fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/jbd2.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/ctype.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <linux/cleancache.h>
  42 #include <asm/uaccess.h>
  43
  44 #include <linux/kthread.h>
  45 #include <linux/freezer.h>
  46
  47 #include "ext4.h"
  48 #include "ext4_extents.h"       /* Needed for trace points definition */
  49 #include "ext4_jbd2.h"
  50 #include "xattr.h"
  51 #include "acl.h"
  52 #include "mballoc.h"
  53
  54 #define CREATE_TRACE_POINTS
  55 #include <trace/events/ext4.h>
  56
  57 static struct proc_dir_entry *ext4_proc_root;
  58 static struct kset *ext4_kset;
  59 static struct ext4_lazy_init *ext4_li_info;
  60 static struct mutex ext4_li_mtx;
  61 static struct ext4_features *ext4_feat;
  62 static int ext4_mballoc_ready;
  63
  64 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  65                              unsigned long journal_devnum);
  66 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  67 static int ext4_commit_super(struct super_block *sb, int sync);
  68 static void ext4_mark_recovery_complete(struct super_block *sb,
  69                                         struct ext4_super_block *es);
  70 static void ext4_clear_journal_err(struct super_block *sb,
  71                                    struct ext4_super_block *es);
  72 static int ext4_sync_fs(struct super_block *sb, int wait);
  73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  75 static int ext4_unfreeze(struct super_block *sb);
  76 static int ext4_freeze(struct super_block *sb);
  77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  78                        const char *dev_name, void *data);
  79 static inline int ext2_feature_set_ok(struct super_block *sb);
  80 static inline int ext3_feature_set_ok(struct super_block *sb);
  81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  82 static void ext4_destroy_lazyinit_thread(void);
  83 static void ext4_unregister_li_request(struct super_block *sb);
  84 static void ext4_clear_request_list(void);
  85 static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
  86
  87 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  88 static struct file_system_type ext2_fs_type = {
  89         .owner          = THIS_MODULE,
  90         .name           = "ext2",
  91         .mount          = ext4_mount,
  92         .kill_sb        = kill_block_super,
  93         .fs_flags       = FS_REQUIRES_DEV,
  94 };
  95 MODULE_ALIAS_FS("ext2");
  96 MODULE_ALIAS("ext2");
  97 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  98 #else
  99 #define IS_EXT2_SB(sb) (0)
 100 #endif
 101
 102
 103 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 104 static struct file_system_type ext3_fs_type = {
 105         .owner          = THIS_MODULE,
 106         .name           = "ext3",
 107         .mount          = ext4_mount,
 108         .kill_sb        = kill_block_super,
 109         .fs_flags       = FS_REQUIRES_DEV,
 110 };
 111 MODULE_ALIAS_FS("ext3");
 112 MODULE_ALIAS("ext3");
 113 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 114 #else
 115 #define IS_EXT3_SB(sb) (0)
 116 #endif
 117
 118 static int ext4_verify_csum_type(struct super_block *sb,
 119                                  struct ext4_super_block *es)
 120 {
 121         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 122                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 123                 return 1;
 124
 125         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 126 }
 127
 128 static __le32 ext4_superblock_csum(struct super_block *sb,
 129                                    struct ext4_super_block *es)
 130 {
 131         struct ext4_sb_info *sbi = EXT4_SB(sb);
 132         int offset = offsetof(struct ext4_super_block, s_checksum);
 133         __u32 csum;
 134
 135         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 136
 137         return cpu_to_le32(csum);
 138 }
 139
 140 static int ext4_superblock_csum_verify(struct super_block *sb,
 141                                        struct ext4_super_block *es)
 142 {
 143         if (!ext4_has_metadata_csum(sb))
 144                 return 1;
 145
 146         return es->s_checksum == ext4_superblock_csum(sb, es);
 147 }
 148
 149 void ext4_superblock_csum_set(struct super_block *sb)
 150 {
 151         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 152
 153         if (!ext4_has_metadata_csum(sb))
 154                 return;
 155
 156         es->s_checksum = ext4_superblock_csum(sb, es);
 157 }
 158
 159 void *ext4_kvmalloc(size_t size, gfp_t flags)
 160 {
 161         void *ret;
 162
 163         ret = kmalloc(size, flags | __GFP_NOWARN);
 164         if (!ret)
 165                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 166         return ret;
 167 }
 168
 169 void *ext4_kvzalloc(size_t size, gfp_t flags)
 170 {
 171         void *ret;
 172
 173         ret = kzalloc(size, flags | __GFP_NOWARN);
 174         if (!ret)
 175                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 176         return ret;
 177 }
 178
 179 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 180                                struct ext4_group_desc *bg)
 181 {
 182         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 183                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 184                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 185 }
 186
 187 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 188                                struct ext4_group_desc *bg)
 189 {
 190         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 191                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 192                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 193 }
 194
 195 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 196                               struct ext4_group_desc *bg)
 197 {
 198         return le32_to_cpu(bg->bg_inode_table_lo) |
 199                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 200                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 201 }
 202
 203 __u32 ext4_free_group_clusters(struct super_block *sb,
 204                                struct ext4_group_desc *bg)
 205 {
 206         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 207                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 208                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 209 }
 210
 211 __u32 ext4_free_inodes_count(struct super_block *sb,
 212                               struct ext4_group_desc *bg)
 213 {
 214         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 215                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 216                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 217 }
 218
 219 __u32 ext4_used_dirs_count(struct super_block *sb,
 220                               struct ext4_group_desc *bg)
 221 {
 222         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 223                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 224                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 225 }
 226
 227 __u32 ext4_itable_unused_count(struct super_block *sb,
 228                               struct ext4_group_desc *bg)
 229 {
 230         return le16_to_cpu(bg->bg_itable_unused_lo) |
 231                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 232                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 233 }
 234
 235 void ext4_block_bitmap_set(struct super_block *sb,
 236                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 237 {
 238         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 239         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 240                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 241 }
 242
 243 void ext4_inode_bitmap_set(struct super_block *sb,
 244                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 245 {
 246         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 247         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 248                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 249 }
 250
 251 void ext4_inode_table_set(struct super_block *sb,
 252                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 253 {
 254         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 255         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 256                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 257 }
 258
 259 void ext4_free_group_clusters_set(struct super_block *sb,
 260                                   struct ext4_group_desc *bg, __u32 count)
 261 {
 262         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 263         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 264                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 265 }
 266
 267 void ext4_free_inodes_set(struct super_block *sb,
 268                           struct ext4_group_desc *bg, __u32 count)
 269 {
 270         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 271         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 272                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 273 }
 274
 275 void ext4_used_dirs_set(struct super_block *sb,
 276                           struct ext4_group_desc *bg, __u32 count)
 277 {
 278         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 279         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 280                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 281 }
 282
 283 void ext4_itable_unused_set(struct super_block *sb,
 284                           struct ext4_group_desc *bg, __u32 count)
 285 {
 286         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 287         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 288                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 289 }
 290
 291
 292 static void __save_error_info(struct super_block *sb, const char *func,
 293                             unsigned int line)
 294 {
 295         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 296
 297         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 298         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 299         es->s_last_error_time = cpu_to_le32(get_seconds());
 300         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 301         es->s_last_error_line = cpu_to_le32(line);
 302         if (!es->s_first_error_time) {
 303                 es->s_first_error_time = es->s_last_error_time;
 304                 strncpy(es->s_first_error_func, func,
 305                         sizeof(es->s_first_error_func));
 306                 es->s_first_error_line = cpu_to_le32(line);
 307                 es->s_first_error_ino = es->s_last_error_ino;
 308                 es->s_first_error_block = es->s_last_error_block;
 309         }
 310         /*
 311          * Start the daily error reporting function if it hasn't been
 312          * started already
 313          */
 314         if (!es->s_error_count)
 315                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 316         le32_add_cpu(&es->s_error_count, 1);
 317 }
 318
 319 static void save_error_info(struct super_block *sb, const char *func,
 320                             unsigned int line)
 321 {
 322         __save_error_info(sb, func, line);
 323         ext4_commit_super(sb, 1);
 324 }
 325
 326 /*
 327  * The del_gendisk() function uninitializes the disk-specific data
 328  * structures, including the bdi structure, without telling anyone
 329  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 330  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 331  * This is a kludge to prevent these oops until we can put in a proper
 332  * hook in del_gendisk() to inform the VFS and file system layers.
 333  */
 334 static int block_device_ejected(struct super_block *sb)
 335 {
 336         struct inode *bd_inode = sb->s_bdev->bd_inode;
 337         struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
 338
 339         return bdi->dev == NULL;
 340 }
 341
 342 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 343 {
 344         struct super_block              *sb = journal->j_private;
 345         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 346         int                             error = is_journal_aborted(journal);
 347         struct ext4_journal_cb_entry    *jce;
 348
 349         BUG_ON(txn->t_state == T_FINISHED);
 350         spin_lock(&sbi->s_md_lock);
 351         while (!list_empty(&txn->t_private_list)) {
 352                 jce = list_entry(txn->t_private_list.next,
 353                                  struct ext4_journal_cb_entry, jce_list);
 354                 list_del_init(&jce->jce_list);
 355                 spin_unlock(&sbi->s_md_lock);
 356                 jce->jce_func(sb, jce, error);
 357                 spin_lock(&sbi->s_md_lock);
 358         }
 359         spin_unlock(&sbi->s_md_lock);
 360 }
 361
 362 /* Deal with the reporting of failure conditions on a filesystem such as
 363  * inconsistencies detected or read IO failures.
 364  *
 365  * On ext2, we can store the error state of the filesystem in the
 366  * superblock.  That is not possible on ext4, because we may have other
 367  * write ordering constraints on the superblock which prevent us from
 368  * writing it out straight away; and given that the journal is about to
 369  * be aborted, we can't rely on the current, or future, transactions to
 370  * write out the superblock safely.
 371  *
 372  * We'll just use the jbd2_journal_abort() error code to record an error in
 373  * the journal instead.  On recovery, the journal will complain about
 374  * that error until we've noted it down and cleared it.
 375  */
 376
 377 static void ext4_handle_error(struct super_block *sb)
 378 {
 379         if (sb->s_flags & MS_RDONLY)
 380                 return;
 381
 382         if (!test_opt(sb, ERRORS_CONT)) {
 383                 journal_t *journal = EXT4_SB(sb)->s_journal;
 384
 385                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 386                 if (journal)
 387                         jbd2_journal_abort(journal, -EIO);
 388         }
 389         if (test_opt(sb, ERRORS_RO)) {
 390                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 391                 /*
 392                  * Make sure updated value of ->s_mount_flags will be visible
 393                  * before ->s_flags update
 394                  */
 395                 smp_wmb();
 396                 sb->s_flags |= MS_RDONLY;
 397         }
 398         if (test_opt(sb, ERRORS_PANIC))
 399                 panic("EXT4-fs (device %s): panic forced after error\n",
 400                         sb->s_id);
 401 }
 402
 403 #define ext4_error_ratelimit(sb)                                        \
 404                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 405                              "EXT4-fs error")
 406
 407 void __ext4_error(struct super_block *sb, const char *function,
 408                   unsigned int line, const char *fmt, ...)
 409 {
 410         struct va_format vaf;
 411         va_list args;
 412
 413         if (ext4_error_ratelimit(sb)) {
 414                 va_start(args, fmt);
 415                 vaf.fmt = fmt;
 416                 vaf.va = &args;
 417                 printk(KERN_CRIT
 418                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 419                        sb->s_id, function, line, current->comm, &vaf);
 420                 va_end(args);
 421         }
 422         save_error_info(sb, function, line);
 423         ext4_handle_error(sb);
 424 }
 425
 426 void __ext4_error_inode(struct inode *inode, const char *function,
 427                         unsigned int line, ext4_fsblk_t block,
 428                         const char *fmt, ...)
 429 {
 430         va_list args;
 431         struct va_format vaf;
 432         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 433
 434         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 435         es->s_last_error_block = cpu_to_le64(block);
 436         if (ext4_error_ratelimit(inode->i_sb)) {
 437                 va_start(args, fmt);
 438                 vaf.fmt = fmt;
 439                 vaf.va = &args;
 440                 if (block)
 441                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 442                                "inode #%lu: block %llu: comm %s: %pV\n",
 443                                inode->i_sb->s_id, function, line, inode->i_ino,
 444                                block, current->comm, &vaf);
 445                 else
 446                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 447                                "inode #%lu: comm %s: %pV\n",
 448                                inode->i_sb->s_id, function, line, inode->i_ino,
 449                                current->comm, &vaf);
 450                 va_end(args);
 451         }
 452         save_error_info(inode->i_sb, function, line);
 453         ext4_handle_error(inode->i_sb);
 454 }
 455
 456 void __ext4_error_file(struct file *file, const char *function,
 457                        unsigned int line, ext4_fsblk_t block,
 458                        const char *fmt, ...)
 459 {
 460         va_list args;
 461         struct va_format vaf;
 462         struct ext4_super_block *es;
 463         struct inode *inode = file_inode(file);
 464         char pathname[80], *path;
 465
 466         es = EXT4_SB(inode->i_sb)->s_es;
 467         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 468         if (ext4_error_ratelimit(inode->i_sb)) {
 469                 path = d_path(&(file->f_path), pathname, sizeof(pathname));
 470                 if (IS_ERR(path))
 471                         path = "(unknown)";
 472                 va_start(args, fmt);
 473                 vaf.fmt = fmt;
 474                 vaf.va = &args;
 475                 if (block)
 476                         printk(KERN_CRIT
 477                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 478                                "block %llu: comm %s: path %s: %pV\n",
 479                                inode->i_sb->s_id, function, line, inode->i_ino,
 480                                block, current->comm, path, &vaf);
 481                 else
 482                         printk(KERN_CRIT
 483                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 484                                "comm %s: path %s: %pV\n",
 485                                inode->i_sb->s_id, function, line, inode->i_ino,
 486                                current->comm, path, &vaf);
 487                 va_end(args);
 488         }
 489         save_error_info(inode->i_sb, function, line);
 490         ext4_handle_error(inode->i_sb);
 491 }
 492
 493 const char *ext4_decode_error(struct super_block *sb, int errno,
 494                               char nbuf[16])
 495 {
 496         char *errstr = NULL;
 497
 498         switch (errno) {
 499         case -EIO:
 500                 errstr = "IO failure";
 501                 break;
 502         case -ENOMEM:
 503                 errstr = "Out of memory";
 504                 break;
 505         case -EROFS:
 506                 if (!sb || (EXT4_SB(sb)->s_journal &&
 507                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 508                         errstr = "Journal has aborted";
 509                 else
 510                         errstr = "Readonly filesystem";
 511                 break;
 512         default:
 513                 /* If the caller passed in an extra buffer for unknown
 514                  * errors, textualise them now.  Else we just return
 515                  * NULL. */
 516                 if (nbuf) {
 517                         /* Check for truncated error codes... */
 518                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 519                                 errstr = nbuf;
 520                 }
 521                 break;
 522         }
 523
 524         return errstr;
 525 }
 526
 527 /* __ext4_std_error decodes expected errors from journaling functions
 528  * automatically and invokes the appropriate error response.  */
 529
 530 void __ext4_std_error(struct super_block *sb, const char *function,
 531                       unsigned int line, int errno)
 532 {
 533         char nbuf[16];
 534         const char *errstr;
 535
 536         /* Special case: if the error is EROFS, and we're not already
 537          * inside a transaction, then there's really no point in logging
 538          * an error. */
 539         if (errno == -EROFS && journal_current_handle() == NULL &&
 540             (sb->s_flags & MS_RDONLY))
 541                 return;
 542
 543         if (ext4_error_ratelimit(sb)) {
 544                 errstr = ext4_decode_error(sb, errno, nbuf);
 545                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 546                        sb->s_id, function, line, errstr);
 547         }
 548
 549         save_error_info(sb, function, line);
 550         ext4_handle_error(sb);
 551 }
 552
 553 /*
 554  * ext4_abort is a much stronger failure handler than ext4_error.  The
 555  * abort function may be used to deal with unrecoverable failures such
 556  * as journal IO errors or ENOMEM at a critical moment in log management.
 557  *
 558  * We unconditionally force the filesystem into an ABORT|READONLY state,
 559  * unless the error response on the fs has been set to panic in which
 560  * case we take the easy way out and panic immediately.
 561  */
 562
 563 void __ext4_abort(struct super_block *sb, const char *function,
 564                 unsigned int line, const char *fmt, ...)
 565 {
 566         va_list args;
 567
 568         save_error_info(sb, function, line);
 569         va_start(args, fmt);
 570         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 571                function, line);
 572         vprintk(fmt, args);
 573         printk("\n");
 574         va_end(args);
 575
 576         if ((sb->s_flags & MS_RDONLY) == 0) {
 577                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 578                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 579                 /*
 580                  * Make sure updated value of ->s_mount_flags will be visible
 581                  * before ->s_flags update
 582                  */
 583                 smp_wmb();
 584                 sb->s_flags |= MS_RDONLY;
 585                 if (EXT4_SB(sb)->s_journal)
 586                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 587                 save_error_info(sb, function, line);
 588         }
 589         if (test_opt(sb, ERRORS_PANIC))
 590                 panic("EXT4-fs panic from previous error\n");
 591 }
 592
 593 void __ext4_msg(struct super_block *sb,
 594                 const char *prefix, const char *fmt, ...)
 595 {
 596         struct va_format vaf;
 597         va_list args;
 598
 599         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 600                 return;
 601
 602         va_start(args, fmt);
 603         vaf.fmt = fmt;
 604         vaf.va = &args;
 605         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 606         va_end(args);
 607 }
 608
 609 void __ext4_warning(struct super_block *sb, const char *function,
 610                     unsigned int line, const char *fmt, ...)
 611 {
 612         struct va_format vaf;
 613         va_list args;
 614
 615         if (!___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
 616                           "EXT4-fs warning"))
 617                 return;
 618
 619         va_start(args, fmt);
 620         vaf.fmt = fmt;
 621         vaf.va = &args;
 622         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 623                sb->s_id, function, line, &vaf);
 624         va_end(args);
 625 }
 626
 627 void __ext4_grp_locked_error(const char *function, unsigned int line,
 628                              struct super_block *sb, ext4_group_t grp,
 629                              unsigned long ino, ext4_fsblk_t block,
 630                              const char *fmt, ...)
 631 __releases(bitlock)
 632 __acquires(bitlock)
 633 {
 634         struct va_format vaf;
 635         va_list args;
 636         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 637
 638         es->s_last_error_ino = cpu_to_le32(ino);
 639         es->s_last_error_block = cpu_to_le64(block);
 640         __save_error_info(sb, function, line);
 641
 642         if (ext4_error_ratelimit(sb)) {
 643                 va_start(args, fmt);
 644                 vaf.fmt = fmt;
 645                 vaf.va = &args;
 646                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 647                        sb->s_id, function, line, grp);
 648                 if (ino)
 649                         printk(KERN_CONT "inode %lu: ", ino);
 650                 if (block)
 651                         printk(KERN_CONT "block %llu:",
 652                                (unsigned long long) block);
 653                 printk(KERN_CONT "%pV\n", &vaf);
 654                 va_end(args);
 655         }
 656
 657         if (test_opt(sb, ERRORS_CONT)) {
 658                 ext4_commit_super(sb, 0);
 659                 return;
 660         }
 661
 662         ext4_unlock_group(sb, grp);
 663         ext4_handle_error(sb);
 664         /*
 665          * We only get here in the ERRORS_RO case; relocking the group
 666          * may be dangerous, but nothing bad will happen since the
 667          * filesystem will have already been marked read/only and the
 668          * journal has been aborted.  We return 1 as a hint to callers
 669          * who might what to use the return value from
 670          * ext4_grp_locked_error() to distinguish between the
 671          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 672          * aggressively from the ext4 function in question, with a
 673          * more appropriate error code.
 674          */
 675         ext4_lock_group(sb, grp);
 676         return;
 677 }
 678
 679 void ext4_update_dynamic_rev(struct super_block *sb)
 680 {
 681         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 682
 683         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 684                 return;
 685
 686         ext4_warning(sb,
 687                      "updating to rev %d because of new feature flag, "
 688                      "running e2fsck is recommended",
 689                      EXT4_DYNAMIC_REV);
 690
 691         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 692         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 693         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 694         /* leave es->s_feature_*compat flags alone */
 695         /* es->s_uuid will be set by e2fsck if empty */
 696
 697         /*
 698          * The rest of the superblock fields should be zero, and if not it
 699          * means they are likely already in use, so leave them alone.  We
 700          * can leave it up to e2fsck to clean up any inconsistencies there.
