VERSION);
1542                         sb->s_flags |= MS_I_VERSION;
1543                         break;
1544                 case Opt_nodelalloc:
1545                         clear_opt(sbi->s_mount_opt, DELALLOC);
1546                         break;
1547                 case Opt_stripe:
1548                         if (match_int(&args[0], &option))
1549                                 return 0;
1550                         if (option < 0)
1551                                 return 0;
1552                         sbi->s_stripe = option;
1553                         break;
1554                 case Opt_delalloc:
1555                         set_opt(sbi->s_mount_opt, DELALLOC);
1556                         break;
1557                 case Opt_block_validity:
1558                         set_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1559                         break;
1560                 case Opt_noblock_validity:
1561                         clear_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1562                         break;
1563                 case Opt_inode_readahead_blks:
1564                         if (match_int(&args[0], &option))
1565                                 return 0;
1566                         if (option < 0 || option > (1 << 30))
1567                                 return 0;
1568                         if (!is_power_of_2(option)) {
1569                                 ext4_msg(sb, KERN_ERR,
1570                                          "EXT4-fs: inode_readahead_blks"
1571                                          " must be a power of 2");
1572                                 return 0;
1573                         }
1574                         sbi->s_inode_readahead_blks = option;
1575                         break;
1576                 case Opt_journal_ioprio:
1577                         if (match_int(&args[0], &option))
1578                                 return 0;
1579                         if (option < 0 || option > 7)
1580                                 break;
1581                         *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1582                                                             option);
1583                         break;
1584                 case Opt_noauto_da_alloc:
1585                         set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1586                         break;
1587                 case Opt_auto_da_alloc:
1588                         if (args[0].from) {
1589                                 if (match_int(&args[0], &option))
1590                                         return 0;
1591                         } else
1592                                 option = 1;     /* No argument, default to 1 */
1593                         if (option)
1594                                 clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1595                         else
1596                                 set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1597                         break;
1598                 case Opt_discard:
1599                         set_opt(sbi->s_mount_opt, DISCARD);
1600                         break;
1601                 case Opt_nodiscard:
1602                         clear_opt(sbi->s_mount_opt, DISCARD);
1603                         break;
1604                 default:
1605                         ext4_msg(sb, KERN_ERR,
1606                                "Unrecognized mount option \"%s\" "
1607                                "or missing value", p);
1608                         return 0;
1609                 }
1610         }
1611 #ifdef CONFIG_QUOTA
1612         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1613                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1614                      sbi->s_qf_names[USRQUOTA])
1615                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1616
1617                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1618                      sbi->s_qf_names[GRPQUOTA])
1619                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1620
1621                 if ((sbi->s_qf_names[USRQUOTA] &&
1622                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1623                     (sbi->s_qf_names[GRPQUOTA] &&
1624                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1625                         ext4_msg(sb, KERN_ERR, "old and new quota "
1626                                         "format mixing");
1627                         return 0;
1628                 }
1629
1630                 if (!sbi->s_jquota_fmt) {
1631                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1632                                         "not specified");
1633                         return 0;
1634                 }
1635         } else {
1636                 if (sbi->s_jquota_fmt) {
1637                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1638                                         "specified with no journaling "
1639                                         "enabled");
1640                         return 0;
1641                 }
1642         }
1643 #endif
1644         return 1;
1645 }
1646
1647 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1648                             int read_only)
1649 {
1650         struct ext4_sb_info *sbi = EXT4_SB(sb);
1651         int res = 0;
1652
1653         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1654                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1655                          "forcing read-only mode");
1656                 res = MS_RDONLY;
1657         }
1658         if (read_only)
1659                 return res;
1660         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1661                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1662                          "running e2fsck is recommended");
1663         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1664                 ext4_msg(sb, KERN_WARNING,
1665                          "warning: mounting fs with errors, "
1666                          "running e2fsck is recommended");
1667         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1668                  le16_to_cpu(es->s_mnt_count) >=
1669                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1670                 ext4_msg(sb, KERN_WARNING,
1671                          "warning: maximal mount count reached, "
1672                          "running e2fsck is recommended");
1673         else if (le32_to_cpu(es->s_checkinterval) &&
1674                 (le32_to_cpu(es->s_lastcheck) +
1675                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1676                 ext4_msg(sb, KERN_WARNING,
1677                          "warning: checktime reached, "
1678                          "running e2fsck is recommended");
1679         if (!sbi->s_journal)
1680                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1681         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1682                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1683         le16_add_cpu(&es->s_mnt_count, 1);
1684         es->s_mtime = cpu_to_le32(get_seconds());
1685         ext4_update_dynamic_rev(sb);
1686         if (sbi->s_journal)
1687                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1688
1689         ext4_commit_super(sb, 1);
1690         if (test_opt(sb, DEBUG))
1691                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1692                                 "bpg=%lu, ipg=%lu, mo=%04x]\n",
1693                         sb->s_blocksize,
1694                         sbi->s_groups_count,
1695                         EXT4_BLOCKS_PER_GROUP(sb),
1696                         EXT4_INODES_PER_GROUP(sb),
1697                         sbi->s_mount_opt);
1698
1699         return res;
1700 }
1701
1702 static int ext4_fill_flex_info(struct super_block *sb)
1703 {
1704         struct ext4_sb_info *sbi = EXT4_SB(sb);
1705         struct ext4_group_desc *gdp = NULL;
1706         ext4_group_t flex_group_count;
1707         ext4_group_t flex_group;
1708         int groups_per_flex = 0;
1709         size_t size;
1710         int i;
1711
1712         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1713         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1714
1715         if (groups_per_flex < 2) {
1716                 sbi->s_log_groups_per_flex = 0;
1717                 return 1;
1718         }
1719
1720         /* We allocate both existing and potentially added groups */
1721         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1722                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1723                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1724         size = flex_group_count * sizeof(struct flex_groups);
1725         sbi->s_flex_groups = kzalloc(size, GFP_KERNEL);
1726         if (sbi->s_flex_groups == NULL) {
1727                 sbi->s_flex_groups = vmalloc(size);
1728                 if (sbi->s_flex_groups)
1729                         memset(sbi->s_flex_groups, 0, size);
1730         }
1731         if (sbi->s_flex_groups == NULL) {
1732                 ext4_msg(sb, KERN_ERR, "not enough memory for "
1733                                 "%u flex groups", flex_group_count);
1734                 goto failed;
1735         }
1736
1737         for (i = 0; i < sbi->s_groups_count; i++) {
1738                 gdp = ext4_get_group_desc(sb, i, NULL);
1739
1740                 flex_group = ext4_flex_group(sbi, i);
1741                 atomic_add(ext4_free_inodes_count(sb, gdp),
1742                            &sbi->s_flex_groups[flex_group].free_inodes);
1743                 atomic_add(ext4_free_blks_count(sb, gdp),
1744                            &sbi->s_flex_groups[flex_group].free_blocks);
1745                 atomic_add(ext4_used_dirs_count(sb, gdp),
1746                            &sbi->s_flex_groups[flex_group].used_dirs);
1747         }
1748
1749         return 1;
1750 failed:
1751         return 0;
1752 }
1753
1754 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1755                             struct ext4_group_desc *gdp)
1756 {
1757         __u16 crc = 0;
1758
1759         if (sbi->s_es->s_feature_ro_compat &
1760             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1761                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1762                 __le32 le_group = cpu_to_le32(block_group);
1763
1764                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1765                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1766                 crc = crc16(crc, (__u8 *)gdp, offset);
1767                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1768                 /* for checksum of struct ext4_group_desc do the rest...*/
1769                 if ((sbi->s_es->s_feature_incompat &
1770                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1771                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1772                         crc = crc16(crc, (__u8 *)gdp + offset,
1773                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1774                                         offset);
1775         }
1776
1777         return cpu_to_le16(crc);
1778 }
1779
1780 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1781                                 struct ext4_group_desc *gdp)
1782 {
1783         if ((sbi->s_es->s_feature_ro_compat &
1784              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1785             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1786                 return 0;
1787
1788         return 1;
1789 }
1790
1791 /* Called at mount-time, super-block is locked */
1792 static int ext4_check_descriptors(struct super_block *sb)
1793 {
1794         struct ext4_sb_info *sbi = EXT4_SB(sb);
1795         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1796         ext4_fsblk_t last_block;
1797         ext4_fsblk_t block_bitmap;
1798         ext4_fsblk_t inode_bitmap;
1799         ext4_fsblk_t inode_table;
1800         int flexbg_flag = 0;
1801         ext4_group_t i;
1802
1803         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1804                 flexbg_flag = 1;
1805
1806         ext4_debug("Checking group descriptors");
1807
1808         for (i = 0; i < sbi->s_groups_count; i++) {
1809                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1810
1811                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1812                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1813                 else
1814                         last_block = first_block +
1815                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1816
1817                 block_bitmap = ext4_block_bitmap(sb, gdp);
1818                 if (block_bitmap < first_block || block_bitmap > last_block) {
1819                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1820                                "Block bitmap for group %u not in group "
1821                                "(block %llu)!", i, block_bitmap);
1822                         return 0;
1823                 }
1824                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1825                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
1826                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1827                                "Inode bitmap for group %u not in group "
1828                                "(block %llu)!", i, inode_bitmap);
1829                         return 0;
1830                 }
1831                 inode_table = ext4_inode_table(sb, gdp);
1832                 if (inode_table < first_block ||
1833                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
1834                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1835                                "Inode table for group %u not in group "
1836                                "(block %llu)!", i, inode_table);
1837                         return 0;
1838                 }
1839                 ext4_lock_group(sb, i);
1840                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1841                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1842                                  "Checksum for group %u failed (%u!=%u)",
1843                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1844                                      gdp)), le16_to_cpu(gdp->bg_checksum));
1845                         if (!(sb->s_flags & MS_RDONLY)) {
1846                                 ext4_unlock_group(sb, i);
1847                                 return 0;
1848                         }
1849                 }
1850                 ext4_unlock_group(sb, i);
1851                 if (!flexbg_flag)
1852                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1853         }
1854
1855         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1856         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
1857         return 1;
1858 }
1859
1860 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1861  * the superblock) which were deleted from all directories, but held open by
1862  * a process at the time of a crash.  We walk the list and try to delete these
1863  * inodes at recovery time (only with a read-write filesystem).
