fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/jbd2.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/ctype.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <linux/cleancache.h>
  42 #include <asm/uaccess.h>
  43
  44 #include <linux/kthread.h>
  45 #include <linux/freezer.h>
  46
  47 #include "ext4.h"
  48 #include "ext4_extents.h"       /* Needed for trace points definition */
  49 #include "ext4_jbd2.h"
  50 #include "xattr.h"
  51 #include "acl.h"
  52 #include "mballoc.h"
  53
  54 #define CREATE_TRACE_POINTS
  55 #include <trace/events/ext4.h>
  56
  57 static struct proc_dir_entry *ext4_proc_root;
  58 static struct kset *ext4_kset;
  59 static struct ext4_lazy_init *ext4_li_info;
  60 static struct mutex ext4_li_mtx;
  61 static struct ext4_features *ext4_feat;
  62
  63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  64                              unsigned long journal_devnum);
  65 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  66 static int ext4_commit_super(struct super_block *sb, int sync);
  67 static void ext4_mark_recovery_complete(struct super_block *sb,
  68                                         struct ext4_super_block *es);
  69 static void ext4_clear_journal_err(struct super_block *sb,
  70                                    struct ext4_super_block *es);
  71 static int ext4_sync_fs(struct super_block *sb, int wait);
  72 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait);
  73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  75 static int ext4_unfreeze(struct super_block *sb);
  76 static int ext4_freeze(struct super_block *sb);
  77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  78                        const char *dev_name, void *data);
  79 static inline int ext2_feature_set_ok(struct super_block *sb);
  80 static inline int ext3_feature_set_ok(struct super_block *sb);
  81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  82 static void ext4_destroy_lazyinit_thread(void);
  83 static void ext4_unregister_li_request(struct super_block *sb);
  84 static void ext4_clear_request_list(void);
  85 static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
  86
  87 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  88 static struct file_system_type ext2_fs_type = {
  89         .owner          = THIS_MODULE,
  90         .name           = "ext2",
  91         .mount          = ext4_mount,
  92         .kill_sb        = kill_block_super,
  93         .fs_flags       = FS_REQUIRES_DEV,
  94 };
  95 MODULE_ALIAS_FS("ext2");
  96 MODULE_ALIAS("ext2");
  97 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  98 #else
  99 #define IS_EXT2_SB(sb) (0)
 100 #endif
 101
 102
 103 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 104 static struct file_system_type ext3_fs_type = {
 105         .owner          = THIS_MODULE,
 106         .name           = "ext3",
 107         .mount          = ext4_mount,
 108         .kill_sb        = kill_block_super,
 109         .fs_flags       = FS_REQUIRES_DEV,
 110 };
 111 MODULE_ALIAS_FS("ext3");
 112 MODULE_ALIAS("ext3");
 113 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 114 #else
 115 #define IS_EXT3_SB(sb) (0)
 116 #endif
 117
 118 static int ext4_verify_csum_type(struct super_block *sb,
 119                                  struct ext4_super_block *es)
 120 {
 121         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 122                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 123                 return 1;
 124
 125         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 126 }
 127
 128 static __le32 ext4_superblock_csum(struct super_block *sb,
 129                                    struct ext4_super_block *es)
 130 {
 131         struct ext4_sb_info *sbi = EXT4_SB(sb);
 132         int offset = offsetof(struct ext4_super_block, s_checksum);
 133         __u32 csum;
 134
 135         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 136
 137         return cpu_to_le32(csum);
 138 }
 139
 140 int ext4_superblock_csum_verify(struct super_block *sb,
 141                                 struct ext4_super_block *es)
 142 {
 143         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 144                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 145                 return 1;
 146
 147         return es->s_checksum == ext4_superblock_csum(sb, es);
 148 }
 149
 150 void ext4_superblock_csum_set(struct super_block *sb)
 151 {
 152         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 153
 154         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 155                 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 156                 return;
 157
 158         es->s_checksum = ext4_superblock_csum(sb, es);
 159 }
 160
 161 void *ext4_kvmalloc(size_t size, gfp_t flags)
 162 {
 163         void *ret;
 164
 165         ret = kmalloc(size, flags | __GFP_NOWARN);
 166         if (!ret)
 167                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 168         return ret;
 169 }
 170
 171 void *ext4_kvzalloc(size_t size, gfp_t flags)
 172 {
 173         void *ret;
 174
 175         ret = kzalloc(size, flags | __GFP_NOWARN);
 176         if (!ret)
 177                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 178         return ret;
 179 }
 180
 181 void ext4_kvfree(void *ptr)
 182 {
 183         if (is_vmalloc_addr(ptr))
 184                 vfree(ptr);
 185         else
 186                 kfree(ptr);
 187
 188 }
 189
 190 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 191                                struct ext4_group_desc *bg)
 192 {
 193         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 194                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 195                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 196 }
 197
 198 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 199                                struct ext4_group_desc *bg)
 200 {
 201         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 202                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 203                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 204 }
 205
 206 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 207                               struct ext4_group_desc *bg)
 208 {
 209         return le32_to_cpu(bg->bg_inode_table_lo) |
 210                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 211                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 212 }
 213
 214 __u32 ext4_free_group_clusters(struct super_block *sb,
 215                                struct ext4_group_desc *bg)
 216 {
 217         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 218                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 219                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 220 }
 221
 222 __u32 ext4_free_inodes_count(struct super_block *sb,
 223                               struct ext4_group_desc *bg)
 224 {
 225         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 226                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 227                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 228 }
 229
 230 __u32 ext4_used_dirs_count(struct super_block *sb,
 231                               struct ext4_group_desc *bg)
 232 {
 233         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 234                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 235                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 236 }
 237
 238 __u32 ext4_itable_unused_count(struct super_block *sb,
 239                               struct ext4_group_desc *bg)
 240 {
 241         return le16_to_cpu(bg->bg_itable_unused_lo) |
 242                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 243                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 244 }
 245
 246 void ext4_block_bitmap_set(struct super_block *sb,
 247                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 248 {
 249         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 250         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 251                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 252 }
 253
 254 void ext4_inode_bitmap_set(struct super_block *sb,
 255                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 256 {
 257         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 258         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 259                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 260 }
 261
 262 void ext4_inode_table_set(struct super_block *sb,
 263                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 264 {
 265         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 266         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 267                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 268 }
 269
 270 void ext4_free_group_clusters_set(struct super_block *sb,
 271                                   struct ext4_group_desc *bg, __u32 count)
 272 {
 273         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 274         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 275                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 276 }
 277
 278 void ext4_free_inodes_set(struct super_block *sb,
 279                           struct ext4_group_desc *bg, __u32 count)
 280 {
 281         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 282         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 283                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 284 }
 285
 286 void ext4_used_dirs_set(struct super_block *sb,
 287                           struct ext4_group_desc *bg, __u32 count)
 288 {
 289         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 290         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 291                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 292 }
 293
 294 void ext4_itable_unused_set(struct super_block *sb,
 295                           struct ext4_group_desc *bg, __u32 count)
 296 {
 297         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 298         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 299                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 300 }
 301
 302
 303 static void __save_error_info(struct super_block *sb, const char *func,
 304                             unsigned int line)
 305 {
 306         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 307
 308         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 309         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 310         es->s_last_error_time = cpu_to_le32(get_seconds());
 311         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 312         es->s_last_error_line = cpu_to_le32(line);
 313         if (!es->s_first_error_time) {
 314                 es->s_first_error_time = es->s_last_error_time;
 315                 strncpy(es->s_first_error_func, func,
 316                         sizeof(es->s_first_error_func));
 317                 es->s_first_error_line = cpu_to_le32(line);
 318                 es->s_first_error_ino = es->s_last_error_ino;
 319                 es->s_first_error_block = es->s_last_error_block;
 320         }
 321         /*
 322          * Start the daily error reporting function if it hasn't been
 323          * started already
 324          */
 325         if (!es->s_error_count)
 326                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 327         le32_add_cpu(&es->s_error_count, 1);
 328 }
 329
 330 static void save_error_info(struct super_block *sb, const char *func,
 331                             unsigned int line)
 332 {
 333         __save_error_info(sb, func, line);
 334         ext4_commit_super(sb, 1);
 335 }
 336
 337 /*
 338  * The del_gendisk() function uninitializes the disk-specific data
 339  * structures, including the bdi structure, without telling anyone
 340  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 341  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 342  * This is a kludge to prevent these oops until we can put in a proper
 343  * hook in del_gendisk() to inform the VFS and file system layers.
 344  */
 345 static int block_device_ejected(struct super_block *sb)
 346 {
 347         struct inode *bd_inode = sb->s_bdev->bd_inode;
 348         struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
 349
 350         return bdi->dev == NULL;
 351 }
 352
 353 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 354 {
 355         struct super_block              *sb = journal->j_private;
 356         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 357         int                             error = is_journal_aborted(journal);
 358         struct ext4_journal_cb_entry    *jce;
 359
 360         BUG_ON(txn->t_state == T_FINISHED);
 361         spin_lock(&sbi->s_md_lock);
 362         while (!list_empty(&txn->t_private_list)) {
 363                 jce = list_entry(txn->t_private_list.next,
 364                                  struct ext4_journal_cb_entry, jce_list);
 365                 list_del_init(&jce->jce_list);
 366                 spin_unlock(&sbi->s_md_lock);
 367                 jce->jce_func(sb, jce, error);
 368                 spin_lock(&sbi->s_md_lock);
 369         }
 370         spin_unlock(&sbi->s_md_lock);
 371 }
 372
 373 /* Deal with the reporting of failure conditions on a filesystem such as
 374  * inconsistencies detected or read IO failures.
 375  *
 376  * On ext2, we can store the error state of the filesystem in the
 377  * superblock.  That is not possible on ext4, because we may have other
 378  * write ordering constraints on the superblock which prevent us from
 379  * writing it out straight away; and given that the journal is about to
 380  * be aborted, we can't rely on the current, or future, transactions to
 381  * write out the superblock safely.
 382  *
 383  * We'll just use the jbd2_journal_abort() error code to record an error in
 384  * the journal instead.  On recovery, the journal will complain about
 385  * that error until we've noted it down and cleared it.
 386  */
 387
 388 static void ext4_handle_error(struct super_block *sb)
 389 {
 390         if (sb->s_flags & MS_RDONLY)
 391                 return;
 392
 393         if (!test_opt(sb, ERRORS_CONT)) {
 394                 journal_t *journal = EXT4_SB(sb)->s_journal;
 395
 396                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 397                 if (journal)
 398                         jbd2_journal_abort(journal, -EIO);
 399         }
 400         if (test_opt(sb, ERRORS_RO)) {
 401                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 402                 /*
 403                  * Make sure updated value of ->s_mount_flags will be visible
 404                  * before ->s_flags update
 405                  */
 406                 smp_wmb();
 407                 sb->s_flags |= MS_RDONLY;
 408         }
 409         if (test_opt(sb, ERRORS_PANIC))
 410                 panic("EXT4-fs (device %s): panic forced after error\n",
 411                         sb->s_id);
 412 }
 413
 414 #define ext4_error_ratelimit(sb)                                        \
 415                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 416                              "EXT4-fs error")
 417
 418 void __ext4_error(struct super_block *sb, const char *function,
 419                   unsigned int line, const char *fmt, ...)
 420 {
 421         struct va_format vaf;
 422         va_list args;
 423
 424         if (ext4_error_ratelimit(sb)) {
 425                 va_start(args, fmt);
 426                 vaf.fmt = fmt;
 427                 vaf.va = &args;
 428                 printk(KERN_CRIT
 429                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 430                        sb->s_id, function, line, current->comm, &vaf);
 431                 va_end(args);
 432         }
 433         save_error_info(sb, function, line);
 434         ext4_handle_error(sb);
 435 }
 436
 437 void __ext4_error_inode(struct inode *inode, const char *function,
 438                         unsigned int line, ext4_fsblk_t block,
 439                         const char *fmt, ...)
 440 {
 441         va_list args;
 442         struct va_format vaf;
 443         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 444
 445         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 446         es->s_last_error_block = cpu_to_le64(block);
 447         if (ext4_error_ratelimit(inode->i_sb)) {
 448                 va_start(args, fmt);
 449                 vaf.fmt = fmt;
 450                 vaf.va = &args;
 451                 if (block)
 452                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 453                                "inode #%lu: block %llu: comm %s: %pV\n",
 454                                inode->i_sb->s_id, function, line, inode->i_ino,
 455                                block, current->comm, &vaf);
 456                 else
 457                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 458                                "inode #%lu: comm %s: %pV\n",
 459                                inode->i_sb->s_id, function, line, inode->i_ino,
 460                                current->comm, &vaf);
 461                 va_end(args);
 462         }
 463         save_error_info(inode->i_sb, function, line);
 464         ext4_handle_error(inode->i_sb);
 465 }
 466
 467 void __ext4_error_file(struct file *file, const char *function,
 468                        unsigned int line, ext4_fsblk_t block,
 469                        const char *fmt, ...)
 470 {
 471         va_list args;
 472         struct va_format vaf;
 473         struct ext4_super_block *es;
 474         struct inode *inode = file_inode(file);
 475         char pathname[80], *path;
 476
 477         es = EXT4_SB(inode->i_sb)->s_es;
 478         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 479         if (ext4_error_ratelimit(inode->i_sb)) {
 480                 path = d_path(&(file->f_path), pathname, sizeof(pathname));
 481                 if (IS_ERR(path))
 482                         path = "(unknown)";
 483                 va_start(args, fmt);
 484                 vaf.fmt = fmt;
 485                 vaf.va = &args;
 486                 if (block)
 487                         printk(KERN_CRIT
 488                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 489                                "block %llu: comm %s: path %s: %pV\n",
 490                                inode->i_sb->s_id, function, line, inode->i_ino,
 491                                block, current->comm, path, &vaf);
 492                 else
 493                         printk(KERN_CRIT
 494                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 495                                "comm %s: path %s: %pV\n",
 496                                inode->i_sb->s_id, function, line, inode->i_ino,
 497                                current->comm, path, &vaf);
 498                 va_end(args);
 499         }
 500         save_error_info(inode->i_sb, function, line);
 501         ext4_handle_error(inode->i_sb);
 502 }
 503
 504 const char *ext4_decode_error(struct super_block *sb, int errno,
 505                               char nbuf[16])
 506 {
 507         char *errstr = NULL;
 508
 509         switch (errno) {
 510         case -EIO:
 511                 errstr = "IO failure";
 512                 break;
 513         case -ENOMEM:
 514                 errstr = "Out of memory";
 515                 break;
 516         case -EROFS:
 517                 if (!sb || (EXT4_SB(sb)->s_journal &&
 518                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 519                         errstr = "Journal has aborted";
 520                 else
 521                         errstr = "Readonly filesystem";
 522                 break;
 523         default:
 524                 /* If the caller passed in an extra buffer for unknown
 525                  * errors, textualise them now.  Else we just return
 526                  * NULL. */
 527                 if (nbuf) {
 528                         /* Check for truncated error codes... */
 529                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 530                                 errstr = nbuf;
 531                 }
 532                 break;
 533         }
 534
 535         return errstr;
 536 }
 537
 538 /* __ext4_std_error decodes expected errors from journaling functions
 539  * automatically and invokes the appropriate error response.  */
 540
 541 void __ext4_std_error(struct super_block *sb, const char *function,
 542                       unsigned int line, int errno)
 543 {
 544         char nbuf[16];
 545         const char *errstr;
 546
 547         /* Special case: if the error is EROFS, and we're not already
 548          * inside a transaction, then there's really no point in logging
 549          * an error. */
 550         if (errno == -EROFS && journal_current_handle() == NULL &&
 551             (sb->s_flags & MS_RDONLY))
 552                 return;
 553
 554         if (ext4_error_ratelimit(sb)) {
 555                 errstr = ext4_decode_error(sb, errno, nbuf);
 556                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 557                        sb->s_id, function, line, errstr);
 558         }
 559
 560         save_error_info(sb, function, line);
 561         ext4_handle_error(sb);
 562 }
 563
 564 /*
 565  * ext4_abort is a much stronger failure handler than ext4_error.  The
 566  * abort function may be used to deal with unrecoverable failures such
 567  * as journal IO errors or ENOMEM at a critical moment in log management.
 568  *
 569  * We unconditionally force the filesystem into an ABORT|READONLY state,
 570  * unless the error response on the fs has been set to panic in which
 571  * case we take the easy way out and panic immediately.
 572  */
 573
 574 void __ext4_abort(struct super_block *sb, const char *function,
 575                 unsigned int line, const char *fmt, ...)
 576 {
 577         va_list args;
 578
 579         save_error_info(sb, function, line);
 580         va_start(args, fmt);
 581         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 582                function, line);
 583         vprintk(fmt, args);
 584         printk("\n");
 585         va_end(args);
 586
 587         if ((sb->s_flags & MS_RDONLY) == 0) {
 588                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 589                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 590                 /*
 591                  * Make sure updated value of ->s_mount_flags will be visible
 592                  * before ->s_flags update
 593                  */
 594                 smp_wmb();
 595                 sb->s_flags |= MS_RDONLY;
 596                 if (EXT4_SB(sb)->s_journal)
 597                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 598                 save_error_info(sb, function, line);
 599         }
 600         if (test_opt(sb, ERRORS_PANIC))
 601                 panic("EXT4-fs panic from previous error\n");
 602 }
 603
 604 void __ext4_msg(struct super_block *sb,
 605                 const char *prefix, const char *fmt, ...)
 606 {
 607         struct va_format vaf;
 608         va_list args;
 609
 610         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 611                 return;
 612
 613         va_start(args, fmt);
 614         vaf.fmt = fmt;
 615         vaf.va = &args;
 616         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 617         va_end(args);
 618 }
 619
 620 void __ext4_warning(struct super_block *sb, const char *function,
 621                     unsigned int line, const char *fmt, ...)
 622 {
 623         struct va_format vaf;
 624         va_list args;
 625
 626         if (!___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
 627                           "EXT4-fs warning"))
 628                 return;
 629
 630         va_start(args, fmt);
 631         vaf.fmt = fmt;
 632         vaf.va = &args;
 633         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 634                sb->s_id, function, line, &vaf);
 635         va_end(args);
 636 }
 637
 638 void __ext4_grp_locked_error(const char *function, unsigned int line,
 639                              struct super_block *sb, ext4_group_t grp,
 640                              unsigned long ino, ext4_fsblk_t block,
 641                              const char *fmt, ...)
 642 __releases(bitlock)
 643 __acquires(bitlock)
 644 {
 645         struct va_format vaf;
 646         va_list args;
 647         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 648
 649         es->s_last_error_ino = cpu_to_le32(ino);
 650         es->s_last_error_block = cpu_to_le64(block);
 651         __save_error_info(sb, function, line);
 652
 653         if (ext4_error_ratelimit(sb)) {
 654                 va_start(args, fmt);
 655                 vaf.fmt = fmt;
 656                 vaf.va = &args;
 657                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 658                        sb->s_id, function, line, grp);
 659                 if (ino)
 660                         printk(KERN_CONT "inode %lu: ", ino);
 661                 if (block)
 662                         printk(KERN_CONT "block %llu:",
 663                                (unsigned long long) block);
 664                 printk(KERN_CONT "%pV\n", &vaf);
 665                 va_end(args);
 666         }
 667
 668         if (test_opt(sb, ERRORS_CONT)) {
 669                 ext4_commit_super(sb, 0);
 670                 return;
 671         }
 672
 673         ext4_unlock_group(sb, grp);
 674         ext4_handle_error(sb);
 675         /*
 676          * We only get here in the ERRORS_RO case; relocking the group
 677          * may be dangerous, but nothing bad will happen since the
 678          * filesystem will have already been marked read/only and the
 679          * journal has been aborted.  We return 1 as a hint to callers
 680          * who might what to use the return value from
 681          * ext4_grp_locked_error() to distinguish between the
 682          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 683          * aggressively from the ext4 function in question, with a
 684          * more appropriate error code.
 685          */
 686         ext4_lock_group(sb, grp);
 687         return;
 688 }
 689
 690 void ext4_update_dynamic_rev(struct super_block *sb)
 691 {
 692         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 693
 694         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 695                 return;
 696
 697         ext4_warning(sb,
 698                      "updating to rev %d because of new feature flag, "
 699                      "running e2fsck is recommended",
 700                      EXT4_DYNAMIC_REV);
 701
 702         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 703         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 704         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 705         /* leave es->s_feature_*compat flags alone */
 706         /* es->s_uuid will be set by e2fsck if empty */
 707
 708         /*
 709          * The rest of the superblock fields should be zero, and if not it
 710          * means they are likely already in use, so leave them alone.  We
 711          * can leave it up to e2fsck to clean up any inconsistencies there.
