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 static int ext4_mballoc_ready;
  63
  64 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  65                              unsigned long journal_devnum);
  66 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  67 static int ext4_commit_super(struct super_block *sb, int sync);
  68 static void ext4_mark_recovery_complete(struct super_block *sb,
  69                                         struct ext4_super_block *es);
  70 static void ext4_clear_journal_err(struct super_block *sb,
  71                                    struct ext4_super_block *es);
  72 static int ext4_sync_fs(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 static 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         brelse(sbi->s_sbh);
 823 #ifdef CONFIG_QUOTA
 824         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 825                 kfree(sbi->s_qf_names[i]);
 826 #endif
 827
 828         /* Debugging code just in case the in-memory inode orphan list
 829          * isn't empty.  The on-disk one can be non-empty if we've
 830          * detected an error and taken the fs readonly, but the
 831          * in-memory list had better be clean by this point. */
 832         if (!list_empty(&sbi->s_orphan))
 833                 dump_orphan_list(sb, sbi);
 834         J_ASSERT(list_empty(&sbi->s_orphan));
 835
 836         invalidate_bdev(sb->s_bdev);
 837         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 838                 /*
 839                  * Invalidate the journal device's buffers.  We don't want them
 840                  * floating about in memory - the physical journal device may
 841                  * hotswapped, and it breaks the `ro-after' testing code.
 842                  */
 843                 sync_blockdev(sbi->journal_bdev);
 844                 invalidate_bdev(sbi->journal_bdev);
 845                 ext4_blkdev_remove(sbi);
 846         }
 847         if (sbi->s_mb_cache) {
 848                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 849                 sbi->s_mb_cache = NULL;
 850         }
 851         if (sbi->s_mmp_tsk)
 852                 kthread_stop(sbi->s_mmp_tsk);
 853         sb->s_fs_info = NULL;
 854         /*
 855          * Now that we are completely done shutting down the
 856          * superblock, we need to actually destroy the kobject.
 857          */
 858         kobject_put(&sbi->s_kobj);
 859         wait_for_completion(&sbi->s_kobj_unregister);
 860         if (sbi->s_chksum_driver)
 861                 crypto_free_shash(sbi->s_chksum_driver);
 862         kfree(sbi->s_blockgroup_lock);
 863         kfree(sbi);
 864 }
 865
 866 static struct kmem_cache *ext4_inode_cachep;
 867
 868 /*
 869  * Called inside transaction, so use GFP_NOFS
 870  */
 871 static struct inode *ext4_alloc_inode(struct super_block *sb)
 872 {
 873         struct ext4_inode_info *ei;
 874
 875         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 876         if (!ei)
 877                 return NULL;
 878
 879         ei->vfs_inode.i_version = 1;
 880         spin_lock_init(&ei->i_raw_lock);
 881         INIT_LIST_HEAD(&ei->i_prealloc_list);
 882         spin_lock_init(&ei->i_prealloc_lock);
 883         ext4_es_init_tree(&ei->i_es_tree);
 884         rwlock_init(&ei->i_es_lock);
 885         INIT_LIST_HEAD(&ei->i_es_lru);
 886         ei->i_es_all_nr = 0;
 887         ei->i_es_lru_nr = 0;
 888         ei->i_touch_when = 0;
 889         ei->i_reserved_data_blocks = 0;
 890         ei->i_reserved_meta_blocks = 0;
 891         ei->i_allocated_meta_blocks = 0;
 892         ei->i_da_metadata_calc_len = 0;
 893         ei->i_da_metadata_calc_last_lblock = 0;
 894         spin_lock_init(&(ei->i_block_reservation_lock));
 895 #ifdef CONFIG_QUOTA
 896         ei->i_reserved_quota = 0;
 897 #endif
 898         ei->jinode = NULL;
 899         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 900         spin_lock_init(&ei->i_completed_io_lock);
 901         ei->i_sync_tid = 0;
 902         ei->i_datasync_tid = 0;
 903         atomic_set(&ei->i_ioend_count, 0);
 904         atomic_set(&ei->i_unwritten, 0);
 905         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 906
 907         return &ei->vfs_inode;
 908 }
 909
 910 static int ext4_drop_inode(struct inode *inode)
 911 {
 912         int drop = generic_drop_inode(inode);
 913
 914         trace_ext4_drop_inode(inode, drop);
 915         return drop;
 916 }
 917
 918 static void ext4_i_callback(struct rcu_head *head)
 919 {
 920         struct inode *inode = container_of(head, struct inode, i_rcu);
 921         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 922 }
 923
 924 static void ext4_destroy_inode(struct inode *inode)
 925 {
 926         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 927                 ext4_msg(inode->i_sb, KERN_ERR,
 928                          "Inode %lu (%p): orphan list check failed!",
 929                          inode->i_ino, EXT4_I(inode));
 930                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 931                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 932                                 true);
 933                 dump_stack();
 934         }
 935         call_rcu(&inode->i_rcu, ext4_i_callback);
 936 }
 937
 938 static void init_once(void *foo)
 939 {
 940         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 941
 942         INIT_LIST_HEAD(&ei->i_orphan);
 943         init_rwsem(&ei->xattr_sem);
 944         init_rwsem(&ei->i_data_sem);
 945         inode_init_once(&ei->vfs_inode);
 946 }
 947
 948 static int __init init_inodecache(void)
 949 {
 950         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 951                                              sizeof(struct ext4_inode_info),
 952                                              0, (SLAB_RECLAIM_ACCOUNT|
 953                                                 SLAB_MEM_SPREAD),
 954                                              init_once);
 955         if (ext4_inode_cachep == NULL)
 956                 return -ENOMEM;
 957         return 0;
 958 }
 959
 960 static void destroy_inodecache(void)
 961 {
 962         /*
 963          * Make sure all delayed rcu free inodes are flushed before we
 964          * destroy cache.
 965          */
 966         rcu_barrier();
 967         kmem_cache_destroy(ext4_inode_cachep);
 968 }
 969
 970 void ext4_clear_inode(struct inode *inode)
 971 {
 972         invalidate_inode_buffers(inode);
 973         clear_inode(inode);
 974         dquot_drop(inode);
 975         ext4_discard_preallocations(inode);
 976         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 977         ext4_es_lru_del(inode);
 978         if (EXT4_I(inode)->jinode) {
 979                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 980                                                EXT4_I(inode)->jinode);
 981                 jbd2_free_inode(EXT4_I(inode)->jinode);
 982                 EXT4_I(inode)->jinode = NULL;
 983         }
 984 }
 985
 986 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 987                                         u64 ino, u32 generation)
 988 {
 989         struct inode *inode;
 990
 991         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 992                 return ERR_PTR(-ESTALE);
 993         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 994                 return ERR_PTR(-ESTALE);
 995
 996         /* iget isn't really right if the inode is currently unallocated!!
 997          *
 998          * ext4_read_inode will return a bad_inode if the inode had been
 999          * deleted, so we should be safe.
1000          *
1001          * Currently we don't know the generation for parent directory, so
1002          * a generation of 0 means "accept any"
1003          */
1004         inode = ext4_iget(sb, ino);
1005         if (IS_ERR(inode))
1006                 return ERR_CAST(inode);
1007         if (generation && inode->i_generation != generation) {
1008                 iput(inode);
1009                 return ERR_PTR(-ESTALE);
1010         }
1011
1012         return inode;
1013 }
1014
1015 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1016                                         int fh_len, int fh_type)
1017 {
1018         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1019                                     ext4_nfs_get_inode);
1020 }
1021
1022 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1023                                         int fh_len, int fh_type)
1024 {
1025         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1026                                     ext4_nfs_get_inode);
1027 }
1028
1029 /*
1030  * Try to release metadata pages (indirect blocks, directories) which are
1031  * mapped via the block device.  Since these pages could have journal heads
1032  * which would prevent try_to_free_buffers() from freeing them, we must use
1033  * jbd2 layer's try_to_free_buffers() function to release them.
1034  */
1035 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1036                                  gfp_t wait)
1037 {
1038         journal_t *journal = EXT4_SB(sb)->s_journal;
1039
1040         WARN_ON(PageChecked(page));
1041         if (!page_has_buffers(page))
1042                 return 0;
1043         if (journal)
1044                 return jbd2_journal_try_to_free_buffers(journal, page,
1045                                                         wait & ~__GFP_WAIT);
1046         return try_to_free_buffers(page);
1047 }
1048
1049 #ifdef CONFIG_QUOTA
1050 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1051 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1052
1053 static int ext4_write_dquot(struct dquot *dquot);
1054 static int ext4_acquire_dquot(struct dquot *dquot);
1055 static int ext4_release_dquot(struct dquot *dquot);
1056 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1057 static int ext4_write_info(struct super_block *sb, int type);
1058 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1059                          struct path *path);
1060 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1061                                  int format_id);
1062 static int ext4_quota_off(struct super_block *sb, int type);
1063 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1064 static int ext4_quota_on_mount(struct super_block *sb, int type);
1065 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1066                                size_t len, loff_t off);
1067 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1068                                 const char *data, size_t len, loff_t off);
1069 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1070                              unsigned int flags);
1071 static int ext4_enable_quotas(struct super_block *sb);
1072
1073 static const struct dquot_operations ext4_quota_operations = {
1074         .get_reserved_space = ext4_get_reserved_space,
1075         .write_dquot    = ext4_write_dquot,
1076         .acquire_dquot  = ext4_acquire_dquot,
1077         .release_dquot  = ext4_release_dquot,
1078         .mark_dirty     = ext4_mark_dquot_dirty,
1079         .write_info     = ext4_write_info,
1080         .alloc_dquot    = dquot_alloc,
1081         .destroy_dquot  = dquot_destroy,
1082 };
1083
1084 static const struct quotactl_ops ext4_qctl_operations = {
1085         .quota_on       = ext4_quota_on,
1086         .quota_off      = ext4_quota_off,
1087         .quota_sync     = dquot_quota_sync,
1088         .get_info       = dquot_get_dqinfo,
1089         .set_info       = dquot_set_dqinfo,
1090         .get_dqblk      = dquot_get_dqblk,
1091         .set_dqblk      = dquot_set_dqblk
1092 };
1093
1094 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1095         .quota_on_meta  = ext4_quota_on_sysfile,
1096         .quota_off      = ext4_quota_off_sysfile,
1097         .quota_sync     = dquot_quota_sync,
1098         .get_info       = dquot_get_dqinfo,
1099         .set_info       = dquot_set_dqinfo,
1100         .get_dqblk      = dquot_get_dqblk,
1101         .set_dqblk      = dquot_set_dqblk
1102 };
1103 #endif
1104
1105 static const struct super_operations ext4_sops = {
1106         .alloc_inode    = ext4_alloc_inode,
1107         .destroy_inode  = ext4_destroy_inode,
1108         .write_inode    = ext4_write_inode,
1109         .dirty_inode    = ext4_dirty_inode,
1110         .drop_inode     = ext4_drop_inode,
1111         .evict_inode    = ext4_evict_inode,
1112         .put_super      = ext4_put_super,
1113         .sync_fs        = ext4_sync_fs,
1114         .freeze_fs      = ext4_freeze,
1115         .unfreeze_fs    = ext4_unfreeze,
1116         .statfs         = ext4_statfs,
1117         .remount_fs     = ext4_remount,
1118         .show_options   = ext4_show_options,
1119 #ifdef CONFIG_QUOTA
1120         .quota_read     = ext4_quota_read,
1121         .quota_write    = ext4_quota_write,
1122 #endif
1123         .bdev_try_to_free_page = bdev_try_to_free_page,
1124 };
1125
1126 static const struct super_operations ext4_nojournal_sops = {
1127         .alloc_inode    = ext4_alloc_inode,
1128         .destroy_inode  = ext4_destroy_inode,
1129         .write_inode    = ext4_write_inode,
1130         .dirty_inode    = ext4_dirty_inode,
1131         .drop_inode     = ext4_drop_inode,
1132         .evict_inode    = ext4_evict_inode,
1133         .sync_fs        = ext4_sync_fs,
1134         .put_super      = ext4_put_super,
1135         .statfs         = ext4_statfs,
1136         .remount_fs     = ext4_remount,
1137         .show_options   = ext4_show_options,
1138 #ifdef CONFIG_QUOTA
1139         .quota_read     = ext4_quota_read,
1140         .quota_write    = ext4_quota_write,
1141 #endif
1142         .bdev_try_to_free_page = bdev_try_to_free_page,
1143 };
1144
1145 static const struct export_operations ext4_export_ops = {
1146         .fh_to_dentry = ext4_fh_to_dentry,
1147         .fh_to_parent = ext4_fh_to_parent,
1148         .get_parent = ext4_get_parent,
1149 };
1150
1151 enum {
1152         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1153         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1154         Opt_nouid32, Opt_debug, Opt_removed,
1155         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1156         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1157         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1158         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1159         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1160         Opt_data_err_abort, Opt_data_err_ignore,
1161         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1162         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1163         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1164         Opt_usrquota, Opt_grpquota, Opt_i_version,
1165         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1166         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1167         Opt_inode_readahead_blks, Opt_journal_ioprio,
1168         Opt_dioread_nolock, Opt_dioread_lock,
1169         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1170         Opt_max_dir_size_kb,
1171 };
1172
1173 static const match_table_t tokens = {
1174         {Opt_bsd_df, "bsddf"},
1175         {Opt_minix_df, "minixdf"},
1176         {Opt_grpid, "grpid"},
1177         {Opt_grpid, "bsdgroups"},
1178         {Opt_nogrpid, "nogrpid"},
1179         {Opt_nogrpid, "sysvgroups"},
1180         {Opt_resgid, "resgid=%u"},
1181         {Opt_resuid, "resuid=%u"},
1182         {Opt_sb, "sb=%u"},
1183         {Opt_err_cont, "errors=continue"},
1184         {Opt_err_panic, "errors=panic"},
1185         {Opt_err_ro, "errors=remount-ro"},
1186         {Opt_nouid32, "nouid32"},
1187         {Opt_debug, "debug"},
1188         {Opt_removed, "oldalloc"},
1189         {Opt_removed, "orlov"},
1190         {Opt_user_xattr, "user_xattr"},
1191         {Opt_nouser_xattr, "nouser_xattr"},
1192         {Opt_acl, "acl"},
1193         {Opt_noacl, "noacl"},
1194         {Opt_noload, "norecovery"},
1195         {Opt_noload, "noload"},
1196         {Opt_removed, "nobh"},
1197         {Opt_removed, "bh"},
1198         {Opt_commit, "commit=%u"},
1199         {Opt_min_batch_time, "min_batch_time=%u"},
1200         {Opt_max_batch_time, "max_batch_time=%u"},
1201         {Opt_journal_dev, "journal_dev=%u"},
1202         {Opt_journal_path, "journal_path=%s"},
1203         {Opt_journal_checksum, "journal_checksum"},
1204         {Opt_journal_async_commit, "journal_async_commit"},
1205         {Opt_abort, "abort"},
1206         {Opt_data_journal, "data=journal"},
1207         {Opt_data_ordered, "data=ordered"},
1208         {Opt_data_writeback, "data=writeback"},
1209         {Opt_data_err_abort, "data_err=abort"},
1210         {Opt_data_err_ignore, "data_err=ignore"},
1211         {Opt_offusrjquota, "usrjquota="},
1212         {Opt_usrjquota, "usrjquota=%s"},
1213         {Opt_offgrpjquota, "grpjquota="},
1214         {Opt_grpjquota, "grpjquota=%s"},
1215         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1216         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1217         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1218         {Opt_grpquota, "grpquota"},
1219         {Opt_noquota, "noquota"},
1220         {Opt_quota, "quota"},
1221         {Opt_usrquota, "usrquota"},
1222         {Opt_barrier, "barrier=%u"},
1223         {Opt_barrier, "barrier"},
1224         {Opt_nobarrier, "nobarrier"},
1225         {Opt_i_version, "i_version"},
1226         {Opt_stripe, "stripe=%u"},
1227         {Opt_delalloc, "delalloc"},
1228         {Opt_nodelalloc, "nodelalloc"},
1229         {Opt_removed, "mblk_io_submit"},
1230         {Opt_removed, "nomblk_io_submit"},
1231         {Opt_block_validity, "block_validity"},
1232         {Opt_noblock_validity, "noblock_validity"},
1233         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1234         {Opt_journal_ioprio, "journal_ioprio=%u"},
1235         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1236         {Opt_auto_da_alloc, "auto_da_alloc"},
1237         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1238         {Opt_dioread_nolock, "dioread_nolock"},
1239         {Opt_dioread_lock, "dioread_lock"},
1240         {Opt_discard, "discard"},
1241         {Opt_nodiscard, "nodiscard"},
1242         {Opt_init_itable, "init_itable=%u"},
1243         {Opt_init_itable, "init_itable"},
1244         {Opt_noinit_itable, "noinit_itable"},
1245         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1246         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1247         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1248         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1249         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1250         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1251         {Opt_err, NULL},
1252 };
1253
1254 static ext4_fsblk_t get_sb_block(void **data)
1255 {
1256         ext4_fsblk_t    sb_block;
1257         char            *options = (char *) *data;
1258
1259         if (!options || strncmp(options, "sb=", 3) != 0)
1260                 return 1;       /* Default location */
1261
1262         options += 3;
1263         /* TODO: use simple_strtoll with >32bit ext4 */
1264         sb_block = simple_strtoul(options, &options, 0);
1265         if (*options && *options != ',') {
1266                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1267                        (char *) *data);
1268                 return 1;
1269         }
1270         if (*options == ',')
1271                 options++;
1272         *data = (void *) options;
1273
1274         return sb_block;
1275 }
1276
1277 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1278 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1279         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1280
1281 #ifdef CONFIG_QUOTA
1282 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1283 {
1284         struct ext4_sb_info *sbi = EXT4_SB(sb);
1285         char *qname;
1286         int ret = -1;
1287
1288         if (sb_any_quota_loaded(sb) &&
1289                 !sbi->s_qf_names[qtype]) {
1290                 ext4_msg(sb, KERN_ERR,
1291                         "Cannot change journaled "
1292                         "quota options when quota turned on");
1293                 return -1;
1294         }
1295         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1296                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1297                          "when QUOTA feature is enabled");
1298                 return -1;
1299         }
1300         qname = match_strdup(args);
1301         if (!qname) {
1302                 ext4_msg(sb, KERN_ERR,
1303                         "Not enough memory for storing quotafile name");
1304                 return -1;
1305         }
1306         if (sbi->s_qf_names[qtype]) {
1307                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1308                         ret = 1;
1309                 else
1310                         ext4_msg(sb, KERN_ERR,
1311                                  "%s quota file already specified",
1312                                  QTYPE2NAME(qtype));
1313                 goto errout;
1314         }
1315         if (strchr(qname, '/')) {
1316                 ext4_msg(sb, KERN_ERR,
1317                         "quotafile must be on filesystem root");
1318                 goto errout;
1319         }
1320         sbi->s_qf_names[qtype] = qname;
1321         set_opt(sb, QUOTA);
1322         return 1;
1323 errout:
1324         kfree(qname);
1325         return ret;
1326 }
1327
1328 static int clear_qf_name(struct super_block *sb, int qtype)
1329 {
1330
1331         struct ext4_sb_info *sbi = EXT4_SB(sb);
1332
1333         if (sb_any_quota_loaded(sb) &&
1334                 sbi->s_qf_names[qtype]) {
1335                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1336                         " when quota turned on");
1337                 return -1;
1338         }
1339         kfree(sbi->s_qf_names[qtype]);
1340         sbi->s_qf_names[qtype] = NULL;
1341         return 1;
1342 }
1343 #endif
1344
1345 #define MOPT_SET        0x0001
1346 #define MOPT_CLEAR      0x0002
1347 #define MOPT_NOSUPPORT  0x0004
1348 #define MOPT_EXPLICIT   0x0008
1349 #define MOPT_CLEAR_ERR  0x0010
1350 #define MOPT_GTE0       0x0020
1351 #ifdef CONFIG_QUOTA
1352 #define MOPT_Q          0
1353 #define MOPT_QFMT       0x0040
1354 #else
1355 #define MOPT_Q          MOPT_NOSUPPORT
1356 #define MOPT_QFMT       MOPT_NOSUPPORT
1357 #endif
1358 #define MOPT_DATAJ      0x0080
1359 #define MOPT_NO_EXT2    0x0100
1360 #define MOPT_NO_EXT3    0x0200
1361 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1362 #define MOPT_STRING     0x0400
1363
1364 static const struct mount_opts {
1365         int     token;
1366         int     mount_opt;
1367         int     flags;
1368 } ext4_mount_opts[] = {
1369         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1370         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1371         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1372         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1373         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1374         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1375         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1376          MOPT_EXT4_ONLY | MOPT_SET},