1864  *
1865  * In order to keep the orphan inode chain consistent during traversal (in
1866  * case of crash during recovery), we link each inode into the superblock
1867  * orphan list_head and handle it the same way as an inode deletion during
1868  * normal operation (which journals the operations for us).
1869  *
1870  * We only do an iget() and an iput() on each inode, which is very safe if we
1871  * accidentally point at an in-use or already deleted inode.  The worst that
1872  * can happen in this case is that we get a "bit already cleared" message from
1873  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1874  * e2fsck was run on this filesystem, and it must have already done the orphan
1875  * inode cleanup for us, so we can safely abort without any further action.
1876  */
1877 static void ext4_orphan_cleanup(struct super_block *sb,
1878                                 struct ext4_super_block *es)
1879 {
1880         unsigned int s_flags = sb->s_flags;
1881         int nr_orphans = 0, nr_truncates = 0;
1882 #ifdef CONFIG_QUOTA
1883         int i;
1884 #endif
1885         if (!es->s_last_orphan) {
1886                 jbd_debug(4, "no orphan inodes to clean up\n");
1887                 return;
1888         }
1889
1890         if (bdev_read_only(sb->s_bdev)) {
1891                 ext4_msg(sb, KERN_ERR, "write access "
1892                         "unavailable, skipping orphan cleanup");
1893                 return;
1894         }
1895
1896         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1897                 if (es->s_last_orphan)
1898                         jbd_debug(1, "Errors on filesystem, "
1899                                   "clearing orphan list.\n");
1900                 es->s_last_orphan = 0;
1901                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1902                 return;
1903         }
1904
1905         if (s_flags & MS_RDONLY) {
1906                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
1907                 sb->s_flags &= ~MS_RDONLY;
1908         }
1909 #ifdef CONFIG_QUOTA
1910         /* Needed for iput() to work correctly and not trash data */
1911         sb->s_flags |= MS_ACTIVE;
1912         /* Turn on quotas so that they are updated correctly */
1913         for (i = 0; i < MAXQUOTAS; i++) {
1914                 if (EXT4_SB(sb)->s_qf_names[i]) {
1915                         int ret = ext4_quota_on_mount(sb, i);
1916                         if (ret < 0)
1917                                 ext4_msg(sb, KERN_ERR,
1918                                         "Cannot turn on journaled "
1919                                         "quota: error %d", ret);
1920                 }
1921         }
1922 #endif
1923
1924         while (es->s_last_orphan) {
1925                 struct inode *inode;
1926
1927                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
1928                 if (IS_ERR(inode)) {
1929                         es->s_last_orphan = 0;
1930                         break;
1931                 }
1932
1933                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1934                 vfs_dq_init(inode);
1935                 if (inode->i_nlink) {
1936                         ext4_msg(sb, KERN_DEBUG,
1937                                 "%s: truncating inode %lu to %lld bytes",
1938                                 __func__, inode->i_ino, inode->i_size);
1939                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
1940                                   inode->i_ino, inode->i_size);
1941                         ext4_truncate(inode);
1942                         nr_truncates++;
1943                 } else {
1944                         ext4_msg(sb, KERN_DEBUG,
1945                                 "%s: deleting unreferenced inode %lu",
1946                                 __func__, inode->i_ino);
1947                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1948                                   inode->i_ino);
1949                         nr_orphans++;
1950                 }
1951                 iput(inode);  /* The delete magic happens here! */
1952         }
1953
1954 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
1955
1956         if (nr_orphans)
1957                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
1958                        PLURAL(nr_orphans));
1959         if (nr_truncates)
1960                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
1961                        PLURAL(nr_truncates));
1962 #ifdef CONFIG_QUOTA
1963         /* Turn quotas off */
1964         for (i = 0; i < MAXQUOTAS; i++) {
1965                 if (sb_dqopt(sb)->files[i])
1966                         vfs_quota_off(sb, i, 0);
1967         }
1968 #endif
1969         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1970 }
1971
1972 /*
1973  * Maximal extent format file size.
1974  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1975  * extent format containers, within a sector_t, and within i_blocks
1976  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1977  * so that won't be a limiting factor.
1978  *
1979  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1980  */
1981 static loff_t ext4_max_size(int blkbits, int has_huge_files)
1982 {
1983         loff_t res;
1984         loff_t upper_limit = MAX_LFS_FILESIZE;
1985
1986         /* small i_blocks in vfs inode? */
1987         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1988                 /*
1989                  * CONFIG_LBDAF is not enabled implies the inode
1990                  * i_block represent total blocks in 512 bytes
1991                  * 32 == size of vfs inode i_blocks * 8
1992                  */
1993                 upper_limit = (1LL << 32) - 1;
1994
1995                 /* total blocks in file system block size */
1996                 upper_limit >>= (blkbits - 9);
1997                 upper_limit <<= blkbits;
1998         }
1999
2000         /* 32-bit extent-start container, ee_block */
2001         res = 1LL << 32;
2002         res <<= blkbits;
2003         res -= 1;
2004
2005         /* Sanity check against vm- & vfs- imposed limits */
2006         if (res > upper_limit)
2007                 res = upper_limit;
2008
2009         return res;
2010 }
2011
2012 /*
2013  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2014  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2015  * We need to be 1 filesystem block less than the 2^48 sector limit.
2016  */
2017 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2018 {
2019         loff_t res = EXT4_NDIR_BLOCKS;
2020         int meta_blocks;
2021         loff_t upper_limit;
2022         /* This is calculated to be the largest file size for a dense, block
2023          * mapped file such that the file's total number of 512-byte sectors,
2024          * including data and all indirect blocks, does not exceed (2^48 - 1).
2025          *
2026          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2027          * number of 512-byte sectors of the file.
2028          */
2029
2030         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2031                 /*
2032                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2033                  * the inode i_block field represents total file blocks in
2034                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2035                  */
2036                 upper_limit = (1LL << 32) - 1;
2037
2038                 /* total blocks in file system block size */
2039                 upper_limit >>= (bits - 9);
2040
2041         } else {
2042                 /*
2043                  * We use 48 bit ext4_inode i_blocks
2044                  * With EXT4_HUGE_FILE_FL set the i_blocks
2045                  * represent total number of blocks in
2046                  * file system block size
2047                  */
2048                 upper_limit = (1LL << 48) - 1;
2049
2050         }
2051
2052         /* indirect blocks */
2053         meta_blocks = 1;
2054         /* double indirect blocks */
2055         meta_blocks += 1 + (1LL << (bits-2));
2056         /* tripple indirect blocks */
2057         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2058
2059         upper_limit -= meta_blocks;
2060         upper_limit <<= bits;
2061
2062         res += 1LL << (bits-2);
2063         res += 1LL << (2*(bits-2));
2064         res += 1LL << (3*(bits-2));
2065         res <<= bits;
2066         if (res > upper_limit)
2067                 res = upper_limit;
2068
2069         if (res > MAX_LFS_FILESIZE)
2070                 res = MAX_LFS_FILESIZE;
2071
2072         return res;
2073 }
2074
2075 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2076                                    ext4_fsblk_t logical_sb_block, int nr)
2077 {
2078         struct ext4_sb_info *sbi = EXT4_SB(sb);
2079         ext4_group_t bg, first_meta_bg;
2080         int has_super = 0;
2081
2082         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2083
2084         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2085             nr < first_meta_bg)
2086                 return logical_sb_block + nr + 1;
2087         bg = sbi->s_desc_per_block * nr;
2088         if (ext4_bg_has_super(sb, bg))
2089                 has_super = 1;
2090
2091         return (has_super + ext4_group_first_block_no(sb, bg));
2092 }
2093
2094 /**
2095  * ext4_get_stripe_size: Get the stripe size.
2096  * @sbi: In memory super block info
2097  *
2098  * If we have specified it via mount option, then
2099  * use the mount option value. If the value specified at mount time is
2100  * greater than the blocks per group use the super block value.
2101  * If the super block value is greater than blocks per group return 0.
2102  * Allocator needs it be less than blocks per group.
