fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/backing-dev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/ctype.h>
  38 #include <linux/log2.h>
  39 #include <linux/crc16.h>
  40 #include <linux/cleancache.h>
  41 #include <asm/uaccess.h>
  42
  43 #include <linux/kthread.h>
  44 #include <linux/freezer.h>
  45
  46 #include "ext4.h"
  47 #include "ext4_extents.h"       /* Needed for trace points definition */
  48 #include "ext4_jbd2.h"
  49 #include "xattr.h"
  50 #include "acl.h"
  51 #include "mballoc.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/ext4.h>
  55
  56 static struct ext4_lazy_init *ext4_li_info;
  57 static struct mutex ext4_li_mtx;
  58 static struct ratelimit_state ext4_mount_msg_ratelimit;
  59
  60 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  61                              unsigned long journal_devnum);
  62 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  63 static int ext4_commit_super(struct super_block *sb, int sync);
  64 static void ext4_mark_recovery_complete(struct super_block *sb,
  65                                         struct ext4_super_block *es);
  66 static void ext4_clear_journal_err(struct super_block *sb,
  67                                    struct ext4_super_block *es);
  68 static int ext4_sync_fs(struct super_block *sb, int wait);
  69 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  70 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  71 static int ext4_unfreeze(struct super_block *sb);
  72 static int ext4_freeze(struct super_block *sb);
  73 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  74                        const char *dev_name, void *data);
  75 static inline int ext2_feature_set_ok(struct super_block *sb);
  76 static inline int ext3_feature_set_ok(struct super_block *sb);
  77 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  78 static void ext4_destroy_lazyinit_thread(void);
  79 static void ext4_unregister_li_request(struct super_block *sb);
  80 static void ext4_clear_request_list(void);
  81 static struct inode *ext4_get_journal_inode(struct super_block *sb,
  82                                             unsigned int journal_inum);
  83
  84 /*
  85  * Lock ordering
  86  *
  87  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
  88  * i_mmap_rwsem (inode->i_mmap_rwsem)!
  89  *
  90  * page fault path:
  91  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
  92  *   page lock -> i_data_sem (rw)
  93  *
  94  * buffered write path:
  95  * sb_start_write -> i_mutex -> mmap_sem
  96  * sb_start_write -> i_mutex -> transaction start -> page lock ->
  97  *   i_data_sem (rw)
  98  *
  99  * truncate:
 100  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 101  *   i_mmap_rwsem (w) -> page lock
 102  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 103  *   transaction start -> i_data_sem (rw)
 104  *
 105  * direct IO:
 106  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
 107  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
 108  *   transaction start -> i_data_sem (rw)
 109  *
 110  * writepages:
 111  * transaction start -> page lock(s) -> i_data_sem (rw)
 112  */
 113
 114 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 115 static struct file_system_type ext2_fs_type = {
 116         .owner          = THIS_MODULE,
 117         .name           = "ext2",
 118         .mount          = ext4_mount,
 119         .kill_sb        = kill_block_super,
 120         .fs_flags       = FS_REQUIRES_DEV,
 121 };
 122 MODULE_ALIAS_FS("ext2");
 123 MODULE_ALIAS("ext2");
 124 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
 125 #else
 126 #define IS_EXT2_SB(sb) (0)
 127 #endif
 128
 129
 130 static struct file_system_type ext3_fs_type = {
 131         .owner          = THIS_MODULE,
 132         .name           = "ext3",
 133         .mount          = ext4_mount,
 134         .kill_sb        = kill_block_super,
 135         .fs_flags       = FS_REQUIRES_DEV,
 136 };
 137 MODULE_ALIAS_FS("ext3");
 138 MODULE_ALIAS("ext3");
 139 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 140
 141 static int ext4_verify_csum_type(struct super_block *sb,
 142                                  struct ext4_super_block *es)
 143 {
 144         if (!ext4_has_feature_metadata_csum(sb))
 145                 return 1;
 146
 147         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 148 }
 149
 150 static __le32 ext4_superblock_csum(struct super_block *sb,
 151                                    struct ext4_super_block *es)
 152 {
 153         struct ext4_sb_info *sbi = EXT4_SB(sb);
 154         int offset = offsetof(struct ext4_super_block, s_checksum);
 155         __u32 csum;
 156
 157         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 158
 159         return cpu_to_le32(csum);
 160 }
 161
 162 static int ext4_superblock_csum_verify(struct super_block *sb,
 163                                        struct ext4_super_block *es)
 164 {
 165         if (!ext4_has_metadata_csum(sb))
 166                 return 1;
 167
 168         return es->s_checksum == ext4_superblock_csum(sb, es);
 169 }
 170
 171 void ext4_superblock_csum_set(struct super_block *sb)
 172 {
 173         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 174
 175         if (!ext4_has_metadata_csum(sb))
 176                 return;
 177
 178         es->s_checksum = ext4_superblock_csum(sb, es);
 179 }
 180
 181 void *ext4_kvmalloc(size_t size, gfp_t flags)
 182 {
 183         void *ret;
 184
 185         ret = kmalloc(size, flags | __GFP_NOWARN);
 186         if (!ret)
 187                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 188         return ret;
 189 }
 190
 191 void *ext4_kvzalloc(size_t size, gfp_t flags)
 192 {
 193         void *ret;
 194
 195         ret = kzalloc(size, flags | __GFP_NOWARN);
 196         if (!ret)
 197                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 198         return ret;
 199 }
 200
 201 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 202                                struct ext4_group_desc *bg)
 203 {
 204         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 205                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 206                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 207 }
 208
 209 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 210                                struct ext4_group_desc *bg)
 211 {
 212         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 213                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 214                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 215 }
 216
 217 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 218                               struct ext4_group_desc *bg)
 219 {
 220         return le32_to_cpu(bg->bg_inode_table_lo) |
 221                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 222                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 223 }
 224
 225 __u32 ext4_free_group_clusters(struct super_block *sb,
 226                                struct ext4_group_desc *bg)
 227 {
 228         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 229                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 230                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 231 }
 232
 233 __u32 ext4_free_inodes_count(struct super_block *sb,
 234                               struct ext4_group_desc *bg)
 235 {
 236         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 237                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 238                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 239 }
 240
 241 __u32 ext4_used_dirs_count(struct super_block *sb,
 242                               struct ext4_group_desc *bg)
 243 {
 244         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 245                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 246                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 247 }
 248
 249 __u32 ext4_itable_unused_count(struct super_block *sb,
 250                               struct ext4_group_desc *bg)
 251 {
 252         return le16_to_cpu(bg->bg_itable_unused_lo) |
 253                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 254                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 255 }
 256
 257 void ext4_block_bitmap_set(struct super_block *sb,
 258                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 259 {
 260         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 261         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 262                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 263 }
 264
 265 void ext4_inode_bitmap_set(struct super_block *sb,
 266                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 267 {
 268         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 269         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 270                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 271 }
 272
 273 void ext4_inode_table_set(struct super_block *sb,
 274                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 275 {
 276         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 277         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 278                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 279 }
 280
 281 void ext4_free_group_clusters_set(struct super_block *sb,
 282                                   struct ext4_group_desc *bg, __u32 count)
 283 {
 284         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 285         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 286                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 287 }
 288
 289 void ext4_free_inodes_set(struct super_block *sb,
 290                           struct ext4_group_desc *bg, __u32 count)
 291 {
 292         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 293         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 294                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 295 }
 296
 297 void ext4_used_dirs_set(struct super_block *sb,
 298                           struct ext4_group_desc *bg, __u32 count)
 299 {
 300         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 301         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 302                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 303 }
 304
 305 void ext4_itable_unused_set(struct super_block *sb,
 306                           struct ext4_group_desc *bg, __u32 count)
 307 {
 308         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 309         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 310                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 311 }
 312
 313
 314 static void __save_error_info(struct super_block *sb, const char *func,
 315                             unsigned int line)
 316 {
 317         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 318
 319         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 320         if (bdev_read_only(sb->s_bdev))
 321                 return;
 322         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 323         es->s_last_error_time = cpu_to_le32(get_seconds());
 324         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 325         es->s_last_error_line = cpu_to_le32(line);
 326         if (!es->s_first_error_time) {
 327                 es->s_first_error_time = es->s_last_error_time;
 328                 strncpy(es->s_first_error_func, func,
 329                         sizeof(es->s_first_error_func));
 330                 es->s_first_error_line = cpu_to_le32(line);
 331                 es->s_first_error_ino = es->s_last_error_ino;
 332                 es->s_first_error_block = es->s_last_error_block;
 333         }
 334         /*
 335          * Start the daily error reporting function if it hasn't been
 336          * started already
 337          */
 338         if (!es->s_error_count)
 339                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 340         le32_add_cpu(&es->s_error_count, 1);
 341 }
 342
 343 static void save_error_info(struct super_block *sb, const char *func,
 344                             unsigned int line)
 345 {
 346         __save_error_info(sb, func, line);
 347         ext4_commit_super(sb, 1);
 348 }
 349
 350 /*
 351  * The del_gendisk() function uninitializes the disk-specific data
 352  * structures, including the bdi structure, without telling anyone
 353  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 354  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 355  * This is a kludge to prevent these oops until we can put in a proper
 356  * hook in del_gendisk() to inform the VFS and file system layers.
 357  */
 358 static int block_device_ejected(struct super_block *sb)
 359 {
 360         struct inode *bd_inode = sb->s_bdev->bd_inode;
 361         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 362
 363         return bdi->dev == NULL;
 364 }
 365
 366 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 367 {
 368         struct super_block              *sb = journal->j_private;
 369         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 370         int                             error = is_journal_aborted(journal);
 371         struct ext4_journal_cb_entry    *jce;
 372
 373         BUG_ON(txn->t_state == T_FINISHED);
 374         spin_lock(&sbi->s_md_lock);
 375         while (!list_empty(&txn->t_private_list)) {
 376                 jce = list_entry(txn->t_private_list.next,
 377                                  struct ext4_journal_cb_entry, jce_list);
 378                 list_del_init(&jce->jce_list);
 379                 spin_unlock(&sbi->s_md_lock);
 380                 jce->jce_func(sb, jce, error);
 381                 spin_lock(&sbi->s_md_lock);
 382         }
 383         spin_unlock(&sbi->s_md_lock);
 384 }
 385
 386 /* Deal with the reporting of failure conditions on a filesystem such as
 387  * inconsistencies detected or read IO failures.
 388  *
 389  * On ext2, we can store the error state of the filesystem in the
 390  * superblock.  That is not possible on ext4, because we may have other
 391  * write ordering constraints on the superblock which prevent us from
 392  * writing it out straight away; and given that the journal is about to
 393  * be aborted, we can't rely on the current, or future, transactions to
 394  * write out the superblock safely.
 395  *
 396  * We'll just use the jbd2_journal_abort() error code to record an error in
 397  * the journal instead.  On recovery, the journal will complain about
 398  * that error until we've noted it down and cleared it.
 399  */
 400
 401 static void ext4_handle_error(struct super_block *sb)
 402 {
 403         if (sb->s_flags & MS_RDONLY)
 404                 return;
 405
 406         if (!test_opt(sb, ERRORS_CONT)) {
 407                 journal_t *journal = EXT4_SB(sb)->s_journal;
 408
 409                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 410                 if (journal)
 411                         jbd2_journal_abort(journal, -EIO);
 412         }
 413         if (test_opt(sb, ERRORS_RO)) {
 414                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 415                 /*
 416                  * Make sure updated value of ->s_mount_flags will be visible
 417                  * before ->s_flags update
 418                  */
 419                 smp_wmb();
 420                 sb->s_flags |= MS_RDONLY;
 421         }
 422         if (test_opt(sb, ERRORS_PANIC)) {
 423                 if (EXT4_SB(sb)->s_journal &&
 424                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 425                         return;
 426                 panic("EXT4-fs (device %s): panic forced after error\n",
 427                         sb->s_id);
 428         }
 429 }
 430
 431 #define ext4_error_ratelimit(sb)                                        \
 432                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 433                              "EXT4-fs error")
 434
 435 void __ext4_error(struct super_block *sb, const char *function,
 436                   unsigned int line, const char *fmt, ...)
 437 {
 438         struct va_format vaf;
 439         va_list args;
 440
 441         if (ext4_error_ratelimit(sb)) {
 442                 va_start(args, fmt);
 443                 vaf.fmt = fmt;
 444                 vaf.va = &args;
 445                 printk(KERN_CRIT
 446                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 447                        sb->s_id, function, line, current->comm, &vaf);
 448                 va_end(args);
 449         }
 450         save_error_info(sb, function, line);
 451         ext4_handle_error(sb);
 452 }
 453
 454 void __ext4_error_inode(struct inode *inode, const char *function,
 455                         unsigned int line, ext4_fsblk_t block,
 456                         const char *fmt, ...)
 457 {
 458         va_list args;
 459         struct va_format vaf;
 460         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 461
 462         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 463         es->s_last_error_block = cpu_to_le64(block);
 464         if (ext4_error_ratelimit(inode->i_sb)) {
 465                 va_start(args, fmt);
 466                 vaf.fmt = fmt;
 467                 vaf.va = &args;
 468                 if (block)
 469                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 470                                "inode #%lu: block %llu: comm %s: %pV\n",
 471                                inode->i_sb->s_id, function, line, inode->i_ino,
 472                                block, current->comm, &vaf);
 473                 else
 474                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 475                                "inode #%lu: comm %s: %pV\n",
 476                                inode->i_sb->s_id, function, line, inode->i_ino,
 477                                current->comm, &vaf);
 478                 va_end(args);
 479         }
 480         save_error_info(inode->i_sb, function, line);
 481         ext4_handle_error(inode->i_sb);
 482 }
 483
 484 void __ext4_error_file(struct file *file, const char *function,
 485                        unsigned int line, ext4_fsblk_t block,
 486                        const char *fmt, ...)
 487 {
 488         va_list args;
 489         struct va_format vaf;
 490         struct ext4_super_block *es;
 491         struct inode *inode = file_inode(file);
 492         char pathname[80], *path;
 493
 494         es = EXT4_SB(inode->i_sb)->s_es;
 495         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 496         if (ext4_error_ratelimit(inode->i_sb)) {
 497                 path = file_path(file, pathname, sizeof(pathname));
 498                 if (IS_ERR(path))
 499                         path = "(unknown)";
 500                 va_start(args, fmt);
 501                 vaf.fmt = fmt;
 502                 vaf.va = &args;
 503                 if (block)
 504                         printk(KERN_CRIT
 505                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 506                                "block %llu: comm %s: path %s: %pV\n",
 507                                inode->i_sb->s_id, function, line, inode->i_ino,
 508                                block, current->comm, path, &vaf);
 509                 else
 510                         printk(KERN_CRIT
 511                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 512                                "comm %s: path %s: %pV\n",
 513                                inode->i_sb->s_id, function, line, inode->i_ino,
 514                                current->comm, path, &vaf);
 515                 va_end(args);
 516         }
 517         save_error_info(inode->i_sb, function, line);
 518         ext4_handle_error(inode->i_sb);
 519 }
 520
 521 const char *ext4_decode_error(struct super_block *sb, int errno,
 522                               char nbuf[16])
 523 {
 524         char *errstr = NULL;
 525
 526         switch (errno) {
 527         case -EFSCORRUPTED:
 528                 errstr = "Corrupt filesystem";
 529                 break;
 530         case -EFSBADCRC:
 531                 errstr = "Filesystem failed CRC";
 532                 break;
 533         case -EIO:
 534                 errstr = "IO failure";
 535                 break;
 536         case -ENOMEM:
 537                 errstr = "Out of memory";
 538                 break;
 539         case -EROFS:
 540                 if (!sb || (EXT4_SB(sb)->s_journal &&
 541                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 542                         errstr = "Journal has aborted";
 543                 else
 544                         errstr = "Readonly filesystem";
 545                 break;
 546         default:
 547                 /* If the caller passed in an extra buffer for unknown
 548                  * errors, textualise them now.  Else we just return
 549                  * NULL. */
 550                 if (nbuf) {
 551                         /* Check for truncated error codes... */
 552                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 553                                 errstr = nbuf;
 554                 }
 555                 break;
 556         }
 557
 558         return errstr;
 559 }
 560
 561 /* __ext4_std_error decodes expected errors from journaling functions
 562  * automatically and invokes the appropriate error response.  */
 563
 564 void __ext4_std_error(struct super_block *sb, const char *function,
 565                       unsigned int line, int errno)
 566 {
 567         char nbuf[16];
 568         const char *errstr;
 569
 570         /* Special case: if the error is EROFS, and we're not already
 571          * inside a transaction, then there's really no point in logging
 572          * an error. */
 573         if (errno == -EROFS && journal_current_handle() == NULL &&
 574             (sb->s_flags & MS_RDONLY))
 575                 return;
 576
 577         if (ext4_error_ratelimit(sb)) {
 578                 errstr = ext4_decode_error(sb, errno, nbuf);
 579                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 580                        sb->s_id, function, line, errstr);
 581         }
 582
 583         save_error_info(sb, function, line);
 584         ext4_handle_error(sb);
 585 }
 586
 587 /*
 588  * ext4_abort is a much stronger failure handler than ext4_error.  The
 589  * abort function may be used to deal with unrecoverable failures such
 590  * as journal IO errors or ENOMEM at a critical moment in log management.
 591  *
 592  * We unconditionally force the filesystem into an ABORT|READONLY state,
 593  * unless the error response on the fs has been set to panic in which
 594  * case we take the easy way out and panic immediately.
 595  */
 596
 597 void __ext4_abort(struct super_block *sb, const char *function,
 598                 unsigned int line, const char *fmt, ...)
 599 {
 600         va_list args;
 601
 602         save_error_info(sb, function, line);
 603         va_start(args, fmt);
 604         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 605                function, line);
 606         vprintk(fmt, args);
 607         printk("\n");
 608         va_end(args);
 609
 610         if ((sb->s_flags & MS_RDONLY) == 0) {
 611                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 612                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 613                 /*
 614                  * Make sure updated value of ->s_mount_flags will be visible
 615                  * before ->s_flags update
 616                  */
 617                 smp_wmb();
 618                 sb->s_flags |= MS_RDONLY;
 619                 if (EXT4_SB(sb)->s_journal)
 620                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 621                 save_error_info(sb, function, line);
 622         }
 623         if (test_opt(sb, ERRORS_PANIC)) {
 624                 if (EXT4_SB(sb)->s_journal &&
 625                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 626                         return;
 627                 panic("EXT4-fs panic from previous error\n");
 628         }
 629 }
 630
 631 void __ext4_msg(struct super_block *sb,
 632                 const char *prefix, const char *fmt, ...)
 633 {
 634         struct va_format vaf;
 635         va_list args;
 636
 637         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 638                 return;
 639
 640         va_start(args, fmt);
 641         vaf.fmt = fmt;
 642         vaf.va = &args;
 643         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 644         va_end(args);
 645 }
 646
 647 #define ext4_warning_ratelimit(sb)                                      \
 648                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 649                              "EXT4-fs warning")
 650
 651 void __ext4_warning(struct super_block *sb, const char *function,
 652                     unsigned int line, const char *fmt, ...)
 653 {
 654         struct va_format vaf;
 655         va_list args;
 656
 657         if (!ext4_warning_ratelimit(sb))
 658                 return;
 659
 660         va_start(args, fmt);
 661         vaf.fmt = fmt;
 662         vaf.va = &args;
 663         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 664                sb->s_id, function, line, &vaf);
 665         va_end(args);
 666 }
 667
 668 void __ext4_warning_inode(const struct inode *inode, const char *function,
 669                           unsigned int line, const char *fmt, ...)
 670 {
 671         struct va_format vaf;
 672         va_list args;
 673
 674         if (!ext4_warning_ratelimit(inode->i_sb))
 675                 return;
 676
 677         va_start(args, fmt);
 678         vaf.fmt = fmt;
 679         vaf.va = &args;
 680         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 681                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 682                function, line, inode->i_ino, current->comm, &vaf);
 683         va_end(args);
 684 }
 685
 686 void __ext4_grp_locked_error(const char *function, unsigned int line,
 687                              struct super_block *sb, ext4_group_t grp,
 688                              unsigned long ino, ext4_fsblk_t block,
 689                              const char *fmt, ...)
 690 __releases(bitlock)
 691 __acquires(bitlock)
 692 {
 693         struct va_format vaf;
 694         va_list args;
 695         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 696
 697         es->s_last_error_ino = cpu_to_le32(ino);
 698         es->s_last_error_block = cpu_to_le64(block);
 699         __save_error_info(sb, function, line);
 700
 701         if (ext4_error_ratelimit(sb)) {
 702                 va_start(args, fmt);
 703                 vaf.fmt = fmt;
 704                 vaf.va = &args;
 705                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 706                        sb->s_id, function, line, grp);
 707                 if (ino)
 708                         printk(KERN_CONT "inode %lu: ", ino);
 709                 if (block)
 710                         printk(KERN_CONT "block %llu:",
 711                                (unsigned long long) block);
 712                 printk(KERN_CONT "%pV\n", &vaf);
 713                 va_end(args);
 714         }
 715
 716         if (test_opt(sb, ERRORS_CONT)) {
 717                 ext4_commit_super(sb, 0);
 718                 return;
 719         }
 720
 721         ext4_unlock_group(sb, grp);
 722         ext4_handle_error(sb);
 723         /*
 724          * We only get here in the ERRORS_RO case; relocking the group
 725          * may be dangerous, but nothing bad will happen since the
 726          * filesystem will have already been marked read/only and the
 727          * journal has been aborted.  We return 1 as a hint to callers
 728          * who might what to use the return value from
 729          * ext4_grp_locked_error() to distinguish between the
 730          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 731          * aggressively from the ext4 function in question, with a
 732          * more appropriate error code.
