fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/backing-dev.h>
  28 #include <linux/parser.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/ctype.h>
  38 #include <linux/log2.h>
  39 #include <linux/crc16.h>
  40 #include <linux/cleancache.h>
  41 #include <asm/uaccess.h>
  42
  43 #include <linux/kthread.h>
  44 #include <linux/freezer.h>
  45
  46 #include "ext4.h"
  47 #include "ext4_extents.h"       /* Needed for trace points definition */
  48 #include "ext4_jbd2.h"
  49 #include "xattr.h"
  50 #include "acl.h"
  51 #include "mballoc.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/ext4.h>
  55
  56 static struct ext4_lazy_init *ext4_li_info;
  57 static struct mutex ext4_li_mtx;
  58 static int ext4_mballoc_ready;
  59 static struct ratelimit_state ext4_mount_msg_ratelimit;
  60
  61 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  62                              unsigned long journal_devnum);
  63 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  64 static int ext4_commit_super(struct super_block *sb, int sync);
  65 static void ext4_mark_recovery_complete(struct super_block *sb,
  66                                         struct ext4_super_block *es);
  67 static void ext4_clear_journal_err(struct super_block *sb,
  68                                    struct ext4_super_block *es);
  69 static int ext4_sync_fs(struct super_block *sb, int wait);
  70 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  71 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  72 static int ext4_unfreeze(struct super_block *sb);
  73 static int ext4_freeze(struct super_block *sb);
  74 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  75                        const char *dev_name, void *data);
  76 static inline int ext2_feature_set_ok(struct super_block *sb);
  77 static inline int ext3_feature_set_ok(struct super_block *sb);
  78 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  79 static void ext4_destroy_lazyinit_thread(void);
  80 static void ext4_unregister_li_request(struct super_block *sb);
  81 static void ext4_clear_request_list(void);
  82
  83 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
  84 static struct file_system_type ext2_fs_type = {
  85         .owner          = THIS_MODULE,
  86         .name           = "ext2",
  87         .mount          = ext4_mount,
  88         .kill_sb        = kill_block_super,
  89         .fs_flags       = FS_REQUIRES_DEV,
  90 };
  91 MODULE_ALIAS_FS("ext2");
  92 MODULE_ALIAS("ext2");
  93 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  94 #else
  95 #define IS_EXT2_SB(sb) (0)
  96 #endif
  97
  98
  99 static struct file_system_type ext3_fs_type = {
 100         .owner          = THIS_MODULE,
 101         .name           = "ext3",
 102         .mount          = ext4_mount,
 103         .kill_sb        = kill_block_super,
 104         .fs_flags       = FS_REQUIRES_DEV,
 105 };
 106 MODULE_ALIAS_FS("ext3");
 107 MODULE_ALIAS("ext3");
 108 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 109
 110 static int ext4_verify_csum_type(struct super_block *sb,
 111                                  struct ext4_super_block *es)
 112 {
 113         if (!ext4_has_feature_metadata_csum(sb))
 114                 return 1;
 115
 116         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 117 }
 118
 119 static __le32 ext4_superblock_csum(struct super_block *sb,
 120                                    struct ext4_super_block *es)
 121 {
 122         struct ext4_sb_info *sbi = EXT4_SB(sb);
 123         int offset = offsetof(struct ext4_super_block, s_checksum);
 124         __u32 csum;
 125
 126         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 127
 128         return cpu_to_le32(csum);
 129 }
 130
 131 static int ext4_superblock_csum_verify(struct super_block *sb,
 132                                        struct ext4_super_block *es)
 133 {
 134         if (!ext4_has_metadata_csum(sb))
 135                 return 1;
 136
 137         return es->s_checksum == ext4_superblock_csum(sb, es);
 138 }
 139
 140 void ext4_superblock_csum_set(struct super_block *sb)
 141 {
 142         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 143
 144         if (!ext4_has_metadata_csum(sb))
 145                 return;
 146
 147         es->s_checksum = ext4_superblock_csum(sb, es);
 148 }
 149
 150 void *ext4_kvmalloc(size_t size, gfp_t flags)
 151 {
 152         void *ret;
 153
 154         ret = kmalloc(size, flags | __GFP_NOWARN);
 155         if (!ret)
 156                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 157         return ret;
 158 }
 159
 160 void *ext4_kvzalloc(size_t size, gfp_t flags)
 161 {
 162         void *ret;
 163
 164         ret = kzalloc(size, flags | __GFP_NOWARN);
 165         if (!ret)
 166                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 167         return ret;
 168 }
 169
 170 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 171                                struct ext4_group_desc *bg)
 172 {
 173         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 174                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 175                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 176 }
 177
 178 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 179                                struct ext4_group_desc *bg)
 180 {
 181         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 182                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 183                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 184 }
 185
 186 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 187                               struct ext4_group_desc *bg)
 188 {
 189         return le32_to_cpu(bg->bg_inode_table_lo) |
 190                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 191                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 192 }
 193
 194 __u32 ext4_free_group_clusters(struct super_block *sb,
 195                                struct ext4_group_desc *bg)
 196 {
 197         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 198                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 199                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 200 }
 201
 202 __u32 ext4_free_inodes_count(struct super_block *sb,
 203                               struct ext4_group_desc *bg)
 204 {
 205         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 206                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 207                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 208 }
 209
 210 __u32 ext4_used_dirs_count(struct super_block *sb,
 211                               struct ext4_group_desc *bg)
 212 {
 213         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 214                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 215                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 216 }
 217
 218 __u32 ext4_itable_unused_count(struct super_block *sb,
 219                               struct ext4_group_desc *bg)
 220 {
 221         return le16_to_cpu(bg->bg_itable_unused_lo) |
 222                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 223                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 224 }
 225
 226 void ext4_block_bitmap_set(struct super_block *sb,
 227                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 228 {
 229         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 230         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 231                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 232 }
 233
 234 void ext4_inode_bitmap_set(struct super_block *sb,
 235                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 236 {
 237         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 238         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 239                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 240 }
 241
 242 void ext4_inode_table_set(struct super_block *sb,
 243                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 244 {
 245         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 246         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 247                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 248 }
 249
 250 void ext4_free_group_clusters_set(struct super_block *sb,
 251                                   struct ext4_group_desc *bg, __u32 count)
 252 {
 253         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 254         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 255                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 256 }
 257
 258 void ext4_free_inodes_set(struct super_block *sb,
 259                           struct ext4_group_desc *bg, __u32 count)
 260 {
 261         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 262         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 263                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 264 }
 265
 266 void ext4_used_dirs_set(struct super_block *sb,
 267                           struct ext4_group_desc *bg, __u32 count)
 268 {
 269         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 270         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 271                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 272 }
 273
 274 void ext4_itable_unused_set(struct super_block *sb,
 275                           struct ext4_group_desc *bg, __u32 count)
 276 {
 277         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 278         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 279                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 280 }
 281
 282
 283 static void __save_error_info(struct super_block *sb, const char *func,
 284                             unsigned int line)
 285 {
 286         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 287
 288         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 289         if (bdev_read_only(sb->s_bdev))
 290                 return;
 291         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 292         es->s_last_error_time = cpu_to_le32(get_seconds());
 293         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 294         es->s_last_error_line = cpu_to_le32(line);
 295         if (!es->s_first_error_time) {
 296                 es->s_first_error_time = es->s_last_error_time;
 297                 strncpy(es->s_first_error_func, func,
 298                         sizeof(es->s_first_error_func));
 299                 es->s_first_error_line = cpu_to_le32(line);
 300                 es->s_first_error_ino = es->s_last_error_ino;
 301                 es->s_first_error_block = es->s_last_error_block;
 302         }
 303         /*
 304          * Start the daily error reporting function if it hasn't been
 305          * started already
 306          */
 307         if (!es->s_error_count)
 308                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 309         le32_add_cpu(&es->s_error_count, 1);
 310 }
 311
 312 static void save_error_info(struct super_block *sb, const char *func,
 313                             unsigned int line)
 314 {
 315         __save_error_info(sb, func, line);
 316         if (!bdev_read_only(sb->s_bdev))
 317                 ext4_commit_super(sb, 1);
 318 }
 319
 320 /*
 321  * The del_gendisk() function uninitializes the disk-specific data
 322  * structures, including the bdi structure, without telling anyone
 323  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 324  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 325  * This is a kludge to prevent these oops until we can put in a proper
 326  * hook in del_gendisk() to inform the VFS and file system layers.
 327  */
 328 static int block_device_ejected(struct super_block *sb)
 329 {
 330         struct inode *bd_inode = sb->s_bdev->bd_inode;
 331         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 332
 333         return bdi->dev == NULL;
 334 }
 335
 336 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 337 {
 338         struct super_block              *sb = journal->j_private;
 339         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 340         int                             error = is_journal_aborted(journal);
 341         struct ext4_journal_cb_entry    *jce;
 342
 343         BUG_ON(txn->t_state == T_FINISHED);
 344         spin_lock(&sbi->s_md_lock);
 345         while (!list_empty(&txn->t_private_list)) {
 346                 jce = list_entry(txn->t_private_list.next,
 347                                  struct ext4_journal_cb_entry, jce_list);
 348                 list_del_init(&jce->jce_list);
 349                 spin_unlock(&sbi->s_md_lock);
 350                 jce->jce_func(sb, jce, error);
 351                 spin_lock(&sbi->s_md_lock);
 352         }
 353         spin_unlock(&sbi->s_md_lock);
 354 }
 355
 356 /* Deal with the reporting of failure conditions on a filesystem such as
 357  * inconsistencies detected or read IO failures.
 358  *
 359  * On ext2, we can store the error state of the filesystem in the
 360  * superblock.  That is not possible on ext4, because we may have other
 361  * write ordering constraints on the superblock which prevent us from
 362  * writing it out straight away; and given that the journal is about to
 363  * be aborted, we can't rely on the current, or future, transactions to
 364  * write out the superblock safely.
 365  *
 366  * We'll just use the jbd2_journal_abort() error code to record an error in
 367  * the journal instead.  On recovery, the journal will complain about
 368  * that error until we've noted it down and cleared it.
 369  */
 370
 371 static void ext4_handle_error(struct super_block *sb)
 372 {
 373         if (sb->s_flags & MS_RDONLY)
 374                 return;
 375
 376         if (!test_opt(sb, ERRORS_CONT)) {
 377                 journal_t *journal = EXT4_SB(sb)->s_journal;
 378
 379                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 380                 if (journal)
 381                         jbd2_journal_abort(journal, -EIO);
 382         }
 383         if (test_opt(sb, ERRORS_RO)) {
 384                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 385                 /*
 386                  * Make sure updated value of ->s_mount_flags will be visible
 387                  * before ->s_flags update
 388                  */
 389                 smp_wmb();
 390                 sb->s_flags |= MS_RDONLY;
 391         }
 392         if (test_opt(sb, ERRORS_PANIC)) {
 393                 if (EXT4_SB(sb)->s_journal &&
 394                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 395                         return;
 396                 panic("EXT4-fs (device %s): panic forced after error\n",
 397                         sb->s_id);
 398         }
 399 }
 400
 401 #define ext4_error_ratelimit(sb)                                        \
 402                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 403                              "EXT4-fs error")
 404
 405 void __ext4_error(struct super_block *sb, const char *function,
 406                   unsigned int line, const char *fmt, ...)
 407 {
 408         struct va_format vaf;
 409         va_list args;
 410
 411         if (ext4_error_ratelimit(sb)) {
 412                 va_start(args, fmt);
 413                 vaf.fmt = fmt;
 414                 vaf.va = &args;
 415                 printk(KERN_CRIT
 416                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 417                        sb->s_id, function, line, current->comm, &vaf);
 418                 va_end(args);
 419         }
 420         save_error_info(sb, function, line);
 421         ext4_handle_error(sb);
 422 }
 423
 424 void __ext4_error_inode(struct inode *inode, const char *function,
 425                         unsigned int line, ext4_fsblk_t block,
 426                         const char *fmt, ...)
 427 {
 428         va_list args;
 429         struct va_format vaf;
 430         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 431
 432         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 433         es->s_last_error_block = cpu_to_le64(block);
 434         if (ext4_error_ratelimit(inode->i_sb)) {
 435                 va_start(args, fmt);
 436                 vaf.fmt = fmt;
 437                 vaf.va = &args;
 438                 if (block)
 439                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 440                                "inode #%lu: block %llu: comm %s: %pV\n",
 441                                inode->i_sb->s_id, function, line, inode->i_ino,
 442                                block, current->comm, &vaf);
 443                 else
 444                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 445                                "inode #%lu: comm %s: %pV\n",
 446                                inode->i_sb->s_id, function, line, inode->i_ino,
 447                                current->comm, &vaf);
 448                 va_end(args);
 449         }
 450         save_error_info(inode->i_sb, function, line);
 451         ext4_handle_error(inode->i_sb);
 452 }
 453
 454 void __ext4_error_file(struct file *file, const char *function,
 455                        unsigned int line, ext4_fsblk_t block,
 456                        const char *fmt, ...)
 457 {
 458         va_list args;
 459         struct va_format vaf;
 460         struct ext4_super_block *es;
 461         struct inode *inode = file_inode(file);
 462         char pathname[80], *path;
 463
 464         es = EXT4_SB(inode->i_sb)->s_es;
 465         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 466         if (ext4_error_ratelimit(inode->i_sb)) {
 467                 path = file_path(file, pathname, sizeof(pathname));
 468                 if (IS_ERR(path))
 469                         path = "(unknown)";
 470                 va_start(args, fmt);
 471                 vaf.fmt = fmt;
 472                 vaf.va = &args;
 473                 if (block)
 474                         printk(KERN_CRIT
 475                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 476                                "block %llu: comm %s: path %s: %pV\n",
 477                                inode->i_sb->s_id, function, line, inode->i_ino,
 478                                block, current->comm, path, &vaf);
 479                 else
 480                         printk(KERN_CRIT
 481                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 482                                "comm %s: path %s: %pV\n",
 483                                inode->i_sb->s_id, function, line, inode->i_ino,
 484                                current->comm, path, &vaf);
 485                 va_end(args);
 486         }
 487         save_error_info(inode->i_sb, function, line);
 488         ext4_handle_error(inode->i_sb);
 489 }
 490
 491 const char *ext4_decode_error(struct super_block *sb, int errno,
 492                               char nbuf[16])
 493 {
 494         char *errstr = NULL;
 495
 496         switch (errno) {
 497         case -EFSCORRUPTED:
 498                 errstr = "Corrupt filesystem";
 499                 break;
 500         case -EFSBADCRC:
 501                 errstr = "Filesystem failed CRC";
 502                 break;
 503         case -EIO:
 504                 errstr = "IO failure";
 505                 break;
 506         case -ENOMEM:
 507                 errstr = "Out of memory";
 508                 break;
 509         case -EROFS:
 510                 if (!sb || (EXT4_SB(sb)->s_journal &&
 511                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 512                         errstr = "Journal has aborted";
 513                 else
 514                         errstr = "Readonly filesystem";
 515                 break;
 516         default:
 517                 /* If the caller passed in an extra buffer for unknown
 518                  * errors, textualise them now.  Else we just return
 519                  * NULL. */
 520                 if (nbuf) {
 521                         /* Check for truncated error codes... */
 522                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 523                                 errstr = nbuf;
 524                 }
 525                 break;
 526         }
 527
 528         return errstr;
 529 }
 530
 531 /* __ext4_std_error decodes expected errors from journaling functions
 532  * automatically and invokes the appropriate error response.  */
 533
 534 void __ext4_std_error(struct super_block *sb, const char *function,
 535                       unsigned int line, int errno)
 536 {
 537         char nbuf[16];
 538         const char *errstr;
 539
 540         /* Special case: if the error is EROFS, and we're not already
 541          * inside a transaction, then there's really no point in logging
 542          * an error. */
 543         if (errno == -EROFS && journal_current_handle() == NULL &&
 544             (sb->s_flags & MS_RDONLY))
 545                 return;
 546
 547         if (ext4_error_ratelimit(sb)) {
 548                 errstr = ext4_decode_error(sb, errno, nbuf);
 549                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 550                        sb->s_id, function, line, errstr);
 551         }
 552
 553         save_error_info(sb, function, line);
 554         ext4_handle_error(sb);
 555 }
 556
 557 /*
 558  * ext4_abort is a much stronger failure handler than ext4_error.  The
 559  * abort function may be used to deal with unrecoverable failures such
 560  * as journal IO errors or ENOMEM at a critical moment in log management.
 561  *
 562  * We unconditionally force the filesystem into an ABORT|READONLY state,
 563  * unless the error response on the fs has been set to panic in which
 564  * case we take the easy way out and panic immediately.
 565  */
 566
 567 void __ext4_abort(struct super_block *sb, const char *function,
 568                 unsigned int line, const char *fmt, ...)
 569 {
 570         va_list args;
 571
 572         save_error_info(sb, function, line);
 573         va_start(args, fmt);
 574         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 575                function, line);
 576         vprintk(fmt, args);
 577         printk("\n");
 578         va_end(args);
 579
 580         if ((sb->s_flags & MS_RDONLY) == 0) {
 581                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 582                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 583                 /*
 584                  * Make sure updated value of ->s_mount_flags will be visible
 585                  * before ->s_flags update
 586                  */
 587                 smp_wmb();
 588                 sb->s_flags |= MS_RDONLY;
 589                 if (EXT4_SB(sb)->s_journal)
 590                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 591                 save_error_info(sb, function, line);
 592         }
 593         if (test_opt(sb, ERRORS_PANIC)) {
 594                 if (EXT4_SB(sb)->s_journal &&
 595                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 596                         return;
 597                 panic("EXT4-fs panic from previous error\n");
 598         }
 599 }
 600
 601 void __ext4_msg(struct super_block *sb,
 602                 const char *prefix, const char *fmt, ...)
 603 {
 604         struct va_format vaf;
 605         va_list args;
 606
 607         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 608                 return;
 609
 610         va_start(args, fmt);
 611         vaf.fmt = fmt;
 612         vaf.va = &args;
 613         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 614         va_end(args);
 615 }
 616
 617 #define ext4_warning_ratelimit(sb)                                      \
 618                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 619                              "EXT4-fs warning")
 620
 621 void __ext4_warning(struct super_block *sb, const char *function,
 622                     unsigned int line, const char *fmt, ...)
 623 {
 624         struct va_format vaf;
 625         va_list args;
 626
 627         if (!ext4_warning_ratelimit(sb))
 628                 return;
 629
 630         va_start(args, fmt);
 631         vaf.fmt = fmt;
 632         vaf.va = &args;
 633         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 634                sb->s_id, function, line, &vaf);
 635         va_end(args);
 636 }
 637
 638 void __ext4_warning_inode(const struct inode *inode, const char *function,
 639                           unsigned int line, const char *fmt, ...)
 640 {
 641         struct va_format vaf;
 642         va_list args;
 643
 644         if (!ext4_warning_ratelimit(inode->i_sb))
 645                 return;
 646
 647         va_start(args, fmt);
 648         vaf.fmt = fmt;
 649         vaf.va = &args;
 650         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 651                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 652                function, line, inode->i_ino, current->comm, &vaf);
 653         va_end(args);
 654 }
 655
 656 void __ext4_grp_locked_error(const char *function, unsigned int line,
 657                              struct super_block *sb, ext4_group_t grp,
 658                              unsigned long ino, ext4_fsblk_t block,
 659                              const char *fmt, ...)
 660 __releases(bitlock)
 661 __acquires(bitlock)
 662 {
 663         struct va_format vaf;
 664         va_list args;
 665         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 666
 667         es->s_last_error_ino = cpu_to_le32(ino);
 668         es->s_last_error_block = cpu_to_le64(block);
 669         __save_error_info(sb, function, line);
 670
 671         if (ext4_error_ratelimit(sb)) {
 672                 va_start(args, fmt);
 673                 vaf.fmt = fmt;
 674                 vaf.va = &args;
 675                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 676                        sb->s_id, function, line, grp);
 677                 if (ino)
 678                         printk(KERN_CONT "inode %lu: ", ino);
 679                 if (block)
 680                         printk(KERN_CONT "block %llu:",
 681                                (unsigned long long) block);
 682                 printk(KERN_CONT "%pV\n", &vaf);
 683                 va_end(args);
 684         }
 685
 686         if (test_opt(sb, ERRORS_CONT)) {
 687                 ext4_commit_super(sb, 0);
 688                 return;
 689         }
 690
 691         ext4_unlock_group(sb, grp);
 692         ext4_commit_super(sb, 1);
 693         ext4_handle_error(sb);
 694         /*
 695          * We only get here in the ERRORS_RO case; relocking the group
 696          * may be dangerous, but nothing bad will happen since the
 697          * filesystem will have already been marked read/only and the
 698          * journal has been aborted.  We return 1 as a hint to callers
 699          * who might what to use the return value from
 700          * ext4_grp_locked_error() to distinguish between the
 701          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 702          * aggressively from the ext4 function in question, with a
 703          * more appropriate error code.
 704          */
 705         ext4_lock_group(sb, grp);
 706         return;
 707 }
 708
 709 void ext4_update_dynamic_rev(struct super_block *sb)
 710 {
 711         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 712
 713         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 714                 return;
 715
 716         ext4_warning(sb,
 717                      "updating to rev %d because of new feature flag, "
 718                      "running e2fsck is recommended",
 719                      EXT4_DYNAMIC_REV);
 720
 721         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 722         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 723         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 724         /* leave es->s_feature_*compat flags alone */
 725         /* es->s_uuid will be set by e2fsck if empty */
 726
 727         /*
 728          * The rest of the superblock fields should be zero, and if not it
 729          * means they are likely already in use, so leave them alone.  We
 730          * can leave it up to e2fsck to clean up any inconsistencies there.
