fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/jbd2.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/parser.h>
  28 #include <linux/smp_lock.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/marker.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <asm/uaccess.h>
  42
  43 #include "ext4.h"
  44 #include "ext4_jbd2.h"
  45 #include "xattr.h"
  46 #include "acl.h"
  47 #include "namei.h"
  48 #include "group.h"
  49
  50 struct proc_dir_entry *ext4_proc_root;
  51
  52 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  53                              unsigned long journal_devnum);
  54 static int ext4_commit_super(struct super_block *sb,
  55                               struct ext4_super_block *es, int sync);
  56 static void ext4_mark_recovery_complete(struct super_block *sb,
  57                                         struct ext4_super_block *es);
  58 static void ext4_clear_journal_err(struct super_block *sb,
  59                                    struct ext4_super_block *es);
  60 static int ext4_sync_fs(struct super_block *sb, int wait);
  61 static const char *ext4_decode_error(struct super_block *sb, int errno,
  62                                      char nbuf[16]);
  63 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  64 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  65 static int ext4_unfreeze(struct super_block *sb);
  66 static void ext4_write_super(struct super_block *sb);
  67 static int ext4_freeze(struct super_block *sb);
  68
  69
  70 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
  71                                struct ext4_group_desc *bg)
  72 {
  73         return le32_to_cpu(bg->bg_block_bitmap_lo) |
  74                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  75                 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
  76 }
  77
  78 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
  79                                struct ext4_group_desc *bg)
  80 {
  81         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
  82                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  83                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
  84 }
  85
  86 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
  87                               struct ext4_group_desc *bg)
  88 {
  89         return le32_to_cpu(bg->bg_inode_table_lo) |
  90                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  91                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
  92 }
  93
  94 __u32 ext4_free_blks_count(struct super_block *sb,
  95                               struct ext4_group_desc *bg)
  96 {
  97         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
  98                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  99                 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 100 }
 101
 102 __u32 ext4_free_inodes_count(struct super_block *sb,
 103                               struct ext4_group_desc *bg)
 104 {
 105         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 106                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 107                 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 108 }
 109
 110 __u32 ext4_used_dirs_count(struct super_block *sb,
 111                               struct ext4_group_desc *bg)
 112 {
 113         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 114                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 115                 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 116 }
 117
 118 __u32 ext4_itable_unused_count(struct super_block *sb,
 119                               struct ext4_group_desc *bg)
 120 {
 121         return le16_to_cpu(bg->bg_itable_unused_lo) |
 122                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 123                 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 124 }
 125
 126 void ext4_block_bitmap_set(struct super_block *sb,
 127                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 128 {
 129         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 130         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 131                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 132 }
 133
 134 void ext4_inode_bitmap_set(struct super_block *sb,
 135                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 136 {
 137         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 138         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 139                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 140 }
 141
 142 void ext4_inode_table_set(struct super_block *sb,
 143                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 144 {
 145         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 146         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 147                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 148 }
 149
 150 void ext4_free_blks_set(struct super_block *sb,
 151                           struct ext4_group_desc *bg, __u32 count)
 152 {
 153         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 154         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 155                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 156 }
 157
 158 void ext4_free_inodes_set(struct super_block *sb,
 159                           struct ext4_group_desc *bg, __u32 count)
 160 {
 161         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 162         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 163                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 164 }
 165
 166 void ext4_used_dirs_set(struct super_block *sb,
 167                           struct ext4_group_desc *bg, __u32 count)
 168 {
 169         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 170         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 171                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 172 }
 173
 174 void ext4_itable_unused_set(struct super_block *sb,
 175                           struct ext4_group_desc *bg, __u32 count)
 176 {
 177         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 178         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 179                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 180 }
 181
 182 /*
 183  * Wrappers for jbd2_journal_start/end.
 184  *
 185  * The only special thing we need to do here is to make sure that all
 186  * journal_end calls result in the superblock being marked dirty, so
 187  * that sync() will call the filesystem's write_super callback if
 188  * appropriate.
 189  */
 190 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 191 {
 192         journal_t *journal;
 193
 194         if (sb->s_flags & MS_RDONLY)
 195                 return ERR_PTR(-EROFS);
 196
 197         /* Special case here: if the journal has aborted behind our
 198          * backs (eg. EIO in the commit thread), then we still need to
 199          * take the FS itself readonly cleanly. */
 200         journal = EXT4_SB(sb)->s_journal;
 201         if (journal) {
 202                 if (is_journal_aborted(journal)) {
 203                         ext4_abort(sb, __func__,
 204                                    "Detected aborted journal");
 205                         return ERR_PTR(-EROFS);
 206                 }
 207                 return jbd2_journal_start(journal, nblocks);
 208         }
 209         /*
 210          * We're not journaling, return the appropriate indication.
 211          */
 212         current->journal_info = EXT4_NOJOURNAL_HANDLE;
 213         return current->journal_info;
 214 }
 215
 216 /*
 217  * The only special thing we need to do here is to make sure that all
 218  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 219  * that sync() will call the filesystem's write_super callback if
 220  * appropriate.
 221  */
 222 int __ext4_journal_stop(const char *where, handle_t *handle)
 223 {
 224         struct super_block *sb;
 225         int err;
 226         int rc;
 227
 228         if (!ext4_handle_valid(handle)) {
 229                 /*
 230                  * Do this here since we don't call jbd2_journal_stop() in
 231                  * no-journal mode.
 232                  */
 233                 current->journal_info = NULL;
 234                 return 0;
 235         }
 236         sb = handle->h_transaction->t_journal->j_private;
 237         err = handle->h_err;
 238         rc = jbd2_journal_stop(handle);
 239
 240         if (!err)
 241                 err = rc;
 242         if (err)
 243                 __ext4_std_error(sb, where, err);
 244         return err;
 245 }
 246
 247 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 248                 struct buffer_head *bh, handle_t *handle, int err)
 249 {
 250         char nbuf[16];
 251         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 252
 253         BUG_ON(!ext4_handle_valid(handle));
 254
 255         if (bh)
 256                 BUFFER_TRACE(bh, "abort");
 257
 258         if (!handle->h_err)
 259                 handle->h_err = err;
 260
 261         if (is_handle_aborted(handle))
 262                 return;
 263
 264         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
 265                caller, errstr, err_fn);
 266
 267         jbd2_journal_abort_handle(handle);
 268 }
 269
 270 /* Deal with the reporting of failure conditions on a filesystem such as
 271  * inconsistencies detected or read IO failures.
 272  *
 273  * On ext2, we can store the error state of the filesystem in the
 274  * superblock.  That is not possible on ext4, because we may have other
 275  * write ordering constraints on the superblock which prevent us from
 276  * writing it out straight away; and given that the journal is about to
 277  * be aborted, we can't rely on the current, or future, transactions to
 278  * write out the superblock safely.
 279  *
 280  * We'll just use the jbd2_journal_abort() error code to record an error in
 281  * the journal instead.  On recovery, the journal will compain about
 282  * that error until we've noted it down and cleared it.
 283  */
 284
 285 static void ext4_handle_error(struct super_block *sb)
 286 {
 287         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 288
 289         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 290         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 291
 292         if (sb->s_flags & MS_RDONLY)
 293                 return;
 294
 295         if (!test_opt(sb, ERRORS_CONT)) {
 296                 journal_t *journal = EXT4_SB(sb)->s_journal;
 297
 298                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 299                 if (journal)
 300                         jbd2_journal_abort(journal, -EIO);
 301         }
 302         if (test_opt(sb, ERRORS_RO)) {
 303                 printk(KERN_CRIT "Remounting filesystem read-only\n");
 304                 sb->s_flags |= MS_RDONLY;
 305         }
 306         ext4_commit_super(sb, es, 1);
 307         if (test_opt(sb, ERRORS_PANIC))
 308                 panic("EXT4-fs (device %s): panic forced after error\n",
 309                         sb->s_id);
 310 }
 311
 312 void ext4_error(struct super_block *sb, const char *function,
 313                 const char *fmt, ...)
 314 {
 315         va_list args;
 316
 317         va_start(args, fmt);
 318         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 319         vprintk(fmt, args);
 320         printk("\n");
 321         va_end(args);
 322
 323         ext4_handle_error(sb);
 324 }
 325
 326 static const char *ext4_decode_error(struct super_block *sb, int errno,
 327                                      char nbuf[16])
 328 {
 329         char *errstr = NULL;
 330
 331         switch (errno) {
 332         case -EIO:
 333                 errstr = "IO failure";
 334                 break;
 335         case -ENOMEM:
 336                 errstr = "Out of memory";
 337                 break;
 338         case -EROFS:
 339                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
 340                         errstr = "Journal has aborted";
 341                 else
 342                         errstr = "Readonly filesystem";
 343                 break;
 344         default:
 345                 /* If the caller passed in an extra buffer for unknown
 346                  * errors, textualise them now.  Else we just return
 347                  * NULL. */
 348                 if (nbuf) {
 349                         /* Check for truncated error codes... */
 350                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 351                                 errstr = nbuf;
 352                 }
 353                 break;
 354         }
 355
 356         return errstr;
 357 }
 358
 359 /* __ext4_std_error decodes expected errors from journaling functions
 360  * automatically and invokes the appropriate error response.  */
 361
 362 void __ext4_std_error(struct super_block *sb, const char *function, int errno)
 363 {
 364         char nbuf[16];
 365         const char *errstr;
 366
 367         /* Special case: if the error is EROFS, and we're not already
 368          * inside a transaction, then there's really no point in logging
 369          * an error. */
 370         if (errno == -EROFS && journal_current_handle() == NULL &&
 371             (sb->s_flags & MS_RDONLY))
 372                 return;
 373
 374         errstr = ext4_decode_error(sb, errno, nbuf);
 375         printk(KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
 376                sb->s_id, function, errstr);
 377
 378         ext4_handle_error(sb);
 379 }
 380
 381 /*
 382  * ext4_abort is a much stronger failure handler than ext4_error.  The
 383  * abort function may be used to deal with unrecoverable failures such
 384  * as journal IO errors or ENOMEM at a critical moment in log management.
 385  *
 386  * We unconditionally force the filesystem into an ABORT|READONLY state,
 387  * unless the error response on the fs has been set to panic in which
 388  * case we take the easy way out and panic immediately.
 389  */
 390
 391 void ext4_abort(struct super_block *sb, const char *function,
 392                 const char *fmt, ...)
 393 {
 394         va_list args;
 395
 396         printk(KERN_CRIT "ext4_abort called.\n");
 397
 398         va_start(args, fmt);
 399         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 400         vprintk(fmt, args);
 401         printk("\n");
 402         va_end(args);
 403
 404         if (test_opt(sb, ERRORS_PANIC))
 405                 panic("EXT4-fs panic from previous error\n");
 406
 407         if (sb->s_flags & MS_RDONLY)
 408                 return;
 409
 410         printk(KERN_CRIT "Remounting filesystem read-only\n");
 411         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 412         sb->s_flags |= MS_RDONLY;
 413         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 414         if (EXT4_SB(sb)->s_journal)
 415                 jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 416 }
 417
 418 void ext4_warning(struct super_block *sb, const char *function,
 419                   const char *fmt, ...)
 420 {
 421         va_list args;
 422
 423         va_start(args, fmt);
 424         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
 425                sb->s_id, function);
 426         vprintk(fmt, args);
 427         printk("\n");
 428         va_end(args);
 429 }
 430
 431 void ext4_grp_locked_error(struct super_block *sb, ext4_group_t grp,
 432                                 const char *function, const char *fmt, ...)
 433 __releases(bitlock)
 434 __acquires(bitlock)
 435 {
 436         va_list args;
 437         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 438
 439         va_start(args, fmt);
 440         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 441         vprintk(fmt, args);
 442         printk("\n");
 443         va_end(args);
 444
 445         if (test_opt(sb, ERRORS_CONT)) {
 446                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 447                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 448                 ext4_commit_super(sb, es, 0);
 449                 return;
 450         }
 451         ext4_unlock_group(sb, grp);
 452         ext4_handle_error(sb);
 453         /*
 454          * We only get here in the ERRORS_RO case; relocking the group
 455          * may be dangerous, but nothing bad will happen since the
 456          * filesystem will have already been marked read/only and the
 457          * journal has been aborted.  We return 1 as a hint to callers
 458          * who might what to use the return value from
 459          * ext4_grp_locked_error() to distinguish beween the
 460          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 461          * aggressively from the ext4 function in question, with a
 462          * more appropriate error code.
 463          */
 464         ext4_lock_group(sb, grp);
 465         return;
 466 }
 467
 468
 469 void ext4_update_dynamic_rev(struct super_block *sb)
 470 {
 471         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 472
 473         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 474                 return;
 475
 476         ext4_warning(sb, __func__,
 477                      "updating to rev %d because of new feature flag, "
 478                      "running e2fsck is recommended",
 479                      EXT4_DYNAMIC_REV);
 480
 481         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 482         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 483         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 484         /* leave es->s_feature_*compat flags alone */
 485         /* es->s_uuid will be set by e2fsck if empty */
 486
 487         /*
 488          * The rest of the superblock fields should be zero, and if not it
 489          * means they are likely already in use, so leave them alone.  We
 490          * can leave it up to e2fsck to clean up any inconsistencies there.
 491          */
 492 }
 493
 494 /*
 495  * Open the external journal device
 496  */
 497 static struct block_device *ext4_blkdev_get(dev_t dev)
 498 {
 499         struct block_device *bdev;
 500         char b[BDEVNAME_SIZE];
 501
 502         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 503         if (IS_ERR(bdev))
 504                 goto fail;
 505         return bdev;
 506
 507 fail:
 508         printk(KERN_ERR "EXT4-fs: failed to open journal device %s: %ld\n",
 509                         __bdevname(dev, b), PTR_ERR(bdev));
 510         return NULL;
 511 }
 512
 513 /*
 514  * Release the journal device
 515  */
 516 static int ext4_blkdev_put(struct block_device *bdev)
 517 {
 518         bd_release(bdev);
 519         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
 520 }
 521
 522 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 523 {
 524         struct block_device *bdev;
 525         int ret = -ENODEV;
 526
 527         bdev = sbi->journal_bdev;
 528         if (bdev) {
 529                 ret = ext4_blkdev_put(bdev);
 530                 sbi->journal_bdev = NULL;
 531         }
 532         return ret;
 533 }
 534
 535 static inline struct inode *orphan_list_entry(struct list_head *l)
 536 {
 537         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 538 }
 539
 540 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 541 {
 542         struct list_head *l;
 543
 544         printk(KERN_ERR "sb orphan head is %d\n",
 545                le32_to_cpu(sbi->s_es->s_last_orphan));
 546
 547         printk(KERN_ERR "sb_info orphan list:\n");
 548         list_for_each(l, &sbi->s_orphan) {
 549                 struct inode *inode = orphan_list_entry(l);
 550                 printk(KERN_ERR "  "
 551                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 552                        inode->i_sb->s_id, inode->i_ino, inode,
 553                        inode->i_mode, inode->i_nlink,
 554                        NEXT_ORPHAN(inode));
 555         }
 556 }
 557
 558 static void ext4_put_super(struct super_block *sb)
 559 {
 560         struct ext4_sb_info *sbi = EXT4_SB(sb);
 561         struct ext4_super_block *es = sbi->s_es;
 562         int i, err;
 563
 564         ext4_mb_release(sb);
 565         ext4_ext_release(sb);
 566         ext4_xattr_put_super(sb);
 567         if (sbi->s_journal) {
 568                 err = jbd2_journal_destroy(sbi->s_journal);
 569                 sbi->s_journal = NULL;
 570                 if (err < 0)
 571                         ext4_abort(sb, __func__,
 572                                    "Couldn't clean up the journal");
 573         }
 574         if (!(sb->s_flags & MS_RDONLY)) {
 575                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 576                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 577                 ext4_commit_super(sb, es, 1);
 578         }
 579         if (sbi->s_proc) {
 580                 remove_proc_entry("inode_readahead_blks", sbi->s_proc);
 581                 remove_proc_entry(sb->s_id, ext4_proc_root);
 582         }
 583
 584         for (i = 0; i < sbi->s_gdb_count; i++)
 585                 brelse(sbi->s_group_desc[i]);
 586         kfree(sbi->s_group_desc);
 587         kfree(sbi->s_flex_groups);
 588         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 589         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 590         percpu_counter_destroy(&sbi->s_dirs_counter);
 591         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
 592         brelse(sbi->s_sbh);
 593 #ifdef CONFIG_QUOTA
 594         for (i = 0; i < MAXQUOTAS; i++)
 595                 kfree(sbi->s_qf_names[i]);
 596 #endif
 597
 598         /* Debugging code just in case the in-memory inode orphan list
 599          * isn't empty.  The on-disk one can be non-empty if we've
 600          * detected an error and taken the fs readonly, but the
 601          * in-memory list had better be clean by this point. */
 602         if (!list_empty(&sbi->s_orphan))
 603                 dump_orphan_list(sb, sbi);
 604         J_ASSERT(list_empty(&sbi->s_orphan));
 605
 606         invalidate_bdev(sb->s_bdev);
 607         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 608                 /*
 609                  * Invalidate the journal device's buffers.  We don't want them
 610                  * floating about in memory - the physical journal device may
 611                  * hotswapped, and it breaks the `ro-after' testing code.
