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         struct va_format vaf;
 601         va_list args;
 602
 603         save_error_info(sb, function, line);
 604         va_start(args, fmt);
 605         vaf.fmt = fmt;
 606         vaf.va = &args;
 607         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
 608                sb->s_id, function, line, &vaf);
 609         va_end(args);
 610
 611         if ((sb->s_flags & MS_RDONLY) == 0) {
 612                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 613                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 614                 /*
 615                  * Make sure updated value of ->s_mount_flags will be visible
 616                  * before ->s_flags update
 617                  */
 618                 smp_wmb();
 619                 sb->s_flags |= MS_RDONLY;
 620                 if (EXT4_SB(sb)->s_journal)
 621                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 622                 save_error_info(sb, function, line);
 623         }
 624         if (test_opt(sb, ERRORS_PANIC)) {
 625                 if (EXT4_SB(sb)->s_journal &&
 626                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 627                         return;
 628                 panic("EXT4-fs panic from previous error\n");
 629         }
 630 }
 631
 632 void __ext4_msg(struct super_block *sb,
 633                 const char *prefix, const char *fmt, ...)
 634 {
 635         struct va_format vaf;
 636         va_list args;
 637
 638         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 639                 return;
 640
 641         va_start(args, fmt);
 642         vaf.fmt = fmt;
 643         vaf.va = &args;
 644         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 645         va_end(args);
 646 }
 647
 648 #define ext4_warning_ratelimit(sb)                                      \
 649                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 650                              "EXT4-fs warning")
 651
 652 void __ext4_warning(struct super_block *sb, const char *function,
 653                     unsigned int line, const char *fmt, ...)
 654 {
 655         struct va_format vaf;
 656         va_list args;
 657
 658         if (!ext4_warning_ratelimit(sb))
 659                 return;
 660
 661         va_start(args, fmt);
 662         vaf.fmt = fmt;
 663         vaf.va = &args;
 664         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 665                sb->s_id, function, line, &vaf);
 666         va_end(args);
 667 }
 668
 669 void __ext4_warning_inode(const struct inode *inode, const char *function,
 670                           unsigned int line, const char *fmt, ...)
 671 {
 672         struct va_format vaf;
 673         va_list args;
 674
 675         if (!ext4_warning_ratelimit(inode->i_sb))
 676                 return;
 677
 678         va_start(args, fmt);
 679         vaf.fmt = fmt;
 680         vaf.va = &args;
 681         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 682                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 683                function, line, inode->i_ino, current->comm, &vaf);
 684         va_end(args);
 685 }
 686
 687 void __ext4_grp_locked_error(const char *function, unsigned int line,
 688                              struct super_block *sb, ext4_group_t grp,
 689                              unsigned long ino, ext4_fsblk_t block,
 690                              const char *fmt, ...)
 691 __releases(bitlock)
 692 __acquires(bitlock)
 693 {
 694         struct va_format vaf;
 695         va_list args;
 696         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 697
 698         es->s_last_error_ino = cpu_to_le32(ino);
 699         es->s_last_error_block = cpu_to_le64(block);
 700         __save_error_info(sb, function, line);
 701
 702         if (ext4_error_ratelimit(sb)) {
 703                 va_start(args, fmt);
 704                 vaf.fmt = fmt;
 705                 vaf.va = &args;
 706                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 707                        sb->s_id, function, line, grp);
 708                 if (ino)
 709                         printk(KERN_CONT "inode %lu: ", ino);
 710                 if (block)
 711                         printk(KERN_CONT "block %llu:",
 712                                (unsigned long long) block);
 713                 printk(KERN_CONT "%pV\n", &vaf);
 714                 va_end(args);
 715         }
 716
 717         if (test_opt(sb, ERRORS_CONT)) {
 718                 ext4_commit_super(sb, 0);
 719                 return;
 720         }
 721
 722         ext4_unlock_group(sb, grp);
 723         ext4_handle_error(sb);
 724         /*
 725          * We only get here in the ERRORS_RO case; relocking the group
 726          * may be dangerous, but nothing bad will happen since the
 727          * filesystem will have already been marked read/only and the
 728          * journal has been aborted.  We return 1 as a hint to callers
 729          * who might what to use the return value from
 730          * ext4_grp_locked_error() to distinguish between the
 731          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 732          * aggressively from the ext4 function in question, with a
 733          * more appropriate error code.
 734          */
 735         ext4_lock_group(sb, grp);
 736         return;
 737 }
 738
 739 void ext4_update_dynamic_rev(struct super_block *sb)
 740 {
 741         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 742
 743         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 744                 return;
 745
 746         ext4_warning(sb,
 747                      "updating to rev %d because of new feature flag, "
 748                      "running e2fsck is recommended",
 749                      EXT4_DYNAMIC_REV);
 750
 751         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 752         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 753         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 754         /* leave es->s_feature_*compat flags alone */
 755         /* es->s_uuid will be set by e2fsck if empty */
 756
 757         /*
 758          * The rest of the superblock fields should be zero, and if not it
 759          * means they are likely already in use, so leave them alone.  We
 760          * can leave it up to e2fsck to clean up any inconsistencies there.
 761          */
 762 }
 763
 764 /*
 765  * Open the external journal device
 766  */
 767 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 768 {
 769         struct block_device *bdev;
 770         char b[BDEVNAME_SIZE];
 771
 772         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 773         if (IS_ERR(bdev))
 774                 goto fail;
 775         return bdev;
 776
 777 fail:
 778         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 779                         __bdevname(dev, b), PTR_ERR(bdev));
 780         return NULL;
 781 }
 782
 783 /*
 784  * Release the journal device
 785  */
 786 static void ext4_blkdev_put(struct block_device *bdev)
 787 {
 788         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 789 }
 790
 791 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 792 {
 793         struct block_device *bdev;
 794         bdev = sbi->journal_bdev;
 795         if (bdev) {
 796                 ext4_blkdev_put(bdev);
 797                 sbi->journal_bdev = NULL;
 798         }
 799 }
 800
 801 static inline struct inode *orphan_list_entry(struct list_head *l)
 802 {
 803         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 804 }
 805
 806 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 807 {
 808         struct list_head *l;
 809
 810         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 811                  le32_to_cpu(sbi->s_es->s_last_orphan));
 812
 813         printk(KERN_ERR "sb_info orphan list:\n");
 814         list_for_each(l, &sbi->s_orphan) {
 815                 struct inode *inode = orphan_list_entry(l);
 816                 printk(KERN_ERR "  "
 817                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 818                        inode->i_sb->s_id, inode->i_ino, inode,
 819                        inode->i_mode, inode->i_nlink,
 820                        NEXT_ORPHAN(inode));
 821         }
 822 }
 823
 824 static void ext4_put_super(struct super_block *sb)
 825 {
 826         struct ext4_sb_info *sbi = EXT4_SB(sb);
 827         struct ext4_super_block *es = sbi->s_es;
 828         int i, err;
 829
 830         ext4_unregister_li_request(sb);
 831         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 832
 833         flush_workqueue(sbi->rsv_conversion_wq);
 834         destroy_workqueue(sbi->rsv_conversion_wq);
 835
 836         if (sbi->s_journal) {
 837                 err = jbd2_journal_destroy(sbi->s_journal);
 838                 sbi->s_journal = NULL;
 839                 if (err < 0)
 840                         ext4_abort(sb, "Couldn't clean up the journal");
 841         }
 842
 843         ext4_unregister_sysfs(sb);
 844         ext4_es_unregister_shrinker(sbi);
 845         del_timer_sync(&sbi->s_err_report);
 846         ext4_release_system_zone(sb);
 847         ext4_mb_release(sb);
 848         ext4_ext_release(sb);
 849
 850         if (!(sb->s_flags & MS_RDONLY)) {
 851                 ext4_clear_feature_journal_needs_recovery(sb);
 852                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 853         }
 854         if (!(sb->s_flags & MS_RDONLY))
 855                 ext4_commit_super(sb, 1);
 856
 857         for (i = 0; i < sbi->s_gdb_count; i++)
 858                 brelse(sbi->s_group_desc[i]);
 859         kvfree(sbi->s_group_desc);
 860         kvfree(sbi->s_flex_groups);
 861         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 862         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 863         percpu_counter_destroy(&sbi->s_dirs_counter);
 864         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 865         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
 866         brelse(sbi->s_sbh);
 867 #ifdef CONFIG_QUOTA
 868         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 869                 kfree(sbi->s_qf_names[i]);
 870 #endif
 871
 872         /* Debugging code just in case the in-memory inode orphan list
 873          * isn't empty.  The on-disk one can be non-empty if we've
 874          * detected an error and taken the fs readonly, but the
 875          * in-memory list had better be clean by this point. */
 876         if (!list_empty(&sbi->s_orphan))
 877                 dump_orphan_list(sb, sbi);
 878         J_ASSERT(list_empty(&sbi->s_orphan));
 879
 880         sync_blockdev(sb->s_bdev);
 881         invalidate_bdev(sb->s_bdev);
 882         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 883                 /*
 884                  * Invalidate the journal device's buffers.  We don't want them
 885                  * floating about in memory - the physical journal device may
 886                  * hotswapped, and it breaks the `ro-after' testing code.
 887                  */
 888                 sync_blockdev(sbi->journal_bdev);
 889                 invalidate_bdev(sbi->journal_bdev);
 890                 ext4_blkdev_remove(sbi);
 891         }
 892         if (sbi->s_mb_cache) {
 893                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 894                 sbi->s_mb_cache = NULL;
 895         }
 896         if (sbi->s_mmp_tsk)
 897                 kthread_stop(sbi->s_mmp_tsk);
 898         sb->s_fs_info = NULL;
 899         /*
 900          * Now that we are completely done shutting down the
 901          * superblock, we need to actually destroy the kobject.
 902          */
 903         kobject_put(&sbi->s_kobj);
 904         wait_for_completion(&sbi->s_kobj_unregister);
 905         if (sbi->s_chksum_driver)
 906                 crypto_free_shash(sbi->s_chksum_driver);
 907         kfree(sbi->s_blockgroup_lock);
 908         kfree(sbi);
 909 }
 910
 911 static struct kmem_cache *ext4_inode_cachep;
 912
 913 /*
 914  * Called inside transaction, so use GFP_NOFS
 915  */
 916 static struct inode *ext4_alloc_inode(struct super_block *sb)
 917 {
 918         struct ext4_inode_info *ei;
 919
 920         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 921         if (!ei)
 922                 return NULL;
 923
 924         ei->vfs_inode.i_version = 1;
 925         spin_lock_init(&ei->i_raw_lock);
 926         INIT_LIST_HEAD(&ei->i_prealloc_list);
 927         spin_lock_init(&ei->i_prealloc_lock);
 928         ext4_es_init_tree(&ei->i_es_tree);
 929         rwlock_init(&ei->i_es_lock);
 930         INIT_LIST_HEAD(&ei->i_es_list);
 931         ei->i_es_all_nr = 0;
 932         ei->i_es_shk_nr = 0;
 933         ei->i_es_shrink_lblk = 0;
 934         ei->i_reserved_data_blocks = 0;
 935         ei->i_reserved_meta_blocks = 0;
 936         ei->i_allocated_meta_blocks = 0;
 937         ei->i_da_metadata_calc_len = 0;
 938         ei->i_da_metadata_calc_last_lblock = 0;
 939         spin_lock_init(&(ei->i_block_reservation_lock));
 940 #ifdef CONFIG_QUOTA
 941         ei->i_reserved_quota = 0;
 942         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 943 #endif
 944         ei->jinode = NULL;
 945         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 946         spin_lock_init(&ei->i_completed_io_lock);
 947         ei->i_sync_tid = 0;
 948         ei->i_datasync_tid = 0;
 949         atomic_set(&ei->i_unwritten, 0);
 950         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 951         return &ei->vfs_inode;
 952 }
 953
 954 static int ext4_drop_inode(struct inode *inode)
 955 {
 956         int drop = generic_drop_inode(inode);
 957
 958         trace_ext4_drop_inode(inode, drop);
 959         return drop;
 960 }
 961
 962 static void ext4_i_callback(struct rcu_head *head)
 963 {
 964         struct inode *inode = container_of(head, struct inode, i_rcu);
 965         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 966 }
 967
 968 static void ext4_destroy_inode(struct inode *inode)
 969 {
 970         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 971                 ext4_msg(inode->i_sb, KERN_ERR,
 972                          "Inode %lu (%p): orphan list check failed!",
 973                          inode->i_ino, EXT4_I(inode));
 974                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 975                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 976                                 true);
 977                 dump_stack();
 978         }
 979         call_rcu(&inode->i_rcu, ext4_i_callback);
 980 }
 981
 982 static void init_once(void *foo)
 983 {
 984         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 985
 986         INIT_LIST_HEAD(&ei->i_orphan);
 987         init_rwsem(&ei->xattr_sem);
 988         init_rwsem(&ei->i_data_sem);
 989         init_rwsem(&ei->i_mmap_sem);
 990         inode_init_once(&ei->vfs_inode);
 991 }
 992
 993 static int __init init_inodecache(void)
 994 {
 995         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 996                                              sizeof(struct ext4_inode_info),
 997                                              0, (SLAB_RECLAIM_ACCOUNT|
 998                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 999                                              init_once);
1000         if (ext4_inode_cachep == NULL)
1001                 return -ENOMEM;
1002         return 0;
1003 }
1004
1005 static void destroy_inodecache(void)
1006 {
1007         /*
1008          * Make sure all delayed rcu free inodes are flushed before we
1009          * destroy cache.
1010          */
1011         rcu_barrier();
1012         kmem_cache_destroy(ext4_inode_cachep);
1013 }
1014
1015 void ext4_clear_inode(struct inode *inode)
1016 {
1017         invalidate_inode_buffers(inode);
1018         clear_inode(inode);
1019         dquot_drop(inode);
1020         ext4_discard_preallocations(inode);
1021         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1022         if (EXT4_I(inode)->jinode) {
1023                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1024                                                EXT4_I(inode)->jinode);
1025                 jbd2_free_inode(EXT4_I(inode)->jinode);
1026                 EXT4_I(inode)->jinode = NULL;
1027         }
1028 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1029         fscrypt_put_encryption_info(inode, NULL);
1030 #endif
1031 }
1032
1033 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1034                                         u64 ino, u32 generation)
1035 {
1036         struct inode *inode;
1037
1038         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1039                 return ERR_PTR(-ESTALE);
1040         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1041                 return ERR_PTR(-ESTALE);
1042
1043         /* iget isn't really right if the inode is currently unallocated!!
1044          *
1045          * ext4_read_inode will return a bad_inode if the inode had been
1046          * deleted, so we should be safe.
1047          *
1048          * Currently we don't know the generation for parent directory, so
1049          * a generation of 0 means "accept any"
1050          */
1051         inode = ext4_iget_normal(sb, ino);
1052         if (IS_ERR(inode))
1053                 return ERR_CAST(inode);
1054         if (generation && inode->i_generation != generation) {
1055                 iput(inode);
1056                 return ERR_PTR(-ESTALE);
1057         }
1058
1059         return inode;
1060 }
1061
1062 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1063                                         int fh_len, int fh_type)
1064 {
1065         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1066                                     ext4_nfs_get_inode);
1067 }
1068
1069 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1070                                         int fh_len, int fh_type)
1071 {
1072         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1073                                     ext4_nfs_get_inode);
1074 }
1075
1076 /*
1077  * Try to release metadata pages (indirect blocks, directories) which are
1078  * mapped via the block device.  Since these pages could have journal heads
1079  * which would prevent try_to_free_buffers() from freeing them, we must use
1080  * jbd2 layer's try_to_free_buffers() function to release them.
