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 = inode_to_bdi(bd_inode);
 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         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 887 #endif
 888         ei->jinode = NULL;
 889         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 890         spin_lock_init(&ei->i_completed_io_lock);
 891         ei->i_sync_tid = 0;
 892         ei->i_datasync_tid = 0;
 893         atomic_set(&ei->i_ioend_count, 0);
 894         atomic_set(&ei->i_unwritten, 0);
 895         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 896
 897         return &ei->vfs_inode;
 898 }
 899
 900 static int ext4_drop_inode(struct inode *inode)
 901 {
 902         int drop = generic_drop_inode(inode);
 903
 904         trace_ext4_drop_inode(inode, drop);
 905         return drop;
 906 }
 907
 908 static void ext4_i_callback(struct rcu_head *head)
 909 {
 910         struct inode *inode = container_of(head, struct inode, i_rcu);
 911         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 912 }
 913
 914 static void ext4_destroy_inode(struct inode *inode)
 915 {
 916         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 917                 ext4_msg(inode->i_sb, KERN_ERR,
 918                          "Inode %lu (%p): orphan list check failed!",
 919                          inode->i_ino, EXT4_I(inode));
 920                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 921                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 922                                 true);
 923                 dump_stack();
 924         }
 925         call_rcu(&inode->i_rcu, ext4_i_callback);
 926 }
 927
 928 static void init_once(void *foo)
 929 {
 930         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 931
 932         INIT_LIST_HEAD(&ei->i_orphan);
 933         init_rwsem(&ei->xattr_sem);
 934         init_rwsem(&ei->i_data_sem);
 935         inode_init_once(&ei->vfs_inode);
 936 }
 937
 938 static int __init init_inodecache(void)
 939 {
 940         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 941                                              sizeof(struct ext4_inode_info),
 942                                              0, (SLAB_RECLAIM_ACCOUNT|
 943                                                 SLAB_MEM_SPREAD),
 944                                              init_once);
 945         if (ext4_inode_cachep == NULL)
 946                 return -ENOMEM;
 947         return 0;
 948 }
 949
 950 static void destroy_inodecache(void)
 951 {
 952         /*
 953          * Make sure all delayed rcu free inodes are flushed before we
 954          * destroy cache.
 955          */
 956         rcu_barrier();
 957         kmem_cache_destroy(ext4_inode_cachep);
 958 }
 959
 960 void ext4_clear_inode(struct inode *inode)
 961 {
 962         invalidate_inode_buffers(inode);
 963         clear_inode(inode);
 964         dquot_drop(inode);
 965         ext4_discard_preallocations(inode);
 966         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 967         if (EXT4_I(inode)->jinode) {
 968                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 969                                                EXT4_I(inode)->jinode);
 970                 jbd2_free_inode(EXT4_I(inode)->jinode);
 971                 EXT4_I(inode)->jinode = NULL;
 972         }
 973 }
 974
 975 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 976                                         u64 ino, u32 generation)
 977 {
 978         struct inode *inode;
 979
 980         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 981                 return ERR_PTR(-ESTALE);
 982         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 983                 return ERR_PTR(-ESTALE);
 984
 985         /* iget isn't really right if the inode is currently unallocated!!
 986          *
 987          * ext4_read_inode will return a bad_inode if the inode had been
 988          * deleted, so we should be safe.
 989          *
 990          * Currently we don't know the generation for parent directory, so
 991          * a generation of 0 means "accept any"
 992          */
 993         inode = ext4_iget_normal(sb, ino);
 994         if (IS_ERR(inode))
 995                 return ERR_CAST(inode);
 996         if (generation && inode->i_generation != generation) {
 997                 iput(inode);
 998                 return ERR_PTR(-ESTALE);
 999         }
1000
1001         return inode;
1002 }
1003
1004 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1005                                         int fh_len, int fh_type)
1006 {
1007         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1008                                     ext4_nfs_get_inode);
1009 }
1010
1011 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1012                                         int fh_len, int fh_type)
1013 {
1014         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1015                                     ext4_nfs_get_inode);
1016 }
1017
1018 /*
1019  * Try to release metadata pages (indirect blocks, directories) which are
1020  * mapped via the block device.  Since these pages could have journal heads
1021  * which would prevent try_to_free_buffers() from freeing them, we must use
1022  * jbd2 layer's try_to_free_buffers() function to release them.
1023  */
1024 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1025                                  gfp_t wait)
1026 {
1027         journal_t *journal = EXT4_SB(sb)->s_journal;
1028
1029         WARN_ON(PageChecked(page));
1030         if (!page_has_buffers(page))
1031                 return 0;
1032         if (journal)
1033                 return jbd2_journal_try_to_free_buffers(journal, page,
1034                                                         wait & ~__GFP_WAIT);
1035         return try_to_free_buffers(page);
1036 }
1037
1038 #ifdef CONFIG_QUOTA
1039 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1040 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1041
1042 static int ext4_write_dquot(struct dquot *dquot);
1043 static int ext4_acquire_dquot(struct dquot *dquot);
1044 static int ext4_release_dquot(struct dquot *dquot);
1045 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1046 static int ext4_write_info(struct super_block *sb, int type);
1047 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1048                          struct path *path);
1049 static int ext4_quota_off(struct super_block *sb, int type);
1050 static int ext4_quota_on_mount(struct super_block *sb, int type);
1051 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1052                                size_t len, loff_t off);
1053 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1054                                 const char *data, size_t len, loff_t off);
1055 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1056                              unsigned int flags);
1057 static int ext4_enable_quotas(struct super_block *sb);
1058
1059 static struct dquot **ext4_get_dquots(struct inode *inode)
1060 {
1061         return EXT4_I(inode)->i_dquot;
1062 }
1063
1064 static const struct dquot_operations ext4_quota_operations = {
1065         .get_reserved_space = ext4_get_reserved_space,
1066         .write_dquot    = ext4_write_dquot,
1067         .acquire_dquot  = ext4_acquire_dquot,
1068         .release_dquot  = ext4_release_dquot,
1069         .mark_dirty     = ext4_mark_dquot_dirty,
1070         .write_info     = ext4_write_info,
1071         .alloc_dquot    = dquot_alloc,
1072         .destroy_dquot  = dquot_destroy,
1073 };
1074
1075 static const struct quotactl_ops ext4_qctl_operations = {
1076         .quota_on       = ext4_quota_on,
1077         .quota_off      = ext4_quota_off,
1078         .quota_sync     = dquot_quota_sync,
1079         .get_info       = dquot_get_dqinfo,
1080         .set_info       = dquot_set_dqinfo,
1081         .get_dqblk      = dquot_get_dqblk,
1082         .set_dqblk      = dquot_set_dqblk
1083 };
1084 #endif
1085
1086 static const struct super_operations ext4_sops = {
1087         .alloc_inode    = ext4_alloc_inode,
1088         .destroy_inode  = ext4_destroy_inode,
1089         .write_inode    = ext4_write_inode,
1090         .dirty_inode    = ext4_dirty_inode,
1091         .drop_inode     = ext4_drop_inode,
1092         .evict_inode    = ext4_evict_inode,
1093         .put_super      = ext4_put_super,
1094         .sync_fs        = ext4_sync_fs,
1095         .freeze_fs      = ext4_freeze,
1096         .unfreeze_fs    = ext4_unfreeze,
1097         .statfs         = ext4_statfs,
1098         .remount_fs     = ext4_remount,
1099         .show_options   = ext4_show_options,
1100 #ifdef CONFIG_QUOTA
1101         .quota_read     = ext4_quota_read,
1102         .quota_write    = ext4_quota_write,
1103         .get_dquots     = ext4_get_dquots,
1104 #endif
1105         .bdev_try_to_free_page = bdev_try_to_free_page,
1106 };
1107
1108 static const struct export_operations ext4_export_ops = {
1109         .fh_to_dentry = ext4_fh_to_dentry,
1110         .fh_to_parent = ext4_fh_to_parent,
1111         .get_parent = ext4_get_parent,
1112 };
1113
1114 enum {
1115         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1116         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1117         Opt_nouid32, Opt_debug, Opt_removed,
1118         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1119         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1120         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1121         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1122         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1123         Opt_data_err_abort, Opt_data_err_ignore,
1124         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1125         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1126         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1127         Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
1128         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1129         Opt_lazytime, Opt_nolazytime,
1130         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1131         Opt_inode_readahead_blks, Opt_journal_ioprio,
1132         Opt_dioread_nolock, Opt_dioread_lock,
1133         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1134         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1135 };
1136
1137 static const match_table_t tokens = {
1138         {Opt_bsd_df, "bsddf"},
1139         {Opt_minix_df, "minixdf"},
1140         {Opt_grpid, "grpid"},
1141         {Opt_grpid, "bsdgroups"},
1142         {Opt_nogrpid, "nogrpid"},
1143         {Opt_nogrpid, "sysvgroups"},
1144         {Opt_resgid, "resgid=%u"},
1145         {Opt_resuid, "resuid=%u"},
1146         {Opt_sb, "sb=%u"},
1147         {Opt_err_cont, "errors=continue"},
1148         {Opt_err_panic, "errors=panic"},
1149         {Opt_err_ro, "errors=remount-ro"},
1150         {Opt_nouid32, "nouid32"},
1151         {Opt_debug, "debug"},
1152         {Opt_removed, "oldalloc"},
1153         {Opt_removed, "orlov"},
1154         {Opt_user_xattr, "user_xattr"},
1155         {Opt_nouser_xattr, "nouser_xattr"},
1156         {Opt_acl, "acl"},
1157         {Opt_noacl, "noacl"},
1158         {Opt_noload, "norecovery"},
1159         {Opt_noload, "noload"},
1160         {Opt_removed, "nobh"},
1161         {Opt_removed, "bh"},
1162         {Opt_commit, "commit=%u"},
1163         {Opt_min_batch_time, "min_batch_time=%u"},
1164         {Opt_max_batch_time, "max_batch_time=%u"},
1165         {Opt_journal_dev, "journal_dev=%u"},
1166         {Opt_journal_path, "journal_path=%s"},
1167         {Opt_journal_checksum, "journal_checksum"},
1168         {Opt_nojournal_checksum, "nojournal_checksum"},
1169         {Opt_journal_async_commit, "journal_async_commit"},
1170         {Opt_abort, "abort"},
1171         {Opt_data_journal, "data=journal"},
1172         {Opt_data_ordered, "data=ordered"},
1173         {Opt_data_writeback, "data=writeback"},
1174         {Opt_data_err_abort, "data_err=abort"},
1175         {Opt_data_err_ignore, "data_err=ignore"},
1176         {Opt_offusrjquota, "usrjquota="},
1177         {Opt_usrjquota, "usrjquota=%s"},
1178         {Opt_offgrpjquota, "grpjquota="},
1179         {Opt_grpjquota, "grpjquota=%s"},
1180         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1181         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1182         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1183         {Opt_grpquota, "grpquota"},
1184         {Opt_noquota, "noquota"},
1185         {Opt_quota, "quota"},
1186         {Opt_usrquota, "usrquota"},
1187         {Opt_barrier, "barrier=%u"},
1188         {Opt_barrier, "barrier"},
1189         {Opt_nobarrier, "nobarrier"},
1190         {Opt_i_version, "i_version"},
1191         {Opt_dax, "dax"},
1192         {Opt_stripe, "stripe=%u"},
1193         {Opt_delalloc, "delalloc"},
1194         {Opt_lazytime, "lazytime"},
1195         {Opt_nolazytime, "nolazytime"},
1196         {Opt_nodelalloc, "nodelalloc"},
1197         {Opt_removed, "mblk_io_submit"},
1198         {Opt_removed, "nomblk_io_submit"},
1199         {Opt_block_validity, "block_validity"},
1200         {Opt_noblock_validity, "noblock_validity"},
1201         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1202         {Opt_journal_ioprio, "journal_ioprio=%u"},
1203         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1204         {Opt_auto_da_alloc, "auto_da_alloc"},
1205         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1206         {Opt_dioread_nolock, "dioread_nolock"},
1207         {Opt_dioread_lock, "dioread_lock"},
1208         {Opt_discard, "discard"},
1209         {Opt_nodiscard, "nodiscard"},
1210         {Opt_init_itable, "init_itable=%u"},
1211         {Opt_init_itable, "init_itable"},
1212         {Opt_noinit_itable, "noinit_itable"},
1213         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1214         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1215         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1216         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1217         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1218         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1219         {Opt_err, NULL},
1220 };
1221
1222 static ext4_fsblk_t get_sb_block(void **data)
1223 {
1224         ext4_fsblk_t    sb_block;
1225         char            *options = (char *) *data;
1226
1227         if (!options || strncmp(options, "sb=", 3) != 0)
1228                 return 1;       /* Default location */
1229
1230         options += 3;
1231         /* TODO: use simple_strtoll with >32bit ext4 */
1232         sb_block = simple_strtoul(options, &options, 0);
1233         if (*options && *options != ',') {
1234                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1235                        (char *) *data);
1236                 return 1;
1237         }
1238         if (*options == ',')
1239                 options++;
1240         *data = (void *) options;
1241
1242         return sb_block;
1243 }
1244
1245 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1246 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1247         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1248
1249 #ifdef CONFIG_QUOTA
1250 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1251 {
1252         struct ext4_sb_info *sbi = EXT4_SB(sb);
1253         char *qname;
1254         int ret = -1;
1255
1256         if (sb_any_quota_loaded(sb) &&
1257                 !sbi->s_qf_names[qtype]) {
1258                 ext4_msg(sb, KERN_ERR,
1259                         "Cannot change journaled "
1260                         "quota options when quota turned on");
1261                 return -1;
1262         }
1263         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1264                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1265                          "when QUOTA feature is enabled");
1266                 return -1;
1267         }
1268         qname = match_strdup(args);
1269         if (!qname) {
1270                 ext4_msg(sb, KERN_ERR,
1271                         "Not enough memory for storing quotafile name");
1272                 return -1;
1273         }
1274         if (sbi->s_qf_names[qtype]) {
1275                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1276                         ret = 1;
1277                 else
1278                         ext4_msg(sb, KERN_ERR,
1279                                  "%s quota file already specified",
1280                                  QTYPE2NAME(qtype));
1281                 goto errout;
1282         }
1283         if (strchr(qname, '/')) {
1284                 ext4_msg(sb, KERN_ERR,
1285                         "quotafile must be on filesystem root");
1286                 goto errout;
1287         }
1288         sbi->s_qf_names[qtype] = qname;
1289         set_opt(sb, QUOTA);
1290         return 1;
1291 errout:
1292         kfree(qname);
1293         return ret;
1294 }
1295
1296 static int clear_qf_name(struct super_block *sb, int qtype)
1297 {
1298
1299         struct ext4_sb_info *sbi = EXT4_SB(sb);
1300
1301         if (sb_any_quota_loaded(sb) &&
1302                 sbi->s_qf_names[qtype]) {
1303                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1304                         " when quota turned on");
1305                 return -1;
1306         }
1307         kfree(sbi->s_qf_names[qtype]);
1308         sbi->s_qf_names[qtype] = NULL;
1309         return 1;
1310 }
1311 #endif
1312
1313 #define MOPT_SET        0x0001
1314 #define MOPT_CLEAR      0x0002
1315 #define MOPT_NOSUPPORT  0x0004
1316 #define MOPT_EXPLICIT   0x0008
1317 #define MOPT_CLEAR_ERR  0x0010
1318 #define MOPT_GTE0       0x0020
1319 #ifdef CONFIG_QUOTA
1320 #define MOPT_Q          0
1321 #define MOPT_QFMT       0x0040
1322 #else
1323 #define MOPT_Q          MOPT_NOSUPPORT
1324 #define MOPT_QFMT       MOPT_NOSUPPORT
1325 #endif
1326 #define MOPT_DATAJ      0x0080
1327 #define MOPT_NO_EXT2    0x0100
1328 #define MOPT_NO_EXT3    0x0200
1329 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1330 #define MOPT_STRING     0x0400
1331
1332 static const struct mount_opts {
1333         int     token;
1334         int     mount_opt;
1335         int     flags;
1336 } ext4_mount_opts[] = {
1337         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1338         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1339         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1340         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1341         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1342         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1343         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1344          MOPT_EXT4_ONLY | MOPT_SET},
1345         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1346          MOPT_EXT4_ONLY | MOPT_CLEAR},
1347         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1348         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1349         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1350          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1351         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1352          MOPT_EXT4_ONLY | MOPT_CLEAR},
1353         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1354          MOPT_EXT4_ONLY | MOPT_CLEAR},
1355         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1356          MOPT_EXT4_ONLY | MOPT_SET},
1357         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1358                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1359          MOPT_EXT4_ONLY | MOPT_SET},
1360         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1361         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1362         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1363         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1364         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1365          MOPT_NO_EXT2 | MOPT_SET},
1366         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1367          MOPT_NO_EXT2 | MOPT_CLEAR},
1368         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1369         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1370         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1371         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1372         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1373         {Opt_commit, 0, MOPT_GTE0},
1374         {Opt_max_batch_time, 0, MOPT_GTE0},
1375         {Opt_min_batch_time, 0, MOPT_GTE0},
1376         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1377         {Opt_init_itable, 0, MOPT_GTE0},
1378         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1379         {Opt_stripe, 0, MOPT_GTE0},
1380         {Opt_resuid, 0, MOPT_GTE0},
1381         {Opt_resgid, 0, MOPT_GTE0},
1382         {Opt_journal_dev, 0, MOPT_GTE0},
1383         {Opt_journal_path, 0, MOPT_STRING},
1384         {Opt_journal_ioprio, 0, MOPT_GTE0},
1385         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1386         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1387         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1388          MOPT_NO_EXT2 | MOPT_DATAJ},
1389         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1390         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1391 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1392         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1393         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1394 #else
1395         {Opt_acl, 0, MOPT_NOSUPPORT},
1396         {Opt_noacl, 0, MOPT_NOSUPPORT},
1397 #endif
1398         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1399         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1400         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1401         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1402                                                         MOPT_SET | MOPT_Q},
1403         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1404                                                         MOPT_SET | MOPT_Q},
1405         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1406                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1407         {Opt_usrjquota, 0, MOPT_Q},
1408         {Opt_grpjquota, 0, MOPT_Q},
1409         {Opt_offusrjquota, 0, MOPT_Q},
1410         {Opt_offgrpjquota, 0, MOPT_Q},
1411         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1412         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1413         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1414         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1415         {Opt_err, 0, 0}
1416 };
1417
1418 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1419                             substring_t *args, unsigned long *journal_devnum,
1420                             unsigned int *journal_ioprio, int is_remount)
1421 {
1422         struct ext4_sb_info *sbi = EXT4_SB(sb);
1423         const struct mount_opts *m;
1424         kuid_t uid;
1425         kgid_t gid;
1426         int arg = 0;
1427
1428 #ifdef CONFIG_QUOTA
1429         if (token == Opt_usrjquota)
1430                 return set_qf_name(sb, USRQUOTA, &args[0]);
1431         else if (token == Opt_grpjquota)
1432                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1433         else if (token == Opt_offusrjquota)
1434                 return clear_qf_name(sb, USRQUOTA);
1435         else if (token == Opt_offgrpjquota)
1436                 return clear_qf_name(sb, GRPQUOTA);
1437 #endif
1438         switch (token) {
1439         case Opt_noacl:
1440         case Opt_nouser_xattr:
1441                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1442                 break;
1443         case Opt_sb:
1444                 return 1;       /* handled by get_sb_block() */
1445         case Opt_removed:
1446                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1447                 return 1;
1448         case Opt_abort:
1449                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1450                 return 1;
1451         case Opt_i_version:
1452                 sb->s_flags |= MS_I_VERSION;
1453                 return 1;
1454         case Opt_lazytime:
1455                 sb->s_flags |= MS_LAZYTIME;
1456                 return 1;
1457         case Opt_nolazytime:
1458                 sb->s_flags &= ~MS_LAZYTIME;
1459                 return 1;
1460         }
1461
1462         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1463                 if (token == m->token)
1464                         break;
1465
1466         if (m->token == Opt_err) {
1467                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1468                          "or missing value", opt);
1469                 return -1;
1470         }
1471
1472         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1473                 ext4_msg(sb, KERN_ERR,
1474                          "Mount option \"%s\" incompatible with ext2", opt);
1475                 return -1;
1476         }
1477         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1478                 ext4_msg(sb, KERN_ERR,
1479                          "Mount option \"%s\" incompatible with ext3", opt);
1480                 return -1;
1481         }
1482
1483         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1484                 return -1;
1485         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1486                 return -1;
1487         if (m->flags & MOPT_EXPLICIT)
1488                 set_opt2(sb, EXPLICIT_DELALLOC);
1489         if (m->flags & MOPT_CLEAR_ERR)
1490                 clear_opt(sb, ERRORS_MASK);
1491         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1492                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1493                          "options when quota turned on");
1494                 return -1;
1495         }
1496
1497         if (m->flags & MOPT_NOSUPPORT) {
1498                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1499         } else if (token == Opt_commit) {
1500                 if (arg == 0)
1501                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1502                 sbi->s_commit_interval = HZ * arg;
1503         } else if (token == Opt_max_batch_time) {
1504                 sbi->s_max_batch_time = arg;
1505         } else if (token == Opt_min_batch_time) {
1506                 sbi->s_min_batch_time = arg;
1507         } else if (token == Opt_inode_readahead_blks) {
1508                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1509                         ext4_msg(sb, KERN_ERR,
1510                                  "EXT4-fs: inode_readahead_blks must be "
1511                                  "0 or a power of 2 smaller than 2^31");
1512                         return -1;
1513                 }
1514                 sbi->s_inode_readahead_blks = arg;
1515         } else if (token == Opt_init_itable) {
1516                 set_opt(sb, INIT_INODE_TABLE);
