fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/jbd2.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/ctype.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <linux/cleancache.h>
  42 #include <asm/uaccess.h>
  43
  44 #include <linux/kthread.h>
  45 #include <linux/freezer.h>
  46
  47 #include "ext4.h"
  48 #include "ext4_extents.h"       /* Needed for trace points definition */
  49 #include "ext4_jbd2.h"
  50 #include "xattr.h"
  51 #include "acl.h"
  52 #include "mballoc.h"
  53
  54 #define CREATE_TRACE_POINTS
  55 #include <trace/events/ext4.h>
  56
  57 static struct proc_dir_entry *ext4_proc_root;
  58 static struct kset *ext4_kset;
  59 static struct ext4_lazy_init *ext4_li_info;
  60 static struct mutex ext4_li_mtx;
  61 static struct ext4_features *ext4_feat;
  62
  63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  64                              unsigned long journal_devnum);
  65 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  66 static int ext4_commit_super(struct super_block *sb, int sync);
  67 static void ext4_mark_recovery_complete(struct super_block *sb,
  68                                         struct ext4_super_block *es);
  69 static void ext4_clear_journal_err(struct super_block *sb,
  70                                    struct ext4_super_block *es);
  71 static int ext4_sync_fs(struct super_block *sb, int wait);
  72 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait);
  73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  75 static int ext4_unfreeze(struct super_block *sb);
  76 static int ext4_freeze(struct super_block *sb);
  77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  78                        const char *dev_name, void *data);
  79 static inline int ext2_feature_set_ok(struct super_block *sb);
  80 static inline int ext3_feature_set_ok(struct super_block *sb);
  81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  82 static void ext4_destroy_lazyinit_thread(void);
  83 static void ext4_unregister_li_request(struct super_block *sb);
  84 static void ext4_clear_request_list(void);
  85 static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
  86
  87 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  88 static struct file_system_type ext2_fs_type = {
  89         .owner          = THIS_MODULE,
  90         .name           = "ext2",
  91         .mount          = ext4_mount,
  92         .kill_sb        = kill_block_super,
  93         .fs_flags       = FS_REQUIRES_DEV,
  94 };
  95 MODULE_ALIAS_FS("ext2");
  96 MODULE_ALIAS("ext2");
  97 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  98 #else
  99 #define IS_EXT2_SB(sb) (0)
 100 #endif
 101
 102
 103 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 104 static struct file_system_type ext3_fs_type = {
 105         .owner          = THIS_MODULE,
 106         .name           = "ext3",
 107         .mount          = ext4_mount,
 108         .kill_sb        = kill_block_super,
 109         .fs_flags       = FS_REQUIRES_DEV,
 110 };
 111 MODULE_ALIAS_FS("ext3");
 112 MODULE_ALIAS("ext3");
 113 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 114 #else
 115 #define IS_EXT3_SB(sb) (0)
 116 #endif
 117
 118 static int ext4_verify_csum_type(struct super_block *sb,
 119                                  struct ext4_super_block *es)
 120 {
 121         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 122                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 123                 return 1;
 124
 125         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 126 }
 127
 128 static __le32 ext4_superblock_csum(struct super_block *sb,
 129                                    struct ext4_super_block *es)
 130 {
 131         struct ext4_sb_info *sbi = EXT4_SB(sb);
 132         int offset = offsetof(struct ext4_super_block, s_checksum);
 133         __u32 csum;
 134
 135         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 136
 137         return cpu_to_le32(csum);
 138 }
 139
 140 int ext4_superblock_csum_verify(struct super_block *sb,
 141                                 struct ext4_super_block *es)
 142 {
 143         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 144                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 145                 return 1;
 146
 147         return es->s_checksum == ext4_superblock_csum(sb, es);
 148 }
 149
 150 void ext4_superblock_csum_set(struct super_block *sb)
 151 {
 152         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 153
 154         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 155                 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 156                 return;
 157
 158         es->s_checksum = ext4_superblock_csum(sb, es);
 159 }
 160
 161 void *ext4_kvmalloc(size_t size, gfp_t flags)
 162 {
 163         void *ret;
 164
 165         ret = kmalloc(size, flags | __GFP_NOWARN);
 166         if (!ret)
 167                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 168         return ret;
 169 }
 170
 171 void *ext4_kvzalloc(size_t size, gfp_t flags)
 172 {
 173         void *ret;
 174
 175         ret = kzalloc(size, flags | __GFP_NOWARN);
 176         if (!ret)
 177                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 178         return ret;
 179 }
 180
 181 void ext4_kvfree(void *ptr)
 182 {
 183         if (is_vmalloc_addr(ptr))
 184                 vfree(ptr);
 185         else
 186                 kfree(ptr);
 187
 188 }
 189
 190 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 191                                struct ext4_group_desc *bg)
 192 {
 193         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 194                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 195                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 196 }
 197
 198 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 199                                struct ext4_group_desc *bg)
 200 {
 201         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 202                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 203                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 204 }
 205
 206 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 207                               struct ext4_group_desc *bg)
 208 {
 209         return le32_to_cpu(bg->bg_inode_table_lo) |
 210                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 211                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 212 }
 213
 214 __u32 ext4_free_group_clusters(struct super_block *sb,
 215                                struct ext4_group_desc *bg)
 216 {
 217         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 218                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 219                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 220 }
 221
 222 __u32 ext4_free_inodes_count(struct super_block *sb,
 223                               struct ext4_group_desc *bg)
 224 {
 225         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 226                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 227                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 228 }
 229
 230 __u32 ext4_used_dirs_count(struct super_block *sb,
 231                               struct ext4_group_desc *bg)
 232 {
 233         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 234                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 235                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 236 }
 237
 238 __u32 ext4_itable_unused_count(struct super_block *sb,
 239                               struct ext4_group_desc *bg)
 240 {
 241         return le16_to_cpu(bg->bg_itable_unused_lo) |
 242                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 243                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 244 }
 245
 246 void ext4_block_bitmap_set(struct super_block *sb,
 247                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 248 {
 249         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 250         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 251                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 252 }
 253
 254 void ext4_inode_bitmap_set(struct super_block *sb,
 255                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 256 {
 257         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 258         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 259                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 260 }
 261
 262 void ext4_inode_table_set(struct super_block *sb,
 263                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 264 {
 265         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 266         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 267                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 268 }
 269
 270 void ext4_free_group_clusters_set(struct super_block *sb,
 271                                   struct ext4_group_desc *bg, __u32 count)
 272 {
 273         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 274         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 275                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 276 }
 277
 278 void ext4_free_inodes_set(struct super_block *sb,
 279                           struct ext4_group_desc *bg, __u32 count)
 280 {
 281         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 282         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 283                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 284 }
 285
 286 void ext4_used_dirs_set(struct super_block *sb,
 287                           struct ext4_group_desc *bg, __u32 count)
 288 {
 289         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 290         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 291                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 292 }
 293
 294 void ext4_itable_unused_set(struct super_block *sb,
 295                           struct ext4_group_desc *bg, __u32 count)
 296 {
 297         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 298         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 299                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 300 }
 301
 302
 303 static void __save_error_info(struct super_block *sb, const char *func,
 304                             unsigned int line)
 305 {
 306         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 307
 308         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 309         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 310         es->s_last_error_time = cpu_to_le32(get_seconds());
 311         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 312         es->s_last_error_line = cpu_to_le32(line);
 313         if (!es->s_first_error_time) {
 314                 es->s_first_error_time = es->s_last_error_time;
 315                 strncpy(es->s_first_error_func, func,
 316                         sizeof(es->s_first_error_func));
 317                 es->s_first_error_line = cpu_to_le32(line);
 318                 es->s_first_error_ino = es->s_last_error_ino;
 319                 es->s_first_error_block = es->s_last_error_block;
 320         }
 321         /*
 322          * Start the daily error reporting function if it hasn't been
 323          * started already
 324          */
 325         if (!es->s_error_count)
 326                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 327         le32_add_cpu(&es->s_error_count, 1);
 328 }
 329
 330 static void save_error_info(struct super_block *sb, const char *func,
 331                             unsigned int line)
 332 {
 333         __save_error_info(sb, func, line);
 334         ext4_commit_super(sb, 1);
 335 }
 336
 337 /*
 338  * The del_gendisk() function uninitializes the disk-specific data
 339  * structures, including the bdi structure, without telling anyone
 340  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 341  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 342  * This is a kludge to prevent these oops until we can put in a proper
 343  * hook in del_gendisk() to inform the VFS and file system layers.
 344  */
 345 static int block_device_ejected(struct super_block *sb)
 346 {
 347         struct inode *bd_inode = sb->s_bdev->bd_inode;
 348         struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
 349
 350         return bdi->dev == NULL;
 351 }
 352
 353 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 354 {
 355         struct super_block              *sb = journal->j_private;
 356         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 357         int                             error = is_journal_aborted(journal);
 358         struct ext4_journal_cb_entry    *jce;
 359
 360         BUG_ON(txn->t_state == T_FINISHED);
 361         spin_lock(&sbi->s_md_lock);
 362         while (!list_empty(&txn->t_private_list)) {
 363                 jce = list_entry(txn->t_private_list.next,
 364                                  struct ext4_journal_cb_entry, jce_list);
 365                 list_del_init(&jce->jce_list);
 366                 spin_unlock(&sbi->s_md_lock);
 367                 jce->jce_func(sb, jce, error);
 368                 spin_lock(&sbi->s_md_lock);
 369         }
 370         spin_unlock(&sbi->s_md_lock);
 371 }
 372
 373 /* Deal with the reporting of failure conditions on a filesystem such as
 374  * inconsistencies detected or read IO failures.
 375  *
 376  * On ext2, we can store the error state of the filesystem in the
 377  * superblock.  That is not possible on ext4, because we may have other
 378  * write ordering constraints on the superblock which prevent us from
 379  * writing it out straight away; and given that the journal is about to
 380  * be aborted, we can't rely on the current, or future, transactions to
 381  * write out the superblock safely.
 382  *
 383  * We'll just use the jbd2_journal_abort() error code to record an error in
 384  * the journal instead.  On recovery, the journal will complain about
 385  * that error until we've noted it down and cleared it.
 386  */
 387
 388 static void ext4_handle_error(struct super_block *sb)
 389 {
 390         if (sb->s_flags & MS_RDONLY)
 391                 return;
 392
 393         if (!test_opt(sb, ERRORS_CONT)) {
 394                 journal_t *journal = EXT4_SB(sb)->s_journal;
 395
 396                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 397                 if (journal)
 398                         jbd2_journal_abort(journal, -EIO);
 399         }
 400         if (test_opt(sb, ERRORS_RO)) {
 401                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 402                 /*
 403                  * Make sure updated value of ->s_mount_flags will be visible
 404                  * before ->s_flags update
 405                  */
 406                 smp_wmb();
 407                 sb->s_flags |= MS_RDONLY;
 408         }
 409         if (test_opt(sb, ERRORS_PANIC))
 410                 panic("EXT4-fs (device %s): panic forced after error\n",
 411                         sb->s_id);
 412 }
 413
 414 #define ext4_error_ratelimit(sb)                                        \
 415                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 416                              "EXT4-fs error")
 417
 418 void __ext4_error(struct super_block *sb, const char *function,
 419                   unsigned int line, const char *fmt, ...)
 420 {
 421         struct va_format vaf;
 422         va_list args;
 423
 424         if (ext4_error_ratelimit(sb)) {
 425                 va_start(args, fmt);
 426                 vaf.fmt = fmt;
 427                 vaf.va = &args;
 428                 printk(KERN_CRIT
 429                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 430                        sb->s_id, function, line, current->comm, &vaf);
 431                 va_end(args);
 432         }
 433         save_error_info(sb, function, line);
 434         ext4_handle_error(sb);
 435 }
 436
 437 void __ext4_error_inode(struct inode *inode, const char *function,
 438                         unsigned int line, ext4_fsblk_t block,
 439                         const char *fmt, ...)
 440 {
 441         va_list args;
 442         struct va_format vaf;
 443         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 444
 445         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 446         es->s_last_error_block = cpu_to_le64(block);
 447         if (ext4_error_ratelimit(inode->i_sb)) {
 448                 va_start(args, fmt);
 449                 vaf.fmt = fmt;
 450                 vaf.va = &args;
 451                 if (block)
 452                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 453                                "inode #%lu: block %llu: comm %s: %pV\n",
 454                                inode->i_sb->s_id, function, line, inode->i_ino,
 455                                block, current->comm, &vaf);
 456                 else
 457                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 458                                "inode #%lu: comm %s: %pV\n",
 459                                inode->i_sb->s_id, function, line, inode->i_ino,
 460                                current->comm, &vaf);
 461                 va_end(args);
 462         }
 463         save_error_info(inode->i_sb, function, line);
 464         ext4_handle_error(inode->i_sb);
 465 }
 466
 467 void __ext4_error_file(struct file *file, const char *function,
 468                        unsigned int line, ext4_fsblk_t block,
 469                        const char *fmt, ...)
 470 {
 471         va_list args;
 472         struct va_format vaf;
 473         struct ext4_super_block *es;
 474         struct inode *inode = file_inode(file);
 475         char pathname[80], *path;
 476
 477         es = EXT4_SB(inode->i_sb)->s_es;
 478         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 479         if (ext4_error_ratelimit(inode->i_sb)) {
 480                 path = d_path(&(file->f_path), pathname, sizeof(pathname));
 481                 if (IS_ERR(path))
 482                         path = "(unknown)";
 483                 va_start(args, fmt);
 484                 vaf.fmt = fmt;
 485                 vaf.va = &args;
 486                 if (block)
 487                         printk(KERN_CRIT
 488                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 489                                "block %llu: comm %s: path %s: %pV\n",
 490                                inode->i_sb->s_id, function, line, inode->i_ino,
 491                                block, current->comm, path, &vaf);
 492                 else
 493                         printk(KERN_CRIT
 494                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 495                                "comm %s: path %s: %pV\n",
 496                                inode->i_sb->s_id, function, line, inode->i_ino,
 497                                current->comm, path, &vaf);
 498                 va_end(args);
 499         }
 500         save_error_info(inode->i_sb, function, line);
 501         ext4_handle_error(inode->i_sb);
 502 }
 503
 504 const char *ext4_decode_error(struct super_block *sb, int errno,
 505                               char nbuf[16])
 506 {
 507         char *errstr = NULL;
 508
 509         switch (errno) {
 510         case -EIO:
 511                 errstr = "IO failure";
 512                 break;
 513         case -ENOMEM:
 514                 errstr = "Out of memory";
 515                 break;
 516         case -EROFS:
 517                 if (!sb || (EXT4_SB(sb)->s_journal &&
 518                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 519                         errstr = "Journal has aborted";
 520                 else
 521                         errstr = "Readonly filesystem";
 522                 break;
 523         default:
 524                 /* If the caller passed in an extra buffer for unknown
 525                  * errors, textualise them now.  Else we just return
 526                  * NULL. */
 527                 if (nbuf) {
 528                         /* Check for truncated error codes... */
 529                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 530                                 errstr = nbuf;
 531                 }
 532                 break;
 533         }
 534
 535         return errstr;
 536 }
 537
 538 /* __ext4_std_error decodes expected errors from journaling functions
 539  * automatically and invokes the appropriate error response.  */
 540
 541 void __ext4_std_error(struct super_block *sb, const char *function,
 542                       unsigned int line, int errno)
 543 {
 544         char nbuf[16];
 545         const char *errstr;
 546
 547         /* Special case: if the error is EROFS, and we're not already
 548          * inside a transaction, then there's really no point in logging
 549          * an error. */
 550         if (errno == -EROFS && journal_current_handle() == NULL &&
 551             (sb->s_flags & MS_RDONLY))
 552                 return;
 553
 554         if (ext4_error_ratelimit(sb)) {
 555                 errstr = ext4_decode_error(sb, errno, nbuf);
 556                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 557                        sb->s_id, function, line, errstr);
 558         }
 559
 560         save_error_info(sb, function, line);
 561         ext4_handle_error(sb);
 562 }
 563
 564 /*
 565  * ext4_abort is a much stronger failure handler than ext4_error.  The
 566  * abort function may be used to deal with unrecoverable failures such
 567  * as journal IO errors or ENOMEM at a critical moment in log management.
 568  *
 569  * We unconditionally force the filesystem into an ABORT|READONLY state,
 570  * unless the error response on the fs has been set to panic in which
 571  * case we take the easy way out and panic immediately.
 572  */
 573
 574 void __ext4_abort(struct super_block *sb, const char *function,
 575                 unsigned int line, const char *fmt, ...)
 576 {
 577         va_list args;
 578
 579         save_error_info(sb, function, line);
 580         va_start(args, fmt);
 581         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 582                function, line);
 583         vprintk(fmt, args);
 584         printk("\n");
 585         va_end(args);
 586
 587         if ((sb->s_flags & MS_RDONLY) == 0) {
 588                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 589                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 590                 /*
 591                  * Make sure updated value of ->s_mount_flags will be visible
 592                  * before ->s_flags update
 593                  */
 594                 smp_wmb();
 595                 sb->s_flags |= MS_RDONLY;
 596                 if (EXT4_SB(sb)->s_journal)
 597                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 598                 save_error_info(sb, function, line);
 599         }
 600         if (test_opt(sb, ERRORS_PANIC))
 601                 panic("EXT4-fs panic from previous error\n");
 602 }
 603
 604 void __ext4_msg(struct super_block *sb,
 605                 const char *prefix, const char *fmt, ...)
 606 {
 607         struct va_format vaf;
 608         va_list args;
 609
 610         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 611                 return;
 612
 613         va_start(args, fmt);
 614         vaf.fmt = fmt;
 615         vaf.va = &args;
 616         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 617         va_end(args);
 618 }
 619
 620 void __ext4_warning(struct super_block *sb, const char *function,
 621                     unsigned int line, const char *fmt, ...)
 622 {
 623         struct va_format vaf;
 624         va_list args;
 625
 626         if (!___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
 627                           "EXT4-fs warning"))
 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_grp_locked_error(const char *function, unsigned int line,
 639                              struct super_block *sb, ext4_group_t grp,
 640                              unsigned long ino, ext4_fsblk_t block,
 641                              const char *fmt, ...)
 642 __releases(bitlock)
 643 __acquires(bitlock)
 644 {
 645         struct va_format vaf;
 646         va_list args;
 647         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 648
 649         es->s_last_error_ino = cpu_to_le32(ino);
 650         es->s_last_error_block = cpu_to_le64(block);
 651         __save_error_info(sb, function, line);
 652
 653         if (ext4_error_ratelimit(sb)) {
 654                 va_start(args, fmt);
 655                 vaf.fmt = fmt;
 656                 vaf.va = &args;
 657                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 658                        sb->s_id, function, line, grp);
 659                 if (ino)
 660                         printk(KERN_CONT "inode %lu: ", ino);
 661                 if (block)
 662                         printk(KERN_CONT "block %llu:",
 663                                (unsigned long long) block);
 664                 printk(KERN_CONT "%pV\n", &vaf);
 665                 va_end(args);
 666         }
 667
 668         if (test_opt(sb, ERRORS_CONT)) {
 669                 ext4_commit_super(sb, 0);
 670                 return;
 671         }
 672
 673         ext4_unlock_group(sb, grp);
 674         ext4_handle_error(sb);
 675         /*
 676          * We only get here in the ERRORS_RO case; relocking the group
 677          * may be dangerous, but nothing bad will happen since the
 678          * filesystem will have already been marked read/only and the
 679          * journal has been aborted.  We return 1 as a hint to callers
 680          * who might what to use the return value from
 681          * ext4_grp_locked_error() to distinguish between the
 682          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 683          * aggressively from the ext4 function in question, with a
 684          * more appropriate error code.
 685          */
 686         ext4_lock_group(sb, grp);
 687         return;
 688 }
 689
 690 void ext4_update_dynamic_rev(struct super_block *sb)
 691 {
 692         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 693
 694         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 695                 return;
 696
 697         ext4_warning(sb,
 698                      "updating to rev %d because of new feature flag, "
 699                      "running e2fsck is recommended",
 700                      EXT4_DYNAMIC_REV);
 701
 702         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 703         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 704         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 705         /* leave es->s_feature_*compat flags alone */
 706         /* es->s_uuid will be set by e2fsck if empty */
 707
 708         /*
 709          * The rest of the superblock fields should be zero, and if not it
 710          * means they are likely already in use, so leave them alone.  We
 711          * can leave it up to e2fsck to clean up any inconsistencies there.