1377         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1378          MOPT_EXT4_ONLY | MOPT_CLEAR},
1379         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1380         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1381         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1382          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1383         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1384          MOPT_EXT4_ONLY | MOPT_CLEAR},
1385         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1386          MOPT_EXT4_ONLY | MOPT_SET},
1387         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1388                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1389          MOPT_EXT4_ONLY | MOPT_SET},
1390         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1391         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1392         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1393         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1394         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1395          MOPT_NO_EXT2 | MOPT_SET},
1396         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1397          MOPT_NO_EXT2 | MOPT_CLEAR},
1398         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1399         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1400         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1401         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1402         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1403         {Opt_commit, 0, MOPT_GTE0},
1404         {Opt_max_batch_time, 0, MOPT_GTE0},
1405         {Opt_min_batch_time, 0, MOPT_GTE0},
1406         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1407         {Opt_init_itable, 0, MOPT_GTE0},
1408         {Opt_stripe, 0, MOPT_GTE0},
1409         {Opt_resuid, 0, MOPT_GTE0},
1410         {Opt_resgid, 0, MOPT_GTE0},
1411         {Opt_journal_dev, 0, MOPT_GTE0},
1412         {Opt_journal_path, 0, MOPT_STRING},
1413         {Opt_journal_ioprio, 0, MOPT_GTE0},
1414         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1415         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1416         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1417          MOPT_NO_EXT2 | MOPT_DATAJ},
1418         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1419         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1420 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1421         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1422         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1423 #else
1424         {Opt_acl, 0, MOPT_NOSUPPORT},
1425         {Opt_noacl, 0, MOPT_NOSUPPORT},
1426 #endif
1427         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1428         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1429         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1430         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1431                                                         MOPT_SET | MOPT_Q},
1432         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1433                                                         MOPT_SET | MOPT_Q},
1434         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1435                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1436         {Opt_usrjquota, 0, MOPT_Q},
1437         {Opt_grpjquota, 0, MOPT_Q},
1438         {Opt_offusrjquota, 0, MOPT_Q},
1439         {Opt_offgrpjquota, 0, MOPT_Q},
1440         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1441         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1442         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1443         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1444         {Opt_err, 0, 0}
1445 };
1446
1447 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1448                             substring_t *args, unsigned long *journal_devnum,
1449                             unsigned int *journal_ioprio, int is_remount)
1450 {
1451         struct ext4_sb_info *sbi = EXT4_SB(sb);
1452         const struct mount_opts *m;
1453         kuid_t uid;
1454         kgid_t gid;
1455         int arg = 0;
1456
1457 #ifdef CONFIG_QUOTA
1458         if (token == Opt_usrjquota)
1459                 return set_qf_name(sb, USRQUOTA, &args[0]);
1460         else if (token == Opt_grpjquota)
1461                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1462         else if (token == Opt_offusrjquota)
1463                 return clear_qf_name(sb, USRQUOTA);
1464         else if (token == Opt_offgrpjquota)
1465                 return clear_qf_name(sb, GRPQUOTA);
1466 #endif
1467         switch (token) {
1468         case Opt_noacl:
1469         case Opt_nouser_xattr:
1470                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1471                 break;
1472         case Opt_sb:
1473                 return 1;       /* handled by get_sb_block() */
1474         case Opt_removed:
1475                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1476                 return 1;
1477         case Opt_abort:
1478                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1479                 return 1;
1480         case Opt_i_version:
1481                 sb->s_flags |= MS_I_VERSION;
1482                 return 1;
1483         }
1484
1485         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1486                 if (token == m->token)
1487                         break;
1488
1489         if (m->token == Opt_err) {
1490                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1491                          "or missing value", opt);
1492                 return -1;
1493         }
1494
1495         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1496                 ext4_msg(sb, KERN_ERR,
1497                          "Mount option \"%s\" incompatible with ext2", opt);
1498                 return -1;
1499         }
1500         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1501                 ext4_msg(sb, KERN_ERR,
1502                          "Mount option \"%s\" incompatible with ext3", opt);
1503                 return -1;
1504         }
1505
1506         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1507                 return -1;
1508         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1509                 return -1;
1510         if (m->flags & MOPT_EXPLICIT)
1511                 set_opt2(sb, EXPLICIT_DELALLOC);
1512         if (m->flags & MOPT_CLEAR_ERR)
1513                 clear_opt(sb, ERRORS_MASK);
1514         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1515                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1516                          "options when quota turned on");
1517                 return -1;
1518         }
1519
1520         if (m->flags & MOPT_NOSUPPORT) {
1521                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1522         } else if (token == Opt_commit) {
1523                 if (arg == 0)
1524                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1525                 sbi->s_commit_interval = HZ * arg;
1526         } else if (token == Opt_max_batch_time) {
1527                 sbi->s_max_batch_time = arg;
1528         } else if (token == Opt_min_batch_time) {
1529                 sbi->s_min_batch_time = arg;
1530         } else if (token == Opt_inode_readahead_blks) {
1531                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1532                         ext4_msg(sb, KERN_ERR,
1533                                  "EXT4-fs: inode_readahead_blks must be "
1534                                  "0 or a power of 2 smaller than 2^31");
1535                         return -1;
1536                 }
1537                 sbi->s_inode_readahead_blks = arg;
1538         } else if (token == Opt_init_itable) {
1539                 set_opt(sb, INIT_INODE_TABLE);
1540                 if (!args->from)
1541                         arg = EXT4_DEF_LI_WAIT_MULT;
1542                 sbi->s_li_wait_mult = arg;
1543         } else if (token == Opt_max_dir_size_kb) {
1544                 sbi->s_max_dir_size_kb = arg;
1545         } else if (token == Opt_stripe) {
1546                 sbi->s_stripe = arg;
1547         } else if (token == Opt_resuid) {
1548                 uid = make_kuid(current_user_ns(), arg);
1549                 if (!uid_valid(uid)) {
1550                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1551                         return -1;
1552                 }
1553                 sbi->s_resuid = uid;
1554         } else if (token == Opt_resgid) {
1555                 gid = make_kgid(current_user_ns(), arg);
1556                 if (!gid_valid(gid)) {
1557                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1558                         return -1;
1559                 }
1560                 sbi->s_resgid = gid;
1561         } else if (token == Opt_journal_dev) {
1562                 if (is_remount) {
1563                         ext4_msg(sb, KERN_ERR,
1564                                  "Cannot specify journal on remount");
1565                         return -1;
1566                 }
1567                 *journal_devnum = arg;
1568         } else if (token == Opt_journal_path) {
1569                 char *journal_path;
1570                 struct inode *journal_inode;
1571                 struct path path;
1572                 int error;
1573
1574                 if (is_remount) {
1575                         ext4_msg(sb, KERN_ERR,
1576                                  "Cannot specify journal on remount");
1577                         return -1;
1578                 }
1579                 journal_path = match_strdup(&args[0]);
1580                 if (!journal_path) {
1581                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1582                                 "journal device string");
1583                         return -1;
1584                 }
1585
1586                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1587                 if (error) {
1588                         ext4_msg(sb, KERN_ERR, "error: could not find "
1589                                 "journal device path: error %d", error);
1590                         kfree(journal_path);
1591                         return -1;
1592                 }
1593
1594                 journal_inode = path.dentry->d_inode;
1595                 if (!S_ISBLK(journal_inode->i_mode)) {
1596                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1597                                 "is not a block device", journal_path);
1598                         path_put(&path);
1599                         kfree(journal_path);
1600                         return -1;
1601                 }
1602
1603                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1604                 path_put(&path);
1605                 kfree(journal_path);
1606         } else if (token == Opt_journal_ioprio) {
1607                 if (arg > 7) {
1608                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1609                                  " (must be 0-7)");
1610                         return -1;
1611                 }
1612                 *journal_ioprio =
1613                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1614         } else if (m->flags & MOPT_DATAJ) {
1615                 if (is_remount) {
1616                         if (!sbi->s_journal)
1617                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1618                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1619                                 ext4_msg(sb, KERN_ERR,
1620                                          "Cannot change data mode on remount");
1621                                 return -1;
1622                         }
1623                 } else {
1624                         clear_opt(sb, DATA_FLAGS);
1625                         sbi->s_mount_opt |= m->mount_opt;
1626                 }
1627 #ifdef CONFIG_QUOTA
1628         } else if (m->flags & MOPT_QFMT) {
1629                 if (sb_any_quota_loaded(sb) &&
1630                     sbi->s_jquota_fmt != m->mount_opt) {
1631                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1632                                  "quota options when quota turned on");
1633                         return -1;
1634                 }
1635                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1636                                                EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1637                         ext4_msg(sb, KERN_ERR,
1638                                  "Cannot set journaled quota options "
1639                                  "when QUOTA feature is enabled");
1640                         return -1;
1641                 }
1642                 sbi->s_jquota_fmt = m->mount_opt;
1643 #endif
1644         } else {
1645                 if (!args->from)
1646                         arg = 1;
1647                 if (m->flags & MOPT_CLEAR)
1648                         arg = !arg;
1649                 else if (unlikely(!(m->flags & MOPT_SET))) {
1650                         ext4_msg(sb, KERN_WARNING,
1651                                  "buggy handling of option %s", opt);
1652                         WARN_ON(1);
1653                         return -1;
1654                 }
1655                 if (arg != 0)
1656                         sbi->s_mount_opt |= m->mount_opt;
1657                 else
1658                         sbi->s_mount_opt &= ~m->mount_opt;
1659         }
1660         return 1;
1661 }
1662
1663 static int parse_options(char *options, struct super_block *sb,
1664                          unsigned long *journal_devnum,
1665                          unsigned int *journal_ioprio,
1666                          int is_remount)
1667 {
1668         struct ext4_sb_info *sbi = EXT4_SB(sb);
1669         char *p;
1670         substring_t args[MAX_OPT_ARGS];
1671         int token;
1672
1673         if (!options)
1674                 return 1;
1675
1676         while ((p = strsep(&options, ",")) != NULL) {
1677                 if (!*p)
1678                         continue;
1679                 /*
1680                  * Initialize args struct so we know whether arg was
1681                  * found; some options take optional arguments.
1682                  */
1683                 args[0].to = args[0].from = NULL;
1684                 token = match_token(p, tokens, args);
1685                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1686                                      journal_ioprio, is_remount) < 0)
1687                         return 0;
1688         }
1689 #ifdef CONFIG_QUOTA
1690         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1691             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1692                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1693                          "feature is enabled");
1694                 return 0;
1695         }
1696         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1697                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1698                         clear_opt(sb, USRQUOTA);
1699
1700                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1701                         clear_opt(sb, GRPQUOTA);
1702
1703                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1704                         ext4_msg(sb, KERN_ERR, "old and new quota "
1705                                         "format mixing");
1706                         return 0;
1707                 }
1708
1709                 if (!sbi->s_jquota_fmt) {
1710                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1711                                         "not specified");
1712                         return 0;
1713                 }
1714         }
1715 #endif
1716         if (test_opt(sb, DIOREAD_NOLOCK)) {
1717                 int blocksize =
1718                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1719
1720                 if (blocksize < PAGE_CACHE_SIZE) {
1721                         ext4_msg(sb, KERN_ERR, "can't mount with "
1722                                  "dioread_nolock if block size != PAGE_SIZE");
1723                         return 0;
1724                 }
1725         }
1726         return 1;
1727 }
1728
1729 static inline void ext4_show_quota_options(struct seq_file *seq,
1730                                            struct super_block *sb)
1731 {
1732 #if defined(CONFIG_QUOTA)
1733         struct ext4_sb_info *sbi = EXT4_SB(sb);
1734
1735         if (sbi->s_jquota_fmt) {
1736                 char *fmtname = "";
1737
1738                 switch (sbi->s_jquota_fmt) {
1739                 case QFMT_VFS_OLD:
1740                         fmtname = "vfsold";
1741                         break;
1742                 case QFMT_VFS_V0:
1743                         fmtname = "vfsv0";
1744                         break;
1745                 case QFMT_VFS_V1:
1746                         fmtname = "vfsv1";
1747                         break;
1748                 }
1749                 seq_printf(seq, ",jqfmt=%s", fmtname);
1750         }
1751
1752         if (sbi->s_qf_names[USRQUOTA])
1753                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1754
1755         if (sbi->s_qf_names[GRPQUOTA])
1756                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1757 #endif
1758 }
1759
1760 static const char *token2str(int token)
1761 {
1762         const struct match_token *t;
1763
1764         for (t = tokens; t->token != Opt_err; t++)
1765                 if (t->token == token && !strchr(t->pattern, '='))
1766                         break;
1767         return t->pattern;
1768 }
1769
1770 /*
1771  * Show an option if
1772  *  - it's set to a non-default value OR
1773  *  - if the per-sb default is different from the global default
1774  */
1775 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1776                               int nodefs)
1777 {
1778         struct ext4_sb_info *sbi = EXT4_SB(sb);
1779         struct ext4_super_block *es = sbi->s_es;
1780         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1781         const struct mount_opts *m;
1782         char sep = nodefs ? '\n' : ',';
1783
1784 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1785 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1786
1787         if (sbi->s_sb_block != 1)
1788                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1789
1790         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1791                 int want_set = m->flags & MOPT_SET;
1792                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1793                     (m->flags & MOPT_CLEAR_ERR))
1794                         continue;
1795                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1796                         continue; /* skip if same as the default */
1797                 if ((want_set &&
1798                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1799                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1800                         continue; /* select Opt_noFoo vs Opt_Foo */
1801                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1802         }
1803
1804         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1805             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1806                 SEQ_OPTS_PRINT("resuid=%u",
1807                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1808         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1809             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1810                 SEQ_OPTS_PRINT("resgid=%u",
1811                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1812         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1813         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1814                 SEQ_OPTS_PUTS("errors=remount-ro");
1815         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1816                 SEQ_OPTS_PUTS("errors=continue");
1817         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1818                 SEQ_OPTS_PUTS("errors=panic");
1819         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1820                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1821         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1822                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1823         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1824                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1825         if (sb->s_flags & MS_I_VERSION)
1826                 SEQ_OPTS_PUTS("i_version");
1827         if (nodefs || sbi->s_stripe)
1828                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1829         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1830                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1831                         SEQ_OPTS_PUTS("data=journal");
1832                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1833                         SEQ_OPTS_PUTS("data=ordered");
1834                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1835                         SEQ_OPTS_PUTS("data=writeback");
1836         }
1837         if (nodefs ||
1838             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1839                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1840                                sbi->s_inode_readahead_blks);
1841
1842         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1843                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1844                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1845         if (nodefs || sbi->s_max_dir_size_kb)
1846                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1847
1848         ext4_show_quota_options(seq, sb);
1849         return 0;
1850 }
1851
1852 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1853 {
1854         return _ext4_show_options(seq, root->d_sb, 0);
1855 }
1856
1857 static int options_seq_show(struct seq_file *seq, void *offset)
1858 {
1859         struct super_block *sb = seq->private;
1860         int rc;
1861
1862         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1863         rc = _ext4_show_options(seq, sb, 1);
1864         seq_puts(seq, "\n");
1865         return rc;
1866 }
1867
1868 static int options_open_fs(struct inode *inode, struct file *file)
1869 {
1870         return single_open(file, options_seq_show, PDE_DATA(inode));
1871 }
1872
1873 static const struct file_operations ext4_seq_options_fops = {
1874         .owner = THIS_MODULE,
1875         .open = options_open_fs,
1876         .read = seq_read,
1877         .llseek = seq_lseek,
1878         .release = single_release,
1879 };
1880
1881 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1882                             int read_only)
1883 {
1884         struct ext4_sb_info *sbi = EXT4_SB(sb);
1885         int res = 0;
1886
1887         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1888                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1889                          "forcing read-only mode");
1890                 res = MS_RDONLY;
1891         }
1892         if (read_only)
1893                 goto done;
