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
  82 /*
  83  * Lock ordering
  84  *
  85  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
  86  * i_mmap_rwsem (inode->i_mmap_rwsem)!
  87  *
  88  * page fault path:
  89  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
  90  *   page lock -> i_data_sem (rw)
  91  *
  92  * buffered write path:
  93  * sb_start_write -> i_mutex -> mmap_sem
  94  * sb_start_write -> i_mutex -> transaction start -> page lock ->
  95  *   i_data_sem (rw)
  96  *
  97  * truncate:
  98  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
  99  *   i_mmap_rwsem (w) -> page lock
 100  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 101  *   transaction start -> i_data_sem (rw)
 102  *
 103  * direct IO:
 104  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
 105  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
 106  *   transaction start -> i_data_sem (rw)
 107  *
 108  * writepages:
 109  * transaction start -> page lock(s) -> i_data_sem (rw)
 110  */
 111
 112 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 113 static struct file_system_type ext2_fs_type = {
 114         .owner          = THIS_MODULE,
 115         .name           = "ext2",
 116         .mount          = ext4_mount,
 117         .kill_sb        = kill_block_super,
 118         .fs_flags       = FS_REQUIRES_DEV,
 119 };
 120 MODULE_ALIAS_FS("ext2");
 121 MODULE_ALIAS("ext2");
 122 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
 123 #else
 124 #define IS_EXT2_SB(sb) (0)
 125 #endif
 126
 127
 128 static struct file_system_type ext3_fs_type = {
 129         .owner          = THIS_MODULE,
 130         .name           = "ext3",
 131         .mount          = ext4_mount,
 132         .kill_sb        = kill_block_super,
 133         .fs_flags       = FS_REQUIRES_DEV,
 134 };
 135 MODULE_ALIAS_FS("ext3");
 136 MODULE_ALIAS("ext3");
 137 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 138
 139 static int ext4_verify_csum_type(struct super_block *sb,
 140                                  struct ext4_super_block *es)
 141 {
 142         if (!ext4_has_feature_metadata_csum(sb))
 143                 return 1;
 144
 145         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 146 }
 147
 148 static __le32 ext4_superblock_csum(struct super_block *sb,
 149                                    struct ext4_super_block *es)
 150 {
 151         struct ext4_sb_info *sbi = EXT4_SB(sb);
 152         int offset = offsetof(struct ext4_super_block, s_checksum);
 153         __u32 csum;
 154
 155         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 156
 157         return cpu_to_le32(csum);
 158 }
 159
 160 static int ext4_superblock_csum_verify(struct super_block *sb,
 161                                        struct ext4_super_block *es)
 162 {
 163         if (!ext4_has_metadata_csum(sb))
 164                 return 1;
 165
 166         return es->s_checksum == ext4_superblock_csum(sb, es);
 167 }
 168
 169 void ext4_superblock_csum_set(struct super_block *sb)
 170 {
 171         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 172
 173         if (!ext4_has_metadata_csum(sb))
 174                 return;
 175
 176         es->s_checksum = ext4_superblock_csum(sb, es);
 177 }
 178
 179 void *ext4_kvmalloc(size_t size, gfp_t flags)
 180 {
 181         void *ret;
 182
 183         ret = kmalloc(size, flags | __GFP_NOWARN);
 184         if (!ret)
 185                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 186         return ret;
 187 }
 188
 189 void *ext4_kvzalloc(size_t size, gfp_t flags)
 190 {
 191         void *ret;
 192
 193         ret = kzalloc(size, flags | __GFP_NOWARN);
 194         if (!ret)
 195                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 196         return ret;
 197 }
 198
 199 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 200                                struct ext4_group_desc *bg)
 201 {
 202         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 203                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 204                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 205 }
 206
 207 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 208                                struct ext4_group_desc *bg)
 209 {
 210         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 211                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 212                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 213 }
 214
 215 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 216                               struct ext4_group_desc *bg)
 217 {
 218         return le32_to_cpu(bg->bg_inode_table_lo) |
 219                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 220                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 221 }
 222
 223 __u32 ext4_free_group_clusters(struct super_block *sb,
 224                                struct ext4_group_desc *bg)
 225 {
 226         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 227                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 228                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 229 }
 230
 231 __u32 ext4_free_inodes_count(struct super_block *sb,
 232                               struct ext4_group_desc *bg)
 233 {
 234         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 235                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 236                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 237 }
 238
 239 __u32 ext4_used_dirs_count(struct super_block *sb,
 240                               struct ext4_group_desc *bg)
 241 {
 242         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 243                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 244                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 245 }
 246
 247 __u32 ext4_itable_unused_count(struct super_block *sb,
 248                               struct ext4_group_desc *bg)
 249 {
 250         return le16_to_cpu(bg->bg_itable_unused_lo) |
 251                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 252                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 253 }
 254
 255 void ext4_block_bitmap_set(struct super_block *sb,
 256                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 257 {
 258         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 259         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 260                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 261 }
 262
 263 void ext4_inode_bitmap_set(struct super_block *sb,
 264                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 265 {
 266         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 267         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 268                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 269 }
 270
 271 void ext4_inode_table_set(struct super_block *sb,
 272                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 273 {
 274         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 275         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 276                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 277 }
 278
 279 void ext4_free_group_clusters_set(struct super_block *sb,
 280                                   struct ext4_group_desc *bg, __u32 count)
 281 {
 282         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 283         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 284                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 285 }
 286
 287 void ext4_free_inodes_set(struct super_block *sb,
 288                           struct ext4_group_desc *bg, __u32 count)
 289 {
 290         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 291         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 292                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 293 }
 294
 295 void ext4_used_dirs_set(struct super_block *sb,
 296                           struct ext4_group_desc *bg, __u32 count)
 297 {
 298         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 299         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 300                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 301 }
 302
 303 void ext4_itable_unused_set(struct super_block *sb,
 304                           struct ext4_group_desc *bg, __u32 count)
 305 {
 306         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 307         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 308                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 309 }
 310
 311
 312 static void __save_error_info(struct super_block *sb, const char *func,
 313                             unsigned int line)
 314 {
 315         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 316
 317         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 318         if (bdev_read_only(sb->s_bdev))
 319                 return;
 320         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 321         es->s_last_error_time = cpu_to_le32(get_seconds());
 322         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 323         es->s_last_error_line = cpu_to_le32(line);
 324         if (!es->s_first_error_time) {
 325                 es->s_first_error_time = es->s_last_error_time;
 326                 strncpy(es->s_first_error_func, func,
 327                         sizeof(es->s_first_error_func));
 328                 es->s_first_error_line = cpu_to_le32(line);
 329                 es->s_first_error_ino = es->s_last_error_ino;
 330                 es->s_first_error_block = es->s_last_error_block;
 331         }
 332         /*
 333          * Start the daily error reporting function if it hasn't been
 334          * started already
 335          */
 336         if (!es->s_error_count)
 337                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 338         le32_add_cpu(&es->s_error_count, 1);
 339 }
 340
 341 static void save_error_info(struct super_block *sb, const char *func,
 342                             unsigned int line)
 343 {
 344         __save_error_info(sb, func, line);
 345         ext4_commit_super(sb, 1);
 346 }
 347
 348 /*
 349  * The del_gendisk() function uninitializes the disk-specific data
 350  * structures, including the bdi structure, without telling anyone
 351  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 352  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 353  * This is a kludge to prevent these oops until we can put in a proper
 354  * hook in del_gendisk() to inform the VFS and file system layers.
 355  */
 356 static int block_device_ejected(struct super_block *sb)
 357 {
 358         struct inode *bd_inode = sb->s_bdev->bd_inode;
 359         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 360
 361         return bdi->dev == NULL;
 362 }
 363
 364 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 365 {
 366         struct super_block              *sb = journal->j_private;
 367         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 368         int                             error = is_journal_aborted(journal);
 369         struct ext4_journal_cb_entry    *jce;
 370
 371         BUG_ON(txn->t_state == T_FINISHED);
 372         spin_lock(&sbi->s_md_lock);
 373         while (!list_empty(&txn->t_private_list)) {
 374                 jce = list_entry(txn->t_private_list.next,
 375                                  struct ext4_journal_cb_entry, jce_list);
 376                 list_del_init(&jce->jce_list);
 377                 spin_unlock(&sbi->s_md_lock);
 378                 jce->jce_func(sb, jce, error);
 379                 spin_lock(&sbi->s_md_lock);
 380         }
 381         spin_unlock(&sbi->s_md_lock);
 382 }
 383
 384 /* Deal with the reporting of failure conditions on a filesystem such as
 385  * inconsistencies detected or read IO failures.
 386  *
 387  * On ext2, we can store the error state of the filesystem in the
 388  * superblock.  That is not possible on ext4, because we may have other
 389  * write ordering constraints on the superblock which prevent us from
 390  * writing it out straight away; and given that the journal is about to
 391  * be aborted, we can't rely on the current, or future, transactions to
 392  * write out the superblock safely.
 393  *
 394  * We'll just use the jbd2_journal_abort() error code to record an error in
 395  * the journal instead.  On recovery, the journal will complain about
 396  * that error until we've noted it down and cleared it.
 397  */
 398
 399 static void ext4_handle_error(struct super_block *sb)
 400 {
 401         if (sb->s_flags & MS_RDONLY)
 402                 return;
 403
 404         if (!test_opt(sb, ERRORS_CONT)) {
 405                 journal_t *journal = EXT4_SB(sb)->s_journal;
 406
 407                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 408                 if (journal)
 409                         jbd2_journal_abort(journal, -EIO);
 410         }
 411         if (test_opt(sb, ERRORS_RO)) {
 412                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 413                 /*
 414                  * Make sure updated value of ->s_mount_flags will be visible
 415                  * before ->s_flags update
 416                  */
 417                 smp_wmb();
 418                 sb->s_flags |= MS_RDONLY;
 419         }
 420         if (test_opt(sb, ERRORS_PANIC)) {
 421                 if (EXT4_SB(sb)->s_journal &&
 422                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 423                         return;
 424                 panic("EXT4-fs (device %s): panic forced after error\n",
 425                         sb->s_id);
 426         }
 427 }
 428
 429 #define ext4_error_ratelimit(sb)                                        \
 430                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 431                              "EXT4-fs error")
 432
 433 void __ext4_error(struct super_block *sb, const char *function,
 434                   unsigned int line, const char *fmt, ...)
 435 {
 436         struct va_format vaf;
 437         va_list args;
 438
 439         if (ext4_error_ratelimit(sb)) {
 440                 va_start(args, fmt);
 441                 vaf.fmt = fmt;
 442                 vaf.va = &args;
 443                 printk(KERN_CRIT
 444                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 445                        sb->s_id, function, line, current->comm, &vaf);
 446                 va_end(args);
 447         }
 448         save_error_info(sb, function, line);
 449         ext4_handle_error(sb);
 450 }
 451
 452 void __ext4_error_inode(struct inode *inode, const char *function,
 453                         unsigned int line, ext4_fsblk_t block,
 454                         const char *fmt, ...)
 455 {
 456         va_list args;
 457         struct va_format vaf;
 458         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 459
 460         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 461         es->s_last_error_block = cpu_to_le64(block);
 462         if (ext4_error_ratelimit(inode->i_sb)) {
 463                 va_start(args, fmt);
 464                 vaf.fmt = fmt;
 465                 vaf.va = &args;
 466                 if (block)
 467                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 468                                "inode #%lu: block %llu: comm %s: %pV\n",
 469                                inode->i_sb->s_id, function, line, inode->i_ino,
 470                                block, current->comm, &vaf);
 471                 else
 472                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 473                                "inode #%lu: comm %s: %pV\n",
 474                                inode->i_sb->s_id, function, line, inode->i_ino,
 475                                current->comm, &vaf);
 476                 va_end(args);
 477         }
 478         save_error_info(inode->i_sb, function, line);
 479         ext4_handle_error(inode->i_sb);
 480 }
 481
 482 void __ext4_error_file(struct file *file, const char *function,
 483                        unsigned int line, ext4_fsblk_t block,
 484                        const char *fmt, ...)
 485 {
 486         va_list args;
 487         struct va_format vaf;
 488         struct ext4_super_block *es;
 489         struct inode *inode = file_inode(file);
 490         char pathname[80], *path;
 491
 492         es = EXT4_SB(inode->i_sb)->s_es;
 493         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 494         if (ext4_error_ratelimit(inode->i_sb)) {
 495                 path = file_path(file, pathname, sizeof(pathname));
 496                 if (IS_ERR(path))
 497                         path = "(unknown)";
 498                 va_start(args, fmt);
 499                 vaf.fmt = fmt;
 500                 vaf.va = &args;
 501                 if (block)
 502                         printk(KERN_CRIT
 503                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 504                                "block %llu: comm %s: path %s: %pV\n",
 505                                inode->i_sb->s_id, function, line, inode->i_ino,
 506                                block, current->comm, path, &vaf);
 507                 else
 508                         printk(KERN_CRIT
 509                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 510                                "comm %s: path %s: %pV\n",
 511                                inode->i_sb->s_id, function, line, inode->i_ino,
 512                                current->comm, path, &vaf);
 513                 va_end(args);
 514         }
 515         save_error_info(inode->i_sb, function, line);
 516         ext4_handle_error(inode->i_sb);
 517 }
 518
 519 const char *ext4_decode_error(struct super_block *sb, int errno,
 520                               char nbuf[16])
 521 {
 522         char *errstr = NULL;
 523
 524         switch (errno) {
 525         case -EFSCORRUPTED:
 526                 errstr = "Corrupt filesystem";
 527                 break;
 528         case -EFSBADCRC:
 529                 errstr = "Filesystem failed CRC";
 530                 break;
 531         case -EIO:
 532                 errstr = "IO failure";
 533                 break;
 534         case -ENOMEM:
 535                 errstr = "Out of memory";
 536                 break;
 537         case -EROFS:
 538                 if (!sb || (EXT4_SB(sb)->s_journal &&
 539                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 540                         errstr = "Journal has aborted";
 541                 else
 542                         errstr = "Readonly filesystem";
 543                 break;
 544         default:
 545                 /* If the caller passed in an extra buffer for unknown
 546                  * errors, textualise them now.  Else we just return
 547                  * NULL. */
 548                 if (nbuf) {
 549                         /* Check for truncated error codes... */
 550                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 551                                 errstr = nbuf;
 552                 }
 553                 break;
 554         }
 555
 556         return errstr;
 557 }
 558
 559 /* __ext4_std_error decodes expected errors from journaling functions
 560  * automatically and invokes the appropriate error response.  */
 561
 562 void __ext4_std_error(struct super_block *sb, const char *function,
 563                       unsigned int line, int errno)
 564 {
 565         char nbuf[16];
 566         const char *errstr;
 567
 568         /* Special case: if the error is EROFS, and we're not already
 569          * inside a transaction, then there's really no point in logging
 570          * an error. */
 571         if (errno == -EROFS && journal_current_handle() == NULL &&
 572             (sb->s_flags & MS_RDONLY))
 573                 return;
 574
 575         if (ext4_error_ratelimit(sb)) {
 576                 errstr = ext4_decode_error(sb, errno, nbuf);
 577                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 578                        sb->s_id, function, line, errstr);
 579         }
 580
 581         save_error_info(sb, function, line);
 582         ext4_handle_error(sb);
 583 }
 584
 585 /*
 586  * ext4_abort is a much stronger failure handler than ext4_error.  The
 587  * abort function may be used to deal with unrecoverable failures such
 588  * as journal IO errors or ENOMEM at a critical moment in log management.
 589  *
 590  * We unconditionally force the filesystem into an ABORT|READONLY state,
 591  * unless the error response on the fs has been set to panic in which
 592  * case we take the easy way out and panic immediately.
 593  */
 594
 595 void __ext4_abort(struct super_block *sb, const char *function,
 596                 unsigned int line, const char *fmt, ...)
 597 {
 598         va_list args;
 599
 600         save_error_info(sb, function, line);
 601         va_start(args, fmt);
 602         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 603                function, line);
 604         vprintk(fmt, args);
 605         printk("\n");
 606         va_end(args);
 607
 608         if ((sb->s_flags & MS_RDONLY) == 0) {
 609                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 610                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 611                 /*
 612                  * Make sure updated value of ->s_mount_flags will be visible
 613                  * before ->s_flags update
 614                  */
 615                 smp_wmb();
 616                 sb->s_flags |= MS_RDONLY;
 617                 if (EXT4_SB(sb)->s_journal)
 618                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 619                 save_error_info(sb, function, line);
 620         }
 621         if (test_opt(sb, ERRORS_PANIC)) {
 622                 if (EXT4_SB(sb)->s_journal &&
 623                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 624                         return;
 625                 panic("EXT4-fs panic from previous error\n");
 626         }
 627 }
 628
 629 void __ext4_msg(struct super_block *sb,
 630                 const char *prefix, const char *fmt, ...)
 631 {
 632         struct va_format vaf;
 633         va_list args;
 634
 635         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 636                 return;
 637
 638         va_start(args, fmt);
 639         vaf.fmt = fmt;
 640         vaf.va = &args;
 641         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 642         va_end(args);
 643 }
 644
 645 #define ext4_warning_ratelimit(sb)                                      \
 646                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 647                              "EXT4-fs warning")
 648
 649 void __ext4_warning(struct super_block *sb, const char *function,
 650                     unsigned int line, const char *fmt, ...)
 651 {
 652         struct va_format vaf;
 653         va_list args;
 654
 655         if (!ext4_warning_ratelimit(sb))
 656                 return;
 657
 658         va_start(args, fmt);
 659         vaf.fmt = fmt;
 660         vaf.va = &args;
 661         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 662                sb->s_id, function, line, &vaf);
 663         va_end(args);
 664 }
 665
 666 void __ext4_warning_inode(const struct inode *inode, const char *function,
 667                           unsigned int line, const char *fmt, ...)
 668 {
 669         struct va_format vaf;
 670         va_list args;
 671
 672         if (!ext4_warning_ratelimit(inode->i_sb))
 673                 return;
 674
 675         va_start(args, fmt);
 676         vaf.fmt = fmt;
 677         vaf.va = &args;
 678         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 679                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 680                function, line, inode->i_ino, current->comm, &vaf);
 681         va_end(args);
 682 }
 683
 684 void __ext4_grp_locked_error(const char *function, unsigned int line,
 685                              struct super_block *sb, ext4_group_t grp,
 686                              unsigned long ino, ext4_fsblk_t block,
 687                              const char *fmt, ...)
 688 __releases(bitlock)
 689 __acquires(bitlock)
 690 {
 691         struct va_format vaf;
 692         va_list args;
 693         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 694
 695         es->s_last_error_ino = cpu_to_le32(ino);
 696         es->s_last_error_block = cpu_to_le64(block);
 697         __save_error_info(sb, function, line);
 698
 699         if (ext4_error_ratelimit(sb)) {
 700                 va_start(args, fmt);
 701                 vaf.fmt = fmt;
 702                 vaf.va = &args;
 703                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 704                        sb->s_id, function, line, grp);
 705                 if (ino)
 706                         printk(KERN_CONT "inode %lu: ", ino);
 707                 if (block)
 708                         printk(KERN_CONT "block %llu:",
 709                                (unsigned long long) block);
 710                 printk(KERN_CONT "%pV\n", &vaf);
 711                 va_end(args);
 712         }
 713
 714         if (test_opt(sb, ERRORS_CONT)) {
 715                 ext4_commit_super(sb, 0);
 716                 return;
 717         }
 718
 719         ext4_unlock_group(sb, grp);
 720         ext4_handle_error(sb);
 721         /*
 722          * We only get here in the ERRORS_RO case; relocking the group
 723          * may be dangerous, but nothing bad will happen since the
 724          * filesystem will have already been marked read/only and the
 725          * journal has been aborted.  We return 1 as a hint to callers
 726          * who might what to use the return value from
 727          * ext4_grp_locked_error() to distinguish between the
 728          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 729          * aggressively from the ext4 function in question, with a
 730          * more appropriate error code.
 731          */
 732         ext4_lock_group(sb, grp);
 733         return;
 734 }
 735
 736 void ext4_update_dynamic_rev(struct super_block *sb)
 737 {
 738         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 739
 740         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 741                 return;
 742
 743         ext4_warning(sb,
 744                      "updating to rev %d because of new feature flag, "
 745                      "running e2fsck is recommended",
 746                      EXT4_DYNAMIC_REV);
 747
 748         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 749         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 750         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 751         /* leave es->s_feature_*compat flags alone */
 752         /* es->s_uuid will be set by e2fsck if empty */
 753
 754         /*
 755          * The rest of the superblock fields should be zero, and if not it
 756          * means they are likely already in use, so leave them alone.  We
 757          * can leave it up to e2fsck to clean up any inconsistencies there.
