fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/jbd2.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/ctype.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <linux/cleancache.h>
  42 #include <asm/uaccess.h>
  43
  44 #include <linux/kthread.h>
  45 #include <linux/freezer.h>
  46
  47 #include "ext4.h"
  48 #include "ext4_extents.h"       /* Needed for trace points definition */
  49 #include "ext4_jbd2.h"
  50 #include "xattr.h"
  51 #include "acl.h"
  52 #include "mballoc.h"
  53
  54 #define CREATE_TRACE_POINTS
  55 #include <trace/events/ext4.h>
  56
  57 static struct proc_dir_entry *ext4_proc_root;
  58 static struct kset *ext4_kset;
  59 static struct ext4_lazy_init *ext4_li_info;
  60 static struct mutex ext4_li_mtx;
  61 static struct ext4_features *ext4_feat;
  62 static int ext4_mballoc_ready;
  63
  64 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  65                              unsigned long journal_devnum);
  66 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  67 static int ext4_commit_super(struct super_block *sb, int sync);
  68 static void ext4_mark_recovery_complete(struct super_block *sb,
  69                                         struct ext4_super_block *es);
  70 static void ext4_clear_journal_err(struct super_block *sb,
  71                                    struct ext4_super_block *es);
  72 static int ext4_sync_fs(struct super_block *sb, int wait);
  73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  75 static int ext4_unfreeze(struct super_block *sb);
  76 static int ext4_freeze(struct super_block *sb);
  77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  78                        const char *dev_name, void *data);
  79 static inline int ext2_feature_set_ok(struct super_block *sb);
  80 static inline int ext3_feature_set_ok(struct super_block *sb);
  81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  82 static void ext4_destroy_lazyinit_thread(void);
  83 static void ext4_unregister_li_request(struct super_block *sb);
  84 static void ext4_clear_request_list(void);
  85 static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
  86
  87 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  88 static struct file_system_type ext2_fs_type = {
  89         .owner          = THIS_MODULE,
  90         .name           = "ext2",
  91         .mount          = ext4_mount,
  92         .kill_sb        = kill_block_super,
  93         .fs_flags       = FS_REQUIRES_DEV,
  94 };
  95 MODULE_ALIAS_FS("ext2");
  96 MODULE_ALIAS("ext2");
  97 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  98 #else
  99 #define IS_EXT2_SB(sb) (0)
 100 #endif
 101
 102
 103 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 104 static struct file_system_type ext3_fs_type = {
 105         .owner          = THIS_MODULE,
 106         .name           = "ext3",
 107         .mount          = ext4_mount,
 108         .kill_sb        = kill_block_super,
 109         .fs_flags       = FS_REQUIRES_DEV,
 110 };
 111 MODULE_ALIAS_FS("ext3");
 112 MODULE_ALIAS("ext3");
 113 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 114 #else
 115 #define IS_EXT3_SB(sb) (0)
 116 #endif
 117
 118 static int ext4_verify_csum_type(struct super_block *sb,
 119                                  struct ext4_super_block *es)
 120 {
 121         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 122                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 123                 return 1;
 124
 125         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 126 }
 127
 128 static __le32 ext4_superblock_csum(struct super_block *sb,
 129                                    struct ext4_super_block *es)
 130 {
 131         struct ext4_sb_info *sbi = EXT4_SB(sb);
 132         int offset = offsetof(struct ext4_super_block, s_checksum);
 133         __u32 csum;
 134
 135         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 136
 137         return cpu_to_le32(csum);
 138 }
 139
 140 static int ext4_superblock_csum_verify(struct super_block *sb,
 141                                        struct ext4_super_block *es)
 142 {
 143         if (!ext4_has_metadata_csum(sb))
 144                 return 1;
 145
 146         return es->s_checksum == ext4_superblock_csum(sb, es);
 147 }
 148
 149 void ext4_superblock_csum_set(struct super_block *sb)
 150 {
 151         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 152
 153         if (!ext4_has_metadata_csum(sb))
 154                 return;
 155
 156         es->s_checksum = ext4_superblock_csum(sb, es);
 157 }
 158
 159 void *ext4_kvmalloc(size_t size, gfp_t flags)
 160 {
 161         void *ret;
 162
 163         ret = kmalloc(size, flags | __GFP_NOWARN);
 164         if (!ret)
 165                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 166         return ret;
 167 }
 168
 169 void *ext4_kvzalloc(size_t size, gfp_t flags)
 170 {
 171         void *ret;
 172
 173         ret = kzalloc(size, flags | __GFP_NOWARN);
 174         if (!ret)
 175                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 176         return ret;
 177 }
 178
 179 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 180                                struct ext4_group_desc *bg)
 181 {
 182         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 183                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 184                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 185 }
 186
 187 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 188                                struct ext4_group_desc *bg)
 189 {
 190         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 191                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 192                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 193 }
 194
 195 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 196                               struct ext4_group_desc *bg)
 197 {
 198         return le32_to_cpu(bg->bg_inode_table_lo) |
 199                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 200                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 201 }
 202
 203 __u32 ext4_free_group_clusters(struct super_block *sb,
 204                                struct ext4_group_desc *bg)
 205 {
 206         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 207                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 208                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 209 }
 210
 211 __u32 ext4_free_inodes_count(struct super_block *sb,
 212                               struct ext4_group_desc *bg)
 213 {
 214         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 215                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 216                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 217 }
 218
 219 __u32 ext4_used_dirs_count(struct super_block *sb,
 220                               struct ext4_group_desc *bg)
 221 {
 222         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 223                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 224                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 225 }
 226
 227 __u32 ext4_itable_unused_count(struct super_block *sb,
 228                               struct ext4_group_desc *bg)
 229 {
 230         return le16_to_cpu(bg->bg_itable_unused_lo) |
 231                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 232                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 233 }
 234
 235 void ext4_block_bitmap_set(struct super_block *sb,
 236                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 237 {
 238         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 239         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 240                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 241 }
 242
 243 void ext4_inode_bitmap_set(struct super_block *sb,
 244                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 245 {
 246         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 247         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 248                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 249 }
 250
 251 void ext4_inode_table_set(struct super_block *sb,
 252                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 253 {
 254         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 255         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 256                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 257 }
 258
 259 void ext4_free_group_clusters_set(struct super_block *sb,
 260                                   struct ext4_group_desc *bg, __u32 count)
 261 {
 262         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 263         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 264                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 265 }
 266
 267 void ext4_free_inodes_set(struct super_block *sb,
 268                           struct ext4_group_desc *bg, __u32 count)
 269 {
 270         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 271         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 272                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 273 }
 274
 275 void ext4_used_dirs_set(struct super_block *sb,
 276                           struct ext4_group_desc *bg, __u32 count)
 277 {
 278         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 279         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 280                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 281 }
 282
 283 void ext4_itable_unused_set(struct super_block *sb,
 284                           struct ext4_group_desc *bg, __u32 count)
 285 {
 286         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 287         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 288                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 289 }
 290
 291
 292 static void __save_error_info(struct super_block *sb, const char *func,
 293                             unsigned int line)
 294 {
 295         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 296
 297         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 298         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 299         es->s_last_error_time = cpu_to_le32(get_seconds());
 300         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 301         es->s_last_error_line = cpu_to_le32(line);
 302         if (!es->s_first_error_time) {
 303                 es->s_first_error_time = es->s_last_error_time;
 304                 strncpy(es->s_first_error_func, func,
 305                         sizeof(es->s_first_error_func));
 306                 es->s_first_error_line = cpu_to_le32(line);
 307                 es->s_first_error_ino = es->s_last_error_ino;
 308                 es->s_first_error_block = es->s_last_error_block;
 309         }
 310         /*
 311          * Start the daily error reporting function if it hasn't been
 312          * started already
 313          */
 314         if (!es->s_error_count)
 315                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 316         le32_add_cpu(&es->s_error_count, 1);
 317 }
 318
 319 static void save_error_info(struct super_block *sb, const char *func,
 320                             unsigned int line)
 321 {
 322         __save_error_info(sb, func, line);
 323         ext4_commit_super(sb, 1);
 324 }
 325
 326 /*
 327  * The del_gendisk() function uninitializes the disk-specific data
 328  * structures, including the bdi structure, without telling anyone
 329  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 330  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 331  * This is a kludge to prevent these oops until we can put in a proper
 332  * hook in del_gendisk() to inform the VFS and file system layers.
 333  */
 334 static int block_device_ejected(struct super_block *sb)
 335 {
 336         struct inode *bd_inode = sb->s_bdev->bd_inode;
 337         struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
 338
 339         return bdi->dev == NULL;
 340 }
 341
 342 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 343 {
 344         struct super_block              *sb = journal->j_private;
 345         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 346         int                             error = is_journal_aborted(journal);
 347         struct ext4_journal_cb_entry    *jce;
 348
 349         BUG_ON(txn->t_state == T_FINISHED);
 350         spin_lock(&sbi->s_md_lock);
 351         while (!list_empty(&txn->t_private_list)) {
 352                 jce = list_entry(txn->t_private_list.next,
 353                                  struct ext4_journal_cb_entry, jce_list);
 354                 list_del_init(&jce->jce_list);
 355                 spin_unlock(&sbi->s_md_lock);
 356                 jce->jce_func(sb, jce, error);
 357                 spin_lock(&sbi->s_md_lock);
 358         }
 359         spin_unlock(&sbi->s_md_lock);
 360 }
 361
 362 /* Deal with the reporting of failure conditions on a filesystem such as
 363  * inconsistencies detected or read IO failures.
