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         brelse(sbi->s_sbh);
 824 #ifdef CONFIG_QUOTA
 825         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 826                 kfree(sbi->s_qf_names[i]);
 827 #endif
 828
 829         /* Debugging code just in case the in-memory inode orphan list
 830          * isn't empty.  The on-disk one can be non-empty if we've
 831          * detected an error and taken the fs readonly, but the
 832          * in-memory list had better be clean by this point. */
 833         if (!list_empty(&sbi->s_orphan))
 834                 dump_orphan_list(sb, sbi);
 835         J_ASSERT(list_empty(&sbi->s_orphan));
 836
 837         invalidate_bdev(sb->s_bdev);
 838         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 839                 /*
 840                  * Invalidate the journal device's buffers.  We don't want them
 841                  * floating about in memory - the physical journal device may
 842                  * hotswapped, and it breaks the `ro-after' testing code.
 843                  */
 844                 sync_blockdev(sbi->journal_bdev);
 845                 invalidate_bdev(sbi->journal_bdev);
 846                 ext4_blkdev_remove(sbi);
 847         }
 848         if (sbi->s_mb_cache) {
 849                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 850                 sbi->s_mb_cache = NULL;
 851         }
 852         if (sbi->s_mmp_tsk)
 853                 kthread_stop(sbi->s_mmp_tsk);
 854         sb->s_fs_info = NULL;
 855         /*
 856          * Now that we are completely done shutting down the
 857          * superblock, we need to actually destroy the kobject.
 858          */
 859         kobject_put(&sbi->s_kobj);
 860         wait_for_completion(&sbi->s_kobj_unregister);
 861         if (sbi->s_chksum_driver)
 862                 crypto_free_shash(sbi->s_chksum_driver);
 863         kfree(sbi->s_blockgroup_lock);
 864         kfree(sbi);
 865 }
 866
 867 static struct kmem_cache *ext4_inode_cachep;
 868
 869 /*
 870  * Called inside transaction, so use GFP_NOFS
 871  */
 872 static struct inode *ext4_alloc_inode(struct super_block *sb)
 873 {
 874         struct ext4_inode_info *ei;
 875
 876         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 877         if (!ei)
 878                 return NULL;
 879
 880         ei->vfs_inode.i_version = 1;
 881         spin_lock_init(&ei->i_raw_lock);
 882         INIT_LIST_HEAD(&ei->i_prealloc_list);
 883         spin_lock_init(&ei->i_prealloc_lock);
 884         ext4_es_init_tree(&ei->i_es_tree);
 885         rwlock_init(&ei->i_es_lock);
 886         INIT_LIST_HEAD(&ei->i_es_lru);
 887         ei->i_es_all_nr = 0;
 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         }
1716 #endif
1717         if (test_opt(sb, DIOREAD_NOLOCK)) {
1718                 int blocksize =
1719                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1720
1721                 if (blocksize < PAGE_CACHE_SIZE) {
1722                         ext4_msg(sb, KERN_ERR, "can't mount with "
1723                                  "dioread_nolock if block size != PAGE_SIZE");
1724                         return 0;
1725                 }
1726         }
1727         return 1;
1728 }
1729
1730 static inline void ext4_show_quota_options(struct seq_file *seq,
1731                                            struct super_block *sb)
1732 {
1733 #if defined(CONFIG_QUOTA)
1734         struct ext4_sb_info *sbi = EXT4_SB(sb);
1735
1736         if (sbi->s_jquota_fmt) {
1737                 char *fmtname = "";
1738
1739                 switch (sbi->s_jquota_fmt) {
1740                 case QFMT_VFS_OLD:
1741                         fmtname = "vfsold";
1742                         break;
1743                 case QFMT_VFS_V0:
1744                         fmtname = "vfsv0";
1745                         break;
1746                 case QFMT_VFS_V1:
1747                         fmtname = "vfsv1";
1748                         break;
1749                 }
1750                 seq_printf(seq, ",jqfmt=%s", fmtname);
1751         }
1752
1753         if (sbi->s_qf_names[USRQUOTA])
1754                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1755
1756         if (sbi->s_qf_names[GRPQUOTA])
1757                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1758 #endif
1759 }
1760
1761 static const char *token2str(int token)
1762 {
1763         const struct match_token *t;
1764
1765         for (t = tokens; t->token != Opt_err; t++)
1766                 if (t->token == token && !strchr(t->pattern, '='))
1767                         break;
1768         return t->pattern;
1769 }
1770
1771 /*
1772  * Show an option if
1773  *  - it's set to a non-default value OR
1774  *  - if the per-sb default is different from the global default
1775  */
1776 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1777                               int nodefs)
1778 {
1779         struct ext4_sb_info *sbi = EXT4_SB(sb);
1780         struct ext4_super_block *es = sbi->s_es;
1781         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1782         const struct mount_opts *m;
1783         char sep = nodefs ? '\n' : ',';
1784
1785 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1786 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1787
1788         if (sbi->s_sb_block != 1)
1789                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1790
1791         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1792                 int want_set = m->flags & MOPT_SET;
1793                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1794                     (m->flags & MOPT_CLEAR_ERR))
1795                         continue;
1796                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1797                         continue; /* skip if same as the default */
1798                 if ((want_set &&
1799                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1800                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1801                         continue; /* select Opt_noFoo vs Opt_Foo */
1802                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1803         }
1804
1805         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1806             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1807                 SEQ_OPTS_PRINT("resuid=%u",
1808                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1809         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1810             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1811                 SEQ_OPTS_PRINT("resgid=%u",
1812                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1813         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1814         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1815                 SEQ_OPTS_PUTS("errors=remount-ro");
1816         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1817                 SEQ_OPTS_PUTS("errors=continue");
1818         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1819                 SEQ_OPTS_PUTS("errors=panic");
1820         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1821                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1822         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1823                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1824         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1825                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1826         if (sb->s_flags & MS_I_VERSION)
1827                 SEQ_OPTS_PUTS("i_version");
1828         if (nodefs || sbi->s_stripe)
1829                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1830         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1831                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1832                         SEQ_OPTS_PUTS("data=journal");
1833                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1834                         SEQ_OPTS_PUTS("data=ordered");
1835                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1836                         SEQ_OPTS_PUTS("data=writeback");
1837         }
1838         if (nodefs ||
1839             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1840                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1841                                sbi->s_inode_readahead_blks);
1842
1843         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1844                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1845                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1846         if (nodefs || sbi->s_max_dir_size_kb)
1847                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1848
1849         ext4_show_quota_options(seq, sb);
1850         return 0;
1851 }
1852
1853 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1854 {
1855         return _ext4_show_options(seq, root->d_sb, 0);
1856 }
1857
1858 static int options_seq_show(struct seq_file *seq, void *offset)
1859 {
1860         struct super_block *sb = seq->private;
1861         int rc;
1862
1863         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1864         rc = _ext4_show_options(seq, sb, 1);
1865         seq_puts(seq, "\n");
1866         return rc;
1867 }
1868
1869 static int options_open_fs(struct inode *inode, struct file *file)
1870 {
1871         return single_open(file, options_seq_show, PDE_DATA(inode));
1872 }
1873
1874 static const struct file_operations ext4_seq_options_fops = {
1875         .owner = THIS_MODULE,
1876         .open = options_open_fs,
1877         .read = seq_read,
1878         .llseek = seq_lseek,
1879         .release = single_release,
1880 };
1881
1882 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1883                             int read_only)
1884 {
1885         struct ext4_sb_info *sbi = EXT4_SB(sb);
1886         int res = 0;
1887
1888         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1889                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1890                          "forcing read-only mode");
1891                 res = MS_RDONLY;
1892         }
1893         if (read_only)
1894                 goto done;
1895         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1896                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1897                          "running e2fsck is recommended");
1898         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1899                 ext4_msg(sb, KERN_WARNING,
1900                          "warning: mounting fs with errors, "
1901                          "running e2fsck is recommended");
1902         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1903                  le16_to_cpu(es->s_mnt_count) >=
1904                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1905                 ext4_msg(sb, KERN_WARNING,
1906                          "warning: maximal mount count reached, "
1907                          "running e2fsck is recommended");
1908         else if (le32_to_cpu(es->s_checkinterval) &&
1909                 (le32_to_cpu(es->s_lastcheck) +
1910                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1911                 ext4_msg(sb, KERN_WARNING,
1912                          "warning: checktime reached, "
1913                          "running e2fsck is recommended");
1914         if (!sbi->s_journal)
1915                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1916         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1917                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1918         le16_add_cpu(&es->s_mnt_count, 1);
1919         es->s_mtime = cpu_to_le32(get_seconds());
1920         ext4_update_dynamic_rev(sb);
1921         if (sbi->s_journal)
1922                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1923
1924         ext4_commit_super(sb, 1);
1925 done:
1926         if (test_opt(sb, DEBUG))
1927                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1928                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1929                         sb->s_blocksize,
1930                         sbi->s_groups_count,
1931                         EXT4_BLOCKS_PER_GROUP(sb),
1932                         EXT4_INODES_PER_GROUP(sb),
1933                         sbi->s_mount_opt, sbi->s_mount_opt2);
1934
1935         cleancache_init_fs(sb);
1936         return res;
1937 }
1938
1939 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1940 {
1941         struct ext4_sb_info *sbi = EXT4_SB(sb);
1942         struct flex_groups *new_groups;
1943         int size;
1944
1945         if (!sbi->s_log_groups_per_flex)
1946                 return 0;
1947
1948         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1949         if (size <= sbi->s_flex_groups_allocated)
1950                 return 0;
1951
1952         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1953         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1954         if (!new_groups) {
1955                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1956                          size / (int) sizeof(struct flex_groups));
1957                 return -ENOMEM;
1958         }
1959
1960         if (sbi->s_flex_groups) {
1961                 memcpy(new_groups, sbi->s_flex_groups,
1962                        (sbi->s_flex_groups_allocated *
1963                         sizeof(struct flex_groups)));
1964                 ext4_kvfree(sbi->s_flex_groups);
1965         }
1966         sbi->s_flex_groups = new_groups;
1967         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1968         return 0;
1969 }
1970
1971 static int ext4_fill_flex_info(struct super_block *sb)
1972 {
1973         struct ext4_sb_info *sbi = EXT4_SB(sb);
1974         struct ext4_group_desc *gdp = NULL;
1975         ext4_group_t flex_group;
1976         int i, err;
1977
1978         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1979         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1980                 sbi->s_log_groups_per_flex = 0;
1981                 return 1;
1982         }
1983
1984         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1985         if (err)
1986                 goto failed;
1987
1988         for (i = 0; i < sbi->s_groups_count; i++) {
1989                 gdp = ext4_get_group_desc(sb, i, NULL);
1990
1991                 flex_group = ext4_flex_group(sbi, i);
1992                 atomic_add(ext4_free_inodes_count(sb, gdp),
1993                            &sbi->s_flex_groups[flex_group].free_inodes);
1994                 atomic64_add(ext4_free_group_clusters(sb, gdp),
1995                              &sbi->s_flex_groups[flex_group].free_clusters);
1996                 atomic_add(ext4_used_dirs_count(sb, gdp),
1997                            &sbi->s_flex_groups[flex_group].used_dirs);
1998         }
1999
2000         return 1;
2001 failed:
2002         return 0;
2003 }
2004
2005 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2006                                    struct ext4_group_desc *gdp)
2007 {
2008         int offset;
2009         __u16 crc = 0;
2010         __le32 le_group = cpu_to_le32(block_group);
2011
2012         if ((sbi->s_es->s_feature_ro_compat &
2013              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
2014                 /* Use new metadata_csum algorithm */
2015                 __le16 save_csum;
2016                 __u32 csum32;
2017
2018                 save_csum = gdp->bg_checksum;
2019                 gdp->bg_checksum = 0;
2020                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2021                                      sizeof(le_group));
2022                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2023                                      sbi->s_desc_size);
2024                 gdp->bg_checksum = save_csum;
2025
2026                 crc = csum32 & 0xFFFF;
2027                 goto out;
2028         }
2029
2030         /* old crc16 code */
2031         offset = offsetof(struct ext4_group_desc, bg_checksum);
2032
2033         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2034         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2035         crc = crc16(crc, (__u8 *)gdp, offset);
2036         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2037         /* for checksum of struct ext4_group_desc do the rest...*/
2038         if ((sbi->s_es->s_feature_incompat &
2039              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2040             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2041                 crc = crc16(crc, (__u8 *)gdp + offset,
2042                             le16_to_cpu(sbi->s_es->s_desc_size) -
2043                                 offset);
2044
2045 out:
2046         return cpu_to_le16(crc);
2047 }
2048
2049 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2050                                 struct ext4_group_desc *gdp)
2051 {
2052         if (ext4_has_group_desc_csum(sb) &&
2053             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2054                                                       block_group, gdp)))
2055                 return 0;
2056
2057         return 1;
2058 }
2059
2060 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2061                               struct ext4_group_desc *gdp)
2062 {
2063         if (!ext4_has_group_desc_csum(sb))
2064                 return;
2065         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2066 }
2067
2068 /* Called at mount-time, super-block is locked */
2069 static int ext4_check_descriptors(struct super_block *sb,
2070                                   ext4_group_t *first_not_zeroed)
2071 {
2072         struct ext4_sb_info *sbi = EXT4_SB(sb);
2073         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2074         ext4_fsblk_t last_block;
2075         ext4_fsblk_t block_bitmap;
2076         ext4_fsblk_t inode_bitmap;
2077         ext4_fsblk_t inode_table;
2078         int flexbg_flag = 0;
2079         ext4_group_t i, grp = sbi->s_groups_count;
2080
2081         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2082                 flexbg_flag = 1;
2083
2084         ext4_debug("Checking group descriptors");
2085
2086         for (i = 0; i < sbi->s_groups_count; i++) {
2087                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2088
2089                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2090                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2091                 else
2092                         last_block = first_block +
2093                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2094
2095                 if ((grp == sbi->s_groups_count) &&
2096                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2097                         grp = i;
2098
2099                 block_bitmap = ext4_block_bitmap(sb, gdp);
2100                 if (block_bitmap < first_block || block_bitmap > last_block) {
2101                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2102                                "Block bitmap for group %u not in group "
2103                                "(block %llu)!", i, block_bitmap);
2104                         return 0;
2105                 }
2106                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2107                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2108                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2109                                "Inode bitmap for group %u not in group "
2110                                "(block %llu)!", i, inode_bitmap);
2111                         return 0;
2112                 }
2113                 inode_table = ext4_inode_table(sb, gdp);
2114                 if (inode_table < first_block ||
2115                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2116                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2117                                "Inode table for group %u not in group "
2118                                "(block %llu)!", i, inode_table);
2119                         return 0;
2120                 }
2121                 ext4_lock_group(sb, i);
2122                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2123                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2124                                  "Checksum for group %u failed (%u!=%u)",
2125                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2126                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2127                         if (!(sb->s_flags & MS_RDONLY)) {
2128                                 ext4_unlock_group(sb, i);
2129                                 return 0;
2130                         }
2131                 }
2132                 ext4_unlock_group(sb, i);
2133                 if (!flexbg_flag)
2134                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2135         }
2136         if (NULL != first_not_zeroed)
2137                 *first_not_zeroed = grp;
2138         return 1;
2139 }
2140
2141 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2142  * the superblock) which were deleted from all directories, but held open by
2143  * a process at the time of a crash.  We walk the list and try to delete these
2144  * inodes at recovery time (only with a read-write filesystem).