 731          */
 732 }
 733
 734 /*
 735  * Open the external journal device
 736  */
 737 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 738 {
 739         struct block_device *bdev;
 740         char b[BDEVNAME_SIZE];
 741
 742         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 743         if (IS_ERR(bdev))
 744                 goto fail;
 745         return bdev;
 746
 747 fail:
 748         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 749                         __bdevname(dev, b), PTR_ERR(bdev));
 750         return NULL;
 751 }
 752
 753 /*
 754  * Release the journal device
 755  */
 756 static void ext4_blkdev_put(struct block_device *bdev)
 757 {
 758         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 759 }
 760
 761 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 762 {
 763         struct block_device *bdev;
 764         bdev = sbi->journal_bdev;
 765         if (bdev) {
 766                 ext4_blkdev_put(bdev);
 767                 sbi->journal_bdev = NULL;
 768         }
 769 }
 770
 771 static inline struct inode *orphan_list_entry(struct list_head *l)
 772 {
 773         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 774 }
 775
 776 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 777 {
 778         struct list_head *l;
 779
 780         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 781                  le32_to_cpu(sbi->s_es->s_last_orphan));
 782
 783         printk(KERN_ERR "sb_info orphan list:\n");
 784         list_for_each(l, &sbi->s_orphan) {
 785                 struct inode *inode = orphan_list_entry(l);
 786                 printk(KERN_ERR "  "
 787                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 788                        inode->i_sb->s_id, inode->i_ino, inode,
 789                        inode->i_mode, inode->i_nlink,
 790                        NEXT_ORPHAN(inode));
 791         }
 792 }
 793
 794 static void ext4_put_super(struct super_block *sb)
 795 {
 796         struct ext4_sb_info *sbi = EXT4_SB(sb);
 797         struct ext4_super_block *es = sbi->s_es;
 798         struct buffer_head **group_desc;
 799         struct flex_groups **flex_groups;
 800         int aborted = 0;
 801         int i, err;
 802
 803         ext4_unregister_li_request(sb);
 804         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 805
 806         flush_workqueue(sbi->rsv_conversion_wq);
 807         destroy_workqueue(sbi->rsv_conversion_wq);
 808
 809         if (sbi->s_journal) {
 810                 aborted = is_journal_aborted(sbi->s_journal);
 811                 err = jbd2_journal_destroy(sbi->s_journal);
 812                 sbi->s_journal = NULL;
 813                 if ((err < 0) && !aborted)
 814                         ext4_abort(sb, "Couldn't clean up the journal");
 815         }
 816
 817         ext4_unregister_sysfs(sb);
 818         ext4_es_unregister_shrinker(sbi);
 819         del_timer_sync(&sbi->s_err_report);
 820         ext4_release_system_zone(sb);
 821         ext4_mb_release(sb);
 822         ext4_ext_release(sb);
 823         ext4_xattr_put_super(sb);
 824
 825         if (!(sb->s_flags & MS_RDONLY) && !aborted) {
 826                 ext4_clear_feature_journal_needs_recovery(sb);
 827                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 828         }
 829         if (!(sb->s_flags & MS_RDONLY))
 830                 ext4_commit_super(sb, 1);
 831
 832         rcu_read_lock();
 833         group_desc = rcu_dereference(sbi->s_group_desc);
 834         for (i = 0; i < sbi->s_gdb_count; i++)
 835                 brelse(group_desc[i]);
 836         kvfree(group_desc);
 837         flex_groups = rcu_dereference(sbi->s_flex_groups);
 838         if (flex_groups) {
 839                 for (i = 0; i < sbi->s_flex_groups_allocated; i++)
 840                         kvfree(flex_groups[i]);
 841                 kvfree(flex_groups);
 842         }
 843         rcu_read_unlock();
 844         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 845         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 846         percpu_counter_destroy(&sbi->s_dirs_counter);
 847         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 848         brelse(sbi->s_sbh);
 849 #ifdef CONFIG_QUOTA
 850         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 851                 kfree(sbi->s_qf_names[i]);
 852 #endif
 853
 854         /* Debugging code just in case the in-memory inode orphan list
 855          * isn't empty.  The on-disk one can be non-empty if we've
 856          * detected an error and taken the fs readonly, but the
 857          * in-memory list had better be clean by this point. */
 858         if (!list_empty(&sbi->s_orphan))
 859                 dump_orphan_list(sb, sbi);
 860         J_ASSERT(list_empty(&sbi->s_orphan));
 861
 862         sync_blockdev(sb->s_bdev);
 863         invalidate_bdev(sb->s_bdev);
 864         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 865                 /*
 866                  * Invalidate the journal device's buffers.  We don't want them
 867                  * floating about in memory - the physical journal device may
 868                  * hotswapped, and it breaks the `ro-after' testing code.
 869                  */
 870                 sync_blockdev(sbi->journal_bdev);
 871                 invalidate_bdev(sbi->journal_bdev);
 872                 ext4_blkdev_remove(sbi);
 873         }
 874         if (sbi->s_mb_cache) {
 875                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 876                 sbi->s_mb_cache = NULL;
 877         }
 878         if (sbi->s_mmp_tsk)
 879                 kthread_stop(sbi->s_mmp_tsk);
 880         sb->s_fs_info = NULL;
 881         /*
 882          * Now that we are completely done shutting down the
 883          * superblock, we need to actually destroy the kobject.
 884          */
 885         kobject_put(&sbi->s_kobj);
 886         wait_for_completion(&sbi->s_kobj_unregister);
 887         if (sbi->s_chksum_driver)
 888                 crypto_free_shash(sbi->s_chksum_driver);
 889         kfree(sbi->s_blockgroup_lock);
 890         kfree(sbi);
 891 }
 892
 893 static struct kmem_cache *ext4_inode_cachep;
 894
 895 /*
 896  * Called inside transaction, so use GFP_NOFS
 897  */
 898 static struct inode *ext4_alloc_inode(struct super_block *sb)
 899 {
 900         struct ext4_inode_info *ei;
 901
 902         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 903         if (!ei)
 904                 return NULL;
 905
 906         ei->vfs_inode.i_version = 1;
 907         spin_lock_init(&ei->i_raw_lock);
 908         INIT_LIST_HEAD(&ei->i_prealloc_list);
 909         spin_lock_init(&ei->i_prealloc_lock);
 910         ext4_es_init_tree(&ei->i_es_tree);
 911         rwlock_init(&ei->i_es_lock);
 912         INIT_LIST_HEAD(&ei->i_es_list);
 913         ei->i_es_all_nr = 0;
 914         ei->i_es_shk_nr = 0;
 915         ei->i_es_shrink_lblk = 0;
 916         ei->i_reserved_data_blocks = 0;
 917         ei->i_reserved_meta_blocks = 0;
 918         ei->i_allocated_meta_blocks = 0;
 919         ei->i_da_metadata_calc_len = 0;
 920         ei->i_da_metadata_calc_last_lblock = 0;
 921         spin_lock_init(&(ei->i_block_reservation_lock));
 922 #ifdef CONFIG_QUOTA
 923         ei->i_reserved_quota = 0;
 924         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 925 #endif
 926         ei->jinode = NULL;
 927         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 928         spin_lock_init(&ei->i_completed_io_lock);
 929         ei->i_sync_tid = 0;
 930         ei->i_datasync_tid = 0;
 931         atomic_set(&ei->i_ioend_count, 0);
 932         atomic_set(&ei->i_unwritten, 0);
 933         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 934 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 935         ei->i_crypt_info = NULL;
 936 #endif
 937         return &ei->vfs_inode;
 938 }
 939
 940 static int ext4_drop_inode(struct inode *inode)
 941 {
 942         int drop = generic_drop_inode(inode);
 943
 944         trace_ext4_drop_inode(inode, drop);
 945         return drop;
 946 }
 947
 948 static void ext4_i_callback(struct rcu_head *head)
 949 {
 950         struct inode *inode = container_of(head, struct inode, i_rcu);
 951         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 952 }
 953
 954 static void ext4_destroy_inode(struct inode *inode)
 955 {
 956         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 957                 ext4_msg(inode->i_sb, KERN_ERR,
 958                          "Inode %lu (%p): orphan list check failed!",
 959                          inode->i_ino, EXT4_I(inode));
 960                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 961                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 962                                 true);
 963                 dump_stack();
 964         }
 965         call_rcu(&inode->i_rcu, ext4_i_callback);
 966 }
 967
 968 static void init_once(void *foo)
 969 {
 970         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 971
 972         INIT_LIST_HEAD(&ei->i_orphan);
 973         init_rwsem(&ei->xattr_sem);
 974         init_rwsem(&ei->i_data_sem);
 975         init_rwsem(&ei->i_mmap_sem);
 976         inode_init_once(&ei->vfs_inode);
 977 }
 978
 979 static int __init init_inodecache(void)
 980 {
 981         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 982                                              sizeof(struct ext4_inode_info),
 983                                              0, (SLAB_RECLAIM_ACCOUNT|
 984                                                 SLAB_MEM_SPREAD),
 985                                              init_once);
 986         if (ext4_inode_cachep == NULL)
 987                 return -ENOMEM;
 988         return 0;
 989 }
 990
 991 static void destroy_inodecache(void)
 992 {
 993         /*
 994          * Make sure all delayed rcu free inodes are flushed before we
 995          * destroy cache.
 996          */
 997         rcu_barrier();
 998         kmem_cache_destroy(ext4_inode_cachep);
 999 }
1000
1001 void ext4_clear_inode(struct inode *inode)
1002 {
1003         invalidate_inode_buffers(inode);
1004         clear_inode(inode);
1005         dquot_drop(inode);
1006         ext4_discard_preallocations(inode);
1007         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1008         if (EXT4_I(inode)->jinode) {
1009                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1010                                                EXT4_I(inode)->jinode);
1011                 jbd2_free_inode(EXT4_I(inode)->jinode);
1012                 EXT4_I(inode)->jinode = NULL;
1013         }
1014 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1015         if (EXT4_I(inode)->i_crypt_info)
1016                 ext4_free_encryption_info(inode, EXT4_I(inode)->i_crypt_info);
1017 #endif
1018 }
1019
1020 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1021                                         u64 ino, u32 generation)
1022 {
1023         struct inode *inode;
1024
1025         /*
1026          * Currently we don't know the generation for parent directory, so
1027          * a generation of 0 means "accept any"
1028          */
1029         inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1030         if (IS_ERR(inode))
1031                 return ERR_CAST(inode);
1032         if (generation && inode->i_generation != generation) {
1033                 iput(inode);
1034                 return ERR_PTR(-ESTALE);
1035         }
1036
1037         return inode;
1038 }
1039
1040 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1041                                         int fh_len, int fh_type)
1042 {
1043         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1044                                     ext4_nfs_get_inode);
1045 }
1046
1047 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1048                                         int fh_len, int fh_type)
1049 {
1050         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1051                                     ext4_nfs_get_inode);
1052 }
1053
1054 static int ext4_nfs_commit_metadata(struct inode *inode)
1055 {
1056         struct writeback_control wbc = {
1057                 .sync_mode = WB_SYNC_ALL
1058         };
1059
1060         trace_ext4_nfs_commit_metadata(inode);
1061         return ext4_write_inode(inode, &wbc);
1062 }
1063
1064 /*
1065  * Try to release metadata pages (indirect blocks, directories) which are
1066  * mapped via the block device.  Since these pages could have journal heads
1067  * which would prevent try_to_free_buffers() from freeing them, we must use
1068  * jbd2 layer's try_to_free_buffers() function to release them.
1069  */
1070 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1071                                  gfp_t wait)
1072 {
1073         journal_t *journal = EXT4_SB(sb)->s_journal;
1074
1075         WARN_ON(PageChecked(page));
1076         if (!page_has_buffers(page))
1077                 return 0;
1078         if (journal)
1079                 return jbd2_journal_try_to_free_buffers(journal, page,
1080                                                 wait & ~__GFP_DIRECT_RECLAIM);
1081         return try_to_free_buffers(page);
1082 }
1083
1084 #ifdef CONFIG_QUOTA
1085 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1086 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1087
1088 static int ext4_write_dquot(struct dquot *dquot);
1089 static int ext4_acquire_dquot(struct dquot *dquot);
1090 static int ext4_release_dquot(struct dquot *dquot);
1091 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1092 static int ext4_write_info(struct super_block *sb, int type);
1093 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1094                          struct path *path);
1095 static int ext4_quota_off(struct super_block *sb, int type);
1096 static int ext4_quota_on_mount(struct super_block *sb, int type);
1097 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1098                                size_t len, loff_t off);
1099 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1100                                 const char *data, size_t len, loff_t off);
1101 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1102                              unsigned int flags);
1103 static int ext4_enable_quotas(struct super_block *sb);
1104
1105 static struct dquot **ext4_get_dquots(struct inode *inode)
1106 {
1107         return EXT4_I(inode)->i_dquot;
1108 }
1109
1110 static const struct dquot_operations ext4_quota_operations = {
1111         .get_reserved_space = ext4_get_reserved_space,
1112         .write_dquot    = ext4_write_dquot,
1113         .acquire_dquot  = ext4_acquire_dquot,
1114         .release_dquot  = ext4_release_dquot,
1115         .mark_dirty     = ext4_mark_dquot_dirty,
1116         .write_info     = ext4_write_info,
1117         .alloc_dquot    = dquot_alloc,
1118         .destroy_dquot  = dquot_destroy,
1119 };
1120
1121 static const struct quotactl_ops ext4_qctl_operations = {
1122         .quota_on       = ext4_quota_on,
1123         .quota_off      = ext4_quota_off,
1124         .quota_sync     = dquot_quota_sync,
1125         .get_state      = dquot_get_state,
1126         .set_info       = dquot_set_dqinfo,
1127         .get_dqblk      = dquot_get_dqblk,
1128         .set_dqblk      = dquot_set_dqblk
1129 };
1130 #endif
1131
1132 static const struct super_operations ext4_sops = {
1133         .alloc_inode    = ext4_alloc_inode,
1134         .destroy_inode  = ext4_destroy_inode,
1135         .write_inode    = ext4_write_inode,
1136         .dirty_inode    = ext4_dirty_inode,
1137         .drop_inode     = ext4_drop_inode,
1138         .evict_inode    = ext4_evict_inode,
1139         .put_super      = ext4_put_super,
1140         .sync_fs        = ext4_sync_fs,
1141         .freeze_fs      = ext4_freeze,
1142         .unfreeze_fs    = ext4_unfreeze,
1143         .statfs         = ext4_statfs,
1144         .remount_fs     = ext4_remount,
1145         .show_options   = ext4_show_options,
1146 #ifdef CONFIG_QUOTA
1147         .quota_read     = ext4_quota_read,
1148         .quota_write    = ext4_quota_write,
1149         .get_dquots     = ext4_get_dquots,
1150 #endif
1151         .bdev_try_to_free_page = bdev_try_to_free_page,
1152 };
1153
1154 static const struct export_operations ext4_export_ops = {
1155         .fh_to_dentry = ext4_fh_to_dentry,
1156         .fh_to_parent = ext4_fh_to_parent,
1157         .get_parent = ext4_get_parent,
1158         .commit_metadata = ext4_nfs_commit_metadata,
1159 };
1160
1161 enum {
1162         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1163         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1164         Opt_nouid32, Opt_debug, Opt_removed,
1165         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1166         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1167         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1168         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1169         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1170         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1171         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1172         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1173         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1174         Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
1175         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1176         Opt_lazytime, Opt_nolazytime,
1177         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1178         Opt_inode_readahead_blks, Opt_journal_ioprio,
1179         Opt_dioread_nolock, Opt_dioread_lock,
1180         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1181         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1182 };
1183
1184 static const match_table_t tokens = {
1185         {Opt_bsd_df, "bsddf"},
1186         {Opt_minix_df, "minixdf"},
1187         {Opt_grpid, "grpid"},
1188         {Opt_grpid, "bsdgroups"},
1189         {Opt_nogrpid, "nogrpid"},
1190         {Opt_nogrpid, "sysvgroups"},
1191         {Opt_resgid, "resgid=%u"},
1192         {Opt_resuid, "resuid=%u"},
1193         {Opt_sb, "sb=%u"},
1194         {Opt_err_cont, "errors=continue"},
1195         {Opt_err_panic, "errors=panic"},
1196         {Opt_err_ro, "errors=remount-ro"},
1197         {Opt_nouid32, "nouid32"},
1198         {Opt_debug, "debug"},
1199         {Opt_removed, "oldalloc"},
1200         {Opt_removed, "orlov"},
1201         {Opt_user_xattr, "user_xattr"},
1202         {Opt_nouser_xattr, "nouser_xattr"},
1203         {Opt_acl, "acl"},
1204         {Opt_noacl, "noacl"},
1205         {Opt_noload, "norecovery"},
1206         {Opt_noload, "noload"},
1207         {Opt_removed, "nobh"},
1208         {Opt_removed, "bh"},
1209         {Opt_commit, "commit=%u"},
1210         {Opt_min_batch_time, "min_batch_time=%u"},
1211         {Opt_max_batch_time, "max_batch_time=%u"},
1212         {Opt_journal_dev, "journal_dev=%u"},
1213         {Opt_journal_path, "journal_path=%s"},
1214         {Opt_journal_checksum, "journal_checksum"},
1215         {Opt_nojournal_checksum, "nojournal_checksum"},
1216         {Opt_journal_async_commit, "journal_async_commit"},
1217         {Opt_abort, "abort"},
1218         {Opt_data_journal, "data=journal"},
1219         {Opt_data_ordered, "data=ordered"},
1220         {Opt_data_writeback, "data=writeback"},
1221         {Opt_data_err_abort, "data_err=abort"},
1222         {Opt_data_err_ignore, "data_err=ignore"},
1223         {Opt_offusrjquota, "usrjquota="},
1224         {Opt_usrjquota, "usrjquota=%s"},
1225         {Opt_offgrpjquota, "grpjquota="},
1226         {Opt_grpjquota, "grpjquota=%s"},
1227         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1228         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1229         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1230         {Opt_grpquota, "grpquota"},
1231         {Opt_noquota, "noquota"},
1232         {Opt_quota, "quota"},
1233         {Opt_usrquota, "usrquota"},
1234         {Opt_barrier, "barrier=%u"},
1235         {Opt_barrier, "barrier"},
1236         {Opt_nobarrier, "nobarrier"},
1237         {Opt_i_version, "i_version"},
1238         {Opt_dax, "dax"},
1239         {Opt_stripe, "stripe=%u"},
1240         {Opt_delalloc, "delalloc"},
1241         {Opt_lazytime, "lazytime"},
1242         {Opt_nolazytime, "nolazytime"},
1243         {Opt_nodelalloc, "nodelalloc"},
1244         {Opt_removed, "mblk_io_submit"},
1245         {Opt_removed, "nomblk_io_submit"},
1246         {Opt_block_validity, "block_validity"},
1247         {Opt_noblock_validity, "noblock_validity"},
1248         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1249         {Opt_journal_ioprio, "journal_ioprio=%u"},
1250         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1251         {Opt_auto_da_alloc, "auto_da_alloc"},
1252         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1253         {Opt_dioread_nolock, "dioread_nolock"},
1254         {Opt_dioread_lock, "dioread_lock"},
1255         {Opt_discard, "discard"},
1256         {Opt_nodiscard, "nodiscard"},
1257         {Opt_init_itable, "init_itable=%u"},
1258         {Opt_init_itable, "init_itable"},
1259         {Opt_noinit_itable, "noinit_itable"},
1260         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1261         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1262         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1263         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1264         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1265         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1266         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1267         {Opt_err, NULL},
1268 };
1269
1270 static ext4_fsblk_t get_sb_block(void **data)
1271 {
1272         ext4_fsblk_t    sb_block;
1273         char            *options = (char *) *data;
1274
1275         if (!options || strncmp(options, "sb=", 3) != 0)
1276                 return 1;       /* Default location */
1277
1278         options += 3;
1279         /* TODO: use simple_strtoll with >32bit ext4 */
1280         sb_block = simple_strtoul(options, &options, 0);
1281         if (*options && *options != ',') {
1282                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1283                        (char *) *data);
1284                 return 1;
1285         }
1286         if (*options == ',')
1287                 options++;
1288         *data = (void *) options;
1289
1290         return sb_block;
1291 }
1292
1293 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1294 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1295         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1296
1297 #ifdef CONFIG_QUOTA
1298 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1299 {
1300         struct ext4_sb_info *sbi = EXT4_SB(sb);
1301         char *qname;
1302         int ret = -1;
1303
1304         if (sb_any_quota_loaded(sb) &&
1305                 !sbi->s_qf_names[qtype]) {
1306                 ext4_msg(sb, KERN_ERR,
1307                         "Cannot change journaled "
1308                         "quota options when quota turned on");
1309                 return -1;
1310         }
1311         if (ext4_has_feature_quota(sb)) {
1312                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1313                          "ignored when QUOTA feature is enabled");
1314                 return 1;
1315         }
1316         qname = match_strdup(args);
1317         if (!qname) {
1318                 ext4_msg(sb, KERN_ERR,
1319                         "Not enough memory for storing quotafile name");
1320                 return -1;
1321         }
1322         if (sbi->s_qf_names[qtype]) {
1323                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1324                         ret = 1;
1325                 else
1326                         ext4_msg(sb, KERN_ERR,
1327                                  "%s quota file already specified",
1328                                  QTYPE2NAME(qtype));
1329                 goto errout;
1330         }
1331         if (strchr(qname, '/')) {
1332                 ext4_msg(sb, KERN_ERR,
1333                         "quotafile must be on filesystem root");
1334                 goto errout;
1335         }
1336         sbi->s_qf_names[qtype] = qname;
1337         set_opt(sb, QUOTA);
1338         return 1;
1339 errout:
1340         kfree(qname);
1341         return ret;
1342 }
1343
1344 static int clear_qf_name(struct super_block *sb, int qtype)
1345 {
1346
1347         struct ext4_sb_info *sbi = EXT4_SB(sb);
1348
1349         if (sb_any_quota_loaded(sb) &&
1350                 sbi->s_qf_names[qtype]) {
1351                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1352                         " when quota turned on");
1353                 return -1;
1354         }
1355         kfree(sbi->s_qf_names[qtype]);
1356         sbi->s_qf_names[qtype] = NULL;
1357         return 1;
1358 }
1359 #endif
1360
1361 #define MOPT_SET        0x0001
1362 #define MOPT_CLEAR      0x0002
1363 #define MOPT_NOSUPPORT  0x0004
1364 #define MOPT_EXPLICIT   0x0008
1365 #define MOPT_CLEAR_ERR  0x0010
1366 #define MOPT_GTE0       0x0020
1367 #ifdef CONFIG_QUOTA
1368 #define MOPT_Q          0
1369 #define MOPT_QFMT       0x0040
1370 #else
1371 #define MOPT_Q          MOPT_NOSUPPORT
1372 #define MOPT_QFMT       MOPT_NOSUPPORT
1373 #endif
1374 #define MOPT_DATAJ      0x0080
1375 #define MOPT_NO_EXT2    0x0100
1376 #define MOPT_NO_EXT3    0x0200
1377 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1378 #define MOPT_STRING     0x0400
1379
1380 static const struct mount_opts {
1381         int     token;
1382         int     mount_opt;
1383         int     flags;
1384 } ext4_mount_opts[] = {
1385         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1386         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1387         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1388         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1389         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1390         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1391         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1392          MOPT_EXT4_ONLY | MOPT_SET},
1393         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1394          MOPT_EXT4_ONLY | MOPT_CLEAR},
1395         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1396         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1397         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1398          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1399         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1400          MOPT_EXT4_ONLY | MOPT_CLEAR},
1401         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1402          MOPT_EXT4_ONLY | MOPT_CLEAR},
1403         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1404          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1405         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1406                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1407          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1408         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1409         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1410         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1411         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1412         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1413          MOPT_NO_EXT2 | MOPT_SET},
1414         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1415          MOPT_NO_EXT2 | MOPT_CLEAR},
1416         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1417         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1418         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1419         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1420         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1421         {Opt_commit, 0, MOPT_GTE0},
1422         {Opt_max_batch_time, 0, MOPT_GTE0},
1423         {Opt_min_batch_time, 0, MOPT_GTE0},
1424         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1425         {Opt_init_itable, 0, MOPT_GTE0},
1426         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1427         {Opt_stripe, 0, MOPT_GTE0},
1428         {Opt_resuid, 0, MOPT_GTE0},
1429         {Opt_resgid, 0, MOPT_GTE0},
1430         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1431         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1432         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1433         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1434         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1435         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1436          MOPT_NO_EXT2 | MOPT_DATAJ},
1437         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1438         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1439 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1440         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1441         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1442 #else
1443         {Opt_acl, 0, MOPT_NOSUPPORT},
1444         {Opt_noacl, 0, MOPT_NOSUPPORT},
1445 #endif
1446         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1447         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1448         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1449         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1450                                                         MOPT_SET | MOPT_Q},
1451         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1452                                                         MOPT_SET | MOPT_Q},
1453         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1454                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1455         {Opt_usrjquota, 0, MOPT_Q | MOPT_STRING},
1456         {Opt_grpjquota, 0, MOPT_Q | MOPT_STRING},
1457         {Opt_offusrjquota, 0, MOPT_Q},
1458         {Opt_offgrpjquota, 0, MOPT_Q},
1459         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1460         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1461         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1462         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1463         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1464         {Opt_err, 0, 0}
1465 };
1466
1467 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1468                             substring_t *args, unsigned long *journal_devnum,
1469                             unsigned int *journal_ioprio, int is_remount)
1470 {
1471         struct ext4_sb_info *sbi = EXT4_SB(sb);
1472         const struct mount_opts *m;
1473         kuid_t uid;
1474         kgid_t gid;
1475         int arg = 0;
1476
1477 #ifdef CONFIG_QUOTA
1478         if (token == Opt_usrjquota)
1479                 return set_qf_name(sb, USRQUOTA, &args[0]);
1480         else if (token == Opt_grpjquota)
1481                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1482         else if (token == Opt_offusrjquota)
1483                 return clear_qf_name(sb, USRQUOTA);
1484         else if (token == Opt_offgrpjquota)
1485                 return clear_qf_name(sb, GRPQUOTA);
1486 #endif
1487         switch (token) {
1488         case Opt_noacl:
1489         case Opt_nouser_xattr:
1490                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1491                 break;
1492         case Opt_sb:
1493                 return 1;       /* handled by get_sb_block() */
1494         case Opt_removed:
1495                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1496                 return 1;
1497         case Opt_abort:
1498                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1499                 return 1;
1500         case Opt_i_version:
1501                 sb->s_flags |= MS_I_VERSION;
1502                 return 1;
1503         case Opt_lazytime:
1504                 sb->s_flags |= MS_LAZYTIME;
1505                 return 1;
1506         case Opt_nolazytime:
1507                 sb->s_flags &= ~MS_LAZYTIME;
1508                 return 1;
1509         }
1510
1511         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1512                 if (token == m->token)
1513                         break;
1514
1515         if (m->token == Opt_err) {
1516                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1517                          "or missing value", opt);
1518                 return -1;
1519         }
1520
1521         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1522                 ext4_msg(sb, KERN_ERR,
1523                          "Mount option \"%s\" incompatible with ext2", opt);
1524                 return -1;
1525         }
1526         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1527                 ext4_msg(sb, KERN_ERR,