1517                 if (!args->from)
1518                         arg = EXT4_DEF_LI_WAIT_MULT;
1519                 sbi->s_li_wait_mult = arg;
1520         } else if (token == Opt_max_dir_size_kb) {
1521                 sbi->s_max_dir_size_kb = arg;
1522         } else if (token == Opt_stripe) {
1523                 sbi->s_stripe = arg;
1524         } else if (token == Opt_resuid) {
1525                 uid = make_kuid(current_user_ns(), arg);
1526                 if (!uid_valid(uid)) {
1527                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1528                         return -1;
1529                 }
1530                 sbi->s_resuid = uid;
1531         } else if (token == Opt_resgid) {
1532                 gid = make_kgid(current_user_ns(), arg);
1533                 if (!gid_valid(gid)) {
1534                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1535                         return -1;
1536                 }
1537                 sbi->s_resgid = gid;
1538         } else if (token == Opt_journal_dev) {
1539                 if (is_remount) {
1540                         ext4_msg(sb, KERN_ERR,
1541                                  "Cannot specify journal on remount");
1542                         return -1;
1543                 }
1544                 *journal_devnum = arg;
1545         } else if (token == Opt_journal_path) {
1546                 char *journal_path;
1547                 struct inode *journal_inode;
1548                 struct path path;
1549                 int error;
1550
1551                 if (is_remount) {
1552                         ext4_msg(sb, KERN_ERR,
1553                                  "Cannot specify journal on remount");
1554                         return -1;
1555                 }
1556                 journal_path = match_strdup(&args[0]);
1557                 if (!journal_path) {
1558                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1559                                 "journal device string");
1560                         return -1;
1561                 }
1562
1563                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1564                 if (error) {
1565                         ext4_msg(sb, KERN_ERR, "error: could not find "
1566                                 "journal device path: error %d", error);
1567                         kfree(journal_path);
1568                         return -1;
1569                 }
1570
1571                 journal_inode = path.dentry->d_inode;
1572                 if (!S_ISBLK(journal_inode->i_mode)) {
1573                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1574                                 "is not a block device", journal_path);
1575                         path_put(&path);
1576                         kfree(journal_path);
1577                         return -1;
1578                 }
1579
1580                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1581                 path_put(&path);
1582                 kfree(journal_path);
1583         } else if (token == Opt_journal_ioprio) {
1584                 if (arg > 7) {
1585                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1586                                  " (must be 0-7)");
1587                         return -1;
1588                 }
1589                 *journal_ioprio =
1590                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1591         } else if (m->flags & MOPT_DATAJ) {
1592                 if (is_remount) {
1593                         if (!sbi->s_journal)
1594                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1595                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1596                                 ext4_msg(sb, KERN_ERR,
1597                                          "Cannot change data mode on remount");
1598                                 return -1;
1599                         }
1600                 } else {
1601                         clear_opt(sb, DATA_FLAGS);
1602                         sbi->s_mount_opt |= m->mount_opt;
1603                 }
1604 #ifdef CONFIG_QUOTA
1605         } else if (m->flags & MOPT_QFMT) {
1606                 if (sb_any_quota_loaded(sb) &&
1607                     sbi->s_jquota_fmt != m->mount_opt) {
1608                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1609                                  "quota options when quota turned on");
1610                         return -1;
1611                 }
1612                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1613                                                EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1614                         ext4_msg(sb, KERN_ERR,
1615                                  "Cannot set journaled quota options "
1616                                  "when QUOTA feature is enabled");
1617                         return -1;
1618                 }
1619                 sbi->s_jquota_fmt = m->mount_opt;
1620 #endif
1621 #ifndef CONFIG_FS_DAX
1622         } else if (token == Opt_dax) {
1623                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1624                 return -1;
1625 #endif
1626         } else {
1627                 if (!args->from)
1628                         arg = 1;
1629                 if (m->flags & MOPT_CLEAR)
1630                         arg = !arg;
1631                 else if (unlikely(!(m->flags & MOPT_SET))) {
1632                         ext4_msg(sb, KERN_WARNING,
1633                                  "buggy handling of option %s", opt);
1634                         WARN_ON(1);
1635                         return -1;
1636                 }
1637                 if (arg != 0)
1638                         sbi->s_mount_opt |= m->mount_opt;
1639                 else
1640                         sbi->s_mount_opt &= ~m->mount_opt;
1641         }
1642         return 1;
1643 }
1644
1645 static int parse_options(char *options, struct super_block *sb,
1646                          unsigned long *journal_devnum,
1647                          unsigned int *journal_ioprio,
1648                          int is_remount)
1649 {
1650         struct ext4_sb_info *sbi = EXT4_SB(sb);
1651         char *p;
1652         substring_t args[MAX_OPT_ARGS];
1653         int token;
1654
1655         if (!options)
1656                 return 1;
1657
1658         while ((p = strsep(&options, ",")) != NULL) {
1659                 if (!*p)
1660                         continue;
1661                 /*
1662                  * Initialize args struct so we know whether arg was
1663                  * found; some options take optional arguments.
1664                  */
1665                 args[0].to = args[0].from = NULL;
1666                 token = match_token(p, tokens, args);
1667                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1668                                      journal_ioprio, is_remount) < 0)
1669                         return 0;
1670         }
1671 #ifdef CONFIG_QUOTA
1672         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1673             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1674                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1675                          "feature is enabled");
1676                 return 0;
1677         }
1678         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1679                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1680                         clear_opt(sb, USRQUOTA);
1681
1682                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1683                         clear_opt(sb, GRPQUOTA);
1684
1685                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1686                         ext4_msg(sb, KERN_ERR, "old and new quota "
1687                                         "format mixing");
1688                         return 0;
1689                 }
1690
1691                 if (!sbi->s_jquota_fmt) {
1692                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1693                                         "not specified");
1694                         return 0;
1695                 }
1696         }
1697 #endif
1698         if (test_opt(sb, DIOREAD_NOLOCK)) {
1699                 int blocksize =
1700                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1701
1702                 if (blocksize < PAGE_CACHE_SIZE) {
1703                         ext4_msg(sb, KERN_ERR, "can't mount with "
1704                                  "dioread_nolock if block size != PAGE_SIZE");
1705                         return 0;
1706                 }
1707         }
1708         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1709             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1710                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1711                          "in data=ordered mode");
1712                 return 0;
1713         }
1714         return 1;
1715 }
1716
1717 static inline void ext4_show_quota_options(struct seq_file *seq,
1718                                            struct super_block *sb)
1719 {
1720 #if defined(CONFIG_QUOTA)
1721         struct ext4_sb_info *sbi = EXT4_SB(sb);
1722
1723         if (sbi->s_jquota_fmt) {
1724                 char *fmtname = "";
1725
1726                 switch (sbi->s_jquota_fmt) {
1727                 case QFMT_VFS_OLD:
1728                         fmtname = "vfsold";
1729                         break;
1730                 case QFMT_VFS_V0:
1731                         fmtname = "vfsv0";
1732                         break;
1733                 case QFMT_VFS_V1:
1734                         fmtname = "vfsv1";
1735                         break;
1736                 }
1737                 seq_printf(seq, ",jqfmt=%s", fmtname);
1738         }
1739
1740         if (sbi->s_qf_names[USRQUOTA])
1741                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1742
1743         if (sbi->s_qf_names[GRPQUOTA])
1744                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1745 #endif
1746 }
1747
1748 static const char *token2str(int token)
1749 {
1750         const struct match_token *t;
1751
1752         for (t = tokens; t->token != Opt_err; t++)
1753                 if (t->token == token && !strchr(t->pattern, '='))
1754                         break;
1755         return t->pattern;
1756 }
1757
1758 /*
1759  * Show an option if
1760  *  - it's set to a non-default value OR
1761  *  - if the per-sb default is different from the global default
1762  */
1763 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1764                               int nodefs)
1765 {
1766         struct ext4_sb_info *sbi = EXT4_SB(sb);
1767         struct ext4_super_block *es = sbi->s_es;
1768         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1769         const struct mount_opts *m;
1770         char sep = nodefs ? '\n' : ',';
1771
1772 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1773 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1774
1775         if (sbi->s_sb_block != 1)
1776                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1777
1778         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1779                 int want_set = m->flags & MOPT_SET;
1780                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1781                     (m->flags & MOPT_CLEAR_ERR))
1782                         continue;
1783                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1784                         continue; /* skip if same as the default */
1785                 if ((want_set &&
1786                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1787                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1788                         continue; /* select Opt_noFoo vs Opt_Foo */
1789                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1790         }
1791
1792         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1793             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1794                 SEQ_OPTS_PRINT("resuid=%u",
1795                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1796         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1797             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1798                 SEQ_OPTS_PRINT("resgid=%u",
1799                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1800         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1801         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1802                 SEQ_OPTS_PUTS("errors=remount-ro");
1803         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1804                 SEQ_OPTS_PUTS("errors=continue");
1805         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1806                 SEQ_OPTS_PUTS("errors=panic");
1807         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1808                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1809         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1810                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1811         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1812                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1813         if (sb->s_flags & MS_I_VERSION)
1814                 SEQ_OPTS_PUTS("i_version");
1815         if (nodefs || sbi->s_stripe)
1816                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1817         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1818                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1819                         SEQ_OPTS_PUTS("data=journal");
1820                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1821                         SEQ_OPTS_PUTS("data=ordered");
1822                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1823                         SEQ_OPTS_PUTS("data=writeback");
1824         }
1825         if (nodefs ||
1826             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1827                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1828                                sbi->s_inode_readahead_blks);
1829
1830         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1831                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1832                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1833         if (nodefs || sbi->s_max_dir_size_kb)
1834                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1835
1836         ext4_show_quota_options(seq, sb);
1837         return 0;
1838 }
1839
1840 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1841 {
1842         return _ext4_show_options(seq, root->d_sb, 0);
1843 }
1844
1845 static int options_seq_show(struct seq_file *seq, void *offset)
1846 {
1847         struct super_block *sb = seq->private;
1848         int rc;
1849
1850         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1851         rc = _ext4_show_options(seq, sb, 1);
1852         seq_puts(seq, "\n");
1853         return rc;
1854 }
1855
1856 static int options_open_fs(struct inode *inode, struct file *file)
1857 {
1858         return single_open(file, options_seq_show, PDE_DATA(inode));
1859 }
1860
1861 static const struct file_operations ext4_seq_options_fops = {
1862         .owner = THIS_MODULE,
1863         .open = options_open_fs,
1864         .read = seq_read,
1865         .llseek = seq_lseek,
1866         .release = single_release,
1867 };
1868
1869 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1870                             int read_only)
1871 {
1872         struct ext4_sb_info *sbi = EXT4_SB(sb);
1873         int res = 0;
1874
1875         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1876                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1877                          "forcing read-only mode");
1878                 res = MS_RDONLY;
1879         }
1880         if (read_only)
1881                 goto done;
1882         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1883                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1884                          "running e2fsck is recommended");
1885         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1886                 ext4_msg(sb, KERN_WARNING,
1887                          "warning: mounting fs with errors, "
1888                          "running e2fsck is recommended");
1889         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1890                  le16_to_cpu(es->s_mnt_count) >=
1891                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1892                 ext4_msg(sb, KERN_WARNING,
1893                          "warning: maximal mount count reached, "
1894                          "running e2fsck is recommended");
1895         else if (le32_to_cpu(es->s_checkinterval) &&
1896                 (le32_to_cpu(es->s_lastcheck) +
1897                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1898                 ext4_msg(sb, KERN_WARNING,
1899                          "warning: checktime reached, "
1900                          "running e2fsck is recommended");
1901         if (!sbi->s_journal)
1902                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1903         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1904                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1905         le16_add_cpu(&es->s_mnt_count, 1);
1906         es->s_mtime = cpu_to_le32(get_seconds());
1907         ext4_update_dynamic_rev(sb);
1908         if (sbi->s_journal)
1909                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1910
1911         ext4_commit_super(sb, 1);
1912 done:
1913         if (test_opt(sb, DEBUG))
1914                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1915                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1916                         sb->s_blocksize,
1917                         sbi->s_groups_count,
1918                         EXT4_BLOCKS_PER_GROUP(sb),
1919                         EXT4_INODES_PER_GROUP(sb),
1920                         sbi->s_mount_opt, sbi->s_mount_opt2);
1921
1922         cleancache_init_fs(sb);
1923         return res;
1924 }
1925
1926 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1927 {
1928         struct ext4_sb_info *sbi = EXT4_SB(sb);
1929         struct flex_groups *new_groups;
1930         int size;
1931
1932         if (!sbi->s_log_groups_per_flex)
1933                 return 0;
1934
1935         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1936         if (size <= sbi->s_flex_groups_allocated)
1937                 return 0;
1938
1939         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1940         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1941         if (!new_groups) {
1942                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1943                          size / (int) sizeof(struct flex_groups));
1944                 return -ENOMEM;
1945         }
1946
1947         if (sbi->s_flex_groups) {
1948                 memcpy(new_groups, sbi->s_flex_groups,
1949                        (sbi->s_flex_groups_allocated *
1950                         sizeof(struct flex_groups)));
1951                 kvfree(sbi->s_flex_groups);
1952         }
1953         sbi->s_flex_groups = new_groups;
1954         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1955         return 0;
1956 }
1957
1958 static int ext4_fill_flex_info(struct super_block *sb)
1959 {
1960         struct ext4_sb_info *sbi = EXT4_SB(sb);
1961         struct ext4_group_desc *gdp = NULL;
1962         ext4_group_t flex_group;
1963         int i, err;
1964
1965         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1966         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1967                 sbi->s_log_groups_per_flex = 0;
1968                 return 1;
1969         }
1970
1971         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1972         if (err)
1973                 goto failed;
1974
1975         for (i = 0; i < sbi->s_groups_count; i++) {
1976                 gdp = ext4_get_group_desc(sb, i, NULL);
1977
1978                 flex_group = ext4_flex_group(sbi, i);
1979                 atomic_add(ext4_free_inodes_count(sb, gdp),
1980                            &sbi->s_flex_groups[flex_group].free_inodes);
1981                 atomic64_add(ext4_free_group_clusters(sb, gdp),
1982                              &sbi->s_flex_groups[flex_group].free_clusters);
1983                 atomic_add(ext4_used_dirs_count(sb, gdp),
1984                            &sbi->s_flex_groups[flex_group].used_dirs);
1985         }
1986
1987         return 1;
1988 failed:
1989         return 0;
1990 }
1991
1992 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1993                                    struct ext4_group_desc *gdp)
1994 {
1995         int offset;
1996         __u16 crc = 0;
1997         __le32 le_group = cpu_to_le32(block_group);
1998
1999         if (ext4_has_metadata_csum(sbi->s_sb)) {
2000                 /* Use new metadata_csum algorithm */
2001                 __le16 save_csum;
2002                 __u32 csum32;
2003
2004                 save_csum = gdp->bg_checksum;
2005                 gdp->bg_checksum = 0;
2006                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2007                                      sizeof(le_group));
2008                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2009                                      sbi->s_desc_size);
2010                 gdp->bg_checksum = save_csum;
2011
2012                 crc = csum32 & 0xFFFF;
2013                 goto out;
2014         }
2015
2016         /* old crc16 code */
2017         if (!(sbi->s_es->s_feature_ro_compat &
2018               cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
2019                 return 0;
2020
2021         offset = offsetof(struct ext4_group_desc, bg_checksum);
2022
2023         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2024         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2025         crc = crc16(crc, (__u8 *)gdp, offset);
2026         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2027         /* for checksum of struct ext4_group_desc do the rest...*/
2028         if ((sbi->s_es->s_feature_incompat &
2029              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2030             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2031                 crc = crc16(crc, (__u8 *)gdp + offset,
2032                             le16_to_cpu(sbi->s_es->s_desc_size) -
2033                                 offset);
2034
2035 out:
2036         return cpu_to_le16(crc);
2037 }
2038
2039 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2040                                 struct ext4_group_desc *gdp)
2041 {
2042         if (ext4_has_group_desc_csum(sb) &&
2043             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2044                                                       block_group, gdp)))
2045                 return 0;
2046
2047         return 1;
2048 }
2049
2050 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2051                               struct ext4_group_desc *gdp)
2052 {
2053         if (!ext4_has_group_desc_csum(sb))
2054                 return;
2055         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2056 }
2057
2058 /* Called at mount-time, super-block is locked */
2059 static int ext4_check_descriptors(struct super_block *sb,
2060                                   ext4_group_t *first_not_zeroed)
2061 {
2062         struct ext4_sb_info *sbi = EXT4_SB(sb);
2063         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2064         ext4_fsblk_t last_block;
2065         ext4_fsblk_t block_bitmap;
2066         ext4_fsblk_t inode_bitmap;
2067         ext4_fsblk_t inode_table;
2068         int flexbg_flag = 0;
2069         ext4_group_t i, grp = sbi->s_groups_count;
2070
2071         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2072                 flexbg_flag = 1;
2073
2074         ext4_debug("Checking group descriptors");
2075
2076         for (i = 0; i < sbi->s_groups_count; i++) {
2077                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2078
2079                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2080                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2081                 else
2082                         last_block = first_block +
2083                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2084
2085                 if ((grp == sbi->s_groups_count) &&
2086                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2087                         grp = i;
2088
2089                 block_bitmap = ext4_block_bitmap(sb, gdp);
2090                 if (block_bitmap < first_block || block_bitmap > last_block) {
2091                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2092                                "Block bitmap for group %u not in group "
2093                                "(block %llu)!", i, block_bitmap);
2094                         return 0;
2095                 }
2096                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2097                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2098                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2099                                "Inode bitmap for group %u not in group "
2100                                "(block %llu)!", i, inode_bitmap);
2101                         return 0;
2102                 }
2103                 inode_table = ext4_inode_table(sb, gdp);
2104                 if (inode_table < first_block ||
2105                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2106                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2107                                "Inode table for group %u not in group "
2108                                "(block %llu)!", i, inode_table);
2109                         return 0;
2110                 }
2111                 ext4_lock_group(sb, i);
2112                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2113                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2114                                  "Checksum for group %u failed (%u!=%u)",
2115                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2116                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2117                         if (!(sb->s_flags & MS_RDONLY)) {
2118                                 ext4_unlock_group(sb, i);
2119                                 return 0;
2120                         }
2121                 }
2122                 ext4_unlock_group(sb, i);
2123                 if (!flexbg_flag)
2124                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2125         }
2126         if (NULL != first_not_zeroed)
2127                 *first_not_zeroed = grp;
2128         return 1;
2129 }
2130
2131 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2132  * the superblock) which were deleted from all directories, but held open by
2133  * a process at the time of a crash.  We walk the list and try to delete these
2134  * inodes at recovery time (only with a read-write filesystem).