 758          */
 759 }
 760
 761 /*
 762  * Open the external journal device
 763  */
 764 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 765 {
 766         struct block_device *bdev;
 767         char b[BDEVNAME_SIZE];
 768
 769         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 770         if (IS_ERR(bdev))
 771                 goto fail;
 772         return bdev;
 773
 774 fail:
 775         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 776                         __bdevname(dev, b), PTR_ERR(bdev));
 777         return NULL;
 778 }
 779
 780 /*
 781  * Release the journal device
 782  */
 783 static void ext4_blkdev_put(struct block_device *bdev)
 784 {
 785         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 786 }
 787
 788 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 789 {
 790         struct block_device *bdev;
 791         bdev = sbi->journal_bdev;
 792         if (bdev) {
 793                 ext4_blkdev_put(bdev);
 794                 sbi->journal_bdev = NULL;
 795         }
 796 }
 797
 798 static inline struct inode *orphan_list_entry(struct list_head *l)
 799 {
 800         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 801 }
 802
 803 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 804 {
 805         struct list_head *l;
 806
 807         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 808                  le32_to_cpu(sbi->s_es->s_last_orphan));
 809
 810         printk(KERN_ERR "sb_info orphan list:\n");
 811         list_for_each(l, &sbi->s_orphan) {
 812                 struct inode *inode = orphan_list_entry(l);
 813                 printk(KERN_ERR "  "
 814                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 815                        inode->i_sb->s_id, inode->i_ino, inode,
 816                        inode->i_mode, inode->i_nlink,
 817                        NEXT_ORPHAN(inode));
 818         }
 819 }
 820
 821 static void ext4_put_super(struct super_block *sb)
 822 {
 823         struct ext4_sb_info *sbi = EXT4_SB(sb);
 824         struct ext4_super_block *es = sbi->s_es;
 825         int i, err;
 826
 827         ext4_unregister_li_request(sb);
 828         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 829
 830         flush_workqueue(sbi->rsv_conversion_wq);
 831         destroy_workqueue(sbi->rsv_conversion_wq);
 832
 833         if (sbi->s_journal) {
 834                 err = jbd2_journal_destroy(sbi->s_journal);
 835                 sbi->s_journal = NULL;
 836                 if (err < 0)
 837                         ext4_abort(sb, "Couldn't clean up the journal");
 838         }
 839
 840         ext4_unregister_sysfs(sb);
 841         ext4_es_unregister_shrinker(sbi);
 842         del_timer_sync(&sbi->s_err_report);
 843         ext4_release_system_zone(sb);
 844         ext4_mb_release(sb);
 845         ext4_ext_release(sb);
 846
 847         if (!(sb->s_flags & MS_RDONLY)) {
 848                 ext4_clear_feature_journal_needs_recovery(sb);
 849                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 850         }
 851         if (!(sb->s_flags & MS_RDONLY))
 852                 ext4_commit_super(sb, 1);
 853
 854         for (i = 0; i < sbi->s_gdb_count; i++)
 855                 brelse(sbi->s_group_desc[i]);
 856         kvfree(sbi->s_group_desc);
 857         kvfree(sbi->s_flex_groups);
 858         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 859         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 860         percpu_counter_destroy(&sbi->s_dirs_counter);
 861         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 862         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
 863         brelse(sbi->s_sbh);
 864 #ifdef CONFIG_QUOTA
 865         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 866                 kfree(sbi->s_qf_names[i]);
 867 #endif
 868
 869         /* Debugging code just in case the in-memory inode orphan list
 870          * isn't empty.  The on-disk one can be non-empty if we've
 871          * detected an error and taken the fs readonly, but the
 872          * in-memory list had better be clean by this point. */
 873         if (!list_empty(&sbi->s_orphan))
 874                 dump_orphan_list(sb, sbi);
 875         J_ASSERT(list_empty(&sbi->s_orphan));
 876
 877         sync_blockdev(sb->s_bdev);
 878         invalidate_bdev(sb->s_bdev);
 879         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 880                 /*
 881                  * Invalidate the journal device's buffers.  We don't want them
 882                  * floating about in memory - the physical journal device may
 883                  * hotswapped, and it breaks the `ro-after' testing code.
 884                  */
 885                 sync_blockdev(sbi->journal_bdev);
 886                 invalidate_bdev(sbi->journal_bdev);
 887                 ext4_blkdev_remove(sbi);
 888         }
 889         if (sbi->s_mb_cache) {
 890                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 891                 sbi->s_mb_cache = NULL;
 892         }
 893         if (sbi->s_mmp_tsk)
 894                 kthread_stop(sbi->s_mmp_tsk);
 895         sb->s_fs_info = NULL;
 896         /*
 897          * Now that we are completely done shutting down the
 898          * superblock, we need to actually destroy the kobject.
 899          */
 900         kobject_put(&sbi->s_kobj);
 901         wait_for_completion(&sbi->s_kobj_unregister);
 902         if (sbi->s_chksum_driver)
 903                 crypto_free_shash(sbi->s_chksum_driver);
 904         kfree(sbi->s_blockgroup_lock);
 905         kfree(sbi);
 906 }
 907
 908 static struct kmem_cache *ext4_inode_cachep;
 909
 910 /*
 911  * Called inside transaction, so use GFP_NOFS
 912  */
 913 static struct inode *ext4_alloc_inode(struct super_block *sb)
 914 {
 915         struct ext4_inode_info *ei;
 916
 917         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 918         if (!ei)
 919                 return NULL;
 920
 921         ei->vfs_inode.i_version = 1;
 922         spin_lock_init(&ei->i_raw_lock);
 923         INIT_LIST_HEAD(&ei->i_prealloc_list);
 924         spin_lock_init(&ei->i_prealloc_lock);
 925         ext4_es_init_tree(&ei->i_es_tree);
 926         rwlock_init(&ei->i_es_lock);
 927         INIT_LIST_HEAD(&ei->i_es_list);
 928         ei->i_es_all_nr = 0;
 929         ei->i_es_shk_nr = 0;
 930         ei->i_es_shrink_lblk = 0;
 931         ei->i_reserved_data_blocks = 0;
 932         ei->i_reserved_meta_blocks = 0;
 933         ei->i_allocated_meta_blocks = 0;
 934         ei->i_da_metadata_calc_len = 0;
 935         ei->i_da_metadata_calc_last_lblock = 0;
 936         spin_lock_init(&(ei->i_block_reservation_lock));
 937 #ifdef CONFIG_QUOTA
 938         ei->i_reserved_quota = 0;
 939         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 940 #endif
 941         ei->jinode = NULL;
 942         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 943         spin_lock_init(&ei->i_completed_io_lock);
 944         ei->i_sync_tid = 0;
 945         ei->i_datasync_tid = 0;
 946         atomic_set(&ei->i_unwritten, 0);
 947         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 948         return &ei->vfs_inode;
 949 }
 950
 951 static int ext4_drop_inode(struct inode *inode)
 952 {
 953         int drop = generic_drop_inode(inode);
 954
 955         trace_ext4_drop_inode(inode, drop);
 956         return drop;
 957 }
 958
 959 static void ext4_i_callback(struct rcu_head *head)
 960 {
 961         struct inode *inode = container_of(head, struct inode, i_rcu);
 962         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 963 }
 964
 965 static void ext4_destroy_inode(struct inode *inode)
 966 {
 967         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 968                 ext4_msg(inode->i_sb, KERN_ERR,
 969                          "Inode %lu (%p): orphan list check failed!",
 970                          inode->i_ino, EXT4_I(inode));
 971                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 972                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 973                                 true);
 974                 dump_stack();
 975         }
 976         call_rcu(&inode->i_rcu, ext4_i_callback);
 977 }
 978
 979 static void init_once(void *foo)
 980 {
 981         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 982
 983         INIT_LIST_HEAD(&ei->i_orphan);
 984         init_rwsem(&ei->xattr_sem);
 985         init_rwsem(&ei->i_data_sem);
 986         init_rwsem(&ei->i_mmap_sem);
 987         inode_init_once(&ei->vfs_inode);
 988 }
 989
 990 static int __init init_inodecache(void)
 991 {
 992         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 993                                              sizeof(struct ext4_inode_info),
 994                                              0, (SLAB_RECLAIM_ACCOUNT|
 995                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 996                                              init_once);
 997         if (ext4_inode_cachep == NULL)
 998                 return -ENOMEM;
 999         return 0;
1000 }
1001
1002 static void destroy_inodecache(void)
1003 {
1004         /*
1005          * Make sure all delayed rcu free inodes are flushed before we
1006          * destroy cache.
1007          */
1008         rcu_barrier();
1009         kmem_cache_destroy(ext4_inode_cachep);
1010 }
1011
1012 void ext4_clear_inode(struct inode *inode)
1013 {
1014         invalidate_inode_buffers(inode);
1015         clear_inode(inode);
1016         dquot_drop(inode);
1017         ext4_discard_preallocations(inode);
1018         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1019         if (EXT4_I(inode)->jinode) {
1020                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1021                                                EXT4_I(inode)->jinode);
1022                 jbd2_free_inode(EXT4_I(inode)->jinode);
1023                 EXT4_I(inode)->jinode = NULL;
1024         }
1025 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1026         fscrypt_put_encryption_info(inode, NULL);
1027 #endif
1028 }
1029
1030 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1031                                         u64 ino, u32 generation)
1032 {
1033         struct inode *inode;
1034
1035         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1036                 return ERR_PTR(-ESTALE);
1037         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1038                 return ERR_PTR(-ESTALE);
1039
1040         /* iget isn't really right if the inode is currently unallocated!!
1041          *
1042          * ext4_read_inode will return a bad_inode if the inode had been
1043          * deleted, so we should be safe.
1044          *
1045          * Currently we don't know the generation for parent directory, so
1046          * a generation of 0 means "accept any"
1047          */
1048         inode = ext4_iget_normal(sb, ino);
1049         if (IS_ERR(inode))
1050                 return ERR_CAST(inode);
1051         if (generation && inode->i_generation != generation) {
1052                 iput(inode);
1053                 return ERR_PTR(-ESTALE);
1054         }
1055
1056         return inode;
1057 }
1058
1059 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1060                                         int fh_len, int fh_type)
1061 {
1062         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1063                                     ext4_nfs_get_inode);
1064 }
1065
1066 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1067                                         int fh_len, int fh_type)
1068 {
1069         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1070                                     ext4_nfs_get_inode);
1071 }
1072
1073 /*
1074  * Try to release metadata pages (indirect blocks, directories) which are
1075  * mapped via the block device.  Since these pages could have journal heads
1076  * which would prevent try_to_free_buffers() from freeing them, we must use
1077  * jbd2 layer's try_to_free_buffers() function to release them.
1078  */
1079 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1080                                  gfp_t wait)
1081 {
1082         journal_t *journal = EXT4_SB(sb)->s_journal;
1083
1084         WARN_ON(PageChecked(page));
1085         if (!page_has_buffers(page))
1086                 return 0;
1087         if (journal)
1088                 return jbd2_journal_try_to_free_buffers(journal, page,
1089                                                 wait & ~__GFP_DIRECT_RECLAIM);
1090         return try_to_free_buffers(page);
1091 }
1092
1093 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1094 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1095 {
1096         return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1097                                  EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1098 }
1099
1100 static int ext4_key_prefix(struct inode *inode, u8 **key)
1101 {
1102         *key = EXT4_SB(inode->i_sb)->key_prefix;
1103         return EXT4_SB(inode->i_sb)->key_prefix_size;
1104 }
1105
1106 static int ext4_prepare_context(struct inode *inode)
1107 {
1108         return ext4_convert_inline_data(inode);
1109 }
1110
1111 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1112                                                         void *fs_data)
1113 {
1114         handle_t *handle;
1115         int res, res2;
1116
1117         /* fs_data is null when internally used. */
1118         if (fs_data) {
1119                 res  = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1120                                 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx,
1121                                 len, 0);
1122                 if (!res) {
1123                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1124                         ext4_clear_inode_state(inode,
1125                                         EXT4_STATE_MAY_INLINE_DATA);
1126                 }
1127                 return res;
1128         }
1129
1130         handle = ext4_journal_start(inode, EXT4_HT_MISC,
1131                         ext4_jbd2_credits_xattr(inode));
1132         if (IS_ERR(handle))
1133                 return PTR_ERR(handle);
1134
1135         res = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1136                         EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx,
1137                         len, 0);
1138         if (!res) {
1139                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1140                 res = ext4_mark_inode_dirty(handle, inode);
1141                 if (res)
1142                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1143         }
1144         res2 = ext4_journal_stop(handle);
1145         if (!res)
1146                 res = res2;
1147         return res;
1148 }
1149
1150 static int ext4_dummy_context(struct inode *inode)
1151 {
1152         return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1153 }
1154
1155 static unsigned ext4_max_namelen(struct inode *inode)
1156 {
1157         return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1158                 EXT4_NAME_LEN;
1159 }
1160
1161 static struct fscrypt_operations ext4_cryptops = {
1162         .get_context            = ext4_get_context,
1163         .key_prefix             = ext4_key_prefix,
1164         .prepare_context        = ext4_prepare_context,
1165         .set_context            = ext4_set_context,
1166         .dummy_context          = ext4_dummy_context,
1167         .is_encrypted           = ext4_encrypted_inode,
1168         .empty_dir              = ext4_empty_dir,
1169         .max_namelen            = ext4_max_namelen,
1170 };
1171 #else
1172 static struct fscrypt_operations ext4_cryptops = {
1173         .is_encrypted           = ext4_encrypted_inode,
1174 };
1175 #endif
1176
1177 #ifdef CONFIG_QUOTA
1178 static char *quotatypes[] = INITQFNAMES;
1179 #define QTYPE2NAME(t) (quotatypes[t])
1180
1181 static int ext4_write_dquot(struct dquot *dquot);
1182 static int ext4_acquire_dquot(struct dquot *dquot);
1183 static int ext4_release_dquot(struct dquot *dquot);
1184 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1185 static int ext4_write_info(struct super_block *sb, int type);
1186 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1187                          struct path *path);
1188 static int ext4_quota_off(struct super_block *sb, int type);
1189 static int ext4_quota_on_mount(struct super_block *sb, int type);
1190 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1191                                size_t len, loff_t off);
1192 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1193                                 const char *data, size_t len, loff_t off);
1194 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1195                              unsigned int flags);
1196 static int ext4_enable_quotas(struct super_block *sb);
1197 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1198
1199 static struct dquot **ext4_get_dquots(struct inode *inode)
1200 {
1201         return EXT4_I(inode)->i_dquot;
1202 }
1203
1204 static const struct dquot_operations ext4_quota_operations = {
1205         .get_reserved_space = ext4_get_reserved_space,
1206         .write_dquot    = ext4_write_dquot,
1207         .acquire_dquot  = ext4_acquire_dquot,
1208         .release_dquot  = ext4_release_dquot,
1209         .mark_dirty     = ext4_mark_dquot_dirty,
1210         .write_info     = ext4_write_info,
1211         .alloc_dquot    = dquot_alloc,
1212         .destroy_dquot  = dquot_destroy,
1213         .get_projid     = ext4_get_projid,
1214         .get_next_id    = ext4_get_next_id,
1215 };
1216
1217 static const struct quotactl_ops ext4_qctl_operations = {
1218         .quota_on       = ext4_quota_on,
1219         .quota_off      = ext4_quota_off,
1220         .quota_sync     = dquot_quota_sync,
1221         .get_state      = dquot_get_state,
1222         .set_info       = dquot_set_dqinfo,
1223         .get_dqblk      = dquot_get_dqblk,
1224         .set_dqblk      = dquot_set_dqblk,
1225         .get_nextdqblk  = dquot_get_next_dqblk,
1226 };
1227 #endif
1228
1229 static const struct super_operations ext4_sops = {
1230         .alloc_inode    = ext4_alloc_inode,
1231         .destroy_inode  = ext4_destroy_inode,
1232         .write_inode    = ext4_write_inode,
1233         .dirty_inode    = ext4_dirty_inode,
1234         .drop_inode     = ext4_drop_inode,
1235         .evict_inode    = ext4_evict_inode,
1236         .put_super      = ext4_put_super,
1237         .sync_fs        = ext4_sync_fs,
1238         .freeze_fs      = ext4_freeze,
1239         .unfreeze_fs    = ext4_unfreeze,
1240         .statfs         = ext4_statfs,
1241         .remount_fs     = ext4_remount,
1242         .show_options   = ext4_show_options,
1243 #ifdef CONFIG_QUOTA
1244         .quota_read     = ext4_quota_read,
1245         .quota_write    = ext4_quota_write,
1246         .get_dquots     = ext4_get_dquots,
1247 #endif
1248         .bdev_try_to_free_page = bdev_try_to_free_page,
1249 };
1250
1251 static const struct export_operations ext4_export_ops = {
1252         .fh_to_dentry = ext4_fh_to_dentry,
1253         .fh_to_parent = ext4_fh_to_parent,
1254         .get_parent = ext4_get_parent,
1255 };
1256
1257 enum {
1258         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1259         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1260         Opt_nouid32, Opt_debug, Opt_removed,
1261         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1262         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1263         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1264         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1265         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1266         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1267         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1268         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1269         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1270         Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
1271         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1272         Opt_lazytime, Opt_nolazytime,
1273         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1274         Opt_inode_readahead_blks, Opt_journal_ioprio,
1275         Opt_dioread_nolock, Opt_dioread_lock,
1276         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1277         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1278 };
1279
1280 static const match_table_t tokens = {
1281         {Opt_bsd_df, "bsddf"},
1282         {Opt_minix_df, "minixdf"},
1283         {Opt_grpid, "grpid"},
1284         {Opt_grpid, "bsdgroups"},
1285         {Opt_nogrpid, "nogrpid"},
1286         {Opt_nogrpid, "sysvgroups"},
1287         {Opt_resgid, "resgid=%u"},
1288         {Opt_resuid, "resuid=%u"},
1289         {Opt_sb, "sb=%u"},
1290         {Opt_err_cont, "errors=continue"},
1291         {Opt_err_panic, "errors=panic"},
1292         {Opt_err_ro, "errors=remount-ro"},
1293         {Opt_nouid32, "nouid32"},
1294         {Opt_debug, "debug"},
1295         {Opt_removed, "oldalloc"},
1296         {Opt_removed, "orlov"},
1297         {Opt_user_xattr, "user_xattr"},
1298         {Opt_nouser_xattr, "nouser_xattr"},
1299         {Opt_acl, "acl"},
1300         {Opt_noacl, "noacl"},
1301         {Opt_noload, "norecovery"},
1302         {Opt_noload, "noload"},
1303         {Opt_removed, "nobh"},
1304         {Opt_removed, "bh"},
1305         {Opt_commit, "commit=%u"},
1306         {Opt_min_batch_time, "min_batch_time=%u"},
1307         {Opt_max_batch_time, "max_batch_time=%u"},
1308         {Opt_journal_dev, "journal_dev=%u"},
1309         {Opt_journal_path, "journal_path=%s"},
1310         {Opt_journal_checksum, "journal_checksum"},
1311         {Opt_nojournal_checksum, "nojournal_checksum"},
1312         {Opt_journal_async_commit, "journal_async_commit"},
1313         {Opt_abort, "abort"},
1314         {Opt_data_journal, "data=journal"},
1315         {Opt_data_ordered, "data=ordered"},
1316         {Opt_data_writeback, "data=writeback"},
1317         {Opt_data_err_abort, "data_err=abort"},
1318         {Opt_data_err_ignore, "data_err=ignore"},
1319         {Opt_offusrjquota, "usrjquota="},
1320         {Opt_usrjquota, "usrjquota=%s"},
1321         {Opt_offgrpjquota, "grpjquota="},
1322         {Opt_grpjquota, "grpjquota=%s"},
1323         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1324         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1325         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1326         {Opt_grpquota, "grpquota"},
1327         {Opt_noquota, "noquota"},
1328         {Opt_quota, "quota"},
1329         {Opt_usrquota, "usrquota"},
1330         {Opt_barrier, "barrier=%u"},
1331         {Opt_barrier, "barrier"},
1332         {Opt_nobarrier, "nobarrier"},
1333         {Opt_i_version, "i_version"},
1334         {Opt_dax, "dax"},
1335         {Opt_stripe, "stripe=%u"},
1336         {Opt_delalloc, "delalloc"},
1337         {Opt_lazytime, "lazytime"},
1338         {Opt_nolazytime, "nolazytime"},
1339         {Opt_nodelalloc, "nodelalloc"},
1340         {Opt_removed, "mblk_io_submit"},
1341         {Opt_removed, "nomblk_io_submit"},
1342         {Opt_block_validity, "block_validity"},
1343         {Opt_noblock_validity, "noblock_validity"},
1344         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1345         {Opt_journal_ioprio, "journal_ioprio=%u"},
1346         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1347         {Opt_auto_da_alloc, "auto_da_alloc"},
1348         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1349         {Opt_dioread_nolock, "dioread_nolock"},
1350         {Opt_dioread_lock, "dioread_lock"},
1351         {Opt_discard, "discard"},
1352         {Opt_nodiscard, "nodiscard"},
1353         {Opt_init_itable, "init_itable=%u"},
1354         {Opt_init_itable, "init_itable"},
1355         {Opt_noinit_itable, "noinit_itable"},
1356         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1357         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1358         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1359         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1360         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1361         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1362         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1363         {Opt_err, NULL},
1364 };
1365
1366 static ext4_fsblk_t get_sb_block(void **data)
1367 {
1368         ext4_fsblk_t    sb_block;
1369         char            *options = (char *) *data;
1370
1371         if (!options || strncmp(options, "sb=", 3) != 0)
1372                 return 1;       /* Default location */
1373
1374         options += 3;
1375         /* TODO: use simple_strtoll with >32bit ext4 */
1376         sb_block = simple_strtoul(options, &options, 0);
1377         if (*options && *options != ',') {
1378                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1379                        (char *) *data);
1380                 return 1;
1381         }
1382         if (*options == ',')
1383                 options++;
1384         *data = (void *) options;
1385
1386         return sb_block;
1387 }
1388
1389 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1390 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1391         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1392
1393 #ifdef CONFIG_QUOTA
1394 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1395 {
1396         struct ext4_sb_info *sbi = EXT4_SB(sb);
1397         char *qname;
1398         int ret = -1;
1399
1400         if (sb_any_quota_loaded(sb) &&
1401                 !sbi->s_qf_names[qtype]) {
1402                 ext4_msg(sb, KERN_ERR,
1403                         "Cannot change journaled "
1404                         "quota options when quota turned on");
1405                 return -1;
1406         }
1407         if (ext4_has_feature_quota(sb)) {
1408                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1409                          "ignored when QUOTA feature is enabled");
1410                 return 1;
1411         }
1412         qname = match_strdup(args);
1413         if (!qname) {
1414                 ext4_msg(sb, KERN_ERR,
1415                         "Not enough memory for storing quotafile name");
1416                 return -1;
1417         }
1418         if (sbi->s_qf_names[qtype]) {
1419                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1420                         ret = 1;
1421                 else
1422                         ext4_msg(sb, KERN_ERR,
1423                                  "%s quota file already specified",
1424                                  QTYPE2NAME(qtype));
1425                 goto errout;
1426         }
1427         if (strchr(qname, '/')) {
1428                 ext4_msg(sb, KERN_ERR,
1429                         "quotafile must be on filesystem root");
1430                 goto errout;
1431         }
1432         sbi->s_qf_names[qtype] = qname;
1433         set_opt(sb, QUOTA);
1434         return 1;
1435 errout:
1436         kfree(qname);
1437         return ret;
1438 }
1439
1440 static int clear_qf_name(struct super_block *sb, int qtype)
1441 {
1442
1443         struct ext4_sb_info *sbi = EXT4_SB(sb);
1444
1445         if (sb_any_quota_loaded(sb) &&
1446                 sbi->s_qf_names[qtype]) {
1447                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1448                         " when quota turned on");
1449                 return -1;
1450         }
1451         kfree(sbi->s_qf_names[qtype]);
1452         sbi->s_qf_names[qtype] = NULL;
1453         return 1;
1454 }
1455 #endif
1456
1457 #define MOPT_SET        0x0001
1458 #define MOPT_CLEAR      0x0002
1459 #define MOPT_NOSUPPORT  0x0004
1460 #define MOPT_EXPLICIT   0x0008
1461 #define MOPT_CLEAR_ERR  0x0010
1462 #define MOPT_GTE0       0x0020
1463 #ifdef CONFIG_QUOTA
1464 #define MOPT_Q          0
1465 #define MOPT_QFMT       0x0040
1466 #else
1467 #define MOPT_Q          MOPT_NOSUPPORT
1468 #define MOPT_QFMT       MOPT_NOSUPPORT
1469 #endif
1470 #define MOPT_DATAJ      0x0080
1471 #define MOPT_NO_EXT2    0x0100
1472 #define MOPT_NO_EXT3    0x0200
1473 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1474 #define MOPT_STRING     0x0400
1475
1476 static const struct mount_opts {
1477         int     token;
1478         int     mount_opt;
1479         int     flags;
1480 } ext4_mount_opts[] = {
1481         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1482         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1483         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1484         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1485         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1486         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1487         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1488          MOPT_EXT4_ONLY | MOPT_SET},
1489         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1490          MOPT_EXT4_ONLY | MOPT_CLEAR},
1491         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1492         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1493         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1494          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1495         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1496          MOPT_EXT4_ONLY | MOPT_CLEAR},
1497         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1498          MOPT_EXT4_ONLY | MOPT_CLEAR},
1499         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1500          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1501         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1502                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1503          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1504         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1505         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1506         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1507         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1508         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1509          MOPT_NO_EXT2},
1510         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1511          MOPT_NO_EXT2},
1512         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1513         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1514         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1515         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1516         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1517         {Opt_commit, 0, MOPT_GTE0},
1518         {Opt_max_batch_time, 0, MOPT_GTE0},
1519         {Opt_min_batch_time, 0, MOPT_GTE0},
1520         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1521         {Opt_init_itable, 0, MOPT_GTE0},
1522         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1523         {Opt_stripe, 0, MOPT_GTE0},
1524         {Opt_resuid, 0, MOPT_GTE0},
1525         {Opt_resgid, 0, MOPT_GTE0},
1526         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1527         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1528         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1529         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1530         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1531         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1532          MOPT_NO_EXT2 | MOPT_DATAJ},
1533         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1534         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1535 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1536         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1537         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1538 #else
1539         {Opt_acl, 0, MOPT_NOSUPPORT},
1540         {Opt_noacl, 0, MOPT_NOSUPPORT},
1541 #endif
1542         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1543         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1544         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1545         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1546                                                         MOPT_SET | MOPT_Q},
1547         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1548                                                         MOPT_SET | MOPT_Q},
1549         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1550                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1551         {Opt_usrjquota, 0, MOPT_Q},
1552         {Opt_grpjquota, 0, MOPT_Q},
1553         {Opt_offusrjquota, 0, MOPT_Q},
1554         {Opt_offgrpjquota, 0, MOPT_Q},
1555         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1556         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1557         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1558         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1559         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1560         {Opt_err, 0, 0}