1528                          "Mount option \"%s\" incompatible with ext3", opt);
1529                 return -1;
1530         }
1531
1532         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1533                 return -1;
1534         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1535                 return -1;
1536         if (m->flags & MOPT_EXPLICIT) {
1537                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1538                         set_opt2(sb, EXPLICIT_DELALLOC);
1539                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1540                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1541                 } else
1542                         return -1;
1543         }
1544         if (m->flags & MOPT_CLEAR_ERR)
1545                 clear_opt(sb, ERRORS_MASK);
1546         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1547                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1548                          "options when quota turned on");
1549                 return -1;
1550         }
1551
1552         if (m->flags & MOPT_NOSUPPORT) {
1553                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1554         } else if (token == Opt_commit) {
1555                 if (arg == 0)
1556                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1557                 sbi->s_commit_interval = HZ * arg;
1558         } else if (token == Opt_max_batch_time) {
1559                 sbi->s_max_batch_time = arg;
1560         } else if (token == Opt_min_batch_time) {
1561                 sbi->s_min_batch_time = arg;
1562         } else if (token == Opt_inode_readahead_blks) {
1563                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1564                         ext4_msg(sb, KERN_ERR,
1565                                  "EXT4-fs: inode_readahead_blks must be "
1566                                  "0 or a power of 2 smaller than 2^31");
1567                         return -1;
1568                 }
1569                 sbi->s_inode_readahead_blks = arg;
1570         } else if (token == Opt_init_itable) {
1571                 set_opt(sb, INIT_INODE_TABLE);
1572                 if (!args->from)
1573                         arg = EXT4_DEF_LI_WAIT_MULT;
1574                 sbi->s_li_wait_mult = arg;
1575         } else if (token == Opt_max_dir_size_kb) {
1576                 sbi->s_max_dir_size_kb = arg;
1577         } else if (token == Opt_stripe) {
1578                 sbi->s_stripe = arg;
1579         } else if (token == Opt_resuid) {
1580                 uid = make_kuid(current_user_ns(), arg);
1581                 if (!uid_valid(uid)) {
1582                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1583                         return -1;
1584                 }
1585                 sbi->s_resuid = uid;
1586         } else if (token == Opt_resgid) {
1587                 gid = make_kgid(current_user_ns(), arg);
1588                 if (!gid_valid(gid)) {
1589                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1590                         return -1;
1591                 }
1592                 sbi->s_resgid = gid;
1593         } else if (token == Opt_journal_dev) {
1594                 if (is_remount) {
1595                         ext4_msg(sb, KERN_ERR,
1596                                  "Cannot specify journal on remount");
1597                         return -1;
1598                 }
1599                 *journal_devnum = arg;
1600         } else if (token == Opt_journal_path) {
1601                 char *journal_path;
1602                 struct inode *journal_inode;
1603                 struct path path;
1604                 int error;
1605
1606                 if (is_remount) {
1607                         ext4_msg(sb, KERN_ERR,
1608                                  "Cannot specify journal on remount");
1609                         return -1;
1610                 }
1611                 journal_path = match_strdup(&args[0]);
1612                 if (!journal_path) {
1613                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1614                                 "journal device string");
1615                         return -1;
1616                 }
1617
1618                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1619                 if (error) {
1620                         ext4_msg(sb, KERN_ERR, "error: could not find "
1621                                 "journal device path: error %d", error);
1622                         kfree(journal_path);
1623                         return -1;
1624                 }
1625
1626                 journal_inode = d_inode(path.dentry);
1627                 if (!S_ISBLK(journal_inode->i_mode)) {
1628                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1629                                 "is not a block device", journal_path);
1630                         path_put(&path);
1631                         kfree(journal_path);
1632                         return -1;
1633                 }
1634
1635                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1636                 path_put(&path);
1637                 kfree(journal_path);
1638         } else if (token == Opt_journal_ioprio) {
1639                 if (arg > 7) {
1640                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1641                                  " (must be 0-7)");
1642                         return -1;
1643                 }
1644                 *journal_ioprio =
1645                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1646         } else if (token == Opt_test_dummy_encryption) {
1647 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1648                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1649                 ext4_msg(sb, KERN_WARNING,
1650                          "Test dummy encryption mode enabled");
1651 #else
1652                 ext4_msg(sb, KERN_WARNING,
1653                          "Test dummy encryption mount option ignored");
1654 #endif
1655         } else if (m->flags & MOPT_DATAJ) {
1656                 if (is_remount) {
1657                         if (!sbi->s_journal)
1658                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1659                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1660                                 ext4_msg(sb, KERN_ERR,
1661                                          "Cannot change data mode on remount");
1662                                 return -1;
1663                         }
1664                 } else {
1665                         clear_opt(sb, DATA_FLAGS);
1666                         sbi->s_mount_opt |= m->mount_opt;
1667                 }
1668 #ifdef CONFIG_QUOTA
1669         } else if (m->flags & MOPT_QFMT) {
1670                 if (sb_any_quota_loaded(sb) &&
1671                     sbi->s_jquota_fmt != m->mount_opt) {
1672                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1673                                  "quota options when quota turned on");
1674                         return -1;
1675                 }
1676                 if (ext4_has_feature_quota(sb)) {
1677                         ext4_msg(sb, KERN_INFO,
1678                                  "Quota format mount options ignored "
1679                                  "when QUOTA feature is enabled");
1680                         return 1;
1681                 }
1682                 sbi->s_jquota_fmt = m->mount_opt;
1683 #endif
1684         } else if (token == Opt_dax) {
1685 #ifdef CONFIG_FS_DAX
1686                 ext4_msg(sb, KERN_WARNING,
1687                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1688                         sbi->s_mount_opt |= m->mount_opt;
1689 #else
1690                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1691                 return -1;
1692 #endif
1693         } else {
1694                 if (!args->from)
1695                         arg = 1;
1696                 if (m->flags & MOPT_CLEAR)
1697                         arg = !arg;
1698                 else if (unlikely(!(m->flags & MOPT_SET))) {
1699                         ext4_msg(sb, KERN_WARNING,
1700                                  "buggy handling of option %s", opt);
1701                         WARN_ON(1);
1702                         return -1;
1703                 }
1704                 if (arg != 0)
1705                         sbi->s_mount_opt |= m->mount_opt;
1706                 else
1707                         sbi->s_mount_opt &= ~m->mount_opt;
1708         }
1709         return 1;
1710 }
1711
1712 static int parse_options(char *options, struct super_block *sb,
1713                          unsigned long *journal_devnum,
1714                          unsigned int *journal_ioprio,
1715                          int is_remount)
1716 {
1717         struct ext4_sb_info *sbi = EXT4_SB(sb);
1718         char *p;
1719         substring_t args[MAX_OPT_ARGS];
1720         int token;
1721
1722         if (!options)
1723                 return 1;
1724
1725         while ((p = strsep(&options, ",")) != NULL) {
1726                 if (!*p)
1727                         continue;
1728                 /*
1729                  * Initialize args struct so we know whether arg was
1730                  * found; some options take optional arguments.
1731                  */
1732                 args[0].to = args[0].from = NULL;
1733                 token = match_token(p, tokens, args);
1734                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1735                                      journal_ioprio, is_remount) < 0)
1736                         return 0;
1737         }
1738 #ifdef CONFIG_QUOTA
1739         if (ext4_has_feature_quota(sb) &&
1740             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1741                 ext4_msg(sb, KERN_INFO, "Quota feature enabled, usrquota and grpquota "
1742                          "mount options ignored.");
1743                 clear_opt(sb, USRQUOTA);
1744                 clear_opt(sb, GRPQUOTA);
1745         } else if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1746                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1747                         clear_opt(sb, USRQUOTA);
1748
1749                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1750                         clear_opt(sb, GRPQUOTA);
1751
1752                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1753                         ext4_msg(sb, KERN_ERR, "old and new quota "
1754                                         "format mixing");
1755                         return 0;
1756                 }
1757
1758                 if (!sbi->s_jquota_fmt) {
1759                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1760                                         "not specified");
1761                         return 0;
1762                 }
1763         }
1764 #endif
1765         if (test_opt(sb, DIOREAD_NOLOCK)) {
1766                 int blocksize =
1767                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1768
1769                 if (blocksize < PAGE_CACHE_SIZE) {
1770                         ext4_msg(sb, KERN_ERR, "can't mount with "
1771                                  "dioread_nolock if block size != PAGE_SIZE");
1772                         return 0;
1773                 }
1774         }
1775         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1776             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1777                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1778                          "in data=ordered mode");
1779                 return 0;
1780         }
1781         return 1;
1782 }
1783
1784 static inline void ext4_show_quota_options(struct seq_file *seq,
1785                                            struct super_block *sb)
1786 {
1787 #if defined(CONFIG_QUOTA)
1788         struct ext4_sb_info *sbi = EXT4_SB(sb);
1789
1790         if (sbi->s_jquota_fmt) {
1791                 char *fmtname = "";
1792
1793                 switch (sbi->s_jquota_fmt) {
1794                 case QFMT_VFS_OLD:
1795                         fmtname = "vfsold";
1796                         break;
1797                 case QFMT_VFS_V0:
1798                         fmtname = "vfsv0";
1799                         break;
1800                 case QFMT_VFS_V1:
1801                         fmtname = "vfsv1";
1802                         break;
1803                 }
1804                 seq_printf(seq, ",jqfmt=%s", fmtname);
1805         }
1806
1807         if (sbi->s_qf_names[USRQUOTA])
1808                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1809
1810         if (sbi->s_qf_names[GRPQUOTA])
1811                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1812 #endif
1813 }
1814
1815 static const char *token2str(int token)
1816 {
1817         const struct match_token *t;
1818
1819         for (t = tokens; t->token != Opt_err; t++)
1820                 if (t->token == token && !strchr(t->pattern, '='))
1821                         break;
1822         return t->pattern;
1823 }
1824
1825 /*
1826  * Show an option if
1827  *  - it's set to a non-default value OR
1828  *  - if the per-sb default is different from the global default
1829  */
1830 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1831                               int nodefs)
1832 {
1833         struct ext4_sb_info *sbi = EXT4_SB(sb);
1834         struct ext4_super_block *es = sbi->s_es;
1835         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1836         const struct mount_opts *m;
1837         char sep = nodefs ? '\n' : ',';
1838
1839 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1840 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1841
1842         if (sbi->s_sb_block != 1)
1843                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1844
1845         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1846                 int want_set = m->flags & MOPT_SET;
1847                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1848                     (m->flags & MOPT_CLEAR_ERR))
1849                         continue;
1850                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1851                         continue; /* skip if same as the default */
1852                 if ((want_set &&
1853                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1854                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1855                         continue; /* select Opt_noFoo vs Opt_Foo */
1856                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1857         }
1858
1859         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1860             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1861                 SEQ_OPTS_PRINT("resuid=%u",
1862                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1863         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1864             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1865                 SEQ_OPTS_PRINT("resgid=%u",
1866                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1867         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1868         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1869                 SEQ_OPTS_PUTS("errors=remount-ro");
1870         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1871                 SEQ_OPTS_PUTS("errors=continue");
1872         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1873                 SEQ_OPTS_PUTS("errors=panic");
1874         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1875                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1876         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1877                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1878         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1879                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1880         if (sb->s_flags & MS_I_VERSION)
1881                 SEQ_OPTS_PUTS("i_version");
1882         if (nodefs || sbi->s_stripe)
1883                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1884         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1885                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1886                         SEQ_OPTS_PUTS("data=journal");
1887                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1888                         SEQ_OPTS_PUTS("data=ordered");
1889                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1890                         SEQ_OPTS_PUTS("data=writeback");
1891         }
1892         if (nodefs ||
1893             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1894                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1895                                sbi->s_inode_readahead_blks);
1896
1897         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1898                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1899                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1900         if (nodefs || sbi->s_max_dir_size_kb)
1901                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1902
1903         ext4_show_quota_options(seq, sb);
1904         return 0;
1905 }
1906
1907 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1908 {
1909         return _ext4_show_options(seq, root->d_sb, 0);
1910 }
1911
1912 int ext4_seq_options_show(struct seq_file *seq, void *offset)
1913 {
1914         struct super_block *sb = seq->private;
1915         int rc;
1916
1917         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1918         rc = _ext4_show_options(seq, sb, 1);
1919         seq_puts(seq, "\n");
1920         return rc;
1921 }
1922
1923 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1924                             int read_only)
1925 {
1926         struct ext4_sb_info *sbi = EXT4_SB(sb);
1927         int res = 0;
1928
1929         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1930                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1931                          "forcing read-only mode");
1932                 res = MS_RDONLY;
1933         }
1934         if (read_only)
1935                 goto done;
1936         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1937                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1938                          "running e2fsck is recommended");
1939         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1940                 ext4_msg(sb, KERN_WARNING,
1941                          "warning: mounting fs with errors, "
1942                          "running e2fsck is recommended");
1943         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1944                  le16_to_cpu(es->s_mnt_count) >=
1945                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1946                 ext4_msg(sb, KERN_WARNING,
1947                          "warning: maximal mount count reached, "
1948                          "running e2fsck is recommended");
1949         else if (le32_to_cpu(es->s_checkinterval) &&
1950                 (le32_to_cpu(es->s_lastcheck) +
1951                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1952                 ext4_msg(sb, KERN_WARNING,
1953                          "warning: checktime reached, "
1954                          "running e2fsck is recommended");
1955         if (!sbi->s_journal)
1956                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1957         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1958                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1959         le16_add_cpu(&es->s_mnt_count, 1);
1960         es->s_mtime = cpu_to_le32(get_seconds());
1961         ext4_update_dynamic_rev(sb);
1962         if (sbi->s_journal)
1963                 ext4_set_feature_journal_needs_recovery(sb);
1964
1965         ext4_commit_super(sb, 1);
1966 done:
1967         if (test_opt(sb, DEBUG))
1968                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1969                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1970                         sb->s_blocksize,
1971                         sbi->s_groups_count,
1972                         EXT4_BLOCKS_PER_GROUP(sb),
1973                         EXT4_INODES_PER_GROUP(sb),
1974                         sbi->s_mount_opt, sbi->s_mount_opt2);
1975
1976         cleancache_init_fs(sb);
1977         return res;
1978 }
1979
1980 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1981 {
1982         struct ext4_sb_info *sbi = EXT4_SB(sb);
1983         struct flex_groups **old_groups, **new_groups;
1984         int size, i, j;
1985
1986         if (!sbi->s_log_groups_per_flex)
1987                 return 0;
1988
1989         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1990         if (size <= sbi->s_flex_groups_allocated)
1991                 return 0;
1992
1993         new_groups = ext4_kvzalloc(roundup_pow_of_two(size *
1994                                    sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
1995         if (!new_groups) {
1996                 ext4_msg(sb, KERN_ERR,
1997                          "not enough memory for %d flex group pointers", size);
1998                 return -ENOMEM;
1999         }
2000         for (i = sbi->s_flex_groups_allocated; i < size; i++) {
2001                 new_groups[i] = ext4_kvzalloc(roundup_pow_of_two(
2002                                               sizeof(struct flex_groups)),
2003                                               GFP_KERNEL);
2004                 if (!new_groups[i]) {
2005                         for (j = sbi->s_flex_groups_allocated; j < i; j++)
2006                                 kvfree(new_groups[j]);
2007                         kvfree(new_groups);
2008                         ext4_msg(sb, KERN_ERR,
2009                                  "not enough memory for %d flex groups", size);
2010                         return -ENOMEM;
2011                 }
2012         }
2013         rcu_read_lock();
2014         old_groups = rcu_dereference(sbi->s_flex_groups);
2015         if (old_groups)
2016                 memcpy(new_groups, old_groups,
2017                        (sbi->s_flex_groups_allocated *
2018                         sizeof(struct flex_groups *)));
2019         rcu_read_unlock();
2020         rcu_assign_pointer(sbi->s_flex_groups, new_groups);
2021         sbi->s_flex_groups_allocated = size;
2022         if (old_groups)
2023                 ext4_kvfree_array_rcu(old_groups);
2024         return 0;
2025 }
2026
2027 static int ext4_fill_flex_info(struct super_block *sb)
2028 {
2029         struct ext4_sb_info *sbi = EXT4_SB(sb);
2030         struct ext4_group_desc *gdp = NULL;
2031         struct flex_groups *fg;
2032         ext4_group_t flex_group;
2033         int i, err;
2034
2035         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2036         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2037                 sbi->s_log_groups_per_flex = 0;
2038                 return 1;
2039         }
2040
2041         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2042         if (err)
2043                 goto failed;
2044
2045         for (i = 0; i < sbi->s_groups_count; i++) {
2046                 gdp = ext4_get_group_desc(sb, i, NULL);
2047
2048                 flex_group = ext4_flex_group(sbi, i);
2049                 fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
2050                 atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
2051                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2052                              &fg->free_clusters);
2053                 atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
2054         }
2055
2056         return 1;
2057 failed:
2058         return 0;
2059 }
2060
2061 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2062                                    struct ext4_group_desc *gdp)
2063 {
2064         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2065         __u16 crc = 0;
2066         __le32 le_group = cpu_to_le32(block_group);
2067         struct ext4_sb_info *sbi = EXT4_SB(sb);
2068
2069         if (ext4_has_metadata_csum(sbi->s_sb)) {
2070                 /* Use new metadata_csum algorithm */
2071                 __u32 csum32;
2072                 __u16 dummy_csum = 0;
2073
2074                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2075                                      sizeof(le_group));
2076                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2077                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2078                                      sizeof(dummy_csum));
2079                 offset += sizeof(dummy_csum);
2080                 if (offset < sbi->s_desc_size)
2081                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2082                                              sbi->s_desc_size - offset);
2083
2084                 crc = csum32 & 0xFFFF;
2085                 goto out;
2086         }
2087
2088         /* old crc16 code */
2089         if (!ext4_has_feature_gdt_csum(sb))
2090                 return 0;
2091
2092         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2093         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2094         crc = crc16(crc, (__u8 *)gdp, offset);
2095         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2096         /* for checksum of struct ext4_group_desc do the rest...*/
2097         if (ext4_has_feature_64bit(sb) &&
2098             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2099                 crc = crc16(crc, (__u8 *)gdp + offset,
2100                             le16_to_cpu(sbi->s_es->s_desc_size) -
2101                                 offset);
2102
2103 out:
2104         return cpu_to_le16(crc);
2105 }
2106
2107 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2108                                 struct ext4_group_desc *gdp)
2109 {
2110         if (ext4_has_group_desc_csum(sb) &&
2111             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2112                 return 0;
2113
2114         return 1;
2115 }
2116
2117 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2118                               struct ext4_group_desc *gdp)
2119 {
2120         if (!ext4_has_group_desc_csum(sb))
2121                 return;
2122         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2123 }
2124
2125 /* Called at mount-time, super-block is locked */
2126 static int ext4_check_descriptors(struct super_block *sb,
2127                                   ext4_fsblk_t sb_block,
2128                                   ext4_group_t *first_not_zeroed)
2129 {
2130         struct ext4_sb_info *sbi = EXT4_SB(sb);
2131         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2132         ext4_fsblk_t last_block;
2133         ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2134         ext4_fsblk_t block_bitmap;
2135         ext4_fsblk_t inode_bitmap;
2136         ext4_fsblk_t inode_table;
2137         int flexbg_flag = 0;
2138         ext4_group_t i, grp = sbi->s_groups_count;
2139
2140         if (ext4_has_feature_flex_bg(sb))
2141                 flexbg_flag = 1;
2142
2143         ext4_debug("Checking group descriptors");
2144
2145         for (i = 0; i < sbi->s_groups_count; i++) {
2146                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2147
2148                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2149                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2150                 else
2151                         last_block = first_block +
2152                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2153
2154                 if ((grp == sbi->s_groups_count) &&
2155                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2156                         grp = i;
2157
2158                 block_bitmap = ext4_block_bitmap(sb, gdp);
2159                 if (block_bitmap == sb_block) {
2160                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2161                                  "Block bitmap for group %u overlaps "
2162                                  "superblock", i);
2163                         if (!(sb->s_flags & MS_RDONLY))
2164                                 return 0;
2165                 }
2166                 if (block_bitmap >= sb_block + 1 &&
2167                     block_bitmap <= last_bg_block) {
2168                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2169                                  "Block bitmap for group %u overlaps "
2170                                  "block group descriptors", i);
2171                         if (!(sb->s_flags & MS_RDONLY))
2172                                 return 0;
2173                 }
2174                 if (block_bitmap < first_block || block_bitmap > last_block) {
2175                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2176                                "Block bitmap for group %u not in group "
2177                                "(block %llu)!", i, block_bitmap);
2178                         return 0;
2179                 }
2180                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2181                 if (inode_bitmap == sb_block) {
2182                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2183                                  "Inode bitmap for group %u overlaps "
2184                                  "superblock", i);
2185                         if (!(sb->s_flags & MS_RDONLY))
2186                                 return 0;
2187                 }
2188                 if (inode_bitmap >= sb_block + 1 &&
2189                     inode_bitmap <= last_bg_block) {
2190                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2191                                  "Inode bitmap for group %u overlaps "
2192                                  "block group descriptors", i);
2193                         if (!(sb->s_flags & MS_RDONLY))
2194                                 return 0;
2195                 }
2196                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2197                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2198                                "Inode bitmap for group %u not in group "
2199                                "(block %llu)!", i, inode_bitmap);
2200                         return 0;
2201                 }
2202                 inode_table = ext4_inode_table(sb, gdp);
2203                 if (inode_table == sb_block) {
2204                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2205                                  "Inode table for group %u overlaps "
2206                                  "superblock", i);
2207                         if (!(sb->s_flags & MS_RDONLY))
2208                                 return 0;
2209                 }
2210                 if (inode_table >= sb_block + 1 &&
2211                     inode_table <= last_bg_block) {
2212                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2213                                  "Inode table for group %u overlaps "
2214                                  "block group descriptors", i);
2215                         if (!(sb->s_flags & MS_RDONLY))
2216                                 return 0;
2217                 }
2218                 if (inode_table < first_block ||
2219                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2220                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2221                                "Inode table for group %u not in group "
2222                                "(block %llu)!", i, inode_table);
2223                         return 0;
2224                 }
2225                 ext4_lock_group(sb, i);
2226                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2227                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2228                                  "Checksum for group %u failed (%u!=%u)",
2229                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2230                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2231                         if (!(sb->s_flags & MS_RDONLY)) {
2232                                 ext4_unlock_group(sb, i);
2233                                 return 0;
2234                         }
2235                 }
2236                 ext4_unlock_group(sb, i);
2237                 if (!flexbg_flag)
2238                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2239         }
2240         if (NULL != first_not_zeroed)
2241                 *first_not_zeroed = grp;
2242         return 1;
2243 }
2244
2245 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2246  * the superblock) which were deleted from all directories, but held open by
2247  * a process at the time of a crash.  We walk the list and try to delete these
2248  * inodes at recovery time (only with a read-write filesystem).