 612                  */
 613                 sync_blockdev(sbi->journal_bdev);
 614                 invalidate_bdev(sbi->journal_bdev);
 615                 ext4_blkdev_remove(sbi);
 616         }
 617         sb->s_fs_info = NULL;
 618         kfree(sbi->s_blockgroup_lock);
 619         kfree(sbi);
 620         return;
 621 }
 622
 623 static struct kmem_cache *ext4_inode_cachep;
 624
 625 /*
 626  * Called inside transaction, so use GFP_NOFS
 627  */
 628 static struct inode *ext4_alloc_inode(struct super_block *sb)
 629 {
 630         struct ext4_inode_info *ei;
 631
 632         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 633         if (!ei)
 634                 return NULL;
 635 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 636         ei->i_acl = EXT4_ACL_NOT_CACHED;
 637         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 638 #endif
 639         ei->vfs_inode.i_version = 1;
 640         ei->vfs_inode.i_data.writeback_index = 0;
 641         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 642         INIT_LIST_HEAD(&ei->i_prealloc_list);
 643         spin_lock_init(&ei->i_prealloc_lock);
 644         /*
 645          * Note:  We can be called before EXT4_SB(sb)->s_journal is set,
 646          * therefore it can be null here.  Don't check it, just initialize
 647          * jinode.
 648          */
 649         jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
 650         ei->i_reserved_data_blocks = 0;
 651         ei->i_reserved_meta_blocks = 0;
 652         ei->i_allocated_meta_blocks = 0;
 653         ei->i_delalloc_reserved_flag = 0;
 654         spin_lock_init(&(ei->i_block_reservation_lock));
 655         return &ei->vfs_inode;
 656 }
 657
 658 static void ext4_destroy_inode(struct inode *inode)
 659 {
 660         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 661                 printk("EXT4 Inode %p: orphan list check failed!\n",
 662                         EXT4_I(inode));
 663                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 664                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 665                                 true);
 666                 dump_stack();
 667         }
 668         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 669 }
 670
 671 static void init_once(void *foo)
 672 {
 673         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 674
 675         INIT_LIST_HEAD(&ei->i_orphan);
 676 #ifdef CONFIG_EXT4_FS_XATTR
 677         init_rwsem(&ei->xattr_sem);
 678 #endif
 679         init_rwsem(&ei->i_data_sem);
 680         inode_init_once(&ei->vfs_inode);
 681 }
 682
 683 static int init_inodecache(void)
 684 {
 685         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 686                                              sizeof(struct ext4_inode_info),
 687                                              0, (SLAB_RECLAIM_ACCOUNT|
 688                                                 SLAB_MEM_SPREAD),
 689                                              init_once);
 690         if (ext4_inode_cachep == NULL)
 691                 return -ENOMEM;
 692         return 0;
 693 }
 694
 695 static void destroy_inodecache(void)
 696 {
 697         kmem_cache_destroy(ext4_inode_cachep);
 698 }
 699
 700 static void ext4_clear_inode(struct inode *inode)
 701 {
 702 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 703         if (EXT4_I(inode)->i_acl &&
 704                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
 705                 posix_acl_release(EXT4_I(inode)->i_acl);
 706                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
 707         }
 708         if (EXT4_I(inode)->i_default_acl &&
 709                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
 710                 posix_acl_release(EXT4_I(inode)->i_default_acl);
 711                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
 712         }
 713 #endif
 714         ext4_discard_preallocations(inode);
 715         if (EXT4_JOURNAL(inode))
 716                 jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
 717                                        &EXT4_I(inode)->jinode);
 718 }
 719
 720 static inline void ext4_show_quota_options(struct seq_file *seq,
 721                                            struct super_block *sb)
 722 {
 723 #if defined(CONFIG_QUOTA)
 724         struct ext4_sb_info *sbi = EXT4_SB(sb);
 725
 726         if (sbi->s_jquota_fmt)
 727                 seq_printf(seq, ",jqfmt=%s",
 728                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold" : "vfsv0");
 729
 730         if (sbi->s_qf_names[USRQUOTA])
 731                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 732
 733         if (sbi->s_qf_names[GRPQUOTA])
 734                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 735
 736         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
 737                 seq_puts(seq, ",usrquota");
 738
 739         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
 740                 seq_puts(seq, ",grpquota");
 741 #endif
 742 }
 743
 744 /*
 745  * Show an option if
 746  *  - it's set to a non-default value OR
 747  *  - if the per-sb default is different from the global default
 748  */
 749 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 750 {
 751         int def_errors;
 752         unsigned long def_mount_opts;
 753         struct super_block *sb = vfs->mnt_sb;
 754         struct ext4_sb_info *sbi = EXT4_SB(sb);
 755         struct ext4_super_block *es = sbi->s_es;
 756
 757         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 758         def_errors     = le16_to_cpu(es->s_errors);
 759
 760         if (sbi->s_sb_block != 1)
 761                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 762         if (test_opt(sb, MINIX_DF))
 763                 seq_puts(seq, ",minixdf");
 764         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
 765                 seq_puts(seq, ",grpid");
 766         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 767                 seq_puts(seq, ",nogrpid");
 768         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 769             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 770                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 771         }
 772         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 773             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 774                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 775         }
 776         if (test_opt(sb, ERRORS_RO)) {
 777                 if (def_errors == EXT4_ERRORS_PANIC ||
 778                     def_errors == EXT4_ERRORS_CONTINUE) {
 779                         seq_puts(seq, ",errors=remount-ro");
 780                 }
 781         }
 782         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
 783                 seq_puts(seq, ",errors=continue");
 784         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
 785                 seq_puts(seq, ",errors=panic");
 786         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
 787                 seq_puts(seq, ",nouid32");
 788         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
 789                 seq_puts(seq, ",debug");
 790         if (test_opt(sb, OLDALLOC))
 791                 seq_puts(seq, ",oldalloc");
 792 #ifdef CONFIG_EXT4_FS_XATTR
 793         if (test_opt(sb, XATTR_USER) &&
 794                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
 795                 seq_puts(seq, ",user_xattr");
 796         if (!test_opt(sb, XATTR_USER) &&
 797             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 798                 seq_puts(seq, ",nouser_xattr");
 799         }
 800 #endif
 801 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 802         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
 803                 seq_puts(seq, ",acl");
 804         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 805                 seq_puts(seq, ",noacl");
 806 #endif
 807         if (!test_opt(sb, RESERVATION))
 808                 seq_puts(seq, ",noreservation");
 809         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
 810                 seq_printf(seq, ",commit=%u",
 811                            (unsigned) (sbi->s_commit_interval / HZ));
 812         }
 813         if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
 814                 seq_printf(seq, ",min_batch_time=%u",
 815                            (unsigned) sbi->s_min_batch_time);
 816         }
 817         if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
 818                 seq_printf(seq, ",max_batch_time=%u",
 819                            (unsigned) sbi->s_min_batch_time);
 820         }
 821
 822         /*
 823          * We're changing the default of barrier mount option, so
 824          * let's always display its mount state so it's clear what its
 825          * status is.
 826          */
 827         seq_puts(seq, ",barrier=");
 828         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
 829         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
 830                 seq_puts(seq, ",journal_async_commit");
 831         if (test_opt(sb, NOBH))
 832                 seq_puts(seq, ",nobh");
 833         if (test_opt(sb, I_VERSION))
 834                 seq_puts(seq, ",i_version");
 835         if (!test_opt(sb, DELALLOC))
 836                 seq_puts(seq, ",nodelalloc");
 837
 838
 839         if (sbi->s_stripe)
 840                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
 841         /*
 842          * journal mode get enabled in different ways
 843          * So just print the value even if we didn't specify it
 844          */
 845         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 846                 seq_puts(seq, ",data=journal");
 847         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 848                 seq_puts(seq, ",data=ordered");
 849         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 850                 seq_puts(seq, ",data=writeback");
 851
 852         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
 853                 seq_printf(seq, ",inode_readahead_blks=%u",
 854                            sbi->s_inode_readahead_blks);
 855
 856         if (test_opt(sb, DATA_ERR_ABORT))
 857                 seq_puts(seq, ",data_err=abort");
 858
 859         ext4_show_quota_options(seq, sb);
 860         return 0;
 861 }
 862
 863
 864 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 865                 u64 ino, u32 generation)
 866 {
 867         struct inode *inode;
 868
 869         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 870                 return ERR_PTR(-ESTALE);
 871         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 872                 return ERR_PTR(-ESTALE);
 873
 874         /* iget isn't really right if the inode is currently unallocated!!
 875          *
 876          * ext4_read_inode will return a bad_inode if the inode had been
 877          * deleted, so we should be safe.
 878          *
 879          * Currently we don't know the generation for parent directory, so
 880          * a generation of 0 means "accept any"
 881          */
 882         inode = ext4_iget(sb, ino);
 883         if (IS_ERR(inode))
 884                 return ERR_CAST(inode);
 885         if (generation && inode->i_generation != generation) {
 886                 iput(inode);
 887                 return ERR_PTR(-ESTALE);
 888         }
 889
 890         return inode;
 891 }
 892
 893 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 894                 int fh_len, int fh_type)
 895 {
 896         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 897                                     ext4_nfs_get_inode);
 898 }
 899
 900 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 901                 int fh_len, int fh_type)
 902 {
 903         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 904                                     ext4_nfs_get_inode);
 905 }
 906
 907 /*
 908  * Try to release metadata pages (indirect blocks, directories) which are
 909  * mapped via the block device.  Since these pages could have journal heads
 910  * which would prevent try_to_free_buffers() from freeing them, we must use
 911  * jbd2 layer's try_to_free_buffers() function to release them.