 712          */
 713 }
 714
 715 /*
 716  * Open the external journal device
 717  */
 718 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 719 {
 720         struct block_device *bdev;
 721         char b[BDEVNAME_SIZE];
 722
 723         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 724         if (IS_ERR(bdev))
 725                 goto fail;
 726         return bdev;
 727
 728 fail:
 729         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 730                         __bdevname(dev, b), PTR_ERR(bdev));
 731         return NULL;
 732 }
 733
 734 /*
 735  * Release the journal device
 736  */
 737 static void ext4_blkdev_put(struct block_device *bdev)
 738 {
 739         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 740 }
 741
 742 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 743 {
 744         struct block_device *bdev;
 745         bdev = sbi->journal_bdev;
 746         if (bdev) {
 747                 ext4_blkdev_put(bdev);
 748                 sbi->journal_bdev = NULL;
 749         }
 750 }
 751
 752 static inline struct inode *orphan_list_entry(struct list_head *l)
 753 {
 754         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 755 }
 756
 757 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 758 {
 759         struct list_head *l;
 760
 761         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 762                  le32_to_cpu(sbi->s_es->s_last_orphan));
 763
 764         printk(KERN_ERR "sb_info orphan list:\n");
 765         list_for_each(l, &sbi->s_orphan) {
 766                 struct inode *inode = orphan_list_entry(l);
 767                 printk(KERN_ERR "  "
 768                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 769                        inode->i_sb->s_id, inode->i_ino, inode,
 770                        inode->i_mode, inode->i_nlink,
 771                        NEXT_ORPHAN(inode));
 772         }
 773 }
 774
 775 static void ext4_put_super(struct super_block *sb)
 776 {
 777         struct ext4_sb_info *sbi = EXT4_SB(sb);
 778         struct ext4_super_block *es = sbi->s_es;
 779         int i, err;
 780
 781         ext4_unregister_li_request(sb);
 782         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 783
 784         flush_workqueue(sbi->rsv_conversion_wq);
 785         destroy_workqueue(sbi->rsv_conversion_wq);
 786
 787         if (sbi->s_journal) {
 788                 err = jbd2_journal_destroy(sbi->s_journal);
 789                 sbi->s_journal = NULL;
 790                 if (err < 0)
 791                         ext4_abort(sb, "Couldn't clean up the journal");
 792         }
 793
 794         ext4_es_unregister_shrinker(sbi);
 795         del_timer_sync(&sbi->s_err_report);
 796         ext4_release_system_zone(sb);
 797         ext4_mb_release(sb);
 798         ext4_ext_release(sb);
 799         ext4_xattr_put_super(sb);
 800
 801         if (!(sb->s_flags & MS_RDONLY)) {
 802                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 803                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 804         }
 805         if (!(sb->s_flags & MS_RDONLY))
 806                 ext4_commit_super(sb, 1);
 807
 808         if (sbi->s_proc) {
 809                 remove_proc_entry("options", sbi->s_proc);
 810                 remove_proc_entry(sb->s_id, ext4_proc_root);
 811         }
 812         kobject_del(&sbi->s_kobj);
 813
 814         for (i = 0; i < sbi->s_gdb_count; i++)
 815                 brelse(sbi->s_group_desc[i]);
 816         ext4_kvfree(sbi->s_group_desc);
 817         ext4_kvfree(sbi->s_flex_groups);
 818         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 819         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 820         percpu_counter_destroy(&sbi->s_dirs_counter);
 821         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 822         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
 823         brelse(sbi->s_sbh);
 824 #ifdef CONFIG_QUOTA
 825         for (i = 0; i < MAXQUOTAS; i++)
 826                 kfree(sbi->s_qf_names[i]);
 827 #endif
 828
 829         /* Debugging code just in case the in-memory inode orphan list
 830          * isn't empty.  The on-disk one can be non-empty if we've
 831          * detected an error and taken the fs readonly, but the
 832          * in-memory list had better be clean by this point. */
 833         if (!list_empty(&sbi->s_orphan))
 834                 dump_orphan_list(sb, sbi);
 835         J_ASSERT(list_empty(&sbi->s_orphan));
 836
 837         invalidate_bdev(sb->s_bdev);
 838         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 839                 /*
 840                  * Invalidate the journal device's buffers.  We don't want them
 841                  * floating about in memory - the physical journal device may
 842                  * hotswapped, and it breaks the `ro-after' testing code.
 843                  */
 844                 sync_blockdev(sbi->journal_bdev);
 845                 invalidate_bdev(sbi->journal_bdev);
 846                 ext4_blkdev_remove(sbi);
 847         }
 848         if (sbi->s_mmp_tsk)
 849                 kthread_stop(sbi->s_mmp_tsk);
 850         sb->s_fs_info = NULL;
 851         /*
 852          * Now that we are completely done shutting down the
 853          * superblock, we need to actually destroy the kobject.
 854          */
 855         kobject_put(&sbi->s_kobj);
 856         wait_for_completion(&sbi->s_kobj_unregister);
 857         if (sbi->s_chksum_driver)
 858                 crypto_free_shash(sbi->s_chksum_driver);
 859         kfree(sbi->s_blockgroup_lock);
 860         kfree(sbi);
 861 }
 862
 863 static struct kmem_cache *ext4_inode_cachep;
 864
 865 /*
 866  * Called inside transaction, so use GFP_NOFS
 867  */
 868 static struct inode *ext4_alloc_inode(struct super_block *sb)
 869 {
 870         struct ext4_inode_info *ei;
 871
 872         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 873         if (!ei)
 874                 return NULL;
 875
 876         ei->vfs_inode.i_version = 1;
 877         INIT_LIST_HEAD(&ei->i_prealloc_list);
 878         spin_lock_init(&ei->i_prealloc_lock);
 879         ext4_es_init_tree(&ei->i_es_tree);
 880         rwlock_init(&ei->i_es_lock);
 881         INIT_LIST_HEAD(&ei->i_es_lru);
 882         ei->i_es_lru_nr = 0;
 883         ei->i_touch_when = 0;
 884         ei->i_reserved_data_blocks = 0;
 885         ei->i_reserved_meta_blocks = 0;
 886         ei->i_allocated_meta_blocks = 0;
 887         ei->i_da_metadata_calc_len = 0;
 888         ei->i_da_metadata_calc_last_lblock = 0;
 889         spin_lock_init(&(ei->i_block_reservation_lock));
 890 #ifdef CONFIG_QUOTA
 891         ei->i_reserved_quota = 0;
 892 #endif
 893         ei->jinode = NULL;
 894         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 895         spin_lock_init(&ei->i_completed_io_lock);
 896         ei->i_sync_tid = 0;
 897         ei->i_datasync_tid = 0;
 898         atomic_set(&ei->i_ioend_count, 0);
 899         atomic_set(&ei->i_unwritten, 0);
 900         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 901
 902         return &ei->vfs_inode;
 903 }
 904
 905 static int ext4_drop_inode(struct inode *inode)
 906 {
 907         int drop = generic_drop_inode(inode);
 908
 909         trace_ext4_drop_inode(inode, drop);
 910         return drop;
 911 }
 912
 913 static void ext4_i_callback(struct rcu_head *head)
 914 {
 915         struct inode *inode = container_of(head, struct inode, i_rcu);
 916         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 917 }
 918
 919 static void ext4_destroy_inode(struct inode *inode)
 920 {
 921         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 922                 ext4_msg(inode->i_sb, KERN_ERR,
 923                          "Inode %lu (%p): orphan list check failed!",
 924                          inode->i_ino, EXT4_I(inode));
 925                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 926                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 927                                 true);
 928                 dump_stack();
 929         }
 930         call_rcu(&inode->i_rcu, ext4_i_callback);
 931 }
 932
 933 static void init_once(void *foo)
 934 {
 935         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 936
 937         INIT_LIST_HEAD(&ei->i_orphan);
 938         init_rwsem(&ei->xattr_sem);
 939         init_rwsem(&ei->i_data_sem);
 940         inode_init_once(&ei->vfs_inode);
 941 }
 942
 943 static int init_inodecache(void)
 944 {
 945         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 946                                              sizeof(struct ext4_inode_info),
 947                                              0, (SLAB_RECLAIM_ACCOUNT|
 948                                                 SLAB_MEM_SPREAD),
 949                                              init_once);
 950         if (ext4_inode_cachep == NULL)
 951                 return -ENOMEM;
 952         return 0;
 953 }
 954
 955 static void destroy_inodecache(void)
 956 {
 957         /*
 958          * Make sure all delayed rcu free inodes are flushed before we
 959          * destroy cache.
 960          */
 961         rcu_barrier();
 962         kmem_cache_destroy(ext4_inode_cachep);
 963 }
 964
 965 void ext4_clear_inode(struct inode *inode)
 966 {
 967         invalidate_inode_buffers(inode);
 968         clear_inode(inode);
 969         dquot_drop(inode);
 970         ext4_discard_preallocations(inode);
 971         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 972         ext4_es_lru_del(inode);
 973         if (EXT4_I(inode)->jinode) {
 974                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 975                                                EXT4_I(inode)->jinode);
 976                 jbd2_free_inode(EXT4_I(inode)->jinode);
 977                 EXT4_I(inode)->jinode = NULL;
 978         }
 979 }
 980
 981 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 982                                         u64 ino, u32 generation)
 983 {
 984         struct inode *inode;
 985
 986         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 987                 return ERR_PTR(-ESTALE);
 988         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 989                 return ERR_PTR(-ESTALE);
 990
 991         /* iget isn't really right if the inode is currently unallocated!!
 992          *
 993          * ext4_read_inode will return a bad_inode if the inode had been
 994          * deleted, so we should be safe.
 995          *
 996          * Currently we don't know the generation for parent directory, so
 997          * a generation of 0 means "accept any"
 998          */
 999         inode = ext4_iget(sb, ino);
1000         if (IS_ERR(inode))
1001                 return ERR_CAST(inode);
1002         if (generation && inode->i_generation != generation) {
1003                 iput(inode);
1004                 return ERR_PTR(-ESTALE);
1005         }
1006
1007         return inode;
1008 }
1009
1010 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1011                                         int fh_len, int fh_type)
1012 {
1013         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1014                                     ext4_nfs_get_inode);
1015 }
1016
1017 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1018                                         int fh_len, int fh_type)
1019 {
1020         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1021                                     ext4_nfs_get_inode);
1022 }
1023
1024 /*
1025  * Try to release metadata pages (indirect blocks, directories) which are
1026  * mapped via the block device.  Since these pages could have journal heads
1027  * which would prevent try_to_free_buffers() from freeing them, we must use
1028  * jbd2 layer's try_to_free_buffers() function to release them.
1029  */
1030 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1031                                  gfp_t wait)
1032 {
1033         journal_t *journal = EXT4_SB(sb)->s_journal;
1034
1035         WARN_ON(PageChecked(page));
1036         if (!page_has_buffers(page))
1037                 return 0;
1038         if (journal)
1039                 return jbd2_journal_try_to_free_buffers(journal, page,
1040                                                         wait & ~__GFP_WAIT);
1041         return try_to_free_buffers(page);
1042 }
1043
1044 #ifdef CONFIG_QUOTA
1045 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1046 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1047
1048 static int ext4_write_dquot(struct dquot *dquot);
1049 static int ext4_acquire_dquot(struct dquot *dquot);
1050 static int ext4_release_dquot(struct dquot *dquot);
1051 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1052 static int ext4_write_info(struct super_block *sb, int type);
1053 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1054                          struct path *path);
1055 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1056                                  int format_id);
1057 static int ext4_quota_off(struct super_block *sb, int type);
1058 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1059 static int ext4_quota_on_mount(struct super_block *sb, int type);
1060 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1061                                size_t len, loff_t off);
1062 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1063                                 const char *data, size_t len, loff_t off);
1064 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1065                              unsigned int flags);
1066 static int ext4_enable_quotas(struct super_block *sb);
1067
1068 static const struct dquot_operations ext4_quota_operations = {
1069         .get_reserved_space = ext4_get_reserved_space,
1070         .write_dquot    = ext4_write_dquot,
1071         .acquire_dquot  = ext4_acquire_dquot,
1072         .release_dquot  = ext4_release_dquot,
1073         .mark_dirty     = ext4_mark_dquot_dirty,
1074         .write_info     = ext4_write_info,
1075         .alloc_dquot    = dquot_alloc,
1076         .destroy_dquot  = dquot_destroy,
1077 };
1078
1079 static const struct quotactl_ops ext4_qctl_operations = {
1080         .quota_on       = ext4_quota_on,
1081         .quota_off      = ext4_quota_off,
1082         .quota_sync     = dquot_quota_sync,
1083         .get_info       = dquot_get_dqinfo,
1084         .set_info       = dquot_set_dqinfo,
1085         .get_dqblk      = dquot_get_dqblk,
1086         .set_dqblk      = dquot_set_dqblk
1087 };
1088
1089 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1090         .quota_on_meta  = ext4_quota_on_sysfile,
1091         .quota_off      = ext4_quota_off_sysfile,
1092         .quota_sync     = dquot_quota_sync,
1093         .get_info       = dquot_get_dqinfo,
1094         .set_info       = dquot_set_dqinfo,
1095         .get_dqblk      = dquot_get_dqblk,
1096         .set_dqblk      = dquot_set_dqblk
1097 };
1098 #endif
1099
1100 static const struct super_operations ext4_sops = {
1101         .alloc_inode    = ext4_alloc_inode,
1102         .destroy_inode  = ext4_destroy_inode,
1103         .write_inode    = ext4_write_inode,
1104         .dirty_inode    = ext4_dirty_inode,
1105         .drop_inode     = ext4_drop_inode,
1106         .evict_inode    = ext4_evict_inode,
1107         .put_super      = ext4_put_super,
1108         .sync_fs        = ext4_sync_fs,
1109         .freeze_fs      = ext4_freeze,
1110         .unfreeze_fs    = ext4_unfreeze,
1111         .statfs         = ext4_statfs,
1112         .remount_fs     = ext4_remount,
1113         .show_options   = ext4_show_options,
1114 #ifdef CONFIG_QUOTA
1115         .quota_read     = ext4_quota_read,
1116         .quota_write    = ext4_quota_write,
1117 #endif
1118         .bdev_try_to_free_page = bdev_try_to_free_page,
1119 };
1120
1121 static const struct super_operations ext4_nojournal_sops = {
1122         .alloc_inode    = ext4_alloc_inode,
1123         .destroy_inode  = ext4_destroy_inode,
1124         .write_inode    = ext4_write_inode,
1125         .dirty_inode    = ext4_dirty_inode,
1126         .drop_inode     = ext4_drop_inode,
1127         .evict_inode    = ext4_evict_inode,
1128         .sync_fs        = ext4_sync_fs_nojournal,
1129         .put_super      = ext4_put_super,
1130         .statfs         = ext4_statfs,
1131         .remount_fs     = ext4_remount,
1132         .show_options   = ext4_show_options,
1133 #ifdef CONFIG_QUOTA
1134         .quota_read     = ext4_quota_read,
1135         .quota_write    = ext4_quota_write,
1136 #endif
1137         .bdev_try_to_free_page = bdev_try_to_free_page,
1138 };
1139
1140 static const struct export_operations ext4_export_ops = {
1141         .fh_to_dentry = ext4_fh_to_dentry,
1142         .fh_to_parent = ext4_fh_to_parent,
1143         .get_parent = ext4_get_parent,
1144 };
1145
1146 enum {
1147         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1148         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1149         Opt_nouid32, Opt_debug, Opt_removed,
1150         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1151         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1152         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1153         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1154         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1155         Opt_data_err_abort, Opt_data_err_ignore,
1156         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1157         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1158         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1159         Opt_usrquota, Opt_grpquota, Opt_i_version,
1160         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1161         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1162         Opt_inode_readahead_blks, Opt_journal_ioprio,
1163         Opt_dioread_nolock, Opt_dioread_lock,
1164         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1165         Opt_max_dir_size_kb,
1166 };
1167
1168 static const match_table_t tokens = {
1169         {Opt_bsd_df, "bsddf"},
1170         {Opt_minix_df, "minixdf"},
1171         {Opt_grpid, "grpid"},
1172         {Opt_grpid, "bsdgroups"},
1173         {Opt_nogrpid, "nogrpid"},
1174         {Opt_nogrpid, "sysvgroups"},
1175         {Opt_resgid, "resgid=%u"},
1176         {Opt_resuid, "resuid=%u"},
1177         {Opt_sb, "sb=%u"},
1178         {Opt_err_cont, "errors=continue"},
1179         {Opt_err_panic, "errors=panic"},
1180         {Opt_err_ro, "errors=remount-ro"},
1181         {Opt_nouid32, "nouid32"},
1182         {Opt_debug, "debug"},
1183         {Opt_removed, "oldalloc"},
1184         {Opt_removed, "orlov"},
1185         {Opt_user_xattr, "user_xattr"},
1186         {Opt_nouser_xattr, "nouser_xattr"},
1187         {Opt_acl, "acl"},
1188         {Opt_noacl, "noacl"},
1189         {Opt_noload, "norecovery"},
1190         {Opt_noload, "noload"},
1191         {Opt_removed, "nobh"},
1192         {Opt_removed, "bh"},
1193         {Opt_commit, "commit=%u"},
1194         {Opt_min_batch_time, "min_batch_time=%u"},
1195         {Opt_max_batch_time, "max_batch_time=%u"},
1196         {Opt_journal_dev, "journal_dev=%u"},
1197         {Opt_journal_path, "journal_path=%s"},
1198         {Opt_journal_checksum, "journal_checksum"},
1199         {Opt_journal_async_commit, "journal_async_commit"},
1200         {Opt_abort, "abort"},
1201         {Opt_data_journal, "data=journal"},
1202         {Opt_data_ordered, "data=ordered"},
1203         {Opt_data_writeback, "data=writeback"},
1204         {Opt_data_err_abort, "data_err=abort"},
1205         {Opt_data_err_ignore, "data_err=ignore"},
1206         {Opt_offusrjquota, "usrjquota="},
1207         {Opt_usrjquota, "usrjquota=%s"},
1208         {Opt_offgrpjquota, "grpjquota="},
1209         {Opt_grpjquota, "grpjquota=%s"},
1210         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1211         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1212         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1213         {Opt_grpquota, "grpquota"},
1214         {Opt_noquota, "noquota"},
1215         {Opt_quota, "quota"},
1216         {Opt_usrquota, "usrquota"},
1217         {Opt_barrier, "barrier=%u"},
1218         {Opt_barrier, "barrier"},
1219         {Opt_nobarrier, "nobarrier"},
1220         {Opt_i_version, "i_version"},
1221         {Opt_stripe, "stripe=%u"},
1222         {Opt_delalloc, "delalloc"},
1223         {Opt_nodelalloc, "nodelalloc"},
1224         {Opt_removed, "mblk_io_submit"},
1225         {Opt_removed, "nomblk_io_submit"},
1226         {Opt_block_validity, "block_validity"},
1227         {Opt_noblock_validity, "noblock_validity"},
1228         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1229         {Opt_journal_ioprio, "journal_ioprio=%u"},
1230         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1231         {Opt_auto_da_alloc, "auto_da_alloc"},
1232         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1233         {Opt_dioread_nolock, "dioread_nolock"},
1234         {Opt_dioread_lock, "dioread_lock"},
1235         {Opt_discard, "discard"},
1236         {Opt_nodiscard, "nodiscard"},
1237         {Opt_init_itable, "init_itable=%u"},
1238         {Opt_init_itable, "init_itable"},
1239         {Opt_noinit_itable, "noinit_itable"},
1240         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1241         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1242         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1243         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1244         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1245         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1246         {Opt_err, NULL},
1247 };
1248
1249 static ext4_fsblk_t get_sb_block(void **data)
1250 {
1251         ext4_fsblk_t    sb_block;
1252         char            *options = (char *) *data;
1253
1254         if (!options || strncmp(options, "sb=", 3) != 0)
1255                 return 1;       /* Default location */
1256
1257         options += 3;
1258         /* TODO: use simple_strtoll with >32bit ext4 */
1259         sb_block = simple_strtoul(options, &options, 0);
1260         if (*options && *options != ',') {
1261                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1262                        (char *) *data);
1263                 return 1;
1264         }
1265         if (*options == ',')
1266                 options++;
1267         *data = (void *) options;
1268
1269         return sb_block;
1270 }
1271
1272 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1273 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1274         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1275
1276 #ifdef CONFIG_QUOTA
1277 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1278 {
1279         struct ext4_sb_info *sbi = EXT4_SB(sb);
1280         char *qname;
1281         int ret = -1;
1282
1283         if (sb_any_quota_loaded(sb) &&
1284                 !sbi->s_qf_names[qtype]) {
1285                 ext4_msg(sb, KERN_ERR,
1286                         "Cannot change journaled "
1287                         "quota options when quota turned on");
1288                 return -1;
1289         }
1290         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1291                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1292                          "when QUOTA feature is enabled");
1293                 return -1;
1294         }
1295         qname = match_strdup(args);
1296         if (!qname) {
1297                 ext4_msg(sb, KERN_ERR,
1298                         "Not enough memory for storing quotafile name");
1299                 return -1;
1300         }
1301         if (sbi->s_qf_names[qtype]) {
1302                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1303                         ret = 1;
1304                 else
1305                         ext4_msg(sb, KERN_ERR,
1306                                  "%s quota file already specified",
1307                                  QTYPE2NAME(qtype));
1308                 goto errout;
1309         }
1310         if (strchr(qname, '/')) {
1311                 ext4_msg(sb, KERN_ERR,
1312                         "quotafile must be on filesystem root");
1313                 goto errout;
1314         }
1315         sbi->s_qf_names[qtype] = qname;
1316         set_opt(sb, QUOTA);
1317         return 1;
1318 errout:
1319         kfree(qname);
1320         return ret;
1321 }
1322
1323 static int clear_qf_name(struct super_block *sb, int qtype)
1324 {
1325
1326         struct ext4_sb_info *sbi = EXT4_SB(sb);
1327
1328         if (sb_any_quota_loaded(sb) &&
1329                 sbi->s_qf_names[qtype]) {
1330                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1331                         " when quota turned on");
1332                 return -1;
1333         }
1334         kfree(sbi->s_qf_names[qtype]);
1335         sbi->s_qf_names[qtype] = NULL;
1336         return 1;
1337 }
1338 #endif
1339
1340 #define MOPT_SET        0x0001
1341 #define MOPT_CLEAR      0x0002
1342 #define MOPT_NOSUPPORT  0x0004
1343 #define MOPT_EXPLICIT   0x0008
1344 #define MOPT_CLEAR_ERR  0x0010
1345 #define MOPT_GTE0       0x0020
1346 #ifdef CONFIG_QUOTA
1347 #define MOPT_Q          0
1348 #define MOPT_QFMT       0x0040
1349 #else
1350 #define MOPT_Q          MOPT_NOSUPPORT
1351 #define MOPT_QFMT       MOPT_NOSUPPORT
1352 #endif
1353 #define MOPT_DATAJ      0x0080
1354 #define MOPT_NO_EXT2    0x0100
1355 #define MOPT_NO_EXT3    0x0200
1356 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1357 #define MOPT_STRING     0x0400
1358
1359 static const struct mount_opts {
1360         int     token;
1361         int     mount_opt;
1362         int     flags;
1363 } ext4_mount_opts[] = {
1364         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1365         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1366         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1367         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1368         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1369         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1370         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1371          MOPT_EXT4_ONLY | MOPT_SET},
1372         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1373          MOPT_EXT4_ONLY | MOPT_CLEAR},
1374         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1375         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1376         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1377          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1378         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1379          MOPT_EXT4_ONLY | MOPT_CLEAR},
1380         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1381          MOPT_EXT4_ONLY | MOPT_SET},
1382         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1383                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1384          MOPT_EXT4_ONLY | MOPT_SET},
1385         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1386         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1387         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1388         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1389         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1390          MOPT_NO_EXT2 | MOPT_SET},
1391         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1392          MOPT_NO_EXT2 | MOPT_CLEAR},
1393         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1394         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1395         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1396         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1397         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1398         {Opt_commit, 0, MOPT_GTE0},
1399         {Opt_max_batch_time, 0, MOPT_GTE0},
1400         {Opt_min_batch_time, 0, MOPT_GTE0},
1401         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1402         {Opt_init_itable, 0, MOPT_GTE0},
1403         {Opt_stripe, 0, MOPT_GTE0},
1404         {Opt_resuid, 0, MOPT_GTE0},
1405         {Opt_resgid, 0, MOPT_GTE0},
1406         {Opt_journal_dev, 0, MOPT_GTE0},
1407         {Opt_journal_path, 0, MOPT_STRING},
1408         {Opt_journal_ioprio, 0, MOPT_GTE0},
1409         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1410         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1411         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1412          MOPT_NO_EXT2 | MOPT_DATAJ},
1413         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1414         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1415 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1416         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1417         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1418 #else
1419         {Opt_acl, 0, MOPT_NOSUPPORT},
1420         {Opt_noacl, 0, MOPT_NOSUPPORT},
1421 #endif
1422         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1423         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1424         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1425         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1426                                                         MOPT_SET | MOPT_Q},
1427         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1428                                                         MOPT_SET | MOPT_Q},
1429         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1430                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1431         {Opt_usrjquota, 0, MOPT_Q},
1432         {Opt_grpjquota, 0, MOPT_Q},
1433         {Opt_offusrjquota, 0, MOPT_Q},
1434         {Opt_offgrpjquota, 0, MOPT_Q},
1435         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1436         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1437         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1438         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1439         {Opt_err, 0, 0}
1440 };
1441
1442 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1443                             substring_t *args, unsigned long *journal_devnum,
1444                             unsigned int *journal_ioprio, int is_remount)
1445 {
1446         struct ext4_sb_info *sbi = EXT4_SB(sb);
1447         const struct mount_opts *m;
1448         kuid_t uid;
1449         kgid_t gid;
1450         int arg = 0;
1451
1452 #ifdef CONFIG_QUOTA
1453         if (token == Opt_usrjquota)
1454                 return set_qf_name(sb, USRQUOTA, &args[0]);
1455         else if (token == Opt_grpjquota)