2249  *
2250  * In order to keep the orphan inode chain consistent during traversal (in
2251  * case of crash during recovery), we link each inode into the superblock
2252  * orphan list_head and handle it the same way as an inode deletion during
2253  * normal operation (which journals the operations for us).
2254  *
2255  * We only do an iget() and an iput() on each inode, which is very safe if we
2256  * accidentally point at an in-use or already deleted inode.  The worst that
2257  * can happen in this case is that we get a "bit already cleared" message from
2258  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2259  * e2fsck was run on this filesystem, and it must have already done the orphan
2260  * inode cleanup for us, so we can safely abort without any further action.
2261  */
2262 static void ext4_orphan_cleanup(struct super_block *sb,
2263                                 struct ext4_super_block *es)
2264 {
2265         unsigned int s_flags = sb->s_flags;
2266         int nr_orphans = 0, nr_truncates = 0;
2267 #ifdef CONFIG_QUOTA
2268         int quota_update = 0;
2269         int i;
2270 #endif
2271         if (!es->s_last_orphan) {
2272                 jbd_debug(4, "no orphan inodes to clean up\n");
2273                 return;
2274         }
2275
2276         if (bdev_read_only(sb->s_bdev)) {
2277                 ext4_msg(sb, KERN_ERR, "write access "
2278                         "unavailable, skipping orphan cleanup");
2279                 return;
2280         }
2281
2282         /* Check if feature set would not allow a r/w mount */
2283         if (!ext4_feature_set_ok(sb, 0)) {
2284                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2285                          "unknown ROCOMPAT features");
2286                 return;
2287         }
2288
2289         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2290                 /* don't clear list on RO mount w/ errors */
2291                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2292                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2293                                   "clearing orphan list.\n");
2294                         es->s_last_orphan = 0;
2295                 }
2296                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2297                 return;
2298         }
2299
2300         if (s_flags & MS_RDONLY) {
2301                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2302                 sb->s_flags &= ~MS_RDONLY;
2303         }
2304 #ifdef CONFIG_QUOTA
2305         /* Needed for iput() to work correctly and not trash data */
2306         sb->s_flags |= MS_ACTIVE;
2307
2308         /*
2309          * Turn on quotas which were not enabled for read-only mounts if
2310          * filesystem has quota feature, so that they are updated correctly.
2311          */
2312         if (ext4_has_feature_quota(sb) && (s_flags & MS_RDONLY)) {
2313                 int ret = ext4_enable_quotas(sb);
2314
2315                 if (!ret)
2316                         quota_update = 1;
2317                 else
2318                         ext4_msg(sb, KERN_ERR,
2319                                 "Cannot turn on quotas: error %d", ret);
2320         }
2321
2322         /* Turn on journaled quotas used for old sytle */
2323         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2324                 if (EXT4_SB(sb)->s_qf_names[i]) {
2325                         int ret = ext4_quota_on_mount(sb, i);
2326
2327                         if (!ret)
2328                                 quota_update = 1;
2329                         else
2330                                 ext4_msg(sb, KERN_ERR,
2331                                         "Cannot turn on journaled "
2332                                         "quota: type %d: error %d", i, ret);
2333                 }
2334         }
2335 #endif
2336
2337         while (es->s_last_orphan) {
2338                 struct inode *inode;
2339
2340                 /*
2341                  * We may have encountered an error during cleanup; if
2342                  * so, skip the rest.
2343                  */
2344                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2345                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2346                         es->s_last_orphan = 0;
2347                         break;
2348                 }
2349
2350                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2351                 if (IS_ERR(inode)) {
2352                         es->s_last_orphan = 0;
2353                         break;
2354                 }
2355
2356                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2357                 dquot_initialize(inode);
2358                 if (inode->i_nlink) {
2359                         if (test_opt(sb, DEBUG))
2360                                 ext4_msg(sb, KERN_DEBUG,
2361                                         "%s: truncating inode %lu to %lld bytes",
2362                                         __func__, inode->i_ino, inode->i_size);
2363                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2364                                   inode->i_ino, inode->i_size);
2365                         mutex_lock(&inode->i_mutex);
2366                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2367                         ext4_truncate(inode);
2368                         mutex_unlock(&inode->i_mutex);
2369                         nr_truncates++;
2370                 } else {
2371                         if (test_opt(sb, DEBUG))
2372                                 ext4_msg(sb, KERN_DEBUG,
2373                                         "%s: deleting unreferenced inode %lu",
2374                                         __func__, inode->i_ino);
2375                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2376                                   inode->i_ino);
2377                         nr_orphans++;
2378                 }
2379                 iput(inode);  /* The delete magic happens here! */
2380         }
2381
2382 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2383
2384         if (nr_orphans)
2385                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2386                        PLURAL(nr_orphans));
2387         if (nr_truncates)
2388                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2389                        PLURAL(nr_truncates));
2390 #ifdef CONFIG_QUOTA
2391         /* Turn off quotas if they were enabled for orphan cleanup */
2392         if (quota_update) {
2393                 for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2394                         if (sb_dqopt(sb)->files[i])
2395                                 dquot_quota_off(sb, i);
2396                 }
2397         }
2398 #endif
2399         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2400 }
2401
2402 /*
2403  * Maximal extent format file size.
2404  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2405  * extent format containers, within a sector_t, and within i_blocks
2406  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2407  * so that won't be a limiting factor.
2408  *
2409  * However there is other limiting factor. We do store extents in the form
2410  * of starting block and length, hence the resulting length of the extent
2411  * covering maximum file size must fit into on-disk format containers as
2412  * well. Given that length is always by 1 unit bigger than max unit (because
2413  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2414  *
2415  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2416  */
2417 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2418 {
2419         loff_t res;
2420         loff_t upper_limit = MAX_LFS_FILESIZE;
2421
2422         /* small i_blocks in vfs inode? */
2423         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2424                 /*
2425                  * CONFIG_LBDAF is not enabled implies the inode
2426                  * i_block represent total blocks in 512 bytes
2427                  * 32 == size of vfs inode i_blocks * 8
2428                  */
2429                 upper_limit = (1LL << 32) - 1;
2430
2431                 /* total blocks in file system block size */
2432                 upper_limit >>= (blkbits - 9);
2433                 upper_limit <<= blkbits;
2434         }
2435
2436         /*
2437          * 32-bit extent-start container, ee_block. We lower the maxbytes
2438          * by one fs block, so ee_len can cover the extent of maximum file
2439          * size
2440          */
2441         res = (1LL << 32) - 1;
2442         res <<= blkbits;
2443
2444         /* Sanity check against vm- & vfs- imposed limits */
2445         if (res > upper_limit)
2446                 res = upper_limit;
2447
2448         return res;
2449 }
2450
2451 /*
2452  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2453  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2454  * We need to be 1 filesystem block less than the 2^48 sector limit.
2455  */
2456 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2457 {
2458         loff_t res = EXT4_NDIR_BLOCKS;
2459         int meta_blocks;
2460         loff_t upper_limit;
2461         /* This is calculated to be the largest file size for a dense, block
2462          * mapped file such that the file's total number of 512-byte sectors,
2463          * including data and all indirect blocks, does not exceed (2^48 - 1).
2464          *
2465          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2466          * number of 512-byte sectors of the file.
2467          */
2468
2469         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2470                 /*
2471                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2472                  * the inode i_block field represents total file blocks in
2473                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2474                  */
2475                 upper_limit = (1LL << 32) - 1;
2476
2477                 /* total blocks in file system block size */
2478                 upper_limit >>= (bits - 9);
2479
2480         } else {
2481                 /*
2482                  * We use 48 bit ext4_inode i_blocks
2483                  * With EXT4_HUGE_FILE_FL set the i_blocks
2484                  * represent total number of blocks in
2485                  * file system block size
2486                  */
2487                 upper_limit = (1LL << 48) - 1;
2488
2489         }
2490
2491         /* indirect blocks */
2492         meta_blocks = 1;
2493         /* double indirect blocks */
2494         meta_blocks += 1 + (1LL << (bits-2));
2495         /* tripple indirect blocks */
2496         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2497
2498         upper_limit -= meta_blocks;
2499         upper_limit <<= bits;
2500
2501         res += 1LL << (bits-2);
2502         res += 1LL << (2*(bits-2));
2503         res += 1LL << (3*(bits-2));
2504         res <<= bits;
2505         if (res > upper_limit)
2506                 res = upper_limit;
2507
2508         if (res > MAX_LFS_FILESIZE)
2509                 res = MAX_LFS_FILESIZE;
2510
2511         return res;
2512 }
2513
2514 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2515                                    ext4_fsblk_t logical_sb_block, int nr)
2516 {
2517         struct ext4_sb_info *sbi = EXT4_SB(sb);
2518         ext4_group_t bg, first_meta_bg;
2519         int has_super = 0;
2520
2521         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2522
2523         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2524                 return logical_sb_block + nr + 1;
2525         bg = sbi->s_desc_per_block * nr;
2526         if (ext4_bg_has_super(sb, bg))
2527                 has_super = 1;
2528
2529         /*
2530          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2531          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2532          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2533          * compensate.
2534          */
2535         if (sb->s_blocksize == 1024 && nr == 0 &&
2536             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2537                 has_super++;
2538
2539         return (has_super + ext4_group_first_block_no(sb, bg));
2540 }
2541
2542 /**
2543  * ext4_get_stripe_size: Get the stripe size.
2544  * @sbi: In memory super block info
2545  *
2546  * If we have specified it via mount option, then
2547  * use the mount option value. If the value specified at mount time is
2548  * greater than the blocks per group use the super block value.
2549  * If the super block value is greater than blocks per group return 0.
2550  * Allocator needs it be less than blocks per group.
2551  *
2552  */
2553 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2554 {
2555         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2556         unsigned long stripe_width =
2557                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2558         int ret;
2559
2560         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2561                 ret = sbi->s_stripe;
2562         else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2563                 ret = stripe_width;
2564         else if (stride && stride <= sbi->s_blocks_per_group)
2565                 ret = stride;
2566         else
2567                 ret = 0;
2568
2569         /*
2570          * If the stripe width is 1, this makes no sense and
2571          * we set it to 0 to turn off stripe handling code.
2572          */
2573         if (ret <= 1)
2574                 ret = 0;
2575
2576         return ret;
2577 }
2578
2579 /*
2580  * Check whether this filesystem can be mounted based on
2581  * the features present and the RDONLY/RDWR mount requested.
2582  * Returns 1 if this filesystem can be mounted as requested,
2583  * 0 if it cannot be.
2584  */
2585 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2586 {
2587         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2588                 ext4_msg(sb, KERN_ERR,
2589                         "Couldn't mount because of "
2590                         "unsupported optional features (%x)",
2591                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2592                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2593                 return 0;
2594         }
2595
2596         if (readonly)
2597                 return 1;
2598
2599         if (ext4_has_feature_readonly(sb)) {
2600                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2601                 sb->s_flags |= MS_RDONLY;
2602                 return 1;
2603         }
2604
2605         /* Check that feature set is OK for a read-write mount */
2606         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2607                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2608                          "unsupported optional features (%x)",
2609                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2610                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2611                 return 0;
2612         }
2613         /*
2614          * Large file size enabled file system can only be mounted
2615          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2616          */
2617         if (ext4_has_feature_huge_file(sb)) {
2618                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2619                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2620                                  "cannot be mounted RDWR without "
2621                                  "CONFIG_LBDAF");
2622                         return 0;
2623                 }
2624         }
2625         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2626                 ext4_msg(sb, KERN_ERR,
2627                          "Can't support bigalloc feature without "
2628                          "extents feature\n");
2629                 return 0;
2630         }
2631
2632 #ifndef CONFIG_QUOTA
2633         if (ext4_has_feature_quota(sb) && !readonly) {
2634                 ext4_msg(sb, KERN_ERR,
2635                          "Filesystem with quota feature cannot be mounted RDWR "
2636                          "without CONFIG_QUOTA");
2637                 return 0;
2638         }
2639 #endif  /* CONFIG_QUOTA */
2640         return 1;
2641 }
2642
2643 /*
2644  * This function is called once a day if we have errors logged
2645  * on the file system
2646  */
2647 static void print_daily_error_info(unsigned long arg)
2648 {
2649         struct super_block *sb = (struct super_block *) arg;
2650         struct ext4_sb_info *sbi;
2651         struct ext4_super_block *es;
2652
2653         sbi = EXT4_SB(sb);
2654         es = sbi->s_es;
2655
2656         if (es->s_error_count)
2657                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2658                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2659                          le32_to_cpu(es->s_error_count));
2660         if (es->s_first_error_time) {
2661                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2662                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2663                        (int) sizeof(es->s_first_error_func),
2664                        es->s_first_error_func,
2665                        le32_to_cpu(es->s_first_error_line));
2666                 if (es->s_first_error_ino)
2667                         printk(": inode %u",
2668                                le32_to_cpu(es->s_first_error_ino));
2669                 if (es->s_first_error_block)
2670                         printk(": block %llu", (unsigned long long)
2671                                le64_to_cpu(es->s_first_error_block));
2672                 printk("\n");
2673         }
2674         if (es->s_last_error_time) {
2675                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2676                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2677                        (int) sizeof(es->s_last_error_func),
2678                        es->s_last_error_func,
2679                        le32_to_cpu(es->s_last_error_line));
2680                 if (es->s_last_error_ino)
2681                         printk(": inode %u",
2682                                le32_to_cpu(es->s_last_error_ino));
2683                 if (es->s_last_error_block)
2684                         printk(": block %llu", (unsigned long long)
2685                                le64_to_cpu(es->s_last_error_block));
2686                 printk("\n");
2687         }
2688         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2689 }
2690
2691 /* Find next suitable group and run ext4_init_inode_table */
2692 static int ext4_run_li_request(struct ext4_li_request *elr)
2693 {
2694         struct ext4_group_desc *gdp = NULL;
2695         ext4_group_t group, ngroups;
2696         struct super_block *sb;
2697         unsigned long timeout = 0;
2698         int ret = 0;
2699
2700         sb = elr->lr_super;
2701         ngroups = EXT4_SB(sb)->s_groups_count;
2702
2703         sb_start_write(sb);
2704         for (group = elr->lr_next_group; group < ngroups; group++) {
2705                 gdp = ext4_get_group_desc(sb, group, NULL);
2706                 if (!gdp) {
2707                         ret = 1;
2708                         break;
2709                 }
2710
2711                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2712                         break;
2713         }
2714
2715         if (group >= ngroups)
2716                 ret = 1;
2717
2718         if (!ret) {
2719                 timeout = jiffies;
2720                 ret = ext4_init_inode_table(sb, group,
2721                                             elr->lr_timeout ? 0 : 1);
2722                 if (elr->lr_timeout == 0) {
2723                         timeout = (jiffies - timeout) *
2724                                   elr->lr_sbi->s_li_wait_mult;
2725                         elr->lr_timeout = timeout;
2726                 }
2727                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2728                 elr->lr_next_group = group + 1;
2729         }
2730         sb_end_write(sb);
2731
2732         return ret;
2733 }
2734
2735 /*
2736  * Remove lr_request from the list_request and free the
2737  * request structure. Should be called with li_list_mtx held
2738  */
2739 static void ext4_remove_li_request(struct ext4_li_request *elr)
2740 {
2741         struct ext4_sb_info *sbi;
2742
2743         if (!elr)
2744                 return;
2745
2746         sbi = elr->lr_sbi;
2747
2748         list_del(&elr->lr_request);
2749         sbi->s_li_request = NULL;
2750         kfree(elr);
2751 }
2752
2753 static void ext4_unregister_li_request(struct super_block *sb)
2754 {
2755         mutex_lock(&ext4_li_mtx);
2756         if (!ext4_li_info) {
2757                 mutex_unlock(&ext4_li_mtx);
2758                 return;
2759         }
2760
2761         mutex_lock(&ext4_li_info->li_list_mtx);
2762         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2763         mutex_unlock(&ext4_li_info->li_list_mtx);
2764         mutex_unlock(&ext4_li_mtx);
2765 }
2766
2767 static struct task_struct *ext4_lazyinit_task;
2768
2769 /*
2770  * This is the function where ext4lazyinit thread lives. It walks
2771  * through the request list searching for next scheduled filesystem.