1081  */
1082 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1083                                  gfp_t wait)
1084 {
1085         journal_t *journal = EXT4_SB(sb)->s_journal;
1086
1087         WARN_ON(PageChecked(page));
1088         if (!page_has_buffers(page))
1089                 return 0;
1090         if (journal)
1091                 return jbd2_journal_try_to_free_buffers(journal, page,
1092                                                 wait & ~__GFP_DIRECT_RECLAIM);
1093         return try_to_free_buffers(page);
1094 }
1095
1096 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1097 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1098 {
1099         return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1100                                  EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1101 }
1102
1103 static int ext4_key_prefix(struct inode *inode, u8 **key)
1104 {
1105         *key = EXT4_SB(inode->i_sb)->key_prefix;
1106         return EXT4_SB(inode->i_sb)->key_prefix_size;
1107 }
1108
1109 static int ext4_prepare_context(struct inode *inode)
1110 {
1111         return ext4_convert_inline_data(inode);
1112 }
1113
1114 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1115                                                         void *fs_data)
1116 {
1117         handle_t *handle;
1118         int res, res2;
1119
1120         /* fs_data is null when internally used. */
1121         if (fs_data) {
1122                 res  = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1123                                 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx,
1124                                 len, 0);
1125                 if (!res) {
1126                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1127                         ext4_clear_inode_state(inode,
1128                                         EXT4_STATE_MAY_INLINE_DATA);
1129                 }
1130                 return res;
1131         }
1132
1133         handle = ext4_journal_start(inode, EXT4_HT_MISC,
1134                         ext4_jbd2_credits_xattr(inode));
1135         if (IS_ERR(handle))
1136                 return PTR_ERR(handle);
1137
1138         res = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1139                         EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx,
1140                         len, 0);
1141         if (!res) {
1142                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1143                 res = ext4_mark_inode_dirty(handle, inode);
1144                 if (res)
1145                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1146         }
1147         res2 = ext4_journal_stop(handle);
1148         if (!res)
1149                 res = res2;
1150         return res;
1151 }
1152
1153 static int ext4_dummy_context(struct inode *inode)
1154 {
1155         return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1156 }
1157
1158 static unsigned ext4_max_namelen(struct inode *inode)
1159 {
1160         return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1161                 EXT4_NAME_LEN;
1162 }
1163
1164 static struct fscrypt_operations ext4_cryptops = {
1165         .get_context            = ext4_get_context,
1166         .key_prefix             = ext4_key_prefix,
1167         .prepare_context        = ext4_prepare_context,
1168         .set_context            = ext4_set_context,
1169         .dummy_context          = ext4_dummy_context,
1170         .is_encrypted           = ext4_encrypted_inode,
1171         .empty_dir              = ext4_empty_dir,
1172         .max_namelen            = ext4_max_namelen,
1173 };
1174 #else
1175 static struct fscrypt_operations ext4_cryptops = {
1176         .is_encrypted           = ext4_encrypted_inode,
1177 };
1178 #endif
1179
1180 #ifdef CONFIG_QUOTA
1181 static char *quotatypes[] = INITQFNAMES;
1182 #define QTYPE2NAME(t) (quotatypes[t])
1183
1184 static int ext4_write_dquot(struct dquot *dquot);
1185 static int ext4_acquire_dquot(struct dquot *dquot);
1186 static int ext4_release_dquot(struct dquot *dquot);
1187 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1188 static int ext4_write_info(struct super_block *sb, int type);
1189 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1190                          struct path *path);
1191 static int ext4_quota_off(struct super_block *sb, int type);
1192 static int ext4_quota_on_mount(struct super_block *sb, int type);
1193 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1194                                size_t len, loff_t off);
1195 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1196                                 const char *data, size_t len, loff_t off);
1197 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1198                              unsigned int flags);
1199 static int ext4_enable_quotas(struct super_block *sb);
1200 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1201
1202 static struct dquot **ext4_get_dquots(struct inode *inode)
1203 {
1204         return EXT4_I(inode)->i_dquot;
1205 }
1206
1207 static const struct dquot_operations ext4_quota_operations = {
1208         .get_reserved_space = ext4_get_reserved_space,
1209         .write_dquot    = ext4_write_dquot,
1210         .acquire_dquot  = ext4_acquire_dquot,
1211         .release_dquot  = ext4_release_dquot,
1212         .mark_dirty     = ext4_mark_dquot_dirty,
1213         .write_info     = ext4_write_info,
1214         .alloc_dquot    = dquot_alloc,
1215         .destroy_dquot  = dquot_destroy,
1216         .get_projid     = ext4_get_projid,
1217         .get_next_id    = ext4_get_next_id,
1218 };
1219
1220 static const struct quotactl_ops ext4_qctl_operations = {
1221         .quota_on       = ext4_quota_on,
1222         .quota_off      = ext4_quota_off,
1223         .quota_sync     = dquot_quota_sync,
1224         .get_state      = dquot_get_state,
1225         .set_info       = dquot_set_dqinfo,
1226         .get_dqblk      = dquot_get_dqblk,
1227         .set_dqblk      = dquot_set_dqblk,
1228         .get_nextdqblk  = dquot_get_next_dqblk,
1229 };
1230 #endif
1231
1232 static const struct super_operations ext4_sops = {
1233         .alloc_inode    = ext4_alloc_inode,
1234         .destroy_inode  = ext4_destroy_inode,
1235         .write_inode    = ext4_write_inode,
1236         .dirty_inode    = ext4_dirty_inode,
1237         .drop_inode     = ext4_drop_inode,
1238         .evict_inode    = ext4_evict_inode,
1239         .put_super      = ext4_put_super,
1240         .sync_fs        = ext4_sync_fs,
1241         .freeze_fs      = ext4_freeze,
1242         .unfreeze_fs    = ext4_unfreeze,
1243         .statfs         = ext4_statfs,
1244         .remount_fs     = ext4_remount,
1245         .show_options   = ext4_show_options,
1246 #ifdef CONFIG_QUOTA
1247         .quota_read     = ext4_quota_read,
1248         .quota_write    = ext4_quota_write,
1249         .get_dquots     = ext4_get_dquots,
1250 #endif
1251         .bdev_try_to_free_page = bdev_try_to_free_page,
1252 };
1253
1254 static const struct export_operations ext4_export_ops = {
1255         .fh_to_dentry = ext4_fh_to_dentry,
1256         .fh_to_parent = ext4_fh_to_parent,
1257         .get_parent = ext4_get_parent,
1258 };
1259
1260 enum {
1261         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1262         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1263         Opt_nouid32, Opt_debug, Opt_removed,
1264         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1265         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1266         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1267         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1268         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1269         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1270         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1271         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1272         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1273         Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1274         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1275         Opt_lazytime, Opt_nolazytime,
1276         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1277         Opt_inode_readahead_blks, Opt_journal_ioprio,
1278         Opt_dioread_nolock, Opt_dioread_lock,
1279         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1280         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1281 };
1282
1283 static const match_table_t tokens = {
1284         {Opt_bsd_df, "bsddf"},
1285         {Opt_minix_df, "minixdf"},
1286         {Opt_grpid, "grpid"},
1287         {Opt_grpid, "bsdgroups"},
1288         {Opt_nogrpid, "nogrpid"},
1289         {Opt_nogrpid, "sysvgroups"},
1290         {Opt_resgid, "resgid=%u"},
1291         {Opt_resuid, "resuid=%u"},
1292         {Opt_sb, "sb=%u"},
1293         {Opt_err_cont, "errors=continue"},
1294         {Opt_err_panic, "errors=panic"},
1295         {Opt_err_ro, "errors=remount-ro"},
1296         {Opt_nouid32, "nouid32"},
1297         {Opt_debug, "debug"},
1298         {Opt_removed, "oldalloc"},
1299         {Opt_removed, "orlov"},
1300         {Opt_user_xattr, "user_xattr"},
1301         {Opt_nouser_xattr, "nouser_xattr"},
1302         {Opt_acl, "acl"},
1303         {Opt_noacl, "noacl"},
1304         {Opt_noload, "norecovery"},
1305         {Opt_noload, "noload"},
1306         {Opt_removed, "nobh"},
1307         {Opt_removed, "bh"},
1308         {Opt_commit, "commit=%u"},
1309         {Opt_min_batch_time, "min_batch_time=%u"},
1310         {Opt_max_batch_time, "max_batch_time=%u"},
1311         {Opt_journal_dev, "journal_dev=%u"},
1312         {Opt_journal_path, "journal_path=%s"},
1313         {Opt_journal_checksum, "journal_checksum"},
1314         {Opt_nojournal_checksum, "nojournal_checksum"},
1315         {Opt_journal_async_commit, "journal_async_commit"},
1316         {Opt_abort, "abort"},
1317         {Opt_data_journal, "data=journal"},
1318         {Opt_data_ordered, "data=ordered"},
1319         {Opt_data_writeback, "data=writeback"},
1320         {Opt_data_err_abort, "data_err=abort"},
1321         {Opt_data_err_ignore, "data_err=ignore"},
1322         {Opt_offusrjquota, "usrjquota="},
1323         {Opt_usrjquota, "usrjquota=%s"},
1324         {Opt_offgrpjquota, "grpjquota="},
1325         {Opt_grpjquota, "grpjquota=%s"},
1326         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1327         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1328         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1329         {Opt_grpquota, "grpquota"},
1330         {Opt_noquota, "noquota"},
1331         {Opt_quota, "quota"},
1332         {Opt_usrquota, "usrquota"},
1333         {Opt_prjquota, "prjquota"},
1334         {Opt_barrier, "barrier=%u"},
1335         {Opt_barrier, "barrier"},
1336         {Opt_nobarrier, "nobarrier"},
1337         {Opt_i_version, "i_version"},
1338         {Opt_dax, "dax"},
1339         {Opt_stripe, "stripe=%u"},
1340         {Opt_delalloc, "delalloc"},
1341         {Opt_lazytime, "lazytime"},
1342         {Opt_nolazytime, "nolazytime"},
1343         {Opt_nodelalloc, "nodelalloc"},
1344         {Opt_removed, "mblk_io_submit"},
1345         {Opt_removed, "nomblk_io_submit"},
1346         {Opt_block_validity, "block_validity"},
1347         {Opt_noblock_validity, "noblock_validity"},
1348         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1349         {Opt_journal_ioprio, "journal_ioprio=%u"},
1350         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1351         {Opt_auto_da_alloc, "auto_da_alloc"},
1352         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1353         {Opt_dioread_nolock, "dioread_nolock"},
1354         {Opt_dioread_lock, "dioread_lock"},
1355         {Opt_discard, "discard"},
1356         {Opt_nodiscard, "nodiscard"},
1357         {Opt_init_itable, "init_itable=%u"},
1358         {Opt_init_itable, "init_itable"},
1359         {Opt_noinit_itable, "noinit_itable"},
1360         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1361         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1362         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1363         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1364         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1365         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1366         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1367         {Opt_err, NULL},
1368 };
1369
1370 static ext4_fsblk_t get_sb_block(void **data)
1371 {
1372         ext4_fsblk_t    sb_block;
1373         char            *options = (char *) *data;
1374
1375         if (!options || strncmp(options, "sb=", 3) != 0)
1376                 return 1;       /* Default location */
1377
1378         options += 3;
1379         /* TODO: use simple_strtoll with >32bit ext4 */
1380         sb_block = simple_strtoul(options, &options, 0);
1381         if (*options && *options != ',') {
1382                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1383                        (char *) *data);
1384                 return 1;
1385         }
1386         if (*options == ',')
1387                 options++;
1388         *data = (void *) options;
1389
1390         return sb_block;
1391 }
1392
1393 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1394 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1395         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1396
1397 #ifdef CONFIG_QUOTA
1398 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1399 {
1400         struct ext4_sb_info *sbi = EXT4_SB(sb);
1401         char *qname;
1402         int ret = -1;
1403
1404         if (sb_any_quota_loaded(sb) &&
1405                 !sbi->s_qf_names[qtype]) {
1406                 ext4_msg(sb, KERN_ERR,
1407                         "Cannot change journaled "
1408                         "quota options when quota turned on");
1409                 return -1;
1410         }
1411         if (ext4_has_feature_quota(sb)) {
1412                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1413                          "ignored when QUOTA feature is enabled");
1414                 return 1;
1415         }
1416         qname = match_strdup(args);
1417         if (!qname) {
1418                 ext4_msg(sb, KERN_ERR,
1419                         "Not enough memory for storing quotafile name");
1420                 return -1;
1421         }
1422         if (sbi->s_qf_names[qtype]) {
1423                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1424                         ret = 1;
1425                 else
1426                         ext4_msg(sb, KERN_ERR,
1427                                  "%s quota file already specified",
1428                                  QTYPE2NAME(qtype));
1429                 goto errout;
1430         }
1431         if (strchr(qname, '/')) {
1432                 ext4_msg(sb, KERN_ERR,
1433                         "quotafile must be on filesystem root");
1434                 goto errout;
1435         }
1436         sbi->s_qf_names[qtype] = qname;
1437         set_opt(sb, QUOTA);
1438         return 1;
1439 errout:
1440         kfree(qname);
1441         return ret;
1442 }
1443
1444 static int clear_qf_name(struct super_block *sb, int qtype)
1445 {
1446
1447         struct ext4_sb_info *sbi = EXT4_SB(sb);
1448
1449         if (sb_any_quota_loaded(sb) &&
1450                 sbi->s_qf_names[qtype]) {
1451                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1452                         " when quota turned on");
1453                 return -1;
1454         }
1455         kfree(sbi->s_qf_names[qtype]);
1456         sbi->s_qf_names[qtype] = NULL;
1457         return 1;
1458 }
1459 #endif
1460
1461 #define MOPT_SET        0x0001
1462 #define MOPT_CLEAR      0x0002
1463 #define MOPT_NOSUPPORT  0x0004
1464 #define MOPT_EXPLICIT   0x0008
1465 #define MOPT_CLEAR_ERR  0x0010
1466 #define MOPT_GTE0       0x0020
1467 #ifdef CONFIG_QUOTA
1468 #define MOPT_Q          0
1469 #define MOPT_QFMT       0x0040
1470 #else
1471 #define MOPT_Q          MOPT_NOSUPPORT
1472 #define MOPT_QFMT       MOPT_NOSUPPORT
1473 #endif
1474 #define MOPT_DATAJ      0x0080
1475 #define MOPT_NO_EXT2    0x0100
1476 #define MOPT_NO_EXT3    0x0200
1477 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1478 #define MOPT_STRING     0x0400
1479
1480 static const struct mount_opts {
1481         int     token;
1482         int     mount_opt;
1483         int     flags;
1484 } ext4_mount_opts[] = {
1485         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1486         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1487         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1488         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1489         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1490         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1491         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1492          MOPT_EXT4_ONLY | MOPT_SET},
1493         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1494          MOPT_EXT4_ONLY | MOPT_CLEAR},
1495         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1496         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1497         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1498          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1499         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1500          MOPT_EXT4_ONLY | MOPT_CLEAR},
1501         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1502          MOPT_EXT4_ONLY | MOPT_CLEAR},
1503         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1504          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1505         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1506                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1507          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1508         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1509         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1510         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1511         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1512         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1513          MOPT_NO_EXT2},
1514         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1515          MOPT_NO_EXT2},
1516         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1517         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1518         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1519         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1520         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1521         {Opt_commit, 0, MOPT_GTE0},
1522         {Opt_max_batch_time, 0, MOPT_GTE0},
1523         {Opt_min_batch_time, 0, MOPT_GTE0},
1524         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1525         {Opt_init_itable, 0, MOPT_GTE0},
1526         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1527         {Opt_stripe, 0, MOPT_GTE0},
1528         {Opt_resuid, 0, MOPT_GTE0},
1529         {Opt_resgid, 0, MOPT_GTE0},
1530         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1531         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1532         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1533         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1534         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1535         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1536          MOPT_NO_EXT2 | MOPT_DATAJ},
1537         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1538         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1539 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1540         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1541         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1542 #else
1543         {Opt_acl, 0, MOPT_NOSUPPORT},
1544         {Opt_noacl, 0, MOPT_NOSUPPORT},
1545 #endif
1546         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1547         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1548         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1549         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1550                                                         MOPT_SET | MOPT_Q},
1551         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1552                                                         MOPT_SET | MOPT_Q},
1553         {Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1554                                                         MOPT_SET | MOPT_Q},
1555         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1556                        EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1557                                                         MOPT_CLEAR | MOPT_Q},
1558         {Opt_usrjquota, 0, MOPT_Q},
1559         {Opt_grpjquota, 0, MOPT_Q},
1560         {Opt_offusrjquota, 0, MOPT_Q},
1561         {Opt_offgrpjquota, 0, MOPT_Q},
1562         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1563         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1564         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1565         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1566         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1567         {Opt_err, 0, 0}
1568 };
1569
1570 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1571                             substring_t *args, unsigned long *journal_devnum,
1572                             unsigned int *journal_ioprio, int is_remount)
1573 {
1574         struct ext4_sb_info *sbi = EXT4_SB(sb);
1575         const struct mount_opts *m;
1576         kuid_t uid;
1577         kgid_t gid;
1578         int arg = 0;
1579
1580 #ifdef CONFIG_QUOTA
1581         if (token == Opt_usrjquota)
1582                 return set_qf_name(sb, USRQUOTA, &args[0]);
1583         else if (token == Opt_grpjquota)
1584                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1585         else if (token == Opt_offusrjquota)
1586                 return clear_qf_name(sb, USRQUOTA);
1587         else if (token == Opt_offgrpjquota)
1588                 return clear_qf_name(sb, GRPQUOTA);
1589 #endif
1590         switch (token) {
1591         case Opt_noacl:
1592         case Opt_nouser_xattr:
1593                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1594                 break;
1595         case Opt_sb:
1596                 return 1;       /* handled by get_sb_block() */
1597         case Opt_removed:
1598                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1599                 return 1;
1600         case Opt_abort:
1601                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1602                 return 1;
1603         case Opt_i_version:
1604                 sb->s_flags |= MS_I_VERSION;
1605                 return 1;
1606         case Opt_lazytime:
1607                 sb->s_flags |= MS_LAZYTIME;
1608                 return 1;
1609         case Opt_nolazytime:
1610                 sb->s_flags &= ~MS_LAZYTIME;
1611                 return 1;
1612         }
1613
1614         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1615                 if (token == m->token)
1616                         break;
1617
1618         if (m->token == Opt_err) {
1619                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1620                          "or missing value", opt);
1621                 return -1;
1622         }
1623
1624         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1625                 ext4_msg(sb, KERN_ERR,
1626                          "Mount option \"%s\" incompatible with ext2", opt);
1627                 return -1;
1628         }
1629         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1630                 ext4_msg(sb, KERN_ERR,
1631                          "Mount option \"%s\" incompatible with ext3", opt);
1632                 return -1;
1633         }
1634
1635         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1636                 return -1;
1637         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1638                 return -1;
1639         if (m->flags & MOPT_EXPLICIT) {
1640                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1641                         set_opt2(sb, EXPLICIT_DELALLOC);
1642                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1643                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1644                 } else
1645                         return -1;
1646         }
1647         if (m->flags & MOPT_CLEAR_ERR)
1648                 clear_opt(sb, ERRORS_MASK);
1649         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1650                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1651                          "options when quota turned on");
1652                 return -1;
1653         }
1654
1655         if (m->flags & MOPT_NOSUPPORT) {
1656                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1657         } else if (token == Opt_commit) {
1658                 if (arg == 0)
1659                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1660                 sbi->s_commit_interval = HZ * arg;
1661         } else if (token == Opt_max_batch_time) {
1662                 sbi->s_max_batch_time = arg;
1663         } else if (token == Opt_min_batch_time) {
1664                 sbi->s_min_batch_time = arg;
1665         } else if (token == Opt_inode_readahead_blks) {
1666                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1667                         ext4_msg(sb, KERN_ERR,
1668                                  "EXT4-fs: inode_readahead_blks must be "
1669                                  "0 or a power of 2 smaller than 2^31");
1670                         return -1;
1671                 }
1672                 sbi->s_inode_readahead_blks = arg;
1673         } else if (token == Opt_init_itable) {
1674                 set_opt(sb, INIT_INODE_TABLE);
1675                 if (!args->from)
1676                         arg = EXT4_DEF_LI_WAIT_MULT;
1677                 sbi->s_li_wait_mult = arg;
1678         } else if (token == Opt_max_dir_size_kb) {
1679                 sbi->s_max_dir_size_kb = arg;
1680         } else if (token == Opt_stripe) {
1681                 sbi->s_stripe = arg;
1682         } else if (token == Opt_resuid) {
1683                 uid = make_kuid(current_user_ns(), arg);
1684                 if (!uid_valid(uid)) {
1685                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1686                         return -1;
1687                 }
1688                 sbi->s_resuid = uid;
1689         } else if (token == Opt_resgid) {
1690                 gid = make_kgid(current_user_ns(), arg);
1691                 if (!gid_valid(gid)) {
1692                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1693                         return -1;
1694                 }
1695                 sbi->s_resgid = gid;
1696         } else if (token == Opt_journal_dev) {
1697                 if (is_remount) {
1698                         ext4_msg(sb, KERN_ERR,
1699                                  "Cannot specify journal on remount");
1700                         return -1;
1701                 }
1702                 *journal_devnum = arg;
1703         } else if (token == Opt_journal_path) {
1704                 char *journal_path;
1705                 struct inode *journal_inode;
1706                 struct path path;
1707                 int error;
1708
1709                 if (is_remount) {
1710                         ext4_msg(sb, KERN_ERR,
1711                                  "Cannot specify journal on remount");
1712                         return -1;
1713                 }
1714                 journal_path = match_strdup(&args[0]);
1715                 if (!journal_path) {
1716                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1717                                 "journal device string");
1718                         return -1;
1719                 }
1720
1721                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1722                 if (error) {
1723                         ext4_msg(sb, KERN_ERR, "error: could not find "
1724                                 "journal device path: error %d", error);
1725                         kfree(journal_path);
1726                         return -1;
1727                 }
1728
1729                 journal_inode = d_inode(path.dentry);
1730                 if (!S_ISBLK(journal_inode->i_mode)) {
1731                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1732                                 "is not a block device", journal_path);
1733                         path_put(&path);
1734                         kfree(journal_path);
1735                         return -1;
1736                 }
1737
1738                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1739                 path_put(&path);
1740                 kfree(journal_path);
1741         } else if (token == Opt_journal_ioprio) {
1742                 if (arg > 7) {
1743                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1744                                  " (must be 0-7)");
1745                         return -1;
1746                 }
1747                 *journal_ioprio =
1748                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1749         } else if (token == Opt_test_dummy_encryption) {
1750 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1751                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1752                 ext4_msg(sb, KERN_WARNING,
1753                          "Test dummy encryption mode enabled");
1754 #else
1755                 ext4_msg(sb, KERN_WARNING,
1756                          "Test dummy encryption mount option ignored");
1757 #endif
1758         } else if (m->flags & MOPT_DATAJ) {
1759                 if (is_remount) {
1760                         if (!sbi->s_journal)
1761                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1762                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1763                                 ext4_msg(sb, KERN_ERR,
1764                                          "Cannot change data mode on remount");
1765                                 return -1;
1766                         }
1767                 } else {
1768                         clear_opt(sb, DATA_FLAGS);
1769                         sbi->s_mount_opt |= m->mount_opt;
1770                 }
1771 #ifdef CONFIG_QUOTA
1772         } else if (m->flags & MOPT_QFMT) {
1773                 if (sb_any_quota_loaded(sb) &&
1774                     sbi->s_jquota_fmt != m->mount_opt) {
1775                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1776                                  "quota options when quota turned on");
1777                         return -1;
1778                 }
1779                 if (ext4_has_feature_quota(sb)) {
1780                         ext4_msg(sb, KERN_INFO,
1781                                  "Quota format mount options ignored "
1782                                  "when QUOTA feature is enabled");
1783                         return 1;
1784                 }
1785                 sbi->s_jquota_fmt = m->mount_opt;
1786 #endif
1787         } else if (token == Opt_dax) {
1788 #ifdef CONFIG_FS_DAX
1789                 ext4_msg(sb, KERN_WARNING,
1790                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1791                         sbi->s_mount_opt |= m->mount_opt;
1792 #else
1793                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1794                 return -1;
1795 #endif
1796         } else if (token == Opt_data_err_abort) {
1797                 sbi->s_mount_opt |= m->mount_opt;
1798         } else if (token == Opt_data_err_ignore) {
1799                 sbi->s_mount_opt &= ~m->mount_opt;
1800         } else {
1801                 if (!args->from)
1802                         arg = 1;
1803                 if (m->flags & MOPT_CLEAR)
1804                         arg = !arg;
1805                 else if (unlikely(!(m->flags & MOPT_SET))) {
1806                         ext4_msg(sb, KERN_WARNING,
1807                                  "buggy handling of option %s", opt);
1808                         WARN_ON(1);
1809                         return -1;
1810                 }
1811                 if (arg != 0)
1812                         sbi->s_mount_opt |= m->mount_opt;
1813                 else
1814                         sbi->s_mount_opt &= ~m->mount_opt;
1815         }
1816         return 1;
1817 }
1818
1819 static int parse_options(char *options, struct super_block *sb,
1820                          unsigned long *journal_devnum,
1821                          unsigned int *journal_ioprio,
1822                          int is_remount)
1823 {
1824         struct ext4_sb_info *sbi = EXT4_SB(sb);
1825         char *p;
1826         substring_t args[MAX_OPT_ARGS];
1827         int token;
1828
1829         if (!options)
1830                 return 1;
1831
1832         while ((p = strsep(&options, ",")) != NULL) {
1833                 if (!*p)
1834                         continue;
1835                 /*
1836                  * Initialize args struct so we know whether arg was
1837                  * found; some options take optional arguments.
