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_sync_fs_nojournal(struct super_block *sb, int wait);
  74 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  75 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  76 static int ext4_unfreeze(struct super_block *sb);
  77 static int ext4_freeze(struct super_block *sb);
  78 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  79                        const char *dev_name, void *data);
  80 static inline int ext2_feature_set_ok(struct super_block *sb);
  81 static inline int ext3_feature_set_ok(struct super_block *sb);
  82 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  83 static void ext4_destroy_lazyinit_thread(void);
  84 static void ext4_unregister_li_request(struct super_block *sb);
  85 static void ext4_clear_request_list(void);
  86 static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
  87
  88 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  89 static struct file_system_type ext2_fs_type = {
  90         .owner          = THIS_MODULE,
  91         .name           = "ext2",
  92         .mount          = ext4_mount,
  93         .kill_sb        = kill_block_super,
  94         .fs_flags       = FS_REQUIRES_DEV,
  95 };
  96 MODULE_ALIAS_FS("ext2");
  97 MODULE_ALIAS("ext2");
  98 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  99 #else
 100 #define IS_EXT2_SB(sb) (0)
 101 #endif
 102
 103
 104 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 105 static struct file_system_type ext3_fs_type = {
 106         .owner          = THIS_MODULE,
 107         .name           = "ext3",
 108         .mount          = ext4_mount,
 109         .kill_sb        = kill_block_super,
 110         .fs_flags       = FS_REQUIRES_DEV,
 111 };
 112 MODULE_ALIAS_FS("ext3");
 113 MODULE_ALIAS("ext3");
 114 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 115 #else
 116 #define IS_EXT3_SB(sb) (0)
 117 #endif
 118
 119 static int ext4_verify_csum_type(struct super_block *sb,
 120                                  struct ext4_super_block *es)
 121 {
 122         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 123                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 124                 return 1;
 125
 126         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 127 }
 128
 129 static __le32 ext4_superblock_csum(struct super_block *sb,
 130                                    struct ext4_super_block *es)
 131 {
 132         struct ext4_sb_info *sbi = EXT4_SB(sb);
 133         int offset = offsetof(struct ext4_super_block, s_checksum);
 134         __u32 csum;
 135
 136         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 137
 138         return cpu_to_le32(csum);
 139 }
 140
 141 static int ext4_superblock_csum_verify(struct super_block *sb,
 142                                        struct ext4_super_block *es)
 143 {
 144         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 145                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 146                 return 1;
 147
 148         return es->s_checksum == ext4_superblock_csum(sb, es);
 149 }
 150
 151 void ext4_superblock_csum_set(struct super_block *sb)
 152 {
 153         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 154
 155         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 156                 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 157                 return;
 158
 159         es->s_checksum = ext4_superblock_csum(sb, es);
 160 }
 161
 162 void *ext4_kvmalloc(size_t size, gfp_t flags)
 163 {
 164         void *ret;
 165
 166         ret = kmalloc(size, flags | __GFP_NOWARN);
 167         if (!ret)
 168                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 169         return ret;
 170 }
 171
 172 void *ext4_kvzalloc(size_t size, gfp_t flags)
 173 {
 174         void *ret;
 175
 176         ret = kzalloc(size, flags | __GFP_NOWARN);
 177         if (!ret)
 178                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 179         return ret;
 180 }
 181
 182 void ext4_kvfree(void *ptr)
 183 {
 184         if (is_vmalloc_addr(ptr))
 185                 vfree(ptr);
 186         else
 187                 kfree(ptr);
 188
 189 }
 190
 191 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 192                                struct ext4_group_desc *bg)
 193 {
 194         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 195                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 196                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 197 }
 198
 199 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 200                                struct ext4_group_desc *bg)
 201 {
 202         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 203                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 204                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 205 }
 206
 207 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 208                               struct ext4_group_desc *bg)
 209 {
 210         return le32_to_cpu(bg->bg_inode_table_lo) |
 211                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 212                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 213 }
 214
 215 __u32 ext4_free_group_clusters(struct super_block *sb,
 216                                struct ext4_group_desc *bg)
 217 {
 218         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 219                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 220                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 221 }
 222
 223 __u32 ext4_free_inodes_count(struct super_block *sb,
 224                               struct ext4_group_desc *bg)
 225 {
 226         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 227                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 228                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 229 }
 230
 231 __u32 ext4_used_dirs_count(struct super_block *sb,
 232                               struct ext4_group_desc *bg)
 233 {
 234         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 235                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 236                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 237 }
 238
 239 __u32 ext4_itable_unused_count(struct super_block *sb,
 240                               struct ext4_group_desc *bg)
 241 {
 242         return le16_to_cpu(bg->bg_itable_unused_lo) |
 243                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 244                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 245 }
 246
 247 void ext4_block_bitmap_set(struct super_block *sb,
 248                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 249 {
 250         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 251         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 252                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 253 }
 254
 255 void ext4_inode_bitmap_set(struct super_block *sb,
 256                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 257 {
 258         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 259         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 260                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 261 }
 262
 263 void ext4_inode_table_set(struct super_block *sb,
 264                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 265 {
 266         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 267         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 268                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 269 }
 270
 271 void ext4_free_group_clusters_set(struct super_block *sb,
 272                                   struct ext4_group_desc *bg, __u32 count)
 273 {
 274         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 275         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 276                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 277 }
 278
 279 void ext4_free_inodes_set(struct super_block *sb,
 280                           struct ext4_group_desc *bg, __u32 count)
 281 {
 282         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 283         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 284                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 285 }
 286
 287 void ext4_used_dirs_set(struct super_block *sb,
 288                           struct ext4_group_desc *bg, __u32 count)
 289 {
 290         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 291         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 292                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 293 }
 294
 295 void ext4_itable_unused_set(struct super_block *sb,
 296                           struct ext4_group_desc *bg, __u32 count)
 297 {
 298         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 299         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 300                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 301 }
 302
 303
 304 static void __save_error_info(struct super_block *sb, const char *func,
 305                             unsigned int line)
 306 {
 307         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 308
 309         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 310         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 311         es->s_last_error_time = cpu_to_le32(get_seconds());
 312         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 313         es->s_last_error_line = cpu_to_le32(line);
 314         if (!es->s_first_error_time) {
 315                 es->s_first_error_time = es->s_last_error_time;
 316                 strncpy(es->s_first_error_func, func,
 317                         sizeof(es->s_first_error_func));
 318                 es->s_first_error_line = cpu_to_le32(line);
 319                 es->s_first_error_ino = es->s_last_error_ino;
 320                 es->s_first_error_block = es->s_last_error_block;
 321         }
 322         /*
 323          * Start the daily error reporting function if it hasn't been
 324          * started already
 325          */
 326         if (!es->s_error_count)
 327                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 328         le32_add_cpu(&es->s_error_count, 1);
 329 }
 330
 331 static void save_error_info(struct super_block *sb, const char *func,
 332                             unsigned int line)
 333 {
 334         __save_error_info(sb, func, line);
 335         ext4_commit_super(sb, 1);
 336 }
 337
 338 /*
 339  * The del_gendisk() function uninitializes the disk-specific data
 340  * structures, including the bdi structure, without telling anyone
 341  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 342  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 343  * This is a kludge to prevent these oops until we can put in a proper
 344  * hook in del_gendisk() to inform the VFS and file system layers.
 345  */
 346 static int block_device_ejected(struct super_block *sb)
 347 {
 348         struct inode *bd_inode = sb->s_bdev->bd_inode;
 349         struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
 350
 351         return bdi->dev == NULL;
 352 }
 353
 354 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 355 {
 356         struct super_block              *sb = journal->j_private;
 357         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 358         int                             error = is_journal_aborted(journal);
 359         struct ext4_journal_cb_entry    *jce;
 360
 361         BUG_ON(txn->t_state == T_FINISHED);
 362         spin_lock(&sbi->s_md_lock);
 363         while (!list_empty(&txn->t_private_list)) {
 364                 jce = list_entry(txn->t_private_list.next,
 365                                  struct ext4_journal_cb_entry, jce_list);
 366                 list_del_init(&jce->jce_list);
 367                 spin_unlock(&sbi->s_md_lock);
 368                 jce->jce_func(sb, jce, error);
 369                 spin_lock(&sbi->s_md_lock);
 370         }
 371         spin_unlock(&sbi->s_md_lock);
 372 }
 373
 374 /* Deal with the reporting of failure conditions on a filesystem such as
 375  * inconsistencies detected or read IO failures.
 376  *
 377  * On ext2, we can store the error state of the filesystem in the
 378  * superblock.  That is not possible on ext4, because we may have other
 379  * write ordering constraints on the superblock which prevent us from
 380  * writing it out straight away; and given that the journal is about to
 381  * be aborted, we can't rely on the current, or future, transactions to
 382  * write out the superblock safely.
 383  *
 384  * We'll just use the jbd2_journal_abort() error code to record an error in
 385  * the journal instead.  On recovery, the journal will complain about
 386  * that error until we've noted it down and cleared it.
 387  */
 388
 389 static void ext4_handle_error(struct super_block *sb)
 390 {
 391         if (sb->s_flags & MS_RDONLY)
 392                 return;
 393
 394         if (!test_opt(sb, ERRORS_CONT)) {
 395                 journal_t *journal = EXT4_SB(sb)->s_journal;
 396
 397                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 398                 if (journal)
 399                         jbd2_journal_abort(journal, -EIO);
 400         }
 401         if (test_opt(sb, ERRORS_RO)) {
 402                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 403                 /*
 404                  * Make sure updated value of ->s_mount_flags will be visible
 405                  * before ->s_flags update
 406                  */
 407                 smp_wmb();
 408                 sb->s_flags |= MS_RDONLY;
 409         }
 410         if (test_opt(sb, ERRORS_PANIC))
 411                 panic("EXT4-fs (device %s): panic forced after error\n",
 412                         sb->s_id);
 413 }
 414
 415 #define ext4_error_ratelimit(sb)                                        \
 416                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 417                              "EXT4-fs error")
 418
 419 void __ext4_error(struct super_block *sb, const char *function,
 420                   unsigned int line, const char *fmt, ...)
 421 {
 422         struct va_format vaf;
 423         va_list args;
 424
 425         if (ext4_error_ratelimit(sb)) {
 426                 va_start(args, fmt);
 427                 vaf.fmt = fmt;
 428                 vaf.va = &args;
 429                 printk(KERN_CRIT
 430                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 431                        sb->s_id, function, line, current->comm, &vaf);
 432                 va_end(args);
 433         }
 434         save_error_info(sb, function, line);
 435         ext4_handle_error(sb);
 436 }
 437
 438 void __ext4_error_inode(struct inode *inode, const char *function,
 439                         unsigned int line, ext4_fsblk_t block,
 440                         const char *fmt, ...)
 441 {
 442         va_list args;
 443         struct va_format vaf;
 444         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 445
 446         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 447         es->s_last_error_block = cpu_to_le64(block);
 448         if (ext4_error_ratelimit(inode->i_sb)) {
 449                 va_start(args, fmt);
 450                 vaf.fmt = fmt;
 451                 vaf.va = &args;
 452                 if (block)
 453                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 454                                "inode #%lu: block %llu: comm %s: %pV\n",
 455                                inode->i_sb->s_id, function, line, inode->i_ino,
 456                                block, current->comm, &vaf);
 457                 else
 458                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 459                                "inode #%lu: comm %s: %pV\n",
 460                                inode->i_sb->s_id, function, line, inode->i_ino,
 461                                current->comm, &vaf);
 462                 va_end(args);
 463         }
 464         save_error_info(inode->i_sb, function, line);
 465         ext4_handle_error(inode->i_sb);
 466 }
 467
 468 void __ext4_error_file(struct file *file, const char *function,
 469                        unsigned int line, ext4_fsblk_t block,
 470                        const char *fmt, ...)
 471 {
 472         va_list args;
 473         struct va_format vaf;
 474         struct ext4_super_block *es;
 475         struct inode *inode = file_inode(file);
 476         char pathname[80], *path;
 477
 478         es = EXT4_SB(inode->i_sb)->s_es;
 479         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 480         if (ext4_error_ratelimit(inode->i_sb)) {
 481                 path = d_path(&(file->f_path), pathname, sizeof(pathname));
 482                 if (IS_ERR(path))
 483                         path = "(unknown)";
 484                 va_start(args, fmt);
 485                 vaf.fmt = fmt;
 486                 vaf.va = &args;
 487                 if (block)
 488                         printk(KERN_CRIT
 489                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 490                                "block %llu: comm %s: path %s: %pV\n",
 491                                inode->i_sb->s_id, function, line, inode->i_ino,
 492                                block, current->comm, path, &vaf);
 493                 else
 494                         printk(KERN_CRIT
 495                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 496                                "comm %s: path %s: %pV\n",
 497                                inode->i_sb->s_id, function, line, inode->i_ino,
 498                                current->comm, path, &vaf);
 499                 va_end(args);
 500         }
 501         save_error_info(inode->i_sb, function, line);
 502         ext4_handle_error(inode->i_sb);
 503 }
 504
 505 const char *ext4_decode_error(struct super_block *sb, int errno,
 506                               char nbuf[16])
 507 {
 508         char *errstr = NULL;
 509
 510         switch (errno) {
 511         case -EIO:
 512                 errstr = "IO failure";
 513                 break;
 514         case -ENOMEM:
 515                 errstr = "Out of memory";
 516                 break;
 517         case -EROFS:
 518                 if (!sb || (EXT4_SB(sb)->s_journal &&
 519                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 520                         errstr = "Journal has aborted";
 521                 else
 522                         errstr = "Readonly filesystem";
 523                 break;
 524         default:
 525                 /* If the caller passed in an extra buffer for unknown
 526                  * errors, textualise them now.  Else we just return
 527                  * NULL. */
 528                 if (nbuf) {
 529                         /* Check for truncated error codes... */
 530                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 531                                 errstr = nbuf;
 532                 }
 533                 break;
 534         }
 535
 536         return errstr;
 537 }
 538
 539 /* __ext4_std_error decodes expected errors from journaling functions
 540  * automatically and invokes the appropriate error response.  */
 541
 542 void __ext4_std_error(struct super_block *sb, const char *function,
 543                       unsigned int line, int errno)
 544 {
 545         char nbuf[16];
 546         const char *errstr;
 547
 548         /* Special case: if the error is EROFS, and we're not already
 549          * inside a transaction, then there's really no point in logging
 550          * an error. */
 551         if (errno == -EROFS && journal_current_handle() == NULL &&
 552             (sb->s_flags & MS_RDONLY))
 553                 return;
 554
 555         if (ext4_error_ratelimit(sb)) {
 556                 errstr = ext4_decode_error(sb, errno, nbuf);
 557                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 558                        sb->s_id, function, line, errstr);
 559         }
 560
 561         save_error_info(sb, function, line);
 562         ext4_handle_error(sb);
 563 }
 564
 565 /*
 566  * ext4_abort is a much stronger failure handler than ext4_error.  The
 567  * abort function may be used to deal with unrecoverable failures such
 568  * as journal IO errors or ENOMEM at a critical moment in log management.
 569  *
 570  * We unconditionally force the filesystem into an ABORT|READONLY state,
 571  * unless the error response on the fs has been set to panic in which
 572  * case we take the easy way out and panic immediately.
 573  */
 574
 575 void __ext4_abort(struct super_block *sb, const char *function,
 576                 unsigned int line, const char *fmt, ...)
 577 {
 578         va_list args;
 579
 580         save_error_info(sb, function, line);
 581         va_start(args, fmt);
 582         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 583                function, line);
 584         vprintk(fmt, args);
 585         printk("\n");
 586         va_end(args);
 587
 588         if ((sb->s_flags & MS_RDONLY) == 0) {
 589                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 590                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 591                 /*
 592                  * Make sure updated value of ->s_mount_flags will be visible
 593                  * before ->s_flags update
 594                  */
 595                 smp_wmb();
 596                 sb->s_flags |= MS_RDONLY;
 597                 if (EXT4_SB(sb)->s_journal)
 598                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 599                 save_error_info(sb, function, line);
 600         }
 601         if (test_opt(sb, ERRORS_PANIC))
 602                 panic("EXT4-fs panic from previous error\n");
 603 }
 604
 605 void __ext4_msg(struct super_block *sb,
 606                 const char *prefix, const char *fmt, ...)
 607 {
 608         struct va_format vaf;
 609         va_list args;
 610
 611         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 612                 return;
 613
 614         va_start(args, fmt);
 615         vaf.fmt = fmt;
 616         vaf.va = &args;
 617         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 618         va_end(args);
 619 }
 620
 621 void __ext4_warning(struct super_block *sb, const char *function,
 622                     unsigned int line, const char *fmt, ...)
 623 {
 624         struct va_format vaf;
 625         va_list args;
 626
 627         if (!___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
 628                           "EXT4-fs warning"))
 629                 return;
 630
 631         va_start(args, fmt);
 632         vaf.fmt = fmt;
 633         vaf.va = &args;
 634         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 635                sb->s_id, function, line, &vaf);
 636         va_end(args);
 637 }
 638
 639 void __ext4_grp_locked_error(const char *function, unsigned int line,
 640                              struct super_block *sb, ext4_group_t grp,
 641                              unsigned long ino, ext4_fsblk_t block,
 642                              const char *fmt, ...)
 643 __releases(bitlock)
 644 __acquires(bitlock)
 645 {
 646         struct va_format vaf;
 647         va_list args;
 648         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 649
 650         es->s_last_error_ino = cpu_to_le32(ino);
 651         es->s_last_error_block = cpu_to_le64(block);
 652         __save_error_info(sb, function, line);
 653
 654         if (ext4_error_ratelimit(sb)) {
 655                 va_start(args, fmt);
 656                 vaf.fmt = fmt;
 657                 vaf.va = &args;
 658                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 659                        sb->s_id, function, line, grp);
 660                 if (ino)
 661                         printk(KERN_CONT "inode %lu: ", ino);
 662                 if (block)
 663                         printk(KERN_CONT "block %llu:",
 664                                (unsigned long long) block);
 665                 printk(KERN_CONT "%pV\n", &vaf);
 666                 va_end(args);
 667         }
 668
 669         if (test_opt(sb, ERRORS_CONT)) {
 670                 ext4_commit_super(sb, 0);
 671                 return;
 672         }
 673
 674         ext4_unlock_group(sb, grp);
 675         ext4_handle_error(sb);
 676         /*
 677          * We only get here in the ERRORS_RO case; relocking the group
 678          * may be dangerous, but nothing bad will happen since the
 679          * filesystem will have already been marked read/only and the
 680          * journal has been aborted.  We return 1 as a hint to callers
 681          * who might what to use the return value from
 682          * ext4_grp_locked_error() to distinguish between the
 683          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 684          * aggressively from the ext4 function in question, with a
 685          * more appropriate error code.
 686          */
 687         ext4_lock_group(sb, grp);
 688         return;
 689 }
 690
 691 void ext4_update_dynamic_rev(struct super_block *sb)
 692 {
 693         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 694
 695         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 696                 return;
 697
 698         ext4_warning(sb,
 699                      "updating to rev %d because of new feature flag, "
 700                      "running e2fsck is recommended",
 701                      EXT4_DYNAMIC_REV);
 702
 703         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 704         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 705         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 706         /* leave es->s_feature_*compat flags alone */
 707         /* es->s_uuid will be set by e2fsck if empty */
 708
 709         /*
 710          * The rest of the superblock fields should be zero, and if not it
 711          * means they are likely already in use, so leave them alone.  We
 712          * can leave it up to e2fsck to clean up any inconsistencies there.