 701          */
 702 }
 703
 704 /*
 705  * Open the external journal device
 706  */
 707 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 708 {
 709         struct block_device *bdev;
 710         char b[BDEVNAME_SIZE];
 711
 712         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 713         if (IS_ERR(bdev))
 714                 goto fail;
 715         return bdev;
 716
 717 fail:
 718         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 719                         __bdevname(dev, b), PTR_ERR(bdev));
 720         return NULL;
 721 }
 722
 723 /*
 724  * Release the journal device
 725  */
 726 static void ext4_blkdev_put(struct block_device *bdev)
 727 {
 728         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 729 }
 730
 731 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 732 {
 733         struct block_device *bdev;
 734         bdev = sbi->journal_bdev;
 735         if (bdev) {
 736                 ext4_blkdev_put(bdev);
 737                 sbi->journal_bdev = NULL;
 738         }
 739 }
 740
 741 static inline struct inode *orphan_list_entry(struct list_head *l)
 742 {
 743         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 744 }
 745
 746 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 747 {
 748         struct list_head *l;
 749
 750         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 751                  le32_to_cpu(sbi->s_es->s_last_orphan));
 752
 753         printk(KERN_ERR "sb_info orphan list:\n");
 754         list_for_each(l, &sbi->s_orphan) {
 755                 struct inode *inode = orphan_list_entry(l);
 756                 printk(KERN_ERR "  "
 757                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 758                        inode->i_sb->s_id, inode->i_ino, inode,
 759                        inode->i_mode, inode->i_nlink,
 760                        NEXT_ORPHAN(inode));
 761         }
 762 }
 763
 764 static void ext4_put_super(struct super_block *sb)
 765 {
 766         struct ext4_sb_info *sbi = EXT4_SB(sb);
 767         struct ext4_super_block *es = sbi->s_es;
 768         int i, err;
 769
 770         ext4_unregister_li_request(sb);
 771         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 772
 773         flush_workqueue(sbi->rsv_conversion_wq);
 774         destroy_workqueue(sbi->rsv_conversion_wq);
 775
 776         if (sbi->s_journal) {
 777                 err = jbd2_journal_destroy(sbi->s_journal);
 778                 sbi->s_journal = NULL;
 779                 if (err < 0)
 780                         ext4_abort(sb, "Couldn't clean up the journal");
 781         }
 782
 783         ext4_es_unregister_shrinker(sbi);
 784         del_timer_sync(&sbi->s_err_report);
 785         ext4_release_system_zone(sb);
 786         ext4_mb_release(sb);
 787         ext4_ext_release(sb);
 788         ext4_xattr_put_super(sb);
 789
 790         if (!(sb->s_flags & MS_RDONLY)) {
 791                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 792                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 793         }
 794         if (!(sb->s_flags & MS_RDONLY))
 795                 ext4_commit_super(sb, 1);
 796
 797         if (sbi->s_proc) {
 798                 remove_proc_entry("options", sbi->s_proc);
 799                 remove_proc_entry(sb->s_id, ext4_proc_root);
 800         }
 801         kobject_del(&sbi->s_kobj);
 802
 803         for (i = 0; i < sbi->s_gdb_count; i++)
 804                 brelse(sbi->s_group_desc[i]);
 805         kvfree(sbi->s_group_desc);
 806         kvfree(sbi->s_flex_groups);
 807         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 808         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 809         percpu_counter_destroy(&sbi->s_dirs_counter);
 810         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 811         brelse(sbi->s_sbh);
 812 #ifdef CONFIG_QUOTA
 813         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 814                 kfree(sbi->s_qf_names[i]);
 815 #endif
 816
 817         /* Debugging code just in case the in-memory inode orphan list
 818          * isn't empty.  The on-disk one can be non-empty if we've
 819          * detected an error and taken the fs readonly, but the
 820          * in-memory list had better be clean by this point. */
 821         if (!list_empty(&sbi->s_orphan))
 822                 dump_orphan_list(sb, sbi);
 823         J_ASSERT(list_empty(&sbi->s_orphan));
 824
 825         invalidate_bdev(sb->s_bdev);
 826         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 827                 /*
 828                  * Invalidate the journal device's buffers.  We don't want them
 829                  * floating about in memory - the physical journal device may
 830                  * hotswapped, and it breaks the `ro-after' testing code.
 831                  */
 832                 sync_blockdev(sbi->journal_bdev);
 833                 invalidate_bdev(sbi->journal_bdev);
 834                 ext4_blkdev_remove(sbi);
 835         }
 836         if (sbi->s_mb_cache) {
 837                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 838                 sbi->s_mb_cache = NULL;
 839         }
 840         if (sbi->s_mmp_tsk)
 841                 kthread_stop(sbi->s_mmp_tsk);
 842         sb->s_fs_info = NULL;
 843         /*
 844          * Now that we are completely done shutting down the
 845          * superblock, we need to actually destroy the kobject.
 846          */
 847         kobject_put(&sbi->s_kobj);
 848         wait_for_completion(&sbi->s_kobj_unregister);
 849         if (sbi->s_chksum_driver)
 850                 crypto_free_shash(sbi->s_chksum_driver);
 851         kfree(sbi->s_blockgroup_lock);
 852         kfree(sbi);
 853 }
 854
 855 static struct kmem_cache *ext4_inode_cachep;
 856
 857 /*
 858  * Called inside transaction, so use GFP_NOFS
 859  */
 860 static struct inode *ext4_alloc_inode(struct super_block *sb)
 861 {
 862         struct ext4_inode_info *ei;
 863
 864         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 865         if (!ei)
 866                 return NULL;
 867
 868         ei->vfs_inode.i_version = 1;
 869         spin_lock_init(&ei->i_raw_lock);
 870         INIT_LIST_HEAD(&ei->i_prealloc_list);
 871         spin_lock_init(&ei->i_prealloc_lock);
 872         ext4_es_init_tree(&ei->i_es_tree);
 873         rwlock_init(&ei->i_es_lock);
 874         INIT_LIST_HEAD(&ei->i_es_list);
 875         ei->i_es_all_nr = 0;
 876         ei->i_es_shk_nr = 0;
 877         ei->i_es_shrink_lblk = 0;
 878         ei->i_reserved_data_blocks = 0;
 879         ei->i_reserved_meta_blocks = 0;
 880         ei->i_allocated_meta_blocks = 0;
 881         ei->i_da_metadata_calc_len = 0;
 882         ei->i_da_metadata_calc_last_lblock = 0;
 883         spin_lock_init(&(ei->i_block_reservation_lock));
 884 #ifdef CONFIG_QUOTA
 885         ei->i_reserved_quota = 0;
 886 #endif
 887         ei->jinode = NULL;
 888         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 889         spin_lock_init(&ei->i_completed_io_lock);
 890         ei->i_sync_tid = 0;
 891         ei->i_datasync_tid = 0;
 892         atomic_set(&ei->i_ioend_count, 0);
 893         atomic_set(&ei->i_unwritten, 0);
 894         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 895
 896         return &ei->vfs_inode;
 897 }
 898
 899 static int ext4_drop_inode(struct inode *inode)
 900 {
 901         int drop = generic_drop_inode(inode);
 902
 903         trace_ext4_drop_inode(inode, drop);
 904         return drop;
 905 }
 906
 907 static void ext4_i_callback(struct rcu_head *head)
 908 {
 909         struct inode *inode = container_of(head, struct inode, i_rcu);
 910         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 911 }
 912
 913 static void ext4_destroy_inode(struct inode *inode)
 914 {
 915         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 916                 ext4_msg(inode->i_sb, KERN_ERR,
 917                          "Inode %lu (%p): orphan list check failed!",
 918                          inode->i_ino, EXT4_I(inode));
 919                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 920                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 921                                 true);
 922                 dump_stack();
 923         }
 924         call_rcu(&inode->i_rcu, ext4_i_callback);
 925 }
 926
 927 static void init_once(void *foo)
 928 {
 929         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 930
 931         INIT_LIST_HEAD(&ei->i_orphan);
 932         init_rwsem(&ei->xattr_sem);
 933         init_rwsem(&ei->i_data_sem);
 934         inode_init_once(&ei->vfs_inode);
 935 }
 936
 937 static int __init init_inodecache(void)
 938 {
 939         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 940                                              sizeof(struct ext4_inode_info),
 941                                              0, (SLAB_RECLAIM_ACCOUNT|
 942                                                 SLAB_MEM_SPREAD),
 943                                              init_once);
 944         if (ext4_inode_cachep == NULL)
 945                 return -ENOMEM;
 946         return 0;
 947 }
 948
 949 static void destroy_inodecache(void)
 950 {
 951         /*
 952          * Make sure all delayed rcu free inodes are flushed before we
 953          * destroy cache.
 954          */
 955         rcu_barrier();
 956         kmem_cache_destroy(ext4_inode_cachep);
 957 }
 958
 959 void ext4_clear_inode(struct inode *inode)
 960 {
 961         invalidate_inode_buffers(inode);
 962         clear_inode(inode);
 963         dquot_drop(inode);
 964         ext4_discard_preallocations(inode);
 965         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 966         if (EXT4_I(inode)->jinode) {
 967                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 968                                                EXT4_I(inode)->jinode);
 969                 jbd2_free_inode(EXT4_I(inode)->jinode);
 970                 EXT4_I(inode)->jinode = NULL;
 971         }
 972 }
 973
 974 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 975                                         u64 ino, u32 generation)
 976 {
 977         struct inode *inode;
 978
 979         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 980                 return ERR_PTR(-ESTALE);
 981         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 982                 return ERR_PTR(-ESTALE);
 983
 984         /* iget isn't really right if the inode is currently unallocated!!
 985          *
 986          * ext4_read_inode will return a bad_inode if the inode had been
 987          * deleted, so we should be safe.
 988          *
 989          * Currently we don't know the generation for parent directory, so
 990          * a generation of 0 means "accept any"
 991          */
 992         inode = ext4_iget_normal(sb, ino);
 993         if (IS_ERR(inode))
 994                 return ERR_CAST(inode);
 995         if (generation && inode->i_generation != generation) {
 996                 iput(inode);
 997                 return ERR_PTR(-ESTALE);
 998         }
 999
1000         return inode;
1001 }
1002
1003 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1004                                         int fh_len, int fh_type)
1005 {
1006         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1007                                     ext4_nfs_get_inode);
1008 }
1009
1010 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1011                                         int fh_len, int fh_type)
1012 {
1013         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1014                                     ext4_nfs_get_inode);
1015 }
1016
1017 /*
1018  * Try to release metadata pages (indirect blocks, directories) which are
1019  * mapped via the block device.  Since these pages could have journal heads
1020  * which would prevent try_to_free_buffers() from freeing them, we must use
1021  * jbd2 layer's try_to_free_buffers() function to release them.
1022  */
1023 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1024                                  gfp_t wait)
1025 {
1026         journal_t *journal = EXT4_SB(sb)->s_journal;
1027
1028         WARN_ON(PageChecked(page));
1029         if (!page_has_buffers(page))
1030                 return 0;
1031         if (journal)
1032                 return jbd2_journal_try_to_free_buffers(journal, page,
1033                                                         wait & ~__GFP_WAIT);
1034         return try_to_free_buffers(page);
1035 }
1036
1037 #ifdef CONFIG_QUOTA
1038 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1039 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1040
1041 static int ext4_write_dquot(struct dquot *dquot);
1042 static int ext4_acquire_dquot(struct dquot *dquot);
1043 static int ext4_release_dquot(struct dquot *dquot);
1044 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1045 static int ext4_write_info(struct super_block *sb, int type);
1046 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1047                          struct path *path);
1048 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1049                                  int format_id);
1050 static int ext4_quota_off(struct super_block *sb, int type);
1051 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1052 static int ext4_quota_on_mount(struct super_block *sb, int type);
1053 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1054                                size_t len, loff_t off);
1055 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1056                                 const char *data, size_t len, loff_t off);
1057 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1058                              unsigned int flags);
1059 static int ext4_enable_quotas(struct super_block *sb);
1060
1061 static const struct dquot_operations ext4_quota_operations = {
1062         .get_reserved_space = ext4_get_reserved_space,
1063         .write_dquot    = ext4_write_dquot,
1064         .acquire_dquot  = ext4_acquire_dquot,
1065         .release_dquot  = ext4_release_dquot,
1066         .mark_dirty     = ext4_mark_dquot_dirty,
1067         .write_info     = ext4_write_info,
1068         .alloc_dquot    = dquot_alloc,
1069         .destroy_dquot  = dquot_destroy,
1070 };
1071
1072 static const struct quotactl_ops ext4_qctl_operations = {
1073         .quota_on       = ext4_quota_on,
1074         .quota_off      = ext4_quota_off,
1075         .quota_sync     = dquot_quota_sync,
1076         .get_info       = dquot_get_dqinfo,
1077         .set_info       = dquot_set_dqinfo,
1078         .get_dqblk      = dquot_get_dqblk,
1079         .set_dqblk      = dquot_set_dqblk
1080 };
1081
1082 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1083         .quota_on_meta  = ext4_quota_on_sysfile,
1084         .quota_off      = ext4_quota_off_sysfile,
1085         .quota_sync     = dquot_quota_sync,
1086         .get_info       = dquot_get_dqinfo,
1087         .set_info       = dquot_set_dqinfo,
1088         .get_dqblk      = dquot_get_dqblk,
1089         .set_dqblk      = dquot_set_dqblk
1090 };
1091 #endif
1092
1093 static const struct super_operations ext4_sops = {
1094         .alloc_inode    = ext4_alloc_inode,
1095         .destroy_inode  = ext4_destroy_inode,
1096         .write_inode    = ext4_write_inode,
1097         .dirty_inode    = ext4_dirty_inode,
1098         .drop_inode     = ext4_drop_inode,
1099         .evict_inode    = ext4_evict_inode,
1100         .put_super      = ext4_put_super,
1101         .sync_fs        = ext4_sync_fs,
1102         .freeze_fs      = ext4_freeze,
1103         .unfreeze_fs    = ext4_unfreeze,
1104         .statfs         = ext4_statfs,
1105         .remount_fs     = ext4_remount,
1106         .show_options   = ext4_show_options,
1107 #ifdef CONFIG_QUOTA
1108         .quota_read     = ext4_quota_read,
1109         .quota_write    = ext4_quota_write,
1110 #endif
1111         .bdev_try_to_free_page = bdev_try_to_free_page,
1112 };
1113
1114 static const struct export_operations ext4_export_ops = {
1115         .fh_to_dentry = ext4_fh_to_dentry,
1116         .fh_to_parent = ext4_fh_to_parent,
1117         .get_parent = ext4_get_parent,
1118 };
1119
1120 enum {
1121         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1122         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1123         Opt_nouid32, Opt_debug, Opt_removed,
1124         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1125         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1126         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1127         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1128         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1129         Opt_data_err_abort, Opt_data_err_ignore,
1130         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1131         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1132         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1133         Opt_usrquota, Opt_grpquota, Opt_i_version,
1134         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1135         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1136         Opt_inode_readahead_blks, Opt_journal_ioprio,
1137         Opt_dioread_nolock, Opt_dioread_lock,
1138         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1139         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1140 };
1141
1142 static const match_table_t tokens = {
1143         {Opt_bsd_df, "bsddf"},
1144         {Opt_minix_df, "minixdf"},
1145         {Opt_grpid, "grpid"},
1146         {Opt_grpid, "bsdgroups"},
1147         {Opt_nogrpid, "nogrpid"},
1148         {Opt_nogrpid, "sysvgroups"},
1149         {Opt_resgid, "resgid=%u"},
1150         {Opt_resuid, "resuid=%u"},
1151         {Opt_sb, "sb=%u"},
1152         {Opt_err_cont, "errors=continue"},
1153         {Opt_err_panic, "errors=panic"},
1154         {Opt_err_ro, "errors=remount-ro"},
1155         {Opt_nouid32, "nouid32"},
1156         {Opt_debug, "debug"},
1157         {Opt_removed, "oldalloc"},
1158         {Opt_removed, "orlov"},
1159         {Opt_user_xattr, "user_xattr"},
1160         {Opt_nouser_xattr, "nouser_xattr"},
1161         {Opt_acl, "acl"},
1162         {Opt_noacl, "noacl"},
1163         {Opt_noload, "norecovery"},
1164         {Opt_noload, "noload"},
1165         {Opt_removed, "nobh"},
1166         {Opt_removed, "bh"},
1167         {Opt_commit, "commit=%u"},
1168         {Opt_min_batch_time, "min_batch_time=%u"},
1169         {Opt_max_batch_time, "max_batch_time=%u"},
1170         {Opt_journal_dev, "journal_dev=%u"},
1171         {Opt_journal_path, "journal_path=%s"},
1172         {Opt_journal_checksum, "journal_checksum"},
1173         {Opt_nojournal_checksum, "nojournal_checksum"},
1174         {Opt_journal_async_commit, "journal_async_commit"},
1175         {Opt_abort, "abort"},
1176         {Opt_data_journal, "data=journal"},
1177         {Opt_data_ordered, "data=ordered"},
1178         {Opt_data_writeback, "data=writeback"},
1179         {Opt_data_err_abort, "data_err=abort"},
1180         {Opt_data_err_ignore, "data_err=ignore"},
1181         {Opt_offusrjquota, "usrjquota="},
1182         {Opt_usrjquota, "usrjquota=%s"},
1183         {Opt_offgrpjquota, "grpjquota="},
1184         {Opt_grpjquota, "grpjquota=%s"},
1185         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1186         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1187         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1188         {Opt_grpquota, "grpquota"},
1189         {Opt_noquota, "noquota"},
1190         {Opt_quota, "quota"},
1191         {Opt_usrquota, "usrquota"},
1192         {Opt_barrier, "barrier=%u"},
1193         {Opt_barrier, "barrier"},
1194         {Opt_nobarrier, "nobarrier"},
1195         {Opt_i_version, "i_version"},
1196         {Opt_stripe, "stripe=%u"},
1197         {Opt_delalloc, "delalloc"},
1198         {Opt_nodelalloc, "nodelalloc"},
1199         {Opt_removed, "mblk_io_submit"},
1200         {Opt_removed, "nomblk_io_submit"},
1201         {Opt_block_validity, "block_validity"},
1202         {Opt_noblock_validity, "noblock_validity"},
1203         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1204         {Opt_journal_ioprio, "journal_ioprio=%u"},
1205         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1206         {Opt_auto_da_alloc, "auto_da_alloc"},
1207         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1208         {Opt_dioread_nolock, "dioread_nolock"},
1209         {Opt_dioread_lock, "dioread_lock"},
1210         {Opt_discard, "discard"},
1211         {Opt_nodiscard, "nodiscard"},
1212         {Opt_init_itable, "init_itable=%u"},
1213         {Opt_init_itable, "init_itable"},
1214         {Opt_noinit_itable, "noinit_itable"},
1215         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1216         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1217         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1218         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1219         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1220         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1221         {Opt_err, NULL},
1222 };
1223
1224 static ext4_fsblk_t get_sb_block(void **data)
1225 {
1226         ext4_fsblk_t    sb_block;
1227         char            *options = (char *) *data;
1228
1229         if (!options || strncmp(options, "sb=", 3) != 0)
1230                 return 1;       /* Default location */
1231
1232         options += 3;
1233         /* TODO: use simple_strtoll with >32bit ext4 */
1234         sb_block = simple_strtoul(options, &options, 0);
1235         if (*options && *options != ',') {
1236                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1237                        (char *) *data);
1238                 return 1;
1239         }
1240         if (*options == ',')
1241                 options++;
1242         *data = (void *) options;
1243
1244         return sb_block;
1245 }
1246
1247 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1248 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1249         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1250
1251 #ifdef CONFIG_QUOTA
1252 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1253 {
1254         struct ext4_sb_info *sbi = EXT4_SB(sb);
1255         char *qname;
1256         int ret = -1;
1257
1258         if (sb_any_quota_loaded(sb) &&
1259                 !sbi->s_qf_names[qtype]) {
1260                 ext4_msg(sb, KERN_ERR,
1261                         "Cannot change journaled "
1262                         "quota options when quota turned on");
1263                 return -1;
1264         }
1265         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1266                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1267                          "when QUOTA feature is enabled");
1268                 return -1;
1269         }
1270         qname = match_strdup(args);
1271         if (!qname) {
1272                 ext4_msg(sb, KERN_ERR,
1273                         "Not enough memory for storing quotafile name");
1274                 return -1;
1275         }
1276         if (sbi->s_qf_names[qtype]) {
1277                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1278                         ret = 1;
1279                 else
1280                         ext4_msg(sb, KERN_ERR,
1281                                  "%s quota file already specified",
1282                                  QTYPE2NAME(qtype));
1283                 goto errout;
1284         }
1285         if (strchr(qname, '/')) {
1286                 ext4_msg(sb, KERN_ERR,
1287                         "quotafile must be on filesystem root");
1288                 goto errout;
1289         }
1290         sbi->s_qf_names[qtype] = qname;
1291         set_opt(sb, QUOTA);
1292         return 1;
1293 errout:
1294         kfree(qname);
1295         return ret;
1296 }
1297
1298 static int clear_qf_name(struct super_block *sb, int qtype)
1299 {
1300
1301         struct ext4_sb_info *sbi = EXT4_SB(sb);
1302
1303         if (sb_any_quota_loaded(sb) &&
1304                 sbi->s_qf_names[qtype]) {
1305                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1306                         " when quota turned on");
1307                 return -1;
1308         }
1309         kfree(sbi->s_qf_names[qtype]);
1310         sbi->s_qf_names[qtype] = NULL;
1311         return 1;
1312 }
1313 #endif
1314
1315 #define MOPT_SET        0x0001
1316 #define MOPT_CLEAR      0x0002
1317 #define MOPT_NOSUPPORT  0x0004
1318 #define MOPT_EXPLICIT   0x0008
1319 #define MOPT_CLEAR_ERR  0x0010
1320 #define MOPT_GTE0       0x0020
1321 #ifdef CONFIG_QUOTA
1322 #define MOPT_Q          0
1323 #define MOPT_QFMT       0x0040
1324 #else
1325 #define MOPT_Q          MOPT_NOSUPPORT
1326 #define MOPT_QFMT       MOPT_NOSUPPORT
1327 #endif
1328 #define MOPT_DATAJ      0x0080
1329 #define MOPT_NO_EXT2    0x0100
1330 #define MOPT_NO_EXT3    0x0200
1331 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1332 #define MOPT_STRING     0x0400
1333
1334 static const struct mount_opts {
1335         int     token;
1336         int     mount_opt;
1337         int     flags;
1338 } ext4_mount_opts[] = {
1339         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1340         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1341         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1342         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1343         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1344         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1345         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1346          MOPT_EXT4_ONLY | MOPT_SET},
1347         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1348          MOPT_EXT4_ONLY | MOPT_CLEAR},
1349         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1350         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1351         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1352          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1353         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1354          MOPT_EXT4_ONLY | MOPT_CLEAR},
1355         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1356          MOPT_EXT4_ONLY | MOPT_CLEAR},
1357         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1358          MOPT_EXT4_ONLY | MOPT_SET},
1359         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1360                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1361          MOPT_EXT4_ONLY | MOPT_SET},
1362         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1363         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1364         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1365         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1366         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1367          MOPT_NO_EXT2 | MOPT_SET},
1368         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1369          MOPT_NO_EXT2 | MOPT_CLEAR},
1370         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1371         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1372         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1373         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1374         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1375         {Opt_commit, 0, MOPT_GTE0},
1376         {Opt_max_batch_time, 0, MOPT_GTE0},
1377         {Opt_min_batch_time, 0, MOPT_GTE0},
1378         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1379         {Opt_init_itable, 0, MOPT_GTE0},
1380         {Opt_stripe, 0, MOPT_GTE0},
1381         {Opt_resuid, 0, MOPT_GTE0},
1382         {Opt_resgid, 0, MOPT_GTE0},
1383         {Opt_journal_dev, 0, MOPT_GTE0},
1384         {Opt_journal_path, 0, MOPT_STRING},
1385         {Opt_journal_ioprio, 0, MOPT_GTE0},
1386         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1387         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1388         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1389          MOPT_NO_EXT2 | MOPT_DATAJ},
1390         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1391         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1392 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1393         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1394         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1395 #else
1396         {Opt_acl, 0, MOPT_NOSUPPORT},
1397         {Opt_noacl, 0, MOPT_NOSUPPORT},
1398 #endif
1399         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1400         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1401         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1402         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1403                                                         MOPT_SET | MOPT_Q},
1404         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1405                                                         MOPT_SET | MOPT_Q},
1406         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1407                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1408         {Opt_usrjquota, 0, MOPT_Q},
1409         {Opt_grpjquota, 0, MOPT_Q},
1410         {Opt_offusrjquota, 0, MOPT_Q},
1411         {Opt_offgrpjquota, 0, MOPT_Q},
1412         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1413         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1414         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1415         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1416         {Opt_err, 0, 0}
1417 };
1418
1419 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1420                             substring_t *args, unsigned long *journal_devnum,
1421                             unsigned int *journal_ioprio, int is_remount)
1422 {
1423         struct ext4_sb_info *sbi = EXT4_SB(sb);
1424         const struct mount_opts *m;
1425         kuid_t uid;
1426         kgid_t gid;
1427         int arg = 0;
1428
1429 #ifdef CONFIG_QUOTA
1430         if (token == Opt_usrjquota)
1431                 return set_qf_name(sb, USRQUOTA, &args[0]);
1432         else if (token == Opt_grpjquota)
1433                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1434         else if (token == Opt_offusrjquota)