 364  *
 365  * On ext2, we can store the error state of the filesystem in the
 366  * superblock.  That is not possible on ext4, because we may have other
 367  * write ordering constraints on the superblock which prevent us from
 368  * writing it out straight away; and given that the journal is about to
 369  * be aborted, we can't rely on the current, or future, transactions to
 370  * write out the superblock safely.
 371  *
 372  * We'll just use the jbd2_journal_abort() error code to record an error in
 373  * the journal instead.  On recovery, the journal will complain about
 374  * that error until we've noted it down and cleared it.
 375  */
 376
 377 static void ext4_handle_error(struct super_block *sb)
 378 {
 379         if (sb->s_flags & MS_RDONLY)
 380                 return;
 381
 382         if (!test_opt(sb, ERRORS_CONT)) {
 383                 journal_t *journal = EXT4_SB(sb)->s_journal;
 384
 385                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 386                 if (journal)
 387                         jbd2_journal_abort(journal, -EIO);
 388         }
 389         if (test_opt(sb, ERRORS_RO)) {
 390                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 391                 /*
 392                  * Make sure updated value of ->s_mount_flags will be visible
 393                  * before ->s_flags update
 394                  */
 395                 smp_wmb();
 396                 sb->s_flags |= MS_RDONLY;
 397         }
 398         if (test_opt(sb, ERRORS_PANIC))
 399                 panic("EXT4-fs (device %s): panic forced after error\n",
 400                         sb->s_id);
 401 }
 402
 403 #define ext4_error_ratelimit(sb)                                        \
 404                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 405                              "EXT4-fs error")
 406
 407 void __ext4_error(struct super_block *sb, const char *function,
 408                   unsigned int line, const char *fmt, ...)
 409 {
 410         struct va_format vaf;
 411         va_list args;
 412
 413         if (ext4_error_ratelimit(sb)) {
 414                 va_start(args, fmt);
 415                 vaf.fmt = fmt;
 416                 vaf.va = &args;
 417                 printk(KERN_CRIT
 418                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 419                        sb->s_id, function, line, current->comm, &vaf);
 420                 va_end(args);
 421         }
 422         save_error_info(sb, function, line);
 423         ext4_handle_error(sb);
 424 }
 425
 426 void __ext4_error_inode(struct inode *inode, const char *function,
 427                         unsigned int line, ext4_fsblk_t block,
 428                         const char *fmt, ...)
 429 {
 430         va_list args;
 431         struct va_format vaf;
 432         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 433
 434         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 435         es->s_last_error_block = cpu_to_le64(block);
 436         if (ext4_error_ratelimit(inode->i_sb)) {
 437                 va_start(args, fmt);
 438                 vaf.fmt = fmt;
 439                 vaf.va = &args;
 440                 if (block)
 441                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 442                                "inode #%lu: block %llu: comm %s: %pV\n",
 443                                inode->i_sb->s_id, function, line, inode->i_ino,
 444                                block, current->comm, &vaf);
 445                 else
 446                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 447                                "inode #%lu: comm %s: %pV\n",
 448                                inode->i_sb->s_id, function, line, inode->i_ino,
 449                                current->comm, &vaf);
 450                 va_end(args);
 451         }
 452         save_error_info(inode->i_sb, function, line);
 453         ext4_handle_error(inode->i_sb);
 454 }
 455
 456 void __ext4_error_file(struct file *file, const char *function,
 457                        unsigned int line, ext4_fsblk_t block,
 458                        const char *fmt, ...)
 459 {
 460         va_list args;
 461         struct va_format vaf;
 462         struct ext4_super_block *es;
 463         struct inode *inode = file_inode(file);
 464         char pathname[80], *path;
 465
 466         es = EXT4_SB(inode->i_sb)->s_es;
 467         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 468         if (ext4_error_ratelimit(inode->i_sb)) {
 469                 path = d_path(&(file->f_path), pathname, sizeof(pathname));
 470                 if (IS_ERR(path))
 471                         path = "(unknown)";
 472                 va_start(args, fmt);
 473                 vaf.fmt = fmt;
 474                 vaf.va = &args;
 475                 if (block)
 476                         printk(KERN_CRIT
 477                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 478                                "block %llu: comm %s: path %s: %pV\n",
 479                                inode->i_sb->s_id, function, line, inode->i_ino,
 480                                block, current->comm, path, &vaf);
 481                 else
 482                         printk(KERN_CRIT
 483                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 484                                "comm %s: path %s: %pV\n",
 485                                inode->i_sb->s_id, function, line, inode->i_ino,
 486                                current->comm, path, &vaf);
 487                 va_end(args);
 488         }
 489         save_error_info(inode->i_sb, function, line);
 490         ext4_handle_error(inode->i_sb);
 491 }
 492
 493 const char *ext4_decode_error(struct super_block *sb, int errno,
 494                               char nbuf[16])
 495 {
 496         char *errstr = NULL;
 497
 498         switch (errno) {
 499         case -EIO:
 500                 errstr = "IO failure";
 501                 break;
 502         case -ENOMEM:
 503                 errstr = "Out of memory";
 504                 break;
 505         case -EROFS:
 506                 if (!sb || (EXT4_SB(sb)->s_journal &&
 507                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 508                         errstr = "Journal has aborted";
 509                 else
 510                         errstr = "Readonly filesystem";
 511                 break;
 512         default:
 513                 /* If the caller passed in an extra buffer for unknown
 514                  * errors, textualise them now.  Else we just return
 515                  * NULL. */
 516                 if (nbuf) {
 517                         /* Check for truncated error codes... */
 518                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 519                                 errstr = nbuf;
 520                 }
 521                 break;
 522         }
 523
 524         return errstr;
 525 }
 526
 527 /* __ext4_std_error decodes expected errors from journaling functions
 528  * automatically and invokes the appropriate error response.  */
 529
 530 void __ext4_std_error(struct super_block *sb, const char *function,
 531                       unsigned int line, int errno)
 532 {
 533         char nbuf[16];
 534         const char *errstr;
 535
 536         /* Special case: if the error is EROFS, and we're not already
 537          * inside a transaction, then there's really no point in logging
 538          * an error. */
 539         if (errno == -EROFS && journal_current_handle() == NULL &&
 540             (sb->s_flags & MS_RDONLY))
 541                 return;
 542
 543         if (ext4_error_ratelimit(sb)) {
 544                 errstr = ext4_decode_error(sb, errno, nbuf);
 545                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 546                        sb->s_id, function, line, errstr);
 547         }
 548
 549         save_error_info(sb, function, line);
 550         ext4_handle_error(sb);
 551 }
 552
 553 /*
 554  * ext4_abort is a much stronger failure handler than ext4_error.  The
 555  * abort function may be used to deal with unrecoverable failures such
 556  * as journal IO errors or ENOMEM at a critical moment in log management.
 557  *
 558  * We unconditionally force the filesystem into an ABORT|READONLY state,
 559  * unless the error response on the fs has been set to panic in which
 560  * case we take the easy way out and panic immediately.
 561  */
 562
 563 void __ext4_abort(struct super_block *sb, const char *function,
 564                 unsigned int line, const char *fmt, ...)
 565 {
 566         va_list args;
 567
 568         save_error_info(sb, function, line);
 569         va_start(args, fmt);
 570         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 571                function, line);
 572         vprintk(fmt, args);
 573         printk("\n");
 574         va_end(args);
 575
 576         if ((sb->s_flags & MS_RDONLY) == 0) {
 577                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 578                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 579                 /*
 580                  * Make sure updated value of ->s_mount_flags will be visible
 581                  * before ->s_flags update
 582                  */
 583                 smp_wmb();
 584                 sb->s_flags |= MS_RDONLY;
 585                 if (EXT4_SB(sb)->s_journal)
 586                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 587                 save_error_info(sb, function, line);
 588         }
 589         if (test_opt(sb, ERRORS_PANIC))
 590                 panic("EXT4-fs panic from previous error\n");
 591 }
 592
 593 void __ext4_msg(struct super_block *sb,
 594                 const char *prefix, const char *fmt, ...)
 595 {
 596         struct va_format vaf;
 597         va_list args;
 598
 599         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 600                 return;
 601
 602         va_start(args, fmt);
 603         vaf.fmt = fmt;
 604         vaf.va = &args;
 605         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 606         va_end(args);
 607 }
 608
 609 void __ext4_warning(struct super_block *sb, const char *function,
 610                     unsigned int line, const char *fmt, ...)
 611 {
 612         struct va_format vaf;
 613         va_list args;
 614
 615         if (!___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
 616                           "EXT4-fs warning"))
 617                 return;
 618
 619         va_start(args, fmt);
 620         vaf.fmt = fmt;
 621         vaf.va = &args;
 622         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 623                sb->s_id, function, line, &vaf);
 624         va_end(args);
 625 }
 626
 627 void __ext4_grp_locked_error(const char *function, unsigned int line,
 628                              struct super_block *sb, ext4_group_t grp,
 629                              unsigned long ino, ext4_fsblk_t block,
 630                              const char *fmt, ...)