1894         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1895                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1896                          "running e2fsck is recommended");
1897         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1898                 ext4_msg(sb, KERN_WARNING,
1899                          "warning: mounting fs with errors, "
1900                          "running e2fsck is recommended");
1901         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1902                  le16_to_cpu(es->s_mnt_count) >=
1903                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1904                 ext4_msg(sb, KERN_WARNING,
1905                          "warning: maximal mount count reached, "
1906                          "running e2fsck is recommended");
1907         else if (le32_to_cpu(es->s_checkinterval) &&
1908                 (le32_to_cpu(es->s_lastcheck) +
1909                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1910                 ext4_msg(sb, KERN_WARNING,
1911                          "warning: checktime reached, "
1912                          "running e2fsck is recommended");
1913         if (!sbi->s_journal)
1914                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1915         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1916                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1917         le16_add_cpu(&es->s_mnt_count, 1);
1918         es->s_mtime = cpu_to_le32(get_seconds());
1919         ext4_update_dynamic_rev(sb);
1920         if (sbi->s_journal)
1921                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1922
1923         ext4_commit_super(sb, 1);
1924 done:
1925         if (test_opt(sb, DEBUG))
1926                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1927                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1928                         sb->s_blocksize,
1929                         sbi->s_groups_count,
1930                         EXT4_BLOCKS_PER_GROUP(sb),
1931                         EXT4_INODES_PER_GROUP(sb),
1932                         sbi->s_mount_opt, sbi->s_mount_opt2);
1933
1934         cleancache_init_fs(sb);
1935         return res;
1936 }
1937
1938 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1939 {
1940         struct ext4_sb_info *sbi = EXT4_SB(sb);
1941         struct flex_groups *new_groups;
1942         int size;
1943
1944         if (!sbi->s_log_groups_per_flex)
1945                 return 0;
1946
1947         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1948         if (size <= sbi->s_flex_groups_allocated)
1949                 return 0;
1950
1951         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1952         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1953         if (!new_groups) {
1954                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1955                          size / (int) sizeof(struct flex_groups));
1956                 return -ENOMEM;
1957         }
1958
1959         if (sbi->s_flex_groups) {
1960                 memcpy(new_groups, sbi->s_flex_groups,
1961                        (sbi->s_flex_groups_allocated *
1962                         sizeof(struct flex_groups)));
1963                 ext4_kvfree(sbi->s_flex_groups);
1964         }
1965         sbi->s_flex_groups = new_groups;
1966         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1967         return 0;
1968 }
1969
1970 static int ext4_fill_flex_info(struct super_block *sb)
1971 {
1972         struct ext4_sb_info *sbi = EXT4_SB(sb);
1973         struct ext4_group_desc *gdp = NULL;
1974         ext4_group_t flex_group;
1975         int i, err;
1976
1977         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1978         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1979                 sbi->s_log_groups_per_flex = 0;
1980                 return 1;
1981         }
1982
1983         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1984         if (err)
1985                 goto failed;
1986
1987         for (i = 0; i < sbi->s_groups_count; i++) {
1988                 gdp = ext4_get_group_desc(sb, i, NULL);
1989
1990                 flex_group = ext4_flex_group(sbi, i);
1991                 atomic_add(ext4_free_inodes_count(sb, gdp),
1992                            &sbi->s_flex_groups[flex_group].free_inodes);
1993                 atomic64_add(ext4_free_group_clusters(sb, gdp),
1994                              &sbi->s_flex_groups[flex_group].free_clusters);
1995                 atomic_add(ext4_used_dirs_count(sb, gdp),
1996                            &sbi->s_flex_groups[flex_group].used_dirs);
1997         }
1998
1999         return 1;
2000 failed:
2001         return 0;
2002 }
2003
2004 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2005                                    struct ext4_group_desc *gdp)
2006 {
2007         int offset;
2008         __u16 crc = 0;
2009         __le32 le_group = cpu_to_le32(block_group);
2010
2011         if ((sbi->s_es->s_feature_ro_compat &
2012              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
2013                 /* Use new metadata_csum algorithm */
2014                 __le16 save_csum;
2015                 __u32 csum32;
2016
2017                 save_csum = gdp->bg_checksum;
2018                 gdp->bg_checksum = 0;
2019                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2020                                      sizeof(le_group));
2021                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2022                                      sbi->s_desc_size);
2023                 gdp->bg_checksum = save_csum;
2024
2025                 crc = csum32 & 0xFFFF;
2026                 goto out;
2027         }
2028
2029         /* old crc16 code */
2030         offset = offsetof(struct ext4_group_desc, bg_checksum);
2031
2032         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2033         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2034         crc = crc16(crc, (__u8 *)gdp, offset);
2035         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2036         /* for checksum of struct ext4_group_desc do the rest...*/
2037         if ((sbi->s_es->s_feature_incompat &
2038              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2039             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2040                 crc = crc16(crc, (__u8 *)gdp + offset,
2041                             le16_to_cpu(sbi->s_es->s_desc_size) -
2042                                 offset);
2043
2044 out:
2045         return cpu_to_le16(crc);
2046 }
2047
2048 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2049                                 struct ext4_group_desc *gdp)
2050 {
2051         if (ext4_has_group_desc_csum(sb) &&
2052             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2053                                                       block_group, gdp)))
2054                 return 0;
2055
2056         return 1;
2057 }
2058
2059 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2060                               struct ext4_group_desc *gdp)
2061 {
2062         if (!ext4_has_group_desc_csum(sb))
2063                 return;
2064         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2065 }
2066
2067 /* Called at mount-time, super-block is locked */
2068 static int ext4_check_descriptors(struct super_block *sb,
2069                                   ext4_group_t *first_not_zeroed)
2070 {
2071         struct ext4_sb_info *sbi = EXT4_SB(sb);
2072         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2073         ext4_fsblk_t last_block;
2074         ext4_fsblk_t block_bitmap;
2075         ext4_fsblk_t inode_bitmap;
2076         ext4_fsblk_t inode_table;
2077         int flexbg_flag = 0;
2078         ext4_group_t i, grp = sbi->s_groups_count;
2079
2080         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2081                 flexbg_flag = 1;
2082
2083         ext4_debug("Checking group descriptors");
2084
2085         for (i = 0; i < sbi->s_groups_count; i++) {
2086                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2087
2088                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2089                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2090                 else
2091                         last_block = first_block +
2092                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2093
2094                 if ((grp == sbi->s_groups_count) &&
2095                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2096                         grp = i;
2097
2098                 block_bitmap = ext4_block_bitmap(sb, gdp);
2099                 if (block_bitmap < first_block || block_bitmap > last_block) {
2100                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2101                                "Block bitmap for group %u not in group "
2102                                "(block %llu)!", i, block_bitmap);
2103                         return 0;
2104                 }
2105                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2106                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2107                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2108                                "Inode bitmap for group %u not in group "
2109                                "(block %llu)!", i, inode_bitmap);
2110                         return 0;
2111                 }
2112                 inode_table = ext4_inode_table(sb, gdp);
2113                 if (inode_table < first_block ||
2114                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2115                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2116                                "Inode table for group %u not in group "
2117                                "(block %llu)!", i, inode_table);
2118                         return 0;
2119                 }
2120                 ext4_lock_group(sb, i);
2121                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2122                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2123                                  "Checksum for group %u failed (%u!=%u)",
2124                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2125                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2126                         if (!(sb->s_flags & MS_RDONLY)) {
2127                                 ext4_unlock_group(sb, i);
2128                                 return 0;
2129                         }
2130                 }
2131                 ext4_unlock_group(sb, i);
2132                 if (!flexbg_flag)
2133                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2134         }
2135         if (NULL != first_not_zeroed)
2136                 *first_not_zeroed = grp;
2137         return 1;
2138 }
2139
2140 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2141  * the superblock) which were deleted from all directories, but held open by
2142  * a process at the time of a crash.  We walk the list and try to delete these
2143  * inodes at recovery time (only with a read-write filesystem).
2144  *
2145  * In order to keep the orphan inode chain consistent during traversal (in
2146  * case of crash during recovery), we link each inode into the superblock
2147  * orphan list_head and handle it the same way as an inode deletion during
2148  * normal operation (which journals the operations for us).
2149  *
2150  * We only do an iget() and an iput() on each inode, which is very safe if we
2151  * accidentally point at an in-use or already deleted inode.  The worst that
2152  * can happen in this case is that we get a "bit already cleared" message from
2153  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2154  * e2fsck was run on this filesystem, and it must have already done the orphan
2155  * inode cleanup for us, so we can safely abort without any further action.
2156  */
2157 static void ext4_orphan_cleanup(struct super_block *sb,
2158                                 struct ext4_super_block *es)
2159 {
2160         unsigned int s_flags = sb->s_flags;
2161         int nr_orphans = 0, nr_truncates = 0;
2162 #ifdef CONFIG_QUOTA
2163         int i;
2164 #endif
2165         if (!es->s_last_orphan) {
2166                 jbd_debug(4, "no orphan inodes to clean up\n");
2167                 return;
2168         }
2169
2170         if (bdev_read_only(sb->s_bdev)) {
2171                 ext4_msg(sb, KERN_ERR, "write access "
2172                         "unavailable, skipping orphan cleanup");
2173                 return;
2174         }
2175
2176         /* Check if feature set would not allow a r/w mount */
2177         if (!ext4_feature_set_ok(sb, 0)) {
2178                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2179                          "unknown ROCOMPAT features");
2180                 return;
2181         }
2182
2183         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2184                 /* don't clear list on RO mount w/ errors */
2185                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2186                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2187                                   "clearing orphan list.\n");
2188                         es->s_last_orphan = 0;
2189                 }
2190                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2191                 return;
2192         }
2193
2194         if (s_flags & MS_RDONLY) {
2195                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2196                 sb->s_flags &= ~MS_RDONLY;
2197         }
2198 #ifdef CONFIG_QUOTA
2199         /* Needed for iput() to work correctly and not trash data */
2200         sb->s_flags |= MS_ACTIVE;
2201         /* Turn on quotas so that they are updated correctly */
2202         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2203                 if (EXT4_SB(sb)->s_qf_names[i]) {
2204                         int ret = ext4_quota_on_mount(sb, i);
2205                         if (ret < 0)
2206                                 ext4_msg(sb, KERN_ERR,
2207                                         "Cannot turn on journaled "
2208                                         "quota: error %d", ret);
2209                 }
2210         }
2211 #endif
2212
2213         while (es->s_last_orphan) {
2214                 struct inode *inode;
2215
2216                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2217                 if (IS_ERR(inode)) {
2218                         es->s_last_orphan = 0;
2219                         break;
2220                 }
2221
2222                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2223                 dquot_initialize(inode);
2224                 if (inode->i_nlink) {
2225                         if (test_opt(sb, DEBUG))
2226                                 ext4_msg(sb, KERN_DEBUG,
2227                                         "%s: truncating inode %lu to %lld bytes",
2228                                         __func__, inode->i_ino, inode->i_size);
2229                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2230                                   inode->i_ino, inode->i_size);
2231                         mutex_lock(&inode->i_mutex);
2232                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2233                         ext4_truncate(inode);
2234                         mutex_unlock(&inode->i_mutex);
2235                         nr_truncates++;
2236                 } else {
2237                         if (test_opt(sb, DEBUG))
2238                                 ext4_msg(sb, KERN_DEBUG,
2239                                         "%s: deleting unreferenced inode %lu",
2240                                         __func__, inode->i_ino);
2241                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2242                                   inode->i_ino);
2243                         nr_orphans++;
2244                 }
2245                 iput(inode);  /* The delete magic happens here! */
2246         }
2247
2248 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2249
2250         if (nr_orphans)
2251                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2252                        PLURAL(nr_orphans));
2253         if (nr_truncates)
2254                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2255                        PLURAL(nr_truncates));
2256 #ifdef CONFIG_QUOTA
2257         /* Turn quotas off */
2258         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2259                 if (sb_dqopt(sb)->files[i])
2260                         dquot_quota_off(sb, i);
2261         }
2262 #endif
2263         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2264 }
2265
2266 /*
2267  * Maximal extent format file size.
2268  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2269  * extent format containers, within a sector_t, and within i_blocks
2270  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2271  * so that won't be a limiting factor.
2272  *
2273  * However there is other limiting factor. We do store extents in the form
2274  * of starting block and length, hence the resulting length of the extent
2275  * covering maximum file size must fit into on-disk format containers as
2276  * well. Given that length is always by 1 unit bigger than max unit (because
2277  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2278  *
2279  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2280  */
2281 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2282 {
2283         loff_t res;
2284         loff_t upper_limit = MAX_LFS_FILESIZE;
2285
2286         /* small i_blocks in vfs inode? */
2287         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2288                 /*
2289                  * CONFIG_LBDAF is not enabled implies the inode
2290                  * i_block represent total blocks in 512 bytes
2291                  * 32 == size of vfs inode i_blocks * 8
2292                  */
2293                 upper_limit = (1LL << 32) - 1;
2294
2295                 /* total blocks in file system block size */
2296                 upper_limit >>= (blkbits - 9);
2297                 upper_limit <<= blkbits;
2298         }
2299
2300         /*
2301          * 32-bit extent-start container, ee_block. We lower the maxbytes
2302          * by one fs block, so ee_len can cover the extent of maximum file
2303          * size
2304          */
2305         res = (1LL << 32) - 1;
2306         res <<= blkbits;
2307
2308         /* Sanity check against vm- & vfs- imposed limits */
2309         if (res > upper_limit)
2310                 res = upper_limit;
2311
2312         return res;
2313 }
2314
2315 /*
2316  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2317  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2318  * We need to be 1 filesystem block less than the 2^48 sector limit.
2319  */
2320 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2321 {
2322         loff_t res = EXT4_NDIR_BLOCKS;
2323         int meta_blocks;
2324         loff_t upper_limit;
2325         /* This is calculated to be the largest file size for a dense, block
2326          * mapped file such that the file's total number of 512-byte sectors,
2327          * including data and all indirect blocks, does not exceed (2^48 - 1).
2328          *
2329          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2330          * number of 512-byte sectors of the file.
2331          */
2332
2333         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2334                 /*
2335                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2336                  * the inode i_block field represents total file blocks in
2337                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2338                  */
2339                 upper_limit = (1LL << 32) - 1;
2340
2341                 /* total blocks in file system block size */
2342                 upper_limit >>= (bits - 9);
2343
2344         } else {
2345                 /*
2346                  * We use 48 bit ext4_inode i_blocks
2347                  * With EXT4_HUGE_FILE_FL set the i_blocks
2348                  * represent total number of blocks in
2349                  * file system block size
2350                  */
2351                 upper_limit = (1LL << 48) - 1;
2352
2353         }
2354
2355         /* indirect blocks */
2356         meta_blocks = 1;
2357         /* double indirect blocks */
2358         meta_blocks += 1 + (1LL << (bits-2));
2359         /* tripple indirect blocks */
2360         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2361
2362         upper_limit -= meta_blocks;
2363         upper_limit <<= bits;
2364
2365         res += 1LL << (bits-2);
2366         res += 1LL << (2*(bits-2));
2367         res += 1LL << (3*(bits-2));
2368         res <<= bits;
2369         if (res > upper_limit)
2370                 res = upper_limit;
2371
2372         if (res > MAX_LFS_FILESIZE)
2373                 res = MAX_LFS_FILESIZE;
2374
2375         return res;
2376 }
2377
2378 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2379                                    ext4_fsblk_t logical_sb_block, int nr)
2380 {
2381         struct ext4_sb_info *sbi = EXT4_SB(sb);
2382         ext4_group_t bg, first_meta_bg;
2383         int has_super = 0;
2384
2385         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2386
2387         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2388             nr < first_meta_bg)
2389                 return logical_sb_block + nr + 1;
2390         bg = sbi->s_desc_per_block * nr;
2391         if (ext4_bg_has_super(sb, bg))
2392                 has_super = 1;
2393
2394         /*
2395          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2396          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2397          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2398          * compensate.
2399          */
2400         if (sb->s_blocksize == 1024 && nr == 0 &&
2401             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2402                 has_super++;
2403
2404         return (has_super + ext4_group_first_block_no(sb, bg));
2405 }
2406
2407 /**
2408  * ext4_get_stripe_size: Get the stripe size.
2409  * @sbi: In memory super block info
2410  *
2411  * If we have specified it via mount option, then
2412  * use the mount option value. If the value specified at mount time is
2413  * greater than the blocks per group use the super block value.
2414  * If the super block value is greater than blocks per group return 0.
2415  * Allocator needs it be less than blocks per group.
2416  *
2417  */
2418 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2419 {
2420         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2421         unsigned long stripe_width =
2422                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2423         int ret;
2424
2425         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2426                 ret = sbi->s_stripe;
2427         else if (stripe_width <= sbi->s_blocks_per_group)
2428                 ret = stripe_width;
2429         else if (stride <= sbi->s_blocks_per_group)
2430                 ret = stride;
2431         else
2432                 ret = 0;
2433
2434         /*
2435          * If the stripe width is 1, this makes no sense and
2436          * we set it to 0 to turn off stripe handling code.