1456                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1457         else if (token == Opt_offusrjquota)
1458                 return clear_qf_name(sb, USRQUOTA);
1459         else if (token == Opt_offgrpjquota)
1460                 return clear_qf_name(sb, GRPQUOTA);
1461 #endif
1462         switch (token) {
1463         case Opt_noacl:
1464         case Opt_nouser_xattr:
1465                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1466                 break;
1467         case Opt_sb:
1468                 return 1;       /* handled by get_sb_block() */
1469         case Opt_removed:
1470                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1471                 return 1;
1472         case Opt_abort:
1473                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1474                 return 1;
1475         case Opt_i_version:
1476                 sb->s_flags |= MS_I_VERSION;
1477                 return 1;
1478         }
1479
1480         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1481                 if (token == m->token)
1482                         break;
1483
1484         if (m->token == Opt_err) {
1485                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1486                          "or missing value", opt);
1487                 return -1;
1488         }
1489
1490         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1491                 ext4_msg(sb, KERN_ERR,
1492                          "Mount option \"%s\" incompatible with ext2", opt);
1493                 return -1;
1494         }
1495         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1496                 ext4_msg(sb, KERN_ERR,
1497                          "Mount option \"%s\" incompatible with ext3", opt);
1498                 return -1;
1499         }
1500
1501         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1502                 return -1;
1503         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1504                 return -1;
1505         if (m->flags & MOPT_EXPLICIT)
1506                 set_opt2(sb, EXPLICIT_DELALLOC);
1507         if (m->flags & MOPT_CLEAR_ERR)
1508                 clear_opt(sb, ERRORS_MASK);
1509         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1510                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1511                          "options when quota turned on");
1512                 return -1;
1513         }
1514
1515         if (m->flags & MOPT_NOSUPPORT) {
1516                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1517         } else if (token == Opt_commit) {
1518                 if (arg == 0)
1519                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1520                 sbi->s_commit_interval = HZ * arg;
1521         } else if (token == Opt_max_batch_time) {
1522                 if (arg == 0)
1523                         arg = EXT4_DEF_MAX_BATCH_TIME;
1524                 sbi->s_max_batch_time = arg;
1525         } else if (token == Opt_min_batch_time) {
1526                 sbi->s_min_batch_time = arg;
1527         } else if (token == Opt_inode_readahead_blks) {
1528                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1529                         ext4_msg(sb, KERN_ERR,
1530                                  "EXT4-fs: inode_readahead_blks must be "
1531                                  "0 or a power of 2 smaller than 2^31");
1532                         return -1;
1533                 }
1534                 sbi->s_inode_readahead_blks = arg;
1535         } else if (token == Opt_init_itable) {
1536                 set_opt(sb, INIT_INODE_TABLE);
1537                 if (!args->from)
1538                         arg = EXT4_DEF_LI_WAIT_MULT;
1539                 sbi->s_li_wait_mult = arg;
1540         } else if (token == Opt_max_dir_size_kb) {
1541                 sbi->s_max_dir_size_kb = arg;
1542         } else if (token == Opt_stripe) {
1543                 sbi->s_stripe = arg;
1544         } else if (token == Opt_resuid) {
1545                 uid = make_kuid(current_user_ns(), arg);
1546                 if (!uid_valid(uid)) {
1547                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1548                         return -1;
1549                 }
1550                 sbi->s_resuid = uid;
1551         } else if (token == Opt_resgid) {
1552                 gid = make_kgid(current_user_ns(), arg);
1553                 if (!gid_valid(gid)) {
1554                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1555                         return -1;
1556                 }
1557                 sbi->s_resgid = gid;
1558         } else if (token == Opt_journal_dev) {
1559                 if (is_remount) {
1560                         ext4_msg(sb, KERN_ERR,
1561                                  "Cannot specify journal on remount");
1562                         return -1;
1563                 }
1564                 *journal_devnum = arg;
1565         } else if (token == Opt_journal_path) {
1566                 char *journal_path;
1567                 struct inode *journal_inode;
1568                 struct path path;
1569                 int error;
1570
1571                 if (is_remount) {
1572                         ext4_msg(sb, KERN_ERR,
1573                                  "Cannot specify journal on remount");
1574                         return -1;
1575                 }
1576                 journal_path = match_strdup(&args[0]);
1577                 if (!journal_path) {
1578                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1579                                 "journal device string");
1580                         return -1;
1581                 }
1582
1583                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1584                 if (error) {
1585                         ext4_msg(sb, KERN_ERR, "error: could not find "
1586                                 "journal device path: error %d", error);
1587                         kfree(journal_path);
1588                         return -1;
1589                 }
1590
1591                 journal_inode = path.dentry->d_inode;
1592                 if (!S_ISBLK(journal_inode->i_mode)) {
1593                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1594                                 "is not a block device", journal_path);
1595                         path_put(&path);
1596                         kfree(journal_path);
1597                         return -1;
1598                 }
1599
1600                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1601                 path_put(&path);
1602                 kfree(journal_path);
1603         } else if (token == Opt_journal_ioprio) {
1604                 if (arg > 7) {
1605                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1606                                  " (must be 0-7)");
1607                         return -1;
1608                 }
1609                 *journal_ioprio =
1610                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1611         } else if (m->flags & MOPT_DATAJ) {
1612                 if (is_remount) {
1613                         if (!sbi->s_journal)
1614                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1615                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1616                                 ext4_msg(sb, KERN_ERR,
1617                                          "Cannot change data mode on remount");
1618                                 return -1;
1619                         }
1620                 } else {
1621                         clear_opt(sb, DATA_FLAGS);
1622                         sbi->s_mount_opt |= m->mount_opt;
1623                 }
1624 #ifdef CONFIG_QUOTA
1625         } else if (m->flags & MOPT_QFMT) {
1626                 if (sb_any_quota_loaded(sb) &&
1627                     sbi->s_jquota_fmt != m->mount_opt) {
1628                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1629                                  "quota options when quota turned on");
1630                         return -1;
1631                 }
1632                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1633                                                EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1634                         ext4_msg(sb, KERN_ERR,
1635                                  "Cannot set journaled quota options "
1636                                  "when QUOTA feature is enabled");
1637                         return -1;
1638                 }
1639                 sbi->s_jquota_fmt = m->mount_opt;
1640 #endif
1641         } else {
1642                 if (!args->from)
1643                         arg = 1;
1644                 if (m->flags & MOPT_CLEAR)
1645                         arg = !arg;
1646                 else if (unlikely(!(m->flags & MOPT_SET))) {
1647                         ext4_msg(sb, KERN_WARNING,
1648                                  "buggy handling of option %s", opt);
1649                         WARN_ON(1);
1650                         return -1;
1651                 }
1652                 if (arg != 0)
1653                         sbi->s_mount_opt |= m->mount_opt;
1654                 else
1655                         sbi->s_mount_opt &= ~m->mount_opt;
1656         }
1657         return 1;
1658 }
1659
1660 static int parse_options(char *options, struct super_block *sb,
1661                          unsigned long *journal_devnum,
1662                          unsigned int *journal_ioprio,
1663                          int is_remount)
1664 {
1665         struct ext4_sb_info *sbi = EXT4_SB(sb);
1666         char *p;
1667         substring_t args[MAX_OPT_ARGS];
1668         int token;
1669
1670         if (!options)
1671                 return 1;
1672
1673         while ((p = strsep(&options, ",")) != NULL) {
1674                 if (!*p)
1675                         continue;
1676                 /*
1677                  * Initialize args struct so we know whether arg was
1678                  * found; some options take optional arguments.
1679                  */
1680                 args[0].to = args[0].from = NULL;
1681                 token = match_token(p, tokens, args);
1682                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1683                                      journal_ioprio, is_remount) < 0)
1684                         return 0;
1685         }
1686 #ifdef CONFIG_QUOTA
1687         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1688             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1689                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1690                          "feature is enabled");
1691                 return 0;
1692         }
1693         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1694                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1695                         clear_opt(sb, USRQUOTA);
1696
1697                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1698                         clear_opt(sb, GRPQUOTA);
1699
1700                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1701                         ext4_msg(sb, KERN_ERR, "old and new quota "
1702                                         "format mixing");
1703                         return 0;
1704                 }
1705
1706                 if (!sbi->s_jquota_fmt) {
1707                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1708                                         "not specified");
1709                         return 0;
1710                 }
1711         } else {
1712                 if (sbi->s_jquota_fmt) {
1713                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1714                                         "specified with no journaling "
1715                                         "enabled");
1716                         return 0;
1717                 }
1718         }
1719 #endif
1720         if (test_opt(sb, DIOREAD_NOLOCK)) {
1721                 int blocksize =
1722                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1723
1724                 if (blocksize < PAGE_CACHE_SIZE) {
1725                         ext4_msg(sb, KERN_ERR, "can't mount with "
1726                                  "dioread_nolock if block size != PAGE_SIZE");
1727                         return 0;
1728                 }
1729         }
1730         return 1;
1731 }
1732
1733 static inline void ext4_show_quota_options(struct seq_file *seq,
1734                                            struct super_block *sb)
1735 {
1736 #if defined(CONFIG_QUOTA)
1737         struct ext4_sb_info *sbi = EXT4_SB(sb);
1738
1739         if (sbi->s_jquota_fmt) {
1740                 char *fmtname = "";
1741
1742                 switch (sbi->s_jquota_fmt) {
1743                 case QFMT_VFS_OLD:
1744                         fmtname = "vfsold";
1745                         break;
1746                 case QFMT_VFS_V0:
1747                         fmtname = "vfsv0";
1748                         break;
1749                 case QFMT_VFS_V1:
1750                         fmtname = "vfsv1";
1751                         break;
1752                 }
1753                 seq_printf(seq, ",jqfmt=%s", fmtname);
1754         }
1755
1756         if (sbi->s_qf_names[USRQUOTA])
1757                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1758
1759         if (sbi->s_qf_names[GRPQUOTA])
1760                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1761 #endif
1762 }
1763
1764 static const char *token2str(int token)
1765 {
1766         const struct match_token *t;
1767
1768         for (t = tokens; t->token != Opt_err; t++)
1769                 if (t->token == token && !strchr(t->pattern, '='))
1770                         break;
1771         return t->pattern;
1772 }
1773
1774 /*
1775  * Show an option if
1776  *  - it's set to a non-default value OR
1777  *  - if the per-sb default is different from the global default
1778  */
1779 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1780                               int nodefs)
1781 {
1782         struct ext4_sb_info *sbi = EXT4_SB(sb);
1783         struct ext4_super_block *es = sbi->s_es;
1784         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1785         const struct mount_opts *m;
1786         char sep = nodefs ? '\n' : ',';
1787
1788 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1789 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1790
1791         if (sbi->s_sb_block != 1)
1792                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1793
1794         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1795                 int want_set = m->flags & MOPT_SET;
1796                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1797                     (m->flags & MOPT_CLEAR_ERR))
1798                         continue;
1799                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1800                         continue; /* skip if same as the default */
1801                 if ((want_set &&
1802                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1803                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1804                         continue; /* select Opt_noFoo vs Opt_Foo */
1805                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1806         }
1807
1808         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1809             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1810                 SEQ_OPTS_PRINT("resuid=%u",
1811                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1812         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1813             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1814                 SEQ_OPTS_PRINT("resgid=%u",
1815                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1816         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1817         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1818                 SEQ_OPTS_PUTS("errors=remount-ro");
1819         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1820                 SEQ_OPTS_PUTS("errors=continue");
1821         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1822                 SEQ_OPTS_PUTS("errors=panic");
1823         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1824                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1825         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1826                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1827         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1828                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1829         if (sb->s_flags & MS_I_VERSION)
1830                 SEQ_OPTS_PUTS("i_version");
1831         if (nodefs || sbi->s_stripe)
1832                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1833         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1834                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1835                         SEQ_OPTS_PUTS("data=journal");
1836                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1837                         SEQ_OPTS_PUTS("data=ordered");
1838                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1839                         SEQ_OPTS_PUTS("data=writeback");
1840         }
1841         if (nodefs ||
1842             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1843                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1844                                sbi->s_inode_readahead_blks);
1845
1846         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1847                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1848                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1849         if (nodefs || sbi->s_max_dir_size_kb)
1850                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1851
1852         ext4_show_quota_options(seq, sb);
1853         return 0;
1854 }
1855
1856 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1857 {
1858         return _ext4_show_options(seq, root->d_sb, 0);
1859 }
1860
1861 static int options_seq_show(struct seq_file *seq, void *offset)
1862 {
1863         struct super_block *sb = seq->private;
1864         int rc;
1865
1866         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1867         rc = _ext4_show_options(seq, sb, 1);
1868         seq_puts(seq, "\n");
1869         return rc;
1870 }
1871
1872 static int options_open_fs(struct inode *inode, struct file *file)
1873 {
1874         return single_open(file, options_seq_show, PDE_DATA(inode));
1875 }
1876
1877 static const struct file_operations ext4_seq_options_fops = {
1878         .owner = THIS_MODULE,
1879         .open = options_open_fs,
1880         .read = seq_read,
1881         .llseek = seq_lseek,
1882         .release = single_release,
1883 };
1884
1885 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1886                             int read_only)
1887 {
1888         struct ext4_sb_info *sbi = EXT4_SB(sb);
1889         int res = 0;
1890
1891         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1892                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1893                          "forcing read-only mode");
1894                 res = MS_RDONLY;
1895         }
1896         if (read_only)
1897                 goto done;
1898         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1899                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1900                          "running e2fsck is recommended");
1901         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1902                 ext4_msg(sb, KERN_WARNING,
1903                          "warning: mounting fs with errors, "
1904                          "running e2fsck is recommended");
1905         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1906                  le16_to_cpu(es->s_mnt_count) >=
1907                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1908                 ext4_msg(sb, KERN_WARNING,
1909                          "warning: maximal mount count reached, "
1910                          "running e2fsck is recommended");
1911         else if (le32_to_cpu(es->s_checkinterval) &&
1912                 (le32_to_cpu(es->s_lastcheck) +
1913                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1914                 ext4_msg(sb, KERN_WARNING,
1915                          "warning: checktime reached, "
1916                          "running e2fsck is recommended");
1917         if (!sbi->s_journal)
1918                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1919         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1920                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1921         le16_add_cpu(&es->s_mnt_count, 1);
1922         es->s_mtime = cpu_to_le32(get_seconds());
1923         ext4_update_dynamic_rev(sb);
1924         if (sbi->s_journal)
1925                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1926
1927         ext4_commit_super(sb, 1);
1928 done:
1929         if (test_opt(sb, DEBUG))
1930                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1931                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1932                         sb->s_blocksize,
1933                         sbi->s_groups_count,
1934                         EXT4_BLOCKS_PER_GROUP(sb),
1935                         EXT4_INODES_PER_GROUP(sb),
1936                         sbi->s_mount_opt, sbi->s_mount_opt2);
1937
1938         cleancache_init_fs(sb);
1939         return res;
1940 }
1941
1942 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1943 {
1944         struct ext4_sb_info *sbi = EXT4_SB(sb);
1945         struct flex_groups *new_groups;
1946         int size;
1947
1948         if (!sbi->s_log_groups_per_flex)
1949                 return 0;
1950
1951         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1952         if (size <= sbi->s_flex_groups_allocated)
1953                 return 0;
1954
1955         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1956         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1957         if (!new_groups) {
1958                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1959                          size / (int) sizeof(struct flex_groups));
1960                 return -ENOMEM;
1961         }
1962
1963         if (sbi->s_flex_groups) {
1964                 memcpy(new_groups, sbi->s_flex_groups,
1965                        (sbi->s_flex_groups_allocated *
1966                         sizeof(struct flex_groups)));
1967                 ext4_kvfree(sbi->s_flex_groups);
1968         }
1969         sbi->s_flex_groups = new_groups;
1970         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1971         return 0;
1972 }
1973
1974 static int ext4_fill_flex_info(struct super_block *sb)
1975 {
1976         struct ext4_sb_info *sbi = EXT4_SB(sb);
1977         struct ext4_group_desc *gdp = NULL;
1978         ext4_group_t flex_group;
1979         int i, err;
1980
1981         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1982         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1983                 sbi->s_log_groups_per_flex = 0;
1984                 return 1;
1985         }
1986
1987         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1988         if (err)
1989                 goto failed;
1990
1991         for (i = 0; i < sbi->s_groups_count; i++) {
1992                 gdp = ext4_get_group_desc(sb, i, NULL);
1993
1994                 flex_group = ext4_flex_group(sbi, i);
1995                 atomic_add(ext4_free_inodes_count(sb, gdp),
1996                            &sbi->s_flex_groups[flex_group].free_inodes);
1997                 atomic64_add(ext4_free_group_clusters(sb, gdp),
1998                              &sbi->s_flex_groups[flex_group].free_clusters);
1999                 atomic_add(ext4_used_dirs_count(sb, gdp),
2000                            &sbi->s_flex_groups[flex_group].used_dirs);
2001         }
2002
2003         return 1;
2004 failed:
2005         return 0;
2006 }
2007
2008 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2009                                    struct ext4_group_desc *gdp)
2010 {
2011         int offset;
2012         __u16 crc = 0;
2013         __le32 le_group = cpu_to_le32(block_group);
2014
2015         if ((sbi->s_es->s_feature_ro_compat &
2016              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
2017                 /* Use new metadata_csum algorithm */
2018                 __le16 save_csum;
2019                 __u32 csum32;
2020
2021                 save_csum = gdp->bg_checksum;
2022                 gdp->bg_checksum = 0;
2023                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2024                                      sizeof(le_group));
2025                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2026                                      sbi->s_desc_size);
2027                 gdp->bg_checksum = save_csum;
2028
2029                 crc = csum32 & 0xFFFF;
2030                 goto out;
2031         }
2032
2033         /* old crc16 code */
2034         offset = offsetof(struct ext4_group_desc, bg_checksum);
2035
2036         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2037         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2038         crc = crc16(crc, (__u8 *)gdp, offset);
2039         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2040         /* for checksum of struct ext4_group_desc do the rest...*/
2041         if ((sbi->s_es->s_feature_incompat &
2042              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2043             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2044                 crc = crc16(crc, (__u8 *)gdp + offset,
2045                             le16_to_cpu(sbi->s_es->s_desc_size) -
2046                                 offset);
2047
2048 out:
2049         return cpu_to_le16(crc);
2050 }
2051
2052 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2053                                 struct ext4_group_desc *gdp)
2054 {
2055         if (ext4_has_group_desc_csum(sb) &&
2056             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2057                                                       block_group, gdp)))
2058                 return 0;
2059
2060         return 1;
2061 }
2062
2063 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2064                               struct ext4_group_desc *gdp)
2065 {
2066         if (!ext4_has_group_desc_csum(sb))
2067                 return;
2068         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2069 }
2070
2071 /* Called at mount-time, super-block is locked */
2072 static int ext4_check_descriptors(struct super_block *sb,
2073                                   ext4_group_t *first_not_zeroed)
2074 {
2075         struct ext4_sb_info *sbi = EXT4_SB(sb);
2076         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2077         ext4_fsblk_t last_block;
2078         ext4_fsblk_t block_bitmap;
2079         ext4_fsblk_t inode_bitmap;
2080         ext4_fsblk_t inode_table;
2081         int flexbg_flag = 0;
2082         ext4_group_t i, grp = sbi->s_groups_count;
2083
2084         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2085                 flexbg_flag = 1;
2086
2087         ext4_debug("Checking group descriptors");
2088
2089         for (i = 0; i < sbi->s_groups_count; i++) {
2090                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2091
2092                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2093                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2094                 else
2095                         last_block = first_block +
2096                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2097
2098                 if ((grp == sbi->s_groups_count) &&
2099                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2100                         grp = i;
2101
2102                 block_bitmap = ext4_block_bitmap(sb, gdp);
2103                 if (block_bitmap < first_block || block_bitmap > last_block) {
2104                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2105                                "Block bitmap for group %u not in group "
2106                                "(block %llu)!", i, block_bitmap);
2107                         return 0;
2108                 }
2109                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2110                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2111                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2112                                "Inode bitmap for group %u not in group "
2113                                "(block %llu)!", i, inode_bitmap);
2114                         return 0;
2115                 }
2116                 inode_table = ext4_inode_table(sb, gdp);
2117                 if (inode_table < first_block ||
2118                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2119                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2120                                "Inode table for group %u not in group "
2121                                "(block %llu)!", i, inode_table);
2122                         return 0;
2123                 }
2124                 ext4_lock_group(sb, i);
2125                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2126                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2127                                  "Checksum for group %u failed (%u!=%u)",
2128                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2129                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2130                         if (!(sb->s_flags & MS_RDONLY)) {
2131                                 ext4_unlock_group(sb, i);
2132                                 return 0;
2133                         }
2134                 }
2135                 ext4_unlock_group(sb, i);
2136                 if (!flexbg_flag)
2137                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2138         }
2139         if (NULL != first_not_zeroed)
2140                 *first_not_zeroed = grp;
2141
2142         ext4_free_blocks_count_set(sbi->s_es,
2143                                    EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2144         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2145         return 1;
2146 }
2147
2148 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2149  * the superblock) which were deleted from all directories, but held open by
2150  * a process at the time of a crash.  We walk the list and try to delete these
2151  * inodes at recovery time (only with a read-write filesystem).