1435                 return clear_qf_name(sb, USRQUOTA);
1436         else if (token == Opt_offgrpjquota)
1437                 return clear_qf_name(sb, GRPQUOTA);
1438 #endif
1439         switch (token) {
1440         case Opt_noacl:
1441         case Opt_nouser_xattr:
1442                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1443                 break;
1444         case Opt_sb:
1445                 return 1;       /* handled by get_sb_block() */
1446         case Opt_removed:
1447                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1448                 return 1;
1449         case Opt_abort:
1450                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1451                 return 1;
1452         case Opt_i_version:
1453                 sb->s_flags |= MS_I_VERSION;
1454                 return 1;
1455         }
1456
1457         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1458                 if (token == m->token)
1459                         break;
1460
1461         if (m->token == Opt_err) {
1462                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1463                          "or missing value", opt);
1464                 return -1;
1465         }
1466
1467         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1468                 ext4_msg(sb, KERN_ERR,
1469                          "Mount option \"%s\" incompatible with ext2", opt);
1470                 return -1;
1471         }
1472         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1473                 ext4_msg(sb, KERN_ERR,
1474                          "Mount option \"%s\" incompatible with ext3", opt);
1475                 return -1;
1476         }
1477
1478         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1479                 return -1;
1480         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1481                 return -1;
1482         if (m->flags & MOPT_EXPLICIT)
1483                 set_opt2(sb, EXPLICIT_DELALLOC);
1484         if (m->flags & MOPT_CLEAR_ERR)
1485                 clear_opt(sb, ERRORS_MASK);
1486         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1487                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1488                          "options when quota turned on");
1489                 return -1;
1490         }
1491
1492         if (m->flags & MOPT_NOSUPPORT) {
1493                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1494         } else if (token == Opt_commit) {
1495                 if (arg == 0)
1496                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1497                 sbi->s_commit_interval = HZ * arg;
1498         } else if (token == Opt_max_batch_time) {
1499                 sbi->s_max_batch_time = arg;
1500         } else if (token == Opt_min_batch_time) {
1501                 sbi->s_min_batch_time = arg;
1502         } else if (token == Opt_inode_readahead_blks) {
1503                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1504                         ext4_msg(sb, KERN_ERR,
1505                                  "EXT4-fs: inode_readahead_blks must be "
1506                                  "0 or a power of 2 smaller than 2^31");
1507                         return -1;
1508                 }
1509                 sbi->s_inode_readahead_blks = arg;
1510         } else if (token == Opt_init_itable) {
1511                 set_opt(sb, INIT_INODE_TABLE);
1512                 if (!args->from)
1513                         arg = EXT4_DEF_LI_WAIT_MULT;
1514                 sbi->s_li_wait_mult = arg;
1515         } else if (token == Opt_max_dir_size_kb) {
1516                 sbi->s_max_dir_size_kb = arg;
1517         } else if (token == Opt_stripe) {
1518                 sbi->s_stripe = arg;
1519         } else if (token == Opt_resuid) {
1520                 uid = make_kuid(current_user_ns(), arg);
1521                 if (!uid_valid(uid)) {
1522                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1523                         return -1;
1524                 }
1525                 sbi->s_resuid = uid;
1526         } else if (token == Opt_resgid) {
1527                 gid = make_kgid(current_user_ns(), arg);
1528                 if (!gid_valid(gid)) {
1529                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1530                         return -1;
1531                 }
1532                 sbi->s_resgid = gid;
1533         } else if (token == Opt_journal_dev) {
1534                 if (is_remount) {
1535                         ext4_msg(sb, KERN_ERR,
1536                                  "Cannot specify journal on remount");
1537                         return -1;
1538                 }
1539                 *journal_devnum = arg;
1540         } else if (token == Opt_journal_path) {
1541                 char *journal_path;
1542                 struct inode *journal_inode;
1543                 struct path path;
1544                 int error;
1545
1546                 if (is_remount) {
1547                         ext4_msg(sb, KERN_ERR,
1548                                  "Cannot specify journal on remount");
1549                         return -1;
1550                 }
1551                 journal_path = match_strdup(&args[0]);
1552                 if (!journal_path) {
1553                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1554                                 "journal device string");
1555                         return -1;
1556                 }
1557
1558                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1559                 if (error) {
1560                         ext4_msg(sb, KERN_ERR, "error: could not find "
1561                                 "journal device path: error %d", error);
1562                         kfree(journal_path);
1563                         return -1;
1564                 }
1565
1566                 journal_inode = path.dentry->d_inode;
1567                 if (!S_ISBLK(journal_inode->i_mode)) {
1568                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1569                                 "is not a block device", journal_path);
1570                         path_put(&path);
1571                         kfree(journal_path);
1572                         return -1;
1573                 }
1574
1575                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1576                 path_put(&path);
1577                 kfree(journal_path);
1578         } else if (token == Opt_journal_ioprio) {
1579                 if (arg > 7) {
1580                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1581                                  " (must be 0-7)");
1582                         return -1;
1583                 }
1584                 *journal_ioprio =
1585                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1586         } else if (m->flags & MOPT_DATAJ) {
1587                 if (is_remount) {
1588                         if (!sbi->s_journal)
1589                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1590                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1591                                 ext4_msg(sb, KERN_ERR,
1592                                          "Cannot change data mode on remount");
1593                                 return -1;
1594                         }
1595                 } else {
1596                         clear_opt(sb, DATA_FLAGS);
1597                         sbi->s_mount_opt |= m->mount_opt;
1598                 }
1599 #ifdef CONFIG_QUOTA
1600         } else if (m->flags & MOPT_QFMT) {
1601                 if (sb_any_quota_loaded(sb) &&
1602                     sbi->s_jquota_fmt != m->mount_opt) {
1603                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1604                                  "quota options when quota turned on");
1605                         return -1;
1606                 }
1607                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1608                                                EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1609                         ext4_msg(sb, KERN_ERR,
1610                                  "Cannot set journaled quota options "
1611                                  "when QUOTA feature is enabled");
1612                         return -1;
1613                 }
1614                 sbi->s_jquota_fmt = m->mount_opt;
1615 #endif
1616         } else {
1617                 if (!args->from)
1618                         arg = 1;
1619                 if (m->flags & MOPT_CLEAR)
1620                         arg = !arg;
1621                 else if (unlikely(!(m->flags & MOPT_SET))) {
1622                         ext4_msg(sb, KERN_WARNING,
1623                                  "buggy handling of option %s", opt);
1624                         WARN_ON(1);
1625                         return -1;
1626                 }
1627                 if (arg != 0)
1628                         sbi->s_mount_opt |= m->mount_opt;
1629                 else
1630                         sbi->s_mount_opt &= ~m->mount_opt;
1631         }
1632         return 1;
1633 }
1634
1635 static int parse_options(char *options, struct super_block *sb,
1636                          unsigned long *journal_devnum,
1637                          unsigned int *journal_ioprio,
1638                          int is_remount)
1639 {
1640         struct ext4_sb_info *sbi = EXT4_SB(sb);
1641         char *p;
1642         substring_t args[MAX_OPT_ARGS];
1643         int token;
1644
1645         if (!options)
1646                 return 1;
1647
1648         while ((p = strsep(&options, ",")) != NULL) {
1649                 if (!*p)
1650                         continue;
1651                 /*
1652                  * Initialize args struct so we know whether arg was
1653                  * found; some options take optional arguments.
1654                  */
1655                 args[0].to = args[0].from = NULL;
1656                 token = match_token(p, tokens, args);
1657                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1658                                      journal_ioprio, is_remount) < 0)
1659                         return 0;
1660         }
1661 #ifdef CONFIG_QUOTA
1662         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1663             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1664                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1665                          "feature is enabled");
1666                 return 0;
1667         }
1668         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1669                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1670                         clear_opt(sb, USRQUOTA);
1671
1672                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1673                         clear_opt(sb, GRPQUOTA);
1674
1675                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1676                         ext4_msg(sb, KERN_ERR, "old and new quota "
1677                                         "format mixing");
1678                         return 0;
1679                 }
1680
1681                 if (!sbi->s_jquota_fmt) {
1682                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1683                                         "not specified");
1684                         return 0;
1685                 }
1686         }
1687 #endif
1688         if (test_opt(sb, DIOREAD_NOLOCK)) {
1689                 int blocksize =
1690                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1691
1692                 if (blocksize < PAGE_CACHE_SIZE) {
1693                         ext4_msg(sb, KERN_ERR, "can't mount with "
1694                                  "dioread_nolock if block size != PAGE_SIZE");
1695                         return 0;
1696                 }
1697         }
1698         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1699             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1700                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1701                          "in data=ordered mode");
1702                 return 0;
1703         }
1704         return 1;
1705 }
1706
1707 static inline void ext4_show_quota_options(struct seq_file *seq,
1708                                            struct super_block *sb)
1709 {
1710 #if defined(CONFIG_QUOTA)
1711         struct ext4_sb_info *sbi = EXT4_SB(sb);
1712
1713         if (sbi->s_jquota_fmt) {
1714                 char *fmtname = "";
1715
1716                 switch (sbi->s_jquota_fmt) {
1717                 case QFMT_VFS_OLD:
1718                         fmtname = "vfsold";
1719                         break;
1720                 case QFMT_VFS_V0:
1721                         fmtname = "vfsv0";
1722                         break;
1723                 case QFMT_VFS_V1:
1724                         fmtname = "vfsv1";
1725                         break;
1726                 }
1727                 seq_printf(seq, ",jqfmt=%s", fmtname);
1728         }
1729
1730         if (sbi->s_qf_names[USRQUOTA])
1731                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1732
1733         if (sbi->s_qf_names[GRPQUOTA])
1734                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1735 #endif
1736 }
1737
1738 static const char *token2str(int token)
1739 {
1740         const struct match_token *t;
1741
1742         for (t = tokens; t->token != Opt_err; t++)
1743                 if (t->token == token && !strchr(t->pattern, '='))
1744                         break;
1745         return t->pattern;
1746 }
1747
1748 /*
1749  * Show an option if
1750  *  - it's set to a non-default value OR
1751  *  - if the per-sb default is different from the global default
1752  */
1753 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1754                               int nodefs)
1755 {
1756         struct ext4_sb_info *sbi = EXT4_SB(sb);
1757         struct ext4_super_block *es = sbi->s_es;
1758         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1759         const struct mount_opts *m;
1760         char sep = nodefs ? '\n' : ',';
1761
1762 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1763 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1764
1765         if (sbi->s_sb_block != 1)
1766                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1767
1768         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1769                 int want_set = m->flags & MOPT_SET;
1770                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1771                     (m->flags & MOPT_CLEAR_ERR))
1772                         continue;
1773                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1774                         continue; /* skip if same as the default */
1775                 if ((want_set &&
1776                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1777                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1778                         continue; /* select Opt_noFoo vs Opt_Foo */
1779                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1780         }
1781
1782         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1783             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1784                 SEQ_OPTS_PRINT("resuid=%u",
1785                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1786         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1787             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1788                 SEQ_OPTS_PRINT("resgid=%u",
1789                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1790         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1791         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1792                 SEQ_OPTS_PUTS("errors=remount-ro");
1793         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1794                 SEQ_OPTS_PUTS("errors=continue");
1795         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1796                 SEQ_OPTS_PUTS("errors=panic");
1797         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1798                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1799         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1800                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1801         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1802                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1803         if (sb->s_flags & MS_I_VERSION)
1804                 SEQ_OPTS_PUTS("i_version");
1805         if (nodefs || sbi->s_stripe)
1806                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1807         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1808                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1809                         SEQ_OPTS_PUTS("data=journal");
1810                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1811                         SEQ_OPTS_PUTS("data=ordered");
1812                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1813                         SEQ_OPTS_PUTS("data=writeback");
1814         }
1815         if (nodefs ||
1816             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1817                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1818                                sbi->s_inode_readahead_blks);
1819
1820         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1821                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1822                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1823         if (nodefs || sbi->s_max_dir_size_kb)
1824                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1825
1826         ext4_show_quota_options(seq, sb);
1827         return 0;
1828 }
1829
1830 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1831 {
1832         return _ext4_show_options(seq, root->d_sb, 0);
1833 }
1834
1835 static int options_seq_show(struct seq_file *seq, void *offset)
1836 {
1837         struct super_block *sb = seq->private;
1838         int rc;
1839
1840         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1841         rc = _ext4_show_options(seq, sb, 1);
1842         seq_puts(seq, "\n");
1843         return rc;
1844 }
1845
1846 static int options_open_fs(struct inode *inode, struct file *file)
1847 {
1848         return single_open(file, options_seq_show, PDE_DATA(inode));
1849 }
1850
1851 static const struct file_operations ext4_seq_options_fops = {
1852         .owner = THIS_MODULE,
1853         .open = options_open_fs,
1854         .read = seq_read,
1855         .llseek = seq_lseek,
1856         .release = single_release,
1857 };
1858
1859 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1860                             int read_only)
1861 {
1862         struct ext4_sb_info *sbi = EXT4_SB(sb);
1863         int res = 0;
1864
1865         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1866                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1867                          "forcing read-only mode");
1868                 res = MS_RDONLY;
1869         }
1870         if (read_only)
1871                 goto done;
1872         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1873                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1874                          "running e2fsck is recommended");
1875         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1876                 ext4_msg(sb, KERN_WARNING,
1877                          "warning: mounting fs with errors, "
1878                          "running e2fsck is recommended");
1879         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1880                  le16_to_cpu(es->s_mnt_count) >=
1881                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1882                 ext4_msg(sb, KERN_WARNING,
1883                          "warning: maximal mount count reached, "
1884                          "running e2fsck is recommended");
1885         else if (le32_to_cpu(es->s_checkinterval) &&
1886                 (le32_to_cpu(es->s_lastcheck) +
1887                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1888                 ext4_msg(sb, KERN_WARNING,
1889                          "warning: checktime reached, "
1890                          "running e2fsck is recommended");
1891         if (!sbi->s_journal)
1892                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1893         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1894                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1895         le16_add_cpu(&es->s_mnt_count, 1);
1896         es->s_mtime = cpu_to_le32(get_seconds());
1897         ext4_update_dynamic_rev(sb);
1898         if (sbi->s_journal)
1899                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1900
1901         ext4_commit_super(sb, 1);
1902 done:
1903         if (test_opt(sb, DEBUG))
1904                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1905                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1906                         sb->s_blocksize,
1907                         sbi->s_groups_count,
1908                         EXT4_BLOCKS_PER_GROUP(sb),
1909                         EXT4_INODES_PER_GROUP(sb),
1910                         sbi->s_mount_opt, sbi->s_mount_opt2);
1911
1912         cleancache_init_fs(sb);
1913         return res;
1914 }
1915
1916 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1917 {
1918         struct ext4_sb_info *sbi = EXT4_SB(sb);
1919         struct flex_groups *new_groups;
1920         int size;
1921
1922         if (!sbi->s_log_groups_per_flex)
1923                 return 0;
1924
1925         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1926         if (size <= sbi->s_flex_groups_allocated)
1927                 return 0;
1928
1929         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1930         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1931         if (!new_groups) {
1932                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1933                          size / (int) sizeof(struct flex_groups));
1934                 return -ENOMEM;
1935         }
1936
1937         if (sbi->s_flex_groups) {
1938                 memcpy(new_groups, sbi->s_flex_groups,
1939                        (sbi->s_flex_groups_allocated *
1940                         sizeof(struct flex_groups)));
1941                 kvfree(sbi->s_flex_groups);
1942         }
1943         sbi->s_flex_groups = new_groups;
1944         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1945         return 0;
1946 }
1947
1948 static int ext4_fill_flex_info(struct super_block *sb)
1949 {
1950         struct ext4_sb_info *sbi = EXT4_SB(sb);
1951         struct ext4_group_desc *gdp = NULL;
1952         ext4_group_t flex_group;
1953         int i, err;
1954
1955         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1956         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1957                 sbi->s_log_groups_per_flex = 0;
1958                 return 1;
1959         }
1960
1961         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1962         if (err)
1963                 goto failed;
1964
1965         for (i = 0; i < sbi->s_groups_count; i++) {
1966                 gdp = ext4_get_group_desc(sb, i, NULL);
1967
1968                 flex_group = ext4_flex_group(sbi, i);
1969                 atomic_add(ext4_free_inodes_count(sb, gdp),
1970                            &sbi->s_flex_groups[flex_group].free_inodes);
1971                 atomic64_add(ext4_free_group_clusters(sb, gdp),
1972                              &sbi->s_flex_groups[flex_group].free_clusters);
1973                 atomic_add(ext4_used_dirs_count(sb, gdp),
1974                            &sbi->s_flex_groups[flex_group].used_dirs);
1975         }
1976
1977         return 1;
1978 failed:
1979         return 0;
1980 }
1981
1982 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1983                                    struct ext4_group_desc *gdp)
1984 {
1985         int offset;
1986         __u16 crc = 0;
1987         __le32 le_group = cpu_to_le32(block_group);
1988
1989         if (ext4_has_metadata_csum(sbi->s_sb)) {
1990                 /* Use new metadata_csum algorithm */
1991                 __le16 save_csum;
1992                 __u32 csum32;
1993
1994                 save_csum = gdp->bg_checksum;
1995                 gdp->bg_checksum = 0;
1996                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
1997                                      sizeof(le_group));
1998                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
1999                                      sbi->s_desc_size);
2000                 gdp->bg_checksum = save_csum;
2001
2002                 crc = csum32 & 0xFFFF;
2003                 goto out;
2004         }
2005
2006         /* old crc16 code */
2007         if (!(sbi->s_es->s_feature_ro_compat &
2008               cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
2009                 return 0;
2010
2011         offset = offsetof(struct ext4_group_desc, bg_checksum);
2012
2013         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2014         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2015         crc = crc16(crc, (__u8 *)gdp, offset);
2016         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2017         /* for checksum of struct ext4_group_desc do the rest...*/
2018         if ((sbi->s_es->s_feature_incompat &
2019              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2020             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2021                 crc = crc16(crc, (__u8 *)gdp + offset,
2022                             le16_to_cpu(sbi->s_es->s_desc_size) -
2023                                 offset);
2024
2025 out:
2026         return cpu_to_le16(crc);
2027 }
2028
2029 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2030                                 struct ext4_group_desc *gdp)
2031 {
2032         if (ext4_has_group_desc_csum(sb) &&
2033             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2034                                                       block_group, gdp)))
2035                 return 0;
2036
2037         return 1;
2038 }
2039
2040 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2041                               struct ext4_group_desc *gdp)
2042 {
2043         if (!ext4_has_group_desc_csum(sb))
2044                 return;
2045         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2046 }
2047
2048 /* Called at mount-time, super-block is locked */
2049 static int ext4_check_descriptors(struct super_block *sb,
2050                                   ext4_group_t *first_not_zeroed)
2051 {
2052         struct ext4_sb_info *sbi = EXT4_SB(sb);
2053         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2054         ext4_fsblk_t last_block;
2055         ext4_fsblk_t block_bitmap;
2056         ext4_fsblk_t inode_bitmap;
2057         ext4_fsblk_t inode_table;
2058         int flexbg_flag = 0;
2059         ext4_group_t i, grp = sbi->s_groups_count;
2060
2061         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2062                 flexbg_flag = 1;
2063
2064         ext4_debug("Checking group descriptors");
2065
2066         for (i = 0; i < sbi->s_groups_count; i++) {
2067                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2068
2069                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2070                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2071                 else
2072                         last_block = first_block +
2073                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2074
2075                 if ((grp == sbi->s_groups_count) &&
2076                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2077                         grp = i;
2078
2079                 block_bitmap = ext4_block_bitmap(sb, gdp);
2080                 if (block_bitmap < first_block || block_bitmap > last_block) {
2081                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2082                                "Block bitmap for group %u not in group "
2083                                "(block %llu)!", i, block_bitmap);
2084                         return 0;
2085                 }
2086                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2087                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2088                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2089                                "Inode bitmap for group %u not in group "
2090                                "(block %llu)!", i, inode_bitmap);
2091                         return 0;
2092                 }
2093                 inode_table = ext4_inode_table(sb, gdp);
2094                 if (inode_table < first_block ||
2095                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2096                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2097                                "Inode table for group %u not in group "
2098                                "(block %llu)!", i, inode_table);
2099                         return 0;
2100                 }
2101                 ext4_lock_group(sb, i);
2102                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2103                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2104                                  "Checksum for group %u failed (%u!=%u)",
2105                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2106                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2107                         if (!(sb->s_flags & MS_RDONLY)) {
2108                                 ext4_unlock_group(sb, i);
2109                                 return 0;
2110                         }
2111                 }
2112                 ext4_unlock_group(sb, i);
2113                 if (!flexbg_flag)
2114                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2115         }
2116         if (NULL != first_not_zeroed)
2117                 *first_not_zeroed = grp;
2118         return 1;
2119 }
2120
2121 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2122  * the superblock) which were deleted from all directories, but held open by
2123  * a process at the time of a crash.  We walk the list and try to delete these
2124  * inodes at recovery time (only with a read-write filesystem).