 631 __releases(bitlock)
 632 __acquires(bitlock)
 633 {
 634         struct va_format vaf;
 635         va_list args;
 636         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 637
 638         es->s_last_error_ino = cpu_to_le32(ino);
 639         es->s_last_error_block = cpu_to_le64(block);
 640         __save_error_info(sb, function, line);
 641
 642         if (ext4_error_ratelimit(sb)) {
 643                 va_start(args, fmt);
 644                 vaf.fmt = fmt;
 645                 vaf.va = &args;
 646                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 647                        sb->s_id, function, line, grp);
 648                 if (ino)
 649                         printk(KERN_CONT "inode %lu: ", ino);
 650                 if (block)
 651                         printk(KERN_CONT "block %llu:",
 652                                (unsigned long long) block);
 653                 printk(KERN_CONT "%pV\n", &vaf);
 654                 va_end(args);
 655         }
 656
 657         if (test_opt(sb, ERRORS_CONT)) {
 658                 ext4_commit_super(sb, 0);
 659                 return;
 660         }
 661
 662         ext4_unlock_group(sb, grp);
 663         ext4_handle_error(sb);
 664         /*
 665          * We only get here in the ERRORS_RO case; relocking the group
 666          * may be dangerous, but nothing bad will happen since the
 667          * filesystem will have already been marked read/only and the
 668          * journal has been aborted.  We return 1 as a hint to callers
 669          * who might what to use the return value from
 670          * ext4_grp_locked_error() to distinguish between the
 671          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 672          * aggressively from the ext4 function in question, with a
 673          * more appropriate error code.
 674          */
 675         ext4_lock_group(sb, grp);
 676         return;
 677 }
 678
 679 void ext4_update_dynamic_rev(struct super_block *sb)
 680 {
 681         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 682
 683         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 684                 return;
 685
 686         ext4_warning(sb,
 687                      "updating to rev %d because of new feature flag, "
 688                      "running e2fsck is recommended",
 689                      EXT4_DYNAMIC_REV);
 690
 691         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 692         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 693         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 694         /* leave es->s_feature_*compat flags alone */
 695         /* es->s_uuid will be set by e2fsck if empty */
 696
 697         /*
 698          * The rest of the superblock fields should be zero, and if not it
 699          * means they are likely already in use, so leave them alone.  We
 700          * can leave it up to e2fsck to clean up any inconsistencies there.
 701          */
 702 }
 703
 704 /*
 705  * Open the external journal device
 706  */
 707 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 708 {
 709         struct block_device *bdev;
 710         char b[BDEVNAME_SIZE];
 711
 712         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 713         if (IS_ERR(bdev))
 714                 goto fail;
 715         return bdev;
 716
 717 fail:
 718         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 719                         __bdevname(dev, b), PTR_ERR(bdev));
 720         return NULL;
 721 }
 722
 723 /*
 724  * Release the journal device
 725  */
 726 static void ext4_blkdev_put(struct block_device *bdev)
 727 {
 728         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 729 }
 730
 731 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 732 {
 733         struct block_device *bdev;
 734         bdev = sbi->journal_bdev;
 735         if (bdev) {
 736                 ext4_blkdev_put(bdev);
 737                 sbi->journal_bdev = NULL;
 738         }
 739 }
 740
 741 static inline struct inode *orphan_list_entry(struct list_head *l)
 742 {
 743         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 744 }
 745
 746 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 747 {
 748         struct list_head *l;
 749
 750         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 751                  le32_to_cpu(sbi->s_es->s_last_orphan));
 752
 753         printk(KERN_ERR "sb_info orphan list:\n");
 754         list_for_each(l, &sbi->s_orphan) {
 755                 struct inode *inode = orphan_list_entry(l);
 756                 printk(KERN_ERR "  "
 757                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 758                        inode->i_sb->s_id, inode->i_ino, inode,
 759                        inode->i_mode, inode->i_nlink,
 760                        NEXT_ORPHAN(inode));
 761         }
 762 }
 763
 764 static void ext4_put_super(struct super_block *sb)
 765 {
 766         struct ext4_sb_info *sbi = EXT4_SB(sb);
 767         struct ext4_super_block *es = sbi->s_es;
 768         int i, err;
 769
 770         ext4_unregister_li_request(sb);
 771         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 772
 773         flush_workqueue(sbi->rsv_conversion_wq);
 774         destroy_workqueue(sbi->rsv_conversion_wq);
 775
 776         if (sbi->s_journal) {
 777                 err = jbd2_journal_destroy(sbi->s_journal);
 778                 sbi->s_journal = NULL;
 779                 if (err < 0)
 780                         ext4_abort(sb, "Couldn't clean up the journal");
 781         }
 782
 783         ext4_es_unregister_shrinker(sbi);
 784         del_timer_sync(&sbi->s_err_report);
 785         ext4_release_system_zone(sb);
 786         ext4_mb_release(sb);
 787         ext4_ext_release(sb);
 788         ext4_xattr_put_super(sb);
 789
 790         if (!(sb->s_flags & MS_RDONLY)) {
 791                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 792                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 793         }
 794         if (!(sb->s_flags & MS_RDONLY))
 795                 ext4_commit_super(sb, 1);
 796
 797         if (sbi->s_proc) {
 798                 remove_proc_entry("options", sbi->s_proc);
 799                 remove_proc_entry(sb->s_id, ext4_proc_root);
 800         }
 801         kobject_del(&sbi->s_kobj);
 802
 803         for (i = 0; i < sbi->s_gdb_count; i++)
 804                 brelse(sbi->s_group_desc[i]);
 805         kvfree(sbi->s_group_desc);
 806         kvfree(sbi->s_flex_groups);
 807         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 808         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 809         percpu_counter_destroy(&sbi->s_dirs_counter);
 810         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 811         brelse(sbi->s_sbh);
 812 #ifdef CONFIG_QUOTA
 813         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 814                 kfree(sbi->s_qf_names[i]);
 815 #endif
 816
 817         /* Debugging code just in case the in-memory inode orphan list
 818          * isn't empty.  The on-disk one can be non-empty if we've
 819          * detected an error and taken the fs readonly, but the
 820          * in-memory list had better be clean by this point. */
 821         if (!list_empty(&sbi->s_orphan))
 822                 dump_orphan_list(sb, sbi);
 823         J_ASSERT(list_empty(&sbi->s_orphan));
 824
 825         invalidate_bdev(sb->s_bdev);
 826         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 827                 /*
 828                  * Invalidate the journal device's buffers.  We don't want them
 829                  * floating about in memory - the physical journal device may
 830                  * hotswapped, and it breaks the `ro-after' testing code.
 831                  */
 832                 sync_blockdev(sbi->journal_bdev);
 833                 invalidate_bdev(sbi->journal_bdev);
 834                 ext4_blkdev_remove(sbi);
 835         }
 836         if (sbi->s_mb_cache) {
 837                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 838                 sbi->s_mb_cache = NULL;
 839         }
 840         if (sbi->s_mmp_tsk)
 841                 kthread_stop(sbi->s_mmp_tsk);
 842         sb->s_fs_info = NULL;
 843         /*
 844          * Now that we are completely done shutting down the
 845          * superblock, we need to actually destroy the kobject.
 846          */
 847         kobject_put(&sbi->s_kobj);
 848         wait_for_completion(&sbi->s_kobj_unregister);
 849         if (sbi->s_chksum_driver)
 850                 crypto_free_shash(sbi->s_chksum_driver);
 851         kfree(sbi->s_blockgroup_lock);
 852         kfree(sbi);
 853 }
 854
 855 static struct kmem_cache *ext4_inode_cachep;
 856
 857 /*
 858  * Called inside transaction, so use GFP_NOFS
 859  */
 860 static struct inode *ext4_alloc_inode(struct super_block *sb)
 861 {
 862         struct ext4_inode_info *ei;
 863
 864         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 865         if (!ei)
 866                 return NULL;
 867
 868         ei->vfs_inode.i_version = 1;
 869         spin_lock_init(&ei->i_raw_lock);
 870         INIT_LIST_HEAD(&ei->i_prealloc_list);
 871         spin_lock_init(&ei->i_prealloc_lock);
 872         ext4_es_init_tree(&ei->i_es_tree);
 873         rwlock_init(&ei->i_es_lock);
 874         INIT_LIST_HEAD(&ei->i_es_list);
 875         ei->i_es_all_nr = 0;
 876         ei->i_es_shk_nr = 0;
 877         ei->i_es_shrink_lblk = 0;
 878         ei->i_reserved_data_blocks = 0;
 879         ei->i_reserved_meta_blocks = 0;
 880         ei->i_allocated_meta_blocks = 0;
 881         ei->i_da_metadata_calc_len = 0;
 882         ei->i_da_metadata_calc_last_lblock = 0;
 883         spin_lock_init(&(ei->i_block_reservation_lock));
 884 #ifdef CONFIG_QUOTA
 885         ei->i_reserved_quota = 0;
 886         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_on_sysfile(struct super_block *sb, int type,
1050                                  int format_id);
1051 static int ext4_quota_off(struct super_block *sb, int type);
1052 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1053 static int ext4_quota_on_mount(struct super_block *sb, int type);
1054 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1055                                size_t len, loff_t off);
1056 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1057                                 const char *data, size_t len, loff_t off);
1058 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1059                              unsigned int flags);
1060 static int ext4_enable_quotas(struct super_block *sb);
1061
1062 static struct dquot **ext4_get_dquots(struct inode *inode)
1063 {
1064         return EXT4_I(inode)->i_dquot;
1065 }
1066
1067 static const struct dquot_operations ext4_quota_operations = {
1068         .get_reserved_space = ext4_get_reserved_space,
1069         .write_dquot    = ext4_write_dquot,
1070         .acquire_dquot  = ext4_acquire_dquot,
1071         .release_dquot  = ext4_release_dquot,
1072         .mark_dirty     = ext4_mark_dquot_dirty,
1073         .write_info     = ext4_write_info,
1074         .alloc_dquot    = dquot_alloc,
1075         .destroy_dquot  = dquot_destroy,
1076 };
1077
1078 static const struct quotactl_ops ext4_qctl_operations = {
1079         .quota_on       = ext4_quota_on,
1080         .quota_off      = ext4_quota_off,
1081         .quota_sync     = dquot_quota_sync,
1082         .get_info       = dquot_get_dqinfo,
1083         .set_info       = dquot_set_dqinfo,
1084         .get_dqblk      = dquot_get_dqblk,
1085         .set_dqblk      = dquot_set_dqblk
1086 };
1087
1088 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1089         .quota_on_meta  = ext4_quota_on_sysfile,
1090         .quota_off      = ext4_quota_off_sysfile,
1091         .quota_sync     = dquot_quota_sync,
1092         .get_info       = dquot_get_dqinfo,
1093         .set_info       = dquot_set_dqinfo,
1094         .get_dqblk      = dquot_get_dqblk,
1095         .set_dqblk      = dquot_set_dqblk
1096 };
1097 #endif
1098
1099 static const struct super_operations ext4_sops = {
1100         .alloc_inode    = ext4_alloc_inode,
1101         .destroy_inode  = ext4_destroy_inode,
1102         .write_inode    = ext4_write_inode,
1103         .dirty_inode    = ext4_dirty_inode,
1104         .drop_inode     = ext4_drop_inode,
1105         .evict_inode    = ext4_evict_inode,