2772  * When such a fs is found, run the lazy initialization request
2773  * (ext4_rn_li_request) and keep track of the time spend in this
2774  * function. Based on that time we compute next schedule time of
2775  * the request. When walking through the list is complete, compute
2776  * next waking time and put itself into sleep.
2777  */
2778 static int ext4_lazyinit_thread(void *arg)
2779 {
2780         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2781         struct list_head *pos, *n;
2782         struct ext4_li_request *elr;
2783         unsigned long next_wakeup, cur;
2784
2785         BUG_ON(NULL == eli);
2786
2787 cont_thread:
2788         while (true) {
2789                 next_wakeup = MAX_JIFFY_OFFSET;
2790
2791                 mutex_lock(&eli->li_list_mtx);
2792                 if (list_empty(&eli->li_request_list)) {
2793                         mutex_unlock(&eli->li_list_mtx);
2794                         goto exit_thread;
2795                 }
2796
2797                 list_for_each_safe(pos, n, &eli->li_request_list) {
2798                         elr = list_entry(pos, struct ext4_li_request,
2799                                          lr_request);
2800
2801                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2802                                 if (ext4_run_li_request(elr) != 0) {
2803                                         /* error, remove the lazy_init job */
2804                                         ext4_remove_li_request(elr);
2805                                         continue;
2806                                 }
2807                         }
2808
2809                         if (time_before(elr->lr_next_sched, next_wakeup))
2810                                 next_wakeup = elr->lr_next_sched;
2811                 }
2812                 mutex_unlock(&eli->li_list_mtx);
2813
2814                 try_to_freeze();
2815
2816                 cur = jiffies;
2817                 if ((time_after_eq(cur, next_wakeup)) ||
2818                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2819                         cond_resched();
2820                         continue;
2821                 }
2822
2823                 schedule_timeout_interruptible(next_wakeup - cur);
2824
2825                 if (kthread_should_stop()) {
2826                         ext4_clear_request_list();
2827                         goto exit_thread;
2828                 }
2829         }
2830
2831 exit_thread:
2832         /*
2833          * It looks like the request list is empty, but we need
2834          * to check it under the li_list_mtx lock, to prevent any
2835          * additions into it, and of course we should lock ext4_li_mtx
2836          * to atomically free the list and ext4_li_info, because at
2837          * this point another ext4 filesystem could be registering
2838          * new one.
2839          */
2840         mutex_lock(&ext4_li_mtx);
2841         mutex_lock(&eli->li_list_mtx);
2842         if (!list_empty(&eli->li_request_list)) {
2843                 mutex_unlock(&eli->li_list_mtx);
2844                 mutex_unlock(&ext4_li_mtx);
2845                 goto cont_thread;
2846         }
2847         mutex_unlock(&eli->li_list_mtx);
2848         kfree(ext4_li_info);
2849         ext4_li_info = NULL;
2850         mutex_unlock(&ext4_li_mtx);
2851
2852         return 0;
2853 }
2854
2855 static void ext4_clear_request_list(void)
2856 {
2857         struct list_head *pos, *n;
2858         struct ext4_li_request *elr;
2859
2860         mutex_lock(&ext4_li_info->li_list_mtx);
2861         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2862                 elr = list_entry(pos, struct ext4_li_request,
2863                                  lr_request);
2864                 ext4_remove_li_request(elr);
2865         }
2866         mutex_unlock(&ext4_li_info->li_list_mtx);
2867 }
2868
2869 static int ext4_run_lazyinit_thread(void)
2870 {
2871         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2872                                          ext4_li_info, "ext4lazyinit");
2873         if (IS_ERR(ext4_lazyinit_task)) {
2874                 int err = PTR_ERR(ext4_lazyinit_task);
2875                 ext4_clear_request_list();
2876                 kfree(ext4_li_info);
2877                 ext4_li_info = NULL;
2878                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2879                                  "initialization thread\n",
2880                                  err);
2881                 return err;
2882         }
2883         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2884         return 0;
2885 }
2886
2887 /*
2888  * Check whether it make sense to run itable init. thread or not.
2889  * If there is at least one uninitialized inode table, return
2890  * corresponding group number, else the loop goes through all
2891  * groups and return total number of groups.
2892  */
2893 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2894 {
2895         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2896         struct ext4_group_desc *gdp = NULL;
2897
2898         if (!ext4_has_group_desc_csum(sb))
2899                 return ngroups;
2900
2901         for (group = 0; group < ngroups; group++) {
2902                 gdp = ext4_get_group_desc(sb, group, NULL);
2903                 if (!gdp)
2904                         continue;
2905
2906                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2907                         break;
2908         }
2909
2910         return group;
2911 }
2912
2913 static int ext4_li_info_new(void)
2914 {
2915         struct ext4_lazy_init *eli = NULL;
2916
2917         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2918         if (!eli)
2919                 return -ENOMEM;
2920
2921         INIT_LIST_HEAD(&eli->li_request_list);
2922         mutex_init(&eli->li_list_mtx);
2923
2924         eli->li_state |= EXT4_LAZYINIT_QUIT;
2925
2926         ext4_li_info = eli;
2927
2928         return 0;
2929 }
2930
2931 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2932                                             ext4_group_t start)
2933 {
2934         struct ext4_sb_info *sbi = EXT4_SB(sb);
2935         struct ext4_li_request *elr;
2936
2937         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2938         if (!elr)
2939                 return NULL;
2940
2941         elr->lr_super = sb;
2942         elr->lr_sbi = sbi;
2943         elr->lr_next_group = start;
2944
2945         /*
2946          * Randomize first schedule time of the request to
2947          * spread the inode table initialization requests
2948          * better.
2949          */
2950         elr->lr_next_sched = jiffies + (prandom_u32() %
2951                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2952         return elr;
2953 }
2954
2955 int ext4_register_li_request(struct super_block *sb,
2956                              ext4_group_t first_not_zeroed)
2957 {
2958         struct ext4_sb_info *sbi = EXT4_SB(sb);
2959         struct ext4_li_request *elr = NULL;
2960         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2961         int ret = 0;
2962
2963         mutex_lock(&ext4_li_mtx);
2964         if (sbi->s_li_request != NULL) {
2965                 /*
2966                  * Reset timeout so it can be computed again, because
2967                  * s_li_wait_mult might have changed.
2968                  */
2969                 sbi->s_li_request->lr_timeout = 0;
2970                 goto out;
2971         }
2972
2973         if (first_not_zeroed == ngroups ||
2974             (sb->s_flags & MS_RDONLY) ||
2975             !test_opt(sb, INIT_INODE_TABLE))
2976                 goto out;
2977
2978         elr = ext4_li_request_new(sb, first_not_zeroed);
2979         if (!elr) {
2980                 ret = -ENOMEM;
2981                 goto out;
2982         }
2983
2984         if (NULL == ext4_li_info) {
2985                 ret = ext4_li_info_new();
2986                 if (ret)
2987                         goto out;
2988         }
2989
2990         mutex_lock(&ext4_li_info->li_list_mtx);
2991         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
2992         mutex_unlock(&ext4_li_info->li_list_mtx);
2993
2994         sbi->s_li_request = elr;
2995         /*
2996          * set elr to NULL here since it has been inserted to
2997          * the request_list and the removal and free of it is
2998          * handled by ext4_clear_request_list from now on.
2999          */
3000         elr = NULL;
3001
3002         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3003                 ret = ext4_run_lazyinit_thread();
3004                 if (ret)
3005                         goto out;
3006         }
3007 out:
3008         mutex_unlock(&ext4_li_mtx);
3009         if (ret)
3010                 kfree(elr);
3011         return ret;
3012 }
3013
3014 /*
3015  * We do not need to lock anything since this is called on
3016  * module unload.
3017  */
3018 static void ext4_destroy_lazyinit_thread(void)
3019 {
3020         /*
3021          * If thread exited earlier
3022          * there's nothing to be done.
3023          */
3024         if (!ext4_li_info || !ext4_lazyinit_task)
3025                 return;
3026
3027         kthread_stop(ext4_lazyinit_task);
3028 }
3029
3030 static int set_journal_csum_feature_set(struct super_block *sb)
3031 {
3032         int ret = 1;
3033         int compat, incompat;
3034         struct ext4_sb_info *sbi = EXT4_SB(sb);
3035
3036         if (ext4_has_metadata_csum(sb)) {
3037                 /* journal checksum v3 */
3038                 compat = 0;
3039                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3040         } else {
3041                 /* journal checksum v1 */
3042                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3043                 incompat = 0;
3044         }
3045
3046         jbd2_journal_clear_features(sbi->s_journal,
3047                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3048                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3049                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3050         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3051                 ret = jbd2_journal_set_features(sbi->s_journal,
3052                                 compat, 0,
3053                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3054                                 incompat);
3055         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3056                 ret = jbd2_journal_set_features(sbi->s_journal,
3057                                 compat, 0,
3058                                 incompat);
3059                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3060                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3061         } else {
3062                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3063                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3064         }
3065
3066         return ret;
3067 }
3068
3069 /*
3070  * Note: calculating the overhead so we can be compatible with
3071  * historical BSD practice is quite difficult in the face of
3072  * clusters/bigalloc.  This is because multiple metadata blocks from
3073  * different block group can end up in the same allocation cluster.
3074  * Calculating the exact overhead in the face of clustered allocation
3075  * requires either O(all block bitmaps) in memory or O(number of block
3076  * groups**2) in time.  We will still calculate the superblock for
3077  * older file systems --- and if we come across with a bigalloc file
3078  * system with zero in s_overhead_clusters the estimate will be close to
3079  * correct especially for very large cluster sizes --- but for newer
3080  * file systems, it's better to calculate this figure once at mkfs
3081  * time, and store it in the superblock.  If the superblock value is
3082  * present (even for non-bigalloc file systems), we will use it.
3083  */
3084 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3085                           char *buf)
3086 {
3087         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3088         struct ext4_group_desc  *gdp;
3089         ext4_fsblk_t            first_block, last_block, b;
3090         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3091         int                     s, j, count = 0;
3092
3093         if (!ext4_has_feature_bigalloc(sb))
3094                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3095                         sbi->s_itb_per_group + 2);
3096
3097         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3098                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3099         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3100         for (i = 0; i < ngroups; i++) {
3101                 gdp = ext4_get_group_desc(sb, i, NULL);
3102                 b = ext4_block_bitmap(sb, gdp);
3103                 if (b >= first_block && b <= last_block) {
3104                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3105                         count++;
3106                 }
3107                 b = ext4_inode_bitmap(sb, gdp);
3108                 if (b >= first_block && b <= last_block) {
3109                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3110                         count++;
3111                 }
3112                 b = ext4_inode_table(sb, gdp);
3113                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3114                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3115                                 int c = EXT4_B2C(sbi, b - first_block);
3116                                 ext4_set_bit(c, buf);
3117                                 count++;
3118                         }
3119                 if (i != grp)
3120                         continue;
3121                 s = 0;
3122                 if (ext4_bg_has_super(sb, grp)) {
3123                         ext4_set_bit(s++, buf);
3124                         count++;
3125                 }
3126                 j = ext4_bg_num_gdb(sb, grp);
3127                 if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3128                         ext4_error(sb, "Invalid number of block group "
3129                                    "descriptor blocks: %d", j);
3130                         j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3131                 }
3132                 count += j;
3133                 for (; j > 0; j--)
3134                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3135         }
3136         if (!count)
3137                 return 0;
3138         return EXT4_CLUSTERS_PER_GROUP(sb) -
3139                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3140 }
3141
3142 /*
3143  * Compute the overhead and stash it in sbi->s_overhead
3144  */
3145 int ext4_calculate_overhead(struct super_block *sb)
3146 {
3147         struct ext4_sb_info *sbi = EXT4_SB(sb);
3148         struct ext4_super_block *es = sbi->s_es;
3149         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3150         ext4_fsblk_t overhead = 0;
3151         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3152
3153         if (!buf)
3154                 return -ENOMEM;
3155
3156         /*
3157          * Compute the overhead (FS structures).  This is constant
3158          * for a given filesystem unless the number of block groups
3159          * changes so we cache the previous value until it does.
3160          */
3161
3162         /*
3163          * All of the blocks before first_data_block are overhead
3164          */
3165         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3166
3167         /*
3168          * Add the overhead found in each block group
3169          */
3170         for (i = 0; i < ngroups; i++) {
3171                 int blks;
3172
3173                 blks = count_overhead(sb, i, buf);
3174                 overhead += blks;
3175                 if (blks)
3176                         memset(buf, 0, PAGE_SIZE);
3177                 cond_resched();
3178         }
3179         /* Add the internal journal blocks as well */
3180         if (sbi->s_journal && !sbi->journal_bdev)
3181                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3182
3183         sbi->s_overhead = overhead;
3184         smp_wmb();
3185         free_page((unsigned long) buf);
3186         return 0;
3187 }
3188
3189 static void ext4_clamp_want_extra_isize(struct super_block *sb)
3190 {
3191         struct ext4_sb_info *sbi = EXT4_SB(sb);
3192         struct ext4_super_block *es = sbi->s_es;
3193         unsigned def_extra_isize = sizeof(struct ext4_inode) -
3194                                                 EXT4_GOOD_OLD_INODE_SIZE;
3195
3196         if (sbi->s_inode_size == EXT4_GOOD_OLD_INODE_SIZE) {
3197                 sbi->s_want_extra_isize = 0;
3198                 return;
3199         }
3200         if (sbi->s_want_extra_isize < 4) {
3201                 sbi->s_want_extra_isize = def_extra_isize;
3202                 if (ext4_has_feature_extra_isize(sb)) {
3203                         if (sbi->s_want_extra_isize <
3204                             le16_to_cpu(es->s_want_extra_isize))
3205                                 sbi->s_want_extra_isize =
3206                                         le16_to_cpu(es->s_want_extra_isize);
3207                         if (sbi->s_want_extra_isize <
3208                             le16_to_cpu(es->s_min_extra_isize))
3209                                 sbi->s_want_extra_isize =
3210                                         le16_to_cpu(es->s_min_extra_isize);
3211                 }
3212         }
3213         /* Check if enough inode space is available */
3214         if ((sbi->s_want_extra_isize > sbi->s_inode_size) ||
3215             (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3216                                                         sbi->s_inode_size)) {
3217                 sbi->s_want_extra_isize = def_extra_isize;
3218                 ext4_msg(sb, KERN_INFO,
3219                          "required extra inode space not available");
3220         }
3221 }
3222
3223 static void ext4_set_resv_clusters(struct super_block *sb)
3224 {
3225         ext4_fsblk_t resv_clusters;
3226         struct ext4_sb_info *sbi = EXT4_SB(sb);
3227
3228         /*
3229          * There's no need to reserve anything when we aren't using extents.
3230          * The space estimates are exact, there are no unwritten extents,
3231          * hole punching doesn't need new metadata... This is needed especially
3232          * to keep ext2/3 backward compatibility.
3233          */
3234         if (!ext4_has_feature_extents(sb))
3235                 return;
3236         /*
3237          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3238          * This should cover the situations where we can not afford to run
3239          * out of space like for example punch hole, or converting
3240          * unwritten extents in delalloc path. In most cases such
3241          * allocation would require 1, or 2 blocks, higher numbers are
3242          * very rare.
3243          */
3244         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3245                          sbi->s_cluster_bits);
3246
3247         do_div(resv_clusters, 50);
3248         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3249
3250         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3251 }
3252
3253 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3254 {
3255         char *orig_data = kstrdup(data, GFP_KERNEL);
3256         struct buffer_head *bh, **group_desc;
3257         struct ext4_super_block *es = NULL;
3258         struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3259         struct flex_groups **flex_groups;
3260         ext4_fsblk_t block;
3261         ext4_fsblk_t sb_block = get_sb_block(&data);
3262         ext4_fsblk_t logical_sb_block;
3263         unsigned long offset = 0;
3264         unsigned long journal_devnum = 0;
3265         unsigned long def_mount_opts;
3266         struct inode *root;
3267         const char *descr;
3268         int ret = -ENOMEM;
3269         int blocksize, clustersize;
3270         unsigned int db_count;
3271         unsigned int i;
3272         int needs_recovery, has_huge_files, has_bigalloc;
3273         __u64 blocks_count;
3274         int err = 0;
3275         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3276         ext4_group_t first_not_zeroed;
3277
3278         if ((data && !orig_data) || !sbi)
3279                 goto out_free_base;
3280
3281         sbi->s_blockgroup_lock =
3282                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3283         if (!sbi->s_blockgroup_lock)
3284                 goto out_free_base;
3285
3286         sb->s_fs_info = sbi;
3287         sbi->s_sb = sb;
3288         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3289         sbi->s_sb_block = sb_block;
3290         if (sb->s_bdev->bd_part)
3291                 sbi->s_sectors_written_start =
3292                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3293
3294         /* Cleanup superblock name */
3295         strreplace(sb->s_id, '/', '!');
3296
3297         /* -EINVAL is default */
3298         ret = -EINVAL;
3299         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3300         if (!blocksize) {
3301                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3302                 goto out_fail;
3303         }
3304
3305         /*
3306          * The ext4 superblock will not be buffer aligned for other than 1kB
3307          * block sizes.  We need to calculate the offset from buffer start.
3308          */
3309         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3310                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3311                 offset = do_div(logical_sb_block, blocksize);
3312         } else {
3313                 logical_sb_block = sb_block;
3314         }
3315
3316         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3317                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3318                 goto out_fail;
3319         }
3320         /*
3321          * Note: s_es must be initialized as soon as possible because
3322          *       some ext4 macro-instructions depend on its value
3323          */
3324         es = (struct ext4_super_block *) (bh->b_data + offset);
3325         sbi->s_es = es;
3326         sb->s_magic = le16_to_cpu(es->s_magic);
3327         if (sb->s_magic != EXT4_SUPER_MAGIC)
3328                 goto cantfind_ext4;
3329         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3330
3331         /* Warn if metadata_csum and gdt_csum are both set. */
3332         if (ext4_has_feature_metadata_csum(sb) &&
3333             ext4_has_feature_gdt_csum(sb))
3334                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3335                              "redundant flags; please run fsck.");
3336
3337         /* Check for a known checksum algorithm */
3338         if (!ext4_verify_csum_type(sb, es)) {
3339                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3340                          "unknown checksum algorithm.");
3341                 silent = 1;
3342                 goto cantfind_ext4;
3343         }
3344
3345         /* Load the checksum driver */
3346         if (ext4_has_feature_metadata_csum(sb)) {
3347                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3348                 if (IS_ERR(sbi->s_chksum_driver)) {
3349                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3350                         ret = PTR_ERR(sbi->s_chksum_driver);
3351                         sbi->s_chksum_driver = NULL;
3352                         goto failed_mount;
3353                 }
3354         }
3355
3356         /* Check superblock checksum */
3357         if (!ext4_superblock_csum_verify(sb, es)) {
3358                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3359                          "invalid superblock checksum.  Run e2fsck?");
3360                 silent = 1;
3361                 ret = -EFSBADCRC;
3362                 goto cantfind_ext4;
3363         }
3364
3365         /* Precompute checksum seed for all metadata */
3366         if (ext4_has_feature_csum_seed(sb))
3367                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3368         else if (ext4_has_metadata_csum(sb))
3369                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3370                                                sizeof(es->s_uuid));
3371
3372         /* Set defaults before we parse the mount options */
3373         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3374         set_opt(sb, INIT_INODE_TABLE);
3375         if (def_mount_opts & EXT4_DEFM_DEBUG)
3376                 set_opt(sb, DEBUG);
3377         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3378                 set_opt(sb, GRPID);
3379         if (def_mount_opts & EXT4_DEFM_UID16)
3380                 set_opt(sb, NO_UID32);
3381         /* xattr user namespace & acls are now defaulted on */
3382         set_opt(sb, XATTR_USER);
3383 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3384         set_opt(sb, POSIX_ACL);
3385 #endif
3386         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3387         if (ext4_has_metadata_csum(sb))
3388                 set_opt(sb, JOURNAL_CHECKSUM);
3389
3390         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3391                 set_opt(sb, JOURNAL_DATA);
3392         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3393                 set_opt(sb, ORDERED_DATA);
3394         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3395                 set_opt(sb, WRITEBACK_DATA);
3396
3397         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3398                 set_opt(sb, ERRORS_PANIC);
3399         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3400                 set_opt(sb, ERRORS_CONT);
3401         else
3402                 set_opt(sb, ERRORS_RO);
3403         /* block_validity enabled by default; disable with noblock_validity */
3404         set_opt(sb, BLOCK_VALIDITY);
3405         if (def_mount_opts & EXT4_DEFM_DISCARD)
3406                 set_opt(sb, DISCARD);
3407
3408         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3409         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3410         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3411         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3412         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3413
3414         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3415                 set_opt(sb, BARRIER);
3416
3417         /*
3418          * enable delayed allocation by default
3419          * Use -o nodelalloc to turn it off
3420          */
3421         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3422             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3423                 set_opt(sb, DELALLOC);
3424
3425         /*
3426          * set default s_li_wait_mult for lazyinit, for the case there is
3427          * no mount option specified.