2135  *
2136  * In order to keep the orphan inode chain consistent during traversal (in
2137  * case of crash during recovery), we link each inode into the superblock
2138  * orphan list_head and handle it the same way as an inode deletion during
2139  * normal operation (which journals the operations for us).
2140  *
2141  * We only do an iget() and an iput() on each inode, which is very safe if we
2142  * accidentally point at an in-use or already deleted inode.  The worst that
2143  * can happen in this case is that we get a "bit already cleared" message from
2144  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2145  * e2fsck was run on this filesystem, and it must have already done the orphan
2146  * inode cleanup for us, so we can safely abort without any further action.
2147  */
2148 static void ext4_orphan_cleanup(struct super_block *sb,
2149                                 struct ext4_super_block *es)
2150 {
2151         unsigned int s_flags = sb->s_flags;
2152         int nr_orphans = 0, nr_truncates = 0;
2153 #ifdef CONFIG_QUOTA
2154         int i;
2155 #endif
2156         if (!es->s_last_orphan) {
2157                 jbd_debug(4, "no orphan inodes to clean up\n");
2158                 return;
2159         }
2160
2161         if (bdev_read_only(sb->s_bdev)) {
2162                 ext4_msg(sb, KERN_ERR, "write access "
2163                         "unavailable, skipping orphan cleanup");
2164                 return;
2165         }
2166
2167         /* Check if feature set would not allow a r/w mount */
2168         if (!ext4_feature_set_ok(sb, 0)) {
2169                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2170                          "unknown ROCOMPAT features");
2171                 return;
2172         }
2173
2174         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2175                 /* don't clear list on RO mount w/ errors */
2176                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2177                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2178                                   "clearing orphan list.\n");
2179                         es->s_last_orphan = 0;
2180                 }
2181                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2182                 return;
2183         }
2184
2185         if (s_flags & MS_RDONLY) {
2186                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2187                 sb->s_flags &= ~MS_RDONLY;
2188         }
2189 #ifdef CONFIG_QUOTA
2190         /* Needed for iput() to work correctly and not trash data */
2191         sb->s_flags |= MS_ACTIVE;
2192         /* Turn on quotas so that they are updated correctly */
2193         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2194                 if (EXT4_SB(sb)->s_qf_names[i]) {
2195                         int ret = ext4_quota_on_mount(sb, i);
2196                         if (ret < 0)
2197                                 ext4_msg(sb, KERN_ERR,
2198                                         "Cannot turn on journaled "
2199                                         "quota: error %d", ret);
2200                 }
2201         }
2202 #endif
2203
2204         while (es->s_last_orphan) {
2205                 struct inode *inode;
2206
2207                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2208                 if (IS_ERR(inode)) {
2209                         es->s_last_orphan = 0;
2210                         break;
2211                 }
2212
2213                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2214                 dquot_initialize(inode);
2215                 if (inode->i_nlink) {
2216                         if (test_opt(sb, DEBUG))
2217                                 ext4_msg(sb, KERN_DEBUG,
2218                                         "%s: truncating inode %lu to %lld bytes",
2219                                         __func__, inode->i_ino, inode->i_size);
2220                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2221                                   inode->i_ino, inode->i_size);
2222                         mutex_lock(&inode->i_mutex);
2223                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2224                         ext4_truncate(inode);
2225                         mutex_unlock(&inode->i_mutex);
2226                         nr_truncates++;
2227                 } else {
2228                         if (test_opt(sb, DEBUG))
2229                                 ext4_msg(sb, KERN_DEBUG,
2230                                         "%s: deleting unreferenced inode %lu",
2231                                         __func__, inode->i_ino);
2232                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2233                                   inode->i_ino);
2234                         nr_orphans++;
2235                 }
2236                 iput(inode);  /* The delete magic happens here! */
2237         }
2238
2239 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2240
2241         if (nr_orphans)
2242                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2243                        PLURAL(nr_orphans));
2244         if (nr_truncates)
2245                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2246                        PLURAL(nr_truncates));
2247 #ifdef CONFIG_QUOTA
2248         /* Turn quotas off */
2249         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2250                 if (sb_dqopt(sb)->files[i])
2251                         dquot_quota_off(sb, i);
2252         }
2253 #endif
2254         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2255 }
2256
2257 /*
2258  * Maximal extent format file size.
2259  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2260  * extent format containers, within a sector_t, and within i_blocks
2261  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2262  * so that won't be a limiting factor.
2263  *
2264  * However there is other limiting factor. We do store extents in the form
2265  * of starting block and length, hence the resulting length of the extent
2266  * covering maximum file size must fit into on-disk format containers as
2267  * well. Given that length is always by 1 unit bigger than max unit (because
2268  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2269  *
2270  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2271  */
2272 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2273 {
2274         loff_t res;
2275         loff_t upper_limit = MAX_LFS_FILESIZE;
2276
2277         /* small i_blocks in vfs inode? */
2278         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2279                 /*
2280                  * CONFIG_LBDAF is not enabled implies the inode
2281                  * i_block represent total blocks in 512 bytes
2282                  * 32 == size of vfs inode i_blocks * 8
2283                  */
2284                 upper_limit = (1LL << 32) - 1;
2285
2286                 /* total blocks in file system block size */
2287                 upper_limit >>= (blkbits - 9);
2288                 upper_limit <<= blkbits;
2289         }
2290
2291         /*
2292          * 32-bit extent-start container, ee_block. We lower the maxbytes
2293          * by one fs block, so ee_len can cover the extent of maximum file
2294          * size
2295          */
2296         res = (1LL << 32) - 1;
2297         res <<= blkbits;
2298
2299         /* Sanity check against vm- & vfs- imposed limits */
2300         if (res > upper_limit)
2301                 res = upper_limit;
2302
2303         return res;
2304 }
2305
2306 /*
2307  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2308  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2309  * We need to be 1 filesystem block less than the 2^48 sector limit.
2310  */
2311 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2312 {
2313         loff_t res = EXT4_NDIR_BLOCKS;
2314         int meta_blocks;
2315         loff_t upper_limit;
2316         /* This is calculated to be the largest file size for a dense, block
2317          * mapped file such that the file's total number of 512-byte sectors,
2318          * including data and all indirect blocks, does not exceed (2^48 - 1).
2319          *
2320          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2321          * number of 512-byte sectors of the file.
2322          */
2323
2324         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2325                 /*
2326                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2327                  * the inode i_block field represents total file blocks in
2328                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2329                  */
2330                 upper_limit = (1LL << 32) - 1;
2331
2332                 /* total blocks in file system block size */
2333                 upper_limit >>= (bits - 9);
2334
2335         } else {
2336                 /*
2337                  * We use 48 bit ext4_inode i_blocks
2338                  * With EXT4_HUGE_FILE_FL set the i_blocks
2339                  * represent total number of blocks in
2340                  * file system block size
2341                  */
2342                 upper_limit = (1LL << 48) - 1;
2343
2344         }
2345
2346         /* indirect blocks */
2347         meta_blocks = 1;
2348         /* double indirect blocks */
2349         meta_blocks += 1 + (1LL << (bits-2));
2350         /* tripple indirect blocks */
2351         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2352
2353         upper_limit -= meta_blocks;
2354         upper_limit <<= bits;
2355
2356         res += 1LL << (bits-2);
2357         res += 1LL << (2*(bits-2));
2358         res += 1LL << (3*(bits-2));
2359         res <<= bits;
2360         if (res > upper_limit)
2361                 res = upper_limit;
2362
2363         if (res > MAX_LFS_FILESIZE)
2364                 res = MAX_LFS_FILESIZE;
2365
2366         return res;
2367 }
2368
2369 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2370                                    ext4_fsblk_t logical_sb_block, int nr)
2371 {
2372         struct ext4_sb_info *sbi = EXT4_SB(sb);
2373         ext4_group_t bg, first_meta_bg;
2374         int has_super = 0;
2375
2376         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2377
2378         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2379             nr < first_meta_bg)
2380                 return logical_sb_block + nr + 1;
2381         bg = sbi->s_desc_per_block * nr;
2382         if (ext4_bg_has_super(sb, bg))
2383                 has_super = 1;
2384
2385         /*
2386          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2387          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2388          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2389          * compensate.
2390          */
2391         if (sb->s_blocksize == 1024 && nr == 0 &&
2392             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2393                 has_super++;
2394
2395         return (has_super + ext4_group_first_block_no(sb, bg));
2396 }
2397
2398 /**
2399  * ext4_get_stripe_size: Get the stripe size.
2400  * @sbi: In memory super block info
2401  *
2402  * If we have specified it via mount option, then
2403  * use the mount option value. If the value specified at mount time is
2404  * greater than the blocks per group use the super block value.
2405  * If the super block value is greater than blocks per group return 0.
2406  * Allocator needs it be less than blocks per group.
2407  *
2408  */
2409 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2410 {
2411         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2412         unsigned long stripe_width =
2413                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2414         int ret;
2415
2416         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2417                 ret = sbi->s_stripe;
2418         else if (stripe_width <= sbi->s_blocks_per_group)
2419                 ret = stripe_width;
2420         else if (stride <= sbi->s_blocks_per_group)
2421                 ret = stride;
2422         else
2423                 ret = 0;
2424
2425         /*
2426          * If the stripe width is 1, this makes no sense and
2427          * we set it to 0 to turn off stripe handling code.
2428          */
2429         if (ret <= 1)
2430                 ret = 0;
2431
2432         return ret;
2433 }
2434
2435 /* sysfs supprt */
2436
2437 struct ext4_attr {
2438         struct attribute attr;
2439         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2440         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2441                          const char *, size_t);
2442         union {
2443                 int offset;
2444                 int deprecated_val;
2445         } u;
2446 };
2447
2448 static int parse_strtoull(const char *buf,
2449                 unsigned long long max, unsigned long long *value)
2450 {
2451         int ret;
2452
2453         ret = kstrtoull(skip_spaces(buf), 0, value);
2454         if (!ret && *value > max)
2455                 ret = -EINVAL;
2456         return ret;
2457 }
2458
2459 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2460                                               struct ext4_sb_info *sbi,
2461                                               char *buf)
2462 {
2463         return snprintf(buf, PAGE_SIZE, "%llu\n",
2464                 (s64) EXT4_C2B(sbi,
2465                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2466 }
2467
2468 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2469                                          struct ext4_sb_info *sbi, char *buf)
2470 {
2471         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2472
2473         if (!sb->s_bdev->bd_part)
2474                 return snprintf(buf, PAGE_SIZE, "0\n");
2475         return snprintf(buf, PAGE_SIZE, "%lu\n",
2476                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2477                          sbi->s_sectors_written_start) >> 1);
2478 }
2479
2480 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2481                                           struct ext4_sb_info *sbi, char *buf)
2482 {
2483         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2484
2485         if (!sb->s_bdev->bd_part)
2486                 return snprintf(buf, PAGE_SIZE, "0\n");
2487         return snprintf(buf, PAGE_SIZE, "%llu\n",
2488                         (unsigned long long)(sbi->s_kbytes_written +
2489                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2490                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2491 }
2492
2493 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2494                                           struct ext4_sb_info *sbi,
2495                                           const char *buf, size_t count)
2496 {
2497         unsigned long t;
2498         int ret;
2499
2500         ret = kstrtoul(skip_spaces(buf), 0, &t);
2501         if (ret)
2502                 return ret;
2503
2504         if (t && (!is_power_of_2(t) || t > 0x40000000))
2505                 return -EINVAL;
2506
2507         sbi->s_inode_readahead_blks = t;
2508         return count;
2509 }
2510
2511 static ssize_t sbi_ui_show(struct ext4_attr *a,
2512                            struct ext4_sb_info *sbi, char *buf)
2513 {
2514         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2515
2516         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2517 }
2518
2519 static ssize_t sbi_ui_store(struct ext4_attr *a,
2520                             struct ext4_sb_info *sbi,
2521                             const char *buf, size_t count)
2522 {
2523         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2524         unsigned long t;
2525         int ret;
2526
2527         ret = kstrtoul(skip_spaces(buf), 0, &t);
2528         if (ret)
2529                 return ret;
2530         *ui = t;
2531         return count;
2532 }
2533
2534 static ssize_t es_ui_show(struct ext4_attr *a,
2535                            struct ext4_sb_info *sbi, char *buf)
2536 {
2537
2538         unsigned int *ui = (unsigned int *) (((char *) sbi->s_es) +
2539                            a->u.offset);
2540
2541         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2542 }
2543
2544 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2545                                   struct ext4_sb_info *sbi, char *buf)
2546 {
2547         return snprintf(buf, PAGE_SIZE, "%llu\n",
2548                 (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2549 }
2550
2551 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2552                                    struct ext4_sb_info *sbi,
2553                                    const char *buf, size_t count)
2554 {
2555         unsigned long long val;
2556         int ret;
2557
2558         if (parse_strtoull(buf, -1ULL, &val))
2559                 return -EINVAL;
2560         ret = ext4_reserve_clusters(sbi, val);
2561
2562         return ret ? ret : count;
2563 }
2564
2565 static ssize_t trigger_test_error(struct ext4_attr *a,
2566                                   struct ext4_sb_info *sbi,
2567                                   const char *buf, size_t count)
2568 {
2569         int len = count;
2570
2571         if (!capable(CAP_SYS_ADMIN))
2572                 return -EPERM;
2573
2574         if (len && buf[len-1] == '\n')
2575                 len--;
2576
2577         if (len)
2578                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2579         return count;
2580 }
2581
2582 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2583                                    struct ext4_sb_info *sbi, char *buf)
2584 {
2585         return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2586 }
2587
2588 #define EXT4_ATTR_OFFSET(_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_sb_info, _elname),\
2595         },                                                      \
2596 }
2597
2598 #define EXT4_ATTR_OFFSET_ES(_name,_mode,_show,_store,_elname)           \
2599 static struct ext4_attr ext4_attr_##_name = {                           \
2600         .attr = {.name = __stringify(_name), .mode = _mode },           \
2601         .show   = _show,                                                \
2602         .store  = _store,                                               \
2603         .u = {                                                          \
2604                 .offset = offsetof(struct ext4_super_block, _elname),   \
2605         },                                                              \
2606 }
2607
2608 #define EXT4_ATTR(name, mode, show, store) \
2609 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2610
2611 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2612 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2613 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2614
2615 #define EXT4_RO_ATTR_ES_UI(name, elname)        \
2616         EXT4_ATTR_OFFSET_ES(name, 0444, es_ui_show, NULL, elname)
2617 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2618         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2619
2620 #define ATTR_LIST(name) &ext4_attr_##name.attr
2621 #define EXT4_DEPRECATED_ATTR(_name, _val)       \
2622 static struct ext4_attr ext4_attr_##_name = {                   \
2623         .attr = {.name = __stringify(_name), .mode = 0444 },    \
2624         .show   = sbi_deprecated_show,                          \
2625         .u = {                                                  \
2626                 .deprecated_val = _val,                         \
2627         },                                                      \
2628 }
2629
2630 EXT4_RO_ATTR(delayed_allocation_blocks);
2631 EXT4_RO_ATTR(session_write_kbytes);
2632 EXT4_RO_ATTR(lifetime_write_kbytes);
2633 EXT4_RW_ATTR(reserved_clusters);
2634 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2635                  inode_readahead_blks_store, s_inode_readahead_blks);
2636 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2637 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2638 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2639 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2640 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2641 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2642 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2643 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2644 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2645 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2646 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2647 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2648 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2649 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2650 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2651 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2652 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
2653 EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
2654 EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
2655
2656 static struct attribute *ext4_attrs[] = {
2657         ATTR_LIST(delayed_allocation_blocks),
2658         ATTR_LIST(session_write_kbytes),
2659         ATTR_LIST(lifetime_write_kbytes),
2660         ATTR_LIST(reserved_clusters),
2661         ATTR_LIST(inode_readahead_blks),
2662         ATTR_LIST(inode_goal),
2663         ATTR_LIST(mb_stats),
2664         ATTR_LIST(mb_max_to_scan),
2665         ATTR_LIST(mb_min_to_scan),
2666         ATTR_LIST(mb_order2_req),
2667         ATTR_LIST(mb_stream_req),
2668         ATTR_LIST(mb_group_prealloc),
2669         ATTR_LIST(max_writeback_mb_bump),
2670         ATTR_LIST(extent_max_zeroout_kb),
2671         ATTR_LIST(trigger_fs_error),
2672         ATTR_LIST(err_ratelimit_interval_ms),
2673         ATTR_LIST(err_ratelimit_burst),
2674         ATTR_LIST(warning_ratelimit_interval_ms),
2675         ATTR_LIST(warning_ratelimit_burst),
2676         ATTR_LIST(msg_ratelimit_interval_ms),
2677         ATTR_LIST(msg_ratelimit_burst),
2678         ATTR_LIST(errors_count),
2679         ATTR_LIST(first_error_time),
2680         ATTR_LIST(last_error_time),
2681         NULL,
2682 };
2683
2684 /* Features this copy of ext4 supports */
2685 EXT4_INFO_ATTR(lazy_itable_init);
2686 EXT4_INFO_ATTR(batched_discard);
2687 EXT4_INFO_ATTR(meta_bg_resize);
2688
2689 static struct attribute *ext4_feat_attrs[] = {
2690         ATTR_LIST(lazy_itable_init),
2691         ATTR_LIST(batched_discard),
2692         ATTR_LIST(meta_bg_resize),
2693         NULL,
2694 };
2695
2696 static ssize_t ext4_attr_show(struct kobject *kobj,
2697                               struct attribute *attr, char *buf)
2698 {
2699         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2700                                                 s_kobj);
2701         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2702
2703         return a->show ? a->show(a, sbi, buf) : 0;
2704 }
2705
2706 static ssize_t ext4_attr_store(struct kobject *kobj,
2707                                struct attribute *attr,
2708                                const char *buf, size_t len)
2709 {
2710         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2711                                                 s_kobj);
2712         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2713
2714         return a->store ? a->store(a, sbi, buf, len) : 0;
2715 }
2716
2717 static void ext4_sb_release(struct kobject *kobj)
2718 {
2719         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2720                                                 s_kobj);
2721         complete(&sbi->s_kobj_unregister);
2722 }
2723
2724 static const struct sysfs_ops ext4_attr_ops = {
2725         .show   = ext4_attr_show,
2726         .store  = ext4_attr_store,
2727 };
2728
2729 static struct kobj_type ext4_ktype = {
2730         .default_attrs  = ext4_attrs,
2731         .sysfs_ops      = &ext4_attr_ops,
2732         .release        = ext4_sb_release,
2733 };
2734
2735 static void ext4_feat_release(struct kobject *kobj)
2736 {
2737         complete(&ext4_feat->f_kobj_unregister);
2738 }
2739
2740 static ssize_t ext4_feat_show(struct kobject *kobj,
2741                               struct attribute *attr, char *buf)
2742 {
2743         return snprintf(buf, PAGE_SIZE, "supported\n");
2744 }
2745
2746 /*
2747  * We can not use ext4_attr_show/store because it relies on the kobject
2748  * being embedded in the ext4_sb_info structure which is definitely not
2749  * true in this case.