2152  *
2153  * In order to keep the orphan inode chain consistent during traversal (in
2154  * case of crash during recovery), we link each inode into the superblock
2155  * orphan list_head and handle it the same way as an inode deletion during
2156  * normal operation (which journals the operations for us).
2157  *
2158  * We only do an iget() and an iput() on each inode, which is very safe if we
2159  * accidentally point at an in-use or already deleted inode.  The worst that
2160  * can happen in this case is that we get a "bit already cleared" message from
2161  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2162  * e2fsck was run on this filesystem, and it must have already done the orphan
2163  * inode cleanup for us, so we can safely abort without any further action.
2164  */
2165 static void ext4_orphan_cleanup(struct super_block *sb,
2166                                 struct ext4_super_block *es)
2167 {
2168         unsigned int s_flags = sb->s_flags;
2169         int nr_orphans = 0, nr_truncates = 0;
2170 #ifdef CONFIG_QUOTA
2171         int i;
2172 #endif
2173         if (!es->s_last_orphan) {
2174                 jbd_debug(4, "no orphan inodes to clean up\n");
2175                 return;
2176         }
2177
2178         if (bdev_read_only(sb->s_bdev)) {
2179                 ext4_msg(sb, KERN_ERR, "write access "
2180                         "unavailable, skipping orphan cleanup");
2181                 return;
2182         }
2183
2184         /* Check if feature set would not allow a r/w mount */
2185         if (!ext4_feature_set_ok(sb, 0)) {
2186                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2187                          "unknown ROCOMPAT features");
2188                 return;
2189         }
2190
2191         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2192                 /* don't clear list on RO mount w/ errors */
2193                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2194                         jbd_debug(1, "Errors on filesystem, "
2195                                   "clearing orphan list.\n");
2196                         es->s_last_orphan = 0;
2197                 }
2198                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2199                 return;
2200         }
2201
2202         if (s_flags & MS_RDONLY) {
2203                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2204                 sb->s_flags &= ~MS_RDONLY;
2205         }
2206 #ifdef CONFIG_QUOTA
2207         /* Needed for iput() to work correctly and not trash data */
2208         sb->s_flags |= MS_ACTIVE;
2209         /* Turn on quotas so that they are updated correctly */
2210         for (i = 0; i < MAXQUOTAS; i++) {
2211                 if (EXT4_SB(sb)->s_qf_names[i]) {
2212                         int ret = ext4_quota_on_mount(sb, i);
2213                         if (ret < 0)
2214                                 ext4_msg(sb, KERN_ERR,
2215                                         "Cannot turn on journaled "
2216                                         "quota: error %d", ret);
2217                 }
2218         }
2219 #endif
2220
2221         while (es->s_last_orphan) {
2222                 struct inode *inode;
2223
2224                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2225                 if (IS_ERR(inode)) {
2226                         es->s_last_orphan = 0;
2227                         break;
2228                 }
2229
2230                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2231                 dquot_initialize(inode);
2232                 if (inode->i_nlink) {
2233                         if (test_opt(sb, DEBUG))
2234                                 ext4_msg(sb, KERN_DEBUG,
2235                                         "%s: truncating inode %lu to %lld bytes",
2236                                         __func__, inode->i_ino, inode->i_size);
2237                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2238                                   inode->i_ino, inode->i_size);
2239                         mutex_lock(&inode->i_mutex);
2240                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2241                         ext4_truncate(inode);
2242                         mutex_unlock(&inode->i_mutex);
2243                         nr_truncates++;
2244                 } else {
2245                         if (test_opt(sb, DEBUG))
2246                                 ext4_msg(sb, KERN_DEBUG,
2247                                         "%s: deleting unreferenced inode %lu",
2248                                         __func__, inode->i_ino);
2249                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2250                                   inode->i_ino);
2251                         nr_orphans++;
2252                 }
2253                 iput(inode);  /* The delete magic happens here! */
2254         }
2255
2256 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2257
2258         if (nr_orphans)
2259                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2260                        PLURAL(nr_orphans));
2261         if (nr_truncates)
2262                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2263                        PLURAL(nr_truncates));
2264 #ifdef CONFIG_QUOTA
2265         /* Turn quotas off */
2266         for (i = 0; i < MAXQUOTAS; i++) {
2267                 if (sb_dqopt(sb)->files[i])
2268                         dquot_quota_off(sb, i);
2269         }
2270 #endif
2271         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2272 }
2273
2274 /*
2275  * Maximal extent format file size.
2276  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2277  * extent format containers, within a sector_t, and within i_blocks
2278  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2279  * so that won't be a limiting factor.
2280  *
2281  * However there is other limiting factor. We do store extents in the form
2282  * of starting block and length, hence the resulting length of the extent
2283  * covering maximum file size must fit into on-disk format containers as
2284  * well. Given that length is always by 1 unit bigger than max unit (because
2285  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2286  *
2287  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2288  */
2289 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2290 {
2291         loff_t res;
2292         loff_t upper_limit = MAX_LFS_FILESIZE;
2293
2294         /* small i_blocks in vfs inode? */
2295         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2296                 /*
2297                  * CONFIG_LBDAF is not enabled implies the inode
2298                  * i_block represent total blocks in 512 bytes
2299                  * 32 == size of vfs inode i_blocks * 8
2300                  */
2301                 upper_limit = (1LL << 32) - 1;
2302
2303                 /* total blocks in file system block size */
2304                 upper_limit >>= (blkbits - 9);
2305                 upper_limit <<= blkbits;
2306         }
2307
2308         /*
2309          * 32-bit extent-start container, ee_block. We lower the maxbytes
2310          * by one fs block, so ee_len can cover the extent of maximum file
2311          * size
2312          */
2313         res = (1LL << 32) - 1;
2314         res <<= blkbits;
2315
2316         /* Sanity check against vm- & vfs- imposed limits */
2317         if (res > upper_limit)
2318                 res = upper_limit;
2319
2320         return res;
2321 }
2322
2323 /*
2324  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2325  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2326  * We need to be 1 filesystem block less than the 2^48 sector limit.
2327  */
2328 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2329 {
2330         loff_t res = EXT4_NDIR_BLOCKS;
2331         int meta_blocks;
2332         loff_t upper_limit;
2333         /* This is calculated to be the largest file size for a dense, block
2334          * mapped file such that the file's total number of 512-byte sectors,
2335          * including data and all indirect blocks, does not exceed (2^48 - 1).
2336          *
2337          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2338          * number of 512-byte sectors of the file.
2339          */
2340
2341         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2342                 /*
2343                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2344                  * the inode i_block field represents total file blocks in
2345                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2346                  */
2347                 upper_limit = (1LL << 32) - 1;
2348
2349                 /* total blocks in file system block size */
2350                 upper_limit >>= (bits - 9);
2351
2352         } else {
2353                 /*
2354                  * We use 48 bit ext4_inode i_blocks
2355                  * With EXT4_HUGE_FILE_FL set the i_blocks
2356                  * represent total number of blocks in
2357                  * file system block size
2358                  */
2359                 upper_limit = (1LL << 48) - 1;
2360
2361         }
2362
2363         /* indirect blocks */
2364         meta_blocks = 1;
2365         /* double indirect blocks */
2366         meta_blocks += 1 + (1LL << (bits-2));
2367         /* tripple indirect blocks */
2368         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2369
2370         upper_limit -= meta_blocks;
2371         upper_limit <<= bits;
2372
2373         res += 1LL << (bits-2);
2374         res += 1LL << (2*(bits-2));
2375         res += 1LL << (3*(bits-2));
2376         res <<= bits;
2377         if (res > upper_limit)
2378                 res = upper_limit;
2379
2380         if (res > MAX_LFS_FILESIZE)
2381                 res = MAX_LFS_FILESIZE;
2382
2383         return res;
2384 }
2385
2386 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2387                                    ext4_fsblk_t logical_sb_block, int nr)
2388 {
2389         struct ext4_sb_info *sbi = EXT4_SB(sb);
2390         ext4_group_t bg, first_meta_bg;
2391         int has_super = 0;
2392
2393         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2394
2395         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2396             nr < first_meta_bg)
2397                 return logical_sb_block + nr + 1;
2398         bg = sbi->s_desc_per_block * nr;
2399         if (ext4_bg_has_super(sb, bg))
2400                 has_super = 1;
2401
2402         return (has_super + ext4_group_first_block_no(sb, bg));
2403 }
2404
2405 /**
2406  * ext4_get_stripe_size: Get the stripe size.
2407  * @sbi: In memory super block info
2408  *
2409  * If we have specified it via mount option, then
2410  * use the mount option value. If the value specified at mount time is
2411  * greater than the blocks per group use the super block value.
2412  * If the super block value is greater than blocks per group return 0.
2413  * Allocator needs it be less than blocks per group.
2414  *
2415  */
2416 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2417 {
2418         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2419         unsigned long stripe_width =
2420                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2421         int ret;
2422
2423         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2424                 ret = sbi->s_stripe;
2425         else if (stripe_width <= sbi->s_blocks_per_group)
2426                 ret = stripe_width;
2427         else if (stride <= sbi->s_blocks_per_group)
2428                 ret = stride;
2429         else
2430                 ret = 0;
2431
2432         /*
2433          * If the stripe width is 1, this makes no sense and
2434          * we set it to 0 to turn off stripe handling code.
2435          */
2436         if (ret <= 1)
2437                 ret = 0;
2438
2439         return ret;
2440 }
2441
2442 /* sysfs supprt */
2443
2444 struct ext4_attr {
2445         struct attribute attr;
2446         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2447         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2448                          const char *, size_t);
2449         union {
2450                 int offset;
2451                 int deprecated_val;
2452         } u;
2453 };
2454
2455 static int parse_strtoull(const char *buf,
2456                 unsigned long long max, unsigned long long *value)
2457 {
2458         int ret;
2459
2460         ret = kstrtoull(skip_spaces(buf), 0, value);
2461         if (!ret && *value > max)
2462                 ret = -EINVAL;
2463         return ret;
2464 }
2465
2466 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2467                                               struct ext4_sb_info *sbi,
2468                                               char *buf)
2469 {
2470         return snprintf(buf, PAGE_SIZE, "%llu\n",
2471                 (s64) EXT4_C2B(sbi,
2472                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2473 }
2474
2475 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2476                                          struct ext4_sb_info *sbi, char *buf)
2477 {
2478         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2479
2480         if (!sb->s_bdev->bd_part)
2481                 return snprintf(buf, PAGE_SIZE, "0\n");
2482         return snprintf(buf, PAGE_SIZE, "%lu\n",
2483                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2484                          sbi->s_sectors_written_start) >> 1);
2485 }
2486
2487 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2488                                           struct ext4_sb_info *sbi, char *buf)
2489 {
2490         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2491
2492         if (!sb->s_bdev->bd_part)
2493                 return snprintf(buf, PAGE_SIZE, "0\n");
2494         return snprintf(buf, PAGE_SIZE, "%llu\n",
2495                         (unsigned long long)(sbi->s_kbytes_written +
2496                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2497                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2498 }
2499
2500 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2501                                           struct ext4_sb_info *sbi,
2502                                           const char *buf, size_t count)
2503 {
2504         unsigned long t;
2505         int ret;
2506
2507         ret = kstrtoul(skip_spaces(buf), 0, &t);
2508         if (ret)
2509                 return ret;
2510
2511         if (t && (!is_power_of_2(t) || t > 0x40000000))
2512                 return -EINVAL;
2513
2514         sbi->s_inode_readahead_blks = t;
2515         return count;
2516 }
2517
2518 static ssize_t sbi_ui_show(struct ext4_attr *a,
2519                            struct ext4_sb_info *sbi, char *buf)
2520 {
2521         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2522
2523         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2524 }
2525
2526 static ssize_t sbi_ui_store(struct ext4_attr *a,
2527                             struct ext4_sb_info *sbi,
2528                             const char *buf, size_t count)
2529 {
2530         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2531         unsigned long t;
2532         int ret;
2533
2534         ret = kstrtoul(skip_spaces(buf), 0, &t);
2535         if (ret)
2536                 return ret;
2537         *ui = t;
2538         return count;
2539 }
2540
2541 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2542                                   struct ext4_sb_info *sbi, char *buf)
2543 {
2544         return snprintf(buf, PAGE_SIZE, "%llu\n",
2545                 (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2546 }
2547
2548 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2549                                    struct ext4_sb_info *sbi,
2550                                    const char *buf, size_t count)
2551 {
2552         unsigned long long val;
2553         int ret;
2554
2555         if (parse_strtoull(buf, -1ULL, &val))
2556                 return -EINVAL;
2557         ret = ext4_reserve_clusters(sbi, val);
2558
2559         return ret ? ret : count;
2560 }
2561
2562 static ssize_t trigger_test_error(struct ext4_attr *a,
2563                                   struct ext4_sb_info *sbi,
2564                                   const char *buf, size_t count)
2565 {
2566         int len = count;
2567
2568         if (!capable(CAP_SYS_ADMIN))
2569                 return -EPERM;
2570
2571         if (len && buf[len-1] == '\n')
2572                 len--;
2573
2574         if (len)
2575                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2576         return count;
2577 }
2578
2579 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2580                                    struct ext4_sb_info *sbi, char *buf)
2581 {
2582         return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2583 }
2584
2585 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2586 static struct ext4_attr ext4_attr_##_name = {                   \
2587         .attr = {.name = __stringify(_name), .mode = _mode },   \
2588         .show   = _show,                                        \
2589         .store  = _store,                                       \
2590         .u = {                                                  \
2591                 .offset = offsetof(struct ext4_sb_info, _elname),\
2592         },                                                      \
2593 }
2594 #define EXT4_ATTR(name, mode, show, store) \
2595 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2596
2597 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2598 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2599 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2600 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2601         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2602 #define ATTR_LIST(name) &ext4_attr_##name.attr
2603 #define EXT4_DEPRECATED_ATTR(_name, _val)       \
2604 static struct ext4_attr ext4_attr_##_name = {                   \
2605         .attr = {.name = __stringify(_name), .mode = 0444 },    \
2606         .show   = sbi_deprecated_show,                          \
2607         .u = {                                                  \
2608                 .deprecated_val = _val,                         \
2609         },                                                      \
2610 }
2611
2612 EXT4_RO_ATTR(delayed_allocation_blocks);
2613 EXT4_RO_ATTR(session_write_kbytes);
2614 EXT4_RO_ATTR(lifetime_write_kbytes);
2615 EXT4_RW_ATTR(reserved_clusters);
2616 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2617                  inode_readahead_blks_store, s_inode_readahead_blks);
2618 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2619 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2620 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2621 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2622 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2623 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2624 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2625 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2626 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2627 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2628 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2629 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2630 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2631 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2632 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2633 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2634
2635 static struct attribute *ext4_attrs[] = {
2636         ATTR_LIST(delayed_allocation_blocks),
2637         ATTR_LIST(session_write_kbytes),
2638         ATTR_LIST(lifetime_write_kbytes),
2639         ATTR_LIST(reserved_clusters),
2640         ATTR_LIST(inode_readahead_blks),
2641         ATTR_LIST(inode_goal),
2642         ATTR_LIST(mb_stats),
2643         ATTR_LIST(mb_max_to_scan),
2644         ATTR_LIST(mb_min_to_scan),
2645         ATTR_LIST(mb_order2_req),
2646         ATTR_LIST(mb_stream_req),
2647         ATTR_LIST(mb_group_prealloc),
2648         ATTR_LIST(max_writeback_mb_bump),
2649         ATTR_LIST(extent_max_zeroout_kb),
2650         ATTR_LIST(trigger_fs_error),
2651         ATTR_LIST(err_ratelimit_interval_ms),
2652         ATTR_LIST(err_ratelimit_burst),
2653         ATTR_LIST(warning_ratelimit_interval_ms),
2654         ATTR_LIST(warning_ratelimit_burst),
2655         ATTR_LIST(msg_ratelimit_interval_ms),
2656         ATTR_LIST(msg_ratelimit_burst),
2657         NULL,
2658 };
2659
2660 /* Features this copy of ext4 supports */
2661 EXT4_INFO_ATTR(lazy_itable_init);
2662 EXT4_INFO_ATTR(batched_discard);
2663 EXT4_INFO_ATTR(meta_bg_resize);
2664
2665 static struct attribute *ext4_feat_attrs[] = {
2666         ATTR_LIST(lazy_itable_init),
2667         ATTR_LIST(batched_discard),
2668         ATTR_LIST(meta_bg_resize),
2669         NULL,
2670 };
2671
2672 static ssize_t ext4_attr_show(struct kobject *kobj,
2673                               struct attribute *attr, char *buf)
2674 {
2675         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2676                                                 s_kobj);
2677         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2678
2679         return a->show ? a->show(a, sbi, buf) : 0;
2680 }
2681
2682 static ssize_t ext4_attr_store(struct kobject *kobj,
2683                                struct attribute *attr,
2684                                const char *buf, size_t len)
2685 {
2686         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2687                                                 s_kobj);
2688         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2689
2690         return a->store ? a->store(a, sbi, buf, len) : 0;
2691 }
2692
2693 static void ext4_sb_release(struct kobject *kobj)
2694 {
2695         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2696                                                 s_kobj);
2697         complete(&sbi->s_kobj_unregister);
2698 }
2699
2700 static const struct sysfs_ops ext4_attr_ops = {
2701         .show   = ext4_attr_show,
2702         .store  = ext4_attr_store,
2703 };
2704
2705 static struct kobj_type ext4_ktype = {
2706         .default_attrs  = ext4_attrs,
2707         .sysfs_ops      = &ext4_attr_ops,
2708         .release        = ext4_sb_release,
2709 };
2710
2711 static void ext4_feat_release(struct kobject *kobj)
2712 {
2713         complete(&ext4_feat->f_kobj_unregister);
2714 }
2715
2716 static struct kobj_type ext4_feat_ktype = {
2717         .default_attrs  = ext4_feat_attrs,
2718         .sysfs_ops      = &ext4_attr_ops,
2719         .release        = ext4_feat_release,
2720 };
2721
2722 /*
2723  * Check whether this filesystem can be mounted based on
2724  * the features present and the RDONLY/RDWR mount requested.