2437          */
2438         if (ret <= 1)
2439                 ret = 0;
2440
2441         return ret;
2442 }
2443
2444 /* sysfs supprt */
2445
2446 struct ext4_attr {
2447         struct attribute attr;
2448         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2449         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2450                          const char *, size_t);
2451         union {
2452                 int offset;
2453                 int deprecated_val;
2454         } u;
2455 };
2456
2457 static int parse_strtoull(const char *buf,
2458                 unsigned long long max, unsigned long long *value)
2459 {
2460         int ret;
2461
2462         ret = kstrtoull(skip_spaces(buf), 0, value);
2463         if (!ret && *value > max)
2464                 ret = -EINVAL;
2465         return ret;
2466 }
2467
2468 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2469                                               struct ext4_sb_info *sbi,
2470                                               char *buf)
2471 {
2472         return snprintf(buf, PAGE_SIZE, "%llu\n",
2473                 (s64) EXT4_C2B(sbi,
2474                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2475 }
2476
2477 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2478                                          struct ext4_sb_info *sbi, char *buf)
2479 {
2480         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2481
2482         if (!sb->s_bdev->bd_part)
2483                 return snprintf(buf, PAGE_SIZE, "0\n");
2484         return snprintf(buf, PAGE_SIZE, "%lu\n",
2485                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2486                          sbi->s_sectors_written_start) >> 1);
2487 }
2488
2489 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2490                                           struct ext4_sb_info *sbi, char *buf)
2491 {
2492         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2493
2494         if (!sb->s_bdev->bd_part)
2495                 return snprintf(buf, PAGE_SIZE, "0\n");
2496         return snprintf(buf, PAGE_SIZE, "%llu\n",
2497                         (unsigned long long)(sbi->s_kbytes_written +
2498                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2499                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2500 }
2501
2502 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2503                                           struct ext4_sb_info *sbi,
2504                                           const char *buf, size_t count)
2505 {
2506         unsigned long t;
2507         int ret;
2508
2509         ret = kstrtoul(skip_spaces(buf), 0, &t);
2510         if (ret)
2511                 return ret;
2512
2513         if (t && (!is_power_of_2(t) || t > 0x40000000))
2514                 return -EINVAL;
2515
2516         sbi->s_inode_readahead_blks = t;
2517         return count;
2518 }
2519
2520 static ssize_t sbi_ui_show(struct ext4_attr *a,
2521                            struct ext4_sb_info *sbi, char *buf)
2522 {
2523         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2524
2525         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2526 }
2527
2528 static ssize_t sbi_ui_store(struct ext4_attr *a,
2529                             struct ext4_sb_info *sbi,
2530                             const char *buf, size_t count)
2531 {
2532         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2533         unsigned long t;
2534         int ret;
2535
2536         ret = kstrtoul(skip_spaces(buf), 0, &t);
2537         if (ret)
2538                 return ret;
2539         *ui = t;
2540         return count;
2541 }
2542
2543 static ssize_t es_ui_show(struct ext4_attr *a,
2544                            struct ext4_sb_info *sbi, char *buf)
2545 {
2546
2547         unsigned int *ui = (unsigned int *) (((char *) sbi->s_es) +
2548                            a->u.offset);
2549
2550         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2551 }
2552
2553 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2554                                   struct ext4_sb_info *sbi, char *buf)
2555 {
2556         return snprintf(buf, PAGE_SIZE, "%llu\n",
2557                 (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2558 }
2559
2560 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2561                                    struct ext4_sb_info *sbi,
2562                                    const char *buf, size_t count)
2563 {
2564         unsigned long long val;
2565         int ret;
2566
2567         if (parse_strtoull(buf, -1ULL, &val))
2568                 return -EINVAL;
2569         ret = ext4_reserve_clusters(sbi, val);
2570
2571         return ret ? ret : count;
2572 }
2573
2574 static ssize_t trigger_test_error(struct ext4_attr *a,
2575                                   struct ext4_sb_info *sbi,
2576                                   const char *buf, size_t count)
2577 {
2578         int len = count;
2579
2580         if (!capable(CAP_SYS_ADMIN))
2581                 return -EPERM;
2582
2583         if (len && buf[len-1] == '\n')
2584                 len--;
2585
2586         if (len)
2587                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2588         return count;
2589 }
2590
2591 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2592                                    struct ext4_sb_info *sbi, char *buf)
2593 {
2594         return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2595 }
2596
2597 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2598 static struct ext4_attr ext4_attr_##_name = {                   \
2599         .attr = {.name = __stringify(_name), .mode = _mode },   \
2600         .show   = _show,                                        \
2601         .store  = _store,                                       \
2602         .u = {                                                  \
2603                 .offset = offsetof(struct ext4_sb_info, _elname),\
2604         },                                                      \
2605 }
2606
2607 #define EXT4_ATTR_OFFSET_ES(_name,_mode,_show,_store,_elname)           \
2608 static struct ext4_attr ext4_attr_##_name = {                           \
2609         .attr = {.name = __stringify(_name), .mode = _mode },           \
2610         .show   = _show,                                                \
2611         .store  = _store,                                               \
2612         .u = {                                                          \
2613                 .offset = offsetof(struct ext4_super_block, _elname),   \
2614         },                                                              \
2615 }
2616
2617 #define EXT4_ATTR(name, mode, show, store) \
2618 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2619
2620 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2621 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2622 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2623
2624 #define EXT4_RO_ATTR_ES_UI(name, elname)        \
2625         EXT4_ATTR_OFFSET_ES(name, 0444, es_ui_show, NULL, elname)
2626 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2627         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2628
2629 #define ATTR_LIST(name) &ext4_attr_##name.attr
2630 #define EXT4_DEPRECATED_ATTR(_name, _val)       \
2631 static struct ext4_attr ext4_attr_##_name = {                   \
2632         .attr = {.name = __stringify(_name), .mode = 0444 },    \
2633         .show   = sbi_deprecated_show,                          \
2634         .u = {                                                  \
2635                 .deprecated_val = _val,                         \
2636         },                                                      \
2637 }
2638
2639 EXT4_RO_ATTR(delayed_allocation_blocks);
2640 EXT4_RO_ATTR(session_write_kbytes);
2641 EXT4_RO_ATTR(lifetime_write_kbytes);
2642 EXT4_RW_ATTR(reserved_clusters);
2643 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2644                  inode_readahead_blks_store, s_inode_readahead_blks);
2645 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2646 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2647 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2648 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2649 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2650 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2651 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2652 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2653 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2654 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2655 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2656 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2657 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2658 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2659 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2660 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2661 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
2662 EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
2663 EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
2664
2665 static struct attribute *ext4_attrs[] = {
2666         ATTR_LIST(delayed_allocation_blocks),
2667         ATTR_LIST(session_write_kbytes),
2668         ATTR_LIST(lifetime_write_kbytes),
2669         ATTR_LIST(reserved_clusters),
2670         ATTR_LIST(inode_readahead_blks),
2671         ATTR_LIST(inode_goal),
2672         ATTR_LIST(mb_stats),
2673         ATTR_LIST(mb_max_to_scan),
2674         ATTR_LIST(mb_min_to_scan),
2675         ATTR_LIST(mb_order2_req),
2676         ATTR_LIST(mb_stream_req),
2677         ATTR_LIST(mb_group_prealloc),
2678         ATTR_LIST(max_writeback_mb_bump),
2679         ATTR_LIST(extent_max_zeroout_kb),
2680         ATTR_LIST(trigger_fs_error),
2681         ATTR_LIST(err_ratelimit_interval_ms),
2682         ATTR_LIST(err_ratelimit_burst),
2683         ATTR_LIST(warning_ratelimit_interval_ms),
2684         ATTR_LIST(warning_ratelimit_burst),
2685         ATTR_LIST(msg_ratelimit_interval_ms),
2686         ATTR_LIST(msg_ratelimit_burst),
2687         ATTR_LIST(errors_count),
2688         ATTR_LIST(first_error_time),
2689         ATTR_LIST(last_error_time),
2690         NULL,
2691 };
2692
2693 /* Features this copy of ext4 supports */
2694 EXT4_INFO_ATTR(lazy_itable_init);
2695 EXT4_INFO_ATTR(batched_discard);
2696 EXT4_INFO_ATTR(meta_bg_resize);
2697
2698 static struct attribute *ext4_feat_attrs[] = {
2699         ATTR_LIST(lazy_itable_init),
2700         ATTR_LIST(batched_discard),
2701         ATTR_LIST(meta_bg_resize),
2702         NULL,
2703 };
2704
2705 static ssize_t ext4_attr_show(struct kobject *kobj,
2706                               struct attribute *attr, char *buf)
2707 {
2708         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2709                                                 s_kobj);
2710         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2711
2712         return a->show ? a->show(a, sbi, buf) : 0;
2713 }
2714
2715 static ssize_t ext4_attr_store(struct kobject *kobj,
2716                                struct attribute *attr,
2717                                const char *buf, size_t len)
2718 {
2719         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2720                                                 s_kobj);
2721         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2722
2723         return a->store ? a->store(a, sbi, buf, len) : 0;
2724 }
2725
2726 static void ext4_sb_release(struct kobject *kobj)
2727 {
2728         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2729                                                 s_kobj);
2730         complete(&sbi->s_kobj_unregister);
2731 }
2732
2733 static const struct sysfs_ops ext4_attr_ops = {
2734         .show   = ext4_attr_show,
2735         .store  = ext4_attr_store,
2736 };
2737
2738 static struct kobj_type ext4_ktype = {
2739         .default_attrs  = ext4_attrs,
2740         .sysfs_ops      = &ext4_attr_ops,
2741         .release        = ext4_sb_release,
2742 };
2743
2744 static void ext4_feat_release(struct kobject *kobj)
2745 {
2746         complete(&ext4_feat->f_kobj_unregister);
2747 }
2748
2749 static ssize_t ext4_feat_show(struct kobject *kobj,
2750                               struct attribute *attr, char *buf)
2751 {
2752         return snprintf(buf, PAGE_SIZE, "supported\n");
2753 }
2754
2755 /*
2756  * We can not use ext4_attr_show/store because it relies on the kobject
2757  * being embedded in the ext4_sb_info structure which is definitely not
2758  * true in this case.
2759  */
2760 static const struct sysfs_ops ext4_feat_ops = {
2761         .show   = ext4_feat_show,
2762         .store  = NULL,
2763 };
2764
2765 static struct kobj_type ext4_feat_ktype = {
2766         .default_attrs  = ext4_feat_attrs,
2767         .sysfs_ops      = &ext4_feat_ops,
2768         .release        = ext4_feat_release,
2769 };
2770
2771 /*
2772  * Check whether this filesystem can be mounted based on
2773  * the features present and the RDONLY/RDWR mount requested.
2774  * Returns 1 if this filesystem can be mounted as requested,
2775  * 0 if it cannot be.
2776  */
2777 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2778 {
2779         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2780                 ext4_msg(sb, KERN_ERR,
2781                         "Couldn't mount because of "
2782                         "unsupported optional features (%x)",
2783                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2784                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2785                 return 0;
2786         }
2787
2788         if (readonly)
2789                 return 1;
2790
2791         /* Check that feature set is OK for a read-write mount */
2792         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2793                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2794                          "unsupported optional features (%x)",
2795                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2796                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2797                 return 0;
2798         }
2799         /*
2800          * Large file size enabled file system can only be mounted
2801          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2802          */
2803         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2804                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2805                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2806                                  "cannot be mounted RDWR without "
2807                                  "CONFIG_LBDAF");
2808                         return 0;
2809                 }
2810         }
2811         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2812             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2813                 ext4_msg(sb, KERN_ERR,
2814                          "Can't support bigalloc feature without "
2815                          "extents feature\n");
2816                 return 0;
2817         }
2818
2819 #ifndef CONFIG_QUOTA
2820         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2821             !readonly) {
2822                 ext4_msg(sb, KERN_ERR,
2823                          "Filesystem with quota feature cannot be mounted RDWR "
2824                          "without CONFIG_QUOTA");
2825                 return 0;
2826         }
2827 #endif  /* CONFIG_QUOTA */
2828         return 1;
2829 }
2830
2831 /*
2832  * This function is called once a day if we have errors logged
2833  * on the file system
2834  */
2835 static void print_daily_error_info(unsigned long arg)
2836 {
2837         struct super_block *sb = (struct super_block *) arg;
2838         struct ext4_sb_info *sbi;
2839         struct ext4_super_block *es;
2840
2841         sbi = EXT4_SB(sb);
2842         es = sbi->s_es;
2843
2844         if (es->s_error_count)
2845                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2846                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2847                          le32_to_cpu(es->s_error_count));
2848         if (es->s_first_error_time) {
2849                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2850                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2851                        (int) sizeof(es->s_first_error_func),
2852                        es->s_first_error_func,
2853                        le32_to_cpu(es->s_first_error_line));
2854                 if (es->s_first_error_ino)
2855                         printk(": inode %u",
2856                                le32_to_cpu(es->s_first_error_ino));
2857                 if (es->s_first_error_block)
2858                         printk(": block %llu", (unsigned long long)
2859                                le64_to_cpu(es->s_first_error_block));
2860                 printk("\n");
2861         }
2862         if (es->s_last_error_time) {
2863                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2864                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2865                        (int) sizeof(es->s_last_error_func),
2866                        es->s_last_error_func,
2867                        le32_to_cpu(es->s_last_error_line));
2868                 if (es->s_last_error_ino)
2869                         printk(": inode %u",
2870                                le32_to_cpu(es->s_last_error_ino));
2871                 if (es->s_last_error_block)
2872                         printk(": block %llu", (unsigned long long)
2873                                le64_to_cpu(es->s_last_error_block));
2874                 printk("\n");
2875         }
2876         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2877 }
2878
2879 /* Find next suitable group and run ext4_init_inode_table */
2880 static int ext4_run_li_request(struct ext4_li_request *elr)
2881 {
2882         struct ext4_group_desc *gdp = NULL;
2883         ext4_group_t group, ngroups;
2884         struct super_block *sb;
2885         unsigned long timeout = 0;
2886         int ret = 0;
2887
2888         sb = elr->lr_super;
2889         ngroups = EXT4_SB(sb)->s_groups_count;
2890
2891         sb_start_write(sb);
2892         for (group = elr->lr_next_group; group < ngroups; group++) {
2893                 gdp = ext4_get_group_desc(sb, group, NULL);
2894                 if (!gdp) {
2895                         ret = 1;
2896                         break;
2897                 }
2898
2899                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2900                         break;
2901         }
2902
2903         if (group >= ngroups)
2904                 ret = 1;
2905
2906         if (!ret) {
2907                 timeout = jiffies;
2908                 ret = ext4_init_inode_table(sb, group,
2909                                             elr->lr_timeout ? 0 : 1);
2910                 if (elr->lr_timeout == 0) {
2911                         timeout = (jiffies - timeout) *
2912                                   elr->lr_sbi->s_li_wait_mult;
2913                         elr->lr_timeout = timeout;
2914                 }
2915                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2916                 elr->lr_next_group = group + 1;
2917         }
2918         sb_end_write(sb);
2919
2920         return ret;
2921 }
2922
2923 /*
2924  * Remove lr_request from the list_request and free the
2925  * request structure. Should be called with li_list_mtx held
2926  */
2927 static void ext4_remove_li_request(struct ext4_li_request *elr)
2928 {
2929         struct ext4_sb_info *sbi;
2930
2931         if (!elr)
2932                 return;
2933
2934         sbi = elr->lr_sbi;
2935
2936         list_del(&elr->lr_request);
2937         sbi->s_li_request = NULL;
2938         kfree(elr);
2939 }
2940
2941 static void ext4_unregister_li_request(struct super_block *sb)
2942 {
2943         mutex_lock(&ext4_li_mtx);
2944         if (!ext4_li_info) {
2945                 mutex_unlock(&ext4_li_mtx);
2946                 return;
2947         }
2948
2949         mutex_lock(&ext4_li_info->li_list_mtx);
2950         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2951         mutex_unlock(&ext4_li_info->li_list_mtx);
2952         mutex_unlock(&ext4_li_mtx);
2953 }
2954
2955 static struct task_struct *ext4_lazyinit_task;
2956
2957 /*
2958  * This is the function where ext4lazyinit thread lives. It walks
2959  * through the request list searching for next scheduled filesystem.
2960  * When such a fs is found, run the lazy initialization request
2961  * (ext4_rn_li_request) and keep track of the time spend in this
2962  * function. Based on that time we compute next schedule time of
2963  * the request. When walking through the list is complete, compute
2964  * next waking time and put itself into sleep.
2965  */
2966 static int ext4_lazyinit_thread(void *arg)
2967 {
2968         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2969         struct list_head *pos, *n;
2970         struct ext4_li_request *elr;
2971         unsigned long next_wakeup, cur;
2972
2973         BUG_ON(NULL == eli);
2974
2975 cont_thread:
2976         while (true) {
2977                 next_wakeup = MAX_JIFFY_OFFSET;
2978
2979                 mutex_lock(&eli->li_list_mtx);
2980                 if (list_empty(&eli->li_request_list)) {
2981                         mutex_unlock(&eli->li_list_mtx);
2982                         goto exit_thread;
2983                 }
2984
2985                 list_for_each_safe(pos, n, &eli->li_request_list) {
2986                         elr = list_entry(pos, struct ext4_li_request,
2987                                          lr_request);
2988
2989                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2990                                 if (ext4_run_li_request(elr) != 0) {
2991                                         /* error, remove the lazy_init job */
2992                                         ext4_remove_li_request(elr);
2993                                         continue;
2994                                 }
2995                         }
2996
2997                         if (time_before(elr->lr_next_sched, next_wakeup))
2998                                 next_wakeup = elr->lr_next_sched;
2999                 }
3000                 mutex_unlock(&eli->li_list_mtx);
3001
3002                 try_to_freeze();
3003
3004                 cur = jiffies;
3005                 if ((time_after_eq(cur, next_wakeup)) ||
3006                     (MAX_JIFFY_OFFSET == next_wakeup)) {
3007                         cond_resched();
3008                         continue;
3009                 }
3010
3011                 schedule_timeout_interruptible(next_wakeup - cur);
3012
3013                 if (kthread_should_stop()) {
3014                         ext4_clear_request_list();
3015                         goto exit_thread;
3016                 }
3017         }
3018
3019 exit_thread:
3020         /*
3021          * It looks like the request list is empty, but we need
3022          * to check it under the li_list_mtx lock, to prevent any
3023          * additions into it, and of course we should lock ext4_li_mtx
3024          * to atomically free the list and ext4_li_info, because at
3025          * this point another ext4 filesystem could be registering
3026          * new one.
3027          */
3028         mutex_lock(&ext4_li_mtx);
3029         mutex_lock(&eli->li_list_mtx);
3030         if (!list_empty(&eli->li_request_list)) {
3031                 mutex_unlock(&eli->li_list_mtx);
3032                 mutex_unlock(&ext4_li_mtx);
3033                 goto cont_thread;
3034         }
3035         mutex_unlock(&eli->li_list_mtx);
3036         kfree(ext4_li_info);
3037         ext4_li_info = NULL;
3038         mutex_unlock(&ext4_li_mtx);
3039
3040         return 0;
3041 }
3042
3043 static void ext4_clear_request_list(void)
3044 {
3045         struct list_head *pos, *n;
3046         struct ext4_li_request *elr;
3047
3048         mutex_lock(&ext4_li_info->li_list_mtx);
3049         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3050                 elr = list_entry(pos, struct ext4_li_request,
3051                                  lr_request);
3052                 ext4_remove_li_request(elr);
3053         }
3054         mutex_unlock(&ext4_li_info->li_list_mtx);
3055 }
3056
3057 static int ext4_run_lazyinit_thread(void)
3058 {
3059         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3060                                          ext4_li_info, "ext4lazyinit");
3061         if (IS_ERR(ext4_lazyinit_task)) {
3062                 int err = PTR_ERR(ext4_lazyinit_task);
3063                 ext4_clear_request_list();
3064                 kfree(ext4_li_info);
3065                 ext4_li_info = NULL;
3066                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3067                                  "initialization thread\n",
3068                                  err);
3069                 return err;
3070         }
3071         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3072         return 0;
3073 }
3074
3075 /*
3076  * Check whether it make sense to run itable init. thread or not.
3077  * If there is at least one uninitialized inode table, return
3078  * corresponding group number, else the loop goes through all
3079  * groups and return total number of groups.
3080  */
3081 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3082 {
3083         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3084         struct ext4_group_desc *gdp = NULL;
3085
3086         for (group = 0; group < ngroups; group++) {
3087                 gdp = ext4_get_group_desc(sb, group, NULL);
3088                 if (!gdp)
3089                         continue;
3090
3091                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3092                         break;
3093         }
3094
3095         return group;
3096 }
3097
3098 static int ext4_li_info_new(void)
3099 {
3100         struct ext4_lazy_init *eli = NULL;
3101
3102         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3103         if (!eli)
3104                 return -ENOMEM;
3105
3106         INIT_LIST_HEAD(&eli->li_request_list);
3107         mutex_init(&eli->li_list_mtx);
3108
3109         eli->li_state |= EXT4_LAZYINIT_QUIT;
3110
3111         ext4_li_info = eli;
3112
3113         return 0;
3114 }
3115
3116 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3117                                             ext4_group_t start)
3118 {
3119         struct ext4_sb_info *sbi = EXT4_SB(sb);
3120         struct ext4_li_request *elr;
3121
3122         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3123         if (!elr)
3124                 return NULL;
3125
3126         elr->lr_super = sb;
3127         elr->lr_sbi = sbi;
3128         elr->lr_next_group = start;
3129
3130         /*
3131          * Randomize first schedule time of the request to
3132          * spread the inode table initialization requests
3133          * better.