2145  *
2146  * In order to keep the orphan inode chain consistent during traversal (in
2147  * case of crash during recovery), we link each inode into the superblock
2148  * orphan list_head and handle it the same way as an inode deletion during
2149  * normal operation (which journals the operations for us).
2150  *
2151  * We only do an iget() and an iput() on each inode, which is very safe if we
2152  * accidentally point at an in-use or already deleted inode.  The worst that
2153  * can happen in this case is that we get a "bit already cleared" message from
2154  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2155  * e2fsck was run on this filesystem, and it must have already done the orphan
2156  * inode cleanup for us, so we can safely abort without any further action.
2157  */
2158 static void ext4_orphan_cleanup(struct super_block *sb,
2159                                 struct ext4_super_block *es)
2160 {
2161         unsigned int s_flags = sb->s_flags;
2162         int nr_orphans = 0, nr_truncates = 0;
2163 #ifdef CONFIG_QUOTA
2164         int i;
2165 #endif
2166         if (!es->s_last_orphan) {
2167                 jbd_debug(4, "no orphan inodes to clean up\n");
2168                 return;
2169         }
2170
2171         if (bdev_read_only(sb->s_bdev)) {
2172                 ext4_msg(sb, KERN_ERR, "write access "
2173                         "unavailable, skipping orphan cleanup");
2174                 return;
2175         }
2176
2177         /* Check if feature set would not allow a r/w mount */
2178         if (!ext4_feature_set_ok(sb, 0)) {
2179                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2180                          "unknown ROCOMPAT features");
2181                 return;
2182         }
2183
2184         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2185                 /* don't clear list on RO mount w/ errors */
2186                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2187                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2188                                   "clearing orphan list.\n");
2189                         es->s_last_orphan = 0;
2190                 }
2191                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2192                 return;
2193         }
2194
2195         if (s_flags & MS_RDONLY) {
2196                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2197                 sb->s_flags &= ~MS_RDONLY;
2198         }
2199 #ifdef CONFIG_QUOTA
2200         /* Needed for iput() to work correctly and not trash data */
2201         sb->s_flags |= MS_ACTIVE;
2202         /* Turn on quotas so that they are updated correctly */
2203         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2204                 if (EXT4_SB(sb)->s_qf_names[i]) {
2205                         int ret = ext4_quota_on_mount(sb, i);
2206                         if (ret < 0)
2207                                 ext4_msg(sb, KERN_ERR,
2208                                         "Cannot turn on journaled "
2209                                         "quota: error %d", ret);
2210                 }
2211         }
2212 #endif
2213
2214         while (es->s_last_orphan) {
2215                 struct inode *inode;
2216
2217                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2218                 if (IS_ERR(inode)) {
2219                         es->s_last_orphan = 0;
2220                         break;
2221                 }
2222
2223                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2224                 dquot_initialize(inode);
2225                 if (inode->i_nlink) {
2226                         if (test_opt(sb, DEBUG))
2227                                 ext4_msg(sb, KERN_DEBUG,
2228                                         "%s: truncating inode %lu to %lld bytes",
2229                                         __func__, inode->i_ino, inode->i_size);
2230                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2231                                   inode->i_ino, inode->i_size);
2232                         mutex_lock(&inode->i_mutex);
2233                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2234                         ext4_truncate(inode);
2235                         mutex_unlock(&inode->i_mutex);
2236                         nr_truncates++;
2237                 } else {
2238                         if (test_opt(sb, DEBUG))
2239                                 ext4_msg(sb, KERN_DEBUG,
2240                                         "%s: deleting unreferenced inode %lu",
2241                                         __func__, inode->i_ino);
2242                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2243                                   inode->i_ino);
2244                         nr_orphans++;
2245                 }
2246                 iput(inode);  /* The delete magic happens here! */
2247         }
2248
2249 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2250
2251         if (nr_orphans)
2252                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2253                        PLURAL(nr_orphans));
2254         if (nr_truncates)
2255                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2256                        PLURAL(nr_truncates));
2257 #ifdef CONFIG_QUOTA
2258         /* Turn quotas off */
2259         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2260                 if (sb_dqopt(sb)->files[i])
2261                         dquot_quota_off(sb, i);
2262         }
2263 #endif
2264         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2265 }
2266
2267 /*
2268  * Maximal extent format file size.
2269  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2270  * extent format containers, within a sector_t, and within i_blocks
2271  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2272  * so that won't be a limiting factor.
2273  *
2274  * However there is other limiting factor. We do store extents in the form
2275  * of starting block and length, hence the resulting length of the extent
2276  * covering maximum file size must fit into on-disk format containers as
2277  * well. Given that length is always by 1 unit bigger than max unit (because
2278  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2279  *
2280  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2281  */
2282 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2283 {
2284         loff_t res;
2285         loff_t upper_limit = MAX_LFS_FILESIZE;
2286
2287         /* small i_blocks in vfs inode? */
2288         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2289                 /*
2290                  * CONFIG_LBDAF is not enabled implies the inode
2291                  * i_block represent total blocks in 512 bytes
2292                  * 32 == size of vfs inode i_blocks * 8
2293                  */
2294                 upper_limit = (1LL << 32) - 1;
2295
2296                 /* total blocks in file system block size */
2297                 upper_limit >>= (blkbits - 9);
2298                 upper_limit <<= blkbits;
2299         }
2300
2301         /*
2302          * 32-bit extent-start container, ee_block. We lower the maxbytes
2303          * by one fs block, so ee_len can cover the extent of maximum file
2304          * size
2305          */
2306         res = (1LL << 32) - 1;
2307         res <<= blkbits;
2308
2309         /* Sanity check against vm- & vfs- imposed limits */
2310         if (res > upper_limit)
2311                 res = upper_limit;
2312
2313         return res;
2314 }
2315
2316 /*
2317  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2318  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2319  * We need to be 1 filesystem block less than the 2^48 sector limit.
2320  */
2321 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2322 {
2323         loff_t res = EXT4_NDIR_BLOCKS;
2324         int meta_blocks;
2325         loff_t upper_limit;
2326         /* This is calculated to be the largest file size for a dense, block
2327          * mapped file such that the file's total number of 512-byte sectors,
2328          * including data and all indirect blocks, does not exceed (2^48 - 1).
2329          *
2330          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2331          * number of 512-byte sectors of the file.
2332          */
2333
2334         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2335                 /*
2336                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2337                  * the inode i_block field represents total file blocks in
2338                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2339                  */
2340                 upper_limit = (1LL << 32) - 1;
2341
2342                 /* total blocks in file system block size */
2343                 upper_limit >>= (bits - 9);
2344
2345         } else {
2346                 /*
2347                  * We use 48 bit ext4_inode i_blocks
2348                  * With EXT4_HUGE_FILE_FL set the i_blocks
2349                  * represent total number of blocks in
2350                  * file system block size
2351                  */
2352                 upper_limit = (1LL << 48) - 1;
2353
2354         }
2355
2356         /* indirect blocks */
2357         meta_blocks = 1;
2358         /* double indirect blocks */
2359         meta_blocks += 1 + (1LL << (bits-2));
2360         /* tripple indirect blocks */
2361         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2362
2363         upper_limit -= meta_blocks;
2364         upper_limit <<= bits;
2365
2366         res += 1LL << (bits-2);
2367         res += 1LL << (2*(bits-2));
2368         res += 1LL << (3*(bits-2));
2369         res <<= bits;
2370         if (res > upper_limit)
2371                 res = upper_limit;
2372
2373         if (res > MAX_LFS_FILESIZE)
2374                 res = MAX_LFS_FILESIZE;
2375
2376         return res;
2377 }
2378
2379 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2380                                    ext4_fsblk_t logical_sb_block, int nr)
2381 {
2382         struct ext4_sb_info *sbi = EXT4_SB(sb);
2383         ext4_group_t bg, first_meta_bg;
2384         int has_super = 0;
2385
2386         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2387
2388         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2389             nr < first_meta_bg)
2390                 return logical_sb_block + nr + 1;
2391         bg = sbi->s_desc_per_block * nr;
2392         if (ext4_bg_has_super(sb, bg))
2393                 has_super = 1;
2394
2395         /*
2396          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2397          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2398          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2399          * compensate.
2400          */
2401         if (sb->s_blocksize == 1024 && nr == 0 &&
2402             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2403                 has_super++;
2404
2405         return (has_super + ext4_group_first_block_no(sb, bg));
2406 }
2407
2408 /**
2409  * ext4_get_stripe_size: Get the stripe size.
2410  * @sbi: In memory super block info
2411  *
2412  * If we have specified it via mount option, then
2413  * use the mount option value. If the value specified at mount time is
2414  * greater than the blocks per group use the super block value.
2415  * If the super block value is greater than blocks per group return 0.
2416  * Allocator needs it be less than blocks per group.
2417  *
2418  */
2419 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2420 {
2421         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2422         unsigned long stripe_width =
2423                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2424         int ret;
2425
2426         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2427                 ret = sbi->s_stripe;
2428         else if (stripe_width <= sbi->s_blocks_per_group)
2429                 ret = stripe_width;
2430         else if (stride <= sbi->s_blocks_per_group)
2431                 ret = stride;
2432         else
2433                 ret = 0;
2434
2435         /*
2436          * If the stripe width is 1, this makes no sense and
2437          * we set it to 0 to turn off stripe handling code.
2438          */
2439         if (ret <= 1)
2440                 ret = 0;
2441
2442         return ret;
2443 }
2444
2445 /* sysfs supprt */
2446
2447 struct ext4_attr {
2448         struct attribute attr;
2449         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2450         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2451                          const char *, size_t);
2452         union {
2453                 int offset;
2454                 int deprecated_val;
2455         } u;
2456 };
2457
2458 static int parse_strtoull(const char *buf,
2459                 unsigned long long max, unsigned long long *value)
2460 {
2461         int ret;
2462
2463         ret = kstrtoull(skip_spaces(buf), 0, value);
2464         if (!ret && *value > max)
2465                 ret = -EINVAL;
2466         return ret;
2467 }
2468
2469 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2470                                               struct ext4_sb_info *sbi,
2471                                               char *buf)
2472 {
2473         return snprintf(buf, PAGE_SIZE, "%llu\n",
2474                 (s64) EXT4_C2B(sbi,
2475                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2476 }
2477
2478 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2479                                          struct ext4_sb_info *sbi, char *buf)
2480 {
2481         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2482
2483         if (!sb->s_bdev->bd_part)
2484                 return snprintf(buf, PAGE_SIZE, "0\n");
2485         return snprintf(buf, PAGE_SIZE, "%lu\n",
2486                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2487                          sbi->s_sectors_written_start) >> 1);
2488 }
2489
2490 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2491                                           struct ext4_sb_info *sbi, char *buf)
2492 {
2493         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2494
2495         if (!sb->s_bdev->bd_part)
2496                 return snprintf(buf, PAGE_SIZE, "0\n");
2497         return snprintf(buf, PAGE_SIZE, "%llu\n",
2498                         (unsigned long long)(sbi->s_kbytes_written +
2499                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2500                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2501 }
2502
2503 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2504                                           struct ext4_sb_info *sbi,
2505                                           const char *buf, size_t count)
2506 {
2507         unsigned long t;
2508         int ret;
2509
2510         ret = kstrtoul(skip_spaces(buf), 0, &t);
2511         if (ret)
2512                 return ret;
2513
2514         if (t && (!is_power_of_2(t) || t > 0x40000000))
2515                 return -EINVAL;
2516
2517         sbi->s_inode_readahead_blks = t;
2518         return count;
2519 }
2520
2521 static ssize_t sbi_ui_show(struct ext4_attr *a,
2522                            struct ext4_sb_info *sbi, char *buf)
2523 {
2524         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2525
2526         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2527 }
2528
2529 static ssize_t sbi_ui_store(struct ext4_attr *a,
2530                             struct ext4_sb_info *sbi,
2531                             const char *buf, size_t count)
2532 {
2533         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2534         unsigned long t;
2535         int ret;
2536
2537         ret = kstrtoul(skip_spaces(buf), 0, &t);
2538         if (ret)
2539                 return ret;
2540         *ui = t;
2541         return count;
2542 }
2543
2544 static ssize_t es_ui_show(struct ext4_attr *a,
2545                            struct ext4_sb_info *sbi, char *buf)
2546 {
2547
2548         unsigned int *ui = (unsigned int *) (((char *) sbi->s_es) +
2549                            a->u.offset);
2550
2551         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2552 }
2553
2554 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2555                                   struct ext4_sb_info *sbi, char *buf)
2556 {
2557         return snprintf(buf, PAGE_SIZE, "%llu\n",
2558                 (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2559 }
2560
2561 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2562                                    struct ext4_sb_info *sbi,
2563                                    const char *buf, size_t count)
2564 {
2565         unsigned long long val;
2566         int ret;
2567
2568         if (parse_strtoull(buf, -1ULL, &val))
2569                 return -EINVAL;
2570         ret = ext4_reserve_clusters(sbi, val);
2571
2572         return ret ? ret : count;
2573 }
2574
2575 static ssize_t trigger_test_error(struct ext4_attr *a,
2576                                   struct ext4_sb_info *sbi,
2577                                   const char *buf, size_t count)
2578 {
2579         int len = count;
2580
2581         if (!capable(CAP_SYS_ADMIN))
2582                 return -EPERM;
2583
2584         if (len && buf[len-1] == '\n')
2585                 len--;
2586
2587         if (len)
2588                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2589         return count;
2590 }
2591
2592 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2593                                    struct ext4_sb_info *sbi, char *buf)
2594 {
2595         return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2596 }
2597
2598 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2599 static struct ext4_attr ext4_attr_##_name = {                   \
2600         .attr = {.name = __stringify(_name), .mode = _mode },   \
2601         .show   = _show,                                        \
2602         .store  = _store,                                       \
2603         .u = {                                                  \
2604                 .offset = offsetof(struct ext4_sb_info, _elname),\
2605         },                                                      \
2606 }
2607
2608 #define EXT4_ATTR_OFFSET_ES(_name,_mode,_show,_store,_elname)           \
2609 static struct ext4_attr ext4_attr_##_name = {                           \
2610         .attr = {.name = __stringify(_name), .mode = _mode },           \
2611         .show   = _show,                                                \
2612         .store  = _store,                                               \
2613         .u = {                                                          \