 733          */
 734         ext4_lock_group(sb, grp);
 735         return;
 736 }
 737
 738 void ext4_update_dynamic_rev(struct super_block *sb)
 739 {
 740         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 741
 742         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 743                 return;
 744
 745         ext4_warning(sb,
 746                      "updating to rev %d because of new feature flag, "
 747                      "running e2fsck is recommended",
 748                      EXT4_DYNAMIC_REV);
 749
 750         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 751         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 752         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 753         /* leave es->s_feature_*compat flags alone */
 754         /* es->s_uuid will be set by e2fsck if empty */
 755
 756         /*
 757          * The rest of the superblock fields should be zero, and if not it
 758          * means they are likely already in use, so leave them alone.  We
 759          * can leave it up to e2fsck to clean up any inconsistencies there.
 760          */
 761 }
 762
 763 /*
 764  * Open the external journal device
 765  */
 766 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 767 {
 768         struct block_device *bdev;
 769         char b[BDEVNAME_SIZE];
 770
 771         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 772         if (IS_ERR(bdev))
 773                 goto fail;
 774         return bdev;
 775
 776 fail:
 777         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 778                         __bdevname(dev, b), PTR_ERR(bdev));
 779         return NULL;
 780 }
 781
 782 /*
 783  * Release the journal device
 784  */
 785 static void ext4_blkdev_put(struct block_device *bdev)
 786 {
 787         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 788 }
 789
 790 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 791 {
 792         struct block_device *bdev;
 793         bdev = sbi->journal_bdev;
 794         if (bdev) {
 795                 ext4_blkdev_put(bdev);
 796                 sbi->journal_bdev = NULL;
 797         }
 798 }
 799
 800 static inline struct inode *orphan_list_entry(struct list_head *l)
 801 {
 802         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 803 }
 804
 805 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 806 {
 807         struct list_head *l;
 808
 809         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 810                  le32_to_cpu(sbi->s_es->s_last_orphan));
 811
 812         printk(KERN_ERR "sb_info orphan list:\n");
 813         list_for_each(l, &sbi->s_orphan) {
 814                 struct inode *inode = orphan_list_entry(l);
 815                 printk(KERN_ERR "  "
 816                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 817                        inode->i_sb->s_id, inode->i_ino, inode,
 818                        inode->i_mode, inode->i_nlink,
 819                        NEXT_ORPHAN(inode));
 820         }
 821 }
 822
 823 static void ext4_put_super(struct super_block *sb)
 824 {
 825         struct ext4_sb_info *sbi = EXT4_SB(sb);
 826         struct ext4_super_block *es = sbi->s_es;
 827         int i, err;
 828
 829         ext4_unregister_li_request(sb);
 830         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 831
 832         flush_workqueue(sbi->rsv_conversion_wq);
 833         destroy_workqueue(sbi->rsv_conversion_wq);
 834
 835         if (sbi->s_journal) {
 836                 err = jbd2_journal_destroy(sbi->s_journal);
 837                 sbi->s_journal = NULL;
 838                 if (err < 0)
 839                         ext4_abort(sb, "Couldn't clean up the journal");
 840         }
 841
 842         ext4_unregister_sysfs(sb);
 843         ext4_es_unregister_shrinker(sbi);
 844         del_timer_sync(&sbi->s_err_report);
 845         ext4_release_system_zone(sb);
 846         ext4_mb_release(sb);
 847         ext4_ext_release(sb);
 848
 849         if (!(sb->s_flags & MS_RDONLY)) {
 850                 ext4_clear_feature_journal_needs_recovery(sb);
 851                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 852         }
 853         if (!(sb->s_flags & MS_RDONLY))
 854                 ext4_commit_super(sb, 1);
 855
 856         for (i = 0; i < sbi->s_gdb_count; i++)
 857                 brelse(sbi->s_group_desc[i]);
 858         kvfree(sbi->s_group_desc);
 859         kvfree(sbi->s_flex_groups);
 860         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 861         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 862         percpu_counter_destroy(&sbi->s_dirs_counter);
 863         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 864         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
 865         brelse(sbi->s_sbh);
 866 #ifdef CONFIG_QUOTA
 867         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 868                 kfree(sbi->s_qf_names[i]);
 869 #endif
 870
 871         /* Debugging code just in case the in-memory inode orphan list
 872          * isn't empty.  The on-disk one can be non-empty if we've
 873          * detected an error and taken the fs readonly, but the
 874          * in-memory list had better be clean by this point. */
 875         if (!list_empty(&sbi->s_orphan))
 876                 dump_orphan_list(sb, sbi);
 877         J_ASSERT(list_empty(&sbi->s_orphan));
 878
 879         sync_blockdev(sb->s_bdev);
 880         invalidate_bdev(sb->s_bdev);
 881         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 882                 /*
 883                  * Invalidate the journal device's buffers.  We don't want them
 884                  * floating about in memory - the physical journal device may
 885                  * hotswapped, and it breaks the `ro-after' testing code.
 886                  */
 887                 sync_blockdev(sbi->journal_bdev);
 888                 invalidate_bdev(sbi->journal_bdev);
 889                 ext4_blkdev_remove(sbi);
 890         }
 891         if (sbi->s_mb_cache) {
 892                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 893                 sbi->s_mb_cache = NULL;
 894         }
 895         if (sbi->s_mmp_tsk)
 896                 kthread_stop(sbi->s_mmp_tsk);
 897         sb->s_fs_info = NULL;
 898         /*
 899          * Now that we are completely done shutting down the
 900          * superblock, we need to actually destroy the kobject.
 901          */
 902         kobject_put(&sbi->s_kobj);
 903         wait_for_completion(&sbi->s_kobj_unregister);
 904         if (sbi->s_chksum_driver)
 905                 crypto_free_shash(sbi->s_chksum_driver);
 906         kfree(sbi->s_blockgroup_lock);
 907         kfree(sbi);
 908 }
 909
 910 static struct kmem_cache *ext4_inode_cachep;
 911
 912 /*
 913  * Called inside transaction, so use GFP_NOFS
 914  */
 915 static struct inode *ext4_alloc_inode(struct super_block *sb)
 916 {
 917         struct ext4_inode_info *ei;
 918
 919         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 920         if (!ei)
 921                 return NULL;
 922
 923         ei->vfs_inode.i_version = 1;
 924         spin_lock_init(&ei->i_raw_lock);
 925         INIT_LIST_HEAD(&ei->i_prealloc_list);
 926         spin_lock_init(&ei->i_prealloc_lock);
 927         ext4_es_init_tree(&ei->i_es_tree);
 928         rwlock_init(&ei->i_es_lock);
 929         INIT_LIST_HEAD(&ei->i_es_list);
 930         ei->i_es_all_nr = 0;
 931         ei->i_es_shk_nr = 0;
 932         ei->i_es_shrink_lblk = 0;
 933         ei->i_reserved_data_blocks = 0;
 934         ei->i_reserved_meta_blocks = 0;
 935         ei->i_allocated_meta_blocks = 0;
 936         ei->i_da_metadata_calc_len = 0;
 937         ei->i_da_metadata_calc_last_lblock = 0;
 938         spin_lock_init(&(ei->i_block_reservation_lock));
 939 #ifdef CONFIG_QUOTA
 940         ei->i_reserved_quota = 0;
 941         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 942 #endif
 943         ei->jinode = NULL;
 944         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 945         spin_lock_init(&ei->i_completed_io_lock);
 946         ei->i_sync_tid = 0;
 947         ei->i_datasync_tid = 0;
 948         atomic_set(&ei->i_unwritten, 0);
 949         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 950         return &ei->vfs_inode;
 951 }
 952
 953 static int ext4_drop_inode(struct inode *inode)
 954 {
 955         int drop = generic_drop_inode(inode);
 956
 957         trace_ext4_drop_inode(inode, drop);
 958         return drop;
 959 }
 960
 961 static void ext4_i_callback(struct rcu_head *head)
 962 {
 963         struct inode *inode = container_of(head, struct inode, i_rcu);
 964         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 965 }
 966
 967 static void ext4_destroy_inode(struct inode *inode)
 968 {
 969         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 970                 ext4_msg(inode->i_sb, KERN_ERR,
 971                          "Inode %lu (%p): orphan list check failed!",
 972                          inode->i_ino, EXT4_I(inode));
 973                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 974                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 975                                 true);
 976                 dump_stack();
 977         }
 978         call_rcu(&inode->i_rcu, ext4_i_callback);
 979 }
 980
 981 static void init_once(void *foo)
 982 {
 983         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 984
 985         INIT_LIST_HEAD(&ei->i_orphan);
 986         init_rwsem(&ei->xattr_sem);
 987         init_rwsem(&ei->i_data_sem);
 988         init_rwsem(&ei->i_mmap_sem);
 989         inode_init_once(&ei->vfs_inode);
 990 }
 991
 992 static int __init init_inodecache(void)
 993 {
 994         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 995                                              sizeof(struct ext4_inode_info),
 996                                              0, (SLAB_RECLAIM_ACCOUNT|
 997                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 998                                              init_once);
 999         if (ext4_inode_cachep == NULL)
1000                 return -ENOMEM;
1001         return 0;
1002 }
1003
1004 static void destroy_inodecache(void)
1005 {
1006         /*
1007          * Make sure all delayed rcu free inodes are flushed before we
1008          * destroy cache.
1009          */
1010         rcu_barrier();
1011         kmem_cache_destroy(ext4_inode_cachep);
1012 }
1013
1014 void ext4_clear_inode(struct inode *inode)
1015 {
1016         invalidate_inode_buffers(inode);
1017         clear_inode(inode);
1018         dquot_drop(inode);
1019         ext4_discard_preallocations(inode);
1020         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1021         if (EXT4_I(inode)->jinode) {
1022                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1023                                                EXT4_I(inode)->jinode);
1024                 jbd2_free_inode(EXT4_I(inode)->jinode);
1025                 EXT4_I(inode)->jinode = NULL;
1026         }
1027 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1028         fscrypt_put_encryption_info(inode, NULL);
1029 #endif
1030 }
1031
1032 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1033                                         u64 ino, u32 generation)
1034 {
1035         struct inode *inode;
1036
1037         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1038                 return ERR_PTR(-ESTALE);
1039         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1040                 return ERR_PTR(-ESTALE);
1041
1042         /* iget isn't really right if the inode is currently unallocated!!
1043          *
1044          * ext4_read_inode will return a bad_inode if the inode had been
1045          * deleted, so we should be safe.
1046          *
1047          * Currently we don't know the generation for parent directory, so
1048          * a generation of 0 means "accept any"
1049          */
1050         inode = ext4_iget_normal(sb, ino);
1051         if (IS_ERR(inode))
1052                 return ERR_CAST(inode);
1053         if (generation && inode->i_generation != generation) {
1054                 iput(inode);
1055                 return ERR_PTR(-ESTALE);
1056         }
1057
1058         return inode;
1059 }
1060
1061 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1062                                         int fh_len, int fh_type)
1063 {
1064         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1065                                     ext4_nfs_get_inode);
1066 }
1067
1068 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1069                                         int fh_len, int fh_type)
1070 {
1071         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1072                                     ext4_nfs_get_inode);
1073 }
1074
1075 /*
1076  * Try to release metadata pages (indirect blocks, directories) which are
1077  * mapped via the block device.  Since these pages could have journal heads
1078  * which would prevent try_to_free_buffers() from freeing them, we must use
1079  * jbd2 layer's try_to_free_buffers() function to release them.
1080  */
1081 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1082                                  gfp_t wait)
1083 {
1084         journal_t *journal = EXT4_SB(sb)->s_journal;
1085
1086         WARN_ON(PageChecked(page));
1087         if (!page_has_buffers(page))
1088                 return 0;
1089         if (journal)
1090                 return jbd2_journal_try_to_free_buffers(journal, page,
1091                                                 wait & ~__GFP_DIRECT_RECLAIM);
1092         return try_to_free_buffers(page);
1093 }
1094
1095 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1096 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1097 {
1098         return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1099                                  EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1100 }
1101
1102 static int ext4_key_prefix(struct inode *inode, u8 **key)
1103 {
1104         *key = EXT4_SB(inode->i_sb)->key_prefix;
1105         return EXT4_SB(inode->i_sb)->key_prefix_size;
1106 }
1107
1108 static int ext4_prepare_context(struct inode *inode)
1109 {
1110         return ext4_convert_inline_data(inode);
1111 }
1112
1113 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1114                                                         void *fs_data)
1115 {
1116         handle_t *handle;
1117         int res, res2;
1118
1119         /* fs_data is null when internally used. */
1120         if (fs_data) {
1121                 res  = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1122                                 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx,
1123                                 len, 0);
1124                 if (!res) {
1125                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1126                         ext4_clear_inode_state(inode,
1127                                         EXT4_STATE_MAY_INLINE_DATA);
1128                 }
1129                 return res;
1130         }
1131
1132         handle = ext4_journal_start(inode, EXT4_HT_MISC,
1133                         ext4_jbd2_credits_xattr(inode));
1134         if (IS_ERR(handle))
1135                 return PTR_ERR(handle);
1136
1137         res = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1138                         EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx,
1139                         len, 0);
1140         if (!res) {
1141                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1142                 res = ext4_mark_inode_dirty(handle, inode);
1143                 if (res)
1144                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1145         }
1146         res2 = ext4_journal_stop(handle);
1147         if (!res)
1148                 res = res2;
1149         return res;
1150 }
1151
1152 static int ext4_dummy_context(struct inode *inode)
1153 {
1154         return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1155 }
1156
1157 static unsigned ext4_max_namelen(struct inode *inode)
1158 {
1159         return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1160                 EXT4_NAME_LEN;
1161 }
1162
1163 static struct fscrypt_operations ext4_cryptops = {
1164         .get_context            = ext4_get_context,
1165         .key_prefix             = ext4_key_prefix,
1166         .prepare_context        = ext4_prepare_context,
1167         .set_context            = ext4_set_context,
1168         .dummy_context          = ext4_dummy_context,
1169         .is_encrypted           = ext4_encrypted_inode,
1170         .empty_dir              = ext4_empty_dir,
1171         .max_namelen            = ext4_max_namelen,
1172 };
1173 #else
1174 static struct fscrypt_operations ext4_cryptops = {
1175         .is_encrypted           = ext4_encrypted_inode,
1176 };
1177 #endif
1178
1179 #ifdef CONFIG_QUOTA
1180 static char *quotatypes[] = INITQFNAMES;
1181 #define QTYPE2NAME(t) (quotatypes[t])
1182
1183 static int ext4_write_dquot(struct dquot *dquot);
1184 static int ext4_acquire_dquot(struct dquot *dquot);
1185 static int ext4_release_dquot(struct dquot *dquot);
1186 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1187 static int ext4_write_info(struct super_block *sb, int type);
1188 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1189                          struct path *path);
1190 static int ext4_quota_off(struct super_block *sb, int type);
1191 static int ext4_quota_on_mount(struct super_block *sb, int type);
1192 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1193                                size_t len, loff_t off);
1194 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1195                                 const char *data, size_t len, loff_t off);
1196 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1197                              unsigned int flags);
1198 static int ext4_enable_quotas(struct super_block *sb);
1199 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1200
1201 static struct dquot **ext4_get_dquots(struct inode *inode)
1202 {
1203         return EXT4_I(inode)->i_dquot;
1204 }
1205
1206 static const struct dquot_operations ext4_quota_operations = {
1207         .get_reserved_space = ext4_get_reserved_space,
1208         .write_dquot    = ext4_write_dquot,
1209         .acquire_dquot  = ext4_acquire_dquot,
1210         .release_dquot  = ext4_release_dquot,
1211         .mark_dirty     = ext4_mark_dquot_dirty,
1212         .write_info     = ext4_write_info,
1213         .alloc_dquot    = dquot_alloc,
1214         .destroy_dquot  = dquot_destroy,
1215         .get_projid     = ext4_get_projid,
1216         .get_next_id    = ext4_get_next_id,
1217 };
1218
1219 static const struct quotactl_ops ext4_qctl_operations = {
1220         .quota_on       = ext4_quota_on,
1221         .quota_off      = ext4_quota_off,
1222         .quota_sync     = dquot_quota_sync,
1223         .get_state      = dquot_get_state,
1224         .set_info       = dquot_set_dqinfo,
1225         .get_dqblk      = dquot_get_dqblk,
1226         .set_dqblk      = dquot_set_dqblk,
1227         .get_nextdqblk  = dquot_get_next_dqblk,
1228 };
1229 #endif
1230
1231 static const struct super_operations ext4_sops = {
1232         .alloc_inode    = ext4_alloc_inode,
1233         .destroy_inode  = ext4_destroy_inode,
1234         .write_inode    = ext4_write_inode,
1235         .dirty_inode    = ext4_dirty_inode,
1236         .drop_inode     = ext4_drop_inode,
1237         .evict_inode    = ext4_evict_inode,
1238         .put_super      = ext4_put_super,
1239         .sync_fs        = ext4_sync_fs,
1240         .freeze_fs      = ext4_freeze,
1241         .unfreeze_fs    = ext4_unfreeze,
1242         .statfs         = ext4_statfs,
1243         .remount_fs     = ext4_remount,
1244         .show_options   = ext4_show_options,
1245 #ifdef CONFIG_QUOTA
1246         .quota_read     = ext4_quota_read,
1247         .quota_write    = ext4_quota_write,
1248         .get_dquots     = ext4_get_dquots,
1249 #endif
1250         .bdev_try_to_free_page = bdev_try_to_free_page,
1251 };
1252
1253 static const struct export_operations ext4_export_ops = {
1254         .fh_to_dentry = ext4_fh_to_dentry,
1255         .fh_to_parent = ext4_fh_to_parent,
1256         .get_parent = ext4_get_parent,
1257 };
1258
1259 enum {
1260         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1261         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1262         Opt_nouid32, Opt_debug, Opt_removed,
1263         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1264         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1265         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1266         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1267         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1268         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1269         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1270         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1271         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1272         Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1273         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1274         Opt_lazytime, Opt_nolazytime,
1275         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1276         Opt_inode_readahead_blks, Opt_journal_ioprio,
1277         Opt_dioread_nolock, Opt_dioread_lock,
1278         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1279         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1280 };
1281
1282 static const match_table_t tokens = {
1283         {Opt_bsd_df, "bsddf"},
1284         {Opt_minix_df, "minixdf"},
1285         {Opt_grpid, "grpid"},
1286         {Opt_grpid, "bsdgroups"},
1287         {Opt_nogrpid, "nogrpid"},
1288         {Opt_nogrpid, "sysvgroups"},
1289         {Opt_resgid, "resgid=%u"},
1290         {Opt_resuid, "resuid=%u"},
1291         {Opt_sb, "sb=%u"},
1292         {Opt_err_cont, "errors=continue"},
1293         {Opt_err_panic, "errors=panic"},
1294         {Opt_err_ro, "errors=remount-ro"},
1295         {Opt_nouid32, "nouid32"},
1296         {Opt_debug, "debug"},
1297         {Opt_removed, "oldalloc"},
1298         {Opt_removed, "orlov"},
1299         {Opt_user_xattr, "user_xattr"},
1300         {Opt_nouser_xattr, "nouser_xattr"},
1301         {Opt_acl, "acl"},
1302         {Opt_noacl, "noacl"},
1303         {Opt_noload, "norecovery"},
1304         {Opt_noload, "noload"},
1305         {Opt_removed, "nobh"},
1306         {Opt_removed, "bh"},
1307         {Opt_commit, "commit=%u"},
1308         {Opt_min_batch_time, "min_batch_time=%u"},
1309         {Opt_max_batch_time, "max_batch_time=%u"},
1310         {Opt_journal_dev, "journal_dev=%u"},
1311         {Opt_journal_path, "journal_path=%s"},
1312         {Opt_journal_checksum, "journal_checksum"},
1313         {Opt_nojournal_checksum, "nojournal_checksum"},
1314         {Opt_journal_async_commit, "journal_async_commit"},
1315         {Opt_abort, "abort"},
1316         {Opt_data_journal, "data=journal"},
1317         {Opt_data_ordered, "data=ordered"},
1318         {Opt_data_writeback, "data=writeback"},
1319         {Opt_data_err_abort, "data_err=abort"},
1320         {Opt_data_err_ignore, "data_err=ignore"},
1321         {Opt_offusrjquota, "usrjquota="},
1322         {Opt_usrjquota, "usrjquota=%s"},
1323         {Opt_offgrpjquota, "grpjquota="},
1324         {Opt_grpjquota, "grpjquota=%s"},