3428          */
3429         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3430
3431         if (sbi->s_es->s_mount_opts[0]) {
3432                 char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3433                                               sizeof(sbi->s_es->s_mount_opts),
3434                                               GFP_KERNEL);
3435                 if (!s_mount_opts)
3436                         goto failed_mount;
3437                 if (!parse_options(s_mount_opts, sb, &journal_devnum,
3438                                    &journal_ioprio, 0)) {
3439                         ext4_msg(sb, KERN_WARNING,
3440                                  "failed to parse options in superblock: %s",
3441                                  s_mount_opts);
3442                 }
3443                 kfree(s_mount_opts);
3444         }
3445         sbi->s_def_mount_opt = sbi->s_mount_opt;
3446         if (!parse_options((char *) data, sb, &journal_devnum,
3447                            &journal_ioprio, 0))
3448                 goto failed_mount;
3449
3450         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3451                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3452                             "with data=journal disables delayed "
3453                             "allocation and O_DIRECT support!\n");
3454                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3455                         ext4_msg(sb, KERN_ERR, "can't mount with "
3456                                  "both data=journal and delalloc");
3457                         goto failed_mount;
3458                 }
3459                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3460                         ext4_msg(sb, KERN_ERR, "can't mount with "
3461                                  "both data=journal and dioread_nolock");
3462                         goto failed_mount;
3463                 }
3464                 if (test_opt(sb, DAX)) {
3465                         ext4_msg(sb, KERN_ERR, "can't mount with "
3466                                  "both data=journal and dax");
3467                         goto failed_mount;
3468                 }
3469                 if (ext4_has_feature_encrypt(sb)) {
3470                         ext4_msg(sb, KERN_WARNING,
3471                                  "encrypted files will use data=ordered "
3472                                  "instead of data journaling mode");
3473                 }
3474                 if (test_opt(sb, DELALLOC))
3475                         clear_opt(sb, DELALLOC);
3476         } else {
3477                 sb->s_iflags |= SB_I_CGROUPWB;
3478         }
3479
3480         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3481                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3482
3483         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3484             (ext4_has_compat_features(sb) ||
3485              ext4_has_ro_compat_features(sb) ||
3486              ext4_has_incompat_features(sb)))
3487                 ext4_msg(sb, KERN_WARNING,
3488                        "feature flags set on rev 0 fs, "
3489                        "running e2fsck is recommended");
3490
3491         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3492                 set_opt2(sb, HURD_COMPAT);
3493                 if (ext4_has_feature_64bit(sb)) {
3494                         ext4_msg(sb, KERN_ERR,
3495                                  "The Hurd can't support 64-bit file systems");
3496                         goto failed_mount;
3497                 }
3498         }
3499
3500         if (IS_EXT2_SB(sb)) {
3501                 if (ext2_feature_set_ok(sb))
3502                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3503                                  "using the ext4 subsystem");
3504                 else {
3505                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3506                                  "to feature incompatibilities");
3507                         goto failed_mount;
3508                 }
3509         }
3510
3511         if (IS_EXT3_SB(sb)) {
3512                 if (ext3_feature_set_ok(sb))
3513                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3514                                  "using the ext4 subsystem");
3515                 else {
3516                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3517                                  "to feature incompatibilities");
3518                         goto failed_mount;
3519                 }
3520         }
3521
3522         /*
3523          * Check feature flags regardless of the revision level, since we
3524          * previously didn't change the revision level when setting the flags,
3525          * so there is a chance incompat flags are set on a rev 0 filesystem.
3526          */
3527         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3528                 goto failed_mount;
3529
3530         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3531         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3532             blocksize > EXT4_MAX_BLOCK_SIZE) {
3533                 ext4_msg(sb, KERN_ERR,
3534                        "Unsupported filesystem blocksize %d (%d log_block_size)",
3535                          blocksize, le32_to_cpu(es->s_log_block_size));
3536                 goto failed_mount;
3537         }
3538         if (le32_to_cpu(es->s_log_block_size) >
3539             (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3540                 ext4_msg(sb, KERN_ERR,
3541                          "Invalid log block size: %u",
3542                          le32_to_cpu(es->s_log_block_size));
3543                 goto failed_mount;
3544         }
3545         if (le32_to_cpu(es->s_log_cluster_size) >
3546             (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3547                 ext4_msg(sb, KERN_ERR,
3548                          "Invalid log cluster size: %u",
3549                          le32_to_cpu(es->s_log_cluster_size));
3550                 goto failed_mount;
3551         }
3552
3553         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3554                 ext4_msg(sb, KERN_ERR,
3555                          "Number of reserved GDT blocks insanely large: %d",
3556                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3557                 goto failed_mount;
3558         }
3559
3560         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3561                 if (blocksize != PAGE_SIZE) {
3562                         ext4_msg(sb, KERN_ERR,
3563                                         "error: unsupported blocksize for dax");
3564                         goto failed_mount;
3565                 }
3566                 if (!sb->s_bdev->bd_disk->fops->direct_access) {
3567                         ext4_msg(sb, KERN_ERR,
3568                                         "error: device does not support dax");
3569                         goto failed_mount;
3570                 }
3571         }
3572
3573         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3574                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3575                          es->s_encryption_level);
3576                 goto failed_mount;
3577         }
3578
3579         if (sb->s_blocksize != blocksize) {
3580                 /* Validate the filesystem blocksize */
3581                 if (!sb_set_blocksize(sb, blocksize)) {
3582                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3583                                         blocksize);
3584                         goto failed_mount;
3585                 }
3586
3587                 brelse(bh);
3588                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3589                 offset = do_div(logical_sb_block, blocksize);
3590                 bh = sb_bread_unmovable(sb, logical_sb_block);
3591                 if (!bh) {
3592                         ext4_msg(sb, KERN_ERR,
3593                                "Can't read superblock on 2nd try");
3594                         goto failed_mount;
3595                 }
3596                 es = (struct ext4_super_block *)(bh->b_data + offset);
3597                 sbi->s_es = es;
3598                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3599                         ext4_msg(sb, KERN_ERR,
3600                                "Magic mismatch, very weird!");
3601                         goto failed_mount;
3602                 }
3603         }
3604
3605         has_huge_files = ext4_has_feature_huge_file(sb);
3606         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3607                                                       has_huge_files);
3608         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3609
3610         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3611                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3612                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3613         } else {
3614                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3615                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3616                 if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
3617                         ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
3618                                  sbi->s_first_ino);
3619                         goto failed_mount;
3620                 }
3621                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3622                     (!is_power_of_2(sbi->s_inode_size)) ||
3623                     (sbi->s_inode_size > blocksize)) {
3624                         ext4_msg(sb, KERN_ERR,
3625                                "unsupported inode size: %d",
3626                                sbi->s_inode_size);
3627                         goto failed_mount;
3628                 }
3629                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3630                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3631         }
3632
3633         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3634         if (ext4_has_feature_64bit(sb)) {
3635                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3636                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3637                     !is_power_of_2(sbi->s_desc_size)) {
3638                         ext4_msg(sb, KERN_ERR,
3639                                "unsupported descriptor size %lu",
3640                                sbi->s_desc_size);
3641                         goto failed_mount;
3642                 }
3643         } else
3644                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3645
3646         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3647         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3648
3649         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3650         if (sbi->s_inodes_per_block == 0)
3651                 goto cantfind_ext4;
3652         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3653             sbi->s_inodes_per_group > blocksize * 8) {
3654                 ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3655                          sbi->s_inodes_per_group);
3656                 goto failed_mount;
3657         }
3658         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3659                                         sbi->s_inodes_per_block;
3660         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3661         sbi->s_sbh = bh;
3662         sbi->s_mount_state = le16_to_cpu(es->s_state);
3663         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3664         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3665
3666         for (i = 0; i < 4; i++)
3667                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3668         sbi->s_def_hash_version = es->s_def_hash_version;
3669         if (ext4_has_feature_dir_index(sb)) {
3670                 i = le32_to_cpu(es->s_flags);
3671                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3672                         sbi->s_hash_unsigned = 3;
3673                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3674 #ifdef __CHAR_UNSIGNED__
3675                         if (!(sb->s_flags & MS_RDONLY))
3676                                 es->s_flags |=
3677                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3678                         sbi->s_hash_unsigned = 3;
3679 #else
3680                         if (!(sb->s_flags & MS_RDONLY))
3681                                 es->s_flags |=
3682                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3683 #endif
3684                 }
3685         }
3686
3687         /* Handle clustersize */
3688         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3689         has_bigalloc = ext4_has_feature_bigalloc(sb);
3690         if (has_bigalloc) {
3691                 if (clustersize < blocksize) {
3692                         ext4_msg(sb, KERN_ERR,
3693                                  "cluster size (%d) smaller than "
3694                                  "block size (%d)", clustersize, blocksize);
3695                         goto failed_mount;
3696                 }
3697                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3698                         le32_to_cpu(es->s_log_block_size);
3699                 sbi->s_clusters_per_group =
3700                         le32_to_cpu(es->s_clusters_per_group);
3701                 if (sbi->s_clusters_per_group > blocksize * 8) {
3702                         ext4_msg(sb, KERN_ERR,
3703                                  "#clusters per group too big: %lu",
3704                                  sbi->s_clusters_per_group);
3705                         goto failed_mount;
3706                 }
3707                 if (sbi->s_blocks_per_group !=
3708                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3709                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3710                                  "clusters per group (%lu) inconsistent",
3711                                  sbi->s_blocks_per_group,
3712                                  sbi->s_clusters_per_group);
3713                         goto failed_mount;
3714                 }
3715         } else {
3716                 if (clustersize != blocksize) {
3717                         ext4_msg(sb, KERN_ERR,
3718                                  "fragment/cluster size (%d) != "
3719                                  "block size (%d)", clustersize, blocksize);
3720                         goto failed_mount;
3721                 }
3722                 if (sbi->s_blocks_per_group > blocksize * 8) {
3723                         ext4_msg(sb, KERN_ERR,
3724                                  "#blocks per group too big: %lu",
3725                                  sbi->s_blocks_per_group);
3726                         goto failed_mount;
3727                 }
3728                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3729                 sbi->s_cluster_bits = 0;
3730         }
3731         sbi->s_cluster_ratio = clustersize / blocksize;
3732
3733         /* Do we have standard group size of clustersize * 8 blocks ? */
3734         if (sbi->s_blocks_per_group == clustersize << 3)
3735                 set_opt2(sb, STD_GROUP_SIZE);
3736
3737         /*
3738          * Test whether we have more sectors than will fit in sector_t,
3739          * and whether the max offset is addressable by the page cache.
3740          */
3741         err = generic_check_addressable(sb->s_blocksize_bits,
3742                                         ext4_blocks_count(es));
3743         if (err) {
3744                 ext4_msg(sb, KERN_ERR, "filesystem"
3745                          " too large to mount safely on this system");
3746                 if (sizeof(sector_t) < 8)
3747                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3748                 goto failed_mount;
3749         }
3750
3751         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3752                 goto cantfind_ext4;
3753
3754         /* check blocks count against device size */
3755         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3756         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3757                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3758                        "exceeds size of device (%llu blocks)",
3759                        ext4_blocks_count(es), blocks_count);
3760                 goto failed_mount;
3761         }
3762
3763         /*
3764          * It makes no sense for the first data block to be beyond the end
3765          * of the filesystem.
3766          */
3767         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3768                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3769                          "block %u is beyond end of filesystem (%llu)",
3770                          le32_to_cpu(es->s_first_data_block),
3771                          ext4_blocks_count(es));
3772                 goto failed_mount;
3773         }
3774         if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
3775             (sbi->s_cluster_ratio == 1)) {
3776                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3777                          "block is 0 with a 1k block and cluster size");
3778                 goto failed_mount;
3779         }
3780
3781         blocks_count = (ext4_blocks_count(es) -
3782                         le32_to_cpu(es->s_first_data_block) +
3783                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3784         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3785         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3786                 ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
3787                        "(block count %llu, first data block %u, "
3788                        "blocks per group %lu)", blocks_count,
3789                        ext4_blocks_count(es),
3790                        le32_to_cpu(es->s_first_data_block),
3791                        EXT4_BLOCKS_PER_GROUP(sb));
3792                 goto failed_mount;
3793         }
3794         sbi->s_groups_count = blocks_count;
3795         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3796                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3797         if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
3798             le32_to_cpu(es->s_inodes_count)) {
3799                 ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
3800                          le32_to_cpu(es->s_inodes_count),
3801                          ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
3802                 ret = -EINVAL;
3803                 goto failed_mount;
3804         }
3805         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3806                    EXT4_DESC_PER_BLOCK(sb);
3807         if (ext4_has_feature_meta_bg(sb)) {
3808                 if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3809                         ext4_msg(sb, KERN_WARNING,
3810                                  "first meta block group too large: %u "
3811                                  "(group descriptor block count %u)",
3812                                  le32_to_cpu(es->s_first_meta_bg), db_count);
3813                         goto failed_mount;
3814                 }
3815         }
3816         rcu_assign_pointer(sbi->s_group_desc,
3817                            ext4_kvmalloc(db_count *
3818                                           sizeof(struct buffer_head *),
3819                                           GFP_KERNEL));
3820         if (sbi->s_group_desc == NULL) {
3821                 ext4_msg(sb, KERN_ERR, "not enough memory");
3822                 ret = -ENOMEM;
3823                 goto failed_mount;
3824         }
3825
3826         bgl_lock_init(sbi->s_blockgroup_lock);
3827
3828         for (i = 0; i < db_count; i++) {
3829                 struct buffer_head *bh;
3830
3831                 block = descriptor_loc(sb, logical_sb_block, i);
3832                 bh = sb_bread_unmovable(sb, block);
3833                 if (!bh) {
3834                         ext4_msg(sb, KERN_ERR,
3835                                "can't read group descriptor %d", i);
3836                         db_count = i;
3837                         goto failed_mount2;
3838                 }
3839                 rcu_read_lock();
3840                 rcu_dereference(sbi->s_group_desc)[i] = bh;
3841                 rcu_read_unlock();
3842         }
3843         sbi->s_gdb_count = db_count;
3844         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3845                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3846                 ret = -EFSCORRUPTED;
3847                 goto failed_mount2;
3848         }
3849
3850         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3851         spin_lock_init(&sbi->s_next_gen_lock);
3852
3853         setup_timer(&sbi->s_err_report, print_daily_error_info,
3854                 (unsigned long) sb);
3855
3856         /* Register extent status tree shrinker */
3857         if (ext4_es_register_shrinker(sbi))
3858                 goto failed_mount3;
3859
3860         sbi->s_stripe = ext4_get_stripe_size(sbi);
3861         sbi->s_extent_max_zeroout_kb = 32;
3862
3863         /*
3864          * set up enough so that it can read an inode
3865          */
3866         sb->s_op = &ext4_sops;
3867         sb->s_export_op = &ext4_export_ops;
3868         sb->s_xattr = ext4_xattr_handlers;
3869 #ifdef CONFIG_QUOTA
3870         sb->dq_op = &ext4_quota_operations;
3871         if (ext4_has_feature_quota(sb))
3872                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3873         else
3874                 sb->s_qcop = &ext4_qctl_operations;
3875         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
3876 #endif
3877         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3878
3879         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3880         mutex_init(&sbi->s_orphan_lock);
3881
3882         sb->s_root = NULL;
3883
3884         needs_recovery = (es->s_last_orphan != 0 ||
3885                           ext4_has_feature_journal_needs_recovery(sb));
3886
3887         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3888                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3889                         goto failed_mount3a;
3890
3891         /*
3892          * The first inode we look at is the journal inode.  Don't try
3893          * root first: it may be modified in the journal!
3894          */
3895         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3896                 err = ext4_load_journal(sb, es, journal_devnum);
3897                 if (err)
3898                         goto failed_mount3a;
3899         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3900                    ext4_has_feature_journal_needs_recovery(sb)) {
3901                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3902                        "suppressed and not mounted read-only");
3903                 goto failed_mount_wq;
3904         } else {
3905                 /* Nojournal mode, all journal mount options are illegal */
3906                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3907                         ext4_msg(sb, KERN_ERR, "can't mount with "
3908                                  "journal_checksum, fs mounted w/o journal");
3909                         goto failed_mount_wq;
3910                 }
3911                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3912                         ext4_msg(sb, KERN_ERR, "can't mount with "
3913                                  "journal_async_commit, fs mounted w/o journal");
3914                         goto failed_mount_wq;
3915                 }
3916                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3917                         ext4_msg(sb, KERN_ERR, "can't mount with "
3918                                  "commit=%lu, fs mounted w/o journal",
3919                                  sbi->s_commit_interval / HZ);
3920                         goto failed_mount_wq;
3921                 }
3922                 if (EXT4_MOUNT_DATA_FLAGS &
3923                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3924                         ext4_msg(sb, KERN_ERR, "can't mount with "
3925                                  "data=, fs mounted w/o journal");
3926                         goto failed_mount_wq;
3927                 }
3928                 sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
3929                 clear_opt(sb, JOURNAL_CHECKSUM);
3930                 clear_opt(sb, DATA_FLAGS);
3931                 sbi->s_journal = NULL;
3932                 needs_recovery = 0;
3933                 goto no_journal;
3934         }
3935
3936         if (ext4_has_feature_64bit(sb) &&
3937             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3938                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3939                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3940                 goto failed_mount_wq;
3941         }
3942
3943         if (!set_journal_csum_feature_set(sb)) {
3944                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3945                          "feature set");
3946                 goto failed_mount_wq;
3947         }
3948
3949         /* We have now updated the journal if required, so we can
3950          * validate the data journaling mode. */
3951         switch (test_opt(sb, DATA_FLAGS)) {
3952         case 0:
3953                 /* No mode set, assume a default based on the journal
3954                  * capabilities: ORDERED_DATA if the journal can
3955                  * cope, else JOURNAL_DATA
3956                  */
3957                 if (jbd2_journal_check_available_features
3958                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3959                         set_opt(sb, ORDERED_DATA);
3960                 else
3961                         set_opt(sb, JOURNAL_DATA);
3962                 break;
3963
3964         case EXT4_MOUNT_ORDERED_DATA:
3965         case EXT4_MOUNT_WRITEBACK_DATA:
3966                 if (!jbd2_journal_check_available_features
3967                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3968                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3969                                "requested data journaling mode");
3970                         goto failed_mount_wq;
3971                 }
3972         default:
3973                 break;
3974         }
3975         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3976
3977         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3978
3979 no_journal:
3980         if (ext4_mballoc_ready) {
3981                 sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
3982                 if (!sbi->s_mb_cache) {
3983                         ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
3984                         goto failed_mount_wq;
3985                 }
3986         }
3987
3988         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
3989             (blocksize != PAGE_CACHE_SIZE)) {
3990                 ext4_msg(sb, KERN_ERR,
3991                          "Unsupported blocksize for fs encryption");
3992                 goto failed_mount_wq;
3993         }
3994
3995         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
3996             !ext4_has_feature_encrypt(sb)) {
3997                 ext4_set_feature_encrypt(sb);
3998                 ext4_commit_super(sb, 1);
3999         }
4000
4001         /*
4002          * Get the # of file system overhead blocks from the
4003          * superblock if present.
4004          */
4005         if (es->s_overhead_clusters)
4006                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4007         else {
4008                 err = ext4_calculate_overhead(sb);
4009                 if (err)
4010                         goto failed_mount_wq;
4011         }
4012
4013         /*
4014          * The maximum number of concurrent works can be high and
4015          * concurrency isn't really necessary.  Limit it to 1.
4016          */
4017         EXT4_SB(sb)->rsv_conversion_wq =
4018                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4019         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4020                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4021                 ret = -ENOMEM;
4022                 goto failed_mount4;
4023         }
4024
4025         /*
4026          * The jbd2_journal_load will have done any necessary log recovery,
4027          * so we can safely mount the rest of the filesystem now.
4028          */
4029
4030         root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4031         if (IS_ERR(root)) {
4032                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4033                 ret = PTR_ERR(root);
4034                 root = NULL;
4035                 goto failed_mount4;
4036         }
4037         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4038                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4039                 iput(root);
4040                 goto failed_mount4;
4041         }
4042         sb->s_root = d_make_root(root);
4043         if (!sb->s_root) {
4044                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4045                 ret = -ENOMEM;
4046                 goto failed_mount4;
4047         }
4048
4049         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4050                 sb->s_flags |= MS_RDONLY;
4051
4052         ext4_clamp_want_extra_isize(sb);
4053
4054         ext4_set_resv_clusters(sb);
4055
4056         err = ext4_setup_system_zone(sb);
4057         if (err) {
4058                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4059                          "zone (%d)", err);
4060                 goto failed_mount4a;
4061         }
4062
4063         ext4_ext_init(sb);
4064         err = ext4_mb_init(sb);
4065         if (err) {
4066                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4067                          err);
4068                 goto failed_mount5;
4069         }
4070
4071         block = ext4_count_free_clusters(sb);
4072         ext4_free_blocks_count_set(sbi->s_es,
4073                                    EXT4_C2B(sbi, block));
4074         ext4_superblock_csum_set(sb);
4075         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4076                                   GFP_KERNEL);
4077         if (!err) {
4078                 unsigned long freei = ext4_count_free_inodes(sb);
4079                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4080                 ext4_superblock_csum_set(sb);
4081                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4082                                           GFP_KERNEL);
4083         }
4084         if (!err)
4085                 err = percpu_counter_init(&sbi->s_dirs_counter,
4086                                           ext4_count_dirs(sb), GFP_KERNEL);
4087         if (!err)
4088                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4089                                           GFP_KERNEL);
4090         if (err) {
4091                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4092                 goto failed_mount6;
4093         }
4094
4095         if (ext4_has_feature_flex_bg(sb))
4096                 if (!ext4_fill_flex_info(sb)) {
4097                         ext4_msg(sb, KERN_ERR,
4098                                "unable to initialize "
4099                                "flex_bg meta info!");
4100                         goto failed_mount6;
4101                 }
4102
4103         err = ext4_register_li_request(sb, first_not_zeroed);
4104         if (err)
4105                 goto failed_mount6;
4106
4107         err = ext4_register_sysfs(sb);
4108         if (err)
4109                 goto failed_mount7;
4110
4111 #ifdef CONFIG_QUOTA
4112         /* Enable quota usage during mount. */
4113         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4114                 err = ext4_enable_quotas(sb);
4115                 if (err)
4116                         goto failed_mount8;
4117         }
4118 #endif  /* CONFIG_QUOTA */
4119
4120         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4121         ext4_orphan_cleanup(sb, es);
4122         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4123         if (needs_recovery) {
4124                 ext4_msg(sb, KERN_INFO, "recovery complete");
4125                 ext4_mark_recovery_complete(sb, es);
4126         }
4127         if (EXT4_SB(sb)->s_journal) {
4128                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4129                         descr = " journalled data mode";
4130                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4131                         descr = " ordered data mode";
4132                 else
4133                         descr = " writeback data mode";
4134         } else
4135                 descr = "out journal";
4136
4137         if (test_opt(sb, DISCARD)) {
4138                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4139                 if (!blk_queue_discard(q))
4140                         ext4_msg(sb, KERN_WARNING,
4141                                  "mounting with \"discard\" option, but "
4142                                  "the device does not support discard");
4143         }
4144
4145         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4146                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4147                          "Opts: %.*s%s%s", descr,
4148                          (int) sizeof(sbi->s_es->s_mount_opts),
4149                          sbi->s_es->s_mount_opts,
4150                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4151
4152         if (es->s_error_count)
4153                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4154
4155         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4156         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4157         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4158         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4159
4160         kfree(orig_data);
4161         return 0;
4162
4163 cantfind_ext4:
4164         if (!silent)
4165                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4166         goto failed_mount;
4167
4168 #ifdef CONFIG_QUOTA
4169 failed_mount8:
4170         ext4_unregister_sysfs(sb);
4171         kobject_put(&sbi->s_kobj);
4172 #endif
4173 failed_mount7:
4174         ext4_unregister_li_request(sb);
4175 failed_mount6:
4176         ext4_mb_release(sb);
4177         rcu_read_lock();
4178         flex_groups = rcu_dereference(sbi->s_flex_groups);
4179         if (flex_groups) {
4180                 for (i = 0; i < sbi->s_flex_groups_allocated; i++)
4181                         kvfree(flex_groups[i]);
4182                 kvfree(flex_groups);
4183         }
4184         rcu_read_unlock();
4185         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4186         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4187         percpu_counter_destroy(&sbi->s_dirs_counter);
4188         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4189 failed_mount5:
4190         ext4_ext_release(sb);
4191         ext4_release_system_zone(sb);
4192 failed_mount4a:
4193         dput(sb->s_root);
4194         sb->s_root = NULL;
4195 failed_mount4:
4196         ext4_msg(sb, KERN_ERR, "mount failed");
4197         if (EXT4_SB(sb)->rsv_conversion_wq)
4198                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4199 failed_mount_wq:
4200         if (sbi->s_journal) {
4201                 jbd2_journal_destroy(sbi->s_journal);
4202                 sbi->s_journal = NULL;
4203         }
4204 failed_mount3a:
4205         ext4_es_unregister_shrinker(sbi);
4206 failed_mount3:
4207         del_timer_sync(&sbi->s_err_report);
4208         if (sbi->s_mmp_tsk)
4209                 kthread_stop(sbi->s_mmp_tsk);
4210 failed_mount2:
4211         rcu_read_lock();
4212         group_desc = rcu_dereference(sbi->s_group_desc);
4213         for (i = 0; i < db_count; i++)
4214                 brelse(group_desc[i]);
4215         kvfree(group_desc);
4216         rcu_read_unlock();
4217 failed_mount:
4218         if (sbi->s_chksum_driver)
4219                 crypto_free_shash(sbi->s_chksum_driver);
4220 #ifdef CONFIG_QUOTA
4221         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4222                 kfree(sbi->s_qf_names[i]);
4223 #endif
4224         ext4_blkdev_remove(sbi);
4225         brelse(bh);
4226 out_fail:
4227         sb->s_fs_info = NULL;
4228         kfree(sbi->s_blockgroup_lock);
4229 out_free_base:
4230         kfree(sbi);
4231         kfree(orig_data);
4232         return err ? err : ret;
4233 }
4234
4235 /*
4236  * Setup any per-fs journal parameters now.  We'll do this both on
4237  * initial mount, once the journal has been initialised but before we've
4238  * done any recovery; and again on any subsequent remount.