2125  *
2126  * In order to keep the orphan inode chain consistent during traversal (in
2127  * case of crash during recovery), we link each inode into the superblock
2128  * orphan list_head and handle it the same way as an inode deletion during
2129  * normal operation (which journals the operations for us).
2130  *
2131  * We only do an iget() and an iput() on each inode, which is very safe if we
2132  * accidentally point at an in-use or already deleted inode.  The worst that
2133  * can happen in this case is that we get a "bit already cleared" message from
2134  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2135  * e2fsck was run on this filesystem, and it must have already done the orphan
2136  * inode cleanup for us, so we can safely abort without any further action.
2137  */
2138 static void ext4_orphan_cleanup(struct super_block *sb,
2139                                 struct ext4_super_block *es)
2140 {
2141         unsigned int s_flags = sb->s_flags;
2142         int nr_orphans = 0, nr_truncates = 0;
2143 #ifdef CONFIG_QUOTA
2144         int i;
2145 #endif
2146         if (!es->s_last_orphan) {
2147                 jbd_debug(4, "no orphan inodes to clean up\n");
2148                 return;
2149         }
2150
2151         if (bdev_read_only(sb->s_bdev)) {
2152                 ext4_msg(sb, KERN_ERR, "write access "
2153                         "unavailable, skipping orphan cleanup");
2154                 return;
2155         }
2156
2157         /* Check if feature set would not allow a r/w mount */
2158         if (!ext4_feature_set_ok(sb, 0)) {
2159                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2160                          "unknown ROCOMPAT features");
2161                 return;
2162         }
2163
2164         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2165                 /* don't clear list on RO mount w/ errors */
2166                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2167                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2168                                   "clearing orphan list.\n");
2169                         es->s_last_orphan = 0;
2170                 }
2171                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2172                 return;
2173         }
2174
2175         if (s_flags & MS_RDONLY) {
2176                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2177                 sb->s_flags &= ~MS_RDONLY;
2178         }
2179 #ifdef CONFIG_QUOTA
2180         /* Needed for iput() to work correctly and not trash data */
2181         sb->s_flags |= MS_ACTIVE;
2182         /* Turn on quotas so that they are updated correctly */
2183         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2184                 if (EXT4_SB(sb)->s_qf_names[i]) {
2185                         int ret = ext4_quota_on_mount(sb, i);
2186                         if (ret < 0)
2187                                 ext4_msg(sb, KERN_ERR,
2188                                         "Cannot turn on journaled "
2189                                         "quota: error %d", ret);
2190                 }
2191         }
2192 #endif
2193
2194         while (es->s_last_orphan) {
2195                 struct inode *inode;
2196
2197                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2198                 if (IS_ERR(inode)) {
2199                         es->s_last_orphan = 0;
2200                         break;
2201                 }
2202
2203                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2204                 dquot_initialize(inode);
2205                 if (inode->i_nlink) {
2206                         if (test_opt(sb, DEBUG))
2207                                 ext4_msg(sb, KERN_DEBUG,
2208                                         "%s: truncating inode %lu to %lld bytes",
2209                                         __func__, inode->i_ino, inode->i_size);
2210                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2211                                   inode->i_ino, inode->i_size);
2212                         mutex_lock(&inode->i_mutex);
2213                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2214                         ext4_truncate(inode);
2215                         mutex_unlock(&inode->i_mutex);
2216                         nr_truncates++;
2217                 } else {
2218                         if (test_opt(sb, DEBUG))
2219                                 ext4_msg(sb, KERN_DEBUG,
2220                                         "%s: deleting unreferenced inode %lu",
2221                                         __func__, inode->i_ino);
2222                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2223                                   inode->i_ino);
2224                         nr_orphans++;
2225                 }
2226                 iput(inode);  /* The delete magic happens here! */
2227         }
2228
2229 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2230
2231         if (nr_orphans)
2232                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2233                        PLURAL(nr_orphans));
2234         if (nr_truncates)
2235                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2236                        PLURAL(nr_truncates));
2237 #ifdef CONFIG_QUOTA
2238         /* Turn quotas off */
2239         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2240                 if (sb_dqopt(sb)->files[i])
2241                         dquot_quota_off(sb, i);
2242         }
2243 #endif
2244         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2245 }
2246
2247 /*
2248  * Maximal extent format file size.
2249  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2250  * extent format containers, within a sector_t, and within i_blocks
2251  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2252  * so that won't be a limiting factor.
2253  *
2254  * However there is other limiting factor. We do store extents in the form
2255  * of starting block and length, hence the resulting length of the extent
2256  * covering maximum file size must fit into on-disk format containers as
2257  * well. Given that length is always by 1 unit bigger than max unit (because
2258  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2259  *
2260  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2261  */
2262 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2263 {
2264         loff_t res;
2265         loff_t upper_limit = MAX_LFS_FILESIZE;
2266
2267         /* small i_blocks in vfs inode? */
2268         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2269                 /*
2270                  * CONFIG_LBDAF is not enabled implies the inode
2271                  * i_block represent total blocks in 512 bytes
2272                  * 32 == size of vfs inode i_blocks * 8
2273                  */
2274                 upper_limit = (1LL << 32) - 1;
2275
2276                 /* total blocks in file system block size */
2277                 upper_limit >>= (blkbits - 9);
2278                 upper_limit <<= blkbits;
2279         }
2280
2281         /*
2282          * 32-bit extent-start container, ee_block. We lower the maxbytes
2283          * by one fs block, so ee_len can cover the extent of maximum file
2284          * size
2285          */
2286         res = (1LL << 32) - 1;
2287         res <<= blkbits;
2288
2289         /* Sanity check against vm- & vfs- imposed limits */
2290         if (res > upper_limit)
2291                 res = upper_limit;
2292
2293         return res;
2294 }
2295
2296 /*
2297  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2298  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2299  * We need to be 1 filesystem block less than the 2^48 sector limit.
2300  */
2301 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2302 {
2303         loff_t res = EXT4_NDIR_BLOCKS;
2304         int meta_blocks;
2305         loff_t upper_limit;
2306         /* This is calculated to be the largest file size for a dense, block
2307          * mapped file such that the file's total number of 512-byte sectors,
2308          * including data and all indirect blocks, does not exceed (2^48 - 1).
2309          *
2310          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2311          * number of 512-byte sectors of the file.
2312          */
2313
2314         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2315                 /*
2316                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2317                  * the inode i_block field represents total file blocks in
2318                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2319                  */
2320                 upper_limit = (1LL << 32) - 1;
2321
2322                 /* total blocks in file system block size */
2323                 upper_limit >>= (bits - 9);
2324
2325         } else {
2326                 /*
2327                  * We use 48 bit ext4_inode i_blocks
2328                  * With EXT4_HUGE_FILE_FL set the i_blocks
2329                  * represent total number of blocks in
2330                  * file system block size
2331                  */
2332                 upper_limit = (1LL << 48) - 1;
2333
2334         }
2335
2336         /* indirect blocks */
2337         meta_blocks = 1;
2338         /* double indirect blocks */
2339         meta_blocks += 1 + (1LL << (bits-2));
2340         /* tripple indirect blocks */
2341         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2342
2343         upper_limit -= meta_blocks;
2344         upper_limit <<= bits;
2345
2346         res += 1LL << (bits-2);
2347         res += 1LL << (2*(bits-2));
2348         res += 1LL << (3*(bits-2));
2349         res <<= bits;
2350         if (res > upper_limit)
2351                 res = upper_limit;
2352
2353         if (res > MAX_LFS_FILESIZE)
2354                 res = MAX_LFS_FILESIZE;
2355
2356         return res;
2357 }
2358
2359 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2360                                    ext4_fsblk_t logical_sb_block, int nr)
2361 {
2362         struct ext4_sb_info *sbi = EXT4_SB(sb);
2363         ext4_group_t bg, first_meta_bg;
2364         int has_super = 0;
2365
2366         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2367
2368         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2369             nr < first_meta_bg)
2370                 return logical_sb_block + nr + 1;
2371         bg = sbi->s_desc_per_block * nr;
2372         if (ext4_bg_has_super(sb, bg))
2373                 has_super = 1;
2374
2375         /*
2376          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2377          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2378          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2379          * compensate.
2380          */
2381         if (sb->s_blocksize == 1024 && nr == 0 &&
2382             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2383                 has_super++;
2384
2385         return (has_super + ext4_group_first_block_no(sb, bg));
2386 }
2387
2388 /**
2389  * ext4_get_stripe_size: Get the stripe size.
2390  * @sbi: In memory super block info
2391  *
2392  * If we have specified it via mount option, then
2393  * use the mount option value. If the value specified at mount time is
2394  * greater than the blocks per group use the super block value.
2395  * If the super block value is greater than blocks per group return 0.
2396  * Allocator needs it be less than blocks per group.
2397  *
2398  */
2399 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2400 {
2401         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2402         unsigned long stripe_width =
2403                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2404         int ret;
2405
2406         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2407                 ret = sbi->s_stripe;
2408         else if (stripe_width <= sbi->s_blocks_per_group)
2409                 ret = stripe_width;
2410         else if (stride <= sbi->s_blocks_per_group)
2411                 ret = stride;
2412         else
2413                 ret = 0;
2414
2415         /*
2416          * If the stripe width is 1, this makes no sense and
2417          * we set it to 0 to turn off stripe handling code.
2418          */
2419         if (ret <= 1)
2420                 ret = 0;
2421
2422         return ret;
2423 }
2424
2425 /* sysfs supprt */
2426
2427 struct ext4_attr {
2428         struct attribute attr;
2429         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2430         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2431                          const char *, size_t);
2432         union {
2433                 int offset;
2434                 int deprecated_val;
2435         } u;
2436 };
2437
2438 static int parse_strtoull(const char *buf,
2439                 unsigned long long max, unsigned long long *value)
2440 {
2441         int ret;
2442
2443         ret = kstrtoull(skip_spaces(buf), 0, value);
2444         if (!ret && *value > max)
2445                 ret = -EINVAL;
2446         return ret;
2447 }
2448
2449 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2450                                               struct ext4_sb_info *sbi,
2451                                               char *buf)
2452 {
2453         return snprintf(buf, PAGE_SIZE, "%llu\n",
2454                 (s64) EXT4_C2B(sbi,
2455                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2456 }
2457
2458 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2459                                          struct ext4_sb_info *sbi, char *buf)
2460 {
2461         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2462
2463         if (!sb->s_bdev->bd_part)
2464                 return snprintf(buf, PAGE_SIZE, "0\n");
2465         return snprintf(buf, PAGE_SIZE, "%lu\n",
2466                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2467                          sbi->s_sectors_written_start) >> 1);
2468 }
2469
2470 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2471                                           struct ext4_sb_info *sbi, char *buf)
2472 {
2473         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2474
2475         if (!sb->s_bdev->bd_part)
2476                 return snprintf(buf, PAGE_SIZE, "0\n");
2477         return snprintf(buf, PAGE_SIZE, "%llu\n",
2478                         (unsigned long long)(sbi->s_kbytes_written +
2479                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2480                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2481 }
2482
2483 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2484                                           struct ext4_sb_info *sbi,
2485                                           const char *buf, size_t count)
2486 {
2487         unsigned long t;
2488         int ret;
2489
2490         ret = kstrtoul(skip_spaces(buf), 0, &t);
2491         if (ret)
2492                 return ret;
2493
2494         if (t && (!is_power_of_2(t) || t > 0x40000000))
2495                 return -EINVAL;
2496
2497         sbi->s_inode_readahead_blks = t;
2498         return count;
2499 }
2500
2501 static ssize_t sbi_ui_show(struct ext4_attr *a,
2502                            struct ext4_sb_info *sbi, char *buf)
2503 {
2504         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2505
2506         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2507 }
2508
2509 static ssize_t sbi_ui_store(struct ext4_attr *a,
2510                             struct ext4_sb_info *sbi,
2511                             const char *buf, size_t count)
2512 {
2513         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2514         unsigned long t;
2515         int ret;
2516
2517         ret = kstrtoul(skip_spaces(buf), 0, &t);
2518         if (ret)
2519                 return ret;
2520         *ui = t;
2521         return count;
2522 }
2523
2524 static ssize_t es_ui_show(struct ext4_attr *a,
2525                            struct ext4_sb_info *sbi, char *buf)
2526 {
2527
2528         unsigned int *ui = (unsigned int *) (((char *) sbi->s_es) +
2529                            a->u.offset);
2530
2531         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2532 }
2533
2534 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2535                                   struct ext4_sb_info *sbi, char *buf)
2536 {
2537         return snprintf(buf, PAGE_SIZE, "%llu\n",
2538                 (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2539 }
2540
2541 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2542                                    struct ext4_sb_info *sbi,
2543                                    const char *buf, size_t count)
2544 {
2545         unsigned long long val;
2546         int ret;
2547
2548         if (parse_strtoull(buf, -1ULL, &val))
2549                 return -EINVAL;
2550         ret = ext4_reserve_clusters(sbi, val);
2551
2552         return ret ? ret : count;
2553 }
2554
2555 static ssize_t trigger_test_error(struct ext4_attr *a,
2556                                   struct ext4_sb_info *sbi,
2557                                   const char *buf, size_t count)
2558 {
2559         int len = count;
2560
2561         if (!capable(CAP_SYS_ADMIN))
2562                 return -EPERM;
2563
2564         if (len && buf[len-1] == '\n')
2565                 len--;
2566
2567         if (len)
2568                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2569         return count;
2570 }
2571
2572 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2573                                    struct ext4_sb_info *sbi, char *buf)
2574 {
2575         return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2576 }
2577
2578 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2579 static struct ext4_attr ext4_attr_##_name = {                   \
2580         .attr = {.name = __stringify(_name), .mode = _mode },   \
2581         .show   = _show,                                        \
2582         .store  = _store,                                       \
2583         .u = {                                                  \
2584                 .offset = offsetof(struct ext4_sb_info, _elname),\
2585         },                                                      \
2586 }
2587
2588 #define EXT4_ATTR_OFFSET_ES(_name,_mode,_show,_store,_elname)           \
2589 static struct ext4_attr ext4_attr_##_name = {                           \
2590         .attr = {.name = __stringify(_name), .mode = _mode },           \
2591         .show   = _show,                                                \
2592         .store  = _store,                                               \
2593         .u = {                                                          \
2594                 .offset = offsetof(struct ext4_super_block, _elname),   \
2595         },                                                              \
2596 }
2597
2598 #define EXT4_ATTR(name, mode, show, store) \
2599 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2600
2601 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2602 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2603 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2604
2605 #define EXT4_RO_ATTR_ES_UI(name, elname)        \
2606         EXT4_ATTR_OFFSET_ES(name, 0444, es_ui_show, NULL, elname)
2607 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2608         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2609
2610 #define ATTR_LIST(name) &ext4_attr_##name.attr
2611 #define EXT4_DEPRECATED_ATTR(_name, _val)       \
2612 static struct ext4_attr ext4_attr_##_name = {                   \
2613         .attr = {.name = __stringify(_name), .mode = 0444 },    \
2614         .show   = sbi_deprecated_show,                          \
2615         .u = {                                                  \
2616                 .deprecated_val = _val,                         \
2617         },                                                      \
2618 }
2619
2620 EXT4_RO_ATTR(delayed_allocation_blocks);
2621 EXT4_RO_ATTR(session_write_kbytes);
2622 EXT4_RO_ATTR(lifetime_write_kbytes);
2623 EXT4_RW_ATTR(reserved_clusters);
2624 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2625                  inode_readahead_blks_store, s_inode_readahead_blks);
2626 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2627 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2628 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2629 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2630 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2631 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2632 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2633 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2634 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2635 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2636 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2637 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2638 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2639 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2640 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2641 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2642 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
2643 EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
2644 EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
2645
2646 static struct attribute *ext4_attrs[] = {
2647         ATTR_LIST(delayed_allocation_blocks),
2648         ATTR_LIST(session_write_kbytes),
2649         ATTR_LIST(lifetime_write_kbytes),
2650         ATTR_LIST(reserved_clusters),
2651         ATTR_LIST(inode_readahead_blks),
2652         ATTR_LIST(inode_goal),
2653         ATTR_LIST(mb_stats),
2654         ATTR_LIST(mb_max_to_scan),
2655         ATTR_LIST(mb_min_to_scan),
2656         ATTR_LIST(mb_order2_req),
2657         ATTR_LIST(mb_stream_req),
2658         ATTR_LIST(mb_group_prealloc),
2659         ATTR_LIST(max_writeback_mb_bump),
2660         ATTR_LIST(extent_max_zeroout_kb),
2661         ATTR_LIST(trigger_fs_error),
2662         ATTR_LIST(err_ratelimit_interval_ms),
2663         ATTR_LIST(err_ratelimit_burst),
2664         ATTR_LIST(warning_ratelimit_interval_ms),
2665         ATTR_LIST(warning_ratelimit_burst),
2666         ATTR_LIST(msg_ratelimit_interval_ms),
2667         ATTR_LIST(msg_ratelimit_burst),
2668         ATTR_LIST(errors_count),
2669         ATTR_LIST(first_error_time),
2670         ATTR_LIST(last_error_time),
2671         NULL,
2672 };
2673
2674 /* Features this copy of ext4 supports */
2675 EXT4_INFO_ATTR(lazy_itable_init);
2676 EXT4_INFO_ATTR(batched_discard);
2677 EXT4_INFO_ATTR(meta_bg_resize);
2678
2679 static struct attribute *ext4_feat_attrs[] = {
2680         ATTR_LIST(lazy_itable_init),
2681         ATTR_LIST(batched_discard),
2682         ATTR_LIST(meta_bg_resize),
2683         NULL,
2684 };
2685
2686 static ssize_t ext4_attr_show(struct kobject *kobj,
2687                               struct attribute *attr, char *buf)
2688 {
2689         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2690                                                 s_kobj);
2691         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2692
2693         return a->show ? a->show(a, sbi, buf) : 0;
2694 }
2695
2696 static ssize_t ext4_attr_store(struct kobject *kobj,
2697                                struct attribute *attr,
2698                                const char *buf, size_t len)
2699 {
2700         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2701                                                 s_kobj);
2702         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2703
2704         return a->store ? a->store(a, sbi, buf, len) : 0;
2705 }
2706
2707 static void ext4_sb_release(struct kobject *kobj)
2708 {
2709         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2710                                                 s_kobj);
2711         complete(&sbi->s_kobj_unregister);
2712 }
2713
2714 static const struct sysfs_ops ext4_attr_ops = {
2715         .show   = ext4_attr_show,
2716         .store  = ext4_attr_store,
2717 };
2718
2719 static struct kobj_type ext4_ktype = {
2720         .default_attrs  = ext4_attrs,
2721         .sysfs_ops      = &ext4_attr_ops,
2722         .release        = ext4_sb_release,
2723 };
2724
2725 static void ext4_feat_release(struct kobject *kobj)
2726 {
2727         complete(&ext4_feat->f_kobj_unregister);
2728 }
2729
2730 static ssize_t ext4_feat_show(struct kobject *kobj,
2731                               struct attribute *attr, char *buf)
2732 {
2733         return snprintf(buf, PAGE_SIZE, "supported\n");
2734 }
2735
2736 /*
2737  * We can not use ext4_attr_show/store because it relies on the kobject
2738  * being embedded in the ext4_sb_info structure which is definitely not
2739  * true in this case.
2740  */
2741 static const struct sysfs_ops ext4_feat_ops = {
2742         .show   = ext4_feat_show,
2743         .store  = NULL,
2744 };
2745
2746 static struct kobj_type ext4_feat_ktype = {
2747         .default_attrs  = ext4_feat_attrs,
2748         .sysfs_ops      = &ext4_feat_ops,
2749         .release        = ext4_feat_release,
2750 };
2751
2752 /*
2753  * Check whether this filesystem can be mounted based on
2754  * the features present and the RDONLY/RDWR mount requested.