 713          */
 714 }
 715
 716 /*
 717  * Open the external journal device
 718  */
 719 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 720 {
 721         struct block_device *bdev;
 722         char b[BDEVNAME_SIZE];
 723
 724         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 725         if (IS_ERR(bdev))
 726                 goto fail;
 727         return bdev;
 728
 729 fail:
 730         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 731                         __bdevname(dev, b), PTR_ERR(bdev));
 732         return NULL;
 733 }
 734
 735 /*
 736  * Release the journal device
 737  */
 738 static void ext4_blkdev_put(struct block_device *bdev)
 739 {
 740         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 741 }
 742
 743 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 744 {
 745         struct block_device *bdev;
 746         bdev = sbi->journal_bdev;
 747         if (bdev) {
 748                 ext4_blkdev_put(bdev);
 749                 sbi->journal_bdev = NULL;
 750         }
 751 }
 752
 753 static inline struct inode *orphan_list_entry(struct list_head *l)
 754 {
 755         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 756 }
 757
 758 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 759 {
 760         struct list_head *l;
 761
 762         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 763                  le32_to_cpu(sbi->s_es->s_last_orphan));
 764
 765         printk(KERN_ERR "sb_info orphan list:\n");
 766         list_for_each(l, &sbi->s_orphan) {
 767                 struct inode *inode = orphan_list_entry(l);
 768                 printk(KERN_ERR "  "
 769                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 770                        inode->i_sb->s_id, inode->i_ino, inode,
 771                        inode->i_mode, inode->i_nlink,
 772                        NEXT_ORPHAN(inode));
 773         }
 774 }
 775
 776 static void ext4_put_super(struct super_block *sb)
 777 {
 778         struct ext4_sb_info *sbi = EXT4_SB(sb);
 779         struct ext4_super_block *es = sbi->s_es;
 780         int i, err;
 781
 782         ext4_unregister_li_request(sb);
 783         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 784
 785         flush_workqueue(sbi->rsv_conversion_wq);
 786         destroy_workqueue(sbi->rsv_conversion_wq);
 787
 788         if (sbi->s_journal) {
 789                 err = jbd2_journal_destroy(sbi->s_journal);
 790                 sbi->s_journal = NULL;
 791                 if (err < 0)
 792                         ext4_abort(sb, "Couldn't clean up the journal");
 793         }
 794
 795         ext4_es_unregister_shrinker(sbi);
 796         del_timer_sync(&sbi->s_err_report);
 797         ext4_release_system_zone(sb);
 798         ext4_mb_release(sb);
 799         ext4_ext_release(sb);
 800         ext4_xattr_put_super(sb);
 801
 802         if (!(sb->s_flags & MS_RDONLY)) {
 803                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 804                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 805         }
 806         if (!(sb->s_flags & MS_RDONLY))
 807                 ext4_commit_super(sb, 1);
 808
 809         if (sbi->s_proc) {
 810                 remove_proc_entry("options", sbi->s_proc);
 811                 remove_proc_entry(sb->s_id, ext4_proc_root);
 812         }
 813         kobject_del(&sbi->s_kobj);
 814
 815         for (i = 0; i < sbi->s_gdb_count; i++)
 816                 brelse(sbi->s_group_desc[i]);
 817         ext4_kvfree(sbi->s_group_desc);
 818         ext4_kvfree(sbi->s_flex_groups);
 819         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 820         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 821         percpu_counter_destroy(&sbi->s_dirs_counter);
 822         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 823         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
 824         brelse(sbi->s_sbh);
 825 #ifdef CONFIG_QUOTA
 826         for (i = 0; i < MAXQUOTAS; i++)
 827                 kfree(sbi->s_qf_names[i]);
 828 #endif
 829
 830         /* Debugging code just in case the in-memory inode orphan list
 831          * isn't empty.  The on-disk one can be non-empty if we've
 832          * detected an error and taken the fs readonly, but the
 833          * in-memory list had better be clean by this point. */
 834         if (!list_empty(&sbi->s_orphan))
 835                 dump_orphan_list(sb, sbi);
 836         J_ASSERT(list_empty(&sbi->s_orphan));
 837
 838         invalidate_bdev(sb->s_bdev);
 839         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 840                 /*
 841                  * Invalidate the journal device's buffers.  We don't want them
 842                  * floating about in memory - the physical journal device may
 843                  * hotswapped, and it breaks the `ro-after' testing code.
 844                  */
 845                 sync_blockdev(sbi->journal_bdev);
 846                 invalidate_bdev(sbi->journal_bdev);
 847                 ext4_blkdev_remove(sbi);
 848         }
 849         if (sbi->s_mb_cache) {
 850                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 851                 sbi->s_mb_cache = NULL;
 852         }
 853         if (sbi->s_mmp_tsk)
 854                 kthread_stop(sbi->s_mmp_tsk);
 855         sb->s_fs_info = NULL;
 856         /*
 857          * Now that we are completely done shutting down the
 858          * superblock, we need to actually destroy the kobject.
 859          */
 860         kobject_put(&sbi->s_kobj);
 861         wait_for_completion(&sbi->s_kobj_unregister);
 862         if (sbi->s_chksum_driver)
 863                 crypto_free_shash(sbi->s_chksum_driver);
 864         kfree(sbi->s_blockgroup_lock);
 865         kfree(sbi);
 866 }
 867
 868 static struct kmem_cache *ext4_inode_cachep;
 869
 870 /*
 871  * Called inside transaction, so use GFP_NOFS
 872  */
 873 static struct inode *ext4_alloc_inode(struct super_block *sb)
 874 {
 875         struct ext4_inode_info *ei;
 876
 877         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 878         if (!ei)
 879                 return NULL;
 880
 881         ei->vfs_inode.i_version = 1;
 882         spin_lock_init(&ei->i_raw_lock);
 883         INIT_LIST_HEAD(&ei->i_prealloc_list);
 884         spin_lock_init(&ei->i_prealloc_lock);
 885         ext4_es_init_tree(&ei->i_es_tree);
 886         rwlock_init(&ei->i_es_lock);
 887         INIT_LIST_HEAD(&ei->i_es_lru);
 888         ei->i_es_lru_nr = 0;
 889         ei->i_touch_when = 0;
 890         ei->i_reserved_data_blocks = 0;
 891         ei->i_reserved_meta_blocks = 0;
 892         ei->i_allocated_meta_blocks = 0;
 893         ei->i_da_metadata_calc_len = 0;
 894         ei->i_da_metadata_calc_last_lblock = 0;
 895         spin_lock_init(&(ei->i_block_reservation_lock));
 896 #ifdef CONFIG_QUOTA
 897         ei->i_reserved_quota = 0;
 898 #endif
 899         ei->jinode = NULL;
 900         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 901         spin_lock_init(&ei->i_completed_io_lock);
 902         ei->i_sync_tid = 0;
 903         ei->i_datasync_tid = 0;
 904         atomic_set(&ei->i_ioend_count, 0);
 905         atomic_set(&ei->i_unwritten, 0);
 906         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 907
 908         return &ei->vfs_inode;
 909 }
 910
 911 static int ext4_drop_inode(struct inode *inode)
 912 {
 913         int drop = generic_drop_inode(inode);
 914
 915         trace_ext4_drop_inode(inode, drop);
 916         return drop;
 917 }
 918
 919 static void ext4_i_callback(struct rcu_head *head)
 920 {
 921         struct inode *inode = container_of(head, struct inode, i_rcu);
 922         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 923 }
 924
 925 static void ext4_destroy_inode(struct inode *inode)
 926 {
 927         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 928                 ext4_msg(inode->i_sb, KERN_ERR,
 929                          "Inode %lu (%p): orphan list check failed!",
 930                          inode->i_ino, EXT4_I(inode));
 931                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 932                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 933                                 true);
 934                 dump_stack();
 935         }
 936         call_rcu(&inode->i_rcu, ext4_i_callback);
 937 }
 938
 939 static void init_once(void *foo)
 940 {
 941         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 942
 943         INIT_LIST_HEAD(&ei->i_orphan);
 944         init_rwsem(&ei->xattr_sem);
 945         init_rwsem(&ei->i_data_sem);
 946         inode_init_once(&ei->vfs_inode);
 947 }
 948
 949 static int __init init_inodecache(void)
 950 {
 951         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 952                                              sizeof(struct ext4_inode_info),
 953                                              0, (SLAB_RECLAIM_ACCOUNT|
 954                                                 SLAB_MEM_SPREAD),
 955                                              init_once);
 956         if (ext4_inode_cachep == NULL)
 957                 return -ENOMEM;
 958         return 0;
 959 }
 960
 961 static void destroy_inodecache(void)
 962 {
 963         /*
 964          * Make sure all delayed rcu free inodes are flushed before we
 965          * destroy cache.
 966          */
 967         rcu_barrier();
 968         kmem_cache_destroy(ext4_inode_cachep);
 969 }
 970
 971 void ext4_clear_inode(struct inode *inode)
 972 {
 973         invalidate_inode_buffers(inode);
 974         clear_inode(inode);
 975         dquot_drop(inode);
 976         ext4_discard_preallocations(inode);
 977         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 978         ext4_es_lru_del(inode);
 979         if (EXT4_I(inode)->jinode) {
 980                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 981                                                EXT4_I(inode)->jinode);
 982                 jbd2_free_inode(EXT4_I(inode)->jinode);
 983                 EXT4_I(inode)->jinode = NULL;
 984         }
 985 }
 986
 987 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 988                                         u64 ino, u32 generation)
 989 {
 990         struct inode *inode;
 991
 992         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 993                 return ERR_PTR(-ESTALE);
 994         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 995                 return ERR_PTR(-ESTALE);
 996
 997         /* iget isn't really right if the inode is currently unallocated!!
 998          *
 999          * ext4_read_inode will return a bad_inode if the inode had been
1000          * deleted, so we should be safe.
1001          *
1002          * Currently we don't know the generation for parent directory, so
1003          * a generation of 0 means "accept any"
1004          */
1005         inode = ext4_iget(sb, ino);
1006         if (IS_ERR(inode))
1007                 return ERR_CAST(inode);
1008         if (generation && inode->i_generation != generation) {
1009                 iput(inode);
1010                 return ERR_PTR(-ESTALE);
1011         }
1012
1013         return inode;
1014 }
1015
1016 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1017                                         int fh_len, int fh_type)
1018 {
1019         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1020                                     ext4_nfs_get_inode);
1021 }
1022
1023 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1024                                         int fh_len, int fh_type)
1025 {
1026         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1027                                     ext4_nfs_get_inode);
1028 }
1029
1030 /*
1031  * Try to release metadata pages (indirect blocks, directories) which are
1032  * mapped via the block device.  Since these pages could have journal heads
1033  * which would prevent try_to_free_buffers() from freeing them, we must use
1034  * jbd2 layer's try_to_free_buffers() function to release them.
1035  */
1036 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1037                                  gfp_t wait)
1038 {
1039         journal_t *journal = EXT4_SB(sb)->s_journal;
1040
1041         WARN_ON(PageChecked(page));
1042         if (!page_has_buffers(page))
1043                 return 0;
1044         if (journal)
1045                 return jbd2_journal_try_to_free_buffers(journal, page,
1046                                                         wait & ~__GFP_WAIT);
1047         return try_to_free_buffers(page);
1048 }
1049
1050 #ifdef CONFIG_QUOTA
1051 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1052 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1053
1054 static int ext4_write_dquot(struct dquot *dquot);
1055 static int ext4_acquire_dquot(struct dquot *dquot);
1056 static int ext4_release_dquot(struct dquot *dquot);
1057 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1058 static int ext4_write_info(struct super_block *sb, int type);
1059 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1060                          struct path *path);
1061 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1062                                  int format_id);
1063 static int ext4_quota_off(struct super_block *sb, int type);
1064 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1065 static int ext4_quota_on_mount(struct super_block *sb, int type);
1066 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1067                                size_t len, loff_t off);
1068 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1069                                 const char *data, size_t len, loff_t off);
1070 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1071                              unsigned int flags);
1072 static int ext4_enable_quotas(struct super_block *sb);
1073
1074 static const struct dquot_operations ext4_quota_operations = {
1075         .get_reserved_space = ext4_get_reserved_space,
1076         .write_dquot    = ext4_write_dquot,
1077         .acquire_dquot  = ext4_acquire_dquot,
1078         .release_dquot  = ext4_release_dquot,
1079         .mark_dirty     = ext4_mark_dquot_dirty,
1080         .write_info     = ext4_write_info,
1081         .alloc_dquot    = dquot_alloc,
1082         .destroy_dquot  = dquot_destroy,
1083 };
1084
1085 static const struct quotactl_ops ext4_qctl_operations = {
1086         .quota_on       = ext4_quota_on,
1087         .quota_off      = ext4_quota_off,
1088         .quota_sync     = dquot_quota_sync,
1089         .get_info       = dquot_get_dqinfo,
1090         .set_info       = dquot_set_dqinfo,
1091         .get_dqblk      = dquot_get_dqblk,
1092         .set_dqblk      = dquot_set_dqblk
1093 };
1094
1095 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1096         .quota_on_meta  = ext4_quota_on_sysfile,
1097         .quota_off      = ext4_quota_off_sysfile,
1098         .quota_sync     = dquot_quota_sync,
1099         .get_info       = dquot_get_dqinfo,
1100         .set_info       = dquot_set_dqinfo,
1101         .get_dqblk      = dquot_get_dqblk,
1102         .set_dqblk      = dquot_set_dqblk
1103 };
1104 #endif
1105
1106 static const struct super_operations ext4_sops = {
1107         .alloc_inode    = ext4_alloc_inode,
1108         .destroy_inode  = ext4_destroy_inode,
1109         .write_inode    = ext4_write_inode,
1110         .dirty_inode    = ext4_dirty_inode,
1111         .drop_inode     = ext4_drop_inode,
1112         .evict_inode    = ext4_evict_inode,
1113         .put_super      = ext4_put_super,
1114         .sync_fs        = ext4_sync_fs,
1115         .freeze_fs      = ext4_freeze,
1116         .unfreeze_fs    = ext4_unfreeze,
1117         .statfs         = ext4_statfs,
1118         .remount_fs     = ext4_remount,
1119         .show_options   = ext4_show_options,
1120 #ifdef CONFIG_QUOTA
1121         .quota_read     = ext4_quota_read,
1122         .quota_write    = ext4_quota_write,
1123 #endif
1124         .bdev_try_to_free_page = bdev_try_to_free_page,
1125 };
1126
1127 static const struct super_operations ext4_nojournal_sops = {
1128         .alloc_inode    = ext4_alloc_inode,
1129         .destroy_inode  = ext4_destroy_inode,
1130         .write_inode    = ext4_write_inode,
1131         .dirty_inode    = ext4_dirty_inode,
1132         .drop_inode     = ext4_drop_inode,
1133         .evict_inode    = ext4_evict_inode,
1134         .sync_fs        = ext4_sync_fs_nojournal,
1135         .put_super      = ext4_put_super,
1136         .statfs         = ext4_statfs,
1137         .remount_fs     = ext4_remount,
1138         .show_options   = ext4_show_options,
1139 #ifdef CONFIG_QUOTA
1140         .quota_read     = ext4_quota_read,
1141         .quota_write    = ext4_quota_write,
1142 #endif
1143         .bdev_try_to_free_page = bdev_try_to_free_page,
1144 };
1145
1146 static const struct export_operations ext4_export_ops = {
1147         .fh_to_dentry = ext4_fh_to_dentry,
1148         .fh_to_parent = ext4_fh_to_parent,
1149         .get_parent = ext4_get_parent,
1150 };
1151
1152 enum {
1153         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1154         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1155         Opt_nouid32, Opt_debug, Opt_removed,
1156         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1157         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1158         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1159         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1160         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1161         Opt_data_err_abort, Opt_data_err_ignore,
1162         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1163         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1164         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1165         Opt_usrquota, Opt_grpquota, Opt_i_version,
1166         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1167         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1168         Opt_inode_readahead_blks, Opt_journal_ioprio,
1169         Opt_dioread_nolock, Opt_dioread_lock,
1170         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1171         Opt_max_dir_size_kb,
1172 };
1173
1174 static const match_table_t tokens = {
1175         {Opt_bsd_df, "bsddf"},
1176         {Opt_minix_df, "minixdf"},
1177         {Opt_grpid, "grpid"},
1178         {Opt_grpid, "bsdgroups"},
1179         {Opt_nogrpid, "nogrpid"},
1180         {Opt_nogrpid, "sysvgroups"},
1181         {Opt_resgid, "resgid=%u"},
1182         {Opt_resuid, "resuid=%u"},
1183         {Opt_sb, "sb=%u"},
1184         {Opt_err_cont, "errors=continue"},
1185         {Opt_err_panic, "errors=panic"},
1186         {Opt_err_ro, "errors=remount-ro"},
1187         {Opt_nouid32, "nouid32"},
1188         {Opt_debug, "debug"},
1189         {Opt_removed, "oldalloc"},
1190         {Opt_removed, "orlov"},
1191         {Opt_user_xattr, "user_xattr"},
1192         {Opt_nouser_xattr, "nouser_xattr"},
1193         {Opt_acl, "acl"},
1194         {Opt_noacl, "noacl"},
1195         {Opt_noload, "norecovery"},
1196         {Opt_noload, "noload"},
1197         {Opt_removed, "nobh"},
1198         {Opt_removed, "bh"},
1199         {Opt_commit, "commit=%u"},
1200         {Opt_min_batch_time, "min_batch_time=%u"},
1201         {Opt_max_batch_time, "max_batch_time=%u"},
1202         {Opt_journal_dev, "journal_dev=%u"},
1203         {Opt_journal_path, "journal_path=%s"},
1204         {Opt_journal_checksum, "journal_checksum"},
1205         {Opt_journal_async_commit, "journal_async_commit"},
1206         {Opt_abort, "abort"},
1207         {Opt_data_journal, "data=journal"},
1208         {Opt_data_ordered, "data=ordered"},
1209         {Opt_data_writeback, "data=writeback"},
1210         {Opt_data_err_abort, "data_err=abort"},
1211         {Opt_data_err_ignore, "data_err=ignore"},
1212         {Opt_offusrjquota, "usrjquota="},
1213         {Opt_usrjquota, "usrjquota=%s"},
1214         {Opt_offgrpjquota, "grpjquota="},
1215         {Opt_grpjquota, "grpjquota=%s"},
1216         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1217         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1218         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1219         {Opt_grpquota, "grpquota"},
1220         {Opt_noquota, "noquota"},
1221         {Opt_quota, "quota"},
1222         {Opt_usrquota, "usrquota"},
1223         {Opt_barrier, "barrier=%u"},
1224         {Opt_barrier, "barrier"},
1225         {Opt_nobarrier, "nobarrier"},
1226         {Opt_i_version, "i_version"},
1227         {Opt_stripe, "stripe=%u"},
1228         {Opt_delalloc, "delalloc"},
1229         {Opt_nodelalloc, "nodelalloc"},
1230         {Opt_removed, "mblk_io_submit"},
1231         {Opt_removed, "nomblk_io_submit"},
1232         {Opt_block_validity, "block_validity"},
1233         {Opt_noblock_validity, "noblock_validity"},
1234         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1235         {Opt_journal_ioprio, "journal_ioprio=%u"},
1236         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1237         {Opt_auto_da_alloc, "auto_da_alloc"},
1238         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1239         {Opt_dioread_nolock, "dioread_nolock"},
1240         {Opt_dioread_lock, "dioread_lock"},
1241         {Opt_discard, "discard"},
1242         {Opt_nodiscard, "nodiscard"},
1243         {Opt_init_itable, "init_itable=%u"},
1244         {Opt_init_itable, "init_itable"},
1245         {Opt_noinit_itable, "noinit_itable"},
1246         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1247         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1248         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1249         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1250         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1251         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1252         {Opt_err, NULL},
1253 };
1254
1255 static ext4_fsblk_t get_sb_block(void **data)
1256 {
1257         ext4_fsblk_t    sb_block;
1258         char            *options = (char *) *data;
1259
1260         if (!options || strncmp(options, "sb=", 3) != 0)
1261                 return 1;       /* Default location */
1262
1263         options += 3;
1264         /* TODO: use simple_strtoll with >32bit ext4 */
1265         sb_block = simple_strtoul(options, &options, 0);
1266         if (*options && *options != ',') {
1267                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1268                        (char *) *data);
1269                 return 1;
1270         }
1271         if (*options == ',')
1272                 options++;
1273         *data = (void *) options;
1274
1275         return sb_block;
1276 }
1277
1278 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1279 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1280         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1281
1282 #ifdef CONFIG_QUOTA
1283 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1284 {
1285         struct ext4_sb_info *sbi = EXT4_SB(sb);
1286         char *qname;
1287         int ret = -1;
1288
1289         if (sb_any_quota_loaded(sb) &&
1290                 !sbi->s_qf_names[qtype]) {
1291                 ext4_msg(sb, KERN_ERR,
1292                         "Cannot change journaled "
1293                         "quota options when quota turned on");
1294                 return -1;
1295         }
1296         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1297                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1298                          "when QUOTA feature is enabled");
1299                 return -1;
1300         }
1301         qname = match_strdup(args);
1302         if (!qname) {
1303                 ext4_msg(sb, KERN_ERR,
1304                         "Not enough memory for storing quotafile name");
1305                 return -1;
1306         }
1307         if (sbi->s_qf_names[qtype]) {
1308                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1309                         ret = 1;
1310                 else
1311                         ext4_msg(sb, KERN_ERR,
1312                                  "%s quota file already specified",
1313                                  QTYPE2NAME(qtype));
1314                 goto errout;
1315         }
1316         if (strchr(qname, '/')) {
1317                 ext4_msg(sb, KERN_ERR,
1318                         "quotafile must be on filesystem root");
1319                 goto errout;
1320         }
1321         sbi->s_qf_names[qtype] = qname;
1322         set_opt(sb, QUOTA);
1323         return 1;
1324 errout:
1325         kfree(qname);
1326         return ret;
1327 }
1328
1329 static int clear_qf_name(struct super_block *sb, int qtype)
1330 {
1331
1332         struct ext4_sb_info *sbi = EXT4_SB(sb);
1333
1334         if (sb_any_quota_loaded(sb) &&
1335                 sbi->s_qf_names[qtype]) {
1336                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1337                         " when quota turned on");
1338                 return -1;
1339         }
1340         kfree(sbi->s_qf_names[qtype]);
1341         sbi->s_qf_names[qtype] = NULL;
1342         return 1;
1343 }
1344 #endif
1345
1346 #define MOPT_SET        0x0001
1347 #define MOPT_CLEAR      0x0002
1348 #define MOPT_NOSUPPORT  0x0004
1349 #define MOPT_EXPLICIT   0x0008
1350 #define MOPT_CLEAR_ERR  0x0010
1351 #define MOPT_GTE0       0x0020
1352 #ifdef CONFIG_QUOTA
1353 #define MOPT_Q          0
1354 #define MOPT_QFMT       0x0040
1355 #else
1356 #define MOPT_Q          MOPT_NOSUPPORT
1357 #define MOPT_QFMT       MOPT_NOSUPPORT
1358 #endif
1359 #define MOPT_DATAJ      0x0080
1360 #define MOPT_NO_EXT2    0x0100
1361 #define MOPT_NO_EXT3    0x0200
1362 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1363 #define MOPT_STRING     0x0400
1364
1365 static const struct mount_opts {
1366         int     token;
1367         int     mount_opt;
1368         int     flags;
1369 } ext4_mount_opts[] = {
1370         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1371         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1372         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1373         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1374         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1375         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1376         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1377          MOPT_EXT4_ONLY | MOPT_SET},
1378         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1379          MOPT_EXT4_ONLY | MOPT_CLEAR},
1380         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1381         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1382         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1383          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1384         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1385          MOPT_EXT4_ONLY | MOPT_CLEAR},
1386         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1387          MOPT_EXT4_ONLY | MOPT_SET},
1388         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1389                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1390          MOPT_EXT4_ONLY | MOPT_SET},
1391         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1392         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1393         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1394         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1395         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1396          MOPT_NO_EXT2 | MOPT_SET},
1397         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1398          MOPT_NO_EXT2 | MOPT_CLEAR},
1399         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1400         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1401         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1402         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1403         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1404         {Opt_commit, 0, MOPT_GTE0},
1405         {Opt_max_batch_time, 0, MOPT_GTE0},
1406         {Opt_min_batch_time, 0, MOPT_GTE0},
1407         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1408         {Opt_init_itable, 0, MOPT_GTE0},
1409         {Opt_stripe, 0, MOPT_GTE0},
1410         {Opt_resuid, 0, MOPT_GTE0},
1411         {Opt_resgid, 0, MOPT_GTE0},
1412         {Opt_journal_dev, 0, MOPT_GTE0},
1413         {Opt_journal_path, 0, MOPT_STRING},
1414         {Opt_journal_ioprio, 0, MOPT_GTE0},
1415         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1416         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1417         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1418          MOPT_NO_EXT2 | MOPT_DATAJ},
1419         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1420         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1421 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1422         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1423         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1424 #else
1425         {Opt_acl, 0, MOPT_NOSUPPORT},
1426         {Opt_noacl, 0, MOPT_NOSUPPORT},
1427 #endif
1428         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1429         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1430         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1431         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1432                                                         MOPT_SET | MOPT_Q},
1433         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1434                                                         MOPT_SET | MOPT_Q},
1435         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1436                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1437         {Opt_usrjquota, 0, MOPT_Q},
1438         {Opt_grpjquota, 0, MOPT_Q},
1439         {Opt_offusrjquota, 0, MOPT_Q},
1440         {Opt_offgrpjquota, 0, MOPT_Q},
1441         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1442         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1443         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1444         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1445         {Opt_err, 0, 0}
1446 };
1447
1448 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1449                             substring_t *args, unsigned long *journal_devnum,
1450                             unsigned int *journal_ioprio, int is_remount)
1451 {
1452         struct ext4_sb_info *sbi = EXT4_SB(sb);
1453         const struct mount_opts *m;
1454         kuid_t uid;
1455         kgid_t gid;
1456         int arg = 0;
1457
1458 #ifdef CONFIG_QUOTA
1459         if (token == Opt_usrjquota)