2614                 .offset = offsetof(struct ext4_super_block, _elname),   \
2615         },                                                              \
2616 }
2617
2618 #define EXT4_ATTR(name, mode, show, store) \
2619 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2620
2621 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2622 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2623 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2624
2625 #define EXT4_RO_ATTR_ES_UI(name, elname)        \
2626         EXT4_ATTR_OFFSET_ES(name, 0444, es_ui_show, NULL, elname)
2627 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2628         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2629
2630 #define ATTR_LIST(name) &ext4_attr_##name.attr
2631 #define EXT4_DEPRECATED_ATTR(_name, _val)       \
2632 static struct ext4_attr ext4_attr_##_name = {                   \
2633         .attr = {.name = __stringify(_name), .mode = 0444 },    \
2634         .show   = sbi_deprecated_show,                          \
2635         .u = {                                                  \
2636                 .deprecated_val = _val,                         \
2637         },                                                      \
2638 }
2639
2640 EXT4_RO_ATTR(delayed_allocation_blocks);
2641 EXT4_RO_ATTR(session_write_kbytes);
2642 EXT4_RO_ATTR(lifetime_write_kbytes);
2643 EXT4_RW_ATTR(reserved_clusters);
2644 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2645                  inode_readahead_blks_store, s_inode_readahead_blks);
2646 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2647 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2648 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2649 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2650 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2651 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2652 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2653 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2654 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2655 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2656 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2657 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2658 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2659 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2660 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2661 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2662 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
2663 EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
2664 EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
2665
2666 static struct attribute *ext4_attrs[] = {
2667         ATTR_LIST(delayed_allocation_blocks),
2668         ATTR_LIST(session_write_kbytes),
2669         ATTR_LIST(lifetime_write_kbytes),
2670         ATTR_LIST(reserved_clusters),
2671         ATTR_LIST(inode_readahead_blks),
2672         ATTR_LIST(inode_goal),
2673         ATTR_LIST(mb_stats),
2674         ATTR_LIST(mb_max_to_scan),
2675         ATTR_LIST(mb_min_to_scan),
2676         ATTR_LIST(mb_order2_req),
2677         ATTR_LIST(mb_stream_req),
2678         ATTR_LIST(mb_group_prealloc),
2679         ATTR_LIST(max_writeback_mb_bump),
2680         ATTR_LIST(extent_max_zeroout_kb),
2681         ATTR_LIST(trigger_fs_error),
2682         ATTR_LIST(err_ratelimit_interval_ms),
2683         ATTR_LIST(err_ratelimit_burst),
2684         ATTR_LIST(warning_ratelimit_interval_ms),
2685         ATTR_LIST(warning_ratelimit_burst),
2686         ATTR_LIST(msg_ratelimit_interval_ms),
2687         ATTR_LIST(msg_ratelimit_burst),
2688         ATTR_LIST(errors_count),
2689         ATTR_LIST(first_error_time),
2690         ATTR_LIST(last_error_time),
2691         NULL,
2692 };
2693
2694 /* Features this copy of ext4 supports */
2695 EXT4_INFO_ATTR(lazy_itable_init);
2696 EXT4_INFO_ATTR(batched_discard);
2697 EXT4_INFO_ATTR(meta_bg_resize);
2698
2699 static struct attribute *ext4_feat_attrs[] = {
2700         ATTR_LIST(lazy_itable_init),
2701         ATTR_LIST(batched_discard),
2702         ATTR_LIST(meta_bg_resize),
2703         NULL,
2704 };
2705
2706 static ssize_t ext4_attr_show(struct kobject *kobj,
2707                               struct attribute *attr, char *buf)
2708 {
2709         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2710                                                 s_kobj);
2711         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2712
2713         return a->show ? a->show(a, sbi, buf) : 0;
2714 }
2715
2716 static ssize_t ext4_attr_store(struct kobject *kobj,
2717                                struct attribute *attr,
2718                                const char *buf, size_t len)
2719 {
2720         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2721                                                 s_kobj);
2722         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2723
2724         return a->store ? a->store(a, sbi, buf, len) : 0;
2725 }
2726
2727 static void ext4_sb_release(struct kobject *kobj)
2728 {
2729         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2730                                                 s_kobj);
2731         complete(&sbi->s_kobj_unregister);
2732 }
2733
2734 static const struct sysfs_ops ext4_attr_ops = {
2735         .show   = ext4_attr_show,
2736         .store  = ext4_attr_store,
2737 };
2738
2739 static struct kobj_type ext4_ktype = {
2740         .default_attrs  = ext4_attrs,
2741         .sysfs_ops      = &ext4_attr_ops,
2742         .release        = ext4_sb_release,
2743 };
2744
2745 static void ext4_feat_release(struct kobject *kobj)
2746 {
2747         complete(&ext4_feat->f_kobj_unregister);
2748 }
2749
2750 static ssize_t ext4_feat_show(struct kobject *kobj,
2751                               struct attribute *attr, char *buf)
2752 {
2753         return snprintf(buf, PAGE_SIZE, "supported\n");
2754 }
2755
2756 /*
2757  * We can not use ext4_attr_show/store because it relies on the kobject
2758  * being embedded in the ext4_sb_info structure which is definitely not
2759  * true in this case.
2760  */
2761 static const struct sysfs_ops ext4_feat_ops = {
2762         .show   = ext4_feat_show,
2763         .store  = NULL,
2764 };
2765
2766 static struct kobj_type ext4_feat_ktype = {
2767         .default_attrs  = ext4_feat_attrs,
2768         .sysfs_ops      = &ext4_feat_ops,
2769         .release        = ext4_feat_release,
2770 };
2771
2772 /*
2773  * Check whether this filesystem can be mounted based on
2774  * the features present and the RDONLY/RDWR mount requested.
2775  * Returns 1 if this filesystem can be mounted as requested,
2776  * 0 if it cannot be.
2777  */
2778 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2779 {
2780         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2781                 ext4_msg(sb, KERN_ERR,
2782                         "Couldn't mount because of "
2783                         "unsupported optional features (%x)",
2784                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2785                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2786                 return 0;
2787         }
2788
2789         if (readonly)
2790                 return 1;
2791
2792         /* Check that feature set is OK for a read-write mount */
2793         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2794                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2795                          "unsupported optional features (%x)",
2796                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2797                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2798                 return 0;
2799         }
2800         /*
2801          * Large file size enabled file system can only be mounted
2802          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2803          */
2804         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2805                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2806                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2807                                  "cannot be mounted RDWR without "
2808                                  "CONFIG_LBDAF");
2809                         return 0;
2810                 }
2811         }
2812         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2813             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2814                 ext4_msg(sb, KERN_ERR,
2815                          "Can't support bigalloc feature without "
2816                          "extents feature\n");
2817                 return 0;
2818         }
2819
2820 #ifndef CONFIG_QUOTA
2821         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2822             !readonly) {
2823                 ext4_msg(sb, KERN_ERR,
2824                          "Filesystem with quota feature cannot be mounted RDWR "
2825                          "without CONFIG_QUOTA");
2826                 return 0;
2827         }
2828 #endif  /* CONFIG_QUOTA */
2829         return 1;
2830 }
2831
2832 /*
2833  * This function is called once a day if we have errors logged
2834  * on the file system
2835  */
2836 static void print_daily_error_info(unsigned long arg)
2837 {
2838         struct super_block *sb = (struct super_block *) arg;
2839         struct ext4_sb_info *sbi;
2840         struct ext4_super_block *es;
2841
2842         sbi = EXT4_SB(sb);
2843         es = sbi->s_es;
2844
2845         if (es->s_error_count)
2846                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2847                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2848                          le32_to_cpu(es->s_error_count));
2849         if (es->s_first_error_time) {
2850                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2851                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2852                        (int) sizeof(es->s_first_error_func),
2853                        es->s_first_error_func,
2854                        le32_to_cpu(es->s_first_error_line));
2855                 if (es->s_first_error_ino)
2856                         printk(": inode %u",
2857                                le32_to_cpu(es->s_first_error_ino));
2858                 if (es->s_first_error_block)
2859                         printk(": block %llu", (unsigned long long)
2860                                le64_to_cpu(es->s_first_error_block));
2861                 printk("\n");
2862         }
2863         if (es->s_last_error_time) {
2864                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2865                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2866                        (int) sizeof(es->s_last_error_func),
2867                        es->s_last_error_func,
2868                        le32_to_cpu(es->s_last_error_line));
2869                 if (es->s_last_error_ino)
2870                         printk(": inode %u",
2871                                le32_to_cpu(es->s_last_error_ino));
2872                 if (es->s_last_error_block)
2873                         printk(": block %llu", (unsigned long long)
2874                                le64_to_cpu(es->s_last_error_block));
2875                 printk("\n");
2876         }
2877         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2878 }
2879
2880 /* Find next suitable group and run ext4_init_inode_table */
2881 static int ext4_run_li_request(struct ext4_li_request *elr)
2882 {
2883         struct ext4_group_desc *gdp = NULL;
2884         ext4_group_t group, ngroups;
2885         struct super_block *sb;
2886         unsigned long timeout = 0;
2887         int ret = 0;
2888
2889         sb = elr->lr_super;
2890         ngroups = EXT4_SB(sb)->s_groups_count;
2891
2892         sb_start_write(sb);
2893         for (group = elr->lr_next_group; group < ngroups; group++) {
2894                 gdp = ext4_get_group_desc(sb, group, NULL);
2895                 if (!gdp) {
2896                         ret = 1;
2897                         break;
2898                 }
2899
2900                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2901                         break;
2902         }
2903
2904         if (group >= ngroups)
2905                 ret = 1;
2906
2907         if (!ret) {
2908                 timeout = jiffies;
2909                 ret = ext4_init_inode_table(sb, group,
2910                                             elr->lr_timeout ? 0 : 1);
2911                 if (elr->lr_timeout == 0) {
2912                         timeout = (jiffies - timeout) *
2913                                   elr->lr_sbi->s_li_wait_mult;
2914                         elr->lr_timeout = timeout;
2915                 }
2916                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2917                 elr->lr_next_group = group + 1;
2918         }
2919         sb_end_write(sb);
2920
2921         return ret;
2922 }
2923
2924 /*
2925  * Remove lr_request from the list_request and free the
2926  * request structure. Should be called with li_list_mtx held
2927  */
2928 static void ext4_remove_li_request(struct ext4_li_request *elr)
2929 {
2930         struct ext4_sb_info *sbi;
2931
2932         if (!elr)
2933                 return;
2934
2935         sbi = elr->lr_sbi;
2936
2937         list_del(&elr->lr_request);
2938         sbi->s_li_request = NULL;
2939         kfree(elr);
2940 }
2941
2942 static void ext4_unregister_li_request(struct super_block *sb)
2943 {
2944         mutex_lock(&ext4_li_mtx);
2945         if (!ext4_li_info) {
2946                 mutex_unlock(&ext4_li_mtx);
2947                 return;
2948         }
2949
2950         mutex_lock(&ext4_li_info->li_list_mtx);
2951         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2952         mutex_unlock(&ext4_li_info->li_list_mtx);
2953         mutex_unlock(&ext4_li_mtx);
2954 }
2955
2956 static struct task_struct *ext4_lazyinit_task;
2957
2958 /*
2959  * This is the function where ext4lazyinit thread lives. It walks
2960  * through the request list searching for next scheduled filesystem.
2961  * When such a fs is found, run the lazy initialization request
2962  * (ext4_rn_li_request) and keep track of the time spend in this
2963  * function. Based on that time we compute next schedule time of
2964  * the request. When walking through the list is complete, compute
2965  * next waking time and put itself into sleep.
2966  */
2967 static int ext4_lazyinit_thread(void *arg)
2968 {
2969         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2970         struct list_head *pos, *n;
2971         struct ext4_li_request *elr;
2972         unsigned long next_wakeup, cur;
2973
2974         BUG_ON(NULL == eli);
2975
2976 cont_thread:
2977         while (true) {
2978                 next_wakeup = MAX_JIFFY_OFFSET;
2979
2980                 mutex_lock(&eli->li_list_mtx);
2981                 if (list_empty(&eli->li_request_list)) {
2982                         mutex_unlock(&eli->li_list_mtx);
2983                         goto exit_thread;
2984                 }
2985
2986                 list_for_each_safe(pos, n, &eli->li_request_list) {
2987                         elr = list_entry(pos, struct ext4_li_request,
2988                                          lr_request);
2989
2990                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2991                                 if (ext4_run_li_request(elr) != 0) {
2992                                         /* error, remove the lazy_init job */
2993                                         ext4_remove_li_request(elr);
2994                                         continue;
2995                                 }
2996                         }
2997
2998                         if (time_before(elr->lr_next_sched, next_wakeup))
2999                                 next_wakeup = elr->lr_next_sched;
3000                 }
3001                 mutex_unlock(&eli->li_list_mtx);
3002
3003                 try_to_freeze();
3004
3005                 cur = jiffies;
3006                 if ((time_after_eq(cur, next_wakeup)) ||
3007                     (MAX_JIFFY_OFFSET == next_wakeup)) {
3008                         cond_resched();
3009                         continue;
3010                 }
3011
3012                 schedule_timeout_interruptible(next_wakeup - cur);
3013
3014                 if (kthread_should_stop()) {
3015                         ext4_clear_request_list();
3016                         goto exit_thread;
3017                 }
3018         }
3019
3020 exit_thread:
3021         /*
3022          * It looks like the request list is empty, but we need
3023          * to check it under the li_list_mtx lock, to prevent any
3024          * additions into it, and of course we should lock ext4_li_mtx
3025          * to atomically free the list and ext4_li_info, because at
3026          * this point another ext4 filesystem could be registering
3027          * new one.
3028          */
3029         mutex_lock(&ext4_li_mtx);
3030         mutex_lock(&eli->li_list_mtx);
3031         if (!list_empty(&eli->li_request_list)) {
3032                 mutex_unlock(&eli->li_list_mtx);
3033                 mutex_unlock(&ext4_li_mtx);
3034                 goto cont_thread;
3035         }
3036         mutex_unlock(&eli->li_list_mtx);
3037         kfree(ext4_li_info);
3038         ext4_li_info = NULL;
3039         mutex_unlock(&ext4_li_mtx);
3040
3041         return 0;
3042 }
3043
3044 static void ext4_clear_request_list(void)
3045 {
3046         struct list_head *pos, *n;
3047         struct ext4_li_request *elr;
3048
3049         mutex_lock(&ext4_li_info->li_list_mtx);
3050         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3051                 elr = list_entry(pos, struct ext4_li_request,
3052                                  lr_request);
3053                 ext4_remove_li_request(elr);
3054         }
3055         mutex_unlock(&ext4_li_info->li_list_mtx);
3056 }
3057
3058 static int ext4_run_lazyinit_thread(void)
3059 {
3060         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3061                                          ext4_li_info, "ext4lazyinit");
3062         if (IS_ERR(ext4_lazyinit_task)) {
3063                 int err = PTR_ERR(ext4_lazyinit_task);
3064                 ext4_clear_request_list();
3065                 kfree(ext4_li_info);
3066                 ext4_li_info = NULL;
3067                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3068                                  "initialization thread\n",
3069                                  err);
3070                 return err;
3071         }
3072         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3073         return 0;
3074 }
3075
3076 /*
3077  * Check whether it make sense to run itable init. thread or not.