2725  * Returns 1 if this filesystem can be mounted as requested,
2726  * 0 if it cannot be.
2727  */
2728 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2729 {
2730         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2731                 ext4_msg(sb, KERN_ERR,
2732                         "Couldn't mount because of "
2733                         "unsupported optional features (%x)",
2734                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2735                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2736                 return 0;
2737         }
2738
2739         if (readonly)
2740                 return 1;
2741
2742         /* Check that feature set is OK for a read-write mount */
2743         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2744                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2745                          "unsupported optional features (%x)",
2746                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2747                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2748                 return 0;
2749         }
2750         /*
2751          * Large file size enabled file system can only be mounted
2752          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2753          */
2754         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2755                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2756                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2757                                  "cannot be mounted RDWR without "
2758                                  "CONFIG_LBDAF");
2759                         return 0;
2760                 }
2761         }
2762         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2763             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2764                 ext4_msg(sb, KERN_ERR,
2765                          "Can't support bigalloc feature without "
2766                          "extents feature\n");
2767                 return 0;
2768         }
2769
2770 #ifndef CONFIG_QUOTA
2771         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2772             !readonly) {
2773                 ext4_msg(sb, KERN_ERR,
2774                          "Filesystem with quota feature cannot be mounted RDWR "
2775                          "without CONFIG_QUOTA");
2776                 return 0;
2777         }
2778 #endif  /* CONFIG_QUOTA */
2779         return 1;
2780 }
2781
2782 /*
2783  * This function is called once a day if we have errors logged
2784  * on the file system
2785  */
2786 static void print_daily_error_info(unsigned long arg)
2787 {
2788         struct super_block *sb = (struct super_block *) arg;
2789         struct ext4_sb_info *sbi;
2790         struct ext4_super_block *es;
2791
2792         sbi = EXT4_SB(sb);
2793         es = sbi->s_es;
2794
2795         if (es->s_error_count)
2796                 ext4_msg(sb, KERN_NOTICE, "error count: %u",
2797                          le32_to_cpu(es->s_error_count));
2798         if (es->s_first_error_time) {
2799                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2800                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2801                        (int) sizeof(es->s_first_error_func),
2802                        es->s_first_error_func,
2803                        le32_to_cpu(es->s_first_error_line));
2804                 if (es->s_first_error_ino)
2805                         printk(": inode %u",
2806                                le32_to_cpu(es->s_first_error_ino));
2807                 if (es->s_first_error_block)
2808                         printk(": block %llu", (unsigned long long)
2809                                le64_to_cpu(es->s_first_error_block));
2810                 printk("\n");
2811         }
2812         if (es->s_last_error_time) {
2813                 printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2814                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2815                        (int) sizeof(es->s_last_error_func),
2816                        es->s_last_error_func,
2817                        le32_to_cpu(es->s_last_error_line));
2818                 if (es->s_last_error_ino)
2819                         printk(": inode %u",
2820                                le32_to_cpu(es->s_last_error_ino));
2821                 if (es->s_last_error_block)
2822                         printk(": block %llu", (unsigned long long)
2823                                le64_to_cpu(es->s_last_error_block));
2824                 printk("\n");
2825         }
2826         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2827 }
2828
2829 /* Find next suitable group and run ext4_init_inode_table */
2830 static int ext4_run_li_request(struct ext4_li_request *elr)
2831 {
2832         struct ext4_group_desc *gdp = NULL;
2833         ext4_group_t group, ngroups;
2834         struct super_block *sb;
2835         unsigned long timeout = 0;
2836         int ret = 0;
2837
2838         sb = elr->lr_super;
2839         ngroups = EXT4_SB(sb)->s_groups_count;
2840
2841         sb_start_write(sb);
2842         for (group = elr->lr_next_group; group < ngroups; group++) {
2843                 gdp = ext4_get_group_desc(sb, group, NULL);
2844                 if (!gdp) {
2845                         ret = 1;
2846                         break;
2847                 }
2848
2849                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2850                         break;
2851         }
2852
2853         if (group >= ngroups)
2854                 ret = 1;
2855
2856         if (!ret) {
2857                 timeout = jiffies;
2858                 ret = ext4_init_inode_table(sb, group,
2859                                             elr->lr_timeout ? 0 : 1);
2860                 if (elr->lr_timeout == 0) {
2861                         timeout = (jiffies - timeout) *
2862                                   elr->lr_sbi->s_li_wait_mult;
2863                         elr->lr_timeout = timeout;
2864                 }
2865                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2866                 elr->lr_next_group = group + 1;
2867         }
2868         sb_end_write(sb);
2869
2870         return ret;
2871 }
2872
2873 /*
2874  * Remove lr_request from the list_request and free the
2875  * request structure. Should be called with li_list_mtx held
2876  */
2877 static void ext4_remove_li_request(struct ext4_li_request *elr)
2878 {
2879         struct ext4_sb_info *sbi;
2880
2881         if (!elr)
2882                 return;
2883
2884         sbi = elr->lr_sbi;
2885
2886         list_del(&elr->lr_request);
2887         sbi->s_li_request = NULL;
2888         kfree(elr);
2889 }
2890
2891 static void ext4_unregister_li_request(struct super_block *sb)
2892 {
2893         mutex_lock(&ext4_li_mtx);
2894         if (!ext4_li_info) {
2895                 mutex_unlock(&ext4_li_mtx);
2896                 return;
2897         }
2898
2899         mutex_lock(&ext4_li_info->li_list_mtx);
2900         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2901         mutex_unlock(&ext4_li_info->li_list_mtx);
2902         mutex_unlock(&ext4_li_mtx);
2903 }
2904
2905 static struct task_struct *ext4_lazyinit_task;
2906
2907 /*
2908  * This is the function where ext4lazyinit thread lives. It walks
2909  * through the request list searching for next scheduled filesystem.
2910  * When such a fs is found, run the lazy initialization request
2911  * (ext4_rn_li_request) and keep track of the time spend in this
2912  * function. Based on that time we compute next schedule time of
2913  * the request. When walking through the list is complete, compute
2914  * next waking time and put itself into sleep.
2915  */
2916 static int ext4_lazyinit_thread(void *arg)
2917 {
2918         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2919         struct list_head *pos, *n;
2920         struct ext4_li_request *elr;
2921         unsigned long next_wakeup, cur;
2922
2923         BUG_ON(NULL == eli);
2924
2925 cont_thread:
2926         while (true) {
2927                 next_wakeup = MAX_JIFFY_OFFSET;
2928
2929                 mutex_lock(&eli->li_list_mtx);
2930                 if (list_empty(&eli->li_request_list)) {
2931                         mutex_unlock(&eli->li_list_mtx);
2932                         goto exit_thread;
2933                 }
2934
2935                 list_for_each_safe(pos, n, &eli->li_request_list) {
2936                         elr = list_entry(pos, struct ext4_li_request,
2937                                          lr_request);
2938
2939                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2940                                 if (ext4_run_li_request(elr) != 0) {
2941                                         /* error, remove the lazy_init job */
2942                                         ext4_remove_li_request(elr);
2943                                         continue;
2944                                 }
2945                         }
2946
2947                         if (time_before(elr->lr_next_sched, next_wakeup))
2948                                 next_wakeup = elr->lr_next_sched;
2949                 }
2950                 mutex_unlock(&eli->li_list_mtx);
2951
2952                 try_to_freeze();
2953
2954                 cur = jiffies;
2955                 if ((time_after_eq(cur, next_wakeup)) ||
2956                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2957                         cond_resched();
2958                         continue;
2959                 }
2960
2961                 schedule_timeout_interruptible(next_wakeup - cur);
2962
2963                 if (kthread_should_stop()) {
2964                         ext4_clear_request_list();
2965                         goto exit_thread;
2966                 }
2967         }
2968
2969 exit_thread:
2970         /*
2971          * It looks like the request list is empty, but we need
2972          * to check it under the li_list_mtx lock, to prevent any
2973          * additions into it, and of course we should lock ext4_li_mtx
2974          * to atomically free the list and ext4_li_info, because at
2975          * this point another ext4 filesystem could be registering
2976          * new one.
2977          */
2978         mutex_lock(&ext4_li_mtx);
2979         mutex_lock(&eli->li_list_mtx);
2980         if (!list_empty(&eli->li_request_list)) {
2981                 mutex_unlock(&eli->li_list_mtx);
2982                 mutex_unlock(&ext4_li_mtx);
2983                 goto cont_thread;
2984         }
2985         mutex_unlock(&eli->li_list_mtx);
2986         kfree(ext4_li_info);
2987         ext4_li_info = NULL;
2988         mutex_unlock(&ext4_li_mtx);
2989
2990         return 0;
2991 }
2992
2993 static void ext4_clear_request_list(void)
2994 {
2995         struct list_head *pos, *n;
2996         struct ext4_li_request *elr;
2997
2998         mutex_lock(&ext4_li_info->li_list_mtx);
2999         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3000                 elr = list_entry(pos, struct ext4_li_request,
3001                                  lr_request);
3002                 ext4_remove_li_request(elr);
3003         }
3004         mutex_unlock(&ext4_li_info->li_list_mtx);
3005 }
3006
3007 static int ext4_run_lazyinit_thread(void)
3008 {
3009         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3010                                          ext4_li_info, "ext4lazyinit");
3011         if (IS_ERR(ext4_lazyinit_task)) {
3012                 int err = PTR_ERR(ext4_lazyinit_task);
3013                 ext4_clear_request_list();
3014                 kfree(ext4_li_info);
3015                 ext4_li_info = NULL;
3016                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3017                                  "initialization thread\n",
3018                                  err);
3019                 return err;
3020         }
3021         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3022         return 0;
3023 }
3024
3025 /*
3026  * Check whether it make sense to run itable init. thread or not.
3027  * If there is at least one uninitialized inode table, return
3028  * corresponding group number, else the loop goes through all
3029  * groups and return total number of groups.
3030  */
3031 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3032 {
3033         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3034         struct ext4_group_desc *gdp = NULL;
3035
3036         for (group = 0; group < ngroups; group++) {
3037                 gdp = ext4_get_group_desc(sb, group, NULL);
3038                 if (!gdp)
3039                         continue;
3040
3041                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3042                         break;
3043         }
3044
3045         return group;
3046 }
3047
3048 static int ext4_li_info_new(void)
3049 {
3050         struct ext4_lazy_init *eli = NULL;
3051
3052         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3053         if (!eli)
3054                 return -ENOMEM;
3055
3056         INIT_LIST_HEAD(&eli->li_request_list);
3057         mutex_init(&eli->li_list_mtx);
3058
3059         eli->li_state |= EXT4_LAZYINIT_QUIT;
3060
3061         ext4_li_info = eli;
3062
3063         return 0;
3064 }
3065
3066 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3067                                             ext4_group_t start)
3068 {
3069         struct ext4_sb_info *sbi = EXT4_SB(sb);
3070         struct ext4_li_request *elr;
3071
3072         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3073         if (!elr)
3074                 return NULL;
3075
3076         elr->lr_super = sb;
3077         elr->lr_sbi = sbi;
3078         elr->lr_next_group = start;
3079
3080         /*
3081          * Randomize first schedule time of the request to
3082          * spread the inode table initialization requests
3083          * better.
3084          */
3085         elr->lr_next_sched = jiffies + (prandom_u32() %
3086                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3087         return elr;
3088 }
3089
3090 int ext4_register_li_request(struct super_block *sb,
3091                              ext4_group_t first_not_zeroed)
3092 {
3093         struct ext4_sb_info *sbi = EXT4_SB(sb);
3094         struct ext4_li_request *elr = NULL;
3095         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3096         int ret = 0;
3097
3098         mutex_lock(&ext4_li_mtx);
3099         if (sbi->s_li_request != NULL) {
3100                 /*
3101                  * Reset timeout so it can be computed again, because
3102                  * s_li_wait_mult might have changed.
3103                  */
3104                 sbi->s_li_request->lr_timeout = 0;
3105                 goto out;
3106         }
3107
3108         if (first_not_zeroed == ngroups ||
3109             (sb->s_flags & MS_RDONLY) ||
3110             !test_opt(sb, INIT_INODE_TABLE))
3111                 goto out;
3112
3113         elr = ext4_li_request_new(sb, first_not_zeroed);
3114         if (!elr) {
3115                 ret = -ENOMEM;
3116                 goto out;
3117         }
3118
3119         if (NULL == ext4_li_info) {
3120                 ret = ext4_li_info_new();
3121                 if (ret)
3122                         goto out;
3123         }
3124
3125         mutex_lock(&ext4_li_info->li_list_mtx);
3126         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3127         mutex_unlock(&ext4_li_info->li_list_mtx);
3128
3129         sbi->s_li_request = elr;
3130         /*
3131          * set elr to NULL here since it has been inserted to
3132          * the request_list and the removal and free of it is
3133          * handled by ext4_clear_request_list from now on.
3134          */
3135         elr = NULL;
3136
3137         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3138                 ret = ext4_run_lazyinit_thread();
3139                 if (ret)
3140                         goto out;
3141         }
3142 out:
3143         mutex_unlock(&ext4_li_mtx);
3144         if (ret)
3145                 kfree(elr);
3146         return ret;
3147 }
3148
3149 /*
3150  * We do not need to lock anything since this is called on
3151  * module unload.
3152  */
3153 static void ext4_destroy_lazyinit_thread(void)
3154 {
3155         /*
3156          * If thread exited earlier
3157          * there's nothing to be done.
3158          */
3159         if (!ext4_li_info || !ext4_lazyinit_task)
3160                 return;
3161
3162         kthread_stop(ext4_lazyinit_task);
3163 }
3164
3165 static int set_journal_csum_feature_set(struct super_block *sb)
3166 {
3167         int ret = 1;
3168         int compat, incompat;
3169         struct ext4_sb_info *sbi = EXT4_SB(sb);
3170
3171         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3172                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3173                 /* journal checksum v2 */
3174                 compat = 0;
3175                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3176         } else {
3177                 /* journal checksum v1 */
3178                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3179                 incompat = 0;
3180         }
3181
3182         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3183                 ret = jbd2_journal_set_features(sbi->s_journal,
3184                                 compat, 0,
3185                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3186                                 incompat);
3187         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3188                 ret = jbd2_journal_set_features(sbi->s_journal,
3189                                 compat, 0,
3190                                 incompat);
3191                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3192                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3193         } else {
3194                 jbd2_journal_clear_features(sbi->s_journal,
3195                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3196                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3197                                 JBD2_FEATURE_INCOMPAT_CSUM_V2);
3198         }
3199
3200         return ret;
3201 }
3202
3203 /*
3204  * Note: calculating the overhead so we can be compatible with
3205  * historical BSD practice is quite difficult in the face of
3206  * clusters/bigalloc.  This is because multiple metadata blocks from
3207  * different block group can end up in the same allocation cluster.
3208  * Calculating the exact overhead in the face of clustered allocation
3209  * requires either O(all block bitmaps) in memory or O(number of block
3210  * groups**2) in time.  We will still calculate the superblock for
3211  * older file systems --- and if we come across with a bigalloc file
3212  * system with zero in s_overhead_clusters the estimate will be close to
3213  * correct especially for very large cluster sizes --- but for newer
3214  * file systems, it's better to calculate this figure once at mkfs
3215  * time, and store it in the superblock.  If the superblock value is
3216  * present (even for non-bigalloc file systems), we will use it.
3217  */
3218 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3219                           char *buf)
3220 {
3221         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3222         struct ext4_group_desc  *gdp;
3223         ext4_fsblk_t            first_block, last_block, b;
3224         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3225         int                     s, j, count = 0;
3226
3227         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3228                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3229                         sbi->s_itb_per_group + 2);
3230
3231         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3232                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3233         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3234         for (i = 0; i < ngroups; i++) {
3235                 gdp = ext4_get_group_desc(sb, i, NULL);
3236                 b = ext4_block_bitmap(sb, gdp);
3237                 if (b >= first_block && b <= last_block) {
3238                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3239                         count++;
3240                 }
3241                 b = ext4_inode_bitmap(sb, gdp);
3242                 if (b >= first_block && b <= last_block) {
3243                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3244                         count++;
3245                 }
3246                 b = ext4_inode_table(sb, gdp);
3247                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3248                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3249                                 int c = EXT4_B2C(sbi, b - first_block);
3250                                 ext4_set_bit(c, buf);
3251                                 count++;
3252                         }
3253                 if (i != grp)
3254                         continue;
3255                 s = 0;
3256                 if (ext4_bg_has_super(sb, grp)) {
3257                         ext4_set_bit(s++, buf);
3258                         count++;
3259                 }
3260                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3261                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3262                         count++;
3263                 }
3264         }
3265         if (!count)
3266                 return 0;
3267         return EXT4_CLUSTERS_PER_GROUP(sb) -
3268                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3269 }
3270
3271 /*
3272  * Compute the overhead and stash it in sbi->s_overhead
3273  */
3274 int ext4_calculate_overhead(struct super_block *sb)
3275 {
3276         struct ext4_sb_info *sbi = EXT4_SB(sb);
3277         struct ext4_super_block *es = sbi->s_es;
3278         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3279         ext4_fsblk_t overhead = 0;
3280         char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3281
3282         if (!buf)
3283                 return -ENOMEM;
3284
3285         /*
3286          * Compute the overhead (FS structures).  This is constant
3287          * for a given filesystem unless the number of block groups
3288          * changes so we cache the previous value until it does.
3289          */
3290
3291         /*
3292          * All of the blocks before first_data_block are overhead
3293          */
3294         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3295
3296         /*
3297          * Add the overhead found in each block group
3298          */
3299         for (i = 0; i < ngroups; i++) {
3300                 int blks;
3301
3302                 blks = count_overhead(sb, i, buf);
3303                 overhead += blks;
3304                 if (blks)
3305                         memset(buf, 0, PAGE_SIZE);
3306                 cond_resched();
3307         }
3308         /* Add the journal blocks as well */
3309         if (sbi->s_journal)
3310                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3311
3312         sbi->s_overhead = overhead;
3313         smp_wmb();
3314         free_page((unsigned long) buf);
3315         return 0;
3316 }
3317
3318
3319 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3320 {
3321         ext4_fsblk_t resv_clusters;
3322
3323         /*
3324          * There's no need to reserve anything when we aren't using extents.
3325          * The space estimates are exact, there are no unwritten extents,
3326          * hole punching doesn't need new metadata... This is needed especially
3327          * to keep ext2/3 backward compatibility.
3328          */
3329         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3330                 return 0;
3331         /*
3332          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3333          * This should cover the situations where we can not afford to run
3334          * out of space like for example punch hole, or converting
3335          * uninitialized extents in delalloc path. In most cases such
3336          * allocation would require 1, or 2 blocks, higher numbers are
3337          * very rare.
3338          */
3339         resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3340                         EXT4_SB(sb)->s_cluster_bits;
3341
3342         do_div(resv_clusters, 50);
3343         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3344
3345         return resv_clusters;
3346 }
3347
3348
3349 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3350 {
3351         ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3352                                 sbi->s_cluster_bits;
3353
3354         if (count >= clusters)
3355                 return -EINVAL;
3356
3357         atomic64_set(&sbi->s_resv_clusters, count);
3358         return 0;
3359 }
3360
3361 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3362 {
3363         char *orig_data = kstrdup(data, GFP_KERNEL);
3364         struct buffer_head *bh;
3365         struct ext4_super_block *es = NULL;
3366         struct ext4_sb_info *sbi;
3367         ext4_fsblk_t block;
3368         ext4_fsblk_t sb_block = get_sb_block(&data);
3369         ext4_fsblk_t logical_sb_block;
3370         unsigned long offset = 0;
3371         unsigned long journal_devnum = 0;
3372         unsigned long def_mount_opts;
3373         struct inode *root;
3374         char *cp;
3375         const char *descr;
3376         int ret = -ENOMEM;
3377         int blocksize, clustersize;
3378         unsigned int db_count;
3379         unsigned int i;
3380         int needs_recovery, has_huge_files, has_bigalloc;
3381         __u64 blocks_count;
3382         int err = 0;
3383         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3384         ext4_group_t first_not_zeroed;
3385
3386         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3387         if (!sbi)
3388                 goto out_free_orig;
3389
3390         sbi->s_blockgroup_lock =
3391                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3392         if (!sbi->s_blockgroup_lock) {
3393                 kfree(sbi);
3394                 goto out_free_orig;
3395         }
3396         sb->s_fs_info = sbi;
3397         sbi->s_sb = sb;
3398         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3399         sbi->s_sb_block = sb_block;
3400         if (sb->s_bdev->bd_part)
3401                 sbi->s_sectors_written_start =
3402                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3403
3404         /* Cleanup superblock name */
3405         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3406                 *cp = '!';
3407
3408         /* -EINVAL is default */
3409         ret = -EINVAL;
3410         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3411         if (!blocksize) {
3412                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3413                 goto out_fail;
3414         }
3415
3416         /*
3417          * The ext4 superblock will not be buffer aligned for other than 1kB
3418          * block sizes.  We need to calculate the offset from buffer start.