3134          */
3135         elr->lr_next_sched = jiffies + (prandom_u32() %
3136                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3137         return elr;
3138 }
3139
3140 int ext4_register_li_request(struct super_block *sb,
3141                              ext4_group_t first_not_zeroed)
3142 {
3143         struct ext4_sb_info *sbi = EXT4_SB(sb);
3144         struct ext4_li_request *elr = NULL;
3145         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3146         int ret = 0;
3147
3148         mutex_lock(&ext4_li_mtx);
3149         if (sbi->s_li_request != NULL) {
3150                 /*
3151                  * Reset timeout so it can be computed again, because
3152                  * s_li_wait_mult might have changed.
3153                  */
3154                 sbi->s_li_request->lr_timeout = 0;
3155                 goto out;
3156         }
3157
3158         if (first_not_zeroed == ngroups ||
3159             (sb->s_flags & MS_RDONLY) ||
3160             !test_opt(sb, INIT_INODE_TABLE))
3161                 goto out;
3162
3163         elr = ext4_li_request_new(sb, first_not_zeroed);
3164         if (!elr) {
3165                 ret = -ENOMEM;
3166                 goto out;
3167         }
3168
3169         if (NULL == ext4_li_info) {
3170                 ret = ext4_li_info_new();
3171                 if (ret)
3172                         goto out;
3173         }
3174
3175         mutex_lock(&ext4_li_info->li_list_mtx);
3176         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3177         mutex_unlock(&ext4_li_info->li_list_mtx);
3178
3179         sbi->s_li_request = elr;
3180         /*
3181          * set elr to NULL here since it has been inserted to
3182          * the request_list and the removal and free of it is
3183          * handled by ext4_clear_request_list from now on.
3184          */
3185         elr = NULL;
3186
3187         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3188                 ret = ext4_run_lazyinit_thread();
3189                 if (ret)
3190                         goto out;
3191         }
3192 out:
3193         mutex_unlock(&ext4_li_mtx);
3194         if (ret)
3195                 kfree(elr);
3196         return ret;
3197 }
3198
3199 /*
3200  * We do not need to lock anything since this is called on
3201  * module unload.
3202  */
3203 static void ext4_destroy_lazyinit_thread(void)
3204 {
3205         /*
3206          * If thread exited earlier
3207          * there's nothing to be done.
3208          */
3209         if (!ext4_li_info || !ext4_lazyinit_task)
3210                 return;
3211
3212         kthread_stop(ext4_lazyinit_task);
3213 }
3214
3215 static int set_journal_csum_feature_set(struct super_block *sb)
3216 {
3217         int ret = 1;
3218         int compat, incompat;
3219         struct ext4_sb_info *sbi = EXT4_SB(sb);
3220
3221         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3222                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3223                 /* journal checksum v3 */
3224                 compat = 0;
3225                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3226         } else {
3227                 /* journal checksum v1 */
3228                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3229                 incompat = 0;
3230         }
3231
3232         jbd2_journal_clear_features(sbi->s_journal,
3233                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3234                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3235                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3236         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3237                 ret = jbd2_journal_set_features(sbi->s_journal,
3238                                 compat, 0,
3239                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3240                                 incompat);
3241         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3242                 ret = jbd2_journal_set_features(sbi->s_journal,
3243                                 compat, 0,
3244                                 incompat);
3245                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3246                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3247         } else {
3248                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3249                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3250         }
3251
3252         return ret;
3253 }
3254
3255 /*
3256  * Note: calculating the overhead so we can be compatible with
3257  * historical BSD practice is quite difficult in the face of
3258  * clusters/bigalloc.  This is because multiple metadata blocks from
3259  * different block group can end up in the same allocation cluster.
3260  * Calculating the exact overhead in the face of clustered allocation
3261  * requires either O(all block bitmaps) in memory or O(number of block
3262  * groups**2) in time.  We will still calculate the superblock for
3263  * older file systems --- and if we come across with a bigalloc file
3264  * system with zero in s_overhead_clusters the estimate will be close to
3265  * correct especially for very large cluster sizes --- but for newer
3266  * file systems, it's better to calculate this figure once at mkfs
3267  * time, and store it in the superblock.  If the superblock value is
3268  * present (even for non-bigalloc file systems), we will use it.
3269  */
3270 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3271                           char *buf)
3272 {
3273         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3274         struct ext4_group_desc  *gdp;
3275         ext4_fsblk_t            first_block, last_block, b;
3276         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3277         int                     s, j, count = 0;
3278
3279         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3280                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3281                         sbi->s_itb_per_group + 2);
3282
3283         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3284                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3285         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3286         for (i = 0; i < ngroups; i++) {
3287                 gdp = ext4_get_group_desc(sb, i, NULL);
3288                 b = ext4_block_bitmap(sb, gdp);
3289                 if (b >= first_block && b <= last_block) {
3290                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3291                         count++;
3292                 }
3293                 b = ext4_inode_bitmap(sb, gdp);
3294                 if (b >= first_block && b <= last_block) {
3295                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3296                         count++;
3297                 }
3298                 b = ext4_inode_table(sb, gdp);
3299                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3300                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3301                                 int c = EXT4_B2C(sbi, b - first_block);
3302                                 ext4_set_bit(c, buf);
3303                                 count++;
3304                         }
3305                 if (i != grp)
3306                         continue;
3307                 s = 0;
3308                 if (ext4_bg_has_super(sb, grp)) {
3309                         ext4_set_bit(s++, buf);
3310                         count++;
3311                 }
3312                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3313                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3314                         count++;
3315                 }
3316         }
3317         if (!count)
3318                 return 0;
3319         return EXT4_CLUSTERS_PER_GROUP(sb) -
3320                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3321 }
3322
3323 /*
3324  * Compute the overhead and stash it in sbi->s_overhead
3325  */
3326 int ext4_calculate_overhead(struct super_block *sb)
3327 {
3328         struct ext4_sb_info *sbi = EXT4_SB(sb);
3329         struct ext4_super_block *es = sbi->s_es;
3330         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3331         ext4_fsblk_t overhead = 0;
3332         char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3333
3334         if (!buf)
3335                 return -ENOMEM;
3336
3337         /*
3338          * Compute the overhead (FS structures).  This is constant
3339          * for a given filesystem unless the number of block groups
3340          * changes so we cache the previous value until it does.
3341          */
3342
3343         /*
3344          * All of the blocks before first_data_block are overhead
3345          */
3346         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3347
3348         /*
3349          * Add the overhead found in each block group
3350          */
3351         for (i = 0; i < ngroups; i++) {
3352                 int blks;
3353
3354                 blks = count_overhead(sb, i, buf);
3355                 overhead += blks;
3356                 if (blks)
3357                         memset(buf, 0, PAGE_SIZE);
3358                 cond_resched();
3359         }
3360         /* Add the journal blocks as well */
3361         if (sbi->s_journal)
3362                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3363
3364         sbi->s_overhead = overhead;
3365         smp_wmb();
3366         free_page((unsigned long) buf);
3367         return 0;
3368 }
3369
3370
3371 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3372 {
3373         ext4_fsblk_t resv_clusters;
3374
3375         /*
3376          * There's no need to reserve anything when we aren't using extents.
3377          * The space estimates are exact, there are no unwritten extents,
3378          * hole punching doesn't need new metadata... This is needed especially
3379          * to keep ext2/3 backward compatibility.
3380          */
3381         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3382                 return 0;
3383         /*
3384          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3385          * This should cover the situations where we can not afford to run
3386          * out of space like for example punch hole, or converting
3387          * unwritten extents in delalloc path. In most cases such
3388          * allocation would require 1, or 2 blocks, higher numbers are
3389          * very rare.
3390          */
3391         resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3392                         EXT4_SB(sb)->s_cluster_bits;
3393
3394         do_div(resv_clusters, 50);
3395         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3396
3397         return resv_clusters;
3398 }
3399
3400
3401 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3402 {
3403         ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3404                                 sbi->s_cluster_bits;
3405
3406         if (count >= clusters)
3407                 return -EINVAL;
3408
3409         atomic64_set(&sbi->s_resv_clusters, count);
3410         return 0;
3411 }
3412
3413 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3414 {
3415         char *orig_data = kstrdup(data, GFP_KERNEL);
3416         struct buffer_head *bh;
3417         struct ext4_super_block *es = NULL;
3418         struct ext4_sb_info *sbi;
3419         ext4_fsblk_t block;
3420         ext4_fsblk_t sb_block = get_sb_block(&data);
3421         ext4_fsblk_t logical_sb_block;
3422         unsigned long offset = 0;
3423         unsigned long journal_devnum = 0;
3424         unsigned long def_mount_opts;
3425         struct inode *root;
3426         char *cp;
3427         const char *descr;
3428         int ret = -ENOMEM;
3429         int blocksize, clustersize;
3430         unsigned int db_count;
3431         unsigned int i;
3432         int needs_recovery, has_huge_files, has_bigalloc;
3433         __u64 blocks_count;
3434         int err = 0;
3435         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3436         ext4_group_t first_not_zeroed;
3437
3438         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3439         if (!sbi)
3440                 goto out_free_orig;
3441
3442         sbi->s_blockgroup_lock =
3443                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3444         if (!sbi->s_blockgroup_lock) {
3445                 kfree(sbi);
3446                 goto out_free_orig;
3447         }
3448         sb->s_fs_info = sbi;
3449         sbi->s_sb = sb;
3450         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3451         sbi->s_sb_block = sb_block;
3452         if (sb->s_bdev->bd_part)
3453                 sbi->s_sectors_written_start =
3454                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3455
3456         /* Cleanup superblock name */
3457         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3458                 *cp = '!';
3459
3460         /* -EINVAL is default */
3461         ret = -EINVAL;
3462         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3463         if (!blocksize) {
3464                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3465                 goto out_fail;
3466         }
3467
3468         /*
3469          * The ext4 superblock will not be buffer aligned for other than 1kB
3470          * block sizes.  We need to calculate the offset from buffer start.
3471          */
3472         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3473                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3474                 offset = do_div(logical_sb_block, blocksize);
3475         } else {
3476                 logical_sb_block = sb_block;
3477         }
3478
3479         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3480                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3481                 goto out_fail;
3482         }
3483         /*
3484          * Note: s_es must be initialized as soon as possible because
3485          *       some ext4 macro-instructions depend on its value
3486          */
3487         es = (struct ext4_super_block *) (bh->b_data + offset);
3488         sbi->s_es = es;
3489         sb->s_magic = le16_to_cpu(es->s_magic);
3490         if (sb->s_magic != EXT4_SUPER_MAGIC)
3491                 goto cantfind_ext4;
3492         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3493
3494         /* Warn if metadata_csum and gdt_csum are both set. */
3495         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3496                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3497             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3498                 ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3499                              "redundant flags; please run fsck.");
3500
3501         /* Check for a known checksum algorithm */
3502         if (!ext4_verify_csum_type(sb, es)) {
3503                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3504                          "unknown checksum algorithm.");
3505                 silent = 1;
3506                 goto cantfind_ext4;
3507         }
3508
3509         /* Load the checksum driver */
3510         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3511                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3512                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3513                 if (IS_ERR(sbi->s_chksum_driver)) {
3514                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3515                         ret = PTR_ERR(sbi->s_chksum_driver);
3516                         sbi->s_chksum_driver = NULL;
3517                         goto failed_mount;
3518                 }
3519         }
3520
3521         /* Check superblock checksum */
3522         if (!ext4_superblock_csum_verify(sb, es)) {
3523                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3524                          "invalid superblock checksum.  Run e2fsck?");
3525                 silent = 1;
3526                 goto cantfind_ext4;
3527         }
3528
3529         /* Precompute checksum seed for all metadata */
3530         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3531                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3532                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3533                                                sizeof(es->s_uuid));
3534
3535         /* Set defaults before we parse the mount options */
3536         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3537         set_opt(sb, INIT_INODE_TABLE);
3538         if (def_mount_opts & EXT4_DEFM_DEBUG)
3539                 set_opt(sb, DEBUG);
3540         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3541                 set_opt(sb, GRPID);
3542         if (def_mount_opts & EXT4_DEFM_UID16)
3543                 set_opt(sb, NO_UID32);
3544         /* xattr user namespace & acls are now defaulted on */
3545         set_opt(sb, XATTR_USER);
3546 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3547         set_opt(sb, POSIX_ACL);
3548 #endif
3549         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3550                 set_opt(sb, JOURNAL_DATA);
3551         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3552                 set_opt(sb, ORDERED_DATA);
3553         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3554                 set_opt(sb, WRITEBACK_DATA);
3555
3556         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3557                 set_opt(sb, ERRORS_PANIC);
3558         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3559                 set_opt(sb, ERRORS_CONT);
3560         else
3561                 set_opt(sb, ERRORS_RO);
3562         /* block_validity enabled by default; disable with noblock_validity */
3563         set_opt(sb, BLOCK_VALIDITY);
3564         if (def_mount_opts & EXT4_DEFM_DISCARD)
3565                 set_opt(sb, DISCARD);
3566
3567         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3568         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3569         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3570         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3571         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3572
3573         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3574                 set_opt(sb, BARRIER);
3575
3576         /*
3577          * enable delayed allocation by default
3578          * Use -o nodelalloc to turn it off
3579          */
3580         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3581             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3582                 set_opt(sb, DELALLOC);
3583
3584         /*
3585          * set default s_li_wait_mult for lazyinit, for the case there is
3586          * no mount option specified.
3587          */
3588         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3589
3590         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3591                            &journal_devnum, &journal_ioprio, 0)) {
3592                 ext4_msg(sb, KERN_WARNING,
3593                          "failed to parse options in superblock: %s",
3594                          sbi->s_es->s_mount_opts);
3595         }
3596         sbi->s_def_mount_opt = sbi->s_mount_opt;
3597         if (!parse_options((char *) data, sb, &journal_devnum,
3598                            &journal_ioprio, 0))
3599                 goto failed_mount;
3600
3601         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3602                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3603                             "with data=journal disables delayed "
3604                             "allocation and O_DIRECT support!\n");
3605                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3606                         ext4_msg(sb, KERN_ERR, "can't mount with "
3607                                  "both data=journal and delalloc");
3608                         goto failed_mount;
3609                 }
3610                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3611                         ext4_msg(sb, KERN_ERR, "can't mount with "
3612                                  "both data=journal and dioread_nolock");
3613                         goto failed_mount;
3614                 }
3615                 if (test_opt(sb, DELALLOC))
3616                         clear_opt(sb, DELALLOC);
3617         }
3618
3619         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3620                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3621
3622         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3623             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3624              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3625              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3626                 ext4_msg(sb, KERN_WARNING,
3627                        "feature flags set on rev 0 fs, "
3628                        "running e2fsck is recommended");
3629
3630         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3631                 set_opt2(sb, HURD_COMPAT);
3632                 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
3633                                               EXT4_FEATURE_INCOMPAT_64BIT)) {
3634                         ext4_msg(sb, KERN_ERR,
3635                                  "The Hurd can't support 64-bit file systems");
3636                         goto failed_mount;
3637                 }
3638         }
3639
3640         if (IS_EXT2_SB(sb)) {
3641                 if (ext2_feature_set_ok(sb))
3642                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3643                                  "using the ext4 subsystem");
3644                 else {
3645                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3646                                  "to feature incompatibilities");
3647                         goto failed_mount;
3648                 }
3649         }
3650
3651         if (IS_EXT3_SB(sb)) {
3652                 if (ext3_feature_set_ok(sb))
3653                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3654                                  "using the ext4 subsystem");
3655                 else {
3656                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3657                                  "to feature incompatibilities");
3658                         goto failed_mount;
3659                 }
3660         }
3661
3662         /*
3663          * Check feature flags regardless of the revision level, since we
3664          * previously didn't change the revision level when setting the flags,
3665          * so there is a chance incompat flags are set on a rev 0 filesystem.
3666          */
3667         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3668                 goto failed_mount;
3669
3670         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3671         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3672             blocksize > EXT4_MAX_BLOCK_SIZE) {
3673                 ext4_msg(sb, KERN_ERR,
3674                        "Unsupported filesystem blocksize %d", blocksize);
3675                 goto failed_mount;
3676         }
3677
3678         if (sb->s_blocksize != blocksize) {
3679                 /* Validate the filesystem blocksize */
3680                 if (!sb_set_blocksize(sb, blocksize)) {
3681                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3682                                         blocksize);
3683                         goto failed_mount;
3684                 }
3685
3686                 brelse(bh);
3687                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3688                 offset = do_div(logical_sb_block, blocksize);
3689                 bh = sb_bread_unmovable(sb, logical_sb_block);
3690                 if (!bh) {
3691                         ext4_msg(sb, KERN_ERR,
3692                                "Can't read superblock on 2nd try");
3693                         goto failed_mount;
3694                 }
3695                 es = (struct ext4_super_block *)(bh->b_data + offset);
3696                 sbi->s_es = es;
3697                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3698                         ext4_msg(sb, KERN_ERR,
3699                                "Magic mismatch, very weird!");
3700                         goto failed_mount;
3701                 }
3702         }
3703
3704         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3705                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3706         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3707                                                       has_huge_files);
3708         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3709
3710         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3711                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3712                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3713         } else {
3714                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3715                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3716                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3717                     (!is_power_of_2(sbi->s_inode_size)) ||
3718                     (sbi->s_inode_size > blocksize)) {
3719                         ext4_msg(sb, KERN_ERR,
3720                                "unsupported inode size: %d",
3721                                sbi->s_inode_size);
3722                         goto failed_mount;
3723                 }
3724                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3725                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3726         }
3727
3728         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3729         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3730                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3731                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3732                     !is_power_of_2(sbi->s_desc_size)) {
3733                         ext4_msg(sb, KERN_ERR,
3734                                "unsupported descriptor size %lu",
3735                                sbi->s_desc_size);
3736                         goto failed_mount;
3737                 }
3738         } else
3739                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3740
3741         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3742         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3743         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3744                 goto cantfind_ext4;
3745
3746         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3747         if (sbi->s_inodes_per_block == 0)
3748                 goto cantfind_ext4;
3749         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3750                                         sbi->s_inodes_per_block;
3751         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3752         sbi->s_sbh = bh;
3753         sbi->s_mount_state = le16_to_cpu(es->s_state);
3754         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3755         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3756
3757         for (i = 0; i < 4; i++)
3758                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3759         sbi->s_def_hash_version = es->s_def_hash_version;
3760         if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3761                 i = le32_to_cpu(es->s_flags);
3762                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3763                         sbi->s_hash_unsigned = 3;
3764                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3765 #ifdef __CHAR_UNSIGNED__
3766                         if (!(sb->s_flags & MS_RDONLY))
3767                                 es->s_flags |=
3768                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3769                         sbi->s_hash_unsigned = 3;
3770 #else
3771                         if (!(sb->s_flags & MS_RDONLY))
3772                                 es->s_flags |=
3773                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3774 #endif
3775                 }
3776         }
3777
3778         /* Handle clustersize */
3779         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3780         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3781                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3782         if (has_bigalloc) {
3783                 if (clustersize < blocksize) {
3784                         ext4_msg(sb, KERN_ERR,
3785                                  "cluster size (%d) smaller than "
3786                                  "block size (%d)", clustersize, blocksize);
3787                         goto failed_mount;
3788                 }
3789                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3790                         le32_to_cpu(es->s_log_block_size);
3791                 sbi->s_clusters_per_group =
3792                         le32_to_cpu(es->s_clusters_per_group);
3793                 if (sbi->s_clusters_per_group > blocksize * 8) {
3794                         ext4_msg(sb, KERN_ERR,
3795                                  "#clusters per group too big: %lu",
3796                                  sbi->s_clusters_per_group);
3797                         goto failed_mount;
3798                 }
3799                 if (sbi->s_blocks_per_group !=
3800                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3801                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3802                                  "clusters per group (%lu) inconsistent",
3803                                  sbi->s_blocks_per_group,
3804                                  sbi->s_clusters_per_group);
3805                         goto failed_mount;
3806                 }
3807         } else {
3808                 if (clustersize != blocksize) {
3809                         ext4_warning(sb, "fragment/cluster size (%d) != "
3810                                      "block size (%d)", clustersize,
3811                                      blocksize);
3812                         clustersize = blocksize;
3813                 }
3814                 if (sbi->s_blocks_per_group > blocksize * 8) {
3815                         ext4_msg(sb, KERN_ERR,
3816                                  "#blocks per group too big: %lu",
3817                                  sbi->s_blocks_per_group);
3818                         goto failed_mount;
3819                 }
3820                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3821                 sbi->s_cluster_bits = 0;
3822         }
3823         sbi->s_cluster_ratio = clustersize / blocksize;
3824
3825         if (sbi->s_inodes_per_group > blocksize * 8) {
3826                 ext4_msg(sb, KERN_ERR,
3827                        "#inodes per group too big: %lu",
3828                        sbi->s_inodes_per_group);
3829                 goto failed_mount;
3830         }
3831
3832         /* Do we have standard group size of clustersize * 8 blocks ? */
3833         if (sbi->s_blocks_per_group == clustersize << 3)
3834                 set_opt2(sb, STD_GROUP_SIZE);
3835
3836         /*
3837          * Test whether we have more sectors than will fit in sector_t,
3838          * and whether the max offset is addressable by the page cache.