 912  */
 913 static int bdev_try_to_free_page(struct super_block *sb, struct page *page, gfp_t wait)
 914 {
 915         journal_t *journal = EXT4_SB(sb)->s_journal;
 916
 917         WARN_ON(PageChecked(page));
 918         if (!page_has_buffers(page))
 919                 return 0;
 920         if (journal)
 921                 return jbd2_journal_try_to_free_buffers(journal, page,
 922                                                         wait & ~__GFP_WAIT);
 923         return try_to_free_buffers(page);
 924 }
 925
 926 #ifdef CONFIG_QUOTA
 927 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
 928 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 929
 930 static int ext4_write_dquot(struct dquot *dquot);
 931 static int ext4_acquire_dquot(struct dquot *dquot);
 932 static int ext4_release_dquot(struct dquot *dquot);
 933 static int ext4_mark_dquot_dirty(struct dquot *dquot);
 934 static int ext4_write_info(struct super_block *sb, int type);
 935 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 936                                 char *path, int remount);
 937 static int ext4_quota_on_mount(struct super_block *sb, int type);
 938 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 939                                size_t len, loff_t off);
 940 static ssize_t ext4_quota_write(struct super_block *sb, int type,
 941                                 const char *data, size_t len, loff_t off);
 942
 943 static struct dquot_operations ext4_quota_operations = {
 944         .initialize     = dquot_initialize,
 945         .drop           = dquot_drop,
 946         .alloc_space    = dquot_alloc_space,
 947         .reserve_space  = dquot_reserve_space,
 948         .claim_space    = dquot_claim_space,
 949         .release_rsv    = dquot_release_reserved_space,
 950         .get_reserved_space = ext4_get_reserved_space,
 951         .alloc_inode    = dquot_alloc_inode,
 952         .free_space     = dquot_free_space,
 953         .free_inode     = dquot_free_inode,
 954         .transfer       = dquot_transfer,
 955         .write_dquot    = ext4_write_dquot,
 956         .acquire_dquot  = ext4_acquire_dquot,
 957         .release_dquot  = ext4_release_dquot,
 958         .mark_dirty     = ext4_mark_dquot_dirty,
 959         .write_info     = ext4_write_info,
 960         .alloc_dquot    = dquot_alloc,
 961         .destroy_dquot  = dquot_destroy,
 962 };
 963
 964 static struct quotactl_ops ext4_qctl_operations = {
 965         .quota_on       = ext4_quota_on,
 966         .quota_off      = vfs_quota_off,
 967         .quota_sync     = vfs_quota_sync,
 968         .get_info       = vfs_get_dqinfo,
 969         .set_info       = vfs_set_dqinfo,
 970         .get_dqblk      = vfs_get_dqblk,
 971         .set_dqblk      = vfs_set_dqblk
 972 };
 973 #endif
 974
 975 static const struct super_operations ext4_sops = {
 976         .alloc_inode    = ext4_alloc_inode,
 977         .destroy_inode  = ext4_destroy_inode,
 978         .write_inode    = ext4_write_inode,
 979         .dirty_inode    = ext4_dirty_inode,
 980         .delete_inode   = ext4_delete_inode,
 981         .put_super      = ext4_put_super,
 982         .write_super    = ext4_write_super,
 983         .sync_fs        = ext4_sync_fs,
 984         .freeze_fs      = ext4_freeze,
 985         .unfreeze_fs    = ext4_unfreeze,
 986         .statfs         = ext4_statfs,
 987         .remount_fs     = ext4_remount,
 988         .clear_inode    = ext4_clear_inode,
 989         .show_options   = ext4_show_options,
 990 #ifdef CONFIG_QUOTA
 991         .quota_read     = ext4_quota_read,
 992         .quota_write    = ext4_quota_write,
 993 #endif
 994         .bdev_try_to_free_page = bdev_try_to_free_page,
 995 };
 996
 997 static const struct export_operations ext4_export_ops = {
 998         .fh_to_dentry = ext4_fh_to_dentry,
 999         .fh_to_parent = ext4_fh_to_parent,
1000         .get_parent = ext4_get_parent,
1001 };
1002
1003 enum {
1004         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1005         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1006         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1007         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1008         Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
1009         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1010         Opt_journal_update, Opt_journal_dev,
1011         Opt_journal_checksum, Opt_journal_async_commit,
1012         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1013         Opt_data_err_abort, Opt_data_err_ignore,
1014         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1015         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
1016         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
1017         Opt_grpquota, Opt_i_version,
1018         Opt_stripe, Opt_delalloc, Opt_nodelalloc,
1019         Opt_inode_readahead_blks, Opt_journal_ioprio
1020 };
1021
1022 static const match_table_t tokens = {
1023         {Opt_bsd_df, "bsddf"},
1024         {Opt_minix_df, "minixdf"},
1025         {Opt_grpid, "grpid"},
1026         {Opt_grpid, "bsdgroups"},
1027         {Opt_nogrpid, "nogrpid"},
1028         {Opt_nogrpid, "sysvgroups"},
1029         {Opt_resgid, "resgid=%u"},
1030         {Opt_resuid, "resuid=%u"},
1031         {Opt_sb, "sb=%u"},
1032         {Opt_err_cont, "errors=continue"},
1033         {Opt_err_panic, "errors=panic"},
1034         {Opt_err_ro, "errors=remount-ro"},
1035         {Opt_nouid32, "nouid32"},
1036         {Opt_debug, "debug"},
1037         {Opt_oldalloc, "oldalloc"},
1038         {Opt_orlov, "orlov"},
1039         {Opt_user_xattr, "user_xattr"},
1040         {Opt_nouser_xattr, "nouser_xattr"},
1041         {Opt_acl, "acl"},
1042         {Opt_noacl, "noacl"},
1043         {Opt_reservation, "reservation"},
1044         {Opt_noreservation, "noreservation"},
1045         {Opt_noload, "noload"},
1046         {Opt_nobh, "nobh"},
1047         {Opt_bh, "bh"},
1048         {Opt_commit, "commit=%u"},
1049         {Opt_min_batch_time, "min_batch_time=%u"},
1050         {Opt_max_batch_time, "max_batch_time=%u"},
1051         {Opt_journal_update, "journal=update"},
1052         {Opt_journal_dev, "journal_dev=%u"},
1053         {Opt_journal_checksum, "journal_checksum"},
1054         {Opt_journal_async_commit, "journal_async_commit"},
1055         {Opt_abort, "abort"},
1056         {Opt_data_journal, "data=journal"},
1057         {Opt_data_ordered, "data=ordered"},
1058         {Opt_data_writeback, "data=writeback"},
1059         {Opt_data_err_abort, "data_err=abort"},
1060         {Opt_data_err_ignore, "data_err=ignore"},
1061         {Opt_offusrjquota, "usrjquota="},
1062         {Opt_usrjquota, "usrjquota=%s"},
1063         {Opt_offgrpjquota, "grpjquota="},
1064         {Opt_grpjquota, "grpjquota=%s"},
1065         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1066         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1067         {Opt_grpquota, "grpquota"},
1068         {Opt_noquota, "noquota"},
1069         {Opt_quota, "quota"},
1070         {Opt_usrquota, "usrquota"},
1071         {Opt_barrier, "barrier=%u"},
1072         {Opt_i_version, "i_version"},
1073         {Opt_stripe, "stripe=%u"},
1074         {Opt_resize, "resize"},
1075         {Opt_delalloc, "delalloc"},
1076         {Opt_nodelalloc, "nodelalloc"},
1077         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1078         {Opt_journal_ioprio, "journal_ioprio=%u"},
1079         {Opt_err, NULL},
1080 };
1081
1082 static ext4_fsblk_t get_sb_block(void **data)
1083 {
1084         ext4_fsblk_t    sb_block;
1085         char            *options = (char *) *data;
1086
1087         if (!options || strncmp(options, "sb=", 3) != 0)
1088                 return 1;       /* Default location */
1089         options += 3;
1090         /*todo: use simple_strtoll with >32bit ext4 */
1091         sb_block = simple_strtoul(options, &options, 0);
1092         if (*options && *options != ',') {
1093                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1094                        (char *) *data);
1095                 return 1;
1096         }
1097         if (*options == ',')
1098                 options++;
1099         *data = (void *) options;
1100         return sb_block;
1101 }
1102
1103 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1104
1105 static int parse_options(char *options, struct super_block *sb,
1106                          unsigned long *journal_devnum,
1107                          unsigned int *journal_ioprio,
1108                          ext4_fsblk_t *n_blocks_count, int is_remount)
1109 {
1110         struct ext4_sb_info *sbi = EXT4_SB(sb);
1111         char *p;
1112         substring_t args[MAX_OPT_ARGS];
1113         int data_opt = 0;
1114         int option;
1115 #ifdef CONFIG_QUOTA
1116         int qtype, qfmt;
1117         char *qname;
1118 #endif
1119
1120         if (!options)
1121                 return 1;
1122
1123         while ((p = strsep(&options, ",")) != NULL) {
1124                 int token;
1125                 if (!*p)
1126                         continue;
1127
1128                 token = match_token(p, tokens, args);
1129                 switch (token) {
1130                 case Opt_bsd_df:
1131                         clear_opt(sbi->s_mount_opt, MINIX_DF);
1132                         break;
1133                 case Opt_minix_df:
1134                         set_opt(sbi->s_mount_opt, MINIX_DF);
1135                         break;
1136                 case Opt_grpid:
1137                         set_opt(sbi->s_mount_opt, GRPID);
1138                         break;
1139                 case Opt_nogrpid:
1140                         clear_opt(sbi->s_mount_opt, GRPID);
1141                         break;
1142                 case Opt_resuid:
1143                         if (match_int(&args[0], &option))
1144                                 return 0;
1145                         sbi->s_resuid = option;
1146                         break;
1147                 case Opt_resgid:
1148                         if (match_int(&args[0], &option))
1149                                 return 0;
1150                         sbi->s_resgid = option;
1151                         break;
1152                 case Opt_sb:
1153                         /* handled by get_sb_block() instead of here */
1154                         /* *sb_block = match_int(&args[0]); */
1155                         break;
1156                 case Opt_err_panic:
1157                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1158                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1159                         set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1160                         break;
1161                 case Opt_err_ro:
1162                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1163                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1164                         set_opt(sbi->s_mount_opt, ERRORS_RO);
1165                         break;
1166                 case Opt_err_cont:
1167                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1168                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1169                         set_opt(sbi->s_mount_opt, ERRORS_CONT);
1170                         break;
1171                 case Opt_nouid32:
1172                         set_opt(sbi->s_mount_opt, NO_UID32);
1173                         break;
1174                 case Opt_debug:
1175                         set_opt(sbi->s_mount_opt, DEBUG);
1176                         break;
1177                 case Opt_oldalloc:
1178                         set_opt(sbi->s_mount_opt, OLDALLOC);
1179                         break;
1180                 case Opt_orlov:
1181                         clear_opt(sbi->s_mount_opt, OLDALLOC);
1182                         break;
1183 #ifdef CONFIG_EXT4_FS_XATTR
1184                 case Opt_user_xattr:
1185                         set_opt(sbi->s_mount_opt, XATTR_USER);
1186                         break;
1187                 case Opt_nouser_xattr:
1188                         clear_opt(sbi->s_mount_opt, XATTR_USER);
1189                         break;
1190 #else
1191                 case Opt_user_xattr:
1192                 case Opt_nouser_xattr:
1193                         printk(KERN_ERR "EXT4 (no)user_xattr options "
1194                                "not supported\n");
1195                         break;
1196 #endif
1197 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1198                 case Opt_acl:
1199                         set_opt(sbi->s_mount_opt, POSIX_ACL);
1200                         break;
1201                 case Opt_noacl:
1202                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
1203                         break;
1204 #else
1205                 case Opt_acl:
1206                 case Opt_noacl:
1207                         printk(KERN_ERR "EXT4 (no)acl options "
1208                                "not supported\n");
1209                         break;
1210 #endif
1211                 case Opt_reservation:
1212                         set_opt(sbi->s_mount_opt, RESERVATION);
1213                         break;
1214                 case Opt_noreservation:
1215                         clear_opt(sbi->s_mount_opt, RESERVATION);
1216                         break;
1217                 case Opt_journal_update:
1218                         /* @@@ FIXME */
1219                         /* Eventually we will want to be able to create
1220                            a journal file here.  For now, only allow the
1221                            user to specify an existing inode to be the
1222                            journal file. */
1223                         if (is_remount) {
1224                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1225                                        "journal on remount\n");
1226                                 return 0;
1227                         }
1228                         set_opt(sbi->s_mount_opt, UPDATE_JOURNAL);
1229                         break;
1230                 case Opt_journal_dev:
1231                         if (is_remount) {
1232                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1233                                        "journal on remount\n");
1234                                 return 0;
1235                         }
1236                         if (match_int(&args[0], &option))
1237                                 return 0;
1238                         *journal_devnum = option;
1239                         break;
1240                 case Opt_journal_checksum:
1241                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1242                         break;
1243                 case Opt_journal_async_commit:
1244                         set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1245                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1246                         break;
1247                 case Opt_noload:
1248                         set_opt(sbi->s_mount_opt, NOLOAD);
1249                         break;
1250                 case Opt_commit:
1251                         if (match_int(&args[0], &option))
1252                                 return 0;
1253                         if (option < 0)
1254                                 return 0;
1255                         if (option == 0)
1256                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1257                         sbi->s_commit_interval = HZ * option;
1258                         break;
1259                 case Opt_max_batch_time:
1260                         if (match_int(&args[0], &option))
1261                                 return 0;
1262                         if (option < 0)
1263                                 return 0;
1264                         if (option == 0)
1265                                 option = EXT4_DEF_MAX_BATCH_TIME;
1266                         sbi->s_max_batch_time = option;
1267                         break;
1268                 case Opt_min_batch_time:
1269                         if (match_int(&args[0], &option))
1270                                 return 0;
1271                         if (option < 0)
1272                                 return 0;
1273                         sbi->s_min_batch_time = option;
1274                         break;
1275                 case Opt_data_journal:
1276                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1277                         goto datacheck;
1278                 case Opt_data_ordered:
1279                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1280                         goto datacheck;
1281                 case Opt_data_writeback:
1282                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1283                 datacheck:
1284                         if (is_remount) {
1285                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1286                                                 != data_opt) {
1287                                         printk(KERN_ERR
1288                                                 "EXT4-fs: cannot change data "
1289                                                 "mode on remount\n");
1290                                         return 0;
1291                                 }
1292                         } else {
1293                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1294                                 sbi->s_mount_opt |= data_opt;
1295                         }
1296                         break;
1297                 case Opt_data_err_abort:
1298                         set_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1299                         break;
1300                 case Opt_data_err_ignore:
1301                         clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1302                         break;
1303 #ifdef CONFIG_QUOTA
1304                 case Opt_usrjquota:
1305                         qtype = USRQUOTA;
1306                         goto set_qf_name;
1307                 case Opt_grpjquota:
1308                         qtype = GRPQUOTA;
1309 set_qf_name:
1310                         if (sb_any_quota_loaded(sb) &&
1311                             !sbi->s_qf_names[qtype]) {
1312                                 printk(KERN_ERR
1313                                        "EXT4-fs: Cannot change journaled "
1314                                        "quota options when quota turned on.\n");
1315                                 return 0;
1316                         }
1317                         qname = match_strdup(&args[0]);
1318                         if (!qname) {
1319                                 printk(KERN_ERR
1320                                         "EXT4-fs: not enough memory for "
1321                                         "storing quotafile name.\n");
1322                                 return 0;
1323                         }
1324                         if (sbi->s_qf_names[qtype] &&
1325                             strcmp(sbi->s_qf_names[qtype], qname)) {
1326                                 printk(KERN_ERR
1327                                         "EXT4-fs: %s quota file already "
1328                                         "specified.\n", QTYPE2NAME(qtype));
1329                                 kfree(qname);
1330                                 return 0;
1331                         }
1332                         sbi->s_qf_names[qtype] = qname;
1333                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1334                                 printk(KERN_ERR
1335                                         "EXT4-fs: quotafile must be on "
1336                                         "filesystem root.\n");
1337                                 kfree(sbi->s_qf_names[qtype]);
1338                                 sbi->s_qf_names[qtype] = NULL;
1339                                 return 0;
1340                         }
1341                         set_opt(sbi->s_mount_opt, QUOTA);
1342                         break;
1343                 case Opt_offusrjquota:
1344                         qtype = USRQUOTA;
1345                         goto clear_qf_name;
1346                 case Opt_offgrpjquota:
1347                         qtype = GRPQUOTA;
1348 clear_qf_name:
1349                         if (sb_any_quota_loaded(sb) &&
1350                             sbi->s_qf_names[qtype]) {
1351                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1352                                         "journaled quota options when "
1353                                         "quota turned on.\n");
1354                                 return 0;
1355                         }
1356                         /*
1357                          * The space will be released later when all options
1358                          * are confirmed to be correct
1359                          */
1360                         sbi->s_qf_names[qtype] = NULL;
1361                         break;
1362                 case Opt_jqfmt_vfsold:
1363                         qfmt = QFMT_VFS_OLD;
1364                         goto set_qf_format;
1365                 case Opt_jqfmt_vfsv0:
1366                         qfmt = QFMT_VFS_V0;
1367 set_qf_format:
1368                         if (sb_any_quota_loaded(sb) &&
1369                             sbi->s_jquota_fmt != qfmt) {
1370                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1371                                         "journaled quota options when "
1372                                         "quota turned on.\n");
1373                                 return 0;
1374                         }
1375                         sbi->s_jquota_fmt = qfmt;
1376                         break;
1377                 case Opt_quota:
1378                 case Opt_usrquota:
1379                         set_opt(sbi->s_mount_opt, QUOTA);
1380                         set_opt(sbi->s_mount_opt, USRQUOTA);
1381                         break;
1382                 case Opt_grpquota:
1383                         set_opt(sbi->s_mount_opt, QUOTA);
1384                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1385                         break;
1386                 case Opt_noquota:
1387                         if (sb_any_quota_loaded(sb)) {
1388                                 printk(KERN_ERR "EXT4-fs: Cannot change quota "
1389                                         "options when quota turned on.\n");
1390                                 return 0;
1391                         }
1392                         clear_opt(sbi->s_mount_opt, QUOTA);