 712          */
 713 }
 714
 715 /*
 716  * Open the external journal device
 717  */
 718 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 719 {
 720         struct block_device *bdev;
 721         char b[BDEVNAME_SIZE];
 722
 723         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 724         if (IS_ERR(bdev))
 725                 goto fail;
 726         return bdev;
 727
 728 fail:
 729         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 730                         __bdevname(dev, b), PTR_ERR(bdev));
 731         return NULL;
 732 }
 733
 734 /*
 735  * Release the journal device
 736  */
 737 static void ext4_blkdev_put(struct block_device *bdev)
 738 {
 739         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 740 }
 741
 742 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 743 {
 744         struct block_device *bdev;
 745         bdev = sbi->journal_bdev;
 746         if (bdev) {
 747                 ext4_blkdev_put(bdev);
 748                 sbi->journal_bdev = NULL;
 749         }
 750 }
 751
 752 static inline struct inode *orphan_list_entry(struct list_head *l)
 753 {
 754         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 755 }
 756
 757 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 758 {
 759         struct list_head *l;
 760
 761         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 762                  le32_to_cpu(sbi->s_es->s_last_orphan));
 763
 764         printk(KERN_ERR "sb_info orphan list:\n");
 765         list_for_each(l, &sbi->s_orphan) {
 766                 struct inode *inode = orphan_list_entry(l);
 767                 printk(KERN_ERR "  "
 768                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 769                        inode->i_sb->s_id, inode->i_ino, inode,
 770                        inode->i_mode, inode->i_nlink,
 771                        NEXT_ORPHAN(inode));
 772         }
 773 }
 774
 775 static void ext4_put_super(struct super_block *sb)
 776 {
 777         struct ext4_sb_info *sbi = EXT4_SB(sb);
 778         struct ext4_super_block *es = sbi->s_es;
 779         int i, err;
 780
 781         ext4_unregister_li_request(sb);
 782         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 783
 784         flush_workqueue(sbi->rsv_conversion_wq);
 785         destroy_workqueue(sbi->rsv_conversion_wq);
 786
 787         if (sbi->s_journal) {
 788                 err = jbd2_journal_destroy(sbi->s_journal);
 789                 sbi->s_journal = NULL;
 790                 if (err < 0)
 791                         ext4_abort(sb, "Couldn't clean up the journal");
 792         }
 793
 794         ext4_es_unregister_shrinker(sbi);
 795         del_timer_sync(&sbi->s_err_report);
 796         ext4_release_system_zone(sb);
 797         ext4_mb_release(sb);
 798         ext4_ext_release(sb);
 799         ext4_xattr_put_super(sb);
 800
 801         if (!(sb->s_flags & MS_RDONLY)) {
 802                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 803                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 804         }
 805         if (!(sb->s_flags & MS_RDONLY))
 806                 ext4_commit_super(sb, 1);
 807
 808         if (sbi->s_proc) {
 809                 remove_proc_entry("options", sbi->s_proc);
 810                 remove_proc_entry(sb->s_id, ext4_proc_root);
 811         }
 812         kobject_del(&sbi->s_kobj);
 813
 814         for (i = 0; i < sbi->s_gdb_count; i++)
 815                 brelse(sbi->s_group_desc[i]);
 816         ext4_kvfree(sbi->s_group_desc);
 817         ext4_kvfree(sbi->s_flex_groups);
 818         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 819         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 820         percpu_counter_destroy(&sbi->s_dirs_counter);
 821         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 822         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
 823         brelse(sbi->s_sbh);
 824 #ifdef CONFIG_QUOTA
 825         for (i = 0; i < MAXQUOTAS; i++)
 826                 kfree(sbi->s_qf_names[i]);
 827 #endif
 828
 829         /* Debugging code just in case the in-memory inode orphan list
 830          * isn't empty.  The on-disk one can be non-empty if we've
 831          * detected an error and taken the fs readonly, but the
 832          * in-memory list had better be clean by this point. */
 833         if (!list_empty(&sbi->s_orphan))
 834                 dump_orphan_list(sb, sbi);
 835         J_ASSERT(list_empty(&sbi->s_orphan));
 836
 837         invalidate_bdev(sb->s_bdev);
 838         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 839                 /*
 840                  * Invalidate the journal device's buffers.  We don't want them
 841                  * floating about in memory - the physical journal device may
 842                  * hotswapped, and it breaks the `ro-after' testing code.
 843                  */
 844                 sync_blockdev(sbi->journal_bdev);
 845                 invalidate_bdev(sbi->journal_bdev);
 846                 ext4_blkdev_remove(sbi);
 847         }
 848         if (sbi->s_mmp_tsk)
 849                 kthread_stop(sbi->s_mmp_tsk);
 850         sb->s_fs_info = NULL;
 851         /*
 852          * Now that we are completely done shutting down the
 853          * superblock, we need to actually destroy the kobject.
 854          */
 855         kobject_put(&sbi->s_kobj);
 856         wait_for_completion(&sbi->s_kobj_unregister);
 857         if (sbi->s_chksum_driver)
 858                 crypto_free_shash(sbi->s_chksum_driver);
 859         kfree(sbi->s_blockgroup_lock);
 860         kfree(sbi);
 861 }
 862
 863 static struct kmem_cache *ext4_inode_cachep;
 864
 865 /*
 866  * Called inside transaction, so use GFP_NOFS
 867  */
 868 static struct inode *ext4_alloc_inode(struct super_block *sb)
 869 {
 870         struct ext4_inode_info *ei;
 871
 872         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 873         if (!ei)
 874                 return NULL;
 875
 876         ei->vfs_inode.i_version = 1;
 877         INIT_LIST_HEAD(&ei->i_prealloc_list);
 878         spin_lock_init(&ei->i_prealloc_lock);
 879         ext4_es_init_tree(&ei->i_es_tree);
 880         rwlock_init(&ei->i_es_lock);
 881         INIT_LIST_HEAD(&ei->i_es_lru);
 882         ei->i_es_lru_nr = 0;
 883         ei->i_touch_when = 0;
 884         ei->i_reserved_data_blocks = 0;
 885         ei->i_reserved_meta_blocks = 0;
 886         ei->i_allocated_meta_blocks = 0;
 887         ei->i_da_metadata_calc_len = 0;
 888         ei->i_da_metadata_calc_last_lblock = 0;
 889         spin_lock_init(&(ei->i_block_reservation_lock));
 890 #ifdef CONFIG_QUOTA
 891         ei->i_reserved_quota = 0;
 892 #endif
 893         ei->jinode = NULL;
 894         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 895         spin_lock_init(&ei->i_completed_io_lock);
 896         ei->i_sync_tid = 0;
 897         ei->i_datasync_tid = 0;
 898         atomic_set(&ei->i_ioend_count, 0);
 899         atomic_set(&ei->i_unwritten, 0);
 900         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 901
 902         return &ei->vfs_inode;
 903 }
 904
 905 static int ext4_drop_inode(struct inode *inode)
 906 {
 907         int drop = generic_drop_inode(inode);
 908
 909         trace_ext4_drop_inode(inode, drop);
 910         return drop;
 911 }
 912
 913 static void ext4_i_callback(struct rcu_head *head)
 914 {
 915         struct inode *inode = container_of(head, struct inode, i_rcu);
 916         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 917 }
 918
 919 static void ext4_destroy_inode(struct inode *inode)
 920 {
 921         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 922                 ext4_msg(inode->i_sb, KERN_ERR,
 923                          "Inode %lu (%p): orphan list check failed!",
 924                          inode->i_ino, EXT4_I(inode));
 925                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 926                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 927                                 true);
 928                 dump_stack();
 929         }
 930         call_rcu(&inode->i_rcu, ext4_i_callback);
 931 }
 932
 933 static void init_once(void *foo)
 934 {
 935         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 936
 937         INIT_LIST_HEAD(&ei->i_orphan);
 938         init_rwsem(&ei->xattr_sem);
 939         init_rwsem(&ei->i_data_sem);
 940         inode_init_once(&ei->vfs_inode);
 941 }
 942
 943 static int init_inodecache(void)
 944 {
 945         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 946                                              sizeof(struct ext4_inode_info),
 947                                              0, (SLAB_RECLAIM_ACCOUNT|
 948                                                 SLAB_MEM_SPREAD),
 949                                              init_once);
 950         if (ext4_inode_cachep == NULL)
 951                 return -ENOMEM;
 952         return 0;
 953 }
 954
 955 static void destroy_inodecache(void)
 956 {
 957         /*
 958          * Make sure all delayed rcu free inodes are flushed before we
 959          * destroy cache.
 960          */
 961         rcu_barrier();
 962         kmem_cache_destroy(ext4_inode_cachep);
 963 }
 964
 965 void ext4_clear_inode(struct inode *inode)
 966 {
 967         invalidate_inode_buffers(inode);
 968         clear_inode(inode);
 969         dquot_drop(inode);
 970         ext4_discard_preallocations(inode);
 971         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 972         ext4_es_lru_del(inode);
 973         if (EXT4_I(inode)->jinode) {
 974                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 975                                                EXT4_I(inode)->jinode);
 976                 jbd2_free_inode(EXT4_I(inode)->jinode);
 977                 EXT4_I(inode)->jinode = NULL;
 978         }
 979 }
 980
 981 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 982                                         u64 ino, u32 generation)
 983 {
 984         struct inode *inode;
 985
 986         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 987                 return ERR_PTR(-ESTALE);
 988         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 989                 return ERR_PTR(-ESTALE);
 990
 991         /* iget isn't really right if the inode is currently unallocated!!
 992          *
 993          * ext4_read_inode will return a bad_inode if the inode had been
 994          * deleted, so we should be safe.
 995          *
 996          * Currently we don't know the generation for parent directory, so
 997          * a generation of 0 means "accept any"
 998          */
 999         inode = ext4_iget(sb, ino);
1000         if (IS_ERR(inode))
1001                 return ERR_CAST(inode);
1002         if (generation && inode->i_generation != generation) {
1003                 iput(inode);
1004                 return ERR_PTR(-ESTALE);
1005         }
1006
1007         return inode;
1008 }
1009
1010 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1011                                         int fh_len, int fh_type)
1012 {
1013         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1014                                     ext4_nfs_get_inode);
1015 }
1016
1017 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1018                                         int fh_len, int fh_type)
1019 {
1020         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1021                                     ext4_nfs_get_inode);
1022 }
1023
1024 /*
1025  * Try to release metadata pages (indirect blocks, directories) which are
1026  * mapped via the block device.  Since these pages could have journal heads
1027  * which would prevent try_to_free_buffers() from freeing them, we must use
1028  * jbd2 layer's try_to_free_buffers() function to release them.
1029  */
1030 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1031                                  gfp_t wait)
1032 {
1033         journal_t *journal = EXT4_SB(sb)->s_journal;
1034
1035         WARN_ON(PageChecked(page));
1036         if (!page_has_buffers(page))
1037                 return 0;
1038         if (journal)
1039                 return jbd2_journal_try_to_free_buffers(journal, page,
1040                                                         wait & ~__GFP_WAIT);
1041         return try_to_free_buffers(page);
1042 }
1043
1044 #ifdef CONFIG_QUOTA
1045 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1046 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1047
1048 static int ext4_write_dquot(struct dquot *dquot);
1049 static int ext4_acquire_dquot(struct dquot *dquot);
1050 static int ext4_release_dquot(struct dquot *dquot);
1051 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1052 static int ext4_write_info(struct super_block *sb, int type);
1053 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1054                          struct path *path);
1055 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1056                                  int format_id);
1057 static int ext4_quota_off(struct super_block *sb, int type);
1058 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1059 static int ext4_quota_on_mount(struct super_block *sb, int type);
1060 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1061                                size_t len, loff_t off);
1062 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1063                                 const char *data, size_t len, loff_t off);
1064 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1065                              unsigned int flags);
1066 static int ext4_enable_quotas(struct super_block *sb);
1067
1068 static const struct dquot_operations ext4_quota_operations = {
1069         .get_reserved_space = ext4_get_reserved_space,
1070         .write_dquot    = ext4_write_dquot,
1071         .acquire_dquot  = ext4_acquire_dquot,
1072         .release_dquot  = ext4_release_dquot,
1073         .mark_dirty     = ext4_mark_dquot_dirty,
1074         .write_info     = ext4_write_info,
1075         .alloc_dquot    = dquot_alloc,
1076         .destroy_dquot  = dquot_destroy,
1077 };
1078
1079 static const struct quotactl_ops ext4_qctl_operations = {
1080         .quota_on       = ext4_quota_on,
1081         .quota_off      = ext4_quota_off,
1082         .quota_sync     = dquot_quota_sync,
1083         .get_info       = dquot_get_dqinfo,
1084         .set_info       = dquot_set_dqinfo,
1085         .get_dqblk      = dquot_get_dqblk,
1086         .set_dqblk      = dquot_set_dqblk
1087 };
1088
1089 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1090         .quota_on_meta  = ext4_quota_on_sysfile,
1091         .quota_off      = ext4_quota_off_sysfile,
1092         .quota_sync     = dquot_quota_sync,
1093         .get_info       = dquot_get_dqinfo,
1094         .set_info       = dquot_set_dqinfo,
1095         .get_dqblk      = dquot_get_dqblk,
1096         .set_dqblk      = dquot_set_dqblk
1097 };
1098 #endif
1099
1100 static const struct super_operations ext4_sops = {
1101         .alloc_inode    = ext4_alloc_inode,
1102         .destroy_inode  = ext4_destroy_inode,
1103         .write_inode    = ext4_write_inode,
1104         .dirty_inode    = ext4_dirty_inode,
1105         .drop_inode     = ext4_drop_inode,
1106         .evict_inode    = ext4_evict_inode,
1107         .put_super      = ext4_put_super,
1108         .sync_fs        = ext4_sync_fs,
1109         .freeze_fs      = ext4_freeze,
1110         .unfreeze_fs    = ext4_unfreeze,
1111         .statfs         = ext4_statfs,
1112         .remount_fs     = ext4_remount,
1113         .show_options   = ext4_show_options,
1114 #ifdef CONFIG_QUOTA
1115         .quota_read     = ext4_quota_read,
1116         .quota_write    = ext4_quota_write,
1117 #endif
1118         .bdev_try_to_free_page = bdev_try_to_free_page,
1119 };
1120
1121 static const struct super_operations ext4_nojournal_sops = {
1122         .alloc_inode    = ext4_alloc_inode,
1123         .destroy_inode  = ext4_destroy_inode,
1124         .write_inode    = ext4_write_inode,
1125         .dirty_inode    = ext4_dirty_inode,
1126         .drop_inode     = ext4_drop_inode,
1127         .evict_inode    = ext4_evict_inode,
1128         .sync_fs        = ext4_sync_fs_nojournal,
1129         .put_super      = ext4_put_super,
1130         .statfs         = ext4_statfs,
1131         .remount_fs     = ext4_remount,
1132         .show_options   = ext4_show_options,
1133 #ifdef CONFIG_QUOTA
1134         .quota_read     = ext4_quota_read,
1135         .quota_write    = ext4_quota_write,
1136 #endif
1137         .bdev_try_to_free_page = bdev_try_to_free_page,
1138 };
1139
1140 static const struct export_operations ext4_export_ops = {
1141         .fh_to_dentry = ext4_fh_to_dentry,
1142         .fh_to_parent = ext4_fh_to_parent,
1143         .get_parent = ext4_get_parent,
1144 };
1145
1146 enum {
1147         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1148         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1149         Opt_nouid32, Opt_debug, Opt_removed,
1150         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1151         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1152         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1153         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1154         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1155         Opt_data_err_abort, Opt_data_err_ignore,
1156         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1157         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1158         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1159         Opt_usrquota, Opt_grpquota, Opt_i_version,
1160         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1161         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1162         Opt_inode_readahead_blks, Opt_journal_ioprio,
1163         Opt_dioread_nolock, Opt_dioread_lock,
1164         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1165         Opt_max_dir_size_kb,
1166 };
1167
1168 static const match_table_t tokens = {
1169         {Opt_bsd_df, "bsddf"},
1170         {Opt_minix_df, "minixdf"},
1171         {Opt_grpid, "grpid"},
1172         {Opt_grpid, "bsdgroups"},
1173         {Opt_nogrpid, "nogrpid"},
1174         {Opt_nogrpid, "sysvgroups"},
1175         {Opt_resgid, "resgid=%u"},
1176         {Opt_resuid, "resuid=%u"},
1177         {Opt_sb, "sb=%u"},
1178         {Opt_err_cont, "errors=continue"},
1179         {Opt_err_panic, "errors=panic"},
1180         {Opt_err_ro, "errors=remount-ro"},
1181         {Opt_nouid32, "nouid32"},
1182         {Opt_debug, "debug"},
1183         {Opt_removed, "oldalloc"},
1184         {Opt_removed, "orlov"},
1185         {Opt_user_xattr, "user_xattr"},
1186         {Opt_nouser_xattr, "nouser_xattr"},
1187         {Opt_acl, "acl"},
1188         {Opt_noacl, "noacl"},
1189         {Opt_noload, "norecovery"},
1190         {Opt_noload, "noload"},
1191         {Opt_removed, "nobh"},
1192         {Opt_removed, "bh"},
1193         {Opt_commit, "commit=%u"},
1194         {Opt_min_batch_time, "min_batch_time=%u"},
1195         {Opt_max_batch_time, "max_batch_time=%u"},
1196         {Opt_journal_dev, "journal_dev=%u"},
1197         {Opt_journal_path, "journal_path=%s"},
1198         {Opt_journal_checksum, "journal_checksum"},
1199         {Opt_journal_async_commit, "journal_async_commit"},
1200         {Opt_abort, "abort"},
1201         {Opt_data_journal, "data=journal"},
1202         {Opt_data_ordered, "data=ordered"},
1203         {Opt_data_writeback, "data=writeback"},
1204         {Opt_data_err_abort, "data_err=abort"},
1205         {Opt_data_err_ignore, "data_err=ignore"},
1206         {Opt_offusrjquota, "usrjquota="},
1207         {Opt_usrjquota, "usrjquota=%s"},
1208         {Opt_offgrpjquota, "grpjquota="},
1209         {Opt_grpjquota, "grpjquota=%s"},
1210         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1211         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1212         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1213         {Opt_grpquota, "grpquota"},
1214         {Opt_noquota, "noquota"},
1215         {Opt_quota, "quota"},
1216         {Opt_usrquota, "usrquota"},
1217         {Opt_barrier, "barrier=%u"},
1218         {Opt_barrier, "barrier"},
1219         {Opt_nobarrier, "nobarrier"},
1220         {Opt_i_version, "i_version"},
1221         {Opt_stripe, "stripe=%u"},
1222         {Opt_delalloc, "delalloc"},
1223         {Opt_nodelalloc, "nodelalloc"},
1224         {Opt_removed, "mblk_io_submit"},
1225         {Opt_removed, "nomblk_io_submit"},
1226         {Opt_block_validity, "block_validity"},
1227         {Opt_noblock_validity, "noblock_validity"},
1228         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1229         {Opt_journal_ioprio, "journal_ioprio=%u"},
1230         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1231         {Opt_auto_da_alloc, "auto_da_alloc"},
1232         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1233         {Opt_dioread_nolock, "dioread_nolock"},
1234         {Opt_dioread_lock, "dioread_lock"},
1235         {Opt_discard, "discard"},
1236         {Opt_nodiscard, "nodiscard"},
1237         {Opt_init_itable, "init_itable=%u"},
1238         {Opt_init_itable, "init_itable"},
1239         {Opt_noinit_itable, "noinit_itable"},
1240         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1241         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1242         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1243         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1244         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1245         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1246         {Opt_err, NULL},
1247 };
1248
1249 static ext4_fsblk_t get_sb_block(void **data)
1250 {
1251         ext4_fsblk_t    sb_block;
1252         char            *options = (char *) *data;
1253
1254         if (!options || strncmp(options, "sb=", 3) != 0)
1255                 return 1;       /* Default location */
1256
1257         options += 3;
1258         /* TODO: use simple_strtoll with >32bit ext4 */
1259         sb_block = simple_strtoul(options, &options, 0);
1260         if (*options && *options != ',') {
1261                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1262                        (char *) *data);
1263                 return 1;
1264         }
1265         if (*options == ',')
1266                 options++;
1267         *data = (void *) options;
1268
1269         return sb_block;
1270 }
1271
1272 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1273 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1274         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1275
1276 #ifdef CONFIG_QUOTA
1277 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1278 {
1279         struct ext4_sb_info *sbi = EXT4_SB(sb);
1280         char *qname;
1281         int ret = -1;
1282
1283         if (sb_any_quota_loaded(sb) &&
1284                 !sbi->s_qf_names[qtype]) {
1285                 ext4_msg(sb, KERN_ERR,
1286                         "Cannot change journaled "
1287                         "quota options when quota turned on");
1288                 return -1;
1289         }
1290         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1291                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1292                          "when QUOTA feature is enabled");
1293                 return -1;
1294         }
1295         qname = match_strdup(args);
1296         if (!qname) {
1297                 ext4_msg(sb, KERN_ERR,
1298                         "Not enough memory for storing quotafile name");
1299                 return -1;
1300         }
1301         if (sbi->s_qf_names[qtype]) {
1302                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1303                         ret = 1;
1304                 else
1305                         ext4_msg(sb, KERN_ERR,
1306                                  "%s quota file already specified",
1307                                  QTYPE2NAME(qtype));
1308                 goto errout;
1309         }
1310         if (strchr(qname, '/')) {
1311                 ext4_msg(sb, KERN_ERR,
1312                         "quotafile must be on filesystem root");
1313                 goto errout;
1314         }
1315         sbi->s_qf_names[qtype] = qname;
1316         set_opt(sb, QUOTA);
1317         return 1;
1318 errout:
1319         kfree(qname);
1320         return ret;
1321 }
1322
1323 static int clear_qf_name(struct super_block *sb, int qtype)
1324 {
1325
1326         struct ext4_sb_info *sbi = EXT4_SB(sb);
1327
1328         if (sb_any_quota_loaded(sb) &&
1329                 sbi->s_qf_names[qtype]) {
1330                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1331                         " when quota turned on");
1332                 return -1;
1333         }
1334         kfree(sbi->s_qf_names[qtype]);
1335         sbi->s_qf_names[qtype] = NULL;
1336         return 1;
1337 }
1338 #endif
1339
1340 #define MOPT_SET        0x0001
1341 #define MOPT_CLEAR      0x0002
1342 #define MOPT_NOSUPPORT  0x0004
1343 #define MOPT_EXPLICIT   0x0008
1344 #define MOPT_CLEAR_ERR  0x0010
1345 #define MOPT_GTE0       0x0020
1346 #ifdef CONFIG_QUOTA
1347 #define MOPT_Q          0
1348 #define MOPT_QFMT       0x0040
1349 #else
1350 #define MOPT_Q          MOPT_NOSUPPORT
1351 #define MOPT_QFMT       MOPT_NOSUPPORT
1352 #endif
1353 #define MOPT_DATAJ      0x0080
1354 #define MOPT_NO_EXT2    0x0100
1355 #define MOPT_NO_EXT3    0x0200
1356 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1357 #define MOPT_STRING     0x0400
1358
1359 static const struct mount_opts {
1360         int     token;
1361         int     mount_opt;
1362         int     flags;
1363 } ext4_mount_opts[] = {
1364         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1365         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1366         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1367         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1368         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1369         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1370         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1371          MOPT_EXT4_ONLY | MOPT_SET},
1372         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1373          MOPT_EXT4_ONLY | MOPT_CLEAR},
1374         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1375         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1376         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1377          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1378         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1379          MOPT_EXT4_ONLY | MOPT_CLEAR},
1380         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1381          MOPT_EXT4_ONLY | MOPT_SET},
1382         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1383                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1384          MOPT_EXT4_ONLY | MOPT_SET},
1385         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1386         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1387         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1388         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1389         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1390          MOPT_NO_EXT2 | MOPT_SET},
1391         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1392          MOPT_NO_EXT2 | MOPT_CLEAR},
1393         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1394         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1395         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1396         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1397         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1398         {Opt_commit, 0, MOPT_GTE0},
1399         {Opt_max_batch_time, 0, MOPT_GTE0},
1400         {Opt_min_batch_time, 0, MOPT_GTE0},
1401         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1402         {Opt_init_itable, 0, MOPT_GTE0},
1403         {Opt_stripe, 0, MOPT_GTE0},
1404         {Opt_resuid, 0, MOPT_GTE0},
1405         {Opt_resgid, 0, MOPT_GTE0},
1406         {Opt_journal_dev, 0, MOPT_GTE0},
1407         {Opt_journal_path, 0, MOPT_STRING},
1408         {Opt_journal_ioprio, 0, MOPT_GTE0},
1409         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1410         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1411         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1412          MOPT_NO_EXT2 | MOPT_DATAJ},
1413         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1414         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1415 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1416         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1417         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1418 #else
1419         {Opt_acl, 0, MOPT_NOSUPPORT},
1420         {Opt_noacl, 0, MOPT_NOSUPPORT},
1421 #endif
1422         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1423         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1424         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1425         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1426                                                         MOPT_SET | MOPT_Q},
1427         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1428                                                         MOPT_SET | MOPT_Q},
1429         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1430                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1431         {Opt_usrjquota, 0, MOPT_Q},
1432         {Opt_grpjquota, 0, MOPT_Q},
1433         {Opt_offusrjquota, 0, MOPT_Q},
1434         {Opt_offgrpjquota, 0, MOPT_Q},
1435         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1436         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1437         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1438         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1439         {Opt_err, 0, 0}
1440 };
1441
1442 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1443                             substring_t *args, unsigned long *journal_devnum,
1444                             unsigned int *journal_ioprio, int is_remount)
1445 {
1446         struct ext4_sb_info *sbi = EXT4_SB(sb);
1447         const struct mount_opts *m;
1448         kuid_t uid;
1449         kgid_t gid;
1450         int arg = 0;
1451
1452 #ifdef CONFIG_QUOTA