3419          */
3420         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3421                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3422                 offset = do_div(logical_sb_block, blocksize);
3423         } else {
3424                 logical_sb_block = sb_block;
3425         }
3426
3427         if (!(bh = sb_bread(sb, logical_sb_block))) {
3428                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3429                 goto out_fail;
3430         }
3431         /*
3432          * Note: s_es must be initialized as soon as possible because
3433          *       some ext4 macro-instructions depend on its value
3434          */
3435         es = (struct ext4_super_block *) (bh->b_data + offset);
3436         sbi->s_es = es;
3437         sb->s_magic = le16_to_cpu(es->s_magic);
3438         if (sb->s_magic != EXT4_SUPER_MAGIC)
3439                 goto cantfind_ext4;
3440         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3441
3442         /* Warn if metadata_csum and gdt_csum are both set. */
3443         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3444                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3445             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3446                 ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3447                              "redundant flags; please run fsck.");
3448
3449         /* Check for a known checksum algorithm */
3450         if (!ext4_verify_csum_type(sb, es)) {
3451                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3452                          "unknown checksum algorithm.");
3453                 silent = 1;
3454                 goto cantfind_ext4;
3455         }
3456
3457         /* Load the checksum driver */
3458         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3459                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3460                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3461                 if (IS_ERR(sbi->s_chksum_driver)) {
3462                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3463                         ret = PTR_ERR(sbi->s_chksum_driver);
3464                         sbi->s_chksum_driver = NULL;
3465                         goto failed_mount;
3466                 }
3467         }
3468
3469         /* Check superblock checksum */
3470         if (!ext4_superblock_csum_verify(sb, es)) {
3471                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3472                          "invalid superblock checksum.  Run e2fsck?");
3473                 silent = 1;
3474                 goto cantfind_ext4;
3475         }
3476
3477         /* Precompute checksum seed for all metadata */
3478         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3479                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3480                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3481                                                sizeof(es->s_uuid));
3482
3483         /* Set defaults before we parse the mount options */
3484         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3485         set_opt(sb, INIT_INODE_TABLE);
3486         if (def_mount_opts & EXT4_DEFM_DEBUG)
3487                 set_opt(sb, DEBUG);
3488         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3489                 set_opt(sb, GRPID);
3490         if (def_mount_opts & EXT4_DEFM_UID16)
3491                 set_opt(sb, NO_UID32);
3492         /* xattr user namespace & acls are now defaulted on */
3493         set_opt(sb, XATTR_USER);
3494 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3495         set_opt(sb, POSIX_ACL);
3496 #endif
3497         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3498                 set_opt(sb, JOURNAL_DATA);
3499         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3500                 set_opt(sb, ORDERED_DATA);
3501         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3502                 set_opt(sb, WRITEBACK_DATA);
3503
3504         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3505                 set_opt(sb, ERRORS_PANIC);
3506         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3507                 set_opt(sb, ERRORS_CONT);
3508         else
3509                 set_opt(sb, ERRORS_RO);
3510         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3511                 set_opt(sb, BLOCK_VALIDITY);
3512         if (def_mount_opts & EXT4_DEFM_DISCARD)
3513                 set_opt(sb, DISCARD);
3514
3515         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3516         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3517         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3518         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3519         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3520
3521         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3522                 set_opt(sb, BARRIER);
3523
3524         /*
3525          * enable delayed allocation by default
3526          * Use -o nodelalloc to turn it off
3527          */
3528         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3529             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3530                 set_opt(sb, DELALLOC);
3531
3532         /*
3533          * set default s_li_wait_mult for lazyinit, for the case there is
3534          * no mount option specified.
3535          */
3536         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3537
3538         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3539                            &journal_devnum, &journal_ioprio, 0)) {
3540                 ext4_msg(sb, KERN_WARNING,
3541                          "failed to parse options in superblock: %s",
3542                          sbi->s_es->s_mount_opts);
3543         }
3544         sbi->s_def_mount_opt = sbi->s_mount_opt;
3545         if (!parse_options((char *) data, sb, &journal_devnum,
3546                            &journal_ioprio, 0))
3547                 goto failed_mount;
3548
3549         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3550                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3551                             "with data=journal disables delayed "
3552                             "allocation and O_DIRECT support!\n");
3553                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3554                         ext4_msg(sb, KERN_ERR, "can't mount with "
3555                                  "both data=journal and delalloc");
3556                         goto failed_mount;
3557                 }
3558                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3559                         ext4_msg(sb, KERN_ERR, "can't mount with "
3560                                  "both data=journal and dioread_nolock");
3561                         goto failed_mount;
3562                 }
3563                 if (test_opt(sb, DELALLOC))
3564                         clear_opt(sb, DELALLOC);
3565         }
3566
3567         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3568                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3569
3570         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3571             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3572              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3573              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3574                 ext4_msg(sb, KERN_WARNING,
3575                        "feature flags set on rev 0 fs, "
3576                        "running e2fsck is recommended");
3577
3578         if (IS_EXT2_SB(sb)) {
3579                 if (ext2_feature_set_ok(sb))
3580                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3581                                  "using the ext4 subsystem");
3582                 else {
3583                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3584                                  "to feature incompatibilities");
3585                         goto failed_mount;
3586                 }
3587         }
3588
3589         if (IS_EXT3_SB(sb)) {
3590                 if (ext3_feature_set_ok(sb))
3591                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3592                                  "using the ext4 subsystem");
3593                 else {
3594                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3595                                  "to feature incompatibilities");
3596                         goto failed_mount;
3597                 }
3598         }
3599
3600         /*
3601          * Check feature flags regardless of the revision level, since we
3602          * previously didn't change the revision level when setting the flags,
3603          * so there is a chance incompat flags are set on a rev 0 filesystem.
3604          */
3605         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3606                 goto failed_mount;
3607
3608         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3609         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3610             blocksize > EXT4_MAX_BLOCK_SIZE) {
3611                 ext4_msg(sb, KERN_ERR,
3612                        "Unsupported filesystem blocksize %d", blocksize);
3613                 goto failed_mount;
3614         }
3615
3616         if (sb->s_blocksize != blocksize) {
3617                 /* Validate the filesystem blocksize */
3618                 if (!sb_set_blocksize(sb, blocksize)) {
3619                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3620                                         blocksize);
3621                         goto failed_mount;
3622                 }
3623
3624                 brelse(bh);
3625                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3626                 offset = do_div(logical_sb_block, blocksize);
3627                 bh = sb_bread(sb, logical_sb_block);
3628                 if (!bh) {
3629                         ext4_msg(sb, KERN_ERR,
3630                                "Can't read superblock on 2nd try");
3631                         goto failed_mount;
3632                 }
3633                 es = (struct ext4_super_block *)(bh->b_data + offset);
3634                 sbi->s_es = es;
3635                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3636                         ext4_msg(sb, KERN_ERR,
3637                                "Magic mismatch, very weird!");
3638                         goto failed_mount;
3639                 }
3640         }
3641
3642         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3643                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3644         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3645                                                       has_huge_files);
3646         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3647
3648         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3649                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3650                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3651         } else {
3652                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3653                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3654                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3655                     (!is_power_of_2(sbi->s_inode_size)) ||
3656                     (sbi->s_inode_size > blocksize)) {
3657                         ext4_msg(sb, KERN_ERR,
3658                                "unsupported inode size: %d",
3659                                sbi->s_inode_size);
3660                         goto failed_mount;
3661                 }
3662                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3663                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3664         }
3665
3666         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3667         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3668                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3669                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3670                     !is_power_of_2(sbi->s_desc_size)) {
3671                         ext4_msg(sb, KERN_ERR,
3672                                "unsupported descriptor size %lu",
3673                                sbi->s_desc_size);
3674                         goto failed_mount;
3675                 }
3676         } else
3677                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3678
3679         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3680         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3681         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3682                 goto cantfind_ext4;
3683
3684         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3685         if (sbi->s_inodes_per_block == 0)
3686                 goto cantfind_ext4;
3687         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3688                                         sbi->s_inodes_per_block;
3689         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3690         sbi->s_sbh = bh;
3691         sbi->s_mount_state = le16_to_cpu(es->s_state);
3692         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3693         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3694
3695         for (i = 0; i < 4; i++)
3696                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3697         sbi->s_def_hash_version = es->s_def_hash_version;
3698         i = le32_to_cpu(es->s_flags);
3699         if (i & EXT2_FLAGS_UNSIGNED_HASH)
3700                 sbi->s_hash_unsigned = 3;
3701         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3702 #ifdef __CHAR_UNSIGNED__
3703                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3704                 sbi->s_hash_unsigned = 3;
3705 #else
3706                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3707 #endif
3708         }
3709
3710         /* Handle clustersize */
3711         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3712         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3713                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3714         if (has_bigalloc) {
3715                 if (clustersize < blocksize) {
3716                         ext4_msg(sb, KERN_ERR,
3717                                  "cluster size (%d) smaller than "
3718                                  "block size (%d)", clustersize, blocksize);
3719                         goto failed_mount;
3720                 }
3721                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3722                         le32_to_cpu(es->s_log_block_size);
3723                 sbi->s_clusters_per_group =
3724                         le32_to_cpu(es->s_clusters_per_group);
3725                 if (sbi->s_clusters_per_group > blocksize * 8) {
3726                         ext4_msg(sb, KERN_ERR,
3727                                  "#clusters per group too big: %lu",
3728                                  sbi->s_clusters_per_group);
3729                         goto failed_mount;
3730                 }
3731                 if (sbi->s_blocks_per_group !=
3732                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3733                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3734                                  "clusters per group (%lu) inconsistent",
3735                                  sbi->s_blocks_per_group,
3736                                  sbi->s_clusters_per_group);
3737                         goto failed_mount;
3738                 }
3739         } else {
3740                 if (clustersize != blocksize) {
3741                         ext4_warning(sb, "fragment/cluster size (%d) != "
3742                                      "block size (%d)", clustersize,
3743                                      blocksize);
3744                         clustersize = blocksize;
3745                 }
3746                 if (sbi->s_blocks_per_group > blocksize * 8) {
3747                         ext4_msg(sb, KERN_ERR,
3748                                  "#blocks per group too big: %lu",
3749                                  sbi->s_blocks_per_group);
3750                         goto failed_mount;
3751                 }
3752                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3753                 sbi->s_cluster_bits = 0;
3754         }
3755         sbi->s_cluster_ratio = clustersize / blocksize;
3756
3757         if (sbi->s_inodes_per_group > blocksize * 8) {
3758                 ext4_msg(sb, KERN_ERR,
3759                        "#inodes per group too big: %lu",
3760                        sbi->s_inodes_per_group);
3761                 goto failed_mount;
3762         }
3763
3764         /* Do we have standard group size of clustersize * 8 blocks ? */
3765         if (sbi->s_blocks_per_group == clustersize << 3)
3766                 set_opt2(sb, STD_GROUP_SIZE);
3767
3768         /*
3769          * Test whether we have more sectors than will fit in sector_t,
3770          * and whether the max offset is addressable by the page cache.
3771          */
3772         err = generic_check_addressable(sb->s_blocksize_bits,
3773                                         ext4_blocks_count(es));
3774         if (err) {
3775                 ext4_msg(sb, KERN_ERR, "filesystem"
3776                          " too large to mount safely on this system");
3777                 if (sizeof(sector_t) < 8)
3778                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3779                 goto failed_mount;
3780         }
3781
3782         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3783                 goto cantfind_ext4;
3784
3785         /* check blocks count against device size */
3786         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3787         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3788                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3789                        "exceeds size of device (%llu blocks)",
3790                        ext4_blocks_count(es), blocks_count);
3791                 goto failed_mount;
3792         }
3793
3794         /*
3795          * It makes no sense for the first data block to be beyond the end
3796          * of the filesystem.
3797          */
3798         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3799                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3800                          "block %u is beyond end of filesystem (%llu)",
3801                          le32_to_cpu(es->s_first_data_block),
3802                          ext4_blocks_count(es));
3803                 goto failed_mount;
3804         }
3805         blocks_count = (ext4_blocks_count(es) -
3806                         le32_to_cpu(es->s_first_data_block) +
3807                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3808         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3809         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3810                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3811                        "(block count %llu, first data block %u, "
3812                        "blocks per group %lu)", sbi->s_groups_count,
3813                        ext4_blocks_count(es),
3814                        le32_to_cpu(es->s_first_data_block),
3815                        EXT4_BLOCKS_PER_GROUP(sb));
3816                 goto failed_mount;
3817         }
3818         sbi->s_groups_count = blocks_count;
3819         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3820                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3821         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3822                    EXT4_DESC_PER_BLOCK(sb);
3823         sbi->s_group_desc = ext4_kvmalloc(db_count *
3824                                           sizeof(struct buffer_head *),
3825                                           GFP_KERNEL);
3826         if (sbi->s_group_desc == NULL) {
3827                 ext4_msg(sb, KERN_ERR, "not enough memory");
3828                 ret = -ENOMEM;
3829                 goto failed_mount;
3830         }
3831
3832         if (ext4_proc_root)
3833                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3834
3835         if (sbi->s_proc)
3836                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3837                                  &ext4_seq_options_fops, sb);
3838
3839         bgl_lock_init(sbi->s_blockgroup_lock);
3840
3841         for (i = 0; i < db_count; i++) {
3842                 block = descriptor_loc(sb, logical_sb_block, i);
3843                 sbi->s_group_desc[i] = sb_bread(sb, block);
3844                 if (!sbi->s_group_desc[i]) {
3845                         ext4_msg(sb, KERN_ERR,
3846                                "can't read group descriptor %d", i);
3847                         db_count = i;
3848                         goto failed_mount2;
3849                 }
3850         }
3851         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3852                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3853                 goto failed_mount2;
3854         }
3855         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3856                 if (!ext4_fill_flex_info(sb)) {
3857                         ext4_msg(sb, KERN_ERR,
3858                                "unable to initialize "
3859                                "flex_bg meta info!");
3860                         goto failed_mount2;
3861                 }
3862
3863         sbi->s_gdb_count = db_count;
3864         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3865         spin_lock_init(&sbi->s_next_gen_lock);
3866
3867         init_timer(&sbi->s_err_report);
3868         sbi->s_err_report.function = print_daily_error_info;
3869         sbi->s_err_report.data = (unsigned long) sb;
3870
3871         /* Register extent status tree shrinker */
3872         ext4_es_register_shrinker(sbi);
3873
3874         err = percpu_counter_init(&sbi->s_freeclusters_counter,
3875                         ext4_count_free_clusters(sb));
3876         if (!err) {
3877                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
3878                                 ext4_count_free_inodes(sb));
3879         }
3880         if (!err) {
3881                 err = percpu_counter_init(&sbi->s_dirs_counter,
3882                                 ext4_count_dirs(sb));
3883         }
3884         if (!err) {
3885                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3886         }
3887         if (!err) {
3888                 err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
3889         }
3890         if (err) {
3891                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3892                 goto failed_mount3;
3893         }
3894
3895         sbi->s_stripe = ext4_get_stripe_size(sbi);
3896         sbi->s_extent_max_zeroout_kb = 32;
3897
3898         /*
3899          * set up enough so that it can read an inode
3900          */
3901         if (!test_opt(sb, NOLOAD) &&
3902             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3903                 sb->s_op = &ext4_sops;
3904         else
3905                 sb->s_op = &ext4_nojournal_sops;
3906         sb->s_export_op = &ext4_export_ops;
3907         sb->s_xattr = ext4_xattr_handlers;
3908 #ifdef CONFIG_QUOTA
3909         sb->dq_op = &ext4_quota_operations;
3910         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3911                 sb->s_qcop = &ext4_qctl_sysfile_operations;
3912         else
3913                 sb->s_qcop = &ext4_qctl_operations;
3914 #endif
3915         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3916
3917         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3918         mutex_init(&sbi->s_orphan_lock);
3919
3920         sb->s_root = NULL;
3921
3922         needs_recovery = (es->s_last_orphan != 0 ||
3923                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3924                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3925
3926         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3927             !(sb->s_flags & MS_RDONLY))
3928                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3929                         goto failed_mount3;
3930
3931         /*
3932          * The first inode we look at is the journal inode.  Don't try
3933          * root first: it may be modified in the journal!
3934          */
3935         if (!test_opt(sb, NOLOAD) &&
3936             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3937                 if (ext4_load_journal(sb, es, journal_devnum))
3938                         goto failed_mount3;
3939         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3940               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3941                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3942                        "suppressed and not mounted read-only");
3943                 goto failed_mount_wq;
3944         } else {
3945                 clear_opt(sb, DATA_FLAGS);
3946                 sbi->s_journal = NULL;
3947                 needs_recovery = 0;
3948                 goto no_journal;
3949         }
3950
3951         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3952             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3953                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3954                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3955                 goto failed_mount_wq;
3956         }
3957
3958         if (!set_journal_csum_feature_set(sb)) {
3959                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3960                          "feature set");
3961                 goto failed_mount_wq;
3962         }
3963
3964         /* We have now updated the journal if required, so we can
3965          * validate the data journaling mode. */
3966         switch (test_opt(sb, DATA_FLAGS)) {
3967         case 0:
3968                 /* No mode set, assume a default based on the journal
3969                  * capabilities: ORDERED_DATA if the journal can
3970                  * cope, else JOURNAL_DATA
3971                  */
3972                 if (jbd2_journal_check_available_features
3973                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3974                         set_opt(sb, ORDERED_DATA);
3975                 else
3976                         set_opt(sb, JOURNAL_DATA);
3977                 break;
3978
3979         case EXT4_MOUNT_ORDERED_DATA:
3980         case EXT4_MOUNT_WRITEBACK_DATA:
3981                 if (!jbd2_journal_check_available_features
3982                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3983                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3984                                "requested data journaling mode");
3985                         goto failed_mount_wq;
3986                 }
3987         default:
3988                 break;
3989         }
3990         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3991
3992         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3993
3994         /*
3995          * The journal may have updated the bg summary counts, so we
3996          * need to update the global counters.
3997          */
3998         percpu_counter_set(&sbi->s_freeclusters_counter,
3999                            ext4_count_free_clusters(sb));
4000         percpu_counter_set(&sbi->s_freeinodes_counter,
4001                            ext4_count_free_inodes(sb));
4002         percpu_counter_set(&sbi->s_dirs_counter,
4003                            ext4_count_dirs(sb));
4004         percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
4005
4006 no_journal:
4007         /*
4008          * Get the # of file system overhead blocks from the
4009          * superblock if present.
4010          */
4011         if (es->s_overhead_clusters)
4012                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4013         else {
4014                 err = ext4_calculate_overhead(sb);
4015                 if (err)
4016                         goto failed_mount_wq;
4017         }
4018
4019         /*
4020          * The maximum number of concurrent works can be high and
4021          * concurrency isn't really necessary.  Limit it to 1.
4022          */
4023         EXT4_SB(sb)->rsv_conversion_wq =
4024                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4025         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4026                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4027                 ret = -ENOMEM;
4028                 goto failed_mount4;
4029         }
4030
4031         /*
4032          * The jbd2_journal_load will have done any necessary log recovery,
4033          * so we can safely mount the rest of the filesystem now.