1325         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1326         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1327         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1328         {Opt_grpquota, "grpquota"},
1329         {Opt_noquota, "noquota"},
1330         {Opt_quota, "quota"},
1331         {Opt_usrquota, "usrquota"},
1332         {Opt_prjquota, "prjquota"},
1333         {Opt_barrier, "barrier=%u"},
1334         {Opt_barrier, "barrier"},
1335         {Opt_nobarrier, "nobarrier"},
1336         {Opt_i_version, "i_version"},
1337         {Opt_dax, "dax"},
1338         {Opt_stripe, "stripe=%u"},
1339         {Opt_delalloc, "delalloc"},
1340         {Opt_lazytime, "lazytime"},
1341         {Opt_nolazytime, "nolazytime"},
1342         {Opt_nodelalloc, "nodelalloc"},
1343         {Opt_removed, "mblk_io_submit"},
1344         {Opt_removed, "nomblk_io_submit"},
1345         {Opt_block_validity, "block_validity"},
1346         {Opt_noblock_validity, "noblock_validity"},
1347         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1348         {Opt_journal_ioprio, "journal_ioprio=%u"},
1349         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1350         {Opt_auto_da_alloc, "auto_da_alloc"},
1351         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1352         {Opt_dioread_nolock, "dioread_nolock"},
1353         {Opt_dioread_lock, "dioread_lock"},
1354         {Opt_discard, "discard"},
1355         {Opt_nodiscard, "nodiscard"},
1356         {Opt_init_itable, "init_itable=%u"},
1357         {Opt_init_itable, "init_itable"},
1358         {Opt_noinit_itable, "noinit_itable"},
1359         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1360         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1361         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1362         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1363         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1364         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1365         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1366         {Opt_err, NULL},
1367 };
1368
1369 static ext4_fsblk_t get_sb_block(void **data)
1370 {
1371         ext4_fsblk_t    sb_block;
1372         char            *options = (char *) *data;
1373
1374         if (!options || strncmp(options, "sb=", 3) != 0)
1375                 return 1;       /* Default location */
1376
1377         options += 3;
1378         /* TODO: use simple_strtoll with >32bit ext4 */
1379         sb_block = simple_strtoul(options, &options, 0);
1380         if (*options && *options != ',') {
1381                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1382                        (char *) *data);
1383                 return 1;
1384         }
1385         if (*options == ',')
1386                 options++;
1387         *data = (void *) options;
1388
1389         return sb_block;
1390 }
1391
1392 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1393 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1394         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1395
1396 #ifdef CONFIG_QUOTA
1397 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1398 {
1399         struct ext4_sb_info *sbi = EXT4_SB(sb);
1400         char *qname;
1401         int ret = -1;
1402
1403         if (sb_any_quota_loaded(sb) &&
1404                 !sbi->s_qf_names[qtype]) {
1405                 ext4_msg(sb, KERN_ERR,
1406                         "Cannot change journaled "
1407                         "quota options when quota turned on");
1408                 return -1;
1409         }
1410         if (ext4_has_feature_quota(sb)) {
1411                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1412                          "ignored when QUOTA feature is enabled");
1413                 return 1;
1414         }
1415         qname = match_strdup(args);
1416         if (!qname) {
1417                 ext4_msg(sb, KERN_ERR,
1418                         "Not enough memory for storing quotafile name");
1419                 return -1;
1420         }
1421         if (sbi->s_qf_names[qtype]) {
1422                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1423                         ret = 1;
1424                 else
1425                         ext4_msg(sb, KERN_ERR,
1426                                  "%s quota file already specified",
1427                                  QTYPE2NAME(qtype));
1428                 goto errout;
1429         }
1430         if (strchr(qname, '/')) {
1431                 ext4_msg(sb, KERN_ERR,
1432                         "quotafile must be on filesystem root");
1433                 goto errout;
1434         }
1435         sbi->s_qf_names[qtype] = qname;
1436         set_opt(sb, QUOTA);
1437         return 1;
1438 errout:
1439         kfree(qname);
1440         return ret;
1441 }
1442
1443 static int clear_qf_name(struct super_block *sb, int qtype)
1444 {
1445
1446         struct ext4_sb_info *sbi = EXT4_SB(sb);
1447
1448         if (sb_any_quota_loaded(sb) &&
1449                 sbi->s_qf_names[qtype]) {
1450                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1451                         " when quota turned on");
1452                 return -1;
1453         }
1454         kfree(sbi->s_qf_names[qtype]);
1455         sbi->s_qf_names[qtype] = NULL;
1456         return 1;
1457 }
1458 #endif
1459
1460 #define MOPT_SET        0x0001
1461 #define MOPT_CLEAR      0x0002
1462 #define MOPT_NOSUPPORT  0x0004
1463 #define MOPT_EXPLICIT   0x0008
1464 #define MOPT_CLEAR_ERR  0x0010
1465 #define MOPT_GTE0       0x0020
1466 #ifdef CONFIG_QUOTA
1467 #define MOPT_Q          0
1468 #define MOPT_QFMT       0x0040
1469 #else
1470 #define MOPT_Q          MOPT_NOSUPPORT
1471 #define MOPT_QFMT       MOPT_NOSUPPORT
1472 #endif
1473 #define MOPT_DATAJ      0x0080
1474 #define MOPT_NO_EXT2    0x0100
1475 #define MOPT_NO_EXT3    0x0200
1476 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1477 #define MOPT_STRING     0x0400
1478
1479 static const struct mount_opts {
1480         int     token;
1481         int     mount_opt;
1482         int     flags;
1483 } ext4_mount_opts[] = {
1484         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1485         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1486         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1487         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1488         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1489         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1490         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1491          MOPT_EXT4_ONLY | MOPT_SET},
1492         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1493          MOPT_EXT4_ONLY | MOPT_CLEAR},
1494         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1495         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1496         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1497          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1498         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1499          MOPT_EXT4_ONLY | MOPT_CLEAR},
1500         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1501          MOPT_EXT4_ONLY | MOPT_CLEAR},
1502         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1503          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1504         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1505                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1506          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1507         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1508         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1509         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1510         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1511         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1512          MOPT_NO_EXT2},
1513         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1514          MOPT_NO_EXT2},
1515         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1516         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1517         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1518         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1519         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1520         {Opt_commit, 0, MOPT_GTE0},
1521         {Opt_max_batch_time, 0, MOPT_GTE0},
1522         {Opt_min_batch_time, 0, MOPT_GTE0},
1523         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1524         {Opt_init_itable, 0, MOPT_GTE0},
1525         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1526         {Opt_stripe, 0, MOPT_GTE0},
1527         {Opt_resuid, 0, MOPT_GTE0},
1528         {Opt_resgid, 0, MOPT_GTE0},
1529         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1530         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1531         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1532         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1533         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1534         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1535          MOPT_NO_EXT2 | MOPT_DATAJ},
1536         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1537         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1538 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1539         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1540         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1541 #else
1542         {Opt_acl, 0, MOPT_NOSUPPORT},
1543         {Opt_noacl, 0, MOPT_NOSUPPORT},
1544 #endif
1545         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1546         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1547         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1548         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1549                                                         MOPT_SET | MOPT_Q},
1550         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1551                                                         MOPT_SET | MOPT_Q},
1552         {Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1553                                                         MOPT_SET | MOPT_Q},
1554         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1555                        EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1556                                                         MOPT_CLEAR | MOPT_Q},
1557         {Opt_usrjquota, 0, MOPT_Q},
1558         {Opt_grpjquota, 0, MOPT_Q},
1559         {Opt_offusrjquota, 0, MOPT_Q},
1560         {Opt_offgrpjquota, 0, MOPT_Q},
1561         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1562         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1563         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1564         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1565         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1566         {Opt_err, 0, 0}
1567 };
1568
1569 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1570                             substring_t *args, unsigned long *journal_devnum,
1571                             unsigned int *journal_ioprio, int is_remount)
1572 {
1573         struct ext4_sb_info *sbi = EXT4_SB(sb);
1574         const struct mount_opts *m;
1575         kuid_t uid;
1576         kgid_t gid;
1577         int arg = 0;
1578
1579 #ifdef CONFIG_QUOTA
1580         if (token == Opt_usrjquota)
1581                 return set_qf_name(sb, USRQUOTA, &args[0]);
1582         else if (token == Opt_grpjquota)
1583                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1584         else if (token == Opt_offusrjquota)
1585                 return clear_qf_name(sb, USRQUOTA);
1586         else if (token == Opt_offgrpjquota)
1587                 return clear_qf_name(sb, GRPQUOTA);
1588 #endif
1589         switch (token) {
1590         case Opt_noacl:
1591         case Opt_nouser_xattr:
1592                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1593                 break;
1594         case Opt_sb:
1595                 return 1;       /* handled by get_sb_block() */
1596         case Opt_removed:
1597                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1598                 return 1;
1599         case Opt_abort:
1600                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1601                 return 1;
1602         case Opt_i_version:
1603                 sb->s_flags |= MS_I_VERSION;
1604                 return 1;
1605         case Opt_lazytime:
1606                 sb->s_flags |= MS_LAZYTIME;
1607                 return 1;
1608         case Opt_nolazytime:
1609                 sb->s_flags &= ~MS_LAZYTIME;
1610                 return 1;
1611         }
1612
1613         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1614                 if (token == m->token)
1615                         break;
1616
1617         if (m->token == Opt_err) {
1618                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1619                          "or missing value", opt);
1620                 return -1;
1621         }
1622
1623         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1624                 ext4_msg(sb, KERN_ERR,
1625                          "Mount option \"%s\" incompatible with ext2", opt);
1626                 return -1;
1627         }
1628         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1629                 ext4_msg(sb, KERN_ERR,
1630                          "Mount option \"%s\" incompatible with ext3", opt);
1631                 return -1;
1632         }
1633
1634         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1635                 return -1;
1636         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1637                 return -1;
1638         if (m->flags & MOPT_EXPLICIT) {
1639                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1640                         set_opt2(sb, EXPLICIT_DELALLOC);
1641                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1642                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1643                 } else
1644                         return -1;
1645         }
1646         if (m->flags & MOPT_CLEAR_ERR)
1647                 clear_opt(sb, ERRORS_MASK);
1648         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1649                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1650                          "options when quota turned on");
1651                 return -1;
1652         }
1653
1654         if (m->flags & MOPT_NOSUPPORT) {
1655                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1656         } else if (token == Opt_commit) {
1657                 if (arg == 0)
1658                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1659                 sbi->s_commit_interval = HZ * arg;
1660         } else if (token == Opt_max_batch_time) {
1661                 sbi->s_max_batch_time = arg;
1662         } else if (token == Opt_min_batch_time) {
1663                 sbi->s_min_batch_time = arg;
1664         } else if (token == Opt_inode_readahead_blks) {
1665                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1666                         ext4_msg(sb, KERN_ERR,
1667                                  "EXT4-fs: inode_readahead_blks must be "
1668                                  "0 or a power of 2 smaller than 2^31");
1669                         return -1;
1670                 }
1671                 sbi->s_inode_readahead_blks = arg;
1672         } else if (token == Opt_init_itable) {
1673                 set_opt(sb, INIT_INODE_TABLE);
1674                 if (!args->from)
1675                         arg = EXT4_DEF_LI_WAIT_MULT;
1676                 sbi->s_li_wait_mult = arg;
1677         } else if (token == Opt_max_dir_size_kb) {
1678                 sbi->s_max_dir_size_kb = arg;
1679         } else if (token == Opt_stripe) {
1680                 sbi->s_stripe = arg;
1681         } else if (token == Opt_resuid) {
1682                 uid = make_kuid(current_user_ns(), arg);
1683                 if (!uid_valid(uid)) {
1684                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1685                         return -1;
1686                 }
1687                 sbi->s_resuid = uid;
1688         } else if (token == Opt_resgid) {
1689                 gid = make_kgid(current_user_ns(), arg);
1690                 if (!gid_valid(gid)) {
1691                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1692                         return -1;
1693                 }
1694                 sbi->s_resgid = gid;
1695         } else if (token == Opt_journal_dev) {
1696                 if (is_remount) {
1697                         ext4_msg(sb, KERN_ERR,
1698                                  "Cannot specify journal on remount");
1699                         return -1;
1700                 }
1701                 *journal_devnum = arg;
1702         } else if (token == Opt_journal_path) {
1703                 char *journal_path;
1704                 struct inode *journal_inode;
1705                 struct path path;
1706                 int error;
1707
1708                 if (is_remount) {
1709                         ext4_msg(sb, KERN_ERR,
1710                                  "Cannot specify journal on remount");
1711                         return -1;
1712                 }
1713                 journal_path = match_strdup(&args[0]);
1714                 if (!journal_path) {
1715                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1716                                 "journal device string");
1717                         return -1;
1718                 }
1719
1720                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1721                 if (error) {
1722                         ext4_msg(sb, KERN_ERR, "error: could not find "
1723                                 "journal device path: error %d", error);
1724                         kfree(journal_path);
1725                         return -1;
1726                 }
1727
1728                 journal_inode = d_inode(path.dentry);
1729                 if (!S_ISBLK(journal_inode->i_mode)) {
1730                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1731                                 "is not a block device", journal_path);
1732                         path_put(&path);
1733                         kfree(journal_path);
1734                         return -1;
1735                 }
1736
1737                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1738                 path_put(&path);
1739                 kfree(journal_path);
1740         } else if (token == Opt_journal_ioprio) {
1741                 if (arg > 7) {
1742                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1743                                  " (must be 0-7)");
1744                         return -1;
1745                 }
1746                 *journal_ioprio =
1747                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1748         } else if (token == Opt_test_dummy_encryption) {
1749 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1750                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1751                 ext4_msg(sb, KERN_WARNING,
1752                          "Test dummy encryption mode enabled");
1753 #else
1754                 ext4_msg(sb, KERN_WARNING,
1755                          "Test dummy encryption mount option ignored");
1756 #endif
1757         } else if (m->flags & MOPT_DATAJ) {
1758                 if (is_remount) {
1759                         if (!sbi->s_journal)
1760                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1761                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1762                                 ext4_msg(sb, KERN_ERR,
1763                                          "Cannot change data mode on remount");
1764                                 return -1;
1765                         }
1766                 } else {
1767                         clear_opt(sb, DATA_FLAGS);
1768                         sbi->s_mount_opt |= m->mount_opt;
1769                 }
1770 #ifdef CONFIG_QUOTA
1771         } else if (m->flags & MOPT_QFMT) {
1772                 if (sb_any_quota_loaded(sb) &&
1773                     sbi->s_jquota_fmt != m->mount_opt) {
1774                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1775                                  "quota options when quota turned on");
1776                         return -1;
1777                 }
1778                 if (ext4_has_feature_quota(sb)) {
1779                         ext4_msg(sb, KERN_INFO,
1780                                  "Quota format mount options ignored "
1781                                  "when QUOTA feature is enabled");
1782                         return 1;
1783                 }
1784                 sbi->s_jquota_fmt = m->mount_opt;
1785 #endif
1786         } else if (token == Opt_dax) {
1787 #ifdef CONFIG_FS_DAX
1788                 ext4_msg(sb, KERN_WARNING,
1789                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1790                         sbi->s_mount_opt |= m->mount_opt;
1791 #else
1792                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1793                 return -1;
1794 #endif
1795         } else if (token == Opt_data_err_abort) {
1796                 sbi->s_mount_opt |= m->mount_opt;
1797         } else if (token == Opt_data_err_ignore) {
1798                 sbi->s_mount_opt &= ~m->mount_opt;
1799         } else {
1800                 if (!args->from)
1801                         arg = 1;
1802                 if (m->flags & MOPT_CLEAR)
1803                         arg = !arg;
1804                 else if (unlikely(!(m->flags & MOPT_SET))) {
1805                         ext4_msg(sb, KERN_WARNING,
1806                                  "buggy handling of option %s", opt);
1807                         WARN_ON(1);
1808                         return -1;
1809                 }
1810                 if (arg != 0)
1811                         sbi->s_mount_opt |= m->mount_opt;
1812                 else
1813                         sbi->s_mount_opt &= ~m->mount_opt;
1814         }
1815         return 1;
1816 }
1817
1818 static int parse_options(char *options, struct super_block *sb,
1819                          unsigned long *journal_devnum,
1820                          unsigned int *journal_ioprio,
1821                          int is_remount)
1822 {
1823         struct ext4_sb_info *sbi = EXT4_SB(sb);
1824         char *p;
1825         substring_t args[MAX_OPT_ARGS];
1826         int token;
1827
1828         if (!options)
1829                 return 1;
1830
1831         while ((p = strsep(&options, ",")) != NULL) {
1832                 if (!*p)
1833                         continue;
1834                 /*
1835                  * Initialize args struct so we know whether arg was
1836                  * found; some options take optional arguments.
1837                  */
1838                 args[0].to = args[0].from = NULL;
1839                 token = match_token(p, tokens, args);
1840                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1841                                      journal_ioprio, is_remount) < 0)
1842                         return 0;
1843         }
1844 #ifdef CONFIG_QUOTA
1845         /*
1846          * We do the test below only for project quotas. 'usrquota' and
1847          * 'grpquota' mount options are allowed even without quota feature
1848          * to support legacy quotas in quota files.