1453         if (token == Opt_usrjquota)
1454                 return set_qf_name(sb, USRQUOTA, &args[0]);
1455         else if (token == Opt_grpjquota)
1456                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1457         else if (token == Opt_offusrjquota)
1458                 return clear_qf_name(sb, USRQUOTA);
1459         else if (token == Opt_offgrpjquota)
1460                 return clear_qf_name(sb, GRPQUOTA);
1461 #endif
1462         switch (token) {
1463         case Opt_noacl:
1464         case Opt_nouser_xattr:
1465                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1466                 break;
1467         case Opt_sb:
1468                 return 1;       /* handled by get_sb_block() */
1469         case Opt_removed:
1470                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1471                 return 1;
1472         case Opt_abort:
1473                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1474                 return 1;
1475         case Opt_i_version:
1476                 sb->s_flags |= MS_I_VERSION;
1477                 return 1;
1478         }
1479
1480         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1481                 if (token == m->token)
1482                         break;
1483
1484         if (m->token == Opt_err) {
1485                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1486                          "or missing value", opt);
1487                 return -1;
1488         }
1489
1490         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1491                 ext4_msg(sb, KERN_ERR,
1492                          "Mount option \"%s\" incompatible with ext2", opt);
1493                 return -1;
1494         }
1495         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1496                 ext4_msg(sb, KERN_ERR,
1497                          "Mount option \"%s\" incompatible with ext3", opt);
1498                 return -1;
1499         }
1500
1501         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1502                 return -1;
1503         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1504                 return -1;
1505         if (m->flags & MOPT_EXPLICIT)
1506                 set_opt2(sb, EXPLICIT_DELALLOC);
1507         if (m->flags & MOPT_CLEAR_ERR)
1508                 clear_opt(sb, ERRORS_MASK);
1509         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1510                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1511                          "options when quota turned on");
1512                 return -1;
1513         }
1514
1515         if (m->flags & MOPT_NOSUPPORT) {
1516                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1517         } else if (token == Opt_commit) {
1518                 if (arg == 0)
1519                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1520                 sbi->s_commit_interval = HZ * arg;
1521         } else if (token == Opt_max_batch_time) {
1522                 sbi->s_max_batch_time = arg;
1523         } else if (token == Opt_min_batch_time) {
1524                 sbi->s_min_batch_time = arg;
1525         } else if (token == Opt_inode_readahead_blks) {
1526                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1527                         ext4_msg(sb, KERN_ERR,
1528                                  "EXT4-fs: inode_readahead_blks must be "
1529                                  "0 or a power of 2 smaller than 2^31");
1530                         return -1;
1531                 }
1532                 sbi->s_inode_readahead_blks = arg;
1533         } else if (token == Opt_init_itable) {
1534                 set_opt(sb, INIT_INODE_TABLE);
1535                 if (!args->from)
1536                         arg = EXT4_DEF_LI_WAIT_MULT;
1537                 sbi->s_li_wait_mult = arg;
1538         } else if (token == Opt_max_dir_size_kb) {
1539                 sbi->s_max_dir_size_kb = arg;
1540         } else if (token == Opt_stripe) {
1541                 sbi->s_stripe = arg;
1542         } else if (token == Opt_resuid) {
1543                 uid = make_kuid(current_user_ns(), arg);
1544                 if (!uid_valid(uid)) {
1545                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1546                         return -1;
1547                 }
1548                 sbi->s_resuid = uid;
1549         } else if (token == Opt_resgid) {
1550                 gid = make_kgid(current_user_ns(), arg);
1551                 if (!gid_valid(gid)) {
1552                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1553                         return -1;
1554                 }
1555                 sbi->s_resgid = gid;
1556         } else if (token == Opt_journal_dev) {
1557                 if (is_remount) {
1558                         ext4_msg(sb, KERN_ERR,
1559                                  "Cannot specify journal on remount");
1560                         return -1;
1561                 }
1562                 *journal_devnum = arg;
1563         } else if (token == Opt_journal_path) {
1564                 char *journal_path;
1565                 struct inode *journal_inode;
1566                 struct path path;
1567                 int error;
1568
1569                 if (is_remount) {
1570                         ext4_msg(sb, KERN_ERR,
1571                                  "Cannot specify journal on remount");
1572                         return -1;
1573                 }
1574                 journal_path = match_strdup(&args[0]);
1575                 if (!journal_path) {
1576                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1577                                 "journal device string");
1578                         return -1;
1579                 }
1580
1581                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1582                 if (error) {
1583                         ext4_msg(sb, KERN_ERR, "error: could not find "
1584                                 "journal device path: error %d", error);
1585                         kfree(journal_path);
1586                         return -1;
1587                 }
1588
1589                 journal_inode = path.dentry->d_inode;
1590                 if (!S_ISBLK(journal_inode->i_mode)) {
1591                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1592                                 "is not a block device", journal_path);
1593                         path_put(&path);
1594                         kfree(journal_path);
1595                         return -1;
1596                 }
1597
1598                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1599                 path_put(&path);
1600                 kfree(journal_path);
1601         } else if (token == Opt_journal_ioprio) {
1602                 if (arg > 7) {
1603                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1604                                  " (must be 0-7)");
1605                         return -1;
1606                 }
1607                 *journal_ioprio =
1608                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1609         } else if (m->flags & MOPT_DATAJ) {
1610                 if (is_remount) {
1611                         if (!sbi->s_journal)
1612                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1613                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1614                                 ext4_msg(sb, KERN_ERR,
1615                                          "Cannot change data mode on remount");
1616                                 return -1;
1617                         }
1618                 } else {
1619                         clear_opt(sb, DATA_FLAGS);
1620                         sbi->s_mount_opt |= m->mount_opt;
1621                 }
1622 #ifdef CONFIG_QUOTA
1623         } else if (m->flags & MOPT_QFMT) {
1624                 if (sb_any_quota_loaded(sb) &&
1625                     sbi->s_jquota_fmt != m->mount_opt) {
1626                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1627                                  "quota options when quota turned on");
1628                         return -1;
1629                 }
1630                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1631                                                EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1632                         ext4_msg(sb, KERN_ERR,
1633                                  "Cannot set journaled quota options "
1634                                  "when QUOTA feature is enabled");
1635                         return -1;
1636                 }
1637                 sbi->s_jquota_fmt = m->mount_opt;
1638 #endif
1639         } else {
1640                 if (!args->from)
1641                         arg = 1;
1642                 if (m->flags & MOPT_CLEAR)
1643                         arg = !arg;
1644                 else if (unlikely(!(m->flags & MOPT_SET))) {
1645                         ext4_msg(sb, KERN_WARNING,
1646                                  "buggy handling of option %s", opt);
1647                         WARN_ON(1);
1648                         return -1;
1649                 }
1650                 if (arg != 0)
1651                         sbi->s_mount_opt |= m->mount_opt;
1652                 else
1653                         sbi->s_mount_opt &= ~m->mount_opt;
1654         }
1655         return 1;
1656 }
1657
1658 static int parse_options(char *options, struct super_block *sb,
1659                          unsigned long *journal_devnum,
1660                          unsigned int *journal_ioprio,
1661                          int is_remount)
1662 {
1663         struct ext4_sb_info *sbi = EXT4_SB(sb);
1664         char *p;
1665         substring_t args[MAX_OPT_ARGS];
1666         int token;
1667
1668         if (!options)
1669                 return 1;
1670
1671         while ((p = strsep(&options, ",")) != NULL) {
1672                 if (!*p)
1673                         continue;
1674                 /*
1675                  * Initialize args struct so we know whether arg was
1676                  * found; some options take optional arguments.
1677                  */
1678                 args[0].to = args[0].from = NULL;
1679                 token = match_token(p, tokens, args);
1680                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1681                                      journal_ioprio, is_remount) < 0)
1682                         return 0;
1683         }
1684 #ifdef CONFIG_QUOTA
1685         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1686             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1687                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1688                          "feature is enabled");
1689                 return 0;
1690         }
1691         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1692                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1693                         clear_opt(sb, USRQUOTA);
1694
1695                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1696                         clear_opt(sb, GRPQUOTA);
1697
1698                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1699                         ext4_msg(sb, KERN_ERR, "old and new quota "
1700                                         "format mixing");
1701                         return 0;
1702                 }
1703
1704                 if (!sbi->s_jquota_fmt) {
1705                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1706                                         "not specified");
1707                         return 0;
1708                 }
1709         }
1710 #endif
1711         if (test_opt(sb, DIOREAD_NOLOCK)) {
1712                 int blocksize =
1713                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1714
1715                 if (blocksize < PAGE_CACHE_SIZE) {
1716                         ext4_msg(sb, KERN_ERR, "can't mount with "
1717                                  "dioread_nolock if block size != PAGE_SIZE");
1718                         return 0;
1719                 }
1720         }
1721         return 1;
1722 }
1723
1724 static inline void ext4_show_quota_options(struct seq_file *seq,
1725                                            struct super_block *sb)
1726 {
1727 #if defined(CONFIG_QUOTA)
1728         struct ext4_sb_info *sbi = EXT4_SB(sb);
1729
1730         if (sbi->s_jquota_fmt) {
1731                 char *fmtname = "";
1732
1733                 switch (sbi->s_jquota_fmt) {
1734                 case QFMT_VFS_OLD:
1735                         fmtname = "vfsold";
1736                         break;
1737                 case QFMT_VFS_V0:
1738                         fmtname = "vfsv0";
1739                         break;
1740                 case QFMT_VFS_V1:
1741                         fmtname = "vfsv1";
1742                         break;
1743                 }
1744                 seq_printf(seq, ",jqfmt=%s", fmtname);
1745         }
1746
1747         if (sbi->s_qf_names[USRQUOTA])
1748                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1749
1750         if (sbi->s_qf_names[GRPQUOTA])
1751                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1752 #endif
1753 }
1754
1755 static const char *token2str(int token)
1756 {
1757         const struct match_token *t;
1758
1759         for (t = tokens; t->token != Opt_err; t++)
1760                 if (t->token == token && !strchr(t->pattern, '='))
1761                         break;
1762         return t->pattern;
1763 }
1764
1765 /*
1766  * Show an option if
1767  *  - it's set to a non-default value OR
1768  *  - if the per-sb default is different from the global default
1769  */
1770 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1771                               int nodefs)
1772 {
1773         struct ext4_sb_info *sbi = EXT4_SB(sb);
1774         struct ext4_super_block *es = sbi->s_es;
1775         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1776         const struct mount_opts *m;
1777         char sep = nodefs ? '\n' : ',';
1778
1779 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1780 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1781
1782         if (sbi->s_sb_block != 1)
1783                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1784
1785         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1786                 int want_set = m->flags & MOPT_SET;
1787                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1788                     (m->flags & MOPT_CLEAR_ERR))
1789                         continue;
1790                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1791                         continue; /* skip if same as the default */
1792                 if ((want_set &&
1793                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1794                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1795                         continue; /* select Opt_noFoo vs Opt_Foo */
1796                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1797         }
1798
1799         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1800             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1801                 SEQ_OPTS_PRINT("resuid=%u",
1802                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1803         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1804             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1805                 SEQ_OPTS_PRINT("resgid=%u",
1806                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1807         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1808         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1809                 SEQ_OPTS_PUTS("errors=remount-ro");
1810         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1811                 SEQ_OPTS_PUTS("errors=continue");
1812         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1813                 SEQ_OPTS_PUTS("errors=panic");
1814         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1815                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1816         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1817                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1818         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1819                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1820         if (sb->s_flags & MS_I_VERSION)
1821                 SEQ_OPTS_PUTS("i_version");
1822         if (nodefs || sbi->s_stripe)
1823                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1824         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1825                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1826                         SEQ_OPTS_PUTS("data=journal");
1827                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1828                         SEQ_OPTS_PUTS("data=ordered");
1829                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1830                         SEQ_OPTS_PUTS("data=writeback");
1831         }
1832         if (nodefs ||
1833             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1834                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1835                                sbi->s_inode_readahead_blks);
1836
1837         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1838                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1839                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1840         if (nodefs || sbi->s_max_dir_size_kb)
1841                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1842
1843         ext4_show_quota_options(seq, sb);
1844         return 0;
1845 }
1846
1847 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1848 {
1849         return _ext4_show_options(seq, root->d_sb, 0);
1850 }
1851
1852 static int options_seq_show(struct seq_file *seq, void *offset)
1853 {
1854         struct super_block *sb = seq->private;
1855         int rc;
1856
1857         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1858         rc = _ext4_show_options(seq, sb, 1);
1859         seq_puts(seq, "\n");
1860         return rc;
1861 }
1862
1863 static int options_open_fs(struct inode *inode, struct file *file)
1864 {
1865         return single_open(file, options_seq_show, PDE_DATA(inode));
1866 }
1867
1868 static const struct file_operations ext4_seq_options_fops = {
1869         .owner = THIS_MODULE,
1870         .open = options_open_fs,
1871         .read = seq_read,
1872         .llseek = seq_lseek,
1873         .release = single_release,
1874 };
1875
1876 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1877                             int read_only)
1878 {
1879         struct ext4_sb_info *sbi = EXT4_SB(sb);
1880         int res = 0;
1881
1882         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1883                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1884                          "forcing read-only mode");
1885                 res = MS_RDONLY;
1886         }
1887         if (read_only)
1888                 goto done;
1889         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1890                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1891                          "running e2fsck is recommended");
1892         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1893                 ext4_msg(sb, KERN_WARNING,
1894                          "warning: mounting fs with errors, "
1895                          "running e2fsck is recommended");
1896         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1897                  le16_to_cpu(es->s_mnt_count) >=
1898                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1899                 ext4_msg(sb, KERN_WARNING,
1900                          "warning: maximal mount count reached, "
1901                          "running e2fsck is recommended");
1902         else if (le32_to_cpu(es->s_checkinterval) &&
1903                 (le32_to_cpu(es->s_lastcheck) +
1904                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1905                 ext4_msg(sb, KERN_WARNING,
1906                          "warning: checktime reached, "
1907                          "running e2fsck is recommended");
1908         if (!sbi->s_journal)
1909                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1910         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1911                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1912         le16_add_cpu(&es->s_mnt_count, 1);
1913         es->s_mtime = cpu_to_le32(get_seconds());
1914         ext4_update_dynamic_rev(sb);
1915         if (sbi->s_journal)
1916                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1917
1918         ext4_commit_super(sb, 1);
1919 done:
1920         if (test_opt(sb, DEBUG))
1921                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1922                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1923                         sb->s_blocksize,
1924                         sbi->s_groups_count,
1925                         EXT4_BLOCKS_PER_GROUP(sb),
1926                         EXT4_INODES_PER_GROUP(sb),
1927                         sbi->s_mount_opt, sbi->s_mount_opt2);
1928
1929         cleancache_init_fs(sb);
1930         return res;
1931 }
1932
1933 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1934 {
1935         struct ext4_sb_info *sbi = EXT4_SB(sb);
1936         struct flex_groups *new_groups;
1937         int size;
1938
1939         if (!sbi->s_log_groups_per_flex)
1940                 return 0;
1941
1942         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1943         if (size <= sbi->s_flex_groups_allocated)
1944                 return 0;
1945
1946         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1947         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1948         if (!new_groups) {
1949                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1950                          size / (int) sizeof(struct flex_groups));
1951                 return -ENOMEM;
1952         }
1953
1954         if (sbi->s_flex_groups) {
1955                 memcpy(new_groups, sbi->s_flex_groups,
1956                        (sbi->s_flex_groups_allocated *
1957                         sizeof(struct flex_groups)));
1958                 ext4_kvfree(sbi->s_flex_groups);
1959         }
1960         sbi->s_flex_groups = new_groups;
1961         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1962         return 0;
1963 }
1964
1965 static int ext4_fill_flex_info(struct super_block *sb)
1966 {
1967         struct ext4_sb_info *sbi = EXT4_SB(sb);
1968         struct ext4_group_desc *gdp = NULL;
1969         ext4_group_t flex_group;
1970         int i, err;
1971
1972         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1973         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1974                 sbi->s_log_groups_per_flex = 0;
1975                 return 1;
1976         }
1977
1978         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1979         if (err)
1980                 goto failed;
1981
1982         for (i = 0; i < sbi->s_groups_count; i++) {
1983                 gdp = ext4_get_group_desc(sb, i, NULL);
1984
1985                 flex_group = ext4_flex_group(sbi, i);
1986                 atomic_add(ext4_free_inodes_count(sb, gdp),
1987                            &sbi->s_flex_groups[flex_group].free_inodes);
1988                 atomic64_add(ext4_free_group_clusters(sb, gdp),
1989                              &sbi->s_flex_groups[flex_group].free_clusters);
1990                 atomic_add(ext4_used_dirs_count(sb, gdp),
1991                            &sbi->s_flex_groups[flex_group].used_dirs);
1992         }
1993
1994         return 1;
1995 failed:
1996         return 0;
1997 }
1998
1999 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2000                                    struct ext4_group_desc *gdp)
2001 {
2002         int offset;
2003         __u16 crc = 0;
2004         __le32 le_group = cpu_to_le32(block_group);
2005
2006         if ((sbi->s_es->s_feature_ro_compat &
2007              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
2008                 /* Use new metadata_csum algorithm */
2009                 __le16 save_csum;
2010                 __u32 csum32;
2011
2012                 save_csum = gdp->bg_checksum;
2013                 gdp->bg_checksum = 0;
2014                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2015                                      sizeof(le_group));
2016                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2017                                      sbi->s_desc_size);
2018                 gdp->bg_checksum = save_csum;
2019
2020                 crc = csum32 & 0xFFFF;
2021                 goto out;
2022         }
2023
2024         /* old crc16 code */
2025         offset = offsetof(struct ext4_group_desc, bg_checksum);
2026
2027         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2028         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2029         crc = crc16(crc, (__u8 *)gdp, offset);
2030         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2031         /* for checksum of struct ext4_group_desc do the rest...*/
2032         if ((sbi->s_es->s_feature_incompat &
2033              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2034             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2035                 crc = crc16(crc, (__u8 *)gdp + offset,
2036                             le16_to_cpu(sbi->s_es->s_desc_size) -
2037                                 offset);
2038
2039 out:
2040         return cpu_to_le16(crc);
2041 }
2042
2043 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2044                                 struct ext4_group_desc *gdp)
2045 {
2046         if (ext4_has_group_desc_csum(sb) &&
2047             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2048                                                       block_group, gdp)))
2049                 return 0;
2050
2051         return 1;
2052 }
2053
2054 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2055                               struct ext4_group_desc *gdp)
2056 {
2057         if (!ext4_has_group_desc_csum(sb))
2058                 return;
2059         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2060 }
2061
2062 /* Called at mount-time, super-block is locked */
2063 static int ext4_check_descriptors(struct super_block *sb,
2064                                   ext4_group_t *first_not_zeroed)
2065 {
2066         struct ext4_sb_info *sbi = EXT4_SB(sb);
2067         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2068         ext4_fsblk_t last_block;
2069         ext4_fsblk_t block_bitmap;
2070         ext4_fsblk_t inode_bitmap;
2071         ext4_fsblk_t inode_table;
2072         int flexbg_flag = 0;
2073         ext4_group_t i, grp = sbi->s_groups_count;
2074
2075         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2076                 flexbg_flag = 1;
2077
2078         ext4_debug("Checking group descriptors");
2079
2080         for (i = 0; i < sbi->s_groups_count; i++) {
2081                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2082
2083                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2084                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2085                 else
2086                         last_block = first_block +
2087                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2088
2089                 if ((grp == sbi->s_groups_count) &&
2090                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2091                         grp = i;
2092
2093                 block_bitmap = ext4_block_bitmap(sb, gdp);
2094                 if (block_bitmap < first_block || block_bitmap > last_block) {
2095                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2096                                "Block bitmap for group %u not in group "
2097                                "(block %llu)!", i, block_bitmap);
2098                         return 0;
2099                 }
2100                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2101                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2102                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2103                                "Inode bitmap for group %u not in group "
2104                                "(block %llu)!", i, inode_bitmap);
2105                         return 0;
2106                 }
2107                 inode_table = ext4_inode_table(sb, gdp);
2108                 if (inode_table < first_block ||
2109                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2110                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2111                                "Inode table for group %u not in group "
2112                                "(block %llu)!", i, inode_table);
2113                         return 0;
2114                 }
2115                 ext4_lock_group(sb, i);
2116                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2117                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2118                                  "Checksum for group %u failed (%u!=%u)",
2119                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2120                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2121                         if (!(sb->s_flags & MS_RDONLY)) {
2122                                 ext4_unlock_group(sb, i);
2123                                 return 0;
2124                         }
2125                 }
2126                 ext4_unlock_group(sb, i);
2127                 if (!flexbg_flag)
2128                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2129         }
2130         if (NULL != first_not_zeroed)
2131                 *first_not_zeroed = grp;
2132
2133         ext4_free_blocks_count_set(sbi->s_es,
2134                                    EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2135         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2136         return 1;
2137 }
2138
2139 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2140  * the superblock) which were deleted from all directories, but held open by
2141  * a process at the time of a crash.  We walk the list and try to delete these
2142  * inodes at recovery time (only with a read-write filesystem).