3839          */
3840         err = generic_check_addressable(sb->s_blocksize_bits,
3841                                         ext4_blocks_count(es));
3842         if (err) {
3843                 ext4_msg(sb, KERN_ERR, "filesystem"
3844                          " too large to mount safely on this system");
3845                 if (sizeof(sector_t) < 8)
3846                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3847                 goto failed_mount;
3848         }
3849
3850         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3851                 goto cantfind_ext4;
3852
3853         /* check blocks count against device size */
3854         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3855         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3856                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3857                        "exceeds size of device (%llu blocks)",
3858                        ext4_blocks_count(es), blocks_count);
3859                 goto failed_mount;
3860         }
3861
3862         /*
3863          * It makes no sense for the first data block to be beyond the end
3864          * of the filesystem.
3865          */
3866         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3867                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3868                          "block %u is beyond end of filesystem (%llu)",
3869                          le32_to_cpu(es->s_first_data_block),
3870                          ext4_blocks_count(es));
3871                 goto failed_mount;
3872         }
3873         blocks_count = (ext4_blocks_count(es) -
3874                         le32_to_cpu(es->s_first_data_block) +
3875                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3876         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3877         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3878                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3879                        "(block count %llu, first data block %u, "
3880                        "blocks per group %lu)", sbi->s_groups_count,
3881                        ext4_blocks_count(es),
3882                        le32_to_cpu(es->s_first_data_block),
3883                        EXT4_BLOCKS_PER_GROUP(sb));
3884                 goto failed_mount;
3885         }
3886         sbi->s_groups_count = blocks_count;
3887         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3888                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3889         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3890                    EXT4_DESC_PER_BLOCK(sb);
3891         sbi->s_group_desc = ext4_kvmalloc(db_count *
3892                                           sizeof(struct buffer_head *),
3893                                           GFP_KERNEL);
3894         if (sbi->s_group_desc == NULL) {
3895                 ext4_msg(sb, KERN_ERR, "not enough memory");
3896                 ret = -ENOMEM;
3897                 goto failed_mount;
3898         }
3899
3900         if (ext4_proc_root)
3901                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3902
3903         if (sbi->s_proc)
3904                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3905                                  &ext4_seq_options_fops, sb);
3906
3907         bgl_lock_init(sbi->s_blockgroup_lock);
3908
3909         for (i = 0; i < db_count; i++) {
3910                 block = descriptor_loc(sb, logical_sb_block, i);
3911                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3912                 if (!sbi->s_group_desc[i]) {
3913                         ext4_msg(sb, KERN_ERR,
3914                                "can't read group descriptor %d", i);
3915                         db_count = i;
3916                         goto failed_mount2;
3917                 }
3918         }
3919         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3920                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3921                 goto failed_mount2;
3922         }
3923
3924         sbi->s_gdb_count = db_count;
3925         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3926         spin_lock_init(&sbi->s_next_gen_lock);
3927
3928         init_timer(&sbi->s_err_report);
3929         sbi->s_err_report.function = print_daily_error_info;
3930         sbi->s_err_report.data = (unsigned long) sb;
3931
3932         /* Register extent status tree shrinker */
3933         if (ext4_es_register_shrinker(sbi))
3934                 goto failed_mount3;
3935
3936         sbi->s_stripe = ext4_get_stripe_size(sbi);
3937         sbi->s_extent_max_zeroout_kb = 32;
3938
3939         /*
3940          * set up enough so that it can read an inode
3941          */
3942         if (!test_opt(sb, NOLOAD) &&
3943             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3944                 sb->s_op = &ext4_sops;
3945         else
3946                 sb->s_op = &ext4_nojournal_sops;
3947         sb->s_export_op = &ext4_export_ops;
3948         sb->s_xattr = ext4_xattr_handlers;
3949 #ifdef CONFIG_QUOTA
3950         sb->dq_op = &ext4_quota_operations;
3951         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3952                 sb->s_qcop = &ext4_qctl_sysfile_operations;
3953         else
3954                 sb->s_qcop = &ext4_qctl_operations;
3955 #endif
3956         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3957
3958         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3959         mutex_init(&sbi->s_orphan_lock);
3960
3961         sb->s_root = NULL;
3962
3963         needs_recovery = (es->s_last_orphan != 0 ||
3964                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3965                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3966
3967         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3968             !(sb->s_flags & MS_RDONLY))
3969                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3970                         goto failed_mount3;
3971
3972         /*
3973          * The first inode we look at is the journal inode.  Don't try
3974          * root first: it may be modified in the journal!
3975          */
3976         if (!test_opt(sb, NOLOAD) &&
3977             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3978                 if (ext4_load_journal(sb, es, journal_devnum))
3979                         goto failed_mount3;
3980         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3981               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3982                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3983                        "suppressed and not mounted read-only");
3984                 goto failed_mount_wq;
3985         } else {
3986                 clear_opt(sb, DATA_FLAGS);
3987                 sbi->s_journal = NULL;
3988                 needs_recovery = 0;
3989                 goto no_journal;
3990         }
3991
3992         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3993             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3994                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3995                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3996                 goto failed_mount_wq;
3997         }
3998
3999         if (!set_journal_csum_feature_set(sb)) {
4000                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4001                          "feature set");
4002                 goto failed_mount_wq;
4003         }
4004
4005         /* We have now updated the journal if required, so we can
4006          * validate the data journaling mode. */
4007         switch (test_opt(sb, DATA_FLAGS)) {
4008         case 0:
4009                 /* No mode set, assume a default based on the journal
4010                  * capabilities: ORDERED_DATA if the journal can
4011                  * cope, else JOURNAL_DATA
4012                  */
4013                 if (jbd2_journal_check_available_features
4014                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4015                         set_opt(sb, ORDERED_DATA);
4016                 else
4017                         set_opt(sb, JOURNAL_DATA);
4018                 break;
4019
4020         case EXT4_MOUNT_ORDERED_DATA:
4021         case EXT4_MOUNT_WRITEBACK_DATA:
4022                 if (!jbd2_journal_check_available_features
4023                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4024                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4025                                "requested data journaling mode");
4026                         goto failed_mount_wq;
4027                 }
4028         default:
4029                 break;
4030         }
4031         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4032
4033         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4034
4035 no_journal:
4036         if (ext4_mballoc_ready) {
4037                 sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
4038                 if (!sbi->s_mb_cache) {
4039                         ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4040                         goto failed_mount_wq;
4041                 }
4042         }
4043
4044         /*
4045          * Get the # of file system overhead blocks from the
4046          * superblock if present.
4047          */
4048         if (es->s_overhead_clusters)
4049                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4050         else {
4051                 err = ext4_calculate_overhead(sb);
4052                 if (err)
4053                         goto failed_mount_wq;
4054         }
4055
4056         /*
4057          * The maximum number of concurrent works can be high and
4058          * concurrency isn't really necessary.  Limit it to 1.
4059          */
4060         EXT4_SB(sb)->rsv_conversion_wq =
4061                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4062         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4063                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4064                 ret = -ENOMEM;
4065                 goto failed_mount4;
4066         }
4067
4068         /*
4069          * The jbd2_journal_load will have done any necessary log recovery,
4070          * so we can safely mount the rest of the filesystem now.
4071          */
4072
4073         root = ext4_iget(sb, EXT4_ROOT_INO);
4074         if (IS_ERR(root)) {
4075                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4076                 ret = PTR_ERR(root);
4077                 root = NULL;
4078                 goto failed_mount4;
4079         }
4080         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4081                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4082                 iput(root);
4083                 goto failed_mount4;
4084         }
4085         sb->s_root = d_make_root(root);
4086         if (!sb->s_root) {
4087                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4088                 ret = -ENOMEM;
4089                 goto failed_mount4;
4090         }
4091
4092         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4093                 sb->s_flags |= MS_RDONLY;
4094
4095         /* determine the minimum size of new large inodes, if present */
4096         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4097                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4098                                                      EXT4_GOOD_OLD_INODE_SIZE;
4099                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4100                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4101                         if (sbi->s_want_extra_isize <
4102                             le16_to_cpu(es->s_want_extra_isize))
4103                                 sbi->s_want_extra_isize =
4104                                         le16_to_cpu(es->s_want_extra_isize);
4105                         if (sbi->s_want_extra_isize <
4106                             le16_to_cpu(es->s_min_extra_isize))
4107                                 sbi->s_want_extra_isize =
4108                                         le16_to_cpu(es->s_min_extra_isize);
4109                 }
4110         }
4111         /* Check if enough inode space is available */
4112         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4113                                                         sbi->s_inode_size) {
4114                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4115                                                        EXT4_GOOD_OLD_INODE_SIZE;
4116                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4117                          "available");
4118         }
4119
4120         err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4121         if (err) {
4122                 ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4123                          "reserved pool", ext4_calculate_resv_clusters(sb));
4124                 goto failed_mount4a;
4125         }
4126
4127         err = ext4_setup_system_zone(sb);
4128         if (err) {
4129                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4130                          "zone (%d)", err);
4131                 goto failed_mount4a;
4132         }
4133
4134         ext4_ext_init(sb);
4135         err = ext4_mb_init(sb);
4136         if (err) {
4137                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4138                          err);
4139                 goto failed_mount5;
4140         }
4141
4142         block = ext4_count_free_clusters(sb);
4143         ext4_free_blocks_count_set(sbi->s_es,
4144                                    EXT4_C2B(sbi, block));
4145         err = percpu_counter_init(&sbi->s_freeclusters_counter, block);
4146         if (!err) {
4147                 unsigned long freei = ext4_count_free_inodes(sb);
4148                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4149                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei);
4150         }
4151         if (!err)
4152                 err = percpu_counter_init(&sbi->s_dirs_counter,
4153                                           ext4_count_dirs(sb));
4154         if (!err)
4155                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
4156         if (err) {
4157                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4158                 goto failed_mount6;
4159         }
4160
4161         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
4162                 if (!ext4_fill_flex_info(sb)) {
4163                         ext4_msg(sb, KERN_ERR,
4164                                "unable to initialize "
4165                                "flex_bg meta info!");
4166                         goto failed_mount6;
4167                 }
4168
4169         err = ext4_register_li_request(sb, first_not_zeroed);
4170         if (err)
4171                 goto failed_mount6;
4172
4173         sbi->s_kobj.kset = ext4_kset;
4174         init_completion(&sbi->s_kobj_unregister);
4175         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4176                                    "%s", sb->s_id);
4177         if (err)
4178                 goto failed_mount7;
4179
4180 #ifdef CONFIG_QUOTA
4181         /* Enable quota usage during mount. */
4182         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4183             !(sb->s_flags & MS_RDONLY)) {
4184                 err = ext4_enable_quotas(sb);
4185                 if (err)
4186                         goto failed_mount8;
4187         }
4188 #endif  /* CONFIG_QUOTA */
4189
4190         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4191         ext4_orphan_cleanup(sb, es);
4192         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4193         if (needs_recovery) {
4194                 ext4_msg(sb, KERN_INFO, "recovery complete");
4195                 ext4_mark_recovery_complete(sb, es);
4196         }
4197         if (EXT4_SB(sb)->s_journal) {
4198                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4199                         descr = " journalled data mode";
4200                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4201                         descr = " ordered data mode";
4202                 else
4203                         descr = " writeback data mode";
4204         } else
4205                 descr = "out journal";
4206
4207         if (test_opt(sb, DISCARD)) {
4208                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4209                 if (!blk_queue_discard(q))
4210                         ext4_msg(sb, KERN_WARNING,
4211                                  "mounting with \"discard\" option, but "
4212                                  "the device does not support discard");
4213         }
4214
4215         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4216                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4217                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4218
4219         if (es->s_error_count)
4220                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4221
4222         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4223         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4224         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4225         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4226
4227         kfree(orig_data);
4228         return 0;
4229
4230 cantfind_ext4:
4231         if (!silent)
4232                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4233         goto failed_mount;
4234
4235 #ifdef CONFIG_QUOTA
4236 failed_mount8:
4237         kobject_del(&sbi->s_kobj);
4238 #endif
4239 failed_mount7:
4240         ext4_unregister_li_request(sb);
4241 failed_mount6:
4242         ext4_mb_release(sb);
4243         if (sbi->s_flex_groups)
4244                 ext4_kvfree(sbi->s_flex_groups);
4245         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4246         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4247         percpu_counter_destroy(&sbi->s_dirs_counter);
4248         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4249 failed_mount5:
4250         ext4_ext_release(sb);
4251         ext4_release_system_zone(sb);
4252 failed_mount4a:
4253         dput(sb->s_root);
4254         sb->s_root = NULL;
4255 failed_mount4:
4256         ext4_msg(sb, KERN_ERR, "mount failed");
4257         if (EXT4_SB(sb)->rsv_conversion_wq)
4258                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4259 failed_mount_wq:
4260         if (sbi->s_journal) {
4261                 jbd2_journal_destroy(sbi->s_journal);
4262                 sbi->s_journal = NULL;
4263         }
4264         ext4_es_unregister_shrinker(sbi);
4265 failed_mount3:
4266         del_timer_sync(&sbi->s_err_report);
4267         if (sbi->s_mmp_tsk)
4268                 kthread_stop(sbi->s_mmp_tsk);
4269 failed_mount2:
4270         for (i = 0; i < db_count; i++)
4271                 brelse(sbi->s_group_desc[i]);
4272         ext4_kvfree(sbi->s_group_desc);
4273 failed_mount:
4274         if (sbi->s_chksum_driver)
4275                 crypto_free_shash(sbi->s_chksum_driver);
4276         if (sbi->s_proc) {
4277                 remove_proc_entry("options", sbi->s_proc);
4278                 remove_proc_entry(sb->s_id, ext4_proc_root);
4279         }
4280 #ifdef CONFIG_QUOTA
4281         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4282                 kfree(sbi->s_qf_names[i]);
4283 #endif
4284         ext4_blkdev_remove(sbi);
4285         brelse(bh);
4286 out_fail:
4287         sb->s_fs_info = NULL;
4288         kfree(sbi->s_blockgroup_lock);
4289         kfree(sbi);
4290 out_free_orig:
4291         kfree(orig_data);
4292         return err ? err : ret;
4293 }
4294
4295 /*
4296  * Setup any per-fs journal parameters now.  We'll do this both on
4297  * initial mount, once the journal has been initialised but before we've
4298  * done any recovery; and again on any subsequent remount.