1393                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1394                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1395                         break;
1396 #else
1397                 case Opt_quota:
1398                 case Opt_usrquota:
1399                 case Opt_grpquota:
1400                         printk(KERN_ERR
1401                                 "EXT4-fs: quota options not supported.\n");
1402                         break;
1403                 case Opt_usrjquota:
1404                 case Opt_grpjquota:
1405                 case Opt_offusrjquota:
1406                 case Opt_offgrpjquota:
1407                 case Opt_jqfmt_vfsold:
1408                 case Opt_jqfmt_vfsv0:
1409                         printk(KERN_ERR
1410                                 "EXT4-fs: journaled quota options not "
1411                                 "supported.\n");
1412                         break;
1413                 case Opt_noquota:
1414                         break;
1415 #endif
1416                 case Opt_abort:
1417                         set_opt(sbi->s_mount_opt, ABORT);
1418                         break;
1419                 case Opt_barrier:
1420                         if (match_int(&args[0], &option))
1421                                 return 0;
1422                         if (option)
1423                                 set_opt(sbi->s_mount_opt, BARRIER);
1424                         else
1425                                 clear_opt(sbi->s_mount_opt, BARRIER);
1426                         break;
1427                 case Opt_ignore:
1428                         break;
1429                 case Opt_resize:
1430                         if (!is_remount) {
1431                                 printk("EXT4-fs: resize option only available "
1432                                         "for remount\n");
1433                                 return 0;
1434                         }
1435                         if (match_int(&args[0], &option) != 0)
1436                                 return 0;
1437                         *n_blocks_count = option;
1438                         break;
1439                 case Opt_nobh:
1440                         set_opt(sbi->s_mount_opt, NOBH);
1441                         break;
1442                 case Opt_bh:
1443                         clear_opt(sbi->s_mount_opt, NOBH);
1444                         break;
1445                 case Opt_i_version:
1446                         set_opt(sbi->s_mount_opt, I_VERSION);
1447                         sb->s_flags |= MS_I_VERSION;
1448                         break;
1449                 case Opt_nodelalloc:
1450                         clear_opt(sbi->s_mount_opt, DELALLOC);
1451                         break;
1452                 case Opt_stripe:
1453                         if (match_int(&args[0], &option))
1454                                 return 0;
1455                         if (option < 0)
1456                                 return 0;
1457                         sbi->s_stripe = option;
1458                         break;
1459                 case Opt_delalloc:
1460                         set_opt(sbi->s_mount_opt, DELALLOC);
1461                         break;
1462                 case Opt_inode_readahead_blks:
1463                         if (match_int(&args[0], &option))
1464                                 return 0;
1465                         if (option < 0 || option > (1 << 30))
1466                                 return 0;
1467                         sbi->s_inode_readahead_blks = option;
1468                         break;
1469                 case Opt_journal_ioprio:
1470                         if (match_int(&args[0], &option))
1471                                 return 0;
1472                         if (option < 0 || option > 7)
1473                                 break;
1474                         *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1475                                                             option);
1476                         break;
1477                 default:
1478                         printk(KERN_ERR
1479                                "EXT4-fs: Unrecognized mount option \"%s\" "
1480                                "or missing value\n", p);
1481                         return 0;
1482                 }
1483         }
1484 #ifdef CONFIG_QUOTA
1485         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1486                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1487                      sbi->s_qf_names[USRQUOTA])
1488                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1489
1490                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1491                      sbi->s_qf_names[GRPQUOTA])
1492                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1493
1494                 if ((sbi->s_qf_names[USRQUOTA] &&
1495                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1496                     (sbi->s_qf_names[GRPQUOTA] &&
1497                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1498                         printk(KERN_ERR "EXT4-fs: old and new quota "
1499                                         "format mixing.\n");
1500                         return 0;
1501                 }
1502
1503                 if (!sbi->s_jquota_fmt) {
1504                         printk(KERN_ERR "EXT4-fs: journaled quota format "
1505                                         "not specified.\n");
1506                         return 0;
1507                 }
1508         } else {
1509                 if (sbi->s_jquota_fmt) {
1510                         printk(KERN_ERR "EXT4-fs: journaled quota format "
1511                                         "specified with no journaling "
1512                                         "enabled.\n");
1513                         return 0;
1514                 }
1515         }
1516 #endif
1517         return 1;
1518 }
1519
1520 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1521                             int read_only)
1522 {
1523         struct ext4_sb_info *sbi = EXT4_SB(sb);
1524         int res = 0;
1525
1526         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1527                 printk(KERN_ERR "EXT4-fs warning: revision level too high, "
1528                        "forcing read-only mode\n");
1529                 res = MS_RDONLY;
1530         }
1531         if (read_only)
1532                 return res;
1533         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1534                 printk(KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1535                        "running e2fsck is recommended\n");
1536         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1537                 printk(KERN_WARNING
1538                        "EXT4-fs warning: mounting fs with errors, "
1539                        "running e2fsck is recommended\n");
1540         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1541                  le16_to_cpu(es->s_mnt_count) >=
1542                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1543                 printk(KERN_WARNING
1544                        "EXT4-fs warning: maximal mount count reached, "
1545                        "running e2fsck is recommended\n");
1546         else if (le32_to_cpu(es->s_checkinterval) &&
1547                 (le32_to_cpu(es->s_lastcheck) +
1548                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1549                 printk(KERN_WARNING
1550                        "EXT4-fs warning: checktime reached, "
1551                        "running e2fsck is recommended\n");
1552         if (!sbi->s_journal)
1553                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1554         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1555                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1556         le16_add_cpu(&es->s_mnt_count, 1);
1557         es->s_mtime = cpu_to_le32(get_seconds());
1558         ext4_update_dynamic_rev(sb);
1559         if (sbi->s_journal)
1560                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1561
1562         ext4_commit_super(sb, es, 1);
1563         if (test_opt(sb, DEBUG))
1564                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1565                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1566                         sb->s_blocksize,
1567                         sbi->s_groups_count,
1568                         EXT4_BLOCKS_PER_GROUP(sb),
1569                         EXT4_INODES_PER_GROUP(sb),
1570                         sbi->s_mount_opt);
1571
1572         if (EXT4_SB(sb)->s_journal) {
1573                 printk(KERN_INFO "EXT4 FS on %s, %s journal on %s\n",
1574                        sb->s_id, EXT4_SB(sb)->s_journal->j_inode ? "internal" :
1575                        "external", EXT4_SB(sb)->s_journal->j_devname);
1576         } else {
1577                 printk(KERN_INFO "EXT4 FS on %s, no journal\n", sb->s_id);
1578         }
1579         return res;
1580 }
1581
1582 static int ext4_fill_flex_info(struct super_block *sb)
1583 {
1584         struct ext4_sb_info *sbi = EXT4_SB(sb);
1585         struct ext4_group_desc *gdp = NULL;
1586         struct buffer_head *bh;
1587         ext4_group_t flex_group_count;
1588         ext4_group_t flex_group;
1589         int groups_per_flex = 0;
1590         int i;
1591
1592         if (!sbi->s_es->s_log_groups_per_flex) {
1593                 sbi->s_log_groups_per_flex = 0;
1594                 return 1;
1595         }
1596
1597         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1598         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1599
1600         /* We allocate both existing and potentially added groups */
1601         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1602                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1603                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1604         sbi->s_flex_groups = kzalloc(flex_group_count *
1605                                      sizeof(struct flex_groups), GFP_KERNEL);
1606         if (sbi->s_flex_groups == NULL) {
1607                 printk(KERN_ERR "EXT4-fs: not enough memory for "
1608                                 "%u flex groups\n", flex_group_count);
1609                 goto failed;
1610         }
1611
1612         for (i = 0; i < sbi->s_groups_count; i++) {
1613                 gdp = ext4_get_group_desc(sb, i, &bh);
1614
1615                 flex_group = ext4_flex_group(sbi, i);
1616                 sbi->s_flex_groups[flex_group].free_inodes +=
1617                         ext4_free_inodes_count(sb, gdp);
1618                 sbi->s_flex_groups[flex_group].free_blocks +=
1619                         ext4_free_blks_count(sb, gdp);
1620         }
1621
1622         return 1;
1623 failed:
1624         return 0;
1625 }
1626
1627 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1628                             struct ext4_group_desc *gdp)
1629 {
1630         __u16 crc = 0;
1631
1632         if (sbi->s_es->s_feature_ro_compat &
1633             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1634                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1635                 __le32 le_group = cpu_to_le32(block_group);
1636
1637                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1638                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1639                 crc = crc16(crc, (__u8 *)gdp, offset);
1640                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1641                 /* for checksum of struct ext4_group_desc do the rest...*/
1642                 if ((sbi->s_es->s_feature_incompat &
1643                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1644                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1645                         crc = crc16(crc, (__u8 *)gdp + offset,
1646                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1647                                         offset);
1648         }
1649
1650         return cpu_to_le16(crc);
1651 }
1652
1653 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1654                                 struct ext4_group_desc *gdp)
1655 {
1656         if ((sbi->s_es->s_feature_ro_compat &
1657              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1658             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1659                 return 0;
1660
1661         return 1;
1662 }
1663
1664 /* Called at mount-time, super-block is locked */
1665 static int ext4_check_descriptors(struct super_block *sb)
1666 {
1667         struct ext4_sb_info *sbi = EXT4_SB(sb);
1668         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1669         ext4_fsblk_t last_block;
1670         ext4_fsblk_t block_bitmap;
1671         ext4_fsblk_t inode_bitmap;
1672         ext4_fsblk_t inode_table;
1673         int flexbg_flag = 0;
1674         ext4_group_t i;
1675
1676         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1677                 flexbg_flag = 1;
1678
1679         ext4_debug("Checking group descriptors");
1680
1681         for (i = 0; i < sbi->s_groups_count; i++) {
1682                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1683
1684                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1685                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1686                 else
1687                         last_block = first_block +
1688                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1689
1690                 block_bitmap = ext4_block_bitmap(sb, gdp);
1691                 if (block_bitmap < first_block || block_bitmap > last_block) {
1692                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1693                                "Block bitmap for group %u not in group "
1694                                "(block %llu)!\n", i, block_bitmap);
1695                         return 0;
1696                 }
1697                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1698                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
1699                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1700                                "Inode bitmap for group %u not in group "
1701                                "(block %llu)!\n", i, inode_bitmap);
1702                         return 0;
1703                 }
1704                 inode_table = ext4_inode_table(sb, gdp);
1705                 if (inode_table < first_block ||
1706                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
1707                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1708                                "Inode table for group %u not in group "
1709                                "(block %llu)!\n", i, inode_table);
1710                         return 0;
1711                 }
1712                 spin_lock(sb_bgl_lock(sbi, i));
1713                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1714                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1715                                "Checksum for group %u failed (%u!=%u)\n",
1716                                i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1717                                gdp)), le16_to_cpu(gdp->bg_checksum));
1718                         if (!(sb->s_flags & MS_RDONLY)) {
1719                                 spin_unlock(sb_bgl_lock(sbi, i));
1720                                 return 0;
1721                         }
1722                 }
1723                 spin_unlock(sb_bgl_lock(sbi, i));
1724                 if (!flexbg_flag)
1725                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1726         }
1727
1728         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1729         sbi->s_es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
1730         return 1;
1731 }
1732
1733 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1734  * the superblock) which were deleted from all directories, but held open by
1735  * a process at the time of a crash.  We walk the list and try to delete these
1736  * inodes at recovery time (only with a read-write filesystem).
1737  *
1738  * In order to keep the orphan inode chain consistent during traversal (in
1739  * case of crash during recovery), we link each inode into the superblock
1740  * orphan list_head and handle it the same way as an inode deletion during
1741  * normal operation (which journals the operations for us).
1742  *
1743  * We only do an iget() and an iput() on each inode, which is very safe if we
1744  * accidentally point at an in-use or already deleted inode.  The worst that
1745  * can happen in this case is that we get a "bit already cleared" message from
1746  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1747  * e2fsck was run on this filesystem, and it must have already done the orphan
1748  * inode cleanup for us, so we can safely abort without any further action.
1749  */
1750 static void ext4_orphan_cleanup(struct super_block *sb,
1751                                 struct ext4_super_block *es)
1752 {
1753         unsigned int s_flags = sb->s_flags;
1754         int nr_orphans = 0, nr_truncates = 0;
1755 #ifdef CONFIG_QUOTA
1756         int i;
1757 #endif
1758         if (!es->s_last_orphan) {
1759                 jbd_debug(4, "no orphan inodes to clean up\n");
1760                 return;
1761         }
1762
1763         if (bdev_read_only(sb->s_bdev)) {
1764                 printk(KERN_ERR "EXT4-fs: write access "
1765                         "unavailable, skipping orphan cleanup.\n");
1766                 return;
1767         }
1768
1769         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1770                 if (es->s_last_orphan)
1771                         jbd_debug(1, "Errors on filesystem, "
1772                                   "clearing orphan list.\n");
1773                 es->s_last_orphan = 0;
1774                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1775                 return;
1776         }
1777
1778         if (s_flags & MS_RDONLY) {
1779                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1780                        sb->s_id);
1781                 sb->s_flags &= ~MS_RDONLY;
1782         }
1783 #ifdef CONFIG_QUOTA
1784         /* Needed for iput() to work correctly and not trash data */
1785         sb->s_flags |= MS_ACTIVE;
1786         /* Turn on quotas so that they are updated correctly */
1787         for (i = 0; i < MAXQUOTAS; i++) {
1788                 if (EXT4_SB(sb)->s_qf_names[i]) {
1789                         int ret = ext4_quota_on_mount(sb, i);
1790                         if (ret < 0)
1791                                 printk(KERN_ERR
1792                                         "EXT4-fs: Cannot turn on journaled "
1793                                         "quota: error %d\n", ret);
1794                 }
1795         }
1796 #endif
1797
1798         while (es->s_last_orphan) {
1799                 struct inode *inode;
1800
1801                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
1802                 if (IS_ERR(inode)) {
1803                         es->s_last_orphan = 0;
1804                         break;
1805                 }
1806
1807                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1808                 vfs_dq_init(inode);
1809                 if (inode->i_nlink) {
1810                         printk(KERN_DEBUG
1811                                 "%s: truncating inode %lu to %lld bytes\n",
1812                                 __func__, inode->i_ino, inode->i_size);
1813                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
1814                                   inode->i_ino, inode->i_size);
1815                         ext4_truncate(inode);
1816                         nr_truncates++;
1817                 } else {
1818                         printk(KERN_DEBUG
1819                                 "%s: deleting unreferenced inode %lu\n",
1820                                 __func__, inode->i_ino);
1821                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1822                                   inode->i_ino);
1823                         nr_orphans++;
1824                 }
1825                 iput(inode);  /* The delete magic happens here! */
1826         }
1827
1828 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
1829
1830         if (nr_orphans)
1831                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1832                        sb->s_id, PLURAL(nr_orphans));
1833         if (nr_truncates)
1834                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1835                        sb->s_id, PLURAL(nr_truncates));
1836 #ifdef CONFIG_QUOTA
1837         /* Turn quotas off */
1838         for (i = 0; i < MAXQUOTAS; i++) {
1839                 if (sb_dqopt(sb)->files[i])
1840                         vfs_quota_off(sb, i, 0);
1841         }
1842 #endif
1843         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1844 }
1845 /*
1846  * Maximal extent format file size.
1847  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1848  * extent format containers, within a sector_t, and within i_blocks
1849  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1850  * so that won't be a limiting factor.
1851  *
1852  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1853  */
1854 static loff_t ext4_max_size(int blkbits, int has_huge_files)
1855 {
1856         loff_t res;
1857         loff_t upper_limit = MAX_LFS_FILESIZE;
1858
1859         /* small i_blocks in vfs inode? */
1860         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1861                 /*
1862                  * CONFIG_LBD is not enabled implies the inode
1863                  * i_block represent total blocks in 512 bytes
1864                  * 32 == size of vfs inode i_blocks * 8
1865                  */
1866                 upper_limit = (1LL << 32) - 1;
1867
1868                 /* total blocks in file system block size */
1869                 upper_limit >>= (blkbits - 9);
1870                 upper_limit <<= blkbits;
1871         }
1872
1873         /* 32-bit extent-start container, ee_block */
1874         res = 1LL << 32;
1875         res <<= blkbits;
1876         res -= 1;
1877
1878         /* Sanity check against vm- & vfs- imposed limits */
1879         if (res > upper_limit)
1880                 res = upper_limit;
1881
1882         return res;
1883 }
1884
1885 /*
1886  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
1887  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
1888  * We need to be 1 filesystem block less than the 2^48 sector limit.