1106         .put_super      = ext4_put_super,
1107         .sync_fs        = ext4_sync_fs,
1108         .freeze_fs      = ext4_freeze,
1109         .unfreeze_fs    = ext4_unfreeze,
1110         .statfs         = ext4_statfs,
1111         .remount_fs     = ext4_remount,
1112         .show_options   = ext4_show_options,
1113 #ifdef CONFIG_QUOTA
1114         .quota_read     = ext4_quota_read,
1115         .quota_write    = ext4_quota_write,
1116         .get_dquots     = ext4_get_dquots,
1117 #endif
1118         .bdev_try_to_free_page = bdev_try_to_free_page,
1119 };
1120
1121 static const struct export_operations ext4_export_ops = {
1122         .fh_to_dentry = ext4_fh_to_dentry,
1123         .fh_to_parent = ext4_fh_to_parent,
1124         .get_parent = ext4_get_parent,
1125 };
1126
1127 enum {
1128         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1129         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1130         Opt_nouid32, Opt_debug, Opt_removed,
1131         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1132         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1133         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1134         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1135         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1136         Opt_data_err_abort, Opt_data_err_ignore,
1137         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1138         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1139         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1140         Opt_usrquota, Opt_grpquota, Opt_i_version,
1141         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1142         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1143         Opt_inode_readahead_blks, Opt_journal_ioprio,
1144         Opt_dioread_nolock, Opt_dioread_lock,
1145         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1146         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1147 };
1148
1149 static const match_table_t tokens = {
1150         {Opt_bsd_df, "bsddf"},
1151         {Opt_minix_df, "minixdf"},
1152         {Opt_grpid, "grpid"},
1153         {Opt_grpid, "bsdgroups"},
1154         {Opt_nogrpid, "nogrpid"},
1155         {Opt_nogrpid, "sysvgroups"},
1156         {Opt_resgid, "resgid=%u"},
1157         {Opt_resuid, "resuid=%u"},
1158         {Opt_sb, "sb=%u"},
1159         {Opt_err_cont, "errors=continue"},
1160         {Opt_err_panic, "errors=panic"},
1161         {Opt_err_ro, "errors=remount-ro"},
1162         {Opt_nouid32, "nouid32"},
1163         {Opt_debug, "debug"},
1164         {Opt_removed, "oldalloc"},
1165         {Opt_removed, "orlov"},
1166         {Opt_user_xattr, "user_xattr"},
1167         {Opt_nouser_xattr, "nouser_xattr"},
1168         {Opt_acl, "acl"},
1169         {Opt_noacl, "noacl"},
1170         {Opt_noload, "norecovery"},
1171         {Opt_noload, "noload"},
1172         {Opt_removed, "nobh"},
1173         {Opt_removed, "bh"},
1174         {Opt_commit, "commit=%u"},
1175         {Opt_min_batch_time, "min_batch_time=%u"},
1176         {Opt_max_batch_time, "max_batch_time=%u"},
1177         {Opt_journal_dev, "journal_dev=%u"},
1178         {Opt_journal_path, "journal_path=%s"},
1179         {Opt_journal_checksum, "journal_checksum"},
1180         {Opt_nojournal_checksum, "nojournal_checksum"},
1181         {Opt_journal_async_commit, "journal_async_commit"},
1182         {Opt_abort, "abort"},
1183         {Opt_data_journal, "data=journal"},
1184         {Opt_data_ordered, "data=ordered"},
1185         {Opt_data_writeback, "data=writeback"},
1186         {Opt_data_err_abort, "data_err=abort"},
1187         {Opt_data_err_ignore, "data_err=ignore"},
1188         {Opt_offusrjquota, "usrjquota="},
1189         {Opt_usrjquota, "usrjquota=%s"},
1190         {Opt_offgrpjquota, "grpjquota="},
1191         {Opt_grpjquota, "grpjquota=%s"},
1192         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1193         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1194         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1195         {Opt_grpquota, "grpquota"},
1196         {Opt_noquota, "noquota"},
1197         {Opt_quota, "quota"},
1198         {Opt_usrquota, "usrquota"},
1199         {Opt_barrier, "barrier=%u"},
1200         {Opt_barrier, "barrier"},
1201         {Opt_nobarrier, "nobarrier"},
1202         {Opt_i_version, "i_version"},
1203         {Opt_stripe, "stripe=%u"},
1204         {Opt_delalloc, "delalloc"},
1205         {Opt_nodelalloc, "nodelalloc"},
1206         {Opt_removed, "mblk_io_submit"},
1207         {Opt_removed, "nomblk_io_submit"},
1208         {Opt_block_validity, "block_validity"},
1209         {Opt_noblock_validity, "noblock_validity"},
1210         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1211         {Opt_journal_ioprio, "journal_ioprio=%u"},
1212         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1213         {Opt_auto_da_alloc, "auto_da_alloc"},
1214         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1215         {Opt_dioread_nolock, "dioread_nolock"},
1216         {Opt_dioread_lock, "dioread_lock"},
1217         {Opt_discard, "discard"},
1218         {Opt_nodiscard, "nodiscard"},
1219         {Opt_init_itable, "init_itable=%u"},
1220         {Opt_init_itable, "init_itable"},
1221         {Opt_noinit_itable, "noinit_itable"},
1222         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1223         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1224         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1225         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1226         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1227         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1228         {Opt_err, NULL},
1229 };
1230
1231 static ext4_fsblk_t get_sb_block(void **data)
1232 {
1233         ext4_fsblk_t    sb_block;
1234         char            *options = (char *) *data;
1235
1236         if (!options || strncmp(options, "sb=", 3) != 0)
1237                 return 1;       /* Default location */
1238
1239         options += 3;
1240         /* TODO: use simple_strtoll with >32bit ext4 */
1241         sb_block = simple_strtoul(options, &options, 0);
1242         if (*options && *options != ',') {
1243                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1244                        (char *) *data);
1245                 return 1;
1246         }
1247         if (*options == ',')
1248                 options++;
1249         *data = (void *) options;
1250
1251         return sb_block;
1252 }
1253
1254 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1255 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1256         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1257
1258 #ifdef CONFIG_QUOTA
1259 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1260 {
1261         struct ext4_sb_info *sbi = EXT4_SB(sb);
1262         char *qname;
1263         int ret = -1;
1264
1265         if (sb_any_quota_loaded(sb) &&
1266                 !sbi->s_qf_names[qtype]) {
1267                 ext4_msg(sb, KERN_ERR,
1268                         "Cannot change journaled "
1269                         "quota options when quota turned on");
1270                 return -1;
1271         }
1272         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1273                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1274                          "when QUOTA feature is enabled");
1275                 return -1;
1276         }
1277         qname = match_strdup(args);
1278         if (!qname) {
1279                 ext4_msg(sb, KERN_ERR,
1280                         "Not enough memory for storing quotafile name");
1281                 return -1;
1282         }
1283         if (sbi->s_qf_names[qtype]) {
1284                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1285                         ret = 1;
1286                 else
1287                         ext4_msg(sb, KERN_ERR,
1288                                  "%s quota file already specified",
1289                                  QTYPE2NAME(qtype));
1290                 goto errout;
1291         }
1292         if (strchr(qname, '/')) {
1293                 ext4_msg(sb, KERN_ERR,
1294                         "quotafile must be on filesystem root");
1295                 goto errout;
1296         }
1297         sbi->s_qf_names[qtype] = qname;
1298         set_opt(sb, QUOTA);
1299         return 1;
1300 errout:
1301         kfree(qname);
1302         return ret;
1303 }
1304
1305 static int clear_qf_name(struct super_block *sb, int qtype)
1306 {
1307
1308         struct ext4_sb_info *sbi = EXT4_SB(sb);
1309
1310         if (sb_any_quota_loaded(sb) &&
1311                 sbi->s_qf_names[qtype]) {
1312                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1313                         " when quota turned on");
1314                 return -1;
1315         }
1316         kfree(sbi->s_qf_names[qtype]);
1317         sbi->s_qf_names[qtype] = NULL;
1318         return 1;
1319 }
1320 #endif
1321
1322 #define MOPT_SET        0x0001
1323 #define MOPT_CLEAR      0x0002
1324 #define MOPT_NOSUPPORT  0x0004
1325 #define MOPT_EXPLICIT   0x0008
1326 #define MOPT_CLEAR_ERR  0x0010
1327 #define MOPT_GTE0       0x0020
1328 #ifdef CONFIG_QUOTA
1329 #define MOPT_Q          0
1330 #define MOPT_QFMT       0x0040
1331 #else
1332 #define MOPT_Q          MOPT_NOSUPPORT
1333 #define MOPT_QFMT       MOPT_NOSUPPORT
1334 #endif
1335 #define MOPT_DATAJ      0x0080
1336 #define MOPT_NO_EXT2    0x0100
1337 #define MOPT_NO_EXT3    0x0200
1338 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1339 #define MOPT_STRING     0x0400
1340
1341 static const struct mount_opts {
1342         int     token;
1343         int     mount_opt;
1344         int     flags;
1345 } ext4_mount_opts[] = {
1346         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1347         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1348         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1349         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1350         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1351         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1352         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1353          MOPT_EXT4_ONLY | MOPT_SET},
1354         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1355          MOPT_EXT4_ONLY | MOPT_CLEAR},
1356         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1357         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1358         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1359          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1360         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1361          MOPT_EXT4_ONLY | MOPT_CLEAR},
1362         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1363          MOPT_EXT4_ONLY | MOPT_CLEAR},
1364         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1365          MOPT_EXT4_ONLY | MOPT_SET},
1366         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1367                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1368          MOPT_EXT4_ONLY | MOPT_SET},
1369         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1370         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1371         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1372         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1373         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1374          MOPT_NO_EXT2 | MOPT_SET},
1375         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1376          MOPT_NO_EXT2 | MOPT_CLEAR},
1377         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1378         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1379         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1380         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1381         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1382         {Opt_commit, 0, MOPT_GTE0},
1383         {Opt_max_batch_time, 0, MOPT_GTE0},
1384         {Opt_min_batch_time, 0, MOPT_GTE0},
1385         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1386         {Opt_init_itable, 0, MOPT_GTE0},
1387         {Opt_stripe, 0, MOPT_GTE0},
1388         {Opt_resuid, 0, MOPT_GTE0},
1389         {Opt_resgid, 0, MOPT_GTE0},
1390         {Opt_journal_dev, 0, MOPT_GTE0},