2750  */
2751 static const struct sysfs_ops ext4_feat_ops = {
2752         .show   = ext4_feat_show,
2753         .store  = NULL,
2754 };
2755
2756 static struct kobj_type ext4_feat_ktype = {
2757         .default_attrs  = ext4_feat_attrs,
2758         .sysfs_ops      = &ext4_feat_ops,
2759         .release        = ext4_feat_release,
2760 };
2761
2762 /*
2763  * Check whether this filesystem can be mounted based on
2764  * the features present and the RDONLY/RDWR mount requested.
2765  * Returns 1 if this filesystem can be mounted as requested,
2766  * 0 if it cannot be.
2767  */
2768 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2769 {
2770         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2771                 ext4_msg(sb, KERN_ERR,
2772                         "Couldn't mount because of "
2773                         "unsupported optional features (%x)",
2774                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2775                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2776                 return 0;
2777         }
2778
2779         if (readonly)
2780                 return 1;
2781
2782         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_READONLY)) {
2783                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2784                 sb->s_flags |= MS_RDONLY;
2785                 return 1;
2786         }
2787
2788         /* Check that feature set is OK for a read-write mount */
2789         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2790                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2791                          "unsupported optional features (%x)",
2792                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2793                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2794                 return 0;
2795         }
2796         /*
2797          * Large file size enabled file system can only be mounted
2798          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2799          */
2800         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2801                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2802                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2803                                  "cannot be mounted RDWR without "
2804                                  "CONFIG_LBDAF");
2805                         return 0;
2806                 }
2807         }
2808         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2809             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2810                 ext4_msg(sb, KERN_ERR,
2811                          "Can't support bigalloc feature without "
2812                          "extents feature\n");
2813                 return 0;
2814         }
2815
2816 #ifndef CONFIG_QUOTA
2817         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2818             !readonly) {
2819                 ext4_msg(sb, KERN_ERR,
2820                          "Filesystem with quota feature cannot be mounted RDWR "
2821                          "without CONFIG_QUOTA");
2822                 return 0;
2823         }
2824 #endif  /* CONFIG_QUOTA */
2825         return 1;
2826 }
2827
2828 /*
2829  * This function is called once a day if we have errors logged
2830  * on the file system
2831  */
2832 static void print_daily_error_info(unsigned long arg)
2833 {
2834         struct super_block *sb = (struct super_block *) arg;
2835         struct ext4_sb_info *sbi;
2836         struct ext4_super_block *es;
2837
2838         sbi = EXT4_SB(sb);
2839         es = sbi->s_es;
2840
2841         if (es->s_error_count)
2842                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2843                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2844                          le32_to_cpu(es->s_error_count));
2845         if (es->s_first_error_time) {
2846                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2847                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2848                        (int) sizeof(es->s_first_error_func),
2849                        es->s_first_error_func,
2850                        le32_to_cpu(es->s_first_error_line));
2851                 if (es->s_first_error_ino)
2852                         printk(": inode %u",
2853                                le32_to_cpu(es->s_first_error_ino));
2854                 if (es->s_first_error_block)
2855                         printk(": block %llu", (unsigned long long)
2856                                le64_to_cpu(es->s_first_error_block));
2857                 printk("\n");
2858         }
2859         if (es->s_last_error_time) {
2860                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2861                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2862                        (int) sizeof(es->s_last_error_func),
2863                        es->s_last_error_func,
2864                        le32_to_cpu(es->s_last_error_line));
2865                 if (es->s_last_error_ino)
2866                         printk(": inode %u",
2867                                le32_to_cpu(es->s_last_error_ino));
2868                 if (es->s_last_error_block)
2869                         printk(": block %llu", (unsigned long long)
2870                                le64_to_cpu(es->s_last_error_block));
2871                 printk("\n");
2872         }
2873         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2874 }
2875
2876 /* Find next suitable group and run ext4_init_inode_table */
2877 static int ext4_run_li_request(struct ext4_li_request *elr)
2878 {
2879         struct ext4_group_desc *gdp = NULL;
2880         ext4_group_t group, ngroups;
2881         struct super_block *sb;
2882         unsigned long timeout = 0;
2883         int ret = 0;
2884
2885         sb = elr->lr_super;
2886         ngroups = EXT4_SB(sb)->s_groups_count;
2887
2888         sb_start_write(sb);
2889         for (group = elr->lr_next_group; group < ngroups; group++) {
2890                 gdp = ext4_get_group_desc(sb, group, NULL);
2891                 if (!gdp) {
2892                         ret = 1;
2893                         break;
2894                 }
2895
2896                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2897                         break;
2898         }
2899
2900         if (group >= ngroups)
2901                 ret = 1;
2902
2903         if (!ret) {
2904                 timeout = jiffies;
2905                 ret = ext4_init_inode_table(sb, group,
2906                                             elr->lr_timeout ? 0 : 1);
2907                 if (elr->lr_timeout == 0) {
2908                         timeout = (jiffies - timeout) *
2909                                   elr->lr_sbi->s_li_wait_mult;
2910                         elr->lr_timeout = timeout;
2911                 }
2912                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2913                 elr->lr_next_group = group + 1;
2914         }
2915         sb_end_write(sb);
2916
2917         return ret;
2918 }
2919
2920 /*
2921  * Remove lr_request from the list_request and free the
2922  * request structure. Should be called with li_list_mtx held
2923  */
2924 static void ext4_remove_li_request(struct ext4_li_request *elr)
2925 {
2926         struct ext4_sb_info *sbi;
2927
2928         if (!elr)
2929                 return;
2930
2931         sbi = elr->lr_sbi;
2932
2933         list_del(&elr->lr_request);
2934         sbi->s_li_request = NULL;
2935         kfree(elr);
2936 }
2937
2938 static void ext4_unregister_li_request(struct super_block *sb)
2939 {
2940         mutex_lock(&ext4_li_mtx);
2941         if (!ext4_li_info) {
2942                 mutex_unlock(&ext4_li_mtx);
2943                 return;
2944         }
2945
2946         mutex_lock(&ext4_li_info->li_list_mtx);
2947         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2948         mutex_unlock(&ext4_li_info->li_list_mtx);
2949         mutex_unlock(&ext4_li_mtx);
2950 }
2951
2952 static struct task_struct *ext4_lazyinit_task;
2953
2954 /*
2955  * This is the function where ext4lazyinit thread lives. It walks
2956  * through the request list searching for next scheduled filesystem.
2957  * When such a fs is found, run the lazy initialization request
2958  * (ext4_rn_li_request) and keep track of the time spend in this
2959  * function. Based on that time we compute next schedule time of
2960  * the request. When walking through the list is complete, compute
2961  * next waking time and put itself into sleep.
2962  */
2963 static int ext4_lazyinit_thread(void *arg)
2964 {
2965         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2966         struct list_head *pos, *n;
2967         struct ext4_li_request *elr;
2968         unsigned long next_wakeup, cur;
2969
2970         BUG_ON(NULL == eli);
2971
2972 cont_thread:
2973         while (true) {
2974                 next_wakeup = MAX_JIFFY_OFFSET;
2975
2976                 mutex_lock(&eli->li_list_mtx);
2977                 if (list_empty(&eli->li_request_list)) {
2978                         mutex_unlock(&eli->li_list_mtx);
2979                         goto exit_thread;
2980                 }
2981
2982                 list_for_each_safe(pos, n, &eli->li_request_list) {
2983                         elr = list_entry(pos, struct ext4_li_request,
2984                                          lr_request);
2985
2986                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2987                                 if (ext4_run_li_request(elr) != 0) {
2988                                         /* error, remove the lazy_init job */
2989                                         ext4_remove_li_request(elr);
2990                                         continue;
2991                                 }
2992                         }
2993
2994                         if (time_before(elr->lr_next_sched, next_wakeup))
2995                                 next_wakeup = elr->lr_next_sched;
2996                 }
2997                 mutex_unlock(&eli->li_list_mtx);
2998
2999                 try_to_freeze();
3000
3001                 cur = jiffies;
3002                 if ((time_after_eq(cur, next_wakeup)) ||
3003                     (MAX_JIFFY_OFFSET == next_wakeup)) {
3004                         cond_resched();
3005                         continue;
3006                 }
3007
3008                 schedule_timeout_interruptible(next_wakeup - cur);
3009
3010                 if (kthread_should_stop()) {
3011                         ext4_clear_request_list();
3012                         goto exit_thread;
3013                 }
3014         }
3015
3016 exit_thread:
3017         /*
3018          * It looks like the request list is empty, but we need
3019          * to check it under the li_list_mtx lock, to prevent any
3020          * additions into it, and of course we should lock ext4_li_mtx
3021          * to atomically free the list and ext4_li_info, because at
3022          * this point another ext4 filesystem could be registering
3023          * new one.
3024          */
3025         mutex_lock(&ext4_li_mtx);
3026         mutex_lock(&eli->li_list_mtx);
3027         if (!list_empty(&eli->li_request_list)) {
3028                 mutex_unlock(&eli->li_list_mtx);
3029                 mutex_unlock(&ext4_li_mtx);
3030                 goto cont_thread;
3031         }
3032         mutex_unlock(&eli->li_list_mtx);
3033         kfree(ext4_li_info);
3034         ext4_li_info = NULL;
3035         mutex_unlock(&ext4_li_mtx);
3036
3037         return 0;
3038 }
3039
3040 static void ext4_clear_request_list(void)
3041 {
3042         struct list_head *pos, *n;
3043         struct ext4_li_request *elr;
3044
3045         mutex_lock(&ext4_li_info->li_list_mtx);
3046         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3047                 elr = list_entry(pos, struct ext4_li_request,
3048                                  lr_request);
3049                 ext4_remove_li_request(elr);
3050         }
3051         mutex_unlock(&ext4_li_info->li_list_mtx);
3052 }
3053
3054 static int ext4_run_lazyinit_thread(void)
3055 {
3056         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3057                                          ext4_li_info, "ext4lazyinit");
3058         if (IS_ERR(ext4_lazyinit_task)) {
3059                 int err = PTR_ERR(ext4_lazyinit_task);
3060                 ext4_clear_request_list();
3061                 kfree(ext4_li_info);
3062                 ext4_li_info = NULL;
3063                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3064                                  "initialization thread\n",
3065                                  err);
3066                 return err;
3067         }
3068         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3069         return 0;
3070 }
3071
3072 /*
3073  * Check whether it make sense to run itable init. thread or not.
3074  * If there is at least one uninitialized inode table, return
3075  * corresponding group number, else the loop goes through all
3076  * groups and return total number of groups.
3077  */
3078 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3079 {
3080         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3081         struct ext4_group_desc *gdp = NULL;
3082
3083         for (group = 0; group < ngroups; group++) {
3084                 gdp = ext4_get_group_desc(sb, group, NULL);
3085                 if (!gdp)
3086                         continue;
3087
3088                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3089                         break;
3090         }
3091
3092         return group;
3093 }
3094
3095 static int ext4_li_info_new(void)
3096 {
3097         struct ext4_lazy_init *eli = NULL;
3098
3099         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3100         if (!eli)
3101                 return -ENOMEM;
3102
3103         INIT_LIST_HEAD(&eli->li_request_list);
3104         mutex_init(&eli->li_list_mtx);
3105
3106         eli->li_state |= EXT4_LAZYINIT_QUIT;
3107
3108         ext4_li_info = eli;
3109
3110         return 0;
3111 }
3112
3113 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3114                                             ext4_group_t start)
3115 {
3116         struct ext4_sb_info *sbi = EXT4_SB(sb);
3117         struct ext4_li_request *elr;
3118
3119         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3120         if (!elr)
3121                 return NULL;
3122
3123         elr->lr_super = sb;
3124         elr->lr_sbi = sbi;
3125         elr->lr_next_group = start;
3126
3127         /*
3128          * Randomize first schedule time of the request to
3129          * spread the inode table initialization requests
3130          * better.
3131          */
3132         elr->lr_next_sched = jiffies + (prandom_u32() %
3133                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3134         return elr;
3135 }
3136
3137 int ext4_register_li_request(struct super_block *sb,
3138                              ext4_group_t first_not_zeroed)
3139 {
3140         struct ext4_sb_info *sbi = EXT4_SB(sb);
3141         struct ext4_li_request *elr = NULL;
3142         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3143         int ret = 0;
3144
3145         mutex_lock(&ext4_li_mtx);
3146         if (sbi->s_li_request != NULL) {
3147                 /*
3148                  * Reset timeout so it can be computed again, because
3149                  * s_li_wait_mult might have changed.
3150                  */
3151                 sbi->s_li_request->lr_timeout = 0;
3152                 goto out;
3153         }
3154
3155         if (first_not_zeroed == ngroups ||
3156             (sb->s_flags & MS_RDONLY) ||
3157             !test_opt(sb, INIT_INODE_TABLE))
3158                 goto out;
3159
3160         elr = ext4_li_request_new(sb, first_not_zeroed);
3161         if (!elr) {
3162                 ret = -ENOMEM;
3163                 goto out;
3164         }
3165
3166         if (NULL == ext4_li_info) {
3167                 ret = ext4_li_info_new();
3168                 if (ret)
3169                         goto out;
3170         }
3171
3172         mutex_lock(&ext4_li_info->li_list_mtx);
3173         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3174         mutex_unlock(&ext4_li_info->li_list_mtx);
3175
3176         sbi->s_li_request = elr;
3177         /*
3178          * set elr to NULL here since it has been inserted to
3179          * the request_list and the removal and free of it is
3180          * handled by ext4_clear_request_list from now on.
3181          */
3182         elr = NULL;
3183
3184         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3185                 ret = ext4_run_lazyinit_thread();
3186                 if (ret)
3187                         goto out;
3188         }
3189 out:
3190         mutex_unlock(&ext4_li_mtx);
3191         if (ret)
3192                 kfree(elr);
3193         return ret;
3194 }
3195
3196 /*
3197  * We do not need to lock anything since this is called on
3198  * module unload.
3199  */
3200 static void ext4_destroy_lazyinit_thread(void)
3201 {
3202         /*
3203          * If thread exited earlier
3204          * there's nothing to be done.