1889  */
1890 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
1891 {
1892         loff_t res = EXT4_NDIR_BLOCKS;
1893         int meta_blocks;
1894         loff_t upper_limit;
1895         /* This is calculated to be the largest file size for a
1896          * dense, bitmapped file such that the total number of
1897          * sectors in the file, including data and all indirect blocks,
1898          * does not exceed 2^48 -1
1899          * __u32 i_blocks_lo and _u16 i_blocks_high representing the
1900          * total number of  512 bytes blocks of the file
1901          */
1902
1903         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1904                 /*
1905                  * !has_huge_files or CONFIG_LBD is not enabled
1906                  * implies the inode i_block represent total blocks in
1907                  * 512 bytes 32 == size of vfs inode i_blocks * 8
1908                  */
1909                 upper_limit = (1LL << 32) - 1;
1910
1911                 /* total blocks in file system block size */
1912                 upper_limit >>= (bits - 9);
1913
1914         } else {
1915                 /*
1916                  * We use 48 bit ext4_inode i_blocks
1917                  * With EXT4_HUGE_FILE_FL set the i_blocks
1918                  * represent total number of blocks in
1919                  * file system block size
1920                  */
1921                 upper_limit = (1LL << 48) - 1;
1922
1923         }
1924
1925         /* indirect blocks */
1926         meta_blocks = 1;
1927         /* double indirect blocks */
1928         meta_blocks += 1 + (1LL << (bits-2));
1929         /* tripple indirect blocks */
1930         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
1931
1932         upper_limit -= meta_blocks;
1933         upper_limit <<= bits;
1934
1935         res += 1LL << (bits-2);
1936         res += 1LL << (2*(bits-2));
1937         res += 1LL << (3*(bits-2));
1938         res <<= bits;
1939         if (res > upper_limit)
1940                 res = upper_limit;
1941
1942         if (res > MAX_LFS_FILESIZE)
1943                 res = MAX_LFS_FILESIZE;
1944
1945         return res;
1946 }
1947
1948 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1949                                 ext4_fsblk_t logical_sb_block, int nr)
1950 {
1951         struct ext4_sb_info *sbi = EXT4_SB(sb);
1952         ext4_group_t bg, first_meta_bg;
1953         int has_super = 0;
1954
1955         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1956
1957         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1958             nr < first_meta_bg)
1959                 return logical_sb_block + nr + 1;
1960         bg = sbi->s_desc_per_block * nr;
1961         if (ext4_bg_has_super(sb, bg))
1962                 has_super = 1;
1963         return (has_super + ext4_group_first_block_no(sb, bg));
1964 }
1965
1966 /**
1967  * ext4_get_stripe_size: Get the stripe size.
1968  * @sbi: In memory super block info
1969  *
1970  * If we have specified it via mount option, then
1971  * use the mount option value. If the value specified at mount time is
1972  * greater than the blocks per group use the super block value.
1973  * If the super block value is greater than blocks per group return 0.
1974  * Allocator needs it be less than blocks per group.
1975  *
1976  */
1977 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
1978 {
1979         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
1980         unsigned long stripe_width =
1981                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
1982
1983         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
1984                 return sbi->s_stripe;
1985
1986         if (stripe_width <= sbi->s_blocks_per_group)
1987                 return stripe_width;
1988
1989         if (stride <= sbi->s_blocks_per_group)
1990                 return stride;
1991
1992         return 0;
1993 }
1994
1995 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
1996                                 __releases(kernel_lock)
1997                                 __acquires(kernel_lock)
1998
1999 {
2000         struct buffer_head *bh;
2001         struct ext4_super_block *es = NULL;
2002         struct ext4_sb_info *sbi;
2003         ext4_fsblk_t block;
2004         ext4_fsblk_t sb_block = get_sb_block(&data);
2005         ext4_fsblk_t logical_sb_block;
2006         unsigned long offset = 0;
2007         unsigned long journal_devnum = 0;
2008         unsigned long def_mount_opts;
2009         struct inode *root;
2010         char *cp;
2011         const char *descr;
2012         int ret = -EINVAL;
2013         int blocksize;
2014         unsigned int db_count;
2015         unsigned int i;
2016         int needs_recovery, has_huge_files;
2017         int features;
2018         __u64 blocks_count;
2019         int err;
2020         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
2021
2022         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
2023         if (!sbi)
2024                 return -ENOMEM;
2025
2026         sbi->s_blockgroup_lock =
2027                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
2028         if (!sbi->s_blockgroup_lock) {
2029                 kfree(sbi);
2030                 return -ENOMEM;
2031         }
2032         sb->s_fs_info = sbi;
2033         sbi->s_mount_opt = 0;
2034         sbi->s_resuid = EXT4_DEF_RESUID;
2035         sbi->s_resgid = EXT4_DEF_RESGID;
2036         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
2037         sbi->s_sb_block = sb_block;
2038
2039         unlock_kernel();
2040
2041         /* Cleanup superblock name */
2042         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
2043                 *cp = '!';
2044
2045         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
2046         if (!blocksize) {
2047                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
2048                 goto out_fail;
2049         }
2050
2051         /*
2052          * The ext4 superblock will not be buffer aligned for other than 1kB
2053          * block sizes.  We need to calculate the offset from buffer start.
2054          */
2055         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
2056                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2057                 offset = do_div(logical_sb_block, blocksize);
2058         } else {
2059                 logical_sb_block = sb_block;
2060         }
2061
2062         if (!(bh = sb_bread(sb, logical_sb_block))) {
2063                 printk(KERN_ERR "EXT4-fs: unable to read superblock\n");
2064                 goto out_fail;
2065         }
2066         /*
2067          * Note: s_es must be initialized as soon as possible because
2068          *       some ext4 macro-instructions depend on its value
2069          */
2070         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2071         sbi->s_es = es;
2072         sb->s_magic = le16_to_cpu(es->s_magic);
2073         if (sb->s_magic != EXT4_SUPER_MAGIC)
2074                 goto cantfind_ext4;
2075
2076         /* Set defaults before we parse the mount options */
2077         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
2078         if (def_mount_opts & EXT4_DEFM_DEBUG)
2079                 set_opt(sbi->s_mount_opt, DEBUG);
2080         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
2081                 set_opt(sbi->s_mount_opt, GRPID);
2082         if (def_mount_opts & EXT4_DEFM_UID16)
2083                 set_opt(sbi->s_mount_opt, NO_UID32);
2084 #ifdef CONFIG_EXT4_FS_XATTR
2085         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
2086                 set_opt(sbi->s_mount_opt, XATTR_USER);
2087 #endif
2088 #ifdef CONFIG_EXT4_FS_POSIX_ACL
2089         if (def_mount_opts & EXT4_DEFM_ACL)
2090                 set_opt(sbi->s_mount_opt, POSIX_ACL);
2091 #endif
2092         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
2093                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
2094         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
2095                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
2096         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
2097                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
2098
2099         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
2100                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
2101         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
2102                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
2103         else
2104                 set_opt(sbi->s_mount_opt, ERRORS_RO);
2105
2106         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
2107         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
2108         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
2109         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
2110         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
2111
2112         set_opt(sbi->s_mount_opt, RESERVATION);
2113         set_opt(sbi->s_mount_opt, BARRIER);
2114
2115         /*
2116          * enable delayed allocation by default
2117          * Use -o nodelalloc to turn it off
2118          */
2119         set_opt(sbi->s_mount_opt, DELALLOC);
2120
2121
2122         if (!parse_options((char *) data, sb, &journal_devnum,
2123                            &journal_ioprio, NULL, 0))
2124                 goto failed_mount;
2125
2126         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2127                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2128
2129         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
2130             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
2131              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
2132              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
2133                 printk(KERN_WARNING
2134                        "EXT4-fs warning: feature flags set on rev 0 fs, "
2135                        "running e2fsck is recommended\n");
2136
2137         /*
2138          * Check feature flags regardless of the revision level, since we
2139          * previously didn't change the revision level when setting the flags,
2140          * so there is a chance incompat flags are set on a rev 0 filesystem.
2141          */
2142         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
2143         if (features) {
2144                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
2145                        "unsupported optional features (%x).\n", sb->s_id,
2146                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2147                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2148                 goto failed_mount;
2149         }
2150         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
2151         if (!(sb->s_flags & MS_RDONLY) && features) {
2152                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
2153                        "unsupported optional features (%x).\n", sb->s_id,
2154                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2155                         ~EXT4_FEATURE_RO_COMPAT_SUPP));
2156                 goto failed_mount;
2157         }
2158         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2159                                     EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
2160         if (has_huge_files) {
2161                 /*
2162                  * Large file size enabled file system can only be
2163                  * mount if kernel is build with CONFIG_LBD
2164                  */
2165                 if (sizeof(root->i_blocks) < sizeof(u64) &&
2166                                 !(sb->s_flags & MS_RDONLY)) {
2167                         printk(KERN_ERR "EXT4-fs: %s: Filesystem with huge "
2168                                         "files cannot be mounted read-write "
2169                                         "without CONFIG_LBD.\n", sb->s_id);
2170                         goto failed_mount;
2171                 }
2172         }
2173         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
2174
2175         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
2176             blocksize > EXT4_MAX_BLOCK_SIZE) {
2177                 printk(KERN_ERR
2178                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
2179                        blocksize, sb->s_id);
2180                 goto failed_mount;
2181         }
2182
2183         if (sb->s_blocksize != blocksize) {
2184
2185                 /* Validate the filesystem blocksize */
2186                 if (!sb_set_blocksize(sb, blocksize)) {
2187                         printk(KERN_ERR "EXT4-fs: bad block size %d.\n",
2188                                         blocksize);
2189                         goto failed_mount;
2190                 }
2191
2192                 brelse(bh);
2193                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2194                 offset = do_div(logical_sb_block, blocksize);
2195                 bh = sb_bread(sb, logical_sb_block);
2196                 if (!bh) {
2197                         printk(KERN_ERR
2198                                "EXT4-fs: Can't read superblock on 2nd try.\n");
2199                         goto failed_mount;
2200                 }
2201                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
2202                 sbi->s_es = es;
2203                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
2204                         printk(KERN_ERR
2205                                "EXT4-fs: Magic mismatch, very weird !\n");
2206                         goto failed_mount;
2207                 }
2208         }
2209
2210         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
2211                                                       has_huge_files);
2212         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
2213
2214         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2215                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2216                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2217         } else {
2218                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2219                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2220                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2221                     (!is_power_of_2(sbi->s_inode_size)) ||
2222                     (sbi->s_inode_size > blocksize)) {
2223                         printk(KERN_ERR
2224                                "EXT4-fs: unsupported inode size: %d\n",
2225                                sbi->s_inode_size);
2226                         goto failed_mount;
2227                 }
2228                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2229                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2230         }
2231         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2232         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2233                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2234                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2235                     !is_power_of_2(sbi->s_desc_size)) {
2236                         printk(KERN_ERR
2237                                "EXT4-fs: unsupported descriptor size %lu\n",
2238                                sbi->s_desc_size);
2239                         goto failed_mount;
2240                 }
2241         } else
2242                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2243         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2244         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2245         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2246                 goto cantfind_ext4;
2247         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2248         if (sbi->s_inodes_per_block == 0)
2249                 goto cantfind_ext4;
2250         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2251                                         sbi->s_inodes_per_block;
2252         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2253         sbi->s_sbh = bh;
2254         sbi->s_mount_state = le16_to_cpu(es->s_state);
2255         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2256         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2257         for (i = 0; i < 4; i++)
2258                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2259         sbi->s_def_hash_version = es->s_def_hash_version;
2260         i = le32_to_cpu(es->s_flags);
2261         if (i & EXT2_FLAGS_UNSIGNED_HASH)
2262                 sbi->s_hash_unsigned = 3;
2263         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
2264 #ifdef __CHAR_UNSIGNED__
2265                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
2266                 sbi->s_hash_unsigned = 3;
2267 #else
2268                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
2269 #endif
2270                 sb->s_dirt = 1;
2271         }
2272
2273         if (sbi->s_blocks_per_group > blocksize * 8) {
2274                 printk(KERN_ERR
2275                        "EXT4-fs: #blocks per group too big: %lu\n",
2276                        sbi->s_blocks_per_group);
2277                 goto failed_mount;
2278         }
2279         if (sbi->s_inodes_per_group > blocksize * 8) {
2280                 printk(KERN_ERR
2281                        "EXT4-fs: #inodes per group too big: %lu\n",
2282                        sbi->s_inodes_per_group);
2283                 goto failed_mount;
2284         }
2285
2286         if (ext4_blocks_count(es) >
2287                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
2288                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
2289                         " too large to mount safely\n", sb->s_id);
2290                 if (sizeof(sector_t) < 8)
2291                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
2292                                         "enabled\n");
2293                 goto failed_mount;
2294         }
2295
2296         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2297                 goto cantfind_ext4;
2298
2299         /*
2300          * It makes no sense for the first data block to be beyond the end
2301          * of the filesystem.
2302          */
2303         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
2304                 printk(KERN_WARNING "EXT4-fs: bad geometry: first data"
2305                        "block %u is beyond end of filesystem (%llu)\n",
2306                        le32_to_cpu(es->s_first_data_block),
2307                        ext4_blocks_count(es));
2308                 goto failed_mount;
2309         }
2310         blocks_count = (ext4_blocks_count(es) -
2311                         le32_to_cpu(es->s_first_data_block) +
2312                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2313         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2314         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
2315                 printk(KERN_WARNING "EXT4-fs: groups count too large: %u "
2316                        "(block count %llu, first data block %u, "
2317                        "blocks per group %lu)\n", sbi->s_groups_count,
2318                        ext4_blocks_count(es),
2319                        le32_to_cpu(es->s_first_data_block),
2320                        EXT4_BLOCKS_PER_GROUP(sb));
2321                 goto failed_mount;
2322         }
2323         sbi->s_groups_count = blocks_count;
2324         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2325                    EXT4_DESC_PER_BLOCK(sb);
2326         sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
2327                                     GFP_KERNEL);
2328         if (sbi->s_group_desc == NULL) {
2329                 printk(KERN_ERR "EXT4-fs: not enough memory\n");
2330                 goto failed_mount;
2331         }
2332
2333 #ifdef CONFIG_PROC_FS
2334         if (ext4_proc_root)
2335                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
2336
2337         if (sbi->s_proc)
2338                 proc_create_data("inode_readahead_blks", 0644, sbi->s_proc,
2339                                  &ext4_ui_proc_fops,
2340                                  &sbi->s_inode_readahead_blks);
2341 #endif
2342
2343         bgl_lock_init(sbi->s_blockgroup_lock);
2344
2345         for (i = 0; i < db_count; i++) {
2346                 block = descriptor_loc(sb, logical_sb_block, i);
2347                 sbi->s_group_desc[i] = sb_bread(sb, block);
2348                 if (!sbi->s_group_desc[i]) {
2349                         printk(KERN_ERR "EXT4-fs: "
2350                                "can't read group descriptor %d\n", i);
2351                         db_count = i;
2352                         goto failed_mount2;
2353                 }
2354         }
2355         if (!ext4_check_descriptors(sb)) {
2356                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
2357                 goto failed_mount2;
2358         }
2359         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2360                 if (!ext4_fill_flex_info(sb)) {
2361                         printk(KERN_ERR
2362                                "EXT4-fs: unable to initialize "
2363                                "flex_bg meta info!\n");
2364                         goto failed_mount2;
2365                 }
2366
2367         sbi->s_gdb_count = db_count;
2368         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2369         spin_lock_init(&sbi->s_next_gen_lock);
2370
2371         err = percpu_counter_init(&sbi->s_freeblocks_counter,
2372                         ext4_count_free_blocks(sb));
2373         if (!err) {
2374                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
2375                                 ext4_count_free_inodes(sb));
2376         }
2377         if (!err) {
2378                 err = percpu_counter_init(&sbi->s_dirs_counter,
2379                                 ext4_count_dirs(sb));
2380         }
2381         if (!err) {
2382                 err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
2383         }
2384         if (err) {
2385                 printk(KERN_ERR "EXT4-fs: insufficient memory\n");
2386                 goto failed_mount3;
2387         }
2388
2389         sbi->s_stripe = ext4_get_stripe_size(sbi);
2390
2391         /*
2392          * set up enough so that it can read an inode
2393          */
2394         sb->s_op = &ext4_sops;
2395         sb->s_export_op = &ext4_export_ops;
2396         sb->s_xattr = ext4_xattr_handlers;
2397 #ifdef CONFIG_QUOTA
2398         sb->s_qcop = &ext4_qctl_operations;
2399         sb->dq_op = &ext4_quota_operations;
2400 #endif
2401         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2402
2403         sb->s_root = NULL;
2404
2405         needs_recovery = (es->s_last_orphan != 0 ||
2406                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2407                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2408
2409         /*
2410          * The first inode we look at is the journal inode.  Don't try
2411          * root first: it may be modified in the journal!