2755  * Returns 1 if this filesystem can be mounted as requested,
2756  * 0 if it cannot be.
2757  */
2758 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2759 {
2760         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2761                 ext4_msg(sb, KERN_ERR,
2762                         "Couldn't mount because of "
2763                         "unsupported optional features (%x)",
2764                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2765                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2766                 return 0;
2767         }
2768
2769         if (readonly)
2770                 return 1;
2771
2772         /* Check that feature set is OK for a read-write mount */
2773         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2774                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2775                          "unsupported optional features (%x)",
2776                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2777                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2778                 return 0;
2779         }
2780         /*
2781          * Large file size enabled file system can only be mounted
2782          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2783          */
2784         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2785                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2786                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2787                                  "cannot be mounted RDWR without "
2788                                  "CONFIG_LBDAF");
2789                         return 0;
2790                 }
2791         }
2792         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2793             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2794                 ext4_msg(sb, KERN_ERR,
2795                          "Can't support bigalloc feature without "
2796                          "extents feature\n");
2797                 return 0;
2798         }
2799
2800 #ifndef CONFIG_QUOTA
2801         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2802             !readonly) {
2803                 ext4_msg(sb, KERN_ERR,
2804                          "Filesystem with quota feature cannot be mounted RDWR "
2805                          "without CONFIG_QUOTA");
2806                 return 0;
2807         }
2808 #endif  /* CONFIG_QUOTA */
2809         return 1;
2810 }
2811
2812 /*
2813  * This function is called once a day if we have errors logged
2814  * on the file system
2815  */
2816 static void print_daily_error_info(unsigned long arg)
2817 {
2818         struct super_block *sb = (struct super_block *) arg;
2819         struct ext4_sb_info *sbi;
2820         struct ext4_super_block *es;
2821
2822         sbi = EXT4_SB(sb);
2823         es = sbi->s_es;
2824
2825         if (es->s_error_count)
2826                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2827                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2828                          le32_to_cpu(es->s_error_count));
2829         if (es->s_first_error_time) {
2830                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2831                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2832                        (int) sizeof(es->s_first_error_func),
2833                        es->s_first_error_func,
2834                        le32_to_cpu(es->s_first_error_line));
2835                 if (es->s_first_error_ino)
2836                         printk(": inode %u",
2837                                le32_to_cpu(es->s_first_error_ino));
2838                 if (es->s_first_error_block)
2839                         printk(": block %llu", (unsigned long long)
2840                                le64_to_cpu(es->s_first_error_block));
2841                 printk("\n");
2842         }
2843         if (es->s_last_error_time) {
2844                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2845                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2846                        (int) sizeof(es->s_last_error_func),
2847                        es->s_last_error_func,
2848                        le32_to_cpu(es->s_last_error_line));
2849                 if (es->s_last_error_ino)
2850                         printk(": inode %u",
2851                                le32_to_cpu(es->s_last_error_ino));
2852                 if (es->s_last_error_block)
2853                         printk(": block %llu", (unsigned long long)
2854                                le64_to_cpu(es->s_last_error_block));
2855                 printk("\n");
2856         }
2857         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2858 }
2859
2860 /* Find next suitable group and run ext4_init_inode_table */
2861 static int ext4_run_li_request(struct ext4_li_request *elr)
2862 {
2863         struct ext4_group_desc *gdp = NULL;
2864         ext4_group_t group, ngroups;
2865         struct super_block *sb;
2866         unsigned long timeout = 0;
2867         int ret = 0;
2868
2869         sb = elr->lr_super;
2870         ngroups = EXT4_SB(sb)->s_groups_count;
2871
2872         sb_start_write(sb);
2873         for (group = elr->lr_next_group; group < ngroups; group++) {
2874                 gdp = ext4_get_group_desc(sb, group, NULL);
2875                 if (!gdp) {
2876                         ret = 1;
2877                         break;
2878                 }
2879
2880                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2881                         break;
2882         }
2883
2884         if (group >= ngroups)
2885                 ret = 1;
2886
2887         if (!ret) {
2888                 timeout = jiffies;
2889                 ret = ext4_init_inode_table(sb, group,
2890                                             elr->lr_timeout ? 0 : 1);
2891                 if (elr->lr_timeout == 0) {
2892                         timeout = (jiffies - timeout) *
2893                                   elr->lr_sbi->s_li_wait_mult;
2894                         elr->lr_timeout = timeout;
2895                 }
2896                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2897                 elr->lr_next_group = group + 1;
2898         }
2899         sb_end_write(sb);
2900
2901         return ret;
2902 }
2903
2904 /*
2905  * Remove lr_request from the list_request and free the
2906  * request structure. Should be called with li_list_mtx held
2907  */
2908 static void ext4_remove_li_request(struct ext4_li_request *elr)
2909 {
2910         struct ext4_sb_info *sbi;
2911
2912         if (!elr)
2913                 return;
2914
2915         sbi = elr->lr_sbi;
2916
2917         list_del(&elr->lr_request);
2918         sbi->s_li_request = NULL;
2919         kfree(elr);
2920 }
2921
2922 static void ext4_unregister_li_request(struct super_block *sb)
2923 {
2924         mutex_lock(&ext4_li_mtx);
2925         if (!ext4_li_info) {
2926                 mutex_unlock(&ext4_li_mtx);
2927                 return;
2928         }
2929
2930         mutex_lock(&ext4_li_info->li_list_mtx);
2931         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2932         mutex_unlock(&ext4_li_info->li_list_mtx);
2933         mutex_unlock(&ext4_li_mtx);
2934 }
2935
2936 static struct task_struct *ext4_lazyinit_task;
2937
2938 /*
2939  * This is the function where ext4lazyinit thread lives. It walks
2940  * through the request list searching for next scheduled filesystem.
2941  * When such a fs is found, run the lazy initialization request
2942  * (ext4_rn_li_request) and keep track of the time spend in this
2943  * function. Based on that time we compute next schedule time of
2944  * the request. When walking through the list is complete, compute
2945  * next waking time and put itself into sleep.
2946  */
2947 static int ext4_lazyinit_thread(void *arg)
2948 {
2949         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2950         struct list_head *pos, *n;
2951         struct ext4_li_request *elr;
2952         unsigned long next_wakeup, cur;
2953
2954         BUG_ON(NULL == eli);
2955
2956 cont_thread:
2957         while (true) {
2958                 next_wakeup = MAX_JIFFY_OFFSET;
2959
2960                 mutex_lock(&eli->li_list_mtx);
2961                 if (list_empty(&eli->li_request_list)) {
2962                         mutex_unlock(&eli->li_list_mtx);
2963                         goto exit_thread;
2964                 }
2965
2966                 list_for_each_safe(pos, n, &eli->li_request_list) {
2967                         elr = list_entry(pos, struct ext4_li_request,
2968                                          lr_request);
2969
2970                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2971                                 if (ext4_run_li_request(elr) != 0) {
2972                                         /* error, remove the lazy_init job */
2973                                         ext4_remove_li_request(elr);
2974                                         continue;
2975                                 }
2976                         }
2977
2978                         if (time_before(elr->lr_next_sched, next_wakeup))
2979                                 next_wakeup = elr->lr_next_sched;
2980                 }
2981                 mutex_unlock(&eli->li_list_mtx);
2982
2983                 try_to_freeze();
2984
2985                 cur = jiffies;
2986                 if ((time_after_eq(cur, next_wakeup)) ||
2987                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2988                         cond_resched();
2989                         continue;
2990                 }
2991
2992                 schedule_timeout_interruptible(next_wakeup - cur);
2993
2994                 if (kthread_should_stop()) {
2995                         ext4_clear_request_list();
2996                         goto exit_thread;
2997                 }
2998         }
2999
3000 exit_thread:
3001         /*
3002          * It looks like the request list is empty, but we need
3003          * to check it under the li_list_mtx lock, to prevent any
3004          * additions into it, and of course we should lock ext4_li_mtx
3005          * to atomically free the list and ext4_li_info, because at
3006          * this point another ext4 filesystem could be registering
3007          * new one.
3008          */
3009         mutex_lock(&ext4_li_mtx);
3010         mutex_lock(&eli->li_list_mtx);
3011         if (!list_empty(&eli->li_request_list)) {
3012                 mutex_unlock(&eli->li_list_mtx);
3013                 mutex_unlock(&ext4_li_mtx);
3014                 goto cont_thread;
3015         }
3016         mutex_unlock(&eli->li_list_mtx);
3017         kfree(ext4_li_info);
3018         ext4_li_info = NULL;
3019         mutex_unlock(&ext4_li_mtx);
3020
3021         return 0;
3022 }
3023
3024 static void ext4_clear_request_list(void)
3025 {
3026         struct list_head *pos, *n;
3027         struct ext4_li_request *elr;
3028
3029         mutex_lock(&ext4_li_info->li_list_mtx);
3030         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3031                 elr = list_entry(pos, struct ext4_li_request,
3032                                  lr_request);
3033                 ext4_remove_li_request(elr);
3034         }
3035         mutex_unlock(&ext4_li_info->li_list_mtx);
3036 }
3037
3038 static int ext4_run_lazyinit_thread(void)
3039 {
3040         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3041                                          ext4_li_info, "ext4lazyinit");
3042         if (IS_ERR(ext4_lazyinit_task)) {
3043                 int err = PTR_ERR(ext4_lazyinit_task);
3044                 ext4_clear_request_list();
3045                 kfree(ext4_li_info);
3046                 ext4_li_info = NULL;
3047                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3048                                  "initialization thread\n",
3049                                  err);
3050                 return err;
3051         }
3052         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3053         return 0;
3054 }
3055
3056 /*
3057  * Check whether it make sense to run itable init. thread or not.
3058  * If there is at least one uninitialized inode table, return
3059  * corresponding group number, else the loop goes through all
3060  * groups and return total number of groups.
3061  */
3062 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3063 {
3064         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3065         struct ext4_group_desc *gdp = NULL;
3066
3067         for (group = 0; group < ngroups; group++) {
3068                 gdp = ext4_get_group_desc(sb, group, NULL);
3069                 if (!gdp)
3070                         continue;
3071
3072                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3073                         break;
3074         }
3075
3076         return group;
3077 }
3078
3079 static int ext4_li_info_new(void)
3080 {
3081         struct ext4_lazy_init *eli = NULL;
3082
3083         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3084         if (!eli)
3085                 return -ENOMEM;
3086
3087         INIT_LIST_HEAD(&eli->li_request_list);
3088         mutex_init(&eli->li_list_mtx);
3089
3090         eli->li_state |= EXT4_LAZYINIT_QUIT;
3091
3092         ext4_li_info = eli;
3093
3094         return 0;
3095 }
3096
3097 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3098                                             ext4_group_t start)
3099 {
3100         struct ext4_sb_info *sbi = EXT4_SB(sb);
3101         struct ext4_li_request *elr;
3102
3103         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3104         if (!elr)
3105                 return NULL;
3106
3107         elr->lr_super = sb;
3108         elr->lr_sbi = sbi;
3109         elr->lr_next_group = start;
3110
3111         /*
3112          * Randomize first schedule time of the request to
3113          * spread the inode table initialization requests
3114          * better.
3115          */
3116         elr->lr_next_sched = jiffies + (prandom_u32() %
3117                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3118         return elr;
3119 }
3120
3121 int ext4_register_li_request(struct super_block *sb,
3122                              ext4_group_t first_not_zeroed)
3123 {
3124         struct ext4_sb_info *sbi = EXT4_SB(sb);
3125         struct ext4_li_request *elr = NULL;
3126         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3127         int ret = 0;
3128
3129         mutex_lock(&ext4_li_mtx);
3130         if (sbi->s_li_request != NULL) {
3131                 /*
3132                  * Reset timeout so it can be computed again, because
3133                  * s_li_wait_mult might have changed.
3134                  */
3135                 sbi->s_li_request->lr_timeout = 0;
3136                 goto out;
3137         }
3138
3139         if (first_not_zeroed == ngroups ||
3140             (sb->s_flags & MS_RDONLY) ||
3141             !test_opt(sb, INIT_INODE_TABLE))
3142                 goto out;
3143
3144         elr = ext4_li_request_new(sb, first_not_zeroed);
3145         if (!elr) {
3146                 ret = -ENOMEM;
3147                 goto out;
3148         }
3149
3150         if (NULL == ext4_li_info) {
3151                 ret = ext4_li_info_new();
3152                 if (ret)
3153                         goto out;
3154         }
3155
3156         mutex_lock(&ext4_li_info->li_list_mtx);
3157         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3158         mutex_unlock(&ext4_li_info->li_list_mtx);
3159
3160         sbi->s_li_request = elr;
3161         /*
3162          * set elr to NULL here since it has been inserted to
3163          * the request_list and the removal and free of it is
3164          * handled by ext4_clear_request_list from now on.
3165          */
3166         elr = NULL;
3167
3168         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3169                 ret = ext4_run_lazyinit_thread();
3170                 if (ret)
3171                         goto out;
3172         }
3173 out:
3174         mutex_unlock(&ext4_li_mtx);
3175         if (ret)
3176                 kfree(elr);
3177         return ret;
3178 }
3179
3180 /*
3181  * We do not need to lock anything since this is called on
3182  * module unload.
3183  */
3184 static void ext4_destroy_lazyinit_thread(void)
3185 {
3186         /*
3187          * If thread exited earlier
3188          * there's nothing to be done.
3189          */
3190         if (!ext4_li_info || !ext4_lazyinit_task)
3191                 return;
3192
3193         kthread_stop(ext4_lazyinit_task);
3194 }
3195
3196 static int set_journal_csum_feature_set(struct super_block *sb)
3197 {
3198         int ret = 1;
3199         int compat, incompat;
3200         struct ext4_sb_info *sbi = EXT4_SB(sb);
3201
3202         if (ext4_has_metadata_csum(sb)) {
3203                 /* journal checksum v3 */
3204                 compat = 0;
3205                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3206         } else {
3207                 /* journal checksum v1 */
3208                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3209                 incompat = 0;
3210         }
3211
3212         jbd2_journal_clear_features(sbi->s_journal,
3213                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3214                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3215                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3216         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3217                 ret = jbd2_journal_set_features(sbi->s_journal,
3218                                 compat, 0,
3219                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3220                                 incompat);
3221         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3222                 ret = jbd2_journal_set_features(sbi->s_journal,
3223                                 compat, 0,
3224                                 incompat);
3225                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3226                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3227         } else {
3228                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3229                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3230         }
3231
3232         return ret;
3233 }
3234
3235 /*
3236  * Note: calculating the overhead so we can be compatible with
3237  * historical BSD practice is quite difficult in the face of
3238  * clusters/bigalloc.  This is because multiple metadata blocks from
3239  * different block group can end up in the same allocation cluster.
3240  * Calculating the exact overhead in the face of clustered allocation
3241  * requires either O(all block bitmaps) in memory or O(number of block
3242  * groups**2) in time.  We will still calculate the superblock for
3243  * older file systems --- and if we come across with a bigalloc file
3244  * system with zero in s_overhead_clusters the estimate will be close to
3245  * correct especially for very large cluster sizes --- but for newer
3246  * file systems, it's better to calculate this figure once at mkfs
3247  * time, and store it in the superblock.  If the superblock value is
3248  * present (even for non-bigalloc file systems), we will use it.
3249  */
3250 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3251                           char *buf)
3252 {
3253         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3254         struct ext4_group_desc  *gdp;
3255         ext4_fsblk_t            first_block, last_block, b;
3256         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3257         int                     s, j, count = 0;
3258
3259         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3260                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3261                         sbi->s_itb_per_group + 2);
3262
3263         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3264                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3265         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3266         for (i = 0; i < ngroups; i++) {
3267                 gdp = ext4_get_group_desc(sb, i, NULL);
3268                 b = ext4_block_bitmap(sb, gdp);
3269                 if (b >= first_block && b <= last_block) {
3270                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3271                         count++;
3272                 }
3273                 b = ext4_inode_bitmap(sb, gdp);
3274                 if (b >= first_block && b <= last_block) {
3275                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3276                         count++;
3277                 }
3278                 b = ext4_inode_table(sb, gdp);
3279                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3280                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3281                                 int c = EXT4_B2C(sbi, b - first_block);
3282                                 ext4_set_bit(c, buf);
3283                                 count++;
3284                         }
3285                 if (i != grp)
3286                         continue;
3287                 s = 0;
3288                 if (ext4_bg_has_super(sb, grp)) {
3289                         ext4_set_bit(s++, buf);
3290                         count++;
3291                 }
3292                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3293                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3294                         count++;
3295                 }
3296         }
3297         if (!count)
3298                 return 0;
3299         return EXT4_CLUSTERS_PER_GROUP(sb) -
3300                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3301 }
3302
3303 /*
3304  * Compute the overhead and stash it in sbi->s_overhead
3305  */
3306 int ext4_calculate_overhead(struct super_block *sb)
3307 {
3308         struct ext4_sb_info *sbi = EXT4_SB(sb);
3309         struct ext4_super_block *es = sbi->s_es;
3310         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3311         ext4_fsblk_t overhead = 0;
3312         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3313
3314         if (!buf)
3315                 return -ENOMEM;
3316
3317         /*
3318          * Compute the overhead (FS structures).  This is constant
3319          * for a given filesystem unless the number of block groups
3320          * changes so we cache the previous value until it does.
3321          */
3322
3323         /*
3324          * All of the blocks before first_data_block are overhead
3325          */
3326         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3327
3328         /*
3329          * Add the overhead found in each block group
3330          */
3331         for (i = 0; i < ngroups; i++) {
3332                 int blks;
3333
3334                 blks = count_overhead(sb, i, buf);
3335                 overhead += blks;
3336                 if (blks)
3337                         memset(buf, 0, PAGE_SIZE);
3338                 cond_resched();
3339         }
3340         /* Add the internal journal blocks as well */
3341         if (sbi->s_journal && !sbi->journal_bdev)
3342                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3343
3344         sbi->s_overhead = overhead;
3345         smp_wmb();
3346         free_page((unsigned long) buf);
3347         return 0;
3348 }
3349
3350
3351 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3352 {
3353         ext4_fsblk_t resv_clusters;
3354
3355         /*
3356          * There's no need to reserve anything when we aren't using extents.
3357          * The space estimates are exact, there are no unwritten extents,
3358          * hole punching doesn't need new metadata... This is needed especially
3359          * to keep ext2/3 backward compatibility.
3360          */
3361         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3362                 return 0;
3363         /*
3364          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3365          * This should cover the situations where we can not afford to run
3366          * out of space like for example punch hole, or converting
3367          * unwritten extents in delalloc path. In most cases such
3368          * allocation would require 1, or 2 blocks, higher numbers are
3369          * very rare.
3370          */
3371         resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3372                         EXT4_SB(sb)->s_cluster_bits;
3373
3374         do_div(resv_clusters, 50);
3375         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3376
3377         return resv_clusters;
3378 }
3379
3380
3381 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3382 {
3383         ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3384                                 sbi->s_cluster_bits;
3385
3386         if (count >= clusters)
3387                 return -EINVAL;
3388
3389         atomic64_set(&sbi->s_resv_clusters, count);
3390         return 0;
3391 }
3392
3393 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3394 {
3395         char *orig_data = kstrdup(data, GFP_KERNEL);
3396         struct buffer_head *bh;
3397         struct ext4_super_block *es = NULL;
3398         struct ext4_sb_info *sbi;
3399         ext4_fsblk_t block;
3400         ext4_fsblk_t sb_block = get_sb_block(&data);
3401         ext4_fsblk_t logical_sb_block;
3402         unsigned long offset = 0;
3403         unsigned long journal_devnum = 0;
3404         unsigned long def_mount_opts;
3405         struct inode *root;
3406         char *cp;
3407         const char *descr;
3408         int ret = -ENOMEM;
3409         int blocksize, clustersize;
3410         unsigned int db_count;
3411         unsigned int i;
3412         int needs_recovery, has_huge_files, has_bigalloc;
3413         __u64 blocks_count;
3414         int err = 0;
3415         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3416         ext4_group_t first_not_zeroed;
3417
3418         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3419         if (!sbi)
3420                 goto out_free_orig;
3421
3422         sbi->s_blockgroup_lock =
3423                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3424         if (!sbi->s_blockgroup_lock) {
3425                 kfree(sbi);
3426                 goto out_free_orig;
3427         }
3428         sb->s_fs_info = sbi;
3429         sbi->s_sb = sb;
3430         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3431         sbi->s_sb_block = sb_block;
3432         if (sb->s_bdev->bd_part)
3433                 sbi->s_sectors_written_start =
3434                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3435
3436         /* Cleanup superblock name */
3437         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3438                 *cp = '!';
3439
3440         /* -EINVAL is default */
3441         ret = -EINVAL;
3442         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3443         if (!blocksize) {
3444                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3445                 goto out_fail;
3446         }
3447
3448         /*
3449          * The ext4 superblock will not be buffer aligned for other than 1kB
3450          * block sizes.  We need to calculate the offset from buffer start.