3078  * If there is at least one uninitialized inode table, return
3079  * corresponding group number, else the loop goes through all
3080  * groups and return total number of groups.
3081  */
3082 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3083 {
3084         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3085         struct ext4_group_desc *gdp = NULL;
3086
3087         for (group = 0; group < ngroups; group++) {
3088                 gdp = ext4_get_group_desc(sb, group, NULL);
3089                 if (!gdp)
3090                         continue;
3091
3092                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3093                         break;
3094         }
3095
3096         return group;
3097 }
3098
3099 static int ext4_li_info_new(void)
3100 {
3101         struct ext4_lazy_init *eli = NULL;
3102
3103         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3104         if (!eli)
3105                 return -ENOMEM;
3106
3107         INIT_LIST_HEAD(&eli->li_request_list);
3108         mutex_init(&eli->li_list_mtx);
3109
3110         eli->li_state |= EXT4_LAZYINIT_QUIT;
3111
3112         ext4_li_info = eli;
3113
3114         return 0;
3115 }
3116
3117 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3118                                             ext4_group_t start)
3119 {
3120         struct ext4_sb_info *sbi = EXT4_SB(sb);
3121         struct ext4_li_request *elr;
3122
3123         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3124         if (!elr)
3125                 return NULL;
3126
3127         elr->lr_super = sb;
3128         elr->lr_sbi = sbi;
3129         elr->lr_next_group = start;
3130
3131         /*
3132          * Randomize first schedule time of the request to
3133          * spread the inode table initialization requests
3134          * better.
3135          */
3136         elr->lr_next_sched = jiffies + (prandom_u32() %
3137                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3138         return elr;
3139 }
3140
3141 int ext4_register_li_request(struct super_block *sb,
3142                              ext4_group_t first_not_zeroed)
3143 {
3144         struct ext4_sb_info *sbi = EXT4_SB(sb);
3145         struct ext4_li_request *elr = NULL;
3146         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3147         int ret = 0;
3148
3149         mutex_lock(&ext4_li_mtx);
3150         if (sbi->s_li_request != NULL) {
3151                 /*
3152                  * Reset timeout so it can be computed again, because
3153                  * s_li_wait_mult might have changed.
3154                  */
3155                 sbi->s_li_request->lr_timeout = 0;
3156                 goto out;
3157         }
3158
3159         if (first_not_zeroed == ngroups ||
3160             (sb->s_flags & MS_RDONLY) ||
3161             !test_opt(sb, INIT_INODE_TABLE))
3162                 goto out;
3163
3164         elr = ext4_li_request_new(sb, first_not_zeroed);
3165         if (!elr) {
3166                 ret = -ENOMEM;
3167                 goto out;
3168         }
3169
3170         if (NULL == ext4_li_info) {
3171                 ret = ext4_li_info_new();
3172                 if (ret)
3173                         goto out;
3174         }
3175
3176         mutex_lock(&ext4_li_info->li_list_mtx);
3177         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3178         mutex_unlock(&ext4_li_info->li_list_mtx);
3179
3180         sbi->s_li_request = elr;
3181         /*
3182          * set elr to NULL here since it has been inserted to
3183          * the request_list and the removal and free of it is
3184          * handled by ext4_clear_request_list from now on.
3185          */
3186         elr = NULL;
3187
3188         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3189                 ret = ext4_run_lazyinit_thread();
3190                 if (ret)
3191                         goto out;
3192         }
3193 out:
3194         mutex_unlock(&ext4_li_mtx);
3195         if (ret)
3196                 kfree(elr);
3197         return ret;
3198 }
3199
3200 /*
3201  * We do not need to lock anything since this is called on
3202  * module unload.
3203  */
3204 static void ext4_destroy_lazyinit_thread(void)
3205 {
3206         /*
3207          * If thread exited earlier
3208          * there's nothing to be done.
3209          */
3210         if (!ext4_li_info || !ext4_lazyinit_task)
3211                 return;
3212
3213         kthread_stop(ext4_lazyinit_task);
3214 }
3215
3216 static int set_journal_csum_feature_set(struct super_block *sb)
3217 {
3218         int ret = 1;
3219         int compat, incompat;
3220         struct ext4_sb_info *sbi = EXT4_SB(sb);
3221
3222         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3223                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3224                 /* journal checksum v3 */
3225                 compat = 0;
3226                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3227         } else {
3228                 /* journal checksum v1 */
3229                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3230                 incompat = 0;
3231         }
3232
3233         jbd2_journal_clear_features(sbi->s_journal,
3234                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3235                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3236                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3237         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3238                 ret = jbd2_journal_set_features(sbi->s_journal,
3239                                 compat, 0,
3240                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3241                                 incompat);
3242         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3243                 ret = jbd2_journal_set_features(sbi->s_journal,
3244                                 compat, 0,
3245                                 incompat);
3246                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3247                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3248         } else {
3249                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3250                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3251         }
3252
3253         return ret;
3254 }
3255
3256 /*
3257  * Note: calculating the overhead so we can be compatible with
3258  * historical BSD practice is quite difficult in the face of
3259  * clusters/bigalloc.  This is because multiple metadata blocks from
3260  * different block group can end up in the same allocation cluster.
3261  * Calculating the exact overhead in the face of clustered allocation
3262  * requires either O(all block bitmaps) in memory or O(number of block
3263  * groups**2) in time.  We will still calculate the superblock for
3264  * older file systems --- and if we come across with a bigalloc file
3265  * system with zero in s_overhead_clusters the estimate will be close to
3266  * correct especially for very large cluster sizes --- but for newer
3267  * file systems, it's better to calculate this figure once at mkfs
3268  * time, and store it in the superblock.  If the superblock value is
3269  * present (even for non-bigalloc file systems), we will use it.
3270  */
3271 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3272                           char *buf)
3273 {
3274         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3275         struct ext4_group_desc  *gdp;
3276         ext4_fsblk_t            first_block, last_block, b;
3277         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3278         int                     s, j, count = 0;
3279
3280         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3281                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3282                         sbi->s_itb_per_group + 2);
3283
3284         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3285                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3286         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3287         for (i = 0; i < ngroups; i++) {
3288                 gdp = ext4_get_group_desc(sb, i, NULL);
3289                 b = ext4_block_bitmap(sb, gdp);
3290                 if (b >= first_block && b <= last_block) {
3291                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3292                         count++;
3293                 }
3294                 b = ext4_inode_bitmap(sb, gdp);
3295                 if (b >= first_block && b <= last_block) {
3296                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3297                         count++;
3298                 }
3299                 b = ext4_inode_table(sb, gdp);
3300                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3301                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3302                                 int c = EXT4_B2C(sbi, b - first_block);
3303                                 ext4_set_bit(c, buf);
3304                                 count++;
3305                         }
3306                 if (i != grp)
3307                         continue;
3308                 s = 0;
3309                 if (ext4_bg_has_super(sb, grp)) {
3310                         ext4_set_bit(s++, buf);
3311                         count++;
3312                 }
3313                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3314                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3315                         count++;
3316                 }
3317         }
3318         if (!count)
3319                 return 0;
3320         return EXT4_CLUSTERS_PER_GROUP(sb) -
3321                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3322 }
3323
3324 /*
3325  * Compute the overhead and stash it in sbi->s_overhead
3326  */
3327 int ext4_calculate_overhead(struct super_block *sb)
3328 {
3329         struct ext4_sb_info *sbi = EXT4_SB(sb);
3330         struct ext4_super_block *es = sbi->s_es;
3331         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3332         ext4_fsblk_t overhead = 0;
3333         char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3334
3335         if (!buf)
3336                 return -ENOMEM;
3337
3338         /*
3339          * Compute the overhead (FS structures).  This is constant
3340          * for a given filesystem unless the number of block groups
3341          * changes so we cache the previous value until it does.
3342          */
3343
3344         /*
3345          * All of the blocks before first_data_block are overhead
3346          */
3347         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3348
3349         /*
3350          * Add the overhead found in each block group
3351          */
3352         for (i = 0; i < ngroups; i++) {
3353                 int blks;
3354
3355                 blks = count_overhead(sb, i, buf);
3356                 overhead += blks;
3357                 if (blks)
3358                         memset(buf, 0, PAGE_SIZE);
3359                 cond_resched();
3360         }
3361         /* Add the journal blocks as well */
3362         if (sbi->s_journal)
3363                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3364
3365         sbi->s_overhead = overhead;
3366         smp_wmb();
3367         free_page((unsigned long) buf);
3368         return 0;
3369 }
3370
3371
3372 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3373 {
3374         ext4_fsblk_t resv_clusters;
3375
3376         /*
3377          * There's no need to reserve anything when we aren't using extents.
3378          * The space estimates are exact, there are no unwritten extents,
3379          * hole punching doesn't need new metadata... This is needed especially
3380          * to keep ext2/3 backward compatibility.
3381          */
3382         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3383                 return 0;
3384         /*
3385          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3386          * This should cover the situations where we can not afford to run
3387          * out of space like for example punch hole, or converting
3388          * unwritten extents in delalloc path. In most cases such
3389          * allocation would require 1, or 2 blocks, higher numbers are
3390          * very rare.
3391          */
3392         resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3393                         EXT4_SB(sb)->s_cluster_bits;
3394
3395         do_div(resv_clusters, 50);
3396         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3397
3398         return resv_clusters;
3399 }
3400
3401
3402 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3403 {
3404         ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3405                                 sbi->s_cluster_bits;
3406
3407         if (count >= clusters)
3408                 return -EINVAL;
3409
3410         atomic64_set(&sbi->s_resv_clusters, count);
3411         return 0;
3412 }
3413
3414 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3415 {
3416         char *orig_data = kstrdup(data, GFP_KERNEL);
3417         struct buffer_head *bh;
3418         struct ext4_super_block *es = NULL;
3419         struct ext4_sb_info *sbi;
3420         ext4_fsblk_t block;
3421         ext4_fsblk_t sb_block = get_sb_block(&data);
3422         ext4_fsblk_t logical_sb_block;
3423         unsigned long offset = 0;
3424         unsigned long journal_devnum = 0;
3425         unsigned long def_mount_opts;
3426         struct inode *root;
3427         char *cp;
3428         const char *descr;
3429         int ret = -ENOMEM;
3430         int blocksize, clustersize;
3431         unsigned int db_count;
3432         unsigned int i;
3433         int needs_recovery, has_huge_files, has_bigalloc;
3434         __u64 blocks_count;
3435         int err = 0;
3436         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3437         ext4_group_t first_not_zeroed;
3438
3439         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3440         if (!sbi)
3441                 goto out_free_orig;
3442
3443         sbi->s_blockgroup_lock =
3444                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3445         if (!sbi->s_blockgroup_lock) {
3446                 kfree(sbi);
3447                 goto out_free_orig;
3448         }
3449         sb->s_fs_info = sbi;
3450         sbi->s_sb = sb;
3451         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3452         sbi->s_sb_block = sb_block;
3453         if (sb->s_bdev->bd_part)
3454                 sbi->s_sectors_written_start =
3455                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3456
3457         /* Cleanup superblock name */
3458         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3459                 *cp = '!';
3460
3461         /* -EINVAL is default */
3462         ret = -EINVAL;
3463         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3464         if (!blocksize) {
3465                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3466                 goto out_fail;
3467         }
3468
3469         /*
3470          * The ext4 superblock will not be buffer aligned for other than 1kB
3471          * block sizes.  We need to calculate the offset from buffer start.
3472          */
3473         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3474                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3475                 offset = do_div(logical_sb_block, blocksize);
3476         } else {
3477                 logical_sb_block = sb_block;
3478         }
3479
3480         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3481                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3482                 goto out_fail;
3483         }
3484         /*
3485          * Note: s_es must be initialized as soon as possible because
3486          *       some ext4 macro-instructions depend on its value
3487          */
3488         es = (struct ext4_super_block *) (bh->b_data + offset);
3489         sbi->s_es = es;
3490         sb->s_magic = le16_to_cpu(es->s_magic);
3491         if (sb->s_magic != EXT4_SUPER_MAGIC)
3492                 goto cantfind_ext4;
3493         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3494
3495         /* Warn if metadata_csum and gdt_csum are both set. */
3496         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3497                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3498             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3499                 ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3500                              "redundant flags; please run fsck.");
3501
3502         /* Check for a known checksum algorithm */
3503         if (!ext4_verify_csum_type(sb, es)) {
3504                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3505                          "unknown checksum algorithm.");
3506                 silent = 1;
3507                 goto cantfind_ext4;
3508         }
3509
3510         /* Load the checksum driver */
3511         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3512                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3513                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3514                 if (IS_ERR(sbi->s_chksum_driver)) {
3515                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3516                         ret = PTR_ERR(sbi->s_chksum_driver);
3517                         sbi->s_chksum_driver = NULL;
3518                         goto failed_mount;
3519                 }
3520         }
3521
3522         /* Check superblock checksum */
3523         if (!ext4_superblock_csum_verify(sb, es)) {
3524                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3525                          "invalid superblock checksum.  Run e2fsck?");
3526                 silent = 1;
3527                 goto cantfind_ext4;
3528         }
3529
3530         /* Precompute checksum seed for all metadata */
3531         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3532                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3533                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3534                                                sizeof(es->s_uuid));
3535
3536         /* Set defaults before we parse the mount options */
3537         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3538         set_opt(sb, INIT_INODE_TABLE);
3539         if (def_mount_opts & EXT4_DEFM_DEBUG)
3540                 set_opt(sb, DEBUG);
3541         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3542                 set_opt(sb, GRPID);
3543         if (def_mount_opts & EXT4_DEFM_UID16)
3544                 set_opt(sb, NO_UID32);
3545         /* xattr user namespace & acls are now defaulted on */
3546         set_opt(sb, XATTR_USER);
3547 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3548         set_opt(sb, POSIX_ACL);
3549 #endif
3550         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3551                 set_opt(sb, JOURNAL_DATA);
3552         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3553                 set_opt(sb, ORDERED_DATA);
3554         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3555                 set_opt(sb, WRITEBACK_DATA);
3556
3557         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3558                 set_opt(sb, ERRORS_PANIC);
3559         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3560                 set_opt(sb, ERRORS_CONT);
3561         else
3562                 set_opt(sb, ERRORS_RO);
3563         /* block_validity enabled by default; disable with noblock_validity */
3564         set_opt(sb, BLOCK_VALIDITY);
3565         if (def_mount_opts & EXT4_DEFM_DISCARD)
3566                 set_opt(sb, DISCARD);
3567
3568         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3569         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3570         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3571         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3572         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3573
3574         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3575                 set_opt(sb, BARRIER);
3576
3577         /*
3578          * enable delayed allocation by default
3579          * Use -o nodelalloc to turn it off
3580          */
3581         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3582             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3583                 set_opt(sb, DELALLOC);
3584
3585         /*
3586          * set default s_li_wait_mult for lazyinit, for the case there is
3587          * no mount option specified.