2143  *
2144  * In order to keep the orphan inode chain consistent during traversal (in
2145  * case of crash during recovery), we link each inode into the superblock
2146  * orphan list_head and handle it the same way as an inode deletion during
2147  * normal operation (which journals the operations for us).
2148  *
2149  * We only do an iget() and an iput() on each inode, which is very safe if we
2150  * accidentally point at an in-use or already deleted inode.  The worst that
2151  * can happen in this case is that we get a "bit already cleared" message from
2152  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2153  * e2fsck was run on this filesystem, and it must have already done the orphan
2154  * inode cleanup for us, so we can safely abort without any further action.
2155  */
2156 static void ext4_orphan_cleanup(struct super_block *sb,
2157                                 struct ext4_super_block *es)
2158 {
2159         unsigned int s_flags = sb->s_flags;
2160         int nr_orphans = 0, nr_truncates = 0;
2161 #ifdef CONFIG_QUOTA
2162         int i;
2163 #endif
2164         if (!es->s_last_orphan) {
2165                 jbd_debug(4, "no orphan inodes to clean up\n");
2166                 return;
2167         }
2168
2169         if (bdev_read_only(sb->s_bdev)) {
2170                 ext4_msg(sb, KERN_ERR, "write access "
2171                         "unavailable, skipping orphan cleanup");
2172                 return;
2173         }
2174
2175         /* Check if feature set would not allow a r/w mount */
2176         if (!ext4_feature_set_ok(sb, 0)) {
2177                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2178                          "unknown ROCOMPAT features");
2179                 return;
2180         }
2181
2182         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2183                 /* don't clear list on RO mount w/ errors */
2184                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2185                         jbd_debug(1, "Errors on filesystem, "
2186                                   "clearing orphan list.\n");
2187                         es->s_last_orphan = 0;
2188                 }
2189                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2190                 return;
2191         }
2192
2193         if (s_flags & MS_RDONLY) {
2194                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2195                 sb->s_flags &= ~MS_RDONLY;
2196         }
2197 #ifdef CONFIG_QUOTA
2198         /* Needed for iput() to work correctly and not trash data */
2199         sb->s_flags |= MS_ACTIVE;
2200         /* Turn on quotas so that they are updated correctly */
2201         for (i = 0; i < MAXQUOTAS; i++) {
2202                 if (EXT4_SB(sb)->s_qf_names[i]) {
2203                         int ret = ext4_quota_on_mount(sb, i);
2204                         if (ret < 0)
2205                                 ext4_msg(sb, KERN_ERR,
2206                                         "Cannot turn on journaled "
2207                                         "quota: error %d", ret);
2208                 }
2209         }
2210 #endif
2211
2212         while (es->s_last_orphan) {
2213                 struct inode *inode;
2214
2215                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2216                 if (IS_ERR(inode)) {
2217                         es->s_last_orphan = 0;
2218                         break;
2219                 }
2220
2221                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2222                 dquot_initialize(inode);
2223                 if (inode->i_nlink) {
2224                         if (test_opt(sb, DEBUG))
2225                                 ext4_msg(sb, KERN_DEBUG,
2226                                         "%s: truncating inode %lu to %lld bytes",
2227                                         __func__, inode->i_ino, inode->i_size);
2228                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2229                                   inode->i_ino, inode->i_size);
2230                         mutex_lock(&inode->i_mutex);
2231                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2232                         ext4_truncate(inode);
2233                         mutex_unlock(&inode->i_mutex);
2234                         nr_truncates++;
2235                 } else {
2236                         if (test_opt(sb, DEBUG))
2237                                 ext4_msg(sb, KERN_DEBUG,
2238                                         "%s: deleting unreferenced inode %lu",
2239                                         __func__, inode->i_ino);
2240                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2241                                   inode->i_ino);
2242                         nr_orphans++;
2243                 }
2244                 iput(inode);  /* The delete magic happens here! */
2245         }
2246
2247 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2248
2249         if (nr_orphans)
2250                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2251                        PLURAL(nr_orphans));
2252         if (nr_truncates)
2253                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2254                        PLURAL(nr_truncates));
2255 #ifdef CONFIG_QUOTA
2256         /* Turn quotas off */
2257         for (i = 0; i < MAXQUOTAS; i++) {
2258                 if (sb_dqopt(sb)->files[i])
2259                         dquot_quota_off(sb, i);
2260         }
2261 #endif
2262         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2263 }
2264
2265 /*
2266  * Maximal extent format file size.
2267  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2268  * extent format containers, within a sector_t, and within i_blocks
2269  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2270  * so that won't be a limiting factor.
2271  *
2272  * However there is other limiting factor. We do store extents in the form
2273  * of starting block and length, hence the resulting length of the extent
2274  * covering maximum file size must fit into on-disk format containers as
2275  * well. Given that length is always by 1 unit bigger than max unit (because
2276  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2277  *
2278  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2279  */
2280 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2281 {
2282         loff_t res;
2283         loff_t upper_limit = MAX_LFS_FILESIZE;
2284
2285         /* small i_blocks in vfs inode? */
2286         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2287                 /*
2288                  * CONFIG_LBDAF is not enabled implies the inode
2289                  * i_block represent total blocks in 512 bytes
2290                  * 32 == size of vfs inode i_blocks * 8
2291                  */
2292                 upper_limit = (1LL << 32) - 1;
2293
2294                 /* total blocks in file system block size */
2295                 upper_limit >>= (blkbits - 9);
2296                 upper_limit <<= blkbits;
2297         }
2298
2299         /*
2300          * 32-bit extent-start container, ee_block. We lower the maxbytes
2301          * by one fs block, so ee_len can cover the extent of maximum file
2302          * size
2303          */
2304         res = (1LL << 32) - 1;
2305         res <<= blkbits;
2306
2307         /* Sanity check against vm- & vfs- imposed limits */
2308         if (res > upper_limit)
2309                 res = upper_limit;
2310
2311         return res;
2312 }
2313
2314 /*
2315  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2316  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2317  * We need to be 1 filesystem block less than the 2^48 sector limit.
2318  */
2319 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2320 {
2321         loff_t res = EXT4_NDIR_BLOCKS;
2322         int meta_blocks;
2323         loff_t upper_limit;
2324         /* This is calculated to be the largest file size for a dense, block
2325          * mapped file such that the file's total number of 512-byte sectors,
2326          * including data and all indirect blocks, does not exceed (2^48 - 1).
2327          *
2328          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2329          * number of 512-byte sectors of the file.
2330          */
2331
2332         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2333                 /*
2334                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2335                  * the inode i_block field represents total file blocks in
2336                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2337                  */
2338                 upper_limit = (1LL << 32) - 1;
2339
2340                 /* total blocks in file system block size */
2341                 upper_limit >>= (bits - 9);
2342
2343         } else {
2344                 /*
2345                  * We use 48 bit ext4_inode i_blocks
2346                  * With EXT4_HUGE_FILE_FL set the i_blocks
2347                  * represent total number of blocks in
2348                  * file system block size
2349                  */
2350                 upper_limit = (1LL << 48) - 1;
2351
2352         }
2353
2354         /* indirect blocks */
2355         meta_blocks = 1;
2356         /* double indirect blocks */
2357         meta_blocks += 1 + (1LL << (bits-2));
2358         /* tripple indirect blocks */
2359         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2360
2361         upper_limit -= meta_blocks;
2362         upper_limit <<= bits;
2363
2364         res += 1LL << (bits-2);
2365         res += 1LL << (2*(bits-2));
2366         res += 1LL << (3*(bits-2));
2367         res <<= bits;
2368         if (res > upper_limit)
2369                 res = upper_limit;
2370
2371         if (res > MAX_LFS_FILESIZE)
2372                 res = MAX_LFS_FILESIZE;
2373
2374         return res;
2375 }
2376
2377 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2378                                    ext4_fsblk_t logical_sb_block, int nr)
2379 {
2380         struct ext4_sb_info *sbi = EXT4_SB(sb);
2381         ext4_group_t bg, first_meta_bg;
2382         int has_super = 0;
2383
2384         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2385
2386         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2387             nr < first_meta_bg)
2388                 return logical_sb_block + nr + 1;
2389         bg = sbi->s_desc_per_block * nr;
2390         if (ext4_bg_has_super(sb, bg))
2391                 has_super = 1;
2392
2393         return (has_super + ext4_group_first_block_no(sb, bg));
2394 }
2395
2396 /**
2397  * ext4_get_stripe_size: Get the stripe size.
2398  * @sbi: In memory super block info
2399  *
2400  * If we have specified it via mount option, then
2401  * use the mount option value. If the value specified at mount time is
2402  * greater than the blocks per group use the super block value.
2403  * If the super block value is greater than blocks per group return 0.
2404  * Allocator needs it be less than blocks per group.
2405  *
2406  */
2407 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2408 {
2409         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2410         unsigned long stripe_width =
2411                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2412         int ret;
2413
2414         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2415                 ret = sbi->s_stripe;
2416         else if (stripe_width <= sbi->s_blocks_per_group)
2417                 ret = stripe_width;
2418         else if (stride <= sbi->s_blocks_per_group)
2419                 ret = stride;
2420         else
2421                 ret = 0;
2422
2423         /*
2424          * If the stripe width is 1, this makes no sense and
2425          * we set it to 0 to turn off stripe handling code.
2426          */
2427         if (ret <= 1)
2428                 ret = 0;
2429
2430         return ret;
2431 }
2432
2433 /* sysfs supprt */
2434
2435 struct ext4_attr {
2436         struct attribute attr;
2437         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2438         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2439                          const char *, size_t);
2440         union {
2441                 int offset;
2442                 int deprecated_val;
2443         } u;
2444 };
2445
2446 static int parse_strtoull(const char *buf,
2447                 unsigned long long max, unsigned long long *value)
2448 {
2449         int ret;
2450
2451         ret = kstrtoull(skip_spaces(buf), 0, value);
2452         if (!ret && *value > max)
2453                 ret = -EINVAL;
2454         return ret;
2455 }
2456
2457 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2458                                               struct ext4_sb_info *sbi,
2459                                               char *buf)
2460 {
2461         return snprintf(buf, PAGE_SIZE, "%llu\n",
2462                 (s64) EXT4_C2B(sbi,
2463                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2464 }
2465
2466 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2467                                          struct ext4_sb_info *sbi, char *buf)
2468 {
2469         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2470
2471         if (!sb->s_bdev->bd_part)
2472                 return snprintf(buf, PAGE_SIZE, "0\n");
2473         return snprintf(buf, PAGE_SIZE, "%lu\n",
2474                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2475                          sbi->s_sectors_written_start) >> 1);
2476 }
2477
2478 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2479                                           struct ext4_sb_info *sbi, char *buf)
2480 {
2481         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2482
2483         if (!sb->s_bdev->bd_part)
2484                 return snprintf(buf, PAGE_SIZE, "0\n");
2485         return snprintf(buf, PAGE_SIZE, "%llu\n",
2486                         (unsigned long long)(sbi->s_kbytes_written +
2487                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2488                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2489 }
2490
2491 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2492                                           struct ext4_sb_info *sbi,
2493                                           const char *buf, size_t count)
2494 {
2495         unsigned long t;
2496         int ret;
2497
2498         ret = kstrtoul(skip_spaces(buf), 0, &t);
2499         if (ret)
2500                 return ret;
2501
2502         if (t && (!is_power_of_2(t) || t > 0x40000000))
2503                 return -EINVAL;
2504
2505         sbi->s_inode_readahead_blks = t;
2506         return count;
2507 }
2508
2509 static ssize_t sbi_ui_show(struct ext4_attr *a,
2510                            struct ext4_sb_info *sbi, char *buf)
2511 {
2512         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2513
2514         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2515 }
2516
2517 static ssize_t sbi_ui_store(struct ext4_attr *a,
2518                             struct ext4_sb_info *sbi,
2519                             const char *buf, size_t count)
2520 {
2521         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2522         unsigned long t;
2523         int ret;
2524
2525         ret = kstrtoul(skip_spaces(buf), 0, &t);
2526         if (ret)
2527                 return ret;
2528         *ui = t;
2529         return count;
2530 }
2531
2532 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2533                                   struct ext4_sb_info *sbi, char *buf)
2534 {
2535         return snprintf(buf, PAGE_SIZE, "%llu\n",
2536                 (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2537 }
2538
2539 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2540                                    struct ext4_sb_info *sbi,
2541                                    const char *buf, size_t count)
2542 {
2543         unsigned long long val;
2544         int ret;
2545
2546         if (parse_strtoull(buf, -1ULL, &val))
2547                 return -EINVAL;
2548         ret = ext4_reserve_clusters(sbi, val);
2549
2550         return ret ? ret : count;
2551 }
2552
2553 static ssize_t trigger_test_error(struct ext4_attr *a,
2554                                   struct ext4_sb_info *sbi,
2555                                   const char *buf, size_t count)
2556 {
2557         int len = count;
2558
2559         if (!capable(CAP_SYS_ADMIN))
2560                 return -EPERM;
2561
2562         if (len && buf[len-1] == '\n')
2563                 len--;
2564
2565         if (len)
2566                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2567         return count;
2568 }
2569
2570 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2571                                    struct ext4_sb_info *sbi, char *buf)
2572 {
2573         return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2574 }
2575
2576 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2577 static struct ext4_attr ext4_attr_##_name = {                   \
2578         .attr = {.name = __stringify(_name), .mode = _mode },   \
2579         .show   = _show,                                        \
2580         .store  = _store,                                       \
2581         .u = {                                                  \
2582                 .offset = offsetof(struct ext4_sb_info, _elname),\
2583         },                                                      \
2584 }
2585 #define EXT4_ATTR(name, mode, show, store) \
2586 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2587
2588 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2589 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2590 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2591 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2592         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2593 #define ATTR_LIST(name) &ext4_attr_##name.attr
2594 #define EXT4_DEPRECATED_ATTR(_name, _val)       \
2595 static struct ext4_attr ext4_attr_##_name = {                   \
2596         .attr = {.name = __stringify(_name), .mode = 0444 },    \
2597         .show   = sbi_deprecated_show,                          \
2598         .u = {                                                  \
2599                 .deprecated_val = _val,                         \
2600         },                                                      \
2601 }
2602
2603 EXT4_RO_ATTR(delayed_allocation_blocks);
2604 EXT4_RO_ATTR(session_write_kbytes);
2605 EXT4_RO_ATTR(lifetime_write_kbytes);
2606 EXT4_RW_ATTR(reserved_clusters);
2607 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2608                  inode_readahead_blks_store, s_inode_readahead_blks);
2609 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2610 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2611 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2612 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2613 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2614 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2615 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2616 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2617 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2618 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2619 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2620 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2621 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2622 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2623 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2624 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2625
2626 static struct attribute *ext4_attrs[] = {
2627         ATTR_LIST(delayed_allocation_blocks),
2628         ATTR_LIST(session_write_kbytes),
2629         ATTR_LIST(lifetime_write_kbytes),
2630         ATTR_LIST(reserved_clusters),
2631         ATTR_LIST(inode_readahead_blks),
2632         ATTR_LIST(inode_goal),
2633         ATTR_LIST(mb_stats),
2634         ATTR_LIST(mb_max_to_scan),
2635         ATTR_LIST(mb_min_to_scan),
2636         ATTR_LIST(mb_order2_req),
2637         ATTR_LIST(mb_stream_req),
2638         ATTR_LIST(mb_group_prealloc),
2639         ATTR_LIST(max_writeback_mb_bump),
2640         ATTR_LIST(extent_max_zeroout_kb),
2641         ATTR_LIST(trigger_fs_error),
2642         ATTR_LIST(err_ratelimit_interval_ms),
2643         ATTR_LIST(err_ratelimit_burst),
2644         ATTR_LIST(warning_ratelimit_interval_ms),
2645         ATTR_LIST(warning_ratelimit_burst),
2646         ATTR_LIST(msg_ratelimit_interval_ms),
2647         ATTR_LIST(msg_ratelimit_burst),
2648         NULL,
2649 };
2650
2651 /* Features this copy of ext4 supports */
2652 EXT4_INFO_ATTR(lazy_itable_init);
2653 EXT4_INFO_ATTR(batched_discard);
2654 EXT4_INFO_ATTR(meta_bg_resize);
2655
2656 static struct attribute *ext4_feat_attrs[] = {
2657         ATTR_LIST(lazy_itable_init),
2658         ATTR_LIST(batched_discard),
2659         ATTR_LIST(meta_bg_resize),
2660         NULL,
2661 };
2662
2663 static ssize_t ext4_attr_show(struct kobject *kobj,
2664                               struct attribute *attr, char *buf)
2665 {
2666         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2667                                                 s_kobj);
2668         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2669
2670         return a->show ? a->show(a, sbi, buf) : 0;
2671 }
2672
2673 static ssize_t ext4_attr_store(struct kobject *kobj,
2674                                struct attribute *attr,
2675                                const char *buf, size_t len)
2676 {
2677         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2678                                                 s_kobj);
2679         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2680
2681         return a->store ? a->store(a, sbi, buf, len) : 0;
2682 }
2683
2684 static void ext4_sb_release(struct kobject *kobj)
2685 {
2686         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2687                                                 s_kobj);
2688         complete(&sbi->s_kobj_unregister);
2689 }
2690
2691 static const struct sysfs_ops ext4_attr_ops = {
2692         .show   = ext4_attr_show,
2693         .store  = ext4_attr_store,
2694 };
2695
2696 static struct kobj_type ext4_ktype = {
2697         .default_attrs  = ext4_attrs,
2698         .sysfs_ops      = &ext4_attr_ops,
2699         .release        = ext4_sb_release,
2700 };
2701
2702 static void ext4_feat_release(struct kobject *kobj)
2703 {
2704         complete(&ext4_feat->f_kobj_unregister);
2705 }
2706
2707 static struct kobj_type ext4_feat_ktype = {
2708         .default_attrs  = ext4_feat_attrs,
2709         .sysfs_ops      = &ext4_attr_ops,
2710         .release        = ext4_feat_release,
2711 };
2712
2713 /*
2714  * Check whether this filesystem can be mounted based on
2715  * the features present and the RDONLY/RDWR mount requested.
2716  * Returns 1 if this filesystem can be mounted as requested,
2717  * 0 if it cannot be.