3205          */
3206         if (!ext4_li_info || !ext4_lazyinit_task)
3207                 return;
3208
3209         kthread_stop(ext4_lazyinit_task);
3210 }
3211
3212 static int set_journal_csum_feature_set(struct super_block *sb)
3213 {
3214         int ret = 1;
3215         int compat, incompat;
3216         struct ext4_sb_info *sbi = EXT4_SB(sb);
3217
3218         if (ext4_has_metadata_csum(sb)) {
3219                 /* journal checksum v3 */
3220                 compat = 0;
3221                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3222         } else {
3223                 /* journal checksum v1 */
3224                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3225                 incompat = 0;
3226         }
3227
3228         jbd2_journal_clear_features(sbi->s_journal,
3229                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3230                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3231                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3232         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3233                 ret = jbd2_journal_set_features(sbi->s_journal,
3234                                 compat, 0,
3235                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3236                                 incompat);
3237         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3238                 ret = jbd2_journal_set_features(sbi->s_journal,
3239                                 compat, 0,
3240                                 incompat);
3241                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3242                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3243         } else {
3244                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3245                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3246         }
3247
3248         return ret;
3249 }
3250
3251 /*
3252  * Note: calculating the overhead so we can be compatible with
3253  * historical BSD practice is quite difficult in the face of
3254  * clusters/bigalloc.  This is because multiple metadata blocks from
3255  * different block group can end up in the same allocation cluster.
3256  * Calculating the exact overhead in the face of clustered allocation
3257  * requires either O(all block bitmaps) in memory or O(number of block
3258  * groups**2) in time.  We will still calculate the superblock for
3259  * older file systems --- and if we come across with a bigalloc file
3260  * system with zero in s_overhead_clusters the estimate will be close to
3261  * correct especially for very large cluster sizes --- but for newer
3262  * file systems, it's better to calculate this figure once at mkfs
3263  * time, and store it in the superblock.  If the superblock value is
3264  * present (even for non-bigalloc file systems), we will use it.
3265  */
3266 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3267                           char *buf)
3268 {
3269         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3270         struct ext4_group_desc  *gdp;
3271         ext4_fsblk_t            first_block, last_block, b;
3272         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3273         int                     s, j, count = 0;
3274
3275         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3276                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3277                         sbi->s_itb_per_group + 2);
3278
3279         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3280                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3281         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3282         for (i = 0; i < ngroups; i++) {
3283                 gdp = ext4_get_group_desc(sb, i, NULL);
3284                 b = ext4_block_bitmap(sb, gdp);
3285                 if (b >= first_block && b <= last_block) {
3286                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3287                         count++;
3288                 }
3289                 b = ext4_inode_bitmap(sb, gdp);
3290                 if (b >= first_block && b <= last_block) {
3291                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3292                         count++;
3293                 }
3294                 b = ext4_inode_table(sb, gdp);
3295                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3296                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3297                                 int c = EXT4_B2C(sbi, b - first_block);
3298                                 ext4_set_bit(c, buf);
3299                                 count++;
3300                         }
3301                 if (i != grp)
3302                         continue;
3303                 s = 0;
3304                 if (ext4_bg_has_super(sb, grp)) {
3305                         ext4_set_bit(s++, buf);
3306                         count++;
3307                 }
3308                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3309                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3310                         count++;
3311                 }
3312         }
3313         if (!count)
3314                 return 0;
3315         return EXT4_CLUSTERS_PER_GROUP(sb) -
3316                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3317 }
3318
3319 /*
3320  * Compute the overhead and stash it in sbi->s_overhead
3321  */
3322 int ext4_calculate_overhead(struct super_block *sb)
3323 {
3324         struct ext4_sb_info *sbi = EXT4_SB(sb);
3325         struct ext4_super_block *es = sbi->s_es;
3326         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3327         ext4_fsblk_t overhead = 0;
3328         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3329
3330         if (!buf)
3331                 return -ENOMEM;
3332
3333         /*
3334          * Compute the overhead (FS structures).  This is constant
3335          * for a given filesystem unless the number of block groups
3336          * changes so we cache the previous value until it does.
3337          */
3338
3339         /*
3340          * All of the blocks before first_data_block are overhead
3341          */
3342         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3343
3344         /*
3345          * Add the overhead found in each block group
3346          */
3347         for (i = 0; i < ngroups; i++) {
3348                 int blks;
3349
3350                 blks = count_overhead(sb, i, buf);
3351                 overhead += blks;
3352                 if (blks)
3353                         memset(buf, 0, PAGE_SIZE);
3354                 cond_resched();
3355         }
3356         /* Add the internal journal blocks as well */
3357         if (sbi->s_journal && !sbi->journal_bdev)
3358                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3359
3360         sbi->s_overhead = overhead;
3361         smp_wmb();
3362         free_page((unsigned long) buf);
3363         return 0;
3364 }
3365
3366
3367 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3368 {
3369         ext4_fsblk_t resv_clusters;
3370
3371         /*
3372          * There's no need to reserve anything when we aren't using extents.
3373          * The space estimates are exact, there are no unwritten extents,
3374          * hole punching doesn't need new metadata... This is needed especially
3375          * to keep ext2/3 backward compatibility.
3376          */
3377         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3378                 return 0;
3379         /*
3380          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3381          * This should cover the situations where we can not afford to run
3382          * out of space like for example punch hole, or converting
3383          * unwritten extents in delalloc path. In most cases such
3384          * allocation would require 1, or 2 blocks, higher numbers are
3385          * very rare.
3386          */
3387         resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3388                         EXT4_SB(sb)->s_cluster_bits;
3389
3390         do_div(resv_clusters, 50);
3391         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3392
3393         return resv_clusters;
3394 }
3395
3396
3397 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3398 {
3399         ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3400                                 sbi->s_cluster_bits;
3401
3402         if (count >= clusters)
3403                 return -EINVAL;
3404
3405         atomic64_set(&sbi->s_resv_clusters, count);
3406         return 0;
3407 }
3408
3409 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3410 {
3411         char *orig_data = kstrdup(data, GFP_KERNEL);
3412         struct buffer_head *bh;
3413         struct ext4_super_block *es = NULL;
3414         struct ext4_sb_info *sbi;
3415         ext4_fsblk_t block;
3416         ext4_fsblk_t sb_block = get_sb_block(&data);
3417         ext4_fsblk_t logical_sb_block;
3418         unsigned long offset = 0;
3419         unsigned long journal_devnum = 0;
3420         unsigned long def_mount_opts;
3421         struct inode *root;
3422         char *cp;
3423         const char *descr;
3424         int ret = -ENOMEM;
3425         int blocksize, clustersize;
3426         unsigned int db_count;
3427         unsigned int i;
3428         int needs_recovery, has_huge_files, has_bigalloc;
3429         __u64 blocks_count;
3430         int err = 0;
3431         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3432         ext4_group_t first_not_zeroed;
3433
3434         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3435         if (!sbi)
3436                 goto out_free_orig;
3437
3438         sbi->s_blockgroup_lock =
3439                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3440         if (!sbi->s_blockgroup_lock) {
3441                 kfree(sbi);
3442                 goto out_free_orig;
3443         }
3444         sb->s_fs_info = sbi;
3445         sbi->s_sb = sb;
3446         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3447         sbi->s_sb_block = sb_block;
3448         if (sb->s_bdev->bd_part)
3449                 sbi->s_sectors_written_start =
3450                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3451
3452         /* Cleanup superblock name */
3453         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3454                 *cp = '!';
3455
3456         /* -EINVAL is default */
3457         ret = -EINVAL;
3458         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3459         if (!blocksize) {
3460                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3461                 goto out_fail;
3462         }
3463
3464         /*
3465          * The ext4 superblock will not be buffer aligned for other than 1kB
3466          * block sizes.  We need to calculate the offset from buffer start.
3467          */
3468         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3469                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3470                 offset = do_div(logical_sb_block, blocksize);
3471         } else {
3472                 logical_sb_block = sb_block;
3473         }
3474
3475         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3476                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3477                 goto out_fail;
3478         }
3479         /*
3480          * Note: s_es must be initialized as soon as possible because
3481          *       some ext4 macro-instructions depend on its value
3482          */
3483         es = (struct ext4_super_block *) (bh->b_data + offset);
3484         sbi->s_es = es;
3485         sb->s_magic = le16_to_cpu(es->s_magic);
3486         if (sb->s_magic != EXT4_SUPER_MAGIC)
3487                 goto cantfind_ext4;
3488         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3489
3490         /* Warn if metadata_csum and gdt_csum are both set. */
3491         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3492                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3493             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3494                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3495                              "redundant flags; please run fsck.");
3496
3497         /* Check for a known checksum algorithm */
3498         if (!ext4_verify_csum_type(sb, es)) {
3499                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3500                          "unknown checksum algorithm.");
3501                 silent = 1;
3502                 goto cantfind_ext4;
3503         }
3504
3505         /* Load the checksum driver */
3506         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3507                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3508                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3509                 if (IS_ERR(sbi->s_chksum_driver)) {
3510                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3511                         ret = PTR_ERR(sbi->s_chksum_driver);
3512                         sbi->s_chksum_driver = NULL;
3513                         goto failed_mount;
3514                 }
3515         }
3516
3517         /* Check superblock checksum */
3518         if (!ext4_superblock_csum_verify(sb, es)) {
3519                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3520                          "invalid superblock checksum.  Run e2fsck?");
3521                 silent = 1;
3522                 goto cantfind_ext4;
3523         }
3524
3525         /* Precompute checksum seed for all metadata */
3526         if (ext4_has_metadata_csum(sb))
3527                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3528                                                sizeof(es->s_uuid));
3529
3530         /* Set defaults before we parse the mount options */
3531         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3532         set_opt(sb, INIT_INODE_TABLE);
3533         if (def_mount_opts & EXT4_DEFM_DEBUG)
3534                 set_opt(sb, DEBUG);
3535         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3536                 set_opt(sb, GRPID);
3537         if (def_mount_opts & EXT4_DEFM_UID16)
3538                 set_opt(sb, NO_UID32);
3539         /* xattr user namespace & acls are now defaulted on */
3540         set_opt(sb, XATTR_USER);
3541 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3542         set_opt(sb, POSIX_ACL);
3543 #endif
3544         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3545         if (ext4_has_metadata_csum(sb))
3546                 set_opt(sb, JOURNAL_CHECKSUM);
3547
3548         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3549                 set_opt(sb, JOURNAL_DATA);
3550         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3551                 set_opt(sb, ORDERED_DATA);
3552         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3553                 set_opt(sb, WRITEBACK_DATA);
3554
3555         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3556                 set_opt(sb, ERRORS_PANIC);
3557         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3558                 set_opt(sb, ERRORS_CONT);
3559         else
3560                 set_opt(sb, ERRORS_RO);
3561         /* block_validity enabled by default; disable with noblock_validity */
3562         set_opt(sb, BLOCK_VALIDITY);
3563         if (def_mount_opts & EXT4_DEFM_DISCARD)
3564                 set_opt(sb, DISCARD);
3565
3566         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3567         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3568         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3569         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3570         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3571
3572         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3573                 set_opt(sb, BARRIER);
3574
3575         /*
3576          * enable delayed allocation by default
3577          * Use -o nodelalloc to turn it off
3578          */
3579         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3580             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3581                 set_opt(sb, DELALLOC);
3582
3583         /*
3584          * set default s_li_wait_mult for lazyinit, for the case there is
3585          * no mount option specified.
3586          */
3587         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3588
3589         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3590                            &journal_devnum, &journal_ioprio, 0)) {
3591                 ext4_msg(sb, KERN_WARNING,
3592                          "failed to parse options in superblock: %s",
3593                          sbi->s_es->s_mount_opts);
3594         }
3595         sbi->s_def_mount_opt = sbi->s_mount_opt;
3596         if (!parse_options((char *) data, sb, &journal_devnum,
3597                            &journal_ioprio, 0))
3598                 goto failed_mount;
3599
3600         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3601                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3602                             "with data=journal disables delayed "
3603                             "allocation and O_DIRECT support!\n");
3604                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3605                         ext4_msg(sb, KERN_ERR, "can't mount with "
3606                                  "both data=journal and delalloc");
3607                         goto failed_mount;
3608                 }
3609                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3610                         ext4_msg(sb, KERN_ERR, "can't mount with "
3611                                  "both data=journal and dioread_nolock");
3612                         goto failed_mount;
3613                 }
3614                 if (test_opt(sb, DAX)) {
3615                         ext4_msg(sb, KERN_ERR, "can't mount with "
3616                                  "both data=journal and dax");
3617                         goto failed_mount;
3618                 }
3619                 if (test_opt(sb, DELALLOC))
3620                         clear_opt(sb, DELALLOC);
3621         }
3622
3623         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3624                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3625
3626         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3627             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3628              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3629              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3630                 ext4_msg(sb, KERN_WARNING,
3631                        "feature flags set on rev 0 fs, "
3632                        "running e2fsck is recommended");
3633
3634         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3635                 set_opt2(sb, HURD_COMPAT);
3636                 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
3637                                               EXT4_FEATURE_INCOMPAT_64BIT)) {
3638                         ext4_msg(sb, KERN_ERR,
3639                                  "The Hurd can't support 64-bit file systems");
3640                         goto failed_mount;
3641                 }
3642         }
3643
3644         if (IS_EXT2_SB(sb)) {
3645                 if (ext2_feature_set_ok(sb))
3646                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3647                                  "using the ext4 subsystem");
3648                 else {
3649                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3650                                  "to feature incompatibilities");
3651                         goto failed_mount;
3652                 }
3653         }
3654
3655         if (IS_EXT3_SB(sb)) {
3656                 if (ext3_feature_set_ok(sb))
3657                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3658                                  "using the ext4 subsystem");
3659                 else {
3660                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3661                                  "to feature incompatibilities");
3662                         goto failed_mount;
3663                 }
3664         }
3665
3666         /*
3667          * Check feature flags regardless of the revision level, since we
3668          * previously didn't change the revision level when setting the flags,
3669          * so there is a chance incompat flags are set on a rev 0 filesystem.
3670          */
3671         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3672                 goto failed_mount;
3673
3674         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3675         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3676             blocksize > EXT4_MAX_BLOCK_SIZE) {
3677                 ext4_msg(sb, KERN_ERR,
3678                        "Unsupported filesystem blocksize %d", blocksize);
3679                 goto failed_mount;
3680         }
3681
3682         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3683                 if (blocksize != PAGE_SIZE) {
3684                         ext4_msg(sb, KERN_ERR,
3685                                         "error: unsupported blocksize for dax");
3686                         goto failed_mount;
3687                 }
3688                 if (!sb->s_bdev->bd_disk->fops->direct_access) {
3689                         ext4_msg(sb, KERN_ERR,
3690                                         "error: device does not support dax");
3691                         goto failed_mount;
3692                 }
3693         }
3694
3695         if (sb->s_blocksize != blocksize) {
3696                 /* Validate the filesystem blocksize */
3697                 if (!sb_set_blocksize(sb, blocksize)) {
3698                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3699                                         blocksize);
3700                         goto failed_mount;
3701                 }
3702
3703                 brelse(bh);
3704                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3705                 offset = do_div(logical_sb_block, blocksize);
3706                 bh = sb_bread_unmovable(sb, logical_sb_block);
3707                 if (!bh) {
3708                         ext4_msg(sb, KERN_ERR,
3709                                "Can't read superblock on 2nd try");
3710                         goto failed_mount;
3711                 }
3712                 es = (struct ext4_super_block *)(bh->b_data + offset);
3713                 sbi->s_es = es;
3714                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3715                         ext4_msg(sb, KERN_ERR,
3716                                "Magic mismatch, very weird!");
3717                         goto failed_mount;
3718                 }
3719         }
3720
3721         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3722                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3723         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3724                                                       has_huge_files);
3725         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3726
3727         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3728                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3729                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3730         } else {
3731                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3732                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3733                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3734                     (!is_power_of_2(sbi->s_inode_size)) ||
3735                     (sbi->s_inode_size > blocksize)) {
3736                         ext4_msg(sb, KERN_ERR,
3737                                "unsupported inode size: %d",
3738                                sbi->s_inode_size);
3739                         goto failed_mount;
3740                 }
3741                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3742                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3743         }
3744
3745         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3746         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3747                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3748                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3749                     !is_power_of_2(sbi->s_desc_size)) {
3750                         ext4_msg(sb, KERN_ERR,
3751                                "unsupported descriptor size %lu",
3752                                sbi->s_desc_size);
3753                         goto failed_mount;
3754                 }
3755         } else
3756                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3757
3758         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3759         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3760         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3761                 goto cantfind_ext4;
3762
3763         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3764         if (sbi->s_inodes_per_block == 0)
3765                 goto cantfind_ext4;
3766         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3767                                         sbi->s_inodes_per_block;
3768         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3769         sbi->s_sbh = bh;
3770         sbi->s_mount_state = le16_to_cpu(es->s_state);
3771         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3772         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3773
3774         for (i = 0; i < 4; i++)
3775                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3776         sbi->s_def_hash_version = es->s_def_hash_version;
3777         if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3778                 i = le32_to_cpu(es->s_flags);
3779                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3780                         sbi->s_hash_unsigned = 3;
3781                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3782 #ifdef __CHAR_UNSIGNED__
3783                         if (!(sb->s_flags & MS_RDONLY))
3784                                 es->s_flags |=
3785                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3786                         sbi->s_hash_unsigned = 3;
3787 #else
3788                         if (!(sb->s_flags & MS_RDONLY))
3789                                 es->s_flags |=
3790                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3791 #endif
3792                 }
3793         }
3794
3795         /* Handle clustersize */
3796         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3797         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3798                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3799         if (has_bigalloc) {
3800                 if (clustersize < blocksize) {
3801                         ext4_msg(sb, KERN_ERR,
3802                                  "cluster size (%d) smaller than "
3803                                  "block size (%d)", clustersize, blocksize);
3804                         goto failed_mount;
3805                 }
3806                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3807                         le32_to_cpu(es->s_log_block_size);
3808                 sbi->s_clusters_per_group =
3809                         le32_to_cpu(es->s_clusters_per_group);
3810                 if (sbi->s_clusters_per_group > blocksize * 8) {
3811                         ext4_msg(sb, KERN_ERR,
3812                                  "#clusters per group too big: %lu",
3813                                  sbi->s_clusters_per_group);
3814                         goto failed_mount;
3815                 }
3816                 if (sbi->s_blocks_per_group !=
3817                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3818                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3819                                  "clusters per group (%lu) inconsistent",
3820                                  sbi->s_blocks_per_group,
3821                                  sbi->s_clusters_per_group);
3822                         goto failed_mount;
3823                 }
3824         } else {
3825                 if (clustersize != blocksize) {
3826                         ext4_warning(sb, "fragment/cluster size (%d) != "
3827                                      "block size (%d)", clustersize,
3828                                      blocksize);
3829                         clustersize = blocksize;
3830                 }
3831                 if (sbi->s_blocks_per_group > blocksize * 8) {
3832                         ext4_msg(sb, KERN_ERR,
3833                                  "#blocks per group too big: %lu",
3834                                  sbi->s_blocks_per_group);
3835                         goto failed_mount;
3836                 }
3837                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3838                 sbi->s_cluster_bits = 0;
3839         }
3840         sbi->s_cluster_ratio = clustersize / blocksize;
3841
3842         if (sbi->s_inodes_per_group > blocksize * 8) {
3843                 ext4_msg(sb, KERN_ERR,
3844                        "#inodes per group too big: %lu",
3845                        sbi->s_inodes_per_group);
3846                 goto failed_mount;
3847         }
3848
3849         /* Do we have standard group size of clustersize * 8 blocks ? */
3850         if (sbi->s_blocks_per_group == clustersize << 3)
3851                 set_opt2(sb, STD_GROUP_SIZE);
3852
3853         /*
3854          * Test whether we have more sectors than will fit in sector_t,
3855          * and whether the max offset is addressable by the page cache.