1561 };
1562
1563 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1564                             substring_t *args, unsigned long *journal_devnum,
1565                             unsigned int *journal_ioprio, int is_remount)
1566 {
1567         struct ext4_sb_info *sbi = EXT4_SB(sb);
1568         const struct mount_opts *m;
1569         kuid_t uid;
1570         kgid_t gid;
1571         int arg = 0;
1572
1573 #ifdef CONFIG_QUOTA
1574         if (token == Opt_usrjquota)
1575                 return set_qf_name(sb, USRQUOTA, &args[0]);
1576         else if (token == Opt_grpjquota)
1577                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1578         else if (token == Opt_offusrjquota)
1579                 return clear_qf_name(sb, USRQUOTA);
1580         else if (token == Opt_offgrpjquota)
1581                 return clear_qf_name(sb, GRPQUOTA);
1582 #endif
1583         switch (token) {
1584         case Opt_noacl:
1585         case Opt_nouser_xattr:
1586                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1587                 break;
1588         case Opt_sb:
1589                 return 1;       /* handled by get_sb_block() */
1590         case Opt_removed:
1591                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1592                 return 1;
1593         case Opt_abort:
1594                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1595                 return 1;
1596         case Opt_i_version:
1597                 sb->s_flags |= MS_I_VERSION;
1598                 return 1;
1599         case Opt_lazytime:
1600                 sb->s_flags |= MS_LAZYTIME;
1601                 return 1;
1602         case Opt_nolazytime:
1603                 sb->s_flags &= ~MS_LAZYTIME;
1604                 return 1;
1605         }
1606
1607         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1608                 if (token == m->token)
1609                         break;
1610
1611         if (m->token == Opt_err) {
1612                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1613                          "or missing value", opt);
1614                 return -1;
1615         }
1616
1617         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1618                 ext4_msg(sb, KERN_ERR,
1619                          "Mount option \"%s\" incompatible with ext2", opt);
1620                 return -1;
1621         }
1622         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1623                 ext4_msg(sb, KERN_ERR,
1624                          "Mount option \"%s\" incompatible with ext3", opt);
1625                 return -1;
1626         }
1627
1628         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1629                 return -1;
1630         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1631                 return -1;
1632         if (m->flags & MOPT_EXPLICIT) {
1633                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1634                         set_opt2(sb, EXPLICIT_DELALLOC);
1635                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1636                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1637                 } else
1638                         return -1;
1639         }
1640         if (m->flags & MOPT_CLEAR_ERR)
1641                 clear_opt(sb, ERRORS_MASK);
1642         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1643                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1644                          "options when quota turned on");
1645                 return -1;
1646         }
1647
1648         if (m->flags & MOPT_NOSUPPORT) {
1649                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1650         } else if (token == Opt_commit) {
1651                 if (arg == 0)
1652                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1653                 sbi->s_commit_interval = HZ * arg;
1654         } else if (token == Opt_max_batch_time) {
1655                 sbi->s_max_batch_time = arg;
1656         } else if (token == Opt_min_batch_time) {
1657                 sbi->s_min_batch_time = arg;
1658         } else if (token == Opt_inode_readahead_blks) {
1659                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1660                         ext4_msg(sb, KERN_ERR,
1661                                  "EXT4-fs: inode_readahead_blks must be "
1662                                  "0 or a power of 2 smaller than 2^31");
1663                         return -1;
1664                 }
1665                 sbi->s_inode_readahead_blks = arg;
1666         } else if (token == Opt_init_itable) {
1667                 set_opt(sb, INIT_INODE_TABLE);
1668                 if (!args->from)
1669                         arg = EXT4_DEF_LI_WAIT_MULT;
1670                 sbi->s_li_wait_mult = arg;
1671         } else if (token == Opt_max_dir_size_kb) {
1672                 sbi->s_max_dir_size_kb = arg;
1673         } else if (token == Opt_stripe) {
1674                 sbi->s_stripe = arg;
1675         } else if (token == Opt_resuid) {
1676                 uid = make_kuid(current_user_ns(), arg);
1677                 if (!uid_valid(uid)) {
1678                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1679                         return -1;
1680                 }
1681                 sbi->s_resuid = uid;
1682         } else if (token == Opt_resgid) {
1683                 gid = make_kgid(current_user_ns(), arg);
1684                 if (!gid_valid(gid)) {
1685                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1686                         return -1;
1687                 }
1688                 sbi->s_resgid = gid;
1689         } else if (token == Opt_journal_dev) {
1690                 if (is_remount) {
1691                         ext4_msg(sb, KERN_ERR,
1692                                  "Cannot specify journal on remount");
1693                         return -1;
1694                 }
1695                 *journal_devnum = arg;
1696         } else if (token == Opt_journal_path) {
1697                 char *journal_path;
1698                 struct inode *journal_inode;
1699                 struct path path;
1700                 int error;
1701
1702                 if (is_remount) {
1703                         ext4_msg(sb, KERN_ERR,
1704                                  "Cannot specify journal on remount");
1705                         return -1;
1706                 }
1707                 journal_path = match_strdup(&args[0]);
1708                 if (!journal_path) {
1709                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1710                                 "journal device string");
1711                         return -1;
1712                 }
1713
1714                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1715                 if (error) {
1716                         ext4_msg(sb, KERN_ERR, "error: could not find "
1717                                 "journal device path: error %d", error);
1718                         kfree(journal_path);
1719                         return -1;
1720                 }
1721
1722                 journal_inode = d_inode(path.dentry);
1723                 if (!S_ISBLK(journal_inode->i_mode)) {
1724                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1725                                 "is not a block device", journal_path);
1726                         path_put(&path);
1727                         kfree(journal_path);
1728                         return -1;
1729                 }
1730
1731                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1732                 path_put(&path);
1733                 kfree(journal_path);
1734         } else if (token == Opt_journal_ioprio) {
1735                 if (arg > 7) {
1736                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1737                                  " (must be 0-7)");
1738                         return -1;
1739                 }
1740                 *journal_ioprio =
1741                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1742         } else if (token == Opt_test_dummy_encryption) {
1743 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1744                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1745                 ext4_msg(sb, KERN_WARNING,
1746                          "Test dummy encryption mode enabled");
1747 #else
1748                 ext4_msg(sb, KERN_WARNING,
1749                          "Test dummy encryption mount option ignored");
1750 #endif
1751         } else if (m->flags & MOPT_DATAJ) {
1752                 if (is_remount) {
1753                         if (!sbi->s_journal)
1754                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1755                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1756                                 ext4_msg(sb, KERN_ERR,
1757                                          "Cannot change data mode on remount");
1758                                 return -1;
1759                         }
1760                 } else {
1761                         clear_opt(sb, DATA_FLAGS);
1762                         sbi->s_mount_opt |= m->mount_opt;
1763                 }
1764 #ifdef CONFIG_QUOTA
1765         } else if (m->flags & MOPT_QFMT) {
1766                 if (sb_any_quota_loaded(sb) &&
1767                     sbi->s_jquota_fmt != m->mount_opt) {
1768                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1769                                  "quota options when quota turned on");
1770                         return -1;
1771                 }
1772                 if (ext4_has_feature_quota(sb)) {
1773                         ext4_msg(sb, KERN_INFO,
1774                                  "Quota format mount options ignored "
1775                                  "when QUOTA feature is enabled");
1776                         return 1;
1777                 }
1778                 sbi->s_jquota_fmt = m->mount_opt;
1779 #endif
1780         } else if (token == Opt_dax) {
1781 #ifdef CONFIG_FS_DAX
1782                 ext4_msg(sb, KERN_WARNING,
1783                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1784                         sbi->s_mount_opt |= m->mount_opt;
1785 #else
1786                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1787                 return -1;
1788 #endif
1789         } else if (token == Opt_data_err_abort) {
1790                 sbi->s_mount_opt |= m->mount_opt;
1791         } else if (token == Opt_data_err_ignore) {
1792                 sbi->s_mount_opt &= ~m->mount_opt;
1793         } else {
1794                 if (!args->from)
1795                         arg = 1;
1796                 if (m->flags & MOPT_CLEAR)
1797                         arg = !arg;
1798                 else if (unlikely(!(m->flags & MOPT_SET))) {
1799                         ext4_msg(sb, KERN_WARNING,
1800                                  "buggy handling of option %s", opt);
1801                         WARN_ON(1);
1802                         return -1;
1803                 }
1804                 if (arg != 0)
1805                         sbi->s_mount_opt |= m->mount_opt;
1806                 else
1807                         sbi->s_mount_opt &= ~m->mount_opt;
1808         }
1809         return 1;
1810 }
1811
1812 static int parse_options(char *options, struct super_block *sb,
1813                          unsigned long *journal_devnum,
1814                          unsigned int *journal_ioprio,
1815                          int is_remount)
1816 {
1817         struct ext4_sb_info *sbi = EXT4_SB(sb);
1818         char *p;
1819         substring_t args[MAX_OPT_ARGS];
1820         int token;
1821
1822         if (!options)
1823                 return 1;
1824
1825         while ((p = strsep(&options, ",")) != NULL) {
1826                 if (!*p)
1827                         continue;
1828                 /*
1829                  * Initialize args struct so we know whether arg was
1830                  * found; some options take optional arguments.
1831                  */
1832                 args[0].to = args[0].from = NULL;
1833                 token = match_token(p, tokens, args);
1834                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1835                                      journal_ioprio, is_remount) < 0)
1836                         return 0;
1837         }
1838 #ifdef CONFIG_QUOTA
1839         if (ext4_has_feature_quota(sb) &&
1840             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1841                 ext4_msg(sb, KERN_INFO, "Quota feature enabled, usrquota and grpquota "
1842                          "mount options ignored.");
1843                 clear_opt(sb, USRQUOTA);
1844                 clear_opt(sb, GRPQUOTA);
1845         } else if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1846                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1847                         clear_opt(sb, USRQUOTA);
1848
1849                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1850                         clear_opt(sb, GRPQUOTA);
1851
1852                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1853                         ext4_msg(sb, KERN_ERR, "old and new quota "
1854                                         "format mixing");
1855                         return 0;
1856                 }
1857
1858                 if (!sbi->s_jquota_fmt) {
1859                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1860                                         "not specified");
1861                         return 0;
1862                 }
1863         }
1864 #endif
1865         if (test_opt(sb, DIOREAD_NOLOCK)) {
1866                 int blocksize =
1867                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1868
1869                 if (blocksize < PAGE_SIZE) {
1870                         ext4_msg(sb, KERN_ERR, "can't mount with "
1871                                  "dioread_nolock if block size != PAGE_SIZE");
1872                         return 0;
1873                 }
1874         }
1875         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1876             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1877                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1878                          "in data=ordered mode");
1879                 return 0;
1880         }
1881         return 1;
1882 }
1883
1884 static inline void ext4_show_quota_options(struct seq_file *seq,
1885                                            struct super_block *sb)
1886 {
1887 #if defined(CONFIG_QUOTA)
1888         struct ext4_sb_info *sbi = EXT4_SB(sb);
1889
1890         if (sbi->s_jquota_fmt) {
1891                 char *fmtname = "";
1892
1893                 switch (sbi->s_jquota_fmt) {
1894                 case QFMT_VFS_OLD:
1895                         fmtname = "vfsold";
1896                         break;
1897                 case QFMT_VFS_V0:
1898                         fmtname = "vfsv0";
1899                         break;
1900                 case QFMT_VFS_V1:
1901                         fmtname = "vfsv1";
1902                         break;
1903                 }
1904                 seq_printf(seq, ",jqfmt=%s", fmtname);
1905         }
1906
1907         if (sbi->s_qf_names[USRQUOTA])
1908                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1909
1910         if (sbi->s_qf_names[GRPQUOTA])
1911                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1912 #endif
1913 }
1914
1915 static const char *token2str(int token)
1916 {
1917         const struct match_token *t;
1918
1919         for (t = tokens; t->token != Opt_err; t++)
1920                 if (t->token == token && !strchr(t->pattern, '='))
1921                         break;
1922         return t->pattern;
1923 }
1924
1925 /*
1926  * Show an option if
1927  *  - it's set to a non-default value OR
1928  *  - if the per-sb default is different from the global default
1929  */
1930 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1931                               int nodefs)
1932 {
1933         struct ext4_sb_info *sbi = EXT4_SB(sb);
1934         struct ext4_super_block *es = sbi->s_es;
1935         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1936         const struct mount_opts *m;
1937         char sep = nodefs ? '\n' : ',';
1938
1939 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1940 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1941
1942         if (sbi->s_sb_block != 1)
1943                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1944
1945         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1946                 int want_set = m->flags & MOPT_SET;
1947                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1948                     (m->flags & MOPT_CLEAR_ERR))
1949                         continue;
1950                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1951                         continue; /* skip if same as the default */
1952                 if ((want_set &&
1953                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1954                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1955                         continue; /* select Opt_noFoo vs Opt_Foo */
1956                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1957         }
1958
1959         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1960             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1961                 SEQ_OPTS_PRINT("resuid=%u",
1962                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1963         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1964             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1965                 SEQ_OPTS_PRINT("resgid=%u",
1966                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1967         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1968         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1969                 SEQ_OPTS_PUTS("errors=remount-ro");
1970         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1971                 SEQ_OPTS_PUTS("errors=continue");
1972         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1973                 SEQ_OPTS_PUTS("errors=panic");
1974         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1975                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1976         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1977                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1978         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1979                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1980         if (sb->s_flags & MS_I_VERSION)
1981                 SEQ_OPTS_PUTS("i_version");
1982         if (nodefs || sbi->s_stripe)
1983                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1984         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1985                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1986                         SEQ_OPTS_PUTS("data=journal");
1987                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1988                         SEQ_OPTS_PUTS("data=ordered");
1989                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1990                         SEQ_OPTS_PUTS("data=writeback");
1991         }
1992         if (nodefs ||
1993             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1994                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1995                                sbi->s_inode_readahead_blks);
1996
1997         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1998                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1999                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2000         if (nodefs || sbi->s_max_dir_size_kb)
2001                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2002         if (test_opt(sb, DATA_ERR_ABORT))
2003                 SEQ_OPTS_PUTS("data_err=abort");
2004
2005         ext4_show_quota_options(seq, sb);
2006         return 0;
2007 }
2008
2009 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2010 {
2011         return _ext4_show_options(seq, root->d_sb, 0);
2012 }
2013
2014 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2015 {
2016         struct super_block *sb = seq->private;
2017         int rc;
2018
2019         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2020         rc = _ext4_show_options(seq, sb, 1);
2021         seq_puts(seq, "\n");
2022         return rc;
2023 }
2024
2025 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2026                             int read_only)
2027 {
2028         struct ext4_sb_info *sbi = EXT4_SB(sb);
2029         int res = 0;
2030
2031         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2032                 ext4_msg(sb, KERN_ERR, "revision level too high, "
2033                          "forcing read-only mode");
2034                 res = MS_RDONLY;
2035         }
2036         if (read_only)
2037                 goto done;
2038         if (!(sbi->s_mount_state & EXT4_VALID_FS))
2039                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2040                          "running e2fsck is recommended");
2041         else if (sbi->s_mount_state & EXT4_ERROR_FS)
2042                 ext4_msg(sb, KERN_WARNING,
2043                          "warning: mounting fs with errors, "
2044                          "running e2fsck is recommended");
2045         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2046                  le16_to_cpu(es->s_mnt_count) >=
2047                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2048                 ext4_msg(sb, KERN_WARNING,
2049                          "warning: maximal mount count reached, "
2050                          "running e2fsck is recommended");
2051         else if (le32_to_cpu(es->s_checkinterval) &&
2052                 (le32_to_cpu(es->s_lastcheck) +
2053                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2054                 ext4_msg(sb, KERN_WARNING,
2055                          "warning: checktime reached, "
2056                          "running e2fsck is recommended");
2057         if (!sbi->s_journal)
2058                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2059         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2060                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2061         le16_add_cpu(&es->s_mnt_count, 1);
2062         es->s_mtime = cpu_to_le32(get_seconds());
2063         ext4_update_dynamic_rev(sb);
2064         if (sbi->s_journal)
2065                 ext4_set_feature_journal_needs_recovery(sb);
2066
2067         ext4_commit_super(sb, 1);
2068 done:
2069         if (test_opt(sb, DEBUG))
2070                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2071                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2072                         sb->s_blocksize,
2073                         sbi->s_groups_count,
2074                         EXT4_BLOCKS_PER_GROUP(sb),
2075                         EXT4_INODES_PER_GROUP(sb),
2076                         sbi->s_mount_opt, sbi->s_mount_opt2);
2077
2078         cleancache_init_fs(sb);
2079         return res;
2080 }
2081
2082 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2083 {
2084         struct ext4_sb_info *sbi = EXT4_SB(sb);
2085         struct flex_groups *new_groups;
2086         int size;
2087
2088         if (!sbi->s_log_groups_per_flex)
2089                 return 0;
2090
2091         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2092         if (size <= sbi->s_flex_groups_allocated)
2093                 return 0;
2094
2095         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2096         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2097         if (!new_groups) {
2098                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2099                          size / (int) sizeof(struct flex_groups));
2100                 return -ENOMEM;
2101         }
2102
2103         if (sbi->s_flex_groups) {
2104                 memcpy(new_groups, sbi->s_flex_groups,
2105                        (sbi->s_flex_groups_allocated *
2106                         sizeof(struct flex_groups)));
2107                 kvfree(sbi->s_flex_groups);
2108         }
2109         sbi->s_flex_groups = new_groups;
2110         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2111         return 0;
2112 }
2113
2114 static int ext4_fill_flex_info(struct super_block *sb)
2115 {
2116         struct ext4_sb_info *sbi = EXT4_SB(sb);
2117         struct ext4_group_desc *gdp = NULL;
2118         ext4_group_t flex_group;
2119         int i, err;
2120
2121         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2122         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2123                 sbi->s_log_groups_per_flex = 0;
2124                 return 1;
2125         }
2126
2127         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2128         if (err)
2129                 goto failed;
2130
2131         for (i = 0; i < sbi->s_groups_count; i++) {
2132                 gdp = ext4_get_group_desc(sb, i, NULL);
2133
2134                 flex_group = ext4_flex_group(sbi, i);
2135                 atomic_add(ext4_free_inodes_count(sb, gdp),
2136                            &sbi->s_flex_groups[flex_group].free_inodes);
2137                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2138                              &sbi->s_flex_groups[flex_group].free_clusters);
2139                 atomic_add(ext4_used_dirs_count(sb, gdp),
2140                            &sbi->s_flex_groups[flex_group].used_dirs);
2141         }
2142
2143         return 1;
2144 failed:
2145         return 0;
2146 }
2147
2148 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2149                                    struct ext4_group_desc *gdp)
2150 {
2151         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2152         __u16 crc = 0;
2153         __le32 le_group = cpu_to_le32(block_group);
2154         struct ext4_sb_info *sbi = EXT4_SB(sb);
2155
2156         if (ext4_has_metadata_csum(sbi->s_sb)) {
2157                 /* Use new metadata_csum algorithm */
2158                 __u32 csum32;
2159                 __u16 dummy_csum = 0;
2160
2161                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2162                                      sizeof(le_group));
2163                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2164                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2165                                      sizeof(dummy_csum));
2166                 offset += sizeof(dummy_csum);
2167                 if (offset < sbi->s_desc_size)
2168                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2169                                              sbi->s_desc_size - offset);
2170
2171                 crc = csum32 & 0xFFFF;
2172                 goto out;
2173         }
2174
2175         /* old crc16 code */
2176         if (!ext4_has_feature_gdt_csum(sb))
2177                 return 0;
2178
2179         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2180         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2181         crc = crc16(crc, (__u8 *)gdp, offset);
2182         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2183         /* for checksum of struct ext4_group_desc do the rest...*/
2184         if (ext4_has_feature_64bit(sb) &&
2185             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2186                 crc = crc16(crc, (__u8 *)gdp + offset,
2187                             le16_to_cpu(sbi->s_es->s_desc_size) -
2188                                 offset);
2189
2190 out:
2191         return cpu_to_le16(crc);
2192 }
2193
2194 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2195                                 struct ext4_group_desc *gdp)
2196 {
2197         if (ext4_has_group_desc_csum(sb) &&
2198             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2199                 return 0;
2200
2201         return 1;
2202 }
2203
2204 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2205                               struct ext4_group_desc *gdp)
2206 {
2207         if (!ext4_has_group_desc_csum(sb))
2208                 return;
2209         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2210 }
2211
2212 /* Called at mount-time, super-block is locked */
2213 static int ext4_check_descriptors(struct super_block *sb,
2214                                   ext4_fsblk_t sb_block,
2215                                   ext4_group_t *first_not_zeroed)
2216 {
2217         struct ext4_sb_info *sbi = EXT4_SB(sb);
2218         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2219         ext4_fsblk_t last_block;
2220         ext4_fsblk_t block_bitmap;
2221         ext4_fsblk_t inode_bitmap;
2222         ext4_fsblk_t inode_table;
2223         int flexbg_flag = 0;
2224         ext4_group_t i, grp = sbi->s_groups_count;
2225
2226         if (ext4_has_feature_flex_bg(sb))
2227                 flexbg_flag = 1;
2228
2229         ext4_debug("Checking group descriptors");
2230
2231         for (i = 0; i < sbi->s_groups_count; i++) {
2232                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2233
2234                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2235                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2236                 else
2237                         last_block = first_block +
2238                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2239
2240                 if ((grp == sbi->s_groups_count) &&
2241                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2242                         grp = i;
2243
2244                 block_bitmap = ext4_block_bitmap(sb, gdp);
2245                 if (block_bitmap == sb_block) {
2246                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2247                                  "Block bitmap for group %u overlaps "
2248                                  "superblock", i);
2249                 }
2250                 if (block_bitmap < first_block || block_bitmap > last_block) {
2251                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2252                                "Block bitmap for group %u not in group "
2253                                "(block %llu)!", i, block_bitmap);
2254                         return 0;
2255                 }
2256                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2257                 if (inode_bitmap == sb_block) {
2258                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2259                                  "Inode bitmap for group %u overlaps "
2260                                  "superblock", i);
2261                 }
2262                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2263                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2264                                "Inode bitmap for group %u not in group "
2265                                "(block %llu)!", i, inode_bitmap);
2266                         return 0;
2267                 }
2268                 inode_table = ext4_inode_table(sb, gdp);
2269                 if (inode_table == sb_block) {
2270                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2271                                  "Inode table for group %u overlaps "
2272                                  "superblock", i);
2273                 }
2274                 if (inode_table < first_block ||
2275                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2276                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2277                                "Inode table for group %u not in group "
2278                                "(block %llu)!", i, inode_table);
2279                         return 0;
2280                 }
2281                 ext4_lock_group(sb, i);
2282                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2283                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2284                                  "Checksum for group %u failed (%u!=%u)",
2285                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2286                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2287                         if (!(sb->s_flags & MS_RDONLY)) {
2288                                 ext4_unlock_group(sb, i);
2289                                 return 0;
2290                         }
2291                 }
2292                 ext4_unlock_group(sb, i);
2293                 if (!flexbg_flag)
2294                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2295         }
2296         if (NULL != first_not_zeroed)
2297                 *first_not_zeroed = grp;
2298         return 1;
2299 }
2300
2301 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2302  * the superblock) which were deleted from all directories, but held open by
2303  * a process at the time of a crash.  We walk the list and try to delete these
2304  * inodes at recovery time (only with a read-write filesystem).