3588          */
3589         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3590
3591         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3592                            &journal_devnum, &journal_ioprio, 0)) {
3593                 ext4_msg(sb, KERN_WARNING,
3594                          "failed to parse options in superblock: %s",
3595                          sbi->s_es->s_mount_opts);
3596         }
3597         sbi->s_def_mount_opt = sbi->s_mount_opt;
3598         if (!parse_options((char *) data, sb, &journal_devnum,
3599                            &journal_ioprio, 0))
3600                 goto failed_mount;
3601
3602         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3603                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3604                             "with data=journal disables delayed "
3605                             "allocation and O_DIRECT support!\n");
3606                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3607                         ext4_msg(sb, KERN_ERR, "can't mount with "
3608                                  "both data=journal and delalloc");
3609                         goto failed_mount;
3610                 }
3611                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3612                         ext4_msg(sb, KERN_ERR, "can't mount with "
3613                                  "both data=journal and dioread_nolock");
3614                         goto failed_mount;
3615                 }
3616                 if (test_opt(sb, DELALLOC))
3617                         clear_opt(sb, DELALLOC);
3618         }
3619
3620         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3621                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3622
3623         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3624             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3625              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3626              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3627                 ext4_msg(sb, KERN_WARNING,
3628                        "feature flags set on rev 0 fs, "
3629                        "running e2fsck is recommended");
3630
3631         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3632                 set_opt2(sb, HURD_COMPAT);
3633                 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
3634                                               EXT4_FEATURE_INCOMPAT_64BIT)) {
3635                         ext4_msg(sb, KERN_ERR,
3636                                  "The Hurd can't support 64-bit file systems");
3637                         goto failed_mount;
3638                 }
3639         }
3640
3641         if (IS_EXT2_SB(sb)) {
3642                 if (ext2_feature_set_ok(sb))
3643                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3644                                  "using the ext4 subsystem");
3645                 else {
3646                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3647                                  "to feature incompatibilities");
3648                         goto failed_mount;
3649                 }
3650         }
3651
3652         if (IS_EXT3_SB(sb)) {
3653                 if (ext3_feature_set_ok(sb))
3654                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3655                                  "using the ext4 subsystem");
3656                 else {
3657                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3658                                  "to feature incompatibilities");
3659                         goto failed_mount;
3660                 }
3661         }
3662
3663         /*
3664          * Check feature flags regardless of the revision level, since we
3665          * previously didn't change the revision level when setting the flags,
3666          * so there is a chance incompat flags are set on a rev 0 filesystem.
3667          */
3668         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3669                 goto failed_mount;
3670
3671         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3672         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3673             blocksize > EXT4_MAX_BLOCK_SIZE) {
3674                 ext4_msg(sb, KERN_ERR,
3675                        "Unsupported filesystem blocksize %d", blocksize);
3676                 goto failed_mount;
3677         }
3678
3679         if (sb->s_blocksize != blocksize) {
3680                 /* Validate the filesystem blocksize */
3681                 if (!sb_set_blocksize(sb, blocksize)) {
3682                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3683                                         blocksize);
3684                         goto failed_mount;
3685                 }
3686
3687                 brelse(bh);
3688                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3689                 offset = do_div(logical_sb_block, blocksize);
3690                 bh = sb_bread_unmovable(sb, logical_sb_block);
3691                 if (!bh) {
3692                         ext4_msg(sb, KERN_ERR,
3693                                "Can't read superblock on 2nd try");
3694                         goto failed_mount;
3695                 }
3696                 es = (struct ext4_super_block *)(bh->b_data + offset);
3697                 sbi->s_es = es;
3698                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3699                         ext4_msg(sb, KERN_ERR,
3700                                "Magic mismatch, very weird!");
3701                         goto failed_mount;
3702                 }
3703         }
3704
3705         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3706                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3707         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3708                                                       has_huge_files);
3709         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3710
3711         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3712                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3713                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3714         } else {
3715                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3716                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3717                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3718                     (!is_power_of_2(sbi->s_inode_size)) ||
3719                     (sbi->s_inode_size > blocksize)) {
3720                         ext4_msg(sb, KERN_ERR,
3721                                "unsupported inode size: %d",
3722                                sbi->s_inode_size);
3723                         goto failed_mount;
3724                 }
3725                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3726                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3727         }
3728
3729         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3730         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3731                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3732                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3733                     !is_power_of_2(sbi->s_desc_size)) {
3734                         ext4_msg(sb, KERN_ERR,
3735                                "unsupported descriptor size %lu",
3736                                sbi->s_desc_size);
3737                         goto failed_mount;
3738                 }
3739         } else
3740                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3741
3742         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3743         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3744         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3745                 goto cantfind_ext4;
3746
3747         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3748         if (sbi->s_inodes_per_block == 0)
3749                 goto cantfind_ext4;
3750         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3751                                         sbi->s_inodes_per_block;
3752         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3753         sbi->s_sbh = bh;
3754         sbi->s_mount_state = le16_to_cpu(es->s_state);
3755         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3756         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3757
3758         for (i = 0; i < 4; i++)
3759                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3760         sbi->s_def_hash_version = es->s_def_hash_version;
3761         if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3762                 i = le32_to_cpu(es->s_flags);
3763                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3764                         sbi->s_hash_unsigned = 3;
3765                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3766 #ifdef __CHAR_UNSIGNED__
3767                         if (!(sb->s_flags & MS_RDONLY))
3768                                 es->s_flags |=
3769                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3770                         sbi->s_hash_unsigned = 3;
3771 #else
3772                         if (!(sb->s_flags & MS_RDONLY))
3773                                 es->s_flags |=
3774                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3775 #endif
3776                 }
3777         }
3778
3779         /* Handle clustersize */
3780         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3781         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3782                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3783         if (has_bigalloc) {
3784                 if (clustersize < blocksize) {
3785                         ext4_msg(sb, KERN_ERR,
3786                                  "cluster size (%d) smaller than "
3787                                  "block size (%d)", clustersize, blocksize);
3788                         goto failed_mount;
3789                 }
3790                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3791                         le32_to_cpu(es->s_log_block_size);
3792                 sbi->s_clusters_per_group =
3793                         le32_to_cpu(es->s_clusters_per_group);
3794                 if (sbi->s_clusters_per_group > blocksize * 8) {
3795                         ext4_msg(sb, KERN_ERR,
3796                                  "#clusters per group too big: %lu",
3797                                  sbi->s_clusters_per_group);
3798                         goto failed_mount;
3799                 }
3800                 if (sbi->s_blocks_per_group !=
3801                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3802                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3803                                  "clusters per group (%lu) inconsistent",
3804                                  sbi->s_blocks_per_group,
3805                                  sbi->s_clusters_per_group);
3806                         goto failed_mount;
3807                 }
3808         } else {
3809                 if (clustersize != blocksize) {
3810                         ext4_warning(sb, "fragment/cluster size (%d) != "
3811                                      "block size (%d)", clustersize,
3812                                      blocksize);
3813                         clustersize = blocksize;
3814                 }
3815                 if (sbi->s_blocks_per_group > blocksize * 8) {
3816                         ext4_msg(sb, KERN_ERR,
3817                                  "#blocks per group too big: %lu",
3818                                  sbi->s_blocks_per_group);
3819                         goto failed_mount;
3820                 }
3821                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3822                 sbi->s_cluster_bits = 0;
3823         }
3824         sbi->s_cluster_ratio = clustersize / blocksize;
3825
3826         if (sbi->s_inodes_per_group > blocksize * 8) {
3827                 ext4_msg(sb, KERN_ERR,
3828                        "#inodes per group too big: %lu",
3829                        sbi->s_inodes_per_group);
3830                 goto failed_mount;
3831         }
3832
3833         /* Do we have standard group size of clustersize * 8 blocks ? */
3834         if (sbi->s_blocks_per_group == clustersize << 3)
3835                 set_opt2(sb, STD_GROUP_SIZE);
3836
3837         /*
3838          * Test whether we have more sectors than will fit in sector_t,
3839          * and whether the max offset is addressable by the page cache.
3840          */
3841         err = generic_check_addressable(sb->s_blocksize_bits,
3842                                         ext4_blocks_count(es));
3843         if (err) {
3844                 ext4_msg(sb, KERN_ERR, "filesystem"
3845                          " too large to mount safely on this system");
3846                 if (sizeof(sector_t) < 8)
3847                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3848                 goto failed_mount;
3849         }
3850
3851         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3852                 goto cantfind_ext4;
3853
3854         /* check blocks count against device size */
3855         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3856         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3857                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3858                        "exceeds size of device (%llu blocks)",
3859                        ext4_blocks_count(es), blocks_count);
3860                 goto failed_mount;
3861         }
3862
3863         /*
3864          * It makes no sense for the first data block to be beyond the end
3865          * of the filesystem.
3866          */
3867         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3868                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3869                          "block %u is beyond end of filesystem (%llu)",
3870                          le32_to_cpu(es->s_first_data_block),
3871                          ext4_blocks_count(es));
3872                 goto failed_mount;
3873         }
3874         blocks_count = (ext4_blocks_count(es) -
3875                         le32_to_cpu(es->s_first_data_block) +
3876                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3877         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3878         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3879                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3880                        "(block count %llu, first data block %u, "
3881                        "blocks per group %lu)", sbi->s_groups_count,
3882                        ext4_blocks_count(es),
3883                        le32_to_cpu(es->s_first_data_block),
3884                        EXT4_BLOCKS_PER_GROUP(sb));
3885                 goto failed_mount;
3886         }
3887         sbi->s_groups_count = blocks_count;
3888         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3889                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3890         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3891                    EXT4_DESC_PER_BLOCK(sb);
3892         sbi->s_group_desc = ext4_kvmalloc(db_count *
3893                                           sizeof(struct buffer_head *),
3894                                           GFP_KERNEL);
3895         if (sbi->s_group_desc == NULL) {
3896                 ext4_msg(sb, KERN_ERR, "not enough memory");
3897                 ret = -ENOMEM;
3898                 goto failed_mount;
3899         }
3900
3901         if (ext4_proc_root)
3902                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3903
3904         if (sbi->s_proc)
3905                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3906                                  &ext4_seq_options_fops, sb);
3907
3908         bgl_lock_init(sbi->s_blockgroup_lock);
3909
3910         for (i = 0; i < db_count; i++) {
3911                 block = descriptor_loc(sb, logical_sb_block, i);
3912                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3913                 if (!sbi->s_group_desc[i]) {
3914                         ext4_msg(sb, KERN_ERR,
3915                                "can't read group descriptor %d", i);
3916                         db_count = i;
3917                         goto failed_mount2;
3918                 }
3919         }
3920         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3921                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3922                 goto failed_mount2;
3923         }
3924
3925         sbi->s_gdb_count = db_count;
3926         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3927         spin_lock_init(&sbi->s_next_gen_lock);
3928
3929         init_timer(&sbi->s_err_report);
3930         sbi->s_err_report.function = print_daily_error_info;
3931         sbi->s_err_report.data = (unsigned long) sb;
3932
3933         /* Register extent status tree shrinker */
3934         if (ext4_es_register_shrinker(sbi))
3935                 goto failed_mount3;
3936
3937         sbi->s_stripe = ext4_get_stripe_size(sbi);
3938         sbi->s_extent_max_zeroout_kb = 32;
3939
3940         /*
3941          * set up enough so that it can read an inode
3942          */
3943         if (!test_opt(sb, NOLOAD) &&
3944             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3945                 sb->s_op = &ext4_sops;
3946         else
3947                 sb->s_op = &ext4_nojournal_sops;
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 no_journal:
4037         if (ext4_mballoc_ready) {
4038                 sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
4039                 if (!sbi->s_mb_cache) {
4040                         ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4041                         goto failed_mount_wq;
4042                 }
4043         }
4044
4045         /*
4046          * Get the # of file system overhead blocks from the
4047          * superblock if present.
4048          */
4049         if (es->s_overhead_clusters)
4050                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4051         else {
4052                 err = ext4_calculate_overhead(sb);
4053                 if (err)
4054                         goto failed_mount_wq;
4055         }
4056
4057         /*
4058          * The maximum number of concurrent works can be high and
4059          * concurrency isn't really necessary.  Limit it to 1.
4060          */
4061         EXT4_SB(sb)->rsv_conversion_wq =
4062                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4063         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4064                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4065                 ret = -ENOMEM;
4066                 goto failed_mount4;
4067         }
4068
4069         /*
4070          * The jbd2_journal_load will have done any necessary log recovery,
4071          * so we can safely mount the rest of the filesystem now.