1460                 return set_qf_name(sb, USRQUOTA, &args[0]);
1461         else if (token == Opt_grpjquota)
1462                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1463         else if (token == Opt_offusrjquota)
1464                 return clear_qf_name(sb, USRQUOTA);
1465         else if (token == Opt_offgrpjquota)
1466                 return clear_qf_name(sb, GRPQUOTA);
1467 #endif
1468         switch (token) {
1469         case Opt_noacl:
1470         case Opt_nouser_xattr:
1471                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1472                 break;
1473         case Opt_sb:
1474                 return 1;       /* handled by get_sb_block() */
1475         case Opt_removed:
1476                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1477                 return 1;
1478         case Opt_abort:
1479                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1480                 return 1;
1481         case Opt_i_version:
1482                 sb->s_flags |= MS_I_VERSION;
1483                 return 1;
1484         }
1485
1486         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1487                 if (token == m->token)
1488                         break;
1489
1490         if (m->token == Opt_err) {
1491                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1492                          "or missing value", opt);
1493                 return -1;
1494         }
1495
1496         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1497                 ext4_msg(sb, KERN_ERR,
1498                          "Mount option \"%s\" incompatible with ext2", opt);
1499                 return -1;
1500         }
1501         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1502                 ext4_msg(sb, KERN_ERR,
1503                          "Mount option \"%s\" incompatible with ext3", opt);
1504                 return -1;
1505         }
1506
1507         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1508                 return -1;
1509         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1510                 return -1;
1511         if (m->flags & MOPT_EXPLICIT)
1512                 set_opt2(sb, EXPLICIT_DELALLOC);
1513         if (m->flags & MOPT_CLEAR_ERR)
1514                 clear_opt(sb, ERRORS_MASK);
1515         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1516                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1517                          "options when quota turned on");
1518                 return -1;
1519         }
1520
1521         if (m->flags & MOPT_NOSUPPORT) {
1522                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1523         } else if (token == Opt_commit) {
1524                 if (arg == 0)
1525                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1526                 sbi->s_commit_interval = HZ * arg;
1527         } else if (token == Opt_max_batch_time) {
1528                 sbi->s_max_batch_time = arg;
1529         } else if (token == Opt_min_batch_time) {
1530                 sbi->s_min_batch_time = arg;
1531         } else if (token == Opt_inode_readahead_blks) {
1532                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1533                         ext4_msg(sb, KERN_ERR,
1534                                  "EXT4-fs: inode_readahead_blks must be "
1535                                  "0 or a power of 2 smaller than 2^31");
1536                         return -1;
1537                 }
1538                 sbi->s_inode_readahead_blks = arg;
1539         } else if (token == Opt_init_itable) {
1540                 set_opt(sb, INIT_INODE_TABLE);
1541                 if (!args->from)
1542                         arg = EXT4_DEF_LI_WAIT_MULT;
1543                 sbi->s_li_wait_mult = arg;
1544         } else if (token == Opt_max_dir_size_kb) {
1545                 sbi->s_max_dir_size_kb = arg;
1546         } else if (token == Opt_stripe) {
1547                 sbi->s_stripe = arg;
1548         } else if (token == Opt_resuid) {
1549                 uid = make_kuid(current_user_ns(), arg);
1550                 if (!uid_valid(uid)) {
1551                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1552                         return -1;
1553                 }
1554                 sbi->s_resuid = uid;
1555         } else if (token == Opt_resgid) {
1556                 gid = make_kgid(current_user_ns(), arg);
1557                 if (!gid_valid(gid)) {
1558                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1559                         return -1;
1560                 }
1561                 sbi->s_resgid = gid;
1562         } else if (token == Opt_journal_dev) {
1563                 if (is_remount) {
1564                         ext4_msg(sb, KERN_ERR,
1565                                  "Cannot specify journal on remount");
1566                         return -1;
1567                 }
1568                 *journal_devnum = arg;
1569         } else if (token == Opt_journal_path) {
1570                 char *journal_path;
1571                 struct inode *journal_inode;
1572                 struct path path;
1573                 int error;
1574
1575                 if (is_remount) {
1576                         ext4_msg(sb, KERN_ERR,
1577                                  "Cannot specify journal on remount");
1578                         return -1;
1579                 }
1580                 journal_path = match_strdup(&args[0]);
1581                 if (!journal_path) {
1582                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1583                                 "journal device string");
1584                         return -1;
1585                 }
1586
1587                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1588                 if (error) {
1589                         ext4_msg(sb, KERN_ERR, "error: could not find "
1590                                 "journal device path: error %d", error);
1591                         kfree(journal_path);
1592                         return -1;
1593                 }
1594
1595                 journal_inode = path.dentry->d_inode;
1596                 if (!S_ISBLK(journal_inode->i_mode)) {
1597                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1598                                 "is not a block device", journal_path);
1599                         path_put(&path);
1600                         kfree(journal_path);
1601                         return -1;
1602                 }
1603
1604                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1605                 path_put(&path);
1606                 kfree(journal_path);
1607         } else if (token == Opt_journal_ioprio) {
1608                 if (arg > 7) {
1609                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1610                                  " (must be 0-7)");
1611                         return -1;
1612                 }
1613                 *journal_ioprio =
1614                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1615         } else if (m->flags & MOPT_DATAJ) {
1616                 if (is_remount) {
1617                         if (!sbi->s_journal)
1618                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1619                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1620                                 ext4_msg(sb, KERN_ERR,
1621                                          "Cannot change data mode on remount");
1622                                 return -1;
1623                         }
1624                 } else {
1625                         clear_opt(sb, DATA_FLAGS);
1626                         sbi->s_mount_opt |= m->mount_opt;
1627                 }
1628 #ifdef CONFIG_QUOTA
1629         } else if (m->flags & MOPT_QFMT) {
1630                 if (sb_any_quota_loaded(sb) &&
1631                     sbi->s_jquota_fmt != m->mount_opt) {
1632                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1633                                  "quota options when quota turned on");
1634                         return -1;
1635                 }
1636                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1637                                                EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1638                         ext4_msg(sb, KERN_ERR,
1639                                  "Cannot set journaled quota options "
1640                                  "when QUOTA feature is enabled");
1641                         return -1;
1642                 }
1643                 sbi->s_jquota_fmt = m->mount_opt;
1644 #endif
1645         } else {
1646                 if (!args->from)
1647                         arg = 1;
1648                 if (m->flags & MOPT_CLEAR)
1649                         arg = !arg;
1650                 else if (unlikely(!(m->flags & MOPT_SET))) {
1651                         ext4_msg(sb, KERN_WARNING,
1652                                  "buggy handling of option %s", opt);
1653                         WARN_ON(1);
1654                         return -1;
1655                 }
1656                 if (arg != 0)
1657                         sbi->s_mount_opt |= m->mount_opt;
1658                 else
1659                         sbi->s_mount_opt &= ~m->mount_opt;
1660         }
1661         return 1;
1662 }
1663
1664 static int parse_options(char *options, struct super_block *sb,
1665                          unsigned long *journal_devnum,
1666                          unsigned int *journal_ioprio,
1667                          int is_remount)
1668 {
1669         struct ext4_sb_info *sbi = EXT4_SB(sb);
1670         char *p;
1671         substring_t args[MAX_OPT_ARGS];
1672         int token;
1673
1674         if (!options)
1675                 return 1;
1676
1677         while ((p = strsep(&options, ",")) != NULL) {
1678                 if (!*p)
1679                         continue;
1680                 /*
1681                  * Initialize args struct so we know whether arg was
1682                  * found; some options take optional arguments.
1683                  */
1684                 args[0].to = args[0].from = NULL;
1685                 token = match_token(p, tokens, args);
1686                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1687                                      journal_ioprio, is_remount) < 0)
1688                         return 0;
1689         }
1690 #ifdef CONFIG_QUOTA
1691         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1692             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1693                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1694                          "feature is enabled");
1695                 return 0;
1696         }
1697         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1698                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1699                         clear_opt(sb, USRQUOTA);
1700
1701                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1702                         clear_opt(sb, GRPQUOTA);
1703
1704                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1705                         ext4_msg(sb, KERN_ERR, "old and new quota "
1706                                         "format mixing");
1707                         return 0;
1708                 }
1709
1710                 if (!sbi->s_jquota_fmt) {
1711                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1712                                         "not specified");
1713                         return 0;
1714                 }
1715         } else {
1716                 if (sbi->s_jquota_fmt) {
1717                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1718                                         "specified with no journaling "
1719                                         "enabled");
1720                         return 0;
1721                 }
1722         }
1723 #endif
1724         if (test_opt(sb, DIOREAD_NOLOCK)) {
1725                 int blocksize =
1726                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1727
1728                 if (blocksize < PAGE_CACHE_SIZE) {
1729                         ext4_msg(sb, KERN_ERR, "can't mount with "
1730                                  "dioread_nolock if block size != PAGE_SIZE");
1731                         return 0;
1732                 }
1733         }
1734         return 1;
1735 }
1736
1737 static inline void ext4_show_quota_options(struct seq_file *seq,
1738                                            struct super_block *sb)
1739 {
1740 #if defined(CONFIG_QUOTA)
1741         struct ext4_sb_info *sbi = EXT4_SB(sb);
1742
1743         if (sbi->s_jquota_fmt) {
1744                 char *fmtname = "";
1745
1746                 switch (sbi->s_jquota_fmt) {
1747                 case QFMT_VFS_OLD:
1748                         fmtname = "vfsold";
1749                         break;
1750                 case QFMT_VFS_V0:
1751                         fmtname = "vfsv0";
1752                         break;
1753                 case QFMT_VFS_V1:
1754                         fmtname = "vfsv1";
1755                         break;
1756                 }
1757                 seq_printf(seq, ",jqfmt=%s", fmtname);
1758         }
1759
1760         if (sbi->s_qf_names[USRQUOTA])
1761                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1762
1763         if (sbi->s_qf_names[GRPQUOTA])
1764                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1765 #endif
1766 }
1767
1768 static const char *token2str(int token)
1769 {
1770         const struct match_token *t;
1771
1772         for (t = tokens; t->token != Opt_err; t++)
1773                 if (t->token == token && !strchr(t->pattern, '='))
1774                         break;
1775         return t->pattern;
1776 }
1777
1778 /*
1779  * Show an option if
1780  *  - it's set to a non-default value OR
1781  *  - if the per-sb default is different from the global default
1782  */
1783 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1784                               int nodefs)
1785 {
1786         struct ext4_sb_info *sbi = EXT4_SB(sb);
1787         struct ext4_super_block *es = sbi->s_es;
1788         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1789         const struct mount_opts *m;
1790         char sep = nodefs ? '\n' : ',';
1791
1792 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1793 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1794
1795         if (sbi->s_sb_block != 1)
1796                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1797
1798         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1799                 int want_set = m->flags & MOPT_SET;
1800                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1801                     (m->flags & MOPT_CLEAR_ERR))
1802                         continue;
1803                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1804                         continue; /* skip if same as the default */
1805                 if ((want_set &&
1806                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1807                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1808                         continue; /* select Opt_noFoo vs Opt_Foo */
1809                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1810         }
1811
1812         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1813             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1814                 SEQ_OPTS_PRINT("resuid=%u",
1815                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1816         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1817             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1818                 SEQ_OPTS_PRINT("resgid=%u",
1819                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1820         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1821         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1822                 SEQ_OPTS_PUTS("errors=remount-ro");
1823         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1824                 SEQ_OPTS_PUTS("errors=continue");
1825         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1826                 SEQ_OPTS_PUTS("errors=panic");
1827         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1828                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1829         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1830                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1831         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1832                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1833         if (sb->s_flags & MS_I_VERSION)
1834                 SEQ_OPTS_PUTS("i_version");
1835         if (nodefs || sbi->s_stripe)
1836                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1837         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1838                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1839                         SEQ_OPTS_PUTS("data=journal");
1840                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1841                         SEQ_OPTS_PUTS("data=ordered");
1842                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1843                         SEQ_OPTS_PUTS("data=writeback");
1844         }
1845         if (nodefs ||
1846             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1847                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1848                                sbi->s_inode_readahead_blks);
1849
1850         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1851                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1852                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1853         if (nodefs || sbi->s_max_dir_size_kb)
1854                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1855
1856         ext4_show_quota_options(seq, sb);
1857         return 0;
1858 }
1859
1860 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1861 {
1862         return _ext4_show_options(seq, root->d_sb, 0);
1863 }
1864
1865 static int options_seq_show(struct seq_file *seq, void *offset)
1866 {
1867         struct super_block *sb = seq->private;
1868         int rc;
1869
1870         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1871         rc = _ext4_show_options(seq, sb, 1);
1872         seq_puts(seq, "\n");
1873         return rc;
1874 }
1875
1876 static int options_open_fs(struct inode *inode, struct file *file)
1877 {
1878         return single_open(file, options_seq_show, PDE_DATA(inode));
1879 }
1880
1881 static const struct file_operations ext4_seq_options_fops = {
1882         .owner = THIS_MODULE,
1883         .open = options_open_fs,
1884         .read = seq_read,
1885         .llseek = seq_lseek,
1886         .release = single_release,
1887 };
1888
1889 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1890                             int read_only)
1891 {
1892         struct ext4_sb_info *sbi = EXT4_SB(sb);
1893         int res = 0;
1894
1895         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1896                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1897                          "forcing read-only mode");
1898                 res = MS_RDONLY;
1899         }
1900         if (read_only)
1901                 goto done;
1902         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1903                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1904                          "running e2fsck is recommended");
1905         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1906                 ext4_msg(sb, KERN_WARNING,
1907                          "warning: mounting fs with errors, "
1908                          "running e2fsck is recommended");
1909         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1910                  le16_to_cpu(es->s_mnt_count) >=
1911                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1912                 ext4_msg(sb, KERN_WARNING,
1913                          "warning: maximal mount count reached, "
1914                          "running e2fsck is recommended");
1915         else if (le32_to_cpu(es->s_checkinterval) &&
1916                 (le32_to_cpu(es->s_lastcheck) +
1917                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1918                 ext4_msg(sb, KERN_WARNING,
1919                          "warning: checktime reached, "
1920                          "running e2fsck is recommended");
1921         if (!sbi->s_journal)
1922                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1923         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1924                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1925         le16_add_cpu(&es->s_mnt_count, 1);
1926         es->s_mtime = cpu_to_le32(get_seconds());
1927         ext4_update_dynamic_rev(sb);
1928         if (sbi->s_journal)
1929                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1930
1931         ext4_commit_super(sb, 1);
1932 done:
1933         if (test_opt(sb, DEBUG))
1934                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1935                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1936                         sb->s_blocksize,
1937                         sbi->s_groups_count,
1938                         EXT4_BLOCKS_PER_GROUP(sb),
1939                         EXT4_INODES_PER_GROUP(sb),
1940                         sbi->s_mount_opt, sbi->s_mount_opt2);
1941
1942         cleancache_init_fs(sb);
1943         return res;
1944 }
1945
1946 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1947 {
1948         struct ext4_sb_info *sbi = EXT4_SB(sb);
1949         struct flex_groups *new_groups;
1950         int size;
1951
1952         if (!sbi->s_log_groups_per_flex)
1953                 return 0;
1954
1955         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1956         if (size <= sbi->s_flex_groups_allocated)
1957                 return 0;
1958
1959         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1960         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1961         if (!new_groups) {
1962                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1963                          size / (int) sizeof(struct flex_groups));
1964                 return -ENOMEM;
1965         }
1966
1967         if (sbi->s_flex_groups) {
1968                 memcpy(new_groups, sbi->s_flex_groups,
1969                        (sbi->s_flex_groups_allocated *
1970                         sizeof(struct flex_groups)));
1971                 ext4_kvfree(sbi->s_flex_groups);
1972         }
1973         sbi->s_flex_groups = new_groups;
1974         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1975         return 0;
1976 }
1977
1978 static int ext4_fill_flex_info(struct super_block *sb)
1979 {
1980         struct ext4_sb_info *sbi = EXT4_SB(sb);
1981         struct ext4_group_desc *gdp = NULL;
1982         ext4_group_t flex_group;
1983         int i, err;
1984
1985         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1986         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1987                 sbi->s_log_groups_per_flex = 0;
1988                 return 1;
1989         }
1990
1991         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1992         if (err)
1993                 goto failed;
1994
1995         for (i = 0; i < sbi->s_groups_count; i++) {
1996                 gdp = ext4_get_group_desc(sb, i, NULL);
1997
1998                 flex_group = ext4_flex_group(sbi, i);
1999                 atomic_add(ext4_free_inodes_count(sb, gdp),
2000                            &sbi->s_flex_groups[flex_group].free_inodes);
2001                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2002                              &sbi->s_flex_groups[flex_group].free_clusters);
2003                 atomic_add(ext4_used_dirs_count(sb, gdp),
2004                            &sbi->s_flex_groups[flex_group].used_dirs);
2005         }
2006
2007         return 1;
2008 failed:
2009         return 0;
2010 }
2011
2012 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2013                                    struct ext4_group_desc *gdp)
2014 {
2015         int offset;
2016         __u16 crc = 0;
2017         __le32 le_group = cpu_to_le32(block_group);
2018
2019         if ((sbi->s_es->s_feature_ro_compat &
2020              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
2021                 /* Use new metadata_csum algorithm */
2022                 __le16 save_csum;
2023                 __u32 csum32;
2024
2025                 save_csum = gdp->bg_checksum;
2026                 gdp->bg_checksum = 0;
2027                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2028                                      sizeof(le_group));
2029                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2030                                      sbi->s_desc_size);
2031                 gdp->bg_checksum = save_csum;
2032
2033                 crc = csum32 & 0xFFFF;
2034                 goto out;
2035         }
2036
2037         /* old crc16 code */
2038         offset = offsetof(struct ext4_group_desc, bg_checksum);
2039
2040         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2041         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2042         crc = crc16(crc, (__u8 *)gdp, offset);
2043         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2044         /* for checksum of struct ext4_group_desc do the rest...*/
2045         if ((sbi->s_es->s_feature_incompat &
2046              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2047             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2048                 crc = crc16(crc, (__u8 *)gdp + offset,
2049                             le16_to_cpu(sbi->s_es->s_desc_size) -
2050                                 offset);
2051
2052 out:
2053         return cpu_to_le16(crc);
2054 }
2055
2056 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2057                                 struct ext4_group_desc *gdp)
2058 {
2059         if (ext4_has_group_desc_csum(sb) &&
2060             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2061                                                       block_group, gdp)))
2062                 return 0;
2063
2064         return 1;
2065 }
2066
2067 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2068                               struct ext4_group_desc *gdp)
2069 {
2070         if (!ext4_has_group_desc_csum(sb))
2071                 return;
2072         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2073 }
2074
2075 /* Called at mount-time, super-block is locked */
2076 static int ext4_check_descriptors(struct super_block *sb,
2077                                   ext4_group_t *first_not_zeroed)
2078 {
2079         struct ext4_sb_info *sbi = EXT4_SB(sb);
2080         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2081         ext4_fsblk_t last_block;
2082         ext4_fsblk_t block_bitmap;
2083         ext4_fsblk_t inode_bitmap;
2084         ext4_fsblk_t inode_table;
2085         int flexbg_flag = 0;
2086         ext4_group_t i, grp = sbi->s_groups_count;
2087
2088         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2089                 flexbg_flag = 1;
2090
2091         ext4_debug("Checking group descriptors");
2092
2093         for (i = 0; i < sbi->s_groups_count; i++) {
2094                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2095
2096                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2097                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2098                 else
2099                         last_block = first_block +
2100                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2101
2102                 if ((grp == sbi->s_groups_count) &&
2103                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2104                         grp = i;
2105
2106                 block_bitmap = ext4_block_bitmap(sb, gdp);
2107                 if (block_bitmap < first_block || block_bitmap > last_block) {
2108                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2109                                "Block bitmap for group %u not in group "
2110                                "(block %llu)!", i, block_bitmap);
2111                         return 0;
2112                 }
2113                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2114                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2115                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2116                                "Inode bitmap for group %u not in group "
2117                                "(block %llu)!", i, inode_bitmap);
2118                         return 0;
2119                 }
2120                 inode_table = ext4_inode_table(sb, gdp);
2121                 if (inode_table < first_block ||
2122                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2123                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2124                                "Inode table for group %u not in group "
2125                                "(block %llu)!", i, inode_table);
2126                         return 0;
2127                 }
2128                 ext4_lock_group(sb, i);
2129                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2130                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2131                                  "Checksum for group %u failed (%u!=%u)",
2132                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2133                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2134                         if (!(sb->s_flags & MS_RDONLY)) {
2135                                 ext4_unlock_group(sb, i);
2136                                 return 0;
2137                         }
2138                 }
2139                 ext4_unlock_group(sb, i);
2140                 if (!flexbg_flag)
2141                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2142         }
2143         if (NULL != first_not_zeroed)
2144                 *first_not_zeroed = grp;
2145
2146         ext4_free_blocks_count_set(sbi->s_es,
2147                                    EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2148         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2149         return 1;
2150 }
2151
2152 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2153  * the superblock) which were deleted from all directories, but held open by
2154  * a process at the time of a crash.  We walk the list and try to delete these
2155  * inodes at recovery time (only with a read-write filesystem).