1838                  */
1839                 args[0].to = args[0].from = NULL;
1840                 token = match_token(p, tokens, args);
1841                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1842                                      journal_ioprio, is_remount) < 0)
1843                         return 0;
1844         }
1845 #ifdef CONFIG_QUOTA
1846         /*
1847          * We do the test below only for project quotas. 'usrquota' and
1848          * 'grpquota' mount options are allowed even without quota feature
1849          * to support legacy quotas in quota files.
1850          */
1851         if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1852                 ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1853                          "Cannot enable project quota enforcement.");
1854                 return 0;
1855         }
1856         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1857                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1858                         clear_opt(sb, USRQUOTA);
1859
1860                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1861                         clear_opt(sb, GRPQUOTA);
1862
1863                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1864                         ext4_msg(sb, KERN_ERR, "old and new quota "
1865                                         "format mixing");
1866                         return 0;
1867                 }
1868
1869                 if (!sbi->s_jquota_fmt) {
1870                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1871                                         "not specified");
1872                         return 0;
1873                 }
1874         }
1875 #endif
1876         if (test_opt(sb, DIOREAD_NOLOCK)) {
1877                 int blocksize =
1878                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1879
1880                 if (blocksize < PAGE_SIZE) {
1881                         ext4_msg(sb, KERN_ERR, "can't mount with "
1882                                  "dioread_nolock if block size != PAGE_SIZE");
1883                         return 0;
1884                 }
1885         }
1886         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1887             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1888                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1889                          "in data=ordered mode");
1890                 return 0;
1891         }
1892         return 1;
1893 }
1894
1895 static inline void ext4_show_quota_options(struct seq_file *seq,
1896                                            struct super_block *sb)
1897 {
1898 #if defined(CONFIG_QUOTA)
1899         struct ext4_sb_info *sbi = EXT4_SB(sb);
1900
1901         if (sbi->s_jquota_fmt) {
1902                 char *fmtname = "";
1903
1904                 switch (sbi->s_jquota_fmt) {
1905                 case QFMT_VFS_OLD:
1906                         fmtname = "vfsold";
1907                         break;
1908                 case QFMT_VFS_V0:
1909                         fmtname = "vfsv0";
1910                         break;
1911                 case QFMT_VFS_V1:
1912                         fmtname = "vfsv1";
1913                         break;
1914                 }
1915                 seq_printf(seq, ",jqfmt=%s", fmtname);
1916         }
1917
1918         if (sbi->s_qf_names[USRQUOTA])
1919                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1920
1921         if (sbi->s_qf_names[GRPQUOTA])
1922                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1923 #endif
1924 }
1925
1926 static const char *token2str(int token)
1927 {
1928         const struct match_token *t;
1929
1930         for (t = tokens; t->token != Opt_err; t++)
1931                 if (t->token == token && !strchr(t->pattern, '='))
1932                         break;
1933         return t->pattern;
1934 }
1935
1936 /*
1937  * Show an option if
1938  *  - it's set to a non-default value OR
1939  *  - if the per-sb default is different from the global default
1940  */
1941 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1942                               int nodefs)
1943 {
1944         struct ext4_sb_info *sbi = EXT4_SB(sb);
1945         struct ext4_super_block *es = sbi->s_es;
1946         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1947         const struct mount_opts *m;
1948         char sep = nodefs ? '\n' : ',';
1949
1950 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1951 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1952
1953         if (sbi->s_sb_block != 1)
1954                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1955
1956         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1957                 int want_set = m->flags & MOPT_SET;
1958                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1959                     (m->flags & MOPT_CLEAR_ERR))
1960                         continue;
1961                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1962                         continue; /* skip if same as the default */
1963                 if ((want_set &&
1964                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1965                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1966                         continue; /* select Opt_noFoo vs Opt_Foo */
1967                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1968         }
1969
1970         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1971             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1972                 SEQ_OPTS_PRINT("resuid=%u",
1973                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1974         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1975             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1976                 SEQ_OPTS_PRINT("resgid=%u",
1977                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1978         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1979         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1980                 SEQ_OPTS_PUTS("errors=remount-ro");
1981         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1982                 SEQ_OPTS_PUTS("errors=continue");
1983         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1984                 SEQ_OPTS_PUTS("errors=panic");
1985         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1986                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1987         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1988                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1989         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1990                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1991         if (sb->s_flags & MS_I_VERSION)
1992                 SEQ_OPTS_PUTS("i_version");
1993         if (nodefs || sbi->s_stripe)
1994                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1995         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1996                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1997                         SEQ_OPTS_PUTS("data=journal");
1998                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1999                         SEQ_OPTS_PUTS("data=ordered");
2000                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2001                         SEQ_OPTS_PUTS("data=writeback");
2002         }
2003         if (nodefs ||
2004             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2005                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2006                                sbi->s_inode_readahead_blks);
2007
2008         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2009                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2010                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2011         if (nodefs || sbi->s_max_dir_size_kb)
2012                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2013         if (test_opt(sb, DATA_ERR_ABORT))
2014                 SEQ_OPTS_PUTS("data_err=abort");
2015
2016         ext4_show_quota_options(seq, sb);
2017         return 0;
2018 }
2019
2020 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2021 {
2022         return _ext4_show_options(seq, root->d_sb, 0);
2023 }
2024
2025 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2026 {
2027         struct super_block *sb = seq->private;
2028         int rc;
2029
2030         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2031         rc = _ext4_show_options(seq, sb, 1);
2032         seq_puts(seq, "\n");
2033         return rc;
2034 }
2035
2036 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2037                             int read_only)
2038 {
2039         struct ext4_sb_info *sbi = EXT4_SB(sb);
2040         int res = 0;
2041
2042         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2043                 ext4_msg(sb, KERN_ERR, "revision level too high, "
2044                          "forcing read-only mode");
2045                 res = MS_RDONLY;
2046         }
2047         if (read_only)
2048                 goto done;
2049         if (!(sbi->s_mount_state & EXT4_VALID_FS))
2050                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2051                          "running e2fsck is recommended");
2052         else if (sbi->s_mount_state & EXT4_ERROR_FS)
2053                 ext4_msg(sb, KERN_WARNING,
2054                          "warning: mounting fs with errors, "
2055                          "running e2fsck is recommended");
2056         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2057                  le16_to_cpu(es->s_mnt_count) >=
2058                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2059                 ext4_msg(sb, KERN_WARNING,
2060                          "warning: maximal mount count reached, "
2061                          "running e2fsck is recommended");
2062         else if (le32_to_cpu(es->s_checkinterval) &&
2063                 (le32_to_cpu(es->s_lastcheck) +
2064                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2065                 ext4_msg(sb, KERN_WARNING,
2066                          "warning: checktime reached, "
2067                          "running e2fsck is recommended");
2068         if (!sbi->s_journal)
2069                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2070         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2071                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2072         le16_add_cpu(&es->s_mnt_count, 1);
2073         es->s_mtime = cpu_to_le32(get_seconds());
2074         ext4_update_dynamic_rev(sb);
2075         if (sbi->s_journal)
2076                 ext4_set_feature_journal_needs_recovery(sb);
2077
2078         ext4_commit_super(sb, 1);
2079 done:
2080         if (test_opt(sb, DEBUG))
2081                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2082                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2083                         sb->s_blocksize,
2084                         sbi->s_groups_count,
2085                         EXT4_BLOCKS_PER_GROUP(sb),
2086                         EXT4_INODES_PER_GROUP(sb),
2087                         sbi->s_mount_opt, sbi->s_mount_opt2);
2088
2089         cleancache_init_fs(sb);
2090         return res;
2091 }
2092
2093 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2094 {
2095         struct ext4_sb_info *sbi = EXT4_SB(sb);
2096         struct flex_groups *new_groups;
2097         int size;
2098
2099         if (!sbi->s_log_groups_per_flex)
2100                 return 0;
2101
2102         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2103         if (size <= sbi->s_flex_groups_allocated)
2104                 return 0;
2105
2106         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2107         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2108         if (!new_groups) {
2109                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2110                          size / (int) sizeof(struct flex_groups));
2111                 return -ENOMEM;
2112         }
2113
2114         if (sbi->s_flex_groups) {
2115                 memcpy(new_groups, sbi->s_flex_groups,
2116                        (sbi->s_flex_groups_allocated *
2117                         sizeof(struct flex_groups)));
2118                 kvfree(sbi->s_flex_groups);
2119         }
2120         sbi->s_flex_groups = new_groups;
2121         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2122         return 0;
2123 }
2124
2125 static int ext4_fill_flex_info(struct super_block *sb)
2126 {
2127         struct ext4_sb_info *sbi = EXT4_SB(sb);
2128         struct ext4_group_desc *gdp = NULL;
2129         ext4_group_t flex_group;
2130         int i, err;
2131
2132         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2133         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2134                 sbi->s_log_groups_per_flex = 0;
2135                 return 1;
2136         }
2137
2138         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2139         if (err)
2140                 goto failed;
2141
2142         for (i = 0; i < sbi->s_groups_count; i++) {
2143                 gdp = ext4_get_group_desc(sb, i, NULL);
2144
2145                 flex_group = ext4_flex_group(sbi, i);
2146                 atomic_add(ext4_free_inodes_count(sb, gdp),
2147                            &sbi->s_flex_groups[flex_group].free_inodes);
2148                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2149                              &sbi->s_flex_groups[flex_group].free_clusters);
2150                 atomic_add(ext4_used_dirs_count(sb, gdp),
2151                            &sbi->s_flex_groups[flex_group].used_dirs);
2152         }
2153
2154         return 1;
2155 failed:
2156         return 0;
2157 }
2158
2159 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2160                                    struct ext4_group_desc *gdp)
2161 {
2162         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2163         __u16 crc = 0;
2164         __le32 le_group = cpu_to_le32(block_group);
2165         struct ext4_sb_info *sbi = EXT4_SB(sb);
2166
2167         if (ext4_has_metadata_csum(sbi->s_sb)) {
2168                 /* Use new metadata_csum algorithm */
2169                 __u32 csum32;
2170                 __u16 dummy_csum = 0;
2171
2172                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2173                                      sizeof(le_group));
2174                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2175                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2176                                      sizeof(dummy_csum));
2177                 offset += sizeof(dummy_csum);
2178                 if (offset < sbi->s_desc_size)
2179                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2180                                              sbi->s_desc_size - offset);
2181
2182                 crc = csum32 & 0xFFFF;
2183                 goto out;
2184         }
2185
2186         /* old crc16 code */
2187         if (!ext4_has_feature_gdt_csum(sb))
2188                 return 0;
2189
2190         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2191         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2192         crc = crc16(crc, (__u8 *)gdp, offset);
2193         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2194         /* for checksum of struct ext4_group_desc do the rest...*/
2195         if (ext4_has_feature_64bit(sb) &&
2196             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2197                 crc = crc16(crc, (__u8 *)gdp + offset,
2198                             le16_to_cpu(sbi->s_es->s_desc_size) -
2199                                 offset);
2200
2201 out:
2202         return cpu_to_le16(crc);
2203 }
2204
2205 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2206                                 struct ext4_group_desc *gdp)
2207 {
2208         if (ext4_has_group_desc_csum(sb) &&
2209             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2210                 return 0;
2211
2212         return 1;
2213 }
2214
2215 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2216                               struct ext4_group_desc *gdp)
2217 {
2218         if (!ext4_has_group_desc_csum(sb))
2219                 return;
2220         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2221 }
2222
2223 /* Called at mount-time, super-block is locked */
2224 static int ext4_check_descriptors(struct super_block *sb,
2225                                   ext4_fsblk_t sb_block,
2226                                   ext4_group_t *first_not_zeroed)
2227 {
2228         struct ext4_sb_info *sbi = EXT4_SB(sb);
2229         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2230         ext4_fsblk_t last_block;
2231         ext4_fsblk_t block_bitmap;
2232         ext4_fsblk_t inode_bitmap;
2233         ext4_fsblk_t inode_table;
2234         int flexbg_flag = 0;
2235         ext4_group_t i, grp = sbi->s_groups_count;
2236
2237         if (ext4_has_feature_flex_bg(sb))
2238                 flexbg_flag = 1;
2239
2240         ext4_debug("Checking group descriptors");
2241
2242         for (i = 0; i < sbi->s_groups_count; i++) {
2243                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2244
2245                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2246                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2247                 else
2248                         last_block = first_block +
2249                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2250
2251                 if ((grp == sbi->s_groups_count) &&
2252                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2253                         grp = i;
2254
2255                 block_bitmap = ext4_block_bitmap(sb, gdp);
2256                 if (block_bitmap == sb_block) {
2257                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2258                                  "Block bitmap for group %u overlaps "
2259                                  "superblock", i);
2260                 }
2261                 if (block_bitmap < first_block || block_bitmap > last_block) {
2262                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2263                                "Block bitmap for group %u not in group "
2264                                "(block %llu)!", i, block_bitmap);
2265                         return 0;
2266                 }
2267                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2268                 if (inode_bitmap == sb_block) {
2269                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2270                                  "Inode bitmap for group %u overlaps "
2271                                  "superblock", i);
2272                 }
2273                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2274                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2275                                "Inode bitmap for group %u not in group "
2276                                "(block %llu)!", i, inode_bitmap);
2277                         return 0;
2278                 }
2279                 inode_table = ext4_inode_table(sb, gdp);
2280                 if (inode_table == sb_block) {
2281                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2282                                  "Inode table for group %u overlaps "
2283                                  "superblock", i);
2284                 }
2285                 if (inode_table < first_block ||
2286                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2287                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2288                                "Inode table for group %u not in group "
2289                                "(block %llu)!", i, inode_table);
2290                         return 0;
2291                 }
2292                 ext4_lock_group(sb, i);
2293                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2294                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2295                                  "Checksum for group %u failed (%u!=%u)",
2296                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2297                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2298                         if (!(sb->s_flags & MS_RDONLY)) {
2299                                 ext4_unlock_group(sb, i);
2300                                 return 0;
2301                         }
2302                 }
2303                 ext4_unlock_group(sb, i);
2304                 if (!flexbg_flag)
2305                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2306         }
2307         if (NULL != first_not_zeroed)
2308                 *first_not_zeroed = grp;
2309         return 1;
2310 }
2311
2312 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2313  * the superblock) which were deleted from all directories, but held open by
2314  * a process at the time of a crash.  We walk the list and try to delete these
2315  * inodes at recovery time (only with a read-write filesystem).
2316  *
2317  * In order to keep the orphan inode chain consistent during traversal (in
2318  * case of crash during recovery), we link each inode into the superblock
2319  * orphan list_head and handle it the same way as an inode deletion during
2320  * normal operation (which journals the operations for us).
2321  *
2322  * We only do an iget() and an iput() on each inode, which is very safe if we
2323  * accidentally point at an in-use or already deleted inode.  The worst that
2324  * can happen in this case is that we get a "bit already cleared" message from
2325  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2326  * e2fsck was run on this filesystem, and it must have already done the orphan
2327  * inode cleanup for us, so we can safely abort without any further action.
2328  */
2329 static void ext4_orphan_cleanup(struct super_block *sb,
2330                                 struct ext4_super_block *es)
2331 {
2332         unsigned int s_flags = sb->s_flags;
2333         int nr_orphans = 0, nr_truncates = 0;
2334 #ifdef CONFIG_QUOTA
2335         int i;
2336 #endif
2337         if (!es->s_last_orphan) {
2338                 jbd_debug(4, "no orphan inodes to clean up\n");
2339                 return;
2340         }
2341
2342         if (bdev_read_only(sb->s_bdev)) {
2343                 ext4_msg(sb, KERN_ERR, "write access "
2344                         "unavailable, skipping orphan cleanup");
2345                 return;
2346         }
2347
2348         /* Check if feature set would not allow a r/w mount */
2349         if (!ext4_feature_set_ok(sb, 0)) {
2350                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2351                          "unknown ROCOMPAT features");
2352                 return;
2353         }
2354
2355         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2356                 /* don't clear list on RO mount w/ errors */
2357                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2358                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2359                                   "clearing orphan list.\n");
2360                         es->s_last_orphan = 0;
2361                 }
2362                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2363                 return;
2364         }
2365
2366         if (s_flags & MS_RDONLY) {
2367                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2368                 sb->s_flags &= ~MS_RDONLY;
2369         }
2370 #ifdef CONFIG_QUOTA
2371         /* Needed for iput() to work correctly and not trash data */
2372         sb->s_flags |= MS_ACTIVE;
2373         /* Turn on quotas so that they are updated correctly */
2374         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2375                 if (EXT4_SB(sb)->s_qf_names[i]) {
2376                         int ret = ext4_quota_on_mount(sb, i);
2377                         if (ret < 0)
2378                                 ext4_msg(sb, KERN_ERR,
2379                                         "Cannot turn on journaled "
2380                                         "quota: error %d", ret);
2381                 }
2382         }
2383 #endif
2384
2385         while (es->s_last_orphan) {
2386                 struct inode *inode;
2387
2388                 /*
2389                  * We may have encountered an error during cleanup; if
2390                  * so, skip the rest.
2391                  */
2392                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2393                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2394                         es->s_last_orphan = 0;
2395                         break;
2396                 }
2397
2398                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2399                 if (IS_ERR(inode)) {
2400                         es->s_last_orphan = 0;
2401                         break;
2402                 }
2403
2404                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2405                 dquot_initialize(inode);
2406                 if (inode->i_nlink) {
2407                         if (test_opt(sb, DEBUG))
2408                                 ext4_msg(sb, KERN_DEBUG,
2409                                         "%s: truncating inode %lu to %lld bytes",
2410                                         __func__, inode->i_ino, inode->i_size);
2411                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2412                                   inode->i_ino, inode->i_size);
2413                         inode_lock(inode);
2414                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2415                         ext4_truncate(inode);
2416                         inode_unlock(inode);
2417                         nr_truncates++;
2418                 } else {
2419                         if (test_opt(sb, DEBUG))
2420                                 ext4_msg(sb, KERN_DEBUG,
2421                                         "%s: deleting unreferenced inode %lu",
2422                                         __func__, inode->i_ino);
2423                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2424                                   inode->i_ino);
2425                         nr_orphans++;
2426                 }
2427                 iput(inode);  /* The delete magic happens here! */
2428         }
2429
2430 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2431
2432         if (nr_orphans)
2433                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2434                        PLURAL(nr_orphans));
2435         if (nr_truncates)
2436                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2437                        PLURAL(nr_truncates));
2438 #ifdef CONFIG_QUOTA
2439         /* Turn quotas off */
2440         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2441                 if (sb_dqopt(sb)->files[i])
2442                         dquot_quota_off(sb, i);
2443         }
2444 #endif
2445         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2446 }
2447
2448 /*
2449  * Maximal extent format file size.