3856          */
3857         err = generic_check_addressable(sb->s_blocksize_bits,
3858                                         ext4_blocks_count(es));
3859         if (err) {
3860                 ext4_msg(sb, KERN_ERR, "filesystem"
3861                          " too large to mount safely on this system");
3862                 if (sizeof(sector_t) < 8)
3863                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3864                 goto failed_mount;
3865         }
3866
3867         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3868                 goto cantfind_ext4;
3869
3870         /* check blocks count against device size */
3871         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3872         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3873                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3874                        "exceeds size of device (%llu blocks)",
3875                        ext4_blocks_count(es), blocks_count);
3876                 goto failed_mount;
3877         }
3878
3879         /*
3880          * It makes no sense for the first data block to be beyond the end
3881          * of the filesystem.
3882          */
3883         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3884                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3885                          "block %u is beyond end of filesystem (%llu)",
3886                          le32_to_cpu(es->s_first_data_block),
3887                          ext4_blocks_count(es));
3888                 goto failed_mount;
3889         }
3890         blocks_count = (ext4_blocks_count(es) -
3891                         le32_to_cpu(es->s_first_data_block) +
3892                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3893         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3894         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3895                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3896                        "(block count %llu, first data block %u, "
3897                        "blocks per group %lu)", sbi->s_groups_count,
3898                        ext4_blocks_count(es),
3899                        le32_to_cpu(es->s_first_data_block),
3900                        EXT4_BLOCKS_PER_GROUP(sb));
3901                 goto failed_mount;
3902         }
3903         sbi->s_groups_count = blocks_count;
3904         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3905                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3906         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3907                    EXT4_DESC_PER_BLOCK(sb);
3908         sbi->s_group_desc = ext4_kvmalloc(db_count *
3909                                           sizeof(struct buffer_head *),
3910                                           GFP_KERNEL);
3911         if (sbi->s_group_desc == NULL) {
3912                 ext4_msg(sb, KERN_ERR, "not enough memory");
3913                 ret = -ENOMEM;
3914                 goto failed_mount;
3915         }
3916
3917         if (ext4_proc_root)
3918                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3919
3920         if (sbi->s_proc)
3921                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3922                                  &ext4_seq_options_fops, sb);
3923
3924         bgl_lock_init(sbi->s_blockgroup_lock);
3925
3926         for (i = 0; i < db_count; i++) {
3927                 block = descriptor_loc(sb, logical_sb_block, i);
3928                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3929                 if (!sbi->s_group_desc[i]) {
3930                         ext4_msg(sb, KERN_ERR,
3931                                "can't read group descriptor %d", i);
3932                         db_count = i;
3933                         goto failed_mount2;
3934                 }
3935         }
3936         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3937                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3938                 goto failed_mount2;
3939         }
3940
3941         sbi->s_gdb_count = db_count;
3942         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3943         spin_lock_init(&sbi->s_next_gen_lock);
3944
3945         setup_timer(&sbi->s_err_report, print_daily_error_info,
3946                 (unsigned long) sb);
3947
3948         /* Register extent status tree shrinker */
3949         if (ext4_es_register_shrinker(sbi))
3950                 goto failed_mount3;
3951
3952         sbi->s_stripe = ext4_get_stripe_size(sbi);
3953         sbi->s_extent_max_zeroout_kb = 32;
3954
3955         /*
3956          * set up enough so that it can read an inode
3957          */
3958         sb->s_op = &ext4_sops;
3959         sb->s_export_op = &ext4_export_ops;
3960         sb->s_xattr = ext4_xattr_handlers;
3961 #ifdef CONFIG_QUOTA
3962         sb->dq_op = &ext4_quota_operations;
3963         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3964                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3965         else
3966                 sb->s_qcop = &ext4_qctl_operations;
3967         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
3968 #endif
3969         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3970
3971         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3972         mutex_init(&sbi->s_orphan_lock);
3973
3974         sb->s_root = NULL;
3975
3976         needs_recovery = (es->s_last_orphan != 0 ||
3977                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3978                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3979
3980         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3981             !(sb->s_flags & MS_RDONLY))
3982                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3983                         goto failed_mount3a;
3984
3985         /*
3986          * The first inode we look at is the journal inode.  Don't try
3987          * root first: it may be modified in the journal!
3988          */
3989         if (!test_opt(sb, NOLOAD) &&
3990             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3991                 if (ext4_load_journal(sb, es, journal_devnum))
3992                         goto failed_mount3a;
3993         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3994               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3995                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3996                        "suppressed and not mounted read-only");
3997                 goto failed_mount_wq;
3998         } else {
3999                 clear_opt(sb, DATA_FLAGS);
4000                 sbi->s_journal = NULL;
4001                 needs_recovery = 0;
4002                 goto no_journal;
4003         }
4004
4005         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
4006             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4007                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
4008                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4009                 goto failed_mount_wq;
4010         }
4011
4012         if (!set_journal_csum_feature_set(sb)) {
4013                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4014                          "feature set");
4015                 goto failed_mount_wq;
4016         }
4017
4018         /* We have now updated the journal if required, so we can
4019          * validate the data journaling mode. */
4020         switch (test_opt(sb, DATA_FLAGS)) {
4021         case 0:
4022                 /* No mode set, assume a default based on the journal
4023                  * capabilities: ORDERED_DATA if the journal can
4024                  * cope, else JOURNAL_DATA
4025                  */
4026                 if (jbd2_journal_check_available_features
4027                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4028                         set_opt(sb, ORDERED_DATA);
4029                 else
4030                         set_opt(sb, JOURNAL_DATA);
4031                 break;
4032
4033         case EXT4_MOUNT_ORDERED_DATA:
4034         case EXT4_MOUNT_WRITEBACK_DATA:
4035                 if (!jbd2_journal_check_available_features
4036                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4037                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4038                                "requested data journaling mode");
4039                         goto failed_mount_wq;
4040                 }
4041         default:
4042                 break;
4043         }
4044         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4045
4046         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4047
4048 no_journal:
4049         if (ext4_mballoc_ready) {
4050                 sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
4051                 if (!sbi->s_mb_cache) {
4052                         ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4053                         goto failed_mount_wq;
4054                 }
4055         }
4056
4057         /*
4058          * Get the # of file system overhead blocks from the
4059          * superblock if present.
4060          */
4061         if (es->s_overhead_clusters)
4062                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4063         else {
4064                 err = ext4_calculate_overhead(sb);
4065                 if (err)
4066                         goto failed_mount_wq;
4067         }
4068
4069         /*
4070          * The maximum number of concurrent works can be high and
4071          * concurrency isn't really necessary.  Limit it to 1.
4072          */
4073         EXT4_SB(sb)->rsv_conversion_wq =
4074                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4075         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4076                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4077                 ret = -ENOMEM;
4078                 goto failed_mount4;
4079         }
4080
4081         /*
4082          * The jbd2_journal_load will have done any necessary log recovery,
4083          * so we can safely mount the rest of the filesystem now.
4084          */
4085
4086         root = ext4_iget(sb, EXT4_ROOT_INO);
4087         if (IS_ERR(root)) {
4088                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4089                 ret = PTR_ERR(root);
4090                 root = NULL;
4091                 goto failed_mount4;
4092         }
4093         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4094                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4095                 iput(root);
4096                 goto failed_mount4;
4097         }
4098         sb->s_root = d_make_root(root);
4099         if (!sb->s_root) {
4100                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4101                 ret = -ENOMEM;
4102                 goto failed_mount4;
4103         }
4104
4105         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4106                 sb->s_flags |= MS_RDONLY;
4107
4108         /* determine the minimum size of new large inodes, if present */
4109         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4110                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4111                                                      EXT4_GOOD_OLD_INODE_SIZE;
4112                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4113                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4114                         if (sbi->s_want_extra_isize <
4115                             le16_to_cpu(es->s_want_extra_isize))
4116                                 sbi->s_want_extra_isize =
4117                                         le16_to_cpu(es->s_want_extra_isize);
4118                         if (sbi->s_want_extra_isize <
4119                             le16_to_cpu(es->s_min_extra_isize))
4120                                 sbi->s_want_extra_isize =
4121                                         le16_to_cpu(es->s_min_extra_isize);
4122                 }
4123         }
4124         /* Check if enough inode space is available */
4125         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4126                                                         sbi->s_inode_size) {
4127                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4128                                                        EXT4_GOOD_OLD_INODE_SIZE;
4129                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4130                          "available");
4131         }
4132
4133         err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4134         if (err) {
4135                 ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4136                          "reserved pool", ext4_calculate_resv_clusters(sb));
4137                 goto failed_mount4a;
4138         }
4139
4140         err = ext4_setup_system_zone(sb);
4141         if (err) {
4142                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4143                          "zone (%d)", err);
4144                 goto failed_mount4a;
4145         }
4146
4147         ext4_ext_init(sb);
4148         err = ext4_mb_init(sb);
4149         if (err) {
4150                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4151                          err);
4152                 goto failed_mount5;
4153         }
4154
4155         block = ext4_count_free_clusters(sb);
4156         ext4_free_blocks_count_set(sbi->s_es,
4157                                    EXT4_C2B(sbi, block));
4158         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4159                                   GFP_KERNEL);
4160         if (!err) {
4161                 unsigned long freei = ext4_count_free_inodes(sb);
4162                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4163                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4164                                           GFP_KERNEL);
4165         }
4166         if (!err)
4167                 err = percpu_counter_init(&sbi->s_dirs_counter,
4168                                           ext4_count_dirs(sb), GFP_KERNEL);
4169         if (!err)
4170                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4171                                           GFP_KERNEL);
4172         if (err) {
4173                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4174                 goto failed_mount6;
4175         }
4176
4177         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
4178                 if (!ext4_fill_flex_info(sb)) {
4179                         ext4_msg(sb, KERN_ERR,
4180                                "unable to initialize "
4181                                "flex_bg meta info!");
4182                         goto failed_mount6;
4183                 }
4184
4185         err = ext4_register_li_request(sb, first_not_zeroed);
4186         if (err)
4187                 goto failed_mount6;
4188
4189         sbi->s_kobj.kset = ext4_kset;
4190         init_completion(&sbi->s_kobj_unregister);
4191         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4192                                    "%s", sb->s_id);
4193         if (err)
4194                 goto failed_mount7;
4195
4196 #ifdef CONFIG_QUOTA
4197         /* Enable quota usage during mount. */
4198         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4199             !(sb->s_flags & MS_RDONLY)) {
4200                 err = ext4_enable_quotas(sb);
4201                 if (err)
4202                         goto failed_mount8;
4203         }
4204 #endif  /* CONFIG_QUOTA */
4205
4206         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4207         ext4_orphan_cleanup(sb, es);
4208         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4209         if (needs_recovery) {
4210                 ext4_msg(sb, KERN_INFO, "recovery complete");
4211                 ext4_mark_recovery_complete(sb, es);
4212         }
4213         if (EXT4_SB(sb)->s_journal) {
4214                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4215                         descr = " journalled data mode";
4216                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4217                         descr = " ordered data mode";
4218                 else
4219                         descr = " writeback data mode";
4220         } else
4221                 descr = "out journal";
4222
4223         if (test_opt(sb, DISCARD)) {
4224                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4225                 if (!blk_queue_discard(q))
4226                         ext4_msg(sb, KERN_WARNING,
4227                                  "mounting with \"discard\" option, but "
4228                                  "the device does not support discard");
4229         }
4230
4231         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4232                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4233                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4234
4235         if (es->s_error_count)
4236                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4237
4238         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4239         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4240         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4241         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4242
4243         kfree(orig_data);
4244         return 0;
4245
4246 cantfind_ext4:
4247         if (!silent)
4248                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4249         goto failed_mount;
4250
4251 #ifdef CONFIG_QUOTA
4252 failed_mount8:
4253         kobject_del(&sbi->s_kobj);
4254 #endif
4255 failed_mount7:
4256         ext4_unregister_li_request(sb);
4257 failed_mount6:
4258         ext4_mb_release(sb);
4259         if (sbi->s_flex_groups)
4260                 kvfree(sbi->s_flex_groups);
4261         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4262         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4263         percpu_counter_destroy(&sbi->s_dirs_counter);
4264         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4265 failed_mount5:
4266         ext4_ext_release(sb);
4267         ext4_release_system_zone(sb);
4268 failed_mount4a:
4269         dput(sb->s_root);
4270         sb->s_root = NULL;
4271 failed_mount4:
4272         ext4_msg(sb, KERN_ERR, "mount failed");
4273         if (EXT4_SB(sb)->rsv_conversion_wq)
4274                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4275 failed_mount_wq:
4276         if (sbi->s_journal) {
4277                 jbd2_journal_destroy(sbi->s_journal);
4278                 sbi->s_journal = NULL;
4279         }
4280 failed_mount3a:
4281         ext4_es_unregister_shrinker(sbi);
4282 failed_mount3:
4283         del_timer_sync(&sbi->s_err_report);
4284         if (sbi->s_mmp_tsk)
4285                 kthread_stop(sbi->s_mmp_tsk);
4286 failed_mount2:
4287         for (i = 0; i < db_count; i++)
4288                 brelse(sbi->s_group_desc[i]);
4289         kvfree(sbi->s_group_desc);
4290 failed_mount:
4291         if (sbi->s_chksum_driver)
4292                 crypto_free_shash(sbi->s_chksum_driver);
4293         if (sbi->s_proc) {
4294                 remove_proc_entry("options", sbi->s_proc);
4295                 remove_proc_entry(sb->s_id, ext4_proc_root);
4296         }
4297 #ifdef CONFIG_QUOTA
4298         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4299                 kfree(sbi->s_qf_names[i]);
4300 #endif
4301         ext4_blkdev_remove(sbi);
4302         brelse(bh);
4303 out_fail:
4304         sb->s_fs_info = NULL;
4305         kfree(sbi->s_blockgroup_lock);
4306         kfree(sbi);
4307 out_free_orig:
4308         kfree(orig_data);
4309         return err ? err : ret;
4310 }
4311
4312 /*
4313  * Setup any per-fs journal parameters now.  We'll do this both on
4314  * initial mount, once the journal has been initialised but before we've
4315  * done any recovery; and again on any subsequent remount.
4316  */
4317 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4318 {
4319         struct ext4_sb_info *sbi = EXT4_SB(sb);
4320
4321         journal->j_commit_interval = sbi->s_commit_interval;
4322         journal->j_min_batch_time = sbi->s_min_batch_time;
4323         journal->j_max_batch_time = sbi->s_max_batch_time;
4324
4325         write_lock(&journal->j_state_lock);
4326         if (test_opt(sb, BARRIER))
4327                 journal->j_flags |= JBD2_BARRIER;
4328         else
4329                 journal->j_flags &= ~JBD2_BARRIER;
4330         if (test_opt(sb, DATA_ERR_ABORT))
4331                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4332         else
4333                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4334         write_unlock(&journal->j_state_lock);
4335 }
4336
4337 static journal_t *ext4_get_journal(struct super_block *sb,
4338                                    unsigned int journal_inum)
4339 {
4340         struct inode *journal_inode;
4341         journal_t *journal;
4342
4343         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4344
4345         /* First, test for the existence of a valid inode on disk.  Bad
4346          * things happen if we iget() an unused inode, as the subsequent
4347          * iput() will try to delete it. */
4348
4349         journal_inode = ext4_iget(sb, journal_inum);
4350         if (IS_ERR(journal_inode)) {
4351                 ext4_msg(sb, KERN_ERR, "no journal found");
4352                 return NULL;
4353         }
4354         if (!journal_inode->i_nlink) {
4355                 make_bad_inode(journal_inode);
4356                 iput(journal_inode);
4357                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4358                 return NULL;
4359         }
4360
4361         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4362                   journal_inode, journal_inode->i_size);
4363         if (!S_ISREG(journal_inode->i_mode)) {
4364                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4365                 iput(journal_inode);
4366                 return NULL;
4367         }
4368
4369         journal = jbd2_journal_init_inode(journal_inode);
4370         if (!journal) {
4371                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4372                 iput(journal_inode);
4373                 return NULL;
4374         }
4375         journal->j_private = sb;
4376         ext4_init_journal_params(sb, journal);
4377         return journal;
4378 }
4379
4380 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4381                                        dev_t j_dev)
4382 {
4383         struct buffer_head *bh;
4384         journal_t *journal;
4385         ext4_fsblk_t start;
4386         ext4_fsblk_t len;
4387         int hblock, blocksize;
4388         ext4_fsblk_t sb_block;
4389         unsigned long offset;
4390         struct ext4_super_block *es;
4391         struct block_device *bdev;
4392
4393         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4394
4395         bdev = ext4_blkdev_get(j_dev, sb);
4396         if (bdev == NULL)
4397                 return NULL;
4398
4399         blocksize = sb->s_blocksize;
4400         hblock = bdev_logical_block_size(bdev);
4401         if (blocksize < hblock) {
4402                 ext4_msg(sb, KERN_ERR,
4403                         "blocksize too small for journal device");
4404                 goto out_bdev;
4405         }
4406
4407         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4408         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4409         set_blocksize(bdev, blocksize);
4410         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4411                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4412                        "external journal");
4413                 goto out_bdev;
4414         }
4415
4416         es = (struct ext4_super_block *) (bh->b_data + offset);
4417         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4418             !(le32_to_cpu(es->s_feature_incompat) &
4419               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4420                 ext4_msg(sb, KERN_ERR, "external journal has "
4421                                         "bad superblock");
4422                 brelse(bh);
4423                 goto out_bdev;
4424         }
4425
4426         if ((le32_to_cpu(es->s_feature_ro_compat) &
4427              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4428             es->s_checksum != ext4_superblock_csum(sb, es)) {
4429                 ext4_msg(sb, KERN_ERR, "external journal has "
4430                                        "corrupt superblock");
4431                 brelse(bh);
4432                 goto out_bdev;
4433         }
4434
4435         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4436                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4437                 brelse(bh);
4438                 goto out_bdev;
4439         }
4440
4441         len = ext4_blocks_count(es);
4442         start = sb_block + 1;
4443         brelse(bh);     /* we're done with the superblock */
4444
4445         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4446                                         start, len, blocksize);
4447         if (!journal) {
4448                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4449                 goto out_bdev;
4450         }
4451         journal->j_private = sb;
4452         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4453         wait_on_buffer(journal->j_sb_buffer);
4454         if (!buffer_uptodate(journal->j_sb_buffer)) {
4455                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4456                 goto out_journal;
4457         }
4458         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4459                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4460                                         "user (unsupported) - %d",
4461                         be32_to_cpu(journal->j_superblock->s_nr_users));
4462                 goto out_journal;
4463         }
4464         EXT4_SB(sb)->journal_bdev = bdev;
4465         ext4_init_journal_params(sb, journal);
4466         return journal;
4467
4468 out_journal:
4469         jbd2_journal_destroy(journal);
4470 out_bdev:
4471         ext4_blkdev_put(bdev);
4472         return NULL;
4473 }
4474
4475 static int ext4_load_journal(struct super_block *sb,
4476                              struct ext4_super_block *es,
4477                              unsigned long journal_devnum)
4478 {
4479         journal_t *journal;
4480         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4481         dev_t journal_dev;
4482         int err = 0;
4483         int really_read_only;
4484
4485         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4486
4487         if (journal_devnum &&
4488             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4489                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4490                         "numbers have changed");
4491                 journal_dev = new_decode_dev(journal_devnum);
4492         } else
4493                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4494
4495         really_read_only = bdev_read_only(sb->s_bdev);
4496
4497         /*
4498          * Are we loading a blank journal or performing recovery after a
4499          * crash?  For recovery, we need to check in advance whether we
4500          * can get read-write access to the device.