2156  *
2157  * In order to keep the orphan inode chain consistent during traversal (in
2158  * case of crash during recovery), we link each inode into the superblock
2159  * orphan list_head and handle it the same way as an inode deletion during
2160  * normal operation (which journals the operations for us).
2161  *
2162  * We only do an iget() and an iput() on each inode, which is very safe if we
2163  * accidentally point at an in-use or already deleted inode.  The worst that
2164  * can happen in this case is that we get a "bit already cleared" message from
2165  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2166  * e2fsck was run on this filesystem, and it must have already done the orphan
2167  * inode cleanup for us, so we can safely abort without any further action.
2168  */
2169 static void ext4_orphan_cleanup(struct super_block *sb,
2170                                 struct ext4_super_block *es)
2171 {
2172         unsigned int s_flags = sb->s_flags;
2173         int nr_orphans = 0, nr_truncates = 0;
2174 #ifdef CONFIG_QUOTA
2175         int i;
2176 #endif
2177         if (!es->s_last_orphan) {
2178                 jbd_debug(4, "no orphan inodes to clean up\n");
2179                 return;
2180         }
2181
2182         if (bdev_read_only(sb->s_bdev)) {
2183                 ext4_msg(sb, KERN_ERR, "write access "
2184                         "unavailable, skipping orphan cleanup");
2185                 return;
2186         }
2187
2188         /* Check if feature set would not allow a r/w mount */
2189         if (!ext4_feature_set_ok(sb, 0)) {
2190                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2191                          "unknown ROCOMPAT features");
2192                 return;
2193         }
2194
2195         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2196                 /* don't clear list on RO mount w/ errors */
2197                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2198                         jbd_debug(1, "Errors on filesystem, "
2199                                   "clearing orphan list.\n");
2200                         es->s_last_orphan = 0;
2201                 }
2202                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2203                 return;
2204         }
2205
2206         if (s_flags & MS_RDONLY) {
2207                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2208                 sb->s_flags &= ~MS_RDONLY;
2209         }
2210 #ifdef CONFIG_QUOTA
2211         /* Needed for iput() to work correctly and not trash data */
2212         sb->s_flags |= MS_ACTIVE;
2213         /* Turn on quotas so that they are updated correctly */
2214         for (i = 0; i < MAXQUOTAS; i++) {
2215                 if (EXT4_SB(sb)->s_qf_names[i]) {
2216                         int ret = ext4_quota_on_mount(sb, i);
2217                         if (ret < 0)
2218                                 ext4_msg(sb, KERN_ERR,
2219                                         "Cannot turn on journaled "
2220                                         "quota: error %d", ret);
2221                 }
2222         }
2223 #endif
2224
2225         while (es->s_last_orphan) {
2226                 struct inode *inode;
2227
2228                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2229                 if (IS_ERR(inode)) {
2230                         es->s_last_orphan = 0;
2231                         break;
2232                 }
2233
2234                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2235                 dquot_initialize(inode);
2236                 if (inode->i_nlink) {
2237                         if (test_opt(sb, DEBUG))
2238                                 ext4_msg(sb, KERN_DEBUG,
2239                                         "%s: truncating inode %lu to %lld bytes",
2240                                         __func__, inode->i_ino, inode->i_size);
2241                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2242                                   inode->i_ino, inode->i_size);
2243                         mutex_lock(&inode->i_mutex);
2244                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2245                         ext4_truncate(inode);
2246                         mutex_unlock(&inode->i_mutex);
2247                         nr_truncates++;
2248                 } else {
2249                         if (test_opt(sb, DEBUG))
2250                                 ext4_msg(sb, KERN_DEBUG,
2251                                         "%s: deleting unreferenced inode %lu",
2252                                         __func__, inode->i_ino);
2253                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2254                                   inode->i_ino);
2255                         nr_orphans++;
2256                 }
2257                 iput(inode);  /* The delete magic happens here! */
2258         }
2259
2260 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2261
2262         if (nr_orphans)
2263                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2264                        PLURAL(nr_orphans));
2265         if (nr_truncates)
2266                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2267                        PLURAL(nr_truncates));
2268 #ifdef CONFIG_QUOTA
2269         /* Turn quotas off */
2270         for (i = 0; i < MAXQUOTAS; i++) {
2271                 if (sb_dqopt(sb)->files[i])
2272                         dquot_quota_off(sb, i);
2273         }
2274 #endif
2275         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2276 }
2277
2278 /*
2279  * Maximal extent format file size.
2280  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2281  * extent format containers, within a sector_t, and within i_blocks
2282  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2283  * so that won't be a limiting factor.
2284  *
2285  * However there is other limiting factor. We do store extents in the form
2286  * of starting block and length, hence the resulting length of the extent
2287  * covering maximum file size must fit into on-disk format containers as
2288  * well. Given that length is always by 1 unit bigger than max unit (because
2289  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2290  *
2291  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2292  */
2293 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2294 {
2295         loff_t res;
2296         loff_t upper_limit = MAX_LFS_FILESIZE;
2297
2298         /* small i_blocks in vfs inode? */
2299         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2300                 /*
2301                  * CONFIG_LBDAF is not enabled implies the inode
2302                  * i_block represent total blocks in 512 bytes
2303                  * 32 == size of vfs inode i_blocks * 8
2304                  */
2305                 upper_limit = (1LL << 32) - 1;
2306
2307                 /* total blocks in file system block size */
2308                 upper_limit >>= (blkbits - 9);
2309                 upper_limit <<= blkbits;
2310         }
2311
2312         /*
2313          * 32-bit extent-start container, ee_block. We lower the maxbytes
2314          * by one fs block, so ee_len can cover the extent of maximum file
2315          * size
2316          */
2317         res = (1LL << 32) - 1;
2318         res <<= blkbits;
2319
2320         /* Sanity check against vm- & vfs- imposed limits */
2321         if (res > upper_limit)
2322                 res = upper_limit;
2323
2324         return res;
2325 }
2326
2327 /*
2328  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2329  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2330  * We need to be 1 filesystem block less than the 2^48 sector limit.
2331  */
2332 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2333 {
2334         loff_t res = EXT4_NDIR_BLOCKS;
2335         int meta_blocks;
2336         loff_t upper_limit;
2337         /* This is calculated to be the largest file size for a dense, block
2338          * mapped file such that the file's total number of 512-byte sectors,
2339          * including data and all indirect blocks, does not exceed (2^48 - 1).
2340          *
2341          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2342          * number of 512-byte sectors of the file.
2343          */
2344
2345         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2346                 /*
2347                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2348                  * the inode i_block field represents total file blocks in
2349                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2350                  */
2351                 upper_limit = (1LL << 32) - 1;
2352
2353                 /* total blocks in file system block size */
2354                 upper_limit >>= (bits - 9);
2355
2356         } else {
2357                 /*
2358                  * We use 48 bit ext4_inode i_blocks
2359                  * With EXT4_HUGE_FILE_FL set the i_blocks
2360                  * represent total number of blocks in
2361                  * file system block size
2362                  */
2363                 upper_limit = (1LL << 48) - 1;
2364
2365         }
2366
2367         /* indirect blocks */
2368         meta_blocks = 1;
2369         /* double indirect blocks */
2370         meta_blocks += 1 + (1LL << (bits-2));
2371         /* tripple indirect blocks */
2372         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2373
2374         upper_limit -= meta_blocks;
2375         upper_limit <<= bits;
2376
2377         res += 1LL << (bits-2);
2378         res += 1LL << (2*(bits-2));
2379         res += 1LL << (3*(bits-2));
2380         res <<= bits;
2381         if (res > upper_limit)
2382                 res = upper_limit;
2383
2384         if (res > MAX_LFS_FILESIZE)
2385                 res = MAX_LFS_FILESIZE;
2386
2387         return res;
2388 }
2389
2390 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2391                                    ext4_fsblk_t logical_sb_block, int nr)
2392 {
2393         struct ext4_sb_info *sbi = EXT4_SB(sb);
2394         ext4_group_t bg, first_meta_bg;
2395         int has_super = 0;
2396
2397         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2398
2399         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2400             nr < first_meta_bg)
2401                 return logical_sb_block + nr + 1;
2402         bg = sbi->s_desc_per_block * nr;
2403         if (ext4_bg_has_super(sb, bg))
2404                 has_super = 1;
2405
2406         /*
2407          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2408          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2409          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2410          * compensate.
2411          */
2412         if (sb->s_blocksize == 1024 && nr == 0 &&
2413             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2414                 has_super++;
2415
2416         return (has_super + ext4_group_first_block_no(sb, bg));
2417 }
2418
2419 /**
2420  * ext4_get_stripe_size: Get the stripe size.
2421  * @sbi: In memory super block info
2422  *
2423  * If we have specified it via mount option, then
2424  * use the mount option value. If the value specified at mount time is
2425  * greater than the blocks per group use the super block value.
2426  * If the super block value is greater than blocks per group return 0.
2427  * Allocator needs it be less than blocks per group.
2428  *
2429  */
2430 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2431 {
2432         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2433         unsigned long stripe_width =
2434                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2435         int ret;
2436
2437         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2438                 ret = sbi->s_stripe;
2439         else if (stripe_width <= sbi->s_blocks_per_group)
2440                 ret = stripe_width;
2441         else if (stride <= sbi->s_blocks_per_group)
2442                 ret = stride;
2443         else
2444                 ret = 0;
2445
2446         /*
2447          * If the stripe width is 1, this makes no sense and
2448          * we set it to 0 to turn off stripe handling code.
2449          */
2450         if (ret <= 1)
2451                 ret = 0;
2452
2453         return ret;
2454 }
2455
2456 /* sysfs supprt */
2457
2458 struct ext4_attr {
2459         struct attribute attr;
2460         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2461         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2462                          const char *, size_t);
2463         union {
2464                 int offset;
2465                 int deprecated_val;
2466         } u;
2467 };
2468
2469 static int parse_strtoull(const char *buf,
2470                 unsigned long long max, unsigned long long *value)
2471 {
2472         int ret;
2473
2474         ret = kstrtoull(skip_spaces(buf), 0, value);
2475         if (!ret && *value > max)
2476                 ret = -EINVAL;
2477         return ret;
2478 }
2479
2480 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2481                                               struct ext4_sb_info *sbi,
2482                                               char *buf)
2483 {
2484         return snprintf(buf, PAGE_SIZE, "%llu\n",
2485                 (s64) EXT4_C2B(sbi,
2486                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2487 }
2488
2489 static ssize_t session_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, "%lu\n",
2497                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2498                          sbi->s_sectors_written_start) >> 1);
2499 }
2500
2501 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2502                                           struct ext4_sb_info *sbi, char *buf)
2503 {
2504         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2505
2506         if (!sb->s_bdev->bd_part)
2507                 return snprintf(buf, PAGE_SIZE, "0\n");
2508         return snprintf(buf, PAGE_SIZE, "%llu\n",
2509                         (unsigned long long)(sbi->s_kbytes_written +
2510                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2511                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2512 }
2513
2514 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2515                                           struct ext4_sb_info *sbi,
2516                                           const char *buf, size_t count)
2517 {
2518         unsigned long t;
2519         int ret;
2520
2521         ret = kstrtoul(skip_spaces(buf), 0, &t);
2522         if (ret)
2523                 return ret;
2524
2525         if (t && (!is_power_of_2(t) || t > 0x40000000))
2526                 return -EINVAL;
2527
2528         sbi->s_inode_readahead_blks = t;
2529         return count;
2530 }
2531
2532 static ssize_t sbi_ui_show(struct ext4_attr *a,
2533                            struct ext4_sb_info *sbi, char *buf)
2534 {
2535         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2536
2537         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2538 }
2539
2540 static ssize_t sbi_ui_store(struct ext4_attr *a,
2541                             struct ext4_sb_info *sbi,
2542                             const char *buf, size_t count)
2543 {
2544         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2545         unsigned long t;
2546         int ret;
2547
2548         ret = kstrtoul(skip_spaces(buf), 0, &t);
2549         if (ret)
2550                 return ret;
2551         *ui = t;
2552         return count;
2553 }
2554
2555 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2556                                   struct ext4_sb_info *sbi, char *buf)
2557 {
2558         return snprintf(buf, PAGE_SIZE, "%llu\n",
2559                 (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2560 }
2561
2562 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2563                                    struct ext4_sb_info *sbi,
2564                                    const char *buf, size_t count)
2565 {
2566         unsigned long long val;
2567         int ret;
2568
2569         if (parse_strtoull(buf, -1ULL, &val))
2570                 return -EINVAL;
2571         ret = ext4_reserve_clusters(sbi, val);
2572
2573         return ret ? ret : count;
2574 }
2575
2576 static ssize_t trigger_test_error(struct ext4_attr *a,
2577                                   struct ext4_sb_info *sbi,
2578                                   const char *buf, size_t count)
2579 {
2580         int len = count;
2581
2582         if (!capable(CAP_SYS_ADMIN))
2583                 return -EPERM;
2584
2585         if (len && buf[len-1] == '\n')
2586                 len--;
2587
2588         if (len)
2589                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2590         return count;
2591 }
2592
2593 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2594                                    struct ext4_sb_info *sbi, char *buf)
2595 {
2596         return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2597 }
2598
2599 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2600 static struct ext4_attr ext4_attr_##_name = {                   \
2601         .attr = {.name = __stringify(_name), .mode = _mode },   \
2602         .show   = _show,                                        \
2603         .store  = _store,                                       \
2604         .u = {                                                  \
2605                 .offset = offsetof(struct ext4_sb_info, _elname),\
2606         },                                                      \
2607 }
2608 #define EXT4_ATTR(name, mode, show, store) \
2609 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2610
2611 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2612 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2613 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2614 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2615         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2616 #define ATTR_LIST(name) &ext4_attr_##name.attr
2617 #define EXT4_DEPRECATED_ATTR(_name, _val)       \
2618 static struct ext4_attr ext4_attr_##_name = {                   \
2619         .attr = {.name = __stringify(_name), .mode = 0444 },    \
2620         .show   = sbi_deprecated_show,                          \
2621         .u = {                                                  \
2622                 .deprecated_val = _val,                         \
2623         },                                                      \
2624 }
2625
2626 EXT4_RO_ATTR(delayed_allocation_blocks);
2627 EXT4_RO_ATTR(session_write_kbytes);
2628 EXT4_RO_ATTR(lifetime_write_kbytes);
2629 EXT4_RW_ATTR(reserved_clusters);
2630 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2631                  inode_readahead_blks_store, s_inode_readahead_blks);
2632 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2633 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2634 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2635 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2636 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2637 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2638 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2639 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2640 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2641 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2642 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2643 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2644 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2645 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2646 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2647 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2648
2649 static struct attribute *ext4_attrs[] = {
2650         ATTR_LIST(delayed_allocation_blocks),
2651         ATTR_LIST(session_write_kbytes),
2652         ATTR_LIST(lifetime_write_kbytes),
2653         ATTR_LIST(reserved_clusters),
2654         ATTR_LIST(inode_readahead_blks),
2655         ATTR_LIST(inode_goal),
2656         ATTR_LIST(mb_stats),
2657         ATTR_LIST(mb_max_to_scan),
2658         ATTR_LIST(mb_min_to_scan),
2659         ATTR_LIST(mb_order2_req),
2660         ATTR_LIST(mb_stream_req),
2661         ATTR_LIST(mb_group_prealloc),
2662         ATTR_LIST(max_writeback_mb_bump),
2663         ATTR_LIST(extent_max_zeroout_kb),
2664         ATTR_LIST(trigger_fs_error),
2665         ATTR_LIST(err_ratelimit_interval_ms),
2666         ATTR_LIST(err_ratelimit_burst),
2667         ATTR_LIST(warning_ratelimit_interval_ms),
2668         ATTR_LIST(warning_ratelimit_burst),
2669         ATTR_LIST(msg_ratelimit_interval_ms),
2670         ATTR_LIST(msg_ratelimit_burst),
2671         NULL,
2672 };
2673
2674 /* Features this copy of ext4 supports */
2675 EXT4_INFO_ATTR(lazy_itable_init);
2676 EXT4_INFO_ATTR(batched_discard);
2677 EXT4_INFO_ATTR(meta_bg_resize);
2678
2679 static struct attribute *ext4_feat_attrs[] = {
2680         ATTR_LIST(lazy_itable_init),
2681         ATTR_LIST(batched_discard),
2682         ATTR_LIST(meta_bg_resize),
2683         NULL,
2684 };
2685
2686 static ssize_t ext4_attr_show(struct kobject *kobj,
2687                               struct attribute *attr, char *buf)
2688 {
2689         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2690                                                 s_kobj);
2691         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2692
2693         return a->show ? a->show(a, sbi, buf) : 0;
2694 }
2695
2696 static ssize_t ext4_attr_store(struct kobject *kobj,
2697                                struct attribute *attr,
2698                                const char *buf, size_t len)
2699 {
2700         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2701                                                 s_kobj);
2702         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2703
2704         return a->store ? a->store(a, sbi, buf, len) : 0;
2705 }
2706
2707 static void ext4_sb_release(struct kobject *kobj)
2708 {
2709         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2710                                                 s_kobj);
2711         complete(&sbi->s_kobj_unregister);
2712 }
2713
2714 static const struct sysfs_ops ext4_attr_ops = {
2715         .show   = ext4_attr_show,
2716         .store  = ext4_attr_store,
2717 };
2718
2719 static struct kobj_type ext4_ktype = {
2720         .default_attrs  = ext4_attrs,
2721         .sysfs_ops      = &ext4_attr_ops,
2722         .release        = ext4_sb_release,
2723 };
2724
2725 static void ext4_feat_release(struct kobject *kobj)
2726 {
2727         complete(&ext4_feat->f_kobj_unregister);
2728 }
2729
2730 static struct kobj_type ext4_feat_ktype = {
2731         .default_attrs  = ext4_feat_attrs,
2732         .sysfs_ops      = &ext4_attr_ops,
2733         .release        = ext4_feat_release,
2734 };
2735
2736 /*
2737  * Check whether this filesystem can be mounted based on
2738  * the features present and the RDONLY/RDWR mount requested.
2739  * Returns 1 if this filesystem can be mounted as requested,
2740  * 0 if it cannot be.