4239  */
4240 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4241 {
4242         struct ext4_sb_info *sbi = EXT4_SB(sb);
4243
4244         journal->j_commit_interval = sbi->s_commit_interval;
4245         journal->j_min_batch_time = sbi->s_min_batch_time;
4246         journal->j_max_batch_time = sbi->s_max_batch_time;
4247
4248         write_lock(&journal->j_state_lock);
4249         if (test_opt(sb, BARRIER))
4250                 journal->j_flags |= JBD2_BARRIER;
4251         else
4252                 journal->j_flags &= ~JBD2_BARRIER;
4253         if (test_opt(sb, DATA_ERR_ABORT))
4254                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4255         else
4256                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4257         write_unlock(&journal->j_state_lock);
4258 }
4259
4260 static journal_t *ext4_get_journal(struct super_block *sb,
4261                                    unsigned int journal_inum)
4262 {
4263         struct inode *journal_inode;
4264         journal_t *journal;
4265
4266         BUG_ON(!ext4_has_feature_journal(sb));
4267
4268         /*
4269          * Test for the existence of a valid inode on disk.  Bad things
4270          * happen if we iget() an unused inode, as the subsequent iput()
4271          * will try to delete it.
4272          */
4273         journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4274         if (IS_ERR(journal_inode)) {
4275                 ext4_msg(sb, KERN_ERR, "no journal found");
4276                 return NULL;
4277         }
4278         if (!journal_inode->i_nlink) {
4279                 make_bad_inode(journal_inode);
4280                 iput(journal_inode);
4281                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4282                 return NULL;
4283         }
4284
4285         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4286                   journal_inode, journal_inode->i_size);
4287         if (!S_ISREG(journal_inode->i_mode)) {
4288                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4289                 iput(journal_inode);
4290                 return NULL;
4291         }
4292
4293         journal = jbd2_journal_init_inode(journal_inode);
4294         if (!journal) {
4295                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4296                 iput(journal_inode);
4297                 return NULL;
4298         }
4299         journal->j_private = sb;
4300         ext4_init_journal_params(sb, journal);
4301         return journal;
4302 }
4303
4304 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4305                                        dev_t j_dev)
4306 {
4307         struct buffer_head *bh;
4308         journal_t *journal;
4309         ext4_fsblk_t start;
4310         ext4_fsblk_t len;
4311         int hblock, blocksize;
4312         ext4_fsblk_t sb_block;
4313         unsigned long offset;
4314         struct ext4_super_block *es;
4315         struct block_device *bdev;
4316
4317         BUG_ON(!ext4_has_feature_journal(sb));
4318
4319         bdev = ext4_blkdev_get(j_dev, sb);
4320         if (bdev == NULL)
4321                 return NULL;
4322
4323         blocksize = sb->s_blocksize;
4324         hblock = bdev_logical_block_size(bdev);
4325         if (blocksize < hblock) {
4326                 ext4_msg(sb, KERN_ERR,
4327                         "blocksize too small for journal device");
4328                 goto out_bdev;
4329         }
4330
4331         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4332         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4333         set_blocksize(bdev, blocksize);
4334         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4335                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4336                        "external journal");
4337                 goto out_bdev;
4338         }
4339
4340         es = (struct ext4_super_block *) (bh->b_data + offset);
4341         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4342             !(le32_to_cpu(es->s_feature_incompat) &
4343               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4344                 ext4_msg(sb, KERN_ERR, "external journal has "
4345                                         "bad superblock");
4346                 brelse(bh);
4347                 goto out_bdev;
4348         }
4349
4350         if ((le32_to_cpu(es->s_feature_ro_compat) &
4351              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4352             es->s_checksum != ext4_superblock_csum(sb, es)) {
4353                 ext4_msg(sb, KERN_ERR, "external journal has "
4354                                        "corrupt superblock");
4355                 brelse(bh);
4356                 goto out_bdev;
4357         }
4358
4359         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4360                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4361                 brelse(bh);
4362                 goto out_bdev;
4363         }
4364
4365         len = ext4_blocks_count(es);
4366         start = sb_block + 1;
4367         brelse(bh);     /* we're done with the superblock */
4368
4369         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4370                                         start, len, blocksize);
4371         if (!journal) {
4372                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4373                 goto out_bdev;
4374         }
4375         journal->j_private = sb;
4376         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4377         wait_on_buffer(journal->j_sb_buffer);
4378         if (!buffer_uptodate(journal->j_sb_buffer)) {
4379                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4380                 goto out_journal;
4381         }
4382         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4383                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4384                                         "user (unsupported) - %d",
4385                         be32_to_cpu(journal->j_superblock->s_nr_users));
4386                 goto out_journal;
4387         }
4388         EXT4_SB(sb)->journal_bdev = bdev;
4389         ext4_init_journal_params(sb, journal);
4390         return journal;
4391
4392 out_journal:
4393         jbd2_journal_destroy(journal);
4394 out_bdev:
4395         ext4_blkdev_put(bdev);
4396         return NULL;
4397 }
4398
4399 static int ext4_load_journal(struct super_block *sb,
4400                              struct ext4_super_block *es,
4401                              unsigned long journal_devnum)
4402 {
4403         journal_t *journal;
4404         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4405         dev_t journal_dev;
4406         int err = 0;
4407         int really_read_only;
4408
4409         BUG_ON(!ext4_has_feature_journal(sb));
4410
4411         if (journal_devnum &&
4412             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4413                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4414                         "numbers have changed");
4415                 journal_dev = new_decode_dev(journal_devnum);
4416         } else
4417                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4418
4419         really_read_only = bdev_read_only(sb->s_bdev);
4420
4421         /*
4422          * Are we loading a blank journal or performing recovery after a
4423          * crash?  For recovery, we need to check in advance whether we
4424          * can get read-write access to the device.
4425          */
4426         if (ext4_has_feature_journal_needs_recovery(sb)) {
4427                 if (sb->s_flags & MS_RDONLY) {
4428                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4429                                         "required on readonly filesystem");
4430                         if (really_read_only) {
4431                                 ext4_msg(sb, KERN_ERR, "write access "
4432                                         "unavailable, cannot proceed");
4433                                 return -EROFS;
4434                         }
4435                         ext4_msg(sb, KERN_INFO, "write access will "
4436                                "be enabled during recovery");
4437                 }
4438         }
4439
4440         if (journal_inum && journal_dev) {
4441                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4442                        "and inode journals!");
4443                 return -EINVAL;
4444         }
4445
4446         if (journal_inum) {
4447                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4448                         return -EINVAL;
4449         } else {
4450                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4451                         return -EINVAL;
4452         }
4453
4454         if (!(journal->j_flags & JBD2_BARRIER))
4455                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4456
4457         if (!ext4_has_feature_journal_needs_recovery(sb))
4458                 err = jbd2_journal_wipe(journal, !really_read_only);
4459         if (!err) {
4460                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4461                 if (save)
4462                         memcpy(save, ((char *) es) +
4463                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4464                 err = jbd2_journal_load(journal);
4465                 if (save)
4466                         memcpy(((char *) es) + EXT4_S_ERR_START,
4467                                save, EXT4_S_ERR_LEN);
4468                 kfree(save);
4469         }
4470
4471         if (err) {
4472                 ext4_msg(sb, KERN_ERR, "error loading journal");
4473                 jbd2_journal_destroy(journal);
4474                 return err;
4475         }
4476
4477         EXT4_SB(sb)->s_journal = journal;
4478         ext4_clear_journal_err(sb, es);
4479
4480         if (!really_read_only && journal_devnum &&
4481             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4482                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4483
4484                 /* Make sure we flush the recovery flag to disk. */
4485                 ext4_commit_super(sb, 1);
4486         }
4487
4488         return 0;
4489 }
4490
4491 static int ext4_commit_super(struct super_block *sb, int sync)
4492 {
4493         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4494         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4495         int error = 0;
4496
4497         if (!sbh)
4498                 return -EINVAL;
4499         if (block_device_ejected(sb))
4500                 return -ENODEV;
4501
4502         /*
4503          * The superblock bh should be mapped, but it might not be if the
4504          * device was hot-removed. Not much we can do but fail the I/O.
4505          */
4506         if (!buffer_mapped(sbh))
4507                 return error;
4508
4509         if (buffer_write_io_error(sbh)) {
4510                 /*
4511                  * Oh, dear.  A previous attempt to write the
4512                  * superblock failed.  This could happen because the
4513                  * USB device was yanked out.  Or it could happen to
4514                  * be a transient write error and maybe the block will
4515                  * be remapped.  Nothing we can do but to retry the
4516                  * write and hope for the best.
4517                  */
4518                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4519                        "superblock detected");
4520                 clear_buffer_write_io_error(sbh);
4521                 set_buffer_uptodate(sbh);
4522         }
4523         /*
4524          * If the file system is mounted read-only, don't update the
4525          * superblock write time.  This avoids updating the superblock
4526          * write time when we are mounting the root file system
4527          * read/only but we need to replay the journal; at that point,
4528          * for people who are east of GMT and who make their clock
4529          * tick in localtime for Windows bug-for-bug compatibility,
4530          * the clock is set in the future, and this will cause e2fsck
4531          * to complain and force a full file system check.
4532          */
4533         if (!(sb->s_flags & MS_RDONLY))
4534                 es->s_wtime = cpu_to_le32(get_seconds());
4535         if (sb->s_bdev->bd_part)
4536                 es->s_kbytes_written =
4537                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4538                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4539                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4540         else
4541                 es->s_kbytes_written =
4542                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4543         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4544                 ext4_free_blocks_count_set(es,
4545                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4546                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4547         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4548                 es->s_free_inodes_count =
4549                         cpu_to_le32(percpu_counter_sum_positive(
4550                                 &EXT4_SB(sb)->s_freeinodes_counter));
4551         BUFFER_TRACE(sbh, "marking dirty");
4552         ext4_superblock_csum_set(sb);
4553         mark_buffer_dirty(sbh);
4554         if (sync) {
4555                 error = __sync_dirty_buffer(sbh,
4556                         test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
4557                 if (error)
4558                         return error;
4559
4560                 error = buffer_write_io_error(sbh);
4561                 if (error) {
4562                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4563                                "superblock");
4564                         clear_buffer_write_io_error(sbh);
4565                         set_buffer_uptodate(sbh);
4566                 }
4567         }
4568         return error;
4569 }
4570
4571 /*
4572  * Have we just finished recovery?  If so, and if we are mounting (or
4573  * remounting) the filesystem readonly, then we will end up with a
4574  * consistent fs on disk.  Record that fact.
4575  */
4576 static void ext4_mark_recovery_complete(struct super_block *sb,
4577                                         struct ext4_super_block *es)
4578 {
4579         journal_t *journal = EXT4_SB(sb)->s_journal;
4580
4581         if (!ext4_has_feature_journal(sb)) {
4582                 BUG_ON(journal != NULL);
4583                 return;
4584         }
4585         jbd2_journal_lock_updates(journal);
4586         if (jbd2_journal_flush(journal) < 0)
4587                 goto out;
4588
4589         if (ext4_has_feature_journal_needs_recovery(sb) &&
4590             sb->s_flags & MS_RDONLY) {
4591                 ext4_clear_feature_journal_needs_recovery(sb);
4592                 ext4_commit_super(sb, 1);
4593         }
4594
4595 out:
4596         jbd2_journal_unlock_updates(journal);
4597 }
4598
4599 /*
4600  * If we are mounting (or read-write remounting) a filesystem whose journal
4601  * has recorded an error from a previous lifetime, move that error to the
4602  * main filesystem now.
4603  */
4604 static void ext4_clear_journal_err(struct super_block *sb,
4605                                    struct ext4_super_block *es)
4606 {
4607         journal_t *journal;
4608         int j_errno;
4609         const char *errstr;
4610
4611         BUG_ON(!ext4_has_feature_journal(sb));
4612
4613         journal = EXT4_SB(sb)->s_journal;
4614
4615         /*
4616          * Now check for any error status which may have been recorded in the
4617          * journal by a prior ext4_error() or ext4_abort()
4618          */
4619
4620         j_errno = jbd2_journal_errno(journal);
4621         if (j_errno) {
4622                 char nbuf[16];
4623
4624                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4625                 ext4_warning(sb, "Filesystem error recorded "
4626                              "from previous mount: %s", errstr);
4627                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4628
4629                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4630                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4631                 ext4_commit_super(sb, 1);
4632
4633                 jbd2_journal_clear_err(journal);
4634                 jbd2_journal_update_sb_errno(journal);
4635         }
4636 }
4637
4638 /*
4639  * Force the running and committing transactions to commit,
4640  * and wait on the commit.
4641  */
4642 int ext4_force_commit(struct super_block *sb)
4643 {
4644         journal_t *journal;
4645
4646         if (sb->s_flags & MS_RDONLY)
4647                 return 0;
4648
4649         journal = EXT4_SB(sb)->s_journal;
4650         return ext4_journal_force_commit(journal);
4651 }
4652
4653 static int ext4_sync_fs(struct super_block *sb, int wait)
4654 {
4655         int ret = 0;
4656         tid_t target;
4657         bool needs_barrier = false;
4658         struct ext4_sb_info *sbi = EXT4_SB(sb);
4659
4660         trace_ext4_sync_fs(sb, wait);
4661         flush_workqueue(sbi->rsv_conversion_wq);
4662         /*
4663          * Writeback quota in non-journalled quota case - journalled quota has
4664          * no dirty dquots
4665          */
4666         dquot_writeback_dquots(sb, -1);
4667         /*
4668          * Data writeback is possible w/o journal transaction, so barrier must
4669          * being sent at the end of the function. But we can skip it if
4670          * transaction_commit will do it for us.
4671          */
4672         if (sbi->s_journal) {
4673                 target = jbd2_get_latest_transaction(sbi->s_journal);
4674                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4675                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4676                         needs_barrier = true;
4677
4678                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4679                         if (wait)
4680                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4681                                                            target);
4682                 }
4683         } else if (wait && test_opt(sb, BARRIER))
4684                 needs_barrier = true;
4685         if (needs_barrier) {
4686                 int err;
4687                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4688                 if (!ret)
4689                         ret = err;
4690         }
4691
4692         return ret;
4693 }
4694
4695 /*
4696  * LVM calls this function before a (read-only) snapshot is created.  This
4697  * gives us a chance to flush the journal completely and mark the fs clean.
4698  *
4699  * Note that only this function cannot bring a filesystem to be in a clean
4700  * state independently. It relies on upper layer to stop all data & metadata
4701  * modifications.
4702  */
4703 static int ext4_freeze(struct super_block *sb)
4704 {
4705         int error = 0;
4706         journal_t *journal;
4707
4708         if (sb->s_flags & MS_RDONLY)
4709                 return 0;
4710
4711         journal = EXT4_SB(sb)->s_journal;
4712
4713         if (journal) {
4714                 /* Now we set up the journal barrier. */
4715                 jbd2_journal_lock_updates(journal);
4716
4717                 /*
4718                  * Don't clear the needs_recovery flag if we failed to
4719                  * flush the journal.
4720                  */
4721                 error = jbd2_journal_flush(journal);
4722                 if (error < 0)
4723                         goto out;
4724
4725                 /* Journal blocked and flushed, clear needs_recovery flag. */
4726                 ext4_clear_feature_journal_needs_recovery(sb);
4727         }
4728
4729         error = ext4_commit_super(sb, 1);
4730 out:
4731         if (journal)
4732                 /* we rely on upper layer to stop further updates */
4733                 jbd2_journal_unlock_updates(journal);
4734         return error;
4735 }
4736
4737 /*
4738  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4739  * flag here, even though the filesystem is not technically dirty yet.
4740  */
4741 static int ext4_unfreeze(struct super_block *sb)
4742 {
4743         if (sb->s_flags & MS_RDONLY)
4744                 return 0;
4745
4746         if (EXT4_SB(sb)->s_journal) {
4747                 /* Reset the needs_recovery flag before the fs is unlocked. */
4748                 ext4_set_feature_journal_needs_recovery(sb);
4749         }
4750
4751         ext4_commit_super(sb, 1);
4752         return 0;
4753 }
4754
4755 /*
4756  * Structure to save mount options for ext4_remount's benefit
4757  */
4758 struct ext4_mount_options {
4759         unsigned long s_mount_opt;
4760         unsigned long s_mount_opt2;
4761         kuid_t s_resuid;
4762         kgid_t s_resgid;
4763         unsigned long s_commit_interval;
4764         u32 s_min_batch_time, s_max_batch_time;
4765 #ifdef CONFIG_QUOTA
4766         int s_jquota_fmt;
4767         char *s_qf_names[EXT4_MAXQUOTAS];
4768 #endif
4769 };
4770
4771 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4772 {
4773         struct ext4_super_block *es;
4774         struct ext4_sb_info *sbi = EXT4_SB(sb);
4775         unsigned long old_sb_flags;
4776         struct ext4_mount_options old_opts;
4777         int enable_quota = 0;
4778         ext4_group_t g;
4779         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4780         int err = 0;
4781 #ifdef CONFIG_QUOTA
4782         int i, j;
4783 #endif
4784         char *orig_data = kstrdup(data, GFP_KERNEL);
4785
4786         /* Store the original options */
4787         old_sb_flags = sb->s_flags;
4788         old_opts.s_mount_opt = sbi->s_mount_opt;
4789         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4790         old_opts.s_resuid = sbi->s_resuid;
4791         old_opts.s_resgid = sbi->s_resgid;
4792         old_opts.s_commit_interval = sbi->s_commit_interval;
4793         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4794         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4795 #ifdef CONFIG_QUOTA
4796         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4797         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4798                 if (sbi->s_qf_names[i]) {
4799                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4800                                                          GFP_KERNEL);
4801                         if (!old_opts.s_qf_names[i]) {
4802                                 for (j = 0; j < i; j++)
4803                                         kfree(old_opts.s_qf_names[j]);
4804                                 kfree(orig_data);
4805                                 return -ENOMEM;
4806                         }
4807                 } else
4808                         old_opts.s_qf_names[i] = NULL;
4809 #endif
4810         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4811                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4812
4813         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4814                 err = -EINVAL;
4815                 goto restore_opts;
4816         }
4817
4818         ext4_clamp_want_extra_isize(sb);
4819
4820         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4821             test_opt(sb, JOURNAL_CHECKSUM)) {
4822                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4823                          "during remount not supported; ignoring");
4824                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4825         }
4826
4827         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4828                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4829                         ext4_msg(sb, KERN_ERR, "can't mount with "
4830                                  "both data=journal and delalloc");
4831                         err = -EINVAL;
4832                         goto restore_opts;
4833                 }
4834                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4835                         ext4_msg(sb, KERN_ERR, "can't mount with "
4836                                  "both data=journal and dioread_nolock");
4837                         err = -EINVAL;
4838                         goto restore_opts;
4839                 }
4840                 if (test_opt(sb, DAX)) {
4841                         ext4_msg(sb, KERN_ERR, "can't mount with "
4842                                  "both data=journal and dax");
4843                         err = -EINVAL;
4844                         goto restore_opts;
4845                 }
4846         }
4847
4848         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4849                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4850                         "dax flag with busy inodes while remounting");
4851                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4852         }
4853
4854         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4855                 ext4_abort(sb, "Abort forced by user");
4856
4857         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4858                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4859
4860         es = sbi->s_es;
4861
4862         if (sbi->s_journal) {
4863                 ext4_init_journal_params(sb, sbi->s_journal);
4864                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4865         }
4866
4867         if (*flags & MS_LAZYTIME)
4868                 sb->s_flags |= MS_LAZYTIME;
4869
4870         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4871                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4872                         err = -EROFS;
4873                         goto restore_opts;
4874                 }
4875
4876                 if (*flags & MS_RDONLY) {
4877                         err = sync_filesystem(sb);
4878                         if (err < 0)
4879                                 goto restore_opts;
4880                         err = dquot_suspend(sb, -1);
4881                         if (err < 0)
4882                                 goto restore_opts;
4883
4884                         /*
4885                          * First of all, the unconditional stuff we have to do
4886                          * to disable replay of the journal when we next remount
4887                          */
4888                         sb->s_flags |= MS_RDONLY;
4889
4890                         /*
4891                          * OK, test if we are remounting a valid rw partition
4892                          * readonly, and if so set the rdonly flag and then
4893                          * mark the partition as valid again.