2103  *
2104  */
2105 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2106 {
2107         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2108         unsigned long stripe_width =
2109                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2110
2111         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2112                 return sbi->s_stripe;
2113
2114         if (stripe_width <= sbi->s_blocks_per_group)
2115                 return stripe_width;
2116
2117         if (stride <= sbi->s_blocks_per_group)
2118                 return stride;
2119
2120         return 0;
2121 }
2122
2123 /* sysfs supprt */
2124
2125 struct ext4_attr {
2126         struct attribute attr;
2127         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2128         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2129                          const char *, size_t);
2130         int offset;
2131 };
2132
2133 static int parse_strtoul(const char *buf,
2134                 unsigned long max, unsigned long *value)
2135 {
2136         char *endp;
2137
2138         while (*buf && isspace(*buf))
2139                 buf++;
2140         *value = simple_strtoul(buf, &endp, 0);
2141         while (*endp && isspace(*endp))
2142                 endp++;
2143         if (*endp || *value > max)
2144                 return -EINVAL;
2145
2146         return 0;
2147 }
2148
2149 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2150                                               struct ext4_sb_info *sbi,
2151                                               char *buf)
2152 {
2153         return snprintf(buf, PAGE_SIZE, "%llu\n",
2154                         (s64) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2155 }
2156
2157 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2158                                          struct ext4_sb_info *sbi, char *buf)
2159 {
2160         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2161
2162         return snprintf(buf, PAGE_SIZE, "%lu\n",
2163                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2164                          sbi->s_sectors_written_start) >> 1);
2165 }
2166
2167 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2168                                           struct ext4_sb_info *sbi, char *buf)
2169 {
2170         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2171
2172         return snprintf(buf, PAGE_SIZE, "%llu\n",
2173                         sbi->s_kbytes_written +
2174                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2175                           EXT4_SB(sb)->s_sectors_written_start) >> 1));
2176 }
2177
2178 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2179                                           struct ext4_sb_info *sbi,
2180                                           const char *buf, size_t count)
2181 {
2182         unsigned long t;
2183
2184         if (parse_strtoul(buf, 0x40000000, &t))
2185                 return -EINVAL;
2186
2187         if (!is_power_of_2(t))
2188                 return -EINVAL;
2189
2190         sbi->s_inode_readahead_blks = t;
2191         return count;
2192 }
2193
2194 static ssize_t sbi_ui_show(struct ext4_attr *a,
2195                            struct ext4_sb_info *sbi, char *buf)
2196 {
2197         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2198
2199         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2200 }
2201
2202 static ssize_t sbi_ui_store(struct ext4_attr *a,
2203                             struct ext4_sb_info *sbi,
2204                             const char *buf, size_t count)
2205 {
2206         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2207         unsigned long t;
2208
2209         if (parse_strtoul(buf, 0xffffffff, &t))
2210                 return -EINVAL;
2211         *ui = t;
2212         return count;
2213 }
2214
2215 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2216 static struct ext4_attr ext4_attr_##_name = {                   \
2217         .attr = {.name = __stringify(_name), .mode = _mode },   \
2218         .show   = _show,                                        \
2219         .store  = _store,                                       \
2220         .offset = offsetof(struct ext4_sb_info, _elname),       \
2221 }
2222 #define EXT4_ATTR(name, mode, show, store) \
2223 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2224
2225 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2226 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2227 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2228         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2229 #define ATTR_LIST(name) &ext4_attr_##name.attr
2230
2231 EXT4_RO_ATTR(delayed_allocation_blocks);
2232 EXT4_RO_ATTR(session_write_kbytes);
2233 EXT4_RO_ATTR(lifetime_write_kbytes);
2234 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2235                  inode_readahead_blks_store, s_inode_readahead_blks);
2236 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2237 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2238 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2239 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2240 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2241 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2242 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2243 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2244
2245 static struct attribute *ext4_attrs[] = {
2246         ATTR_LIST(delayed_allocation_blocks),
2247         ATTR_LIST(session_write_kbytes),
2248         ATTR_LIST(lifetime_write_kbytes),
2249         ATTR_LIST(inode_readahead_blks),
2250         ATTR_LIST(inode_goal),
2251         ATTR_LIST(mb_stats),
2252         ATTR_LIST(mb_max_to_scan),
2253         ATTR_LIST(mb_min_to_scan),
2254         ATTR_LIST(mb_order2_req),
2255         ATTR_LIST(mb_stream_req),
2256         ATTR_LIST(mb_group_prealloc),
2257         ATTR_LIST(max_writeback_mb_bump),
2258         NULL,
2259 };
2260
2261 static ssize_t ext4_attr_show(struct kobject *kobj,
2262                               struct attribute *attr, char *buf)
2263 {
2264         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2265                                                 s_kobj);
2266         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2267
2268         return a->show ? a->show(a, sbi, buf) : 0;
2269 }
2270
2271 static ssize_t ext4_attr_store(struct kobject *kobj,
2272                                struct attribute *attr,
2273                                const char *buf, size_t len)
2274 {
2275         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2276                                                 s_kobj);
2277         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2278
2279         return a->store ? a->store(a, sbi, buf, len) : 0;
2280 }
2281
2282 static void ext4_sb_release(struct kobject *kobj)
2283 {
2284         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2285                                                 s_kobj);
2286         complete(&sbi->s_kobj_unregister);
2287 }
2288
2289
2290 static struct sysfs_ops ext4_attr_ops = {
2291         .show   = ext4_attr_show,
2292         .store  = ext4_attr_store,
2293 };
2294
2295 static struct kobj_type ext4_ktype = {
2296         .default_attrs  = ext4_attrs,
2297         .sysfs_ops      = &ext4_attr_ops,
2298         .release        = ext4_sb_release,
2299 };
2300
2301 /*
2302  * Check whether this filesystem can be mounted based on
2303  * the features present and the RDONLY/RDWR mount requested.
2304  * Returns 1 if this filesystem can be mounted as requested,
2305  * 0 if it cannot be.
2306  */
2307 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2308 {
2309         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2310                 ext4_msg(sb, KERN_ERR,
2311                         "Couldn't mount because of "
2312                         "unsupported optional features (%x)",
2313                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2314                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2315                 return 0;
2316         }
2317
2318         if (readonly)
2319                 return 1;
2320
2321         /* Check that feature set is OK for a read-write mount */
2322         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2323                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2324                          "unsupported optional features (%x)",
2325                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2326                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2327                 return 0;
2328         }
2329         /*
2330          * Large file size enabled file system can only be mounted
2331          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2332          */
2333         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2334                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2335                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2336                                  "cannot be mounted RDWR without "
2337                                  "CONFIG_LBDAF");
2338                         return 0;
2339                 }
2340         }
2341         return 1;
2342 }
2343
2344 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
2345                                 __releases(kernel_lock)
2346                                 __acquires(kernel_lock)
2347 {
2348         struct buffer_head *bh;
2349         struct ext4_super_block *es = NULL;
2350         struct ext4_sb_info *sbi;
2351         ext4_fsblk_t block;
2352         ext4_fsblk_t sb_block = get_sb_block(&data);
2353         ext4_fsblk_t logical_sb_block;
2354         unsigned long offset = 0;
2355         unsigned long journal_devnum = 0;
2356         unsigned long def_mount_opts;
2357         struct inode *root;
2358         char *cp;
2359         const char *descr;
2360         int ret = -EINVAL;
2361         int blocksize;
2362         unsigned int db_count;
2363         unsigned int i;
2364         int needs_recovery, has_huge_files;
2365         __u64 blocks_count;
2366         int err;
2367         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
2368
2369         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
2370         if (!sbi)
2371                 return -ENOMEM;
2372
2373         sbi->s_blockgroup_lock =
2374                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
2375         if (!sbi->s_blockgroup_lock) {
2376                 kfree(sbi);
2377                 return -ENOMEM;
2378         }
2379         sb->s_fs_info = sbi;
2380         sbi->s_mount_opt = 0;
2381         sbi->s_resuid = EXT4_DEF_RESUID;
2382         sbi->s_resgid = EXT4_DEF_RESGID;
2383         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
2384         sbi->s_sb_block = sb_block;
2385         sbi->s_sectors_written_start = part_stat_read(sb->s_bdev->bd_part,
2386                                                       sectors[1]);
2387
2388         unlock_kernel();
2389
2390         /* Cleanup superblock name */
2391         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
2392                 *cp = '!';
2393
2394         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
2395         if (!blocksize) {
2396                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
2397                 goto out_fail;
2398         }
2399
2400         /*
2401          * The ext4 superblock will not be buffer aligned for other than 1kB
2402          * block sizes.  We need to calculate the offset from buffer start.
2403          */
2404         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
2405                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2406                 offset = do_div(logical_sb_block, blocksize);
2407         } else {
2408                 logical_sb_block = sb_block;
2409         }
2410
2411         if (!(bh = sb_bread(sb, logical_sb_block))) {
2412                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
2413                 goto out_fail;
2414         }
2415         /*
2416          * Note: s_es must be initialized as soon as possible because
2417          *       some ext4 macro-instructions depend on its value
2418          */
2419         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2420         sbi->s_es = es;
2421         sb->s_magic = le16_to_cpu(es->s_magic);
2422         if (sb->s_magic != EXT4_SUPER_MAGIC)
2423                 goto cantfind_ext4;
2424         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
2425
2426         /* Set defaults before we parse the mount options */
2427         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
2428         if (def_mount_opts & EXT4_DEFM_DEBUG)
2429                 set_opt(sbi->s_mount_opt, DEBUG);
2430         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
2431                 set_opt(sbi->s_mount_opt, GRPID);
2432         if (def_mount_opts & EXT4_DEFM_UID16)
2433                 set_opt(sbi->s_mount_opt, NO_UID32);
2434 #ifdef CONFIG_EXT4_FS_XATTR
2435         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
2436                 set_opt(sbi->s_mount_opt, XATTR_USER);
2437 #endif
2438 #ifdef CONFIG_EXT4_FS_POSIX_ACL
2439         if (def_mount_opts & EXT4_DEFM_ACL)
2440                 set_opt(sbi->s_mount_opt, POSIX_ACL);
2441 #endif
2442         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
2443                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
2444         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
2445                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
2446         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
2447                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
2448
2449         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
2450                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
2451         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
2452                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
2453         else
2454                 set_opt(sbi->s_mount_opt, ERRORS_RO);
2455
2456         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
2457         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
2458         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
2459         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
2460         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
2461
2462         set_opt(sbi->s_mount_opt, BARRIER);
2463
2464         /*
2465          * enable delayed allocation by default
2466          * Use -o nodelalloc to turn it off
2467          */
2468         set_opt(sbi->s_mount_opt, DELALLOC);
2469
2470         if (!parse_options((char *) data, sb, &journal_devnum,
2471                            &journal_ioprio, NULL, 0))
2472                 goto failed_mount;
2473
2474         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2475                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2476
2477         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
2478             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
2479              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
2480              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
2481                 ext4_msg(sb, KERN_WARNING,
2482                        "feature flags set on rev 0 fs, "
2483                        "running e2fsck is recommended");
2484
2485         /*
2486          * Check feature flags regardless of the revision level, since we
2487          * previously didn't change the revision level when setting the flags,
2488          * so there is a chance incompat flags are set on a rev 0 filesystem.