2718  */
2719 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2720 {
2721         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2722                 ext4_msg(sb, KERN_ERR,
2723                         "Couldn't mount because of "
2724                         "unsupported optional features (%x)",
2725                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2726                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2727                 return 0;
2728         }
2729
2730         if (readonly)
2731                 return 1;
2732
2733         /* Check that feature set is OK for a read-write mount */
2734         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2735                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2736                          "unsupported optional features (%x)",
2737                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2738                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2739                 return 0;
2740         }
2741         /*
2742          * Large file size enabled file system can only be mounted
2743          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2744          */
2745         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2746                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2747                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2748                                  "cannot be mounted RDWR without "
2749                                  "CONFIG_LBDAF");
2750                         return 0;
2751                 }
2752         }
2753         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2754             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2755                 ext4_msg(sb, KERN_ERR,
2756                          "Can't support bigalloc feature without "
2757                          "extents feature\n");
2758                 return 0;
2759         }
2760
2761 #ifndef CONFIG_QUOTA
2762         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2763             !readonly) {
2764                 ext4_msg(sb, KERN_ERR,
2765                          "Filesystem with quota feature cannot be mounted RDWR "
2766                          "without CONFIG_QUOTA");
2767                 return 0;
2768         }
2769 #endif  /* CONFIG_QUOTA */
2770         return 1;
2771 }
2772
2773 /*
2774  * This function is called once a day if we have errors logged
2775  * on the file system
2776  */
2777 static void print_daily_error_info(unsigned long arg)
2778 {
2779         struct super_block *sb = (struct super_block *) arg;
2780         struct ext4_sb_info *sbi;
2781         struct ext4_super_block *es;
2782
2783         sbi = EXT4_SB(sb);
2784         es = sbi->s_es;
2785
2786         if (es->s_error_count)
2787                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2788                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2789                          le32_to_cpu(es->s_error_count));
2790         if (es->s_first_error_time) {
2791                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2792                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2793                        (int) sizeof(es->s_first_error_func),
2794                        es->s_first_error_func,
2795                        le32_to_cpu(es->s_first_error_line));
2796                 if (es->s_first_error_ino)
2797                         printk(": inode %u",
2798                                le32_to_cpu(es->s_first_error_ino));
2799                 if (es->s_first_error_block)
2800                         printk(": block %llu", (unsigned long long)
2801                                le64_to_cpu(es->s_first_error_block));
2802                 printk("\n");
2803         }
2804         if (es->s_last_error_time) {
2805                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2806                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2807                        (int) sizeof(es->s_last_error_func),
2808                        es->s_last_error_func,
2809                        le32_to_cpu(es->s_last_error_line));
2810                 if (es->s_last_error_ino)
2811                         printk(": inode %u",
2812                                le32_to_cpu(es->s_last_error_ino));
2813                 if (es->s_last_error_block)
2814                         printk(": block %llu", (unsigned long long)
2815                                le64_to_cpu(es->s_last_error_block));
2816                 printk("\n");
2817         }
2818         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2819 }
2820
2821 /* Find next suitable group and run ext4_init_inode_table */
2822 static int ext4_run_li_request(struct ext4_li_request *elr)
2823 {
2824         struct ext4_group_desc *gdp = NULL;
2825         ext4_group_t group, ngroups;
2826         struct super_block *sb;
2827         unsigned long timeout = 0;
2828         int ret = 0;
2829
2830         sb = elr->lr_super;
2831         ngroups = EXT4_SB(sb)->s_groups_count;
2832
2833         sb_start_write(sb);
2834         for (group = elr->lr_next_group; group < ngroups; group++) {
2835                 gdp = ext4_get_group_desc(sb, group, NULL);
2836                 if (!gdp) {
2837                         ret = 1;
2838                         break;
2839                 }
2840
2841                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2842                         break;
2843         }
2844
2845         if (group >= ngroups)
2846                 ret = 1;
2847
2848         if (!ret) {
2849                 timeout = jiffies;
2850                 ret = ext4_init_inode_table(sb, group,
2851                                             elr->lr_timeout ? 0 : 1);
2852                 if (elr->lr_timeout == 0) {
2853                         timeout = (jiffies - timeout) *
2854                                   elr->lr_sbi->s_li_wait_mult;
2855                         elr->lr_timeout = timeout;
2856                 }
2857                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2858                 elr->lr_next_group = group + 1;
2859         }
2860         sb_end_write(sb);
2861
2862         return ret;
2863 }
2864
2865 /*
2866  * Remove lr_request from the list_request and free the
2867  * request structure. Should be called with li_list_mtx held
2868  */
2869 static void ext4_remove_li_request(struct ext4_li_request *elr)
2870 {
2871         struct ext4_sb_info *sbi;
2872
2873         if (!elr)
2874                 return;
2875
2876         sbi = elr->lr_sbi;
2877
2878         list_del(&elr->lr_request);
2879         sbi->s_li_request = NULL;
2880         kfree(elr);
2881 }
2882
2883 static void ext4_unregister_li_request(struct super_block *sb)
2884 {
2885         mutex_lock(&ext4_li_mtx);
2886         if (!ext4_li_info) {
2887                 mutex_unlock(&ext4_li_mtx);
2888                 return;
2889         }
2890
2891         mutex_lock(&ext4_li_info->li_list_mtx);
2892         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2893         mutex_unlock(&ext4_li_info->li_list_mtx);
2894         mutex_unlock(&ext4_li_mtx);
2895 }
2896
2897 static struct task_struct *ext4_lazyinit_task;
2898
2899 /*
2900  * This is the function where ext4lazyinit thread lives. It walks
2901  * through the request list searching for next scheduled filesystem.
2902  * When such a fs is found, run the lazy initialization request
2903  * (ext4_rn_li_request) and keep track of the time spend in this
2904  * function. Based on that time we compute next schedule time of
2905  * the request. When walking through the list is complete, compute
2906  * next waking time and put itself into sleep.
2907  */
2908 static int ext4_lazyinit_thread(void *arg)
2909 {
2910         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2911         struct list_head *pos, *n;
2912         struct ext4_li_request *elr;
2913         unsigned long next_wakeup, cur;
2914
2915         BUG_ON(NULL == eli);
2916
2917 cont_thread:
2918         while (true) {
2919                 next_wakeup = MAX_JIFFY_OFFSET;
2920
2921                 mutex_lock(&eli->li_list_mtx);
2922                 if (list_empty(&eli->li_request_list)) {
2923                         mutex_unlock(&eli->li_list_mtx);
2924                         goto exit_thread;
2925                 }
2926
2927                 list_for_each_safe(pos, n, &eli->li_request_list) {
2928                         elr = list_entry(pos, struct ext4_li_request,
2929                                          lr_request);
2930
2931                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2932                                 if (ext4_run_li_request(elr) != 0) {
2933                                         /* error, remove the lazy_init job */
2934                                         ext4_remove_li_request(elr);
2935                                         continue;
2936                                 }
2937                         }
2938
2939                         if (time_before(elr->lr_next_sched, next_wakeup))
2940                                 next_wakeup = elr->lr_next_sched;
2941                 }
2942                 mutex_unlock(&eli->li_list_mtx);
2943
2944                 try_to_freeze();
2945
2946                 cur = jiffies;
2947                 if ((time_after_eq(cur, next_wakeup)) ||
2948                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2949                         cond_resched();
2950                         continue;
2951                 }
2952
2953                 schedule_timeout_interruptible(next_wakeup - cur);
2954
2955                 if (kthread_should_stop()) {
2956                         ext4_clear_request_list();
2957                         goto exit_thread;
2958                 }
2959         }
2960
2961 exit_thread:
2962         /*
2963          * It looks like the request list is empty, but we need
2964          * to check it under the li_list_mtx lock, to prevent any
2965          * additions into it, and of course we should lock ext4_li_mtx
2966          * to atomically free the list and ext4_li_info, because at
2967          * this point another ext4 filesystem could be registering
2968          * new one.
2969          */
2970         mutex_lock(&ext4_li_mtx);
2971         mutex_lock(&eli->li_list_mtx);
2972         if (!list_empty(&eli->li_request_list)) {
2973                 mutex_unlock(&eli->li_list_mtx);
2974                 mutex_unlock(&ext4_li_mtx);
2975                 goto cont_thread;
2976         }
2977         mutex_unlock(&eli->li_list_mtx);
2978         kfree(ext4_li_info);
2979         ext4_li_info = NULL;
2980         mutex_unlock(&ext4_li_mtx);
2981
2982         return 0;
2983 }
2984
2985 static void ext4_clear_request_list(void)
2986 {
2987         struct list_head *pos, *n;
2988         struct ext4_li_request *elr;
2989
2990         mutex_lock(&ext4_li_info->li_list_mtx);
2991         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2992                 elr = list_entry(pos, struct ext4_li_request,
2993                                  lr_request);
2994                 ext4_remove_li_request(elr);
2995         }
2996         mutex_unlock(&ext4_li_info->li_list_mtx);
2997 }
2998
2999 static int ext4_run_lazyinit_thread(void)
3000 {
3001         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3002                                          ext4_li_info, "ext4lazyinit");
3003         if (IS_ERR(ext4_lazyinit_task)) {
3004                 int err = PTR_ERR(ext4_lazyinit_task);
3005                 ext4_clear_request_list();
3006                 kfree(ext4_li_info);
3007                 ext4_li_info = NULL;
3008                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3009                                  "initialization thread\n",
3010                                  err);
3011                 return err;
3012         }
3013         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3014         return 0;
3015 }
3016
3017 /*
3018  * Check whether it make sense to run itable init. thread or not.
3019  * If there is at least one uninitialized inode table, return
3020  * corresponding group number, else the loop goes through all
3021  * groups and return total number of groups.
3022  */
3023 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3024 {
3025         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3026         struct ext4_group_desc *gdp = NULL;
3027
3028         for (group = 0; group < ngroups; group++) {
3029                 gdp = ext4_get_group_desc(sb, group, NULL);
3030                 if (!gdp)
3031                         continue;
3032
3033                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3034                         break;
3035         }
3036
3037         return group;
3038 }
3039
3040 static int ext4_li_info_new(void)
3041 {
3042         struct ext4_lazy_init *eli = NULL;
3043
3044         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3045         if (!eli)
3046                 return -ENOMEM;
3047
3048         INIT_LIST_HEAD(&eli->li_request_list);
3049         mutex_init(&eli->li_list_mtx);
3050
3051         eli->li_state |= EXT4_LAZYINIT_QUIT;
3052
3053         ext4_li_info = eli;
3054
3055         return 0;
3056 }
3057
3058 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3059                                             ext4_group_t start)
3060 {
3061         struct ext4_sb_info *sbi = EXT4_SB(sb);
3062         struct ext4_li_request *elr;
3063
3064         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3065         if (!elr)
3066                 return NULL;
3067
3068         elr->lr_super = sb;
3069         elr->lr_sbi = sbi;
3070         elr->lr_next_group = start;
3071
3072         /*
3073          * Randomize first schedule time of the request to
3074          * spread the inode table initialization requests
3075          * better.
3076          */
3077         elr->lr_next_sched = jiffies + (prandom_u32() %
3078                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3079         return elr;
3080 }
3081
3082 int ext4_register_li_request(struct super_block *sb,
3083                              ext4_group_t first_not_zeroed)
3084 {
3085         struct ext4_sb_info *sbi = EXT4_SB(sb);
3086         struct ext4_li_request *elr = NULL;
3087         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3088         int ret = 0;
3089
3090         mutex_lock(&ext4_li_mtx);
3091         if (sbi->s_li_request != NULL) {
3092                 /*
3093                  * Reset timeout so it can be computed again, because
3094                  * s_li_wait_mult might have changed.
3095                  */
3096                 sbi->s_li_request->lr_timeout = 0;
3097                 goto out;
3098         }
3099
3100         if (first_not_zeroed == ngroups ||
3101             (sb->s_flags & MS_RDONLY) ||
3102             !test_opt(sb, INIT_INODE_TABLE))
3103                 goto out;
3104
3105         elr = ext4_li_request_new(sb, first_not_zeroed);
3106         if (!elr) {
3107                 ret = -ENOMEM;
3108                 goto out;
3109         }
3110
3111         if (NULL == ext4_li_info) {
3112                 ret = ext4_li_info_new();
3113                 if (ret)
3114                         goto out;
3115         }
3116
3117         mutex_lock(&ext4_li_info->li_list_mtx);
3118         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3119         mutex_unlock(&ext4_li_info->li_list_mtx);
3120
3121         sbi->s_li_request = elr;
3122         /*
3123          * set elr to NULL here since it has been inserted to
3124          * the request_list and the removal and free of it is
3125          * handled by ext4_clear_request_list from now on.
3126          */
3127         elr = NULL;
3128
3129         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3130                 ret = ext4_run_lazyinit_thread();
3131                 if (ret)
3132                         goto out;
3133         }
3134 out:
3135         mutex_unlock(&ext4_li_mtx);
3136         if (ret)
3137                 kfree(elr);
3138         return ret;
3139 }
3140
3141 /*
3142  * We do not need to lock anything since this is called on
3143  * module unload.
3144  */
3145 static void ext4_destroy_lazyinit_thread(void)
3146 {
3147         /*
3148          * If thread exited earlier
3149          * there's nothing to be done.
3150          */
3151         if (!ext4_li_info || !ext4_lazyinit_task)
3152                 return;
3153
3154         kthread_stop(ext4_lazyinit_task);
3155 }
3156
3157 static int set_journal_csum_feature_set(struct super_block *sb)
3158 {
3159         int ret = 1;
3160         int compat, incompat;
3161         struct ext4_sb_info *sbi = EXT4_SB(sb);
3162
3163         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3164                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3165                 /* journal checksum v3 */
3166                 compat = 0;
3167                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3168         } else {
3169                 /* journal checksum v1 */
3170                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3171                 incompat = 0;
3172         }
3173
3174         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3175                 ret = jbd2_journal_set_features(sbi->s_journal,
3176                                 compat, 0,
3177                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3178                                 incompat);
3179         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3180                 ret = jbd2_journal_set_features(sbi->s_journal,
3181                                 compat, 0,
3182                                 incompat);
3183                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3184                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3185         } else {
3186                 jbd2_journal_clear_features(sbi->s_journal,
3187                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3188                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3189                                 JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3190                                 JBD2_FEATURE_INCOMPAT_CSUM_V2);
3191         }
3192
3193         return ret;
3194 }
3195
3196 /*
3197  * Note: calculating the overhead so we can be compatible with
3198  * historical BSD practice is quite difficult in the face of
3199  * clusters/bigalloc.  This is because multiple metadata blocks from
3200  * different block group can end up in the same allocation cluster.
3201  * Calculating the exact overhead in the face of clustered allocation
3202  * requires either O(all block bitmaps) in memory or O(number of block
3203  * groups**2) in time.  We will still calculate the superblock for
3204  * older file systems --- and if we come across with a bigalloc file
3205  * system with zero in s_overhead_clusters the estimate will be close to
3206  * correct especially for very large cluster sizes --- but for newer
3207  * file systems, it's better to calculate this figure once at mkfs
3208  * time, and store it in the superblock.  If the superblock value is
3209  * present (even for non-bigalloc file systems), we will use it.
3210  */
3211 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3212                           char *buf)
3213 {
3214         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3215         struct ext4_group_desc  *gdp;
3216         ext4_fsblk_t            first_block, last_block, b;
3217         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3218         int                     s, j, count = 0;
3219
3220         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3221                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3222                         sbi->s_itb_per_group + 2);
3223
3224         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3225                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3226         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3227         for (i = 0; i < ngroups; i++) {
3228                 gdp = ext4_get_group_desc(sb, i, NULL);
3229                 b = ext4_block_bitmap(sb, gdp);
3230                 if (b >= first_block && b <= last_block) {
3231                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3232                         count++;
3233                 }
3234                 b = ext4_inode_bitmap(sb, gdp);
3235                 if (b >= first_block && b <= last_block) {
3236                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3237                         count++;
3238                 }
3239                 b = ext4_inode_table(sb, gdp);
3240                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3241                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3242                                 int c = EXT4_B2C(sbi, b - first_block);
3243                                 ext4_set_bit(c, buf);
3244                                 count++;
3245                         }
3246                 if (i != grp)
3247                         continue;
3248                 s = 0;
3249                 if (ext4_bg_has_super(sb, grp)) {
3250                         ext4_set_bit(s++, buf);
3251                         count++;
3252                 }
3253                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3254                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3255                         count++;
3256                 }
3257         }
3258         if (!count)
3259                 return 0;
3260         return EXT4_CLUSTERS_PER_GROUP(sb) -
3261                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3262 }
3263
3264 /*
3265  * Compute the overhead and stash it in sbi->s_overhead
3266  */
3267 int ext4_calculate_overhead(struct super_block *sb)
3268 {
3269         struct ext4_sb_info *sbi = EXT4_SB(sb);
3270         struct ext4_super_block *es = sbi->s_es;
3271         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3272         ext4_fsblk_t overhead = 0;
3273         char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3274
3275         if (!buf)
3276                 return -ENOMEM;
3277
3278         /*
3279          * Compute the overhead (FS structures).  This is constant
3280          * for a given filesystem unless the number of block groups
3281          * changes so we cache the previous value until it does.
3282          */
3283
3284         /*
3285          * All of the blocks before first_data_block are overhead
3286          */
3287         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3288
3289         /*
3290          * Add the overhead found in each block group
3291          */
3292         for (i = 0; i < ngroups; i++) {
3293                 int blks;
3294
3295                 blks = count_overhead(sb, i, buf);
3296                 overhead += blks;
3297                 if (blks)
3298                         memset(buf, 0, PAGE_SIZE);
3299                 cond_resched();
3300         }
3301         /* Add the journal blocks as well */
3302         if (sbi->s_journal)
3303                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3304
3305         sbi->s_overhead = overhead;
3306         smp_wmb();
3307         free_page((unsigned long) buf);
3308         return 0;
3309 }
3310
3311
3312 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3313 {
3314         ext4_fsblk_t resv_clusters;
3315
3316         /*
3317          * There's no need to reserve anything when we aren't using extents.
3318          * The space estimates are exact, there are no unwritten extents,
3319          * hole punching doesn't need new metadata... This is needed especially
3320          * to keep ext2/3 backward compatibility.
3321          */
3322         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3323                 return 0;
3324         /*
3325          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3326          * This should cover the situations where we can not afford to run
3327          * out of space like for example punch hole, or converting
3328          * uninitialized extents in delalloc path. In most cases such
3329          * allocation would require 1, or 2 blocks, higher numbers are
3330          * very rare.
3331          */
3332         resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3333                         EXT4_SB(sb)->s_cluster_bits;
3334
3335         do_div(resv_clusters, 50);
3336         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3337
3338         return resv_clusters;
3339 }
3340
3341
3342 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3343 {
3344         ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3345                                 sbi->s_cluster_bits;
3346
3347         if (count >= clusters)
3348                 return -EINVAL;
3349
3350         atomic64_set(&sbi->s_resv_clusters, count);
3351         return 0;
3352 }
3353
3354 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3355 {
3356         char *orig_data = kstrdup(data, GFP_KERNEL);
3357         struct buffer_head *bh;
3358         struct ext4_super_block *es = NULL;
3359         struct ext4_sb_info *sbi;
3360         ext4_fsblk_t block;
3361         ext4_fsblk_t sb_block = get_sb_block(&data);
3362         ext4_fsblk_t logical_sb_block;
3363         unsigned long offset = 0;
3364         unsigned long journal_devnum = 0;
3365         unsigned long def_mount_opts;
3366         struct inode *root;
3367         char *cp;
3368         const char *descr;
3369         int ret = -ENOMEM;
3370         int blocksize, clustersize;
3371         unsigned int db_count;
3372         unsigned int i;
3373         int needs_recovery, has_huge_files, has_bigalloc;
3374         __u64 blocks_count;
3375         int err = 0;
3376         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3377         ext4_group_t first_not_zeroed;
3378
3379         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3380         if (!sbi)
3381                 goto out_free_orig;
3382
3383         sbi->s_blockgroup_lock =
3384                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3385         if (!sbi->s_blockgroup_lock) {
3386                 kfree(sbi);
3387                 goto out_free_orig;
3388         }
3389         sb->s_fs_info = sbi;
3390         sbi->s_sb = sb;
3391         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3392         sbi->s_sb_block = sb_block;
3393         if (sb->s_bdev->bd_part)
3394                 sbi->s_sectors_written_start =
3395                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3396
3397         /* Cleanup superblock name */
3398         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3399                 *cp = '!';
3400
3401         /* -EINVAL is default */
3402         ret = -EINVAL;
3403         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3404         if (!blocksize) {
3405                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3406                 goto out_fail;
3407         }
3408
3409         /*
3410          * The ext4 superblock will not be buffer aligned for other than 1kB
3411          * block sizes.  We need to calculate the offset from buffer start.