3451          */
3452         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3453                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3454                 offset = do_div(logical_sb_block, blocksize);
3455         } else {
3456                 logical_sb_block = sb_block;
3457         }
3458
3459         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3460                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3461                 goto out_fail;
3462         }
3463         /*
3464          * Note: s_es must be initialized as soon as possible because
3465          *       some ext4 macro-instructions depend on its value
3466          */
3467         es = (struct ext4_super_block *) (bh->b_data + offset);
3468         sbi->s_es = es;
3469         sb->s_magic = le16_to_cpu(es->s_magic);
3470         if (sb->s_magic != EXT4_SUPER_MAGIC)
3471                 goto cantfind_ext4;
3472         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3473
3474         /* Warn if metadata_csum and gdt_csum are both set. */
3475         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3476                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3477             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3478                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3479                              "redundant flags; please run fsck.");
3480
3481         /* Check for a known checksum algorithm */
3482         if (!ext4_verify_csum_type(sb, es)) {
3483                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3484                          "unknown checksum algorithm.");
3485                 silent = 1;
3486                 goto cantfind_ext4;
3487         }
3488
3489         /* Load the checksum driver */
3490         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3491                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3492                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3493                 if (IS_ERR(sbi->s_chksum_driver)) {
3494                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3495                         ret = PTR_ERR(sbi->s_chksum_driver);
3496                         sbi->s_chksum_driver = NULL;
3497                         goto failed_mount;
3498                 }
3499         }
3500
3501         /* Check superblock checksum */
3502         if (!ext4_superblock_csum_verify(sb, es)) {
3503                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3504                          "invalid superblock checksum.  Run e2fsck?");
3505                 silent = 1;
3506                 goto cantfind_ext4;
3507         }
3508
3509         /* Precompute checksum seed for all metadata */
3510         if (ext4_has_metadata_csum(sb))
3511                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3512                                                sizeof(es->s_uuid));
3513
3514         /* Set defaults before we parse the mount options */
3515         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3516         set_opt(sb, INIT_INODE_TABLE);
3517         if (def_mount_opts & EXT4_DEFM_DEBUG)
3518                 set_opt(sb, DEBUG);
3519         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3520                 set_opt(sb, GRPID);
3521         if (def_mount_opts & EXT4_DEFM_UID16)
3522                 set_opt(sb, NO_UID32);
3523         /* xattr user namespace & acls are now defaulted on */
3524         set_opt(sb, XATTR_USER);
3525 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3526         set_opt(sb, POSIX_ACL);
3527 #endif
3528         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3529         if (ext4_has_metadata_csum(sb))
3530                 set_opt(sb, JOURNAL_CHECKSUM);
3531
3532         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3533                 set_opt(sb, JOURNAL_DATA);
3534         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3535                 set_opt(sb, ORDERED_DATA);
3536         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3537                 set_opt(sb, WRITEBACK_DATA);
3538
3539         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3540                 set_opt(sb, ERRORS_PANIC);
3541         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3542                 set_opt(sb, ERRORS_CONT);
3543         else
3544                 set_opt(sb, ERRORS_RO);
3545         /* block_validity enabled by default; disable with noblock_validity */
3546         set_opt(sb, BLOCK_VALIDITY);
3547         if (def_mount_opts & EXT4_DEFM_DISCARD)
3548                 set_opt(sb, DISCARD);
3549
3550         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3551         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3552         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3553         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3554         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3555
3556         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3557                 set_opt(sb, BARRIER);
3558
3559         /*
3560          * enable delayed allocation by default
3561          * Use -o nodelalloc to turn it off
3562          */
3563         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3564             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3565                 set_opt(sb, DELALLOC);
3566
3567         /*
3568          * set default s_li_wait_mult for lazyinit, for the case there is
3569          * no mount option specified.
3570          */
3571         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3572
3573         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3574                            &journal_devnum, &journal_ioprio, 0)) {
3575                 ext4_msg(sb, KERN_WARNING,
3576                          "failed to parse options in superblock: %s",
3577                          sbi->s_es->s_mount_opts);
3578         }
3579         sbi->s_def_mount_opt = sbi->s_mount_opt;
3580         if (!parse_options((char *) data, sb, &journal_devnum,
3581                            &journal_ioprio, 0))
3582                 goto failed_mount;
3583
3584         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3585                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3586                             "with data=journal disables delayed "
3587                             "allocation and O_DIRECT support!\n");
3588                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3589                         ext4_msg(sb, KERN_ERR, "can't mount with "
3590                                  "both data=journal and delalloc");
3591                         goto failed_mount;
3592                 }
3593                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3594                         ext4_msg(sb, KERN_ERR, "can't mount with "
3595                                  "both data=journal and dioread_nolock");
3596                         goto failed_mount;
3597                 }
3598                 if (test_opt(sb, DELALLOC))
3599                         clear_opt(sb, DELALLOC);
3600         }
3601
3602         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3603                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3604
3605         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3606             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3607              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3608              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3609                 ext4_msg(sb, KERN_WARNING,
3610                        "feature flags set on rev 0 fs, "
3611                        "running e2fsck is recommended");
3612
3613         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3614                 set_opt2(sb, HURD_COMPAT);
3615                 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
3616                                               EXT4_FEATURE_INCOMPAT_64BIT)) {
3617                         ext4_msg(sb, KERN_ERR,
3618                                  "The Hurd can't support 64-bit file systems");
3619                         goto failed_mount;
3620                 }
3621         }
3622
3623         if (IS_EXT2_SB(sb)) {
3624                 if (ext2_feature_set_ok(sb))
3625                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3626                                  "using the ext4 subsystem");
3627                 else {
3628                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3629                                  "to feature incompatibilities");
3630                         goto failed_mount;
3631                 }
3632         }
3633
3634         if (IS_EXT3_SB(sb)) {
3635                 if (ext3_feature_set_ok(sb))
3636                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3637                                  "using the ext4 subsystem");
3638                 else {
3639                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3640                                  "to feature incompatibilities");
3641                         goto failed_mount;
3642                 }
3643         }
3644
3645         /*
3646          * Check feature flags regardless of the revision level, since we
3647          * previously didn't change the revision level when setting the flags,
3648          * so there is a chance incompat flags are set on a rev 0 filesystem.
3649          */
3650         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3651                 goto failed_mount;
3652
3653         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3654         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3655             blocksize > EXT4_MAX_BLOCK_SIZE) {
3656                 ext4_msg(sb, KERN_ERR,
3657                        "Unsupported filesystem blocksize %d", blocksize);
3658                 goto failed_mount;
3659         }
3660
3661         if (sb->s_blocksize != blocksize) {
3662                 /* Validate the filesystem blocksize */
3663                 if (!sb_set_blocksize(sb, blocksize)) {
3664                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3665                                         blocksize);
3666                         goto failed_mount;
3667                 }
3668
3669                 brelse(bh);
3670                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3671                 offset = do_div(logical_sb_block, blocksize);
3672                 bh = sb_bread_unmovable(sb, logical_sb_block);
3673                 if (!bh) {
3674                         ext4_msg(sb, KERN_ERR,
3675                                "Can't read superblock on 2nd try");
3676                         goto failed_mount;
3677                 }
3678                 es = (struct ext4_super_block *)(bh->b_data + offset);
3679                 sbi->s_es = es;
3680                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3681                         ext4_msg(sb, KERN_ERR,
3682                                "Magic mismatch, very weird!");
3683                         goto failed_mount;
3684                 }
3685         }
3686
3687         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3688                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3689         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3690                                                       has_huge_files);
3691         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3692
3693         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3694                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3695                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3696         } else {
3697                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3698                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3699                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3700                     (!is_power_of_2(sbi->s_inode_size)) ||
3701                     (sbi->s_inode_size > blocksize)) {
3702                         ext4_msg(sb, KERN_ERR,
3703                                "unsupported inode size: %d",
3704                                sbi->s_inode_size);
3705                         goto failed_mount;
3706                 }
3707                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3708                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3709         }
3710
3711         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3712         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3713                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3714                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3715                     !is_power_of_2(sbi->s_desc_size)) {
3716                         ext4_msg(sb, KERN_ERR,
3717                                "unsupported descriptor size %lu",
3718                                sbi->s_desc_size);
3719                         goto failed_mount;
3720                 }
3721         } else
3722                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3723
3724         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3725         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3726         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3727                 goto cantfind_ext4;
3728
3729         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3730         if (sbi->s_inodes_per_block == 0)
3731                 goto cantfind_ext4;
3732         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3733                                         sbi->s_inodes_per_block;
3734         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3735         sbi->s_sbh = bh;
3736         sbi->s_mount_state = le16_to_cpu(es->s_state);
3737         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3738         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3739
3740         for (i = 0; i < 4; i++)
3741                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3742         sbi->s_def_hash_version = es->s_def_hash_version;
3743         if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3744                 i = le32_to_cpu(es->s_flags);
3745                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3746                         sbi->s_hash_unsigned = 3;
3747                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3748 #ifdef __CHAR_UNSIGNED__
3749                         if (!(sb->s_flags & MS_RDONLY))
3750                                 es->s_flags |=
3751                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3752                         sbi->s_hash_unsigned = 3;
3753 #else
3754                         if (!(sb->s_flags & MS_RDONLY))
3755                                 es->s_flags |=
3756                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3757 #endif
3758                 }
3759         }
3760
3761         /* Handle clustersize */
3762         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3763         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3764                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3765         if (has_bigalloc) {
3766                 if (clustersize < blocksize) {
3767                         ext4_msg(sb, KERN_ERR,
3768                                  "cluster size (%d) smaller than "
3769                                  "block size (%d)", clustersize, blocksize);
3770                         goto failed_mount;
3771                 }
3772                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3773                         le32_to_cpu(es->s_log_block_size);
3774                 sbi->s_clusters_per_group =
3775                         le32_to_cpu(es->s_clusters_per_group);
3776                 if (sbi->s_clusters_per_group > blocksize * 8) {
3777                         ext4_msg(sb, KERN_ERR,
3778                                  "#clusters per group too big: %lu",
3779                                  sbi->s_clusters_per_group);
3780                         goto failed_mount;
3781                 }
3782                 if (sbi->s_blocks_per_group !=
3783                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3784                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3785                                  "clusters per group (%lu) inconsistent",
3786                                  sbi->s_blocks_per_group,
3787                                  sbi->s_clusters_per_group);
3788                         goto failed_mount;
3789                 }
3790         } else {
3791                 if (clustersize != blocksize) {
3792                         ext4_warning(sb, "fragment/cluster size (%d) != "
3793                                      "block size (%d)", clustersize,
3794                                      blocksize);
3795                         clustersize = blocksize;
3796                 }
3797                 if (sbi->s_blocks_per_group > blocksize * 8) {
3798                         ext4_msg(sb, KERN_ERR,
3799                                  "#blocks per group too big: %lu",
3800                                  sbi->s_blocks_per_group);
3801                         goto failed_mount;
3802                 }
3803                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3804                 sbi->s_cluster_bits = 0;
3805         }
3806         sbi->s_cluster_ratio = clustersize / blocksize;
3807
3808         if (sbi->s_inodes_per_group > blocksize * 8) {
3809                 ext4_msg(sb, KERN_ERR,
3810                        "#inodes per group too big: %lu",
3811                        sbi->s_inodes_per_group);
3812                 goto failed_mount;
3813         }
3814
3815         /* Do we have standard group size of clustersize * 8 blocks ? */
3816         if (sbi->s_blocks_per_group == clustersize << 3)
3817                 set_opt2(sb, STD_GROUP_SIZE);
3818
3819         /*
3820          * Test whether we have more sectors than will fit in sector_t,
3821          * and whether the max offset is addressable by the page cache.
3822          */
3823         err = generic_check_addressable(sb->s_blocksize_bits,
3824                                         ext4_blocks_count(es));
3825         if (err) {
3826                 ext4_msg(sb, KERN_ERR, "filesystem"
3827                          " too large to mount safely on this system");
3828                 if (sizeof(sector_t) < 8)
3829                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3830                 goto failed_mount;
3831         }
3832
3833         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3834                 goto cantfind_ext4;
3835
3836         /* check blocks count against device size */
3837         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3838         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3839                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3840                        "exceeds size of device (%llu blocks)",
3841                        ext4_blocks_count(es), blocks_count);
3842                 goto failed_mount;
3843         }
3844
3845         /*
3846          * It makes no sense for the first data block to be beyond the end
3847          * of the filesystem.
3848          */
3849         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3850                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3851                          "block %u is beyond end of filesystem (%llu)",
3852                          le32_to_cpu(es->s_first_data_block),
3853                          ext4_blocks_count(es));
3854                 goto failed_mount;
3855         }
3856         blocks_count = (ext4_blocks_count(es) -
3857                         le32_to_cpu(es->s_first_data_block) +
3858                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3859         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3860         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3861                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3862                        "(block count %llu, first data block %u, "
3863                        "blocks per group %lu)", sbi->s_groups_count,
3864                        ext4_blocks_count(es),
3865                        le32_to_cpu(es->s_first_data_block),
3866                        EXT4_BLOCKS_PER_GROUP(sb));
3867                 goto failed_mount;
3868         }
3869         sbi->s_groups_count = blocks_count;
3870         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3871                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3872         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3873                    EXT4_DESC_PER_BLOCK(sb);
3874         sbi->s_group_desc = ext4_kvmalloc(db_count *
3875                                           sizeof(struct buffer_head *),
3876                                           GFP_KERNEL);
3877         if (sbi->s_group_desc == NULL) {
3878                 ext4_msg(sb, KERN_ERR, "not enough memory");
3879                 ret = -ENOMEM;
3880                 goto failed_mount;
3881         }
3882
3883         if (ext4_proc_root)
3884                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3885
3886         if (sbi->s_proc)
3887                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3888                                  &ext4_seq_options_fops, sb);
3889
3890         bgl_lock_init(sbi->s_blockgroup_lock);
3891
3892         for (i = 0; i < db_count; i++) {
3893                 block = descriptor_loc(sb, logical_sb_block, i);
3894                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3895                 if (!sbi->s_group_desc[i]) {
3896                         ext4_msg(sb, KERN_ERR,
3897                                "can't read group descriptor %d", i);
3898                         db_count = i;
3899                         goto failed_mount2;
3900                 }
3901         }
3902         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3903                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3904                 goto failed_mount2;
3905         }
3906
3907         sbi->s_gdb_count = db_count;
3908         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3909         spin_lock_init(&sbi->s_next_gen_lock);
3910
3911         init_timer(&sbi->s_err_report);
3912         sbi->s_err_report.function = print_daily_error_info;
3913         sbi->s_err_report.data = (unsigned long) sb;
3914
3915         /* Register extent status tree shrinker */
3916         if (ext4_es_register_shrinker(sbi))
3917                 goto failed_mount3;
3918
3919         sbi->s_stripe = ext4_get_stripe_size(sbi);
3920         sbi->s_extent_max_zeroout_kb = 32;
3921
3922         /*
3923          * set up enough so that it can read an inode
3924          */
3925         sb->s_op = &ext4_sops;
3926         sb->s_export_op = &ext4_export_ops;
3927         sb->s_xattr = ext4_xattr_handlers;
3928 #ifdef CONFIG_QUOTA
3929         sb->dq_op = &ext4_quota_operations;
3930         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3931                 sb->s_qcop = &ext4_qctl_sysfile_operations;
3932         else
3933                 sb->s_qcop = &ext4_qctl_operations;
3934 #endif
3935         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3936
3937         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3938         mutex_init(&sbi->s_orphan_lock);
3939
3940         sb->s_root = NULL;
3941
3942         needs_recovery = (es->s_last_orphan != 0 ||
3943                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3944                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3945
3946         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3947             !(sb->s_flags & MS_RDONLY))
3948                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3949                         goto failed_mount3a;
3950
3951         /*
3952          * The first inode we look at is the journal inode.  Don't try
3953          * root first: it may be modified in the journal!
3954          */
3955         if (!test_opt(sb, NOLOAD) &&
3956             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3957                 if (ext4_load_journal(sb, es, journal_devnum))
3958                         goto failed_mount3a;
3959         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3960               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3961                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3962                        "suppressed and not mounted read-only");
3963                 goto failed_mount_wq;
3964         } else {
3965                 clear_opt(sb, DATA_FLAGS);
3966                 sbi->s_journal = NULL;
3967                 needs_recovery = 0;
3968                 goto no_journal;
3969         }
3970
3971         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3972             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3973                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3974                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3975                 goto failed_mount_wq;
3976         }
3977
3978         if (!set_journal_csum_feature_set(sb)) {
3979                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3980                          "feature set");
3981                 goto failed_mount_wq;
3982         }
3983
3984         /* We have now updated the journal if required, so we can
3985          * validate the data journaling mode. */
3986         switch (test_opt(sb, DATA_FLAGS)) {
3987         case 0:
3988                 /* No mode set, assume a default based on the journal
3989                  * capabilities: ORDERED_DATA if the journal can
3990                  * cope, else JOURNAL_DATA
3991                  */
3992                 if (jbd2_journal_check_available_features
3993                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3994                         set_opt(sb, ORDERED_DATA);
3995                 else
3996                         set_opt(sb, JOURNAL_DATA);
3997                 break;
3998
3999         case EXT4_MOUNT_ORDERED_DATA:
4000         case EXT4_MOUNT_WRITEBACK_DATA:
4001                 if (!jbd2_journal_check_available_features
4002                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4003                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4004                                "requested data journaling mode");
4005                         goto failed_mount_wq;
4006                 }
4007         default:
4008                 break;
4009         }
4010         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4011
4012         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4013
4014 no_journal:
4015         if (ext4_mballoc_ready) {
4016                 sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
4017                 if (!sbi->s_mb_cache) {
4018                         ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4019                         goto failed_mount_wq;
4020                 }
4021         }
4022
4023         /*
4024          * Get the # of file system overhead blocks from the
4025          * superblock if present.
4026          */
4027         if (es->s_overhead_clusters)
4028                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4029         else {
4030                 err = ext4_calculate_overhead(sb);
4031                 if (err)
4032                         goto failed_mount_wq;
4033         }
4034
4035         /*
4036          * The maximum number of concurrent works can be high and
4037          * concurrency isn't really necessary.  Limit it to 1.
4038          */
4039         EXT4_SB(sb)->rsv_conversion_wq =
4040                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4041         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4042                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4043                 ret = -ENOMEM;
4044                 goto failed_mount4;
4045         }
4046
4047         /*
4048          * The jbd2_journal_load will have done any necessary log recovery,
4049          * so we can safely mount the rest of the filesystem now.
4050          */
4051
4052         root = ext4_iget(sb, EXT4_ROOT_INO);
4053         if (IS_ERR(root)) {
4054                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4055                 ret = PTR_ERR(root);
4056                 root = NULL;
4057                 goto failed_mount4;
4058         }
4059         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4060                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4061                 iput(root);
4062                 goto failed_mount4;
4063         }
4064         sb->s_root = d_make_root(root);
4065         if (!sb->s_root) {
4066                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4067                 ret = -ENOMEM;
4068                 goto failed_mount4;
4069         }
4070
4071         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4072                 sb->s_flags |= MS_RDONLY;
4073
4074         /* determine the minimum size of new large inodes, if present */
4075         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4076                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4077                                                      EXT4_GOOD_OLD_INODE_SIZE;
4078                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4079                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4080                         if (sbi->s_want_extra_isize <
4081                             le16_to_cpu(es->s_want_extra_isize))
4082                                 sbi->s_want_extra_isize =
4083                                         le16_to_cpu(es->s_want_extra_isize);
4084                         if (sbi->s_want_extra_isize <
4085                             le16_to_cpu(es->s_min_extra_isize))
4086                                 sbi->s_want_extra_isize =
4087                                         le16_to_cpu(es->s_min_extra_isize);
4088                 }
4089         }
4090         /* Check if enough inode space is available */
4091         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4092                                                         sbi->s_inode_size) {
4093                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4094                                                        EXT4_GOOD_OLD_INODE_SIZE;
4095                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4096                          "available");
4097         }
4098
4099         err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4100         if (err) {
4101                 ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4102                          "reserved pool", ext4_calculate_resv_clusters(sb));
4103                 goto failed_mount4a;
4104         }
4105
4106         err = ext4_setup_system_zone(sb);
4107         if (err) {
4108                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4109                          "zone (%d)", err);
4110                 goto failed_mount4a;
4111         }
4112
4113         ext4_ext_init(sb);
4114         err = ext4_mb_init(sb);
4115         if (err) {
4116                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4117                          err);
4118                 goto failed_mount5;
4119         }
4120
4121         block = ext4_count_free_clusters(sb);
4122         ext4_free_blocks_count_set(sbi->s_es,
4123                                    EXT4_C2B(sbi, block));
4124         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4125                                   GFP_KERNEL);
4126         if (!err) {
4127                 unsigned long freei = ext4_count_free_inodes(sb);
4128                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4129                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4130                                           GFP_KERNEL);
4131         }
4132         if (!err)
4133                 err = percpu_counter_init(&sbi->s_dirs_counter,
4134                                           ext4_count_dirs(sb), GFP_KERNEL);
4135         if (!err)
4136                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4137                                           GFP_KERNEL);
4138         if (err) {
4139                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4140                 goto failed_mount6;
4141         }
4142
4143         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
4144                 if (!ext4_fill_flex_info(sb)) {
4145                         ext4_msg(sb, KERN_ERR,
4146                                "unable to initialize "
4147                                "flex_bg meta info!");
4148                         goto failed_mount6;
4149                 }
4150
4151         err = ext4_register_li_request(sb, first_not_zeroed);
4152         if (err)
4153                 goto failed_mount6;
4154
4155         sbi->s_kobj.kset = ext4_kset;
4156         init_completion(&sbi->s_kobj_unregister);
4157         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4158                                    "%s", sb->s_id);
4159         if (err)
4160                 goto failed_mount7;
4161
4162 #ifdef CONFIG_QUOTA
4163         /* Enable quota usage during mount. */
4164         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4165             !(sb->s_flags & MS_RDONLY)) {
4166                 err = ext4_enable_quotas(sb);
4167                 if (err)
4168                         goto failed_mount8;
4169         }
4170 #endif  /* CONFIG_QUOTA */
4171
4172         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4173         ext4_orphan_cleanup(sb, es);
4174         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4175         if (needs_recovery) {
4176                 ext4_msg(sb, KERN_INFO, "recovery complete");
4177                 ext4_mark_recovery_complete(sb, es);
4178         }
4179         if (EXT4_SB(sb)->s_journal) {
4180                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4181                         descr = " journalled data mode";
4182                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4183                         descr = " ordered data mode";
4184                 else
4185                         descr = " writeback data mode";
4186         } else
4187                 descr = "out journal";
4188
4189         if (test_opt(sb, DISCARD)) {
4190                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4191                 if (!blk_queue_discard(q))
4192                         ext4_msg(sb, KERN_WARNING,
4193                                  "mounting with \"discard\" option, but "
4194                                  "the device does not support discard");
4195         }
4196
4197         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4198                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4199                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4200
4201         if (es->s_error_count)
4202                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4203
4204         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4205         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4206         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4207         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4208
4209         kfree(orig_data);
4210         return 0;
4211
4212 cantfind_ext4:
4213         if (!silent)
4214                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4215         goto failed_mount;
4216
4217 #ifdef CONFIG_QUOTA
4218 failed_mount8:
4219         kobject_del(&sbi->s_kobj);
4220 #endif
4221 failed_mount7:
4222         ext4_unregister_li_request(sb);
4223 failed_mount6:
4224         ext4_mb_release(sb);
4225         if (sbi->s_flex_groups)
4226                 kvfree(sbi->s_flex_groups);
4227         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4228         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4229         percpu_counter_destroy(&sbi->s_dirs_counter);
4230         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4231 failed_mount5:
4232         ext4_ext_release(sb);
4233         ext4_release_system_zone(sb);
4234 failed_mount4a:
4235         dput(sb->s_root);
4236         sb->s_root = NULL;
4237 failed_mount4:
4238         ext4_msg(sb, KERN_ERR, "mount failed");
4239         if (EXT4_SB(sb)->rsv_conversion_wq)
4240                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4241 failed_mount_wq:
4242         if (sbi->s_journal) {
4243                 jbd2_journal_destroy(sbi->s_journal);
4244                 sbi->s_journal = NULL;
4245         }
4246 failed_mount3a:
4247         ext4_es_unregister_shrinker(sbi);
4248 failed_mount3:
4249         del_timer_sync(&sbi->s_err_report);
4250         if (sbi->s_mmp_tsk)
4251                 kthread_stop(sbi->s_mmp_tsk);
4252 failed_mount2:
4253         for (i = 0; i < db_count; i++)
4254                 brelse(sbi->s_group_desc[i]);
4255         kvfree(sbi->s_group_desc);
4256 failed_mount:
4257         if (sbi->s_chksum_driver)
4258                 crypto_free_shash(sbi->s_chksum_driver);
4259         if (sbi->s_proc) {
4260                 remove_proc_entry("options", sbi->s_proc);
4261                 remove_proc_entry(sb->s_id, ext4_proc_root);
4262         }
4263 #ifdef CONFIG_QUOTA
4264         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4265                 kfree(sbi->s_qf_names[i]);
4266 #endif
4267         ext4_blkdev_remove(sbi);
4268         brelse(bh);
4269 out_fail:
4270         sb->s_fs_info = NULL;
4271         kfree(sbi->s_blockgroup_lock);
4272         kfree(sbi);
4273 out_free_orig:
4274         kfree(orig_data);
4275         return err ? err : ret;
4276 }
4277
4278 /*
4279  * Setup any per-fs journal parameters now.  We'll do this both on
4280  * initial mount, once the journal has been initialised but before we've
4281  * done any recovery; and again on any subsequent remount.