2489          */
2490         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
2491                 goto failed_mount;
2492
2493         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
2494
2495         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
2496             blocksize > EXT4_MAX_BLOCK_SIZE) {
2497                 ext4_msg(sb, KERN_ERR,
2498                        "Unsupported filesystem blocksize %d", blocksize);
2499                 goto failed_mount;
2500         }
2501
2502         if (sb->s_blocksize != blocksize) {
2503                 /* Validate the filesystem blocksize */
2504                 if (!sb_set_blocksize(sb, blocksize)) {
2505                         ext4_msg(sb, KERN_ERR, "bad block size %d",
2506                                         blocksize);
2507                         goto failed_mount;
2508                 }
2509
2510                 brelse(bh);
2511                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2512                 offset = do_div(logical_sb_block, blocksize);
2513                 bh = sb_bread(sb, logical_sb_block);
2514                 if (!bh) {
2515                         ext4_msg(sb, KERN_ERR,
2516                                "Can't read superblock on 2nd try");
2517                         goto failed_mount;
2518                 }
2519                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
2520                 sbi->s_es = es;
2521                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
2522                         ext4_msg(sb, KERN_ERR,
2523                                "Magic mismatch, very weird!");
2524                         goto failed_mount;
2525                 }
2526         }
2527
2528         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2529                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
2530         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
2531                                                       has_huge_files);
2532         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
2533
2534         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2535                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2536                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2537         } else {
2538                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2539                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2540                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2541                     (!is_power_of_2(sbi->s_inode_size)) ||
2542                     (sbi->s_inode_size > blocksize)) {
2543                         ext4_msg(sb, KERN_ERR,
2544                                "unsupported inode size: %d",
2545                                sbi->s_inode_size);
2546                         goto failed_mount;
2547                 }
2548                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2549                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2550         }
2551
2552         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2553         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2554                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2555                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2556                     !is_power_of_2(sbi->s_desc_size)) {
2557                         ext4_msg(sb, KERN_ERR,
2558                                "unsupported descriptor size %lu",
2559                                sbi->s_desc_size);
2560                         goto failed_mount;
2561                 }
2562         } else
2563                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2564
2565         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2566         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2567         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2568                 goto cantfind_ext4;
2569
2570         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2571         if (sbi->s_inodes_per_block == 0)
2572                 goto cantfind_ext4;
2573         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2574                                         sbi->s_inodes_per_block;
2575         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2576         sbi->s_sbh = bh;
2577         sbi->s_mount_state = le16_to_cpu(es->s_state);
2578         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2579         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2580
2581         for (i = 0; i < 4; i++)
2582                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2583         sbi->s_def_hash_version = es->s_def_hash_version;
2584         i = le32_to_cpu(es->s_flags);
2585         if (i & EXT2_FLAGS_UNSIGNED_HASH)
2586                 sbi->s_hash_unsigned = 3;
2587         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
2588 #ifdef __CHAR_UNSIGNED__
2589                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
2590                 sbi->s_hash_unsigned = 3;
2591 #else
2592                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
2593 #endif
2594                 sb->s_dirt = 1;
2595         }
2596
2597         if (sbi->s_blocks_per_group > blocksize * 8) {
2598                 ext4_msg(sb, KERN_ERR,
2599                        "#blocks per group too big: %lu",
2600                        sbi->s_blocks_per_group);
2601                 goto failed_mount;
2602         }
2603         if (sbi->s_inodes_per_group > blocksize * 8) {
2604                 ext4_msg(sb, KERN_ERR,
2605                        "#inodes per group too big: %lu",
2606                        sbi->s_inodes_per_group);
2607                 goto failed_mount;
2608         }
2609
2610         /*
2611          * Test whether we have more sectors than will fit in sector_t,
2612          * and whether the max offset is addressable by the page cache.
2613          */
2614         if ((ext4_blocks_count(es) >
2615              (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) ||
2616             (ext4_blocks_count(es) >
2617              (pgoff_t)(~0ULL) >> (PAGE_CACHE_SHIFT - sb->s_blocksize_bits))) {
2618                 ext4_msg(sb, KERN_ERR, "filesystem"
2619                          " too large to mount safely on this system");
2620                 if (sizeof(sector_t) < 8)
2621                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
2622                 ret = -EFBIG;
2623                 goto failed_mount;
2624         }
2625
2626         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2627                 goto cantfind_ext4;
2628
2629         /* check blocks count against device size */
2630         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
2631         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
2632                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
2633                        "exceeds size of device (%llu blocks)",
2634                        ext4_blocks_count(es), blocks_count);
2635                 goto failed_mount;
2636         }
2637
2638         /*
2639          * It makes no sense for the first data block to be beyond the end
2640          * of the filesystem.
2641          */
2642         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
2643                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data"
2644                          "block %u is beyond end of filesystem (%llu)",
2645                          le32_to_cpu(es->s_first_data_block),
2646                          ext4_blocks_count(es));
2647                 goto failed_mount;
2648         }
2649         blocks_count = (ext4_blocks_count(es) -
2650                         le32_to_cpu(es->s_first_data_block) +
2651                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2652         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2653         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
2654                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
2655                        "(block count %llu, first data block %u, "
2656                        "blocks per group %lu)", sbi->s_groups_count,
2657                        ext4_blocks_count(es),
2658                        le32_to_cpu(es->s_first_data_block),
2659                        EXT4_BLOCKS_PER_GROUP(sb));
2660                 goto failed_mount;
2661         }
2662         sbi->s_groups_count = blocks_count;
2663         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
2664                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
2665         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2666                    EXT4_DESC_PER_BLOCK(sb);
2667         sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
2668                                     GFP_KERNEL);
2669         if (sbi->s_group_desc == NULL) {
2670                 ext4_msg(sb, KERN_ERR, "not enough memory");
2671                 goto failed_mount;
2672         }
2673
2674 #ifdef CONFIG_PROC_FS
2675         if (ext4_proc_root)
2676                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
2677 #endif
2678
2679         bgl_lock_init(sbi->s_blockgroup_lock);
2680
2681         for (i = 0; i < db_count; i++) {
2682                 block = descriptor_loc(sb, logical_sb_block, i);
2683                 sbi->s_group_desc[i] = sb_bread(sb, block);
2684                 if (!sbi->s_group_desc[i]) {
2685                         ext4_msg(sb, KERN_ERR,
2686                                "can't read group descriptor %d", i);
2687                         db_count = i;
2688                         goto failed_mount2;
2689                 }
2690         }
2691         if (!ext4_check_descriptors(sb)) {
2692                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
2693                 goto failed_mount2;
2694         }
2695         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2696                 if (!ext4_fill_flex_info(sb)) {
2697                         ext4_msg(sb, KERN_ERR,
2698                                "unable to initialize "
2699                                "flex_bg meta info!");
2700                         goto failed_mount2;
2701                 }
2702
2703         sbi->s_gdb_count = db_count;
2704         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2705         spin_lock_init(&sbi->s_next_gen_lock);
2706
2707         sbi->s_stripe = ext4_get_stripe_size(sbi);
2708         sbi->s_max_writeback_mb_bump = 128;
2709
2710         /*
2711          * set up enough so that it can read an inode
2712          */
2713         if (!test_opt(sb, NOLOAD) &&
2714             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
2715                 sb->s_op = &ext4_sops;
2716         else
2717                 sb->s_op = &ext4_nojournal_sops;
2718         sb->s_export_op = &ext4_export_ops;
2719         sb->s_xattr = ext4_xattr_handlers;
2720 #ifdef CONFIG_QUOTA
2721         sb->s_qcop = &ext4_qctl_operations;
2722         sb->dq_op = &ext4_quota_operations;
2723 #endif
2724         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2725         mutex_init(&sbi->s_orphan_lock);
2726         mutex_init(&sbi->s_resize_lock);
2727
2728         sb->s_root = NULL;
2729
2730         needs_recovery = (es->s_last_orphan != 0 ||
2731                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2732                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2733
2734         /*
2735          * The first inode we look at is the journal inode.  Don't try
2736          * root first: it may be modified in the journal!
2737          */
2738         if (!test_opt(sb, NOLOAD) &&
2739             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2740                 if (ext4_load_journal(sb, es, journal_devnum))
2741                         goto failed_mount3;
2742                 if (!(sb->s_flags & MS_RDONLY) &&
2743                     EXT4_SB(sb)->s_journal->j_failed_commit) {
2744                         ext4_msg(sb, KERN_CRIT, "error: "
2745                                "ext4_fill_super: Journal transaction "
2746                                "%u is corrupt",
2747                                EXT4_SB(sb)->s_journal->j_failed_commit);
2748                         if (test_opt(sb, ERRORS_RO)) {
2749                                 ext4_msg(sb, KERN_CRIT,
2750                                        "Mounting filesystem read-only");
2751                                 sb->s_flags |= MS_RDONLY;
2752                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2753                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2754                         }
2755                         if (test_opt(sb, ERRORS_PANIC)) {
2756                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2757                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2758                                 ext4_commit_super(sb, 1);
2759                                 goto failed_mount4;
2760                         }
2761                 }
2762         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
2763               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2764                 ext4_msg(sb, KERN_ERR, "required journal recovery "
2765                        "suppressed and not mounted read-only");
2766                 goto failed_mount4;
2767         } else {
2768                 clear_opt(sbi->s_mount_opt, DATA_FLAGS);
2769                 set_opt(sbi->s_mount_opt, WRITEBACK_DATA);
2770                 sbi->s_journal = NULL;
2771                 needs_recovery = 0;
2772                 goto no_journal;
2773         }
2774
2775         if (ext4_blocks_count(es) > 0xffffffffULL &&
2776             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2777                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2778                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
2779                 goto failed_mount4;
2780         }
2781
2782         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2783                 jbd2_journal_set_features(sbi->s_journal,
2784                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2785                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2786         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2787                 jbd2_journal_set_features(sbi->s_journal,
2788                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2789                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2790                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2791         } else {
2792                 jbd2_journal_clear_features(sbi->s_journal,
2793                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2794                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2795         }
2796
2797         /* We have now updated the journal if required, so we can
2798          * validate the data journaling mode. */
2799         switch (test_opt(sb, DATA_FLAGS)) {
2800         case 0:
2801                 /* No mode set, assume a default based on the journal
2802                  * capabilities: ORDERED_DATA if the journal can
2803                  * cope, else JOURNAL_DATA
2804                  */
2805                 if (jbd2_journal_check_available_features
2806                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2807                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
2808                 else
2809                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2810                 break;
2811
2812         case EXT4_MOUNT_ORDERED_DATA:
2813         case EXT4_MOUNT_WRITEBACK_DATA:
2814                 if (!jbd2_journal_check_available_features
2815                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2816                         ext4_msg(sb, KERN_ERR, "Journal does not support "
2817                                "requested data journaling mode");
2818                         goto failed_mount4;
2819                 }
2820         default:
2821                 break;
2822         }
2823         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
2824
2825 no_journal:
2826         err = percpu_counter_init(&sbi->s_freeblocks_counter,
2827                                   ext4_count_free_blocks(sb));
2828         if (!err)
2829                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
2830                                           ext4_count_free_inodes(sb));
2831         if (!err)
2832                 err = percpu_counter_init(&sbi->s_dirs_counter,
2833                                           ext4_count_dirs(sb));
2834         if (!err)
2835                 err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
2836         if (err) {
2837                 ext4_msg(sb, KERN_ERR, "insufficient memory");
2838                 goto failed_mount_wq;
2839         }
2840         if (test_opt(sb, NOBH)) {
2841                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2842                         ext4_msg(sb, KERN_WARNING, "Ignoring nobh option - "
2843                                 "its supported only with writeback mode");
2844                         clear_opt(sbi->s_mount_opt, NOBH);
2845                 }
2846         }
2847         EXT4_SB(sb)->dio_unwritten_wq = create_workqueue("ext4-dio-unwritten");
2848         if (!EXT4_SB(sb)->dio_unwritten_wq) {
2849                 printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
2850                 goto failed_mount_wq;
2851         }
2852
2853         /*
2854          * The jbd2_journal_load will have done any necessary log recovery,
2855          * so we can safely mount the rest of the filesystem now.