4501          */
4502         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4503                 if (sb->s_flags & MS_RDONLY) {
4504                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4505                                         "required on readonly filesystem");
4506                         if (really_read_only) {
4507                                 ext4_msg(sb, KERN_ERR, "write access "
4508                                         "unavailable, cannot proceed");
4509                                 return -EROFS;
4510                         }
4511                         ext4_msg(sb, KERN_INFO, "write access will "
4512                                "be enabled during recovery");
4513                 }
4514         }
4515
4516         if (journal_inum && journal_dev) {
4517                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4518                        "and inode journals!");
4519                 return -EINVAL;
4520         }
4521
4522         if (journal_inum) {
4523                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4524                         return -EINVAL;
4525         } else {
4526                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4527                         return -EINVAL;
4528         }
4529
4530         if (!(journal->j_flags & JBD2_BARRIER))
4531                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4532
4533         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4534                 err = jbd2_journal_wipe(journal, !really_read_only);
4535         if (!err) {
4536                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4537                 if (save)
4538                         memcpy(save, ((char *) es) +
4539                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4540                 err = jbd2_journal_load(journal);
4541                 if (save)
4542                         memcpy(((char *) es) + EXT4_S_ERR_START,
4543                                save, EXT4_S_ERR_LEN);
4544                 kfree(save);
4545         }
4546
4547         if (err) {
4548                 ext4_msg(sb, KERN_ERR, "error loading journal");
4549                 jbd2_journal_destroy(journal);
4550                 return err;
4551         }
4552
4553         EXT4_SB(sb)->s_journal = journal;
4554         ext4_clear_journal_err(sb, es);
4555
4556         if (!really_read_only && journal_devnum &&
4557             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4558                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4559
4560                 /* Make sure we flush the recovery flag to disk. */
4561                 ext4_commit_super(sb, 1);
4562         }
4563
4564         return 0;
4565 }
4566
4567 static int ext4_commit_super(struct super_block *sb, int sync)
4568 {
4569         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4570         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4571         int error = 0;
4572
4573         if (!sbh || block_device_ejected(sb))
4574                 return error;
4575         if (buffer_write_io_error(sbh)) {
4576                 /*
4577                  * Oh, dear.  A previous attempt to write the
4578                  * superblock failed.  This could happen because the
4579                  * USB device was yanked out.  Or it could happen to
4580                  * be a transient write error and maybe the block will
4581                  * be remapped.  Nothing we can do but to retry the
4582                  * write and hope for the best.
4583                  */
4584                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4585                        "superblock detected");
4586                 clear_buffer_write_io_error(sbh);
4587                 set_buffer_uptodate(sbh);
4588         }
4589         /*
4590          * If the file system is mounted read-only, don't update the
4591          * superblock write time.  This avoids updating the superblock
4592          * write time when we are mounting the root file system
4593          * read/only but we need to replay the journal; at that point,
4594          * for people who are east of GMT and who make their clock
4595          * tick in localtime for Windows bug-for-bug compatibility,
4596          * the clock is set in the future, and this will cause e2fsck
4597          * to complain and force a full file system check.
4598          */
4599         if (!(sb->s_flags & MS_RDONLY))
4600                 es->s_wtime = cpu_to_le32(get_seconds());
4601         if (sb->s_bdev->bd_part)
4602                 es->s_kbytes_written =
4603                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4604                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4605                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4606         else
4607                 es->s_kbytes_written =
4608                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4609         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4610                 ext4_free_blocks_count_set(es,
4611                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4612                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4613         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4614                 es->s_free_inodes_count =
4615                         cpu_to_le32(percpu_counter_sum_positive(
4616                                 &EXT4_SB(sb)->s_freeinodes_counter));
4617         BUFFER_TRACE(sbh, "marking dirty");
4618         ext4_superblock_csum_set(sb);
4619         mark_buffer_dirty(sbh);
4620         if (sync) {
4621                 error = sync_dirty_buffer(sbh);
4622                 if (error)
4623                         return error;
4624
4625                 error = buffer_write_io_error(sbh);
4626                 if (error) {
4627                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4628                                "superblock");
4629                         clear_buffer_write_io_error(sbh);
4630                         set_buffer_uptodate(sbh);
4631                 }
4632         }
4633         return error;
4634 }
4635
4636 /*
4637  * Have we just finished recovery?  If so, and if we are mounting (or
4638  * remounting) the filesystem readonly, then we will end up with a
4639  * consistent fs on disk.  Record that fact.
4640  */
4641 static void ext4_mark_recovery_complete(struct super_block *sb,
4642                                         struct ext4_super_block *es)
4643 {
4644         journal_t *journal = EXT4_SB(sb)->s_journal;
4645
4646         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4647                 BUG_ON(journal != NULL);
4648                 return;
4649         }
4650         jbd2_journal_lock_updates(journal);
4651         if (jbd2_journal_flush(journal) < 0)
4652                 goto out;
4653
4654         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4655             sb->s_flags & MS_RDONLY) {
4656                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4657                 ext4_commit_super(sb, 1);
4658         }
4659
4660 out:
4661         jbd2_journal_unlock_updates(journal);
4662 }
4663
4664 /*
4665  * If we are mounting (or read-write remounting) a filesystem whose journal
4666  * has recorded an error from a previous lifetime, move that error to the
4667  * main filesystem now.
4668  */
4669 static void ext4_clear_journal_err(struct super_block *sb,
4670                                    struct ext4_super_block *es)
4671 {
4672         journal_t *journal;
4673         int j_errno;
4674         const char *errstr;
4675
4676         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4677
4678         journal = EXT4_SB(sb)->s_journal;
4679
4680         /*
4681          * Now check for any error status which may have been recorded in the
4682          * journal by a prior ext4_error() or ext4_abort()
4683          */
4684
4685         j_errno = jbd2_journal_errno(journal);
4686         if (j_errno) {
4687                 char nbuf[16];
4688
4689                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4690                 ext4_warning(sb, "Filesystem error recorded "
4691                              "from previous mount: %s", errstr);
4692                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4693
4694                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4695                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4696                 ext4_commit_super(sb, 1);
4697
4698                 jbd2_journal_clear_err(journal);
4699                 jbd2_journal_update_sb_errno(journal);
4700         }
4701 }
4702
4703 /*
4704  * Force the running and committing transactions to commit,
4705  * and wait on the commit.
4706  */
4707 int ext4_force_commit(struct super_block *sb)
4708 {
4709         journal_t *journal;
4710
4711         if (sb->s_flags & MS_RDONLY)
4712                 return 0;
4713
4714         journal = EXT4_SB(sb)->s_journal;
4715         return ext4_journal_force_commit(journal);
4716 }
4717
4718 static int ext4_sync_fs(struct super_block *sb, int wait)
4719 {
4720         int ret = 0;
4721         tid_t target;
4722         bool needs_barrier = false;
4723         struct ext4_sb_info *sbi = EXT4_SB(sb);
4724
4725         trace_ext4_sync_fs(sb, wait);
4726         flush_workqueue(sbi->rsv_conversion_wq);
4727         /*
4728          * Writeback quota in non-journalled quota case - journalled quota has
4729          * no dirty dquots
4730          */
4731         dquot_writeback_dquots(sb, -1);
4732         /*
4733          * Data writeback is possible w/o journal transaction, so barrier must
4734          * being sent at the end of the function. But we can skip it if
4735          * transaction_commit will do it for us.
4736          */
4737         if (sbi->s_journal) {
4738                 target = jbd2_get_latest_transaction(sbi->s_journal);
4739                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4740                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4741                         needs_barrier = true;
4742
4743                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4744                         if (wait)
4745                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4746                                                            target);
4747                 }
4748         } else if (wait && test_opt(sb, BARRIER))
4749                 needs_barrier = true;
4750         if (needs_barrier) {
4751                 int err;
4752                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4753                 if (!ret)
4754                         ret = err;
4755         }
4756
4757         return ret;
4758 }
4759
4760 /*
4761  * LVM calls this function before a (read-only) snapshot is created.  This
4762  * gives us a chance to flush the journal completely and mark the fs clean.
4763  *
4764  * Note that only this function cannot bring a filesystem to be in a clean
4765  * state independently. It relies on upper layer to stop all data & metadata
4766  * modifications.
4767  */
4768 static int ext4_freeze(struct super_block *sb)
4769 {
4770         int error = 0;
4771         journal_t *journal;
4772
4773         if (sb->s_flags & MS_RDONLY)
4774                 return 0;
4775
4776         journal = EXT4_SB(sb)->s_journal;
4777
4778         if (journal) {
4779                 /* Now we set up the journal barrier. */
4780                 jbd2_journal_lock_updates(journal);
4781
4782                 /*
4783                  * Don't clear the needs_recovery flag if we failed to
4784                  * flush the journal.
4785                  */
4786                 error = jbd2_journal_flush(journal);
4787                 if (error < 0)
4788                         goto out;
4789         }
4790
4791         /* Journal blocked and flushed, clear needs_recovery flag. */
4792         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4793         error = ext4_commit_super(sb, 1);
4794 out:
4795         if (journal)
4796                 /* we rely on upper layer to stop further updates */
4797                 jbd2_journal_unlock_updates(journal);
4798         return error;
4799 }
4800
4801 /*
4802  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4803  * flag here, even though the filesystem is not technically dirty yet.
4804  */
4805 static int ext4_unfreeze(struct super_block *sb)
4806 {
4807         if (sb->s_flags & MS_RDONLY)
4808                 return 0;
4809
4810         /* Reset the needs_recovery flag before the fs is unlocked. */
4811         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4812         ext4_commit_super(sb, 1);
4813         return 0;
4814 }
4815
4816 /*
4817  * Structure to save mount options for ext4_remount's benefit
4818  */
4819 struct ext4_mount_options {
4820         unsigned long s_mount_opt;
4821         unsigned long s_mount_opt2;
4822         kuid_t s_resuid;
4823         kgid_t s_resgid;
4824         unsigned long s_commit_interval;
4825         u32 s_min_batch_time, s_max_batch_time;
4826 #ifdef CONFIG_QUOTA
4827         int s_jquota_fmt;
4828         char *s_qf_names[EXT4_MAXQUOTAS];
4829 #endif
4830 };
4831
4832 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4833 {
4834         struct ext4_super_block *es;
4835         struct ext4_sb_info *sbi = EXT4_SB(sb);
4836         unsigned long old_sb_flags;
4837         struct ext4_mount_options old_opts;
4838         int enable_quota = 0;
4839         ext4_group_t g;
4840         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4841         int err = 0;
4842 #ifdef CONFIG_QUOTA
4843         int i, j;
4844 #endif
4845         char *orig_data = kstrdup(data, GFP_KERNEL);
4846
4847         /* Store the original options */
4848         old_sb_flags = sb->s_flags;
4849         old_opts.s_mount_opt = sbi->s_mount_opt;
4850         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4851         old_opts.s_resuid = sbi->s_resuid;
4852         old_opts.s_resgid = sbi->s_resgid;
4853         old_opts.s_commit_interval = sbi->s_commit_interval;
4854         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4855         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4856 #ifdef CONFIG_QUOTA
4857         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4858         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4859                 if (sbi->s_qf_names[i]) {
4860                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4861                                                          GFP_KERNEL);
4862                         if (!old_opts.s_qf_names[i]) {
4863                                 for (j = 0; j < i; j++)
4864                                         kfree(old_opts.s_qf_names[j]);
4865                                 kfree(orig_data);
4866                                 return -ENOMEM;
4867                         }
4868                 } else
4869                         old_opts.s_qf_names[i] = NULL;
4870 #endif
4871         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4872                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4873
4874         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4875                 err = -EINVAL;
4876                 goto restore_opts;
4877         }
4878
4879         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4880             test_opt(sb, JOURNAL_CHECKSUM)) {
4881                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4882                          "during remount not supported; ignoring");
4883                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4884         }
4885
4886         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4887                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4888                         ext4_msg(sb, KERN_ERR, "can't mount with "
4889                                  "both data=journal and delalloc");
4890                         err = -EINVAL;
4891                         goto restore_opts;
4892                 }
4893                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4894                         ext4_msg(sb, KERN_ERR, "can't mount with "
4895                                  "both data=journal and dioread_nolock");
4896                         err = -EINVAL;
4897                         goto restore_opts;
4898                 }
4899                 if (test_opt(sb, DAX)) {
4900                         ext4_msg(sb, KERN_ERR, "can't mount with "
4901                                  "both data=journal and dax");
4902                         err = -EINVAL;
4903                         goto restore_opts;
4904                 }
4905         }
4906
4907         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4908                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4909                         "dax flag with busy inodes while remounting");
4910                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4911         }
4912
4913         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4914                 ext4_abort(sb, "Abort forced by user");
4915
4916         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4917                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4918
4919         es = sbi->s_es;
4920
4921         if (sbi->s_journal) {
4922                 ext4_init_journal_params(sb, sbi->s_journal);
4923                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4924         }
4925
4926         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4927                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4928                         err = -EROFS;
4929                         goto restore_opts;
4930                 }
4931
4932                 if (*flags & MS_RDONLY) {
4933                         err = sync_filesystem(sb);
4934                         if (err < 0)
4935                                 goto restore_opts;
4936                         err = dquot_suspend(sb, -1);
4937                         if (err < 0)
4938                                 goto restore_opts;
4939
4940                         /*
4941                          * First of all, the unconditional stuff we have to do
4942                          * to disable replay of the journal when we next remount
4943                          */
4944                         sb->s_flags |= MS_RDONLY;
4945
4946                         /*
4947                          * OK, test if we are remounting a valid rw partition
4948                          * readonly, and if so set the rdonly flag and then
4949                          * mark the partition as valid again.
4950                          */
4951                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4952                             (sbi->s_mount_state & EXT4_VALID_FS))
4953                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4954
4955                         if (sbi->s_journal)
4956                                 ext4_mark_recovery_complete(sb, es);
4957                 } else {
4958                         /* Make sure we can mount this feature set readwrite */
4959                         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4960                                         EXT4_FEATURE_RO_COMPAT_READONLY) ||
4961                             !ext4_feature_set_ok(sb, 0)) {
4962                                 err = -EROFS;
4963                                 goto restore_opts;
4964                         }
4965                         /*
4966                          * Make sure the group descriptor checksums
4967                          * are sane.  If they aren't, refuse to remount r/w.
4968                          */
4969                         for (g = 0; g < sbi->s_groups_count; g++) {
4970                                 struct ext4_group_desc *gdp =
4971                                         ext4_get_group_desc(sb, g, NULL);
4972
4973                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4974                                         ext4_msg(sb, KERN_ERR,
4975                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4976                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4977                                                le16_to_cpu(gdp->bg_checksum));
4978                                         err = -EINVAL;
4979                                         goto restore_opts;
4980                                 }
4981                         }
4982
4983                         /*
4984                          * If we have an unprocessed orphan list hanging
4985                          * around from a previously readonly bdev mount,
4986                          * require a full umount/remount for now.
4987                          */
4988                         if (es->s_last_orphan) {
4989                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4990                                        "remount RDWR because of unprocessed "
4991                                        "orphan inode list.  Please "
4992                                        "umount/remount instead");
4993                                 err = -EINVAL;
4994                                 goto restore_opts;
4995                         }
4996
4997                         /*
4998                          * Mounting a RDONLY partition read-write, so reread
4999                          * and store the current valid flag.  (It may have
5000                          * been changed by e2fsck since we originally mounted
5001                          * the partition.)