2450  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2451  * extent format containers, within a sector_t, and within i_blocks
2452  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2453  * so that won't be a limiting factor.
2454  *
2455  * However there is other limiting factor. We do store extents in the form
2456  * of starting block and length, hence the resulting length of the extent
2457  * covering maximum file size must fit into on-disk format containers as
2458  * well. Given that length is always by 1 unit bigger than max unit (because
2459  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2460  *
2461  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2462  */
2463 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2464 {
2465         loff_t res;
2466         loff_t upper_limit = MAX_LFS_FILESIZE;
2467
2468         /* small i_blocks in vfs inode? */
2469         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2470                 /*
2471                  * CONFIG_LBDAF is not enabled implies the inode
2472                  * i_block represent total blocks in 512 bytes
2473                  * 32 == size of vfs inode i_blocks * 8
2474                  */
2475                 upper_limit = (1LL << 32) - 1;
2476
2477                 /* total blocks in file system block size */
2478                 upper_limit >>= (blkbits - 9);
2479                 upper_limit <<= blkbits;
2480         }
2481
2482         /*
2483          * 32-bit extent-start container, ee_block. We lower the maxbytes
2484          * by one fs block, so ee_len can cover the extent of maximum file
2485          * size
2486          */
2487         res = (1LL << 32) - 1;
2488         res <<= blkbits;
2489
2490         /* Sanity check against vm- & vfs- imposed limits */
2491         if (res > upper_limit)
2492                 res = upper_limit;
2493
2494         return res;
2495 }
2496
2497 /*
2498  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2499  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2500  * We need to be 1 filesystem block less than the 2^48 sector limit.
2501  */
2502 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2503 {
2504         loff_t res = EXT4_NDIR_BLOCKS;
2505         int meta_blocks;
2506         loff_t upper_limit;
2507         /* This is calculated to be the largest file size for a dense, block
2508          * mapped file such that the file's total number of 512-byte sectors,
2509          * including data and all indirect blocks, does not exceed (2^48 - 1).
2510          *
2511          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2512          * number of 512-byte sectors of the file.
2513          */
2514
2515         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2516                 /*
2517                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2518                  * the inode i_block field represents total file blocks in
2519                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2520                  */
2521                 upper_limit = (1LL << 32) - 1;
2522
2523                 /* total blocks in file system block size */
2524                 upper_limit >>= (bits - 9);
2525
2526         } else {
2527                 /*
2528                  * We use 48 bit ext4_inode i_blocks
2529                  * With EXT4_HUGE_FILE_FL set the i_blocks
2530                  * represent total number of blocks in
2531                  * file system block size
2532                  */
2533                 upper_limit = (1LL << 48) - 1;
2534
2535         }
2536
2537         /* indirect blocks */
2538         meta_blocks = 1;
2539         /* double indirect blocks */
2540         meta_blocks += 1 + (1LL << (bits-2));
2541         /* tripple indirect blocks */
2542         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2543
2544         upper_limit -= meta_blocks;
2545         upper_limit <<= bits;
2546
2547         res += 1LL << (bits-2);
2548         res += 1LL << (2*(bits-2));
2549         res += 1LL << (3*(bits-2));
2550         res <<= bits;
2551         if (res > upper_limit)
2552                 res = upper_limit;
2553
2554         if (res > MAX_LFS_FILESIZE)
2555                 res = MAX_LFS_FILESIZE;
2556
2557         return res;
2558 }
2559
2560 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2561                                    ext4_fsblk_t logical_sb_block, int nr)
2562 {
2563         struct ext4_sb_info *sbi = EXT4_SB(sb);
2564         ext4_group_t bg, first_meta_bg;
2565         int has_super = 0;
2566
2567         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2568
2569         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2570                 return logical_sb_block + nr + 1;
2571         bg = sbi->s_desc_per_block * nr;
2572         if (ext4_bg_has_super(sb, bg))
2573                 has_super = 1;
2574
2575         /*
2576          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2577          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2578          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2579          * compensate.
2580          */
2581         if (sb->s_blocksize == 1024 && nr == 0 &&
2582             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2583                 has_super++;
2584
2585         return (has_super + ext4_group_first_block_no(sb, bg));
2586 }
2587
2588 /**
2589  * ext4_get_stripe_size: Get the stripe size.
2590  * @sbi: In memory super block info
2591  *
2592  * If we have specified it via mount option, then
2593  * use the mount option value. If the value specified at mount time is
2594  * greater than the blocks per group use the super block value.
2595  * If the super block value is greater than blocks per group return 0.
2596  * Allocator needs it be less than blocks per group.
2597  *
2598  */
2599 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2600 {
2601         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2602         unsigned long stripe_width =
2603                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2604         int ret;
2605
2606         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2607                 ret = sbi->s_stripe;
2608         else if (stripe_width <= sbi->s_blocks_per_group)
2609                 ret = stripe_width;
2610         else if (stride <= sbi->s_blocks_per_group)
2611                 ret = stride;
2612         else
2613                 ret = 0;
2614
2615         /*
2616          * If the stripe width is 1, this makes no sense and
2617          * we set it to 0 to turn off stripe handling code.
2618          */
2619         if (ret <= 1)
2620                 ret = 0;
2621
2622         return ret;
2623 }
2624
2625 /*
2626  * Check whether this filesystem can be mounted based on
2627  * the features present and the RDONLY/RDWR mount requested.
2628  * Returns 1 if this filesystem can be mounted as requested,
2629  * 0 if it cannot be.
2630  */
2631 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2632 {
2633         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2634                 ext4_msg(sb, KERN_ERR,
2635                         "Couldn't mount because of "
2636                         "unsupported optional features (%x)",
2637                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2638                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2639                 return 0;
2640         }
2641
2642         if (readonly)
2643                 return 1;
2644
2645         if (ext4_has_feature_readonly(sb)) {
2646                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2647                 sb->s_flags |= MS_RDONLY;
2648                 return 1;
2649         }
2650
2651         /* Check that feature set is OK for a read-write mount */
2652         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2653                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2654                          "unsupported optional features (%x)",
2655                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2656                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2657                 return 0;
2658         }
2659         /*
2660          * Large file size enabled file system can only be mounted
2661          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2662          */
2663         if (ext4_has_feature_huge_file(sb)) {
2664                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2665                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2666                                  "cannot be mounted RDWR without "
2667                                  "CONFIG_LBDAF");
2668                         return 0;
2669                 }
2670         }
2671         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2672                 ext4_msg(sb, KERN_ERR,
2673                          "Can't support bigalloc feature without "
2674                          "extents feature\n");
2675                 return 0;
2676         }
2677
2678 #ifndef CONFIG_QUOTA
2679         if (ext4_has_feature_quota(sb) && !readonly) {
2680                 ext4_msg(sb, KERN_ERR,
2681                          "Filesystem with quota feature cannot be mounted RDWR "
2682                          "without CONFIG_QUOTA");
2683                 return 0;
2684         }
2685         if (ext4_has_feature_project(sb) && !readonly) {
2686                 ext4_msg(sb, KERN_ERR,
2687                          "Filesystem with project quota feature cannot be mounted RDWR "
2688                          "without CONFIG_QUOTA");
2689                 return 0;
2690         }
2691 #endif  /* CONFIG_QUOTA */
2692         return 1;
2693 }
2694
2695 /*
2696  * This function is called once a day if we have errors logged
2697  * on the file system
2698  */
2699 static void print_daily_error_info(unsigned long arg)
2700 {
2701         struct super_block *sb = (struct super_block *) arg;
2702         struct ext4_sb_info *sbi;
2703         struct ext4_super_block *es;
2704
2705         sbi = EXT4_SB(sb);
2706         es = sbi->s_es;
2707
2708         if (es->s_error_count)
2709                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2710                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2711                          le32_to_cpu(es->s_error_count));
2712         if (es->s_first_error_time) {
2713                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2714                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2715                        (int) sizeof(es->s_first_error_func),
2716                        es->s_first_error_func,
2717                        le32_to_cpu(es->s_first_error_line));
2718                 if (es->s_first_error_ino)
2719                         printk(KERN_CONT ": inode %u",
2720                                le32_to_cpu(es->s_first_error_ino));
2721                 if (es->s_first_error_block)
2722                         printk(KERN_CONT ": block %llu", (unsigned long long)
2723                                le64_to_cpu(es->s_first_error_block));
2724                 printk(KERN_CONT "\n");
2725         }
2726         if (es->s_last_error_time) {
2727                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2728                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2729                        (int) sizeof(es->s_last_error_func),
2730                        es->s_last_error_func,
2731                        le32_to_cpu(es->s_last_error_line));
2732                 if (es->s_last_error_ino)
2733                         printk(KERN_CONT ": inode %u",
2734                                le32_to_cpu(es->s_last_error_ino));
2735                 if (es->s_last_error_block)
2736                         printk(KERN_CONT ": block %llu", (unsigned long long)
2737                                le64_to_cpu(es->s_last_error_block));
2738                 printk(KERN_CONT "\n");
2739         }
2740         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2741 }
2742
2743 /* Find next suitable group and run ext4_init_inode_table */
2744 static int ext4_run_li_request(struct ext4_li_request *elr)
2745 {
2746         struct ext4_group_desc *gdp = NULL;
2747         ext4_group_t group, ngroups;
2748         struct super_block *sb;
2749         unsigned long timeout = 0;
2750         int ret = 0;
2751
2752         sb = elr->lr_super;
2753         ngroups = EXT4_SB(sb)->s_groups_count;
2754
2755         for (group = elr->lr_next_group; group < ngroups; group++) {
2756                 gdp = ext4_get_group_desc(sb, group, NULL);
2757                 if (!gdp) {
2758                         ret = 1;
2759                         break;
2760                 }
2761
2762                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2763                         break;
2764         }
2765
2766         if (group >= ngroups)
2767                 ret = 1;
2768
2769         if (!ret) {
2770                 timeout = jiffies;
2771                 ret = ext4_init_inode_table(sb, group,
2772                                             elr->lr_timeout ? 0 : 1);
2773                 if (elr->lr_timeout == 0) {
2774                         timeout = (jiffies - timeout) *
2775                                   elr->lr_sbi->s_li_wait_mult;
2776                         elr->lr_timeout = timeout;
2777                 }
2778                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2779                 elr->lr_next_group = group + 1;
2780         }
2781         return ret;
2782 }
2783
2784 /*
2785  * Remove lr_request from the list_request and free the
2786  * request structure. Should be called with li_list_mtx held
2787  */
2788 static void ext4_remove_li_request(struct ext4_li_request *elr)
2789 {
2790         struct ext4_sb_info *sbi;
2791
2792         if (!elr)
2793                 return;
2794
2795         sbi = elr->lr_sbi;
2796
2797         list_del(&elr->lr_request);
2798         sbi->s_li_request = NULL;
2799         kfree(elr);
2800 }
2801
2802 static void ext4_unregister_li_request(struct super_block *sb)
2803 {
2804         mutex_lock(&ext4_li_mtx);
2805         if (!ext4_li_info) {
2806                 mutex_unlock(&ext4_li_mtx);
2807                 return;
2808         }
2809
2810         mutex_lock(&ext4_li_info->li_list_mtx);
2811         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2812         mutex_unlock(&ext4_li_info->li_list_mtx);
2813         mutex_unlock(&ext4_li_mtx);
2814 }
2815
2816 static struct task_struct *ext4_lazyinit_task;
2817
2818 /*
2819  * This is the function where ext4lazyinit thread lives. It walks
2820  * through the request list searching for next scheduled filesystem.
2821  * When such a fs is found, run the lazy initialization request
2822  * (ext4_rn_li_request) and keep track of the time spend in this
2823  * function. Based on that time we compute next schedule time of
2824  * the request. When walking through the list is complete, compute
2825  * next waking time and put itself into sleep.
2826  */
2827 static int ext4_lazyinit_thread(void *arg)
2828 {
2829         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2830         struct list_head *pos, *n;
2831         struct ext4_li_request *elr;
2832         unsigned long next_wakeup, cur;
2833
2834         BUG_ON(NULL == eli);
2835
2836 cont_thread:
2837         while (true) {
2838                 next_wakeup = MAX_JIFFY_OFFSET;
2839
2840                 mutex_lock(&eli->li_list_mtx);
2841                 if (list_empty(&eli->li_request_list)) {
2842                         mutex_unlock(&eli->li_list_mtx);
2843                         goto exit_thread;
2844                 }
2845                 list_for_each_safe(pos, n, &eli->li_request_list) {
2846                         int err = 0;
2847                         int progress = 0;
2848                         elr = list_entry(pos, struct ext4_li_request,
2849                                          lr_request);
2850
2851                         if (time_before(jiffies, elr->lr_next_sched)) {
2852                                 if (time_before(elr->lr_next_sched, next_wakeup))
2853                                         next_wakeup = elr->lr_next_sched;
2854                                 continue;
2855                         }
2856                         if (down_read_trylock(&elr->lr_super->s_umount)) {
2857                                 if (sb_start_write_trylock(elr->lr_super)) {
2858                                         progress = 1;
2859                                         /*
2860                                          * We hold sb->s_umount, sb can not
2861                                          * be removed from the list, it is
2862                                          * now safe to drop li_list_mtx
2863                                          */
2864                                         mutex_unlock(&eli->li_list_mtx);
2865                                         err = ext4_run_li_request(elr);
2866                                         sb_end_write(elr->lr_super);
2867                                         mutex_lock(&eli->li_list_mtx);
2868                                         n = pos->next;
2869                                 }
2870                                 up_read((&elr->lr_super->s_umount));
2871                         }
2872                         /* error, remove the lazy_init job */
2873                         if (err) {
2874                                 ext4_remove_li_request(elr);
2875                                 continue;
2876                         }
2877                         if (!progress) {
2878                                 elr->lr_next_sched = jiffies +
2879                                         (prandom_u32()
2880                                          % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2881                         }
2882                         if (time_before(elr->lr_next_sched, next_wakeup))
2883                                 next_wakeup = elr->lr_next_sched;
2884                 }
2885                 mutex_unlock(&eli->li_list_mtx);
2886
2887                 try_to_freeze();
2888
2889                 cur = jiffies;
2890                 if ((time_after_eq(cur, next_wakeup)) ||
2891                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2892                         cond_resched();
2893                         continue;
2894                 }
2895
2896                 schedule_timeout_interruptible(next_wakeup - cur);
2897
2898                 if (kthread_should_stop()) {
2899                         ext4_clear_request_list();
2900                         goto exit_thread;
2901                 }
2902         }
2903
2904 exit_thread:
2905         /*
2906          * It looks like the request list is empty, but we need
2907          * to check it under the li_list_mtx lock, to prevent any
2908          * additions into it, and of course we should lock ext4_li_mtx
2909          * to atomically free the list and ext4_li_info, because at
2910          * this point another ext4 filesystem could be registering
2911          * new one.
2912          */
2913         mutex_lock(&ext4_li_mtx);
2914         mutex_lock(&eli->li_list_mtx);
2915         if (!list_empty(&eli->li_request_list)) {
2916                 mutex_unlock(&eli->li_list_mtx);
2917                 mutex_unlock(&ext4_li_mtx);
2918                 goto cont_thread;
2919         }
2920         mutex_unlock(&eli->li_list_mtx);
2921         kfree(ext4_li_info);
2922         ext4_li_info = NULL;
2923         mutex_unlock(&ext4_li_mtx);
2924
2925         return 0;
2926 }
2927
2928 static void ext4_clear_request_list(void)
2929 {
2930         struct list_head *pos, *n;
2931         struct ext4_li_request *elr;
2932
2933         mutex_lock(&ext4_li_info->li_list_mtx);
2934         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2935                 elr = list_entry(pos, struct ext4_li_request,
2936                                  lr_request);
2937                 ext4_remove_li_request(elr);
2938         }
2939         mutex_unlock(&ext4_li_info->li_list_mtx);
2940 }
2941
2942 static int ext4_run_lazyinit_thread(void)
2943 {
2944         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2945                                          ext4_li_info, "ext4lazyinit");
2946         if (IS_ERR(ext4_lazyinit_task)) {
2947                 int err = PTR_ERR(ext4_lazyinit_task);
2948                 ext4_clear_request_list();
2949                 kfree(ext4_li_info);
2950                 ext4_li_info = NULL;
2951                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2952                                  "initialization thread\n",
2953                                  err);
2954                 return err;
2955         }
2956         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2957         return 0;
2958 }
2959
2960 /*
2961  * Check whether it make sense to run itable init. thread or not.
2962  * If there is at least one uninitialized inode table, return
2963  * corresponding group number, else the loop goes through all
2964  * groups and return total number of groups.
2965  */
2966 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2967 {
2968         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2969         struct ext4_group_desc *gdp = NULL;
2970
2971         for (group = 0; group < ngroups; group++) {
2972                 gdp = ext4_get_group_desc(sb, group, NULL);
2973                 if (!gdp)
2974                         continue;
2975
2976                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2977                         break;
2978         }
2979
2980         return group;
2981 }
2982
2983 static int ext4_li_info_new(void)
2984 {
2985         struct ext4_lazy_init *eli = NULL;
2986
2987         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2988         if (!eli)
2989                 return -ENOMEM;
2990
2991         INIT_LIST_HEAD(&eli->li_request_list);
2992         mutex_init(&eli->li_list_mtx);
2993
2994         eli->li_state |= EXT4_LAZYINIT_QUIT;
2995
2996         ext4_li_info = eli;
2997
2998         return 0;
2999 }
3000
3001 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3002                                             ext4_group_t start)
3003 {
3004         struct ext4_sb_info *sbi = EXT4_SB(sb);
3005         struct ext4_li_request *elr;
3006
3007         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3008         if (!elr)
3009                 return NULL;
3010
3011         elr->lr_super = sb;
3012         elr->lr_sbi = sbi;
3013         elr->lr_next_group = start;
3014
3015         /*
3016          * Randomize first schedule time of the request to
3017          * spread the inode table initialization requests
3018          * better.
3019          */
3020         elr->lr_next_sched = jiffies + (prandom_u32() %
3021                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3022         return elr;
3023 }
3024
3025 int ext4_register_li_request(struct super_block *sb,
3026                              ext4_group_t first_not_zeroed)
3027 {
3028         struct ext4_sb_info *sbi = EXT4_SB(sb);
3029         struct ext4_li_request *elr = NULL;
3030         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3031         int ret = 0;
3032
3033         mutex_lock(&ext4_li_mtx);
3034         if (sbi->s_li_request != NULL) {
3035                 /*
3036                  * Reset timeout so it can be computed again, because
3037                  * s_li_wait_mult might have changed.
3038                  */
3039                 sbi->s_li_request->lr_timeout = 0;
3040                 goto out;
3041         }
3042
3043         if (first_not_zeroed == ngroups ||
3044             (sb->s_flags & MS_RDONLY) ||
3045             !test_opt(sb, INIT_INODE_TABLE))
3046                 goto out;
3047
3048         elr = ext4_li_request_new(sb, first_not_zeroed);
3049         if (!elr) {
3050                 ret = -ENOMEM;
3051                 goto out;
3052         }
3053
3054         if (NULL == ext4_li_info) {
3055                 ret = ext4_li_info_new();
3056                 if (ret)
3057                         goto out;
3058         }
3059
3060         mutex_lock(&ext4_li_info->li_list_mtx);
3061         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3062         mutex_unlock(&ext4_li_info->li_list_mtx);
3063
3064         sbi->s_li_request = elr;
3065         /*
3066          * set elr to NULL here since it has been inserted to
3067          * the request_list and the removal and free of it is
3068          * handled by ext4_clear_request_list from now on.