2856          */
2857
2858         root = ext4_iget(sb, EXT4_ROOT_INO);
2859         if (IS_ERR(root)) {
2860                 ext4_msg(sb, KERN_ERR, "get root inode failed");
2861                 ret = PTR_ERR(root);
2862                 goto failed_mount4;
2863         }
2864         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2865                 iput(root);
2866                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
2867                 goto failed_mount4;
2868         }
2869         sb->s_root = d_alloc_root(root);
2870         if (!sb->s_root) {
2871                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
2872                 iput(root);
2873                 ret = -ENOMEM;
2874                 goto failed_mount4;
2875         }
2876
2877         ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
2878
2879         /* determine the minimum size of new large inodes, if present */
2880         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2881                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2882                                                      EXT4_GOOD_OLD_INODE_SIZE;
2883                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2884                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2885                         if (sbi->s_want_extra_isize <
2886                             le16_to_cpu(es->s_want_extra_isize))
2887                                 sbi->s_want_extra_isize =
2888                                         le16_to_cpu(es->s_want_extra_isize);
2889                         if (sbi->s_want_extra_isize <
2890                             le16_to_cpu(es->s_min_extra_isize))
2891                                 sbi->s_want_extra_isize =
2892                                         le16_to_cpu(es->s_min_extra_isize);
2893                 }
2894         }
2895         /* Check if enough inode space is available */
2896         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2897                                                         sbi->s_inode_size) {
2898                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2899                                                        EXT4_GOOD_OLD_INODE_SIZE;
2900                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
2901                          "available");
2902         }
2903
2904         if (test_opt(sb, DELALLOC) &&
2905             (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2906                 ext4_msg(sb, KERN_WARNING, "Ignoring delalloc option - "
2907                          "requested data journaling mode");
2908                 clear_opt(sbi->s_mount_opt, DELALLOC);
2909         }
2910
2911         err = ext4_setup_system_zone(sb);
2912         if (err) {
2913                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
2914                          "zone (%d)", err);
2915                 goto failed_mount4;
2916         }
2917
2918         ext4_ext_init(sb);
2919         err = ext4_mb_init(sb, needs_recovery);
2920         if (err) {
2921                 ext4_msg(sb, KERN_ERR, "failed to initalize mballoc (%d)",
2922                          err);
2923                 goto failed_mount4;
2924         }
2925
2926         sbi->s_kobj.kset = ext4_kset;
2927         init_completion(&sbi->s_kobj_unregister);
2928         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
2929                                    "%s", sb->s_id);
2930         if (err) {
2931                 ext4_mb_release(sb);
2932                 ext4_ext_release(sb);
2933                 goto failed_mount4;
2934         };
2935
2936         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2937         ext4_orphan_cleanup(sb, es);
2938         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2939         if (needs_recovery) {
2940                 ext4_msg(sb, KERN_INFO, "recovery complete");
2941                 ext4_mark_recovery_complete(sb, es);
2942         }
2943         if (EXT4_SB(sb)->s_journal) {
2944                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2945                         descr = " journalled data mode";
2946                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2947                         descr = " ordered data mode";
2948                 else
2949                         descr = " writeback data mode";
2950         } else
2951                 descr = "out journal";
2952
2953         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s", descr);
2954
2955         lock_kernel();
2956         return 0;
2957
2958 cantfind_ext4:
2959         if (!silent)
2960                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
2961         goto failed_mount;
2962
2963 failed_mount4:
2964         ext4_msg(sb, KERN_ERR, "mount failed");
2965         destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
2966 failed_mount_wq:
2967         ext4_release_system_zone(sb);
2968         if (sbi->s_journal) {
2969                 jbd2_journal_destroy(sbi->s_journal);
2970                 sbi->s_journal = NULL;
2971         }
2972         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2973         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2974         percpu_counter_destroy(&sbi->s_dirs_counter);
2975         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
2976 failed_mount3:
2977         if (sbi->s_flex_groups) {
2978                 if (is_vmalloc_addr(sbi->s_flex_groups))
2979                         vfree(sbi->s_flex_groups);
2980                 else
2981                         kfree(sbi->s_flex_groups);
2982         }
2983 failed_mount2:
2984         for (i = 0; i < db_count; i++)
2985                 brelse(sbi->s_group_desc[i]);
2986         kfree(sbi->s_group_desc);
2987 failed_mount:
2988         if (sbi->s_proc) {
2989                 remove_proc_entry(sb->s_id, ext4_proc_root);
2990         }
2991 #ifdef CONFIG_QUOTA
2992         for (i = 0; i < MAXQUOTAS; i++)
2993                 kfree(sbi->s_qf_names[i]);
2994 #endif
2995         ext4_blkdev_remove(sbi);
2996         brelse(bh);
2997 out_fail:
2998         sb->s_fs_info = NULL;
2999         kfree(sbi->s_blockgroup_lock);
3000         kfree(sbi);
3001         lock_kernel();
3002         return ret;
3003 }
3004
3005 /*
3006  * Setup any per-fs journal parameters now.  We'll do this both on
3007  * initial mount, once the journal has been initialised but before we've
3008  * done any recovery; and again on any subsequent remount.
3009  */
3010 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
3011 {
3012         struct ext4_sb_info *sbi = EXT4_SB(sb);
3013
3014         journal->j_commit_interval = sbi->s_commit_interval;
3015         journal->j_min_batch_time = sbi->s_min_batch_time;
3016         journal->j_max_batch_time = sbi->s_max_batch_time;
3017
3018         spin_lock(&journal->j_state_lock);
3019         if (test_opt(sb, BARRIER))
3020                 journal->j_flags |= JBD2_BARRIER;
3021         else
3022                 journal->j_flags &= ~JBD2_BARRIER;
3023         if (test_opt(sb, DATA_ERR_ABORT))
3024                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
3025         else
3026                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
3027         spin_unlock(&journal->j_state_lock);
3028 }
3029
3030 static journal_t *ext4_get_journal(struct super_block *sb,
3031                                    unsigned int journal_inum)
3032 {
3033         struct inode *journal_inode;
3034         journal_t *journal;
3035
3036         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3037
3038         /* First, test for the existence of a valid inode on disk.  Bad
3039          * things happen if we iget() an unused inode, as the subsequent
3040          * iput() will try to delete it. */
3041
3042         journal_inode = ext4_iget(sb, journal_inum);
3043         if (IS_ERR(journal_inode)) {
3044                 ext4_msg(sb, KERN_ERR, "no journal found");
3045                 return NULL;
3046         }
3047         if (!journal_inode->i_nlink) {
3048                 make_bad_inode(journal_inode);
3049                 iput(journal_inode);
3050                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
3051                 return NULL;
3052         }
3053
3054         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
3055                   journal_inode, journal_inode->i_size);
3056         if (!S_ISREG(journal_inode->i_mode)) {
3057                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
3058                 iput(journal_inode);
3059                 return NULL;
3060         }
3061
3062         journal = jbd2_journal_init_inode(journal_inode);
3063         if (!journal) {
3064                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
3065                 iput(journal_inode);
3066                 return NULL;
3067         }
3068         journal->j_private = sb;
3069         ext4_init_journal_params(sb, journal);
3070         return journal;
3071 }
3072
3073 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3074                                        dev_t j_dev)
3075 {
3076         struct buffer_head *bh;
3077         journal_t *journal;
3078         ext4_fsblk_t start;
3079         ext4_fsblk_t len;
3080         int hblock, blocksize;
3081         ext4_fsblk_t sb_block;
3082         unsigned long offset;
3083         struct ext4_super_block *es;
3084         struct block_device *bdev;
3085
3086         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3087
3088         bdev = ext4_blkdev_get(j_dev, sb);
3089         if (bdev == NULL)
3090                 return NULL;
3091
3092         if (bd_claim(bdev, sb)) {
3093                 ext4_msg(sb, KERN_ERR,
3094                         "failed to claim external journal device");
3095                 blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
3096                 return NULL;
3097         }
3098
3099         blocksize = sb->s_blocksize;
3100         hblock = bdev_logical_block_size(bdev);
3101         if (blocksize < hblock) {
3102                 ext4_msg(sb, KERN_ERR,
3103                         "blocksize too small for journal device");
3104                 goto out_bdev;
3105         }
3106
3107         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3108         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3109         set_blocksize(bdev, blocksize);
3110         if (!(bh = __bread(bdev, sb_block, blocksize))) {
3111                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3112                        "external journal");
3113                 goto out_bdev;
3114         }
3115
3116         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3117         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3118             !(le32_to_cpu(es->s_feature_incompat) &
3119               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3120                 ext4_msg(sb, KERN_ERR, "external journal has "
3121                                         "bad superblock");
3122                 brelse(bh);
3123                 goto out_bdev;
3124         }
3125
3126         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3127                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3128                 brelse(bh);
3129                 goto out_bdev;
3130         }
3131
3132         len = ext4_blocks_count(es);
3133         start = sb_block + 1;
3134         brelse(bh);     /* we're done with the superblock */
3135
3136         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
3137                                         start, len, blocksize);
3138         if (!journal) {
3139                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
3140                 goto out_bdev;
3141         }
3142         journal->j_private = sb;
3143         ll_rw_block(READ, 1, &journal->j_sb_buffer);
3144         wait_on_buffer(journal->j_sb_buffer);
3145         if (!buffer_uptodate(journal->j_sb_buffer)) {
3146                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
3147                 goto out_journal;
3148         }
3149         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
3150                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
3151                                         "user (unsupported) - %d",
3152                         be32_to_cpu(journal->j_superblock->s_nr_users));
3153                 goto out_journal;
3154         }
3155         EXT4_SB(sb)->journal_bdev = bdev;
3156         ext4_init_journal_params(sb, journal);
3157         return journal;
3158
3159 out_journal:
3160         jbd2_journal_destroy(journal);
3161 out_bdev:
3162         ext4_blkdev_put(bdev);
3163         return NULL;
3164 }
3165
3166 static int ext4_load_journal(struct super_block *sb,
3167                              struct ext4_super_block *es,
3168                              unsigned long journal_devnum)
3169 {
3170         journal_t *journal;
3171         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
3172         dev_t journal_dev;
3173         int err = 0;
3174         int really_read_only;
3175
3176         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3177
3178         if (journal_devnum &&
3179             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3180                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
3181                         "numbers have changed");
3182                 journal_dev = new_decode_dev(journal_devnum);
3183         } else
3184                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
3185
3186         really_read_only = bdev_read_only(sb->s_bdev);
3187
3188         /*
3189          * Are we loading a blank journal or performing recovery after a
3190          * crash?  For recovery, we need to check in advance whether we
3191          * can get read-write access to the device.