2741  */
2742 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2743 {
2744         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2745                 ext4_msg(sb, KERN_ERR,
2746                         "Couldn't mount because of "
2747                         "unsupported optional features (%x)",
2748                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2749                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2750                 return 0;
2751         }
2752
2753         if (readonly)
2754                 return 1;
2755
2756         /* Check that feature set is OK for a read-write mount */
2757         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2758                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2759                          "unsupported optional features (%x)",
2760                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2761                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2762                 return 0;
2763         }
2764         /*
2765          * Large file size enabled file system can only be mounted
2766          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2767          */
2768         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2769                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2770                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2771                                  "cannot be mounted RDWR without "
2772                                  "CONFIG_LBDAF");
2773                         return 0;
2774                 }
2775         }
2776         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2777             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2778                 ext4_msg(sb, KERN_ERR,
2779                          "Can't support bigalloc feature without "
2780                          "extents feature\n");
2781                 return 0;
2782         }
2783
2784 #ifndef CONFIG_QUOTA
2785         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2786             !readonly) {
2787                 ext4_msg(sb, KERN_ERR,
2788                          "Filesystem with quota feature cannot be mounted RDWR "
2789                          "without CONFIG_QUOTA");
2790                 return 0;
2791         }
2792 #endif  /* CONFIG_QUOTA */
2793         return 1;
2794 }
2795
2796 /*
2797  * This function is called once a day if we have errors logged
2798  * on the file system
2799  */
2800 static void print_daily_error_info(unsigned long arg)
2801 {
2802         struct super_block *sb = (struct super_block *) arg;
2803         struct ext4_sb_info *sbi;
2804         struct ext4_super_block *es;
2805
2806         sbi = EXT4_SB(sb);
2807         es = sbi->s_es;
2808
2809         if (es->s_error_count)
2810                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2811                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2812                          le32_to_cpu(es->s_error_count));
2813         if (es->s_first_error_time) {
2814                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2815                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2816                        (int) sizeof(es->s_first_error_func),
2817                        es->s_first_error_func,
2818                        le32_to_cpu(es->s_first_error_line));
2819                 if (es->s_first_error_ino)
2820                         printk(": inode %u",
2821                                le32_to_cpu(es->s_first_error_ino));
2822                 if (es->s_first_error_block)
2823                         printk(": block %llu", (unsigned long long)
2824                                le64_to_cpu(es->s_first_error_block));
2825                 printk("\n");
2826         }
2827         if (es->s_last_error_time) {
2828                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2829                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2830                        (int) sizeof(es->s_last_error_func),
2831                        es->s_last_error_func,
2832                        le32_to_cpu(es->s_last_error_line));
2833                 if (es->s_last_error_ino)
2834                         printk(": inode %u",
2835                                le32_to_cpu(es->s_last_error_ino));
2836                 if (es->s_last_error_block)
2837                         printk(": block %llu", (unsigned long long)
2838                                le64_to_cpu(es->s_last_error_block));
2839                 printk("\n");
2840         }
2841         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2842 }
2843
2844 /* Find next suitable group and run ext4_init_inode_table */
2845 static int ext4_run_li_request(struct ext4_li_request *elr)
2846 {
2847         struct ext4_group_desc *gdp = NULL;
2848         ext4_group_t group, ngroups;
2849         struct super_block *sb;
2850         unsigned long timeout = 0;
2851         int ret = 0;
2852
2853         sb = elr->lr_super;
2854         ngroups = EXT4_SB(sb)->s_groups_count;
2855
2856         sb_start_write(sb);
2857         for (group = elr->lr_next_group; group < ngroups; group++) {
2858                 gdp = ext4_get_group_desc(sb, group, NULL);
2859                 if (!gdp) {
2860                         ret = 1;
2861                         break;
2862                 }
2863
2864                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2865                         break;
2866         }
2867
2868         if (group >= ngroups)
2869                 ret = 1;
2870
2871         if (!ret) {
2872                 timeout = jiffies;
2873                 ret = ext4_init_inode_table(sb, group,
2874                                             elr->lr_timeout ? 0 : 1);
2875                 if (elr->lr_timeout == 0) {
2876                         timeout = (jiffies - timeout) *
2877                                   elr->lr_sbi->s_li_wait_mult;
2878                         elr->lr_timeout = timeout;
2879                 }
2880                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2881                 elr->lr_next_group = group + 1;
2882         }
2883         sb_end_write(sb);
2884
2885         return ret;
2886 }
2887
2888 /*
2889  * Remove lr_request from the list_request and free the
2890  * request structure. Should be called with li_list_mtx held
2891  */
2892 static void ext4_remove_li_request(struct ext4_li_request *elr)
2893 {
2894         struct ext4_sb_info *sbi;
2895
2896         if (!elr)
2897                 return;
2898
2899         sbi = elr->lr_sbi;
2900
2901         list_del(&elr->lr_request);
2902         sbi->s_li_request = NULL;
2903         kfree(elr);
2904 }
2905
2906 static void ext4_unregister_li_request(struct super_block *sb)
2907 {
2908         mutex_lock(&ext4_li_mtx);
2909         if (!ext4_li_info) {
2910                 mutex_unlock(&ext4_li_mtx);
2911                 return;
2912         }
2913
2914         mutex_lock(&ext4_li_info->li_list_mtx);
2915         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2916         mutex_unlock(&ext4_li_info->li_list_mtx);
2917         mutex_unlock(&ext4_li_mtx);
2918 }
2919
2920 static struct task_struct *ext4_lazyinit_task;
2921
2922 /*
2923  * This is the function where ext4lazyinit thread lives. It walks
2924  * through the request list searching for next scheduled filesystem.
2925  * When such a fs is found, run the lazy initialization request
2926  * (ext4_rn_li_request) and keep track of the time spend in this
2927  * function. Based on that time we compute next schedule time of
2928  * the request. When walking through the list is complete, compute
2929  * next waking time and put itself into sleep.
2930  */
2931 static int ext4_lazyinit_thread(void *arg)
2932 {
2933         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2934         struct list_head *pos, *n;
2935         struct ext4_li_request *elr;
2936         unsigned long next_wakeup, cur;
2937
2938         BUG_ON(NULL == eli);
2939
2940 cont_thread:
2941         while (true) {
2942                 next_wakeup = MAX_JIFFY_OFFSET;
2943
2944                 mutex_lock(&eli->li_list_mtx);
2945                 if (list_empty(&eli->li_request_list)) {
2946                         mutex_unlock(&eli->li_list_mtx);
2947                         goto exit_thread;
2948                 }
2949
2950                 list_for_each_safe(pos, n, &eli->li_request_list) {
2951                         elr = list_entry(pos, struct ext4_li_request,
2952                                          lr_request);
2953
2954                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2955                                 if (ext4_run_li_request(elr) != 0) {
2956                                         /* error, remove the lazy_init job */
2957                                         ext4_remove_li_request(elr);
2958                                         continue;
2959                                 }
2960                         }
2961
2962                         if (time_before(elr->lr_next_sched, next_wakeup))
2963                                 next_wakeup = elr->lr_next_sched;
2964                 }
2965                 mutex_unlock(&eli->li_list_mtx);
2966
2967                 try_to_freeze();
2968
2969                 cur = jiffies;
2970                 if ((time_after_eq(cur, next_wakeup)) ||
2971                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2972                         cond_resched();
2973                         continue;
2974                 }
2975
2976                 schedule_timeout_interruptible(next_wakeup - cur);
2977
2978                 if (kthread_should_stop()) {
2979                         ext4_clear_request_list();
2980                         goto exit_thread;
2981                 }
2982         }
2983
2984 exit_thread:
2985         /*
2986          * It looks like the request list is empty, but we need
2987          * to check it under the li_list_mtx lock, to prevent any
2988          * additions into it, and of course we should lock ext4_li_mtx
2989          * to atomically free the list and ext4_li_info, because at
2990          * this point another ext4 filesystem could be registering
2991          * new one.
2992          */
2993         mutex_lock(&ext4_li_mtx);
2994         mutex_lock(&eli->li_list_mtx);
2995         if (!list_empty(&eli->li_request_list)) {
2996                 mutex_unlock(&eli->li_list_mtx);
2997                 mutex_unlock(&ext4_li_mtx);
2998                 goto cont_thread;
2999         }
3000         mutex_unlock(&eli->li_list_mtx);
3001         kfree(ext4_li_info);
3002         ext4_li_info = NULL;
3003         mutex_unlock(&ext4_li_mtx);
3004
3005         return 0;
3006 }
3007
3008 static void ext4_clear_request_list(void)
3009 {
3010         struct list_head *pos, *n;
3011         struct ext4_li_request *elr;
3012
3013         mutex_lock(&ext4_li_info->li_list_mtx);
3014         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3015                 elr = list_entry(pos, struct ext4_li_request,
3016                                  lr_request);
3017                 ext4_remove_li_request(elr);
3018         }
3019         mutex_unlock(&ext4_li_info->li_list_mtx);
3020 }
3021
3022 static int ext4_run_lazyinit_thread(void)
3023 {
3024         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3025                                          ext4_li_info, "ext4lazyinit");
3026         if (IS_ERR(ext4_lazyinit_task)) {
3027                 int err = PTR_ERR(ext4_lazyinit_task);
3028                 ext4_clear_request_list();
3029                 kfree(ext4_li_info);
3030                 ext4_li_info = NULL;
3031                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3032                                  "initialization thread\n",
3033                                  err);
3034                 return err;
3035         }
3036         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3037         return 0;
3038 }
3039
3040 /*
3041  * Check whether it make sense to run itable init. thread or not.
3042  * If there is at least one uninitialized inode table, return
3043  * corresponding group number, else the loop goes through all
3044  * groups and return total number of groups.
3045  */
3046 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3047 {
3048         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3049         struct ext4_group_desc *gdp = NULL;
3050
3051         for (group = 0; group < ngroups; group++) {
3052                 gdp = ext4_get_group_desc(sb, group, NULL);
3053                 if (!gdp)
3054                         continue;
3055
3056                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3057                         break;
3058         }
3059
3060         return group;
3061 }
3062
3063 static int ext4_li_info_new(void)
3064 {
3065         struct ext4_lazy_init *eli = NULL;
3066
3067         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3068         if (!eli)
3069                 return -ENOMEM;
3070
3071         INIT_LIST_HEAD(&eli->li_request_list);
3072         mutex_init(&eli->li_list_mtx);
3073
3074         eli->li_state |= EXT4_LAZYINIT_QUIT;
3075
3076         ext4_li_info = eli;
3077
3078         return 0;
3079 }
3080
3081 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3082                                             ext4_group_t start)
3083 {
3084         struct ext4_sb_info *sbi = EXT4_SB(sb);
3085         struct ext4_li_request *elr;
3086
3087         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3088         if (!elr)
3089                 return NULL;
3090
3091         elr->lr_super = sb;
3092         elr->lr_sbi = sbi;
3093         elr->lr_next_group = start;
3094
3095         /*
3096          * Randomize first schedule time of the request to
3097          * spread the inode table initialization requests
3098          * better.
3099          */
3100         elr->lr_next_sched = jiffies + (prandom_u32() %
3101                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3102         return elr;
3103 }
3104
3105 int ext4_register_li_request(struct super_block *sb,
3106                              ext4_group_t first_not_zeroed)
3107 {
3108         struct ext4_sb_info *sbi = EXT4_SB(sb);
3109         struct ext4_li_request *elr = NULL;
3110         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3111         int ret = 0;
3112
3113         mutex_lock(&ext4_li_mtx);
3114         if (sbi->s_li_request != NULL) {
3115                 /*
3116                  * Reset timeout so it can be computed again, because
3117                  * s_li_wait_mult might have changed.
3118                  */
3119                 sbi->s_li_request->lr_timeout = 0;
3120                 goto out;
3121         }
3122
3123         if (first_not_zeroed == ngroups ||
3124             (sb->s_flags & MS_RDONLY) ||
3125             !test_opt(sb, INIT_INODE_TABLE))
3126                 goto out;
3127
3128         elr = ext4_li_request_new(sb, first_not_zeroed);
3129         if (!elr) {
3130                 ret = -ENOMEM;
3131                 goto out;
3132         }
3133
3134         if (NULL == ext4_li_info) {
3135                 ret = ext4_li_info_new();
3136                 if (ret)
3137                         goto out;
3138         }
3139
3140         mutex_lock(&ext4_li_info->li_list_mtx);
3141         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3142         mutex_unlock(&ext4_li_info->li_list_mtx);
3143
3144         sbi->s_li_request = elr;
3145         /*
3146          * set elr to NULL here since it has been inserted to
3147          * the request_list and the removal and free of it is
3148          * handled by ext4_clear_request_list from now on.
3149          */
3150         elr = NULL;
3151
3152         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3153                 ret = ext4_run_lazyinit_thread();
3154                 if (ret)
3155                         goto out;
3156         }
3157 out:
3158         mutex_unlock(&ext4_li_mtx);
3159         if (ret)
3160                 kfree(elr);
3161         return ret;
3162 }
3163
3164 /*
3165  * We do not need to lock anything since this is called on
3166  * module unload.
3167  */
3168 static void ext4_destroy_lazyinit_thread(void)
3169 {
3170         /*
3171          * If thread exited earlier
3172          * there's nothing to be done.
3173          */
3174         if (!ext4_li_info || !ext4_lazyinit_task)
3175                 return;
3176
3177         kthread_stop(ext4_lazyinit_task);
3178 }
3179
3180 static int set_journal_csum_feature_set(struct super_block *sb)
3181 {
3182         int ret = 1;
3183         int compat, incompat;
3184         struct ext4_sb_info *sbi = EXT4_SB(sb);
3185
3186         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3187                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3188                 /* journal checksum v2 */
3189                 compat = 0;
3190                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3191         } else {
3192                 /* journal checksum v1 */
3193                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3194                 incompat = 0;
3195         }
3196
3197         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3198                 ret = jbd2_journal_set_features(sbi->s_journal,
3199                                 compat, 0,
3200                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3201                                 incompat);
3202         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3203                 ret = jbd2_journal_set_features(sbi->s_journal,
3204                                 compat, 0,
3205                                 incompat);
3206                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3207                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3208         } else {
3209                 jbd2_journal_clear_features(sbi->s_journal,
3210                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3211                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3212                                 JBD2_FEATURE_INCOMPAT_CSUM_V2);
3213         }
3214
3215         return ret;
3216 }
3217
3218 /*
3219  * Note: calculating the overhead so we can be compatible with
3220  * historical BSD practice is quite difficult in the face of
3221  * clusters/bigalloc.  This is because multiple metadata blocks from
3222  * different block group can end up in the same allocation cluster.
3223  * Calculating the exact overhead in the face of clustered allocation
3224  * requires either O(all block bitmaps) in memory or O(number of block
3225  * groups**2) in time.  We will still calculate the superblock for
3226  * older file systems --- and if we come across with a bigalloc file
3227  * system with zero in s_overhead_clusters the estimate will be close to
3228  * correct especially for very large cluster sizes --- but for newer
3229  * file systems, it's better to calculate this figure once at mkfs
3230  * time, and store it in the superblock.  If the superblock value is
3231  * present (even for non-bigalloc file systems), we will use it.
3232  */
3233 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3234                           char *buf)
3235 {
3236         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3237         struct ext4_group_desc  *gdp;
3238         ext4_fsblk_t            first_block, last_block, b;
3239         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3240         int                     s, j, count = 0;
3241
3242         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3243                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3244                         sbi->s_itb_per_group + 2);
3245
3246         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3247                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3248         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3249         for (i = 0; i < ngroups; i++) {
3250                 gdp = ext4_get_group_desc(sb, i, NULL);
3251                 b = ext4_block_bitmap(sb, gdp);
3252                 if (b >= first_block && b <= last_block) {
3253                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3254                         count++;
3255                 }
3256                 b = ext4_inode_bitmap(sb, gdp);
3257                 if (b >= first_block && b <= last_block) {
3258                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3259                         count++;
3260                 }
3261                 b = ext4_inode_table(sb, gdp);
3262                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3263                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3264                                 int c = EXT4_B2C(sbi, b - first_block);
3265                                 ext4_set_bit(c, buf);
3266                                 count++;
3267                         }
3268                 if (i != grp)
3269                         continue;
3270                 s = 0;
3271                 if (ext4_bg_has_super(sb, grp)) {
3272                         ext4_set_bit(s++, buf);
3273                         count++;
3274                 }
3275                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3276                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3277                         count++;
3278                 }
3279         }
3280         if (!count)
3281                 return 0;
3282         return EXT4_CLUSTERS_PER_GROUP(sb) -
3283                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3284 }
3285
3286 /*
3287  * Compute the overhead and stash it in sbi->s_overhead
3288  */
3289 int ext4_calculate_overhead(struct super_block *sb)
3290 {
3291         struct ext4_sb_info *sbi = EXT4_SB(sb);
3292         struct ext4_super_block *es = sbi->s_es;
3293         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3294         ext4_fsblk_t overhead = 0;
3295         char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3296
3297         if (!buf)
3298                 return -ENOMEM;
3299
3300         /*
3301          * Compute the overhead (FS structures).  This is constant
3302          * for a given filesystem unless the number of block groups
3303          * changes so we cache the previous value until it does.
3304          */
3305
3306         /*
3307          * All of the blocks before first_data_block are overhead
3308          */
3309         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3310
3311         /*
3312          * Add the overhead found in each block group
3313          */
3314         for (i = 0; i < ngroups; i++) {
3315                 int blks;
3316
3317                 blks = count_overhead(sb, i, buf);
3318                 overhead += blks;
3319                 if (blks)
3320                         memset(buf, 0, PAGE_SIZE);
3321                 cond_resched();
3322         }
3323         /* Add the journal blocks as well */
3324         if (sbi->s_journal)
3325                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3326
3327         sbi->s_overhead = overhead;
3328         smp_wmb();
3329         free_page((unsigned long) buf);
3330         return 0;
3331 }
3332
3333
3334 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3335 {
3336         ext4_fsblk_t resv_clusters;
3337
3338         /*
3339          * There's no need to reserve anything when we aren't using extents.
3340          * The space estimates are exact, there are no unwritten extents,
3341          * hole punching doesn't need new metadata... This is needed especially
3342          * to keep ext2/3 backward compatibility.
3343          */
3344         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3345                 return 0;
3346         /*
3347          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3348          * This should cover the situations where we can not afford to run
3349          * out of space like for example punch hole, or converting
3350          * unwritten extents in delalloc path. In most cases such
3351          * allocation would require 1, or 2 blocks, higher numbers are
3352          * very rare.
3353          */
3354         resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3355                         EXT4_SB(sb)->s_cluster_bits;
3356
3357         do_div(resv_clusters, 50);
3358         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3359
3360         return resv_clusters;
3361 }
3362
3363
3364 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3365 {
3366         ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3367                                 sbi->s_cluster_bits;
3368
3369         if (count >= clusters)
3370                 return -EINVAL;
3371
3372         atomic64_set(&sbi->s_resv_clusters, count);
3373         return 0;
3374 }
3375
3376 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3377 {
3378         char *orig_data = kstrdup(data, GFP_KERNEL);
3379         struct buffer_head *bh;
3380         struct ext4_super_block *es = NULL;
3381         struct ext4_sb_info *sbi;
3382         ext4_fsblk_t block;
3383         ext4_fsblk_t sb_block = get_sb_block(&data);
3384         ext4_fsblk_t logical_sb_block;
3385         unsigned long offset = 0;
3386         unsigned long journal_devnum = 0;
3387         unsigned long def_mount_opts;
3388         struct inode *root;
3389         char *cp;
3390         const char *descr;
3391         int ret = -ENOMEM;
3392         int blocksize, clustersize;
3393         unsigned int db_count;
3394         unsigned int i;
3395         int needs_recovery, has_huge_files, has_bigalloc;
3396         __u64 blocks_count;
3397         int err = 0;
3398         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3399         ext4_group_t first_not_zeroed;
3400
3401         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3402         if (!sbi)
3403                 goto out_free_orig;
3404
3405         sbi->s_blockgroup_lock =
3406                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3407         if (!sbi->s_blockgroup_lock) {
3408                 kfree(sbi);
3409                 goto out_free_orig;
3410         }
3411         sb->s_fs_info = sbi;
3412         sbi->s_sb = sb;
3413         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3414         sbi->s_sb_block = sb_block;
3415         if (sb->s_bdev->bd_part)
3416                 sbi->s_sectors_written_start =
3417                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3418
3419         /* Cleanup superblock name */
3420         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3421                 *cp = '!';
3422
3423         /* -EINVAL is default */
3424         ret = -EINVAL;
3425         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3426         if (!blocksize) {
3427                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3428                 goto out_fail;
3429         }
3430
3431         /*
3432          * The ext4 superblock will not be buffer aligned for other than 1kB
3433          * block sizes.  We need to calculate the offset from buffer start.