4034          */
4035
4036         root = ext4_iget(sb, EXT4_ROOT_INO);
4037         if (IS_ERR(root)) {
4038                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4039                 ret = PTR_ERR(root);
4040                 root = NULL;
4041                 goto failed_mount4;
4042         }
4043         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4044                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4045                 iput(root);
4046                 goto failed_mount4;
4047         }
4048         sb->s_root = d_make_root(root);
4049         if (!sb->s_root) {
4050                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4051                 ret = -ENOMEM;
4052                 goto failed_mount4;
4053         }
4054
4055         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4056                 sb->s_flags |= MS_RDONLY;
4057
4058         /* determine the minimum size of new large inodes, if present */
4059         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4060                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4061                                                      EXT4_GOOD_OLD_INODE_SIZE;
4062                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4063                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4064                         if (sbi->s_want_extra_isize <
4065                             le16_to_cpu(es->s_want_extra_isize))
4066                                 sbi->s_want_extra_isize =
4067                                         le16_to_cpu(es->s_want_extra_isize);
4068                         if (sbi->s_want_extra_isize <
4069                             le16_to_cpu(es->s_min_extra_isize))
4070                                 sbi->s_want_extra_isize =
4071                                         le16_to_cpu(es->s_min_extra_isize);
4072                 }
4073         }
4074         /* Check if enough inode space is available */
4075         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4076                                                         sbi->s_inode_size) {
4077                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4078                                                        EXT4_GOOD_OLD_INODE_SIZE;
4079                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4080                          "available");
4081         }
4082
4083         err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4084         if (err) {
4085                 ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4086                          "reserved pool", ext4_calculate_resv_clusters(sb));
4087                 goto failed_mount4a;
4088         }
4089
4090         err = ext4_setup_system_zone(sb);
4091         if (err) {
4092                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4093                          "zone (%d)", err);
4094                 goto failed_mount4a;
4095         }
4096
4097         ext4_ext_init(sb);
4098         err = ext4_mb_init(sb);
4099         if (err) {
4100                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4101                          err);
4102                 goto failed_mount5;
4103         }
4104
4105         err = ext4_register_li_request(sb, first_not_zeroed);
4106         if (err)
4107                 goto failed_mount6;
4108
4109         sbi->s_kobj.kset = ext4_kset;
4110         init_completion(&sbi->s_kobj_unregister);
4111         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4112                                    "%s", sb->s_id);
4113         if (err)
4114                 goto failed_mount7;
4115
4116 #ifdef CONFIG_QUOTA
4117         /* Enable quota usage during mount. */
4118         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4119             !(sb->s_flags & MS_RDONLY)) {
4120                 err = ext4_enable_quotas(sb);
4121                 if (err)
4122                         goto failed_mount8;
4123         }
4124 #endif  /* CONFIG_QUOTA */
4125
4126         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4127         ext4_orphan_cleanup(sb, es);
4128         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4129         if (needs_recovery) {
4130                 ext4_msg(sb, KERN_INFO, "recovery complete");
4131                 ext4_mark_recovery_complete(sb, es);
4132         }
4133         if (EXT4_SB(sb)->s_journal) {
4134                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4135                         descr = " journalled data mode";
4136                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4137                         descr = " ordered data mode";
4138                 else
4139                         descr = " writeback data mode";
4140         } else
4141                 descr = "out journal";
4142
4143         if (test_opt(sb, DISCARD)) {
4144                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4145                 if (!blk_queue_discard(q))
4146                         ext4_msg(sb, KERN_WARNING,
4147                                  "mounting with \"discard\" option, but "
4148                                  "the device does not support discard");
4149         }
4150
4151         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4152                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4153                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4154
4155         if (es->s_error_count)
4156                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4157
4158         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4159         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4160         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4161         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4162
4163         kfree(orig_data);
4164         return 0;
4165
4166 cantfind_ext4:
4167         if (!silent)
4168                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4169         goto failed_mount;
4170
4171 #ifdef CONFIG_QUOTA
4172 failed_mount8:
4173         kobject_del(&sbi->s_kobj);
4174 #endif
4175 failed_mount7:
4176         ext4_unregister_li_request(sb);
4177 failed_mount6:
4178         ext4_mb_release(sb);
4179 failed_mount5:
4180         ext4_ext_release(sb);
4181         ext4_release_system_zone(sb);
4182 failed_mount4a:
4183         dput(sb->s_root);
4184         sb->s_root = NULL;
4185 failed_mount4:
4186         ext4_msg(sb, KERN_ERR, "mount failed");
4187         if (EXT4_SB(sb)->rsv_conversion_wq)
4188                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4189 failed_mount_wq:
4190         if (sbi->s_journal) {
4191                 jbd2_journal_destroy(sbi->s_journal);
4192                 sbi->s_journal = NULL;
4193         }
4194 failed_mount3:
4195         ext4_es_unregister_shrinker(sbi);
4196         del_timer_sync(&sbi->s_err_report);
4197         if (sbi->s_flex_groups)
4198                 ext4_kvfree(sbi->s_flex_groups);
4199         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4200         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4201         percpu_counter_destroy(&sbi->s_dirs_counter);
4202         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4203         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
4204         if (sbi->s_mmp_tsk)
4205                 kthread_stop(sbi->s_mmp_tsk);
4206 failed_mount2:
4207         for (i = 0; i < db_count; i++)
4208                 brelse(sbi->s_group_desc[i]);
4209         ext4_kvfree(sbi->s_group_desc);
4210 failed_mount:
4211         if (sbi->s_chksum_driver)
4212                 crypto_free_shash(sbi->s_chksum_driver);
4213         if (sbi->s_proc) {
4214                 remove_proc_entry("options", sbi->s_proc);
4215                 remove_proc_entry(sb->s_id, ext4_proc_root);
4216         }
4217 #ifdef CONFIG_QUOTA
4218         for (i = 0; i < MAXQUOTAS; i++)
4219                 kfree(sbi->s_qf_names[i]);
4220 #endif
4221         ext4_blkdev_remove(sbi);
4222         brelse(bh);
4223 out_fail:
4224         sb->s_fs_info = NULL;
4225         kfree(sbi->s_blockgroup_lock);
4226         kfree(sbi);
4227 out_free_orig:
4228         kfree(orig_data);
4229         return err ? err : ret;
4230 }
4231
4232 /*
4233  * Setup any per-fs journal parameters now.  We'll do this both on
4234  * initial mount, once the journal has been initialised but before we've
4235  * done any recovery; and again on any subsequent remount.
4236  */
4237 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4238 {
4239         struct ext4_sb_info *sbi = EXT4_SB(sb);
4240
4241         journal->j_commit_interval = sbi->s_commit_interval;
4242         journal->j_min_batch_time = sbi->s_min_batch_time;
4243         journal->j_max_batch_time = sbi->s_max_batch_time;
4244
4245         write_lock(&journal->j_state_lock);
4246         if (test_opt(sb, BARRIER))
4247                 journal->j_flags |= JBD2_BARRIER;
4248         else
4249                 journal->j_flags &= ~JBD2_BARRIER;
4250         if (test_opt(sb, DATA_ERR_ABORT))
4251                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4252         else
4253                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4254         write_unlock(&journal->j_state_lock);
4255 }
4256
4257 static journal_t *ext4_get_journal(struct super_block *sb,
4258                                    unsigned int journal_inum)
4259 {
4260         struct inode *journal_inode;
4261         journal_t *journal;
4262
4263         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4264
4265         /* First, test for the existence of a valid inode on disk.  Bad
4266          * things happen if we iget() an unused inode, as the subsequent
4267          * iput() will try to delete it. */
4268
4269         journal_inode = ext4_iget(sb, journal_inum);
4270         if (IS_ERR(journal_inode)) {
4271                 ext4_msg(sb, KERN_ERR, "no journal found");
4272                 return NULL;
4273         }
4274         if (!journal_inode->i_nlink) {
4275                 make_bad_inode(journal_inode);
4276                 iput(journal_inode);
4277                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4278                 return NULL;
4279         }
4280
4281         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4282                   journal_inode, journal_inode->i_size);
4283         if (!S_ISREG(journal_inode->i_mode)) {
4284                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4285                 iput(journal_inode);
4286                 return NULL;
4287         }
4288
4289         journal = jbd2_journal_init_inode(journal_inode);
4290         if (!journal) {
4291                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4292                 iput(journal_inode);
4293                 return NULL;
4294         }
4295         journal->j_private = sb;
4296         ext4_init_journal_params(sb, journal);
4297         return journal;
4298 }
4299
4300 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4301                                        dev_t j_dev)
4302 {
4303         struct buffer_head *bh;
4304         journal_t *journal;
4305         ext4_fsblk_t start;
4306         ext4_fsblk_t len;
4307         int hblock, blocksize;
4308         ext4_fsblk_t sb_block;
4309         unsigned long offset;
4310         struct ext4_super_block *es;
4311         struct block_device *bdev;
4312
4313         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4314
4315         bdev = ext4_blkdev_get(j_dev, sb);
4316         if (bdev == NULL)
4317                 return NULL;
4318
4319         blocksize = sb->s_blocksize;
4320         hblock = bdev_logical_block_size(bdev);
4321         if (blocksize < hblock) {
4322                 ext4_msg(sb, KERN_ERR,
4323                         "blocksize too small for journal device");
4324                 goto out_bdev;
4325         }
4326
4327         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4328         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4329         set_blocksize(bdev, blocksize);
4330         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4331                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4332                        "external journal");
4333                 goto out_bdev;
4334         }
4335
4336         es = (struct ext4_super_block *) (bh->b_data + offset);
4337         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4338             !(le32_to_cpu(es->s_feature_incompat) &
4339               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4340                 ext4_msg(sb, KERN_ERR, "external journal has "
4341                                         "bad superblock");
4342                 brelse(bh);
4343                 goto out_bdev;
4344         }
4345
4346         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4347                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4348                 brelse(bh);
4349                 goto out_bdev;
4350         }
4351
4352         len = ext4_blocks_count(es);
4353         start = sb_block + 1;
4354         brelse(bh);     /* we're done with the superblock */
4355
4356         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4357                                         start, len, blocksize);
4358         if (!journal) {
4359                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4360                 goto out_bdev;
4361         }
4362         journal->j_private = sb;
4363         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4364         wait_on_buffer(journal->j_sb_buffer);
4365         if (!buffer_uptodate(journal->j_sb_buffer)) {
4366                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4367                 goto out_journal;
4368         }
4369         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4370                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4371                                         "user (unsupported) - %d",
4372                         be32_to_cpu(journal->j_superblock->s_nr_users));
4373                 goto out_journal;
4374         }
4375         EXT4_SB(sb)->journal_bdev = bdev;
4376         ext4_init_journal_params(sb, journal);
4377         return journal;
4378
4379 out_journal:
4380         jbd2_journal_destroy(journal);
4381 out_bdev:
4382         ext4_blkdev_put(bdev);
4383         return NULL;
4384 }
4385
4386 static int ext4_load_journal(struct super_block *sb,
4387                              struct ext4_super_block *es,
4388                              unsigned long journal_devnum)
4389 {
4390         journal_t *journal;
4391         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4392         dev_t journal_dev;
4393         int err = 0;
4394         int really_read_only;
4395
4396         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4397
4398         if (journal_devnum &&
4399             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4400                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4401                         "numbers have changed");
4402                 journal_dev = new_decode_dev(journal_devnum);
4403         } else
4404                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4405
4406         really_read_only = bdev_read_only(sb->s_bdev);
4407
4408         /*
4409          * Are we loading a blank journal or performing recovery after a
4410          * crash?  For recovery, we need to check in advance whether we
4411          * can get read-write access to the device.
4412          */
4413         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4414                 if (sb->s_flags & MS_RDONLY) {
4415                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4416                                         "required on readonly filesystem");
4417                         if (really_read_only) {
4418                                 ext4_msg(sb, KERN_ERR, "write access "
4419                                         "unavailable, cannot proceed");
4420                                 return -EROFS;
4421                         }
4422                         ext4_msg(sb, KERN_INFO, "write access will "
4423                                "be enabled during recovery");
4424                 }
4425         }
4426
4427         if (journal_inum && journal_dev) {
4428                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4429                        "and inode journals!");
4430                 return -EINVAL;
4431         }
4432
4433         if (journal_inum) {
4434                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4435                         return -EINVAL;
4436         } else {
4437                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4438                         return -EINVAL;
4439         }
4440
4441         if (!(journal->j_flags & JBD2_BARRIER))
4442                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4443
4444         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4445                 err = jbd2_journal_wipe(journal, !really_read_only);
4446         if (!err) {
4447                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4448                 if (save)
4449                         memcpy(save, ((char *) es) +
4450                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4451                 err = jbd2_journal_load(journal);
4452                 if (save)
4453                         memcpy(((char *) es) + EXT4_S_ERR_START,
4454                                save, EXT4_S_ERR_LEN);
4455                 kfree(save);
4456         }
4457
4458         if (err) {
4459                 ext4_msg(sb, KERN_ERR, "error loading journal");
4460                 jbd2_journal_destroy(journal);
4461                 return err;
4462         }
4463
4464         EXT4_SB(sb)->s_journal = journal;
4465         ext4_clear_journal_err(sb, es);
4466
4467         if (!really_read_only && journal_devnum &&
4468             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4469                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4470
4471                 /* Make sure we flush the recovery flag to disk. */
4472                 ext4_commit_super(sb, 1);
4473         }
4474
4475         return 0;
4476 }
4477
4478 static int ext4_commit_super(struct super_block *sb, int sync)
4479 {
4480         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4481         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4482         int error = 0;
4483
4484         if (!sbh || block_device_ejected(sb))
4485                 return error;
4486         if (buffer_write_io_error(sbh)) {
4487                 /*
4488                  * Oh, dear.  A previous attempt to write the
4489                  * superblock failed.  This could happen because the
4490                  * USB device was yanked out.  Or it could happen to
4491                  * be a transient write error and maybe the block will
4492                  * be remapped.  Nothing we can do but to retry the
4493                  * write and hope for the best.
4494                  */
4495                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4496                        "superblock detected");
4497                 clear_buffer_write_io_error(sbh);
4498                 set_buffer_uptodate(sbh);
4499         }
4500         /*
4501          * If the file system is mounted read-only, don't update the
4502          * superblock write time.  This avoids updating the superblock
4503          * write time when we are mounting the root file system
4504          * read/only but we need to replay the journal; at that point,
4505          * for people who are east of GMT and who make their clock
4506          * tick in localtime for Windows bug-for-bug compatibility,
4507          * the clock is set in the future, and this will cause e2fsck
4508          * to complain and force a full file system check.
4509          */
4510         if (!(sb->s_flags & MS_RDONLY))
4511                 es->s_wtime = cpu_to_le32(get_seconds());
4512         if (sb->s_bdev->bd_part)
4513                 es->s_kbytes_written =
4514                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4515                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4516                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4517         else
4518                 es->s_kbytes_written =
4519                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4520         ext4_free_blocks_count_set(es,
4521                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4522                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4523         es->s_free_inodes_count =
4524                 cpu_to_le32(percpu_counter_sum_positive(
4525                                 &EXT4_SB(sb)->s_freeinodes_counter));
4526         BUFFER_TRACE(sbh, "marking dirty");
4527         ext4_superblock_csum_set(sb);
4528         mark_buffer_dirty(sbh);
4529         if (sync) {
4530                 error = sync_dirty_buffer(sbh);
4531                 if (error)
4532                         return error;
4533
4534                 error = buffer_write_io_error(sbh);
4535                 if (error) {
4536                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4537                                "superblock");
4538                         clear_buffer_write_io_error(sbh);
4539                         set_buffer_uptodate(sbh);
4540                 }
4541         }
4542         return error;
4543 }
4544
4545 /*
4546  * Have we just finished recovery?  If so, and if we are mounting (or
4547  * remounting) the filesystem readonly, then we will end up with a
4548  * consistent fs on disk.  Record that fact.
4549  */
4550 static void ext4_mark_recovery_complete(struct super_block *sb,
4551                                         struct ext4_super_block *es)
4552 {
4553         journal_t *journal = EXT4_SB(sb)->s_journal;
4554
4555         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4556                 BUG_ON(journal != NULL);
4557                 return;
4558         }
4559         jbd2_journal_lock_updates(journal);
4560         if (jbd2_journal_flush(journal) < 0)
4561                 goto out;
4562
4563         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4564             sb->s_flags & MS_RDONLY) {
4565                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4566                 ext4_commit_super(sb, 1);
4567         }
4568
4569 out:
4570         jbd2_journal_unlock_updates(journal);
4571 }
4572
4573 /*
4574  * If we are mounting (or read-write remounting) a filesystem whose journal
4575  * has recorded an error from a previous lifetime, move that error to the
4576  * main filesystem now.
4577  */
4578 static void ext4_clear_journal_err(struct super_block *sb,
4579                                    struct ext4_super_block *es)
4580 {
4581         journal_t *journal;
4582         int j_errno;
4583         const char *errstr;
4584
4585         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4586
4587         journal = EXT4_SB(sb)->s_journal;
4588
4589         /*
4590          * Now check for any error status which may have been recorded in the
4591          * journal by a prior ext4_error() or ext4_abort()
4592          */
4593
4594         j_errno = jbd2_journal_errno(journal);
4595         if (j_errno) {
4596                 char nbuf[16];
4597
4598                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4599                 ext4_warning(sb, "Filesystem error recorded "
4600                              "from previous mount: %s", errstr);
4601                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4602
4603                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4604                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4605                 ext4_commit_super(sb, 1);
4606
4607                 jbd2_journal_clear_err(journal);
4608                 jbd2_journal_update_sb_errno(journal);
4609         }
4610 }
4611
4612 /*
4613  * Force the running and committing transactions to commit,
4614  * and wait on the commit.
4615  */
4616 int ext4_force_commit(struct super_block *sb)
4617 {
4618         journal_t *journal;
4619
4620         if (sb->s_flags & MS_RDONLY)
4621                 return 0;
4622
4623         journal = EXT4_SB(sb)->s_journal;
4624         return ext4_journal_force_commit(journal);
4625 }
4626
4627 static int ext4_sync_fs(struct super_block *sb, int wait)
4628 {
4629         int ret = 0;
4630         tid_t target;
4631         bool needs_barrier = false;
4632         struct ext4_sb_info *sbi = EXT4_SB(sb);
4633
4634         trace_ext4_sync_fs(sb, wait);
4635         flush_workqueue(sbi->rsv_conversion_wq);
4636         /*
4637          * Writeback quota in non-journalled quota case - journalled quota has
4638          * no dirty dquots
4639          */
4640         dquot_writeback_dquots(sb, -1);
4641         /*
4642          * Data writeback is possible w/o journal transaction, so barrier must
4643          * being sent at the end of the function. But we can skip it if
4644          * transaction_commit will do it for us.
4645          */
4646         target = jbd2_get_latest_transaction(sbi->s_journal);
4647         if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4648             !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4649                 needs_barrier = true;
4650
4651         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4652                 if (wait)
4653                         ret = jbd2_log_wait_commit(sbi->s_journal, target);
4654         }
4655         if (needs_barrier) {
4656                 int err;
4657                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4658                 if (!ret)
4659                         ret = err;
4660         }
4661
4662         return ret;
4663 }
4664
4665 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait)
4666 {
4667         int ret = 0;
4668
4669         trace_ext4_sync_fs(sb, wait);
4670         flush_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4671         dquot_writeback_dquots(sb, -1);
4672         if (wait && test_opt(sb, BARRIER))
4673                 ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4674
4675         return ret;
4676 }
4677
4678 /*
4679  * LVM calls this function before a (read-only) snapshot is created.  This
4680  * gives us a chance to flush the journal completely and mark the fs clean.
4681  *
4682  * Note that only this function cannot bring a filesystem to be in a clean
4683  * state independently. It relies on upper layer to stop all data & metadata
4684  * modifications.
4685  */
4686 static int ext4_freeze(struct super_block *sb)
4687 {
4688         int error = 0;
4689         journal_t *journal;
4690
4691         if (sb->s_flags & MS_RDONLY)
4692                 return 0;
4693
4694         journal = EXT4_SB(sb)->s_journal;
4695
4696         /* Now we set up the journal barrier. */
4697         jbd2_journal_lock_updates(journal);
4698
4699         /*
4700          * Don't clear the needs_recovery flag if we failed to flush
4701          * the journal.
4702          */
4703         error = jbd2_journal_flush(journal);
4704         if (error < 0)
4705                 goto out;
4706
4707         /* Journal blocked and flushed, clear needs_recovery flag. */
4708         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4709         error = ext4_commit_super(sb, 1);
4710 out:
4711         /* we rely on upper layer to stop further updates */
4712         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4713         return error;
4714 }
4715
4716 /*
4717  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4718  * flag here, even though the filesystem is not technically dirty yet.
4719  */
4720 static int ext4_unfreeze(struct super_block *sb)
4721 {
4722         if (sb->s_flags & MS_RDONLY)
4723                 return 0;
4724
4725         /* Reset the needs_recovery flag before the fs is unlocked. */
4726         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4727         ext4_commit_super(sb, 1);
4728         return 0;
4729 }
4730
4731 /*
4732  * Structure to save mount options for ext4_remount's benefit
4733  */
4734 struct ext4_mount_options {
4735         unsigned long s_mount_opt;
4736         unsigned long s_mount_opt2;
4737         kuid_t s_resuid;
4738         kgid_t s_resgid;
4739         unsigned long s_commit_interval;
4740         u32 s_min_batch_time, s_max_batch_time;
4741 #ifdef CONFIG_QUOTA
4742         int s_jquota_fmt;
4743         char *s_qf_names[MAXQUOTAS];
4744 #endif
4745 };
4746
4747 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4748 {
4749         struct ext4_super_block *es;
4750         struct ext4_sb_info *sbi = EXT4_SB(sb);
4751         unsigned long old_sb_flags;
4752         struct ext4_mount_options old_opts;
4753         int enable_quota = 0;
4754         ext4_group_t g;
4755         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4756         int err = 0;
4757 #ifdef CONFIG_QUOTA
4758         int i, j;
4759 #endif
4760         char *orig_data = kstrdup(data, GFP_KERNEL);
4761
4762         /* Store the original options */
4763         old_sb_flags = sb->s_flags;
4764         old_opts.s_mount_opt = sbi->s_mount_opt;
4765         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4766         old_opts.s_resuid = sbi->s_resuid;
4767         old_opts.s_resgid = sbi->s_resgid;
4768         old_opts.s_commit_interval = sbi->s_commit_interval;
4769         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4770         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4771 #ifdef CONFIG_QUOTA
4772         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4773         for (i = 0; i < MAXQUOTAS; i++)
4774                 if (sbi->s_qf_names[i]) {
4775                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4776                                                          GFP_KERNEL);
4777                         if (!old_opts.s_qf_names[i]) {
4778                                 for (j = 0; j < i; j++)
4779                                         kfree(old_opts.s_qf_names[j]);
4780                                 kfree(orig_data);
4781                                 return -ENOMEM;
4782                         }
4783                 } else
4784                         old_opts.s_qf_names[i] = NULL;
4785 #endif
4786         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4787                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4788
4789         /*
4790          * Allow the "check" option to be passed as a remount option.
4791          */
4792         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4793                 err = -EINVAL;
4794                 goto restore_opts;
4795         }
4796
4797         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4798                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4799                         ext4_msg(sb, KERN_ERR, "can't mount with "
4800                                  "both data=journal and delalloc");
4801                         err = -EINVAL;
4802                         goto restore_opts;
4803                 }
4804                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4805                         ext4_msg(sb, KERN_ERR, "can't mount with "
4806                                  "both data=journal and dioread_nolock");
4807                         err = -EINVAL;
4808                         goto restore_opts;
4809                 }
4810         }
4811
4812         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4813                 ext4_abort(sb, "Abort forced by user");
4814
4815         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4816                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4817
4818         es = sbi->s_es;
4819
4820         if (sbi->s_journal) {
4821                 ext4_init_journal_params(sb, sbi->s_journal);
4822                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4823         }
4824
4825         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4826                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4827                         err = -EROFS;
4828                         goto restore_opts;
4829                 }
4830
4831                 if (*flags & MS_RDONLY) {
4832                         err = dquot_suspend(sb, -1);
4833                         if (err < 0)
4834                                 goto restore_opts;
4835
4836                         /*
4837                          * First of all, the unconditional stuff we have to do
4838                          * to disable replay of the journal when we next remount
4839                          */
4840                         sb->s_flags |= MS_RDONLY;
4841
4842                         /*
4843                          * OK, test if we are remounting a valid rw partition
4844                          * readonly, and if so set the rdonly flag and then
4845                          * mark the partition as valid again.