2305  *
2306  * In order to keep the orphan inode chain consistent during traversal (in
2307  * case of crash during recovery), we link each inode into the superblock
2308  * orphan list_head and handle it the same way as an inode deletion during
2309  * normal operation (which journals the operations for us).
2310  *
2311  * We only do an iget() and an iput() on each inode, which is very safe if we
2312  * accidentally point at an in-use or already deleted inode.  The worst that
2313  * can happen in this case is that we get a "bit already cleared" message from
2314  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2315  * e2fsck was run on this filesystem, and it must have already done the orphan
2316  * inode cleanup for us, so we can safely abort without any further action.
2317  */
2318 static void ext4_orphan_cleanup(struct super_block *sb,
2319                                 struct ext4_super_block *es)
2320 {
2321         unsigned int s_flags = sb->s_flags;
2322         int nr_orphans = 0, nr_truncates = 0;
2323 #ifdef CONFIG_QUOTA
2324         int i;
2325 #endif
2326         if (!es->s_last_orphan) {
2327                 jbd_debug(4, "no orphan inodes to clean up\n");
2328                 return;
2329         }
2330
2331         if (bdev_read_only(sb->s_bdev)) {
2332                 ext4_msg(sb, KERN_ERR, "write access "
2333                         "unavailable, skipping orphan cleanup");
2334                 return;
2335         }
2336
2337         /* Check if feature set would not allow a r/w mount */
2338         if (!ext4_feature_set_ok(sb, 0)) {
2339                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2340                          "unknown ROCOMPAT features");
2341                 return;
2342         }
2343
2344         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2345                 /* don't clear list on RO mount w/ errors */
2346                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2347                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2348                                   "clearing orphan list.\n");
2349                         es->s_last_orphan = 0;
2350                 }
2351                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2352                 return;
2353         }
2354
2355         if (s_flags & MS_RDONLY) {
2356                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2357                 sb->s_flags &= ~MS_RDONLY;
2358         }
2359 #ifdef CONFIG_QUOTA
2360         /* Needed for iput() to work correctly and not trash data */
2361         sb->s_flags |= MS_ACTIVE;
2362         /* Turn on quotas so that they are updated correctly */
2363         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2364                 if (EXT4_SB(sb)->s_qf_names[i]) {
2365                         int ret = ext4_quota_on_mount(sb, i);
2366                         if (ret < 0)
2367                                 ext4_msg(sb, KERN_ERR,
2368                                         "Cannot turn on journaled "
2369                                         "quota: error %d", ret);
2370                 }
2371         }
2372 #endif
2373
2374         while (es->s_last_orphan) {
2375                 struct inode *inode;
2376
2377                 /*
2378                  * We may have encountered an error during cleanup; if
2379                  * so, skip the rest.
2380                  */
2381                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2382                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2383                         es->s_last_orphan = 0;
2384                         break;
2385                 }
2386
2387                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2388                 if (IS_ERR(inode)) {
2389                         es->s_last_orphan = 0;
2390                         break;
2391                 }
2392
2393                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2394                 dquot_initialize(inode);
2395                 if (inode->i_nlink) {
2396                         if (test_opt(sb, DEBUG))
2397                                 ext4_msg(sb, KERN_DEBUG,
2398                                         "%s: truncating inode %lu to %lld bytes",
2399                                         __func__, inode->i_ino, inode->i_size);
2400                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2401                                   inode->i_ino, inode->i_size);
2402                         inode_lock(inode);
2403                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2404                         ext4_truncate(inode);
2405                         inode_unlock(inode);
2406                         nr_truncates++;
2407                 } else {
2408                         if (test_opt(sb, DEBUG))
2409                                 ext4_msg(sb, KERN_DEBUG,
2410                                         "%s: deleting unreferenced inode %lu",
2411                                         __func__, inode->i_ino);
2412                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2413                                   inode->i_ino);
2414                         nr_orphans++;
2415                 }
2416                 iput(inode);  /* The delete magic happens here! */
2417         }
2418
2419 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2420
2421         if (nr_orphans)
2422                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2423                        PLURAL(nr_orphans));
2424         if (nr_truncates)
2425                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2426                        PLURAL(nr_truncates));
2427 #ifdef CONFIG_QUOTA
2428         /* Turn quotas off */
2429         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2430                 if (sb_dqopt(sb)->files[i])
2431                         dquot_quota_off(sb, i);
2432         }
2433 #endif
2434         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2435 }
2436
2437 /*
2438  * Maximal extent format file size.
2439  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2440  * extent format containers, within a sector_t, and within i_blocks
2441  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2442  * so that won't be a limiting factor.
2443  *
2444  * However there is other limiting factor. We do store extents in the form
2445  * of starting block and length, hence the resulting length of the extent
2446  * covering maximum file size must fit into on-disk format containers as
2447  * well. Given that length is always by 1 unit bigger than max unit (because
2448  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2449  *
2450  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2451  */
2452 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2453 {
2454         loff_t res;
2455         loff_t upper_limit = MAX_LFS_FILESIZE;
2456
2457         /* small i_blocks in vfs inode? */
2458         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2459                 /*
2460                  * CONFIG_LBDAF is not enabled implies the inode
2461                  * i_block represent total blocks in 512 bytes
2462                  * 32 == size of vfs inode i_blocks * 8
2463                  */
2464                 upper_limit = (1LL << 32) - 1;
2465
2466                 /* total blocks in file system block size */
2467                 upper_limit >>= (blkbits - 9);
2468                 upper_limit <<= blkbits;
2469         }
2470
2471         /*
2472          * 32-bit extent-start container, ee_block. We lower the maxbytes
2473          * by one fs block, so ee_len can cover the extent of maximum file
2474          * size
2475          */
2476         res = (1LL << 32) - 1;
2477         res <<= blkbits;
2478
2479         /* Sanity check against vm- & vfs- imposed limits */
2480         if (res > upper_limit)
2481                 res = upper_limit;
2482
2483         return res;
2484 }
2485
2486 /*
2487  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2488  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2489  * We need to be 1 filesystem block less than the 2^48 sector limit.
2490  */
2491 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2492 {
2493         loff_t res = EXT4_NDIR_BLOCKS;
2494         int meta_blocks;
2495         loff_t upper_limit;
2496         /* This is calculated to be the largest file size for a dense, block
2497          * mapped file such that the file's total number of 512-byte sectors,
2498          * including data and all indirect blocks, does not exceed (2^48 - 1).
2499          *
2500          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2501          * number of 512-byte sectors of the file.
2502          */
2503
2504         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2505                 /*
2506                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2507                  * the inode i_block field represents total file blocks in
2508                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2509                  */
2510                 upper_limit = (1LL << 32) - 1;
2511
2512                 /* total blocks in file system block size */
2513                 upper_limit >>= (bits - 9);
2514
2515         } else {
2516                 /*
2517                  * We use 48 bit ext4_inode i_blocks
2518                  * With EXT4_HUGE_FILE_FL set the i_blocks
2519                  * represent total number of blocks in
2520                  * file system block size
2521                  */
2522                 upper_limit = (1LL << 48) - 1;
2523
2524         }
2525
2526         /* indirect blocks */
2527         meta_blocks = 1;
2528         /* double indirect blocks */
2529         meta_blocks += 1 + (1LL << (bits-2));
2530         /* tripple indirect blocks */
2531         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2532
2533         upper_limit -= meta_blocks;
2534         upper_limit <<= bits;
2535
2536         res += 1LL << (bits-2);
2537         res += 1LL << (2*(bits-2));
2538         res += 1LL << (3*(bits-2));
2539         res <<= bits;
2540         if (res > upper_limit)
2541                 res = upper_limit;
2542
2543         if (res > MAX_LFS_FILESIZE)
2544                 res = MAX_LFS_FILESIZE;
2545
2546         return res;
2547 }
2548
2549 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2550                                    ext4_fsblk_t logical_sb_block, int nr)
2551 {
2552         struct ext4_sb_info *sbi = EXT4_SB(sb);
2553         ext4_group_t bg, first_meta_bg;
2554         int has_super = 0;
2555
2556         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2557
2558         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2559                 return logical_sb_block + nr + 1;
2560         bg = sbi->s_desc_per_block * nr;
2561         if (ext4_bg_has_super(sb, bg))
2562                 has_super = 1;
2563
2564         /*
2565          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2566          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2567          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2568          * compensate.
2569          */
2570         if (sb->s_blocksize == 1024 && nr == 0 &&
2571             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2572                 has_super++;
2573
2574         return (has_super + ext4_group_first_block_no(sb, bg));
2575 }
2576
2577 /**
2578  * ext4_get_stripe_size: Get the stripe size.
2579  * @sbi: In memory super block info
2580  *
2581  * If we have specified it via mount option, then
2582  * use the mount option value. If the value specified at mount time is
2583  * greater than the blocks per group use the super block value.
2584  * If the super block value is greater than blocks per group return 0.
2585  * Allocator needs it be less than blocks per group.
2586  *
2587  */
2588 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2589 {
2590         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2591         unsigned long stripe_width =
2592                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2593         int ret;
2594
2595         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2596                 ret = sbi->s_stripe;
2597         else if (stripe_width <= sbi->s_blocks_per_group)
2598                 ret = stripe_width;
2599         else if (stride <= sbi->s_blocks_per_group)
2600                 ret = stride;
2601         else
2602                 ret = 0;
2603
2604         /*
2605          * If the stripe width is 1, this makes no sense and
2606          * we set it to 0 to turn off stripe handling code.
2607          */
2608         if (ret <= 1)
2609                 ret = 0;
2610
2611         return ret;
2612 }
2613
2614 /*
2615  * Check whether this filesystem can be mounted based on
2616  * the features present and the RDONLY/RDWR mount requested.
2617  * Returns 1 if this filesystem can be mounted as requested,
2618  * 0 if it cannot be.
2619  */
2620 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2621 {
2622         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2623                 ext4_msg(sb, KERN_ERR,
2624                         "Couldn't mount because of "
2625                         "unsupported optional features (%x)",
2626                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2627                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2628                 return 0;
2629         }
2630
2631         if (readonly)
2632                 return 1;
2633
2634         if (ext4_has_feature_readonly(sb)) {
2635                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2636                 sb->s_flags |= MS_RDONLY;
2637                 return 1;
2638         }
2639
2640         /* Check that feature set is OK for a read-write mount */
2641         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2642                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2643                          "unsupported optional features (%x)",
2644                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2645                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2646                 return 0;
2647         }
2648         /*
2649          * Large file size enabled file system can only be mounted
2650          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2651          */
2652         if (ext4_has_feature_huge_file(sb)) {
2653                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2654                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2655                                  "cannot be mounted RDWR without "
2656                                  "CONFIG_LBDAF");
2657                         return 0;
2658                 }
2659         }
2660         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2661                 ext4_msg(sb, KERN_ERR,
2662                          "Can't support bigalloc feature without "
2663                          "extents feature\n");
2664                 return 0;
2665         }
2666
2667 #ifndef CONFIG_QUOTA
2668         if (ext4_has_feature_quota(sb) && !readonly) {
2669                 ext4_msg(sb, KERN_ERR,
2670                          "Filesystem with quota feature cannot be mounted RDWR "
2671                          "without CONFIG_QUOTA");
2672                 return 0;
2673         }
2674         if (ext4_has_feature_project(sb) && !readonly) {
2675                 ext4_msg(sb, KERN_ERR,
2676                          "Filesystem with project quota feature cannot be mounted RDWR "
2677                          "without CONFIG_QUOTA");
2678                 return 0;
2679         }
2680 #endif  /* CONFIG_QUOTA */
2681         return 1;
2682 }
2683
2684 /*
2685  * This function is called once a day if we have errors logged
2686  * on the file system
2687  */
2688 static void print_daily_error_info(unsigned long arg)
2689 {
2690         struct super_block *sb = (struct super_block *) arg;
2691         struct ext4_sb_info *sbi;
2692         struct ext4_super_block *es;
2693
2694         sbi = EXT4_SB(sb);
2695         es = sbi->s_es;
2696
2697         if (es->s_error_count)
2698                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2699                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2700                          le32_to_cpu(es->s_error_count));
2701         if (es->s_first_error_time) {
2702                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2703                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2704                        (int) sizeof(es->s_first_error_func),
2705                        es->s_first_error_func,
2706                        le32_to_cpu(es->s_first_error_line));
2707                 if (es->s_first_error_ino)
2708                         printk(": inode %u",
2709                                le32_to_cpu(es->s_first_error_ino));
2710                 if (es->s_first_error_block)
2711                         printk(": block %llu", (unsigned long long)
2712                                le64_to_cpu(es->s_first_error_block));
2713                 printk("\n");
2714         }
2715         if (es->s_last_error_time) {
2716                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2717                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2718                        (int) sizeof(es->s_last_error_func),
2719                        es->s_last_error_func,
2720                        le32_to_cpu(es->s_last_error_line));
2721                 if (es->s_last_error_ino)
2722                         printk(": inode %u",
2723                                le32_to_cpu(es->s_last_error_ino));
2724                 if (es->s_last_error_block)
2725                         printk(": block %llu", (unsigned long long)
2726                                le64_to_cpu(es->s_last_error_block));
2727                 printk("\n");
2728         }
2729         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2730 }
2731
2732 /* Find next suitable group and run ext4_init_inode_table */
2733 static int ext4_run_li_request(struct ext4_li_request *elr)
2734 {
2735         struct ext4_group_desc *gdp = NULL;
2736         ext4_group_t group, ngroups;
2737         struct super_block *sb;
2738         unsigned long timeout = 0;
2739         int ret = 0;
2740
2741         sb = elr->lr_super;
2742         ngroups = EXT4_SB(sb)->s_groups_count;
2743
2744         sb_start_write(sb);
2745         for (group = elr->lr_next_group; group < ngroups; group++) {
2746                 gdp = ext4_get_group_desc(sb, group, NULL);
2747                 if (!gdp) {
2748                         ret = 1;
2749                         break;
2750                 }
2751
2752                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2753                         break;
2754         }
2755
2756         if (group >= ngroups)
2757                 ret = 1;
2758
2759         if (!ret) {
2760                 timeout = jiffies;
2761                 ret = ext4_init_inode_table(sb, group,
2762                                             elr->lr_timeout ? 0 : 1);
2763                 if (elr->lr_timeout == 0) {
2764                         timeout = (jiffies - timeout) *
2765                                   elr->lr_sbi->s_li_wait_mult;
2766                         elr->lr_timeout = timeout;
2767                 }
2768                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2769                 elr->lr_next_group = group + 1;
2770         }
2771         sb_end_write(sb);
2772
2773         return ret;
2774 }
2775
2776 /*
2777  * Remove lr_request from the list_request and free the
2778  * request structure. Should be called with li_list_mtx held
2779  */
2780 static void ext4_remove_li_request(struct ext4_li_request *elr)
2781 {
2782         struct ext4_sb_info *sbi;
2783
2784         if (!elr)
2785                 return;
2786
2787         sbi = elr->lr_sbi;
2788
2789         list_del(&elr->lr_request);
2790         sbi->s_li_request = NULL;
2791         kfree(elr);
2792 }
2793
2794 static void ext4_unregister_li_request(struct super_block *sb)
2795 {
2796         mutex_lock(&ext4_li_mtx);
2797         if (!ext4_li_info) {
2798                 mutex_unlock(&ext4_li_mtx);
2799                 return;
2800         }
2801
2802         mutex_lock(&ext4_li_info->li_list_mtx);
2803         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2804         mutex_unlock(&ext4_li_info->li_list_mtx);
2805         mutex_unlock(&ext4_li_mtx);
2806 }
2807
2808 static struct task_struct *ext4_lazyinit_task;
2809
2810 /*
2811  * This is the function where ext4lazyinit thread lives. It walks
2812  * through the request list searching for next scheduled filesystem.