1849          */
1850         if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1851                 ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1852                          "Cannot enable project quota enforcement.");
1853                 return 0;
1854         }
1855         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1856                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1857                         clear_opt(sb, USRQUOTA);
1858
1859                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1860                         clear_opt(sb, GRPQUOTA);
1861
1862                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1863                         ext4_msg(sb, KERN_ERR, "old and new quota "
1864                                         "format mixing");
1865                         return 0;
1866                 }
1867
1868                 if (!sbi->s_jquota_fmt) {
1869                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1870                                         "not specified");
1871                         return 0;
1872                 }
1873         }
1874 #endif
1875         if (test_opt(sb, DIOREAD_NOLOCK)) {
1876                 int blocksize =
1877                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1878
1879                 if (blocksize < PAGE_SIZE) {
1880                         ext4_msg(sb, KERN_ERR, "can't mount with "
1881                                  "dioread_nolock if block size != PAGE_SIZE");
1882                         return 0;
1883                 }
1884         }
1885         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1886             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1887                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1888                          "in data=ordered mode");
1889                 return 0;
1890         }
1891         return 1;
1892 }
1893
1894 static inline void ext4_show_quota_options(struct seq_file *seq,
1895                                            struct super_block *sb)
1896 {
1897 #if defined(CONFIG_QUOTA)
1898         struct ext4_sb_info *sbi = EXT4_SB(sb);
1899
1900         if (sbi->s_jquota_fmt) {
1901                 char *fmtname = "";
1902
1903                 switch (sbi->s_jquota_fmt) {
1904                 case QFMT_VFS_OLD:
1905                         fmtname = "vfsold";
1906                         break;
1907                 case QFMT_VFS_V0:
1908                         fmtname = "vfsv0";
1909                         break;
1910                 case QFMT_VFS_V1:
1911                         fmtname = "vfsv1";
1912                         break;
1913                 }
1914                 seq_printf(seq, ",jqfmt=%s", fmtname);
1915         }
1916
1917         if (sbi->s_qf_names[USRQUOTA])
1918                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1919
1920         if (sbi->s_qf_names[GRPQUOTA])
1921                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1922 #endif
1923 }
1924
1925 static const char *token2str(int token)
1926 {
1927         const struct match_token *t;
1928
1929         for (t = tokens; t->token != Opt_err; t++)
1930                 if (t->token == token && !strchr(t->pattern, '='))
1931                         break;
1932         return t->pattern;
1933 }
1934
1935 /*
1936  * Show an option if
1937  *  - it's set to a non-default value OR
1938  *  - if the per-sb default is different from the global default
1939  */
1940 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1941                               int nodefs)
1942 {
1943         struct ext4_sb_info *sbi = EXT4_SB(sb);
1944         struct ext4_super_block *es = sbi->s_es;
1945         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1946         const struct mount_opts *m;
1947         char sep = nodefs ? '\n' : ',';
1948
1949 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1950 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1951
1952         if (sbi->s_sb_block != 1)
1953                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1954
1955         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1956                 int want_set = m->flags & MOPT_SET;
1957                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1958                     (m->flags & MOPT_CLEAR_ERR))
1959                         continue;
1960                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1961                         continue; /* skip if same as the default */
1962                 if ((want_set &&
1963                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1964                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1965                         continue; /* select Opt_noFoo vs Opt_Foo */
1966                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1967         }
1968
1969         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1970             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1971                 SEQ_OPTS_PRINT("resuid=%u",
1972                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1973         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1974             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1975                 SEQ_OPTS_PRINT("resgid=%u",
1976                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1977         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1978         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1979                 SEQ_OPTS_PUTS("errors=remount-ro");
1980         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1981                 SEQ_OPTS_PUTS("errors=continue");
1982         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1983                 SEQ_OPTS_PUTS("errors=panic");
1984         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1985                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1986         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1987                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1988         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1989                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1990         if (sb->s_flags & MS_I_VERSION)
1991                 SEQ_OPTS_PUTS("i_version");
1992         if (nodefs || sbi->s_stripe)
1993                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1994         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1995                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1996                         SEQ_OPTS_PUTS("data=journal");
1997                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1998                         SEQ_OPTS_PUTS("data=ordered");
1999                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2000                         SEQ_OPTS_PUTS("data=writeback");
2001         }
2002         if (nodefs ||
2003             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2004                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2005                                sbi->s_inode_readahead_blks);
2006
2007         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2008                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2009                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2010         if (nodefs || sbi->s_max_dir_size_kb)
2011                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2012         if (test_opt(sb, DATA_ERR_ABORT))
2013                 SEQ_OPTS_PUTS("data_err=abort");
2014
2015         ext4_show_quota_options(seq, sb);
2016         return 0;
2017 }
2018
2019 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2020 {
2021         return _ext4_show_options(seq, root->d_sb, 0);
2022 }
2023
2024 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2025 {
2026         struct super_block *sb = seq->private;
2027         int rc;
2028
2029         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2030         rc = _ext4_show_options(seq, sb, 1);
2031         seq_puts(seq, "\n");
2032         return rc;
2033 }
2034
2035 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2036                             int read_only)
2037 {
2038         struct ext4_sb_info *sbi = EXT4_SB(sb);
2039         int res = 0;
2040
2041         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2042                 ext4_msg(sb, KERN_ERR, "revision level too high, "
2043                          "forcing read-only mode");
2044                 res = MS_RDONLY;
2045         }
2046         if (read_only)
2047                 goto done;
2048         if (!(sbi->s_mount_state & EXT4_VALID_FS))
2049                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2050                          "running e2fsck is recommended");
2051         else if (sbi->s_mount_state & EXT4_ERROR_FS)
2052                 ext4_msg(sb, KERN_WARNING,
2053                          "warning: mounting fs with errors, "
2054                          "running e2fsck is recommended");
2055         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2056                  le16_to_cpu(es->s_mnt_count) >=
2057                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2058                 ext4_msg(sb, KERN_WARNING,
2059                          "warning: maximal mount count reached, "
2060                          "running e2fsck is recommended");
2061         else if (le32_to_cpu(es->s_checkinterval) &&
2062                 (le32_to_cpu(es->s_lastcheck) +
2063                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2064                 ext4_msg(sb, KERN_WARNING,
2065                          "warning: checktime reached, "
2066                          "running e2fsck is recommended");
2067         if (!sbi->s_journal)
2068                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2069         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2070                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2071         le16_add_cpu(&es->s_mnt_count, 1);
2072         es->s_mtime = cpu_to_le32(get_seconds());
2073         ext4_update_dynamic_rev(sb);
2074         if (sbi->s_journal)
2075                 ext4_set_feature_journal_needs_recovery(sb);
2076
2077         ext4_commit_super(sb, 1);
2078 done:
2079         if (test_opt(sb, DEBUG))
2080                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2081                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2082                         sb->s_blocksize,
2083                         sbi->s_groups_count,
2084                         EXT4_BLOCKS_PER_GROUP(sb),
2085                         EXT4_INODES_PER_GROUP(sb),
2086                         sbi->s_mount_opt, sbi->s_mount_opt2);
2087
2088         cleancache_init_fs(sb);
2089         return res;
2090 }
2091
2092 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2093 {
2094         struct ext4_sb_info *sbi = EXT4_SB(sb);
2095         struct flex_groups *new_groups;
2096         int size;
2097
2098         if (!sbi->s_log_groups_per_flex)
2099                 return 0;
2100
2101         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2102         if (size <= sbi->s_flex_groups_allocated)
2103                 return 0;
2104
2105         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2106         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2107         if (!new_groups) {
2108                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2109                          size / (int) sizeof(struct flex_groups));
2110                 return -ENOMEM;
2111         }
2112
2113         if (sbi->s_flex_groups) {
2114                 memcpy(new_groups, sbi->s_flex_groups,
2115                        (sbi->s_flex_groups_allocated *
2116                         sizeof(struct flex_groups)));
2117                 kvfree(sbi->s_flex_groups);
2118         }
2119         sbi->s_flex_groups = new_groups;
2120         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2121         return 0;
2122 }
2123
2124 static int ext4_fill_flex_info(struct super_block *sb)
2125 {
2126         struct ext4_sb_info *sbi = EXT4_SB(sb);
2127         struct ext4_group_desc *gdp = NULL;
2128         ext4_group_t flex_group;
2129         int i, err;
2130
2131         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2132         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2133                 sbi->s_log_groups_per_flex = 0;
2134                 return 1;
2135         }
2136
2137         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2138         if (err)
2139                 goto failed;
2140
2141         for (i = 0; i < sbi->s_groups_count; i++) {
2142                 gdp = ext4_get_group_desc(sb, i, NULL);
2143
2144                 flex_group = ext4_flex_group(sbi, i);
2145                 atomic_add(ext4_free_inodes_count(sb, gdp),
2146                            &sbi->s_flex_groups[flex_group].free_inodes);
2147                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2148                              &sbi->s_flex_groups[flex_group].free_clusters);
2149                 atomic_add(ext4_used_dirs_count(sb, gdp),
2150                            &sbi->s_flex_groups[flex_group].used_dirs);
2151         }
2152
2153         return 1;
2154 failed:
2155         return 0;
2156 }
2157
2158 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2159                                    struct ext4_group_desc *gdp)
2160 {
2161         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2162         __u16 crc = 0;
2163         __le32 le_group = cpu_to_le32(block_group);
2164         struct ext4_sb_info *sbi = EXT4_SB(sb);
2165
2166         if (ext4_has_metadata_csum(sbi->s_sb)) {
2167                 /* Use new metadata_csum algorithm */
2168                 __u32 csum32;
2169                 __u16 dummy_csum = 0;
2170
2171                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2172                                      sizeof(le_group));
2173                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2174                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2175                                      sizeof(dummy_csum));
2176                 offset += sizeof(dummy_csum);
2177                 if (offset < sbi->s_desc_size)
2178                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2179                                              sbi->s_desc_size - offset);
2180
2181                 crc = csum32 & 0xFFFF;
2182                 goto out;
2183         }
2184
2185         /* old crc16 code */
2186         if (!ext4_has_feature_gdt_csum(sb))
2187                 return 0;
2188
2189         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2190         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2191         crc = crc16(crc, (__u8 *)gdp, offset);
2192         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2193         /* for checksum of struct ext4_group_desc do the rest...*/
2194         if (ext4_has_feature_64bit(sb) &&
2195             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2196                 crc = crc16(crc, (__u8 *)gdp + offset,
2197                             le16_to_cpu(sbi->s_es->s_desc_size) -
2198                                 offset);
2199
2200 out:
2201         return cpu_to_le16(crc);
2202 }
2203
2204 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2205                                 struct ext4_group_desc *gdp)
2206 {
2207         if (ext4_has_group_desc_csum(sb) &&
2208             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2209                 return 0;
2210
2211         return 1;
2212 }
2213
2214 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2215                               struct ext4_group_desc *gdp)
2216 {
2217         if (!ext4_has_group_desc_csum(sb))
2218                 return;
2219         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2220 }
2221
2222 /* Called at mount-time, super-block is locked */
2223 static int ext4_check_descriptors(struct super_block *sb,
2224                                   ext4_fsblk_t sb_block,
2225                                   ext4_group_t *first_not_zeroed)
2226 {
2227         struct ext4_sb_info *sbi = EXT4_SB(sb);
2228         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2229         ext4_fsblk_t last_block;
2230         ext4_fsblk_t block_bitmap;
2231         ext4_fsblk_t inode_bitmap;
2232         ext4_fsblk_t inode_table;
2233         int flexbg_flag = 0;
2234         ext4_group_t i, grp = sbi->s_groups_count;
2235
2236         if (ext4_has_feature_flex_bg(sb))
2237                 flexbg_flag = 1;
2238
2239         ext4_debug("Checking group descriptors");
2240
2241         for (i = 0; i < sbi->s_groups_count; i++) {
2242                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2243
2244                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2245                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2246                 else
2247                         last_block = first_block +
2248                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2249
2250                 if ((grp == sbi->s_groups_count) &&
2251                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2252                         grp = i;
2253
2254                 block_bitmap = ext4_block_bitmap(sb, gdp);
2255                 if (block_bitmap == sb_block) {
2256                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2257                                  "Block bitmap for group %u overlaps "
2258                                  "superblock", i);
2259                 }
2260                 if (block_bitmap < first_block || block_bitmap > last_block) {
2261                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2262                                "Block bitmap for group %u not in group "
2263                                "(block %llu)!", i, block_bitmap);
2264                         return 0;
2265                 }
2266                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2267                 if (inode_bitmap == sb_block) {
2268                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2269                                  "Inode bitmap for group %u overlaps "
2270                                  "superblock", i);
2271                 }
2272                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2273                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2274                                "Inode bitmap for group %u not in group "
2275                                "(block %llu)!", i, inode_bitmap);
2276                         return 0;
2277                 }
2278                 inode_table = ext4_inode_table(sb, gdp);
2279                 if (inode_table == sb_block) {
2280                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2281                                  "Inode table for group %u overlaps "
2282                                  "superblock", i);
2283                 }
2284                 if (inode_table < first_block ||
2285                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2286                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2287                                "Inode table for group %u not in group "
2288                                "(block %llu)!", i, inode_table);
2289                         return 0;
2290                 }
2291                 ext4_lock_group(sb, i);
2292                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2293                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2294                                  "Checksum for group %u failed (%u!=%u)",
2295                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2296                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2297                         if (!(sb->s_flags & MS_RDONLY)) {
2298                                 ext4_unlock_group(sb, i);
2299                                 return 0;
2300                         }
2301                 }
2302                 ext4_unlock_group(sb, i);
2303                 if (!flexbg_flag)
2304                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2305         }
2306         if (NULL != first_not_zeroed)
2307                 *first_not_zeroed = grp;
2308         return 1;
2309 }
2310
2311 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2312  * the superblock) which were deleted from all directories, but held open by
2313  * a process at the time of a crash.  We walk the list and try to delete these
2314  * inodes at recovery time (only with a read-write filesystem).
2315  *
2316  * In order to keep the orphan inode chain consistent during traversal (in
2317  * case of crash during recovery), we link each inode into the superblock
2318  * orphan list_head and handle it the same way as an inode deletion during
2319  * normal operation (which journals the operations for us).
2320  *
2321  * We only do an iget() and an iput() on each inode, which is very safe if we
2322  * accidentally point at an in-use or already deleted inode.  The worst that
2323  * can happen in this case is that we get a "bit already cleared" message from
2324  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2325  * e2fsck was run on this filesystem, and it must have already done the orphan
2326  * inode cleanup for us, so we can safely abort without any further action.
2327  */
2328 static void ext4_orphan_cleanup(struct super_block *sb,
2329                                 struct ext4_super_block *es)
2330 {
2331         unsigned int s_flags = sb->s_flags;
2332         int nr_orphans = 0, nr_truncates = 0;
2333 #ifdef CONFIG_QUOTA
2334         int i;
2335 #endif
2336         if (!es->s_last_orphan) {
2337                 jbd_debug(4, "no orphan inodes to clean up\n");
2338                 return;
2339         }
2340
2341         if (bdev_read_only(sb->s_bdev)) {
2342                 ext4_msg(sb, KERN_ERR, "write access "
2343                         "unavailable, skipping orphan cleanup");
2344                 return;
2345         }
2346
2347         /* Check if feature set would not allow a r/w mount */
2348         if (!ext4_feature_set_ok(sb, 0)) {
2349                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2350                          "unknown ROCOMPAT features");
2351                 return;
2352         }
2353
2354         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2355                 /* don't clear list on RO mount w/ errors */
2356                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2357                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2358                                   "clearing orphan list.\n");
2359                         es->s_last_orphan = 0;
2360                 }
2361                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2362                 return;
2363         }
2364
2365         if (s_flags & MS_RDONLY) {
2366                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2367                 sb->s_flags &= ~MS_RDONLY;
2368         }
2369 #ifdef CONFIG_QUOTA
2370         /* Needed for iput() to work correctly and not trash data */
2371         sb->s_flags |= MS_ACTIVE;
2372         /* Turn on quotas so that they are updated correctly */
2373         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2374                 if (EXT4_SB(sb)->s_qf_names[i]) {
2375                         int ret = ext4_quota_on_mount(sb, i);
2376                         if (ret < 0)
2377                                 ext4_msg(sb, KERN_ERR,
2378                                         "Cannot turn on journaled "
2379                                         "quota: error %d", ret);
2380                 }
2381         }
2382 #endif
2383
2384         while (es->s_last_orphan) {
2385                 struct inode *inode;
2386
2387                 /*
2388                  * We may have encountered an error during cleanup; if
2389                  * so, skip the rest.
2390                  */
2391                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2392                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2393                         es->s_last_orphan = 0;
2394                         break;
2395                 }
2396
2397                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2398                 if (IS_ERR(inode)) {
2399                         es->s_last_orphan = 0;
2400                         break;
2401                 }
2402
2403                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2404                 dquot_initialize(inode);
2405                 if (inode->i_nlink) {
2406                         if (test_opt(sb, DEBUG))
2407                                 ext4_msg(sb, KERN_DEBUG,
2408                                         "%s: truncating inode %lu to %lld bytes",
2409                                         __func__, inode->i_ino, inode->i_size);
2410                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2411                                   inode->i_ino, inode->i_size);
2412                         inode_lock(inode);
2413                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2414                         ext4_truncate(inode);
2415                         inode_unlock(inode);
2416                         nr_truncates++;
2417                 } else {
2418                         if (test_opt(sb, DEBUG))
2419                                 ext4_msg(sb, KERN_DEBUG,
2420                                         "%s: deleting unreferenced inode %lu",
2421                                         __func__, inode->i_ino);
2422                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2423                                   inode->i_ino);
2424                         nr_orphans++;
2425                 }
2426                 iput(inode);  /* The delete magic happens here! */
2427         }
2428
2429 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2430
2431         if (nr_orphans)
2432                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2433                        PLURAL(nr_orphans));
2434         if (nr_truncates)
2435                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2436                        PLURAL(nr_truncates));
2437 #ifdef CONFIG_QUOTA
2438         /* Turn quotas off */
2439         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2440                 if (sb_dqopt(sb)->files[i])
2441                         dquot_quota_off(sb, i);
2442         }
2443 #endif
2444         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2445 }
2446
2447 /*
2448  * Maximal extent format file size.
2449  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2450  * extent format containers, within a sector_t, and within i_blocks
2451  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2452  * so that won't be a limiting factor.
2453  *
2454  * However there is other limiting factor. We do store extents in the form
2455  * of starting block and length, hence the resulting length of the extent
2456  * covering maximum file size must fit into on-disk format containers as
2457  * well. Given that length is always by 1 unit bigger than max unit (because
2458  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2459  *
2460  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2461  */
2462 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2463 {
2464         loff_t res;
2465         loff_t upper_limit = MAX_LFS_FILESIZE;
2466
2467         /* small i_blocks in vfs inode? */
2468         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2469                 /*
2470                  * CONFIG_LBDAF is not enabled implies the inode
2471                  * i_block represent total blocks in 512 bytes
2472                  * 32 == size of vfs inode i_blocks * 8
2473                  */
2474                 upper_limit = (1LL << 32) - 1;
2475
2476                 /* total blocks in file system block size */
2477                 upper_limit >>= (blkbits - 9);
2478                 upper_limit <<= blkbits;
2479         }
2480
2481         /*
2482          * 32-bit extent-start container, ee_block. We lower the maxbytes
2483          * by one fs block, so ee_len can cover the extent of maximum file
2484          * size
2485          */
2486         res = (1LL << 32) - 1;
2487         res <<= blkbits;
2488
2489         /* Sanity check against vm- & vfs- imposed limits */
2490         if (res > upper_limit)
2491                 res = upper_limit;
2492
2493         return res;
2494 }
2495
2496 /*
2497  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2498  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2499  * We need to be 1 filesystem block less than the 2^48 sector limit.
2500  */
2501 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2502 {
2503         loff_t res = EXT4_NDIR_BLOCKS;
2504         int meta_blocks;
2505         loff_t upper_limit;
2506         /* This is calculated to be the largest file size for a dense, block
2507          * mapped file such that the file's total number of 512-byte sectors,
2508          * including data and all indirect blocks, does not exceed (2^48 - 1).
2509          *
2510          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2511          * number of 512-byte sectors of the file.
2512          */
2513
2514         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2515                 /*
2516                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2517                  * the inode i_block field represents total file blocks in
2518                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2519                  */
2520                 upper_limit = (1LL << 32) - 1;
2521
2522                 /* total blocks in file system block size */
2523                 upper_limit >>= (bits - 9);
2524
2525         } else {
2526                 /*
2527                  * We use 48 bit ext4_inode i_blocks
2528                  * With EXT4_HUGE_FILE_FL set the i_blocks
2529                  * represent total number of blocks in
2530                  * file system block size
2531                  */
2532                 upper_limit = (1LL << 48) - 1;
2533
2534         }
2535
2536         /* indirect blocks */
2537         meta_blocks = 1;
2538         /* double indirect blocks */
2539         meta_blocks += 1 + (1LL << (bits-2));
2540         /* tripple indirect blocks */
2541         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2542
2543         upper_limit -= meta_blocks;
2544         upper_limit <<= bits;
2545
2546         res += 1LL << (bits-2);
2547         res += 1LL << (2*(bits-2));
2548         res += 1LL << (3*(bits-2));
2549         res <<= bits;
2550         if (res > upper_limit)
2551                 res = upper_limit;
2552
2553         if (res > MAX_LFS_FILESIZE)
2554                 res = MAX_LFS_FILESIZE;
2555
2556         return res;
2557 }
2558
2559 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2560                                    ext4_fsblk_t logical_sb_block, int nr)
2561 {
2562         struct ext4_sb_info *sbi = EXT4_SB(sb);
2563         ext4_group_t bg, first_meta_bg;
2564         int has_super = 0;
2565
2566         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2567
2568         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2569                 return logical_sb_block + nr + 1;
2570         bg = sbi->s_desc_per_block * nr;
2571         if (ext4_bg_has_super(sb, bg))
2572                 has_super = 1;
2573
2574         /*
2575          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2576          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2577          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2578          * compensate.
2579          */
2580         if (sb->s_blocksize == 1024 && nr == 0 &&
2581             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2582                 has_super++;
2583
2584         return (has_super + ext4_group_first_block_no(sb, bg));
2585 }
2586
2587 /**
2588  * ext4_get_stripe_size: Get the stripe size.
2589  * @sbi: In memory super block info
2590  *
2591  * If we have specified it via mount option, then
2592  * use the mount option value. If the value specified at mount time is
2593  * greater than the blocks per group use the super block value.
2594  * If the super block value is greater than blocks per group return 0.
2595  * Allocator needs it be less than blocks per group.
2596  *
2597  */
2598 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2599 {
2600         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2601         unsigned long stripe_width =
2602                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2603         int ret;
2604
2605         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2606                 ret = sbi->s_stripe;
2607         else if (stripe_width <= sbi->s_blocks_per_group)
2608                 ret = stripe_width;
2609         else if (stride <= sbi->s_blocks_per_group)
2610                 ret = stride;
2611         else
2612                 ret = 0;
2613
2614         /*
2615          * If the stripe width is 1, this makes no sense and
2616          * we set it to 0 to turn off stripe handling code.
2617          */
2618         if (ret <= 1)
2619                 ret = 0;
2620
2621         return ret;
2622 }
2623
2624 /*
2625  * Check whether this filesystem can be mounted based on
2626  * the features present and the RDONLY/RDWR mount requested.
2627  * Returns 1 if this filesystem can be mounted as requested,
2628  * 0 if it cannot be.
2629  */
2630 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2631 {
2632         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2633                 ext4_msg(sb, KERN_ERR,
2634                         "Couldn't mount because of "
2635                         "unsupported optional features (%x)",
2636                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2637                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2638                 return 0;
2639         }
2640
2641         if (readonly)
2642                 return 1;
2643
2644         if (ext4_has_feature_readonly(sb)) {
2645                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2646                 sb->s_flags |= MS_RDONLY;
2647                 return 1;
2648         }
2649
2650         /* Check that feature set is OK for a read-write mount */
2651         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2652                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2653                          "unsupported optional features (%x)",
2654                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2655                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2656                 return 0;
2657         }
2658         /*
2659          * Large file size enabled file system can only be mounted
2660          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2661          */
2662         if (ext4_has_feature_huge_file(sb)) {
2663                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2664                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2665                                  "cannot be mounted RDWR without "
2666                                  "CONFIG_LBDAF");
2667                         return 0;
2668                 }
2669         }
2670         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2671                 ext4_msg(sb, KERN_ERR,
2672                          "Can't support bigalloc feature without "
2673                          "extents feature\n");
2674                 return 0;
2675         }
2676
2677 #ifndef CONFIG_QUOTA
2678         if (ext4_has_feature_quota(sb) && !readonly) {
2679                 ext4_msg(sb, KERN_ERR,
2680                          "Filesystem with quota feature cannot be mounted RDWR "
2681                          "without CONFIG_QUOTA");
2682                 return 0;
2683         }
2684         if (ext4_has_feature_project(sb) && !readonly) {
2685                 ext4_msg(sb, KERN_ERR,
2686                          "Filesystem with project quota feature cannot be mounted RDWR "
2687                          "without CONFIG_QUOTA");
2688                 return 0;
2689         }
2690 #endif  /* CONFIG_QUOTA */
2691         return 1;
2692 }
2693
2694 /*
2695  * This function is called once a day if we have errors logged
2696  * on the file system
2697  */
2698 static void print_daily_error_info(unsigned long arg)
2699 {
2700         struct super_block *sb = (struct super_block *) arg;
2701         struct ext4_sb_info *sbi;
2702         struct ext4_super_block *es;
2703
2704         sbi = EXT4_SB(sb);
2705         es = sbi->s_es;
2706
2707         if (es->s_error_count)
2708                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2709                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2710                          le32_to_cpu(es->s_error_count));
2711         if (es->s_first_error_time) {
2712                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2713                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2714                        (int) sizeof(es->s_first_error_func),
2715                        es->s_first_error_func,
2716                        le32_to_cpu(es->s_first_error_line));
2717                 if (es->s_first_error_ino)
2718                         printk(": inode %u",
2719                                le32_to_cpu(es->s_first_error_ino));
2720                 if (es->s_first_error_block)
2721                         printk(": block %llu", (unsigned long long)
2722                                le64_to_cpu(es->s_first_error_block));
2723                 printk("\n");
2724         }
2725         if (es->s_last_error_time) {
2726                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2727                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2728                        (int) sizeof(es->s_last_error_func),
2729                        es->s_last_error_func,
2730                        le32_to_cpu(es->s_last_error_line));
2731                 if (es->s_last_error_ino)
2732                         printk(": inode %u",
2733                                le32_to_cpu(es->s_last_error_ino));
2734                 if (es->s_last_error_block)
2735                         printk(": block %llu", (unsigned long long)
2736                                le64_to_cpu(es->s_last_error_block));
2737                 printk("\n");
2738         }
2739         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2740 }
2741
2742 /* Find next suitable group and run ext4_init_inode_table */
2743 static int ext4_run_li_request(struct ext4_li_request *elr)
2744 {
2745         struct ext4_group_desc *gdp = NULL;
2746         ext4_group_t group, ngroups;
2747         struct super_block *sb;
2748         unsigned long timeout = 0;
2749         int ret = 0;
2750
2751         sb = elr->lr_super;
2752         ngroups = EXT4_SB(sb)->s_groups_count;
2753
2754         for (group = elr->lr_next_group; group < ngroups; group++) {
2755                 gdp = ext4_get_group_desc(sb, group, NULL);
2756                 if (!gdp) {
2757                         ret = 1;
2758                         break;
2759                 }
2760
2761                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2762                         break;
2763         }
2764
2765         if (group >= ngroups)
2766                 ret = 1;
2767
2768         if (!ret) {
2769                 timeout = jiffies;
2770                 ret = ext4_init_inode_table(sb, group,
2771                                             elr->lr_timeout ? 0 : 1);
2772                 if (elr->lr_timeout == 0) {
2773                         timeout = (jiffies - timeout) *
2774                                   elr->lr_sbi->s_li_wait_mult;
2775                         elr->lr_timeout = timeout;
2776                 }
2777                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2778                 elr->lr_next_group = group + 1;
2779         }
2780         return ret;
2781 }
2782
2783 /*
2784  * Remove lr_request from the list_request and free the
2785  * request structure. Should be called with li_list_mtx held
2786  */
2787 static void ext4_remove_li_request(struct ext4_li_request *elr)
2788 {
2789         struct ext4_sb_info *sbi;
2790
2791         if (!elr)
2792                 return;
2793
2794         sbi = elr->lr_sbi;
2795
2796         list_del(&elr->lr_request);
2797         sbi->s_li_request = NULL;
2798         kfree(elr);
2799 }
2800
2801 static void ext4_unregister_li_request(struct super_block *sb)
2802 {
2803         mutex_lock(&ext4_li_mtx);
2804         if (!ext4_li_info) {
2805                 mutex_unlock(&ext4_li_mtx);
2806                 return;
2807         }
2808
2809         mutex_lock(&ext4_li_info->li_list_mtx);
2810         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2811         mutex_unlock(&ext4_li_info->li_list_mtx);
2812         mutex_unlock(&ext4_li_mtx);
2813 }
2814
2815 static struct task_struct *ext4_lazyinit_task;
2816
2817 /*
2818  * This is the function where ext4lazyinit thread lives. It walks
2819  * through the request list searching for next scheduled filesystem.