5002                          */
5003                         if (sbi->s_journal)
5004                                 ext4_clear_journal_err(sb, es);
5005                         sbi->s_mount_state = le16_to_cpu(es->s_state);
5006                         if (!ext4_setup_super(sb, es, 0))
5007                                 sb->s_flags &= ~MS_RDONLY;
5008                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
5009                                                      EXT4_FEATURE_INCOMPAT_MMP))
5010                                 if (ext4_multi_mount_protect(sb,
5011                                                 le64_to_cpu(es->s_mmp_block))) {
5012                                         err = -EROFS;
5013                                         goto restore_opts;
5014                                 }
5015                         enable_quota = 1;
5016                 }
5017         }
5018
5019         /*
5020          * Reinitialize lazy itable initialization thread based on
5021          * current settings
5022          */
5023         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5024                 ext4_unregister_li_request(sb);
5025         else {
5026                 ext4_group_t first_not_zeroed;
5027                 first_not_zeroed = ext4_has_uninit_itable(sb);
5028                 ext4_register_li_request(sb, first_not_zeroed);
5029         }
5030
5031         ext4_setup_system_zone(sb);
5032         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5033                 ext4_commit_super(sb, 1);
5034
5035 #ifdef CONFIG_QUOTA
5036         /* Release old quota file names */
5037         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5038                 kfree(old_opts.s_qf_names[i]);
5039         if (enable_quota) {
5040                 if (sb_any_quota_suspended(sb))
5041                         dquot_resume(sb, -1);
5042                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
5043                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
5044                         err = ext4_enable_quotas(sb);
5045                         if (err)
5046                                 goto restore_opts;
5047                 }
5048         }
5049 #endif
5050
5051         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5052         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5053         kfree(orig_data);
5054         return 0;
5055
5056 restore_opts:
5057         sb->s_flags = old_sb_flags;
5058         sbi->s_mount_opt = old_opts.s_mount_opt;
5059         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5060         sbi->s_resuid = old_opts.s_resuid;
5061         sbi->s_resgid = old_opts.s_resgid;
5062         sbi->s_commit_interval = old_opts.s_commit_interval;
5063         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5064         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5065 #ifdef CONFIG_QUOTA
5066         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5067         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5068                 kfree(sbi->s_qf_names[i]);
5069                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5070         }
5071 #endif
5072         kfree(orig_data);
5073         return err;
5074 }
5075
5076 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5077 {
5078         struct super_block *sb = dentry->d_sb;
5079         struct ext4_sb_info *sbi = EXT4_SB(sb);
5080         struct ext4_super_block *es = sbi->s_es;
5081         ext4_fsblk_t overhead = 0, resv_blocks;
5082         u64 fsid;
5083         s64 bfree;
5084         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5085
5086         if (!test_opt(sb, MINIX_DF))
5087                 overhead = sbi->s_overhead;
5088
5089         buf->f_type = EXT4_SUPER_MAGIC;
5090         buf->f_bsize = sb->s_blocksize;
5091         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5092         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5093                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5094         /* prevent underflow in case that few free space is available */
5095         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5096         buf->f_bavail = buf->f_bfree -
5097                         (ext4_r_blocks_count(es) + resv_blocks);
5098         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5099                 buf->f_bavail = 0;
5100         buf->f_files = le32_to_cpu(es->s_inodes_count);
5101         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5102         buf->f_namelen = EXT4_NAME_LEN;
5103         fsid = le64_to_cpup((void *)es->s_uuid) ^
5104                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5105         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5106         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5107
5108         return 0;
5109 }
5110
5111 /* Helper function for writing quotas on sync - we need to start transaction
5112  * before quota file is locked for write. Otherwise the are possible deadlocks:
5113  * Process 1                         Process 2
5114  * ext4_create()                     quota_sync()
5115  *   jbd2_journal_start()                  write_dquot()
5116  *   dquot_initialize()                         down(dqio_mutex)
5117  *     down(dqio_mutex)                    jbd2_journal_start()
5118  *
5119  */
5120
5121 #ifdef CONFIG_QUOTA
5122
5123 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5124 {
5125         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5126 }
5127
5128 static int ext4_write_dquot(struct dquot *dquot)
5129 {
5130         int ret, err;
5131         handle_t *handle;
5132         struct inode *inode;
5133
5134         inode = dquot_to_inode(dquot);
5135         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5136                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5137         if (IS_ERR(handle))
5138                 return PTR_ERR(handle);
5139         ret = dquot_commit(dquot);
5140         err = ext4_journal_stop(handle);
5141         if (!ret)
5142                 ret = err;
5143         return ret;
5144 }
5145
5146 static int ext4_acquire_dquot(struct dquot *dquot)
5147 {
5148         int ret, err;
5149         handle_t *handle;
5150
5151         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5152                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5153         if (IS_ERR(handle))
5154                 return PTR_ERR(handle);
5155         ret = dquot_acquire(dquot);
5156         err = ext4_journal_stop(handle);
5157         if (!ret)
5158                 ret = err;
5159         return ret;
5160 }
5161
5162 static int ext4_release_dquot(struct dquot *dquot)
5163 {
5164         int ret, err;
5165         handle_t *handle;
5166
5167         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5168                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5169         if (IS_ERR(handle)) {
5170                 /* Release dquot anyway to avoid endless cycle in dqput() */
5171                 dquot_release(dquot);
5172                 return PTR_ERR(handle);
5173         }
5174         ret = dquot_release(dquot);
5175         err = ext4_journal_stop(handle);
5176         if (!ret)
5177                 ret = err;
5178         return ret;
5179 }
5180
5181 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5182 {
5183         struct super_block *sb = dquot->dq_sb;
5184         struct ext4_sb_info *sbi = EXT4_SB(sb);
5185
5186         /* Are we journaling quotas? */
5187         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5188             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5189                 dquot_mark_dquot_dirty(dquot);
5190                 return ext4_write_dquot(dquot);
5191         } else {
5192                 return dquot_mark_dquot_dirty(dquot);
5193         }
5194 }
5195
5196 static int ext4_write_info(struct super_block *sb, int type)
5197 {
5198         int ret, err;
5199         handle_t *handle;
5200
5201         /* Data block + inode block */
5202         handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5203         if (IS_ERR(handle))
5204                 return PTR_ERR(handle);
5205         ret = dquot_commit_info(sb, type);
5206         err = ext4_journal_stop(handle);
5207         if (!ret)
5208                 ret = err;
5209         return ret;
5210 }
5211
5212 /*
5213  * Turn on quotas during mount time - we need to find
5214  * the quota file and such...
5215  */
5216 static int ext4_quota_on_mount(struct super_block *sb, int type)
5217 {
5218         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5219                                         EXT4_SB(sb)->s_jquota_fmt, type);
5220 }
5221
5222 /*
5223  * Standard function to be called on quota_on
5224  */
5225 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5226                          struct path *path)
5227 {
5228         int err;
5229
5230         if (!test_opt(sb, QUOTA))
5231                 return -EINVAL;
5232
5233         /* Quotafile not on the same filesystem? */
5234         if (path->dentry->d_sb != sb)
5235                 return -EXDEV;
5236         /* Journaling quota? */
5237         if (EXT4_SB(sb)->s_qf_names[type]) {
5238                 /* Quotafile not in fs root? */
5239                 if (path->dentry->d_parent != sb->s_root)
5240                         ext4_msg(sb, KERN_WARNING,
5241                                 "Quota file not on filesystem root. "
5242                                 "Journaled quota will not work");
5243         }
5244
5245         /*
5246          * When we journal data on quota file, we have to flush journal to see
5247          * all updates to the file when we bypass pagecache...
5248          */
5249         if (EXT4_SB(sb)->s_journal &&
5250             ext4_should_journal_data(path->dentry->d_inode)) {
5251                 /*
5252                  * We don't need to lock updates but journal_flush() could
5253                  * otherwise be livelocked...
5254                  */
5255                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5256                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5257                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5258                 if (err)
5259                         return err;
5260         }
5261
5262         return dquot_quota_on(sb, type, format_id, path);
5263 }
5264
5265 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5266                              unsigned int flags)
5267 {
5268         int err;
5269         struct inode *qf_inode;
5270         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5271                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5272                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5273         };
5274
5275         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5276
5277         if (!qf_inums[type])
5278                 return -EPERM;
5279
5280         qf_inode = ext4_iget(sb, qf_inums[type]);
5281         if (IS_ERR(qf_inode)) {
5282                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5283                 return PTR_ERR(qf_inode);
5284         }
5285
5286         /* Don't account quota for quota files to avoid recursion */
5287         qf_inode->i_flags |= S_NOQUOTA;
5288         err = dquot_enable(qf_inode, type, format_id, flags);
5289         iput(qf_inode);
5290
5291         return err;
5292 }
5293
5294 /* Enable usage tracking for all quota types. */
5295 static int ext4_enable_quotas(struct super_block *sb)
5296 {
5297         int type, err = 0;
5298         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5299                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5300                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5301         };
5302
5303         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5304         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5305                 if (qf_inums[type]) {
5306                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5307                                                 DQUOT_USAGE_ENABLED);
5308                         if (err) {
5309                                 ext4_warning(sb,
5310                                         "Failed to enable quota tracking "
5311                                         "(type=%d, err=%d). Please run "
5312                                         "e2fsck to fix.", type, err);
5313                                 return err;
5314                         }
5315                 }
5316         }
5317         return 0;
5318 }
5319
5320 static int ext4_quota_off(struct super_block *sb, int type)
5321 {
5322         struct inode *inode = sb_dqopt(sb)->files[type];
5323         handle_t *handle;
5324
5325         /* Force all delayed allocation blocks to be allocated.
5326          * Caller already holds s_umount sem */
5327         if (test_opt(sb, DELALLOC))
5328                 sync_filesystem(sb);
5329
5330         if (!inode)
5331                 goto out;
5332
5333         /* Update modification times of quota files when userspace can
5334          * start looking at them */
5335         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5336         if (IS_ERR(handle))
5337                 goto out;
5338         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5339         ext4_mark_inode_dirty(handle, inode);
5340         ext4_journal_stop(handle);
5341
5342 out:
5343         return dquot_quota_off(sb, type);
5344 }
5345
5346 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5347  * acquiring the locks... As quota files are never truncated and quota code
5348  * itself serializes the operations (and no one else should touch the files)
5349  * we don't have to be afraid of races */
5350 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5351                                size_t len, loff_t off)
5352 {
5353         struct inode *inode = sb_dqopt(sb)->files[type];
5354         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5355         int offset = off & (sb->s_blocksize - 1);
5356         int tocopy;
5357         size_t toread;
5358         struct buffer_head *bh;
5359         loff_t i_size = i_size_read(inode);
5360
5361         if (off > i_size)
5362                 return 0;
5363         if (off+len > i_size)
5364                 len = i_size-off;
5365         toread = len;
5366         while (toread > 0) {
5367                 tocopy = sb->s_blocksize - offset < toread ?
5368                                 sb->s_blocksize - offset : toread;
5369                 bh = ext4_bread(NULL, inode, blk, 0);
5370                 if (IS_ERR(bh))
5371                         return PTR_ERR(bh);
5372                 if (!bh)        /* A hole? */
5373                         memset(data, 0, tocopy);
5374                 else
5375                         memcpy(data, bh->b_data+offset, tocopy);
5376                 brelse(bh);
5377                 offset = 0;
5378                 toread -= tocopy;
5379                 data += tocopy;
5380                 blk++;
5381         }
5382         return len;
5383 }
5384
5385 /* Write to quotafile (we know the transaction is already started and has
5386  * enough credits) */
5387 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5388                                 const char *data, size_t len, loff_t off)
5389 {
5390         struct inode *inode = sb_dqopt(sb)->files[type];
5391         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5392         int err, offset = off & (sb->s_blocksize - 1);
5393         struct buffer_head *bh;
5394         handle_t *handle = journal_current_handle();
5395
5396         if (EXT4_SB(sb)->s_journal && !handle) {
5397                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5398                         " cancelled because transaction is not started",
5399                         (unsigned long long)off, (unsigned long long)len);
5400                 return -EIO;
5401         }
5402         /*
5403          * Since we account only one data block in transaction credits,
5404          * then it is impossible to cross a block boundary.
5405          */
5406         if (sb->s_blocksize - offset < len) {
5407                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5408                         " cancelled because not block aligned",
5409                         (unsigned long long)off, (unsigned long long)len);
5410                 return -EIO;
5411         }
5412
5413         bh = ext4_bread(handle, inode, blk, 1);
5414         if (IS_ERR(bh))
5415                 return PTR_ERR(bh);
5416         if (!bh)
5417                 goto out;
5418         BUFFER_TRACE(bh, "get write access");
5419         err = ext4_journal_get_write_access(handle, bh);
5420         if (err) {
5421                 brelse(bh);
5422                 return err;
5423         }
5424         lock_buffer(bh);
5425         memcpy(bh->b_data+offset, data, len);
5426         flush_dcache_page(bh->b_page);
5427         unlock_buffer(bh);
5428         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5429         brelse(bh);
5430 out:
5431         if (inode->i_size < off + len) {
5432                 i_size_write(inode, off + len);
5433                 EXT4_I(inode)->i_disksize = inode->i_size;
5434                 ext4_mark_inode_dirty(handle, inode);
5435         }
5436         return len;
5437 }
5438
5439 #endif
5440
5441 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5442                        const char *dev_name, void *data)
5443 {
5444         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5445 }
5446
5447 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5448 static inline void register_as_ext2(void)
5449 {
5450         int err = register_filesystem(&ext2_fs_type);
5451         if (err)
5452                 printk(KERN_WARNING
5453                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5454 }
5455
5456 static inline void unregister_as_ext2(void)
5457 {
5458         unregister_filesystem(&ext2_fs_type);
5459 }
5460
5461 static inline int ext2_feature_set_ok(struct super_block *sb)
5462 {
5463         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5464                 return 0;
5465         if (sb->s_flags & MS_RDONLY)
5466                 return 1;
5467         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5468                 return 0;
5469         return 1;
5470 }
5471 #else
5472 static inline void register_as_ext2(void) { }
5473 static inline void unregister_as_ext2(void) { }
5474 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5475 #endif
5476
5477 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5478 static inline void register_as_ext3(void)
5479 {
5480         int err = register_filesystem(&ext3_fs_type);
5481         if (err)
5482                 printk(KERN_WARNING
5483                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5484 }
5485
5486 static inline void unregister_as_ext3(void)
5487 {
5488         unregister_filesystem(&ext3_fs_type);
5489 }
5490
5491 static inline int ext3_feature_set_ok(struct super_block *sb)
5492 {
5493         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5494                 return 0;
5495         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5496                 return 0;
5497         if (sb->s_flags & MS_RDONLY)
5498                 return 1;
5499         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5500                 return 0;
5501         return 1;
5502 }
5503 #else
5504 static inline void register_as_ext3(void) { }
5505 static inline void unregister_as_ext3(void) { }
5506 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5507 #endif
5508
5509 static struct file_system_type ext4_fs_type = {
5510         .owner          = THIS_MODULE,
5511         .name           = "ext4",
5512         .mount          = ext4_mount,
5513         .kill_sb        = kill_block_super,
5514         .fs_flags       = FS_REQUIRES_DEV,
5515 };
5516 MODULE_ALIAS_FS("ext4");
5517
5518 static int __init ext4_init_feat_adverts(void)
5519 {
5520         struct ext4_features *ef;
5521         int ret = -ENOMEM;
5522
5523         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5524         if (!ef)
5525                 goto out;
5526
5527         ef->f_kobj.kset = ext4_kset;
5528         init_completion(&ef->f_kobj_unregister);
5529         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5530                                    "features");
5531         if (ret) {
5532                 kfree(ef);
5533                 goto out;
5534         }
5535
5536         ext4_feat = ef;
5537         ret = 0;
5538 out:
5539         return ret;
5540 }
5541
5542 static void ext4_exit_feat_adverts(void)
5543 {
5544         kobject_put(&ext4_feat->f_kobj);
5545         wait_for_completion(&ext4_feat->f_kobj_unregister);
5546         kfree(ext4_feat);
5547 }
5548
5549 /* Shared across all ext4 file systems */
5550 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5551 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5552
5553 static int __init ext4_init_fs(void)
5554 {
5555         int i, err;
5556
5557         ext4_li_info = NULL;
5558         mutex_init(&ext4_li_mtx);
5559
5560         /* Build-time check for flags consistency */
5561         ext4_check_flag_values();
5562
5563         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5564                 mutex_init(&ext4__aio_mutex[i]);
5565                 init_waitqueue_head(&ext4__ioend_wq[i]);
5566         }
5567
5568         err = ext4_init_es();
5569         if (err)
5570                 return err;
5571
5572         err = ext4_init_pageio();
5573         if (err)
5574                 goto out7;
5575
5576         err = ext4_init_system_zone();
5577         if (err)
5578                 goto out6;
5579         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5580         if (!ext4_kset) {
5581                 err = -ENOMEM;
5582                 goto out5;
5583         }
5584         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5585
5586         err = ext4_init_feat_adverts();
5587         if (err)
5588                 goto out4;
5589
5590         err = ext4_init_mballoc();
5591         if (err)
5592                 goto out2;
5593         else
5594                 ext4_mballoc_ready = 1;
5595         err = init_inodecache();
5596         if (err)
5597                 goto out1;
5598         register_as_ext3();
5599         register_as_ext2();
5600         err = register_filesystem(&ext4_fs_type);
5601         if (err)
5602                 goto out;
5603
5604         return 0;
5605 out:
5606         unregister_as_ext2();
5607         unregister_as_ext3();
5608         destroy_inodecache();
5609 out1:
5610         ext4_mballoc_ready = 0;
5611         ext4_exit_mballoc();
5612 out2:
5613         ext4_exit_feat_adverts();
5614 out4:
5615         if (ext4_proc_root)
5616                 remove_proc_entry("fs/ext4", NULL);
5617         kset_unregister(ext4_kset);
5618 out5:
5619         ext4_exit_system_zone();
5620 out6:
5621         ext4_exit_pageio();
5622 out7:
5623         ext4_exit_es();
5624
5625         return err;
5626 }
5627
5628 static void __exit ext4_exit_fs(void)
5629 {
5630         ext4_destroy_lazyinit_thread();
5631         unregister_as_ext2();
5632         unregister_as_ext3();
5633         unregister_filesystem(&ext4_fs_type);
5634         destroy_inodecache();
5635         ext4_exit_mballoc();
5636         ext4_exit_feat_adverts();
5637         remove_proc_entry("fs/ext4", NULL);
5638         kset_unregister(ext4_kset);
5639         ext4_exit_system_zone();
5640         ext4_exit_pageio();
5641         ext4_exit_es();
5642 }
5643
5644 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5645 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5646 MODULE_LICENSE("GPL");
5647 module_init(ext4_init_fs)
5648 module_exit(ext4_exit_fs)