3412          */
3413         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3414                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3415                 offset = do_div(logical_sb_block, blocksize);
3416         } else {
3417                 logical_sb_block = sb_block;
3418         }
3419
3420         if (!(bh = sb_bread(sb, logical_sb_block))) {
3421                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3422                 goto out_fail;
3423         }
3424         /*
3425          * Note: s_es must be initialized as soon as possible because
3426          *       some ext4 macro-instructions depend on its value
3427          */
3428         es = (struct ext4_super_block *) (bh->b_data + offset);
3429         sbi->s_es = es;
3430         sb->s_magic = le16_to_cpu(es->s_magic);
3431         if (sb->s_magic != EXT4_SUPER_MAGIC)
3432                 goto cantfind_ext4;
3433         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3434
3435         /* Warn if metadata_csum and gdt_csum are both set. */
3436         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3437                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3438             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3439                 ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3440                              "redundant flags; please run fsck.");
3441
3442         /* Check for a known checksum algorithm */
3443         if (!ext4_verify_csum_type(sb, es)) {
3444                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3445                          "unknown checksum algorithm.");
3446                 silent = 1;
3447                 goto cantfind_ext4;
3448         }
3449
3450         /* Load the checksum driver */
3451         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3452                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3453                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3454                 if (IS_ERR(sbi->s_chksum_driver)) {
3455                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3456                         ret = PTR_ERR(sbi->s_chksum_driver);
3457                         sbi->s_chksum_driver = NULL;
3458                         goto failed_mount;
3459                 }
3460         }
3461
3462         /* Check superblock checksum */
3463         if (!ext4_superblock_csum_verify(sb, es)) {
3464                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3465                          "invalid superblock checksum.  Run e2fsck?");
3466                 silent = 1;
3467                 goto cantfind_ext4;
3468         }
3469
3470         /* Precompute checksum seed for all metadata */
3471         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3472                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3473                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3474                                                sizeof(es->s_uuid));
3475
3476         /* Set defaults before we parse the mount options */
3477         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3478         set_opt(sb, INIT_INODE_TABLE);
3479         if (def_mount_opts & EXT4_DEFM_DEBUG)
3480                 set_opt(sb, DEBUG);
3481         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3482                 set_opt(sb, GRPID);
3483         if (def_mount_opts & EXT4_DEFM_UID16)
3484                 set_opt(sb, NO_UID32);
3485         /* xattr user namespace & acls are now defaulted on */
3486         set_opt(sb, XATTR_USER);
3487 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3488         set_opt(sb, POSIX_ACL);
3489 #endif
3490         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3491                 set_opt(sb, JOURNAL_DATA);
3492         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3493                 set_opt(sb, ORDERED_DATA);
3494         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3495                 set_opt(sb, WRITEBACK_DATA);
3496
3497         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3498                 set_opt(sb, ERRORS_PANIC);
3499         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3500                 set_opt(sb, ERRORS_CONT);
3501         else
3502                 set_opt(sb, ERRORS_RO);
3503         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3504                 set_opt(sb, BLOCK_VALIDITY);
3505         if (def_mount_opts & EXT4_DEFM_DISCARD)
3506                 set_opt(sb, DISCARD);
3507
3508         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3509         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3510         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3511         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3512         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3513
3514         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3515                 set_opt(sb, BARRIER);
3516
3517         /*
3518          * enable delayed allocation by default
3519          * Use -o nodelalloc to turn it off
3520          */
3521         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3522             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3523                 set_opt(sb, DELALLOC);
3524
3525         /*
3526          * set default s_li_wait_mult for lazyinit, for the case there is
3527          * no mount option specified.
3528          */
3529         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3530
3531         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3532                            &journal_devnum, &journal_ioprio, 0)) {
3533                 ext4_msg(sb, KERN_WARNING,
3534                          "failed to parse options in superblock: %s",
3535                          sbi->s_es->s_mount_opts);
3536         }
3537         sbi->s_def_mount_opt = sbi->s_mount_opt;
3538         if (!parse_options((char *) data, sb, &journal_devnum,
3539                            &journal_ioprio, 0))
3540                 goto failed_mount;
3541
3542         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3543                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3544                             "with data=journal disables delayed "
3545                             "allocation and O_DIRECT support!\n");
3546                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3547                         ext4_msg(sb, KERN_ERR, "can't mount with "
3548                                  "both data=journal and delalloc");
3549                         goto failed_mount;
3550                 }
3551                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3552                         ext4_msg(sb, KERN_ERR, "can't mount with "
3553                                  "both data=journal and dioread_nolock");
3554                         goto failed_mount;
3555                 }
3556                 if (test_opt(sb, DELALLOC))
3557                         clear_opt(sb, DELALLOC);
3558         }
3559
3560         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3561                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3562
3563         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3564             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3565              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3566              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3567                 ext4_msg(sb, KERN_WARNING,
3568                        "feature flags set on rev 0 fs, "
3569                        "running e2fsck is recommended");
3570
3571         if (IS_EXT2_SB(sb)) {
3572                 if (ext2_feature_set_ok(sb))
3573                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3574                                  "using the ext4 subsystem");
3575                 else {
3576                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3577                                  "to feature incompatibilities");
3578                         goto failed_mount;
3579                 }
3580         }
3581
3582         if (IS_EXT3_SB(sb)) {
3583                 if (ext3_feature_set_ok(sb))
3584                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3585                                  "using the ext4 subsystem");
3586                 else {
3587                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3588                                  "to feature incompatibilities");
3589                         goto failed_mount;
3590                 }
3591         }
3592
3593         /*
3594          * Check feature flags regardless of the revision level, since we
3595          * previously didn't change the revision level when setting the flags,
3596          * so there is a chance incompat flags are set on a rev 0 filesystem.
3597          */
3598         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3599                 goto failed_mount;
3600
3601         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3602         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3603             blocksize > EXT4_MAX_BLOCK_SIZE) {
3604                 ext4_msg(sb, KERN_ERR,
3605                        "Unsupported filesystem blocksize %d", blocksize);
3606                 goto failed_mount;
3607         }
3608
3609         if (sb->s_blocksize != blocksize) {
3610                 /* Validate the filesystem blocksize */
3611                 if (!sb_set_blocksize(sb, blocksize)) {
3612                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3613                                         blocksize);
3614                         goto failed_mount;
3615                 }
3616
3617                 brelse(bh);
3618                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3619                 offset = do_div(logical_sb_block, blocksize);
3620                 bh = sb_bread(sb, logical_sb_block);
3621                 if (!bh) {
3622                         ext4_msg(sb, KERN_ERR,
3623                                "Can't read superblock on 2nd try");
3624                         goto failed_mount;
3625                 }
3626                 es = (struct ext4_super_block *)(bh->b_data + offset);
3627                 sbi->s_es = es;
3628                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3629                         ext4_msg(sb, KERN_ERR,
3630                                "Magic mismatch, very weird!");
3631                         goto failed_mount;
3632                 }
3633         }
3634
3635         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3636                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3637         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3638                                                       has_huge_files);
3639         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3640
3641         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3642                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3643                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3644         } else {
3645                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3646                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3647                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3648                     (!is_power_of_2(sbi->s_inode_size)) ||
3649                     (sbi->s_inode_size > blocksize)) {
3650                         ext4_msg(sb, KERN_ERR,
3651                                "unsupported inode size: %d",
3652                                sbi->s_inode_size);
3653                         goto failed_mount;
3654                 }
3655                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3656                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3657         }
3658
3659         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3660         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3661                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3662                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3663                     !is_power_of_2(sbi->s_desc_size)) {
3664                         ext4_msg(sb, KERN_ERR,
3665                                "unsupported descriptor size %lu",
3666                                sbi->s_desc_size);
3667                         goto failed_mount;
3668                 }
3669         } else
3670                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3671
3672         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3673         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3674         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3675                 goto cantfind_ext4;
3676
3677         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3678         if (sbi->s_inodes_per_block == 0)
3679                 goto cantfind_ext4;
3680         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3681                                         sbi->s_inodes_per_block;
3682         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3683         sbi->s_sbh = bh;
3684         sbi->s_mount_state = le16_to_cpu(es->s_state);
3685         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3686         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3687
3688         for (i = 0; i < 4; i++)
3689                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3690         sbi->s_def_hash_version = es->s_def_hash_version;
3691         if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3692                 i = le32_to_cpu(es->s_flags);
3693                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3694                         sbi->s_hash_unsigned = 3;
3695                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3696 #ifdef __CHAR_UNSIGNED__
3697                         if (!(sb->s_flags & MS_RDONLY))
3698                                 es->s_flags |=
3699                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3700                         sbi->s_hash_unsigned = 3;
3701 #else
3702                         if (!(sb->s_flags & MS_RDONLY))
3703                                 es->s_flags |=
3704                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3705 #endif
3706                 }
3707         }
3708
3709         /* Handle clustersize */
3710         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3711         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3712                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3713         if (has_bigalloc) {
3714                 if (clustersize < blocksize) {
3715                         ext4_msg(sb, KERN_ERR,
3716                                  "cluster size (%d) smaller than "
3717                                  "block size (%d)", clustersize, blocksize);
3718                         goto failed_mount;
3719                 }
3720                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3721                         le32_to_cpu(es->s_log_block_size);
3722                 sbi->s_clusters_per_group =
3723                         le32_to_cpu(es->s_clusters_per_group);
3724                 if (sbi->s_clusters_per_group > blocksize * 8) {
3725                         ext4_msg(sb, KERN_ERR,
3726                                  "#clusters per group too big: %lu",
3727                                  sbi->s_clusters_per_group);
3728                         goto failed_mount;
3729                 }
3730                 if (sbi->s_blocks_per_group !=
3731                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3732                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3733                                  "clusters per group (%lu) inconsistent",
3734                                  sbi->s_blocks_per_group,
3735                                  sbi->s_clusters_per_group);
3736                         goto failed_mount;
3737                 }
3738         } else {
3739                 if (clustersize != blocksize) {
3740                         ext4_warning(sb, "fragment/cluster size (%d) != "
3741                                      "block size (%d)", clustersize,
3742                                      blocksize);
3743                         clustersize = blocksize;
3744                 }
3745                 if (sbi->s_blocks_per_group > blocksize * 8) {
3746                         ext4_msg(sb, KERN_ERR,
3747                                  "#blocks per group too big: %lu",
3748                                  sbi->s_blocks_per_group);
3749                         goto failed_mount;
3750                 }
3751                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3752                 sbi->s_cluster_bits = 0;
3753         }
3754         sbi->s_cluster_ratio = clustersize / blocksize;
3755
3756         if (sbi->s_inodes_per_group > blocksize * 8) {
3757                 ext4_msg(sb, KERN_ERR,
3758                        "#inodes per group too big: %lu",
3759                        sbi->s_inodes_per_group);
3760                 goto failed_mount;
3761         }
3762
3763         /* Do we have standard group size of clustersize * 8 blocks ? */
3764         if (sbi->s_blocks_per_group == clustersize << 3)
3765                 set_opt2(sb, STD_GROUP_SIZE);
3766
3767         /*
3768          * Test whether we have more sectors than will fit in sector_t,
3769          * and whether the max offset is addressable by the page cache.
3770          */
3771         err = generic_check_addressable(sb->s_blocksize_bits,
3772                                         ext4_blocks_count(es));
3773         if (err) {
3774                 ext4_msg(sb, KERN_ERR, "filesystem"
3775                          " too large to mount safely on this system");
3776                 if (sizeof(sector_t) < 8)
3777                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3778                 goto failed_mount;
3779         }
3780
3781         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3782                 goto cantfind_ext4;
3783
3784         /* check blocks count against device size */
3785         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3786         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3787                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3788                        "exceeds size of device (%llu blocks)",
3789                        ext4_blocks_count(es), blocks_count);
3790                 goto failed_mount;
3791         }
3792
3793         /*
3794          * It makes no sense for the first data block to be beyond the end
3795          * of the filesystem.
3796          */
3797         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3798                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3799                          "block %u is beyond end of filesystem (%llu)",
3800                          le32_to_cpu(es->s_first_data_block),
3801                          ext4_blocks_count(es));
3802                 goto failed_mount;
3803         }
3804         blocks_count = (ext4_blocks_count(es) -
3805                         le32_to_cpu(es->s_first_data_block) +
3806                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3807         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3808         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3809                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3810                        "(block count %llu, first data block %u, "
3811                        "blocks per group %lu)", sbi->s_groups_count,
3812                        ext4_blocks_count(es),
3813                        le32_to_cpu(es->s_first_data_block),
3814                        EXT4_BLOCKS_PER_GROUP(sb));
3815                 goto failed_mount;
3816         }
3817         sbi->s_groups_count = blocks_count;
3818         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3819                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3820         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3821                    EXT4_DESC_PER_BLOCK(sb);
3822         sbi->s_group_desc = ext4_kvmalloc(db_count *
3823                                           sizeof(struct buffer_head *),
3824                                           GFP_KERNEL);
3825         if (sbi->s_group_desc == NULL) {
3826                 ext4_msg(sb, KERN_ERR, "not enough memory");
3827                 ret = -ENOMEM;
3828                 goto failed_mount;
3829         }
3830
3831         if (ext4_proc_root)
3832                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3833
3834         if (sbi->s_proc)
3835                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3836                                  &ext4_seq_options_fops, sb);
3837
3838         bgl_lock_init(sbi->s_blockgroup_lock);
3839
3840         for (i = 0; i < db_count; i++) {
3841                 block = descriptor_loc(sb, logical_sb_block, i);
3842                 sbi->s_group_desc[i] = sb_bread(sb, block);
3843                 if (!sbi->s_group_desc[i]) {
3844                         ext4_msg(sb, KERN_ERR,
3845                                "can't read group descriptor %d", i);
3846                         db_count = i;
3847                         goto failed_mount2;
3848                 }
3849         }
3850         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3851                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3852                 goto failed_mount2;
3853         }
3854         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3855                 if (!ext4_fill_flex_info(sb)) {
3856                         ext4_msg(sb, KERN_ERR,
3857                                "unable to initialize "
3858                                "flex_bg meta info!");
3859                         goto failed_mount2;
3860                 }
3861
3862         sbi->s_gdb_count = db_count;
3863         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3864         spin_lock_init(&sbi->s_next_gen_lock);
3865
3866         init_timer(&sbi->s_err_report);
3867         sbi->s_err_report.function = print_daily_error_info;
3868         sbi->s_err_report.data = (unsigned long) sb;
3869
3870         /* Register extent status tree shrinker */
3871         ext4_es_register_shrinker(sbi);
3872
3873         err = percpu_counter_init(&sbi->s_freeclusters_counter,
3874                         ext4_count_free_clusters(sb));
3875         if (!err) {
3876                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
3877                                 ext4_count_free_inodes(sb));
3878         }
3879         if (!err) {
3880                 err = percpu_counter_init(&sbi->s_dirs_counter,
3881                                 ext4_count_dirs(sb));
3882         }
3883         if (!err) {
3884                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3885         }
3886         if (!err) {
3887                 err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
3888         }
3889         if (err) {
3890                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3891                 goto failed_mount3;
3892         }
3893
3894         sbi->s_stripe = ext4_get_stripe_size(sbi);
3895         sbi->s_extent_max_zeroout_kb = 32;
3896
3897         /*
3898          * set up enough so that it can read an inode
3899          */
3900         if (!test_opt(sb, NOLOAD) &&
3901             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3902                 sb->s_op = &ext4_sops;
3903         else
3904                 sb->s_op = &ext4_nojournal_sops;
3905         sb->s_export_op = &ext4_export_ops;
3906         sb->s_xattr = ext4_xattr_handlers;
3907 #ifdef CONFIG_QUOTA
3908         sb->dq_op = &ext4_quota_operations;
3909         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3910                 sb->s_qcop = &ext4_qctl_sysfile_operations;
3911         else
3912                 sb->s_qcop = &ext4_qctl_operations;
3913 #endif
3914         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3915
3916         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3917         mutex_init(&sbi->s_orphan_lock);
3918
3919         sb->s_root = NULL;
3920
3921         needs_recovery = (es->s_last_orphan != 0 ||
3922                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3923                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3924
3925         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3926             !(sb->s_flags & MS_RDONLY))
3927                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3928                         goto failed_mount3;
3929
3930         /*
3931          * The first inode we look at is the journal inode.  Don't try
3932          * root first: it may be modified in the journal!
3933          */
3934         if (!test_opt(sb, NOLOAD) &&
3935             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3936                 if (ext4_load_journal(sb, es, journal_devnum))
3937                         goto failed_mount3;
3938         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3939               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3940                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3941                        "suppressed and not mounted read-only");
3942                 goto failed_mount_wq;
3943         } else {
3944                 clear_opt(sb, DATA_FLAGS);
3945                 sbi->s_journal = NULL;
3946                 needs_recovery = 0;
3947                 goto no_journal;
3948         }
3949
3950         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3951             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3952                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3953                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3954                 goto failed_mount_wq;
3955         }
3956
3957         if (!set_journal_csum_feature_set(sb)) {
3958                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3959                          "feature set");
3960                 goto failed_mount_wq;
3961         }
3962
3963         /* We have now updated the journal if required, so we can
3964          * validate the data journaling mode. */
3965         switch (test_opt(sb, DATA_FLAGS)) {
3966         case 0:
3967                 /* No mode set, assume a default based on the journal
3968                  * capabilities: ORDERED_DATA if the journal can
3969                  * cope, else JOURNAL_DATA
3970                  */
3971                 if (jbd2_journal_check_available_features
3972                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3973                         set_opt(sb, ORDERED_DATA);
3974                 else
3975                         set_opt(sb, JOURNAL_DATA);
3976                 break;
3977
3978         case EXT4_MOUNT_ORDERED_DATA:
3979         case EXT4_MOUNT_WRITEBACK_DATA:
3980                 if (!jbd2_journal_check_available_features
3981                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3982                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3983                                "requested data journaling mode");
3984                         goto failed_mount_wq;
3985                 }
3986         default:
3987                 break;
3988         }
3989         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3990
3991         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3992
3993         /*
3994          * The journal may have updated the bg summary counts, so we
3995          * need to update the global counters.
3996          */
3997         percpu_counter_set(&sbi->s_freeclusters_counter,
3998                            ext4_count_free_clusters(sb));
3999         percpu_counter_set(&sbi->s_freeinodes_counter,
4000                            ext4_count_free_inodes(sb));
4001         percpu_counter_set(&sbi->s_dirs_counter,
4002                            ext4_count_dirs(sb));
4003         percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
4004
4005 no_journal:
4006         /*
4007          * Get the # of file system overhead blocks from the
4008          * superblock if present.
4009          */
4010         if (es->s_overhead_clusters)
4011                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4012         else {
4013                 err = ext4_calculate_overhead(sb);
4014                 if (err)
4015                         goto failed_mount_wq;
4016         }
4017
4018         /*
4019          * The maximum number of concurrent works can be high and
4020          * concurrency isn't really necessary.  Limit it to 1.
4021          */
4022         EXT4_SB(sb)->rsv_conversion_wq =
4023                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4024         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4025                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4026                 ret = -ENOMEM;
4027                 goto failed_mount4;
4028         }
4029
4030         /*
4031          * The jbd2_journal_load will have done any necessary log recovery,
4032          * so we can safely mount the rest of the filesystem now.