4894                          */
4895                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4896                             (sbi->s_mount_state & EXT4_VALID_FS))
4897                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4898
4899                         if (sbi->s_journal)
4900                                 ext4_mark_recovery_complete(sb, es);
4901                 } else {
4902                         /* Make sure we can mount this feature set readwrite */
4903                         if (ext4_has_feature_readonly(sb) ||
4904                             !ext4_feature_set_ok(sb, 0)) {
4905                                 err = -EROFS;
4906                                 goto restore_opts;
4907                         }
4908                         /*
4909                          * Make sure the group descriptor checksums
4910                          * are sane.  If they aren't, refuse to remount r/w.
4911                          */
4912                         for (g = 0; g < sbi->s_groups_count; g++) {
4913                                 struct ext4_group_desc *gdp =
4914                                         ext4_get_group_desc(sb, g, NULL);
4915
4916                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4917                                         ext4_msg(sb, KERN_ERR,
4918                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4919                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
4920                                                le16_to_cpu(gdp->bg_checksum));
4921                                         err = -EFSBADCRC;
4922                                         goto restore_opts;
4923                                 }
4924                         }
4925
4926                         /*
4927                          * If we have an unprocessed orphan list hanging
4928                          * around from a previously readonly bdev mount,
4929                          * require a full umount/remount for now.
4930                          */
4931                         if (es->s_last_orphan) {
4932                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4933                                        "remount RDWR because of unprocessed "
4934                                        "orphan inode list.  Please "
4935                                        "umount/remount instead");
4936                                 err = -EINVAL;
4937                                 goto restore_opts;
4938                         }
4939
4940                         /*
4941                          * Mounting a RDONLY partition read-write, so reread
4942                          * and store the current valid flag.  (It may have
4943                          * been changed by e2fsck since we originally mounted
4944                          * the partition.)
4945                          */
4946                         if (sbi->s_journal)
4947                                 ext4_clear_journal_err(sb, es);
4948                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4949                         if (!ext4_setup_super(sb, es, 0))
4950                                 sb->s_flags &= ~MS_RDONLY;
4951                         if (ext4_has_feature_mmp(sb))
4952                                 if (ext4_multi_mount_protect(sb,
4953                                                 le64_to_cpu(es->s_mmp_block))) {
4954                                         err = -EROFS;
4955                                         goto restore_opts;
4956                                 }
4957                         enable_quota = 1;
4958                 }
4959         }
4960
4961         /*
4962          * Reinitialize lazy itable initialization thread based on
4963          * current settings
4964          */
4965         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4966                 ext4_unregister_li_request(sb);
4967         else {
4968                 ext4_group_t first_not_zeroed;
4969                 first_not_zeroed = ext4_has_uninit_itable(sb);
4970                 ext4_register_li_request(sb, first_not_zeroed);
4971         }
4972
4973         err = ext4_setup_system_zone(sb);
4974         if (err)
4975                 goto restore_opts;
4976
4977         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4978                 ext4_commit_super(sb, 1);
4979
4980 #ifdef CONFIG_QUOTA
4981         /* Release old quota file names */
4982         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4983                 kfree(old_opts.s_qf_names[i]);
4984         if (enable_quota) {
4985                 if (sb_any_quota_suspended(sb))
4986                         dquot_resume(sb, -1);
4987                 else if (ext4_has_feature_quota(sb)) {
4988                         err = ext4_enable_quotas(sb);
4989                         if (err)
4990                                 goto restore_opts;
4991                 }
4992         }
4993 #endif
4994
4995         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
4996         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4997         kfree(orig_data);
4998         return 0;
4999
5000 restore_opts:
5001         sb->s_flags = old_sb_flags;
5002         sbi->s_mount_opt = old_opts.s_mount_opt;
5003         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5004         sbi->s_resuid = old_opts.s_resuid;
5005         sbi->s_resgid = old_opts.s_resgid;
5006         sbi->s_commit_interval = old_opts.s_commit_interval;
5007         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5008         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5009 #ifdef CONFIG_QUOTA
5010         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5011         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5012                 kfree(sbi->s_qf_names[i]);
5013                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5014         }
5015 #endif
5016         kfree(orig_data);
5017         return err;
5018 }
5019
5020 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5021 {
5022         struct super_block *sb = dentry->d_sb;
5023         struct ext4_sb_info *sbi = EXT4_SB(sb);
5024         struct ext4_super_block *es = sbi->s_es;
5025         ext4_fsblk_t overhead = 0, resv_blocks;
5026         u64 fsid;
5027         s64 bfree;
5028         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5029
5030         if (!test_opt(sb, MINIX_DF))
5031                 overhead = sbi->s_overhead;
5032
5033         buf->f_type = EXT4_SUPER_MAGIC;
5034         buf->f_bsize = sb->s_blocksize;
5035         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5036         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5037                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5038         /* prevent underflow in case that few free space is available */
5039         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5040         buf->f_bavail = buf->f_bfree -
5041                         (ext4_r_blocks_count(es) + resv_blocks);
5042         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5043                 buf->f_bavail = 0;
5044         buf->f_files = le32_to_cpu(es->s_inodes_count);
5045         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5046         buf->f_namelen = EXT4_NAME_LEN;
5047         fsid = le64_to_cpup((void *)es->s_uuid) ^
5048                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5049         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5050         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5051
5052         return 0;
5053 }
5054
5055 /* Helper function for writing quotas on sync - we need to start transaction
5056  * before quota file is locked for write. Otherwise the are possible deadlocks:
5057  * Process 1                         Process 2
5058  * ext4_create()                     quota_sync()
5059  *   jbd2_journal_start()                  write_dquot()
5060  *   dquot_initialize()                         down(dqio_mutex)
5061  *     down(dqio_mutex)                    jbd2_journal_start()
5062  *
5063  */
5064
5065 #ifdef CONFIG_QUOTA
5066
5067 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5068 {
5069         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5070 }
5071
5072 static int ext4_write_dquot(struct dquot *dquot)
5073 {
5074         int ret, err;
5075         handle_t *handle;
5076         struct inode *inode;
5077
5078         inode = dquot_to_inode(dquot);
5079         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5080                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5081         if (IS_ERR(handle))
5082                 return PTR_ERR(handle);
5083         ret = dquot_commit(dquot);
5084         err = ext4_journal_stop(handle);
5085         if (!ret)
5086                 ret = err;
5087         return ret;
5088 }
5089
5090 static int ext4_acquire_dquot(struct dquot *dquot)
5091 {
5092         int ret, err;
5093         handle_t *handle;
5094
5095         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5096                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5097         if (IS_ERR(handle))
5098                 return PTR_ERR(handle);
5099         ret = dquot_acquire(dquot);
5100         err = ext4_journal_stop(handle);
5101         if (!ret)
5102                 ret = err;
5103         return ret;
5104 }
5105
5106 static int ext4_release_dquot(struct dquot *dquot)
5107 {
5108         int ret, err;
5109         handle_t *handle;
5110
5111         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5112                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5113         if (IS_ERR(handle)) {
5114                 /* Release dquot anyway to avoid endless cycle in dqput() */
5115                 dquot_release(dquot);
5116                 return PTR_ERR(handle);
5117         }
5118         ret = dquot_release(dquot);
5119         err = ext4_journal_stop(handle);
5120         if (!ret)
5121                 ret = err;
5122         return ret;
5123 }
5124
5125 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5126 {
5127         struct super_block *sb = dquot->dq_sb;
5128         struct ext4_sb_info *sbi = EXT4_SB(sb);
5129
5130         /* Are we journaling quotas? */
5131         if (ext4_has_feature_quota(sb) ||
5132             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5133                 dquot_mark_dquot_dirty(dquot);
5134                 return ext4_write_dquot(dquot);
5135         } else {
5136                 return dquot_mark_dquot_dirty(dquot);
5137         }
5138 }
5139
5140 static int ext4_write_info(struct super_block *sb, int type)
5141 {
5142         int ret, err;
5143         handle_t *handle;
5144
5145         /* Data block + inode block */
5146         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5147         if (IS_ERR(handle))
5148                 return PTR_ERR(handle);
5149         ret = dquot_commit_info(sb, type);
5150         err = ext4_journal_stop(handle);
5151         if (!ret)
5152                 ret = err;
5153         return ret;
5154 }
5155
5156 /*
5157  * Turn on quotas during mount time - we need to find
5158  * the quota file and such...
5159  */
5160 static int ext4_quota_on_mount(struct super_block *sb, int type)
5161 {
5162         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5163                                         EXT4_SB(sb)->s_jquota_fmt, type);
5164 }
5165
5166 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5167 {
5168         struct ext4_inode_info *ei = EXT4_I(inode);
5169
5170         /* The first argument of lockdep_set_subclass has to be
5171          * *exactly* the same as the argument to init_rwsem() --- in
5172          * this case, in init_once() --- or lockdep gets unhappy
5173          * because the name of the lock is set using the
5174          * stringification of the argument to init_rwsem().
5175          */
5176         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5177         lockdep_set_subclass(&ei->i_data_sem, subclass);
5178 }
5179
5180 /*
5181  * Standard function to be called on quota_on
5182  */
5183 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5184                          struct path *path)
5185 {
5186         int err;
5187
5188         if (!test_opt(sb, QUOTA))
5189                 return -EINVAL;
5190
5191         /* Quotafile not on the same filesystem? */
5192         if (path->dentry->d_sb != sb)
5193                 return -EXDEV;
5194
5195         /* Quota already enabled for this file? */
5196         if (IS_NOQUOTA(d_inode(path->dentry)))
5197                 return -EBUSY;
5198
5199         /* Journaling quota? */
5200         if (EXT4_SB(sb)->s_qf_names[type]) {
5201                 /* Quotafile not in fs root? */
5202                 if (path->dentry->d_parent != sb->s_root)
5203                         ext4_msg(sb, KERN_WARNING,
5204                                 "Quota file not on filesystem root. "
5205                                 "Journaled quota will not work");
5206         }
5207
5208         /*
5209          * When we journal data on quota file, we have to flush journal to see
5210          * all updates to the file when we bypass pagecache...
5211          */
5212         if (EXT4_SB(sb)->s_journal &&
5213             ext4_should_journal_data(d_inode(path->dentry))) {
5214                 /*
5215                  * We don't need to lock updates but journal_flush() could
5216                  * otherwise be livelocked...
5217                  */
5218                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5219                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5220                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5221                 if (err)
5222                         return err;
5223         }
5224         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5225         err = dquot_quota_on(sb, type, format_id, path);
5226         if (err)
5227                 lockdep_set_quota_inode(path->dentry->d_inode,
5228                                              I_DATA_SEM_NORMAL);
5229         return err;
5230 }
5231
5232 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5233                              unsigned int flags)
5234 {
5235         int err;
5236         struct inode *qf_inode;
5237         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5238                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5239                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5240         };
5241
5242         BUG_ON(!ext4_has_feature_quota(sb));
5243
5244         if (!qf_inums[type])
5245                 return -EPERM;
5246
5247         qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
5248         if (IS_ERR(qf_inode)) {
5249                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5250                 return PTR_ERR(qf_inode);
5251         }
5252
5253         /* Don't account quota for quota files to avoid recursion */
5254         qf_inode->i_flags |= S_NOQUOTA;
5255         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5256         err = dquot_enable(qf_inode, type, format_id, flags);
5257         if (err)
5258                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5259         iput(qf_inode);
5260
5261         return err;
5262 }
5263
5264 /* Enable usage tracking for all quota types. */
5265 static int ext4_enable_quotas(struct super_block *sb)
5266 {
5267         int type, err = 0;
5268         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5269                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5270                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5271         };
5272
5273         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5274         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5275                 if (qf_inums[type]) {
5276                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5277                                                 DQUOT_USAGE_ENABLED);
5278                         if (err) {
5279                                 for (type--; type >= 0; type--)
5280                                         dquot_quota_off(sb, type);
5281
5282                                 ext4_warning(sb,
5283                                         "Failed to enable quota tracking "
5284                                         "(type=%d, err=%d). Please run "
5285                                         "e2fsck to fix.", type, err);
5286                                 return err;
5287                         }
5288                 }
5289         }
5290         return 0;
5291 }
5292
5293 static int ext4_quota_off(struct super_block *sb, int type)
5294 {
5295         struct inode *inode = sb_dqopt(sb)->files[type];
5296         handle_t *handle;
5297
5298         /* Force all delayed allocation blocks to be allocated.
5299          * Caller already holds s_umount sem */
5300         if (test_opt(sb, DELALLOC))
5301                 sync_filesystem(sb);
5302
5303         if (!inode)
5304                 goto out;
5305
5306         /* Update modification times of quota files when userspace can
5307          * start looking at them */
5308         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5309         if (IS_ERR(handle))
5310                 goto out;
5311         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5312         ext4_mark_inode_dirty(handle, inode);
5313         ext4_journal_stop(handle);
5314
5315 out:
5316         return dquot_quota_off(sb, type);
5317 }
5318
5319 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5320  * acquiring the locks... As quota files are never truncated and quota code
5321  * itself serializes the operations (and no one else should touch the files)
5322  * we don't have to be afraid of races */
5323 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5324                                size_t len, loff_t off)
5325 {
5326         struct inode *inode = sb_dqopt(sb)->files[type];
5327         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5328         int offset = off & (sb->s_blocksize - 1);
5329         int tocopy;
5330         size_t toread;
5331         struct buffer_head *bh;
5332         loff_t i_size = i_size_read(inode);
5333
5334         if (off > i_size)
5335                 return 0;
5336         if (off+len > i_size)
5337                 len = i_size-off;
5338         toread = len;
5339         while (toread > 0) {
5340                 tocopy = sb->s_blocksize - offset < toread ?
5341                                 sb->s_blocksize - offset : toread;
5342                 bh = ext4_bread(NULL, inode, blk, 0);
5343                 if (IS_ERR(bh))
5344                         return PTR_ERR(bh);
5345                 if (!bh)        /* A hole? */
5346                         memset(data, 0, tocopy);
5347                 else
5348                         memcpy(data, bh->b_data+offset, tocopy);
5349                 brelse(bh);
5350                 offset = 0;
5351                 toread -= tocopy;
5352                 data += tocopy;
5353                 blk++;
5354         }
5355         return len;
5356 }
5357
5358 /* Write to quotafile (we know the transaction is already started and has
5359  * enough credits) */
5360 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5361                                 const char *data, size_t len, loff_t off)
5362 {
5363         struct inode *inode = sb_dqopt(sb)->files[type];
5364         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5365         int err, offset = off & (sb->s_blocksize - 1);
5366         int retries = 0;
5367         struct buffer_head *bh;
5368         handle_t *handle = journal_current_handle();
5369
5370         if (EXT4_SB(sb)->s_journal && !handle) {
5371                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5372                         " cancelled because transaction is not started",
5373                         (unsigned long long)off, (unsigned long long)len);
5374                 return -EIO;
5375         }
5376         /*
5377          * Since we account only one data block in transaction credits,
5378          * then it is impossible to cross a block boundary.
5379          */
5380         if (sb->s_blocksize - offset < len) {
5381                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5382                         " cancelled because not block aligned",
5383                         (unsigned long long)off, (unsigned long long)len);
5384                 return -EIO;
5385         }
5386
5387         do {
5388                 bh = ext4_bread(handle, inode, blk,
5389                                 EXT4_GET_BLOCKS_CREATE |
5390                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5391         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5392                  ext4_should_retry_alloc(inode->i_sb, &retries));
5393         if (IS_ERR(bh))
5394                 return PTR_ERR(bh);
5395         if (!bh)
5396                 goto out;
5397         BUFFER_TRACE(bh, "get write access");
5398         err = ext4_journal_get_write_access(handle, bh);
5399         if (err) {
5400                 brelse(bh);
5401                 return err;
5402         }
5403         lock_buffer(bh);
5404         memcpy(bh->b_data+offset, data, len);
5405         flush_dcache_page(bh->b_page);
5406         unlock_buffer(bh);
5407         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5408         brelse(bh);
5409 out:
5410         if (inode->i_size < off + len) {
5411                 i_size_write(inode, off + len);
5412                 EXT4_I(inode)->i_disksize = inode->i_size;
5413                 ext4_mark_inode_dirty(handle, inode);
5414         }
5415         return len;
5416 }
5417
5418 #endif
5419
5420 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5421                        const char *dev_name, void *data)
5422 {
5423         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5424 }
5425
5426 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5427 static inline void register_as_ext2(void)
5428 {
5429         int err = register_filesystem(&ext2_fs_type);
5430         if (err)
5431                 printk(KERN_WARNING
5432                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5433 }
5434
5435 static inline void unregister_as_ext2(void)
5436 {
5437         unregister_filesystem(&ext2_fs_type);
5438 }
5439
5440 static inline int ext2_feature_set_ok(struct super_block *sb)
5441 {
5442         if (ext4_has_unknown_ext2_incompat_features(sb))
5443                 return 0;
5444         if (sb->s_flags & MS_RDONLY)
5445                 return 1;
5446         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5447                 return 0;
5448         return 1;
5449 }
5450 #else
5451 static inline void register_as_ext2(void) { }
5452 static inline void unregister_as_ext2(void) { }
5453 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5454 #endif
5455
5456 static inline void register_as_ext3(void)
5457 {
5458         int err = register_filesystem(&ext3_fs_type);
5459         if (err)
5460                 printk(KERN_WARNING
5461                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5462 }
5463
5464 static inline void unregister_as_ext3(void)
5465 {
5466         unregister_filesystem(&ext3_fs_type);
5467 }
5468
5469 static inline int ext3_feature_set_ok(struct super_block *sb)
5470 {
5471         if (ext4_has_unknown_ext3_incompat_features(sb))
5472                 return 0;
5473         if (!ext4_has_feature_journal(sb))
5474                 return 0;
5475         if (sb->s_flags & MS_RDONLY)
5476                 return 1;
5477         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5478                 return 0;
5479         return 1;
5480 }
5481
5482 static struct file_system_type ext4_fs_type = {
5483         .owner          = THIS_MODULE,
5484         .name           = "ext4",
5485         .mount          = ext4_mount,
5486         .kill_sb        = kill_block_super,
5487         .fs_flags       = FS_REQUIRES_DEV,
5488 };
5489 MODULE_ALIAS_FS("ext4");
5490
5491 /* Shared across all ext4 file systems */
5492 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5493 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5494
5495 static int __init ext4_init_fs(void)
5496 {
5497         int i, err;
5498
5499         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5500         ext4_li_info = NULL;
5501         mutex_init(&ext4_li_mtx);
5502
5503         /* Build-time check for flags consistency */
5504         ext4_check_flag_values();
5505
5506         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5507                 mutex_init(&ext4__aio_mutex[i]);
5508                 init_waitqueue_head(&ext4__ioend_wq[i]);
5509         }
5510
5511         err = ext4_init_es();
5512         if (err)
5513                 return err;
5514
5515         err = ext4_init_pageio();
5516         if (err)
5517                 goto out5;
5518
5519         err = ext4_init_system_zone();
5520         if (err)
5521                 goto out4;
5522
5523         err = ext4_init_sysfs();
5524         if (err)
5525                 goto out3;
5526
5527         err = ext4_init_mballoc();
5528         if (err)
5529                 goto out2;
5530         else
5531                 ext4_mballoc_ready = 1;
5532         err = init_inodecache();
5533         if (err)
5534                 goto out1;
5535         register_as_ext3();
5536         register_as_ext2();
5537         err = register_filesystem(&ext4_fs_type);
5538         if (err)
5539                 goto out;
5540
5541         return 0;
5542 out:
5543         unregister_as_ext2();
5544         unregister_as_ext3();
5545         destroy_inodecache();
5546 out1:
5547         ext4_mballoc_ready = 0;
5548         ext4_exit_mballoc();
5549 out2:
5550         ext4_exit_sysfs();
5551 out3:
5552         ext4_exit_system_zone();
5553 out4:
5554         ext4_exit_pageio();
5555 out5:
5556         ext4_exit_es();
5557
5558         return err;
5559 }
5560
5561 static void __exit ext4_exit_fs(void)
5562 {
5563         ext4_exit_crypto();
5564         ext4_destroy_lazyinit_thread();
5565         unregister_as_ext2();
5566         unregister_as_ext3();
5567         unregister_filesystem(&ext4_fs_type);
5568         destroy_inodecache();
5569         ext4_exit_mballoc();
5570         ext4_exit_sysfs();
5571         ext4_exit_system_zone();
5572         ext4_exit_pageio();
5573         ext4_exit_es();
5574 }
5575
5576 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5577 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5578 MODULE_LICENSE("GPL");
5579 module_init(ext4_init_fs)
5580 module_exit(ext4_exit_fs)