2813  * When such a fs is found, run the lazy initialization request
2814  * (ext4_rn_li_request) and keep track of the time spend in this
2815  * function. Based on that time we compute next schedule time of
2816  * the request. When walking through the list is complete, compute
2817  * next waking time and put itself into sleep.
2818  */
2819 static int ext4_lazyinit_thread(void *arg)
2820 {
2821         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2822         struct list_head *pos, *n;
2823         struct ext4_li_request *elr;
2824         unsigned long next_wakeup, cur;
2825
2826         BUG_ON(NULL == eli);
2827
2828 cont_thread:
2829         while (true) {
2830                 next_wakeup = MAX_JIFFY_OFFSET;
2831
2832                 mutex_lock(&eli->li_list_mtx);
2833                 if (list_empty(&eli->li_request_list)) {
2834                         mutex_unlock(&eli->li_list_mtx);
2835                         goto exit_thread;
2836                 }
2837
2838                 list_for_each_safe(pos, n, &eli->li_request_list) {
2839                         elr = list_entry(pos, struct ext4_li_request,
2840                                          lr_request);
2841
2842                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2843                                 if (ext4_run_li_request(elr) != 0) {
2844                                         /* error, remove the lazy_init job */
2845                                         ext4_remove_li_request(elr);
2846                                         continue;
2847                                 }
2848                         }
2849
2850                         if (time_before(elr->lr_next_sched, next_wakeup))
2851                                 next_wakeup = elr->lr_next_sched;
2852                 }
2853                 mutex_unlock(&eli->li_list_mtx);
2854
2855                 try_to_freeze();
2856
2857                 cur = jiffies;
2858                 if ((time_after_eq(cur, next_wakeup)) ||
2859                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2860                         cond_resched();
2861                         continue;
2862                 }
2863
2864                 schedule_timeout_interruptible(next_wakeup - cur);
2865
2866                 if (kthread_should_stop()) {
2867                         ext4_clear_request_list();
2868                         goto exit_thread;
2869                 }
2870         }
2871
2872 exit_thread:
2873         /*
2874          * It looks like the request list is empty, but we need
2875          * to check it under the li_list_mtx lock, to prevent any
2876          * additions into it, and of course we should lock ext4_li_mtx
2877          * to atomically free the list and ext4_li_info, because at
2878          * this point another ext4 filesystem could be registering
2879          * new one.
2880          */
2881         mutex_lock(&ext4_li_mtx);
2882         mutex_lock(&eli->li_list_mtx);
2883         if (!list_empty(&eli->li_request_list)) {
2884                 mutex_unlock(&eli->li_list_mtx);
2885                 mutex_unlock(&ext4_li_mtx);
2886                 goto cont_thread;
2887         }
2888         mutex_unlock(&eli->li_list_mtx);
2889         kfree(ext4_li_info);
2890         ext4_li_info = NULL;
2891         mutex_unlock(&ext4_li_mtx);
2892
2893         return 0;
2894 }
2895
2896 static void ext4_clear_request_list(void)
2897 {
2898         struct list_head *pos, *n;
2899         struct ext4_li_request *elr;
2900
2901         mutex_lock(&ext4_li_info->li_list_mtx);
2902         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2903                 elr = list_entry(pos, struct ext4_li_request,
2904                                  lr_request);
2905                 ext4_remove_li_request(elr);
2906         }
2907         mutex_unlock(&ext4_li_info->li_list_mtx);
2908 }
2909
2910 static int ext4_run_lazyinit_thread(void)
2911 {
2912         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2913                                          ext4_li_info, "ext4lazyinit");
2914         if (IS_ERR(ext4_lazyinit_task)) {
2915                 int err = PTR_ERR(ext4_lazyinit_task);
2916                 ext4_clear_request_list();
2917                 kfree(ext4_li_info);
2918                 ext4_li_info = NULL;
2919                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2920                                  "initialization thread\n",
2921                                  err);
2922                 return err;
2923         }
2924         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2925         return 0;
2926 }
2927
2928 /*
2929  * Check whether it make sense to run itable init. thread or not.
2930  * If there is at least one uninitialized inode table, return
2931  * corresponding group number, else the loop goes through all
2932  * groups and return total number of groups.
2933  */
2934 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2935 {
2936         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2937         struct ext4_group_desc *gdp = NULL;
2938
2939         for (group = 0; group < ngroups; group++) {
2940                 gdp = ext4_get_group_desc(sb, group, NULL);
2941                 if (!gdp)
2942                         continue;
2943
2944                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2945                         break;
2946         }
2947
2948         return group;
2949 }
2950
2951 static int ext4_li_info_new(void)
2952 {
2953         struct ext4_lazy_init *eli = NULL;
2954
2955         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2956         if (!eli)
2957                 return -ENOMEM;
2958
2959         INIT_LIST_HEAD(&eli->li_request_list);
2960         mutex_init(&eli->li_list_mtx);
2961
2962         eli->li_state |= EXT4_LAZYINIT_QUIT;
2963
2964         ext4_li_info = eli;
2965
2966         return 0;
2967 }
2968
2969 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2970                                             ext4_group_t start)
2971 {
2972         struct ext4_sb_info *sbi = EXT4_SB(sb);
2973         struct ext4_li_request *elr;
2974
2975         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2976         if (!elr)
2977                 return NULL;
2978
2979         elr->lr_super = sb;
2980         elr->lr_sbi = sbi;
2981         elr->lr_next_group = start;
2982
2983         /*
2984          * Randomize first schedule time of the request to
2985          * spread the inode table initialization requests
2986          * better.
2987          */
2988         elr->lr_next_sched = jiffies + (prandom_u32() %
2989                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2990         return elr;
2991 }
2992
2993 int ext4_register_li_request(struct super_block *sb,
2994                              ext4_group_t first_not_zeroed)
2995 {
2996         struct ext4_sb_info *sbi = EXT4_SB(sb);
2997         struct ext4_li_request *elr = NULL;
2998         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2999         int ret = 0;
3000
3001         mutex_lock(&ext4_li_mtx);
3002         if (sbi->s_li_request != NULL) {
3003                 /*
3004                  * Reset timeout so it can be computed again, because
3005                  * s_li_wait_mult might have changed.
3006                  */
3007                 sbi->s_li_request->lr_timeout = 0;
3008                 goto out;
3009         }
3010
3011         if (first_not_zeroed == ngroups ||
3012             (sb->s_flags & MS_RDONLY) ||
3013             !test_opt(sb, INIT_INODE_TABLE))
3014                 goto out;
3015
3016         elr = ext4_li_request_new(sb, first_not_zeroed);
3017         if (!elr) {
3018                 ret = -ENOMEM;
3019                 goto out;
3020         }
3021
3022         if (NULL == ext4_li_info) {
3023                 ret = ext4_li_info_new();
3024                 if (ret)
3025                         goto out;
3026         }
3027
3028         mutex_lock(&ext4_li_info->li_list_mtx);
3029         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3030         mutex_unlock(&ext4_li_info->li_list_mtx);
3031
3032         sbi->s_li_request = elr;
3033         /*
3034          * set elr to NULL here since it has been inserted to
3035          * the request_list and the removal and free of it is
3036          * handled by ext4_clear_request_list from now on.
3037          */
3038         elr = NULL;
3039
3040         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3041                 ret = ext4_run_lazyinit_thread();
3042                 if (ret)
3043                         goto out;
3044         }
3045 out:
3046         mutex_unlock(&ext4_li_mtx);
3047         if (ret)
3048                 kfree(elr);
3049         return ret;
3050 }
3051
3052 /*
3053  * We do not need to lock anything since this is called on
3054  * module unload.
3055  */
3056 static void ext4_destroy_lazyinit_thread(void)
3057 {
3058         /*
3059          * If thread exited earlier
3060          * there's nothing to be done.
3061          */
3062         if (!ext4_li_info || !ext4_lazyinit_task)
3063                 return;
3064
3065         kthread_stop(ext4_lazyinit_task);
3066 }
3067
3068 static int set_journal_csum_feature_set(struct super_block *sb)
3069 {
3070         int ret = 1;
3071         int compat, incompat;
3072         struct ext4_sb_info *sbi = EXT4_SB(sb);
3073
3074         if (ext4_has_metadata_csum(sb)) {
3075                 /* journal checksum v3 */
3076                 compat = 0;
3077                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3078         } else {
3079                 /* journal checksum v1 */
3080                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3081                 incompat = 0;
3082         }
3083
3084         jbd2_journal_clear_features(sbi->s_journal,
3085                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3086                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3087                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3088         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3089                 ret = jbd2_journal_set_features(sbi->s_journal,
3090                                 compat, 0,
3091                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3092                                 incompat);
3093         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3094                 ret = jbd2_journal_set_features(sbi->s_journal,
3095                                 compat, 0,
3096                                 incompat);
3097                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3098                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3099         } else {
3100                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3101                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3102         }
3103
3104         return ret;
3105 }
3106
3107 /*
3108  * Note: calculating the overhead so we can be compatible with
3109  * historical BSD practice is quite difficult in the face of
3110  * clusters/bigalloc.  This is because multiple metadata blocks from
3111  * different block group can end up in the same allocation cluster.
3112  * Calculating the exact overhead in the face of clustered allocation
3113  * requires either O(all block bitmaps) in memory or O(number of block
3114  * groups**2) in time.  We will still calculate the superblock for
3115  * older file systems --- and if we come across with a bigalloc file
3116  * system with zero in s_overhead_clusters the estimate will be close to
3117  * correct especially for very large cluster sizes --- but for newer
3118  * file systems, it's better to calculate this figure once at mkfs
3119  * time, and store it in the superblock.  If the superblock value is
3120  * present (even for non-bigalloc file systems), we will use it.
3121  */
3122 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3123                           char *buf)
3124 {
3125         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3126         struct ext4_group_desc  *gdp;
3127         ext4_fsblk_t            first_block, last_block, b;
3128         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3129         int                     s, j, count = 0;
3130
3131         if (!ext4_has_feature_bigalloc(sb))
3132                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3133                         sbi->s_itb_per_group + 2);
3134
3135         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3136                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3137         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3138         for (i = 0; i < ngroups; i++) {
3139                 gdp = ext4_get_group_desc(sb, i, NULL);
3140                 b = ext4_block_bitmap(sb, gdp);
3141                 if (b >= first_block && b <= last_block) {
3142                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3143                         count++;
3144                 }
3145                 b = ext4_inode_bitmap(sb, gdp);
3146                 if (b >= first_block && b <= last_block) {
3147                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3148                         count++;
3149                 }
3150                 b = ext4_inode_table(sb, gdp);
3151                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3152                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3153                                 int c = EXT4_B2C(sbi, b - first_block);
3154                                 ext4_set_bit(c, buf);
3155                                 count++;
3156                         }
3157                 if (i != grp)
3158                         continue;
3159                 s = 0;
3160                 if (ext4_bg_has_super(sb, grp)) {
3161                         ext4_set_bit(s++, buf);
3162                         count++;
3163                 }
3164                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3165                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3166                         count++;
3167                 }
3168         }
3169         if (!count)
3170                 return 0;
3171         return EXT4_CLUSTERS_PER_GROUP(sb) -
3172                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3173 }
3174
3175 /*
3176  * Compute the overhead and stash it in sbi->s_overhead
3177  */
3178 int ext4_calculate_overhead(struct super_block *sb)
3179 {
3180         struct ext4_sb_info *sbi = EXT4_SB(sb);
3181         struct ext4_super_block *es = sbi->s_es;
3182         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3183         ext4_fsblk_t overhead = 0;
3184         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3185
3186         if (!buf)
3187                 return -ENOMEM;
3188
3189         /*
3190          * Compute the overhead (FS structures).  This is constant
3191          * for a given filesystem unless the number of block groups
3192          * changes so we cache the previous value until it does.
3193          */
3194
3195         /*
3196          * All of the blocks before first_data_block are overhead
3197          */
3198         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3199
3200         /*
3201          * Add the overhead found in each block group
3202          */
3203         for (i = 0; i < ngroups; i++) {
3204                 int blks;
3205
3206                 blks = count_overhead(sb, i, buf);
3207                 overhead += blks;
3208                 if (blks)
3209                         memset(buf, 0, PAGE_SIZE);
3210                 cond_resched();
3211         }
3212         /* Add the internal journal blocks as well */
3213         if (sbi->s_journal && !sbi->journal_bdev)
3214                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3215
3216         sbi->s_overhead = overhead;
3217         smp_wmb();
3218         free_page((unsigned long) buf);
3219         return 0;
3220 }
3221
3222 static void ext4_set_resv_clusters(struct super_block *sb)
3223 {
3224         ext4_fsblk_t resv_clusters;
3225         struct ext4_sb_info *sbi = EXT4_SB(sb);
3226
3227         /*
3228          * There's no need to reserve anything when we aren't using extents.
3229          * The space estimates are exact, there are no unwritten extents,
3230          * hole punching doesn't need new metadata... This is needed especially
3231          * to keep ext2/3 backward compatibility.
3232          */
3233         if (!ext4_has_feature_extents(sb))
3234                 return;
3235         /*
3236          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3237          * This should cover the situations where we can not afford to run
3238          * out of space like for example punch hole, or converting
3239          * unwritten extents in delalloc path. In most cases such
3240          * allocation would require 1, or 2 blocks, higher numbers are
3241          * very rare.
3242          */
3243         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3244                          sbi->s_cluster_bits);
3245
3246         do_div(resv_clusters, 50);
3247         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3248
3249         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3250 }
3251
3252 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3253 {
3254         char *orig_data = kstrdup(data, GFP_KERNEL);
3255         struct buffer_head *bh;
3256         struct ext4_super_block *es = NULL;
3257         struct ext4_sb_info *sbi;
3258         ext4_fsblk_t block;
3259         ext4_fsblk_t sb_block = get_sb_block(&data);
3260         ext4_fsblk_t logical_sb_block;
3261         unsigned long offset = 0;
3262         unsigned long journal_devnum = 0;
3263         unsigned long def_mount_opts;
3264         struct inode *root;
3265         const char *descr;
3266         int ret = -ENOMEM;
3267         int blocksize, clustersize;
3268         unsigned int db_count;
3269         unsigned int i;
3270         int needs_recovery, has_huge_files, has_bigalloc;
3271         __u64 blocks_count;
3272         int err = 0;
3273         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3274         ext4_group_t first_not_zeroed;
3275
3276         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3277         if (!sbi)
3278                 goto out_free_orig;
3279
3280         sbi->s_blockgroup_lock =
3281                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3282         if (!sbi->s_blockgroup_lock) {
3283                 kfree(sbi);
3284                 goto out_free_orig;
3285         }
3286         sb->s_fs_info = sbi;
3287         sbi->s_sb = sb;
3288         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3289         sbi->s_sb_block = sb_block;
3290         if (sb->s_bdev->bd_part)
3291                 sbi->s_sectors_written_start =
3292                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3293
3294         /* Cleanup superblock name */
3295         strreplace(sb->s_id, '/', '!');
3296
3297         /* -EINVAL is default */
3298         ret = -EINVAL;
3299         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3300         if (!blocksize) {
3301                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3302                 goto out_fail;
3303         }
3304
3305         /*
3306          * The ext4 superblock will not be buffer aligned for other than 1kB
3307          * block sizes.  We need to calculate the offset from buffer start.
3308          */
3309         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3310                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3311                 offset = do_div(logical_sb_block, blocksize);
3312         } else {
3313                 logical_sb_block = sb_block;
3314         }
3315
3316         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3317                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3318                 goto out_fail;
3319         }
3320         /*
3321          * Note: s_es must be initialized as soon as possible because
3322          *       some ext4 macro-instructions depend on its value
3323          */
3324         es = (struct ext4_super_block *) (bh->b_data + offset);
3325         sbi->s_es = es;
3326         sb->s_magic = le16_to_cpu(es->s_magic);
3327         if (sb->s_magic != EXT4_SUPER_MAGIC)
3328                 goto cantfind_ext4;
3329         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3330
3331         /* Warn if metadata_csum and gdt_csum are both set. */
3332         if (ext4_has_feature_metadata_csum(sb) &&
3333             ext4_has_feature_gdt_csum(sb))
3334                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3335                              "redundant flags; please run fsck.");
3336
3337         /* Check for a known checksum algorithm */
3338         if (!ext4_verify_csum_type(sb, es)) {
3339                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3340                          "unknown checksum algorithm.");
3341                 silent = 1;
3342                 goto cantfind_ext4;
3343         }
3344
3345         /* Load the checksum driver */
3346         if (ext4_has_feature_metadata_csum(sb)) {
3347                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3348                 if (IS_ERR(sbi->s_chksum_driver)) {
3349                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3350                         ret = PTR_ERR(sbi->s_chksum_driver);
3351                         sbi->s_chksum_driver = NULL;
3352                         goto failed_mount;
3353                 }
3354         }
3355
3356         /* Check superblock checksum */
3357         if (!ext4_superblock_csum_verify(sb, es)) {
3358                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3359                          "invalid superblock checksum.  Run e2fsck?");
3360                 silent = 1;
3361                 ret = -EFSBADCRC;
3362                 goto cantfind_ext4;
3363         }
3364
3365         /* Precompute checksum seed for all metadata */
3366         if (ext4_has_feature_csum_seed(sb))
3367                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3368         else if (ext4_has_metadata_csum(sb))
3369                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3370                                                sizeof(es->s_uuid));
3371
3372         /* Set defaults before we parse the mount options */
3373         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3374         set_opt(sb, INIT_INODE_TABLE);
3375         if (def_mount_opts & EXT4_DEFM_DEBUG)
3376                 set_opt(sb, DEBUG);
3377         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3378                 set_opt(sb, GRPID);
3379         if (def_mount_opts & EXT4_DEFM_UID16)
3380                 set_opt(sb, NO_UID32);
3381         /* xattr user namespace & acls are now defaulted on */
3382         set_opt(sb, XATTR_USER);
3383 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3384         set_opt(sb, POSIX_ACL);
3385 #endif
3386         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3387         if (ext4_has_metadata_csum(sb))
3388                 set_opt(sb, JOURNAL_CHECKSUM);
3389
3390         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3391                 set_opt(sb, JOURNAL_DATA);
3392         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3393                 set_opt(sb, ORDERED_DATA);
3394         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3395                 set_opt(sb, WRITEBACK_DATA);
3396
3397         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3398                 set_opt(sb, ERRORS_PANIC);
3399         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3400                 set_opt(sb, ERRORS_CONT);
3401         else
3402                 set_opt(sb, ERRORS_RO);
3403         /* block_validity enabled by default; disable with noblock_validity */
3404         set_opt(sb, BLOCK_VALIDITY);
3405         if (def_mount_opts & EXT4_DEFM_DISCARD)
3406                 set_opt(sb, DISCARD);
3407
3408         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3409         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3410         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3411         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3412         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3413
3414         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3415                 set_opt(sb, BARRIER);
3416
3417         /*
3418          * enable delayed allocation by default
3419          * Use -o nodelalloc to turn it off
3420          */
3421         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3422             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3423                 set_opt(sb, DELALLOC);
3424
3425         /*
3426          * set default s_li_wait_mult for lazyinit, for the case there is
3427          * no mount option specified.
3428          */
3429         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3430
3431         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3432                            &journal_devnum, &journal_ioprio, 0)) {
3433                 ext4_msg(sb, KERN_WARNING,
3434                          "failed to parse options in superblock: %s",
3435                          sbi->s_es->s_mount_opts);
3436         }
3437         sbi->s_def_mount_opt = sbi->s_mount_opt;
3438         if (!parse_options((char *) data, sb, &journal_devnum,
3439                            &journal_ioprio, 0))
3440                 goto failed_mount;
3441
3442         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3443                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3444                             "with data=journal disables delayed "
3445                             "allocation and O_DIRECT support!\n");
3446                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3447                         ext4_msg(sb, KERN_ERR, "can't mount with "
3448                                  "both data=journal and delalloc");
3449                         goto failed_mount;
3450                 }
3451                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3452                         ext4_msg(sb, KERN_ERR, "can't mount with "
3453                                  "both data=journal and dioread_nolock");
3454                         goto failed_mount;
3455                 }
3456                 if (test_opt(sb, DAX)) {
3457                         ext4_msg(sb, KERN_ERR, "can't mount with "
3458                                  "both data=journal and dax");
3459                         goto failed_mount;
3460                 }
3461                 if (test_opt(sb, DELALLOC))
3462                         clear_opt(sb, DELALLOC);
3463         } else {
3464                 sb->s_iflags |= SB_I_CGROUPWB;
3465         }
3466
3467         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3468                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3469
3470         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3471             (ext4_has_compat_features(sb) ||
3472              ext4_has_ro_compat_features(sb) ||
3473              ext4_has_incompat_features(sb)))
3474                 ext4_msg(sb, KERN_WARNING,
3475                        "feature flags set on rev 0 fs, "
3476                        "running e2fsck is recommended");
3477
3478         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3479                 set_opt2(sb, HURD_COMPAT);
3480                 if (ext4_has_feature_64bit(sb)) {
3481                         ext4_msg(sb, KERN_ERR,
3482                                  "The Hurd can't support 64-bit file systems");
3483                         goto failed_mount;
3484                 }
3485         }
3486
3487         if (IS_EXT2_SB(sb)) {
3488                 if (ext2_feature_set_ok(sb))
3489                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3490                                  "using the ext4 subsystem");
3491                 else {
3492                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3493                                  "to feature incompatibilities");
3494                         goto failed_mount;
3495                 }
3496         }
3497
3498         if (IS_EXT3_SB(sb)) {
3499                 if (ext3_feature_set_ok(sb))
3500                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3501                                  "using the ext4 subsystem");
3502                 else {
3503                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3504                                  "to feature incompatibilities");
3505                         goto failed_mount;
3506                 }
3507         }
3508
3509         /*
3510          * Check feature flags regardless of the revision level, since we
3511          * previously didn't change the revision level when setting the flags,
3512          * so there is a chance incompat flags are set on a rev 0 filesystem.