4846                          */
4847                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4848                             (sbi->s_mount_state & EXT4_VALID_FS))
4849                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4850
4851                         if (sbi->s_journal)
4852                                 ext4_mark_recovery_complete(sb, es);
4853                 } else {
4854                         /* Make sure we can mount this feature set readwrite */
4855                         if (!ext4_feature_set_ok(sb, 0)) {
4856                                 err = -EROFS;
4857                                 goto restore_opts;
4858                         }
4859                         /*
4860                          * Make sure the group descriptor checksums
4861                          * are sane.  If they aren't, refuse to remount r/w.
4862                          */
4863                         for (g = 0; g < sbi->s_groups_count; g++) {
4864                                 struct ext4_group_desc *gdp =
4865                                         ext4_get_group_desc(sb, g, NULL);
4866
4867                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4868                                         ext4_msg(sb, KERN_ERR,
4869                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4870                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4871                                                le16_to_cpu(gdp->bg_checksum));
4872                                         err = -EINVAL;
4873                                         goto restore_opts;
4874                                 }
4875                         }
4876
4877                         /*
4878                          * If we have an unprocessed orphan list hanging
4879                          * around from a previously readonly bdev mount,
4880                          * require a full umount/remount for now.
4881                          */
4882                         if (es->s_last_orphan) {
4883                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4884                                        "remount RDWR because of unprocessed "
4885                                        "orphan inode list.  Please "
4886                                        "umount/remount instead");
4887                                 err = -EINVAL;
4888                                 goto restore_opts;
4889                         }
4890
4891                         /*
4892                          * Mounting a RDONLY partition read-write, so reread
4893                          * and store the current valid flag.  (It may have
4894                          * been changed by e2fsck since we originally mounted
4895                          * the partition.)
4896                          */
4897                         if (sbi->s_journal)
4898                                 ext4_clear_journal_err(sb, es);
4899                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4900                         if (!ext4_setup_super(sb, es, 0))
4901                                 sb->s_flags &= ~MS_RDONLY;
4902                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4903                                                      EXT4_FEATURE_INCOMPAT_MMP))
4904                                 if (ext4_multi_mount_protect(sb,
4905                                                 le64_to_cpu(es->s_mmp_block))) {
4906                                         err = -EROFS;
4907                                         goto restore_opts;
4908                                 }
4909                         enable_quota = 1;
4910                 }
4911         }
4912
4913         /*
4914          * Reinitialize lazy itable initialization thread based on
4915          * current settings
4916          */
4917         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4918                 ext4_unregister_li_request(sb);
4919         else {
4920                 ext4_group_t first_not_zeroed;
4921                 first_not_zeroed = ext4_has_uninit_itable(sb);
4922                 ext4_register_li_request(sb, first_not_zeroed);
4923         }
4924
4925         ext4_setup_system_zone(sb);
4926         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4927                 ext4_commit_super(sb, 1);
4928
4929 #ifdef CONFIG_QUOTA
4930         /* Release old quota file names */
4931         for (i = 0; i < MAXQUOTAS; i++)
4932                 kfree(old_opts.s_qf_names[i]);
4933         if (enable_quota) {
4934                 if (sb_any_quota_suspended(sb))
4935                         dquot_resume(sb, -1);
4936                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4937                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4938                         err = ext4_enable_quotas(sb);
4939                         if (err)
4940                                 goto restore_opts;
4941                 }
4942         }
4943 #endif
4944
4945         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4946         kfree(orig_data);
4947         return 0;
4948
4949 restore_opts:
4950         sb->s_flags = old_sb_flags;
4951         sbi->s_mount_opt = old_opts.s_mount_opt;
4952         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4953         sbi->s_resuid = old_opts.s_resuid;
4954         sbi->s_resgid = old_opts.s_resgid;
4955         sbi->s_commit_interval = old_opts.s_commit_interval;
4956         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4957         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4958 #ifdef CONFIG_QUOTA
4959         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4960         for (i = 0; i < MAXQUOTAS; i++) {
4961                 kfree(sbi->s_qf_names[i]);
4962                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4963         }
4964 #endif
4965         kfree(orig_data);
4966         return err;
4967 }
4968
4969 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4970 {
4971         struct super_block *sb = dentry->d_sb;
4972         struct ext4_sb_info *sbi = EXT4_SB(sb);
4973         struct ext4_super_block *es = sbi->s_es;
4974         ext4_fsblk_t overhead = 0, resv_blocks;
4975         u64 fsid;
4976         s64 bfree;
4977         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4978
4979         if (!test_opt(sb, MINIX_DF))
4980                 overhead = sbi->s_overhead;
4981
4982         buf->f_type = EXT4_SUPER_MAGIC;
4983         buf->f_bsize = sb->s_blocksize;
4984         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4985         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4986                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4987         /* prevent underflow in case that few free space is available */
4988         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4989         buf->f_bavail = buf->f_bfree -
4990                         (ext4_r_blocks_count(es) + resv_blocks);
4991         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4992                 buf->f_bavail = 0;
4993         buf->f_files = le32_to_cpu(es->s_inodes_count);
4994         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4995         buf->f_namelen = EXT4_NAME_LEN;
4996         fsid = le64_to_cpup((void *)es->s_uuid) ^
4997                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4998         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4999         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5000
5001         return 0;
5002 }
5003
5004 /* Helper function for writing quotas on sync - we need to start transaction
5005  * before quota file is locked for write. Otherwise the are possible deadlocks:
5006  * Process 1                         Process 2
5007  * ext4_create()                     quota_sync()
5008  *   jbd2_journal_start()                  write_dquot()
5009  *   dquot_initialize()                         down(dqio_mutex)
5010  *     down(dqio_mutex)                    jbd2_journal_start()
5011  *
5012  */
5013
5014 #ifdef CONFIG_QUOTA
5015
5016 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5017 {
5018         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5019 }
5020
5021 static int ext4_write_dquot(struct dquot *dquot)
5022 {
5023         int ret, err;
5024         handle_t *handle;
5025         struct inode *inode;
5026
5027         inode = dquot_to_inode(dquot);
5028         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5029                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5030         if (IS_ERR(handle))
5031                 return PTR_ERR(handle);
5032         ret = dquot_commit(dquot);
5033         err = ext4_journal_stop(handle);
5034         if (!ret)
5035                 ret = err;
5036         return ret;
5037 }
5038
5039 static int ext4_acquire_dquot(struct dquot *dquot)
5040 {
5041         int ret, err;
5042         handle_t *handle;
5043
5044         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5045                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5046         if (IS_ERR(handle))
5047                 return PTR_ERR(handle);
5048         ret = dquot_acquire(dquot);
5049         err = ext4_journal_stop(handle);
5050         if (!ret)
5051                 ret = err;
5052         return ret;
5053 }
5054
5055 static int ext4_release_dquot(struct dquot *dquot)
5056 {
5057         int ret, err;
5058         handle_t *handle;
5059
5060         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5061                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5062         if (IS_ERR(handle)) {
5063                 /* Release dquot anyway to avoid endless cycle in dqput() */
5064                 dquot_release(dquot);
5065                 return PTR_ERR(handle);
5066         }
5067         ret = dquot_release(dquot);
5068         err = ext4_journal_stop(handle);
5069         if (!ret)
5070                 ret = err;
5071         return ret;
5072 }
5073
5074 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5075 {
5076         struct super_block *sb = dquot->dq_sb;
5077         struct ext4_sb_info *sbi = EXT4_SB(sb);
5078
5079         /* Are we journaling quotas? */
5080         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5081             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5082                 dquot_mark_dquot_dirty(dquot);
5083                 return ext4_write_dquot(dquot);
5084         } else {
5085                 return dquot_mark_dquot_dirty(dquot);
5086         }
5087 }
5088
5089 static int ext4_write_info(struct super_block *sb, int type)
5090 {
5091         int ret, err;
5092         handle_t *handle;
5093
5094         /* Data block + inode block */
5095         handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5096         if (IS_ERR(handle))
5097                 return PTR_ERR(handle);
5098         ret = dquot_commit_info(sb, type);
5099         err = ext4_journal_stop(handle);
5100         if (!ret)
5101                 ret = err;
5102         return ret;
5103 }
5104
5105 /*
5106  * Turn on quotas during mount time - we need to find
5107  * the quota file and such...
5108  */
5109 static int ext4_quota_on_mount(struct super_block *sb, int type)
5110 {
5111         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5112                                         EXT4_SB(sb)->s_jquota_fmt, type);
5113 }
5114
5115 /*
5116  * Standard function to be called on quota_on
5117  */
5118 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5119                          struct path *path)
5120 {
5121         int err;
5122
5123         if (!test_opt(sb, QUOTA))
5124                 return -EINVAL;
5125
5126         /* Quotafile not on the same filesystem? */
5127         if (path->dentry->d_sb != sb)
5128                 return -EXDEV;
5129         /* Journaling quota? */
5130         if (EXT4_SB(sb)->s_qf_names[type]) {
5131                 /* Quotafile not in fs root? */
5132                 if (path->dentry->d_parent != sb->s_root)
5133                         ext4_msg(sb, KERN_WARNING,
5134                                 "Quota file not on filesystem root. "
5135                                 "Journaled quota will not work");
5136         }
5137
5138         /*
5139          * When we journal data on quota file, we have to flush journal to see
5140          * all updates to the file when we bypass pagecache...
5141          */
5142         if (EXT4_SB(sb)->s_journal &&
5143             ext4_should_journal_data(path->dentry->d_inode)) {
5144                 /*
5145                  * We don't need to lock updates but journal_flush() could
5146                  * otherwise be livelocked...
5147                  */
5148                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5149                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5150                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5151                 if (err)
5152                         return err;
5153         }
5154
5155         return dquot_quota_on(sb, type, format_id, path);
5156 }
5157
5158 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5159                              unsigned int flags)
5160 {
5161         int err;
5162         struct inode *qf_inode;
5163         unsigned long qf_inums[MAXQUOTAS] = {
5164                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5165                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5166         };
5167
5168         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5169
5170         if (!qf_inums[type])
5171                 return -EPERM;
5172
5173         qf_inode = ext4_iget(sb, qf_inums[type]);
5174         if (IS_ERR(qf_inode)) {
5175                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5176                 return PTR_ERR(qf_inode);
5177         }
5178
5179         /* Don't account quota for quota files to avoid recursion */
5180         qf_inode->i_flags |= S_NOQUOTA;
5181         err = dquot_enable(qf_inode, type, format_id, flags);
5182         iput(qf_inode);
5183
5184         return err;
5185 }
5186
5187 /* Enable usage tracking for all quota types. */
5188 static int ext4_enable_quotas(struct super_block *sb)
5189 {
5190         int type, err = 0;
5191         unsigned long qf_inums[MAXQUOTAS] = {
5192                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5193                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5194         };
5195
5196         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5197         for (type = 0; type < MAXQUOTAS; type++) {
5198                 if (qf_inums[type]) {
5199                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5200                                                 DQUOT_USAGE_ENABLED);
5201                         if (err) {
5202                                 ext4_warning(sb,
5203                                         "Failed to enable quota tracking "
5204                                         "(type=%d, err=%d). Please run "
5205                                         "e2fsck to fix.", type, err);
5206                                 return err;
5207                         }
5208                 }
5209         }
5210         return 0;
5211 }
5212
5213 /*
5214  * quota_on function that is used when QUOTA feature is set.
5215  */
5216 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5217                                  int format_id)
5218 {
5219         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5220                 return -EINVAL;
5221
5222         /*
5223          * USAGE was enabled at mount time. Only need to enable LIMITS now.
5224          */
5225         return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5226 }
5227
5228 static int ext4_quota_off(struct super_block *sb, int type)
5229 {
5230         struct inode *inode = sb_dqopt(sb)->files[type];
5231         handle_t *handle;
5232
5233         /* Force all delayed allocation blocks to be allocated.
5234          * Caller already holds s_umount sem */
5235         if (test_opt(sb, DELALLOC))
5236                 sync_filesystem(sb);
5237
5238         if (!inode)
5239                 goto out;
5240
5241         /* Update modification times of quota files when userspace can
5242          * start looking at them */
5243         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5244         if (IS_ERR(handle))
5245                 goto out;
5246         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5247         ext4_mark_inode_dirty(handle, inode);
5248         ext4_journal_stop(handle);
5249
5250 out:
5251         return dquot_quota_off(sb, type);
5252 }
5253
5254 /*
5255  * quota_off function that is used when QUOTA feature is set.
5256  */
5257 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5258 {
5259         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5260                 return -EINVAL;
5261
5262         /* Disable only the limits. */
5263         return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5264 }
5265
5266 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5267  * acquiring the locks... As quota files are never truncated and quota code
5268  * itself serializes the operations (and no one else should touch the files)
5269  * we don't have to be afraid of races */
5270 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5271                                size_t len, loff_t off)
5272 {
5273         struct inode *inode = sb_dqopt(sb)->files[type];
5274         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5275         int err = 0;
5276         int offset = off & (sb->s_blocksize - 1);
5277         int tocopy;
5278         size_t toread;
5279         struct buffer_head *bh;
5280         loff_t i_size = i_size_read(inode);
5281
5282         if (off > i_size)
5283                 return 0;
5284         if (off+len > i_size)
5285                 len = i_size-off;
5286         toread = len;
5287         while (toread > 0) {
5288                 tocopy = sb->s_blocksize - offset < toread ?
5289                                 sb->s_blocksize - offset : toread;
5290                 bh = ext4_bread(NULL, inode, blk, 0, &err);
5291                 if (err)
5292                         return err;
5293                 if (!bh)        /* A hole? */
5294                         memset(data, 0, tocopy);
5295                 else
5296                         memcpy(data, bh->b_data+offset, tocopy);
5297                 brelse(bh);
5298                 offset = 0;
5299                 toread -= tocopy;
5300                 data += tocopy;
5301                 blk++;
5302         }
5303         return len;
5304 }
5305
5306 /* Write to quotafile (we know the transaction is already started and has
5307  * enough credits) */
5308 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5309                                 const char *data, size_t len, loff_t off)
5310 {
5311         struct inode *inode = sb_dqopt(sb)->files[type];
5312         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5313         int err = 0;
5314         int offset = off & (sb->s_blocksize - 1);
5315         struct buffer_head *bh;
5316         handle_t *handle = journal_current_handle();
5317
5318         if (EXT4_SB(sb)->s_journal && !handle) {
5319                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5320                         " cancelled because transaction is not started",
5321                         (unsigned long long)off, (unsigned long long)len);
5322                 return -EIO;
5323         }
5324         /*
5325          * Since we account only one data block in transaction credits,
5326          * then it is impossible to cross a block boundary.
5327          */
5328         if (sb->s_blocksize - offset < len) {
5329                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5330                         " cancelled because not block aligned",
5331                         (unsigned long long)off, (unsigned long long)len);
5332                 return -EIO;
5333         }
5334
5335         bh = ext4_bread(handle, inode, blk, 1, &err);
5336         if (!bh)
5337                 goto out;
5338         err = ext4_journal_get_write_access(handle, bh);
5339         if (err) {
5340                 brelse(bh);
5341                 goto out;
5342         }
5343         lock_buffer(bh);
5344         memcpy(bh->b_data+offset, data, len);
5345         flush_dcache_page(bh->b_page);
5346         unlock_buffer(bh);
5347         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5348         brelse(bh);
5349 out:
5350         if (err)
5351                 return err;
5352         if (inode->i_size < off + len) {
5353                 i_size_write(inode, off + len);
5354                 EXT4_I(inode)->i_disksize = inode->i_size;
5355                 ext4_mark_inode_dirty(handle, inode);
5356         }
5357         return len;
5358 }
5359
5360 #endif
5361
5362 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5363                        const char *dev_name, void *data)
5364 {
5365         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5366 }
5367
5368 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5369 static inline void register_as_ext2(void)
5370 {
5371         int err = register_filesystem(&ext2_fs_type);
5372         if (err)
5373                 printk(KERN_WARNING
5374                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5375 }
5376
5377 static inline void unregister_as_ext2(void)
5378 {
5379         unregister_filesystem(&ext2_fs_type);
5380 }
5381
5382 static inline int ext2_feature_set_ok(struct super_block *sb)
5383 {
5384         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5385                 return 0;
5386         if (sb->s_flags & MS_RDONLY)
5387                 return 1;
5388         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5389                 return 0;
5390         return 1;
5391 }
5392 #else
5393 static inline void register_as_ext2(void) { }
5394 static inline void unregister_as_ext2(void) { }
5395 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5396 #endif
5397
5398 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5399 static inline void register_as_ext3(void)
5400 {
5401         int err = register_filesystem(&ext3_fs_type);
5402         if (err)
5403                 printk(KERN_WARNING
5404                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5405 }
5406
5407 static inline void unregister_as_ext3(void)
5408 {
5409         unregister_filesystem(&ext3_fs_type);
5410 }
5411
5412 static inline int ext3_feature_set_ok(struct super_block *sb)
5413 {
5414         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5415                 return 0;
5416         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5417                 return 0;
5418         if (sb->s_flags & MS_RDONLY)
5419                 return 1;
5420         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5421                 return 0;
5422         return 1;
5423 }
5424 #else
5425 static inline void register_as_ext3(void) { }
5426 static inline void unregister_as_ext3(void) { }
5427 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5428 #endif
5429
5430 static struct file_system_type ext4_fs_type = {
5431         .owner          = THIS_MODULE,
5432         .name           = "ext4",
5433         .mount          = ext4_mount,
5434         .kill_sb        = kill_block_super,
5435         .fs_flags       = FS_REQUIRES_DEV,
5436 };
5437 MODULE_ALIAS_FS("ext4");
5438
5439 static int __init ext4_init_feat_adverts(void)
5440 {
5441         struct ext4_features *ef;
5442         int ret = -ENOMEM;
5443
5444         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5445         if (!ef)
5446                 goto out;
5447
5448         ef->f_kobj.kset = ext4_kset;
5449         init_completion(&ef->f_kobj_unregister);
5450         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5451                                    "features");
5452         if (ret) {
5453                 kfree(ef);
5454                 goto out;
5455         }
5456
5457         ext4_feat = ef;
5458         ret = 0;
5459 out:
5460         return ret;
5461 }
5462
5463 static void ext4_exit_feat_adverts(void)
5464 {
5465         kobject_put(&ext4_feat->f_kobj);
5466         wait_for_completion(&ext4_feat->f_kobj_unregister);
5467         kfree(ext4_feat);
5468 }
5469
5470 /* Shared across all ext4 file systems */
5471 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5472 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5473
5474 static int __init ext4_init_fs(void)
5475 {
5476         int i, err;
5477
5478         ext4_li_info = NULL;
5479         mutex_init(&ext4_li_mtx);
5480
5481         /* Build-time check for flags consistency */
5482         ext4_check_flag_values();
5483
5484         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5485                 mutex_init(&ext4__aio_mutex[i]);
5486                 init_waitqueue_head(&ext4__ioend_wq[i]);
5487         }
5488
5489         err = ext4_init_es();
5490         if (err)
5491                 return err;
5492
5493         err = ext4_init_pageio();
5494         if (err)
5495                 goto out7;
5496
5497         err = ext4_init_system_zone();
5498         if (err)
5499                 goto out6;
5500         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5501         if (!ext4_kset) {
5502                 err = -ENOMEM;
5503                 goto out5;
5504         }
5505         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5506
5507         err = ext4_init_feat_adverts();
5508         if (err)
5509                 goto out4;
5510
5511         err = ext4_init_mballoc();
5512         if (err)
5513                 goto out3;
5514
5515         err = ext4_init_xattr();
5516         if (err)
5517                 goto out2;
5518         err = init_inodecache();
5519         if (err)
5520                 goto out1;
5521         register_as_ext3();
5522         register_as_ext2();
5523         err = register_filesystem(&ext4_fs_type);
5524         if (err)
5525                 goto out;
5526
5527         return 0;
5528 out:
5529         unregister_as_ext2();
5530         unregister_as_ext3();
5531         destroy_inodecache();
5532 out1:
5533         ext4_exit_xattr();
5534 out2:
5535         ext4_exit_mballoc();
5536 out3:
5537         ext4_exit_feat_adverts();
5538 out4:
5539         if (ext4_proc_root)
5540                 remove_proc_entry("fs/ext4", NULL);
5541         kset_unregister(ext4_kset);
5542 out5:
5543         ext4_exit_system_zone();
5544 out6:
5545         ext4_exit_pageio();
5546 out7:
5547         ext4_exit_es();
5548
5549         return err;
5550 }
5551
5552 static void __exit ext4_exit_fs(void)
5553 {
5554         ext4_destroy_lazyinit_thread();
5555         unregister_as_ext2();
5556         unregister_as_ext3();
5557         unregister_filesystem(&ext4_fs_type);
5558         destroy_inodecache();
5559         ext4_exit_xattr();
5560         ext4_exit_mballoc();
5561         ext4_exit_feat_adverts();
5562         remove_proc_entry("fs/ext4", NULL);
5563         kset_unregister(ext4_kset);
5564         ext4_exit_system_zone();
5565         ext4_exit_pageio();
5566         ext4_exit_es();
5567 }
5568
5569 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5570 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5571 MODULE_LICENSE("GPL");
5572 module_init(ext4_init_fs)
5573 module_exit(ext4_exit_fs)