3434          */
3435         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3436                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3437                 offset = do_div(logical_sb_block, blocksize);
3438         } else {
3439                 logical_sb_block = sb_block;
3440         }
3441
3442         if (!(bh = sb_bread(sb, logical_sb_block))) {
3443                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3444                 goto out_fail;
3445         }
3446         /*
3447          * Note: s_es must be initialized as soon as possible because
3448          *       some ext4 macro-instructions depend on its value
3449          */
3450         es = (struct ext4_super_block *) (bh->b_data + offset);
3451         sbi->s_es = es;
3452         sb->s_magic = le16_to_cpu(es->s_magic);
3453         if (sb->s_magic != EXT4_SUPER_MAGIC)
3454                 goto cantfind_ext4;
3455         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3456
3457         /* Warn if metadata_csum and gdt_csum are both set. */
3458         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3459                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3460             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3461                 ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3462                              "redundant flags; please run fsck.");
3463
3464         /* Check for a known checksum algorithm */
3465         if (!ext4_verify_csum_type(sb, es)) {
3466                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3467                          "unknown checksum algorithm.");
3468                 silent = 1;
3469                 goto cantfind_ext4;
3470         }
3471
3472         /* Load the checksum driver */
3473         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3474                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3475                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3476                 if (IS_ERR(sbi->s_chksum_driver)) {
3477                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3478                         ret = PTR_ERR(sbi->s_chksum_driver);
3479                         sbi->s_chksum_driver = NULL;
3480                         goto failed_mount;
3481                 }
3482         }
3483
3484         /* Check superblock checksum */
3485         if (!ext4_superblock_csum_verify(sb, es)) {
3486                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3487                          "invalid superblock checksum.  Run e2fsck?");
3488                 silent = 1;
3489                 goto cantfind_ext4;
3490         }
3491
3492         /* Precompute checksum seed for all metadata */
3493         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3494                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3495                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3496                                                sizeof(es->s_uuid));
3497
3498         /* Set defaults before we parse the mount options */
3499         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3500         set_opt(sb, INIT_INODE_TABLE);
3501         if (def_mount_opts & EXT4_DEFM_DEBUG)
3502                 set_opt(sb, DEBUG);
3503         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3504                 set_opt(sb, GRPID);
3505         if (def_mount_opts & EXT4_DEFM_UID16)
3506                 set_opt(sb, NO_UID32);
3507         /* xattr user namespace & acls are now defaulted on */
3508         set_opt(sb, XATTR_USER);
3509 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3510         set_opt(sb, POSIX_ACL);
3511 #endif
3512         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3513                 set_opt(sb, JOURNAL_DATA);
3514         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3515                 set_opt(sb, ORDERED_DATA);
3516         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3517                 set_opt(sb, WRITEBACK_DATA);
3518
3519         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3520                 set_opt(sb, ERRORS_PANIC);
3521         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3522                 set_opt(sb, ERRORS_CONT);
3523         else
3524                 set_opt(sb, ERRORS_RO);
3525         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3526                 set_opt(sb, BLOCK_VALIDITY);
3527         if (def_mount_opts & EXT4_DEFM_DISCARD)
3528                 set_opt(sb, DISCARD);
3529
3530         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3531         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3532         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3533         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3534         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3535
3536         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3537                 set_opt(sb, BARRIER);
3538
3539         /*
3540          * enable delayed allocation by default
3541          * Use -o nodelalloc to turn it off
3542          */
3543         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3544             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3545                 set_opt(sb, DELALLOC);
3546
3547         /*
3548          * set default s_li_wait_mult for lazyinit, for the case there is
3549          * no mount option specified.
3550          */
3551         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3552
3553         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3554                            &journal_devnum, &journal_ioprio, 0)) {
3555                 ext4_msg(sb, KERN_WARNING,
3556                          "failed to parse options in superblock: %s",
3557                          sbi->s_es->s_mount_opts);
3558         }
3559         sbi->s_def_mount_opt = sbi->s_mount_opt;
3560         if (!parse_options((char *) data, sb, &journal_devnum,
3561                            &journal_ioprio, 0))
3562                 goto failed_mount;
3563
3564         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3565                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3566                             "with data=journal disables delayed "
3567                             "allocation and O_DIRECT support!\n");
3568                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3569                         ext4_msg(sb, KERN_ERR, "can't mount with "
3570                                  "both data=journal and delalloc");
3571                         goto failed_mount;
3572                 }
3573                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3574                         ext4_msg(sb, KERN_ERR, "can't mount with "
3575                                  "both data=journal and dioread_nolock");
3576                         goto failed_mount;
3577                 }
3578                 if (test_opt(sb, DELALLOC))
3579                         clear_opt(sb, DELALLOC);
3580         }
3581
3582         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3583                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3584
3585         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3586             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3587              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3588              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3589                 ext4_msg(sb, KERN_WARNING,
3590                        "feature flags set on rev 0 fs, "
3591                        "running e2fsck is recommended");
3592
3593         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3594                 set_opt2(sb, HURD_COMPAT);
3595                 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
3596                                               EXT4_FEATURE_INCOMPAT_64BIT)) {
3597                         ext4_msg(sb, KERN_ERR,
3598                                  "The Hurd can't support 64-bit file systems");
3599                         goto failed_mount;
3600                 }
3601         }
3602
3603         if (IS_EXT2_SB(sb)) {
3604                 if (ext2_feature_set_ok(sb))
3605                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3606                                  "using the ext4 subsystem");
3607                 else {
3608                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3609                                  "to feature incompatibilities");
3610                         goto failed_mount;
3611                 }
3612         }
3613
3614         if (IS_EXT3_SB(sb)) {
3615                 if (ext3_feature_set_ok(sb))
3616                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3617                                  "using the ext4 subsystem");
3618                 else {
3619                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3620                                  "to feature incompatibilities");
3621                         goto failed_mount;
3622                 }
3623         }
3624
3625         /*
3626          * Check feature flags regardless of the revision level, since we
3627          * previously didn't change the revision level when setting the flags,
3628          * so there is a chance incompat flags are set on a rev 0 filesystem.
3629          */
3630         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3631                 goto failed_mount;
3632
3633         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3634         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3635             blocksize > EXT4_MAX_BLOCK_SIZE) {
3636                 ext4_msg(sb, KERN_ERR,
3637                        "Unsupported filesystem blocksize %d", blocksize);
3638                 goto failed_mount;
3639         }
3640
3641         if (sb->s_blocksize != blocksize) {
3642                 /* Validate the filesystem blocksize */
3643                 if (!sb_set_blocksize(sb, blocksize)) {
3644                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3645                                         blocksize);
3646                         goto failed_mount;
3647                 }
3648
3649                 brelse(bh);
3650                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3651                 offset = do_div(logical_sb_block, blocksize);
3652                 bh = sb_bread(sb, logical_sb_block);
3653                 if (!bh) {
3654                         ext4_msg(sb, KERN_ERR,
3655                                "Can't read superblock on 2nd try");
3656                         goto failed_mount;
3657                 }
3658                 es = (struct ext4_super_block *)(bh->b_data + offset);
3659                 sbi->s_es = es;
3660                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3661                         ext4_msg(sb, KERN_ERR,
3662                                "Magic mismatch, very weird!");
3663                         goto failed_mount;
3664                 }
3665         }
3666
3667         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3668                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3669         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3670                                                       has_huge_files);
3671         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3672
3673         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3674                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3675                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3676         } else {
3677                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3678                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3679                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3680                     (!is_power_of_2(sbi->s_inode_size)) ||
3681                     (sbi->s_inode_size > blocksize)) {
3682                         ext4_msg(sb, KERN_ERR,
3683                                "unsupported inode size: %d",
3684                                sbi->s_inode_size);
3685                         goto failed_mount;
3686                 }
3687                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3688                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3689         }
3690
3691         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3692         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3693                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3694                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3695                     !is_power_of_2(sbi->s_desc_size)) {
3696                         ext4_msg(sb, KERN_ERR,
3697                                "unsupported descriptor size %lu",
3698                                sbi->s_desc_size);
3699                         goto failed_mount;
3700                 }
3701         } else
3702                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3703
3704         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3705         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3706         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3707                 goto cantfind_ext4;
3708
3709         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3710         if (sbi->s_inodes_per_block == 0)
3711                 goto cantfind_ext4;
3712         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3713                                         sbi->s_inodes_per_block;
3714         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3715         sbi->s_sbh = bh;
3716         sbi->s_mount_state = le16_to_cpu(es->s_state);
3717         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3718         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3719
3720         for (i = 0; i < 4; i++)
3721                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3722         sbi->s_def_hash_version = es->s_def_hash_version;
3723         if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3724                 i = le32_to_cpu(es->s_flags);
3725                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3726                         sbi->s_hash_unsigned = 3;
3727                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3728 #ifdef __CHAR_UNSIGNED__
3729                         if (!(sb->s_flags & MS_RDONLY))
3730                                 es->s_flags |=
3731                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3732                         sbi->s_hash_unsigned = 3;
3733 #else
3734                         if (!(sb->s_flags & MS_RDONLY))
3735                                 es->s_flags |=
3736                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3737 #endif
3738                 }
3739         }
3740
3741         /* Handle clustersize */
3742         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3743         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3744                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3745         if (has_bigalloc) {
3746                 if (clustersize < blocksize) {
3747                         ext4_msg(sb, KERN_ERR,
3748                                  "cluster size (%d) smaller than "
3749                                  "block size (%d)", clustersize, blocksize);
3750                         goto failed_mount;
3751                 }
3752                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3753                         le32_to_cpu(es->s_log_block_size);
3754                 sbi->s_clusters_per_group =
3755                         le32_to_cpu(es->s_clusters_per_group);
3756                 if (sbi->s_clusters_per_group > blocksize * 8) {
3757                         ext4_msg(sb, KERN_ERR,
3758                                  "#clusters per group too big: %lu",
3759                                  sbi->s_clusters_per_group);
3760                         goto failed_mount;
3761                 }
3762                 if (sbi->s_blocks_per_group !=
3763                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3764                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3765                                  "clusters per group (%lu) inconsistent",
3766                                  sbi->s_blocks_per_group,
3767                                  sbi->s_clusters_per_group);
3768                         goto failed_mount;
3769                 }
3770         } else {
3771                 if (clustersize != blocksize) {
3772                         ext4_warning(sb, "fragment/cluster size (%d) != "
3773                                      "block size (%d)", clustersize,
3774                                      blocksize);
3775                         clustersize = blocksize;
3776                 }
3777                 if (sbi->s_blocks_per_group > blocksize * 8) {
3778                         ext4_msg(sb, KERN_ERR,
3779                                  "#blocks per group too big: %lu",
3780                                  sbi->s_blocks_per_group);
3781                         goto failed_mount;
3782                 }
3783                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3784                 sbi->s_cluster_bits = 0;
3785         }
3786         sbi->s_cluster_ratio = clustersize / blocksize;
3787
3788         if (sbi->s_inodes_per_group > blocksize * 8) {
3789                 ext4_msg(sb, KERN_ERR,
3790                        "#inodes per group too big: %lu",
3791                        sbi->s_inodes_per_group);
3792                 goto failed_mount;
3793         }
3794
3795         /* Do we have standard group size of clustersize * 8 blocks ? */
3796         if (sbi->s_blocks_per_group == clustersize << 3)
3797                 set_opt2(sb, STD_GROUP_SIZE);
3798
3799         /*
3800          * Test whether we have more sectors than will fit in sector_t,
3801          * and whether the max offset is addressable by the page cache.
3802          */
3803         err = generic_check_addressable(sb->s_blocksize_bits,
3804                                         ext4_blocks_count(es));
3805         if (err) {
3806                 ext4_msg(sb, KERN_ERR, "filesystem"
3807                          " too large to mount safely on this system");
3808                 if (sizeof(sector_t) < 8)
3809                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3810                 goto failed_mount;
3811         }
3812
3813         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3814                 goto cantfind_ext4;
3815
3816         /* check blocks count against device size */
3817         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3818         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3819                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3820                        "exceeds size of device (%llu blocks)",
3821                        ext4_blocks_count(es), blocks_count);
3822                 goto failed_mount;
3823         }
3824
3825         /*
3826          * It makes no sense for the first data block to be beyond the end
3827          * of the filesystem.
3828          */
3829         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3830                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3831                          "block %u is beyond end of filesystem (%llu)",
3832                          le32_to_cpu(es->s_first_data_block),
3833                          ext4_blocks_count(es));
3834                 goto failed_mount;
3835         }
3836         blocks_count = (ext4_blocks_count(es) -
3837                         le32_to_cpu(es->s_first_data_block) +
3838                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3839         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3840         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3841                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3842                        "(block count %llu, first data block %u, "
3843                        "blocks per group %lu)", sbi->s_groups_count,
3844                        ext4_blocks_count(es),
3845                        le32_to_cpu(es->s_first_data_block),
3846                        EXT4_BLOCKS_PER_GROUP(sb));
3847                 goto failed_mount;
3848         }
3849         sbi->s_groups_count = blocks_count;
3850         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3851                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3852         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3853                    EXT4_DESC_PER_BLOCK(sb);
3854         sbi->s_group_desc = ext4_kvmalloc(db_count *
3855                                           sizeof(struct buffer_head *),
3856                                           GFP_KERNEL);
3857         if (sbi->s_group_desc == NULL) {
3858                 ext4_msg(sb, KERN_ERR, "not enough memory");
3859                 ret = -ENOMEM;
3860                 goto failed_mount;
3861         }
3862
3863         if (ext4_proc_root)
3864                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3865
3866         if (sbi->s_proc)
3867                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3868                                  &ext4_seq_options_fops, sb);
3869
3870         bgl_lock_init(sbi->s_blockgroup_lock);
3871
3872         for (i = 0; i < db_count; i++) {
3873                 block = descriptor_loc(sb, logical_sb_block, i);
3874                 sbi->s_group_desc[i] = sb_bread(sb, block);
3875                 if (!sbi->s_group_desc[i]) {
3876                         ext4_msg(sb, KERN_ERR,
3877                                "can't read group descriptor %d", i);
3878                         db_count = i;
3879                         goto failed_mount2;
3880                 }
3881         }
3882
3883         /*
3884          * set up enough so that it can read an inode,
3885          * and create new inode for buddy allocator
3886          */
3887         sbi->s_gdb_count = db_count;
3888         if (!test_opt(sb, NOLOAD) &&
3889             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3890                 sb->s_op = &ext4_sops;
3891         else
3892                 sb->s_op = &ext4_nojournal_sops;
3893
3894         ext4_ext_init(sb);
3895         err = ext4_mb_init(sb);
3896         if (err) {
3897                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3898                          err);
3899                 goto failed_mount2;
3900         }
3901
3902         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3903                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3904                 goto failed_mount2a;
3905         }
3906         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3907                 if (!ext4_fill_flex_info(sb)) {
3908                         ext4_msg(sb, KERN_ERR,
3909                                "unable to initialize "
3910                                "flex_bg meta info!");
3911                         goto failed_mount2a;
3912                 }
3913
3914         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3915         spin_lock_init(&sbi->s_next_gen_lock);
3916
3917         init_timer(&sbi->s_err_report);
3918         sbi->s_err_report.function = print_daily_error_info;
3919         sbi->s_err_report.data = (unsigned long) sb;
3920
3921         /* Register extent status tree shrinker */
3922         ext4_es_register_shrinker(sbi);
3923
3924         err = percpu_counter_init(&sbi->s_freeclusters_counter,
3925                         ext4_count_free_clusters(sb));
3926         if (!err) {
3927                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
3928                                 ext4_count_free_inodes(sb));
3929         }
3930         if (!err) {
3931                 err = percpu_counter_init(&sbi->s_dirs_counter,
3932                                 ext4_count_dirs(sb));
3933         }
3934         if (!err) {
3935                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3936         }
3937         if (!err) {
3938                 err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
3939         }
3940         if (err) {
3941                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3942                 goto failed_mount3;
3943         }
3944
3945         sbi->s_stripe = ext4_get_stripe_size(sbi);
3946         sbi->s_extent_max_zeroout_kb = 32;
3947
3948         sb->s_export_op = &ext4_export_ops;
3949         sb->s_xattr = ext4_xattr_handlers;
3950 #ifdef CONFIG_QUOTA
3951         sb->dq_op = &ext4_quota_operations;
3952         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3953                 sb->s_qcop = &ext4_qctl_sysfile_operations;
3954         else
3955                 sb->s_qcop = &ext4_qctl_operations;
3956 #endif
3957         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3958
3959         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3960         mutex_init(&sbi->s_orphan_lock);
3961
3962         sb->s_root = NULL;
3963
3964         needs_recovery = (es->s_last_orphan != 0 ||
3965                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3966                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3967
3968         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3969             !(sb->s_flags & MS_RDONLY))
3970                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3971                         goto failed_mount3;
3972
3973         /*
3974          * The first inode we look at is the journal inode.  Don't try
3975          * root first: it may be modified in the journal!
3976          */
3977         if (!test_opt(sb, NOLOAD) &&
3978             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3979                 if (ext4_load_journal(sb, es, journal_devnum))
3980                         goto failed_mount3;
3981         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3982               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3983                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3984                        "suppressed and not mounted read-only");
3985                 goto failed_mount_wq;
3986         } else {
3987                 clear_opt(sb, DATA_FLAGS);
3988                 sbi->s_journal = NULL;
3989                 needs_recovery = 0;
3990                 goto no_journal;
3991         }
3992
3993         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3994             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3995                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3996                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3997                 goto failed_mount_wq;
3998         }
3999
4000         if (!set_journal_csum_feature_set(sb)) {
4001                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4002                          "feature set");
4003                 goto failed_mount_wq;
4004         }
4005
4006         /* We have now updated the journal if required, so we can
4007          * validate the data journaling mode. */
4008         switch (test_opt(sb, DATA_FLAGS)) {
4009         case 0:
4010                 /* No mode set, assume a default based on the journal
4011                  * capabilities: ORDERED_DATA if the journal can
4012                  * cope, else JOURNAL_DATA
4013                  */
4014                 if (jbd2_journal_check_available_features
4015                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4016                         set_opt(sb, ORDERED_DATA);
4017                 else
4018                         set_opt(sb, JOURNAL_DATA);
4019                 break;
4020
4021         case EXT4_MOUNT_ORDERED_DATA:
4022         case EXT4_MOUNT_WRITEBACK_DATA:
4023                 if (!jbd2_journal_check_available_features
4024                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4025                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4026                                "requested data journaling mode");
4027                         goto failed_mount_wq;
4028                 }
4029         default:
4030                 break;
4031         }
4032         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4033
4034         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4035
4036         /*
4037          * The journal may have updated the bg summary counts, so we
4038          * need to update the global counters.
4039          */
4040         percpu_counter_set(&sbi->s_freeclusters_counter,
4041                            ext4_count_free_clusters(sb));
4042         percpu_counter_set(&sbi->s_freeinodes_counter,
4043                            ext4_count_free_inodes(sb));
4044         percpu_counter_set(&sbi->s_dirs_counter,
4045                            ext4_count_dirs(sb));
4046         percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
4047
4048 no_journal:
4049         if (ext4_mballoc_ready) {
4050                 sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
4051                 if (!sbi->s_mb_cache) {
4052                         ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4053                         goto failed_mount_wq;
4054                 }
4055         }
4056
4057         /*
4058          * Get the # of file system overhead blocks from the
4059          * superblock if present.
4060          */
4061         if (es->s_overhead_clusters)
4062                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4063         else {
4064                 err = ext4_calculate_overhead(sb);
4065                 if (err)
4066                         goto failed_mount_wq;
4067         }
4068
4069         /*
4070          * The maximum number of concurrent works can be high and
4071          * concurrency isn't really necessary.  Limit it to 1.
4072          */
4073         EXT4_SB(sb)->rsv_conversion_wq =
4074                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4075         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4076                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4077                 ret = -ENOMEM;
4078                 goto failed_mount4;
4079         }
4080
4081         /*
4082          * The jbd2_journal_load will have done any necessary log recovery,
4083          * so we can safely mount the rest of the filesystem now.