4299  */
4300 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4301 {
4302         struct ext4_sb_info *sbi = EXT4_SB(sb);
4303
4304         journal->j_commit_interval = sbi->s_commit_interval;
4305         journal->j_min_batch_time = sbi->s_min_batch_time;
4306         journal->j_max_batch_time = sbi->s_max_batch_time;
4307
4308         write_lock(&journal->j_state_lock);
4309         if (test_opt(sb, BARRIER))
4310                 journal->j_flags |= JBD2_BARRIER;
4311         else
4312                 journal->j_flags &= ~JBD2_BARRIER;
4313         if (test_opt(sb, DATA_ERR_ABORT))
4314                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4315         else
4316                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4317         write_unlock(&journal->j_state_lock);
4318 }
4319
4320 static journal_t *ext4_get_journal(struct super_block *sb,
4321                                    unsigned int journal_inum)
4322 {
4323         struct inode *journal_inode;
4324         journal_t *journal;
4325
4326         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4327
4328         /* First, test for the existence of a valid inode on disk.  Bad
4329          * things happen if we iget() an unused inode, as the subsequent
4330          * iput() will try to delete it. */
4331
4332         journal_inode = ext4_iget(sb, journal_inum);
4333         if (IS_ERR(journal_inode)) {
4334                 ext4_msg(sb, KERN_ERR, "no journal found");
4335                 return NULL;
4336         }
4337         if (!journal_inode->i_nlink) {
4338                 make_bad_inode(journal_inode);
4339                 iput(journal_inode);
4340                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4341                 return NULL;
4342         }
4343
4344         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4345                   journal_inode, journal_inode->i_size);
4346         if (!S_ISREG(journal_inode->i_mode)) {
4347                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4348                 iput(journal_inode);
4349                 return NULL;
4350         }
4351
4352         journal = jbd2_journal_init_inode(journal_inode);
4353         if (!journal) {
4354                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4355                 iput(journal_inode);
4356                 return NULL;
4357         }
4358         journal->j_private = sb;
4359         ext4_init_journal_params(sb, journal);
4360         return journal;
4361 }
4362
4363 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4364                                        dev_t j_dev)
4365 {
4366         struct buffer_head *bh;
4367         journal_t *journal;
4368         ext4_fsblk_t start;
4369         ext4_fsblk_t len;
4370         int hblock, blocksize;
4371         ext4_fsblk_t sb_block;
4372         unsigned long offset;
4373         struct ext4_super_block *es;
4374         struct block_device *bdev;
4375
4376         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4377
4378         bdev = ext4_blkdev_get(j_dev, sb);
4379         if (bdev == NULL)
4380                 return NULL;
4381
4382         blocksize = sb->s_blocksize;
4383         hblock = bdev_logical_block_size(bdev);
4384         if (blocksize < hblock) {
4385                 ext4_msg(sb, KERN_ERR,
4386                         "blocksize too small for journal device");
4387                 goto out_bdev;
4388         }
4389
4390         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4391         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4392         set_blocksize(bdev, blocksize);
4393         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4394                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4395                        "external journal");
4396                 goto out_bdev;
4397         }
4398
4399         es = (struct ext4_super_block *) (bh->b_data + offset);
4400         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4401             !(le32_to_cpu(es->s_feature_incompat) &
4402               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4403                 ext4_msg(sb, KERN_ERR, "external journal has "
4404                                         "bad superblock");
4405                 brelse(bh);
4406                 goto out_bdev;
4407         }
4408
4409         if ((le32_to_cpu(es->s_feature_ro_compat) &
4410              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4411             es->s_checksum != ext4_superblock_csum(sb, es)) {
4412                 ext4_msg(sb, KERN_ERR, "external journal has "
4413                                        "corrupt superblock");
4414                 brelse(bh);
4415                 goto out_bdev;
4416         }
4417
4418         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4419                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4420                 brelse(bh);
4421                 goto out_bdev;
4422         }
4423
4424         len = ext4_blocks_count(es);
4425         start = sb_block + 1;
4426         brelse(bh);     /* we're done with the superblock */
4427
4428         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4429                                         start, len, blocksize);
4430         if (!journal) {
4431                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4432                 goto out_bdev;
4433         }
4434         journal->j_private = sb;
4435         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4436         wait_on_buffer(journal->j_sb_buffer);
4437         if (!buffer_uptodate(journal->j_sb_buffer)) {
4438                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4439                 goto out_journal;
4440         }
4441         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4442                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4443                                         "user (unsupported) - %d",
4444                         be32_to_cpu(journal->j_superblock->s_nr_users));
4445                 goto out_journal;
4446         }
4447         EXT4_SB(sb)->journal_bdev = bdev;
4448         ext4_init_journal_params(sb, journal);
4449         return journal;
4450
4451 out_journal:
4452         jbd2_journal_destroy(journal);
4453 out_bdev:
4454         ext4_blkdev_put(bdev);
4455         return NULL;
4456 }
4457
4458 static int ext4_load_journal(struct super_block *sb,
4459                              struct ext4_super_block *es,
4460                              unsigned long journal_devnum)
4461 {
4462         journal_t *journal;
4463         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4464         dev_t journal_dev;
4465         int err = 0;
4466         int really_read_only;
4467
4468         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4469
4470         if (journal_devnum &&
4471             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4472                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4473                         "numbers have changed");
4474                 journal_dev = new_decode_dev(journal_devnum);
4475         } else
4476                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4477
4478         really_read_only = bdev_read_only(sb->s_bdev);
4479
4480         /*
4481          * Are we loading a blank journal or performing recovery after a
4482          * crash?  For recovery, we need to check in advance whether we
4483          * can get read-write access to the device.
4484          */
4485         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4486                 if (sb->s_flags & MS_RDONLY) {
4487                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4488                                         "required on readonly filesystem");
4489                         if (really_read_only) {
4490                                 ext4_msg(sb, KERN_ERR, "write access "
4491                                         "unavailable, cannot proceed");
4492                                 return -EROFS;
4493                         }
4494                         ext4_msg(sb, KERN_INFO, "write access will "
4495                                "be enabled during recovery");
4496                 }
4497         }
4498
4499         if (journal_inum && journal_dev) {
4500                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4501                        "and inode journals!");
4502                 return -EINVAL;
4503         }
4504
4505         if (journal_inum) {
4506                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4507                         return -EINVAL;
4508         } else {
4509                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4510                         return -EINVAL;
4511         }
4512
4513         if (!(journal->j_flags & JBD2_BARRIER))
4514                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4515
4516         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4517                 err = jbd2_journal_wipe(journal, !really_read_only);
4518         if (!err) {
4519                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4520                 if (save)
4521                         memcpy(save, ((char *) es) +
4522                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4523                 err = jbd2_journal_load(journal);
4524                 if (save)
4525                         memcpy(((char *) es) + EXT4_S_ERR_START,
4526                                save, EXT4_S_ERR_LEN);
4527                 kfree(save);
4528         }
4529
4530         if (err) {
4531                 ext4_msg(sb, KERN_ERR, "error loading journal");
4532                 jbd2_journal_destroy(journal);
4533                 return err;
4534         }
4535
4536         EXT4_SB(sb)->s_journal = journal;
4537         ext4_clear_journal_err(sb, es);
4538
4539         if (!really_read_only && journal_devnum &&
4540             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4541                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4542
4543                 /* Make sure we flush the recovery flag to disk. */
4544                 ext4_commit_super(sb, 1);
4545         }
4546
4547         return 0;
4548 }
4549
4550 static int ext4_commit_super(struct super_block *sb, int sync)
4551 {
4552         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4553         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4554         int error = 0;
4555
4556         if (!sbh || block_device_ejected(sb))
4557                 return error;
4558         if (buffer_write_io_error(sbh)) {
4559                 /*
4560                  * Oh, dear.  A previous attempt to write the
4561                  * superblock failed.  This could happen because the
4562                  * USB device was yanked out.  Or it could happen to
4563                  * be a transient write error and maybe the block will
4564                  * be remapped.  Nothing we can do but to retry the
4565                  * write and hope for the best.
4566                  */
4567                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4568                        "superblock detected");
4569                 clear_buffer_write_io_error(sbh);
4570                 set_buffer_uptodate(sbh);
4571         }
4572         /*
4573          * If the file system is mounted read-only, don't update the
4574          * superblock write time.  This avoids updating the superblock
4575          * write time when we are mounting the root file system
4576          * read/only but we need to replay the journal; at that point,
4577          * for people who are east of GMT and who make their clock
4578          * tick in localtime for Windows bug-for-bug compatibility,
4579          * the clock is set in the future, and this will cause e2fsck
4580          * to complain and force a full file system check.
4581          */
4582         if (!(sb->s_flags & MS_RDONLY))
4583                 es->s_wtime = cpu_to_le32(get_seconds());
4584         if (sb->s_bdev->bd_part)
4585                 es->s_kbytes_written =
4586                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4587                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4588                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4589         else
4590                 es->s_kbytes_written =
4591                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4592         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4593                 ext4_free_blocks_count_set(es,
4594                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4595                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4596         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4597                 es->s_free_inodes_count =
4598                         cpu_to_le32(percpu_counter_sum_positive(
4599                                 &EXT4_SB(sb)->s_freeinodes_counter));
4600         BUFFER_TRACE(sbh, "marking dirty");
4601         ext4_superblock_csum_set(sb);
4602         mark_buffer_dirty(sbh);
4603         if (sync) {
4604                 error = sync_dirty_buffer(sbh);
4605                 if (error)
4606                         return error;
4607
4608                 error = buffer_write_io_error(sbh);
4609                 if (error) {
4610                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4611                                "superblock");
4612                         clear_buffer_write_io_error(sbh);
4613                         set_buffer_uptodate(sbh);
4614                 }
4615         }
4616         return error;
4617 }
4618
4619 /*
4620  * Have we just finished recovery?  If so, and if we are mounting (or
4621  * remounting) the filesystem readonly, then we will end up with a
4622  * consistent fs on disk.  Record that fact.
4623  */
4624 static void ext4_mark_recovery_complete(struct super_block *sb,
4625                                         struct ext4_super_block *es)
4626 {
4627         journal_t *journal = EXT4_SB(sb)->s_journal;
4628
4629         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4630                 BUG_ON(journal != NULL);
4631                 return;
4632         }
4633         jbd2_journal_lock_updates(journal);
4634         if (jbd2_journal_flush(journal) < 0)
4635                 goto out;
4636
4637         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4638             sb->s_flags & MS_RDONLY) {
4639                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4640                 ext4_commit_super(sb, 1);
4641         }
4642
4643 out:
4644         jbd2_journal_unlock_updates(journal);
4645 }
4646
4647 /*
4648  * If we are mounting (or read-write remounting) a filesystem whose journal
4649  * has recorded an error from a previous lifetime, move that error to the
4650  * main filesystem now.
4651  */
4652 static void ext4_clear_journal_err(struct super_block *sb,
4653                                    struct ext4_super_block *es)
4654 {
4655         journal_t *journal;
4656         int j_errno;
4657         const char *errstr;
4658
4659         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4660
4661         journal = EXT4_SB(sb)->s_journal;
4662
4663         /*
4664          * Now check for any error status which may have been recorded in the
4665          * journal by a prior ext4_error() or ext4_abort()
4666          */
4667
4668         j_errno = jbd2_journal_errno(journal);
4669         if (j_errno) {
4670                 char nbuf[16];
4671
4672                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4673                 ext4_warning(sb, "Filesystem error recorded "
4674                              "from previous mount: %s", errstr);
4675                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4676
4677                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4678                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4679                 ext4_commit_super(sb, 1);
4680
4681                 jbd2_journal_clear_err(journal);
4682                 jbd2_journal_update_sb_errno(journal);
4683         }
4684 }
4685
4686 /*
4687  * Force the running and committing transactions to commit,
4688  * and wait on the commit.
4689  */
4690 int ext4_force_commit(struct super_block *sb)
4691 {
4692         journal_t *journal;
4693
4694         if (sb->s_flags & MS_RDONLY)
4695                 return 0;
4696
4697         journal = EXT4_SB(sb)->s_journal;
4698         return ext4_journal_force_commit(journal);
4699 }
4700
4701 static int ext4_sync_fs(struct super_block *sb, int wait)
4702 {
4703         int ret = 0;
4704         tid_t target;
4705         bool needs_barrier = false;
4706         struct ext4_sb_info *sbi = EXT4_SB(sb);
4707
4708         trace_ext4_sync_fs(sb, wait);
4709         flush_workqueue(sbi->rsv_conversion_wq);
4710         /*
4711          * Writeback quota in non-journalled quota case - journalled quota has
4712          * no dirty dquots
4713          */
4714         dquot_writeback_dquots(sb, -1);
4715         /*
4716          * Data writeback is possible w/o journal transaction, so barrier must
4717          * being sent at the end of the function. But we can skip it if
4718          * transaction_commit will do it for us.
4719          */
4720         if (sbi->s_journal) {
4721                 target = jbd2_get_latest_transaction(sbi->s_journal);
4722                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4723                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4724                         needs_barrier = true;
4725
4726                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4727                         if (wait)
4728                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4729                                                            target);
4730                 }
4731         } else if (wait && test_opt(sb, BARRIER))
4732                 needs_barrier = true;
4733         if (needs_barrier) {
4734                 int err;
4735                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4736                 if (!ret)
4737                         ret = err;
4738         }
4739
4740         return ret;
4741 }
4742
4743 /*
4744  * LVM calls this function before a (read-only) snapshot is created.  This
4745  * gives us a chance to flush the journal completely and mark the fs clean.
4746  *
4747  * Note that only this function cannot bring a filesystem to be in a clean
4748  * state independently. It relies on upper layer to stop all data & metadata
4749  * modifications.
4750  */
4751 static int ext4_freeze(struct super_block *sb)
4752 {
4753         int error = 0;
4754         journal_t *journal;
4755
4756         if (sb->s_flags & MS_RDONLY)
4757                 return 0;
4758
4759         journal = EXT4_SB(sb)->s_journal;
4760
4761         /* Now we set up the journal barrier. */
4762         jbd2_journal_lock_updates(journal);
4763
4764         /*
4765          * Don't clear the needs_recovery flag if we failed to flush
4766          * the journal.
4767          */
4768         error = jbd2_journal_flush(journal);
4769         if (error < 0)
4770                 goto out;
4771
4772         /* Journal blocked and flushed, clear needs_recovery flag. */
4773         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4774         error = ext4_commit_super(sb, 1);
4775 out:
4776         /* we rely on upper layer to stop further updates */
4777         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4778         return error;
4779 }
4780
4781 /*
4782  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4783  * flag here, even though the filesystem is not technically dirty yet.
4784  */
4785 static int ext4_unfreeze(struct super_block *sb)
4786 {
4787         if (sb->s_flags & MS_RDONLY)
4788                 return 0;
4789
4790         /* Reset the needs_recovery flag before the fs is unlocked. */
4791         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4792         ext4_commit_super(sb, 1);
4793         return 0;
4794 }
4795
4796 /*
4797  * Structure to save mount options for ext4_remount's benefit
4798  */
4799 struct ext4_mount_options {
4800         unsigned long s_mount_opt;
4801         unsigned long s_mount_opt2;
4802         kuid_t s_resuid;
4803         kgid_t s_resgid;
4804         unsigned long s_commit_interval;
4805         u32 s_min_batch_time, s_max_batch_time;
4806 #ifdef CONFIG_QUOTA
4807         int s_jquota_fmt;
4808         char *s_qf_names[EXT4_MAXQUOTAS];
4809 #endif
4810 };
4811
4812 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4813 {
4814         struct ext4_super_block *es;
4815         struct ext4_sb_info *sbi = EXT4_SB(sb);
4816         unsigned long old_sb_flags;
4817         struct ext4_mount_options old_opts;
4818         int enable_quota = 0;
4819         ext4_group_t g;
4820         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4821         int err = 0;
4822 #ifdef CONFIG_QUOTA
4823         int i, j;
4824 #endif
4825         char *orig_data = kstrdup(data, GFP_KERNEL);
4826
4827         /* Store the original options */
4828         old_sb_flags = sb->s_flags;
4829         old_opts.s_mount_opt = sbi->s_mount_opt;
4830         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4831         old_opts.s_resuid = sbi->s_resuid;
4832         old_opts.s_resgid = sbi->s_resgid;
4833         old_opts.s_commit_interval = sbi->s_commit_interval;
4834         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4835         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4836 #ifdef CONFIG_QUOTA
4837         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4838         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4839                 if (sbi->s_qf_names[i]) {
4840                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4841                                                          GFP_KERNEL);
4842                         if (!old_opts.s_qf_names[i]) {
4843                                 for (j = 0; j < i; j++)
4844                                         kfree(old_opts.s_qf_names[j]);
4845                                 kfree(orig_data);
4846                                 return -ENOMEM;
4847                         }
4848                 } else
4849                         old_opts.s_qf_names[i] = NULL;
4850 #endif
4851         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4852                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4853
4854         /*
4855          * Allow the "check" option to be passed as a remount option.
4856          */
4857         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4858                 err = -EINVAL;
4859                 goto restore_opts;
4860         }
4861
4862         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4863                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4864                         ext4_msg(sb, KERN_ERR, "can't mount with "
4865                                  "both data=journal and delalloc");
4866                         err = -EINVAL;
4867                         goto restore_opts;
4868                 }
4869                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4870                         ext4_msg(sb, KERN_ERR, "can't mount with "
4871                                  "both data=journal and dioread_nolock");
4872                         err = -EINVAL;
4873                         goto restore_opts;
4874                 }
4875         }
4876
4877         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4878                 ext4_abort(sb, "Abort forced by user");
4879
4880         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4881                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4882
4883         es = sbi->s_es;
4884
4885         if (sbi->s_journal) {
4886                 ext4_init_journal_params(sb, sbi->s_journal);
4887                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4888         }
4889
4890         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4891                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4892                         err = -EROFS;
4893                         goto restore_opts;
4894                 }
4895
4896                 if (*flags & MS_RDONLY) {
4897                         err = sync_filesystem(sb);
4898                         if (err < 0)
4899                                 goto restore_opts;
4900                         err = dquot_suspend(sb, -1);
4901                         if (err < 0)
4902                                 goto restore_opts;
4903
4904                         /*
4905                          * First of all, the unconditional stuff we have to do
4906                          * to disable replay of the journal when we next remount
4907                          */
4908                         sb->s_flags |= MS_RDONLY;
4909
4910                         /*
4911                          * OK, test if we are remounting a valid rw partition
4912                          * readonly, and if so set the rdonly flag and then
4913                          * mark the partition as valid again.
4914                          */
4915                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4916                             (sbi->s_mount_state & EXT4_VALID_FS))
4917                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4918
4919                         if (sbi->s_journal)
4920                                 ext4_mark_recovery_complete(sb, es);
4921                 } else {
4922                         /* Make sure we can mount this feature set readwrite */
4923                         if (!ext4_feature_set_ok(sb, 0)) {
4924                                 err = -EROFS;
4925                                 goto restore_opts;
4926                         }
4927                         /*
4928                          * Make sure the group descriptor checksums
4929                          * are sane.  If they aren't, refuse to remount r/w.
4930                          */
4931                         for (g = 0; g < sbi->s_groups_count; g++) {
4932                                 struct ext4_group_desc *gdp =
4933                                         ext4_get_group_desc(sb, g, NULL);
4934
4935                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4936                                         ext4_msg(sb, KERN_ERR,
4937                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4938                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4939                                                le16_to_cpu(gdp->bg_checksum));
4940                                         err = -EINVAL;
4941                                         goto restore_opts;
4942                                 }
4943                         }
4944
4945                         /*
4946                          * If we have an unprocessed orphan list hanging
4947                          * around from a previously readonly bdev mount,
4948                          * require a full umount/remount for now.
4949                          */
4950                         if (es->s_last_orphan) {
4951                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4952                                        "remount RDWR because of unprocessed "
4953                                        "orphan inode list.  Please "
4954                                        "umount/remount instead");
4955                                 err = -EINVAL;
4956                                 goto restore_opts;
4957                         }
4958
4959                         /*
4960                          * Mounting a RDONLY partition read-write, so reread
4961                          * and store the current valid flag.  (It may have
4962                          * been changed by e2fsck since we originally mounted
4963                          * the partition.)