2412          */
2413         if (!test_opt(sb, NOLOAD) &&
2414             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2415                 if (ext4_load_journal(sb, es, journal_devnum))
2416                         goto failed_mount3;
2417                 if (!(sb->s_flags & MS_RDONLY) &&
2418                     EXT4_SB(sb)->s_journal->j_failed_commit) {
2419                         printk(KERN_CRIT "EXT4-fs error (device %s): "
2420                                "ext4_fill_super: Journal transaction "
2421                                "%u is corrupt\n", sb->s_id,
2422                                EXT4_SB(sb)->s_journal->j_failed_commit);
2423                         if (test_opt(sb, ERRORS_RO)) {
2424                                 printk(KERN_CRIT
2425                                        "Mounting filesystem read-only\n");
2426                                 sb->s_flags |= MS_RDONLY;
2427                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2428                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2429                         }
2430                         if (test_opt(sb, ERRORS_PANIC)) {
2431                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2432                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2433                                 ext4_commit_super(sb, es, 1);
2434                                 goto failed_mount4;
2435                         }
2436                 }
2437         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
2438               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2439                 printk(KERN_ERR "EXT4-fs: required journal recovery "
2440                        "suppressed and not mounted read-only\n");
2441                 goto failed_mount4;
2442         } else {
2443                 clear_opt(sbi->s_mount_opt, DATA_FLAGS);
2444                 set_opt(sbi->s_mount_opt, WRITEBACK_DATA);
2445                 sbi->s_journal = NULL;
2446                 needs_recovery = 0;
2447                 goto no_journal;
2448         }
2449
2450         if (ext4_blocks_count(es) > 0xffffffffULL &&
2451             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2452                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2453                 printk(KERN_ERR "EXT4-fs: Failed to set 64-bit journal feature\n");
2454                 goto failed_mount4;
2455         }
2456
2457         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2458                 jbd2_journal_set_features(sbi->s_journal,
2459                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2460                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2461         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2462                 jbd2_journal_set_features(sbi->s_journal,
2463                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2464                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2465                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2466         } else {
2467                 jbd2_journal_clear_features(sbi->s_journal,
2468                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2469                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2470         }
2471
2472         /* We have now updated the journal if required, so we can
2473          * validate the data journaling mode. */
2474         switch (test_opt(sb, DATA_FLAGS)) {
2475         case 0:
2476                 /* No mode set, assume a default based on the journal
2477                  * capabilities: ORDERED_DATA if the journal can
2478                  * cope, else JOURNAL_DATA
2479                  */
2480                 if (jbd2_journal_check_available_features
2481                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2482                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
2483                 else
2484                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2485                 break;
2486
2487         case EXT4_MOUNT_ORDERED_DATA:
2488         case EXT4_MOUNT_WRITEBACK_DATA:
2489                 if (!jbd2_journal_check_available_features
2490                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2491                         printk(KERN_ERR "EXT4-fs: Journal does not support "
2492                                "requested data journaling mode\n");
2493                         goto failed_mount4;
2494                 }
2495         default:
2496                 break;
2497         }
2498         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
2499
2500 no_journal:
2501
2502         if (test_opt(sb, NOBH)) {
2503                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2504                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
2505                                 "its supported only with writeback mode\n");
2506                         clear_opt(sbi->s_mount_opt, NOBH);
2507                 }
2508         }
2509         /*
2510          * The jbd2_journal_load will have done any necessary log recovery,
2511          * so we can safely mount the rest of the filesystem now.
2512          */
2513
2514         root = ext4_iget(sb, EXT4_ROOT_INO);
2515         if (IS_ERR(root)) {
2516                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
2517                 ret = PTR_ERR(root);
2518                 goto failed_mount4;
2519         }
2520         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2521                 iput(root);
2522                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
2523                 goto failed_mount4;
2524         }
2525         sb->s_root = d_alloc_root(root);
2526         if (!sb->s_root) {
2527                 printk(KERN_ERR "EXT4-fs: get root dentry failed\n");
2528                 iput(root);
2529                 ret = -ENOMEM;
2530                 goto failed_mount4;
2531         }
2532
2533         ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
2534
2535         /* determine the minimum size of new large inodes, if present */
2536         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2537                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2538                                                      EXT4_GOOD_OLD_INODE_SIZE;
2539                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2540                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2541                         if (sbi->s_want_extra_isize <
2542                             le16_to_cpu(es->s_want_extra_isize))
2543                                 sbi->s_want_extra_isize =
2544                                         le16_to_cpu(es->s_want_extra_isize);
2545                         if (sbi->s_want_extra_isize <
2546                             le16_to_cpu(es->s_min_extra_isize))
2547                                 sbi->s_want_extra_isize =
2548                                         le16_to_cpu(es->s_min_extra_isize);
2549                 }
2550         }
2551         /* Check if enough inode space is available */
2552         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2553                                                         sbi->s_inode_size) {
2554                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2555                                                        EXT4_GOOD_OLD_INODE_SIZE;
2556                 printk(KERN_INFO "EXT4-fs: required extra inode space not"
2557                         "available.\n");
2558         }
2559
2560         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
2561                 printk(KERN_WARNING "EXT4-fs: Ignoring delalloc option - "
2562                                 "requested data journaling mode\n");
2563                 clear_opt(sbi->s_mount_opt, DELALLOC);
2564         } else if (test_opt(sb, DELALLOC))
2565                 printk(KERN_INFO "EXT4-fs: delayed allocation enabled\n");
2566
2567         ext4_ext_init(sb);
2568         err = ext4_mb_init(sb, needs_recovery);
2569         if (err) {
2570                 printk(KERN_ERR "EXT4-fs: failed to initalize mballoc (%d)\n",
2571                        err);
2572                 goto failed_mount4;
2573         }
2574
2575         /*
2576          * akpm: core read_super() calls in here with the superblock locked.
2577          * That deadlocks, because orphan cleanup needs to lock the superblock
2578          * in numerous places.  Here we just pop the lock - it's relatively
2579          * harmless, because we are now ready to accept write_super() requests,
2580          * and aviro says that's the only reason for hanging onto the
2581          * superblock lock.
2582          */
2583         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2584         ext4_orphan_cleanup(sb, es);
2585         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2586         if (needs_recovery) {
2587                 printk(KERN_INFO "EXT4-fs: recovery complete.\n");
2588                 ext4_mark_recovery_complete(sb, es);
2589         }
2590         if (EXT4_SB(sb)->s_journal) {
2591                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2592                         descr = " journalled data mode";
2593                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2594                         descr = " ordered data mode";
2595                 else
2596                         descr = " writeback data mode";
2597         } else
2598                 descr = "out journal";
2599
2600         printk(KERN_INFO "EXT4-fs: mounted filesystem %s with%s\n",
2601                sb->s_id, descr);
2602
2603         lock_kernel();
2604         return 0;
2605
2606 cantfind_ext4:
2607         if (!silent)
2608                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
2609                        sb->s_id);
2610         goto failed_mount;
2611
2612 failed_mount4:
2613         printk(KERN_ERR "EXT4-fs (device %s): mount failed\n", sb->s_id);
2614         if (sbi->s_journal) {
2615                 jbd2_journal_destroy(sbi->s_journal);
2616                 sbi->s_journal = NULL;
2617         }
2618 failed_mount3:
2619         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2620         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2621         percpu_counter_destroy(&sbi->s_dirs_counter);
2622         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
2623 failed_mount2:
2624         for (i = 0; i < db_count; i++)
2625                 brelse(sbi->s_group_desc[i]);
2626         kfree(sbi->s_group_desc);
2627 failed_mount:
2628         if (sbi->s_proc) {
2629                 remove_proc_entry("inode_readahead_blks", sbi->s_proc);
2630                 remove_proc_entry(sb->s_id, ext4_proc_root);
2631         }
2632 #ifdef CONFIG_QUOTA
2633         for (i = 0; i < MAXQUOTAS; i++)
2634                 kfree(sbi->s_qf_names[i]);
2635 #endif
2636         ext4_blkdev_remove(sbi);
2637         brelse(bh);
2638 out_fail:
2639         sb->s_fs_info = NULL;
2640         kfree(sbi);
2641         lock_kernel();
2642         return ret;
2643 }
2644
2645 /*
2646  * Setup any per-fs journal parameters now.  We'll do this both on
2647  * initial mount, once the journal has been initialised but before we've
2648  * done any recovery; and again on any subsequent remount.
2649  */
2650 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2651 {
2652         struct ext4_sb_info *sbi = EXT4_SB(sb);
2653
2654         journal->j_commit_interval = sbi->s_commit_interval;
2655         journal->j_min_batch_time = sbi->s_min_batch_time;
2656         journal->j_max_batch_time = sbi->s_max_batch_time;
2657
2658         spin_lock(&journal->j_state_lock);
2659         if (test_opt(sb, BARRIER))
2660                 journal->j_flags |= JBD2_BARRIER;
2661         else
2662                 journal->j_flags &= ~JBD2_BARRIER;
2663         if (test_opt(sb, DATA_ERR_ABORT))
2664                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
2665         else
2666                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
2667         spin_unlock(&journal->j_state_lock);
2668 }
2669
2670 static journal_t *ext4_get_journal(struct super_block *sb,
2671                                    unsigned int journal_inum)
2672 {
2673         struct inode *journal_inode;
2674         journal_t *journal;
2675
2676         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
2677
2678         /* First, test for the existence of a valid inode on disk.  Bad
2679          * things happen if we iget() an unused inode, as the subsequent
2680          * iput() will try to delete it. */
2681
2682         journal_inode = ext4_iget(sb, journal_inum);
2683         if (IS_ERR(journal_inode)) {
2684                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
2685                 return NULL;
2686         }
2687         if (!journal_inode->i_nlink) {
2688                 make_bad_inode(journal_inode);
2689                 iput(journal_inode);
2690                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
2691                 return NULL;
2692         }
2693
2694         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
2695                   journal_inode, journal_inode->i_size);
2696         if (!S_ISREG(journal_inode->i_mode)) {
2697                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
2698                 iput(journal_inode);
2699                 return NULL;
2700         }
2701
2702         journal = jbd2_journal_init_inode(journal_inode);
2703         if (!journal) {
2704                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
2705                 iput(journal_inode);
2706                 return NULL;
2707         }
2708         journal->j_private = sb;
2709         ext4_init_journal_params(sb, journal);
2710         return journal;
2711 }
2712
2713 static journal_t *ext4_get_dev_journal(struct super_block *sb,
2714                                        dev_t j_dev)
2715 {
2716         struct buffer_head *bh;
2717         journal_t *journal;
2718         ext4_fsblk_t start;
2719         ext4_fsblk_t len;
2720         int hblock, blocksize;
2721         ext4_fsblk_t sb_block;
2722         unsigned long offset;
2723         struct ext4_super_block *es;
2724         struct block_device *bdev;
2725
2726         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
2727
2728         bdev = ext4_blkdev_get(j_dev);
2729         if (bdev == NULL)
2730                 return NULL;
2731
2732         if (bd_claim(bdev, sb)) {
2733                 printk(KERN_ERR
2734                         "EXT4-fs: failed to claim external journal device.\n");
2735                 blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
2736                 return NULL;
2737         }
2738
2739         blocksize = sb->s_blocksize;
2740         hblock = bdev_hardsect_size(bdev);
2741         if (blocksize < hblock) {
2742                 printk(KERN_ERR
2743                         "EXT4-fs: blocksize too small for journal device.\n");
2744                 goto out_bdev;
2745         }
2746
2747         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2748         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2749         set_blocksize(bdev, blocksize);
2750         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2751                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2752                        "external journal\n");
2753                 goto out_bdev;
2754         }
2755
2756         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2757         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2758             !(le32_to_cpu(es->s_feature_incompat) &
2759               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2760                 printk(KERN_ERR "EXT4-fs: external journal has "
2761                                         "bad superblock\n");
2762                 brelse(bh);
2763                 goto out_bdev;
2764         }
2765
2766         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2767                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2768                 brelse(bh);
2769                 goto out_bdev;
2770         }
2771
2772         len = ext4_blocks_count(es);
2773         start = sb_block + 1;
2774         brelse(bh);     /* we're done with the superblock */
2775
2776         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2777                                         start, len, blocksize);
2778         if (!journal) {
2779                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2780                 goto out_bdev;
2781         }
2782         journal->j_private = sb;
2783         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2784         wait_on_buffer(journal->j_sb_buffer);
2785         if (!buffer_uptodate(journal->j_sb_buffer)) {
2786                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2787                 goto out_journal;
2788         }
2789         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2790                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2791                                         "user (unsupported) - %d\n",
2792                         be32_to_cpu(journal->j_superblock->s_nr_users));
2793                 goto out_journal;
2794         }
2795         EXT4_SB(sb)->journal_bdev = bdev;
2796         ext4_init_journal_params(sb, journal);
2797         return journal;
2798 out_journal:
2799         jbd2_journal_destroy(journal);
2800 out_bdev:
2801         ext4_blkdev_put(bdev);
2802         return NULL;
2803 }
2804
2805 static int ext4_load_journal(struct super_block *sb,
2806                              struct ext4_super_block *es,
2807                              unsigned long journal_devnum)
2808 {
2809         journal_t *journal;
2810         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2811         dev_t journal_dev;
2812         int err = 0;
2813         int really_read_only;
2814
2815         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
2816
2817         if (journal_devnum &&
2818             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2819                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2820                         "numbers have changed\n");
2821                 journal_dev = new_decode_dev(journal_devnum);
2822         } else
2823                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2824
2825         really_read_only = bdev_read_only(sb->s_bdev);
2826
2827         /*
2828          * Are we loading a blank journal or performing recovery after a
2829          * crash?  For recovery, we need to check in advance whether we
2830          * can get read-write access to the device.