1391         {Opt_journal_path, 0, MOPT_STRING},
1392         {Opt_journal_ioprio, 0, MOPT_GTE0},
1393         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1394         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1395         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1396          MOPT_NO_EXT2 | MOPT_DATAJ},
1397         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1398         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1399 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1400         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1401         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1402 #else
1403         {Opt_acl, 0, MOPT_NOSUPPORT},
1404         {Opt_noacl, 0, MOPT_NOSUPPORT},
1405 #endif
1406         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1407         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1408         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1409         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1410                                                         MOPT_SET | MOPT_Q},
1411         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1412                                                         MOPT_SET | MOPT_Q},
1413         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1414                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1415         {Opt_usrjquota, 0, MOPT_Q},
1416         {Opt_grpjquota, 0, MOPT_Q},
1417         {Opt_offusrjquota, 0, MOPT_Q},
1418         {Opt_offgrpjquota, 0, MOPT_Q},
1419         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1420         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1421         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1422         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1423         {Opt_err, 0, 0}
1424 };
1425
1426 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1427                             substring_t *args, unsigned long *journal_devnum,
1428                             unsigned int *journal_ioprio, int is_remount)
1429 {
1430         struct ext4_sb_info *sbi = EXT4_SB(sb);
1431         const struct mount_opts *m;
1432         kuid_t uid;
1433         kgid_t gid;
1434         int arg = 0;
1435
1436 #ifdef CONFIG_QUOTA
1437         if (token == Opt_usrjquota)
1438                 return set_qf_name(sb, USRQUOTA, &args[0]);
1439         else if (token == Opt_grpjquota)
1440                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1441         else if (token == Opt_offusrjquota)
1442                 return clear_qf_name(sb, USRQUOTA);
1443         else if (token == Opt_offgrpjquota)
1444                 return clear_qf_name(sb, GRPQUOTA);
1445 #endif
1446         switch (token) {
1447         case Opt_noacl:
1448         case Opt_nouser_xattr:
1449                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1450                 break;
1451         case Opt_sb:
1452                 return 1;       /* handled by get_sb_block() */
1453         case Opt_removed:
1454                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1455                 return 1;
1456         case Opt_abort:
1457                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1458                 return 1;
1459         case Opt_i_version:
1460                 sb->s_flags |= MS_I_VERSION;
1461                 return 1;
1462         }
1463
1464         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1465                 if (token == m->token)
1466                         break;
1467
1468         if (m->token == Opt_err) {
1469                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1470                          "or missing value", opt);
1471                 return -1;
1472         }
1473
1474         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1475                 ext4_msg(sb, KERN_ERR,
1476                          "Mount option \"%s\" incompatible with ext2", opt);
1477                 return -1;
1478         }
1479         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1480                 ext4_msg(sb, KERN_ERR,
1481                          "Mount option \"%s\" incompatible with ext3", opt);
1482                 return -1;
1483         }
1484
1485         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1486                 return -1;
1487         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1488                 return -1;
1489         if (m->flags & MOPT_EXPLICIT)
1490                 set_opt2(sb, EXPLICIT_DELALLOC);
1491         if (m->flags & MOPT_CLEAR_ERR)
1492                 clear_opt(sb, ERRORS_MASK);
1493         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1494                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1495                          "options when quota turned on");
1496                 return -1;
1497         }
1498
1499         if (m->flags & MOPT_NOSUPPORT) {
1500                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1501         } else if (token == Opt_commit) {
1502                 if (arg == 0)
1503                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1504                 sbi->s_commit_interval = HZ * arg;
1505         } else if (token == Opt_max_batch_time) {
1506                 sbi->s_max_batch_time = arg;
1507         } else if (token == Opt_min_batch_time) {
1508                 sbi->s_min_batch_time = arg;
1509         } else if (token == Opt_inode_readahead_blks) {
1510                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1511                         ext4_msg(sb, KERN_ERR,
1512                                  "EXT4-fs: inode_readahead_blks must be "
1513                                  "0 or a power of 2 smaller than 2^31");
1514                         return -1;
1515                 }
1516                 sbi->s_inode_readahead_blks = arg;
1517         } else if (token == Opt_init_itable) {
1518                 set_opt(sb, INIT_INODE_TABLE);
1519                 if (!args->from)
1520                         arg = EXT4_DEF_LI_WAIT_MULT;
1521                 sbi->s_li_wait_mult = arg;
1522         } else if (token == Opt_max_dir_size_kb) {
1523                 sbi->s_max_dir_size_kb = arg;
1524         } else if (token == Opt_stripe) {
1525                 sbi->s_stripe = arg;
1526         } else if (token == Opt_resuid) {
1527                 uid = make_kuid(current_user_ns(), arg);
1528                 if (!uid_valid(uid)) {
1529                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1530                         return -1;
1531                 }
1532                 sbi->s_resuid = uid;
1533         } else if (token == Opt_resgid) {
1534                 gid = make_kgid(current_user_ns(), arg);
1535                 if (!gid_valid(gid)) {
1536                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1537                         return -1;
1538                 }
1539                 sbi->s_resgid = gid;
1540         } else if (token == Opt_journal_dev) {
1541                 if (is_remount) {
1542                         ext4_msg(sb, KERN_ERR,
1543                                  "Cannot specify journal on remount");
1544                         return -1;
1545                 }
1546                 *journal_devnum = arg;
1547         } else if (token == Opt_journal_path) {
1548                 char *journal_path;
1549                 struct inode *journal_inode;
1550                 struct path path;
1551                 int error;
1552
1553                 if (is_remount) {
1554                         ext4_msg(sb, KERN_ERR,
1555                                  "Cannot specify journal on remount");
1556                         return -1;
1557                 }
1558                 journal_path = match_strdup(&args[0]);
1559                 if (!journal_path) {
1560                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1561                                 "journal device string");
1562                         return -1;
1563                 }
1564
1565                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1566                 if (error) {
1567                         ext4_msg(sb, KERN_ERR, "error: could not find "
1568                                 "journal device path: error %d", error);
1569                         kfree(journal_path);
1570                         return -1;
1571                 }
1572
1573                 journal_inode = path.dentry->d_inode;
1574                 if (!S_ISBLK(journal_inode->i_mode)) {
1575                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1576                                 "is not a block device", journal_path);
1577                         path_put(&path);
1578                         kfree(journal_path);
1579                         return -1;
1580                 }
1581
1582                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1583                 path_put(&path);
1584                 kfree(journal_path);
1585         } else if (token == Opt_journal_ioprio) {
1586                 if (arg > 7) {
1587                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1588                                  " (must be 0-7)");
1589                         return -1;
1590                 }
1591                 *journal_ioprio =
1592                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1593         } else if (m->flags & MOPT_DATAJ) {
1594                 if (is_remount) {
1595                         if (!sbi->s_journal)
1596                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1597                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1598                                 ext4_msg(sb, KERN_ERR,
1599                                          "Cannot change data mode on remount");
1600                                 return -1;
1601                         }
1602                 } else {
1603                         clear_opt(sb, DATA_FLAGS);
1604                         sbi->s_mount_opt |= m->mount_opt;
1605                 }
1606 #ifdef CONFIG_QUOTA
1607         } else if (m->flags & MOPT_QFMT) {
1608                 if (sb_any_quota_loaded(sb) &&
1609                     sbi->s_jquota_fmt != m->mount_opt) {
1610                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1611                                  "quota options when quota turned on");
1612                         return -1;
1613                 }
1614                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1615                                                EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1616                         ext4_msg(sb, KERN_ERR,
1617                                  "Cannot set journaled quota options "
1618                                  "when QUOTA feature is enabled");
1619                         return -1;
1620                 }
1621                 sbi->s_jquota_fmt = m->mount_opt;
1622 #endif
1623         } else {
1624                 if (!args->from)
1625                         arg = 1;
1626                 if (m->flags & MOPT_CLEAR)
1627                         arg = !arg;
1628                 else if (unlikely(!(m->flags & MOPT_SET))) {
1629                         ext4_msg(sb, KERN_WARNING,
1630                                  "buggy handling of option %s", opt);
1631                         WARN_ON(1);
1632                         return -1;
1633                 }
1634                 if (arg != 0)
1635                         sbi->s_mount_opt |= m->mount_opt;
1636                 else
1637                         sbi->s_mount_opt &= ~m->mount_opt;
1638         }
1639         return 1;
1640 }
1641
1642 static int parse_options(char *options, struct super_block *sb,
1643                          unsigned long *journal_devnum,
1644                          unsigned int *journal_ioprio,
1645                          int is_remount)
1646 {
1647         struct ext4_sb_info *sbi = EXT4_SB(sb);
1648         char *p;
1649         substring_t args[MAX_OPT_ARGS];
1650         int token;
1651
1652         if (!options)
1653                 return 1;
1654
1655         while ((p = strsep(&options, ",")) != NULL) {
1656                 if (!*p)
1657                         continue;
1658                 /*
1659                  * Initialize args struct so we know whether arg was
1660                  * found; some options take optional arguments.