3069          */
3070         elr = NULL;
3071
3072         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3073                 ret = ext4_run_lazyinit_thread();
3074                 if (ret)
3075                         goto out;
3076         }
3077 out:
3078         mutex_unlock(&ext4_li_mtx);
3079         if (ret)
3080                 kfree(elr);
3081         return ret;
3082 }
3083
3084 /*
3085  * We do not need to lock anything since this is called on
3086  * module unload.
3087  */
3088 static void ext4_destroy_lazyinit_thread(void)
3089 {
3090         /*
3091          * If thread exited earlier
3092          * there's nothing to be done.
3093          */
3094         if (!ext4_li_info || !ext4_lazyinit_task)
3095                 return;
3096
3097         kthread_stop(ext4_lazyinit_task);
3098 }
3099
3100 static int set_journal_csum_feature_set(struct super_block *sb)
3101 {
3102         int ret = 1;
3103         int compat, incompat;
3104         struct ext4_sb_info *sbi = EXT4_SB(sb);
3105
3106         if (ext4_has_metadata_csum(sb)) {
3107                 /* journal checksum v3 */
3108                 compat = 0;
3109                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3110         } else {
3111                 /* journal checksum v1 */
3112                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3113                 incompat = 0;
3114         }
3115
3116         jbd2_journal_clear_features(sbi->s_journal,
3117                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3118                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3119                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3120         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3121                 ret = jbd2_journal_set_features(sbi->s_journal,
3122                                 compat, 0,
3123                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3124                                 incompat);
3125         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3126                 ret = jbd2_journal_set_features(sbi->s_journal,
3127                                 compat, 0,
3128                                 incompat);
3129                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3130                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3131         } else {
3132                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3133                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3134         }
3135
3136         return ret;
3137 }
3138
3139 /*
3140  * Note: calculating the overhead so we can be compatible with
3141  * historical BSD practice is quite difficult in the face of
3142  * clusters/bigalloc.  This is because multiple metadata blocks from
3143  * different block group can end up in the same allocation cluster.
3144  * Calculating the exact overhead in the face of clustered allocation
3145  * requires either O(all block bitmaps) in memory or O(number of block
3146  * groups**2) in time.  We will still calculate the superblock for
3147  * older file systems --- and if we come across with a bigalloc file
3148  * system with zero in s_overhead_clusters the estimate will be close to
3149  * correct especially for very large cluster sizes --- but for newer
3150  * file systems, it's better to calculate this figure once at mkfs
3151  * time, and store it in the superblock.  If the superblock value is
3152  * present (even for non-bigalloc file systems), we will use it.
3153  */
3154 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3155                           char *buf)
3156 {
3157         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3158         struct ext4_group_desc  *gdp;
3159         ext4_fsblk_t            first_block, last_block, b;
3160         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3161         int                     s, j, count = 0;
3162
3163         if (!ext4_has_feature_bigalloc(sb))
3164                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3165                         sbi->s_itb_per_group + 2);
3166
3167         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3168                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3169         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3170         for (i = 0; i < ngroups; i++) {
3171                 gdp = ext4_get_group_desc(sb, i, NULL);
3172                 b = ext4_block_bitmap(sb, gdp);
3173                 if (b >= first_block && b <= last_block) {
3174                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3175                         count++;
3176                 }
3177                 b = ext4_inode_bitmap(sb, gdp);
3178                 if (b >= first_block && b <= last_block) {
3179                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3180                         count++;
3181                 }
3182                 b = ext4_inode_table(sb, gdp);
3183                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3184                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3185                                 int c = EXT4_B2C(sbi, b - first_block);
3186                                 ext4_set_bit(c, buf);
3187                                 count++;
3188                         }
3189                 if (i != grp)
3190                         continue;
3191                 s = 0;
3192                 if (ext4_bg_has_super(sb, grp)) {
3193                         ext4_set_bit(s++, buf);
3194                         count++;
3195                 }
3196                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3197                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3198                         count++;
3199                 }
3200         }
3201         if (!count)
3202                 return 0;
3203         return EXT4_CLUSTERS_PER_GROUP(sb) -
3204                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3205 }
3206
3207 /*
3208  * Compute the overhead and stash it in sbi->s_overhead
3209  */
3210 int ext4_calculate_overhead(struct super_block *sb)
3211 {
3212         struct ext4_sb_info *sbi = EXT4_SB(sb);
3213         struct ext4_super_block *es = sbi->s_es;
3214         struct inode *j_inode;
3215         unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3216         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3217         ext4_fsblk_t overhead = 0;
3218         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3219
3220         if (!buf)
3221                 return -ENOMEM;
3222
3223         /*
3224          * Compute the overhead (FS structures).  This is constant
3225          * for a given filesystem unless the number of block groups
3226          * changes so we cache the previous value until it does.
3227          */
3228
3229         /*
3230          * All of the blocks before first_data_block are overhead
3231          */
3232         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3233
3234         /*
3235          * Add the overhead found in each block group
3236          */
3237         for (i = 0; i < ngroups; i++) {
3238                 int blks;
3239
3240                 blks = count_overhead(sb, i, buf);
3241                 overhead += blks;
3242                 if (blks)
3243                         memset(buf, 0, PAGE_SIZE);
3244                 cond_resched();
3245         }
3246
3247         /*
3248          * Add the internal journal blocks whether the journal has been
3249          * loaded or not
3250          */
3251         if (sbi->s_journal && !sbi->journal_bdev)
3252                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3253         else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3254                 j_inode = ext4_get_journal_inode(sb, j_inum);
3255                 if (j_inode) {
3256                         j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3257                         overhead += EXT4_NUM_B2C(sbi, j_blocks);
3258                         iput(j_inode);
3259                 } else {
3260                         ext4_msg(sb, KERN_ERR, "can't get journal size");
3261                 }
3262         }
3263         sbi->s_overhead = overhead;
3264         smp_wmb();
3265         free_page((unsigned long) buf);
3266         return 0;
3267 }
3268
3269 static void ext4_set_resv_clusters(struct super_block *sb)
3270 {
3271         ext4_fsblk_t resv_clusters;
3272         struct ext4_sb_info *sbi = EXT4_SB(sb);
3273
3274         /*
3275          * There's no need to reserve anything when we aren't using extents.
3276          * The space estimates are exact, there are no unwritten extents,
3277          * hole punching doesn't need new metadata... This is needed especially
3278          * to keep ext2/3 backward compatibility.
3279          */
3280         if (!ext4_has_feature_extents(sb))
3281                 return;
3282         /*
3283          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3284          * This should cover the situations where we can not afford to run
3285          * out of space like for example punch hole, or converting
3286          * unwritten extents in delalloc path. In most cases such
3287          * allocation would require 1, or 2 blocks, higher numbers are
3288          * very rare.
3289          */
3290         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3291                          sbi->s_cluster_bits);
3292
3293         do_div(resv_clusters, 50);
3294         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3295
3296         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3297 }
3298
3299 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3300 {
3301         char *orig_data = kstrdup(data, GFP_KERNEL);
3302         struct buffer_head *bh;
3303         struct ext4_super_block *es = NULL;
3304         struct ext4_sb_info *sbi;
3305         ext4_fsblk_t block;
3306         ext4_fsblk_t sb_block = get_sb_block(&data);
3307         ext4_fsblk_t logical_sb_block;
3308         unsigned long offset = 0;
3309         unsigned long journal_devnum = 0;
3310         unsigned long def_mount_opts;
3311         struct inode *root;
3312         const char *descr;
3313         int ret = -ENOMEM;
3314         int blocksize, clustersize;
3315         unsigned int db_count;
3316         unsigned int i;
3317         int needs_recovery, has_huge_files, has_bigalloc;
3318         __u64 blocks_count;
3319         int err = 0;
3320         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3321         ext4_group_t first_not_zeroed;
3322
3323         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3324         if (!sbi)
3325                 goto out_free_orig;
3326
3327         sbi->s_blockgroup_lock =
3328                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3329         if (!sbi->s_blockgroup_lock) {
3330                 kfree(sbi);
3331                 goto out_free_orig;
3332         }
3333         sb->s_fs_info = sbi;
3334         sbi->s_sb = sb;
3335         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3336         sbi->s_sb_block = sb_block;
3337         if (sb->s_bdev->bd_part)
3338                 sbi->s_sectors_written_start =
3339                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3340
3341         /* Cleanup superblock name */
3342         strreplace(sb->s_id, '/', '!');
3343
3344         /* -EINVAL is default */
3345         ret = -EINVAL;
3346         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3347         if (!blocksize) {
3348                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3349                 goto out_fail;
3350         }
3351
3352         /*
3353          * The ext4 superblock will not be buffer aligned for other than 1kB
3354          * block sizes.  We need to calculate the offset from buffer start.
3355          */
3356         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3357                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3358                 offset = do_div(logical_sb_block, blocksize);
3359         } else {
3360                 logical_sb_block = sb_block;
3361         }
3362
3363         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3364                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3365                 goto out_fail;
3366         }
3367         /*
3368          * Note: s_es must be initialized as soon as possible because
3369          *       some ext4 macro-instructions depend on its value
3370          */
3371         es = (struct ext4_super_block *) (bh->b_data + offset);
3372         sbi->s_es = es;
3373         sb->s_magic = le16_to_cpu(es->s_magic);
3374         if (sb->s_magic != EXT4_SUPER_MAGIC)
3375                 goto cantfind_ext4;
3376         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3377
3378         /* Warn if metadata_csum and gdt_csum are both set. */
3379         if (ext4_has_feature_metadata_csum(sb) &&
3380             ext4_has_feature_gdt_csum(sb))
3381                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3382                              "redundant flags; please run fsck.");
3383
3384         /* Check for a known checksum algorithm */
3385         if (!ext4_verify_csum_type(sb, es)) {
3386                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3387                          "unknown checksum algorithm.");
3388                 silent = 1;
3389                 goto cantfind_ext4;
3390         }
3391
3392         /* Load the checksum driver */
3393         if (ext4_has_feature_metadata_csum(sb)) {
3394                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3395                 if (IS_ERR(sbi->s_chksum_driver)) {
3396                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3397                         ret = PTR_ERR(sbi->s_chksum_driver);
3398                         sbi->s_chksum_driver = NULL;
3399                         goto failed_mount;
3400                 }
3401         }
3402
3403         /* Check superblock checksum */
3404         if (!ext4_superblock_csum_verify(sb, es)) {
3405                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3406                          "invalid superblock checksum.  Run e2fsck?");
3407                 silent = 1;
3408                 ret = -EFSBADCRC;
3409                 goto cantfind_ext4;
3410         }
3411
3412         /* Precompute checksum seed for all metadata */
3413         if (ext4_has_feature_csum_seed(sb))
3414                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3415         else if (ext4_has_metadata_csum(sb))
3416                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3417                                                sizeof(es->s_uuid));
3418
3419         /* Set defaults before we parse the mount options */
3420         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3421         set_opt(sb, INIT_INODE_TABLE);
3422         if (def_mount_opts & EXT4_DEFM_DEBUG)
3423                 set_opt(sb, DEBUG);
3424         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3425                 set_opt(sb, GRPID);
3426         if (def_mount_opts & EXT4_DEFM_UID16)
3427                 set_opt(sb, NO_UID32);
3428         /* xattr user namespace & acls are now defaulted on */
3429         set_opt(sb, XATTR_USER);
3430 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3431         set_opt(sb, POSIX_ACL);
3432 #endif
3433         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3434         if (ext4_has_metadata_csum(sb))
3435                 set_opt(sb, JOURNAL_CHECKSUM);
3436
3437         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3438                 set_opt(sb, JOURNAL_DATA);
3439         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3440                 set_opt(sb, ORDERED_DATA);
3441         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3442                 set_opt(sb, WRITEBACK_DATA);
3443
3444         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3445                 set_opt(sb, ERRORS_PANIC);
3446         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3447                 set_opt(sb, ERRORS_CONT);
3448         else
3449                 set_opt(sb, ERRORS_RO);
3450         /* block_validity enabled by default; disable with noblock_validity */
3451         set_opt(sb, BLOCK_VALIDITY);
3452         if (def_mount_opts & EXT4_DEFM_DISCARD)
3453                 set_opt(sb, DISCARD);
3454
3455         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3456         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3457         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3458         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3459         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3460
3461         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3462                 set_opt(sb, BARRIER);
3463
3464         /*
3465          * enable delayed allocation by default
3466          * Use -o nodelalloc to turn it off
3467          */
3468         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3469             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3470                 set_opt(sb, DELALLOC);
3471
3472         /*
3473          * set default s_li_wait_mult for lazyinit, for the case there is
3474          * no mount option specified.
3475          */
3476         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3477
3478         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3479                            &journal_devnum, &journal_ioprio, 0)) {
3480                 ext4_msg(sb, KERN_WARNING,
3481                          "failed to parse options in superblock: %s",
3482                          sbi->s_es->s_mount_opts);
3483         }
3484         sbi->s_def_mount_opt = sbi->s_mount_opt;
3485         if (!parse_options((char *) data, sb, &journal_devnum,
3486                            &journal_ioprio, 0))
3487                 goto failed_mount;
3488
3489         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3490                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3491                             "with data=journal disables delayed "
3492                             "allocation and O_DIRECT support!\n");
3493                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3494                         ext4_msg(sb, KERN_ERR, "can't mount with "
3495                                  "both data=journal and delalloc");
3496                         goto failed_mount;
3497                 }
3498                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3499                         ext4_msg(sb, KERN_ERR, "can't mount with "
3500                                  "both data=journal and dioread_nolock");
3501                         goto failed_mount;
3502                 }
3503                 if (test_opt(sb, DAX)) {
3504                         ext4_msg(sb, KERN_ERR, "can't mount with "
3505                                  "both data=journal and dax");
3506                         goto failed_mount;
3507                 }
3508                 if (test_opt(sb, DELALLOC))
3509                         clear_opt(sb, DELALLOC);
3510         } else {
3511                 sb->s_iflags |= SB_I_CGROUPWB;
3512         }
3513
3514         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3515                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3516
3517         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3518             (ext4_has_compat_features(sb) ||
3519              ext4_has_ro_compat_features(sb) ||
3520              ext4_has_incompat_features(sb)))
3521                 ext4_msg(sb, KERN_WARNING,
3522                        "feature flags set on rev 0 fs, "
3523                        "running e2fsck is recommended");
3524
3525         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3526                 set_opt2(sb, HURD_COMPAT);
3527                 if (ext4_has_feature_64bit(sb)) {
3528                         ext4_msg(sb, KERN_ERR,
3529                                  "The Hurd can't support 64-bit file systems");
3530                         goto failed_mount;
3531                 }
3532         }
3533
3534         if (IS_EXT2_SB(sb)) {
3535                 if (ext2_feature_set_ok(sb))
3536                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3537                                  "using the ext4 subsystem");
3538                 else {
3539                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3540                                  "to feature incompatibilities");
3541                         goto failed_mount;
3542                 }
3543         }
3544
3545         if (IS_EXT3_SB(sb)) {
3546                 if (ext3_feature_set_ok(sb))
3547                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3548                                  "using the ext4 subsystem");
3549                 else {
3550                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3551                                  "to feature incompatibilities");
3552                         goto failed_mount;
3553                 }
3554         }
3555
3556         /*
3557          * Check feature flags regardless of the revision level, since we
3558          * previously didn't change the revision level when setting the flags,
3559          * so there is a chance incompat flags are set on a rev 0 filesystem.
3560          */
3561         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3562                 goto failed_mount;
3563
3564         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3565         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3566             blocksize > EXT4_MAX_BLOCK_SIZE) {
3567                 ext4_msg(sb, KERN_ERR,
3568                        "Unsupported filesystem blocksize %d", blocksize);
3569                 goto failed_mount;
3570         }
3571
3572         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3573                 ext4_msg(sb, KERN_ERR,
3574                          "Number of reserved GDT blocks insanely large: %d",
3575                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3576                 goto failed_mount;
3577         }
3578
3579         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3580                 err = bdev_dax_supported(sb, blocksize);
3581                 if (err)
3582                         goto failed_mount;
3583         }
3584
3585         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3586                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3587                          es->s_encryption_level);
3588                 goto failed_mount;
3589         }
3590
3591         if (sb->s_blocksize != blocksize) {
3592                 /* Validate the filesystem blocksize */
3593                 if (!sb_set_blocksize(sb, blocksize)) {
3594                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3595                                         blocksize);
3596                         goto failed_mount;
3597                 }
3598
3599                 brelse(bh);
3600                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3601                 offset = do_div(logical_sb_block, blocksize);
3602                 bh = sb_bread_unmovable(sb, logical_sb_block);
3603                 if (!bh) {
3604                         ext4_msg(sb, KERN_ERR,
3605                                "Can't read superblock on 2nd try");
3606                         goto failed_mount;
3607                 }
3608                 es = (struct ext4_super_block *)(bh->b_data + offset);
3609                 sbi->s_es = es;
3610                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3611                         ext4_msg(sb, KERN_ERR,
3612                                "Magic mismatch, very weird!");
3613                         goto failed_mount;
3614                 }
3615         }
3616
3617         has_huge_files = ext4_has_feature_huge_file(sb);
3618         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3619                                                       has_huge_files);
3620         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3621
3622         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3623                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3624                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3625         } else {
3626                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3627                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3628                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3629                     (!is_power_of_2(sbi->s_inode_size)) ||
3630                     (sbi->s_inode_size > blocksize)) {
3631                         ext4_msg(sb, KERN_ERR,
3632                                "unsupported inode size: %d",
3633                                sbi->s_inode_size);
3634                         goto failed_mount;
3635                 }
3636                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3637                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3638         }
3639
3640         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3641         if (ext4_has_feature_64bit(sb)) {
3642                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3643                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3644                     !is_power_of_2(sbi->s_desc_size)) {
3645                         ext4_msg(sb, KERN_ERR,
3646                                "unsupported descriptor size %lu",
3647                                sbi->s_desc_size);
3648                         goto failed_mount;
3649                 }
3650         } else
3651                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3652
3653         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3654         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3655         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3656                 goto cantfind_ext4;
3657
3658         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3659         if (sbi->s_inodes_per_block == 0)
3660                 goto cantfind_ext4;
3661         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3662                                         sbi->s_inodes_per_block;
3663         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3664         sbi->s_sbh = bh;
3665         sbi->s_mount_state = le16_to_cpu(es->s_state);
3666         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3667         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3668
3669         for (i = 0; i < 4; i++)
3670                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3671         sbi->s_def_hash_version = es->s_def_hash_version;
3672         if (ext4_has_feature_dir_index(sb)) {
3673                 i = le32_to_cpu(es->s_flags);
3674                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3675                         sbi->s_hash_unsigned = 3;
3676                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3677 #ifdef __CHAR_UNSIGNED__
3678                         if (!(sb->s_flags & MS_RDONLY))
3679                                 es->s_flags |=
3680                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3681                         sbi->s_hash_unsigned = 3;
3682 #else
3683                         if (!(sb->s_flags & MS_RDONLY))
3684                                 es->s_flags |=
3685                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3686 #endif
3687                 }
3688         }
3689
3690         /* Handle clustersize */
3691         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3692         has_bigalloc = ext4_has_feature_bigalloc(sb);
3693         if (has_bigalloc) {
3694                 if (clustersize < blocksize) {
3695                         ext4_msg(sb, KERN_ERR,
3696                                  "cluster size (%d) smaller than "
3697                                  "block size (%d)", clustersize, blocksize);
3698                         goto failed_mount;
3699                 }
3700                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3701                         le32_to_cpu(es->s_log_block_size);
3702                 sbi->s_clusters_per_group =
3703                         le32_to_cpu(es->s_clusters_per_group);
3704                 if (sbi->s_clusters_per_group > blocksize * 8) {
3705                         ext4_msg(sb, KERN_ERR,
3706                                  "#clusters per group too big: %lu",
3707                                  sbi->s_clusters_per_group);
3708                         goto failed_mount;
3709                 }
3710                 if (sbi->s_blocks_per_group !=
3711                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3712                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3713                                  "clusters per group (%lu) inconsistent",
3714                                  sbi->s_blocks_per_group,
3715                                  sbi->s_clusters_per_group);
3716                         goto failed_mount;
3717                 }
3718         } else {
3719                 if (clustersize != blocksize) {
3720                         ext4_warning(sb, "fragment/cluster size (%d) != "
3721                                      "block size (%d)", clustersize,
3722                                      blocksize);
3723                         clustersize = blocksize;
3724                 }
3725                 if (sbi->s_blocks_per_group > blocksize * 8) {
3726                         ext4_msg(sb, KERN_ERR,
3727                                  "#blocks per group too big: %lu",
3728                                  sbi->s_blocks_per_group);
3729                         goto failed_mount;
3730                 }
3731                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3732                 sbi->s_cluster_bits = 0;
3733         }
3734         sbi->s_cluster_ratio = clustersize / blocksize;
3735
3736         if (sbi->s_inodes_per_group > blocksize * 8) {
3737                 ext4_msg(sb, KERN_ERR,
3738                        "#inodes per group too big: %lu",
3739                        sbi->s_inodes_per_group);
3740                 goto failed_mount;
3741         }
3742
3743         /* Do we have standard group size of clustersize * 8 blocks ? */
3744         if (sbi->s_blocks_per_group == clustersize << 3)
3745                 set_opt2(sb, STD_GROUP_SIZE);
3746
3747         /*
3748          * Test whether we have more sectors than will fit in sector_t,
3749          * and whether the max offset is addressable by the page cache.