2820  * When such a fs is found, run the lazy initialization request
2821  * (ext4_rn_li_request) and keep track of the time spend in this
2822  * function. Based on that time we compute next schedule time of
2823  * the request. When walking through the list is complete, compute
2824  * next waking time and put itself into sleep.
2825  */
2826 static int ext4_lazyinit_thread(void *arg)
2827 {
2828         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2829         struct list_head *pos, *n;
2830         struct ext4_li_request *elr;
2831         unsigned long next_wakeup, cur;
2832
2833         BUG_ON(NULL == eli);
2834
2835 cont_thread:
2836         while (true) {
2837                 next_wakeup = MAX_JIFFY_OFFSET;
2838
2839                 mutex_lock(&eli->li_list_mtx);
2840                 if (list_empty(&eli->li_request_list)) {
2841                         mutex_unlock(&eli->li_list_mtx);
2842                         goto exit_thread;
2843                 }
2844                 list_for_each_safe(pos, n, &eli->li_request_list) {
2845                         int err = 0;
2846                         int progress = 0;
2847                         elr = list_entry(pos, struct ext4_li_request,
2848                                          lr_request);
2849
2850                         if (time_before(jiffies, elr->lr_next_sched)) {
2851                                 if (time_before(elr->lr_next_sched, next_wakeup))
2852                                         next_wakeup = elr->lr_next_sched;
2853                                 continue;
2854                         }
2855                         if (down_read_trylock(&elr->lr_super->s_umount)) {
2856                                 if (sb_start_write_trylock(elr->lr_super)) {
2857                                         progress = 1;
2858                                         /*
2859                                          * We hold sb->s_umount, sb can not
2860                                          * be removed from the list, it is
2861                                          * now safe to drop li_list_mtx
2862                                          */
2863                                         mutex_unlock(&eli->li_list_mtx);
2864                                         err = ext4_run_li_request(elr);
2865                                         sb_end_write(elr->lr_super);
2866                                         mutex_lock(&eli->li_list_mtx);
2867                                         n = pos->next;
2868                                 }
2869                                 up_read((&elr->lr_super->s_umount));
2870                         }
2871                         /* error, remove the lazy_init job */
2872                         if (err) {
2873                                 ext4_remove_li_request(elr);
2874                                 continue;
2875                         }
2876                         if (!progress) {
2877                                 elr->lr_next_sched = jiffies +
2878                                         (prandom_u32()
2879                                          % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2880                         }
2881                         if (time_before(elr->lr_next_sched, next_wakeup))
2882                                 next_wakeup = elr->lr_next_sched;
2883                 }
2884                 mutex_unlock(&eli->li_list_mtx);
2885
2886                 try_to_freeze();
2887
2888                 cur = jiffies;
2889                 if ((time_after_eq(cur, next_wakeup)) ||
2890                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2891                         cond_resched();
2892                         continue;
2893                 }
2894
2895                 schedule_timeout_interruptible(next_wakeup - cur);
2896
2897                 if (kthread_should_stop()) {
2898                         ext4_clear_request_list();
2899                         goto exit_thread;
2900                 }
2901         }
2902
2903 exit_thread:
2904         /*
2905          * It looks like the request list is empty, but we need
2906          * to check it under the li_list_mtx lock, to prevent any
2907          * additions into it, and of course we should lock ext4_li_mtx
2908          * to atomically free the list and ext4_li_info, because at
2909          * this point another ext4 filesystem could be registering
2910          * new one.
2911          */
2912         mutex_lock(&ext4_li_mtx);
2913         mutex_lock(&eli->li_list_mtx);
2914         if (!list_empty(&eli->li_request_list)) {
2915                 mutex_unlock(&eli->li_list_mtx);
2916                 mutex_unlock(&ext4_li_mtx);
2917                 goto cont_thread;
2918         }
2919         mutex_unlock(&eli->li_list_mtx);
2920         kfree(ext4_li_info);
2921         ext4_li_info = NULL;
2922         mutex_unlock(&ext4_li_mtx);
2923
2924         return 0;
2925 }
2926
2927 static void ext4_clear_request_list(void)
2928 {
2929         struct list_head *pos, *n;
2930         struct ext4_li_request *elr;
2931
2932         mutex_lock(&ext4_li_info->li_list_mtx);
2933         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2934                 elr = list_entry(pos, struct ext4_li_request,
2935                                  lr_request);
2936                 ext4_remove_li_request(elr);
2937         }
2938         mutex_unlock(&ext4_li_info->li_list_mtx);
2939 }
2940
2941 static int ext4_run_lazyinit_thread(void)
2942 {
2943         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2944                                          ext4_li_info, "ext4lazyinit");
2945         if (IS_ERR(ext4_lazyinit_task)) {
2946                 int err = PTR_ERR(ext4_lazyinit_task);
2947                 ext4_clear_request_list();
2948                 kfree(ext4_li_info);
2949                 ext4_li_info = NULL;
2950                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2951                                  "initialization thread\n",
2952                                  err);
2953                 return err;
2954         }
2955         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2956         return 0;
2957 }
2958
2959 /*
2960  * Check whether it make sense to run itable init. thread or not.
2961  * If there is at least one uninitialized inode table, return
2962  * corresponding group number, else the loop goes through all
2963  * groups and return total number of groups.
2964  */
2965 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2966 {
2967         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2968         struct ext4_group_desc *gdp = NULL;
2969
2970         for (group = 0; group < ngroups; group++) {
2971                 gdp = ext4_get_group_desc(sb, group, NULL);
2972                 if (!gdp)
2973                         continue;
2974
2975                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2976                         break;
2977         }
2978
2979         return group;
2980 }
2981
2982 static int ext4_li_info_new(void)
2983 {
2984         struct ext4_lazy_init *eli = NULL;
2985
2986         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2987         if (!eli)
2988                 return -ENOMEM;
2989
2990         INIT_LIST_HEAD(&eli->li_request_list);
2991         mutex_init(&eli->li_list_mtx);
2992
2993         eli->li_state |= EXT4_LAZYINIT_QUIT;
2994
2995         ext4_li_info = eli;
2996
2997         return 0;
2998 }
2999
3000 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3001                                             ext4_group_t start)
3002 {
3003         struct ext4_sb_info *sbi = EXT4_SB(sb);
3004         struct ext4_li_request *elr;
3005
3006         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3007         if (!elr)
3008                 return NULL;
3009
3010         elr->lr_super = sb;
3011         elr->lr_sbi = sbi;
3012         elr->lr_next_group = start;
3013
3014         /*
3015          * Randomize first schedule time of the request to
3016          * spread the inode table initialization requests
3017          * better.
3018          */
3019         elr->lr_next_sched = jiffies + (prandom_u32() %
3020                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3021         return elr;
3022 }
3023
3024 int ext4_register_li_request(struct super_block *sb,
3025                              ext4_group_t first_not_zeroed)
3026 {
3027         struct ext4_sb_info *sbi = EXT4_SB(sb);
3028         struct ext4_li_request *elr = NULL;
3029         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3030         int ret = 0;
3031
3032         mutex_lock(&ext4_li_mtx);
3033         if (sbi->s_li_request != NULL) {
3034                 /*
3035                  * Reset timeout so it can be computed again, because
3036                  * s_li_wait_mult might have changed.
3037                  */
3038                 sbi->s_li_request->lr_timeout = 0;
3039                 goto out;
3040         }
3041
3042         if (first_not_zeroed == ngroups ||
3043             (sb->s_flags & MS_RDONLY) ||
3044             !test_opt(sb, INIT_INODE_TABLE))
3045                 goto out;
3046
3047         elr = ext4_li_request_new(sb, first_not_zeroed);
3048         if (!elr) {
3049                 ret = -ENOMEM;
3050                 goto out;
3051         }
3052
3053         if (NULL == ext4_li_info) {
3054                 ret = ext4_li_info_new();
3055                 if (ret)
3056                         goto out;
3057         }
3058
3059         mutex_lock(&ext4_li_info->li_list_mtx);
3060         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3061         mutex_unlock(&ext4_li_info->li_list_mtx);
3062
3063         sbi->s_li_request = elr;
3064         /*
3065          * set elr to NULL here since it has been inserted to
3066          * the request_list and the removal and free of it is
3067          * handled by ext4_clear_request_list from now on.
3068          */
3069         elr = NULL;
3070
3071         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3072                 ret = ext4_run_lazyinit_thread();
3073                 if (ret)
3074                         goto out;
3075         }
3076 out:
3077         mutex_unlock(&ext4_li_mtx);
3078         if (ret)
3079                 kfree(elr);
3080         return ret;
3081 }
3082
3083 /*
3084  * We do not need to lock anything since this is called on
3085  * module unload.
3086  */
3087 static void ext4_destroy_lazyinit_thread(void)
3088 {
3089         /*
3090          * If thread exited earlier
3091          * there's nothing to be done.
3092          */
3093         if (!ext4_li_info || !ext4_lazyinit_task)
3094                 return;
3095
3096         kthread_stop(ext4_lazyinit_task);
3097 }
3098
3099 static int set_journal_csum_feature_set(struct super_block *sb)
3100 {
3101         int ret = 1;
3102         int compat, incompat;
3103         struct ext4_sb_info *sbi = EXT4_SB(sb);
3104
3105         if (ext4_has_metadata_csum(sb)) {
3106                 /* journal checksum v3 */
3107                 compat = 0;
3108                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3109         } else {
3110                 /* journal checksum v1 */
3111                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3112                 incompat = 0;
3113         }
3114
3115         jbd2_journal_clear_features(sbi->s_journal,
3116                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3117                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3118                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3119         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3120                 ret = jbd2_journal_set_features(sbi->s_journal,
3121                                 compat, 0,
3122                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3123                                 incompat);
3124         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3125                 ret = jbd2_journal_set_features(sbi->s_journal,
3126                                 compat, 0,
3127                                 incompat);
3128                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3129                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3130         } else {
3131                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3132                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3133         }
3134
3135         return ret;
3136 }
3137
3138 /*
3139  * Note: calculating the overhead so we can be compatible with
3140  * historical BSD practice is quite difficult in the face of
3141  * clusters/bigalloc.  This is because multiple metadata blocks from
3142  * different block group can end up in the same allocation cluster.
3143  * Calculating the exact overhead in the face of clustered allocation
3144  * requires either O(all block bitmaps) in memory or O(number of block
3145  * groups**2) in time.  We will still calculate the superblock for
3146  * older file systems --- and if we come across with a bigalloc file
3147  * system with zero in s_overhead_clusters the estimate will be close to
3148  * correct especially for very large cluster sizes --- but for newer
3149  * file systems, it's better to calculate this figure once at mkfs
3150  * time, and store it in the superblock.  If the superblock value is
3151  * present (even for non-bigalloc file systems), we will use it.
3152  */
3153 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3154                           char *buf)
3155 {
3156         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3157         struct ext4_group_desc  *gdp;
3158         ext4_fsblk_t            first_block, last_block, b;
3159         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3160         int                     s, j, count = 0;
3161
3162         if (!ext4_has_feature_bigalloc(sb))
3163                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3164                         sbi->s_itb_per_group + 2);
3165
3166         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3167                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3168         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3169         for (i = 0; i < ngroups; i++) {
3170                 gdp = ext4_get_group_desc(sb, i, NULL);
3171                 b = ext4_block_bitmap(sb, gdp);
3172                 if (b >= first_block && b <= last_block) {
3173                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3174                         count++;
3175                 }
3176                 b = ext4_inode_bitmap(sb, gdp);
3177                 if (b >= first_block && b <= last_block) {
3178                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3179                         count++;
3180                 }
3181                 b = ext4_inode_table(sb, gdp);
3182                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3183                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3184                                 int c = EXT4_B2C(sbi, b - first_block);
3185                                 ext4_set_bit(c, buf);
3186                                 count++;
3187                         }
3188                 if (i != grp)
3189                         continue;
3190                 s = 0;
3191                 if (ext4_bg_has_super(sb, grp)) {
3192                         ext4_set_bit(s++, buf);
3193                         count++;
3194                 }
3195                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3196                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3197                         count++;
3198                 }
3199         }
3200         if (!count)
3201                 return 0;
3202         return EXT4_CLUSTERS_PER_GROUP(sb) -
3203                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3204 }
3205
3206 /*
3207  * Compute the overhead and stash it in sbi->s_overhead
3208  */
3209 int ext4_calculate_overhead(struct super_block *sb)
3210 {
3211         struct ext4_sb_info *sbi = EXT4_SB(sb);
3212         struct ext4_super_block *es = sbi->s_es;
3213         struct inode *j_inode;
3214         unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3215         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3216         ext4_fsblk_t overhead = 0;
3217         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3218
3219         if (!buf)
3220                 return -ENOMEM;
3221
3222         /*
3223          * Compute the overhead (FS structures).  This is constant
3224          * for a given filesystem unless the number of block groups
3225          * changes so we cache the previous value until it does.
3226          */
3227
3228         /*
3229          * All of the blocks before first_data_block are overhead
3230          */
3231         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3232
3233         /*
3234          * Add the overhead found in each block group
3235          */
3236         for (i = 0; i < ngroups; i++) {
3237                 int blks;
3238
3239                 blks = count_overhead(sb, i, buf);
3240                 overhead += blks;
3241                 if (blks)
3242                         memset(buf, 0, PAGE_SIZE);
3243                 cond_resched();
3244         }
3245
3246         /*
3247          * Add the internal journal blocks whether the journal has been
3248          * loaded or not
3249          */
3250         if (sbi->s_journal && !sbi->journal_bdev)
3251                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3252         else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3253                 j_inode = ext4_get_journal_inode(sb, j_inum);
3254                 if (j_inode) {
3255                         j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3256                         overhead += EXT4_NUM_B2C(sbi, j_blocks);
3257                         iput(j_inode);
3258                 } else {
3259                         ext4_msg(sb, KERN_ERR, "can't get journal size");
3260                 }
3261         }
3262         sbi->s_overhead = overhead;
3263         smp_wmb();
3264         free_page((unsigned long) buf);
3265         return 0;
3266 }
3267
3268 static void ext4_set_resv_clusters(struct super_block *sb)
3269 {
3270         ext4_fsblk_t resv_clusters;
3271         struct ext4_sb_info *sbi = EXT4_SB(sb);
3272
3273         /*
3274          * There's no need to reserve anything when we aren't using extents.
3275          * The space estimates are exact, there are no unwritten extents,
3276          * hole punching doesn't need new metadata... This is needed especially
3277          * to keep ext2/3 backward compatibility.
3278          */
3279         if (!ext4_has_feature_extents(sb))
3280                 return;
3281         /*
3282          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3283          * This should cover the situations where we can not afford to run
3284          * out of space like for example punch hole, or converting
3285          * unwritten extents in delalloc path. In most cases such
3286          * allocation would require 1, or 2 blocks, higher numbers are
3287          * very rare.
3288          */
3289         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3290                          sbi->s_cluster_bits);
3291
3292         do_div(resv_clusters, 50);
3293         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3294
3295         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3296 }
3297
3298 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3299 {
3300         char *orig_data = kstrdup(data, GFP_KERNEL);
3301         struct buffer_head *bh;
3302         struct ext4_super_block *es = NULL;
3303         struct ext4_sb_info *sbi;
3304         ext4_fsblk_t block;
3305         ext4_fsblk_t sb_block = get_sb_block(&data);
3306         ext4_fsblk_t logical_sb_block;
3307         unsigned long offset = 0;
3308         unsigned long journal_devnum = 0;
3309         unsigned long def_mount_opts;
3310         struct inode *root;
3311         const char *descr;
3312         int ret = -ENOMEM;
3313         int blocksize, clustersize;
3314         unsigned int db_count;
3315         unsigned int i;
3316         int needs_recovery, has_huge_files, has_bigalloc;
3317         __u64 blocks_count;
3318         int err = 0;
3319         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3320         ext4_group_t first_not_zeroed;
3321
3322         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3323         if (!sbi)
3324                 goto out_free_orig;
3325
3326         sbi->s_blockgroup_lock =
3327                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3328         if (!sbi->s_blockgroup_lock) {
3329                 kfree(sbi);
3330                 goto out_free_orig;
3331         }
3332         sb->s_fs_info = sbi;
3333         sbi->s_sb = sb;
3334         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3335         sbi->s_sb_block = sb_block;
3336         if (sb->s_bdev->bd_part)
3337                 sbi->s_sectors_written_start =
3338                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3339
3340         /* Cleanup superblock name */
3341         strreplace(sb->s_id, '/', '!');
3342
3343         /* -EINVAL is default */
3344         ret = -EINVAL;
3345         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3346         if (!blocksize) {
3347                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3348                 goto out_fail;
3349         }
3350
3351         /*
3352          * The ext4 superblock will not be buffer aligned for other than 1kB
3353          * block sizes.  We need to calculate the offset from buffer start.
3354          */
3355         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3356                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3357                 offset = do_div(logical_sb_block, blocksize);
3358         } else {
3359                 logical_sb_block = sb_block;
3360         }
3361
3362         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3363                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3364                 goto out_fail;
3365         }
3366         /*
3367          * Note: s_es must be initialized as soon as possible because
3368          *       some ext4 macro-instructions depend on its value
3369          */
3370         es = (struct ext4_super_block *) (bh->b_data + offset);
3371         sbi->s_es = es;
3372         sb->s_magic = le16_to_cpu(es->s_magic);
3373         if (sb->s_magic != EXT4_SUPER_MAGIC)
3374                 goto cantfind_ext4;
3375         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3376
3377         /* Warn if metadata_csum and gdt_csum are both set. */
3378         if (ext4_has_feature_metadata_csum(sb) &&
3379             ext4_has_feature_gdt_csum(sb))
3380                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3381                              "redundant flags; please run fsck.");
3382
3383         /* Check for a known checksum algorithm */
3384         if (!ext4_verify_csum_type(sb, es)) {
3385                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3386                          "unknown checksum algorithm.");
3387                 silent = 1;
3388                 goto cantfind_ext4;
3389         }
3390
3391         /* Load the checksum driver */
3392         if (ext4_has_feature_metadata_csum(sb)) {
3393                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3394                 if (IS_ERR(sbi->s_chksum_driver)) {
3395                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3396                         ret = PTR_ERR(sbi->s_chksum_driver);
3397                         sbi->s_chksum_driver = NULL;
3398                         goto failed_mount;
3399                 }
3400         }
3401
3402         /* Check superblock checksum */
3403         if (!ext4_superblock_csum_verify(sb, es)) {
3404                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3405                          "invalid superblock checksum.  Run e2fsck?");
3406                 silent = 1;
3407                 ret = -EFSBADCRC;
3408                 goto cantfind_ext4;
3409         }
3410
3411         /* Precompute checksum seed for all metadata */
3412         if (ext4_has_feature_csum_seed(sb))
3413                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3414         else if (ext4_has_metadata_csum(sb))
3415                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3416                                                sizeof(es->s_uuid));
3417
3418         /* Set defaults before we parse the mount options */
3419         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3420         set_opt(sb, INIT_INODE_TABLE);
3421         if (def_mount_opts & EXT4_DEFM_DEBUG)
3422                 set_opt(sb, DEBUG);
3423         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3424                 set_opt(sb, GRPID);
3425         if (def_mount_opts & EXT4_DEFM_UID16)
3426                 set_opt(sb, NO_UID32);
3427         /* xattr user namespace & acls are now defaulted on */
3428         set_opt(sb, XATTR_USER);
3429 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3430         set_opt(sb, POSIX_ACL);
3431 #endif
3432         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3433         if (ext4_has_metadata_csum(sb))
3434                 set_opt(sb, JOURNAL_CHECKSUM);
3435
3436         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3437                 set_opt(sb, JOURNAL_DATA);
3438         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3439                 set_opt(sb, ORDERED_DATA);
3440         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3441                 set_opt(sb, WRITEBACK_DATA);
3442
3443         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3444                 set_opt(sb, ERRORS_PANIC);
3445         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3446                 set_opt(sb, ERRORS_CONT);
3447         else
3448                 set_opt(sb, ERRORS_RO);
3449         /* block_validity enabled by default; disable with noblock_validity */
3450         set_opt(sb, BLOCK_VALIDITY);
3451         if (def_mount_opts & EXT4_DEFM_DISCARD)
3452                 set_opt(sb, DISCARD);
3453
3454         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3455         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3456         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3457         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3458         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3459
3460         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3461                 set_opt(sb, BARRIER);
3462
3463         /*
3464          * enable delayed allocation by default
3465          * Use -o nodelalloc to turn it off
3466          */
3467         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3468             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3469                 set_opt(sb, DELALLOC);
3470
3471         /*
3472          * set default s_li_wait_mult for lazyinit, for the case there is
3473          * no mount option specified.