1661                  */
1662                 args[0].to = args[0].from = NULL;
1663                 token = match_token(p, tokens, args);
1664                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1665                                      journal_ioprio, is_remount) < 0)
1666                         return 0;
1667         }
1668 #ifdef CONFIG_QUOTA
1669         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1670             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1671                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1672                          "feature is enabled");
1673                 return 0;
1674         }
1675         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1676                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1677                         clear_opt(sb, USRQUOTA);
1678
1679                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1680                         clear_opt(sb, GRPQUOTA);
1681
1682                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1683                         ext4_msg(sb, KERN_ERR, "old and new quota "
1684                                         "format mixing");
1685                         return 0;
1686                 }
1687
1688                 if (!sbi->s_jquota_fmt) {
1689                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1690                                         "not specified");
1691                         return 0;
1692                 }
1693         }
1694 #endif
1695         if (test_opt(sb, DIOREAD_NOLOCK)) {
1696                 int blocksize =
1697                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1698
1699                 if (blocksize < PAGE_CACHE_SIZE) {
1700                         ext4_msg(sb, KERN_ERR, "can't mount with "
1701                                  "dioread_nolock if block size != PAGE_SIZE");
1702                         return 0;
1703                 }
1704         }
1705         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1706             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1707                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1708                          "in data=ordered mode");
1709                 return 0;
1710         }
1711         return 1;
1712 }
1713
1714 static inline void ext4_show_quota_options(struct seq_file *seq,
1715                                            struct super_block *sb)
1716 {
1717 #if defined(CONFIG_QUOTA)
1718         struct ext4_sb_info *sbi = EXT4_SB(sb);
1719
1720         if (sbi->s_jquota_fmt) {
1721                 char *fmtname = "";
1722
1723                 switch (sbi->s_jquota_fmt) {
1724                 case QFMT_VFS_OLD:
1725                         fmtname = "vfsold";
1726                         break;
1727                 case QFMT_VFS_V0:
1728                         fmtname = "vfsv0";
1729                         break;
1730                 case QFMT_VFS_V1:
1731                         fmtname = "vfsv1";
1732                         break;
1733                 }
1734                 seq_printf(seq, ",jqfmt=%s", fmtname);
1735         }
1736
1737         if (sbi->s_qf_names[USRQUOTA])
1738                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1739
1740         if (sbi->s_qf_names[GRPQUOTA])
1741                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1742 #endif
1743 }
1744
1745 static const char *token2str(int token)
1746 {
1747         const struct match_token *t;
1748
1749         for (t = tokens; t->token != Opt_err; t++)
1750                 if (t->token == token && !strchr(t->pattern, '='))
1751                         break;
1752         return t->pattern;
1753 }
1754
1755 /*
1756  * Show an option if
1757  *  - it's set to a non-default value OR
1758  *  - if the per-sb default is different from the global default
1759  */
1760 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1761                               int nodefs)
1762 {
1763         struct ext4_sb_info *sbi = EXT4_SB(sb);
1764         struct ext4_super_block *es = sbi->s_es;
1765         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1766         const struct mount_opts *m;
1767         char sep = nodefs ? '\n' : ',';
1768
1769 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1770 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1771
1772         if (sbi->s_sb_block != 1)
1773                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1774
1775         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1776                 int want_set = m->flags & MOPT_SET;
1777                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1778                     (m->flags & MOPT_CLEAR_ERR))
1779                         continue;
1780                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1781                         continue; /* skip if same as the default */
1782                 if ((want_set &&
1783                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1784                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1785                         continue; /* select Opt_noFoo vs Opt_Foo */
1786                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1787         }
1788
1789         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1790             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1791                 SEQ_OPTS_PRINT("resuid=%u",
1792                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1793         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1794             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1795                 SEQ_OPTS_PRINT("resgid=%u",
1796                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1797         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1798         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1799                 SEQ_OPTS_PUTS("errors=remount-ro");
1800         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1801                 SEQ_OPTS_PUTS("errors=continue");
1802         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1803                 SEQ_OPTS_PUTS("errors=panic");
1804         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1805                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1806         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1807                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1808         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1809                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1810         if (sb->s_flags & MS_I_VERSION)
1811                 SEQ_OPTS_PUTS("i_version");
1812         if (nodefs || sbi->s_stripe)
1813                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1814         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1815                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1816                         SEQ_OPTS_PUTS("data=journal");
1817                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1818                         SEQ_OPTS_PUTS("data=ordered");
1819                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1820                         SEQ_OPTS_PUTS("data=writeback");
1821         }
1822         if (nodefs ||
1823             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1824                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1825                                sbi->s_inode_readahead_blks);
1826
1827         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1828                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1829                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1830         if (nodefs || sbi->s_max_dir_size_kb)
1831                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1832
1833         ext4_show_quota_options(seq, sb);
1834         return 0;
1835 }
1836
1837 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1838 {
1839         return _ext4_show_options(seq, root->d_sb, 0);
1840 }
1841
1842 static int options_seq_show(struct seq_file *seq, void *offset)
1843 {
1844         struct super_block *sb = seq->private;
1845         int rc;
1846
1847         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1848         rc = _ext4_show_options(seq, sb, 1);
1849         seq_puts(seq, "\n");
1850         return rc;
1851 }
1852
1853 static int options_open_fs(struct inode *inode, struct file *file)
1854 {
1855         return single_open(file, options_seq_show, PDE_DATA(inode));
1856 }
1857
1858 static const struct file_operations ext4_seq_options_fops = {
1859         .owner = THIS_MODULE,
1860         .open = options_open_fs,
1861         .read = seq_read,
1862         .llseek = seq_lseek,
1863         .release = single_release,
1864 };
1865
1866 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1867                             int read_only)
1868 {
1869         struct ext4_sb_info *sbi = EXT4_SB(sb);
1870         int res = 0;
1871
1872         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1873                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1874                          "forcing read-only mode");
1875                 res = MS_RDONLY;
1876         }
1877         if (read_only)
1878                 goto done;
1879         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1880                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1881                          "running e2fsck is recommended");
1882         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1883                 ext4_msg(sb, KERN_WARNING,
1884                          "warning: mounting fs with errors, "
1885                          "running e2fsck is recommended");
1886         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1887                  le16_to_cpu(es->s_mnt_count) >=
1888                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1889                 ext4_msg(sb, KERN_WARNING,
1890                          "warning: maximal mount count reached, "
1891                          "running e2fsck is recommended");
1892         else if (le32_to_cpu(es->s_checkinterval) &&
1893                 (le32_to_cpu(es->s_lastcheck) +
1894                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1895                 ext4_msg(sb, KERN_WARNING,
1896                          "warning: checktime reached, "
1897                          "running e2fsck is recommended");
1898         if (!sbi->s_journal)
1899                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1900         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1901                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1902         le16_add_cpu(&es->s_mnt_count, 1);
1903         es->s_mtime = cpu_to_le32(get_seconds());
1904         ext4_update_dynamic_rev(sb);
1905         if (sbi->s_journal)
1906                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1907
1908         ext4_commit_super(sb, 1);
1909 done:
1910         if (test_opt(sb, DEBUG))
1911                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1912                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1913                         sb->s_blocksize,
1914                         sbi->s_groups_count,
1915                         EXT4_BLOCKS_PER_GROUP(sb),
1916                         EXT4_INODES_PER_GROUP(sb),
1917                         sbi->s_mount_opt, sbi->s_mount_opt2);
1918
1919         cleancache_init_fs(sb);
1920         return res;
1921 }
1922
1923 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1924 {
1925         struct ext4_sb_info *sbi = EXT4_SB(sb);
1926         struct flex_groups *new_groups;
1927         int size;
1928
1929         if (!sbi->s_log_groups_per_flex)
1930                 return 0;
1931
1932         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1933         if (size <= sbi->s_flex_groups_allocated)
1934                 return 0;
1935
1936         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1937         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1938         if (!new_groups) {
1939                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1940                          size / (int) sizeof(struct flex_groups));
1941                 return -ENOMEM;
1942         }
1943
1944         if (sbi->s_flex_groups) {
1945                 memcpy(new_groups, sbi->s_flex_groups,
1946                        (sbi->s_flex_groups_allocated *
1947                         sizeof(struct flex_groups)));
1948                 kvfree(sbi->s_flex_groups);
1949         }
1950         sbi->s_flex_groups = new_groups;
1951         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1952         return 0;
1953 }
1954
1955 static int ext4_fill_flex_info(struct super_block *sb)
1956 {
1957         struct ext4_sb_info *sbi = EXT4_SB(sb);
1958         struct ext4_group_desc *gdp = NULL;
1959         ext4_group_t flex_group;
1960         int i, err;
1961
1962         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1963         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1964                 sbi->s_log_groups_per_flex = 0;