4964                          */
4965                         if (sbi->s_journal)
4966                                 ext4_clear_journal_err(sb, es);
4967                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4968                         if (!ext4_setup_super(sb, es, 0))
4969                                 sb->s_flags &= ~MS_RDONLY;
4970                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4971                                                      EXT4_FEATURE_INCOMPAT_MMP))
4972                                 if (ext4_multi_mount_protect(sb,
4973                                                 le64_to_cpu(es->s_mmp_block))) {
4974                                         err = -EROFS;
4975                                         goto restore_opts;
4976                                 }
4977                         enable_quota = 1;
4978                 }
4979         }
4980
4981         /*
4982          * Reinitialize lazy itable initialization thread based on
4983          * current settings
4984          */
4985         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4986                 ext4_unregister_li_request(sb);
4987         else {
4988                 ext4_group_t first_not_zeroed;
4989                 first_not_zeroed = ext4_has_uninit_itable(sb);
4990                 ext4_register_li_request(sb, first_not_zeroed);
4991         }
4992
4993         ext4_setup_system_zone(sb);
4994         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4995                 ext4_commit_super(sb, 1);
4996
4997 #ifdef CONFIG_QUOTA
4998         /* Release old quota file names */
4999         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5000                 kfree(old_opts.s_qf_names[i]);
5001         if (enable_quota) {
5002                 if (sb_any_quota_suspended(sb))
5003                         dquot_resume(sb, -1);
5004                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
5005                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
5006                         err = ext4_enable_quotas(sb);
5007                         if (err)
5008                                 goto restore_opts;
5009                 }
5010         }
5011 #endif
5012
5013         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5014         kfree(orig_data);
5015         return 0;
5016
5017 restore_opts:
5018         sb->s_flags = old_sb_flags;
5019         sbi->s_mount_opt = old_opts.s_mount_opt;
5020         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5021         sbi->s_resuid = old_opts.s_resuid;
5022         sbi->s_resgid = old_opts.s_resgid;
5023         sbi->s_commit_interval = old_opts.s_commit_interval;
5024         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5025         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5026 #ifdef CONFIG_QUOTA
5027         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5028         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5029                 kfree(sbi->s_qf_names[i]);
5030                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5031         }
5032 #endif
5033         kfree(orig_data);
5034         return err;
5035 }
5036
5037 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5038 {
5039         struct super_block *sb = dentry->d_sb;
5040         struct ext4_sb_info *sbi = EXT4_SB(sb);
5041         struct ext4_super_block *es = sbi->s_es;
5042         ext4_fsblk_t overhead = 0, resv_blocks;
5043         u64 fsid;
5044         s64 bfree;
5045         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5046
5047         if (!test_opt(sb, MINIX_DF))
5048                 overhead = sbi->s_overhead;
5049
5050         buf->f_type = EXT4_SUPER_MAGIC;
5051         buf->f_bsize = sb->s_blocksize;
5052         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5053         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5054                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5055         /* prevent underflow in case that few free space is available */
5056         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5057         buf->f_bavail = buf->f_bfree -
5058                         (ext4_r_blocks_count(es) + resv_blocks);
5059         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5060                 buf->f_bavail = 0;
5061         buf->f_files = le32_to_cpu(es->s_inodes_count);
5062         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5063         buf->f_namelen = EXT4_NAME_LEN;
5064         fsid = le64_to_cpup((void *)es->s_uuid) ^
5065                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5066         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5067         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5068
5069         return 0;
5070 }
5071
5072 /* Helper function for writing quotas on sync - we need to start transaction
5073  * before quota file is locked for write. Otherwise the are possible deadlocks:
5074  * Process 1                         Process 2
5075  * ext4_create()                     quota_sync()
5076  *   jbd2_journal_start()                  write_dquot()
5077  *   dquot_initialize()                         down(dqio_mutex)
5078  *     down(dqio_mutex)                    jbd2_journal_start()
5079  *
5080  */
5081
5082 #ifdef CONFIG_QUOTA
5083
5084 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5085 {
5086         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5087 }
5088
5089 static int ext4_write_dquot(struct dquot *dquot)
5090 {
5091         int ret, err;
5092         handle_t *handle;
5093         struct inode *inode;
5094
5095         inode = dquot_to_inode(dquot);
5096         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5097                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5098         if (IS_ERR(handle))
5099                 return PTR_ERR(handle);
5100         ret = dquot_commit(dquot);
5101         err = ext4_journal_stop(handle);
5102         if (!ret)
5103                 ret = err;
5104         return ret;
5105 }
5106
5107 static int ext4_acquire_dquot(struct dquot *dquot)
5108 {
5109         int ret, err;
5110         handle_t *handle;
5111
5112         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5113                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5114         if (IS_ERR(handle))
5115                 return PTR_ERR(handle);
5116         ret = dquot_acquire(dquot);
5117         err = ext4_journal_stop(handle);
5118         if (!ret)
5119                 ret = err;
5120         return ret;
5121 }
5122
5123 static int ext4_release_dquot(struct dquot *dquot)
5124 {
5125         int ret, err;
5126         handle_t *handle;
5127
5128         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5129                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5130         if (IS_ERR(handle)) {
5131                 /* Release dquot anyway to avoid endless cycle in dqput() */
5132                 dquot_release(dquot);
5133                 return PTR_ERR(handle);
5134         }
5135         ret = dquot_release(dquot);
5136         err = ext4_journal_stop(handle);
5137         if (!ret)
5138                 ret = err;
5139         return ret;
5140 }
5141
5142 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5143 {
5144         struct super_block *sb = dquot->dq_sb;
5145         struct ext4_sb_info *sbi = EXT4_SB(sb);
5146
5147         /* Are we journaling quotas? */
5148         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5149             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5150                 dquot_mark_dquot_dirty(dquot);
5151                 return ext4_write_dquot(dquot);
5152         } else {
5153                 return dquot_mark_dquot_dirty(dquot);
5154         }
5155 }
5156
5157 static int ext4_write_info(struct super_block *sb, int type)
5158 {
5159         int ret, err;
5160         handle_t *handle;
5161
5162         /* Data block + inode block */
5163         handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5164         if (IS_ERR(handle))
5165                 return PTR_ERR(handle);
5166         ret = dquot_commit_info(sb, type);
5167         err = ext4_journal_stop(handle);
5168         if (!ret)
5169                 ret = err;
5170         return ret;
5171 }
5172
5173 /*
5174  * Turn on quotas during mount time - we need to find
5175  * the quota file and such...
5176  */
5177 static int ext4_quota_on_mount(struct super_block *sb, int type)
5178 {
5179         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5180                                         EXT4_SB(sb)->s_jquota_fmt, type);
5181 }
5182
5183 /*
5184  * Standard function to be called on quota_on
5185  */
5186 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5187                          struct path *path)
5188 {
5189         int err;
5190
5191         if (!test_opt(sb, QUOTA))
5192                 return -EINVAL;
5193
5194         /* Quotafile not on the same filesystem? */
5195         if (path->dentry->d_sb != sb)
5196                 return -EXDEV;
5197         /* Journaling quota? */
5198         if (EXT4_SB(sb)->s_qf_names[type]) {
5199                 /* Quotafile not in fs root? */
5200                 if (path->dentry->d_parent != sb->s_root)
5201                         ext4_msg(sb, KERN_WARNING,
5202                                 "Quota file not on filesystem root. "
5203                                 "Journaled quota will not work");
5204         }
5205
5206         /*
5207          * When we journal data on quota file, we have to flush journal to see
5208          * all updates to the file when we bypass pagecache...
5209          */
5210         if (EXT4_SB(sb)->s_journal &&
5211             ext4_should_journal_data(path->dentry->d_inode)) {
5212                 /*
5213                  * We don't need to lock updates but journal_flush() could
5214                  * otherwise be livelocked...
5215                  */
5216                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5217                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5218                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5219                 if (err)
5220                         return err;
5221         }
5222
5223         return dquot_quota_on(sb, type, format_id, path);
5224 }
5225
5226 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5227                              unsigned int flags)
5228 {
5229         int err;
5230         struct inode *qf_inode;
5231         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5232                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5233                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5234         };
5235
5236         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5237
5238         if (!qf_inums[type])
5239                 return -EPERM;
5240
5241         qf_inode = ext4_iget(sb, qf_inums[type]);
5242         if (IS_ERR(qf_inode)) {
5243                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5244                 return PTR_ERR(qf_inode);
5245         }
5246
5247         /* Don't account quota for quota files to avoid recursion */
5248         qf_inode->i_flags |= S_NOQUOTA;
5249         err = dquot_enable(qf_inode, type, format_id, flags);
5250         iput(qf_inode);
5251
5252         return err;
5253 }
5254
5255 /* Enable usage tracking for all quota types. */
5256 static int ext4_enable_quotas(struct super_block *sb)
5257 {
5258         int type, err = 0;
5259         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5260                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5261                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5262         };
5263
5264         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5265         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5266                 if (qf_inums[type]) {
5267                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5268                                                 DQUOT_USAGE_ENABLED);
5269                         if (err) {
5270                                 ext4_warning(sb,
5271                                         "Failed to enable quota tracking "
5272                                         "(type=%d, err=%d). Please run "
5273                                         "e2fsck to fix.", type, err);
5274                                 return err;
5275                         }
5276                 }
5277         }
5278         return 0;
5279 }
5280
5281 /*
5282  * quota_on function that is used when QUOTA feature is set.
5283  */
5284 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5285                                  int format_id)
5286 {
5287         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5288                 return -EINVAL;
5289
5290         /*
5291          * USAGE was enabled at mount time. Only need to enable LIMITS now.
5292          */
5293         return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5294 }
5295
5296 static int ext4_quota_off(struct super_block *sb, int type)
5297 {
5298         struct inode *inode = sb_dqopt(sb)->files[type];
5299         handle_t *handle;
5300
5301         /* Force all delayed allocation blocks to be allocated.
5302          * Caller already holds s_umount sem */
5303         if (test_opt(sb, DELALLOC))
5304                 sync_filesystem(sb);
5305
5306         if (!inode)
5307                 goto out;
5308
5309         /* Update modification times of quota files when userspace can
5310          * start looking at them */
5311         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5312         if (IS_ERR(handle))
5313                 goto out;
5314         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5315         ext4_mark_inode_dirty(handle, inode);
5316         ext4_journal_stop(handle);
5317
5318 out:
5319         return dquot_quota_off(sb, type);
5320 }
5321
5322 /*
5323  * quota_off function that is used when QUOTA feature is set.
5324  */
5325 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5326 {
5327         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5328                 return -EINVAL;
5329
5330         /* Disable only the limits. */
5331         return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5332 }
5333
5334 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5335  * acquiring the locks... As quota files are never truncated and quota code
5336  * itself serializes the operations (and no one else should touch the files)
5337  * we don't have to be afraid of races */
5338 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5339                                size_t len, loff_t off)
5340 {
5341         struct inode *inode = sb_dqopt(sb)->files[type];
5342         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5343         int offset = off & (sb->s_blocksize - 1);
5344         int tocopy;
5345         size_t toread;
5346         struct buffer_head *bh;
5347         loff_t i_size = i_size_read(inode);
5348
5349         if (off > i_size)
5350                 return 0;
5351         if (off+len > i_size)
5352                 len = i_size-off;
5353         toread = len;
5354         while (toread > 0) {
5355                 tocopy = sb->s_blocksize - offset < toread ?
5356                                 sb->s_blocksize - offset : toread;
5357                 bh = ext4_bread(NULL, inode, blk, 0);
5358                 if (IS_ERR(bh))
5359                         return PTR_ERR(bh);
5360                 if (!bh)        /* A hole? */
5361                         memset(data, 0, tocopy);
5362                 else
5363                         memcpy(data, bh->b_data+offset, tocopy);
5364                 brelse(bh);
5365                 offset = 0;
5366                 toread -= tocopy;
5367                 data += tocopy;
5368                 blk++;
5369         }
5370         return len;
5371 }
5372
5373 /* Write to quotafile (we know the transaction is already started and has
5374  * enough credits) */
5375 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5376                                 const char *data, size_t len, loff_t off)
5377 {
5378         struct inode *inode = sb_dqopt(sb)->files[type];
5379         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5380         int err, offset = off & (sb->s_blocksize - 1);
5381         struct buffer_head *bh;
5382         handle_t *handle = journal_current_handle();
5383
5384         if (EXT4_SB(sb)->s_journal && !handle) {
5385                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5386                         " cancelled because transaction is not started",
5387                         (unsigned long long)off, (unsigned long long)len);
5388                 return -EIO;
5389         }
5390         /*
5391          * Since we account only one data block in transaction credits,
5392          * then it is impossible to cross a block boundary.
5393          */
5394         if (sb->s_blocksize - offset < len) {
5395                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5396                         " cancelled because not block aligned",
5397                         (unsigned long long)off, (unsigned long long)len);
5398                 return -EIO;
5399         }
5400
5401         bh = ext4_bread(handle, inode, blk, 1);
5402         if (IS_ERR(bh))
5403                 return PTR_ERR(bh);
5404         if (!bh)
5405                 goto out;
5406         BUFFER_TRACE(bh, "get write access");
5407         err = ext4_journal_get_write_access(handle, bh);
5408         if (err) {
5409                 brelse(bh);
5410                 return err;
5411         }
5412         lock_buffer(bh);
5413         memcpy(bh->b_data+offset, data, len);
5414         flush_dcache_page(bh->b_page);
5415         unlock_buffer(bh);
5416         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5417         brelse(bh);
5418 out:
5419         if (inode->i_size < off + len) {
5420                 i_size_write(inode, off + len);
5421                 EXT4_I(inode)->i_disksize = inode->i_size;
5422                 ext4_mark_inode_dirty(handle, inode);
5423         }
5424         return len;
5425 }
5426
5427 #endif
5428
5429 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5430                        const char *dev_name, void *data)
5431 {
5432         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5433 }
5434
5435 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5436 static inline void register_as_ext2(void)
5437 {
5438         int err = register_filesystem(&ext2_fs_type);
5439         if (err)
5440                 printk(KERN_WARNING
5441                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5442 }
5443
5444 static inline void unregister_as_ext2(void)
5445 {
5446         unregister_filesystem(&ext2_fs_type);
5447 }
5448
5449 static inline int ext2_feature_set_ok(struct super_block *sb)
5450 {
5451         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5452                 return 0;
5453         if (sb->s_flags & MS_RDONLY)
5454                 return 1;
5455         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5456                 return 0;
5457         return 1;
5458 }
5459 #else
5460 static inline void register_as_ext2(void) { }
5461 static inline void unregister_as_ext2(void) { }
5462 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5463 #endif
5464
5465 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5466 static inline void register_as_ext3(void)
5467 {
5468         int err = register_filesystem(&ext3_fs_type);
5469         if (err)
5470                 printk(KERN_WARNING
5471                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5472 }
5473
5474 static inline void unregister_as_ext3(void)
5475 {
5476         unregister_filesystem(&ext3_fs_type);
5477 }
5478
5479 static inline int ext3_feature_set_ok(struct super_block *sb)
5480 {
5481         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5482                 return 0;
5483         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5484                 return 0;
5485         if (sb->s_flags & MS_RDONLY)
5486                 return 1;
5487         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5488                 return 0;
5489         return 1;
5490 }
5491 #else
5492 static inline void register_as_ext3(void) { }
5493 static inline void unregister_as_ext3(void) { }
5494 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5495 #endif
5496
5497 static struct file_system_type ext4_fs_type = {
5498         .owner          = THIS_MODULE,
5499         .name           = "ext4",
5500         .mount          = ext4_mount,
5501         .kill_sb        = kill_block_super,
5502         .fs_flags       = FS_REQUIRES_DEV,
5503 };
5504 MODULE_ALIAS_FS("ext4");
5505
5506 static int __init ext4_init_feat_adverts(void)
5507 {
5508         struct ext4_features *ef;
5509         int ret = -ENOMEM;
5510
5511         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5512         if (!ef)
5513                 goto out;
5514
5515         ef->f_kobj.kset = ext4_kset;
5516         init_completion(&ef->f_kobj_unregister);
5517         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5518                                    "features");
5519         if (ret) {
5520                 kfree(ef);
5521                 goto out;
5522         }
5523
5524         ext4_feat = ef;
5525         ret = 0;
5526 out:
5527         return ret;
5528 }
5529
5530 static void ext4_exit_feat_adverts(void)
5531 {
5532         kobject_put(&ext4_feat->f_kobj);
5533         wait_for_completion(&ext4_feat->f_kobj_unregister);
5534         kfree(ext4_feat);
5535 }
5536
5537 /* Shared across all ext4 file systems */
5538 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5539 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5540
5541 static int __init ext4_init_fs(void)
5542 {
5543         int i, err;
5544
5545         ext4_li_info = NULL;
5546         mutex_init(&ext4_li_mtx);
5547
5548         /* Build-time check for flags consistency */
5549         ext4_check_flag_values();
5550
5551         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5552                 mutex_init(&ext4__aio_mutex[i]);
5553                 init_waitqueue_head(&ext4__ioend_wq[i]);
5554         }
5555
5556         err = ext4_init_es();
5557         if (err)
5558                 return err;
5559
5560         err = ext4_init_pageio();
5561         if (err)
5562                 goto out7;
5563
5564         err = ext4_init_system_zone();
5565         if (err)
5566                 goto out6;
5567         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5568         if (!ext4_kset) {
5569                 err = -ENOMEM;
5570                 goto out5;
5571         }
5572         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5573
5574         err = ext4_init_feat_adverts();
5575         if (err)
5576                 goto out4;
5577
5578         err = ext4_init_mballoc();
5579         if (err)
5580                 goto out2;
5581         else
5582                 ext4_mballoc_ready = 1;
5583         err = init_inodecache();
5584         if (err)
5585                 goto out1;
5586         register_as_ext3();
5587         register_as_ext2();
5588         err = register_filesystem(&ext4_fs_type);
5589         if (err)
5590                 goto out;
5591
5592         return 0;
5593 out:
5594         unregister_as_ext2();
5595         unregister_as_ext3();
5596         destroy_inodecache();
5597 out1:
5598         ext4_mballoc_ready = 0;
5599         ext4_exit_mballoc();
5600 out2:
5601         ext4_exit_feat_adverts();
5602 out4:
5603         if (ext4_proc_root)
5604                 remove_proc_entry("fs/ext4", NULL);
5605         kset_unregister(ext4_kset);
5606 out5:
5607         ext4_exit_system_zone();
5608 out6:
5609         ext4_exit_pageio();
5610 out7:
5611         ext4_exit_es();
5612
5613         return err;
5614 }
5615
5616 static void __exit ext4_exit_fs(void)
5617 {
5618         ext4_destroy_lazyinit_thread();
5619         unregister_as_ext2();
5620         unregister_as_ext3();
5621         unregister_filesystem(&ext4_fs_type);
5622         destroy_inodecache();
5623         ext4_exit_mballoc();
5624         ext4_exit_feat_adverts();
5625         remove_proc_entry("fs/ext4", NULL);
5626         kset_unregister(ext4_kset);
5627         ext4_exit_system_zone();
5628         ext4_exit_pageio();
5629         ext4_exit_es();
5630 }
5631
5632 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5633 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5634 MODULE_LICENSE("GPL");
5635 module_init(ext4_init_fs)
5636 module_exit(ext4_exit_fs)