4084          */
4085
4086         root = ext4_iget(sb, EXT4_ROOT_INO);
4087         if (IS_ERR(root)) {
4088                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4089                 ret = PTR_ERR(root);
4090                 root = NULL;
4091                 goto failed_mount4;
4092         }
4093         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4094                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4095                 iput(root);
4096                 goto failed_mount4;
4097         }
4098         sb->s_root = d_make_root(root);
4099         if (!sb->s_root) {
4100                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4101                 ret = -ENOMEM;
4102                 goto failed_mount4;
4103         }
4104
4105         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4106                 sb->s_flags |= MS_RDONLY;
4107
4108         /* determine the minimum size of new large inodes, if present */
4109         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4110                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4111                                                      EXT4_GOOD_OLD_INODE_SIZE;
4112                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4113                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4114                         if (sbi->s_want_extra_isize <
4115                             le16_to_cpu(es->s_want_extra_isize))
4116                                 sbi->s_want_extra_isize =
4117                                         le16_to_cpu(es->s_want_extra_isize);
4118                         if (sbi->s_want_extra_isize <
4119                             le16_to_cpu(es->s_min_extra_isize))
4120                                 sbi->s_want_extra_isize =
4121                                         le16_to_cpu(es->s_min_extra_isize);
4122                 }
4123         }
4124         /* Check if enough inode space is available */
4125         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4126                                                         sbi->s_inode_size) {
4127                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4128                                                        EXT4_GOOD_OLD_INODE_SIZE;
4129                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4130                          "available");
4131         }
4132
4133         err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4134         if (err) {
4135                 ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4136                          "reserved pool", ext4_calculate_resv_clusters(sb));
4137                 goto failed_mount5;
4138         }
4139
4140         err = ext4_setup_system_zone(sb);
4141         if (err) {
4142                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4143                          "zone (%d)", err);
4144                 goto failed_mount5;
4145         }
4146
4147         err = ext4_register_li_request(sb, first_not_zeroed);
4148         if (err)
4149                 goto failed_mount6;
4150
4151         sbi->s_kobj.kset = ext4_kset;
4152         init_completion(&sbi->s_kobj_unregister);
4153         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4154                                    "%s", sb->s_id);
4155         if (err)
4156                 goto failed_mount7;
4157
4158 #ifdef CONFIG_QUOTA
4159         /* Enable quota usage during mount. */
4160         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4161             !(sb->s_flags & MS_RDONLY)) {
4162                 err = ext4_enable_quotas(sb);
4163                 if (err)
4164                         goto failed_mount8;
4165         }
4166 #endif  /* CONFIG_QUOTA */
4167
4168         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4169         ext4_orphan_cleanup(sb, es);
4170         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4171         if (needs_recovery) {
4172                 ext4_msg(sb, KERN_INFO, "recovery complete");
4173                 ext4_mark_recovery_complete(sb, es);
4174         }
4175         if (EXT4_SB(sb)->s_journal) {
4176                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4177                         descr = " journalled data mode";
4178                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4179                         descr = " ordered data mode";
4180                 else
4181                         descr = " writeback data mode";
4182         } else
4183                 descr = "out journal";
4184
4185         if (test_opt(sb, DISCARD)) {
4186                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4187                 if (!blk_queue_discard(q))
4188                         ext4_msg(sb, KERN_WARNING,
4189                                  "mounting with \"discard\" option, but "
4190                                  "the device does not support discard");
4191         }
4192
4193         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4194                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4195                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4196
4197         if (es->s_error_count)
4198                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4199
4200         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4201         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4202         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4203         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4204
4205         kfree(orig_data);
4206         return 0;
4207
4208 cantfind_ext4:
4209         if (!silent)
4210                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4211         goto failed_mount;
4212
4213 #ifdef CONFIG_QUOTA
4214 failed_mount8:
4215         kobject_del(&sbi->s_kobj);
4216 #endif
4217 failed_mount7:
4218         ext4_unregister_li_request(sb);
4219 failed_mount6:
4220         ext4_release_system_zone(sb);
4221 failed_mount5:
4222         dput(sb->s_root);
4223         sb->s_root = NULL;
4224 failed_mount4:
4225         ext4_msg(sb, KERN_ERR, "mount failed");
4226         if (EXT4_SB(sb)->rsv_conversion_wq)
4227                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4228 failed_mount_wq:
4229         if (sbi->s_journal) {
4230                 jbd2_journal_destroy(sbi->s_journal);
4231                 sbi->s_journal = NULL;
4232         }
4233 failed_mount3:
4234         ext4_es_unregister_shrinker(sbi);
4235         del_timer_sync(&sbi->s_err_report);
4236         if (sbi->s_flex_groups)
4237                 ext4_kvfree(sbi->s_flex_groups);
4238         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4239         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4240         percpu_counter_destroy(&sbi->s_dirs_counter);
4241         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4242         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
4243         if (sbi->s_mmp_tsk)
4244                 kthread_stop(sbi->s_mmp_tsk);
4245 failed_mount2a:
4246         ext4_mb_release(sb);
4247 failed_mount2:
4248         for (i = 0; i < db_count; i++)
4249                 brelse(sbi->s_group_desc[i]);
4250         ext4_kvfree(sbi->s_group_desc);
4251 failed_mount:
4252         ext4_ext_release(sb);
4253         if (sbi->s_chksum_driver)
4254                 crypto_free_shash(sbi->s_chksum_driver);
4255         if (sbi->s_proc) {
4256                 remove_proc_entry("options", sbi->s_proc);
4257                 remove_proc_entry(sb->s_id, ext4_proc_root);
4258         }
4259 #ifdef CONFIG_QUOTA
4260         for (i = 0; i < MAXQUOTAS; i++)
4261                 kfree(sbi->s_qf_names[i]);
4262 #endif
4263         ext4_blkdev_remove(sbi);
4264         brelse(bh);
4265 out_fail:
4266         sb->s_fs_info = NULL;
4267         kfree(sbi->s_blockgroup_lock);
4268         kfree(sbi);
4269 out_free_orig:
4270         kfree(orig_data);
4271         return err ? err : ret;
4272 }
4273
4274 /*
4275  * Setup any per-fs journal parameters now.  We'll do this both on
4276  * initial mount, once the journal has been initialised but before we've
4277  * done any recovery; and again on any subsequent remount.
4278  */
4279 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4280 {
4281         struct ext4_sb_info *sbi = EXT4_SB(sb);
4282
4283         journal->j_commit_interval = sbi->s_commit_interval;
4284         journal->j_min_batch_time = sbi->s_min_batch_time;
4285         journal->j_max_batch_time = sbi->s_max_batch_time;
4286
4287         write_lock(&journal->j_state_lock);
4288         if (test_opt(sb, BARRIER))
4289                 journal->j_flags |= JBD2_BARRIER;
4290         else
4291                 journal->j_flags &= ~JBD2_BARRIER;
4292         if (test_opt(sb, DATA_ERR_ABORT))
4293                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4294         else
4295                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4296         write_unlock(&journal->j_state_lock);
4297 }
4298
4299 static journal_t *ext4_get_journal(struct super_block *sb,
4300                                    unsigned int journal_inum)
4301 {
4302         struct inode *journal_inode;
4303         journal_t *journal;
4304
4305         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4306
4307         /* First, test for the existence of a valid inode on disk.  Bad
4308          * things happen if we iget() an unused inode, as the subsequent
4309          * iput() will try to delete it. */
4310
4311         journal_inode = ext4_iget(sb, journal_inum);
4312         if (IS_ERR(journal_inode)) {
4313                 ext4_msg(sb, KERN_ERR, "no journal found");
4314                 return NULL;
4315         }
4316         if (!journal_inode->i_nlink) {
4317                 make_bad_inode(journal_inode);
4318                 iput(journal_inode);
4319                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4320                 return NULL;
4321         }
4322
4323         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4324                   journal_inode, journal_inode->i_size);
4325         if (!S_ISREG(journal_inode->i_mode)) {
4326                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4327                 iput(journal_inode);
4328                 return NULL;
4329         }
4330
4331         journal = jbd2_journal_init_inode(journal_inode);
4332         if (!journal) {
4333                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4334                 iput(journal_inode);
4335                 return NULL;
4336         }
4337         journal->j_private = sb;
4338         ext4_init_journal_params(sb, journal);
4339         return journal;
4340 }
4341
4342 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4343                                        dev_t j_dev)
4344 {
4345         struct buffer_head *bh;
4346         journal_t *journal;
4347         ext4_fsblk_t start;
4348         ext4_fsblk_t len;
4349         int hblock, blocksize;
4350         ext4_fsblk_t sb_block;
4351         unsigned long offset;
4352         struct ext4_super_block *es;
4353         struct block_device *bdev;
4354
4355         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4356
4357         bdev = ext4_blkdev_get(j_dev, sb);
4358         if (bdev == NULL)
4359                 return NULL;
4360
4361         blocksize = sb->s_blocksize;
4362         hblock = bdev_logical_block_size(bdev);
4363         if (blocksize < hblock) {
4364                 ext4_msg(sb, KERN_ERR,
4365                         "blocksize too small for journal device");
4366                 goto out_bdev;
4367         }
4368
4369         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4370         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4371         set_blocksize(bdev, blocksize);
4372         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4373                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4374                        "external journal");
4375                 goto out_bdev;
4376         }
4377
4378         es = (struct ext4_super_block *) (bh->b_data + offset);
4379         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4380             !(le32_to_cpu(es->s_feature_incompat) &
4381               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4382                 ext4_msg(sb, KERN_ERR, "external journal has "
4383                                         "bad superblock");
4384                 brelse(bh);
4385                 goto out_bdev;
4386         }
4387
4388         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4389                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4390                 brelse(bh);
4391                 goto out_bdev;
4392         }
4393
4394         len = ext4_blocks_count(es);
4395         start = sb_block + 1;
4396         brelse(bh);     /* we're done with the superblock */
4397
4398         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4399                                         start, len, blocksize);
4400         if (!journal) {
4401                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4402                 goto out_bdev;
4403         }
4404         journal->j_private = sb;
4405         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4406         wait_on_buffer(journal->j_sb_buffer);
4407         if (!buffer_uptodate(journal->j_sb_buffer)) {
4408                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4409                 goto out_journal;
4410         }
4411         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4412                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4413                                         "user (unsupported) - %d",
4414                         be32_to_cpu(journal->j_superblock->s_nr_users));
4415                 goto out_journal;
4416         }
4417         EXT4_SB(sb)->journal_bdev = bdev;
4418         ext4_init_journal_params(sb, journal);
4419         return journal;
4420
4421 out_journal:
4422         jbd2_journal_destroy(journal);
4423 out_bdev:
4424         ext4_blkdev_put(bdev);
4425         return NULL;
4426 }
4427
4428 static int ext4_load_journal(struct super_block *sb,
4429                              struct ext4_super_block *es,
4430                              unsigned long journal_devnum)
4431 {
4432         journal_t *journal;
4433         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4434         dev_t journal_dev;
4435         int err = 0;
4436         int really_read_only;
4437
4438         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4439
4440         if (journal_devnum &&
4441             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4442                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4443                         "numbers have changed");
4444                 journal_dev = new_decode_dev(journal_devnum);
4445         } else
4446                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4447
4448         really_read_only = bdev_read_only(sb->s_bdev);
4449
4450         /*
4451          * Are we loading a blank journal or performing recovery after a
4452          * crash?  For recovery, we need to check in advance whether we
4453          * can get read-write access to the device.
4454          */
4455         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4456                 if (sb->s_flags & MS_RDONLY) {
4457                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4458                                         "required on readonly filesystem");
4459                         if (really_read_only) {
4460                                 ext4_msg(sb, KERN_ERR, "write access "
4461                                         "unavailable, cannot proceed");
4462                                 return -EROFS;
4463                         }
4464                         ext4_msg(sb, KERN_INFO, "write access will "
4465                                "be enabled during recovery");
4466                 }
4467         }
4468
4469         if (journal_inum && journal_dev) {
4470                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4471                        "and inode journals!");
4472                 return -EINVAL;
4473         }
4474
4475         if (journal_inum) {
4476                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4477                         return -EINVAL;
4478         } else {
4479                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4480                         return -EINVAL;
4481         }
4482
4483         if (!(journal->j_flags & JBD2_BARRIER))
4484                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4485
4486         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4487                 err = jbd2_journal_wipe(journal, !really_read_only);
4488         if (!err) {
4489                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4490                 if (save)
4491                         memcpy(save, ((char *) es) +
4492                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4493                 err = jbd2_journal_load(journal);
4494                 if (save)
4495                         memcpy(((char *) es) + EXT4_S_ERR_START,
4496                                save, EXT4_S_ERR_LEN);
4497                 kfree(save);
4498         }
4499
4500         if (err) {
4501                 ext4_msg(sb, KERN_ERR, "error loading journal");
4502                 jbd2_journal_destroy(journal);
4503                 return err;
4504         }
4505
4506         EXT4_SB(sb)->s_journal = journal;
4507         ext4_clear_journal_err(sb, es);
4508
4509         if (!really_read_only && journal_devnum &&
4510             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4511                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4512
4513                 /* Make sure we flush the recovery flag to disk. */
4514                 ext4_commit_super(sb, 1);
4515         }
4516
4517         return 0;
4518 }
4519
4520 static int ext4_commit_super(struct super_block *sb, int sync)
4521 {
4522         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4523         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4524         int error = 0;
4525
4526         if (!sbh || block_device_ejected(sb))
4527                 return error;
4528         if (buffer_write_io_error(sbh)) {
4529                 /*
4530                  * Oh, dear.  A previous attempt to write the
4531                  * superblock failed.  This could happen because the
4532                  * USB device was yanked out.  Or it could happen to
4533                  * be a transient write error and maybe the block will
4534                  * be remapped.  Nothing we can do but to retry the
4535                  * write and hope for the best.
4536                  */
4537                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4538                        "superblock detected");
4539                 clear_buffer_write_io_error(sbh);
4540                 set_buffer_uptodate(sbh);
4541         }
4542         /*
4543          * If the file system is mounted read-only, don't update the
4544          * superblock write time.  This avoids updating the superblock
4545          * write time when we are mounting the root file system
4546          * read/only but we need to replay the journal; at that point,
4547          * for people who are east of GMT and who make their clock
4548          * tick in localtime for Windows bug-for-bug compatibility,
4549          * the clock is set in the future, and this will cause e2fsck
4550          * to complain and force a full file system check.
4551          */
4552         if (!(sb->s_flags & MS_RDONLY))
4553                 es->s_wtime = cpu_to_le32(get_seconds());
4554         if (sb->s_bdev->bd_part)
4555                 es->s_kbytes_written =
4556                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4557                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4558                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4559         else
4560                 es->s_kbytes_written =
4561                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4562         ext4_free_blocks_count_set(es,
4563                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4564                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4565         es->s_free_inodes_count =
4566                 cpu_to_le32(percpu_counter_sum_positive(
4567                                 &EXT4_SB(sb)->s_freeinodes_counter));
4568         BUFFER_TRACE(sbh, "marking dirty");
4569         ext4_superblock_csum_set(sb);
4570         mark_buffer_dirty(sbh);
4571         if (sync) {
4572                 error = sync_dirty_buffer(sbh);
4573                 if (error)
4574                         return error;
4575
4576                 error = buffer_write_io_error(sbh);
4577                 if (error) {
4578                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4579                                "superblock");
4580                         clear_buffer_write_io_error(sbh);
4581                         set_buffer_uptodate(sbh);
4582                 }
4583         }
4584         return error;
4585 }
4586
4587 /*
4588  * Have we just finished recovery?  If so, and if we are mounting (or
4589  * remounting) the filesystem readonly, then we will end up with a
4590  * consistent fs on disk.  Record that fact.
4591  */
4592 static void ext4_mark_recovery_complete(struct super_block *sb,
4593                                         struct ext4_super_block *es)
4594 {
4595         journal_t *journal = EXT4_SB(sb)->s_journal;
4596
4597         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4598                 BUG_ON(journal != NULL);
4599                 return;
4600         }
4601         jbd2_journal_lock_updates(journal);
4602         if (jbd2_journal_flush(journal) < 0)
4603                 goto out;
4604
4605         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4606             sb->s_flags & MS_RDONLY) {
4607                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4608                 ext4_commit_super(sb, 1);
4609         }
4610
4611 out:
4612         jbd2_journal_unlock_updates(journal);
4613 }
4614
4615 /*
4616  * If we are mounting (or read-write remounting) a filesystem whose journal
4617  * has recorded an error from a previous lifetime, move that error to the
4618  * main filesystem now.
4619  */
4620 static void ext4_clear_journal_err(struct super_block *sb,
4621                                    struct ext4_super_block *es)
4622 {
4623         journal_t *journal;
4624         int j_errno;
4625         const char *errstr;
4626
4627         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4628
4629         journal = EXT4_SB(sb)->s_journal;
4630
4631         /*
4632          * Now check for any error status which may have been recorded in the
4633          * journal by a prior ext4_error() or ext4_abort()
4634          */
4635
4636         j_errno = jbd2_journal_errno(journal);
4637         if (j_errno) {
4638                 char nbuf[16];
4639
4640                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4641                 ext4_warning(sb, "Filesystem error recorded "
4642                              "from previous mount: %s", errstr);
4643                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4644
4645                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4646                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4647                 ext4_commit_super(sb, 1);
4648
4649                 jbd2_journal_clear_err(journal);
4650                 jbd2_journal_update_sb_errno(journal);
4651         }
4652 }
4653
4654 /*
4655  * Force the running and committing transactions to commit,
4656  * and wait on the commit.
4657  */
4658 int ext4_force_commit(struct super_block *sb)
4659 {
4660         journal_t *journal;
4661
4662         if (sb->s_flags & MS_RDONLY)
4663                 return 0;
4664
4665         journal = EXT4_SB(sb)->s_journal;
4666         return ext4_journal_force_commit(journal);
4667 }
4668
4669 static int ext4_sync_fs(struct super_block *sb, int wait)
4670 {
4671         int ret = 0;
4672         tid_t target;
4673         bool needs_barrier = false;
4674         struct ext4_sb_info *sbi = EXT4_SB(sb);
4675
4676         trace_ext4_sync_fs(sb, wait);
4677         flush_workqueue(sbi->rsv_conversion_wq);
4678         /*
4679          * Writeback quota in non-journalled quota case - journalled quota has
4680          * no dirty dquots
4681          */
4682         dquot_writeback_dquots(sb, -1);
4683         /*
4684          * Data writeback is possible w/o journal transaction, so barrier must
4685          * being sent at the end of the function. But we can skip it if
4686          * transaction_commit will do it for us.
4687          */
4688         target = jbd2_get_latest_transaction(sbi->s_journal);
4689         if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4690             !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4691                 needs_barrier = true;
4692
4693         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4694                 if (wait)
4695                         ret = jbd2_log_wait_commit(sbi->s_journal, target);
4696         }
4697         if (needs_barrier) {
4698                 int err;
4699                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4700                 if (!ret)
4701                         ret = err;
4702         }
4703
4704         return ret;
4705 }
4706
4707 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait)
4708 {
4709         int ret = 0;
4710
4711         trace_ext4_sync_fs(sb, wait);
4712         flush_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4713         dquot_writeback_dquots(sb, -1);
4714         if (wait && test_opt(sb, BARRIER))
4715                 ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4716
4717         return ret;
4718 }
4719
4720 /*
4721  * LVM calls this function before a (read-only) snapshot is created.  This
4722  * gives us a chance to flush the journal completely and mark the fs clean.
4723  *
4724  * Note that only this function cannot bring a filesystem to be in a clean
4725  * state independently. It relies on upper layer to stop all data & metadata
4726  * modifications.
4727  */
4728 static int ext4_freeze(struct super_block *sb)
4729 {
4730         int error = 0;
4731         journal_t *journal;
4732
4733         if (sb->s_flags & MS_RDONLY)
4734                 return 0;
4735
4736         journal = EXT4_SB(sb)->s_journal;
4737
4738         /* Now we set up the journal barrier. */
4739         jbd2_journal_lock_updates(journal);
4740
4741         /*
4742          * Don't clear the needs_recovery flag if we failed to flush
4743          * the journal.
4744          */
4745         error = jbd2_journal_flush(journal);
4746         if (error < 0)
4747                 goto out;
4748
4749         /* Journal blocked and flushed, clear needs_recovery flag. */
4750         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4751         error = ext4_commit_super(sb, 1);
4752 out:
4753         /* we rely on upper layer to stop further updates */
4754         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4755         return error;
4756 }
4757
4758 /*
4759  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4760  * flag here, even though the filesystem is not technically dirty yet.
4761  */
4762 static int ext4_unfreeze(struct super_block *sb)
4763 {
4764         if (sb->s_flags & MS_RDONLY)
4765                 return 0;
4766
4767         /* Reset the needs_recovery flag before the fs is unlocked. */
4768         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4769         ext4_commit_super(sb, 1);
4770         return 0;
4771 }
4772
4773 /*
4774  * Structure to save mount options for ext4_remount's benefit
4775  */
4776 struct ext4_mount_options {
4777         unsigned long s_mount_opt;
4778         unsigned long s_mount_opt2;
4779         kuid_t s_resuid;
4780         kgid_t s_resgid;
4781         unsigned long s_commit_interval;
4782         u32 s_min_batch_time, s_max_batch_time;
4783 #ifdef CONFIG_QUOTA
4784         int s_jquota_fmt;
4785         char *s_qf_names[MAXQUOTAS];
4786 #endif
4787 };
4788
4789 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4790 {
4791         struct ext4_super_block *es;
4792         struct ext4_sb_info *sbi = EXT4_SB(sb);
4793         unsigned long old_sb_flags;
4794         struct ext4_mount_options old_opts;
4795         int enable_quota = 0;
4796         ext4_group_t g;
4797         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4798         int err = 0;
4799 #ifdef CONFIG_QUOTA
4800         int i, j;
4801 #endif
4802         char *orig_data = kstrdup(data, GFP_KERNEL);
4803
4804         /* Store the original options */
4805         old_sb_flags = sb->s_flags;
4806         old_opts.s_mount_opt = sbi->s_mount_opt;
4807         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4808         old_opts.s_resuid = sbi->s_resuid;
4809         old_opts.s_resgid = sbi->s_resgid;
4810         old_opts.s_commit_interval = sbi->s_commit_interval;
4811         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4812         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4813 #ifdef CONFIG_QUOTA
4814         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4815         for (i = 0; i < MAXQUOTAS; i++)
4816                 if (sbi->s_qf_names[i]) {
4817                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4818                                                          GFP_KERNEL);
4819                         if (!old_opts.s_qf_names[i]) {
4820                                 for (j = 0; j < i; j++)
4821                                         kfree(old_opts.s_qf_names[j]);
4822                                 kfree(orig_data);
4823                                 return -ENOMEM;
4824                         }
4825                 } else
4826                         old_opts.s_qf_names[i] = NULL;
4827 #endif
4828         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4829                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4830
4831         /*
4832          * Allow the "check" option to be passed as a remount option.
4833          */
4834         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4835                 err = -EINVAL;
4836                 goto restore_opts;
4837         }
4838
4839         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4840                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4841                         ext4_msg(sb, KERN_ERR, "can't mount with "
4842                                  "both data=journal and delalloc");
4843                         err = -EINVAL;
4844                         goto restore_opts;
4845                 }
4846                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4847                         ext4_msg(sb, KERN_ERR, "can't mount with "
4848                                  "both data=journal and dioread_nolock");
4849                         err = -EINVAL;
4850                         goto restore_opts;
4851                 }
4852         }
4853
4854         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4855                 ext4_abort(sb, "Abort forced by user");
4856
4857         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4858                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4859
4860         es = sbi->s_es;
4861
4862         if (sbi->s_journal) {
4863                 ext4_init_journal_params(sb, sbi->s_journal);
4864                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4865         }
4866
4867         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4868                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4869                         err = -EROFS;
4870                         goto restore_opts;
4871                 }
4872
4873                 if (*flags & MS_RDONLY) {
4874                         err = sync_filesystem(sb);
4875                         if (err < 0)
4876                                 goto restore_opts;
4877                         err = dquot_suspend(sb, -1);
4878                         if (err < 0)
4879                                 goto restore_opts;
4880
4881                         /*
4882                          * First of all, the unconditional stuff we have to do
4883                          * to disable replay of the journal when we next remount
4884                          */
4885                         sb->s_flags |= MS_RDONLY;
4886
4887                         /*
4888                          * OK, test if we are remounting a valid rw partition
4889                          * readonly, and if so set the rdonly flag and then
4890                          * mark the partition as valid again.