3192          */
3193         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3194                 if (sb->s_flags & MS_RDONLY) {
3195                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
3196                                         "required on readonly filesystem");
3197                         if (really_read_only) {
3198                                 ext4_msg(sb, KERN_ERR, "write access "
3199                                         "unavailable, cannot proceed");
3200                                 return -EROFS;
3201                         }
3202                         ext4_msg(sb, KERN_INFO, "write access will "
3203                                "be enabled during recovery");
3204                 }
3205         }
3206
3207         if (journal_inum && journal_dev) {
3208                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
3209                        "and inode journals!");
3210                 return -EINVAL;
3211         }
3212
3213         if (journal_inum) {
3214                 if (!(journal = ext4_get_journal(sb, journal_inum)))
3215                         return -EINVAL;
3216         } else {
3217                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
3218                         return -EINVAL;
3219         }
3220
3221         if (!(journal->j_flags & JBD2_BARRIER))
3222                 ext4_msg(sb, KERN_INFO, "barriers disabled");
3223
3224         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
3225                 err = jbd2_journal_update_format(journal);
3226                 if (err)  {
3227                         ext4_msg(sb, KERN_ERR, "error updating journal");
3228                         jbd2_journal_destroy(journal);
3229                         return err;
3230                 }
3231         }
3232
3233         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
3234                 err = jbd2_journal_wipe(journal, !really_read_only);
3235         if (!err)
3236                 err = jbd2_journal_load(journal);
3237
3238         if (err) {
3239                 ext4_msg(sb, KERN_ERR, "error loading journal");
3240                 jbd2_journal_destroy(journal);
3241                 return err;
3242         }
3243
3244         EXT4_SB(sb)->s_journal = journal;
3245         ext4_clear_journal_err(sb, es);
3246
3247         if (journal_devnum &&
3248             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3249                 es->s_journal_dev = cpu_to_le32(journal_devnum);
3250
3251                 /* Make sure we flush the recovery flag to disk. */
3252                 ext4_commit_super(sb, 1);
3253         }
3254
3255         return 0;
3256 }
3257
3258 static int ext4_commit_super(struct super_block *sb, int sync)
3259 {
3260         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
3261         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
3262         int error = 0;
3263
3264         if (!sbh)
3265                 return error;
3266         if (buffer_write_io_error(sbh)) {
3267                 /*
3268                  * Oh, dear.  A previous attempt to write the
3269                  * superblock failed.  This could happen because the
3270                  * USB device was yanked out.  Or it could happen to
3271                  * be a transient write error and maybe the block will
3272                  * be remapped.  Nothing we can do but to retry the
3273                  * write and hope for the best.
3274                  */
3275                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
3276                        "superblock detected");
3277                 clear_buffer_write_io_error(sbh);
3278                 set_buffer_uptodate(sbh);
3279         }
3280         /*
3281          * If the file system is mounted read-only, don't update the
3282          * superblock write time.  This avoids updating the superblock
3283          * write time when we are mounting the root file system
3284          * read/only but we need to replay the journal; at that point,
3285          * for people who are east of GMT and who make their clock
3286          * tick in localtime for Windows bug-for-bug compatibility,
3287          * the clock is set in the future, and this will cause e2fsck
3288          * to complain and force a full file system check.
3289          */
3290         if (!(sb->s_flags & MS_RDONLY))
3291                 es->s_wtime = cpu_to_le32(get_seconds());
3292         es->s_kbytes_written =
3293                 cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
3294                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
3295                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
3296         ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
3297                                         &EXT4_SB(sb)->s_freeblocks_counter));
3298         es->s_free_inodes_count = cpu_to_le32(percpu_counter_sum_positive(
3299                                         &EXT4_SB(sb)->s_freeinodes_counter));
3300         sb->s_dirt = 0;
3301         BUFFER_TRACE(sbh, "marking dirty");
3302         mark_buffer_dirty(sbh);
3303         if (sync) {
3304                 error = sync_dirty_buffer(sbh);
3305                 if (error)
3306                         return error;
3307
3308                 error = buffer_write_io_error(sbh);
3309                 if (error) {
3310                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
3311                                "superblock");
3312                         clear_buffer_write_io_error(sbh);
3313                         set_buffer_uptodate(sbh);
3314                 }
3315         }
3316         return error;
3317 }
3318
3319 /*
3320  * Have we just finished recovery?  If so, and if we are mounting (or
3321  * remounting) the filesystem readonly, then we will end up with a
3322  * consistent fs on disk.  Record that fact.
3323  */
3324 static void ext4_mark_recovery_complete(struct super_block *sb,
3325                                         struct ext4_super_block *es)
3326 {
3327         journal_t *journal = EXT4_SB(sb)->s_journal;
3328
3329         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3330                 BUG_ON(journal != NULL);
3331                 return;
3332         }
3333         jbd2_journal_lock_updates(journal);
3334         if (jbd2_journal_flush(journal) < 0)
3335                 goto out;
3336
3337         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
3338             sb->s_flags & MS_RDONLY) {
3339                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3340                 ext4_commit_super(sb, 1);
3341         }
3342
3343 out:
3344         jbd2_journal_unlock_updates(journal);
3345 }
3346
3347 /*
3348  * If we are mounting (or read-write remounting) a filesystem whose journal
3349  * has recorded an error from a previous lifetime, move that error to the
3350  * main filesystem now.
3351  */
3352 static void ext4_clear_journal_err(struct super_block *sb,
3353                                    struct ext4_super_block *es)
3354 {
3355         journal_t *journal;
3356         int j_errno;
3357         const char *errstr;
3358
3359         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3360
3361         journal = EXT4_SB(sb)->s_journal;
3362
3363         /*
3364          * Now check for any error status which may have been recorded in the
3365          * journal by a prior ext4_error() or ext4_abort()
3366          */
3367
3368         j_errno = jbd2_journal_errno(journal);
3369         if (j_errno) {
3370                 char nbuf[16];
3371
3372                 errstr = ext4_decode_error(sb, j_errno, nbuf);
3373                 ext4_warning(sb, __func__, "Filesystem error recorded "
3374                              "from previous mount: %s", errstr);
3375                 ext4_warning(sb, __func__, "Marking fs in need of "
3376                              "filesystem check.");
3377
3378                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
3379                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
3380                 ext4_commit_super(sb, 1);
3381
3382                 jbd2_journal_clear_err(journal);
3383         }
3384 }
3385
3386 /*
3387  * Force the running and committing transactions to commit,
3388  * and wait on the commit.
3389  */
3390 int ext4_force_commit(struct super_block *sb)
3391 {
3392         journal_t *journal;
3393         int ret = 0;
3394
3395         if (sb->s_flags & MS_RDONLY)
3396                 return 0;
3397
3398         journal = EXT4_SB(sb)->s_journal;
3399         if (journal) {
3400                 vfs_check_frozen(sb, SB_FREEZE_TRANS);
3401                 ret = ext4_journal_force_commit(journal);
3402         }
3403
3404         return ret;
3405 }
3406
3407 static void ext4_write_super(struct super_block *sb)
3408 {
3409         lock_super(sb);
3410         ext4_commit_super(sb, 1);
3411         unlock_super(sb);
3412 }
3413
3414 static int ext4_sync_fs(struct super_block *sb, int wait)
3415 {
3416         int ret = 0;
3417         tid_t target;
3418         struct ext4_sb_info *sbi = EXT4_SB(sb);
3419
3420         trace_ext4_sync_fs(sb, wait);
3421         flush_workqueue(sbi->dio_unwritten_wq);
3422         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
3423                 if (wait)
3424                         jbd2_log_wait_commit(sbi->s_journal, target);
3425         }
3426         return ret;
3427 }
3428
3429 /*
3430  * LVM calls this function before a (read-only) snapshot is created.  This
3431  * gives us a chance to flush the journal completely and mark the fs clean.
3432  */
3433 static int ext4_freeze(struct super_block *sb)
3434 {
3435         int error = 0;
3436         journal_t *journal;
3437
3438         if (sb->s_flags & MS_RDONLY)
3439                 return 0;
3440
3441         journal = EXT4_SB(sb)->s_journal;
3442
3443         /* Now we set up the journal barrier. */
3444         jbd2_journal_lock_updates(journal);
3445
3446         /*
3447          * Don't clear the needs_recovery flag if we failed to flush
3448          * the journal.