3750          */
3751         err = generic_check_addressable(sb->s_blocksize_bits,
3752                                         ext4_blocks_count(es));
3753         if (err) {
3754                 ext4_msg(sb, KERN_ERR, "filesystem"
3755                          " too large to mount safely on this system");
3756                 if (sizeof(sector_t) < 8)
3757                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3758                 goto failed_mount;
3759         }
3760
3761         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3762                 goto cantfind_ext4;
3763
3764         /* check blocks count against device size */
3765         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3766         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3767                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3768                        "exceeds size of device (%llu blocks)",
3769                        ext4_blocks_count(es), blocks_count);
3770                 goto failed_mount;
3771         }
3772
3773         /*
3774          * It makes no sense for the first data block to be beyond the end
3775          * of the filesystem.
3776          */
3777         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3778                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3779                          "block %u is beyond end of filesystem (%llu)",
3780                          le32_to_cpu(es->s_first_data_block),
3781                          ext4_blocks_count(es));
3782                 goto failed_mount;
3783         }
3784         blocks_count = (ext4_blocks_count(es) -
3785                         le32_to_cpu(es->s_first_data_block) +
3786                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3787         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3788         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3789                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3790                        "(block count %llu, first data block %u, "
3791                        "blocks per group %lu)", sbi->s_groups_count,
3792                        ext4_blocks_count(es),
3793                        le32_to_cpu(es->s_first_data_block),
3794                        EXT4_BLOCKS_PER_GROUP(sb));
3795                 goto failed_mount;
3796         }
3797         sbi->s_groups_count = blocks_count;
3798         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3799                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3800         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3801                    EXT4_DESC_PER_BLOCK(sb);
3802         sbi->s_group_desc = ext4_kvmalloc(db_count *
3803                                           sizeof(struct buffer_head *),
3804                                           GFP_KERNEL);
3805         if (sbi->s_group_desc == NULL) {
3806                 ext4_msg(sb, KERN_ERR, "not enough memory");
3807                 ret = -ENOMEM;
3808                 goto failed_mount;
3809         }
3810
3811         bgl_lock_init(sbi->s_blockgroup_lock);
3812
3813         for (i = 0; i < db_count; i++) {
3814                 block = descriptor_loc(sb, logical_sb_block, i);
3815                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3816                 if (!sbi->s_group_desc[i]) {
3817                         ext4_msg(sb, KERN_ERR,
3818                                "can't read group descriptor %d", i);
3819                         db_count = i;
3820                         goto failed_mount2;
3821                 }
3822         }
3823         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3824                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3825                 ret = -EFSCORRUPTED;
3826                 goto failed_mount2;
3827         }
3828
3829         sbi->s_gdb_count = db_count;
3830         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3831         spin_lock_init(&sbi->s_next_gen_lock);
3832
3833         setup_timer(&sbi->s_err_report, print_daily_error_info,
3834                 (unsigned long) sb);
3835
3836         /* Register extent status tree shrinker */
3837         if (ext4_es_register_shrinker(sbi))
3838                 goto failed_mount3;
3839
3840         sbi->s_stripe = ext4_get_stripe_size(sbi);
3841         sbi->s_extent_max_zeroout_kb = 32;
3842
3843         /*
3844          * set up enough so that it can read an inode
3845          */
3846         sb->s_op = &ext4_sops;
3847         sb->s_export_op = &ext4_export_ops;
3848         sb->s_xattr = ext4_xattr_handlers;
3849         sb->s_cop = &ext4_cryptops;
3850 #ifdef CONFIG_QUOTA
3851         sb->dq_op = &ext4_quota_operations;
3852         if (ext4_has_feature_quota(sb))
3853                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3854         else
3855                 sb->s_qcop = &ext4_qctl_operations;
3856         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3857 #endif
3858         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3859
3860         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3861         mutex_init(&sbi->s_orphan_lock);
3862
3863         sb->s_root = NULL;
3864
3865         needs_recovery = (es->s_last_orphan != 0 ||
3866                           ext4_has_feature_journal_needs_recovery(sb));
3867
3868         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3869                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3870                         goto failed_mount3a;
3871
3872         /*
3873          * The first inode we look at is the journal inode.  Don't try
3874          * root first: it may be modified in the journal!
3875          */
3876         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3877                 if (ext4_load_journal(sb, es, journal_devnum))
3878                         goto failed_mount3a;
3879         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3880                    ext4_has_feature_journal_needs_recovery(sb)) {
3881                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3882                        "suppressed and not mounted read-only");
3883                 goto failed_mount_wq;
3884         } else {
3885                 /* Nojournal mode, all journal mount options are illegal */
3886                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3887                         ext4_msg(sb, KERN_ERR, "can't mount with "
3888                                  "journal_checksum, fs mounted w/o journal");
3889                         goto failed_mount_wq;
3890                 }
3891                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3892                         ext4_msg(sb, KERN_ERR, "can't mount with "
3893                                  "journal_async_commit, fs mounted w/o journal");
3894                         goto failed_mount_wq;
3895                 }
3896                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3897                         ext4_msg(sb, KERN_ERR, "can't mount with "
3898                                  "commit=%lu, fs mounted w/o journal",
3899                                  sbi->s_commit_interval / HZ);
3900                         goto failed_mount_wq;
3901                 }
3902                 if (EXT4_MOUNT_DATA_FLAGS &
3903                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3904                         ext4_msg(sb, KERN_ERR, "can't mount with "
3905                                  "data=, fs mounted w/o journal");
3906                         goto failed_mount_wq;
3907                 }
3908                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3909                 clear_opt(sb, JOURNAL_CHECKSUM);
3910                 clear_opt(sb, DATA_FLAGS);
3911                 sbi->s_journal = NULL;
3912                 needs_recovery = 0;
3913                 goto no_journal;
3914         }
3915
3916         if (ext4_has_feature_64bit(sb) &&
3917             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3918                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3919                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3920                 goto failed_mount_wq;
3921         }
3922
3923         if (!set_journal_csum_feature_set(sb)) {
3924                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3925                          "feature set");
3926                 goto failed_mount_wq;
3927         }
3928
3929         /* We have now updated the journal if required, so we can
3930          * validate the data journaling mode. */
3931         switch (test_opt(sb, DATA_FLAGS)) {
3932         case 0:
3933                 /* No mode set, assume a default based on the journal
3934                  * capabilities: ORDERED_DATA if the journal can
3935                  * cope, else JOURNAL_DATA
3936                  */
3937                 if (jbd2_journal_check_available_features
3938                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3939                         set_opt(sb, ORDERED_DATA);
3940                 else
3941                         set_opt(sb, JOURNAL_DATA);
3942                 break;
3943
3944         case EXT4_MOUNT_ORDERED_DATA:
3945         case EXT4_MOUNT_WRITEBACK_DATA:
3946                 if (!jbd2_journal_check_available_features
3947                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3948                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3949                                "requested data journaling mode");
3950                         goto failed_mount_wq;
3951                 }
3952         default:
3953                 break;
3954         }
3955         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3956
3957         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3958
3959 no_journal:
3960         sbi->s_mb_cache = ext4_xattr_create_cache();
3961         if (!sbi->s_mb_cache) {
3962                 ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
3963                 goto failed_mount_wq;
3964         }
3965
3966         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
3967             (blocksize != PAGE_SIZE)) {
3968                 ext4_msg(sb, KERN_ERR,
3969                          "Unsupported blocksize for fs encryption");
3970                 goto failed_mount_wq;
3971         }
3972
3973         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
3974             !ext4_has_feature_encrypt(sb)) {
3975                 ext4_set_feature_encrypt(sb);
3976                 ext4_commit_super(sb, 1);
3977         }
3978
3979         /*
3980          * Get the # of file system overhead blocks from the
3981          * superblock if present.
3982          */
3983         if (es->s_overhead_clusters)
3984                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3985         else {
3986                 err = ext4_calculate_overhead(sb);
3987                 if (err)
3988                         goto failed_mount_wq;
3989         }
3990
3991         /*
3992          * The maximum number of concurrent works can be high and
3993          * concurrency isn't really necessary.  Limit it to 1.
3994          */
3995         EXT4_SB(sb)->rsv_conversion_wq =
3996                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3997         if (!EXT4_SB(sb)->rsv_conversion_wq) {
3998                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3999                 ret = -ENOMEM;
4000                 goto failed_mount4;
4001         }
4002
4003         /*
4004          * The jbd2_journal_load will have done any necessary log recovery,
4005          * so we can safely mount the rest of the filesystem now.
4006          */
4007
4008         root = ext4_iget(sb, EXT4_ROOT_INO);
4009         if (IS_ERR(root)) {
4010                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4011                 ret = PTR_ERR(root);
4012                 root = NULL;
4013                 goto failed_mount4;
4014         }
4015         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4016                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4017                 iput(root);
4018                 goto failed_mount4;
4019         }
4020         sb->s_root = d_make_root(root);
4021         if (!sb->s_root) {
4022                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4023                 ret = -ENOMEM;
4024                 goto failed_mount4;
4025         }
4026
4027         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4028                 sb->s_flags |= MS_RDONLY;
4029
4030         /* determine the minimum size of new large inodes, if present */
4031         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4032                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4033                                                      EXT4_GOOD_OLD_INODE_SIZE;
4034                 if (ext4_has_feature_extra_isize(sb)) {
4035                         if (sbi->s_want_extra_isize <
4036                             le16_to_cpu(es->s_want_extra_isize))
4037                                 sbi->s_want_extra_isize =
4038                                         le16_to_cpu(es->s_want_extra_isize);
4039                         if (sbi->s_want_extra_isize <
4040                             le16_to_cpu(es->s_min_extra_isize))
4041                                 sbi->s_want_extra_isize =
4042                                         le16_to_cpu(es->s_min_extra_isize);
4043                 }
4044         }
4045         /* Check if enough inode space is available */
4046         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4047                                                         sbi->s_inode_size) {
4048                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4049                                                        EXT4_GOOD_OLD_INODE_SIZE;
4050                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4051                          "available");
4052         }
4053
4054         ext4_set_resv_clusters(sb);
4055
4056         err = ext4_setup_system_zone(sb);
4057         if (err) {
4058                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4059                          "zone (%d)", err);
4060                 goto failed_mount4a;
4061         }
4062
4063         ext4_ext_init(sb);
4064         err = ext4_mb_init(sb);
4065         if (err) {
4066                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4067                          err);
4068                 goto failed_mount5;
4069         }
4070
4071         block = ext4_count_free_clusters(sb);
4072         ext4_free_blocks_count_set(sbi->s_es,
4073                                    EXT4_C2B(sbi, block));
4074         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4075                                   GFP_KERNEL);
4076         if (!err) {
4077                 unsigned long freei = ext4_count_free_inodes(sb);
4078                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4079                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4080                                           GFP_KERNEL);
4081         }
4082         if (!err)
4083                 err = percpu_counter_init(&sbi->s_dirs_counter,
4084                                           ext4_count_dirs(sb), GFP_KERNEL);
4085         if (!err)
4086                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4087                                           GFP_KERNEL);
4088         if (!err)
4089                 err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4090
4091         if (err) {
4092                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4093                 goto failed_mount6;
4094         }
4095
4096         if (ext4_has_feature_flex_bg(sb))
4097                 if (!ext4_fill_flex_info(sb)) {
4098                         ext4_msg(sb, KERN_ERR,
4099                                "unable to initialize "
4100                                "flex_bg meta info!");
4101                         goto failed_mount6;
4102                 }
4103
4104         err = ext4_register_li_request(sb, first_not_zeroed);
4105         if (err)
4106                 goto failed_mount6;
4107
4108         err = ext4_register_sysfs(sb);
4109         if (err)
4110                 goto failed_mount7;
4111
4112 #ifdef CONFIG_QUOTA
4113         /* Enable quota usage during mount. */
4114         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4115                 err = ext4_enable_quotas(sb);
4116                 if (err)
4117                         goto failed_mount8;
4118         }
4119 #endif  /* CONFIG_QUOTA */
4120
4121         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4122         ext4_orphan_cleanup(sb, es);
4123         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4124         if (needs_recovery) {
4125                 ext4_msg(sb, KERN_INFO, "recovery complete");
4126                 ext4_mark_recovery_complete(sb, es);
4127         }
4128         if (EXT4_SB(sb)->s_journal) {
4129                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4130                         descr = " journalled data mode";
4131                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4132                         descr = " ordered data mode";
4133                 else
4134                         descr = " writeback data mode";
4135         } else
4136                 descr = "out journal";
4137
4138         if (test_opt(sb, DISCARD)) {
4139                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4140                 if (!blk_queue_discard(q))
4141                         ext4_msg(sb, KERN_WARNING,
4142                                  "mounting with \"discard\" option, but "
4143                                  "the device does not support discard");
4144         }
4145
4146         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4147                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4148                          "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4149                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4150
4151         if (es->s_error_count)
4152                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4153
4154         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4155         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4156         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4157         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4158
4159         kfree(orig_data);
4160 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4161         memcpy(sbi->key_prefix, EXT4_KEY_DESC_PREFIX,
4162                                 EXT4_KEY_DESC_PREFIX_SIZE);
4163         sbi->key_prefix_size = EXT4_KEY_DESC_PREFIX_SIZE;
4164 #endif
4165         return 0;
4166
4167 cantfind_ext4:
4168         if (!silent)
4169                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4170         goto failed_mount;
4171
4172 #ifdef CONFIG_QUOTA
4173 failed_mount8:
4174         ext4_unregister_sysfs(sb);
4175 #endif
4176 failed_mount7:
4177         ext4_unregister_li_request(sb);
4178 failed_mount6:
4179         ext4_mb_release(sb);
4180         if (sbi->s_flex_groups)
4181                 kvfree(sbi->s_flex_groups);
4182         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4183         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4184         percpu_counter_destroy(&sbi->s_dirs_counter);
4185         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4186 failed_mount5:
4187         ext4_ext_release(sb);
4188         ext4_release_system_zone(sb);
4189 failed_mount4a:
4190         dput(sb->s_root);
4191         sb->s_root = NULL;
4192 failed_mount4:
4193         ext4_msg(sb, KERN_ERR, "mount failed");
4194         if (EXT4_SB(sb)->rsv_conversion_wq)
4195                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4196 failed_mount_wq:
4197         if (sbi->s_mb_cache) {
4198                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
4199                 sbi->s_mb_cache = NULL;
4200         }
4201         if (sbi->s_journal) {
4202                 jbd2_journal_destroy(sbi->s_journal);
4203                 sbi->s_journal = NULL;
4204         }
4205 failed_mount3a:
4206         ext4_es_unregister_shrinker(sbi);
4207 failed_mount3:
4208         del_timer_sync(&sbi->s_err_report);
4209         if (sbi->s_mmp_tsk)
4210                 kthread_stop(sbi->s_mmp_tsk);
4211 failed_mount2:
4212         for (i = 0; i < db_count; i++)
4213                 brelse(sbi->s_group_desc[i]);
4214         kvfree(sbi->s_group_desc);
4215 failed_mount:
4216         if (sbi->s_chksum_driver)
4217                 crypto_free_shash(sbi->s_chksum_driver);
4218 #ifdef CONFIG_QUOTA
4219         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4220                 kfree(sbi->s_qf_names[i]);
4221 #endif
4222         ext4_blkdev_remove(sbi);
4223         brelse(bh);
4224 out_fail:
4225         sb->s_fs_info = NULL;
4226         kfree(sbi->s_blockgroup_lock);
4227         kfree(sbi);
4228 out_free_orig:
4229         kfree(orig_data);
4230         return err ? err : ret;
4231 }
4232
4233 /*
4234  * Setup any per-fs journal parameters now.  We'll do this both on
4235  * initial mount, once the journal has been initialised but before we've
4236  * done any recovery; and again on any subsequent remount.
4237  */
4238 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4239 {
4240         struct ext4_sb_info *sbi = EXT4_SB(sb);
4241
4242         journal->j_commit_interval = sbi->s_commit_interval;
4243         journal->j_min_batch_time = sbi->s_min_batch_time;
4244         journal->j_max_batch_time = sbi->s_max_batch_time;
4245
4246         write_lock(&journal->j_state_lock);
4247         if (test_opt(sb, BARRIER))
4248                 journal->j_flags |= JBD2_BARRIER;
4249         else
4250                 journal->j_flags &= ~JBD2_BARRIER;
4251         if (test_opt(sb, DATA_ERR_ABORT))
4252                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4253         else
4254                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4255         write_unlock(&journal->j_state_lock);
4256 }
4257
4258 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4259                                              unsigned int journal_inum)
4260 {
4261         struct inode *journal_inode;
4262
4263         /*
4264          * Test for the existence of a valid inode on disk.  Bad things
4265          * happen if we iget() an unused inode, as the subsequent iput()
4266          * will try to delete it.