4891                          */
4892                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4893                             (sbi->s_mount_state & EXT4_VALID_FS))
4894                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4895
4896                         if (sbi->s_journal)
4897                                 ext4_mark_recovery_complete(sb, es);
4898                 } else {
4899                         /* Make sure we can mount this feature set readwrite */
4900                         if (!ext4_feature_set_ok(sb, 0)) {
4901                                 err = -EROFS;
4902                                 goto restore_opts;
4903                         }
4904                         /*
4905                          * Make sure the group descriptor checksums
4906                          * are sane.  If they aren't, refuse to remount r/w.
4907                          */
4908                         for (g = 0; g < sbi->s_groups_count; g++) {
4909                                 struct ext4_group_desc *gdp =
4910                                         ext4_get_group_desc(sb, g, NULL);
4911
4912                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4913                                         ext4_msg(sb, KERN_ERR,
4914                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4915                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4916                                                le16_to_cpu(gdp->bg_checksum));
4917                                         err = -EINVAL;
4918                                         goto restore_opts;
4919                                 }
4920                         }
4921
4922                         /*
4923                          * If we have an unprocessed orphan list hanging
4924                          * around from a previously readonly bdev mount,
4925                          * require a full umount/remount for now.
4926                          */
4927                         if (es->s_last_orphan) {
4928                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4929                                        "remount RDWR because of unprocessed "
4930                                        "orphan inode list.  Please "
4931                                        "umount/remount instead");
4932                                 err = -EINVAL;
4933                                 goto restore_opts;
4934                         }
4935
4936                         /*
4937                          * Mounting a RDONLY partition read-write, so reread
4938                          * and store the current valid flag.  (It may have
4939                          * been changed by e2fsck since we originally mounted
4940                          * the partition.)
4941                          */
4942                         if (sbi->s_journal)
4943                                 ext4_clear_journal_err(sb, es);
4944                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4945                         if (!ext4_setup_super(sb, es, 0))
4946                                 sb->s_flags &= ~MS_RDONLY;
4947                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4948                                                      EXT4_FEATURE_INCOMPAT_MMP))
4949                                 if (ext4_multi_mount_protect(sb,
4950                                                 le64_to_cpu(es->s_mmp_block))) {
4951                                         err = -EROFS;
4952                                         goto restore_opts;
4953                                 }
4954                         enable_quota = 1;
4955                 }
4956         }
4957
4958         /*
4959          * Reinitialize lazy itable initialization thread based on
4960          * current settings
4961          */
4962         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4963                 ext4_unregister_li_request(sb);
4964         else {
4965                 ext4_group_t first_not_zeroed;
4966                 first_not_zeroed = ext4_has_uninit_itable(sb);
4967                 ext4_register_li_request(sb, first_not_zeroed);
4968         }
4969
4970         ext4_setup_system_zone(sb);
4971         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4972                 ext4_commit_super(sb, 1);
4973
4974 #ifdef CONFIG_QUOTA
4975         /* Release old quota file names */
4976         for (i = 0; i < MAXQUOTAS; i++)
4977                 kfree(old_opts.s_qf_names[i]);
4978         if (enable_quota) {
4979                 if (sb_any_quota_suspended(sb))
4980                         dquot_resume(sb, -1);
4981                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4982                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4983                         err = ext4_enable_quotas(sb);
4984                         if (err)
4985                                 goto restore_opts;
4986                 }
4987         }
4988 #endif
4989
4990         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4991         kfree(orig_data);
4992         return 0;
4993
4994 restore_opts:
4995         sb->s_flags = old_sb_flags;
4996         sbi->s_mount_opt = old_opts.s_mount_opt;
4997         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4998         sbi->s_resuid = old_opts.s_resuid;
4999         sbi->s_resgid = old_opts.s_resgid;
5000         sbi->s_commit_interval = old_opts.s_commit_interval;
5001         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5002         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5003 #ifdef CONFIG_QUOTA
5004         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5005         for (i = 0; i < MAXQUOTAS; i++) {
5006                 kfree(sbi->s_qf_names[i]);
5007                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5008         }
5009 #endif
5010         kfree(orig_data);
5011         return err;
5012 }
5013
5014 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5015 {
5016         struct super_block *sb = dentry->d_sb;
5017         struct ext4_sb_info *sbi = EXT4_SB(sb);
5018         struct ext4_super_block *es = sbi->s_es;
5019         ext4_fsblk_t overhead = 0, resv_blocks;
5020         u64 fsid;
5021         s64 bfree;
5022         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5023
5024         if (!test_opt(sb, MINIX_DF))
5025                 overhead = sbi->s_overhead;
5026
5027         buf->f_type = EXT4_SUPER_MAGIC;
5028         buf->f_bsize = sb->s_blocksize;
5029         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5030         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5031                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5032         /* prevent underflow in case that few free space is available */
5033         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5034         buf->f_bavail = buf->f_bfree -
5035                         (ext4_r_blocks_count(es) + resv_blocks);
5036         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5037                 buf->f_bavail = 0;
5038         buf->f_files = le32_to_cpu(es->s_inodes_count);
5039         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5040         buf->f_namelen = EXT4_NAME_LEN;
5041         fsid = le64_to_cpup((void *)es->s_uuid) ^
5042                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5043         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5044         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5045
5046         return 0;
5047 }
5048
5049 /* Helper function for writing quotas on sync - we need to start transaction
5050  * before quota file is locked for write. Otherwise the are possible deadlocks:
5051  * Process 1                         Process 2
5052  * ext4_create()                     quota_sync()
5053  *   jbd2_journal_start()                  write_dquot()
5054  *   dquot_initialize()                         down(dqio_mutex)
5055  *     down(dqio_mutex)                    jbd2_journal_start()
5056  *
5057  */
5058
5059 #ifdef CONFIG_QUOTA
5060
5061 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5062 {
5063         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5064 }
5065
5066 static int ext4_write_dquot(struct dquot *dquot)
5067 {
5068         int ret, err;
5069         handle_t *handle;
5070         struct inode *inode;
5071
5072         inode = dquot_to_inode(dquot);
5073         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5074                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5075         if (IS_ERR(handle))
5076                 return PTR_ERR(handle);
5077         ret = dquot_commit(dquot);
5078         err = ext4_journal_stop(handle);
5079         if (!ret)
5080                 ret = err;
5081         return ret;
5082 }
5083
5084 static int ext4_acquire_dquot(struct dquot *dquot)
5085 {
5086         int ret, err;
5087         handle_t *handle;
5088
5089         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5090                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5091         if (IS_ERR(handle))
5092                 return PTR_ERR(handle);
5093         ret = dquot_acquire(dquot);
5094         err = ext4_journal_stop(handle);
5095         if (!ret)
5096                 ret = err;
5097         return ret;
5098 }
5099
5100 static int ext4_release_dquot(struct dquot *dquot)
5101 {
5102         int ret, err;
5103         handle_t *handle;
5104
5105         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5106                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5107         if (IS_ERR(handle)) {
5108                 /* Release dquot anyway to avoid endless cycle in dqput() */
5109                 dquot_release(dquot);
5110                 return PTR_ERR(handle);
5111         }
5112         ret = dquot_release(dquot);
5113         err = ext4_journal_stop(handle);
5114         if (!ret)
5115                 ret = err;
5116         return ret;
5117 }
5118
5119 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5120 {
5121         struct super_block *sb = dquot->dq_sb;
5122         struct ext4_sb_info *sbi = EXT4_SB(sb);
5123
5124         /* Are we journaling quotas? */
5125         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5126             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5127                 dquot_mark_dquot_dirty(dquot);
5128                 return ext4_write_dquot(dquot);
5129         } else {
5130                 return dquot_mark_dquot_dirty(dquot);
5131         }
5132 }
5133
5134 static int ext4_write_info(struct super_block *sb, int type)
5135 {
5136         int ret, err;
5137         handle_t *handle;
5138
5139         /* Data block + inode block */
5140         handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5141         if (IS_ERR(handle))
5142                 return PTR_ERR(handle);
5143         ret = dquot_commit_info(sb, type);
5144         err = ext4_journal_stop(handle);
5145         if (!ret)
5146                 ret = err;
5147         return ret;
5148 }
5149
5150 /*
5151  * Turn on quotas during mount time - we need to find
5152  * the quota file and such...
5153  */
5154 static int ext4_quota_on_mount(struct super_block *sb, int type)
5155 {
5156         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5157                                         EXT4_SB(sb)->s_jquota_fmt, type);
5158 }
5159
5160 /*
5161  * Standard function to be called on quota_on
5162  */
5163 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5164                          struct path *path)
5165 {
5166         int err;
5167
5168         if (!test_opt(sb, QUOTA))
5169                 return -EINVAL;
5170
5171         /* Quotafile not on the same filesystem? */
5172         if (path->dentry->d_sb != sb)
5173                 return -EXDEV;
5174         /* Journaling quota? */
5175         if (EXT4_SB(sb)->s_qf_names[type]) {
5176                 /* Quotafile not in fs root? */
5177                 if (path->dentry->d_parent != sb->s_root)
5178                         ext4_msg(sb, KERN_WARNING,
5179                                 "Quota file not on filesystem root. "
5180                                 "Journaled quota will not work");
5181         }
5182
5183         /*
5184          * When we journal data on quota file, we have to flush journal to see
5185          * all updates to the file when we bypass pagecache...
5186          */
5187         if (EXT4_SB(sb)->s_journal &&
5188             ext4_should_journal_data(path->dentry->d_inode)) {
5189                 /*
5190                  * We don't need to lock updates but journal_flush() could
5191                  * otherwise be livelocked...
5192                  */
5193                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5194                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5195                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5196                 if (err)
5197                         return err;
5198         }
5199
5200         return dquot_quota_on(sb, type, format_id, path);
5201 }
5202
5203 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5204                              unsigned int flags)
5205 {
5206         int err;
5207         struct inode *qf_inode;
5208         unsigned long qf_inums[MAXQUOTAS] = {
5209                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5210                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5211         };
5212
5213         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5214
5215         if (!qf_inums[type])
5216                 return -EPERM;
5217
5218         qf_inode = ext4_iget(sb, qf_inums[type]);
5219         if (IS_ERR(qf_inode)) {
5220                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5221                 return PTR_ERR(qf_inode);
5222         }
5223
5224         /* Don't account quota for quota files to avoid recursion */
5225         qf_inode->i_flags |= S_NOQUOTA;
5226         err = dquot_enable(qf_inode, type, format_id, flags);
5227         iput(qf_inode);
5228
5229         return err;
5230 }
5231
5232 /* Enable usage tracking for all quota types. */
5233 static int ext4_enable_quotas(struct super_block *sb)
5234 {
5235         int type, err = 0;
5236         unsigned long qf_inums[MAXQUOTAS] = {
5237                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5238                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5239         };
5240
5241         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5242         for (type = 0; type < MAXQUOTAS; type++) {
5243                 if (qf_inums[type]) {
5244                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5245                                                 DQUOT_USAGE_ENABLED);
5246                         if (err) {
5247                                 ext4_warning(sb,
5248                                         "Failed to enable quota tracking "
5249                                         "(type=%d, err=%d). Please run "
5250                                         "e2fsck to fix.", type, err);
5251                                 return err;
5252                         }
5253                 }
5254         }
5255         return 0;
5256 }
5257
5258 /*
5259  * quota_on function that is used when QUOTA feature is set.
5260  */
5261 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5262                                  int format_id)
5263 {
5264         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5265                 return -EINVAL;
5266
5267         /*
5268          * USAGE was enabled at mount time. Only need to enable LIMITS now.
5269          */
5270         return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5271 }
5272
5273 static int ext4_quota_off(struct super_block *sb, int type)
5274 {
5275         struct inode *inode = sb_dqopt(sb)->files[type];
5276         handle_t *handle;
5277
5278         /* Force all delayed allocation blocks to be allocated.
5279          * Caller already holds s_umount sem */
5280         if (test_opt(sb, DELALLOC))
5281                 sync_filesystem(sb);
5282
5283         if (!inode)
5284                 goto out;
5285
5286         /* Update modification times of quota files when userspace can
5287          * start looking at them */
5288         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5289         if (IS_ERR(handle))
5290                 goto out;
5291         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5292         ext4_mark_inode_dirty(handle, inode);
5293         ext4_journal_stop(handle);
5294
5295 out:
5296         return dquot_quota_off(sb, type);
5297 }
5298
5299 /*
5300  * quota_off function that is used when QUOTA feature is set.
5301  */
5302 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5303 {
5304         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5305                 return -EINVAL;
5306
5307         /* Disable only the limits. */
5308         return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5309 }
5310
5311 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5312  * acquiring the locks... As quota files are never truncated and quota code
5313  * itself serializes the operations (and no one else should touch the files)
5314  * we don't have to be afraid of races */
5315 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5316                                size_t len, loff_t off)
5317 {
5318         struct inode *inode = sb_dqopt(sb)->files[type];
5319         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5320         int err = 0;
5321         int offset = off & (sb->s_blocksize - 1);
5322         int tocopy;
5323         size_t toread;
5324         struct buffer_head *bh;
5325         loff_t i_size = i_size_read(inode);
5326
5327         if (off > i_size)
5328                 return 0;
5329         if (off+len > i_size)
5330                 len = i_size-off;
5331         toread = len;
5332         while (toread > 0) {
5333                 tocopy = sb->s_blocksize - offset < toread ?
5334                                 sb->s_blocksize - offset : toread;
5335                 bh = ext4_bread(NULL, inode, blk, 0, &err);
5336                 if (err)
5337                         return err;
5338                 if (!bh)        /* A hole? */
5339                         memset(data, 0, tocopy);
5340                 else
5341                         memcpy(data, bh->b_data+offset, tocopy);
5342                 brelse(bh);
5343                 offset = 0;
5344                 toread -= tocopy;
5345                 data += tocopy;
5346                 blk++;
5347         }
5348         return len;
5349 }
5350
5351 /* Write to quotafile (we know the transaction is already started and has
5352  * enough credits) */
5353 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5354                                 const char *data, size_t len, loff_t off)
5355 {
5356         struct inode *inode = sb_dqopt(sb)->files[type];
5357         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5358         int err = 0;
5359         int offset = off & (sb->s_blocksize - 1);
5360         struct buffer_head *bh;
5361         handle_t *handle = journal_current_handle();
5362
5363         if (EXT4_SB(sb)->s_journal && !handle) {
5364                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5365                         " cancelled because transaction is not started",
5366                         (unsigned long long)off, (unsigned long long)len);
5367                 return -EIO;
5368         }
5369         /*
5370          * Since we account only one data block in transaction credits,
5371          * then it is impossible to cross a block boundary.
5372          */
5373         if (sb->s_blocksize - offset < len) {
5374                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5375                         " cancelled because not block aligned",
5376                         (unsigned long long)off, (unsigned long long)len);
5377                 return -EIO;
5378         }
5379
5380         bh = ext4_bread(handle, inode, blk, 1, &err);
5381         if (!bh)
5382                 goto out;
5383         BUFFER_TRACE(bh, "get write access");
5384         err = ext4_journal_get_write_access(handle, bh);
5385         if (err) {
5386                 brelse(bh);
5387                 goto out;
5388         }
5389         lock_buffer(bh);
5390         memcpy(bh->b_data+offset, data, len);
5391         flush_dcache_page(bh->b_page);
5392         unlock_buffer(bh);
5393         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5394         brelse(bh);
5395 out:
5396         if (err)
5397                 return err;
5398         if (inode->i_size < off + len) {
5399                 i_size_write(inode, off + len);
5400                 EXT4_I(inode)->i_disksize = inode->i_size;
5401                 ext4_mark_inode_dirty(handle, inode);
5402         }
5403         return len;
5404 }
5405
5406 #endif
5407
5408 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5409                        const char *dev_name, void *data)
5410 {
5411         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5412 }
5413
5414 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5415 static inline void register_as_ext2(void)
5416 {
5417         int err = register_filesystem(&ext2_fs_type);
5418         if (err)
5419                 printk(KERN_WARNING
5420                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5421 }
5422
5423 static inline void unregister_as_ext2(void)
5424 {
5425         unregister_filesystem(&ext2_fs_type);
5426 }
5427
5428 static inline int ext2_feature_set_ok(struct super_block *sb)
5429 {
5430         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5431                 return 0;
5432         if (sb->s_flags & MS_RDONLY)
5433                 return 1;
5434         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5435                 return 0;
5436         return 1;
5437 }
5438 #else
5439 static inline void register_as_ext2(void) { }
5440 static inline void unregister_as_ext2(void) { }
5441 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5442 #endif
5443
5444 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5445 static inline void register_as_ext3(void)
5446 {
5447         int err = register_filesystem(&ext3_fs_type);
5448         if (err)
5449                 printk(KERN_WARNING
5450                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5451 }
5452
5453 static inline void unregister_as_ext3(void)
5454 {
5455         unregister_filesystem(&ext3_fs_type);
5456 }
5457
5458 static inline int ext3_feature_set_ok(struct super_block *sb)
5459 {
5460         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5461                 return 0;
5462         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5463                 return 0;
5464         if (sb->s_flags & MS_RDONLY)
5465                 return 1;
5466         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5467                 return 0;
5468         return 1;
5469 }
5470 #else
5471 static inline void register_as_ext3(void) { }
5472 static inline void unregister_as_ext3(void) { }
5473 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5474 #endif
5475
5476 static struct file_system_type ext4_fs_type = {
5477         .owner          = THIS_MODULE,
5478         .name           = "ext4",
5479         .mount          = ext4_mount,
5480         .kill_sb        = kill_block_super,
5481         .fs_flags       = FS_REQUIRES_DEV,
5482 };
5483 MODULE_ALIAS_FS("ext4");
5484
5485 static int __init ext4_init_feat_adverts(void)
5486 {
5487         struct ext4_features *ef;
5488         int ret = -ENOMEM;
5489
5490         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5491         if (!ef)
5492                 goto out;
5493
5494         ef->f_kobj.kset = ext4_kset;
5495         init_completion(&ef->f_kobj_unregister);
5496         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5497                                    "features");
5498         if (ret) {
5499                 kfree(ef);
5500                 goto out;
5501         }
5502
5503         ext4_feat = ef;
5504         ret = 0;
5505 out:
5506         return ret;
5507 }
5508
5509 static void ext4_exit_feat_adverts(void)
5510 {
5511         kobject_put(&ext4_feat->f_kobj);
5512         wait_for_completion(&ext4_feat->f_kobj_unregister);
5513         kfree(ext4_feat);
5514 }
5515
5516 /* Shared across all ext4 file systems */
5517 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5518 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5519
5520 static int __init ext4_init_fs(void)
5521 {
5522         int i, err;
5523
5524         ext4_li_info = NULL;
5525         mutex_init(&ext4_li_mtx);
5526
5527         /* Build-time check for flags consistency */
5528         ext4_check_flag_values();
5529
5530         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5531                 mutex_init(&ext4__aio_mutex[i]);
5532                 init_waitqueue_head(&ext4__ioend_wq[i]);
5533         }
5534
5535         err = ext4_init_es();
5536         if (err)
5537                 return err;
5538
5539         err = ext4_init_pageio();
5540         if (err)
5541                 goto out7;
5542
5543         err = ext4_init_system_zone();
5544         if (err)
5545                 goto out6;
5546         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5547         if (!ext4_kset) {
5548                 err = -ENOMEM;
5549                 goto out5;
5550         }
5551         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5552
5553         err = ext4_init_feat_adverts();
5554         if (err)
5555                 goto out4;
5556
5557         err = ext4_init_mballoc();
5558         if (err)
5559                 goto out2;
5560         else
5561                 ext4_mballoc_ready = 1;
5562         err = init_inodecache();
5563         if (err)
5564                 goto out1;
5565         register_as_ext3();
5566         register_as_ext2();
5567         err = register_filesystem(&ext4_fs_type);
5568         if (err)
5569                 goto out;
5570
5571         return 0;
5572 out:
5573         unregister_as_ext2();
5574         unregister_as_ext3();
5575         destroy_inodecache();
5576 out1:
5577         ext4_mballoc_ready = 0;
5578         ext4_exit_mballoc();
5579 out2:
5580         ext4_exit_feat_adverts();
5581 out4:
5582         if (ext4_proc_root)
5583                 remove_proc_entry("fs/ext4", NULL);
5584         kset_unregister(ext4_kset);
5585 out5:
5586         ext4_exit_system_zone();
5587 out6:
5588         ext4_exit_pageio();
5589 out7:
5590         ext4_exit_es();
5591
5592         return err;
5593 }
5594
5595 static void __exit ext4_exit_fs(void)
5596 {
5597         ext4_destroy_lazyinit_thread();
5598         unregister_as_ext2();
5599         unregister_as_ext3();
5600         unregister_filesystem(&ext4_fs_type);
5601         destroy_inodecache();
5602         ext4_exit_mballoc();
5603         ext4_exit_feat_adverts();
5604         remove_proc_entry("fs/ext4", NULL);
5605         kset_unregister(ext4_kset);
5606         ext4_exit_system_zone();
5607         ext4_exit_pageio();
5608         ext4_exit_es();
5609 }
5610
5611 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5612 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5613 MODULE_LICENSE("GPL");
5614 module_init(ext4_init_fs)
5615 module_exit(ext4_exit_fs)