3449          */
3450         error = jbd2_journal_flush(journal);
3451         if (error < 0)
3452                 goto out;
3453
3454         /* Journal blocked and flushed, clear needs_recovery flag. */
3455         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3456         error = ext4_commit_super(sb, 1);
3457 out:
3458         /* we rely on s_frozen to stop further updates */
3459         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3460         return error;
3461 }
3462
3463 /*
3464  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
3465  * flag here, even though the filesystem is not technically dirty yet.
3466  */
3467 static int ext4_unfreeze(struct super_block *sb)
3468 {
3469         if (sb->s_flags & MS_RDONLY)
3470                 return 0;
3471
3472         lock_super(sb);
3473         /* Reset the needs_recovery flag before the fs is unlocked. */
3474         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3475         ext4_commit_super(sb, 1);
3476         unlock_super(sb);
3477         return 0;
3478 }
3479
3480 static int ext4_remount(struct super_block *sb, int *flags, char *data)
3481 {
3482         struct ext4_super_block *es;
3483         struct ext4_sb_info *sbi = EXT4_SB(sb);
3484         ext4_fsblk_t n_blocks_count = 0;
3485         unsigned long old_sb_flags;
3486         struct ext4_mount_options old_opts;
3487         ext4_group_t g;
3488         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3489         int err;
3490 #ifdef CONFIG_QUOTA
3491         int i;
3492 #endif
3493
3494         lock_kernel();
3495
3496         /* Store the original options */
3497         lock_super(sb);
3498         old_sb_flags = sb->s_flags;
3499         old_opts.s_mount_opt = sbi->s_mount_opt;
3500         old_opts.s_resuid = sbi->s_resuid;
3501         old_opts.s_resgid = sbi->s_resgid;
3502         old_opts.s_commit_interval = sbi->s_commit_interval;
3503         old_opts.s_min_batch_time = sbi->s_min_batch_time;
3504         old_opts.s_max_batch_time = sbi->s_max_batch_time;
3505 #ifdef CONFIG_QUOTA
3506         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
3507         for (i = 0; i < MAXQUOTAS; i++)
3508                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
3509 #endif
3510         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
3511                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
3512
3513         /*
3514          * Allow the "check" option to be passed as a remount option.
3515          */
3516         if (!parse_options(data, sb, NULL, &journal_ioprio,
3517                            &n_blocks_count, 1)) {
3518                 err = -EINVAL;
3519                 goto restore_opts;
3520         }
3521
3522         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
3523                 ext4_abort(sb, __func__, "Abort forced by user");
3524
3525         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3526                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
3527
3528         es = sbi->s_es;
3529
3530         if (sbi->s_journal) {
3531                 ext4_init_journal_params(sb, sbi->s_journal);
3532                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3533         }
3534
3535         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
3536                 n_blocks_count > ext4_blocks_count(es)) {
3537                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
3538                         err = -EROFS;
3539                         goto restore_opts;
3540                 }
3541
3542                 if (*flags & MS_RDONLY) {
3543                         /*
3544                          * First of all, the unconditional stuff we have to do
3545                          * to disable replay of the journal when we next remount
3546                          */
3547                         sb->s_flags |= MS_RDONLY;
3548
3549                         /*
3550                          * OK, test if we are remounting a valid rw partition
3551                          * readonly, and if so set the rdonly flag and then
3552                          * mark the partition as valid again.
3553                          */
3554                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
3555                             (sbi->s_mount_state & EXT4_VALID_FS))
3556                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
3557
3558                         if (sbi->s_journal)
3559                                 ext4_mark_recovery_complete(sb, es);
3560                 } else {
3561                         /* Make sure we can mount this feature set readwrite */
3562                         if (!ext4_feature_set_ok(sb, 0)) {
3563                                 err = -EROFS;
3564                                 goto restore_opts;
3565                         }
3566                         /*
3567                          * Make sure the group descriptor checksums
3568                          * are sane.  If they aren't, refuse to remount r/w.
3569                          */
3570                         for (g = 0; g < sbi->s_groups_count; g++) {
3571                                 struct ext4_group_desc *gdp =
3572                                         ext4_get_group_desc(sb, g, NULL);
3573
3574                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
3575                                         ext4_msg(sb, KERN_ERR,
3576                "ext4_remount: Checksum for group %u failed (%u!=%u)",
3577                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
3578                                                le16_to_cpu(gdp->bg_checksum));
3579                                         err = -EINVAL;
3580                                         goto restore_opts;
3581                                 }
3582                         }
3583
3584                         /*
3585                          * If we have an unprocessed orphan list hanging
3586                          * around from a previously readonly bdev mount,
3587                          * require a full umount/remount for now.
3588                          */
3589                         if (es->s_last_orphan) {
3590                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
3591                                        "remount RDWR because of unprocessed "
3592                                        "orphan inode list.  Please "
3593                                        "umount/remount instead");
3594                                 err = -EINVAL;
3595                                 goto restore_opts;
3596                         }
3597
3598                         /*
3599                          * Mounting a RDONLY partition read-write, so reread
3600                          * and store the current valid flag.  (It may have
3601                          * been changed by e2fsck since we originally mounted
3602                          * the partition.)
3603                          */
3604                         if (sbi->s_journal)
3605                                 ext4_clear_journal_err(sb, es);
3606                         sbi->s_mount_state = le16_to_cpu(es->s_state);
3607                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
3608                                 goto restore_opts;
3609                         if (!ext4_setup_super(sb, es, 0))
3610                                 sb->s_flags &= ~MS_RDONLY;
3611                 }
3612         }
3613         ext4_setup_system_zone(sb);
3614         if (sbi->s_journal == NULL)
3615                 ext4_commit_super(sb, 1);
3616
3617 #ifdef CONFIG_QUOTA
3618         /* Release old quota file names */
3619         for (i = 0; i < MAXQUOTAS; i++)
3620                 if (old_opts.s_qf_names[i] &&
3621                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3622                         kfree(old_opts.s_qf_names[i]);
3623 #endif
3624         unlock_super(sb);
3625         unlock_kernel();
3626         return 0;
3627
3628 restore_opts:
3629         sb->s_flags = old_sb_flags;
3630         sbi->s_mount_opt = old_opts.s_mount_opt;
3631         sbi->s_resuid = old_opts.s_resuid;
3632         sbi->s_resgid = old_opts.s_resgid;
3633         sbi->s_commit_interval = old_opts.s_commit_interval;
3634         sbi->s_min_batch_time = old_opts.s_min_batch_time;
3635         sbi->s_max_batch_time = old_opts.s_max_batch_time;
3636 #ifdef CONFIG_QUOTA
3637         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
3638         for (i = 0; i < MAXQUOTAS; i++) {
3639                 if (sbi->s_qf_names[i] &&
3640                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3641                         kfree(sbi->s_qf_names[i]);
3642                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
3643         }
3644 #endif
3645         unlock_super(sb);
3646         unlock_kernel();
3647         return err;
3648 }
3649
3650 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
3651 {
3652         struct super_block *sb = dentry->d_sb;
3653         struct ext4_sb_info *sbi = EXT4_SB(sb);
3654         struct ext4_super_block *es = sbi->s_es;
3655         u64 fsid;
3656
3657         if (test_opt(sb, MINIX_DF)) {
3658                 sbi->s_overhead_last = 0;
3659         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
3660                 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3661                 ext4_fsblk_t overhead = 0;
3662
3663                 /*
3664                  * Compute the overhead (FS structures).  This is constant
3665                  * for a given filesystem unless the number of block groups
3666                  * changes so we cache the previous value until it does.
3667                  */
3668
3669                 /*
3670                  * All of the blocks before first_data_block are
3671                  * overhead
3672                  */
3673                 overhead = le32_to_cpu(es->s_first_data_block);
3674
3675                 /*
3676                  * Add the overhead attributed to the superblock and
3677                  * block group descriptors.  If the sparse superblocks
3678                  * feature is turned on, then not all groups have this.
3679                  */
3680                 for (i = 0; i < ngroups; i++) {
3681                         overhead += ext4_bg_has_super(sb, i) +
3682                                 ext4_bg_num_gdb(sb, i);
3683                         cond_resched();
3684                 }
3685
3686                 /*
3687                  * Every block group has an inode bitmap, a block
3688                  * bitmap, and an inode table.