3513          */
3514         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3515                 goto failed_mount;
3516
3517         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3518         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3519             blocksize > EXT4_MAX_BLOCK_SIZE) {
3520                 ext4_msg(sb, KERN_ERR,
3521                        "Unsupported filesystem blocksize %d", blocksize);
3522                 goto failed_mount;
3523         }
3524
3525         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3526                 ext4_msg(sb, KERN_ERR,
3527                          "Number of reserved GDT blocks insanely large: %d",
3528                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3529                 goto failed_mount;
3530         }
3531
3532         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3533                 err = bdev_dax_supported(sb, blocksize);
3534                 if (err)
3535                         goto failed_mount;
3536         }
3537
3538         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3539                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3540                          es->s_encryption_level);
3541                 goto failed_mount;
3542         }
3543
3544         if (sb->s_blocksize != blocksize) {
3545                 /* Validate the filesystem blocksize */
3546                 if (!sb_set_blocksize(sb, blocksize)) {
3547                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3548                                         blocksize);
3549                         goto failed_mount;
3550                 }
3551
3552                 brelse(bh);
3553                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3554                 offset = do_div(logical_sb_block, blocksize);
3555                 bh = sb_bread_unmovable(sb, logical_sb_block);
3556                 if (!bh) {
3557                         ext4_msg(sb, KERN_ERR,
3558                                "Can't read superblock on 2nd try");
3559                         goto failed_mount;
3560                 }
3561                 es = (struct ext4_super_block *)(bh->b_data + offset);
3562                 sbi->s_es = es;
3563                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3564                         ext4_msg(sb, KERN_ERR,
3565                                "Magic mismatch, very weird!");
3566                         goto failed_mount;
3567                 }
3568         }
3569
3570         has_huge_files = ext4_has_feature_huge_file(sb);
3571         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3572                                                       has_huge_files);
3573         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3574
3575         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3576                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3577                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3578         } else {
3579                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3580                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3581                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3582                     (!is_power_of_2(sbi->s_inode_size)) ||
3583                     (sbi->s_inode_size > blocksize)) {
3584                         ext4_msg(sb, KERN_ERR,
3585                                "unsupported inode size: %d",
3586                                sbi->s_inode_size);
3587                         goto failed_mount;
3588                 }
3589                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3590                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3591         }
3592
3593         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3594         if (ext4_has_feature_64bit(sb)) {
3595                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3596                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3597                     !is_power_of_2(sbi->s_desc_size)) {
3598                         ext4_msg(sb, KERN_ERR,
3599                                "unsupported descriptor size %lu",
3600                                sbi->s_desc_size);
3601                         goto failed_mount;
3602                 }
3603         } else
3604                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3605
3606         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3607         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3608         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3609                 goto cantfind_ext4;
3610
3611         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3612         if (sbi->s_inodes_per_block == 0)
3613                 goto cantfind_ext4;
3614         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3615                                         sbi->s_inodes_per_block;
3616         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3617         sbi->s_sbh = bh;
3618         sbi->s_mount_state = le16_to_cpu(es->s_state);
3619         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3620         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3621
3622         for (i = 0; i < 4; i++)
3623                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3624         sbi->s_def_hash_version = es->s_def_hash_version;
3625         if (ext4_has_feature_dir_index(sb)) {
3626                 i = le32_to_cpu(es->s_flags);
3627                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3628                         sbi->s_hash_unsigned = 3;
3629                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3630 #ifdef __CHAR_UNSIGNED__
3631                         if (!(sb->s_flags & MS_RDONLY))
3632                                 es->s_flags |=
3633                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3634                         sbi->s_hash_unsigned = 3;
3635 #else
3636                         if (!(sb->s_flags & MS_RDONLY))
3637                                 es->s_flags |=
3638                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3639 #endif
3640                 }
3641         }
3642
3643         /* Handle clustersize */
3644         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3645         has_bigalloc = ext4_has_feature_bigalloc(sb);
3646         if (has_bigalloc) {
3647                 if (clustersize < blocksize) {
3648                         ext4_msg(sb, KERN_ERR,
3649                                  "cluster size (%d) smaller than "
3650                                  "block size (%d)", clustersize, blocksize);
3651                         goto failed_mount;
3652                 }
3653                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3654                         le32_to_cpu(es->s_log_block_size);
3655                 sbi->s_clusters_per_group =
3656                         le32_to_cpu(es->s_clusters_per_group);
3657                 if (sbi->s_clusters_per_group > blocksize * 8) {
3658                         ext4_msg(sb, KERN_ERR,
3659                                  "#clusters per group too big: %lu",
3660                                  sbi->s_clusters_per_group);
3661                         goto failed_mount;
3662                 }
3663                 if (sbi->s_blocks_per_group !=
3664                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3665                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3666                                  "clusters per group (%lu) inconsistent",
3667                                  sbi->s_blocks_per_group,
3668                                  sbi->s_clusters_per_group);
3669                         goto failed_mount;
3670                 }
3671         } else {
3672                 if (clustersize != blocksize) {
3673                         ext4_warning(sb, "fragment/cluster size (%d) != "
3674                                      "block size (%d)", clustersize,
3675                                      blocksize);
3676                         clustersize = blocksize;
3677                 }
3678                 if (sbi->s_blocks_per_group > blocksize * 8) {
3679                         ext4_msg(sb, KERN_ERR,
3680                                  "#blocks per group too big: %lu",
3681                                  sbi->s_blocks_per_group);
3682                         goto failed_mount;
3683                 }
3684                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3685                 sbi->s_cluster_bits = 0;
3686         }
3687         sbi->s_cluster_ratio = clustersize / blocksize;
3688
3689         if (sbi->s_inodes_per_group > blocksize * 8) {
3690                 ext4_msg(sb, KERN_ERR,
3691                        "#inodes per group too big: %lu",
3692                        sbi->s_inodes_per_group);
3693                 goto failed_mount;
3694         }
3695
3696         /* Do we have standard group size of clustersize * 8 blocks ? */
3697         if (sbi->s_blocks_per_group == clustersize << 3)
3698                 set_opt2(sb, STD_GROUP_SIZE);
3699
3700         /*
3701          * Test whether we have more sectors than will fit in sector_t,
3702          * and whether the max offset is addressable by the page cache.
3703          */
3704         err = generic_check_addressable(sb->s_blocksize_bits,
3705                                         ext4_blocks_count(es));
3706         if (err) {
3707                 ext4_msg(sb, KERN_ERR, "filesystem"
3708                          " too large to mount safely on this system");
3709                 if (sizeof(sector_t) < 8)
3710                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3711                 goto failed_mount;
3712         }
3713
3714         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3715                 goto cantfind_ext4;
3716
3717         /* check blocks count against device size */
3718         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3719         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3720                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3721                        "exceeds size of device (%llu blocks)",
3722                        ext4_blocks_count(es), blocks_count);
3723                 goto failed_mount;
3724         }
3725
3726         /*
3727          * It makes no sense for the first data block to be beyond the end
3728          * of the filesystem.
3729          */
3730         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3731                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3732                          "block %u is beyond end of filesystem (%llu)",
3733                          le32_to_cpu(es->s_first_data_block),
3734                          ext4_blocks_count(es));
3735                 goto failed_mount;
3736         }
3737         blocks_count = (ext4_blocks_count(es) -
3738                         le32_to_cpu(es->s_first_data_block) +
3739                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3740         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3741         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3742                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3743                        "(block count %llu, first data block %u, "
3744                        "blocks per group %lu)", sbi->s_groups_count,
3745                        ext4_blocks_count(es),
3746                        le32_to_cpu(es->s_first_data_block),
3747                        EXT4_BLOCKS_PER_GROUP(sb));
3748                 goto failed_mount;
3749         }
3750         sbi->s_groups_count = blocks_count;
3751         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3752                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3753         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3754                    EXT4_DESC_PER_BLOCK(sb);
3755         sbi->s_group_desc = ext4_kvmalloc(db_count *
3756                                           sizeof(struct buffer_head *),
3757                                           GFP_KERNEL);
3758         if (sbi->s_group_desc == NULL) {
3759                 ext4_msg(sb, KERN_ERR, "not enough memory");
3760                 ret = -ENOMEM;
3761                 goto failed_mount;
3762         }
3763
3764         bgl_lock_init(sbi->s_blockgroup_lock);
3765
3766         for (i = 0; i < db_count; i++) {
3767                 block = descriptor_loc(sb, logical_sb_block, i);
3768                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3769                 if (!sbi->s_group_desc[i]) {
3770                         ext4_msg(sb, KERN_ERR,
3771                                "can't read group descriptor %d", i);
3772                         db_count = i;
3773                         goto failed_mount2;
3774                 }
3775         }
3776         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3777                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3778                 ret = -EFSCORRUPTED;
3779                 goto failed_mount2;
3780         }
3781
3782         sbi->s_gdb_count = db_count;
3783         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3784         spin_lock_init(&sbi->s_next_gen_lock);
3785
3786         setup_timer(&sbi->s_err_report, print_daily_error_info,
3787                 (unsigned long) sb);
3788
3789         /* Register extent status tree shrinker */
3790         if (ext4_es_register_shrinker(sbi))
3791                 goto failed_mount3;
3792
3793         sbi->s_stripe = ext4_get_stripe_size(sbi);
3794         sbi->s_extent_max_zeroout_kb = 32;
3795
3796         /*
3797          * set up enough so that it can read an inode
3798          */
3799         sb->s_op = &ext4_sops;
3800         sb->s_export_op = &ext4_export_ops;
3801         sb->s_xattr = ext4_xattr_handlers;
3802         sb->s_cop = &ext4_cryptops;
3803 #ifdef CONFIG_QUOTA
3804         sb->dq_op = &ext4_quota_operations;
3805         if (ext4_has_feature_quota(sb))
3806                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3807         else
3808                 sb->s_qcop = &ext4_qctl_operations;
3809         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3810 #endif
3811         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3812
3813         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3814         mutex_init(&sbi->s_orphan_lock);
3815
3816         sb->s_root = NULL;
3817
3818         needs_recovery = (es->s_last_orphan != 0 ||
3819                           ext4_has_feature_journal_needs_recovery(sb));
3820
3821         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3822                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3823                         goto failed_mount3a;
3824
3825         /*
3826          * The first inode we look at is the journal inode.  Don't try
3827          * root first: it may be modified in the journal!
3828          */
3829         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3830                 if (ext4_load_journal(sb, es, journal_devnum))
3831                         goto failed_mount3a;
3832         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3833                    ext4_has_feature_journal_needs_recovery(sb)) {
3834                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3835                        "suppressed and not mounted read-only");
3836                 goto failed_mount_wq;
3837         } else {
3838                 /* Nojournal mode, all journal mount options are illegal */
3839                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3840                         ext4_msg(sb, KERN_ERR, "can't mount with "
3841                                  "journal_checksum, fs mounted w/o journal");
3842                         goto failed_mount_wq;
3843                 }
3844                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3845                         ext4_msg(sb, KERN_ERR, "can't mount with "
3846                                  "journal_async_commit, fs mounted w/o journal");
3847                         goto failed_mount_wq;
3848                 }
3849                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3850                         ext4_msg(sb, KERN_ERR, "can't mount with "
3851                                  "commit=%lu, fs mounted w/o journal",
3852                                  sbi->s_commit_interval / HZ);
3853                         goto failed_mount_wq;
3854                 }
3855                 if (EXT4_MOUNT_DATA_FLAGS &
3856                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3857                         ext4_msg(sb, KERN_ERR, "can't mount with "
3858                                  "data=, fs mounted w/o journal");
3859                         goto failed_mount_wq;
3860                 }
3861                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3862                 clear_opt(sb, JOURNAL_CHECKSUM);
3863                 clear_opt(sb, DATA_FLAGS);
3864                 sbi->s_journal = NULL;
3865                 needs_recovery = 0;
3866                 goto no_journal;
3867         }
3868
3869         if (ext4_has_feature_64bit(sb) &&
3870             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3871                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3872                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3873                 goto failed_mount_wq;
3874         }
3875
3876         if (!set_journal_csum_feature_set(sb)) {
3877                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3878                          "feature set");
3879                 goto failed_mount_wq;
3880         }
3881
3882         /* We have now updated the journal if required, so we can
3883          * validate the data journaling mode. */
3884         switch (test_opt(sb, DATA_FLAGS)) {
3885         case 0:
3886                 /* No mode set, assume a default based on the journal
3887                  * capabilities: ORDERED_DATA if the journal can
3888                  * cope, else JOURNAL_DATA
3889                  */
3890                 if (jbd2_journal_check_available_features
3891                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3892                         set_opt(sb, ORDERED_DATA);
3893                 else
3894                         set_opt(sb, JOURNAL_DATA);
3895                 break;
3896
3897         case EXT4_MOUNT_ORDERED_DATA:
3898         case EXT4_MOUNT_WRITEBACK_DATA:
3899                 if (!jbd2_journal_check_available_features
3900                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3901                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3902                                "requested data journaling mode");
3903                         goto failed_mount_wq;
3904                 }
3905         default:
3906                 break;
3907         }
3908         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3909
3910         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3911
3912 no_journal:
3913         sbi->s_mb_cache = ext4_xattr_create_cache();
3914         if (!sbi->s_mb_cache) {
3915                 ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
3916                 goto failed_mount_wq;
3917         }
3918
3919         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
3920             (blocksize != PAGE_SIZE)) {
3921                 ext4_msg(sb, KERN_ERR,
3922                          "Unsupported blocksize for fs encryption");
3923                 goto failed_mount_wq;
3924         }
3925
3926         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
3927             !ext4_has_feature_encrypt(sb)) {
3928                 ext4_set_feature_encrypt(sb);
3929                 ext4_commit_super(sb, 1);
3930         }
3931
3932         /*
3933          * Get the # of file system overhead blocks from the
3934          * superblock if present.
3935          */
3936         if (es->s_overhead_clusters)
3937                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3938         else {
3939                 err = ext4_calculate_overhead(sb);
3940                 if (err)
3941                         goto failed_mount_wq;
3942         }
3943
3944         /*
3945          * The maximum number of concurrent works can be high and
3946          * concurrency isn't really necessary.  Limit it to 1.
3947          */
3948         EXT4_SB(sb)->rsv_conversion_wq =
3949                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3950         if (!EXT4_SB(sb)->rsv_conversion_wq) {
3951                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3952                 ret = -ENOMEM;
3953                 goto failed_mount4;
3954         }
3955
3956         /*
3957          * The jbd2_journal_load will have done any necessary log recovery,
3958          * so we can safely mount the rest of the filesystem now.
3959          */
3960
3961         root = ext4_iget(sb, EXT4_ROOT_INO);
3962         if (IS_ERR(root)) {
3963                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3964                 ret = PTR_ERR(root);
3965                 root = NULL;
3966                 goto failed_mount4;
3967         }
3968         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3969                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3970                 iput(root);
3971                 goto failed_mount4;
3972         }
3973         sb->s_root = d_make_root(root);
3974         if (!sb->s_root) {
3975                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3976                 ret = -ENOMEM;
3977                 goto failed_mount4;
3978         }
3979
3980         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3981                 sb->s_flags |= MS_RDONLY;
3982
3983         /* determine the minimum size of new large inodes, if present */
3984         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3985                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3986                                                      EXT4_GOOD_OLD_INODE_SIZE;
3987                 if (ext4_has_feature_extra_isize(sb)) {
3988                         if (sbi->s_want_extra_isize <
3989                             le16_to_cpu(es->s_want_extra_isize))
3990                                 sbi->s_want_extra_isize =
3991                                         le16_to_cpu(es->s_want_extra_isize);
3992                         if (sbi->s_want_extra_isize <
3993                             le16_to_cpu(es->s_min_extra_isize))
3994                                 sbi->s_want_extra_isize =
3995                                         le16_to_cpu(es->s_min_extra_isize);
3996                 }
3997         }
3998         /* Check if enough inode space is available */
3999         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4000                                                         sbi->s_inode_size) {
4001                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4002                                                        EXT4_GOOD_OLD_INODE_SIZE;
4003                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4004                          "available");
4005         }
4006
4007         ext4_set_resv_clusters(sb);
4008
4009         err = ext4_setup_system_zone(sb);
4010         if (err) {
4011                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4012                          "zone (%d)", err);
4013                 goto failed_mount4a;
4014         }
4015
4016         ext4_ext_init(sb);
4017         err = ext4_mb_init(sb);
4018         if (err) {
4019                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4020                          err);
4021                 goto failed_mount5;
4022         }
4023
4024         block = ext4_count_free_clusters(sb);
4025         ext4_free_blocks_count_set(sbi->s_es,
4026                                    EXT4_C2B(sbi, block));
4027         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4028                                   GFP_KERNEL);
4029         if (!err) {
4030                 unsigned long freei = ext4_count_free_inodes(sb);
4031                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4032                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4033                                           GFP_KERNEL);
4034         }
4035         if (!err)
4036                 err = percpu_counter_init(&sbi->s_dirs_counter,
4037                                           ext4_count_dirs(sb), GFP_KERNEL);
4038         if (!err)
4039                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4040                                           GFP_KERNEL);
4041         if (!err)
4042                 err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4043
4044         if (err) {
4045                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4046                 goto failed_mount6;
4047         }
4048
4049         if (ext4_has_feature_flex_bg(sb))
4050                 if (!ext4_fill_flex_info(sb)) {
4051                         ext4_msg(sb, KERN_ERR,
4052                                "unable to initialize "
4053                                "flex_bg meta info!");
4054                         goto failed_mount6;
4055                 }
4056
4057         err = ext4_register_li_request(sb, first_not_zeroed);
4058         if (err)
4059                 goto failed_mount6;
4060
4061         err = ext4_register_sysfs(sb);
4062         if (err)
4063                 goto failed_mount7;
4064
4065 #ifdef CONFIG_QUOTA
4066         /* Enable quota usage during mount. */
4067         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4068                 err = ext4_enable_quotas(sb);
4069                 if (err)
4070                         goto failed_mount8;
4071         }
4072 #endif  /* CONFIG_QUOTA */
4073
4074         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4075         ext4_orphan_cleanup(sb, es);
4076         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4077         if (needs_recovery) {
4078                 ext4_msg(sb, KERN_INFO, "recovery complete");
4079                 ext4_mark_recovery_complete(sb, es);
4080         }
4081         if (EXT4_SB(sb)->s_journal) {
4082                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4083                         descr = " journalled data mode";
4084                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4085                         descr = " ordered data mode";
4086                 else
4087                         descr = " writeback data mode";
4088         } else
4089                 descr = "out journal";
4090
4091         if (test_opt(sb, DISCARD)) {
4092                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4093                 if (!blk_queue_discard(q))
4094                         ext4_msg(sb, KERN_WARNING,
4095                                  "mounting with \"discard\" option, but "
4096                                  "the device does not support discard");
4097         }
4098
4099         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4100                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4101                          "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4102                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4103
4104         if (es->s_error_count)
4105                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4106
4107         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4108         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4109         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4110         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4111
4112         kfree(orig_data);
4113 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4114         memcpy(sbi->key_prefix, EXT4_KEY_DESC_PREFIX,
4115                                 EXT4_KEY_DESC_PREFIX_SIZE);
4116         sbi->key_prefix_size = EXT4_KEY_DESC_PREFIX_SIZE;
4117 #endif
4118         return 0;
4119
4120 cantfind_ext4:
4121         if (!silent)
4122                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4123         goto failed_mount;
4124
4125 #ifdef CONFIG_QUOTA
4126 failed_mount8:
4127         ext4_unregister_sysfs(sb);
4128 #endif
4129 failed_mount7:
4130         ext4_unregister_li_request(sb);
4131 failed_mount6:
4132         ext4_mb_release(sb);
4133         if (sbi->s_flex_groups)
4134                 kvfree(sbi->s_flex_groups);
4135         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4136         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4137         percpu_counter_destroy(&sbi->s_dirs_counter);
4138         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4139 failed_mount5:
4140         ext4_ext_release(sb);
4141         ext4_release_system_zone(sb);
4142 failed_mount4a:
4143         dput(sb->s_root);
4144         sb->s_root = NULL;
4145 failed_mount4:
4146         ext4_msg(sb, KERN_ERR, "mount failed");
4147         if (EXT4_SB(sb)->rsv_conversion_wq)
4148                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4149 failed_mount_wq:
4150         if (sbi->s_mb_cache) {
4151                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
4152                 sbi->s_mb_cache = NULL;
4153         }
4154         if (sbi->s_journal) {
4155                 jbd2_journal_destroy(sbi->s_journal);
4156                 sbi->s_journal = NULL;
4157         }
4158 failed_mount3a:
4159         ext4_es_unregister_shrinker(sbi);
4160 failed_mount3:
4161         del_timer_sync(&sbi->s_err_report);
4162         if (sbi->s_mmp_tsk)
4163                 kthread_stop(sbi->s_mmp_tsk);
4164 failed_mount2:
4165         for (i = 0; i < db_count; i++)
4166                 brelse(sbi->s_group_desc[i]);
4167         kvfree(sbi->s_group_desc);
4168 failed_mount:
4169         if (sbi->s_chksum_driver)
4170                 crypto_free_shash(sbi->s_chksum_driver);
4171 #ifdef CONFIG_QUOTA
4172         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4173                 kfree(sbi->s_qf_names[i]);
4174 #endif
4175         ext4_blkdev_remove(sbi);
4176         brelse(bh);
4177 out_fail:
4178         sb->s_fs_info = NULL;
4179         kfree(sbi->s_blockgroup_lock);
4180         kfree(sbi);
4181 out_free_orig:
4182         kfree(orig_data);
4183         return err ? err : ret;
4184 }
4185
4186 /*
4187  * Setup any per-fs journal parameters now.  We'll do this both on
4188  * initial mount, once the journal has been initialised but before we've
4189  * done any recovery; and again on any subsequent remount.