4267          */
4268         journal_inode = ext4_iget(sb, journal_inum);
4269         if (IS_ERR(journal_inode)) {
4270                 ext4_msg(sb, KERN_ERR, "no journal found");
4271                 return NULL;
4272         }
4273         if (!journal_inode->i_nlink) {
4274                 make_bad_inode(journal_inode);
4275                 iput(journal_inode);
4276                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4277                 return NULL;
4278         }
4279
4280         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4281                   journal_inode, journal_inode->i_size);
4282         if (!S_ISREG(journal_inode->i_mode)) {
4283                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4284                 iput(journal_inode);
4285                 return NULL;
4286         }
4287         return journal_inode;
4288 }
4289
4290 static journal_t *ext4_get_journal(struct super_block *sb,
4291                                    unsigned int journal_inum)
4292 {
4293         struct inode *journal_inode;
4294         journal_t *journal;
4295
4296         BUG_ON(!ext4_has_feature_journal(sb));
4297
4298         journal_inode = ext4_get_journal_inode(sb, journal_inum);
4299         if (!journal_inode)
4300                 return NULL;
4301
4302         journal = jbd2_journal_init_inode(journal_inode);
4303         if (!journal) {
4304                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4305                 iput(journal_inode);
4306                 return NULL;
4307         }
4308         journal->j_private = sb;
4309         ext4_init_journal_params(sb, journal);
4310         return journal;
4311 }
4312
4313 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4314                                        dev_t j_dev)
4315 {
4316         struct buffer_head *bh;
4317         journal_t *journal;
4318         ext4_fsblk_t start;
4319         ext4_fsblk_t len;
4320         int hblock, blocksize;
4321         ext4_fsblk_t sb_block;
4322         unsigned long offset;
4323         struct ext4_super_block *es;
4324         struct block_device *bdev;
4325
4326         BUG_ON(!ext4_has_feature_journal(sb));
4327
4328         bdev = ext4_blkdev_get(j_dev, sb);
4329         if (bdev == NULL)
4330                 return NULL;
4331
4332         blocksize = sb->s_blocksize;
4333         hblock = bdev_logical_block_size(bdev);
4334         if (blocksize < hblock) {
4335                 ext4_msg(sb, KERN_ERR,
4336                         "blocksize too small for journal device");
4337                 goto out_bdev;
4338         }
4339
4340         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4341         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4342         set_blocksize(bdev, blocksize);
4343         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4344                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4345                        "external journal");
4346                 goto out_bdev;
4347         }
4348
4349         es = (struct ext4_super_block *) (bh->b_data + offset);
4350         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4351             !(le32_to_cpu(es->s_feature_incompat) &
4352               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4353                 ext4_msg(sb, KERN_ERR, "external journal has "
4354                                         "bad superblock");
4355                 brelse(bh);
4356                 goto out_bdev;
4357         }
4358
4359         if ((le32_to_cpu(es->s_feature_ro_compat) &
4360              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4361             es->s_checksum != ext4_superblock_csum(sb, es)) {
4362                 ext4_msg(sb, KERN_ERR, "external journal has "
4363                                        "corrupt superblock");
4364                 brelse(bh);
4365                 goto out_bdev;
4366         }
4367
4368         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4369                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4370                 brelse(bh);
4371                 goto out_bdev;
4372         }
4373
4374         len = ext4_blocks_count(es);
4375         start = sb_block + 1;
4376         brelse(bh);     /* we're done with the superblock */
4377
4378         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4379                                         start, len, blocksize);
4380         if (!journal) {
4381                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4382                 goto out_bdev;
4383         }
4384         journal->j_private = sb;
4385         ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4386         wait_on_buffer(journal->j_sb_buffer);
4387         if (!buffer_uptodate(journal->j_sb_buffer)) {
4388                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4389                 goto out_journal;
4390         }
4391         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4392                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4393                                         "user (unsupported) - %d",
4394                         be32_to_cpu(journal->j_superblock->s_nr_users));
4395                 goto out_journal;
4396         }
4397         EXT4_SB(sb)->journal_bdev = bdev;
4398         ext4_init_journal_params(sb, journal);
4399         return journal;
4400
4401 out_journal:
4402         jbd2_journal_destroy(journal);
4403 out_bdev:
4404         ext4_blkdev_put(bdev);
4405         return NULL;
4406 }
4407
4408 static int ext4_load_journal(struct super_block *sb,
4409                              struct ext4_super_block *es,
4410                              unsigned long journal_devnum)
4411 {
4412         journal_t *journal;
4413         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4414         dev_t journal_dev;
4415         int err = 0;
4416         int really_read_only;
4417
4418         BUG_ON(!ext4_has_feature_journal(sb));
4419
4420         if (journal_devnum &&
4421             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4422                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4423                         "numbers have changed");
4424                 journal_dev = new_decode_dev(journal_devnum);
4425         } else
4426                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4427
4428         really_read_only = bdev_read_only(sb->s_bdev);
4429
4430         /*
4431          * Are we loading a blank journal or performing recovery after a
4432          * crash?  For recovery, we need to check in advance whether we
4433          * can get read-write access to the device.
4434          */
4435         if (ext4_has_feature_journal_needs_recovery(sb)) {
4436                 if (sb->s_flags & MS_RDONLY) {
4437                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4438                                         "required on readonly filesystem");
4439                         if (really_read_only) {
4440                                 ext4_msg(sb, KERN_ERR, "write access "
4441                                         "unavailable, cannot proceed");
4442                                 return -EROFS;
4443                         }
4444                         ext4_msg(sb, KERN_INFO, "write access will "
4445                                "be enabled during recovery");
4446                 }
4447         }
4448
4449         if (journal_inum && journal_dev) {
4450                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4451                        "and inode journals!");
4452                 return -EINVAL;
4453         }
4454
4455         if (journal_inum) {
4456                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4457                         return -EINVAL;
4458         } else {
4459                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4460                         return -EINVAL;
4461         }
4462
4463         if (!(journal->j_flags & JBD2_BARRIER))
4464                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4465
4466         if (!ext4_has_feature_journal_needs_recovery(sb))
4467                 err = jbd2_journal_wipe(journal, !really_read_only);
4468         if (!err) {
4469                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4470                 if (save)
4471                         memcpy(save, ((char *) es) +
4472                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4473                 err = jbd2_journal_load(journal);
4474                 if (save)
4475                         memcpy(((char *) es) + EXT4_S_ERR_START,
4476                                save, EXT4_S_ERR_LEN);
4477                 kfree(save);
4478         }
4479
4480         if (err) {
4481                 ext4_msg(sb, KERN_ERR, "error loading journal");
4482                 jbd2_journal_destroy(journal);
4483                 return err;
4484         }
4485
4486         EXT4_SB(sb)->s_journal = journal;
4487         ext4_clear_journal_err(sb, es);
4488
4489         if (!really_read_only && journal_devnum &&
4490             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4491                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4492
4493                 /* Make sure we flush the recovery flag to disk. */
4494                 ext4_commit_super(sb, 1);
4495         }
4496
4497         return 0;
4498 }
4499
4500 static int ext4_commit_super(struct super_block *sb, int sync)
4501 {
4502         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4503         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4504         int error = 0;
4505
4506         if (!sbh || block_device_ejected(sb))
4507                 return error;
4508         /*
4509          * If the file system is mounted read-only, don't update the
4510          * superblock write time.  This avoids updating the superblock
4511          * write time when we are mounting the root file system
4512          * read/only but we need to replay the journal; at that point,
4513          * for people who are east of GMT and who make their clock
4514          * tick in localtime for Windows bug-for-bug compatibility,
4515          * the clock is set in the future, and this will cause e2fsck
4516          * to complain and force a full file system check.
4517          */
4518         if (!(sb->s_flags & MS_RDONLY))
4519                 es->s_wtime = cpu_to_le32(get_seconds());
4520         if (sb->s_bdev->bd_part)
4521                 es->s_kbytes_written =
4522                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4523                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4524                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4525         else
4526                 es->s_kbytes_written =
4527                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4528         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4529                 ext4_free_blocks_count_set(es,
4530                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4531                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4532         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4533                 es->s_free_inodes_count =
4534                         cpu_to_le32(percpu_counter_sum_positive(
4535                                 &EXT4_SB(sb)->s_freeinodes_counter));
4536         BUFFER_TRACE(sbh, "marking dirty");
4537         ext4_superblock_csum_set(sb);
4538         lock_buffer(sbh);
4539         if (buffer_write_io_error(sbh)) {
4540                 /*
4541                  * Oh, dear.  A previous attempt to write the
4542                  * superblock failed.  This could happen because the
4543                  * USB device was yanked out.  Or it could happen to
4544                  * be a transient write error and maybe the block will
4545                  * be remapped.  Nothing we can do but to retry the
4546                  * write and hope for the best.
4547                  */
4548                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4549                        "superblock detected");
4550                 clear_buffer_write_io_error(sbh);
4551                 set_buffer_uptodate(sbh);
4552         }
4553         mark_buffer_dirty(sbh);
4554         unlock_buffer(sbh);
4555         if (sync) {
4556                 error = __sync_dirty_buffer(sbh,
4557                         test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
4558                 if (error)
4559                         return error;
4560
4561                 error = buffer_write_io_error(sbh);
4562                 if (error) {
4563                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4564                                "superblock");
4565                         clear_buffer_write_io_error(sbh);
4566                         set_buffer_uptodate(sbh);
4567                 }
4568         }
4569         return error;
4570 }
4571
4572 /*
4573  * Have we just finished recovery?  If so, and if we are mounting (or
4574  * remounting) the filesystem readonly, then we will end up with a
4575  * consistent fs on disk.  Record that fact.
4576  */
4577 static void ext4_mark_recovery_complete(struct super_block *sb,
4578                                         struct ext4_super_block *es)
4579 {
4580         journal_t *journal = EXT4_SB(sb)->s_journal;
4581
4582         if (!ext4_has_feature_journal(sb)) {
4583                 BUG_ON(journal != NULL);
4584                 return;
4585         }
4586         jbd2_journal_lock_updates(journal);
4587         if (jbd2_journal_flush(journal) < 0)
4588                 goto out;
4589
4590         if (ext4_has_feature_journal_needs_recovery(sb) &&
4591             sb->s_flags & MS_RDONLY) {
4592                 ext4_clear_feature_journal_needs_recovery(sb);
4593                 ext4_commit_super(sb, 1);
4594         }
4595
4596 out:
4597         jbd2_journal_unlock_updates(journal);
4598 }
4599
4600 /*
4601  * If we are mounting (or read-write remounting) a filesystem whose journal
4602  * has recorded an error from a previous lifetime, move that error to the
4603  * main filesystem now.
4604  */
4605 static void ext4_clear_journal_err(struct super_block *sb,
4606                                    struct ext4_super_block *es)
4607 {
4608         journal_t *journal;
4609         int j_errno;
4610         const char *errstr;
4611
4612         BUG_ON(!ext4_has_feature_journal(sb));
4613
4614         journal = EXT4_SB(sb)->s_journal;
4615
4616         /*
4617          * Now check for any error status which may have been recorded in the
4618          * journal by a prior ext4_error() or ext4_abort()
4619          */
4620
4621         j_errno = jbd2_journal_errno(journal);
4622         if (j_errno) {
4623                 char nbuf[16];
4624
4625                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4626                 ext4_warning(sb, "Filesystem error recorded "
4627                              "from previous mount: %s", errstr);
4628                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4629
4630                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4631                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4632                 ext4_commit_super(sb, 1);
4633
4634                 jbd2_journal_clear_err(journal);
4635                 jbd2_journal_update_sb_errno(journal);
4636         }
4637 }
4638
4639 /*
4640  * Force the running and committing transactions to commit,
4641  * and wait on the commit.
4642  */
4643 int ext4_force_commit(struct super_block *sb)
4644 {
4645         journal_t *journal;
4646
4647         if (sb->s_flags & MS_RDONLY)
4648                 return 0;
4649
4650         journal = EXT4_SB(sb)->s_journal;
4651         return ext4_journal_force_commit(journal);
4652 }
4653
4654 static int ext4_sync_fs(struct super_block *sb, int wait)
4655 {
4656         int ret = 0;
4657         tid_t target;
4658         bool needs_barrier = false;
4659         struct ext4_sb_info *sbi = EXT4_SB(sb);
4660
4661         trace_ext4_sync_fs(sb, wait);
4662         flush_workqueue(sbi->rsv_conversion_wq);
4663         /*
4664          * Writeback quota in non-journalled quota case - journalled quota has
4665          * no dirty dquots
4666          */
4667         dquot_writeback_dquots(sb, -1);
4668         /*
4669          * Data writeback is possible w/o journal transaction, so barrier must
4670          * being sent at the end of the function. But we can skip it if
4671          * transaction_commit will do it for us.
4672          */
4673         if (sbi->s_journal) {
4674                 target = jbd2_get_latest_transaction(sbi->s_journal);
4675                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4676                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4677                         needs_barrier = true;
4678
4679                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4680                         if (wait)
4681                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4682                                                            target);
4683                 }
4684         } else if (wait && test_opt(sb, BARRIER))
4685                 needs_barrier = true;
4686         if (needs_barrier) {
4687                 int err;
4688                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4689                 if (!ret)
4690                         ret = err;
4691         }
4692
4693         return ret;
4694 }
4695
4696 /*
4697  * LVM calls this function before a (read-only) snapshot is created.  This
4698  * gives us a chance to flush the journal completely and mark the fs clean.
4699  *
4700  * Note that only this function cannot bring a filesystem to be in a clean
4701  * state independently. It relies on upper layer to stop all data & metadata
4702  * modifications.
4703  */
4704 static int ext4_freeze(struct super_block *sb)
4705 {
4706         int error = 0;
4707         journal_t *journal;
4708
4709         if (sb->s_flags & MS_RDONLY)
4710                 return 0;
4711
4712         journal = EXT4_SB(sb)->s_journal;
4713
4714         if (journal) {
4715                 /* Now we set up the journal barrier. */
4716                 jbd2_journal_lock_updates(journal);
4717
4718                 /*
4719                  * Don't clear the needs_recovery flag if we failed to
4720                  * flush the journal.
4721                  */
4722                 error = jbd2_journal_flush(journal);
4723                 if (error < 0)
4724                         goto out;
4725
4726                 /* Journal blocked and flushed, clear needs_recovery flag. */
4727                 ext4_clear_feature_journal_needs_recovery(sb);
4728         }
4729
4730         error = ext4_commit_super(sb, 1);
4731 out:
4732         if (journal)
4733                 /* we rely on upper layer to stop further updates */
4734                 jbd2_journal_unlock_updates(journal);
4735         return error;
4736 }
4737
4738 /*
4739  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4740  * flag here, even though the filesystem is not technically dirty yet.
4741  */
4742 static int ext4_unfreeze(struct super_block *sb)
4743 {
4744         if (sb->s_flags & MS_RDONLY)
4745                 return 0;
4746
4747         if (EXT4_SB(sb)->s_journal) {
4748                 /* Reset the needs_recovery flag before the fs is unlocked. */
4749                 ext4_set_feature_journal_needs_recovery(sb);
4750         }
4751
4752         ext4_commit_super(sb, 1);
4753         return 0;
4754 }
4755
4756 /*
4757  * Structure to save mount options for ext4_remount's benefit
4758  */
4759 struct ext4_mount_options {
4760         unsigned long s_mount_opt;
4761         unsigned long s_mount_opt2;
4762         kuid_t s_resuid;
4763         kgid_t s_resgid;
4764         unsigned long s_commit_interval;
4765         u32 s_min_batch_time, s_max_batch_time;
4766 #ifdef CONFIG_QUOTA
4767         int s_jquota_fmt;
4768         char *s_qf_names[EXT4_MAXQUOTAS];
4769 #endif
4770 };
4771
4772 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4773 {
4774         struct ext4_super_block *es;
4775         struct ext4_sb_info *sbi = EXT4_SB(sb);
4776         unsigned long old_sb_flags;
4777         struct ext4_mount_options old_opts;
4778         int enable_quota = 0;
4779         ext4_group_t g;
4780         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4781         int err = 0;
4782 #ifdef CONFIG_QUOTA
4783         int i, j;
4784 #endif
4785         char *orig_data = kstrdup(data, GFP_KERNEL);
4786
4787         /* Store the original options */
4788         old_sb_flags = sb->s_flags;
4789         old_opts.s_mount_opt = sbi->s_mount_opt;
4790         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4791         old_opts.s_resuid = sbi->s_resuid;
4792         old_opts.s_resgid = sbi->s_resgid;
4793         old_opts.s_commit_interval = sbi->s_commit_interval;
4794         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4795         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4796 #ifdef CONFIG_QUOTA
4797         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4798         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4799                 if (sbi->s_qf_names[i]) {
4800                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4801                                                          GFP_KERNEL);
4802                         if (!old_opts.s_qf_names[i]) {
4803                                 for (j = 0; j < i; j++)
4804                                         kfree(old_opts.s_qf_names[j]);
4805                                 kfree(orig_data);
4806                                 return -ENOMEM;
4807                         }
4808                 } else
4809                         old_opts.s_qf_names[i] = NULL;
4810 #endif
4811         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4812                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4813
4814         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4815                 err = -EINVAL;
4816                 goto restore_opts;
4817         }
4818
4819         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4820             test_opt(sb, JOURNAL_CHECKSUM)) {
4821                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4822                          "during remount not supported; ignoring");
4823                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4824         }
4825
4826         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4827                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4828                         ext4_msg(sb, KERN_ERR, "can't mount with "
4829                                  "both data=journal and delalloc");
4830                         err = -EINVAL;
4831                         goto restore_opts;
4832                 }
4833                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4834                         ext4_msg(sb, KERN_ERR, "can't mount with "
4835                                  "both data=journal and dioread_nolock");
4836                         err = -EINVAL;
4837                         goto restore_opts;
4838                 }
4839                 if (test_opt(sb, DAX)) {
4840                         ext4_msg(sb, KERN_ERR, "can't mount with "
4841                                  "both data=journal and dax");
4842                         err = -EINVAL;
4843                         goto restore_opts;
4844                 }
4845         }
4846
4847         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4848                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4849                         "dax flag with busy inodes while remounting");
4850                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4851         }
4852
4853         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4854                 ext4_abort(sb, "Abort forced by user");
4855
4856         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4857                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4858
4859         es = sbi->s_es;
4860
4861         if (sbi->s_journal) {
4862                 ext4_init_journal_params(sb, sbi->s_journal);
4863                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4864         }
4865
4866         if (*flags & MS_LAZYTIME)
4867                 sb->s_flags |= MS_LAZYTIME;
4868
4869         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4870                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4871                         err = -EROFS;
4872                         goto restore_opts;
4873                 }
4874
4875                 if (*flags & MS_RDONLY) {
4876                         err = sync_filesystem(sb);
4877                         if (err < 0)
4878                                 goto restore_opts;
4879                         err = dquot_suspend(sb, -1);
4880                         if (err < 0)
4881                                 goto restore_opts;
4882
4883                         /*
4884                          * First of all, the unconditional stuff we have to do
4885                          * to disable replay of the journal when we next remount
4886                          */
4887                         sb->s_flags |= MS_RDONLY;
4888
4889                         /*
4890                          * OK, test if we are remounting a valid rw partition
4891                          * readonly, and if so set the rdonly flag and then
4892                          * mark the partition as valid again.
4893                          */
4894                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4895                             (sbi->s_mount_state & EXT4_VALID_FS))
4896                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4897
4898                         if (sbi->s_journal)
4899                                 ext4_mark_recovery_complete(sb, es);
4900                 } else {
4901                         /* Make sure we can mount this feature set readwrite */
4902                         if (ext4_has_feature_readonly(sb) ||
4903                             !ext4_feature_set_ok(sb, 0)) {
4904                                 err = -EROFS;
4905                                 goto restore_opts;
4906                         }
4907                         /*
4908                          * Make sure the group descriptor checksums
4909                          * are sane.  If they aren't, refuse to remount r/w.
4910                          */
4911                         for (g = 0; g < sbi->s_groups_count; g++) {
4912                                 struct ext4_group_desc *gdp =
4913                                         ext4_get_group_desc(sb, g, NULL);
4914
4915                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4916                                         ext4_msg(sb, KERN_ERR,
4917                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4918                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
4919                                                le16_to_cpu(gdp->bg_checksum));
4920                                         err = -EFSBADCRC;
4921                                         goto restore_opts;
4922                                 }
4923                         }
4924
4925                         /*
4926                          * If we have an unprocessed orphan list hanging
4927                          * around from a previously readonly bdev mount,
4928                          * require a full umount/remount for now.
4929                          */
4930                         if (es->s_last_orphan) {
4931                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4932                                        "remount RDWR because of unprocessed "
4933                                        "orphan inode list.  Please "
4934                                        "umount/remount instead");
4935                                 err = -EINVAL;
4936                                 goto restore_opts;
4937                         }
4938
4939                         /*
4940                          * Mounting a RDONLY partition read-write, so reread
4941                          * and store the current valid flag.  (It may have
4942                          * been changed by e2fsck since we originally mounted
4943                          * the partition.)