4033          */
4034
4035         root = ext4_iget(sb, EXT4_ROOT_INO);
4036         if (IS_ERR(root)) {
4037                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4038                 ret = PTR_ERR(root);
4039                 root = NULL;
4040                 goto failed_mount4;
4041         }
4042         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4043                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4044                 iput(root);
4045                 goto failed_mount4;
4046         }
4047         sb->s_root = d_make_root(root);
4048         if (!sb->s_root) {
4049                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4050                 ret = -ENOMEM;
4051                 goto failed_mount4;
4052         }
4053
4054         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4055                 sb->s_flags |= MS_RDONLY;
4056
4057         /* determine the minimum size of new large inodes, if present */
4058         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4059                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4060                                                      EXT4_GOOD_OLD_INODE_SIZE;
4061                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4062                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4063                         if (sbi->s_want_extra_isize <
4064                             le16_to_cpu(es->s_want_extra_isize))
4065                                 sbi->s_want_extra_isize =
4066                                         le16_to_cpu(es->s_want_extra_isize);
4067                         if (sbi->s_want_extra_isize <
4068                             le16_to_cpu(es->s_min_extra_isize))
4069                                 sbi->s_want_extra_isize =
4070                                         le16_to_cpu(es->s_min_extra_isize);
4071                 }
4072         }
4073         /* Check if enough inode space is available */
4074         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4075                                                         sbi->s_inode_size) {
4076                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4077                                                        EXT4_GOOD_OLD_INODE_SIZE;
4078                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4079                          "available");
4080         }
4081
4082         err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4083         if (err) {
4084                 ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4085                          "reserved pool", ext4_calculate_resv_clusters(sb));
4086                 goto failed_mount4a;
4087         }
4088
4089         err = ext4_setup_system_zone(sb);
4090         if (err) {
4091                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4092                          "zone (%d)", err);
4093                 goto failed_mount4a;
4094         }
4095
4096         ext4_ext_init(sb);
4097         err = ext4_mb_init(sb);
4098         if (err) {
4099                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4100                          err);
4101                 goto failed_mount5;
4102         }
4103
4104         err = ext4_register_li_request(sb, first_not_zeroed);
4105         if (err)
4106                 goto failed_mount6;
4107
4108         sbi->s_kobj.kset = ext4_kset;
4109         init_completion(&sbi->s_kobj_unregister);
4110         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4111                                    "%s", sb->s_id);
4112         if (err)
4113                 goto failed_mount7;
4114
4115 #ifdef CONFIG_QUOTA
4116         /* Enable quota usage during mount. */
4117         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4118             !(sb->s_flags & MS_RDONLY)) {
4119                 err = ext4_enable_quotas(sb);
4120                 if (err)
4121                         goto failed_mount8;
4122         }
4123 #endif  /* CONFIG_QUOTA */
4124
4125         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4126         ext4_orphan_cleanup(sb, es);
4127         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4128         if (needs_recovery) {
4129                 ext4_msg(sb, KERN_INFO, "recovery complete");
4130                 ext4_mark_recovery_complete(sb, es);
4131         }
4132         if (EXT4_SB(sb)->s_journal) {
4133                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4134                         descr = " journalled data mode";
4135                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4136                         descr = " ordered data mode";
4137                 else
4138                         descr = " writeback data mode";
4139         } else
4140                 descr = "out journal";
4141
4142         if (test_opt(sb, DISCARD)) {
4143                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4144                 if (!blk_queue_discard(q))
4145                         ext4_msg(sb, KERN_WARNING,
4146                                  "mounting with \"discard\" option, but "
4147                                  "the device does not support discard");
4148         }
4149
4150         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4151                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4152                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4153
4154         if (es->s_error_count)
4155                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4156
4157         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4158         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4159         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4160         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4161
4162         kfree(orig_data);
4163         return 0;
4164
4165 cantfind_ext4:
4166         if (!silent)
4167                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4168         goto failed_mount;
4169
4170 #ifdef CONFIG_QUOTA
4171 failed_mount8:
4172         kobject_del(&sbi->s_kobj);
4173 #endif
4174 failed_mount7:
4175         ext4_unregister_li_request(sb);
4176 failed_mount6:
4177         ext4_mb_release(sb);
4178 failed_mount5:
4179         ext4_ext_release(sb);
4180         ext4_release_system_zone(sb);
4181 failed_mount4a:
4182         dput(sb->s_root);
4183         sb->s_root = NULL;
4184 failed_mount4:
4185         ext4_msg(sb, KERN_ERR, "mount failed");
4186         if (EXT4_SB(sb)->rsv_conversion_wq)
4187                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4188 failed_mount_wq:
4189         if (sbi->s_journal) {
4190                 jbd2_journal_destroy(sbi->s_journal);
4191                 sbi->s_journal = NULL;
4192         }
4193 failed_mount3:
4194         ext4_es_unregister_shrinker(sbi);
4195         del_timer_sync(&sbi->s_err_report);
4196         if (sbi->s_flex_groups)
4197                 ext4_kvfree(sbi->s_flex_groups);
4198         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4199         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4200         percpu_counter_destroy(&sbi->s_dirs_counter);
4201         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4202         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
4203         if (sbi->s_mmp_tsk)
4204                 kthread_stop(sbi->s_mmp_tsk);
4205 failed_mount2:
4206         for (i = 0; i < db_count; i++)
4207                 brelse(sbi->s_group_desc[i]);
4208         ext4_kvfree(sbi->s_group_desc);
4209 failed_mount:
4210         if (sbi->s_chksum_driver)
4211                 crypto_free_shash(sbi->s_chksum_driver);
4212         if (sbi->s_proc) {
4213                 remove_proc_entry("options", sbi->s_proc);
4214                 remove_proc_entry(sb->s_id, ext4_proc_root);
4215         }
4216 #ifdef CONFIG_QUOTA
4217         for (i = 0; i < MAXQUOTAS; i++)
4218                 kfree(sbi->s_qf_names[i]);
4219 #endif
4220         ext4_blkdev_remove(sbi);
4221         brelse(bh);
4222 out_fail:
4223         sb->s_fs_info = NULL;
4224         kfree(sbi->s_blockgroup_lock);
4225         kfree(sbi);
4226 out_free_orig:
4227         kfree(orig_data);
4228         return err ? err : ret;
4229 }
4230
4231 /*
4232  * Setup any per-fs journal parameters now.  We'll do this both on
4233  * initial mount, once the journal has been initialised but before we've
4234  * done any recovery; and again on any subsequent remount.
4235  */
4236 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4237 {
4238         struct ext4_sb_info *sbi = EXT4_SB(sb);
4239
4240         journal->j_commit_interval = sbi->s_commit_interval;
4241         journal->j_min_batch_time = sbi->s_min_batch_time;
4242         journal->j_max_batch_time = sbi->s_max_batch_time;
4243
4244         write_lock(&journal->j_state_lock);
4245         if (test_opt(sb, BARRIER))
4246                 journal->j_flags |= JBD2_BARRIER;
4247         else
4248                 journal->j_flags &= ~JBD2_BARRIER;
4249         if (test_opt(sb, DATA_ERR_ABORT))
4250                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4251         else
4252                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4253         write_unlock(&journal->j_state_lock);
4254 }
4255
4256 static journal_t *ext4_get_journal(struct super_block *sb,
4257                                    unsigned int journal_inum)
4258 {
4259         struct inode *journal_inode;
4260         journal_t *journal;
4261
4262         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4263
4264         /* First, test for the existence of a valid inode on disk.  Bad
4265          * things happen if we iget() an unused inode, as the subsequent
4266          * iput() will try to delete it. */
4267
4268         journal_inode = ext4_iget(sb, journal_inum);
4269         if (IS_ERR(journal_inode)) {
4270                 ext4_msg(sb, KERN_ERR, "no journal found");
4271                 return NULL;
4272         }
4273         if (!journal_inode->i_nlink) {
4274                 make_bad_inode(journal_inode);
4275                 iput(journal_inode);
4276                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4277                 return NULL;
4278         }
4279
4280         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4281                   journal_inode, journal_inode->i_size);
4282         if (!S_ISREG(journal_inode->i_mode)) {
4283                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4284                 iput(journal_inode);
4285                 return NULL;
4286         }
4287
4288         journal = jbd2_journal_init_inode(journal_inode);
4289         if (!journal) {
4290                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4291                 iput(journal_inode);
4292                 return NULL;
4293         }
4294         journal->j_private = sb;
4295         ext4_init_journal_params(sb, journal);
4296         return journal;
4297 }
4298
4299 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4300                                        dev_t j_dev)
4301 {
4302         struct buffer_head *bh;
4303         journal_t *journal;
4304         ext4_fsblk_t start;
4305         ext4_fsblk_t len;
4306         int hblock, blocksize;
4307         ext4_fsblk_t sb_block;
4308         unsigned long offset;
4309         struct ext4_super_block *es;
4310         struct block_device *bdev;
4311
4312         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4313
4314         bdev = ext4_blkdev_get(j_dev, sb);
4315         if (bdev == NULL)
4316                 return NULL;
4317
4318         blocksize = sb->s_blocksize;
4319         hblock = bdev_logical_block_size(bdev);
4320         if (blocksize < hblock) {
4321                 ext4_msg(sb, KERN_ERR,
4322                         "blocksize too small for journal device");
4323                 goto out_bdev;
4324         }
4325
4326         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4327         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4328         set_blocksize(bdev, blocksize);
4329         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4330                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4331                        "external journal");
4332                 goto out_bdev;
4333         }
4334
4335         es = (struct ext4_super_block *) (bh->b_data + offset);
4336         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4337             !(le32_to_cpu(es->s_feature_incompat) &
4338               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4339                 ext4_msg(sb, KERN_ERR, "external journal has "
4340                                         "bad superblock");
4341                 brelse(bh);
4342                 goto out_bdev;
4343         }
4344
4345         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4346                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4347                 brelse(bh);
4348                 goto out_bdev;
4349         }
4350
4351         len = ext4_blocks_count(es);
4352         start = sb_block + 1;
4353         brelse(bh);     /* we're done with the superblock */
4354
4355         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4356                                         start, len, blocksize);
4357         if (!journal) {
4358                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4359                 goto out_bdev;
4360         }
4361         journal->j_private = sb;
4362         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4363         wait_on_buffer(journal->j_sb_buffer);
4364         if (!buffer_uptodate(journal->j_sb_buffer)) {
4365                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4366                 goto out_journal;
4367         }
4368         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4369                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4370                                         "user (unsupported) - %d",
4371                         be32_to_cpu(journal->j_superblock->s_nr_users));
4372                 goto out_journal;
4373         }
4374         EXT4_SB(sb)->journal_bdev = bdev;
4375         ext4_init_journal_params(sb, journal);
4376         return journal;
4377
4378 out_journal:
4379         jbd2_journal_destroy(journal);
4380 out_bdev:
4381         ext4_blkdev_put(bdev);
4382         return NULL;
4383 }
4384
4385 static int ext4_load_journal(struct super_block *sb,
4386                              struct ext4_super_block *es,
4387                              unsigned long journal_devnum)
4388 {
4389         journal_t *journal;
4390         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4391         dev_t journal_dev;
4392         int err = 0;
4393         int really_read_only;
4394
4395         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4396
4397         if (journal_devnum &&
4398             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4399                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4400                         "numbers have changed");
4401                 journal_dev = new_decode_dev(journal_devnum);
4402         } else
4403                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4404
4405         really_read_only = bdev_read_only(sb->s_bdev);
4406
4407         /*
4408          * Are we loading a blank journal or performing recovery after a
4409          * crash?  For recovery, we need to check in advance whether we
4410          * can get read-write access to the device.
4411          */
4412         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4413                 if (sb->s_flags & MS_RDONLY) {
4414                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4415                                         "required on readonly filesystem");
4416                         if (really_read_only) {
4417                                 ext4_msg(sb, KERN_ERR, "write access "
4418                                         "unavailable, cannot proceed");
4419                                 return -EROFS;
4420                         }
4421                         ext4_msg(sb, KERN_INFO, "write access will "
4422                                "be enabled during recovery");
4423                 }
4424         }
4425
4426         if (journal_inum && journal_dev) {
4427                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4428                        "and inode journals!");
4429                 return -EINVAL;
4430         }
4431
4432         if (journal_inum) {
4433                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4434                         return -EINVAL;
4435         } else {
4436                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4437                         return -EINVAL;
4438         }
4439
4440         if (!(journal->j_flags & JBD2_BARRIER))
4441                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4442
4443         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4444                 err = jbd2_journal_wipe(journal, !really_read_only);
4445         if (!err) {
4446                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4447                 if (save)
4448                         memcpy(save, ((char *) es) +
4449                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4450                 err = jbd2_journal_load(journal);
4451                 if (save)
4452                         memcpy(((char *) es) + EXT4_S_ERR_START,
4453                                save, EXT4_S_ERR_LEN);
4454                 kfree(save);
4455         }
4456
4457         if (err) {
4458                 ext4_msg(sb, KERN_ERR, "error loading journal");
4459                 jbd2_journal_destroy(journal);
4460                 return err;
4461         }
4462
4463         EXT4_SB(sb)->s_journal = journal;
4464         ext4_clear_journal_err(sb, es);
4465
4466         if (!really_read_only && journal_devnum &&
4467             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4468                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4469
4470                 /* Make sure we flush the recovery flag to disk. */
4471                 ext4_commit_super(sb, 1);
4472         }
4473
4474         return 0;
4475 }
4476
4477 static int ext4_commit_super(struct super_block *sb, int sync)
4478 {
4479         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4480         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4481         int error = 0;
4482
4483         if (!sbh || block_device_ejected(sb))
4484                 return error;
4485         if (buffer_write_io_error(sbh)) {
4486                 /*
4487                  * Oh, dear.  A previous attempt to write the
4488                  * superblock failed.  This could happen because the
4489                  * USB device was yanked out.  Or it could happen to
4490                  * be a transient write error and maybe the block will
4491                  * be remapped.  Nothing we can do but to retry the
4492                  * write and hope for the best.
4493                  */
4494                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4495                        "superblock detected");
4496                 clear_buffer_write_io_error(sbh);
4497                 set_buffer_uptodate(sbh);
4498         }
4499         /*
4500          * If the file system is mounted read-only, don't update the
4501          * superblock write time.  This avoids updating the superblock
4502          * write time when we are mounting the root file system
4503          * read/only but we need to replay the journal; at that point,
4504          * for people who are east of GMT and who make their clock
4505          * tick in localtime for Windows bug-for-bug compatibility,
4506          * the clock is set in the future, and this will cause e2fsck
4507          * to complain and force a full file system check.
4508          */
4509         if (!(sb->s_flags & MS_RDONLY))
4510                 es->s_wtime = cpu_to_le32(get_seconds());
4511         if (sb->s_bdev->bd_part)
4512                 es->s_kbytes_written =
4513                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4514                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4515                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4516         else
4517                 es->s_kbytes_written =
4518                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4519         ext4_free_blocks_count_set(es,
4520                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4521                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4522         es->s_free_inodes_count =
4523                 cpu_to_le32(percpu_counter_sum_positive(
4524                                 &EXT4_SB(sb)->s_freeinodes_counter));
4525         BUFFER_TRACE(sbh, "marking dirty");
4526         ext4_superblock_csum_set(sb);
4527         mark_buffer_dirty(sbh);
4528         if (sync) {
4529                 error = sync_dirty_buffer(sbh);
4530                 if (error)
4531                         return error;
4532
4533                 error = buffer_write_io_error(sbh);
4534                 if (error) {
4535                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4536                                "superblock");
4537                         clear_buffer_write_io_error(sbh);
4538                         set_buffer_uptodate(sbh);
4539                 }
4540         }
4541         return error;
4542 }
4543
4544 /*
4545  * Have we just finished recovery?  If so, and if we are mounting (or
4546  * remounting) the filesystem readonly, then we will end up with a
4547  * consistent fs on disk.  Record that fact.
4548  */
4549 static void ext4_mark_recovery_complete(struct super_block *sb,
4550                                         struct ext4_super_block *es)
4551 {
4552         journal_t *journal = EXT4_SB(sb)->s_journal;
4553
4554         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4555                 BUG_ON(journal != NULL);
4556                 return;
4557         }
4558         jbd2_journal_lock_updates(journal);
4559         if (jbd2_journal_flush(journal) < 0)
4560                 goto out;
4561
4562         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4563             sb->s_flags & MS_RDONLY) {
4564                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4565                 ext4_commit_super(sb, 1);
4566         }
4567
4568 out:
4569         jbd2_journal_unlock_updates(journal);
4570 }
4571
4572 /*
4573  * If we are mounting (or read-write remounting) a filesystem whose journal
4574  * has recorded an error from a previous lifetime, move that error to the
4575  * main filesystem now.
4576  */
4577 static void ext4_clear_journal_err(struct super_block *sb,
4578                                    struct ext4_super_block *es)
4579 {
4580         journal_t *journal;
4581         int j_errno;
4582         const char *errstr;
4583
4584         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4585
4586         journal = EXT4_SB(sb)->s_journal;
4587
4588         /*
4589          * Now check for any error status which may have been recorded in the
4590          * journal by a prior ext4_error() or ext4_abort()
4591          */
4592
4593         j_errno = jbd2_journal_errno(journal);
4594         if (j_errno) {
4595                 char nbuf[16];
4596
4597                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4598                 ext4_warning(sb, "Filesystem error recorded "
4599                              "from previous mount: %s", errstr);
4600                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4601
4602                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4603                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4604                 ext4_commit_super(sb, 1);
4605
4606                 jbd2_journal_clear_err(journal);
4607                 jbd2_journal_update_sb_errno(journal);
4608         }
4609 }
4610
4611 /*
4612  * Force the running and committing transactions to commit,
4613  * and wait on the commit.
4614  */
4615 int ext4_force_commit(struct super_block *sb)
4616 {
4617         journal_t *journal;
4618
4619         if (sb->s_flags & MS_RDONLY)
4620                 return 0;
4621
4622         journal = EXT4_SB(sb)->s_journal;
4623         return ext4_journal_force_commit(journal);
4624 }
4625
4626 static int ext4_sync_fs(struct super_block *sb, int wait)
4627 {
4628         int ret = 0;
4629         tid_t target;
4630         bool needs_barrier = false;
4631         struct ext4_sb_info *sbi = EXT4_SB(sb);
4632
4633         trace_ext4_sync_fs(sb, wait);
4634         flush_workqueue(sbi->rsv_conversion_wq);
4635         /*
4636          * Writeback quota in non-journalled quota case - journalled quota has
4637          * no dirty dquots
4638          */
4639         dquot_writeback_dquots(sb, -1);
4640         /*
4641          * Data writeback is possible w/o journal transaction, so barrier must
4642          * being sent at the end of the function. But we can skip it if
4643          * transaction_commit will do it for us.
4644          */
4645         target = jbd2_get_latest_transaction(sbi->s_journal);
4646         if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4647             !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4648                 needs_barrier = true;
4649
4650         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4651                 if (wait)
4652                         ret = jbd2_log_wait_commit(sbi->s_journal, target);
4653         }
4654         if (needs_barrier) {
4655                 int err;
4656                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4657                 if (!ret)
4658                         ret = err;
4659         }
4660
4661         return ret;
4662 }
4663
4664 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait)
4665 {
4666         int ret = 0;
4667
4668         trace_ext4_sync_fs(sb, wait);
4669         flush_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4670         dquot_writeback_dquots(sb, -1);
4671         if (wait && test_opt(sb, BARRIER))
4672                 ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4673
4674         return ret;
4675 }
4676
4677 /*
4678  * LVM calls this function before a (read-only) snapshot is created.  This
4679  * gives us a chance to flush the journal completely and mark the fs clean.
4680  *
4681  * Note that only this function cannot bring a filesystem to be in a clean
4682  * state independently. It relies on upper layer to stop all data & metadata
4683  * modifications.
4684  */
4685 static int ext4_freeze(struct super_block *sb)
4686 {
4687         int error = 0;
4688         journal_t *journal;
4689
4690         if (sb->s_flags & MS_RDONLY)
4691                 return 0;
4692
4693         journal = EXT4_SB(sb)->s_journal;
4694
4695         /* Now we set up the journal barrier. */
4696         jbd2_journal_lock_updates(journal);
4697
4698         /*
4699          * Don't clear the needs_recovery flag if we failed to flush
4700          * the journal.
4701          */
4702         error = jbd2_journal_flush(journal);
4703         if (error < 0)
4704                 goto out;
4705
4706         /* Journal blocked and flushed, clear needs_recovery flag. */
4707         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4708         error = ext4_commit_super(sb, 1);
4709 out:
4710         /* we rely on upper layer to stop further updates */
4711         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4712         return error;
4713 }
4714
4715 /*
4716  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4717  * flag here, even though the filesystem is not technically dirty yet.
4718  */
4719 static int ext4_unfreeze(struct super_block *sb)
4720 {
4721         if (sb->s_flags & MS_RDONLY)
4722                 return 0;
4723
4724         /* Reset the needs_recovery flag before the fs is unlocked. */
4725         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4726         ext4_commit_super(sb, 1);
4727         return 0;
4728 }
4729
4730 /*
4731  * Structure to save mount options for ext4_remount's benefit
4732  */
4733 struct ext4_mount_options {
4734         unsigned long s_mount_opt;
4735         unsigned long s_mount_opt2;
4736         kuid_t s_resuid;
4737         kgid_t s_resgid;
4738         unsigned long s_commit_interval;
4739         u32 s_min_batch_time, s_max_batch_time;
4740 #ifdef CONFIG_QUOTA
4741         int s_jquota_fmt;
4742         char *s_qf_names[MAXQUOTAS];
4743 #endif
4744 };
4745
4746 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4747 {
4748         struct ext4_super_block *es;
4749         struct ext4_sb_info *sbi = EXT4_SB(sb);
4750         unsigned long old_sb_flags;
4751         struct ext4_mount_options old_opts;
4752         int enable_quota = 0;
4753         ext4_group_t g;
4754         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4755         int err = 0;
4756 #ifdef CONFIG_QUOTA
4757         int i, j;
4758 #endif
4759         char *orig_data = kstrdup(data, GFP_KERNEL);
4760
4761         /* Store the original options */
4762         old_sb_flags = sb->s_flags;
4763         old_opts.s_mount_opt = sbi->s_mount_opt;
4764         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4765         old_opts.s_resuid = sbi->s_resuid;
4766         old_opts.s_resgid = sbi->s_resgid;
4767         old_opts.s_commit_interval = sbi->s_commit_interval;
4768         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4769         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4770 #ifdef CONFIG_QUOTA
4771         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4772         for (i = 0; i < MAXQUOTAS; i++)
4773                 if (sbi->s_qf_names[i]) {
4774                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4775                                                          GFP_KERNEL);
4776                         if (!old_opts.s_qf_names[i]) {
4777                                 for (j = 0; j < i; j++)
4778                                         kfree(old_opts.s_qf_names[j]);
4779                                 kfree(orig_data);
4780                                 return -ENOMEM;
4781                         }
4782                 } else
4783                         old_opts.s_qf_names[i] = NULL;
4784 #endif
4785         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4786                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4787
4788         /*
4789          * Allow the "check" option to be passed as a remount option.
4790          */
4791         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4792                 err = -EINVAL;
4793                 goto restore_opts;
4794         }
4795
4796         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4797                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4798                         ext4_msg(sb, KERN_ERR, "can't mount with "
4799                                  "both data=journal and delalloc");
4800                         err = -EINVAL;
4801                         goto restore_opts;
4802                 }
4803                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4804                         ext4_msg(sb, KERN_ERR, "can't mount with "
4805                                  "both data=journal and dioread_nolock");
4806                         err = -EINVAL;
4807                         goto restore_opts;
4808                 }
4809         }
4810
4811         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4812                 ext4_abort(sb, "Abort forced by user");
4813
4814         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4815                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4816
4817         es = sbi->s_es;
4818
4819         if (sbi->s_journal) {
4820                 ext4_init_journal_params(sb, sbi->s_journal);
4821                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4822         }
4823
4824         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4825                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4826                         err = -EROFS;
4827                         goto restore_opts;
4828                 }
4829
4830                 if (*flags & MS_RDONLY) {
4831                         err = dquot_suspend(sb, -1);
4832                         if (err < 0)
4833                                 goto restore_opts;
4834
4835                         /*
4836                          * First of all, the unconditional stuff we have to do
4837                          * to disable replay of the journal when we next remount
4838                          */
4839                         sb->s_flags |= MS_RDONLY;
4840
4841                         /*
4842                          * OK, test if we are remounting a valid rw partition
4843                          * readonly, and if so set the rdonly flag and then
4844                          * mark the partition as valid again.