4282  */
4283 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4284 {
4285         struct ext4_sb_info *sbi = EXT4_SB(sb);
4286
4287         journal->j_commit_interval = sbi->s_commit_interval;
4288         journal->j_min_batch_time = sbi->s_min_batch_time;
4289         journal->j_max_batch_time = sbi->s_max_batch_time;
4290
4291         write_lock(&journal->j_state_lock);
4292         if (test_opt(sb, BARRIER))
4293                 journal->j_flags |= JBD2_BARRIER;
4294         else
4295                 journal->j_flags &= ~JBD2_BARRIER;
4296         if (test_opt(sb, DATA_ERR_ABORT))
4297                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4298         else
4299                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4300         write_unlock(&journal->j_state_lock);
4301 }
4302
4303 static journal_t *ext4_get_journal(struct super_block *sb,
4304                                    unsigned int journal_inum)
4305 {
4306         struct inode *journal_inode;
4307         journal_t *journal;
4308
4309         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4310
4311         /* First, test for the existence of a valid inode on disk.  Bad
4312          * things happen if we iget() an unused inode, as the subsequent
4313          * iput() will try to delete it. */
4314
4315         journal_inode = ext4_iget(sb, journal_inum);
4316         if (IS_ERR(journal_inode)) {
4317                 ext4_msg(sb, KERN_ERR, "no journal found");
4318                 return NULL;
4319         }
4320         if (!journal_inode->i_nlink) {
4321                 make_bad_inode(journal_inode);
4322                 iput(journal_inode);
4323                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4324                 return NULL;
4325         }
4326
4327         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4328                   journal_inode, journal_inode->i_size);
4329         if (!S_ISREG(journal_inode->i_mode)) {
4330                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4331                 iput(journal_inode);
4332                 return NULL;
4333         }
4334
4335         journal = jbd2_journal_init_inode(journal_inode);
4336         if (!journal) {
4337                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4338                 iput(journal_inode);
4339                 return NULL;
4340         }
4341         journal->j_private = sb;
4342         ext4_init_journal_params(sb, journal);
4343         return journal;
4344 }
4345
4346 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4347                                        dev_t j_dev)
4348 {
4349         struct buffer_head *bh;
4350         journal_t *journal;
4351         ext4_fsblk_t start;
4352         ext4_fsblk_t len;
4353         int hblock, blocksize;
4354         ext4_fsblk_t sb_block;
4355         unsigned long offset;
4356         struct ext4_super_block *es;
4357         struct block_device *bdev;
4358
4359         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4360
4361         bdev = ext4_blkdev_get(j_dev, sb);
4362         if (bdev == NULL)
4363                 return NULL;
4364
4365         blocksize = sb->s_blocksize;
4366         hblock = bdev_logical_block_size(bdev);
4367         if (blocksize < hblock) {
4368                 ext4_msg(sb, KERN_ERR,
4369                         "blocksize too small for journal device");
4370                 goto out_bdev;
4371         }
4372
4373         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4374         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4375         set_blocksize(bdev, blocksize);
4376         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4377                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4378                        "external journal");
4379                 goto out_bdev;
4380         }
4381
4382         es = (struct ext4_super_block *) (bh->b_data + offset);
4383         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4384             !(le32_to_cpu(es->s_feature_incompat) &
4385               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4386                 ext4_msg(sb, KERN_ERR, "external journal has "
4387                                         "bad superblock");
4388                 brelse(bh);
4389                 goto out_bdev;
4390         }
4391
4392         if ((le32_to_cpu(es->s_feature_ro_compat) &
4393              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4394             es->s_checksum != ext4_superblock_csum(sb, es)) {
4395                 ext4_msg(sb, KERN_ERR, "external journal has "
4396                                        "corrupt superblock");
4397                 brelse(bh);
4398                 goto out_bdev;
4399         }
4400
4401         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4402                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4403                 brelse(bh);
4404                 goto out_bdev;
4405         }
4406
4407         len = ext4_blocks_count(es);
4408         start = sb_block + 1;
4409         brelse(bh);     /* we're done with the superblock */
4410
4411         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4412                                         start, len, blocksize);
4413         if (!journal) {
4414                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4415                 goto out_bdev;
4416         }
4417         journal->j_private = sb;
4418         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4419         wait_on_buffer(journal->j_sb_buffer);
4420         if (!buffer_uptodate(journal->j_sb_buffer)) {
4421                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4422                 goto out_journal;
4423         }
4424         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4425                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4426                                         "user (unsupported) - %d",
4427                         be32_to_cpu(journal->j_superblock->s_nr_users));
4428                 goto out_journal;
4429         }
4430         EXT4_SB(sb)->journal_bdev = bdev;
4431         ext4_init_journal_params(sb, journal);
4432         return journal;
4433
4434 out_journal:
4435         jbd2_journal_destroy(journal);
4436 out_bdev:
4437         ext4_blkdev_put(bdev);
4438         return NULL;
4439 }
4440
4441 static int ext4_load_journal(struct super_block *sb,
4442                              struct ext4_super_block *es,
4443                              unsigned long journal_devnum)
4444 {
4445         journal_t *journal;
4446         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4447         dev_t journal_dev;
4448         int err = 0;
4449         int really_read_only;
4450
4451         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4452
4453         if (journal_devnum &&
4454             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4455                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4456                         "numbers have changed");
4457                 journal_dev = new_decode_dev(journal_devnum);
4458         } else
4459                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4460
4461         really_read_only = bdev_read_only(sb->s_bdev);
4462
4463         /*
4464          * Are we loading a blank journal or performing recovery after a
4465          * crash?  For recovery, we need to check in advance whether we
4466          * can get read-write access to the device.
4467          */
4468         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4469                 if (sb->s_flags & MS_RDONLY) {
4470                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4471                                         "required on readonly filesystem");
4472                         if (really_read_only) {
4473                                 ext4_msg(sb, KERN_ERR, "write access "
4474                                         "unavailable, cannot proceed");
4475                                 return -EROFS;
4476                         }
4477                         ext4_msg(sb, KERN_INFO, "write access will "
4478                                "be enabled during recovery");
4479                 }
4480         }
4481
4482         if (journal_inum && journal_dev) {
4483                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4484                        "and inode journals!");
4485                 return -EINVAL;
4486         }
4487
4488         if (journal_inum) {
4489                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4490                         return -EINVAL;
4491         } else {
4492                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4493                         return -EINVAL;
4494         }
4495
4496         if (!(journal->j_flags & JBD2_BARRIER))
4497                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4498
4499         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4500                 err = jbd2_journal_wipe(journal, !really_read_only);
4501         if (!err) {
4502                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4503                 if (save)
4504                         memcpy(save, ((char *) es) +
4505                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4506                 err = jbd2_journal_load(journal);
4507                 if (save)
4508                         memcpy(((char *) es) + EXT4_S_ERR_START,
4509                                save, EXT4_S_ERR_LEN);
4510                 kfree(save);
4511         }
4512
4513         if (err) {
4514                 ext4_msg(sb, KERN_ERR, "error loading journal");
4515                 jbd2_journal_destroy(journal);
4516                 return err;
4517         }
4518
4519         EXT4_SB(sb)->s_journal = journal;
4520         ext4_clear_journal_err(sb, es);
4521
4522         if (!really_read_only && journal_devnum &&
4523             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4524                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4525
4526                 /* Make sure we flush the recovery flag to disk. */
4527                 ext4_commit_super(sb, 1);
4528         }
4529
4530         return 0;
4531 }
4532
4533 static int ext4_commit_super(struct super_block *sb, int sync)
4534 {
4535         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4536         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4537         int error = 0;
4538
4539         if (!sbh || block_device_ejected(sb))
4540                 return error;
4541         if (buffer_write_io_error(sbh)) {
4542                 /*
4543                  * Oh, dear.  A previous attempt to write the
4544                  * superblock failed.  This could happen because the
4545                  * USB device was yanked out.  Or it could happen to
4546                  * be a transient write error and maybe the block will
4547                  * be remapped.  Nothing we can do but to retry the
4548                  * write and hope for the best.
4549                  */
4550                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4551                        "superblock detected");
4552                 clear_buffer_write_io_error(sbh);
4553                 set_buffer_uptodate(sbh);
4554         }
4555         /*
4556          * If the file system is mounted read-only, don't update the
4557          * superblock write time.  This avoids updating the superblock
4558          * write time when we are mounting the root file system
4559          * read/only but we need to replay the journal; at that point,
4560          * for people who are east of GMT and who make their clock
4561          * tick in localtime for Windows bug-for-bug compatibility,
4562          * the clock is set in the future, and this will cause e2fsck
4563          * to complain and force a full file system check.
4564          */
4565         if (!(sb->s_flags & MS_RDONLY))
4566                 es->s_wtime = cpu_to_le32(get_seconds());
4567         if (sb->s_bdev->bd_part)
4568                 es->s_kbytes_written =
4569                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4570                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4571                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4572         else
4573                 es->s_kbytes_written =
4574                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4575         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4576                 ext4_free_blocks_count_set(es,
4577                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4578                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4579         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4580                 es->s_free_inodes_count =
4581                         cpu_to_le32(percpu_counter_sum_positive(
4582                                 &EXT4_SB(sb)->s_freeinodes_counter));
4583         BUFFER_TRACE(sbh, "marking dirty");
4584         ext4_superblock_csum_set(sb);
4585         mark_buffer_dirty(sbh);
4586         if (sync) {
4587                 error = sync_dirty_buffer(sbh);
4588                 if (error)
4589                         return error;
4590
4591                 error = buffer_write_io_error(sbh);
4592                 if (error) {
4593                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4594                                "superblock");
4595                         clear_buffer_write_io_error(sbh);
4596                         set_buffer_uptodate(sbh);
4597                 }
4598         }
4599         return error;
4600 }
4601
4602 /*
4603  * Have we just finished recovery?  If so, and if we are mounting (or
4604  * remounting) the filesystem readonly, then we will end up with a
4605  * consistent fs on disk.  Record that fact.
4606  */
4607 static void ext4_mark_recovery_complete(struct super_block *sb,
4608                                         struct ext4_super_block *es)
4609 {
4610         journal_t *journal = EXT4_SB(sb)->s_journal;
4611
4612         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4613                 BUG_ON(journal != NULL);
4614                 return;
4615         }
4616         jbd2_journal_lock_updates(journal);
4617         if (jbd2_journal_flush(journal) < 0)
4618                 goto out;
4619
4620         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4621             sb->s_flags & MS_RDONLY) {
4622                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4623                 ext4_commit_super(sb, 1);
4624         }
4625
4626 out:
4627         jbd2_journal_unlock_updates(journal);
4628 }
4629
4630 /*
4631  * If we are mounting (or read-write remounting) a filesystem whose journal
4632  * has recorded an error from a previous lifetime, move that error to the
4633  * main filesystem now.
4634  */
4635 static void ext4_clear_journal_err(struct super_block *sb,
4636                                    struct ext4_super_block *es)
4637 {
4638         journal_t *journal;
4639         int j_errno;
4640         const char *errstr;
4641
4642         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4643
4644         journal = EXT4_SB(sb)->s_journal;
4645
4646         /*
4647          * Now check for any error status which may have been recorded in the
4648          * journal by a prior ext4_error() or ext4_abort()
4649          */
4650
4651         j_errno = jbd2_journal_errno(journal);
4652         if (j_errno) {
4653                 char nbuf[16];
4654
4655                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4656                 ext4_warning(sb, "Filesystem error recorded "
4657                              "from previous mount: %s", errstr);
4658                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4659
4660                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4661                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4662                 ext4_commit_super(sb, 1);
4663
4664                 jbd2_journal_clear_err(journal);
4665                 jbd2_journal_update_sb_errno(journal);
4666         }
4667 }
4668
4669 /*
4670  * Force the running and committing transactions to commit,
4671  * and wait on the commit.
4672  */
4673 int ext4_force_commit(struct super_block *sb)
4674 {
4675         journal_t *journal;
4676
4677         if (sb->s_flags & MS_RDONLY)
4678                 return 0;
4679
4680         journal = EXT4_SB(sb)->s_journal;
4681         return ext4_journal_force_commit(journal);
4682 }
4683
4684 static int ext4_sync_fs(struct super_block *sb, int wait)
4685 {
4686         int ret = 0;
4687         tid_t target;
4688         bool needs_barrier = false;
4689         struct ext4_sb_info *sbi = EXT4_SB(sb);
4690
4691         trace_ext4_sync_fs(sb, wait);
4692         flush_workqueue(sbi->rsv_conversion_wq);
4693         /*
4694          * Writeback quota in non-journalled quota case - journalled quota has
4695          * no dirty dquots
4696          */
4697         dquot_writeback_dquots(sb, -1);
4698         /*
4699          * Data writeback is possible w/o journal transaction, so barrier must
4700          * being sent at the end of the function. But we can skip it if
4701          * transaction_commit will do it for us.
4702          */
4703         if (sbi->s_journal) {
4704                 target = jbd2_get_latest_transaction(sbi->s_journal);
4705                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4706                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4707                         needs_barrier = true;
4708
4709                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4710                         if (wait)
4711                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4712                                                            target);
4713                 }
4714         } else if (wait && test_opt(sb, BARRIER))
4715                 needs_barrier = true;
4716         if (needs_barrier) {
4717                 int err;
4718                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4719                 if (!ret)
4720                         ret = err;
4721         }
4722
4723         return ret;
4724 }
4725
4726 /*
4727  * LVM calls this function before a (read-only) snapshot is created.  This
4728  * gives us a chance to flush the journal completely and mark the fs clean.
4729  *
4730  * Note that only this function cannot bring a filesystem to be in a clean
4731  * state independently. It relies on upper layer to stop all data & metadata
4732  * modifications.
4733  */
4734 static int ext4_freeze(struct super_block *sb)
4735 {
4736         int error = 0;
4737         journal_t *journal;
4738
4739         if (sb->s_flags & MS_RDONLY)
4740                 return 0;
4741
4742         journal = EXT4_SB(sb)->s_journal;
4743
4744         if (journal) {
4745                 /* Now we set up the journal barrier. */
4746                 jbd2_journal_lock_updates(journal);
4747
4748                 /*
4749                  * Don't clear the needs_recovery flag if we failed to
4750                  * flush the journal.
4751                  */
4752                 error = jbd2_journal_flush(journal);
4753                 if (error < 0)
4754                         goto out;
4755         }
4756
4757         /* Journal blocked and flushed, clear needs_recovery flag. */
4758         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4759         error = ext4_commit_super(sb, 1);
4760 out:
4761         if (journal)
4762                 /* we rely on upper layer to stop further updates */
4763                 jbd2_journal_unlock_updates(journal);
4764         return error;
4765 }
4766
4767 /*
4768  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4769  * flag here, even though the filesystem is not technically dirty yet.
4770  */
4771 static int ext4_unfreeze(struct super_block *sb)
4772 {
4773         if (sb->s_flags & MS_RDONLY)
4774                 return 0;
4775
4776         /* Reset the needs_recovery flag before the fs is unlocked. */
4777         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4778         ext4_commit_super(sb, 1);
4779         return 0;
4780 }
4781
4782 /*
4783  * Structure to save mount options for ext4_remount's benefit
4784  */
4785 struct ext4_mount_options {
4786         unsigned long s_mount_opt;
4787         unsigned long s_mount_opt2;
4788         kuid_t s_resuid;
4789         kgid_t s_resgid;
4790         unsigned long s_commit_interval;
4791         u32 s_min_batch_time, s_max_batch_time;
4792 #ifdef CONFIG_QUOTA
4793         int s_jquota_fmt;
4794         char *s_qf_names[EXT4_MAXQUOTAS];
4795 #endif
4796 };
4797
4798 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4799 {
4800         struct ext4_super_block *es;
4801         struct ext4_sb_info *sbi = EXT4_SB(sb);
4802         unsigned long old_sb_flags;
4803         struct ext4_mount_options old_opts;
4804         int enable_quota = 0;
4805         ext4_group_t g;
4806         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4807         int err = 0;
4808 #ifdef CONFIG_QUOTA
4809         int i, j;
4810 #endif
4811         char *orig_data = kstrdup(data, GFP_KERNEL);
4812
4813         /* Store the original options */
4814         old_sb_flags = sb->s_flags;
4815         old_opts.s_mount_opt = sbi->s_mount_opt;
4816         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4817         old_opts.s_resuid = sbi->s_resuid;
4818         old_opts.s_resgid = sbi->s_resgid;
4819         old_opts.s_commit_interval = sbi->s_commit_interval;
4820         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4821         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4822 #ifdef CONFIG_QUOTA
4823         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4824         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4825                 if (sbi->s_qf_names[i]) {
4826                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4827                                                          GFP_KERNEL);
4828                         if (!old_opts.s_qf_names[i]) {
4829                                 for (j = 0; j < i; j++)
4830                                         kfree(old_opts.s_qf_names[j]);
4831                                 kfree(orig_data);
4832                                 return -ENOMEM;
4833                         }
4834                 } else
4835                         old_opts.s_qf_names[i] = NULL;
4836 #endif
4837         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4838                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4839
4840         /*
4841          * Allow the "check" option to be passed as a remount option.
4842          */
4843         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4844                 err = -EINVAL;
4845                 goto restore_opts;
4846         }
4847
4848         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4849             test_opt(sb, JOURNAL_CHECKSUM)) {
4850                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4851                          "during remount not supported");
4852                 err = -EINVAL;
4853                 goto restore_opts;
4854         }
4855
4856         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4857             test_opt(sb, JOURNAL_CHECKSUM)) {
4858                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4859                          "during remount not supported");
4860                 err = -EINVAL;
4861                 goto restore_opts;
4862         }
4863
4864         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4865                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4866                         ext4_msg(sb, KERN_ERR, "can't mount with "
4867                                  "both data=journal and delalloc");
4868                         err = -EINVAL;
4869                         goto restore_opts;
4870                 }
4871                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4872                         ext4_msg(sb, KERN_ERR, "can't mount with "
4873                                  "both data=journal and dioread_nolock");
4874                         err = -EINVAL;
4875                         goto restore_opts;
4876                 }
4877         }
4878
4879         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4880                 ext4_abort(sb, "Abort forced by user");
4881
4882         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4883                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4884
4885         es = sbi->s_es;
4886
4887         if (sbi->s_journal) {
4888                 ext4_init_journal_params(sb, sbi->s_journal);
4889                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4890         }
4891
4892         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4893                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4894                         err = -EROFS;
4895                         goto restore_opts;
4896                 }
4897
4898                 if (*flags & MS_RDONLY) {
4899                         err = sync_filesystem(sb);
4900                         if (err < 0)
4901                                 goto restore_opts;
4902                         err = dquot_suspend(sb, -1);
4903                         if (err < 0)
4904                                 goto restore_opts;
4905
4906                         /*
4907                          * First of all, the unconditional stuff we have to do
4908                          * to disable replay of the journal when we next remount
4909                          */
4910                         sb->s_flags |= MS_RDONLY;
4911
4912                         /*
4913                          * OK, test if we are remounting a valid rw partition
4914                          * readonly, and if so set the rdonly flag and then
4915                          * mark the partition as valid again.