4190  */
4191 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4192 {
4193         struct ext4_sb_info *sbi = EXT4_SB(sb);
4194
4195         journal->j_commit_interval = sbi->s_commit_interval;
4196         journal->j_min_batch_time = sbi->s_min_batch_time;
4197         journal->j_max_batch_time = sbi->s_max_batch_time;
4198
4199         write_lock(&journal->j_state_lock);
4200         if (test_opt(sb, BARRIER))
4201                 journal->j_flags |= JBD2_BARRIER;
4202         else
4203                 journal->j_flags &= ~JBD2_BARRIER;
4204         if (test_opt(sb, DATA_ERR_ABORT))
4205                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4206         else
4207                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4208         write_unlock(&journal->j_state_lock);
4209 }
4210
4211 static journal_t *ext4_get_journal(struct super_block *sb,
4212                                    unsigned int journal_inum)
4213 {
4214         struct inode *journal_inode;
4215         journal_t *journal;
4216
4217         BUG_ON(!ext4_has_feature_journal(sb));
4218
4219         /* First, test for the existence of a valid inode on disk.  Bad
4220          * things happen if we iget() an unused inode, as the subsequent
4221          * iput() will try to delete it. */
4222
4223         journal_inode = ext4_iget(sb, journal_inum);
4224         if (IS_ERR(journal_inode)) {
4225                 ext4_msg(sb, KERN_ERR, "no journal found");
4226                 return NULL;
4227         }
4228         if (!journal_inode->i_nlink) {
4229                 make_bad_inode(journal_inode);
4230                 iput(journal_inode);
4231                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4232                 return NULL;
4233         }
4234
4235         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4236                   journal_inode, journal_inode->i_size);
4237         if (!S_ISREG(journal_inode->i_mode)) {
4238                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4239                 iput(journal_inode);
4240                 return NULL;
4241         }
4242
4243         journal = jbd2_journal_init_inode(journal_inode);
4244         if (!journal) {
4245                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4246                 iput(journal_inode);
4247                 return NULL;
4248         }
4249         journal->j_private = sb;
4250         ext4_init_journal_params(sb, journal);
4251         return journal;
4252 }
4253
4254 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4255                                        dev_t j_dev)
4256 {
4257         struct buffer_head *bh;
4258         journal_t *journal;
4259         ext4_fsblk_t start;
4260         ext4_fsblk_t len;
4261         int hblock, blocksize;
4262         ext4_fsblk_t sb_block;
4263         unsigned long offset;
4264         struct ext4_super_block *es;
4265         struct block_device *bdev;
4266
4267         BUG_ON(!ext4_has_feature_journal(sb));
4268
4269         bdev = ext4_blkdev_get(j_dev, sb);
4270         if (bdev == NULL)
4271                 return NULL;
4272
4273         blocksize = sb->s_blocksize;
4274         hblock = bdev_logical_block_size(bdev);
4275         if (blocksize < hblock) {
4276                 ext4_msg(sb, KERN_ERR,
4277                         "blocksize too small for journal device");
4278                 goto out_bdev;
4279         }
4280
4281         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4282         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4283         set_blocksize(bdev, blocksize);
4284         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4285                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4286                        "external journal");
4287                 goto out_bdev;
4288         }
4289
4290         es = (struct ext4_super_block *) (bh->b_data + offset);
4291         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4292             !(le32_to_cpu(es->s_feature_incompat) &
4293               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4294                 ext4_msg(sb, KERN_ERR, "external journal has "
4295                                         "bad superblock");
4296                 brelse(bh);
4297                 goto out_bdev;
4298         }
4299
4300         if ((le32_to_cpu(es->s_feature_ro_compat) &
4301              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4302             es->s_checksum != ext4_superblock_csum(sb, es)) {
4303                 ext4_msg(sb, KERN_ERR, "external journal has "
4304                                        "corrupt superblock");
4305                 brelse(bh);
4306                 goto out_bdev;
4307         }
4308
4309         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4310                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4311                 brelse(bh);
4312                 goto out_bdev;
4313         }
4314
4315         len = ext4_blocks_count(es);
4316         start = sb_block + 1;
4317         brelse(bh);     /* we're done with the superblock */
4318
4319         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4320                                         start, len, blocksize);
4321         if (!journal) {
4322                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4323                 goto out_bdev;
4324         }
4325         journal->j_private = sb;
4326         ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4327         wait_on_buffer(journal->j_sb_buffer);
4328         if (!buffer_uptodate(journal->j_sb_buffer)) {
4329                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4330                 goto out_journal;
4331         }
4332         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4333                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4334                                         "user (unsupported) - %d",
4335                         be32_to_cpu(journal->j_superblock->s_nr_users));
4336                 goto out_journal;
4337         }
4338         EXT4_SB(sb)->journal_bdev = bdev;
4339         ext4_init_journal_params(sb, journal);
4340         return journal;
4341
4342 out_journal:
4343         jbd2_journal_destroy(journal);
4344 out_bdev:
4345         ext4_blkdev_put(bdev);
4346         return NULL;
4347 }
4348
4349 static int ext4_load_journal(struct super_block *sb,
4350                              struct ext4_super_block *es,
4351                              unsigned long journal_devnum)
4352 {
4353         journal_t *journal;
4354         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4355         dev_t journal_dev;
4356         int err = 0;
4357         int really_read_only;
4358
4359         BUG_ON(!ext4_has_feature_journal(sb));
4360
4361         if (journal_devnum &&
4362             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4363                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4364                         "numbers have changed");
4365                 journal_dev = new_decode_dev(journal_devnum);
4366         } else
4367                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4368
4369         really_read_only = bdev_read_only(sb->s_bdev);
4370
4371         /*
4372          * Are we loading a blank journal or performing recovery after a
4373          * crash?  For recovery, we need to check in advance whether we
4374          * can get read-write access to the device.
4375          */
4376         if (ext4_has_feature_journal_needs_recovery(sb)) {
4377                 if (sb->s_flags & MS_RDONLY) {
4378                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4379                                         "required on readonly filesystem");
4380                         if (really_read_only) {
4381                                 ext4_msg(sb, KERN_ERR, "write access "
4382                                         "unavailable, cannot proceed");
4383                                 return -EROFS;
4384                         }
4385                         ext4_msg(sb, KERN_INFO, "write access will "
4386                                "be enabled during recovery");
4387                 }
4388         }
4389
4390         if (journal_inum && journal_dev) {
4391                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4392                        "and inode journals!");
4393                 return -EINVAL;
4394         }
4395
4396         if (journal_inum) {
4397                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4398                         return -EINVAL;
4399         } else {
4400                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4401                         return -EINVAL;
4402         }
4403
4404         if (!(journal->j_flags & JBD2_BARRIER))
4405                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4406
4407         if (!ext4_has_feature_journal_needs_recovery(sb))
4408                 err = jbd2_journal_wipe(journal, !really_read_only);
4409         if (!err) {
4410                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4411                 if (save)
4412                         memcpy(save, ((char *) es) +
4413                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4414                 err = jbd2_journal_load(journal);
4415                 if (save)
4416                         memcpy(((char *) es) + EXT4_S_ERR_START,
4417                                save, EXT4_S_ERR_LEN);
4418                 kfree(save);
4419         }
4420
4421         if (err) {
4422                 ext4_msg(sb, KERN_ERR, "error loading journal");
4423                 jbd2_journal_destroy(journal);
4424                 return err;
4425         }
4426
4427         EXT4_SB(sb)->s_journal = journal;
4428         ext4_clear_journal_err(sb, es);
4429
4430         if (!really_read_only && journal_devnum &&
4431             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4432                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4433
4434                 /* Make sure we flush the recovery flag to disk. */
4435                 ext4_commit_super(sb, 1);
4436         }
4437
4438         return 0;
4439 }
4440
4441 static int ext4_commit_super(struct super_block *sb, int sync)
4442 {
4443         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4444         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4445         int error = 0;
4446
4447         if (!sbh || block_device_ejected(sb))
4448                 return error;
4449         /*
4450          * If the file system is mounted read-only, don't update the
4451          * superblock write time.  This avoids updating the superblock
4452          * write time when we are mounting the root file system
4453          * read/only but we need to replay the journal; at that point,
4454          * for people who are east of GMT and who make their clock
4455          * tick in localtime for Windows bug-for-bug compatibility,
4456          * the clock is set in the future, and this will cause e2fsck
4457          * to complain and force a full file system check.
4458          */
4459         if (!(sb->s_flags & MS_RDONLY))
4460                 es->s_wtime = cpu_to_le32(get_seconds());
4461         if (sb->s_bdev->bd_part)
4462                 es->s_kbytes_written =
4463                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4464                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4465                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4466         else
4467                 es->s_kbytes_written =
4468                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4469         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4470                 ext4_free_blocks_count_set(es,
4471                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4472                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4473         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4474                 es->s_free_inodes_count =
4475                         cpu_to_le32(percpu_counter_sum_positive(
4476                                 &EXT4_SB(sb)->s_freeinodes_counter));
4477         BUFFER_TRACE(sbh, "marking dirty");
4478         ext4_superblock_csum_set(sb);
4479         lock_buffer(sbh);
4480         if (buffer_write_io_error(sbh)) {
4481                 /*
4482                  * Oh, dear.  A previous attempt to write the
4483                  * superblock failed.  This could happen because the
4484                  * USB device was yanked out.  Or it could happen to
4485                  * be a transient write error and maybe the block will
4486                  * be remapped.  Nothing we can do but to retry the
4487                  * write and hope for the best.
4488                  */
4489                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4490                        "superblock detected");
4491                 clear_buffer_write_io_error(sbh);
4492                 set_buffer_uptodate(sbh);
4493         }
4494         mark_buffer_dirty(sbh);
4495         unlock_buffer(sbh);
4496         if (sync) {
4497                 error = __sync_dirty_buffer(sbh,
4498                         test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
4499                 if (error)
4500                         return error;
4501
4502                 error = buffer_write_io_error(sbh);
4503                 if (error) {
4504                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4505                                "superblock");
4506                         clear_buffer_write_io_error(sbh);
4507                         set_buffer_uptodate(sbh);
4508                 }
4509         }
4510         return error;
4511 }
4512
4513 /*
4514  * Have we just finished recovery?  If so, and if we are mounting (or
4515  * remounting) the filesystem readonly, then we will end up with a
4516  * consistent fs on disk.  Record that fact.
4517  */
4518 static void ext4_mark_recovery_complete(struct super_block *sb,
4519                                         struct ext4_super_block *es)
4520 {
4521         journal_t *journal = EXT4_SB(sb)->s_journal;
4522
4523         if (!ext4_has_feature_journal(sb)) {
4524                 BUG_ON(journal != NULL);
4525                 return;
4526         }
4527         jbd2_journal_lock_updates(journal);
4528         if (jbd2_journal_flush(journal) < 0)
4529                 goto out;
4530
4531         if (ext4_has_feature_journal_needs_recovery(sb) &&
4532             sb->s_flags & MS_RDONLY) {
4533                 ext4_clear_feature_journal_needs_recovery(sb);
4534                 ext4_commit_super(sb, 1);
4535         }
4536
4537 out:
4538         jbd2_journal_unlock_updates(journal);
4539 }
4540
4541 /*
4542  * If we are mounting (or read-write remounting) a filesystem whose journal
4543  * has recorded an error from a previous lifetime, move that error to the
4544  * main filesystem now.
4545  */
4546 static void ext4_clear_journal_err(struct super_block *sb,
4547                                    struct ext4_super_block *es)
4548 {
4549         journal_t *journal;
4550         int j_errno;
4551         const char *errstr;
4552
4553         BUG_ON(!ext4_has_feature_journal(sb));
4554
4555         journal = EXT4_SB(sb)->s_journal;
4556
4557         /*
4558          * Now check for any error status which may have been recorded in the
4559          * journal by a prior ext4_error() or ext4_abort()
4560          */
4561
4562         j_errno = jbd2_journal_errno(journal);
4563         if (j_errno) {
4564                 char nbuf[16];
4565
4566                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4567                 ext4_warning(sb, "Filesystem error recorded "
4568                              "from previous mount: %s", errstr);
4569                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4570
4571                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4572                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4573                 ext4_commit_super(sb, 1);
4574
4575                 jbd2_journal_clear_err(journal);
4576                 jbd2_journal_update_sb_errno(journal);
4577         }
4578 }
4579
4580 /*
4581  * Force the running and committing transactions to commit,
4582  * and wait on the commit.
4583  */
4584 int ext4_force_commit(struct super_block *sb)
4585 {
4586         journal_t *journal;
4587
4588         if (sb->s_flags & MS_RDONLY)
4589                 return 0;
4590
4591         journal = EXT4_SB(sb)->s_journal;
4592         return ext4_journal_force_commit(journal);
4593 }
4594
4595 static int ext4_sync_fs(struct super_block *sb, int wait)
4596 {
4597         int ret = 0;
4598         tid_t target;
4599         bool needs_barrier = false;
4600         struct ext4_sb_info *sbi = EXT4_SB(sb);
4601
4602         trace_ext4_sync_fs(sb, wait);
4603         flush_workqueue(sbi->rsv_conversion_wq);
4604         /*
4605          * Writeback quota in non-journalled quota case - journalled quota has
4606          * no dirty dquots
4607          */
4608         dquot_writeback_dquots(sb, -1);
4609         /*
4610          * Data writeback is possible w/o journal transaction, so barrier must
4611          * being sent at the end of the function. But we can skip it if
4612          * transaction_commit will do it for us.
4613          */
4614         if (sbi->s_journal) {
4615                 target = jbd2_get_latest_transaction(sbi->s_journal);
4616                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4617                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4618                         needs_barrier = true;
4619
4620                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4621                         if (wait)
4622                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4623                                                            target);
4624                 }
4625         } else if (wait && test_opt(sb, BARRIER))
4626                 needs_barrier = true;
4627         if (needs_barrier) {
4628                 int err;
4629                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4630                 if (!ret)
4631                         ret = err;
4632         }
4633
4634         return ret;
4635 }
4636
4637 /*
4638  * LVM calls this function before a (read-only) snapshot is created.  This
4639  * gives us a chance to flush the journal completely and mark the fs clean.
4640  *
4641  * Note that only this function cannot bring a filesystem to be in a clean
4642  * state independently. It relies on upper layer to stop all data & metadata
4643  * modifications.
4644  */
4645 static int ext4_freeze(struct super_block *sb)
4646 {
4647         int error = 0;
4648         journal_t *journal;
4649
4650         if (sb->s_flags & MS_RDONLY)
4651                 return 0;
4652
4653         journal = EXT4_SB(sb)->s_journal;
4654
4655         if (journal) {
4656                 /* Now we set up the journal barrier. */
4657                 jbd2_journal_lock_updates(journal);
4658
4659                 /*
4660                  * Don't clear the needs_recovery flag if we failed to
4661                  * flush the journal.
4662                  */
4663                 error = jbd2_journal_flush(journal);
4664                 if (error < 0)
4665                         goto out;
4666
4667                 /* Journal blocked and flushed, clear needs_recovery flag. */
4668                 ext4_clear_feature_journal_needs_recovery(sb);
4669         }
4670
4671         error = ext4_commit_super(sb, 1);
4672 out:
4673         if (journal)
4674                 /* we rely on upper layer to stop further updates */
4675                 jbd2_journal_unlock_updates(journal);
4676         return error;
4677 }
4678
4679 /*
4680  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4681  * flag here, even though the filesystem is not technically dirty yet.
4682  */
4683 static int ext4_unfreeze(struct super_block *sb)
4684 {
4685         if (sb->s_flags & MS_RDONLY)
4686                 return 0;
4687
4688         if (EXT4_SB(sb)->s_journal) {
4689                 /* Reset the needs_recovery flag before the fs is unlocked. */
4690                 ext4_set_feature_journal_needs_recovery(sb);
4691         }
4692
4693         ext4_commit_super(sb, 1);
4694         return 0;
4695 }
4696
4697 /*
4698  * Structure to save mount options for ext4_remount's benefit
4699  */
4700 struct ext4_mount_options {
4701         unsigned long s_mount_opt;
4702         unsigned long s_mount_opt2;
4703         kuid_t s_resuid;
4704         kgid_t s_resgid;
4705         unsigned long s_commit_interval;
4706         u32 s_min_batch_time, s_max_batch_time;
4707 #ifdef CONFIG_QUOTA
4708         int s_jquota_fmt;
4709         char *s_qf_names[EXT4_MAXQUOTAS];
4710 #endif
4711 };
4712
4713 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4714 {
4715         struct ext4_super_block *es;
4716         struct ext4_sb_info *sbi = EXT4_SB(sb);
4717         unsigned long old_sb_flags;
4718         struct ext4_mount_options old_opts;
4719         int enable_quota = 0;
4720         ext4_group_t g;
4721         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4722         int err = 0;
4723 #ifdef CONFIG_QUOTA
4724         int i, j;
4725 #endif
4726         char *orig_data = kstrdup(data, GFP_KERNEL);
4727
4728         /* Store the original options */
4729         old_sb_flags = sb->s_flags;
4730         old_opts.s_mount_opt = sbi->s_mount_opt;
4731         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4732         old_opts.s_resuid = sbi->s_resuid;
4733         old_opts.s_resgid = sbi->s_resgid;
4734         old_opts.s_commit_interval = sbi->s_commit_interval;
4735         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4736         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4737 #ifdef CONFIG_QUOTA
4738         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4739         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4740                 if (sbi->s_qf_names[i]) {
4741                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4742                                                          GFP_KERNEL);
4743                         if (!old_opts.s_qf_names[i]) {
4744                                 for (j = 0; j < i; j++)
4745                                         kfree(old_opts.s_qf_names[j]);
4746                                 kfree(orig_data);
4747                                 return -ENOMEM;
4748                         }
4749                 } else
4750                         old_opts.s_qf_names[i] = NULL;
4751 #endif
4752         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4753                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4754
4755         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4756                 err = -EINVAL;
4757                 goto restore_opts;
4758         }
4759
4760         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4761             test_opt(sb, JOURNAL_CHECKSUM)) {
4762                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4763                          "during remount not supported; ignoring");
4764                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4765         }
4766
4767         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4768                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4769                         ext4_msg(sb, KERN_ERR, "can't mount with "
4770                                  "both data=journal and delalloc");
4771                         err = -EINVAL;
4772                         goto restore_opts;
4773                 }
4774                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4775                         ext4_msg(sb, KERN_ERR, "can't mount with "
4776                                  "both data=journal and dioread_nolock");
4777                         err = -EINVAL;
4778                         goto restore_opts;
4779                 }
4780                 if (test_opt(sb, DAX)) {
4781                         ext4_msg(sb, KERN_ERR, "can't mount with "
4782                                  "both data=journal and dax");
4783                         err = -EINVAL;
4784                         goto restore_opts;
4785                 }
4786         }
4787
4788         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4789                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4790                         "dax flag with busy inodes while remounting");
4791                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4792         }
4793
4794         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4795                 ext4_abort(sb, "Abort forced by user");
4796
4797         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4798                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4799
4800         es = sbi->s_es;
4801
4802         if (sbi->s_journal) {
4803                 ext4_init_journal_params(sb, sbi->s_journal);
4804                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4805         }
4806
4807         if (*flags & MS_LAZYTIME)
4808                 sb->s_flags |= MS_LAZYTIME;
4809
4810         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4811                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4812                         err = -EROFS;
4813                         goto restore_opts;
4814                 }
4815
4816                 if (*flags & MS_RDONLY) {
4817                         err = sync_filesystem(sb);
4818                         if (err < 0)
4819                                 goto restore_opts;
4820                         err = dquot_suspend(sb, -1);
4821                         if (err < 0)
4822                                 goto restore_opts;
4823
4824                         /*
4825                          * First of all, the unconditional stuff we have to do
4826                          * to disable replay of the journal when we next remount
4827                          */
4828                         sb->s_flags |= MS_RDONLY;
4829
4830                         /*
4831                          * OK, test if we are remounting a valid rw partition
4832                          * readonly, and if so set the rdonly flag and then
4833                          * mark the partition as valid again.
4834                          */
4835                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4836                             (sbi->s_mount_state & EXT4_VALID_FS))
4837                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4838
4839                         if (sbi->s_journal)
4840                                 ext4_mark_recovery_complete(sb, es);
4841                 } else {
4842                         /* Make sure we can mount this feature set readwrite */
4843                         if (ext4_has_feature_readonly(sb) ||
4844                             !ext4_feature_set_ok(sb, 0)) {
4845                                 err = -EROFS;
4846                                 goto restore_opts;
4847                         }
4848                         /*
4849                          * Make sure the group descriptor checksums
4850                          * are sane.  If they aren't, refuse to remount r/w.