4072          */
4073
4074         root = ext4_iget(sb, EXT4_ROOT_INO);
4075         if (IS_ERR(root)) {
4076                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4077                 ret = PTR_ERR(root);
4078                 root = NULL;
4079                 goto failed_mount4;
4080         }
4081         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4082                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4083                 iput(root);
4084                 goto failed_mount4;
4085         }
4086         sb->s_root = d_make_root(root);
4087         if (!sb->s_root) {
4088                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4089                 ret = -ENOMEM;
4090                 goto failed_mount4;
4091         }
4092
4093         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4094                 sb->s_flags |= MS_RDONLY;
4095
4096         /* determine the minimum size of new large inodes, if present */
4097         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4098                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4099                                                      EXT4_GOOD_OLD_INODE_SIZE;
4100                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4101                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4102                         if (sbi->s_want_extra_isize <
4103                             le16_to_cpu(es->s_want_extra_isize))
4104                                 sbi->s_want_extra_isize =
4105                                         le16_to_cpu(es->s_want_extra_isize);
4106                         if (sbi->s_want_extra_isize <
4107                             le16_to_cpu(es->s_min_extra_isize))
4108                                 sbi->s_want_extra_isize =
4109                                         le16_to_cpu(es->s_min_extra_isize);
4110                 }
4111         }
4112         /* Check if enough inode space is available */
4113         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4114                                                         sbi->s_inode_size) {
4115                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4116                                                        EXT4_GOOD_OLD_INODE_SIZE;
4117                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4118                          "available");
4119         }
4120
4121         err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4122         if (err) {
4123                 ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4124                          "reserved pool", ext4_calculate_resv_clusters(sb));
4125                 goto failed_mount4a;
4126         }
4127
4128         err = ext4_setup_system_zone(sb);
4129         if (err) {
4130                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4131                          "zone (%d)", err);
4132                 goto failed_mount4a;
4133         }
4134
4135         ext4_ext_init(sb);
4136         err = ext4_mb_init(sb);
4137         if (err) {
4138                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4139                          err);
4140                 goto failed_mount5;
4141         }
4142
4143         block = ext4_count_free_clusters(sb);
4144         ext4_free_blocks_count_set(sbi->s_es,
4145                                    EXT4_C2B(sbi, block));
4146         err = percpu_counter_init(&sbi->s_freeclusters_counter, block);
4147         if (!err) {
4148                 unsigned long freei = ext4_count_free_inodes(sb);
4149                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4150                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei);
4151         }
4152         if (!err)
4153                 err = percpu_counter_init(&sbi->s_dirs_counter,
4154                                           ext4_count_dirs(sb));
4155         if (!err)
4156                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
4157         if (err) {
4158                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4159                 goto failed_mount6;
4160         }
4161
4162         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
4163                 if (!ext4_fill_flex_info(sb)) {
4164                         ext4_msg(sb, KERN_ERR,
4165                                "unable to initialize "
4166                                "flex_bg meta info!");
4167                         goto failed_mount6;
4168                 }
4169
4170         err = ext4_register_li_request(sb, first_not_zeroed);
4171         if (err)
4172                 goto failed_mount6;
4173
4174         sbi->s_kobj.kset = ext4_kset;
4175         init_completion(&sbi->s_kobj_unregister);
4176         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4177                                    "%s", sb->s_id);
4178         if (err)
4179                 goto failed_mount7;
4180
4181 #ifdef CONFIG_QUOTA
4182         /* Enable quota usage during mount. */
4183         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4184             !(sb->s_flags & MS_RDONLY)) {
4185                 err = ext4_enable_quotas(sb);
4186                 if (err)
4187                         goto failed_mount8;
4188         }
4189 #endif  /* CONFIG_QUOTA */
4190
4191         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4192         ext4_orphan_cleanup(sb, es);
4193         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4194         if (needs_recovery) {
4195                 ext4_msg(sb, KERN_INFO, "recovery complete");
4196                 ext4_mark_recovery_complete(sb, es);
4197         }
4198         if (EXT4_SB(sb)->s_journal) {
4199                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4200                         descr = " journalled data mode";
4201                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4202                         descr = " ordered data mode";
4203                 else
4204                         descr = " writeback data mode";
4205         } else
4206                 descr = "out journal";
4207
4208         if (test_opt(sb, DISCARD)) {
4209                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4210                 if (!blk_queue_discard(q))
4211                         ext4_msg(sb, KERN_WARNING,
4212                                  "mounting with \"discard\" option, but "
4213                                  "the device does not support discard");
4214         }
4215
4216         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4217                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4218                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4219
4220         if (es->s_error_count)
4221                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4222
4223         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4224         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4225         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4226         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4227
4228         kfree(orig_data);
4229         return 0;
4230
4231 cantfind_ext4:
4232         if (!silent)
4233                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4234         goto failed_mount;
4235
4236 #ifdef CONFIG_QUOTA
4237 failed_mount8:
4238         kobject_del(&sbi->s_kobj);
4239 #endif
4240 failed_mount7:
4241         ext4_unregister_li_request(sb);
4242 failed_mount6:
4243         ext4_mb_release(sb);
4244         if (sbi->s_flex_groups)
4245                 ext4_kvfree(sbi->s_flex_groups);
4246         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4247         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4248         percpu_counter_destroy(&sbi->s_dirs_counter);
4249         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4250 failed_mount5:
4251         ext4_ext_release(sb);
4252         ext4_release_system_zone(sb);
4253 failed_mount4a:
4254         dput(sb->s_root);
4255         sb->s_root = NULL;
4256 failed_mount4:
4257         ext4_msg(sb, KERN_ERR, "mount failed");
4258         if (EXT4_SB(sb)->rsv_conversion_wq)
4259                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4260 failed_mount_wq:
4261         if (sbi->s_journal) {
4262                 jbd2_journal_destroy(sbi->s_journal);
4263                 sbi->s_journal = NULL;
4264         }
4265         ext4_es_unregister_shrinker(sbi);
4266 failed_mount3:
4267         del_timer_sync(&sbi->s_err_report);
4268         if (sbi->s_mmp_tsk)
4269                 kthread_stop(sbi->s_mmp_tsk);
4270 failed_mount2:
4271         for (i = 0; i < db_count; i++)
4272                 brelse(sbi->s_group_desc[i]);
4273         ext4_kvfree(sbi->s_group_desc);
4274 failed_mount:
4275         if (sbi->s_chksum_driver)
4276                 crypto_free_shash(sbi->s_chksum_driver);
4277         if (sbi->s_proc) {
4278                 remove_proc_entry("options", sbi->s_proc);
4279                 remove_proc_entry(sb->s_id, ext4_proc_root);
4280         }
4281 #ifdef CONFIG_QUOTA
4282         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4283                 kfree(sbi->s_qf_names[i]);
4284 #endif
4285         ext4_blkdev_remove(sbi);
4286         brelse(bh);
4287 out_fail:
4288         sb->s_fs_info = NULL;
4289         kfree(sbi->s_blockgroup_lock);
4290         kfree(sbi);
4291 out_free_orig:
4292         kfree(orig_data);
4293         return err ? err : ret;
4294 }
4295
4296 /*
4297  * Setup any per-fs journal parameters now.  We'll do this both on
4298  * initial mount, once the journal has been initialised but before we've
4299  * done any recovery; and again on any subsequent remount.
4300  */
4301 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4302 {
4303         struct ext4_sb_info *sbi = EXT4_SB(sb);
4304
4305         journal->j_commit_interval = sbi->s_commit_interval;
4306         journal->j_min_batch_time = sbi->s_min_batch_time;
4307         journal->j_max_batch_time = sbi->s_max_batch_time;
4308
4309         write_lock(&journal->j_state_lock);
4310         if (test_opt(sb, BARRIER))
4311                 journal->j_flags |= JBD2_BARRIER;
4312         else
4313                 journal->j_flags &= ~JBD2_BARRIER;
4314         if (test_opt(sb, DATA_ERR_ABORT))
4315                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4316         else
4317                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4318         write_unlock(&journal->j_state_lock);
4319 }
4320
4321 static journal_t *ext4_get_journal(struct super_block *sb,
4322                                    unsigned int journal_inum)
4323 {
4324         struct inode *journal_inode;
4325         journal_t *journal;
4326
4327         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4328
4329         /* First, test for the existence of a valid inode on disk.  Bad
4330          * things happen if we iget() an unused inode, as the subsequent
4331          * iput() will try to delete it. */
4332
4333         journal_inode = ext4_iget(sb, journal_inum);
4334         if (IS_ERR(journal_inode)) {
4335                 ext4_msg(sb, KERN_ERR, "no journal found");
4336                 return NULL;
4337         }
4338         if (!journal_inode->i_nlink) {
4339                 make_bad_inode(journal_inode);
4340                 iput(journal_inode);
4341                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4342                 return NULL;
4343         }
4344
4345         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4346                   journal_inode, journal_inode->i_size);
4347         if (!S_ISREG(journal_inode->i_mode)) {
4348                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4349                 iput(journal_inode);
4350                 return NULL;
4351         }
4352
4353         journal = jbd2_journal_init_inode(journal_inode);
4354         if (!journal) {
4355                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4356                 iput(journal_inode);
4357                 return NULL;
4358         }
4359         journal->j_private = sb;
4360         ext4_init_journal_params(sb, journal);
4361         return journal;
4362 }
4363
4364 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4365                                        dev_t j_dev)
4366 {
4367         struct buffer_head *bh;
4368         journal_t *journal;
4369         ext4_fsblk_t start;
4370         ext4_fsblk_t len;
4371         int hblock, blocksize;
4372         ext4_fsblk_t sb_block;
4373         unsigned long offset;
4374         struct ext4_super_block *es;
4375         struct block_device *bdev;
4376
4377         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4378
4379         bdev = ext4_blkdev_get(j_dev, sb);
4380         if (bdev == NULL)
4381                 return NULL;
4382
4383         blocksize = sb->s_blocksize;
4384         hblock = bdev_logical_block_size(bdev);
4385         if (blocksize < hblock) {
4386                 ext4_msg(sb, KERN_ERR,
4387                         "blocksize too small for journal device");
4388                 goto out_bdev;
4389         }
4390
4391         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4392         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4393         set_blocksize(bdev, blocksize);
4394         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4395                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4396                        "external journal");
4397                 goto out_bdev;
4398         }
4399
4400         es = (struct ext4_super_block *) (bh->b_data + offset);
4401         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4402             !(le32_to_cpu(es->s_feature_incompat) &
4403               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4404                 ext4_msg(sb, KERN_ERR, "external journal has "
4405                                         "bad superblock");
4406                 brelse(bh);
4407                 goto out_bdev;
4408         }
4409
4410         if ((le32_to_cpu(es->s_feature_ro_compat) &
4411              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4412             es->s_checksum != ext4_superblock_csum(sb, es)) {
4413                 ext4_msg(sb, KERN_ERR, "external journal has "
4414                                        "corrupt superblock");
4415                 brelse(bh);
4416                 goto out_bdev;
4417         }
4418
4419         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4420                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4421                 brelse(bh);
4422                 goto out_bdev;
4423         }
4424
4425         len = ext4_blocks_count(es);
4426         start = sb_block + 1;
4427         brelse(bh);     /* we're done with the superblock */
4428
4429         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4430                                         start, len, blocksize);
4431         if (!journal) {
4432                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4433                 goto out_bdev;
4434         }
4435         journal->j_private = sb;
4436         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4437         wait_on_buffer(journal->j_sb_buffer);
4438         if (!buffer_uptodate(journal->j_sb_buffer)) {
4439                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4440                 goto out_journal;
4441         }
4442         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4443                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4444                                         "user (unsupported) - %d",
4445                         be32_to_cpu(journal->j_superblock->s_nr_users));
4446                 goto out_journal;
4447         }
4448         EXT4_SB(sb)->journal_bdev = bdev;
4449         ext4_init_journal_params(sb, journal);
4450         return journal;
4451
4452 out_journal:
4453         jbd2_journal_destroy(journal);
4454 out_bdev:
4455         ext4_blkdev_put(bdev);
4456         return NULL;
4457 }
4458
4459 static int ext4_load_journal(struct super_block *sb,
4460                              struct ext4_super_block *es,
4461                              unsigned long journal_devnum)
4462 {
4463         journal_t *journal;
4464         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4465         dev_t journal_dev;
4466         int err = 0;
4467         int really_read_only;
4468
4469         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4470
4471         if (journal_devnum &&
4472             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4473                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4474                         "numbers have changed");
4475                 journal_dev = new_decode_dev(journal_devnum);
4476         } else
4477                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4478
4479         really_read_only = bdev_read_only(sb->s_bdev);
4480
4481         /*
4482          * Are we loading a blank journal or performing recovery after a
4483          * crash?  For recovery, we need to check in advance whether we
4484          * can get read-write access to the device.
4485          */
4486         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4487                 if (sb->s_flags & MS_RDONLY) {
4488                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4489                                         "required on readonly filesystem");
4490                         if (really_read_only) {
4491                                 ext4_msg(sb, KERN_ERR, "write access "
4492                                         "unavailable, cannot proceed");
4493                                 return -EROFS;
4494                         }
4495                         ext4_msg(sb, KERN_INFO, "write access will "
4496                                "be enabled during recovery");
4497                 }
4498         }
4499
4500         if (journal_inum && journal_dev) {
4501                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4502                        "and inode journals!");
4503                 return -EINVAL;
4504         }
4505
4506         if (journal_inum) {
4507                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4508                         return -EINVAL;
4509         } else {
4510                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4511                         return -EINVAL;
4512         }
4513
4514         if (!(journal->j_flags & JBD2_BARRIER))
4515                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4516
4517         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4518                 err = jbd2_journal_wipe(journal, !really_read_only);
4519         if (!err) {
4520                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4521                 if (save)
4522                         memcpy(save, ((char *) es) +
4523                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4524                 err = jbd2_journal_load(journal);
4525                 if (save)
4526                         memcpy(((char *) es) + EXT4_S_ERR_START,
4527                                save, EXT4_S_ERR_LEN);
4528                 kfree(save);
4529         }
4530
4531         if (err) {
4532                 ext4_msg(sb, KERN_ERR, "error loading journal");
4533                 jbd2_journal_destroy(journal);
4534                 return err;
4535         }
4536
4537         EXT4_SB(sb)->s_journal = journal;
4538         ext4_clear_journal_err(sb, es);
4539
4540         if (!really_read_only && journal_devnum &&
4541             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4542                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4543
4544                 /* Make sure we flush the recovery flag to disk. */
4545                 ext4_commit_super(sb, 1);
4546         }
4547
4548         return 0;
4549 }
4550
4551 static int ext4_commit_super(struct super_block *sb, int sync)
4552 {
4553         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4554         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4555         int error = 0;
4556
4557         if (!sbh || block_device_ejected(sb))
4558                 return error;
4559         if (buffer_write_io_error(sbh)) {
4560                 /*
4561                  * Oh, dear.  A previous attempt to write the
4562                  * superblock failed.  This could happen because the
4563                  * USB device was yanked out.  Or it could happen to
4564                  * be a transient write error and maybe the block will
4565                  * be remapped.  Nothing we can do but to retry the
4566                  * write and hope for the best.
4567                  */
4568                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4569                        "superblock detected");
4570                 clear_buffer_write_io_error(sbh);
4571                 set_buffer_uptodate(sbh);
4572         }
4573         /*
4574          * If the file system is mounted read-only, don't update the
4575          * superblock write time.  This avoids updating the superblock
4576          * write time when we are mounting the root file system
4577          * read/only but we need to replay the journal; at that point,
4578          * for people who are east of GMT and who make their clock
4579          * tick in localtime for Windows bug-for-bug compatibility,
4580          * the clock is set in the future, and this will cause e2fsck
4581          * to complain and force a full file system check.
4582          */
4583         if (!(sb->s_flags & MS_RDONLY))
4584                 es->s_wtime = cpu_to_le32(get_seconds());
4585         if (sb->s_bdev->bd_part)
4586                 es->s_kbytes_written =
4587                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4588                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4589                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4590         else
4591                 es->s_kbytes_written =
4592                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4593         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4594                 ext4_free_blocks_count_set(es,
4595                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4596                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4597         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4598                 es->s_free_inodes_count =
4599                         cpu_to_le32(percpu_counter_sum_positive(
4600                                 &EXT4_SB(sb)->s_freeinodes_counter));
4601         BUFFER_TRACE(sbh, "marking dirty");
4602         ext4_superblock_csum_set(sb);
4603         mark_buffer_dirty(sbh);
4604         if (sync) {
4605                 error = sync_dirty_buffer(sbh);
4606                 if (error)
4607                         return error;
4608
4609                 error = buffer_write_io_error(sbh);
4610                 if (error) {
4611                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4612                                "superblock");
4613                         clear_buffer_write_io_error(sbh);
4614                         set_buffer_uptodate(sbh);
4615                 }
4616         }
4617         return error;
4618 }
4619
4620 /*
4621  * Have we just finished recovery?  If so, and if we are mounting (or
4622  * remounting) the filesystem readonly, then we will end up with a
4623  * consistent fs on disk.  Record that fact.