1965                 return 1;
1966         }
1967
1968         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1969         if (err)
1970                 goto failed;
1971
1972         for (i = 0; i < sbi->s_groups_count; i++) {
1973                 gdp = ext4_get_group_desc(sb, i, NULL);
1974
1975                 flex_group = ext4_flex_group(sbi, i);
1976                 atomic_add(ext4_free_inodes_count(sb, gdp),
1977                            &sbi->s_flex_groups[flex_group].free_inodes);
1978                 atomic64_add(ext4_free_group_clusters(sb, gdp),
1979                              &sbi->s_flex_groups[flex_group].free_clusters);
1980                 atomic_add(ext4_used_dirs_count(sb, gdp),
1981                            &sbi->s_flex_groups[flex_group].used_dirs);
1982         }
1983
1984         return 1;
1985 failed:
1986         return 0;
1987 }
1988
1989 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1990                                    struct ext4_group_desc *gdp)
1991 {
1992         int offset;
1993         __u16 crc = 0;
1994         __le32 le_group = cpu_to_le32(block_group);
1995
1996         if (ext4_has_metadata_csum(sbi->s_sb)) {
1997                 /* Use new metadata_csum algorithm */
1998                 __le16 save_csum;
1999                 __u32 csum32;
2000
2001                 save_csum = gdp->bg_checksum;
2002                 gdp->bg_checksum = 0;
2003                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2004                                      sizeof(le_group));
2005                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2006                                      sbi->s_desc_size);
2007                 gdp->bg_checksum = save_csum;
2008
2009                 crc = csum32 & 0xFFFF;
2010                 goto out;
2011         }
2012
2013         /* old crc16 code */
2014         if (!(sbi->s_es->s_feature_ro_compat &
2015               cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
2016                 return 0;
2017
2018         offset = offsetof(struct ext4_group_desc, bg_checksum);
2019
2020         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2021         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2022         crc = crc16(crc, (__u8 *)gdp, offset);
2023         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2024         /* for checksum of struct ext4_group_desc do the rest...*/
2025         if ((sbi->s_es->s_feature_incompat &
2026              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2027             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2028                 crc = crc16(crc, (__u8 *)gdp + offset,
2029                             le16_to_cpu(sbi->s_es->s_desc_size) -
2030                                 offset);
2031
2032 out:
2033         return cpu_to_le16(crc);
2034 }
2035
2036 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2037                                 struct ext4_group_desc *gdp)
2038 {
2039         if (ext4_has_group_desc_csum(sb) &&
2040             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2041                                                       block_group, gdp)))
2042                 return 0;
2043
2044         return 1;
2045 }
2046
2047 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2048                               struct ext4_group_desc *gdp)
2049 {
2050         if (!ext4_has_group_desc_csum(sb))
2051                 return;
2052         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2053 }
2054
2055 /* Called at mount-time, super-block is locked */
2056 static int ext4_check_descriptors(struct super_block *sb,
2057                                   ext4_group_t *first_not_zeroed)
2058 {
2059         struct ext4_sb_info *sbi = EXT4_SB(sb);
2060         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2061         ext4_fsblk_t last_block;
2062         ext4_fsblk_t block_bitmap;
2063         ext4_fsblk_t inode_bitmap;
2064         ext4_fsblk_t inode_table;
2065         int flexbg_flag = 0;
2066         ext4_group_t i, grp = sbi->s_groups_count;
2067
2068         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2069                 flexbg_flag = 1;
2070
2071         ext4_debug("Checking group descriptors");
2072
2073         for (i = 0; i < sbi->s_groups_count; i++) {
2074                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2075
2076                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2077                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2078                 else
2079                         last_block = first_block +
2080                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2081
2082                 if ((grp == sbi->s_groups_count) &&
2083                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2084                         grp = i;
2085
2086                 block_bitmap = ext4_block_bitmap(sb, gdp);
2087                 if (block_bitmap < first_block || block_bitmap > last_block) {
2088                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2089                                "Block bitmap for group %u not in group "
2090                                "(block %llu)!", i, block_bitmap);
2091                         return 0;
2092                 }
2093                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2094                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2095                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2096                                "Inode bitmap for group %u not in group "
2097                                "(block %llu)!", i, inode_bitmap);
2098                         return 0;
2099                 }
2100                 inode_table = ext4_inode_table(sb, gdp);
2101                 if (inode_table < first_block ||
2102                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2103                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2104                                "Inode table for group %u not in group "
2105                                "(block %llu)!", i, inode_table);
2106                         return 0;
2107                 }
2108                 ext4_lock_group(sb, i);
2109                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2110                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2111                                  "Checksum for group %u failed (%u!=%u)",
2112                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2113                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2114                         if (!(sb->s_flags & MS_RDONLY)) {
2115                                 ext4_unlock_group(sb, i);
2116                                 return 0;
2117                         }
2118                 }
2119                 ext4_unlock_group(sb, i);
2120                 if (!flexbg_flag)
2121                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2122         }
2123         if (NULL != first_not_zeroed)
2124                 *first_not_zeroed = grp;
2125         return 1;
2126 }
2127
2128 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2129  * the superblock) which were deleted from all directories, but held open by
2130  * a process at the time of a crash.  We walk the list and try to delete these
2131  * inodes at recovery time (only with a read-write filesystem).
2132  *
2133  * In order to keep the orphan inode chain consistent during traversal (in
2134  * case of crash during recovery), we link each inode into the superblock
2135  * orphan list_head and handle it the same way as an inode deletion during
2136  * normal operation (which journals the operations for us).
2137  *
2138  * We only do an iget() and an iput() on each inode, which is very safe if we
2139  * accidentally point at an in-use or already deleted inode.  The worst that
2140  * can happen in this case is that we get a "bit already cleared" message from
2141  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2142  * e2fsck was run on this filesystem, and it must have already done the orphan
2143  * inode cleanup for us, so we can safely abort without any further action.
2144  */
2145 static void ext4_orphan_cleanup(struct super_block *sb,
2146                                 struct ext4_super_block *es)
2147 {
2148         unsigned int s_flags = sb->s_flags;
2149         int nr_orphans = 0, nr_truncates = 0;
2150 #ifdef CONFIG_QUOTA
2151         int i;
2152 #endif
2153         if (!es->s_last_orphan) {
2154                 jbd_debug(4, "no orphan inodes to clean up\n");
2155                 return;
2156         }
2157
2158         if (bdev_read_only(sb->s_bdev)) {
2159                 ext4_msg(sb, KERN_ERR, "write access "
2160                         "unavailable, skipping orphan cleanup");
2161                 return;
2162         }
2163
2164         /* Check if feature set would not allow a r/w mount */
2165         if (!ext4_feature_set_ok(sb, 0)) {
2166                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2167                          "unknown ROCOMPAT features");
2168                 return;
2169         }
2170
2171         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2172                 /* don't clear list on RO mount w/ errors */
2173                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2174                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2175                                   "clearing orphan list.\n");
2176                         es->s_last_orphan = 0;
2177                 }
2178                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2179                 return;
2180         }
2181
2182         if (s_flags & MS_RDONLY) {
2183                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2184                 sb->s_flags &= ~MS_RDONLY;
2185         }
2186 #ifdef CONFIG_QUOTA
2187         /* Needed for iput() to work correctly and not trash data */
2188         sb->s_flags |= MS_ACTIVE;
2189         /* Turn on quotas so that they are updated correctly */
2190         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2191                 if (EXT4_SB(sb)->s_qf_names[i]) {
2192                         int ret = ext4_quota_on_mount(sb, i);
2193                         if (ret < 0)
2194                                 ext4_msg(sb, KERN_ERR,
2195                                         "Cannot turn on journaled "
2196                                         "quota: error %d", ret);
2197                 }
2198         }
2199 #endif
2200
2201         while (es->s_last_orphan) {
2202                 struct inode *inode;
2203
2204                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2205                 if (IS_ERR(inode)) {
2206                         es->s_last_orphan = 0;
2207                         break;
2208                 }
2209
2210                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2211                 dquot_initialize(inode);
2212                 if (inode->i_nlink) {
2213                         if (test_opt(sb, DEBUG))
2214                                 ext4_msg(sb, KERN_DEBUG,
2215                                         "%s: truncating inode %lu to %lld bytes",
2216                                         __func__, inode->i_ino, inode->i_size);
2217                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2218                                   inode->i_ino, inode->i_size);
2219                         mutex_lock(&inode->i_mutex);
2220                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2221                         ext4_truncate(inode);
2222                         mutex_unlock(&inode->i_mutex);
2223                         nr_truncates++;
2224                 } else {
2225                         if (test_opt(sb, DEBUG))
2226                                 ext4_msg(sb, KERN_DEBUG,
2227                                         "%s: deleting unreferenced inode %lu",
2228                                         __func__, inode->i_ino);
2229                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2230                                   inode->i_ino);
2231                         nr_orphans++;
2232                 }
2233                 iput(inode);  /* The delete magic happens here! */
2234         }
2235
2236 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2237
2238         if (nr_orphans)
2239                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2240                        PLURAL(nr_orphans));
2241         if (nr_truncates)
2242                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2243                        PLURAL(nr_truncates));
2244 #ifdef CONFIG_QUOTA
2245         /* Turn quotas off */
2246         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2247                 if (sb_dqopt(sb)->files[i])
2248                         dquot_quota_off(sb, i);
2249         }
2250 #endif
2251         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2252 }
2253
2254 /*
2255  * Maximal extent format file size.