4845                          */
4846                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4847                             (sbi->s_mount_state & EXT4_VALID_FS))
4848                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4849
4850                         if (sbi->s_journal)
4851                                 ext4_mark_recovery_complete(sb, es);
4852                 } else {
4853                         /* Make sure we can mount this feature set readwrite */
4854                         if (!ext4_feature_set_ok(sb, 0)) {
4855                                 err = -EROFS;
4856                                 goto restore_opts;
4857                         }
4858                         /*
4859                          * Make sure the group descriptor checksums
4860                          * are sane.  If they aren't, refuse to remount r/w.
4861                          */
4862                         for (g = 0; g < sbi->s_groups_count; g++) {
4863                                 struct ext4_group_desc *gdp =
4864                                         ext4_get_group_desc(sb, g, NULL);
4865
4866                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4867                                         ext4_msg(sb, KERN_ERR,
4868                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4869                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4870                                                le16_to_cpu(gdp->bg_checksum));
4871                                         err = -EINVAL;
4872                                         goto restore_opts;
4873                                 }
4874                         }
4875
4876                         /*
4877                          * If we have an unprocessed orphan list hanging
4878                          * around from a previously readonly bdev mount,
4879                          * require a full umount/remount for now.
4880                          */
4881                         if (es->s_last_orphan) {
4882                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4883                                        "remount RDWR because of unprocessed "
4884                                        "orphan inode list.  Please "
4885                                        "umount/remount instead");
4886                                 err = -EINVAL;
4887                                 goto restore_opts;
4888                         }
4889
4890                         /*
4891                          * Mounting a RDONLY partition read-write, so reread
4892                          * and store the current valid flag.  (It may have
4893                          * been changed by e2fsck since we originally mounted
4894                          * the partition.)
4895                          */
4896                         if (sbi->s_journal)
4897                                 ext4_clear_journal_err(sb, es);
4898                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4899                         if (!ext4_setup_super(sb, es, 0))
4900                                 sb->s_flags &= ~MS_RDONLY;
4901                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4902                                                      EXT4_FEATURE_INCOMPAT_MMP))
4903                                 if (ext4_multi_mount_protect(sb,
4904                                                 le64_to_cpu(es->s_mmp_block))) {
4905                                         err = -EROFS;
4906                                         goto restore_opts;
4907                                 }
4908                         enable_quota = 1;
4909                 }
4910         }
4911
4912         /*
4913          * Reinitialize lazy itable initialization thread based on
4914          * current settings
4915          */
4916         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4917                 ext4_unregister_li_request(sb);
4918         else {
4919                 ext4_group_t first_not_zeroed;
4920                 first_not_zeroed = ext4_has_uninit_itable(sb);
4921                 ext4_register_li_request(sb, first_not_zeroed);
4922         }
4923
4924         ext4_setup_system_zone(sb);
4925         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4926                 ext4_commit_super(sb, 1);
4927
4928 #ifdef CONFIG_QUOTA
4929         /* Release old quota file names */
4930         for (i = 0; i < MAXQUOTAS; i++)
4931                 kfree(old_opts.s_qf_names[i]);
4932         if (enable_quota) {
4933                 if (sb_any_quota_suspended(sb))
4934                         dquot_resume(sb, -1);
4935                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4936                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4937                         err = ext4_enable_quotas(sb);
4938                         if (err)
4939                                 goto restore_opts;
4940                 }
4941         }
4942 #endif
4943
4944         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4945         kfree(orig_data);
4946         return 0;
4947
4948 restore_opts:
4949         sb->s_flags = old_sb_flags;
4950         sbi->s_mount_opt = old_opts.s_mount_opt;
4951         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4952         sbi->s_resuid = old_opts.s_resuid;
4953         sbi->s_resgid = old_opts.s_resgid;
4954         sbi->s_commit_interval = old_opts.s_commit_interval;
4955         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4956         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4957 #ifdef CONFIG_QUOTA
4958         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4959         for (i = 0; i < MAXQUOTAS; i++) {
4960                 kfree(sbi->s_qf_names[i]);
4961                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4962         }
4963 #endif
4964         kfree(orig_data);
4965         return err;
4966 }
4967
4968 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4969 {
4970         struct super_block *sb = dentry->d_sb;
4971         struct ext4_sb_info *sbi = EXT4_SB(sb);
4972         struct ext4_super_block *es = sbi->s_es;
4973         ext4_fsblk_t overhead = 0, resv_blocks;
4974         u64 fsid;
4975         s64 bfree;
4976         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4977
4978         if (!test_opt(sb, MINIX_DF))
4979                 overhead = sbi->s_overhead;
4980
4981         buf->f_type = EXT4_SUPER_MAGIC;
4982         buf->f_bsize = sb->s_blocksize;
4983         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4984         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4985                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4986         /* prevent underflow in case that few free space is available */
4987         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4988         buf->f_bavail = buf->f_bfree -
4989                         (ext4_r_blocks_count(es) + resv_blocks);
4990         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4991                 buf->f_bavail = 0;
4992         buf->f_files = le32_to_cpu(es->s_inodes_count);
4993         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4994         buf->f_namelen = EXT4_NAME_LEN;
4995         fsid = le64_to_cpup((void *)es->s_uuid) ^
4996                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4997         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4998         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4999
5000         return 0;
5001 }
5002
5003 /* Helper function for writing quotas on sync - we need to start transaction
5004  * before quota file is locked for write. Otherwise the are possible deadlocks:
5005  * Process 1                         Process 2
5006  * ext4_create()                     quota_sync()
5007  *   jbd2_journal_start()                  write_dquot()
5008  *   dquot_initialize()                         down(dqio_mutex)
5009  *     down(dqio_mutex)                    jbd2_journal_start()
5010  *
5011  */
5012
5013 #ifdef CONFIG_QUOTA
5014
5015 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5016 {
5017         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5018 }
5019
5020 static int ext4_write_dquot(struct dquot *dquot)
5021 {
5022         int ret, err;
5023         handle_t *handle;
5024         struct inode *inode;
5025
5026         inode = dquot_to_inode(dquot);
5027         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5028                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5029         if (IS_ERR(handle))
5030                 return PTR_ERR(handle);
5031         ret = dquot_commit(dquot);
5032         err = ext4_journal_stop(handle);
5033         if (!ret)
5034                 ret = err;
5035         return ret;
5036 }
5037
5038 static int ext4_acquire_dquot(struct dquot *dquot)
5039 {
5040         int ret, err;
5041         handle_t *handle;
5042
5043         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5044                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5045         if (IS_ERR(handle))
5046                 return PTR_ERR(handle);
5047         ret = dquot_acquire(dquot);
5048         err = ext4_journal_stop(handle);
5049         if (!ret)
5050                 ret = err;
5051         return ret;
5052 }
5053
5054 static int ext4_release_dquot(struct dquot *dquot)
5055 {
5056         int ret, err;
5057         handle_t *handle;
5058
5059         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5060                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5061         if (IS_ERR(handle)) {
5062                 /* Release dquot anyway to avoid endless cycle in dqput() */
5063                 dquot_release(dquot);
5064                 return PTR_ERR(handle);
5065         }
5066         ret = dquot_release(dquot);
5067         err = ext4_journal_stop(handle);
5068         if (!ret)
5069                 ret = err;
5070         return ret;
5071 }
5072
5073 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5074 {
5075         struct super_block *sb = dquot->dq_sb;
5076         struct ext4_sb_info *sbi = EXT4_SB(sb);
5077
5078         /* Are we journaling quotas? */
5079         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5080             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5081                 dquot_mark_dquot_dirty(dquot);
5082                 return ext4_write_dquot(dquot);
5083         } else {
5084                 return dquot_mark_dquot_dirty(dquot);
5085         }
5086 }
5087
5088 static int ext4_write_info(struct super_block *sb, int type)
5089 {
5090         int ret, err;
5091         handle_t *handle;
5092
5093         /* Data block + inode block */
5094         handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5095         if (IS_ERR(handle))
5096                 return PTR_ERR(handle);
5097         ret = dquot_commit_info(sb, type);
5098         err = ext4_journal_stop(handle);
5099         if (!ret)
5100                 ret = err;
5101         return ret;
5102 }
5103
5104 /*
5105  * Turn on quotas during mount time - we need to find
5106  * the quota file and such...
5107  */
5108 static int ext4_quota_on_mount(struct super_block *sb, int type)
5109 {
5110         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5111                                         EXT4_SB(sb)->s_jquota_fmt, type);
5112 }
5113
5114 /*
5115  * Standard function to be called on quota_on
5116  */
5117 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5118                          struct path *path)
5119 {
5120         int err;
5121
5122         if (!test_opt(sb, QUOTA))
5123                 return -EINVAL;
5124
5125         /* Quotafile not on the same filesystem? */
5126         if (path->dentry->d_sb != sb)
5127                 return -EXDEV;
5128         /* Journaling quota? */
5129         if (EXT4_SB(sb)->s_qf_names[type]) {
5130                 /* Quotafile not in fs root? */
5131                 if (path->dentry->d_parent != sb->s_root)
5132                         ext4_msg(sb, KERN_WARNING,
5133                                 "Quota file not on filesystem root. "
5134                                 "Journaled quota will not work");
5135         }
5136
5137         /*
5138          * When we journal data on quota file, we have to flush journal to see
5139          * all updates to the file when we bypass pagecache...
5140          */
5141         if (EXT4_SB(sb)->s_journal &&
5142             ext4_should_journal_data(path->dentry->d_inode)) {
5143                 /*
5144                  * We don't need to lock updates but journal_flush() could
5145                  * otherwise be livelocked...
5146                  */
5147                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5148                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5149                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5150                 if (err)
5151                         return err;
5152         }
5153
5154         return dquot_quota_on(sb, type, format_id, path);
5155 }
5156
5157 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5158                              unsigned int flags)
5159 {
5160         int err;
5161         struct inode *qf_inode;
5162         unsigned long qf_inums[MAXQUOTAS] = {
5163                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5164                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5165         };
5166
5167         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5168
5169         if (!qf_inums[type])
5170                 return -EPERM;
5171
5172         qf_inode = ext4_iget(sb, qf_inums[type]);
5173         if (IS_ERR(qf_inode)) {
5174                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5175                 return PTR_ERR(qf_inode);
5176         }
5177
5178         /* Don't account quota for quota files to avoid recursion */
5179         qf_inode->i_flags |= S_NOQUOTA;
5180         err = dquot_enable(qf_inode, type, format_id, flags);
5181         iput(qf_inode);
5182
5183         return err;
5184 }
5185
5186 /* Enable usage tracking for all quota types. */
5187 static int ext4_enable_quotas(struct super_block *sb)
5188 {
5189         int type, err = 0;
5190         unsigned long qf_inums[MAXQUOTAS] = {
5191                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5192                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5193         };
5194
5195         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5196         for (type = 0; type < MAXQUOTAS; type++) {
5197                 if (qf_inums[type]) {
5198                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5199                                                 DQUOT_USAGE_ENABLED);
5200                         if (err) {
5201                                 ext4_warning(sb,
5202                                         "Failed to enable quota tracking "
5203                                         "(type=%d, err=%d). Please run "
5204                                         "e2fsck to fix.", type, err);
5205                                 return err;
5206                         }
5207                 }
5208         }
5209         return 0;
5210 }
5211
5212 /*
5213  * quota_on function that is used when QUOTA feature is set.
5214  */
5215 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5216                                  int format_id)
5217 {
5218         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5219                 return -EINVAL;
5220
5221         /*
5222          * USAGE was enabled at mount time. Only need to enable LIMITS now.
5223          */
5224         return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5225 }
5226
5227 static int ext4_quota_off(struct super_block *sb, int type)
5228 {
5229         struct inode *inode = sb_dqopt(sb)->files[type];
5230         handle_t *handle;
5231
5232         /* Force all delayed allocation blocks to be allocated.
5233          * Caller already holds s_umount sem */
5234         if (test_opt(sb, DELALLOC))
5235                 sync_filesystem(sb);
5236
5237         if (!inode)
5238                 goto out;
5239
5240         /* Update modification times of quota files when userspace can
5241          * start looking at them */
5242         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5243         if (IS_ERR(handle))
5244                 goto out;
5245         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5246         ext4_mark_inode_dirty(handle, inode);
5247         ext4_journal_stop(handle);
5248
5249 out:
5250         return dquot_quota_off(sb, type);
5251 }
5252
5253 /*
5254  * quota_off function that is used when QUOTA feature is set.
5255  */
5256 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5257 {
5258         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5259                 return -EINVAL;
5260
5261         /* Disable only the limits. */
5262         return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5263 }
5264
5265 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5266  * acquiring the locks... As quota files are never truncated and quota code
5267  * itself serializes the operations (and no one else should touch the files)
5268  * we don't have to be afraid of races */
5269 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5270                                size_t len, loff_t off)
5271 {
5272         struct inode *inode = sb_dqopt(sb)->files[type];
5273         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5274         int err = 0;
5275         int offset = off & (sb->s_blocksize - 1);
5276         int tocopy;
5277         size_t toread;
5278         struct buffer_head *bh;
5279         loff_t i_size = i_size_read(inode);
5280
5281         if (off > i_size)
5282                 return 0;
5283         if (off+len > i_size)
5284                 len = i_size-off;
5285         toread = len;
5286         while (toread > 0) {
5287                 tocopy = sb->s_blocksize - offset < toread ?
5288                                 sb->s_blocksize - offset : toread;
5289                 bh = ext4_bread(NULL, inode, blk, 0, &err);
5290                 if (err)
5291                         return err;
5292                 if (!bh)        /* A hole? */
5293                         memset(data, 0, tocopy);
5294                 else
5295                         memcpy(data, bh->b_data+offset, tocopy);
5296                 brelse(bh);
5297                 offset = 0;
5298                 toread -= tocopy;
5299                 data += tocopy;
5300                 blk++;
5301         }
5302         return len;
5303 }
5304
5305 /* Write to quotafile (we know the transaction is already started and has
5306  * enough credits) */
5307 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5308                                 const char *data, size_t len, loff_t off)
5309 {
5310         struct inode *inode = sb_dqopt(sb)->files[type];
5311         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5312         int err = 0;
5313         int offset = off & (sb->s_blocksize - 1);
5314         struct buffer_head *bh;
5315         handle_t *handle = journal_current_handle();
5316
5317         if (EXT4_SB(sb)->s_journal && !handle) {
5318                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5319                         " cancelled because transaction is not started",
5320                         (unsigned long long)off, (unsigned long long)len);
5321                 return -EIO;
5322         }
5323         /*
5324          * Since we account only one data block in transaction credits,
5325          * then it is impossible to cross a block boundary.
5326          */
5327         if (sb->s_blocksize - offset < len) {
5328                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5329                         " cancelled because not block aligned",
5330                         (unsigned long long)off, (unsigned long long)len);
5331                 return -EIO;
5332         }
5333
5334         bh = ext4_bread(handle, inode, blk, 1, &err);
5335         if (!bh)
5336                 goto out;
5337         err = ext4_journal_get_write_access(handle, bh);
5338         if (err) {
5339                 brelse(bh);
5340                 goto out;
5341         }
5342         lock_buffer(bh);
5343         memcpy(bh->b_data+offset, data, len);
5344         flush_dcache_page(bh->b_page);
5345         unlock_buffer(bh);
5346         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5347         brelse(bh);
5348 out:
5349         if (err)
5350                 return err;
5351         if (inode->i_size < off + len) {
5352                 i_size_write(inode, off + len);
5353                 EXT4_I(inode)->i_disksize = inode->i_size;
5354                 ext4_mark_inode_dirty(handle, inode);
5355         }
5356         return len;
5357 }
5358
5359 #endif
5360
5361 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5362                        const char *dev_name, void *data)
5363 {
5364         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5365 }
5366
5367 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5368 static inline void register_as_ext2(void)
5369 {
5370         int err = register_filesystem(&ext2_fs_type);
5371         if (err)
5372                 printk(KERN_WARNING
5373                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5374 }
5375
5376 static inline void unregister_as_ext2(void)
5377 {
5378         unregister_filesystem(&ext2_fs_type);
5379 }
5380
5381 static inline int ext2_feature_set_ok(struct super_block *sb)
5382 {
5383         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5384                 return 0;
5385         if (sb->s_flags & MS_RDONLY)
5386                 return 1;
5387         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5388                 return 0;
5389         return 1;
5390 }
5391 #else
5392 static inline void register_as_ext2(void) { }
5393 static inline void unregister_as_ext2(void) { }
5394 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5395 #endif
5396
5397 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5398 static inline void register_as_ext3(void)
5399 {
5400         int err = register_filesystem(&ext3_fs_type);
5401         if (err)
5402                 printk(KERN_WARNING
5403                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5404 }
5405
5406 static inline void unregister_as_ext3(void)
5407 {
5408         unregister_filesystem(&ext3_fs_type);
5409 }
5410
5411 static inline int ext3_feature_set_ok(struct super_block *sb)
5412 {
5413         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5414                 return 0;
5415         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5416                 return 0;
5417         if (sb->s_flags & MS_RDONLY)
5418                 return 1;
5419         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5420                 return 0;
5421         return 1;
5422 }
5423 #else
5424 static inline void register_as_ext3(void) { }
5425 static inline void unregister_as_ext3(void) { }
5426 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5427 #endif
5428
5429 static struct file_system_type ext4_fs_type = {
5430         .owner          = THIS_MODULE,
5431         .name           = "ext4",
5432         .mount          = ext4_mount,
5433         .kill_sb        = kill_block_super,
5434         .fs_flags       = FS_REQUIRES_DEV,
5435 };
5436 MODULE_ALIAS_FS("ext4");
5437
5438 static int __init ext4_init_feat_adverts(void)
5439 {
5440         struct ext4_features *ef;
5441         int ret = -ENOMEM;
5442
5443         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5444         if (!ef)
5445                 goto out;
5446
5447         ef->f_kobj.kset = ext4_kset;
5448         init_completion(&ef->f_kobj_unregister);
5449         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5450                                    "features");
5451         if (ret) {
5452                 kfree(ef);
5453                 goto out;
5454         }
5455
5456         ext4_feat = ef;
5457         ret = 0;
5458 out:
5459         return ret;
5460 }
5461
5462 static void ext4_exit_feat_adverts(void)
5463 {
5464         kobject_put(&ext4_feat->f_kobj);
5465         wait_for_completion(&ext4_feat->f_kobj_unregister);
5466         kfree(ext4_feat);
5467 }
5468
5469 /* Shared across all ext4 file systems */
5470 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5471 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5472
5473 static int __init ext4_init_fs(void)
5474 {
5475         int i, err;
5476
5477         ext4_li_info = NULL;
5478         mutex_init(&ext4_li_mtx);
5479
5480         /* Build-time check for flags consistency */
5481         ext4_check_flag_values();
5482
5483         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5484                 mutex_init(&ext4__aio_mutex[i]);
5485                 init_waitqueue_head(&ext4__ioend_wq[i]);
5486         }
5487
5488         err = ext4_init_es();
5489         if (err)
5490                 return err;
5491
5492         err = ext4_init_pageio();
5493         if (err)
5494                 goto out7;
5495
5496         err = ext4_init_system_zone();
5497         if (err)
5498                 goto out6;
5499         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5500         if (!ext4_kset) {
5501                 err = -ENOMEM;
5502                 goto out5;
5503         }
5504         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5505
5506         err = ext4_init_feat_adverts();
5507         if (err)
5508                 goto out4;
5509
5510         err = ext4_init_mballoc();
5511         if (err)
5512                 goto out3;
5513
5514         err = ext4_init_xattr();
5515         if (err)
5516                 goto out2;
5517         err = init_inodecache();
5518         if (err)
5519                 goto out1;
5520         register_as_ext3();
5521         register_as_ext2();
5522         err = register_filesystem(&ext4_fs_type);
5523         if (err)
5524                 goto out;
5525
5526         return 0;
5527 out:
5528         unregister_as_ext2();
5529         unregister_as_ext3();
5530         destroy_inodecache();
5531 out1:
5532         ext4_exit_xattr();
5533 out2:
5534         ext4_exit_mballoc();
5535 out3:
5536         ext4_exit_feat_adverts();
5537 out4:
5538         if (ext4_proc_root)
5539                 remove_proc_entry("fs/ext4", NULL);
5540         kset_unregister(ext4_kset);
5541 out5:
5542         ext4_exit_system_zone();
5543 out6:
5544         ext4_exit_pageio();
5545 out7:
5546         ext4_exit_es();
5547
5548         return err;
5549 }
5550
5551 static void __exit ext4_exit_fs(void)
5552 {
5553         ext4_destroy_lazyinit_thread();
5554         unregister_as_ext2();
5555         unregister_as_ext3();
5556         unregister_filesystem(&ext4_fs_type);
5557         destroy_inodecache();
5558         ext4_exit_xattr();
5559         ext4_exit_mballoc();
5560         ext4_exit_feat_adverts();
5561         remove_proc_entry("fs/ext4", NULL);
5562         kset_unregister(ext4_kset);
5563         ext4_exit_system_zone();
5564         ext4_exit_pageio();
5565         ext4_exit_es();
5566 }
5567
5568 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5569 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5570 MODULE_LICENSE("GPL");
5571 module_init(ext4_init_fs)
5572 module_exit(ext4_exit_fs)