3474          */
3475         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3476
3477         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3478                            &journal_devnum, &journal_ioprio, 0)) {
3479                 ext4_msg(sb, KERN_WARNING,
3480                          "failed to parse options in superblock: %s",
3481                          sbi->s_es->s_mount_opts);
3482         }
3483         sbi->s_def_mount_opt = sbi->s_mount_opt;
3484         if (!parse_options((char *) data, sb, &journal_devnum,
3485                            &journal_ioprio, 0))
3486                 goto failed_mount;
3487
3488         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3489                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3490                             "with data=journal disables delayed "
3491                             "allocation and O_DIRECT support!\n");
3492                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3493                         ext4_msg(sb, KERN_ERR, "can't mount with "
3494                                  "both data=journal and delalloc");
3495                         goto failed_mount;
3496                 }
3497                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3498                         ext4_msg(sb, KERN_ERR, "can't mount with "
3499                                  "both data=journal and dioread_nolock");
3500                         goto failed_mount;
3501                 }
3502                 if (test_opt(sb, DAX)) {
3503                         ext4_msg(sb, KERN_ERR, "can't mount with "
3504                                  "both data=journal and dax");
3505                         goto failed_mount;
3506                 }
3507                 if (test_opt(sb, DELALLOC))
3508                         clear_opt(sb, DELALLOC);
3509         } else {
3510                 sb->s_iflags |= SB_I_CGROUPWB;
3511         }
3512
3513         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3514                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3515
3516         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3517             (ext4_has_compat_features(sb) ||
3518              ext4_has_ro_compat_features(sb) ||
3519              ext4_has_incompat_features(sb)))
3520                 ext4_msg(sb, KERN_WARNING,
3521                        "feature flags set on rev 0 fs, "
3522                        "running e2fsck is recommended");
3523
3524         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3525                 set_opt2(sb, HURD_COMPAT);
3526                 if (ext4_has_feature_64bit(sb)) {
3527                         ext4_msg(sb, KERN_ERR,
3528                                  "The Hurd can't support 64-bit file systems");
3529                         goto failed_mount;
3530                 }
3531         }
3532
3533         if (IS_EXT2_SB(sb)) {
3534                 if (ext2_feature_set_ok(sb))
3535                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3536                                  "using the ext4 subsystem");
3537                 else {
3538                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3539                                  "to feature incompatibilities");
3540                         goto failed_mount;
3541                 }
3542         }
3543
3544         if (IS_EXT3_SB(sb)) {
3545                 if (ext3_feature_set_ok(sb))
3546                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3547                                  "using the ext4 subsystem");
3548                 else {
3549                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3550                                  "to feature incompatibilities");
3551                         goto failed_mount;
3552                 }
3553         }
3554
3555         /*
3556          * Check feature flags regardless of the revision level, since we
3557          * previously didn't change the revision level when setting the flags,
3558          * so there is a chance incompat flags are set on a rev 0 filesystem.
3559          */
3560         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3561                 goto failed_mount;
3562
3563         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3564         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3565             blocksize > EXT4_MAX_BLOCK_SIZE) {
3566                 ext4_msg(sb, KERN_ERR,
3567                        "Unsupported filesystem blocksize %d", blocksize);
3568                 goto failed_mount;
3569         }
3570
3571         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3572                 ext4_msg(sb, KERN_ERR,
3573                          "Number of reserved GDT blocks insanely large: %d",
3574                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3575                 goto failed_mount;
3576         }
3577
3578         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3579                 err = bdev_dax_supported(sb, blocksize);
3580                 if (err)
3581                         goto failed_mount;
3582         }
3583
3584         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3585                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3586                          es->s_encryption_level);
3587                 goto failed_mount;
3588         }
3589
3590         if (sb->s_blocksize != blocksize) {
3591                 /* Validate the filesystem blocksize */
3592                 if (!sb_set_blocksize(sb, blocksize)) {
3593                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3594                                         blocksize);
3595                         goto failed_mount;
3596                 }
3597
3598                 brelse(bh);
3599                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3600                 offset = do_div(logical_sb_block, blocksize);
3601                 bh = sb_bread_unmovable(sb, logical_sb_block);
3602                 if (!bh) {
3603                         ext4_msg(sb, KERN_ERR,
3604                                "Can't read superblock on 2nd try");
3605                         goto failed_mount;
3606                 }
3607                 es = (struct ext4_super_block *)(bh->b_data + offset);
3608                 sbi->s_es = es;
3609                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3610                         ext4_msg(sb, KERN_ERR,
3611                                "Magic mismatch, very weird!");
3612                         goto failed_mount;
3613                 }
3614         }
3615
3616         has_huge_files = ext4_has_feature_huge_file(sb);
3617         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3618                                                       has_huge_files);
3619         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3620
3621         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3622                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3623                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3624         } else {
3625                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3626                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3627                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3628                     (!is_power_of_2(sbi->s_inode_size)) ||
3629                     (sbi->s_inode_size > blocksize)) {
3630                         ext4_msg(sb, KERN_ERR,
3631                                "unsupported inode size: %d",
3632                                sbi->s_inode_size);
3633                         goto failed_mount;
3634                 }
3635                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3636                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3637         }
3638
3639         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3640         if (ext4_has_feature_64bit(sb)) {
3641                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3642                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3643                     !is_power_of_2(sbi->s_desc_size)) {
3644                         ext4_msg(sb, KERN_ERR,
3645                                "unsupported descriptor size %lu",
3646                                sbi->s_desc_size);
3647                         goto failed_mount;
3648                 }
3649         } else
3650                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3651
3652         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3653         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3654         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3655                 goto cantfind_ext4;
3656
3657         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3658         if (sbi->s_inodes_per_block == 0)
3659                 goto cantfind_ext4;
3660         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3661                                         sbi->s_inodes_per_block;
3662         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3663         sbi->s_sbh = bh;
3664         sbi->s_mount_state = le16_to_cpu(es->s_state);
3665         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3666         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3667
3668         for (i = 0; i < 4; i++)
3669                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3670         sbi->s_def_hash_version = es->s_def_hash_version;
3671         if (ext4_has_feature_dir_index(sb)) {
3672                 i = le32_to_cpu(es->s_flags);
3673                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3674                         sbi->s_hash_unsigned = 3;
3675                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3676 #ifdef __CHAR_UNSIGNED__
3677                         if (!(sb->s_flags & MS_RDONLY))
3678                                 es->s_flags |=
3679                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3680                         sbi->s_hash_unsigned = 3;
3681 #else
3682                         if (!(sb->s_flags & MS_RDONLY))
3683                                 es->s_flags |=
3684                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3685 #endif
3686                 }
3687         }
3688
3689         /* Handle clustersize */
3690         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3691         has_bigalloc = ext4_has_feature_bigalloc(sb);
3692         if (has_bigalloc) {
3693                 if (clustersize < blocksize) {
3694                         ext4_msg(sb, KERN_ERR,
3695                                  "cluster size (%d) smaller than "
3696                                  "block size (%d)", clustersize, blocksize);
3697                         goto failed_mount;
3698                 }
3699                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3700                         le32_to_cpu(es->s_log_block_size);
3701                 sbi->s_clusters_per_group =
3702                         le32_to_cpu(es->s_clusters_per_group);
3703                 if (sbi->s_clusters_per_group > blocksize * 8) {
3704                         ext4_msg(sb, KERN_ERR,
3705                                  "#clusters per group too big: %lu",
3706                                  sbi->s_clusters_per_group);
3707                         goto failed_mount;
3708                 }
3709                 if (sbi->s_blocks_per_group !=
3710                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3711                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3712                                  "clusters per group (%lu) inconsistent",
3713                                  sbi->s_blocks_per_group,
3714                                  sbi->s_clusters_per_group);
3715                         goto failed_mount;
3716                 }
3717         } else {
3718                 if (clustersize != blocksize) {
3719                         ext4_warning(sb, "fragment/cluster size (%d) != "
3720                                      "block size (%d)", clustersize,
3721                                      blocksize);
3722                         clustersize = blocksize;
3723                 }
3724                 if (sbi->s_blocks_per_group > blocksize * 8) {
3725                         ext4_msg(sb, KERN_ERR,
3726                                  "#blocks per group too big: %lu",
3727                                  sbi->s_blocks_per_group);
3728                         goto failed_mount;
3729                 }
3730                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3731                 sbi->s_cluster_bits = 0;
3732         }
3733         sbi->s_cluster_ratio = clustersize / blocksize;
3734
3735         if (sbi->s_inodes_per_group > blocksize * 8) {
3736                 ext4_msg(sb, KERN_ERR,
3737                        "#inodes per group too big: %lu",
3738                        sbi->s_inodes_per_group);
3739                 goto failed_mount;
3740         }
3741
3742         /* Do we have standard group size of clustersize * 8 blocks ? */
3743         if (sbi->s_blocks_per_group == clustersize << 3)
3744                 set_opt2(sb, STD_GROUP_SIZE);
3745
3746         /*
3747          * Test whether we have more sectors than will fit in sector_t,
3748          * and whether the max offset is addressable by the page cache.
3749          */
3750         err = generic_check_addressable(sb->s_blocksize_bits,
3751                                         ext4_blocks_count(es));
3752         if (err) {
3753                 ext4_msg(sb, KERN_ERR, "filesystem"
3754                          " too large to mount safely on this system");
3755                 if (sizeof(sector_t) < 8)
3756                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3757                 goto failed_mount;
3758         }
3759
3760         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3761                 goto cantfind_ext4;
3762
3763         /* check blocks count against device size */
3764         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3765         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3766                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3767                        "exceeds size of device (%llu blocks)",
3768                        ext4_blocks_count(es), blocks_count);
3769                 goto failed_mount;
3770         }
3771
3772         /*
3773          * It makes no sense for the first data block to be beyond the end
3774          * of the filesystem.
3775          */
3776         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3777                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3778                          "block %u is beyond end of filesystem (%llu)",
3779                          le32_to_cpu(es->s_first_data_block),
3780                          ext4_blocks_count(es));
3781                 goto failed_mount;
3782         }
3783         blocks_count = (ext4_blocks_count(es) -
3784                         le32_to_cpu(es->s_first_data_block) +
3785                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3786         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3787         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3788                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3789                        "(block count %llu, first data block %u, "
3790                        "blocks per group %lu)", sbi->s_groups_count,
3791                        ext4_blocks_count(es),
3792                        le32_to_cpu(es->s_first_data_block),
3793                        EXT4_BLOCKS_PER_GROUP(sb));
3794                 goto failed_mount;
3795         }
3796         sbi->s_groups_count = blocks_count;
3797         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3798                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3799         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3800                    EXT4_DESC_PER_BLOCK(sb);
3801         sbi->s_group_desc = ext4_kvmalloc(db_count *
3802                                           sizeof(struct buffer_head *),
3803                                           GFP_KERNEL);
3804         if (sbi->s_group_desc == NULL) {
3805                 ext4_msg(sb, KERN_ERR, "not enough memory");
3806                 ret = -ENOMEM;
3807                 goto failed_mount;
3808         }
3809
3810         bgl_lock_init(sbi->s_blockgroup_lock);
3811
3812         for (i = 0; i < db_count; i++) {
3813                 block = descriptor_loc(sb, logical_sb_block, i);
3814                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3815                 if (!sbi->s_group_desc[i]) {
3816                         ext4_msg(sb, KERN_ERR,
3817                                "can't read group descriptor %d", i);
3818                         db_count = i;
3819                         goto failed_mount2;
3820                 }
3821         }
3822         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3823                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3824                 ret = -EFSCORRUPTED;
3825                 goto failed_mount2;
3826         }
3827
3828         sbi->s_gdb_count = db_count;
3829         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3830         spin_lock_init(&sbi->s_next_gen_lock);
3831
3832         setup_timer(&sbi->s_err_report, print_daily_error_info,
3833                 (unsigned long) sb);
3834
3835         /* Register extent status tree shrinker */
3836         if (ext4_es_register_shrinker(sbi))
3837                 goto failed_mount3;
3838
3839         sbi->s_stripe = ext4_get_stripe_size(sbi);
3840         sbi->s_extent_max_zeroout_kb = 32;
3841
3842         /*
3843          * set up enough so that it can read an inode
3844          */
3845         sb->s_op = &ext4_sops;
3846         sb->s_export_op = &ext4_export_ops;
3847         sb->s_xattr = ext4_xattr_handlers;
3848         sb->s_cop = &ext4_cryptops;
3849 #ifdef CONFIG_QUOTA
3850         sb->dq_op = &ext4_quota_operations;
3851         if (ext4_has_feature_quota(sb))
3852                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3853         else
3854                 sb->s_qcop = &ext4_qctl_operations;
3855         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3856 #endif
3857         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3858
3859         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3860         mutex_init(&sbi->s_orphan_lock);
3861
3862         sb->s_root = NULL;
3863
3864         needs_recovery = (es->s_last_orphan != 0 ||
3865                           ext4_has_feature_journal_needs_recovery(sb));
3866
3867         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3868                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3869                         goto failed_mount3a;
3870
3871         /*
3872          * The first inode we look at is the journal inode.  Don't try
3873          * root first: it may be modified in the journal!
3874          */
3875         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3876                 if (ext4_load_journal(sb, es, journal_devnum))
3877                         goto failed_mount3a;
3878         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3879                    ext4_has_feature_journal_needs_recovery(sb)) {
3880                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3881                        "suppressed and not mounted read-only");
3882                 goto failed_mount_wq;
3883         } else {
3884                 /* Nojournal mode, all journal mount options are illegal */
3885                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3886                         ext4_msg(sb, KERN_ERR, "can't mount with "
3887                                  "journal_checksum, fs mounted w/o journal");
3888                         goto failed_mount_wq;
3889                 }
3890                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3891                         ext4_msg(sb, KERN_ERR, "can't mount with "
3892                                  "journal_async_commit, fs mounted w/o journal");
3893                         goto failed_mount_wq;
3894                 }
3895                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3896                         ext4_msg(sb, KERN_ERR, "can't mount with "
3897                                  "commit=%lu, fs mounted w/o journal",
3898                                  sbi->s_commit_interval / HZ);
3899                         goto failed_mount_wq;
3900                 }
3901                 if (EXT4_MOUNT_DATA_FLAGS &
3902                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3903                         ext4_msg(sb, KERN_ERR, "can't mount with "
3904                                  "data=, fs mounted w/o journal");
3905                         goto failed_mount_wq;
3906                 }
3907                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3908                 clear_opt(sb, JOURNAL_CHECKSUM);
3909                 clear_opt(sb, DATA_FLAGS);
3910                 sbi->s_journal = NULL;
3911                 needs_recovery = 0;
3912                 goto no_journal;
3913         }
3914
3915         if (ext4_has_feature_64bit(sb) &&
3916             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3917                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3918                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3919                 goto failed_mount_wq;
3920         }
3921
3922         if (!set_journal_csum_feature_set(sb)) {
3923                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3924                          "feature set");
3925                 goto failed_mount_wq;
3926         }
3927
3928         /* We have now updated the journal if required, so we can
3929          * validate the data journaling mode. */
3930         switch (test_opt(sb, DATA_FLAGS)) {
3931         case 0:
3932                 /* No mode set, assume a default based on the journal
3933                  * capabilities: ORDERED_DATA if the journal can
3934                  * cope, else JOURNAL_DATA
3935                  */
3936                 if (jbd2_journal_check_available_features
3937                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3938                         set_opt(sb, ORDERED_DATA);
3939                 else
3940                         set_opt(sb, JOURNAL_DATA);
3941                 break;
3942
3943         case EXT4_MOUNT_ORDERED_DATA:
3944         case EXT4_MOUNT_WRITEBACK_DATA:
3945                 if (!jbd2_journal_check_available_features
3946                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3947                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3948                                "requested data journaling mode");
3949                         goto failed_mount_wq;
3950                 }
3951         default:
3952                 break;
3953         }
3954         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3955
3956         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3957
3958 no_journal:
3959         sbi->s_mb_cache = ext4_xattr_create_cache();
3960         if (!sbi->s_mb_cache) {
3961                 ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
3962                 goto failed_mount_wq;
3963         }
3964
3965         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
3966             (blocksize != PAGE_SIZE)) {
3967                 ext4_msg(sb, KERN_ERR,
3968                          "Unsupported blocksize for fs encryption");
3969                 goto failed_mount_wq;
3970         }
3971
3972         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
3973             !ext4_has_feature_encrypt(sb)) {
3974                 ext4_set_feature_encrypt(sb);
3975                 ext4_commit_super(sb, 1);
3976         }
3977
3978         /*
3979          * Get the # of file system overhead blocks from the
3980          * superblock if present.
3981          */
3982         if (es->s_overhead_clusters)
3983                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3984         else {
3985                 err = ext4_calculate_overhead(sb);
3986                 if (err)
3987                         goto failed_mount_wq;
3988         }
3989
3990         /*
3991          * The maximum number of concurrent works can be high and
3992          * concurrency isn't really necessary.  Limit it to 1.
3993          */
3994         EXT4_SB(sb)->rsv_conversion_wq =
3995                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3996         if (!EXT4_SB(sb)->rsv_conversion_wq) {
3997                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3998                 ret = -ENOMEM;
3999                 goto failed_mount4;
4000         }
4001
4002         /*
4003          * The jbd2_journal_load will have done any necessary log recovery,
4004          * so we can safely mount the rest of the filesystem now.
4005          */
4006
4007         root = ext4_iget(sb, EXT4_ROOT_INO);
4008         if (IS_ERR(root)) {
4009                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4010                 ret = PTR_ERR(root);
4011                 root = NULL;
4012                 goto failed_mount4;
4013         }
4014         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4015                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4016                 iput(root);
4017                 goto failed_mount4;
4018         }
4019         sb->s_root = d_make_root(root);
4020         if (!sb->s_root) {
4021                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4022                 ret = -ENOMEM;
4023                 goto failed_mount4;
4024         }
4025
4026         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4027                 sb->s_flags |= MS_RDONLY;
4028
4029         /* determine the minimum size of new large inodes, if present */
4030         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4031                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4032                                                      EXT4_GOOD_OLD_INODE_SIZE;
4033                 if (ext4_has_feature_extra_isize(sb)) {
4034                         if (sbi->s_want_extra_isize <
4035                             le16_to_cpu(es->s_want_extra_isize))
4036                                 sbi->s_want_extra_isize =
4037                                         le16_to_cpu(es->s_want_extra_isize);
4038                         if (sbi->s_want_extra_isize <
4039                             le16_to_cpu(es->s_min_extra_isize))
4040                                 sbi->s_want_extra_isize =
4041                                         le16_to_cpu(es->s_min_extra_isize);
4042                 }
4043         }
4044         /* Check if enough inode space is available */
4045         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4046                                                         sbi->s_inode_size) {
4047                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4048                                                        EXT4_GOOD_OLD_INODE_SIZE;
4049                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4050                          "available");
4051         }
4052
4053         ext4_set_resv_clusters(sb);
4054
4055         err = ext4_setup_system_zone(sb);
4056         if (err) {
4057                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4058                          "zone (%d)", err);
4059                 goto failed_mount4a;
4060         }
4061
4062         ext4_ext_init(sb);
4063         err = ext4_mb_init(sb);
4064         if (err) {
4065                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4066                          err);
4067                 goto failed_mount5;
4068         }
4069
4070         block = ext4_count_free_clusters(sb);
4071         ext4_free_blocks_count_set(sbi->s_es,
4072                                    EXT4_C2B(sbi, block));
4073         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4074                                   GFP_KERNEL);
4075         if (!err) {
4076                 unsigned long freei = ext4_count_free_inodes(sb);
4077                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4078                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4079                                           GFP_KERNEL);
4080         }
4081         if (!err)
4082                 err = percpu_counter_init(&sbi->s_dirs_counter,
4083                                           ext4_count_dirs(sb), GFP_KERNEL);
4084         if (!err)
4085                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4086                                           GFP_KERNEL);
4087         if (!err)
4088                 err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4089
4090         if (err) {
4091                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4092                 goto failed_mount6;
4093         }
4094
4095         if (ext4_has_feature_flex_bg(sb))
4096                 if (!ext4_fill_flex_info(sb)) {
4097                         ext4_msg(sb, KERN_ERR,
4098                                "unable to initialize "
4099                                "flex_bg meta info!");
4100                         goto failed_mount6;
4101                 }
4102
4103         err = ext4_register_li_request(sb, first_not_zeroed);
4104         if (err)
4105                 goto failed_mount6;
4106
4107         err = ext4_register_sysfs(sb);
4108         if (err)
4109                 goto failed_mount7;
4110
4111 #ifdef CONFIG_QUOTA
4112         /* Enable quota usage during mount. */
4113         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4114                 err = ext4_enable_quotas(sb);
4115                 if (err)
4116                         goto failed_mount8;
4117         }
4118 #endif  /* CONFIG_QUOTA */
4119
4120         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4121         ext4_orphan_cleanup(sb, es);
4122         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4123         if (needs_recovery) {
4124                 ext4_msg(sb, KERN_INFO, "recovery complete");
4125                 ext4_mark_recovery_complete(sb, es);
4126         }
4127         if (EXT4_SB(sb)->s_journal) {
4128                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4129                         descr = " journalled data mode";
4130                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4131                         descr = " ordered data mode";
4132                 else
4133                         descr = " writeback data mode";
4134         } else
4135                 descr = "out journal";
4136
4137         if (test_opt(sb, DISCARD)) {
4138                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4139                 if (!blk_queue_discard(q))
4140                         ext4_msg(sb, KERN_WARNING,
4141                                  "mounting with \"discard\" option, but "
4142                                  "the device does not support discard");
4143         }
4144
4145         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4146                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4147                          "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4148                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4149
4150         if (es->s_error_count)
4151                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4152
4153         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4154         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4155         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4156         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4157
4158         kfree(orig_data);
4159 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4160         memcpy(sbi->key_prefix, EXT4_KEY_DESC_PREFIX,
4161                                 EXT4_KEY_DESC_PREFIX_SIZE);
4162         sbi->key_prefix_size = EXT4_KEY_DESC_PREFIX_SIZE;
4163 #endif
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         ext4_unregister_sysfs(sb);
4174 #endif
4175 failed_mount7:
4176         ext4_unregister_li_request(sb);
4177 failed_mount6:
4178         ext4_mb_release(sb);
4179         if (sbi->s_flex_groups)
4180                 kvfree(sbi->s_flex_groups);
4181         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4182         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4183         percpu_counter_destroy(&sbi->s_dirs_counter);
4184         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4185 failed_mount5:
4186         ext4_ext_release(sb);
4187         ext4_release_system_zone(sb);
4188 failed_mount4a:
4189         dput(sb->s_root);
4190         sb->s_root = NULL;
4191 failed_mount4:
4192         ext4_msg(sb, KERN_ERR, "mount failed");
4193         if (EXT4_SB(sb)->rsv_conversion_wq)
4194                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4195 failed_mount_wq:
4196         if (sbi->s_mb_cache) {
4197                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
4198                 sbi->s_mb_cache = NULL;
4199         }
4200         if (sbi->s_journal) {
4201                 jbd2_journal_destroy(sbi->s_journal);
4202                 sbi->s_journal = NULL;
4203         }
4204 failed_mount3a:
4205         ext4_es_unregister_shrinker(sbi);
4206 failed_mount3:
4207         del_timer_sync(&sbi->s_err_report);
4208         if (sbi->s_mmp_tsk)
4209                 kthread_stop(sbi->s_mmp_tsk);
4210 failed_mount2:
4211         for (i = 0; i < db_count; i++)
4212                 brelse(sbi->s_group_desc[i]);
4213         kvfree(sbi->s_group_desc);
4214 failed_mount:
4215         if (sbi->s_chksum_driver)
4216                 crypto_free_shash(sbi->s_chksum_driver);
4217 #ifdef CONFIG_QUOTA
4218         for (i = 0; i < EXT4_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 struct inode *ext4_get_journal_inode(struct super_block *sb,
4258                                              unsigned int journal_inum)
4259 {
4260         struct inode *journal_inode;
4261
4262         /*
4263          * Test for the existence of a valid inode on disk.  Bad things
4264          * happen if we iget() an unused inode, as the subsequent iput()
4265          * will try to delete it.