4624  */
4625 static void ext4_mark_recovery_complete(struct super_block *sb,
4626                                         struct ext4_super_block *es)
4627 {
4628         journal_t *journal = EXT4_SB(sb)->s_journal;
4629
4630         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4631                 BUG_ON(journal != NULL);
4632                 return;
4633         }
4634         jbd2_journal_lock_updates(journal);
4635         if (jbd2_journal_flush(journal) < 0)
4636                 goto out;
4637
4638         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4639             sb->s_flags & MS_RDONLY) {
4640                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4641                 ext4_commit_super(sb, 1);
4642         }
4643
4644 out:
4645         jbd2_journal_unlock_updates(journal);
4646 }
4647
4648 /*
4649  * If we are mounting (or read-write remounting) a filesystem whose journal
4650  * has recorded an error from a previous lifetime, move that error to the
4651  * main filesystem now.
4652  */
4653 static void ext4_clear_journal_err(struct super_block *sb,
4654                                    struct ext4_super_block *es)
4655 {
4656         journal_t *journal;
4657         int j_errno;
4658         const char *errstr;
4659
4660         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4661
4662         journal = EXT4_SB(sb)->s_journal;
4663
4664         /*
4665          * Now check for any error status which may have been recorded in the
4666          * journal by a prior ext4_error() or ext4_abort()
4667          */
4668
4669         j_errno = jbd2_journal_errno(journal);
4670         if (j_errno) {
4671                 char nbuf[16];
4672
4673                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4674                 ext4_warning(sb, "Filesystem error recorded "
4675                              "from previous mount: %s", errstr);
4676                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4677
4678                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4679                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4680                 ext4_commit_super(sb, 1);
4681
4682                 jbd2_journal_clear_err(journal);
4683                 jbd2_journal_update_sb_errno(journal);
4684         }
4685 }
4686
4687 /*
4688  * Force the running and committing transactions to commit,
4689  * and wait on the commit.
4690  */
4691 int ext4_force_commit(struct super_block *sb)
4692 {
4693         journal_t *journal;
4694
4695         if (sb->s_flags & MS_RDONLY)
4696                 return 0;
4697
4698         journal = EXT4_SB(sb)->s_journal;
4699         return ext4_journal_force_commit(journal);
4700 }
4701
4702 static int ext4_sync_fs(struct super_block *sb, int wait)
4703 {
4704         int ret = 0;
4705         tid_t target;
4706         bool needs_barrier = false;
4707         struct ext4_sb_info *sbi = EXT4_SB(sb);
4708
4709         trace_ext4_sync_fs(sb, wait);
4710         flush_workqueue(sbi->rsv_conversion_wq);
4711         /*
4712          * Writeback quota in non-journalled quota case - journalled quota has
4713          * no dirty dquots
4714          */
4715         dquot_writeback_dquots(sb, -1);
4716         /*
4717          * Data writeback is possible w/o journal transaction, so barrier must
4718          * being sent at the end of the function. But we can skip it if
4719          * transaction_commit will do it for us.
4720          */
4721         target = jbd2_get_latest_transaction(sbi->s_journal);
4722         if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4723             !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4724                 needs_barrier = true;
4725
4726         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4727                 if (wait)
4728                         ret = jbd2_log_wait_commit(sbi->s_journal, target);
4729         }
4730         if (needs_barrier) {
4731                 int err;
4732                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4733                 if (!ret)
4734                         ret = err;
4735         }
4736
4737         return ret;
4738 }
4739
4740 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait)
4741 {
4742         int ret = 0;
4743
4744         trace_ext4_sync_fs(sb, wait);
4745         flush_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4746         dquot_writeback_dquots(sb, -1);
4747         if (wait && test_opt(sb, BARRIER))
4748                 ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4749
4750         return ret;
4751 }
4752
4753 /*
4754  * LVM calls this function before a (read-only) snapshot is created.  This
4755  * gives us a chance to flush the journal completely and mark the fs clean.
4756  *
4757  * Note that only this function cannot bring a filesystem to be in a clean
4758  * state independently. It relies on upper layer to stop all data & metadata
4759  * modifications.
4760  */
4761 static int ext4_freeze(struct super_block *sb)
4762 {
4763         int error = 0;
4764         journal_t *journal;
4765
4766         if (sb->s_flags & MS_RDONLY)
4767                 return 0;
4768
4769         journal = EXT4_SB(sb)->s_journal;
4770
4771         /* Now we set up the journal barrier. */
4772         jbd2_journal_lock_updates(journal);
4773
4774         /*
4775          * Don't clear the needs_recovery flag if we failed to flush
4776          * the journal.
4777          */
4778         error = jbd2_journal_flush(journal);
4779         if (error < 0)
4780                 goto out;
4781
4782         /* Journal blocked and flushed, clear needs_recovery flag. */
4783         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4784         error = ext4_commit_super(sb, 1);
4785 out:
4786         /* we rely on upper layer to stop further updates */
4787         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4788         return error;
4789 }
4790
4791 /*
4792  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4793  * flag here, even though the filesystem is not technically dirty yet.
4794  */
4795 static int ext4_unfreeze(struct super_block *sb)
4796 {
4797         if (sb->s_flags & MS_RDONLY)
4798                 return 0;
4799
4800         /* Reset the needs_recovery flag before the fs is unlocked. */
4801         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4802         ext4_commit_super(sb, 1);
4803         return 0;
4804 }
4805
4806 /*
4807  * Structure to save mount options for ext4_remount's benefit
4808  */
4809 struct ext4_mount_options {
4810         unsigned long s_mount_opt;
4811         unsigned long s_mount_opt2;
4812         kuid_t s_resuid;
4813         kgid_t s_resgid;
4814         unsigned long s_commit_interval;
4815         u32 s_min_batch_time, s_max_batch_time;
4816 #ifdef CONFIG_QUOTA
4817         int s_jquota_fmt;
4818         char *s_qf_names[EXT4_MAXQUOTAS];
4819 #endif
4820 };
4821
4822 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4823 {
4824         struct ext4_super_block *es;
4825         struct ext4_sb_info *sbi = EXT4_SB(sb);
4826         unsigned long old_sb_flags;
4827         struct ext4_mount_options old_opts;
4828         int enable_quota = 0;
4829         ext4_group_t g;
4830         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4831         int err = 0;
4832 #ifdef CONFIG_QUOTA
4833         int i, j;
4834 #endif
4835         char *orig_data = kstrdup(data, GFP_KERNEL);
4836
4837         /* Store the original options */
4838         old_sb_flags = sb->s_flags;
4839         old_opts.s_mount_opt = sbi->s_mount_opt;
4840         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4841         old_opts.s_resuid = sbi->s_resuid;
4842         old_opts.s_resgid = sbi->s_resgid;
4843         old_opts.s_commit_interval = sbi->s_commit_interval;
4844         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4845         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4846 #ifdef CONFIG_QUOTA
4847         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4848         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4849                 if (sbi->s_qf_names[i]) {
4850                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4851                                                          GFP_KERNEL);
4852                         if (!old_opts.s_qf_names[i]) {
4853                                 for (j = 0; j < i; j++)
4854                                         kfree(old_opts.s_qf_names[j]);
4855                                 kfree(orig_data);
4856                                 return -ENOMEM;
4857                         }
4858                 } else
4859                         old_opts.s_qf_names[i] = NULL;
4860 #endif
4861         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4862                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4863
4864         /*
4865          * Allow the "check" option to be passed as a remount option.
4866          */
4867         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4868                 err = -EINVAL;
4869                 goto restore_opts;
4870         }
4871
4872         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4873                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4874                         ext4_msg(sb, KERN_ERR, "can't mount with "
4875                                  "both data=journal and delalloc");
4876                         err = -EINVAL;
4877                         goto restore_opts;
4878                 }
4879                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4880                         ext4_msg(sb, KERN_ERR, "can't mount with "
4881                                  "both data=journal and dioread_nolock");
4882                         err = -EINVAL;
4883                         goto restore_opts;
4884                 }
4885         }
4886
4887         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4888                 ext4_abort(sb, "Abort forced by user");
4889
4890         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4891                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4892
4893         es = sbi->s_es;
4894
4895         if (sbi->s_journal) {
4896                 ext4_init_journal_params(sb, sbi->s_journal);
4897                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4898         }
4899
4900         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4901                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4902                         err = -EROFS;
4903                         goto restore_opts;
4904                 }
4905
4906                 if (*flags & MS_RDONLY) {
4907                         err = sync_filesystem(sb);
4908                         if (err < 0)
4909                                 goto restore_opts;
4910                         err = dquot_suspend(sb, -1);
4911                         if (err < 0)
4912                                 goto restore_opts;
4913
4914                         /*
4915                          * First of all, the unconditional stuff we have to do
4916                          * to disable replay of the journal when we next remount
4917                          */
4918                         sb->s_flags |= MS_RDONLY;
4919
4920                         /*
4921                          * OK, test if we are remounting a valid rw partition
4922                          * readonly, and if so set the rdonly flag and then
4923                          * mark the partition as valid again.
4924                          */
4925                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4926                             (sbi->s_mount_state & EXT4_VALID_FS))
4927                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4928
4929                         if (sbi->s_journal)
4930                                 ext4_mark_recovery_complete(sb, es);
4931                 } else {
4932                         /* Make sure we can mount this feature set readwrite */
4933                         if (!ext4_feature_set_ok(sb, 0)) {
4934                                 err = -EROFS;
4935                                 goto restore_opts;
4936                         }
4937                         /*
4938                          * Make sure the group descriptor checksums
4939                          * are sane.  If they aren't, refuse to remount r/w.
4940                          */
4941                         for (g = 0; g < sbi->s_groups_count; g++) {
4942                                 struct ext4_group_desc *gdp =
4943                                         ext4_get_group_desc(sb, g, NULL);
4944
4945                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4946                                         ext4_msg(sb, KERN_ERR,
4947                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4948                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4949                                                le16_to_cpu(gdp->bg_checksum));
4950                                         err = -EINVAL;
4951                                         goto restore_opts;
4952                                 }
4953                         }
4954
4955                         /*
4956                          * If we have an unprocessed orphan list hanging
4957                          * around from a previously readonly bdev mount,
4958                          * require a full umount/remount for now.
4959                          */
4960                         if (es->s_last_orphan) {
4961                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4962                                        "remount RDWR because of unprocessed "
4963                                        "orphan inode list.  Please "
4964                                        "umount/remount instead");
4965                                 err = -EINVAL;
4966                                 goto restore_opts;
4967                         }
4968
4969                         /*
4970                          * Mounting a RDONLY partition read-write, so reread
4971                          * and store the current valid flag.  (It may have
4972                          * been changed by e2fsck since we originally mounted
4973                          * the partition.)
4974                          */
4975                         if (sbi->s_journal)
4976                                 ext4_clear_journal_err(sb, es);
4977                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4978                         if (!ext4_setup_super(sb, es, 0))
4979                                 sb->s_flags &= ~MS_RDONLY;
4980                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4981                                                      EXT4_FEATURE_INCOMPAT_MMP))
4982                                 if (ext4_multi_mount_protect(sb,
4983                                                 le64_to_cpu(es->s_mmp_block))) {
4984                                         err = -EROFS;
4985                                         goto restore_opts;
4986                                 }
4987                         enable_quota = 1;
4988                 }
4989         }
4990
4991         /*
4992          * Reinitialize lazy itable initialization thread based on
4993          * current settings
4994          */
4995         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4996                 ext4_unregister_li_request(sb);
4997         else {
4998                 ext4_group_t first_not_zeroed;
4999                 first_not_zeroed = ext4_has_uninit_itable(sb);
5000                 ext4_register_li_request(sb, first_not_zeroed);
5001         }
5002
5003         ext4_setup_system_zone(sb);
5004         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5005                 ext4_commit_super(sb, 1);
5006
5007 #ifdef CONFIG_QUOTA
5008         /* Release old quota file names */
5009         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5010                 kfree(old_opts.s_qf_names[i]);
5011         if (enable_quota) {
5012                 if (sb_any_quota_suspended(sb))
5013                         dquot_resume(sb, -1);
5014                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
5015                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
5016                         err = ext4_enable_quotas(sb);
5017                         if (err)
5018                                 goto restore_opts;
5019                 }
5020         }
5021 #endif
5022
5023         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5024         kfree(orig_data);
5025         return 0;
5026
5027 restore_opts:
5028         sb->s_flags = old_sb_flags;
5029         sbi->s_mount_opt = old_opts.s_mount_opt;
5030         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5031         sbi->s_resuid = old_opts.s_resuid;
5032         sbi->s_resgid = old_opts.s_resgid;
5033         sbi->s_commit_interval = old_opts.s_commit_interval;
5034         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5035         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5036 #ifdef CONFIG_QUOTA
5037         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5038         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5039                 kfree(sbi->s_qf_names[i]);
5040                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5041         }
5042 #endif
5043         kfree(orig_data);
5044         return err;
5045 }
5046
5047 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5048 {
5049         struct super_block *sb = dentry->d_sb;
5050         struct ext4_sb_info *sbi = EXT4_SB(sb);
5051         struct ext4_super_block *es = sbi->s_es;
5052         ext4_fsblk_t overhead = 0, resv_blocks;
5053         u64 fsid;
5054         s64 bfree;
5055         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5056
5057         if (!test_opt(sb, MINIX_DF))
5058                 overhead = sbi->s_overhead;
5059
5060         buf->f_type = EXT4_SUPER_MAGIC;
5061         buf->f_bsize = sb->s_blocksize;
5062         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5063         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5064                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5065         /* prevent underflow in case that few free space is available */
5066         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5067         buf->f_bavail = buf->f_bfree -
5068                         (ext4_r_blocks_count(es) + resv_blocks);
5069         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5070                 buf->f_bavail = 0;
5071         buf->f_files = le32_to_cpu(es->s_inodes_count);
5072         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5073         buf->f_namelen = EXT4_NAME_LEN;
5074         fsid = le64_to_cpup((void *)es->s_uuid) ^
5075                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5076         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5077         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5078
5079         return 0;
5080 }
5081
5082 /* Helper function for writing quotas on sync - we need to start transaction
5083  * before quota file is locked for write. Otherwise the are possible deadlocks:
5084  * Process 1                         Process 2
5085  * ext4_create()                     quota_sync()
5086  *   jbd2_journal_start()                  write_dquot()
5087  *   dquot_initialize()                         down(dqio_mutex)
5088  *     down(dqio_mutex)                    jbd2_journal_start()
5089  *
5090  */
5091
5092 #ifdef CONFIG_QUOTA
5093
5094 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5095 {
5096         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5097 }
5098
5099 static int ext4_write_dquot(struct dquot *dquot)
5100 {
5101         int ret, err;
5102         handle_t *handle;
5103         struct inode *inode;
5104
5105         inode = dquot_to_inode(dquot);
5106         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5107                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5108         if (IS_ERR(handle))
5109                 return PTR_ERR(handle);
5110         ret = dquot_commit(dquot);
5111         err = ext4_journal_stop(handle);
5112         if (!ret)
5113                 ret = err;
5114         return ret;
5115 }
5116
5117 static int ext4_acquire_dquot(struct dquot *dquot)
5118 {
5119         int ret, err;
5120         handle_t *handle;
5121
5122         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5123                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5124         if (IS_ERR(handle))
5125                 return PTR_ERR(handle);
5126         ret = dquot_acquire(dquot);
5127         err = ext4_journal_stop(handle);
5128         if (!ret)
5129                 ret = err;
5130         return ret;
5131 }
5132
5133 static int ext4_release_dquot(struct dquot *dquot)
5134 {
5135         int ret, err;
5136         handle_t *handle;
5137
5138         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5139                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5140         if (IS_ERR(handle)) {
5141                 /* Release dquot anyway to avoid endless cycle in dqput() */
5142                 dquot_release(dquot);
5143                 return PTR_ERR(handle);
5144         }
5145         ret = dquot_release(dquot);
5146         err = ext4_journal_stop(handle);
5147         if (!ret)
5148                 ret = err;
5149         return ret;
5150 }
5151
5152 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5153 {
5154         struct super_block *sb = dquot->dq_sb;
5155         struct ext4_sb_info *sbi = EXT4_SB(sb);
5156
5157         /* Are we journaling quotas? */
5158         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5159             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5160                 dquot_mark_dquot_dirty(dquot);
5161                 return ext4_write_dquot(dquot);
5162         } else {
5163                 return dquot_mark_dquot_dirty(dquot);
5164         }
5165 }
5166
5167 static int ext4_write_info(struct super_block *sb, int type)
5168 {
5169         int ret, err;
5170         handle_t *handle;
5171
5172         /* Data block + inode block */
5173         handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5174         if (IS_ERR(handle))
5175                 return PTR_ERR(handle);
5176         ret = dquot_commit_info(sb, type);
5177         err = ext4_journal_stop(handle);
5178         if (!ret)
5179                 ret = err;
5180         return ret;
5181 }
5182
5183 /*
5184  * Turn on quotas during mount time - we need to find
5185  * the quota file and such...