2831          */
2832
2833         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2834                 if (sb->s_flags & MS_RDONLY) {
2835                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2836                                         "required on readonly filesystem.\n");
2837                         if (really_read_only) {
2838                                 printk(KERN_ERR "EXT4-fs: write access "
2839                                         "unavailable, cannot proceed.\n");
2840                                 return -EROFS;
2841                         }
2842                         printk(KERN_INFO "EXT4-fs: write access will "
2843                                "be enabled during recovery.\n");
2844                 }
2845         }
2846
2847         if (journal_inum && journal_dev) {
2848                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2849                        "and inode journals!\n");
2850                 return -EINVAL;
2851         }
2852
2853         if (journal_inum) {
2854                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2855                         return -EINVAL;
2856         } else {
2857                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2858                         return -EINVAL;
2859         }
2860
2861         if (journal->j_flags & JBD2_BARRIER)
2862                 printk(KERN_INFO "EXT4-fs: barriers enabled\n");
2863         else
2864                 printk(KERN_INFO "EXT4-fs: barriers disabled\n");
2865
2866         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2867                 err = jbd2_journal_update_format(journal);
2868                 if (err)  {
2869                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2870                         jbd2_journal_destroy(journal);
2871                         return err;
2872                 }
2873         }
2874
2875         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2876                 err = jbd2_journal_wipe(journal, !really_read_only);
2877         if (!err)
2878                 err = jbd2_journal_load(journal);
2879
2880         if (err) {
2881                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2882                 jbd2_journal_destroy(journal);
2883                 return err;
2884         }
2885
2886         EXT4_SB(sb)->s_journal = journal;
2887         ext4_clear_journal_err(sb, es);
2888
2889         if (journal_devnum &&
2890             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2891                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2892                 sb->s_dirt = 1;
2893
2894                 /* Make sure we flush the recovery flag to disk. */
2895                 ext4_commit_super(sb, es, 1);
2896         }
2897
2898         return 0;
2899 }
2900
2901 static int ext4_commit_super(struct super_block *sb,
2902                               struct ext4_super_block *es, int sync)
2903 {
2904         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2905         int error = 0;
2906
2907         if (!sbh)
2908                 return error;
2909         if (buffer_write_io_error(sbh)) {
2910                 /*
2911                  * Oh, dear.  A previous attempt to write the
2912                  * superblock failed.  This could happen because the
2913                  * USB device was yanked out.  Or it could happen to
2914                  * be a transient write error and maybe the block will
2915                  * be remapped.  Nothing we can do but to retry the
2916                  * write and hope for the best.
2917                  */
2918                 printk(KERN_ERR "EXT4-fs: previous I/O error to "
2919                        "superblock detected for %s.\n", sb->s_id);
2920                 clear_buffer_write_io_error(sbh);
2921                 set_buffer_uptodate(sbh);
2922         }
2923         es->s_wtime = cpu_to_le32(get_seconds());
2924         ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
2925                                         &EXT4_SB(sb)->s_freeblocks_counter));
2926         es->s_free_inodes_count = cpu_to_le32(percpu_counter_sum_positive(
2927                                         &EXT4_SB(sb)->s_freeinodes_counter));
2928
2929         BUFFER_TRACE(sbh, "marking dirty");
2930         mark_buffer_dirty(sbh);
2931         if (sync) {
2932                 error = sync_dirty_buffer(sbh);
2933                 if (error)
2934                         return error;
2935
2936                 error = buffer_write_io_error(sbh);
2937                 if (error) {
2938                         printk(KERN_ERR "EXT4-fs: I/O error while writing "
2939                                "superblock for %s.\n", sb->s_id);
2940                         clear_buffer_write_io_error(sbh);
2941                         set_buffer_uptodate(sbh);
2942                 }
2943         }
2944         return error;
2945 }
2946
2947
2948 /*
2949  * Have we just finished recovery?  If so, and if we are mounting (or
2950  * remounting) the filesystem readonly, then we will end up with a
2951  * consistent fs on disk.  Record that fact.
2952  */
2953 static void ext4_mark_recovery_complete(struct super_block *sb,
2954                                         struct ext4_super_block *es)
2955 {
2956         journal_t *journal = EXT4_SB(sb)->s_journal;
2957
2958         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2959                 BUG_ON(journal != NULL);
2960                 return;
2961         }
2962         jbd2_journal_lock_updates(journal);
2963         if (jbd2_journal_flush(journal) < 0)
2964                 goto out;
2965
2966         lock_super(sb);
2967         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2968             sb->s_flags & MS_RDONLY) {
2969                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2970                 sb->s_dirt = 0;
2971                 ext4_commit_super(sb, es, 1);
2972         }
2973         unlock_super(sb);
2974
2975 out:
2976         jbd2_journal_unlock_updates(journal);
2977 }
2978
2979 /*
2980  * If we are mounting (or read-write remounting) a filesystem whose journal
2981  * has recorded an error from a previous lifetime, move that error to the
2982  * main filesystem now.
2983  */
2984 static void ext4_clear_journal_err(struct super_block *sb,
2985                                    struct ext4_super_block *es)
2986 {
2987         journal_t *journal;
2988         int j_errno;
2989         const char *errstr;
2990
2991         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
2992
2993         journal = EXT4_SB(sb)->s_journal;
2994
2995         /*
2996          * Now check for any error status which may have been recorded in the
2997          * journal by a prior ext4_error() or ext4_abort()
2998          */
2999
3000         j_errno = jbd2_journal_errno(journal);
3001         if (j_errno) {
3002                 char nbuf[16];
3003
3004                 errstr = ext4_decode_error(sb, j_errno, nbuf);
3005                 ext4_warning(sb, __func__, "Filesystem error recorded "
3006                              "from previous mount: %s", errstr);
3007                 ext4_warning(sb, __func__, "Marking fs in need of "
3008                              "filesystem check.");
3009
3010                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
3011                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
3012                 ext4_commit_super(sb, es, 1);
3013
3014                 jbd2_journal_clear_err(journal);
3015         }
3016 }
3017
3018 /*
3019  * Force the running and committing transactions to commit,
3020  * and wait on the commit.
3021  */
3022 int ext4_force_commit(struct super_block *sb)
3023 {
3024         journal_t *journal;
3025         int ret = 0;
3026
3027         if (sb->s_flags & MS_RDONLY)
3028                 return 0;
3029
3030         journal = EXT4_SB(sb)->s_journal;
3031         if (journal) {
3032                 sb->s_dirt = 0;
3033                 ret = ext4_journal_force_commit(journal);
3034         }
3035
3036         return ret;
3037 }
3038
3039 /*
3040  * Ext4 always journals updates to the superblock itself, so we don't
3041  * have to propagate any other updates to the superblock on disk at this
3042  * point.  (We can probably nuke this function altogether, and remove
3043  * any mention to sb->s_dirt in all of fs/ext4; eventual cleanup...)
3044  */
3045 static void ext4_write_super(struct super_block *sb)
3046 {
3047         if (EXT4_SB(sb)->s_journal) {
3048                 if (mutex_trylock(&sb->s_lock) != 0)
3049                         BUG();
3050                 sb->s_dirt = 0;
3051         } else {
3052                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
3053         }
3054 }
3055
3056 static int ext4_sync_fs(struct super_block *sb, int wait)
3057 {
3058         int ret = 0;
3059         tid_t target;
3060
3061         trace_mark(ext4_sync_fs, "dev %s wait %d", sb->s_id, wait);
3062         sb->s_dirt = 0;
3063         if (EXT4_SB(sb)->s_journal) {
3064                 if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal,
3065                                               &target)) {
3066                         if (wait)
3067                                 jbd2_log_wait_commit(EXT4_SB(sb)->s_journal,
3068                                                      target);
3069                 }
3070         } else {
3071                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, wait);
3072         }
3073         return ret;
3074 }
3075
3076 /*
3077  * LVM calls this function before a (read-only) snapshot is created.  This
3078  * gives us a chance to flush the journal completely and mark the fs clean.
3079  */
3080 static int ext4_freeze(struct super_block *sb)
3081 {
3082         int error = 0;
3083         journal_t *journal;
3084         sb->s_dirt = 0;
3085
3086         if (!(sb->s_flags & MS_RDONLY)) {
3087                 journal = EXT4_SB(sb)->s_journal;
3088
3089                 if (journal) {
3090                         /* Now we set up the journal barrier. */
3091                         jbd2_journal_lock_updates(journal);
3092
3093                         /*
3094                          * We don't want to clear needs_recovery flag when we
3095                          * failed to flush the journal.
3096                          */
3097                         error = jbd2_journal_flush(journal);
3098                         if (error < 0)
3099                                 goto out;
3100                 }
3101
3102                 /* Journal blocked and flushed, clear needs_recovery flag. */
3103                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3104                 error = ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
3105                 if (error)
3106                         goto out;
3107         }
3108         return 0;
3109 out:
3110         jbd2_journal_unlock_updates(journal);
3111         return error;
3112 }
3113
3114 /*
3115  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
3116  * flag here, even though the filesystem is not technically dirty yet.
3117  */
3118 static int ext4_unfreeze(struct super_block *sb)
3119 {
3120         if (EXT4_SB(sb)->s_journal && !(sb->s_flags & MS_RDONLY)) {
3121                 lock_super(sb);
3122                 /* Reser the needs_recovery flag before the fs is unlocked. */
3123                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3124                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
3125                 unlock_super(sb);
3126                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3127         }
3128         return 0;
3129 }
3130
3131 static int ext4_remount(struct super_block *sb, int *flags, char *data)
3132 {
3133         struct ext4_super_block *es;
3134         struct ext4_sb_info *sbi = EXT4_SB(sb);
3135         ext4_fsblk_t n_blocks_count = 0;
3136         unsigned long old_sb_flags;
3137         struct ext4_mount_options old_opts;
3138         ext4_group_t g;
3139         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3140         int err;
3141 #ifdef CONFIG_QUOTA
3142         int i;
3143 #endif
3144
3145         /* Store the original options */
3146         old_sb_flags = sb->s_flags;
3147         old_opts.s_mount_opt = sbi->s_mount_opt;
3148         old_opts.s_resuid = sbi->s_resuid;
3149         old_opts.s_resgid = sbi->s_resgid;
3150         old_opts.s_commit_interval = sbi->s_commit_interval;
3151         old_opts.s_min_batch_time = sbi->s_min_batch_time;
3152         old_opts.s_max_batch_time = sbi->s_max_batch_time;
3153 #ifdef CONFIG_QUOTA
3154         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
3155         for (i = 0; i < MAXQUOTAS; i++)
3156                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
3157 #endif
3158         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
3159                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
3160
3161         /*
3162          * Allow the "check" option to be passed as a remount option.
3163          */
3164         if (!parse_options(data, sb, NULL, &journal_ioprio,
3165                            &n_blocks_count, 1)) {
3166                 err = -EINVAL;
3167                 goto restore_opts;
3168         }
3169
3170         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
3171                 ext4_abort(sb, __func__, "Abort forced by user");
3172
3173         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3174                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
3175
3176         es = sbi->s_es;
3177
3178         if (sbi->s_journal) {
3179                 ext4_init_journal_params(sb, sbi->s_journal);
3180                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3181         }
3182
3183         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
3184                 n_blocks_count > ext4_blocks_count(es)) {
3185                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
3186                         err = -EROFS;
3187                         goto restore_opts;
3188                 }
3189
3190                 if (*flags & MS_RDONLY) {
3191                         /*
3192                          * First of all, the unconditional stuff we have to do
3193                          * to disable replay of the journal when we next remount
3194                          */
3195                         sb->s_flags |= MS_RDONLY;
3196
3197                         /*
3198                          * OK, test if we are remounting a valid rw partition
3199                          * readonly, and if so set the rdonly flag and then
3200                          * mark the partition as valid again.
3201                          */
3202                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
3203                             (sbi->s_mount_state & EXT4_VALID_FS))
3204                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
3205
3206                         /*
3207                          * We have to unlock super so that we can wait for
3208                          * transactions.
3209                          */
3210                         if (sbi->s_journal) {
3211                                 unlock_super(sb);
3212                                 ext4_mark_recovery_complete(sb, es);
3213                                 lock_super(sb);
3214                         }
3215                 } else {
3216                         int ret;
3217                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3218                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
3219                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
3220                                        "remount RDWR because of unsupported "
3221                                        "optional features (%x).\n", sb->s_id,
3222                                 (le32_to_cpu(sbi->s_es->s_feature_ro_compat) &
3223                                         ~EXT4_FEATURE_RO_COMPAT_SUPP));
3224                                 err = -EROFS;
3225                                 goto restore_opts;
3226                         }
3227
3228                         /*
3229                          * Make sure the group descriptor checksums
3230                          * are sane.  If they aren't, refuse to
3231                          * remount r/w.
3232                          */
3233                         for (g = 0; g < sbi->s_groups_count; g++) {
3234                                 struct ext4_group_desc *gdp =
3235                                         ext4_get_group_desc(sb, g, NULL);
3236
3237                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
3238                                         printk(KERN_ERR
3239                "EXT4-fs: ext4_remount: "
3240                 "Checksum for group %u failed (%u!=%u)\n",
3241                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
3242                                                le16_to_cpu(gdp->bg_checksum));
3243                                         err = -EINVAL;
3244                                         goto restore_opts;
3245                                 }
3246                         }
3247
3248                         /*
3249                          * If we have an unprocessed orphan list hanging
3250                          * around from a previously readonly bdev mount,
3251                          * require a full umount/remount for now.
3252                          */
3253                         if (es->s_last_orphan) {
3254                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
3255                                        "remount RDWR because of unprocessed "
3256                                        "orphan inode list.  Please "
3257                                        "umount/remount instead.\n",
3258                                        sb->s_id);
3259                                 err = -EINVAL;
3260                                 goto restore_opts;
3261                         }
3262
3263                         /*
3264                          * Mounting a RDONLY partition read-write, so reread
3265                          * and store the current valid flag.  (It may have
3266                          * been changed by e2fsck since we originally mounted
3267                          * the partition.)
3268                          */
3269                         if (sbi->s_journal)
3270                                 ext4_clear_journal_err(sb, es);
3271                         sbi->s_mount_state = le16_to_cpu(es->s_state);
3272                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
3273                                 goto restore_opts;
3274                         if (!ext4_setup_super(sb, es, 0))
3275                                 sb->s_flags &= ~MS_RDONLY;
3276                 }
3277         }
3278         if (sbi->s_journal == NULL)
3279                 ext4_commit_super(sb, es, 1);
3280
3281 #ifdef CONFIG_QUOTA
3282         /* Release old quota file names */
3283         for (i = 0; i < MAXQUOTAS; i++)
3284                 if (old_opts.s_qf_names[i] &&
3285                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3286                         kfree(old_opts.s_qf_names[i]);
3287 #endif
3288         return 0;
3289 restore_opts:
3290         sb->s_flags = old_sb_flags;
3291         sbi->s_mount_opt = old_opts.s_mount_opt;
3292         sbi->s_resuid = old_opts.s_resuid;
3293         sbi->s_resgid = old_opts.s_resgid;
3294         sbi->s_commit_interval = old_opts.s_commit_interval;
3295         sbi->s_min_batch_time = old_opts.s_min_batch_time;
3296         sbi->s_max_batch_time = old_opts.s_max_batch_time;
3297 #ifdef CONFIG_QUOTA
3298         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
3299         for (i = 0; i < MAXQUOTAS; i++) {
3300                 if (sbi->s_qf_names[i] &&
3301                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3302                         kfree(sbi->s_qf_names[i]);
3303                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
3304         }
3305 #endif
3306         return err;
3307 }
3308
3309 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
3310 {
3311         struct super_block *sb = dentry->d_sb;
3312         struct ext4_sb_info *sbi = EXT4_SB(sb);
3313         struct ext4_super_block *es = sbi->s_es;
3314         u64 fsid;
3315
3316         if (test_opt(sb, MINIX_DF)) {
3317                 sbi->s_overhead_last = 0;
3318         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
3319                 ext4_group_t ngroups = sbi->s_groups_count, i;
3320                 ext4_fsblk_t overhead = 0;
3321                 smp_rmb();
3322
3323                 /*
3324                  * Compute the overhead (FS structures).  This is constant
3325                  * for a given filesystem unless the number of block groups
3326                  * changes so we cache the previous value until it does.