3689                  */
3690                 overhead += ngroups * (2 + sbi->s_itb_per_group);
3691                 sbi->s_overhead_last = overhead;
3692                 smp_wmb();
3693                 sbi->s_blocks_last = ext4_blocks_count(es);
3694         }
3695
3696         buf->f_type = EXT4_SUPER_MAGIC;
3697         buf->f_bsize = sb->s_blocksize;
3698         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
3699         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
3700                        percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
3701         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
3702         if (buf->f_bfree < ext4_r_blocks_count(es))
3703                 buf->f_bavail = 0;
3704         buf->f_files = le32_to_cpu(es->s_inodes_count);
3705         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
3706         buf->f_namelen = EXT4_NAME_LEN;
3707         fsid = le64_to_cpup((void *)es->s_uuid) ^
3708                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
3709         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
3710         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
3711
3712         return 0;
3713 }
3714
3715 /* Helper function for writing quotas on sync - we need to start transaction
3716  * before quota file is locked for write. Otherwise the are possible deadlocks:
3717  * Process 1                         Process 2
3718  * ext4_create()                     quota_sync()
3719  *   jbd2_journal_start()                  write_dquot()
3720  *   vfs_dq_init()                         down(dqio_mutex)
3721  *     down(dqio_mutex)                    jbd2_journal_start()
3722  *
3723  */
3724
3725 #ifdef CONFIG_QUOTA
3726
3727 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3728 {
3729         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3730 }
3731
3732 static int ext4_write_dquot(struct dquot *dquot)
3733 {
3734         int ret, err;
3735         handle_t *handle;
3736         struct inode *inode;
3737
3738         inode = dquot_to_inode(dquot);
3739         handle = ext4_journal_start(inode,
3740                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3741         if (IS_ERR(handle))
3742                 return PTR_ERR(handle);
3743         ret = dquot_commit(dquot);
3744         err = ext4_journal_stop(handle);
3745         if (!ret)
3746                 ret = err;
3747         return ret;
3748 }
3749
3750 static int ext4_acquire_dquot(struct dquot *dquot)
3751 {
3752         int ret, err;
3753         handle_t *handle;
3754
3755         handle = ext4_journal_start(dquot_to_inode(dquot),
3756                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3757         if (IS_ERR(handle))
3758                 return PTR_ERR(handle);
3759         ret = dquot_acquire(dquot);
3760         err = ext4_journal_stop(handle);
3761         if (!ret)
3762                 ret = err;
3763         return ret;
3764 }
3765
3766 static int ext4_release_dquot(struct dquot *dquot)
3767 {
3768         int ret, err;
3769         handle_t *handle;
3770
3771         handle = ext4_journal_start(dquot_to_inode(dquot),
3772                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3773         if (IS_ERR(handle)) {
3774                 /* Release dquot anyway to avoid endless cycle in dqput() */
3775                 dquot_release(dquot);
3776                 return PTR_ERR(handle);
3777         }
3778         ret = dquot_release(dquot);
3779         err = ext4_journal_stop(handle);
3780         if (!ret)
3781                 ret = err;
3782         return ret;
3783 }
3784
3785 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3786 {
3787         /* Are we journaling quotas? */
3788         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3789             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3790                 dquot_mark_dquot_dirty(dquot);
3791                 return ext4_write_dquot(dquot);
3792         } else {
3793                 return dquot_mark_dquot_dirty(dquot);
3794         }
3795 }
3796
3797 static int ext4_write_info(struct super_block *sb, int type)
3798 {
3799         int ret, err;
3800         handle_t *handle;
3801
3802         /* Data block + inode block */
3803         handle = ext4_journal_start(sb->s_root->d_inode, 2);
3804         if (IS_ERR(handle))
3805                 return PTR_ERR(handle);
3806         ret = dquot_commit_info(sb, type);
3807         err = ext4_journal_stop(handle);
3808         if (!ret)
3809                 ret = err;
3810         return ret;
3811 }
3812
3813 /*
3814  * Turn on quotas during mount time - we need to find
3815  * the quota file and such...
3816  */
3817 static int ext4_quota_on_mount(struct super_block *sb, int type)
3818 {
3819         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3820                                   EXT4_SB(sb)->s_jquota_fmt, type);
3821 }
3822
3823 /*
3824  * Standard function to be called on quota_on
3825  */
3826 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3827                          char *name, int remount)
3828 {
3829         int err;
3830         struct path path;
3831
3832         if (!test_opt(sb, QUOTA))
3833                 return -EINVAL;
3834         /* When remounting, no checks are needed and in fact, name is NULL */
3835         if (remount)
3836                 return vfs_quota_on(sb, type, format_id, name, remount);
3837
3838         err = kern_path(name, LOOKUP_FOLLOW, &path);
3839         if (err)
3840                 return err;
3841
3842         /* Quotafile not on the same filesystem? */
3843         if (path.mnt->mnt_sb != sb) {
3844                 path_put(&path);
3845                 return -EXDEV;
3846         }
3847         /* Journaling quota? */
3848         if (EXT4_SB(sb)->s_qf_names[type]) {
3849                 /* Quotafile not in fs root? */
3850                 if (path.dentry->d_parent != sb->s_root)
3851                         ext4_msg(sb, KERN_WARNING,
3852                                 "Quota file not on filesystem root. "
3853                                 "Journaled quota will not work");
3854         }
3855
3856         /*
3857          * When we journal data on quota file, we have to flush journal to see
3858          * all updates to the file when we bypass pagecache...
3859          */
3860         if (EXT4_SB(sb)->s_journal &&
3861             ext4_should_journal_data(path.dentry->d_inode)) {
3862                 /*
3863                  * We don't need to lock updates but journal_flush() could
3864                  * otherwise be livelocked...
3865                  */
3866                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
3867                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
3868                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3869                 if (err) {
3870                         path_put(&path);
3871                         return err;
3872                 }
3873         }
3874
3875         err = vfs_quota_on_path(sb, type, format_id, &path);
3876         path_put(&path);
3877         return err;
3878 }
3879
3880 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3881  * acquiring the locks... As quota files are never truncated and quota code
3882  * itself serializes the operations (and noone else should touch the files)
3883  * we don't have to be afraid of races */
3884 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3885                                size_t len, loff_t off)
3886 {
3887         struct inode *inode = sb_dqopt(sb)->files[type];
3888         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3889         int err = 0;
3890         int offset = off & (sb->s_blocksize - 1);
3891         int tocopy;
3892         size_t toread;
3893         struct buffer_head *bh;
3894         loff_t i_size = i_size_read(inode);
3895
3896         if (off > i_size)
3897                 return 0;
3898         if (off+len > i_size)
3899                 len = i_size-off;
3900         toread = len;
3901         while (toread > 0) {
3902                 tocopy = sb->s_blocksize - offset < toread ?
3903                                 sb->s_blocksize - offset : toread;
3904                 bh = ext4_bread(NULL, inode, blk, 0, &err);
3905                 if (err)
3906                         return err;
3907                 if (!bh)        /* A hole? */
3908                         memset(data, 0, tocopy);
3909                 else
3910                         memcpy(data, bh->b_data+offset, tocopy);
3911                 brelse(bh);
3912                 offset = 0;
3913                 toread -= tocopy;
3914                 data += tocopy;
3915                 blk++;
3916         }
3917         return len;
3918 }
3919
3920 /* Write to quotafile (we know the transaction is already started and has
3921  * enough credits) */
3922 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3923                                 const char *data, size_t len, loff_t off)
3924 {
3925         struct inode *inode = sb_dqopt(sb)->files[type];
3926         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3927         int err = 0;
3928         int offset = off & (sb->s_blocksize - 1);
3929         int tocopy;
3930         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3931         size_t towrite = len;
3932         struct buffer_head *bh;
3933         handle_t *handle = journal_current_handle();
3934
3935         if (EXT4_SB(sb)->s_journal && !handle) {
3936                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
3937                         " cancelled because transaction is not started",
3938                         (unsigned long long)off, (unsigned long long)len);
3939                 return -EIO;
3940         }
3941         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3942         while (towrite > 0) {
3943                 tocopy = sb->s_blocksize - offset < towrite ?
3944                                 sb->s_blocksize - offset : towrite;
3945                 bh = ext4_bread(handle, inode, blk, 1, &err);
3946                 if (!bh)
3947                         goto out;
3948                 if (journal_quota) {
3949                         err = ext4_journal_get_write_access(handle, bh);
3950                         if (err) {
3951                                 brelse(bh);
3952                                 goto out;
3953                         }
3954                 }
3955                 lock_buffer(bh);
3956                 memcpy(bh->b_data+offset, data, tocopy);
3957                 flush_dcache_page(bh->b_page);
3958                 unlock_buffer(bh);
3959                 if (journal_quota)
3960                         err = ext4_handle_dirty_metadata(handle, NULL, bh);
3961                 else {
3962                         /* Always do at least ordered writes for quotas */
3963                         err = ext4_jbd2_file_inode(handle, inode);
3964                         mark_buffer_dirty(bh);
3965                 }
3966                 brelse(bh);
3967                 if (err)
3968                         goto out;
3969                 offset = 0;
3970                 towrite -= tocopy;
3971                 data += tocopy;
3972                 blk++;
3973         }
3974 out:
3975         if (len == towrite) {
3976                 mutex_unlock(&inode->i_mutex);
3977                 return err;
3978         }
3979         if (inode->i_size < off+len-towrite) {
3980                 i_size_write(inode, off+len-towrite);
3981                 EXT4_I(inode)->i_disksize = inode->i_size;
3982         }
3983         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3984         ext4_mark_inode_dirty(handle, inode);
3985         mutex_unlock(&inode->i_mutex);
3986         return len - towrite;
3987 }
3988
3989 #endif
3990
3991 static int ext4_get_sb(struct file_system_type *fs_type, int flags,
3992                        const char *dev_name, void *data, struct vfsmount *mnt)
3993 {
3994         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super,mnt);
3995 }
3996
3997 static struct file_system_type ext4_fs_type = {
3998         .owner          = THIS_MODULE,
3999         .name           = "ext4",
4000         .get_sb         = ext4_get_sb,
4001         .kill_sb        = kill_block_super,
4002         .fs_flags       = FS_REQUIRES_DEV,
4003 };
4004
4005 static int __init init_ext4_fs(void)
4006 {
4007         int err;
4008
4009         ext4_check_flag_values();
4010         err = init_ext4_system_zone();
4011         if (err)
4012                 return err;
4013         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
4014         if (!ext4_kset)
4015                 goto out4;
4016         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
4017         err = init_ext4_mballoc();
4018         if (err)
4019                 goto out3;
4020
4021         err = init_ext4_xattr();
4022         if (err)
4023                 goto out2;
4024         err = init_inodecache();
4025         if (err)
4026                 goto out1;
4027         err = register_filesystem(&ext4_fs_type);
4028         if (err)
4029                 goto out;
4030         return 0;
4031 out:
4032         destroy_inodecache();
4033 out1:
4034         exit_ext4_xattr();
4035 out2:
4036         exit_ext4_mballoc();
4037 out3:
4038         remove_proc_entry("fs/ext4", NULL);
4039         kset_unregister(ext4_kset);
4040 out4:
4041         exit_ext4_system_zone();
4042         return err;
4043 }
4044
4045 static void __exit exit_ext4_fs(void)
4046 {
4047         unregister_filesystem(&ext4_fs_type);
4048         destroy_inodecache();
4049         exit_ext4_xattr();
4050         exit_ext4_mballoc();
4051         remove_proc_entry("fs/ext4", NULL);
4052         kset_unregister(ext4_kset);
4053         exit_ext4_system_zone();
4054 }
4055
4056 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
4057 MODULE_DESCRIPTION("Fourth Extended Filesystem");
4058 MODULE_LICENSE("GPL");
4059 module_init(init_ext4_fs)
4060 module_exit(exit_ext4_fs)