5186  */
5187 static int ext4_quota_on_mount(struct super_block *sb, int type)
5188 {
5189         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5190                                         EXT4_SB(sb)->s_jquota_fmt, type);
5191 }
5192
5193 /*
5194  * Standard function to be called on quota_on
5195  */
5196 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5197                          struct path *path)
5198 {
5199         int err;
5200
5201         if (!test_opt(sb, QUOTA))
5202                 return -EINVAL;
5203
5204         /* Quotafile not on the same filesystem? */
5205         if (path->dentry->d_sb != sb)
5206                 return -EXDEV;
5207         /* Journaling quota? */
5208         if (EXT4_SB(sb)->s_qf_names[type]) {
5209                 /* Quotafile not in fs root? */
5210                 if (path->dentry->d_parent != sb->s_root)
5211                         ext4_msg(sb, KERN_WARNING,
5212                                 "Quota file not on filesystem root. "
5213                                 "Journaled quota will not work");
5214         }
5215
5216         /*
5217          * When we journal data on quota file, we have to flush journal to see
5218          * all updates to the file when we bypass pagecache...
5219          */
5220         if (EXT4_SB(sb)->s_journal &&
5221             ext4_should_journal_data(path->dentry->d_inode)) {
5222                 /*
5223                  * We don't need to lock updates but journal_flush() could
5224                  * otherwise be livelocked...
5225                  */
5226                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5227                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5228                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5229                 if (err)
5230                         return err;
5231         }
5232
5233         return dquot_quota_on(sb, type, format_id, path);
5234 }
5235
5236 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5237                              unsigned int flags)
5238 {
5239         int err;
5240         struct inode *qf_inode;
5241         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5242                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5243                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5244         };
5245
5246         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5247
5248         if (!qf_inums[type])
5249                 return -EPERM;
5250
5251         qf_inode = ext4_iget(sb, qf_inums[type]);
5252         if (IS_ERR(qf_inode)) {
5253                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5254                 return PTR_ERR(qf_inode);
5255         }
5256
5257         /* Don't account quota for quota files to avoid recursion */
5258         qf_inode->i_flags |= S_NOQUOTA;
5259         err = dquot_enable(qf_inode, type, format_id, flags);
5260         iput(qf_inode);
5261
5262         return err;
5263 }
5264
5265 /* Enable usage tracking for all quota types. */
5266 static int ext4_enable_quotas(struct super_block *sb)
5267 {
5268         int type, err = 0;
5269         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5270                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5271                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5272         };
5273
5274         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5275         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5276                 if (qf_inums[type]) {
5277                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5278                                                 DQUOT_USAGE_ENABLED);
5279                         if (err) {
5280                                 ext4_warning(sb,
5281                                         "Failed to enable quota tracking "
5282                                         "(type=%d, err=%d). Please run "
5283                                         "e2fsck to fix.", type, err);
5284                                 return err;
5285                         }
5286                 }
5287         }
5288         return 0;
5289 }
5290
5291 /*
5292  * quota_on function that is used when QUOTA feature is set.
5293  */
5294 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5295                                  int format_id)
5296 {
5297         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5298                 return -EINVAL;
5299
5300         /*
5301          * USAGE was enabled at mount time. Only need to enable LIMITS now.
5302          */
5303         return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5304 }
5305
5306 static int ext4_quota_off(struct super_block *sb, int type)
5307 {
5308         struct inode *inode = sb_dqopt(sb)->files[type];
5309         handle_t *handle;
5310
5311         /* Force all delayed allocation blocks to be allocated.
5312          * Caller already holds s_umount sem */
5313         if (test_opt(sb, DELALLOC))
5314                 sync_filesystem(sb);
5315
5316         if (!inode)
5317                 goto out;
5318
5319         /* Update modification times of quota files when userspace can
5320          * start looking at them */
5321         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5322         if (IS_ERR(handle))
5323                 goto out;
5324         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5325         ext4_mark_inode_dirty(handle, inode);
5326         ext4_journal_stop(handle);
5327
5328 out:
5329         return dquot_quota_off(sb, type);
5330 }
5331
5332 /*
5333  * quota_off function that is used when QUOTA feature is set.
5334  */
5335 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5336 {
5337         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5338                 return -EINVAL;
5339
5340         /* Disable only the limits. */
5341         return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5342 }
5343
5344 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5345  * acquiring the locks... As quota files are never truncated and quota code
5346  * itself serializes the operations (and no one else should touch the files)
5347  * we don't have to be afraid of races */
5348 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5349                                size_t len, loff_t off)
5350 {
5351         struct inode *inode = sb_dqopt(sb)->files[type];
5352         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5353         int offset = off & (sb->s_blocksize - 1);
5354         int tocopy;
5355         size_t toread;
5356         struct buffer_head *bh;
5357         loff_t i_size = i_size_read(inode);
5358
5359         if (off > i_size)
5360                 return 0;
5361         if (off+len > i_size)
5362                 len = i_size-off;
5363         toread = len;
5364         while (toread > 0) {
5365                 tocopy = sb->s_blocksize - offset < toread ?
5366                                 sb->s_blocksize - offset : toread;
5367                 bh = ext4_bread(NULL, inode, blk, 0);
5368                 if (IS_ERR(bh))
5369                         return PTR_ERR(bh);
5370                 if (!bh)        /* A hole? */
5371                         memset(data, 0, tocopy);
5372                 else
5373                         memcpy(data, bh->b_data+offset, tocopy);
5374                 brelse(bh);
5375                 offset = 0;
5376                 toread -= tocopy;
5377                 data += tocopy;
5378                 blk++;
5379         }
5380         return len;
5381 }
5382
5383 /* Write to quotafile (we know the transaction is already started and has
5384  * enough credits) */
5385 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5386                                 const char *data, size_t len, loff_t off)
5387 {
5388         struct inode *inode = sb_dqopt(sb)->files[type];
5389         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5390         int err, offset = off & (sb->s_blocksize - 1);
5391         struct buffer_head *bh;
5392         handle_t *handle = journal_current_handle();
5393
5394         if (EXT4_SB(sb)->s_journal && !handle) {
5395                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5396                         " cancelled because transaction is not started",
5397                         (unsigned long long)off, (unsigned long long)len);
5398                 return -EIO;
5399         }
5400         /*
5401          * Since we account only one data block in transaction credits,
5402          * then it is impossible to cross a block boundary.
5403          */
5404         if (sb->s_blocksize - offset < len) {
5405                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5406                         " cancelled because not block aligned",
5407                         (unsigned long long)off, (unsigned long long)len);
5408                 return -EIO;
5409         }
5410
5411         bh = ext4_bread(handle, inode, blk, 1);
5412         if (IS_ERR(bh))
5413                 return PTR_ERR(bh);
5414         if (!bh)
5415                 goto out;
5416         BUFFER_TRACE(bh, "get write access");
5417         err = ext4_journal_get_write_access(handle, bh);
5418         if (err) {
5419                 brelse(bh);
5420                 return err;
5421         }
5422         lock_buffer(bh);
5423         memcpy(bh->b_data+offset, data, len);
5424         flush_dcache_page(bh->b_page);
5425         unlock_buffer(bh);
5426         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5427         brelse(bh);
5428 out:
5429         if (inode->i_size < off + len) {
5430                 i_size_write(inode, off + len);
5431                 EXT4_I(inode)->i_disksize = inode->i_size;
5432                 ext4_mark_inode_dirty(handle, inode);
5433         }
5434         return len;
5435 }
5436
5437 #endif
5438
5439 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5440                        const char *dev_name, void *data)
5441 {
5442         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5443 }
5444
5445 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5446 static inline void register_as_ext2(void)
5447 {
5448         int err = register_filesystem(&ext2_fs_type);
5449         if (err)
5450                 printk(KERN_WARNING
5451                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5452 }
5453
5454 static inline void unregister_as_ext2(void)
5455 {
5456         unregister_filesystem(&ext2_fs_type);
5457 }
5458
5459 static inline int ext2_feature_set_ok(struct super_block *sb)
5460 {
5461         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5462                 return 0;
5463         if (sb->s_flags & MS_RDONLY)
5464                 return 1;
5465         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5466                 return 0;
5467         return 1;
5468 }
5469 #else
5470 static inline void register_as_ext2(void) { }
5471 static inline void unregister_as_ext2(void) { }
5472 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5473 #endif
5474
5475 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5476 static inline void register_as_ext3(void)
5477 {
5478         int err = register_filesystem(&ext3_fs_type);
5479         if (err)
5480                 printk(KERN_WARNING
5481                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5482 }
5483
5484 static inline void unregister_as_ext3(void)
5485 {
5486         unregister_filesystem(&ext3_fs_type);
5487 }
5488
5489 static inline int ext3_feature_set_ok(struct super_block *sb)
5490 {
5491         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5492                 return 0;
5493         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5494                 return 0;
5495         if (sb->s_flags & MS_RDONLY)
5496                 return 1;
5497         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5498                 return 0;
5499         return 1;
5500 }
5501 #else
5502 static inline void register_as_ext3(void) { }
5503 static inline void unregister_as_ext3(void) { }
5504 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5505 #endif
5506
5507 static struct file_system_type ext4_fs_type = {
5508         .owner          = THIS_MODULE,
5509         .name           = "ext4",
5510         .mount          = ext4_mount,
5511         .kill_sb        = kill_block_super,
5512         .fs_flags       = FS_REQUIRES_DEV,
5513 };
5514 MODULE_ALIAS_FS("ext4");
5515
5516 static int __init ext4_init_feat_adverts(void)
5517 {
5518         struct ext4_features *ef;
5519         int ret = -ENOMEM;
5520
5521         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5522         if (!ef)
5523                 goto out;
5524
5525         ef->f_kobj.kset = ext4_kset;
5526         init_completion(&ef->f_kobj_unregister);
5527         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5528                                    "features");
5529         if (ret) {
5530                 kfree(ef);
5531                 goto out;
5532         }
5533
5534         ext4_feat = ef;
5535         ret = 0;
5536 out:
5537         return ret;
5538 }
5539
5540 static void ext4_exit_feat_adverts(void)
5541 {
5542         kobject_put(&ext4_feat->f_kobj);
5543         wait_for_completion(&ext4_feat->f_kobj_unregister);
5544         kfree(ext4_feat);
5545 }
5546
5547 /* Shared across all ext4 file systems */
5548 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5549 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5550
5551 static int __init ext4_init_fs(void)
5552 {
5553         int i, err;
5554
5555         ext4_li_info = NULL;
5556         mutex_init(&ext4_li_mtx);
5557
5558         /* Build-time check for flags consistency */
5559         ext4_check_flag_values();
5560
5561         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5562                 mutex_init(&ext4__aio_mutex[i]);
5563                 init_waitqueue_head(&ext4__ioend_wq[i]);
5564         }
5565
5566         err = ext4_init_es();
5567         if (err)
5568                 return err;
5569
5570         err = ext4_init_pageio();
5571         if (err)
5572                 goto out7;
5573
5574         err = ext4_init_system_zone();
5575         if (err)
5576                 goto out6;
5577         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5578         if (!ext4_kset) {
5579                 err = -ENOMEM;
5580                 goto out5;
5581         }
5582         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5583
5584         err = ext4_init_feat_adverts();
5585         if (err)
5586                 goto out4;
5587
5588         err = ext4_init_mballoc();
5589         if (err)
5590                 goto out2;
5591         else
5592                 ext4_mballoc_ready = 1;
5593         err = init_inodecache();
5594         if (err)
5595                 goto out1;
5596         register_as_ext3();
5597         register_as_ext2();
5598         err = register_filesystem(&ext4_fs_type);
5599         if (err)
5600                 goto out;
5601
5602         return 0;
5603 out:
5604         unregister_as_ext2();
5605         unregister_as_ext3();
5606         destroy_inodecache();
5607 out1:
5608         ext4_mballoc_ready = 0;
5609         ext4_exit_mballoc();
5610 out2:
5611         ext4_exit_feat_adverts();
5612 out4:
5613         if (ext4_proc_root)
5614                 remove_proc_entry("fs/ext4", NULL);
5615         kset_unregister(ext4_kset);
5616 out5:
5617         ext4_exit_system_zone();
5618 out6:
5619         ext4_exit_pageio();
5620 out7:
5621         ext4_exit_es();
5622
5623         return err;
5624 }
5625
5626 static void __exit ext4_exit_fs(void)
5627 {
5628         ext4_destroy_lazyinit_thread();
5629         unregister_as_ext2();
5630         unregister_as_ext3();
5631         unregister_filesystem(&ext4_fs_type);
5632         destroy_inodecache();
5633         ext4_exit_mballoc();
5634         ext4_exit_feat_adverts();
5635         remove_proc_entry("fs/ext4", NULL);
5636         kset_unregister(ext4_kset);
5637         ext4_exit_system_zone();
5638         ext4_exit_pageio();
5639         ext4_exit_es();
5640 }
5641
5642 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5643 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5644 MODULE_LICENSE("GPL");
5645 module_init(ext4_init_fs)
5646 module_exit(ext4_exit_fs)