4266          */
4267         journal_inode = ext4_iget(sb, journal_inum);
4268         if (IS_ERR(journal_inode)) {
4269                 ext4_msg(sb, KERN_ERR, "no journal found");
4270                 return NULL;
4271         }
4272         if (!journal_inode->i_nlink) {
4273                 make_bad_inode(journal_inode);
4274                 iput(journal_inode);
4275                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4276                 return NULL;
4277         }
4278
4279         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4280                   journal_inode, journal_inode->i_size);
4281         if (!S_ISREG(journal_inode->i_mode)) {
4282                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4283                 iput(journal_inode);
4284                 return NULL;
4285         }
4286         return journal_inode;
4287 }
4288
4289 static journal_t *ext4_get_journal(struct super_block *sb,
4290                                    unsigned int journal_inum)
4291 {
4292         struct inode *journal_inode;
4293         journal_t *journal;
4294
4295         BUG_ON(!ext4_has_feature_journal(sb));
4296
4297         journal_inode = ext4_get_journal_inode(sb, journal_inum);
4298         if (!journal_inode)
4299                 return NULL;
4300
4301         journal = jbd2_journal_init_inode(journal_inode);
4302         if (!journal) {
4303                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4304                 iput(journal_inode);
4305                 return NULL;
4306         }
4307         journal->j_private = sb;
4308         ext4_init_journal_params(sb, journal);
4309         return journal;
4310 }
4311
4312 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4313                                        dev_t j_dev)
4314 {
4315         struct buffer_head *bh;
4316         journal_t *journal;
4317         ext4_fsblk_t start;
4318         ext4_fsblk_t len;
4319         int hblock, blocksize;
4320         ext4_fsblk_t sb_block;
4321         unsigned long offset;
4322         struct ext4_super_block *es;
4323         struct block_device *bdev;
4324
4325         BUG_ON(!ext4_has_feature_journal(sb));
4326
4327         bdev = ext4_blkdev_get(j_dev, sb);
4328         if (bdev == NULL)
4329                 return NULL;
4330
4331         blocksize = sb->s_blocksize;
4332         hblock = bdev_logical_block_size(bdev);
4333         if (blocksize < hblock) {
4334                 ext4_msg(sb, KERN_ERR,
4335                         "blocksize too small for journal device");
4336                 goto out_bdev;
4337         }
4338
4339         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4340         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4341         set_blocksize(bdev, blocksize);
4342         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4343                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4344                        "external journal");
4345                 goto out_bdev;
4346         }
4347
4348         es = (struct ext4_super_block *) (bh->b_data + offset);
4349         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4350             !(le32_to_cpu(es->s_feature_incompat) &
4351               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4352                 ext4_msg(sb, KERN_ERR, "external journal has "
4353                                         "bad superblock");
4354                 brelse(bh);
4355                 goto out_bdev;
4356         }
4357
4358         if ((le32_to_cpu(es->s_feature_ro_compat) &
4359              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4360             es->s_checksum != ext4_superblock_csum(sb, es)) {
4361                 ext4_msg(sb, KERN_ERR, "external journal has "
4362                                        "corrupt superblock");
4363                 brelse(bh);
4364                 goto out_bdev;
4365         }
4366
4367         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4368                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4369                 brelse(bh);
4370                 goto out_bdev;
4371         }
4372
4373         len = ext4_blocks_count(es);
4374         start = sb_block + 1;
4375         brelse(bh);     /* we're done with the superblock */
4376
4377         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4378                                         start, len, blocksize);
4379         if (!journal) {
4380                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4381                 goto out_bdev;
4382         }
4383         journal->j_private = sb;
4384         ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4385         wait_on_buffer(journal->j_sb_buffer);
4386         if (!buffer_uptodate(journal->j_sb_buffer)) {
4387                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4388                 goto out_journal;
4389         }
4390         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4391                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4392                                         "user (unsupported) - %d",
4393                         be32_to_cpu(journal->j_superblock->s_nr_users));
4394                 goto out_journal;
4395         }
4396         EXT4_SB(sb)->journal_bdev = bdev;
4397         ext4_init_journal_params(sb, journal);
4398         return journal;
4399
4400 out_journal:
4401         jbd2_journal_destroy(journal);
4402 out_bdev:
4403         ext4_blkdev_put(bdev);
4404         return NULL;
4405 }
4406
4407 static int ext4_load_journal(struct super_block *sb,
4408                              struct ext4_super_block *es,
4409                              unsigned long journal_devnum)
4410 {
4411         journal_t *journal;
4412         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4413         dev_t journal_dev;
4414         int err = 0;
4415         int really_read_only;
4416
4417         BUG_ON(!ext4_has_feature_journal(sb));
4418
4419         if (journal_devnum &&
4420             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4421                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4422                         "numbers have changed");
4423                 journal_dev = new_decode_dev(journal_devnum);
4424         } else
4425                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4426
4427         really_read_only = bdev_read_only(sb->s_bdev);
4428
4429         /*
4430          * Are we loading a blank journal or performing recovery after a
4431          * crash?  For recovery, we need to check in advance whether we
4432          * can get read-write access to the device.
4433          */
4434         if (ext4_has_feature_journal_needs_recovery(sb)) {
4435                 if (sb->s_flags & MS_RDONLY) {
4436                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4437                                         "required on readonly filesystem");
4438                         if (really_read_only) {
4439                                 ext4_msg(sb, KERN_ERR, "write access "
4440                                         "unavailable, cannot proceed");
4441                                 return -EROFS;
4442                         }
4443                         ext4_msg(sb, KERN_INFO, "write access will "
4444                                "be enabled during recovery");
4445                 }
4446         }
4447
4448         if (journal_inum && journal_dev) {
4449                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4450                        "and inode journals!");
4451                 return -EINVAL;
4452         }
4453
4454         if (journal_inum) {
4455                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4456                         return -EINVAL;
4457         } else {
4458                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4459                         return -EINVAL;
4460         }
4461
4462         if (!(journal->j_flags & JBD2_BARRIER))
4463                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4464
4465         if (!ext4_has_feature_journal_needs_recovery(sb))
4466                 err = jbd2_journal_wipe(journal, !really_read_only);
4467         if (!err) {
4468                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4469                 if (save)
4470                         memcpy(save, ((char *) es) +
4471                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4472                 err = jbd2_journal_load(journal);
4473                 if (save)
4474                         memcpy(((char *) es) + EXT4_S_ERR_START,
4475                                save, EXT4_S_ERR_LEN);
4476                 kfree(save);
4477         }
4478
4479         if (err) {
4480                 ext4_msg(sb, KERN_ERR, "error loading journal");
4481                 jbd2_journal_destroy(journal);
4482                 return err;
4483         }
4484
4485         EXT4_SB(sb)->s_journal = journal;
4486         ext4_clear_journal_err(sb, es);
4487
4488         if (!really_read_only && journal_devnum &&
4489             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4490                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4491
4492                 /* Make sure we flush the recovery flag to disk. */
4493                 ext4_commit_super(sb, 1);
4494         }
4495
4496         return 0;
4497 }
4498
4499 static int ext4_commit_super(struct super_block *sb, int sync)
4500 {
4501         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4502         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4503         int error = 0;
4504
4505         if (!sbh || block_device_ejected(sb))
4506                 return error;
4507         /*
4508          * If the file system is mounted read-only, don't update the
4509          * superblock write time.  This avoids updating the superblock
4510          * write time when we are mounting the root file system
4511          * read/only but we need to replay the journal; at that point,
4512          * for people who are east of GMT and who make their clock
4513          * tick in localtime for Windows bug-for-bug compatibility,
4514          * the clock is set in the future, and this will cause e2fsck
4515          * to complain and force a full file system check.
4516          */
4517         if (!(sb->s_flags & MS_RDONLY))
4518                 es->s_wtime = cpu_to_le32(get_seconds());
4519         if (sb->s_bdev->bd_part)
4520                 es->s_kbytes_written =
4521                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4522                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4523                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4524         else
4525                 es->s_kbytes_written =
4526                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4527         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4528                 ext4_free_blocks_count_set(es,
4529                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4530                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4531         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4532                 es->s_free_inodes_count =
4533                         cpu_to_le32(percpu_counter_sum_positive(
4534                                 &EXT4_SB(sb)->s_freeinodes_counter));
4535         BUFFER_TRACE(sbh, "marking dirty");
4536         ext4_superblock_csum_set(sb);
4537         lock_buffer(sbh);
4538         if (buffer_write_io_error(sbh)) {
4539                 /*
4540                  * Oh, dear.  A previous attempt to write the
4541                  * superblock failed.  This could happen because the
4542                  * USB device was yanked out.  Or it could happen to
4543                  * be a transient write error and maybe the block will
4544                  * be remapped.  Nothing we can do but to retry the
4545                  * write and hope for the best.
4546                  */
4547                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4548                        "superblock detected");
4549                 clear_buffer_write_io_error(sbh);
4550                 set_buffer_uptodate(sbh);
4551         }
4552         mark_buffer_dirty(sbh);
4553         unlock_buffer(sbh);
4554         if (sync) {
4555                 error = __sync_dirty_buffer(sbh,
4556                         test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
4557                 if (error)
4558                         return error;
4559
4560                 error = buffer_write_io_error(sbh);
4561                 if (error) {
4562                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4563                                "superblock");
4564                         clear_buffer_write_io_error(sbh);
4565                         set_buffer_uptodate(sbh);
4566                 }
4567         }
4568         return error;
4569 }
4570
4571 /*
4572  * Have we just finished recovery?  If so, and if we are mounting (or
4573  * remounting) the filesystem readonly, then we will end up with a
4574  * consistent fs on disk.  Record that fact.
4575  */
4576 static void ext4_mark_recovery_complete(struct super_block *sb,
4577                                         struct ext4_super_block *es)
4578 {
4579         journal_t *journal = EXT4_SB(sb)->s_journal;
4580
4581         if (!ext4_has_feature_journal(sb)) {
4582                 BUG_ON(journal != NULL);
4583                 return;
4584         }
4585         jbd2_journal_lock_updates(journal);
4586         if (jbd2_journal_flush(journal) < 0)
4587                 goto out;
4588
4589         if (ext4_has_feature_journal_needs_recovery(sb) &&
4590             sb->s_flags & MS_RDONLY) {
4591                 ext4_clear_feature_journal_needs_recovery(sb);
4592                 ext4_commit_super(sb, 1);
4593         }
4594
4595 out:
4596         jbd2_journal_unlock_updates(journal);
4597 }
4598
4599 /*
4600  * If we are mounting (or read-write remounting) a filesystem whose journal
4601  * has recorded an error from a previous lifetime, move that error to the
4602  * main filesystem now.
4603  */
4604 static void ext4_clear_journal_err(struct super_block *sb,
4605                                    struct ext4_super_block *es)
4606 {
4607         journal_t *journal;
4608         int j_errno;
4609         const char *errstr;
4610
4611         BUG_ON(!ext4_has_feature_journal(sb));
4612
4613         journal = EXT4_SB(sb)->s_journal;
4614
4615         /*
4616          * Now check for any error status which may have been recorded in the
4617          * journal by a prior ext4_error() or ext4_abort()
4618          */
4619
4620         j_errno = jbd2_journal_errno(journal);
4621         if (j_errno) {
4622                 char nbuf[16];
4623
4624                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4625                 ext4_warning(sb, "Filesystem error recorded "
4626                              "from previous mount: %s", errstr);
4627                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4628
4629                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4630                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4631                 ext4_commit_super(sb, 1);
4632
4633                 jbd2_journal_clear_err(journal);
4634                 jbd2_journal_update_sb_errno(journal);
4635         }
4636 }
4637
4638 /*
4639  * Force the running and committing transactions to commit,
4640  * and wait on the commit.
4641  */
4642 int ext4_force_commit(struct super_block *sb)
4643 {
4644         journal_t *journal;
4645
4646         if (sb->s_flags & MS_RDONLY)
4647                 return 0;
4648
4649         journal = EXT4_SB(sb)->s_journal;
4650         return ext4_journal_force_commit(journal);
4651 }
4652
4653 static int ext4_sync_fs(struct super_block *sb, int wait)
4654 {
4655         int ret = 0;
4656         tid_t target;
4657         bool needs_barrier = false;
4658         struct ext4_sb_info *sbi = EXT4_SB(sb);
4659
4660         trace_ext4_sync_fs(sb, wait);
4661         flush_workqueue(sbi->rsv_conversion_wq);
4662         /*
4663          * Writeback quota in non-journalled quota case - journalled quota has
4664          * no dirty dquots
4665          */
4666         dquot_writeback_dquots(sb, -1);
4667         /*
4668          * Data writeback is possible w/o journal transaction, so barrier must
4669          * being sent at the end of the function. But we can skip it if
4670          * transaction_commit will do it for us.
4671          */
4672         if (sbi->s_journal) {
4673                 target = jbd2_get_latest_transaction(sbi->s_journal);
4674                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4675                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4676                         needs_barrier = true;
4677
4678                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4679                         if (wait)
4680                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4681                                                            target);
4682                 }
4683         } else if (wait && test_opt(sb, BARRIER))
4684                 needs_barrier = true;
4685         if (needs_barrier) {
4686                 int err;
4687                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4688                 if (!ret)
4689                         ret = err;
4690         }
4691
4692         return ret;
4693 }
4694
4695 /*
4696  * LVM calls this function before a (read-only) snapshot is created.  This
4697  * gives us a chance to flush the journal completely and mark the fs clean.
4698  *
4699  * Note that only this function cannot bring a filesystem to be in a clean
4700  * state independently. It relies on upper layer to stop all data & metadata
4701  * modifications.
4702  */
4703 static int ext4_freeze(struct super_block *sb)
4704 {
4705         int error = 0;
4706         journal_t *journal;
4707
4708         if (sb->s_flags & MS_RDONLY)
4709                 return 0;
4710
4711         journal = EXT4_SB(sb)->s_journal;
4712
4713         if (journal) {
4714                 /* Now we set up the journal barrier. */
4715                 jbd2_journal_lock_updates(journal);
4716
4717                 /*
4718                  * Don't clear the needs_recovery flag if we failed to
4719                  * flush the journal.
4720                  */
4721                 error = jbd2_journal_flush(journal);
4722                 if (error < 0)
4723                         goto out;
4724
4725                 /* Journal blocked and flushed, clear needs_recovery flag. */
4726                 ext4_clear_feature_journal_needs_recovery(sb);
4727         }
4728
4729         error = ext4_commit_super(sb, 1);
4730 out:
4731         if (journal)
4732                 /* we rely on upper layer to stop further updates */
4733                 jbd2_journal_unlock_updates(journal);
4734         return error;
4735 }
4736
4737 /*
4738  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4739  * flag here, even though the filesystem is not technically dirty yet.
4740  */
4741 static int ext4_unfreeze(struct super_block *sb)
4742 {
4743         if (sb->s_flags & MS_RDONLY)
4744                 return 0;
4745
4746         if (EXT4_SB(sb)->s_journal) {
4747                 /* Reset the needs_recovery flag before the fs is unlocked. */
4748                 ext4_set_feature_journal_needs_recovery(sb);
4749         }
4750
4751         ext4_commit_super(sb, 1);
4752         return 0;
4753 }
4754
4755 /*
4756  * Structure to save mount options for ext4_remount's benefit
4757  */
4758 struct ext4_mount_options {
4759         unsigned long s_mount_opt;
4760         unsigned long s_mount_opt2;
4761         kuid_t s_resuid;
4762         kgid_t s_resgid;
4763         unsigned long s_commit_interval;
4764         u32 s_min_batch_time, s_max_batch_time;
4765 #ifdef CONFIG_QUOTA
4766         int s_jquota_fmt;
4767         char *s_qf_names[EXT4_MAXQUOTAS];
4768 #endif
4769 };
4770
4771 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4772 {
4773         struct ext4_super_block *es;
4774         struct ext4_sb_info *sbi = EXT4_SB(sb);
4775         unsigned long old_sb_flags;
4776         struct ext4_mount_options old_opts;
4777         int enable_quota = 0;
4778         ext4_group_t g;
4779         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4780         int err = 0;
4781 #ifdef CONFIG_QUOTA
4782         int i, j;
4783 #endif
4784         char *orig_data = kstrdup(data, GFP_KERNEL);
4785
4786         /* Store the original options */
4787         old_sb_flags = sb->s_flags;
4788         old_opts.s_mount_opt = sbi->s_mount_opt;
4789         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4790         old_opts.s_resuid = sbi->s_resuid;
4791         old_opts.s_resgid = sbi->s_resgid;
4792         old_opts.s_commit_interval = sbi->s_commit_interval;
4793         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4794         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4795 #ifdef CONFIG_QUOTA
4796         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4797         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4798                 if (sbi->s_qf_names[i]) {
4799                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4800                                                          GFP_KERNEL);
4801                         if (!old_opts.s_qf_names[i]) {
4802                                 for (j = 0; j < i; j++)
4803                                         kfree(old_opts.s_qf_names[j]);
4804                                 kfree(orig_data);
4805                                 return -ENOMEM;
4806                         }
4807                 } else
4808                         old_opts.s_qf_names[i] = NULL;
4809 #endif
4810         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4811                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4812
4813         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4814                 err = -EINVAL;
4815                 goto restore_opts;
4816         }
4817
4818         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4819             test_opt(sb, JOURNAL_CHECKSUM)) {
4820                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4821                          "during remount not supported; ignoring");
4822                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4823         }
4824
4825         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4826                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4827                         ext4_msg(sb, KERN_ERR, "can't mount with "
4828                                  "both data=journal and delalloc");
4829                         err = -EINVAL;
4830                         goto restore_opts;
4831                 }
4832                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4833                         ext4_msg(sb, KERN_ERR, "can't mount with "
4834                                  "both data=journal and dioread_nolock");
4835                         err = -EINVAL;
4836                         goto restore_opts;
4837                 }
4838                 if (test_opt(sb, DAX)) {
4839                         ext4_msg(sb, KERN_ERR, "can't mount with "
4840                                  "both data=journal and dax");
4841                         err = -EINVAL;
4842                         goto restore_opts;
4843                 }
4844         }
4845
4846         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4847                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4848                         "dax flag with busy inodes while remounting");
4849                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4850         }
4851
4852         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4853                 ext4_abort(sb, "Abort forced by user");
4854
4855         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4856                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4857
4858         es = sbi->s_es;
4859
4860         if (sbi->s_journal) {
4861                 ext4_init_journal_params(sb, sbi->s_journal);
4862                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4863         }
4864
4865         if (*flags & MS_LAZYTIME)
4866                 sb->s_flags |= MS_LAZYTIME;
4867
4868         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4869                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4870                         err = -EROFS;
4871                         goto restore_opts;
4872                 }
4873
4874                 if (*flags & MS_RDONLY) {
4875                         err = sync_filesystem(sb);
4876                         if (err < 0)
4877                                 goto restore_opts;
4878                         err = dquot_suspend(sb, -1);
4879                         if (err < 0)
4880                                 goto restore_opts;
4881
4882                         /*
4883                          * First of all, the unconditional stuff we have to do
4884                          * to disable replay of the journal when we next remount
4885                          */
4886                         sb->s_flags |= MS_RDONLY;
4887
4888                         /*
4889                          * OK, test if we are remounting a valid rw partition
4890                          * readonly, and if so set the rdonly flag and then
4891                          * mark the partition as valid again.
4892                          */
4893                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4894                             (sbi->s_mount_state & EXT4_VALID_FS))
4895                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4896
4897                         if (sbi->s_journal)
4898                                 ext4_mark_recovery_complete(sb, es);
4899                 } else {
4900                         /* Make sure we can mount this feature set readwrite */
4901                         if (ext4_has_feature_readonly(sb) ||
4902                             !ext4_feature_set_ok(sb, 0)) {
4903                                 err = -EROFS;
4904                                 goto restore_opts;
4905                         }
4906                         /*
4907                          * Make sure the group descriptor checksums
4908                          * are sane.  If they aren't, refuse to remount r/w.