3327                  */
3328
3329                 /*
3330                  * All of the blocks before first_data_block are
3331                  * overhead
3332                  */
3333                 overhead = le32_to_cpu(es->s_first_data_block);
3334
3335                 /*
3336                  * Add the overhead attributed to the superblock and
3337                  * block group descriptors.  If the sparse superblocks
3338                  * feature is turned on, then not all groups have this.
3339                  */
3340                 for (i = 0; i < ngroups; i++) {
3341                         overhead += ext4_bg_has_super(sb, i) +
3342                                 ext4_bg_num_gdb(sb, i);
3343                         cond_resched();
3344                 }
3345
3346                 /*
3347                  * Every block group has an inode bitmap, a block
3348                  * bitmap, and an inode table.
3349                  */
3350                 overhead += ngroups * (2 + sbi->s_itb_per_group);
3351                 sbi->s_overhead_last = overhead;
3352                 smp_wmb();
3353                 sbi->s_blocks_last = ext4_blocks_count(es);
3354         }
3355
3356         buf->f_type = EXT4_SUPER_MAGIC;
3357         buf->f_bsize = sb->s_blocksize;
3358         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
3359         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
3360                        percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
3361         ext4_free_blocks_count_set(es, buf->f_bfree);
3362         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
3363         if (buf->f_bfree < ext4_r_blocks_count(es))
3364                 buf->f_bavail = 0;
3365         buf->f_files = le32_to_cpu(es->s_inodes_count);
3366         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
3367         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
3368         buf->f_namelen = EXT4_NAME_LEN;
3369         fsid = le64_to_cpup((void *)es->s_uuid) ^
3370                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
3371         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
3372         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
3373         return 0;
3374 }
3375
3376 /* Helper function for writing quotas on sync - we need to start transaction before quota file
3377  * is locked for write. Otherwise the are possible deadlocks:
3378  * Process 1                         Process 2
3379  * ext4_create()                     quota_sync()
3380  *   jbd2_journal_start()                  write_dquot()
3381  *   vfs_dq_init()                         down(dqio_mutex)
3382  *     down(dqio_mutex)                    jbd2_journal_start()
3383  *
3384  */
3385
3386 #ifdef CONFIG_QUOTA
3387
3388 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3389 {
3390         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3391 }
3392
3393 static int ext4_write_dquot(struct dquot *dquot)
3394 {
3395         int ret, err;
3396         handle_t *handle;
3397         struct inode *inode;
3398
3399         inode = dquot_to_inode(dquot);
3400         handle = ext4_journal_start(inode,
3401                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3402         if (IS_ERR(handle))
3403                 return PTR_ERR(handle);
3404         ret = dquot_commit(dquot);
3405         err = ext4_journal_stop(handle);
3406         if (!ret)
3407                 ret = err;
3408         return ret;
3409 }
3410
3411 static int ext4_acquire_dquot(struct dquot *dquot)
3412 {
3413         int ret, err;
3414         handle_t *handle;
3415
3416         handle = ext4_journal_start(dquot_to_inode(dquot),
3417                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3418         if (IS_ERR(handle))
3419                 return PTR_ERR(handle);
3420         ret = dquot_acquire(dquot);
3421         err = ext4_journal_stop(handle);
3422         if (!ret)
3423                 ret = err;
3424         return ret;
3425 }
3426
3427 static int ext4_release_dquot(struct dquot *dquot)
3428 {
3429         int ret, err;
3430         handle_t *handle;
3431
3432         handle = ext4_journal_start(dquot_to_inode(dquot),
3433                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3434         if (IS_ERR(handle)) {
3435                 /* Release dquot anyway to avoid endless cycle in dqput() */
3436                 dquot_release(dquot);
3437                 return PTR_ERR(handle);
3438         }
3439         ret = dquot_release(dquot);
3440         err = ext4_journal_stop(handle);
3441         if (!ret)
3442                 ret = err;
3443         return ret;
3444 }
3445
3446 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3447 {
3448         /* Are we journaling quotas? */
3449         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3450             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3451                 dquot_mark_dquot_dirty(dquot);
3452                 return ext4_write_dquot(dquot);
3453         } else {
3454                 return dquot_mark_dquot_dirty(dquot);
3455         }
3456 }
3457
3458 static int ext4_write_info(struct super_block *sb, int type)
3459 {
3460         int ret, err;
3461         handle_t *handle;
3462
3463         /* Data block + inode block */
3464         handle = ext4_journal_start(sb->s_root->d_inode, 2);
3465         if (IS_ERR(handle))
3466                 return PTR_ERR(handle);
3467         ret = dquot_commit_info(sb, type);
3468         err = ext4_journal_stop(handle);
3469         if (!ret)
3470                 ret = err;
3471         return ret;
3472 }
3473
3474 /*
3475  * Turn on quotas during mount time - we need to find
3476  * the quota file and such...
3477  */
3478 static int ext4_quota_on_mount(struct super_block *sb, int type)
3479 {
3480         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3481                         EXT4_SB(sb)->s_jquota_fmt, type);
3482 }
3483
3484 /*
3485  * Standard function to be called on quota_on
3486  */
3487 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3488                          char *name, int remount)
3489 {
3490         int err;
3491         struct path path;
3492
3493         if (!test_opt(sb, QUOTA))
3494                 return -EINVAL;
3495         /* When remounting, no checks are needed and in fact, name is NULL */
3496         if (remount)
3497                 return vfs_quota_on(sb, type, format_id, name, remount);
3498
3499         err = kern_path(name, LOOKUP_FOLLOW, &path);
3500         if (err)
3501                 return err;
3502
3503         /* Quotafile not on the same filesystem? */
3504         if (path.mnt->mnt_sb != sb) {
3505                 path_put(&path);
3506                 return -EXDEV;
3507         }
3508         /* Journaling quota? */
3509         if (EXT4_SB(sb)->s_qf_names[type]) {
3510                 /* Quotafile not in fs root? */
3511                 if (path.dentry->d_parent != sb->s_root)
3512                         printk(KERN_WARNING
3513                                 "EXT4-fs: Quota file not on filesystem root. "
3514                                 "Journaled quota will not work.\n");
3515         }
3516
3517         /*
3518          * When we journal data on quota file, we have to flush journal to see
3519          * all updates to the file when we bypass pagecache...
3520          */
3521         if (EXT4_SB(sb)->s_journal &&
3522             ext4_should_journal_data(path.dentry->d_inode)) {
3523                 /*
3524                  * We don't need to lock updates but journal_flush() could
3525                  * otherwise be livelocked...
3526                  */
3527                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
3528                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
3529                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3530                 if (err) {
3531                         path_put(&path);
3532                         return err;
3533                 }
3534         }
3535
3536         err = vfs_quota_on_path(sb, type, format_id, &path);
3537         path_put(&path);
3538         return err;
3539 }
3540
3541 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3542  * acquiring the locks... As quota files are never truncated and quota code
3543  * itself serializes the operations (and noone else should touch the files)
3544  * we don't have to be afraid of races */
3545 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3546                                size_t len, loff_t off)
3547 {
3548         struct inode *inode = sb_dqopt(sb)->files[type];
3549         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3550         int err = 0;
3551         int offset = off & (sb->s_blocksize - 1);
3552         int tocopy;
3553         size_t toread;
3554         struct buffer_head *bh;
3555         loff_t i_size = i_size_read(inode);
3556
3557         if (off > i_size)
3558                 return 0;
3559         if (off+len > i_size)
3560                 len = i_size-off;
3561         toread = len;
3562         while (toread > 0) {
3563                 tocopy = sb->s_blocksize - offset < toread ?
3564                                 sb->s_blocksize - offset : toread;
3565                 bh = ext4_bread(NULL, inode, blk, 0, &err);
3566                 if (err)
3567                         return err;
3568                 if (!bh)        /* A hole? */
3569                         memset(data, 0, tocopy);
3570                 else
3571                         memcpy(data, bh->b_data+offset, tocopy);
3572                 brelse(bh);
3573                 offset = 0;
3574                 toread -= tocopy;
3575                 data += tocopy;
3576                 blk++;
3577         }
3578         return len;
3579 }
3580
3581 /* Write to quotafile (we know the transaction is already started and has
3582  * enough credits) */
3583 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3584                                 const char *data, size_t len, loff_t off)
3585 {
3586         struct inode *inode = sb_dqopt(sb)->files[type];
3587         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3588         int err = 0;
3589         int offset = off & (sb->s_blocksize - 1);
3590         int tocopy;
3591         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3592         size_t towrite = len;
3593         struct buffer_head *bh;
3594         handle_t *handle = journal_current_handle();
3595
3596         if (EXT4_SB(sb)->s_journal && !handle) {
3597                 printk(KERN_WARNING "EXT4-fs: Quota write (off=%llu, len=%llu)"
3598                         " cancelled because transaction is not started.\n",
3599                         (unsigned long long)off, (unsigned long long)len);
3600                 return -EIO;
3601         }
3602         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3603         while (towrite > 0) {
3604                 tocopy = sb->s_blocksize - offset < towrite ?
3605                                 sb->s_blocksize - offset : towrite;
3606                 bh = ext4_bread(handle, inode, blk, 1, &err);
3607                 if (!bh)
3608                         goto out;
3609                 if (journal_quota) {
3610                         err = ext4_journal_get_write_access(handle, bh);
3611                         if (err) {
3612                                 brelse(bh);
3613                                 goto out;
3614                         }
3615                 }
3616                 lock_buffer(bh);
3617                 memcpy(bh->b_data+offset, data, tocopy);
3618                 flush_dcache_page(bh->b_page);
3619                 unlock_buffer(bh);
3620                 if (journal_quota)
3621                         err = ext4_handle_dirty_metadata(handle, NULL, bh);
3622                 else {
3623                         /* Always do at least ordered writes for quotas */
3624                         err = ext4_jbd2_file_inode(handle, inode);
3625                         mark_buffer_dirty(bh);
3626                 }
3627                 brelse(bh);
3628                 if (err)
3629                         goto out;
3630                 offset = 0;
3631                 towrite -= tocopy;
3632                 data += tocopy;
3633                 blk++;
3634         }
3635 out:
3636         if (len == towrite) {
3637                 mutex_unlock(&inode->i_mutex);
3638                 return err;
3639         }
3640         if (inode->i_size < off+len-towrite) {
3641                 i_size_write(inode, off+len-towrite);
3642                 EXT4_I(inode)->i_disksize = inode->i_size;
3643         }
3644         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3645         ext4_mark_inode_dirty(handle, inode);
3646         mutex_unlock(&inode->i_mutex);
3647         return len - towrite;
3648 }
3649
3650 #endif
3651
3652 static int ext4_get_sb(struct file_system_type *fs_type,
3653         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3654 {
3655         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3656 }
3657
3658 #ifdef CONFIG_PROC_FS
3659 static int ext4_ui_proc_show(struct seq_file *m, void *v)
3660 {
3661         unsigned int *p = m->private;
3662
3663         seq_printf(m, "%u\n", *p);
3664         return 0;
3665 }
3666
3667 static int ext4_ui_proc_open(struct inode *inode, struct file *file)
3668 {
3669         return single_open(file, ext4_ui_proc_show, PDE(inode)->data);
3670 }
3671
3672 static ssize_t ext4_ui_proc_write(struct file *file, const char __user *buf,
3673                                size_t cnt, loff_t *ppos)
3674 {
3675         unsigned long *p = PDE(file->f_path.dentry->d_inode)->data;
3676         char str[32];
3677
3678         if (cnt >= sizeof(str))
3679                 return -EINVAL;
3680         if (copy_from_user(str, buf, cnt))
3681                 return -EFAULT;
3682
3683         *p = simple_strtoul(str, NULL, 0);
3684         return cnt;
3685 }
3686
3687 const struct file_operations ext4_ui_proc_fops = {
3688         .owner          = THIS_MODULE,
3689         .open           = ext4_ui_proc_open,
3690         .read           = seq_read,
3691         .llseek         = seq_lseek,
3692         .release        = single_release,
3693         .write          = ext4_ui_proc_write,
3694 };
3695 #endif
3696
3697 static struct file_system_type ext4_fs_type = {
3698         .owner          = THIS_MODULE,
3699         .name           = "ext4",
3700         .get_sb         = ext4_get_sb,
3701         .kill_sb        = kill_block_super,
3702         .fs_flags       = FS_REQUIRES_DEV,
3703 };
3704
3705 #ifdef CONFIG_EXT4DEV_COMPAT
3706 static int ext4dev_get_sb(struct file_system_type *fs_type,
3707         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3708 {
3709         printk(KERN_WARNING "EXT4-fs: Update your userspace programs "
3710                "to mount using ext4\n");
3711         printk(KERN_WARNING "EXT4-fs: ext4dev backwards compatibility "
3712                "will go away by 2.6.31\n");
3713         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3714 }
3715
3716 static struct file_system_type ext4dev_fs_type = {
3717         .owner          = THIS_MODULE,
3718         .name           = "ext4dev",
3719         .get_sb         = ext4dev_get_sb,
3720         .kill_sb        = kill_block_super,
3721         .fs_flags       = FS_REQUIRES_DEV,
3722 };
3723 MODULE_ALIAS("ext4dev");
3724 #endif
3725
3726 static int __init init_ext4_fs(void)
3727 {
3728         int err;
3729
3730         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
3731         err = init_ext4_mballoc();
3732         if (err)
3733                 return err;
3734
3735         err = init_ext4_xattr();
3736         if (err)
3737                 goto out2;
3738         err = init_inodecache();
3739         if (err)
3740                 goto out1;
3741         err = register_filesystem(&ext4_fs_type);
3742         if (err)
3743                 goto out;
3744 #ifdef CONFIG_EXT4DEV_COMPAT
3745         err = register_filesystem(&ext4dev_fs_type);
3746         if (err) {
3747                 unregister_filesystem(&ext4_fs_type);
3748                 goto out;
3749         }
3750 #endif
3751         return 0;
3752 out:
3753         destroy_inodecache();
3754 out1:
3755         exit_ext4_xattr();
3756 out2:
3757         exit_ext4_mballoc();
3758         return err;
3759 }
3760
3761 static void __exit exit_ext4_fs(void)
3762 {
3763         unregister_filesystem(&ext4_fs_type);
3764 #ifdef CONFIG_EXT4DEV_COMPAT
3765         unregister_filesystem(&ext4dev_fs_type);
3766 #endif
3767         destroy_inodecache();
3768         exit_ext4_xattr();
3769         exit_ext4_mballoc();
3770         remove_proc_entry("fs/ext4", NULL);
3771 }
3772
3773 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
3774 MODULE_DESCRIPTION("Fourth Extended Filesystem");
3775 MODULE_LICENSE("GPL");
3776 module_init(init_ext4_fs)
3777 module_exit(exit_ext4_fs)