4944                          */
4945                         if (sbi->s_journal)
4946                                 ext4_clear_journal_err(sb, es);
4947                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4948                         if (!ext4_setup_super(sb, es, 0))
4949                                 sb->s_flags &= ~MS_RDONLY;
4950                         if (ext4_has_feature_mmp(sb))
4951                                 if (ext4_multi_mount_protect(sb,
4952                                                 le64_to_cpu(es->s_mmp_block))) {
4953                                         err = -EROFS;
4954                                         goto restore_opts;
4955                                 }
4956                         enable_quota = 1;
4957                 }
4958         }
4959
4960         /*
4961          * Reinitialize lazy itable initialization thread based on
4962          * current settings
4963          */
4964         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4965                 ext4_unregister_li_request(sb);
4966         else {
4967                 ext4_group_t first_not_zeroed;
4968                 first_not_zeroed = ext4_has_uninit_itable(sb);
4969                 ext4_register_li_request(sb, first_not_zeroed);
4970         }
4971
4972         ext4_setup_system_zone(sb);
4973         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4974                 ext4_commit_super(sb, 1);
4975
4976 #ifdef CONFIG_QUOTA
4977         /* Release old quota file names */
4978         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4979                 kfree(old_opts.s_qf_names[i]);
4980         if (enable_quota) {
4981                 if (sb_any_quota_suspended(sb))
4982                         dquot_resume(sb, -1);
4983                 else if (ext4_has_feature_quota(sb)) {
4984                         err = ext4_enable_quotas(sb);
4985                         if (err)
4986                                 goto restore_opts;
4987                 }
4988         }
4989 #endif
4990
4991         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
4992         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4993         kfree(orig_data);
4994         return 0;
4995
4996 restore_opts:
4997         sb->s_flags = old_sb_flags;
4998         sbi->s_mount_opt = old_opts.s_mount_opt;
4999         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5000         sbi->s_resuid = old_opts.s_resuid;
5001         sbi->s_resgid = old_opts.s_resgid;
5002         sbi->s_commit_interval = old_opts.s_commit_interval;
5003         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5004         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5005 #ifdef CONFIG_QUOTA
5006         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5007         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5008                 kfree(sbi->s_qf_names[i]);
5009                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5010         }
5011 #endif
5012         kfree(orig_data);
5013         return err;
5014 }
5015
5016 #ifdef CONFIG_QUOTA
5017 static int ext4_statfs_project(struct super_block *sb,
5018                                kprojid_t projid, struct kstatfs *buf)
5019 {
5020         struct kqid qid;
5021         struct dquot *dquot;
5022         u64 limit;
5023         u64 curblock;
5024
5025         qid = make_kqid_projid(projid);
5026         dquot = dqget(sb, qid);
5027         if (IS_ERR(dquot))
5028                 return PTR_ERR(dquot);
5029         spin_lock(&dq_data_lock);
5030
5031         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5032                  dquot->dq_dqb.dqb_bsoftlimit :
5033                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5034         if (limit && buf->f_blocks > limit) {
5035                 curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5036                 buf->f_blocks = limit;
5037                 buf->f_bfree = buf->f_bavail =
5038                         (buf->f_blocks > curblock) ?
5039                          (buf->f_blocks - curblock) : 0;
5040         }
5041
5042         limit = dquot->dq_dqb.dqb_isoftlimit ?
5043                 dquot->dq_dqb.dqb_isoftlimit :
5044                 dquot->dq_dqb.dqb_ihardlimit;
5045         if (limit && buf->f_files > limit) {
5046                 buf->f_files = limit;
5047                 buf->f_ffree =
5048                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5049                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5050         }
5051
5052         spin_unlock(&dq_data_lock);
5053         dqput(dquot);
5054         return 0;
5055 }
5056 #endif
5057
5058 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5059 {
5060         struct super_block *sb = dentry->d_sb;
5061         struct ext4_sb_info *sbi = EXT4_SB(sb);
5062         struct ext4_super_block *es = sbi->s_es;
5063         ext4_fsblk_t overhead = 0, resv_blocks;
5064         u64 fsid;
5065         s64 bfree;
5066         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5067
5068         if (!test_opt(sb, MINIX_DF))
5069                 overhead = sbi->s_overhead;
5070
5071         buf->f_type = EXT4_SUPER_MAGIC;
5072         buf->f_bsize = sb->s_blocksize;
5073         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5074         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5075                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5076         /* prevent underflow in case that few free space is available */
5077         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5078         buf->f_bavail = buf->f_bfree -
5079                         (ext4_r_blocks_count(es) + resv_blocks);
5080         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5081                 buf->f_bavail = 0;
5082         buf->f_files = le32_to_cpu(es->s_inodes_count);
5083         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5084         buf->f_namelen = EXT4_NAME_LEN;
5085         fsid = le64_to_cpup((void *)es->s_uuid) ^
5086                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5087         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5088         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5089
5090 #ifdef CONFIG_QUOTA
5091         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5092             sb_has_quota_limits_enabled(sb, PRJQUOTA))
5093                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5094 #endif
5095         return 0;
5096 }
5097
5098 /* Helper function for writing quotas on sync - we need to start transaction
5099  * before quota file is locked for write. Otherwise the are possible deadlocks:
5100  * Process 1                         Process 2
5101  * ext4_create()                     quota_sync()
5102  *   jbd2_journal_start()                  write_dquot()
5103  *   dquot_initialize()                         down(dqio_mutex)
5104  *     down(dqio_mutex)                    jbd2_journal_start()
5105  *
5106  */
5107
5108 #ifdef CONFIG_QUOTA
5109
5110 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5111 {
5112         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5113 }
5114
5115 static int ext4_write_dquot(struct dquot *dquot)
5116 {
5117         int ret, err;
5118         handle_t *handle;
5119         struct inode *inode;
5120
5121         inode = dquot_to_inode(dquot);
5122         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5123                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5124         if (IS_ERR(handle))
5125                 return PTR_ERR(handle);
5126         ret = dquot_commit(dquot);
5127         err = ext4_journal_stop(handle);
5128         if (!ret)
5129                 ret = err;
5130         return ret;
5131 }
5132
5133 static int ext4_acquire_dquot(struct dquot *dquot)
5134 {
5135         int ret, err;
5136         handle_t *handle;
5137
5138         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5139                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5140         if (IS_ERR(handle))
5141                 return PTR_ERR(handle);
5142         ret = dquot_acquire(dquot);
5143         err = ext4_journal_stop(handle);
5144         if (!ret)
5145                 ret = err;
5146         return ret;
5147 }
5148
5149 static int ext4_release_dquot(struct dquot *dquot)
5150 {
5151         int ret, err;
5152         handle_t *handle;
5153
5154         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5155                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5156         if (IS_ERR(handle)) {
5157                 /* Release dquot anyway to avoid endless cycle in dqput() */
5158                 dquot_release(dquot);
5159                 return PTR_ERR(handle);
5160         }
5161         ret = dquot_release(dquot);
5162         err = ext4_journal_stop(handle);
5163         if (!ret)
5164                 ret = err;
5165         return ret;
5166 }
5167
5168 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5169 {
5170         struct super_block *sb = dquot->dq_sb;
5171         struct ext4_sb_info *sbi = EXT4_SB(sb);
5172
5173         /* Are we journaling quotas? */
5174         if (ext4_has_feature_quota(sb) ||
5175             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5176                 dquot_mark_dquot_dirty(dquot);
5177                 return ext4_write_dquot(dquot);
5178         } else {
5179                 return dquot_mark_dquot_dirty(dquot);
5180         }
5181 }
5182
5183 static int ext4_write_info(struct super_block *sb, int type)
5184 {
5185         int ret, err;
5186         handle_t *handle;
5187
5188         /* Data block + inode block */
5189         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5190         if (IS_ERR(handle))
5191                 return PTR_ERR(handle);
5192         ret = dquot_commit_info(sb, type);
5193         err = ext4_journal_stop(handle);
5194         if (!ret)
5195                 ret = err;
5196         return ret;
5197 }
5198
5199 /*
5200  * Turn on quotas during mount time - we need to find
5201  * the quota file and such...
5202  */
5203 static int ext4_quota_on_mount(struct super_block *sb, int type)
5204 {
5205         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5206                                         EXT4_SB(sb)->s_jquota_fmt, type);
5207 }
5208
5209 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5210 {
5211         struct ext4_inode_info *ei = EXT4_I(inode);
5212
5213         /* The first argument of lockdep_set_subclass has to be
5214          * *exactly* the same as the argument to init_rwsem() --- in
5215          * this case, in init_once() --- or lockdep gets unhappy
5216          * because the name of the lock is set using the
5217          * stringification of the argument to init_rwsem().
5218          */
5219         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5220         lockdep_set_subclass(&ei->i_data_sem, subclass);
5221 }
5222
5223 /*
5224  * Standard function to be called on quota_on
5225  */
5226 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5227                          struct path *path)
5228 {
5229         int err;
5230
5231         if (!test_opt(sb, QUOTA))
5232                 return -EINVAL;
5233
5234         /* Quotafile not on the same filesystem? */
5235         if (path->dentry->d_sb != sb)
5236                 return -EXDEV;
5237         /* Journaling quota? */
5238         if (EXT4_SB(sb)->s_qf_names[type]) {
5239                 /* Quotafile not in fs root? */
5240                 if (path->dentry->d_parent != sb->s_root)
5241                         ext4_msg(sb, KERN_WARNING,
5242                                 "Quota file not on filesystem root. "
5243                                 "Journaled quota will not work");
5244         }
5245
5246         /*
5247          * When we journal data on quota file, we have to flush journal to see
5248          * all updates to the file when we bypass pagecache...
5249          */
5250         if (EXT4_SB(sb)->s_journal &&
5251             ext4_should_journal_data(d_inode(path->dentry))) {
5252                 /*
5253                  * We don't need to lock updates but journal_flush() could
5254                  * otherwise be livelocked...
5255                  */
5256                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5257                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5258                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5259                 if (err)
5260                         return err;
5261         }
5262         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5263         err = dquot_quota_on(sb, type, format_id, path);
5264         if (err)
5265                 lockdep_set_quota_inode(path->dentry->d_inode,
5266                                              I_DATA_SEM_NORMAL);
5267         return err;
5268 }
5269
5270 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5271                              unsigned int flags)
5272 {
5273         int err;
5274         struct inode *qf_inode;
5275         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5276                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5277                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5278                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5279         };
5280
5281         BUG_ON(!ext4_has_feature_quota(sb));
5282
5283         if (!qf_inums[type])
5284                 return -EPERM;
5285
5286         qf_inode = ext4_iget(sb, qf_inums[type]);
5287         if (IS_ERR(qf_inode)) {
5288                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5289                 return PTR_ERR(qf_inode);
5290         }
5291
5292         /* Don't account quota for quota files to avoid recursion */
5293         qf_inode->i_flags |= S_NOQUOTA;
5294         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5295         err = dquot_enable(qf_inode, type, format_id, flags);
5296         iput(qf_inode);
5297         if (err)
5298                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5299
5300         return err;
5301 }
5302
5303 /* Enable usage tracking for all quota types. */
5304 static int ext4_enable_quotas(struct super_block *sb)
5305 {
5306         int type, err = 0;
5307         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5308                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5309                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5310                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5311         };
5312         bool quota_mopt[EXT4_MAXQUOTAS] = {
5313                 test_opt(sb, USRQUOTA),
5314                 test_opt(sb, GRPQUOTA),
5315                 test_opt(sb, PRJQUOTA),
5316         };
5317
5318         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5319         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5320                 if (qf_inums[type]) {
5321                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5322                                 DQUOT_USAGE_ENABLED |
5323                                 (quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5324                         if (err) {
5325                                 ext4_warning(sb,
5326                                         "Failed to enable quota tracking "
5327                                         "(type=%d, err=%d). Please run "
5328                                         "e2fsck to fix.", type, err);
5329                                 return err;
5330                         }
5331                 }
5332         }
5333         return 0;
5334 }
5335
5336 static int ext4_quota_off(struct super_block *sb, int type)
5337 {
5338         struct inode *inode = sb_dqopt(sb)->files[type];
5339         handle_t *handle;
5340
5341         /* Force all delayed allocation blocks to be allocated.
5342          * Caller already holds s_umount sem */
5343         if (test_opt(sb, DELALLOC))
5344                 sync_filesystem(sb);
5345
5346         if (!inode)
5347                 goto out;
5348
5349         /* Update modification times of quota files when userspace can
5350          * start looking at them */
5351         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5352         if (IS_ERR(handle))
5353                 goto out;
5354         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5355         ext4_mark_inode_dirty(handle, inode);
5356         ext4_journal_stop(handle);
5357
5358 out:
5359         return dquot_quota_off(sb, type);
5360 }
5361
5362 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5363  * acquiring the locks... As quota files are never truncated and quota code
5364  * itself serializes the operations (and no one else should touch the files)
5365  * we don't have to be afraid of races */
5366 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5367                                size_t len, loff_t off)
5368 {
5369         struct inode *inode = sb_dqopt(sb)->files[type];
5370         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5371         int offset = off & (sb->s_blocksize - 1);
5372         int tocopy;
5373         size_t toread;
5374         struct buffer_head *bh;
5375         loff_t i_size = i_size_read(inode);
5376
5377         if (off > i_size)
5378                 return 0;
5379         if (off+len > i_size)
5380                 len = i_size-off;
5381         toread = len;
5382         while (toread > 0) {
5383                 tocopy = sb->s_blocksize - offset < toread ?
5384                                 sb->s_blocksize - offset : toread;
5385                 bh = ext4_bread(NULL, inode, blk, 0);
5386                 if (IS_ERR(bh))
5387                         return PTR_ERR(bh);
5388                 if (!bh)        /* A hole? */
5389                         memset(data, 0, tocopy);
5390                 else
5391                         memcpy(data, bh->b_data+offset, tocopy);
5392                 brelse(bh);
5393                 offset = 0;
5394                 toread -= tocopy;
5395                 data += tocopy;
5396                 blk++;
5397         }
5398         return len;
5399 }
5400
5401 /* Write to quotafile (we know the transaction is already started and has
5402  * enough credits) */
5403 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5404                                 const char *data, size_t len, loff_t off)
5405 {
5406         struct inode *inode = sb_dqopt(sb)->files[type];
5407         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5408         int err, offset = off & (sb->s_blocksize - 1);
5409         int retries = 0;
5410         struct buffer_head *bh;
5411         handle_t *handle = journal_current_handle();
5412
5413         if (EXT4_SB(sb)->s_journal && !handle) {
5414                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5415                         " cancelled because transaction is not started",
5416                         (unsigned long long)off, (unsigned long long)len);
5417                 return -EIO;
5418         }
5419         /*
5420          * Since we account only one data block in transaction credits,
5421          * then it is impossible to cross a block boundary.
5422          */
5423         if (sb->s_blocksize - offset < len) {
5424                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5425                         " cancelled because not block aligned",
5426                         (unsigned long long)off, (unsigned long long)len);
5427                 return -EIO;
5428         }
5429
5430         do {
5431                 bh = ext4_bread(handle, inode, blk,
5432                                 EXT4_GET_BLOCKS_CREATE |
5433                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5434         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5435                  ext4_should_retry_alloc(inode->i_sb, &retries));
5436         if (IS_ERR(bh))
5437                 return PTR_ERR(bh);
5438         if (!bh)
5439                 goto out;
5440         BUFFER_TRACE(bh, "get write access");
5441         err = ext4_journal_get_write_access(handle, bh);
5442         if (err) {
5443                 brelse(bh);
5444                 return err;
5445         }
5446         lock_buffer(bh);
5447         memcpy(bh->b_data+offset, data, len);
5448         flush_dcache_page(bh->b_page);
5449         unlock_buffer(bh);
5450         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5451         brelse(bh);
5452 out:
5453         if (inode->i_size < off + len) {
5454                 i_size_write(inode, off + len);
5455                 EXT4_I(inode)->i_disksize = inode->i_size;
5456                 ext4_mark_inode_dirty(handle, inode);
5457         }
5458         return len;
5459 }
5460
5461 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5462 {
5463         const struct quota_format_ops   *ops;
5464
5465         if (!sb_has_quota_loaded(sb, qid->type))
5466                 return -ESRCH;
5467         ops = sb_dqopt(sb)->ops[qid->type];
5468         if (!ops || !ops->get_next_id)
5469                 return -ENOSYS;
5470         return dquot_get_next_id(sb, qid);
5471 }
5472 #endif
5473
5474 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5475                        const char *dev_name, void *data)
5476 {
5477         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5478 }
5479
5480 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5481 static inline void register_as_ext2(void)
5482 {
5483         int err = register_filesystem(&ext2_fs_type);
5484         if (err)
5485                 printk(KERN_WARNING
5486                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5487 }
5488
5489 static inline void unregister_as_ext2(void)
5490 {
5491         unregister_filesystem(&ext2_fs_type);
5492 }
5493
5494 static inline int ext2_feature_set_ok(struct super_block *sb)
5495 {
5496         if (ext4_has_unknown_ext2_incompat_features(sb))
5497                 return 0;
5498         if (sb->s_flags & MS_RDONLY)
5499                 return 1;
5500         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5501                 return 0;
5502         return 1;
5503 }
5504 #else
5505 static inline void register_as_ext2(void) { }
5506 static inline void unregister_as_ext2(void) { }
5507 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5508 #endif
5509
5510 static inline void register_as_ext3(void)
5511 {
5512         int err = register_filesystem(&ext3_fs_type);
5513         if (err)
5514                 printk(KERN_WARNING
5515                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5516 }
5517
5518 static inline void unregister_as_ext3(void)
5519 {
5520         unregister_filesystem(&ext3_fs_type);
5521 }
5522
5523 static inline int ext3_feature_set_ok(struct super_block *sb)
5524 {
5525         if (ext4_has_unknown_ext3_incompat_features(sb))
5526                 return 0;
5527         if (!ext4_has_feature_journal(sb))
5528                 return 0;
5529         if (sb->s_flags & MS_RDONLY)
5530                 return 1;
5531         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5532                 return 0;
5533         return 1;
5534 }
5535
5536 static struct file_system_type ext4_fs_type = {
5537         .owner          = THIS_MODULE,
5538         .name           = "ext4",
5539         .mount          = ext4_mount,
5540         .kill_sb        = kill_block_super,
5541         .fs_flags       = FS_REQUIRES_DEV,
5542 };
5543 MODULE_ALIAS_FS("ext4");
5544
5545 /* Shared across all ext4 file systems */
5546 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5547
5548 static int __init ext4_init_fs(void)
5549 {
5550         int i, err;
5551
5552         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5553         ext4_li_info = NULL;
5554         mutex_init(&ext4_li_mtx);
5555
5556         /* Build-time check for flags consistency */
5557         ext4_check_flag_values();
5558
5559         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5560                 init_waitqueue_head(&ext4__ioend_wq[i]);
5561
5562         err = ext4_init_es();
5563         if (err)
5564                 return err;
5565
5566         err = ext4_init_pageio();
5567         if (err)
5568                 goto out5;
5569
5570         err = ext4_init_system_zone();
5571         if (err)
5572                 goto out4;
5573
5574         err = ext4_init_sysfs();
5575         if (err)
5576                 goto out3;
5577
5578         err = ext4_init_mballoc();
5579         if (err)
5580                 goto out2;
5581         err = init_inodecache();
5582         if (err)
5583                 goto out1;
5584         register_as_ext3();
5585         register_as_ext2();
5586         err = register_filesystem(&ext4_fs_type);
5587         if (err)
5588                 goto out;
5589
5590         return 0;
5591 out:
5592         unregister_as_ext2();
5593         unregister_as_ext3();
5594         destroy_inodecache();
5595 out1:
5596         ext4_exit_mballoc();
5597 out2:
5598         ext4_exit_sysfs();
5599 out3:
5600         ext4_exit_system_zone();
5601 out4:
5602         ext4_exit_pageio();
5603 out5:
5604         ext4_exit_es();
5605
5606         return err;
5607 }
5608
5609 static void __exit ext4_exit_fs(void)
5610 {
5611         ext4_destroy_lazyinit_thread();
5612         unregister_as_ext2();
5613         unregister_as_ext3();
5614         unregister_filesystem(&ext4_fs_type);
5615         destroy_inodecache();
5616         ext4_exit_mballoc();
5617         ext4_exit_sysfs();
5618         ext4_exit_system_zone();
5619         ext4_exit_pageio();
5620         ext4_exit_es();
5621 }
5622
5623 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5624 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5625 MODULE_LICENSE("GPL");
5626 module_init(ext4_init_fs)
5627 module_exit(ext4_exit_fs)