4909                          */
4910                         for (g = 0; g < sbi->s_groups_count; g++) {
4911                                 struct ext4_group_desc *gdp =
4912                                         ext4_get_group_desc(sb, g, NULL);
4913
4914                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4915                                         ext4_msg(sb, KERN_ERR,
4916                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4917                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
4918                                                le16_to_cpu(gdp->bg_checksum));
4919                                         err = -EFSBADCRC;
4920                                         goto restore_opts;
4921                                 }
4922                         }
4923
4924                         /*
4925                          * If we have an unprocessed orphan list hanging
4926                          * around from a previously readonly bdev mount,
4927                          * require a full umount/remount for now.
4928                          */
4929                         if (es->s_last_orphan) {
4930                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4931                                        "remount RDWR because of unprocessed "
4932                                        "orphan inode list.  Please "
4933                                        "umount/remount instead");
4934                                 err = -EINVAL;
4935                                 goto restore_opts;
4936                         }
4937
4938                         /*
4939                          * Mounting a RDONLY partition read-write, so reread
4940                          * and store the current valid flag.  (It may have
4941                          * been changed by e2fsck since we originally mounted
4942                          * the partition.)
4943                          */
4944                         if (sbi->s_journal)
4945                                 ext4_clear_journal_err(sb, es);
4946                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4947                         if (!ext4_setup_super(sb, es, 0))
4948                                 sb->s_flags &= ~MS_RDONLY;
4949                         if (ext4_has_feature_mmp(sb))
4950                                 if (ext4_multi_mount_protect(sb,
4951                                                 le64_to_cpu(es->s_mmp_block))) {
4952                                         err = -EROFS;
4953                                         goto restore_opts;
4954                                 }
4955                         enable_quota = 1;
4956                 }
4957         }
4958
4959         /*
4960          * Reinitialize lazy itable initialization thread based on
4961          * current settings
4962          */
4963         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4964                 ext4_unregister_li_request(sb);
4965         else {
4966                 ext4_group_t first_not_zeroed;
4967                 first_not_zeroed = ext4_has_uninit_itable(sb);
4968                 ext4_register_li_request(sb, first_not_zeroed);
4969         }
4970
4971         ext4_setup_system_zone(sb);
4972         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4973                 ext4_commit_super(sb, 1);
4974
4975 #ifdef CONFIG_QUOTA
4976         /* Release old quota file names */
4977         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4978                 kfree(old_opts.s_qf_names[i]);
4979         if (enable_quota) {
4980                 if (sb_any_quota_suspended(sb))
4981                         dquot_resume(sb, -1);
4982                 else if (ext4_has_feature_quota(sb)) {
4983                         err = ext4_enable_quotas(sb);
4984                         if (err)
4985                                 goto restore_opts;
4986                 }
4987         }
4988 #endif
4989
4990         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
4991         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4992         kfree(orig_data);
4993         return 0;
4994
4995 restore_opts:
4996         sb->s_flags = old_sb_flags;
4997         sbi->s_mount_opt = old_opts.s_mount_opt;
4998         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4999         sbi->s_resuid = old_opts.s_resuid;
5000         sbi->s_resgid = old_opts.s_resgid;
5001         sbi->s_commit_interval = old_opts.s_commit_interval;
5002         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5003         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5004 #ifdef CONFIG_QUOTA
5005         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5006         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5007                 kfree(sbi->s_qf_names[i]);
5008                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5009         }
5010 #endif
5011         kfree(orig_data);
5012         return err;
5013 }
5014
5015 #ifdef CONFIG_QUOTA
5016 static int ext4_statfs_project(struct super_block *sb,
5017                                kprojid_t projid, struct kstatfs *buf)
5018 {
5019         struct kqid qid;
5020         struct dquot *dquot;
5021         u64 limit;
5022         u64 curblock;
5023
5024         qid = make_kqid_projid(projid);
5025         dquot = dqget(sb, qid);
5026         if (IS_ERR(dquot))
5027                 return PTR_ERR(dquot);
5028         spin_lock(&dq_data_lock);
5029
5030         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5031                  dquot->dq_dqb.dqb_bsoftlimit :
5032                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5033         if (limit && buf->f_blocks > limit) {
5034                 curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5035                 buf->f_blocks = limit;
5036                 buf->f_bfree = buf->f_bavail =
5037                         (buf->f_blocks > curblock) ?
5038                          (buf->f_blocks - curblock) : 0;
5039         }
5040
5041         limit = dquot->dq_dqb.dqb_isoftlimit ?
5042                 dquot->dq_dqb.dqb_isoftlimit :
5043                 dquot->dq_dqb.dqb_ihardlimit;
5044         if (limit && buf->f_files > limit) {
5045                 buf->f_files = limit;
5046                 buf->f_ffree =
5047                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5048                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5049         }
5050
5051         spin_unlock(&dq_data_lock);
5052         dqput(dquot);
5053         return 0;
5054 }
5055 #endif
5056
5057 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5058 {
5059         struct super_block *sb = dentry->d_sb;
5060         struct ext4_sb_info *sbi = EXT4_SB(sb);
5061         struct ext4_super_block *es = sbi->s_es;
5062         ext4_fsblk_t overhead = 0, resv_blocks;
5063         u64 fsid;
5064         s64 bfree;
5065         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5066
5067         if (!test_opt(sb, MINIX_DF))
5068                 overhead = sbi->s_overhead;
5069
5070         buf->f_type = EXT4_SUPER_MAGIC;
5071         buf->f_bsize = sb->s_blocksize;
5072         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5073         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5074                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5075         /* prevent underflow in case that few free space is available */
5076         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5077         buf->f_bavail = buf->f_bfree -
5078                         (ext4_r_blocks_count(es) + resv_blocks);
5079         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5080                 buf->f_bavail = 0;
5081         buf->f_files = le32_to_cpu(es->s_inodes_count);
5082         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5083         buf->f_namelen = EXT4_NAME_LEN;
5084         fsid = le64_to_cpup((void *)es->s_uuid) ^
5085                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5086         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5087         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5088
5089 #ifdef CONFIG_QUOTA
5090         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5091             sb_has_quota_limits_enabled(sb, PRJQUOTA))
5092                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5093 #endif
5094         return 0;
5095 }
5096
5097 /* Helper function for writing quotas on sync - we need to start transaction
5098  * before quota file is locked for write. Otherwise the are possible deadlocks:
5099  * Process 1                         Process 2
5100  * ext4_create()                     quota_sync()
5101  *   jbd2_journal_start()                  write_dquot()
5102  *   dquot_initialize()                         down(dqio_mutex)
5103  *     down(dqio_mutex)                    jbd2_journal_start()
5104  *
5105  */
5106
5107 #ifdef CONFIG_QUOTA
5108
5109 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5110 {
5111         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5112 }
5113
5114 static int ext4_write_dquot(struct dquot *dquot)
5115 {
5116         int ret, err;
5117         handle_t *handle;
5118         struct inode *inode;
5119
5120         inode = dquot_to_inode(dquot);
5121         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5122                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5123         if (IS_ERR(handle))
5124                 return PTR_ERR(handle);
5125         ret = dquot_commit(dquot);
5126         err = ext4_journal_stop(handle);
5127         if (!ret)
5128                 ret = err;
5129         return ret;
5130 }
5131
5132 static int ext4_acquire_dquot(struct dquot *dquot)
5133 {
5134         int ret, err;
5135         handle_t *handle;
5136
5137         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5138                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5139         if (IS_ERR(handle))
5140                 return PTR_ERR(handle);
5141         ret = dquot_acquire(dquot);
5142         err = ext4_journal_stop(handle);
5143         if (!ret)
5144                 ret = err;
5145         return ret;
5146 }
5147
5148 static int ext4_release_dquot(struct dquot *dquot)
5149 {
5150         int ret, err;
5151         handle_t *handle;
5152
5153         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5154                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5155         if (IS_ERR(handle)) {
5156                 /* Release dquot anyway to avoid endless cycle in dqput() */
5157                 dquot_release(dquot);
5158                 return PTR_ERR(handle);
5159         }
5160         ret = dquot_release(dquot);
5161         err = ext4_journal_stop(handle);
5162         if (!ret)
5163                 ret = err;
5164         return ret;
5165 }
5166
5167 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5168 {
5169         struct super_block *sb = dquot->dq_sb;
5170         struct ext4_sb_info *sbi = EXT4_SB(sb);
5171
5172         /* Are we journaling quotas? */
5173         if (ext4_has_feature_quota(sb) ||
5174             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5175                 dquot_mark_dquot_dirty(dquot);
5176                 return ext4_write_dquot(dquot);
5177         } else {
5178                 return dquot_mark_dquot_dirty(dquot);
5179         }
5180 }
5181
5182 static int ext4_write_info(struct super_block *sb, int type)
5183 {
5184         int ret, err;
5185         handle_t *handle;
5186
5187         /* Data block + inode block */
5188         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5189         if (IS_ERR(handle))
5190                 return PTR_ERR(handle);
5191         ret = dquot_commit_info(sb, type);
5192         err = ext4_journal_stop(handle);
5193         if (!ret)
5194                 ret = err;
5195         return ret;
5196 }
5197
5198 /*
5199  * Turn on quotas during mount time - we need to find
5200  * the quota file and such...
5201  */
5202 static int ext4_quota_on_mount(struct super_block *sb, int type)
5203 {
5204         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5205                                         EXT4_SB(sb)->s_jquota_fmt, type);
5206 }
5207
5208 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5209 {
5210         struct ext4_inode_info *ei = EXT4_I(inode);
5211
5212         /* The first argument of lockdep_set_subclass has to be
5213          * *exactly* the same as the argument to init_rwsem() --- in
5214          * this case, in init_once() --- or lockdep gets unhappy
5215          * because the name of the lock is set using the
5216          * stringification of the argument to init_rwsem().
5217          */
5218         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5219         lockdep_set_subclass(&ei->i_data_sem, subclass);
5220 }
5221
5222 /*
5223  * Standard function to be called on quota_on
5224  */
5225 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5226                          struct path *path)
5227 {
5228         int err;
5229
5230         if (!test_opt(sb, QUOTA))
5231                 return -EINVAL;
5232
5233         /* Quotafile not on the same filesystem? */
5234         if (path->dentry->d_sb != sb)
5235                 return -EXDEV;
5236         /* Journaling quota? */
5237         if (EXT4_SB(sb)->s_qf_names[type]) {
5238                 /* Quotafile not in fs root? */
5239                 if (path->dentry->d_parent != sb->s_root)
5240                         ext4_msg(sb, KERN_WARNING,
5241                                 "Quota file not on filesystem root. "
5242                                 "Journaled quota will not work");
5243         }
5244
5245         /*
5246          * When we journal data on quota file, we have to flush journal to see
5247          * all updates to the file when we bypass pagecache...
5248          */
5249         if (EXT4_SB(sb)->s_journal &&
5250             ext4_should_journal_data(d_inode(path->dentry))) {
5251                 /*
5252                  * We don't need to lock updates but journal_flush() could
5253                  * otherwise be livelocked...
5254                  */
5255                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5256                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5257                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5258                 if (err)
5259                         return err;
5260         }
5261         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5262         err = dquot_quota_on(sb, type, format_id, path);
5263         if (err)
5264                 lockdep_set_quota_inode(path->dentry->d_inode,
5265                                              I_DATA_SEM_NORMAL);
5266         return err;
5267 }
5268
5269 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5270                              unsigned int flags)
5271 {
5272         int err;
5273         struct inode *qf_inode;
5274         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5275                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5276                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5277                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5278         };
5279
5280         BUG_ON(!ext4_has_feature_quota(sb));
5281
5282         if (!qf_inums[type])
5283                 return -EPERM;
5284
5285         qf_inode = ext4_iget(sb, qf_inums[type]);
5286         if (IS_ERR(qf_inode)) {
5287                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5288                 return PTR_ERR(qf_inode);
5289         }
5290
5291         /* Don't account quota for quota files to avoid recursion */
5292         qf_inode->i_flags |= S_NOQUOTA;
5293         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5294         err = dquot_enable(qf_inode, type, format_id, flags);
5295         iput(qf_inode);
5296         if (err)
5297                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5298
5299         return err;
5300 }
5301
5302 /* Enable usage tracking for all quota types. */
5303 static int ext4_enable_quotas(struct super_block *sb)
5304 {
5305         int type, err = 0;
5306         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5307                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5308                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5309                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5310         };
5311         bool quota_mopt[EXT4_MAXQUOTAS] = {
5312                 test_opt(sb, USRQUOTA),
5313                 test_opt(sb, GRPQUOTA),
5314                 test_opt(sb, PRJQUOTA),
5315         };
5316
5317         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5318         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5319                 if (qf_inums[type]) {
5320                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5321                                 DQUOT_USAGE_ENABLED |
5322                                 (quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5323                         if (err) {
5324                                 ext4_warning(sb,
5325                                         "Failed to enable quota tracking "
5326                                         "(type=%d, err=%d). Please run "
5327                                         "e2fsck to fix.", type, err);
5328                                 return err;
5329                         }
5330                 }
5331         }
5332         return 0;
5333 }
5334
5335 static int ext4_quota_off(struct super_block *sb, int type)
5336 {
5337         struct inode *inode = sb_dqopt(sb)->files[type];
5338         handle_t *handle;
5339
5340         /* Force all delayed allocation blocks to be allocated.
5341          * Caller already holds s_umount sem */
5342         if (test_opt(sb, DELALLOC))
5343                 sync_filesystem(sb);
5344
5345         if (!inode)
5346                 goto out;
5347
5348         /* Update modification times of quota files when userspace can
5349          * start looking at them */
5350         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5351         if (IS_ERR(handle))
5352                 goto out;
5353         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5354         ext4_mark_inode_dirty(handle, inode);
5355         ext4_journal_stop(handle);
5356
5357 out:
5358         return dquot_quota_off(sb, type);
5359 }
5360
5361 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5362  * acquiring the locks... As quota files are never truncated and quota code
5363  * itself serializes the operations (and no one else should touch the files)
5364  * we don't have to be afraid of races */
5365 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5366                                size_t len, loff_t off)
5367 {
5368         struct inode *inode = sb_dqopt(sb)->files[type];
5369         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5370         int offset = off & (sb->s_blocksize - 1);
5371         int tocopy;
5372         size_t toread;
5373         struct buffer_head *bh;
5374         loff_t i_size = i_size_read(inode);
5375
5376         if (off > i_size)
5377                 return 0;
5378         if (off+len > i_size)
5379                 len = i_size-off;
5380         toread = len;
5381         while (toread > 0) {
5382                 tocopy = sb->s_blocksize - offset < toread ?
5383                                 sb->s_blocksize - offset : toread;
5384                 bh = ext4_bread(NULL, inode, blk, 0);
5385                 if (IS_ERR(bh))
5386                         return PTR_ERR(bh);
5387                 if (!bh)        /* A hole? */
5388                         memset(data, 0, tocopy);
5389                 else
5390                         memcpy(data, bh->b_data+offset, tocopy);
5391                 brelse(bh);
5392                 offset = 0;
5393                 toread -= tocopy;
5394                 data += tocopy;
5395                 blk++;
5396         }
5397         return len;
5398 }
5399
5400 /* Write to quotafile (we know the transaction is already started and has
5401  * enough credits) */
5402 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5403                                 const char *data, size_t len, loff_t off)
5404 {
5405         struct inode *inode = sb_dqopt(sb)->files[type];
5406         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5407         int err, offset = off & (sb->s_blocksize - 1);
5408         int retries = 0;
5409         struct buffer_head *bh;
5410         handle_t *handle = journal_current_handle();
5411
5412         if (EXT4_SB(sb)->s_journal && !handle) {
5413                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5414                         " cancelled because transaction is not started",
5415                         (unsigned long long)off, (unsigned long long)len);
5416                 return -EIO;
5417         }
5418         /*
5419          * Since we account only one data block in transaction credits,
5420          * then it is impossible to cross a block boundary.
5421          */
5422         if (sb->s_blocksize - offset < len) {
5423                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5424                         " cancelled because not block aligned",
5425                         (unsigned long long)off, (unsigned long long)len);
5426                 return -EIO;
5427         }
5428
5429         do {
5430                 bh = ext4_bread(handle, inode, blk,
5431                                 EXT4_GET_BLOCKS_CREATE |
5432                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5433         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5434                  ext4_should_retry_alloc(inode->i_sb, &retries));
5435         if (IS_ERR(bh))
5436                 return PTR_ERR(bh);
5437         if (!bh)
5438                 goto out;
5439         BUFFER_TRACE(bh, "get write access");
5440         err = ext4_journal_get_write_access(handle, bh);
5441         if (err) {
5442                 brelse(bh);
5443                 return err;
5444         }
5445         lock_buffer(bh);
5446         memcpy(bh->b_data+offset, data, len);
5447         flush_dcache_page(bh->b_page);
5448         unlock_buffer(bh);
5449         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5450         brelse(bh);
5451 out:
5452         if (inode->i_size < off + len) {
5453                 i_size_write(inode, off + len);
5454                 EXT4_I(inode)->i_disksize = inode->i_size;
5455                 ext4_mark_inode_dirty(handle, inode);
5456         }
5457         return len;
5458 }
5459
5460 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5461 {
5462         const struct quota_format_ops   *ops;
5463
5464         if (!sb_has_quota_loaded(sb, qid->type))
5465                 return -ESRCH;
5466         ops = sb_dqopt(sb)->ops[qid->type];
5467         if (!ops || !ops->get_next_id)
5468                 return -ENOSYS;
5469         return dquot_get_next_id(sb, qid);
5470 }
5471 #endif
5472
5473 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5474                        const char *dev_name, void *data)
5475 {
5476         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5477 }
5478
5479 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5480 static inline void register_as_ext2(void)
5481 {
5482         int err = register_filesystem(&ext2_fs_type);
5483         if (err)
5484                 printk(KERN_WARNING
5485                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5486 }
5487
5488 static inline void unregister_as_ext2(void)
5489 {
5490         unregister_filesystem(&ext2_fs_type);
5491 }
5492
5493 static inline int ext2_feature_set_ok(struct super_block *sb)
5494 {
5495         if (ext4_has_unknown_ext2_incompat_features(sb))
5496                 return 0;
5497         if (sb->s_flags & MS_RDONLY)
5498                 return 1;
5499         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5500                 return 0;
5501         return 1;
5502 }
5503 #else
5504 static inline void register_as_ext2(void) { }
5505 static inline void unregister_as_ext2(void) { }
5506 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5507 #endif
5508
5509 static inline void register_as_ext3(void)
5510 {
5511         int err = register_filesystem(&ext3_fs_type);
5512         if (err)
5513                 printk(KERN_WARNING
5514                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5515 }
5516
5517 static inline void unregister_as_ext3(void)
5518 {
5519         unregister_filesystem(&ext3_fs_type);
5520 }
5521
5522 static inline int ext3_feature_set_ok(struct super_block *sb)
5523 {
5524         if (ext4_has_unknown_ext3_incompat_features(sb))
5525                 return 0;
5526         if (!ext4_has_feature_journal(sb))
5527                 return 0;
5528         if (sb->s_flags & MS_RDONLY)
5529                 return 1;
5530         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5531                 return 0;
5532         return 1;
5533 }
5534
5535 static struct file_system_type ext4_fs_type = {
5536         .owner          = THIS_MODULE,
5537         .name           = "ext4",
5538         .mount          = ext4_mount,
5539         .kill_sb        = kill_block_super,
5540         .fs_flags       = FS_REQUIRES_DEV,
5541 };
5542 MODULE_ALIAS_FS("ext4");
5543
5544 /* Shared across all ext4 file systems */
5545 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5546
5547 static int __init ext4_init_fs(void)
5548 {
5549         int i, err;
5550
5551         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5552         ext4_li_info = NULL;
5553         mutex_init(&ext4_li_mtx);
5554
5555         /* Build-time check for flags consistency */
5556         ext4_check_flag_values();
5557
5558         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5559                 init_waitqueue_head(&ext4__ioend_wq[i]);
5560
5561         err = ext4_init_es();
5562         if (err)
5563                 return err;
5564
5565         err = ext4_init_pageio();
5566         if (err)
5567                 goto out5;
5568
5569         err = ext4_init_system_zone();
5570         if (err)
5571                 goto out4;
5572
5573         err = ext4_init_sysfs();
5574         if (err)
5575                 goto out3;
5576
5577         err = ext4_init_mballoc();
5578         if (err)
5579                 goto out2;
5580         err = init_inodecache();
5581         if (err)
5582                 goto out1;
5583         register_as_ext3();
5584         register_as_ext2();
5585         err = register_filesystem(&ext4_fs_type);
5586         if (err)
5587                 goto out;
5588
5589         return 0;
5590 out:
5591         unregister_as_ext2();
5592         unregister_as_ext3();
5593         destroy_inodecache();
5594 out1:
5595         ext4_exit_mballoc();
5596 out2:
5597         ext4_exit_sysfs();
5598 out3:
5599         ext4_exit_system_zone();
5600 out4:
5601         ext4_exit_pageio();
5602 out5:
5603         ext4_exit_es();
5604
5605         return err;
5606 }
5607
5608 static void __exit ext4_exit_fs(void)
5609 {
5610         ext4_destroy_lazyinit_thread();
5611         unregister_as_ext2();
5612         unregister_as_ext3();
5613         unregister_filesystem(&ext4_fs_type);
5614         destroy_inodecache();
5615         ext4_exit_mballoc();
5616         ext4_exit_sysfs();
5617         ext4_exit_system_zone();
5618         ext4_exit_pageio();
5619         ext4_exit_es();
5620 }
5621
5622 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5623 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5624 MODULE_LICENSE("GPL");
5625 module_init(ext4_init_fs)
5626 module_exit(ext4_exit_fs)