4851                          */
4852                         for (g = 0; g < sbi->s_groups_count; g++) {
4853                                 struct ext4_group_desc *gdp =
4854                                         ext4_get_group_desc(sb, g, NULL);
4855
4856                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4857                                         ext4_msg(sb, KERN_ERR,
4858                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4859                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
4860                                                le16_to_cpu(gdp->bg_checksum));
4861                                         err = -EFSBADCRC;
4862                                         goto restore_opts;
4863                                 }
4864                         }
4865
4866                         /*
4867                          * If we have an unprocessed orphan list hanging
4868                          * around from a previously readonly bdev mount,
4869                          * require a full umount/remount for now.
4870                          */
4871                         if (es->s_last_orphan) {
4872                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4873                                        "remount RDWR because of unprocessed "
4874                                        "orphan inode list.  Please "
4875                                        "umount/remount instead");
4876                                 err = -EINVAL;
4877                                 goto restore_opts;
4878                         }
4879
4880                         /*
4881                          * Mounting a RDONLY partition read-write, so reread
4882                          * and store the current valid flag.  (It may have
4883                          * been changed by e2fsck since we originally mounted
4884                          * the partition.)
4885                          */
4886                         if (sbi->s_journal)
4887                                 ext4_clear_journal_err(sb, es);
4888                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4889                         if (!ext4_setup_super(sb, es, 0))
4890                                 sb->s_flags &= ~MS_RDONLY;
4891                         if (ext4_has_feature_mmp(sb))
4892                                 if (ext4_multi_mount_protect(sb,
4893                                                 le64_to_cpu(es->s_mmp_block))) {
4894                                         err = -EROFS;
4895                                         goto restore_opts;
4896                                 }
4897                         enable_quota = 1;
4898                 }
4899         }
4900
4901         /*
4902          * Reinitialize lazy itable initialization thread based on
4903          * current settings
4904          */
4905         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4906                 ext4_unregister_li_request(sb);
4907         else {
4908                 ext4_group_t first_not_zeroed;
4909                 first_not_zeroed = ext4_has_uninit_itable(sb);
4910                 ext4_register_li_request(sb, first_not_zeroed);
4911         }
4912
4913         ext4_setup_system_zone(sb);
4914         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4915                 ext4_commit_super(sb, 1);
4916
4917 #ifdef CONFIG_QUOTA
4918         /* Release old quota file names */
4919         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4920                 kfree(old_opts.s_qf_names[i]);
4921         if (enable_quota) {
4922                 if (sb_any_quota_suspended(sb))
4923                         dquot_resume(sb, -1);
4924                 else if (ext4_has_feature_quota(sb)) {
4925                         err = ext4_enable_quotas(sb);
4926                         if (err)
4927                                 goto restore_opts;
4928                 }
4929         }
4930 #endif
4931
4932         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
4933         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4934         kfree(orig_data);
4935         return 0;
4936
4937 restore_opts:
4938         sb->s_flags = old_sb_flags;
4939         sbi->s_mount_opt = old_opts.s_mount_opt;
4940         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4941         sbi->s_resuid = old_opts.s_resuid;
4942         sbi->s_resgid = old_opts.s_resgid;
4943         sbi->s_commit_interval = old_opts.s_commit_interval;
4944         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4945         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4946 #ifdef CONFIG_QUOTA
4947         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4948         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
4949                 kfree(sbi->s_qf_names[i]);
4950                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4951         }
4952 #endif
4953         kfree(orig_data);
4954         return err;
4955 }
4956
4957 #ifdef CONFIG_QUOTA
4958 static int ext4_statfs_project(struct super_block *sb,
4959                                kprojid_t projid, struct kstatfs *buf)
4960 {
4961         struct kqid qid;
4962         struct dquot *dquot;
4963         u64 limit;
4964         u64 curblock;
4965
4966         qid = make_kqid_projid(projid);
4967         dquot = dqget(sb, qid);
4968         if (IS_ERR(dquot))
4969                 return PTR_ERR(dquot);
4970         spin_lock(&dq_data_lock);
4971
4972         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
4973                  dquot->dq_dqb.dqb_bsoftlimit :
4974                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
4975         if (limit && buf->f_blocks > limit) {
4976                 curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
4977                 buf->f_blocks = limit;
4978                 buf->f_bfree = buf->f_bavail =
4979                         (buf->f_blocks > curblock) ?
4980                          (buf->f_blocks - curblock) : 0;
4981         }
4982
4983         limit = dquot->dq_dqb.dqb_isoftlimit ?
4984                 dquot->dq_dqb.dqb_isoftlimit :
4985                 dquot->dq_dqb.dqb_ihardlimit;
4986         if (limit && buf->f_files > limit) {
4987                 buf->f_files = limit;
4988                 buf->f_ffree =
4989                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
4990                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
4991         }
4992
4993         spin_unlock(&dq_data_lock);
4994         dqput(dquot);
4995         return 0;
4996 }
4997 #endif
4998
4999 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5000 {
5001         struct super_block *sb = dentry->d_sb;
5002         struct ext4_sb_info *sbi = EXT4_SB(sb);
5003         struct ext4_super_block *es = sbi->s_es;
5004         ext4_fsblk_t overhead = 0, resv_blocks;
5005         u64 fsid;
5006         s64 bfree;
5007         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5008
5009         if (!test_opt(sb, MINIX_DF))
5010                 overhead = sbi->s_overhead;
5011
5012         buf->f_type = EXT4_SUPER_MAGIC;
5013         buf->f_bsize = sb->s_blocksize;
5014         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5015         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5016                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5017         /* prevent underflow in case that few free space is available */
5018         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5019         buf->f_bavail = buf->f_bfree -
5020                         (ext4_r_blocks_count(es) + resv_blocks);
5021         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5022                 buf->f_bavail = 0;
5023         buf->f_files = le32_to_cpu(es->s_inodes_count);
5024         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5025         buf->f_namelen = EXT4_NAME_LEN;
5026         fsid = le64_to_cpup((void *)es->s_uuid) ^
5027                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5028         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5029         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5030
5031 #ifdef CONFIG_QUOTA
5032         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5033             sb_has_quota_limits_enabled(sb, PRJQUOTA))
5034                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5035 #endif
5036         return 0;
5037 }
5038
5039 /* Helper function for writing quotas on sync - we need to start transaction
5040  * before quota file is locked for write. Otherwise the are possible deadlocks:
5041  * Process 1                         Process 2
5042  * ext4_create()                     quota_sync()
5043  *   jbd2_journal_start()                  write_dquot()
5044  *   dquot_initialize()                         down(dqio_mutex)
5045  *     down(dqio_mutex)                    jbd2_journal_start()
5046  *
5047  */
5048
5049 #ifdef CONFIG_QUOTA
5050
5051 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5052 {
5053         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5054 }
5055
5056 static int ext4_write_dquot(struct dquot *dquot)
5057 {
5058         int ret, err;
5059         handle_t *handle;
5060         struct inode *inode;
5061
5062         inode = dquot_to_inode(dquot);
5063         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5064                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5065         if (IS_ERR(handle))
5066                 return PTR_ERR(handle);
5067         ret = dquot_commit(dquot);
5068         err = ext4_journal_stop(handle);
5069         if (!ret)
5070                 ret = err;
5071         return ret;
5072 }
5073
5074 static int ext4_acquire_dquot(struct dquot *dquot)
5075 {
5076         int ret, err;
5077         handle_t *handle;
5078
5079         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5080                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5081         if (IS_ERR(handle))
5082                 return PTR_ERR(handle);
5083         ret = dquot_acquire(dquot);
5084         err = ext4_journal_stop(handle);
5085         if (!ret)
5086                 ret = err;
5087         return ret;
5088 }
5089
5090 static int ext4_release_dquot(struct dquot *dquot)
5091 {
5092         int ret, err;
5093         handle_t *handle;
5094
5095         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5096                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5097         if (IS_ERR(handle)) {
5098                 /* Release dquot anyway to avoid endless cycle in dqput() */
5099                 dquot_release(dquot);
5100                 return PTR_ERR(handle);
5101         }
5102         ret = dquot_release(dquot);
5103         err = ext4_journal_stop(handle);
5104         if (!ret)
5105                 ret = err;
5106         return ret;
5107 }
5108
5109 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5110 {
5111         struct super_block *sb = dquot->dq_sb;
5112         struct ext4_sb_info *sbi = EXT4_SB(sb);
5113
5114         /* Are we journaling quotas? */
5115         if (ext4_has_feature_quota(sb) ||
5116             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5117                 dquot_mark_dquot_dirty(dquot);
5118                 return ext4_write_dquot(dquot);
5119         } else {
5120                 return dquot_mark_dquot_dirty(dquot);
5121         }
5122 }
5123
5124 static int ext4_write_info(struct super_block *sb, int type)
5125 {
5126         int ret, err;
5127         handle_t *handle;
5128
5129         /* Data block + inode block */
5130         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5131         if (IS_ERR(handle))
5132                 return PTR_ERR(handle);
5133         ret = dquot_commit_info(sb, type);
5134         err = ext4_journal_stop(handle);
5135         if (!ret)
5136                 ret = err;
5137         return ret;
5138 }
5139
5140 /*
5141  * Turn on quotas during mount time - we need to find
5142  * the quota file and such...
5143  */
5144 static int ext4_quota_on_mount(struct super_block *sb, int type)
5145 {
5146         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5147                                         EXT4_SB(sb)->s_jquota_fmt, type);
5148 }
5149
5150 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5151 {
5152         struct ext4_inode_info *ei = EXT4_I(inode);
5153
5154         /* The first argument of lockdep_set_subclass has to be
5155          * *exactly* the same as the argument to init_rwsem() --- in
5156          * this case, in init_once() --- or lockdep gets unhappy
5157          * because the name of the lock is set using the
5158          * stringification of the argument to init_rwsem().
5159          */
5160         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5161         lockdep_set_subclass(&ei->i_data_sem, subclass);
5162 }
5163
5164 /*
5165  * Standard function to be called on quota_on
5166  */
5167 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5168                          struct path *path)
5169 {
5170         int err;
5171
5172         if (!test_opt(sb, QUOTA))
5173                 return -EINVAL;
5174
5175         /* Quotafile not on the same filesystem? */
5176         if (path->dentry->d_sb != sb)
5177                 return -EXDEV;
5178         /* Journaling quota? */
5179         if (EXT4_SB(sb)->s_qf_names[type]) {
5180                 /* Quotafile not in fs root? */
5181                 if (path->dentry->d_parent != sb->s_root)
5182                         ext4_msg(sb, KERN_WARNING,
5183                                 "Quota file not on filesystem root. "
5184                                 "Journaled quota will not work");
5185         }
5186
5187         /*
5188          * When we journal data on quota file, we have to flush journal to see
5189          * all updates to the file when we bypass pagecache...
5190          */
5191         if (EXT4_SB(sb)->s_journal &&
5192             ext4_should_journal_data(d_inode(path->dentry))) {
5193                 /*
5194                  * We don't need to lock updates but journal_flush() could
5195                  * otherwise be livelocked...
5196                  */
5197                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5198                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5199                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5200                 if (err)
5201                         return err;
5202         }
5203         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5204         err = dquot_quota_on(sb, type, format_id, path);
5205         if (err)
5206                 lockdep_set_quota_inode(path->dentry->d_inode,
5207                                              I_DATA_SEM_NORMAL);
5208         return err;
5209 }
5210
5211 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5212                              unsigned int flags)
5213 {
5214         int err;
5215         struct inode *qf_inode;
5216         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5217                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5218                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5219                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5220         };
5221
5222         BUG_ON(!ext4_has_feature_quota(sb));
5223
5224         if (!qf_inums[type])
5225                 return -EPERM;
5226
5227         qf_inode = ext4_iget(sb, qf_inums[type]);
5228         if (IS_ERR(qf_inode)) {
5229                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5230                 return PTR_ERR(qf_inode);
5231         }
5232
5233         /* Don't account quota for quota files to avoid recursion */
5234         qf_inode->i_flags |= S_NOQUOTA;
5235         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5236         err = dquot_enable(qf_inode, type, format_id, flags);
5237         iput(qf_inode);
5238         if (err)
5239                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5240
5241         return err;
5242 }
5243
5244 /* Enable usage tracking for all quota types. */
5245 static int ext4_enable_quotas(struct super_block *sb)
5246 {
5247         int type, err = 0;
5248         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5249                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5250                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5251                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5252         };
5253
5254         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5255         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5256                 if (qf_inums[type]) {
5257                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5258                                                 DQUOT_USAGE_ENABLED);
5259                         if (err) {
5260                                 ext4_warning(sb,
5261                                         "Failed to enable quota tracking "
5262                                         "(type=%d, err=%d). Please run "
5263                                         "e2fsck to fix.", type, err);
5264                                 return err;
5265                         }
5266                 }
5267         }
5268         return 0;
5269 }
5270
5271 static int ext4_quota_off(struct super_block *sb, int type)
5272 {
5273         struct inode *inode = sb_dqopt(sb)->files[type];
5274         handle_t *handle;
5275
5276         /* Force all delayed allocation blocks to be allocated.
5277          * Caller already holds s_umount sem */
5278         if (test_opt(sb, DELALLOC))
5279                 sync_filesystem(sb);
5280
5281         if (!inode)
5282                 goto out;
5283
5284         /* Update modification times of quota files when userspace can
5285          * start looking at them */
5286         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5287         if (IS_ERR(handle))
5288                 goto out;
5289         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5290         ext4_mark_inode_dirty(handle, inode);
5291         ext4_journal_stop(handle);
5292
5293 out:
5294         return dquot_quota_off(sb, type);
5295 }
5296
5297 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5298  * acquiring the locks... As quota files are never truncated and quota code
5299  * itself serializes the operations (and no one else should touch the files)
5300  * we don't have to be afraid of races */
5301 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5302                                size_t len, loff_t off)
5303 {
5304         struct inode *inode = sb_dqopt(sb)->files[type];
5305         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5306         int offset = off & (sb->s_blocksize - 1);
5307         int tocopy;
5308         size_t toread;
5309         struct buffer_head *bh;
5310         loff_t i_size = i_size_read(inode);
5311
5312         if (off > i_size)
5313                 return 0;
5314         if (off+len > i_size)
5315                 len = i_size-off;
5316         toread = len;
5317         while (toread > 0) {
5318                 tocopy = sb->s_blocksize - offset < toread ?
5319                                 sb->s_blocksize - offset : toread;
5320                 bh = ext4_bread(NULL, inode, blk, 0);
5321                 if (IS_ERR(bh))
5322                         return PTR_ERR(bh);
5323                 if (!bh)        /* A hole? */
5324                         memset(data, 0, tocopy);
5325                 else
5326                         memcpy(data, bh->b_data+offset, tocopy);
5327                 brelse(bh);
5328                 offset = 0;
5329                 toread -= tocopy;
5330                 data += tocopy;
5331                 blk++;
5332         }
5333         return len;
5334 }
5335
5336 /* Write to quotafile (we know the transaction is already started and has
5337  * enough credits) */
5338 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5339                                 const char *data, size_t len, loff_t off)
5340 {
5341         struct inode *inode = sb_dqopt(sb)->files[type];
5342         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5343         int err, offset = off & (sb->s_blocksize - 1);
5344         int retries = 0;
5345         struct buffer_head *bh;
5346         handle_t *handle = journal_current_handle();
5347
5348         if (EXT4_SB(sb)->s_journal && !handle) {
5349                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5350                         " cancelled because transaction is not started",
5351                         (unsigned long long)off, (unsigned long long)len);
5352                 return -EIO;
5353         }
5354         /*
5355          * Since we account only one data block in transaction credits,
5356          * then it is impossible to cross a block boundary.
5357          */
5358         if (sb->s_blocksize - offset < len) {
5359                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5360                         " cancelled because not block aligned",
5361                         (unsigned long long)off, (unsigned long long)len);
5362                 return -EIO;
5363         }
5364
5365         do {
5366                 bh = ext4_bread(handle, inode, blk,
5367                                 EXT4_GET_BLOCKS_CREATE |
5368                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5369         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5370                  ext4_should_retry_alloc(inode->i_sb, &retries));
5371         if (IS_ERR(bh))
5372                 return PTR_ERR(bh);
5373         if (!bh)
5374                 goto out;
5375         BUFFER_TRACE(bh, "get write access");
5376         err = ext4_journal_get_write_access(handle, bh);
5377         if (err) {
5378                 brelse(bh);
5379                 return err;
5380         }
5381         lock_buffer(bh);
5382         memcpy(bh->b_data+offset, data, len);
5383         flush_dcache_page(bh->b_page);
5384         unlock_buffer(bh);
5385         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5386         brelse(bh);
5387 out:
5388         if (inode->i_size < off + len) {
5389                 i_size_write(inode, off + len);
5390                 EXT4_I(inode)->i_disksize = inode->i_size;
5391                 ext4_mark_inode_dirty(handle, inode);
5392         }
5393         return len;
5394 }
5395
5396 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5397 {
5398         const struct quota_format_ops   *ops;
5399
5400         if (!sb_has_quota_loaded(sb, qid->type))
5401                 return -ESRCH;
5402         ops = sb_dqopt(sb)->ops[qid->type];
5403         if (!ops || !ops->get_next_id)
5404                 return -ENOSYS;
5405         return dquot_get_next_id(sb, qid);
5406 }
5407 #endif
5408
5409 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5410                        const char *dev_name, void *data)
5411 {
5412         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5413 }
5414
5415 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5416 static inline void register_as_ext2(void)
5417 {
5418         int err = register_filesystem(&ext2_fs_type);
5419         if (err)
5420                 printk(KERN_WARNING
5421                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5422 }
5423
5424 static inline void unregister_as_ext2(void)
5425 {
5426         unregister_filesystem(&ext2_fs_type);
5427 }
5428
5429 static inline int ext2_feature_set_ok(struct super_block *sb)
5430 {
5431         if (ext4_has_unknown_ext2_incompat_features(sb))
5432                 return 0;
5433         if (sb->s_flags & MS_RDONLY)
5434                 return 1;
5435         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5436                 return 0;
5437         return 1;
5438 }
5439 #else
5440 static inline void register_as_ext2(void) { }
5441 static inline void unregister_as_ext2(void) { }
5442 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5443 #endif
5444
5445 static inline void register_as_ext3(void)
5446 {
5447         int err = register_filesystem(&ext3_fs_type);
5448         if (err)
5449                 printk(KERN_WARNING
5450                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5451 }
5452
5453 static inline void unregister_as_ext3(void)
5454 {
5455         unregister_filesystem(&ext3_fs_type);
5456 }
5457
5458 static inline int ext3_feature_set_ok(struct super_block *sb)
5459 {
5460         if (ext4_has_unknown_ext3_incompat_features(sb))
5461                 return 0;
5462         if (!ext4_has_feature_journal(sb))
5463                 return 0;
5464         if (sb->s_flags & MS_RDONLY)
5465                 return 1;
5466         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5467                 return 0;
5468         return 1;
5469 }
5470
5471 static struct file_system_type ext4_fs_type = {
5472         .owner          = THIS_MODULE,
5473         .name           = "ext4",
5474         .mount          = ext4_mount,
5475         .kill_sb        = kill_block_super,
5476         .fs_flags       = FS_REQUIRES_DEV,
5477 };
5478 MODULE_ALIAS_FS("ext4");
5479
5480 /* Shared across all ext4 file systems */
5481 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5482
5483 static int __init ext4_init_fs(void)
5484 {
5485         int i, err;
5486
5487         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5488         ext4_li_info = NULL;
5489         mutex_init(&ext4_li_mtx);
5490
5491         /* Build-time check for flags consistency */
5492         ext4_check_flag_values();
5493
5494         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5495                 init_waitqueue_head(&ext4__ioend_wq[i]);
5496
5497         err = ext4_init_es();
5498         if (err)
5499                 return err;
5500
5501         err = ext4_init_pageio();
5502         if (err)
5503                 goto out5;
5504
5505         err = ext4_init_system_zone();
5506         if (err)
5507                 goto out4;
5508
5509         err = ext4_init_sysfs();
5510         if (err)
5511                 goto out3;
5512
5513         err = ext4_init_mballoc();
5514         if (err)
5515                 goto out2;
5516         err = init_inodecache();
5517         if (err)
5518                 goto out1;
5519         register_as_ext3();
5520         register_as_ext2();
5521         err = register_filesystem(&ext4_fs_type);
5522         if (err)
5523                 goto out;
5524
5525         return 0;
5526 out:
5527         unregister_as_ext2();
5528         unregister_as_ext3();
5529         destroy_inodecache();
5530 out1:
5531         ext4_exit_mballoc();
5532 out2:
5533         ext4_exit_sysfs();
5534 out3:
5535         ext4_exit_system_zone();
5536 out4:
5537         ext4_exit_pageio();
5538 out5:
5539         ext4_exit_es();
5540
5541         return err;
5542 }
5543
5544 static void __exit ext4_exit_fs(void)
5545 {
5546         ext4_destroy_lazyinit_thread();
5547         unregister_as_ext2();
5548         unregister_as_ext3();
5549         unregister_filesystem(&ext4_fs_type);
5550         destroy_inodecache();
5551         ext4_exit_mballoc();
5552         ext4_exit_sysfs();
5553         ext4_exit_system_zone();
5554         ext4_exit_pageio();
5555         ext4_exit_es();
5556 }
5557
5558 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5559 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5560 MODULE_LICENSE("GPL");
5561 module_init(ext4_init_fs)
5562 module_exit(ext4_exit_fs)