4916                          */
4917                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4918                             (sbi->s_mount_state & EXT4_VALID_FS))
4919                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4920
4921                         if (sbi->s_journal)
4922                                 ext4_mark_recovery_complete(sb, es);
4923                 } else {
4924                         /* Make sure we can mount this feature set readwrite */
4925                         if (!ext4_feature_set_ok(sb, 0)) {
4926                                 err = -EROFS;
4927                                 goto restore_opts;
4928                         }
4929                         /*
4930                          * Make sure the group descriptor checksums
4931                          * are sane.  If they aren't, refuse to remount r/w.
4932                          */
4933                         for (g = 0; g < sbi->s_groups_count; g++) {
4934                                 struct ext4_group_desc *gdp =
4935                                         ext4_get_group_desc(sb, g, NULL);
4936
4937                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4938                                         ext4_msg(sb, KERN_ERR,
4939                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4940                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4941                                                le16_to_cpu(gdp->bg_checksum));
4942                                         err = -EINVAL;
4943                                         goto restore_opts;
4944                                 }
4945                         }
4946
4947                         /*
4948                          * If we have an unprocessed orphan list hanging
4949                          * around from a previously readonly bdev mount,
4950                          * require a full umount/remount for now.
4951                          */
4952                         if (es->s_last_orphan) {
4953                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4954                                        "remount RDWR because of unprocessed "
4955                                        "orphan inode list.  Please "
4956                                        "umount/remount instead");
4957                                 err = -EINVAL;
4958                                 goto restore_opts;
4959                         }
4960
4961                         /*
4962                          * Mounting a RDONLY partition read-write, so reread
4963                          * and store the current valid flag.  (It may have
4964                          * been changed by e2fsck since we originally mounted
4965                          * the partition.)
4966                          */
4967                         if (sbi->s_journal)
4968                                 ext4_clear_journal_err(sb, es);
4969                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4970                         if (!ext4_setup_super(sb, es, 0))
4971                                 sb->s_flags &= ~MS_RDONLY;
4972                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4973                                                      EXT4_FEATURE_INCOMPAT_MMP))
4974                                 if (ext4_multi_mount_protect(sb,
4975                                                 le64_to_cpu(es->s_mmp_block))) {
4976                                         err = -EROFS;
4977                                         goto restore_opts;
4978                                 }
4979                         enable_quota = 1;
4980                 }
4981         }
4982
4983         /*
4984          * Reinitialize lazy itable initialization thread based on
4985          * current settings
4986          */
4987         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4988                 ext4_unregister_li_request(sb);
4989         else {
4990                 ext4_group_t first_not_zeroed;
4991                 first_not_zeroed = ext4_has_uninit_itable(sb);
4992                 ext4_register_li_request(sb, first_not_zeroed);
4993         }
4994
4995         ext4_setup_system_zone(sb);
4996         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4997                 ext4_commit_super(sb, 1);
4998
4999 #ifdef CONFIG_QUOTA
5000         /* Release old quota file names */
5001         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5002                 kfree(old_opts.s_qf_names[i]);
5003         if (enable_quota) {
5004                 if (sb_any_quota_suspended(sb))
5005                         dquot_resume(sb, -1);
5006                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
5007                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
5008                         err = ext4_enable_quotas(sb);
5009                         if (err)
5010                                 goto restore_opts;
5011                 }
5012         }
5013 #endif
5014
5015         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5016         kfree(orig_data);
5017         return 0;
5018
5019 restore_opts:
5020         sb->s_flags = old_sb_flags;
5021         sbi->s_mount_opt = old_opts.s_mount_opt;
5022         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5023         sbi->s_resuid = old_opts.s_resuid;
5024         sbi->s_resgid = old_opts.s_resgid;
5025         sbi->s_commit_interval = old_opts.s_commit_interval;
5026         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5027         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5028 #ifdef CONFIG_QUOTA
5029         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5030         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5031                 kfree(sbi->s_qf_names[i]);
5032                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5033         }
5034 #endif
5035         kfree(orig_data);
5036         return err;
5037 }
5038
5039 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5040 {
5041         struct super_block *sb = dentry->d_sb;
5042         struct ext4_sb_info *sbi = EXT4_SB(sb);
5043         struct ext4_super_block *es = sbi->s_es;
5044         ext4_fsblk_t overhead = 0, resv_blocks;
5045         u64 fsid;
5046         s64 bfree;
5047         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5048
5049         if (!test_opt(sb, MINIX_DF))
5050                 overhead = sbi->s_overhead;
5051
5052         buf->f_type = EXT4_SUPER_MAGIC;
5053         buf->f_bsize = sb->s_blocksize;
5054         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5055         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5056                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5057         /* prevent underflow in case that few free space is available */
5058         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5059         buf->f_bavail = buf->f_bfree -
5060                         (ext4_r_blocks_count(es) + resv_blocks);
5061         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5062                 buf->f_bavail = 0;
5063         buf->f_files = le32_to_cpu(es->s_inodes_count);
5064         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5065         buf->f_namelen = EXT4_NAME_LEN;
5066         fsid = le64_to_cpup((void *)es->s_uuid) ^
5067                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5068         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5069         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5070
5071         return 0;
5072 }
5073
5074 /* Helper function for writing quotas on sync - we need to start transaction
5075  * before quota file is locked for write. Otherwise the are possible deadlocks:
5076  * Process 1                         Process 2
5077  * ext4_create()                     quota_sync()
5078  *   jbd2_journal_start()                  write_dquot()
5079  *   dquot_initialize()                         down(dqio_mutex)
5080  *     down(dqio_mutex)                    jbd2_journal_start()
5081  *
5082  */
5083
5084 #ifdef CONFIG_QUOTA
5085
5086 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5087 {
5088         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5089 }
5090
5091 static int ext4_write_dquot(struct dquot *dquot)
5092 {
5093         int ret, err;
5094         handle_t *handle;
5095         struct inode *inode;
5096
5097         inode = dquot_to_inode(dquot);
5098         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5099                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5100         if (IS_ERR(handle))
5101                 return PTR_ERR(handle);
5102         ret = dquot_commit(dquot);
5103         err = ext4_journal_stop(handle);
5104         if (!ret)
5105                 ret = err;
5106         return ret;
5107 }
5108
5109 static int ext4_acquire_dquot(struct dquot *dquot)
5110 {
5111         int ret, err;
5112         handle_t *handle;
5113
5114         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5115                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5116         if (IS_ERR(handle))
5117                 return PTR_ERR(handle);
5118         ret = dquot_acquire(dquot);
5119         err = ext4_journal_stop(handle);
5120         if (!ret)
5121                 ret = err;
5122         return ret;
5123 }
5124
5125 static int ext4_release_dquot(struct dquot *dquot)
5126 {
5127         int ret, err;
5128         handle_t *handle;
5129
5130         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5131                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5132         if (IS_ERR(handle)) {
5133                 /* Release dquot anyway to avoid endless cycle in dqput() */
5134                 dquot_release(dquot);
5135                 return PTR_ERR(handle);
5136         }
5137         ret = dquot_release(dquot);
5138         err = ext4_journal_stop(handle);
5139         if (!ret)
5140                 ret = err;
5141         return ret;
5142 }
5143
5144 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5145 {
5146         struct super_block *sb = dquot->dq_sb;
5147         struct ext4_sb_info *sbi = EXT4_SB(sb);
5148
5149         /* Are we journaling quotas? */
5150         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5151             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5152                 dquot_mark_dquot_dirty(dquot);
5153                 return ext4_write_dquot(dquot);
5154         } else {
5155                 return dquot_mark_dquot_dirty(dquot);
5156         }
5157 }
5158
5159 static int ext4_write_info(struct super_block *sb, int type)
5160 {
5161         int ret, err;
5162         handle_t *handle;
5163
5164         /* Data block + inode block */
5165         handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5166         if (IS_ERR(handle))
5167                 return PTR_ERR(handle);
5168         ret = dquot_commit_info(sb, type);
5169         err = ext4_journal_stop(handle);
5170         if (!ret)
5171                 ret = err;
5172         return ret;
5173 }
5174
5175 /*
5176  * Turn on quotas during mount time - we need to find
5177  * the quota file and such...
5178  */
5179 static int ext4_quota_on_mount(struct super_block *sb, int type)
5180 {
5181         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5182                                         EXT4_SB(sb)->s_jquota_fmt, type);
5183 }
5184
5185 /*
5186  * Standard function to be called on quota_on
5187  */
5188 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5189                          struct path *path)
5190 {
5191         int err;
5192
5193         if (!test_opt(sb, QUOTA))
5194                 return -EINVAL;
5195
5196         /* Quotafile not on the same filesystem? */
5197         if (path->dentry->d_sb != sb)
5198                 return -EXDEV;
5199         /* Journaling quota? */
5200         if (EXT4_SB(sb)->s_qf_names[type]) {
5201                 /* Quotafile not in fs root? */
5202                 if (path->dentry->d_parent != sb->s_root)
5203                         ext4_msg(sb, KERN_WARNING,
5204                                 "Quota file not on filesystem root. "
5205                                 "Journaled quota will not work");
5206         }
5207
5208         /*
5209          * When we journal data on quota file, we have to flush journal to see
5210          * all updates to the file when we bypass pagecache...
5211          */
5212         if (EXT4_SB(sb)->s_journal &&
5213             ext4_should_journal_data(path->dentry->d_inode)) {
5214                 /*
5215                  * We don't need to lock updates but journal_flush() could
5216                  * otherwise be livelocked...
5217                  */
5218                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5219                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5220                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5221                 if (err)
5222                         return err;
5223         }
5224
5225         return dquot_quota_on(sb, type, format_id, path);
5226 }
5227
5228 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5229                              unsigned int flags)
5230 {
5231         int err;
5232         struct inode *qf_inode;
5233         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5234                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5235                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5236         };
5237
5238         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5239
5240         if (!qf_inums[type])
5241                 return -EPERM;
5242
5243         qf_inode = ext4_iget(sb, qf_inums[type]);
5244         if (IS_ERR(qf_inode)) {
5245                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5246                 return PTR_ERR(qf_inode);
5247         }
5248
5249         /* Don't account quota for quota files to avoid recursion */
5250         qf_inode->i_flags |= S_NOQUOTA;
5251         err = dquot_enable(qf_inode, type, format_id, flags);
5252         iput(qf_inode);
5253
5254         return err;
5255 }
5256
5257 /* Enable usage tracking for all quota types. */
5258 static int ext4_enable_quotas(struct super_block *sb)
5259 {
5260         int type, err = 0;
5261         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5262                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5263                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5264         };
5265
5266         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5267         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5268                 if (qf_inums[type]) {
5269                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5270                                                 DQUOT_USAGE_ENABLED);
5271                         if (err) {
5272                                 ext4_warning(sb,
5273                                         "Failed to enable quota tracking "
5274                                         "(type=%d, err=%d). Please run "
5275                                         "e2fsck to fix.", type, err);
5276                                 return err;
5277                         }
5278                 }
5279         }
5280         return 0;
5281 }
5282
5283 /*
5284  * quota_on function that is used when QUOTA feature is set.
5285  */
5286 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5287                                  int format_id)
5288 {
5289         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5290                 return -EINVAL;
5291
5292         /*
5293          * USAGE was enabled at mount time. Only need to enable LIMITS now.
5294          */
5295         return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5296 }
5297
5298 static int ext4_quota_off(struct super_block *sb, int type)
5299 {
5300         struct inode *inode = sb_dqopt(sb)->files[type];
5301         handle_t *handle;
5302
5303         /* Force all delayed allocation blocks to be allocated.
5304          * Caller already holds s_umount sem */
5305         if (test_opt(sb, DELALLOC))
5306                 sync_filesystem(sb);
5307
5308         if (!inode)
5309                 goto out;
5310
5311         /* Update modification times of quota files when userspace can
5312          * start looking at them */
5313         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5314         if (IS_ERR(handle))
5315                 goto out;
5316         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5317         ext4_mark_inode_dirty(handle, inode);
5318         ext4_journal_stop(handle);
5319
5320 out:
5321         return dquot_quota_off(sb, type);
5322 }
5323
5324 /*
5325  * quota_off function that is used when QUOTA feature is set.
5326  */
5327 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5328 {
5329         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5330                 return -EINVAL;
5331
5332         /* Disable only the limits. */
5333         return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5334 }
5335
5336 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5337  * acquiring the locks... As quota files are never truncated and quota code
5338  * itself serializes the operations (and no one else should touch the files)
5339  * we don't have to be afraid of races */
5340 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5341                                size_t len, loff_t off)
5342 {
5343         struct inode *inode = sb_dqopt(sb)->files[type];
5344         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5345         int offset = off & (sb->s_blocksize - 1);
5346         int tocopy;
5347         size_t toread;
5348         struct buffer_head *bh;
5349         loff_t i_size = i_size_read(inode);
5350
5351         if (off > i_size)
5352                 return 0;
5353         if (off+len > i_size)
5354                 len = i_size-off;
5355         toread = len;
5356         while (toread > 0) {
5357                 tocopy = sb->s_blocksize - offset < toread ?
5358                                 sb->s_blocksize - offset : toread;
5359                 bh = ext4_bread(NULL, inode, blk, 0);
5360                 if (IS_ERR(bh))
5361                         return PTR_ERR(bh);
5362                 if (!bh)        /* A hole? */
5363                         memset(data, 0, tocopy);
5364                 else
5365                         memcpy(data, bh->b_data+offset, tocopy);
5366                 brelse(bh);
5367                 offset = 0;
5368                 toread -= tocopy;
5369                 data += tocopy;
5370                 blk++;
5371         }
5372         return len;
5373 }
5374
5375 /* Write to quotafile (we know the transaction is already started and has
5376  * enough credits) */
5377 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5378                                 const char *data, size_t len, loff_t off)
5379 {
5380         struct inode *inode = sb_dqopt(sb)->files[type];
5381         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5382         int err, offset = off & (sb->s_blocksize - 1);
5383         struct buffer_head *bh;
5384         handle_t *handle = journal_current_handle();
5385
5386         if (EXT4_SB(sb)->s_journal && !handle) {
5387                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5388                         " cancelled because transaction is not started",
5389                         (unsigned long long)off, (unsigned long long)len);
5390                 return -EIO;
5391         }
5392         /*
5393          * Since we account only one data block in transaction credits,
5394          * then it is impossible to cross a block boundary.
5395          */
5396         if (sb->s_blocksize - offset < len) {
5397                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5398                         " cancelled because not block aligned",
5399                         (unsigned long long)off, (unsigned long long)len);
5400                 return -EIO;
5401         }
5402
5403         bh = ext4_bread(handle, inode, blk, 1);
5404         if (IS_ERR(bh))
5405                 return PTR_ERR(bh);
5406         if (!bh)
5407                 goto out;
5408         BUFFER_TRACE(bh, "get write access");
5409         err = ext4_journal_get_write_access(handle, bh);
5410         if (err) {
5411                 brelse(bh);
5412                 return err;
5413         }
5414         lock_buffer(bh);
5415         memcpy(bh->b_data+offset, data, len);
5416         flush_dcache_page(bh->b_page);
5417         unlock_buffer(bh);
5418         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5419         brelse(bh);
5420 out:
5421         if (inode->i_size < off + len) {
5422                 i_size_write(inode, off + len);
5423                 EXT4_I(inode)->i_disksize = inode->i_size;
5424                 ext4_mark_inode_dirty(handle, inode);
5425         }
5426         return len;
5427 }
5428
5429 #endif
5430
5431 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5432                        const char *dev_name, void *data)
5433 {
5434         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5435 }
5436
5437 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5438 static inline void register_as_ext2(void)
5439 {
5440         int err = register_filesystem(&ext2_fs_type);
5441         if (err)
5442                 printk(KERN_WARNING
5443                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5444 }
5445
5446 static inline void unregister_as_ext2(void)
5447 {
5448         unregister_filesystem(&ext2_fs_type);
5449 }
5450
5451 static inline int ext2_feature_set_ok(struct super_block *sb)
5452 {
5453         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5454                 return 0;
5455         if (sb->s_flags & MS_RDONLY)
5456                 return 1;
5457         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5458                 return 0;
5459         return 1;
5460 }
5461 #else
5462 static inline void register_as_ext2(void) { }
5463 static inline void unregister_as_ext2(void) { }
5464 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5465 #endif
5466
5467 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5468 static inline void register_as_ext3(void)
5469 {
5470         int err = register_filesystem(&ext3_fs_type);
5471         if (err)
5472                 printk(KERN_WARNING
5473                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5474 }
5475
5476 static inline void unregister_as_ext3(void)
5477 {
5478         unregister_filesystem(&ext3_fs_type);
5479 }
5480
5481 static inline int ext3_feature_set_ok(struct super_block *sb)
5482 {
5483         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5484                 return 0;
5485         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5486                 return 0;
5487         if (sb->s_flags & MS_RDONLY)
5488                 return 1;
5489         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5490                 return 0;
5491         return 1;
5492 }
5493 #else
5494 static inline void register_as_ext3(void) { }
5495 static inline void unregister_as_ext3(void) { }
5496 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5497 #endif
5498
5499 static struct file_system_type ext4_fs_type = {
5500         .owner          = THIS_MODULE,
5501         .name           = "ext4",
5502         .mount          = ext4_mount,
5503         .kill_sb        = kill_block_super,
5504         .fs_flags       = FS_REQUIRES_DEV,
5505 };
5506 MODULE_ALIAS_FS("ext4");
5507
5508 static int __init ext4_init_feat_adverts(void)
5509 {
5510         struct ext4_features *ef;
5511         int ret = -ENOMEM;
5512
5513         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5514         if (!ef)
5515                 goto out;
5516
5517         ef->f_kobj.kset = ext4_kset;
5518         init_completion(&ef->f_kobj_unregister);
5519         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5520                                    "features");
5521         if (ret) {
5522                 kfree(ef);
5523                 goto out;
5524         }
5525
5526         ext4_feat = ef;
5527         ret = 0;
5528 out:
5529         return ret;
5530 }
5531
5532 static void ext4_exit_feat_adverts(void)
5533 {
5534         kobject_put(&ext4_feat->f_kobj);
5535         wait_for_completion(&ext4_feat->f_kobj_unregister);
5536         kfree(ext4_feat);
5537 }
5538
5539 /* Shared across all ext4 file systems */
5540 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5541 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5542
5543 static int __init ext4_init_fs(void)
5544 {
5545         int i, err;
5546
5547         ext4_li_info = NULL;
5548         mutex_init(&ext4_li_mtx);
5549
5550         /* Build-time check for flags consistency */
5551         ext4_check_flag_values();
5552
5553         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5554                 mutex_init(&ext4__aio_mutex[i]);
5555                 init_waitqueue_head(&ext4__ioend_wq[i]);
5556         }
5557
5558         err = ext4_init_es();
5559         if (err)
5560                 return err;
5561
5562         err = ext4_init_pageio();
5563         if (err)
5564                 goto out7;
5565
5566         err = ext4_init_system_zone();
5567         if (err)
5568                 goto out6;
5569         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5570         if (!ext4_kset) {
5571                 err = -ENOMEM;
5572                 goto out5;
5573         }
5574         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5575
5576         err = ext4_init_feat_adverts();
5577         if (err)
5578                 goto out4;
5579
5580         err = ext4_init_mballoc();
5581         if (err)
5582                 goto out2;
5583         else
5584                 ext4_mballoc_ready = 1;
5585         err = init_inodecache();
5586         if (err)
5587                 goto out1;
5588         register_as_ext3();
5589         register_as_ext2();
5590         err = register_filesystem(&ext4_fs_type);
5591         if (err)
5592                 goto out;
5593
5594         return 0;
5595 out:
5596         unregister_as_ext2();
5597         unregister_as_ext3();
5598         destroy_inodecache();
5599 out1:
5600         ext4_mballoc_ready = 0;
5601         ext4_exit_mballoc();
5602 out2:
5603         ext4_exit_feat_adverts();
5604 out4:
5605         if (ext4_proc_root)
5606                 remove_proc_entry("fs/ext4", NULL);
5607         kset_unregister(ext4_kset);
5608 out5:
5609         ext4_exit_system_zone();
5610 out6:
5611         ext4_exit_pageio();
5612 out7:
5613         ext4_exit_es();
5614
5615         return err;
5616 }
5617
5618 static void __exit ext4_exit_fs(void)
5619 {
5620         ext4_destroy_lazyinit_thread();
5621         unregister_as_ext2();
5622         unregister_as_ext3();
5623         unregister_filesystem(&ext4_fs_type);
5624         destroy_inodecache();
5625         ext4_exit_mballoc();
5626         ext4_exit_feat_adverts();
5627         remove_proc_entry("fs/ext4", NULL);
5628         kset_unregister(ext4_kset);
5629         ext4_exit_system_zone();
5630         ext4_exit_pageio();
5631         ext4_exit_es();
5632 }
5633
5634 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5635 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5636 MODULE_LICENSE("GPL");
5637 module_init(ext4_init_fs)
5638 module_exit(ext4_exit_fs)