2256  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2257  * extent format containers, within a sector_t, and within i_blocks
2258  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2259  * so that won't be a limiting factor.
2260  *
2261  * However there is other limiting factor. We do store extents in the form
2262  * of starting block and length, hence the resulting length of the extent
2263  * covering maximum file size must fit into on-disk format containers as
2264  * well. Given that length is always by 1 unit bigger than max unit (because
2265  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2266  *
2267  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2268  */
2269 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2270 {
2271         loff_t res;
2272         loff_t upper_limit = MAX_LFS_FILESIZE;
2273
2274         /* small i_blocks in vfs inode? */
2275         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2276                 /*
2277                  * CONFIG_LBDAF is not enabled implies the inode
2278                  * i_block represent total blocks in 512 bytes
2279                  * 32 == size of vfs inode i_blocks * 8
2280                  */
2281                 upper_limit = (1LL << 32) - 1;
2282
2283                 /* total blocks in file system block size */
2284                 upper_limit >>= (blkbits - 9);
2285                 upper_limit <<= blkbits;
2286         }
2287
2288         /*
2289          * 32-bit extent-start container, ee_block. We lower the maxbytes
2290          * by one fs block, so ee_len can cover the extent of maximum file
2291          * size
2292          */
2293         res = (1LL << 32) - 1;
2294         res <<= blkbits;
2295
2296         /* Sanity check against vm- & vfs- imposed limits */
2297         if (res > upper_limit)
2298                 res = upper_limit;
2299
2300         return res;
2301 }
2302
2303 /*
2304  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2305  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2306  * We need to be 1 filesystem block less than the 2^48 sector limit.
2307  */
2308 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2309 {
2310         loff_t res = EXT4_NDIR_BLOCKS;
2311         int meta_blocks;
2312         loff_t upper_limit;
2313         /* This is calculated to be the largest file size for a dense, block
2314          * mapped file such that the file's total number of 512-byte sectors,
2315          * including data and all indirect blocks, does not exceed (2^48 - 1).
2316          *
2317          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2318          * number of 512-byte sectors of the file.
2319          */
2320
2321         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2322                 /*
2323                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2324                  * the inode i_block field represents total file blocks in
2325                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2326                  */
2327                 upper_limit = (1LL << 32) - 1;
2328
2329                 /* total blocks in file system block size */
2330                 upper_limit >>= (bits - 9);
2331
2332         } else {
2333                 /*
2334                  * We use 48 bit ext4_inode i_blocks
2335                  * With EXT4_HUGE_FILE_FL set the i_blocks
2336                  * represent total number of blocks in
2337                  * file system block size
2338                  */
2339                 upper_limit = (1LL << 48) - 1;
2340
2341         }
2342
2343         /* indirect blocks */
2344         meta_blocks = 1;
2345         /* double indirect blocks */
2346         meta_blocks += 1 + (1LL << (bits-2));
2347         /* tripple indirect blocks */
2348         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2349
2350         upper_limit -= meta_blocks;
2351         upper_limit <<= bits;
2352
2353         res += 1LL << (bits-2);
2354         res += 1LL << (2*(bits-2));
2355         res += 1LL << (3*(bits-2));
2356         res <<= bits;
2357         if (res > upper_limit)
2358                 res = upper_limit;
2359
2360         if (res > MAX_LFS_FILESIZE)
2361                 res = MAX_LFS_FILESIZE;
2362
2363         return res;
2364 }
2365
2366 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2367                                    ext4_fsblk_t logical_sb_block, int nr)
2368 {
2369         struct ext4_sb_info *sbi = EXT4_SB(sb);
2370         ext4_group_t bg, first_meta_bg;
2371         int has_super = 0;
2372
2373         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2374
2375         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2376             nr < first_meta_bg)
2377                 return logical_sb_block + nr + 1;
2378         bg = sbi->s_desc_per_block * nr;
2379         if (ext4_bg_has_super(sb, bg))
2380                 has_super = 1;
2381
2382         /*
2383          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2384          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2385          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2386          * compensate.
2387          */
2388         if (sb->s_blocksize == 1024 && nr == 0 &&
2389             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2390                 has_super++;
2391
2392         return (has_super + ext4_group_first_block_no(sb, bg));
2393 }
2394
2395 /**
2396  * ext4_get_stripe_size: Get the stripe size.
2397  * @sbi: In memory super block info
2398  *
2399  * If we have specified it via mount option, then
2400  * use the mount option value. If the value specified at mount time is
2401  * greater than the blocks per group use the super block value.
2402  * If the super block value is greater than blocks per group return 0.
2403  * Allocator needs it be less than blocks per group.
2404  *
2405  */
2406 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2407 {
2408         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2409         unsigned long stripe_width =
2410                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2411         int ret;
2412
2413         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2414                 ret = sbi->s_stripe;
2415         else if (stripe_width <= sbi->s_blocks_per_group)
2416                 ret = stripe_width;
2417         else if (stride <= sbi->s_blocks_per_group)
2418                 ret = stride;
2419         else
2420                 ret = 0;
2421
2422         /*
2423          * If the stripe width is 1, this makes no sense and
2424          * we set it to 0 to turn off stripe handling code.
2425          */
2426         if (ret <= 1)
2427                 ret = 0;
2428
2429         return ret;
2430 }
2431
2432 /* sysfs supprt */
2433
2434 struct ext4_attr {
2435         struct attribute attr;
2436         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2437         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2438                          const char *, size_t);
2439         union {
2440                 int offset;
2441                 int deprecated_val;
2442         } u;
2443 };
2444
2445 static int parse_strtoull(const char *buf,
2446                 unsigned long long max, unsigned long long *value)
2447 {
2448         int ret;
2449
2450         ret = kstrtoull(skip_spaces(buf), 0, value);
2451         if (!ret && *value > max)
2452                 ret = -EINVAL;
2453         return ret;
2454 }
2455
2456 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2457                                               struct ext4_sb_info *sbi,
2458                                               char *buf)
2459 {
2460         return snprintf(buf, PAGE_SIZE, "%llu\n",
2461                 (s64) EXT4_C2B(sbi,
2462                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2463 }
2464
2465 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2466                                          struct ext4_sb_info *sbi, char *buf)
2467 {
2468         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2469
2470         if (!sb->s_bdev->bd_part)
2471                 return snprintf(buf, PAGE_SIZE, "0\n");
2472         return snprintf(buf, PAGE_SIZE, "%lu\n",
2473                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2474                          sbi->s_sectors_written_start) >> 1);
2475 }
2476
2477 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2478                                           struct ext4_sb_info *sbi, char *buf)
2479 {
2480         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2481
2482         if (!sb->s_bdev->bd_part)
2483                 return snprintf(buf, PAGE_SIZE, "0\n");
2484         return snprintf(buf, PAGE_SIZE, "%llu\n",
2485                         (unsigned long long)(sbi->s_kbytes_written +
2486                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2487                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2488 }
2489
2490 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2491                                           struct ext4_sb_info *sbi,
2492                                           const char *buf, size_t count)
2493 {
2494         unsigned long t;
2495         int ret;
2496
2497         ret = kstrtoul(skip_spaces(buf), 0, &t);
2498         if (ret)
2499                 return ret;
2500
2501         if (t && (!is_power_of_2(t) || t > 0x40000000))
2502                 return -EINVAL;
2503
2504         sbi->s_inode_readahead_blks = t;
2505         return count;
2506 }
2507
2508 static ssize_t sbi_ui_show(struct ext4_attr *a,
2509                            struct ext4_sb_info *sbi, char *buf)
2510 {
2511         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2512
2513         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2514 }
2515
2516 static ssize_t sbi_ui_store(struct ext4_attr *a,
2517                             struct ext4_sb_info *sbi,
2518                             const char *buf, size_t count)
2519 {
2520         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2521         unsigned long t;
2522         int ret;
2523
2524         ret = kstrtoul(skip_spaces(buf), 0, &t);
2525         if (ret)
2526                 return ret;
2527         *ui = t;
2528         return count;
2529 }
2530
2531 static ssize_t es_ui_show(struct ext4_attr *a,
2532                            struct ext4_sb_info *sbi, char *buf)
2533 {
2534
2535         unsigned int *ui = (unsigned int *) (((char *) sbi->s_es) +
2536                            a->u.offset);
2537
2538         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2539 }
2540
2541 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2542                                   struct ext4_sb_info *sbi, char *buf)
2543 {
2544         return snprintf(buf, PAGE_SIZE, "%llu\n",
2545                 (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2546 }
2547
2548 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2549                                    struct ext4_sb_info *sbi,
2550                                    const char *buf, size_t count)
2551 {
2552         unsigned long long val;
2553         int ret;
2554
2555         if (parse_strtoull(buf, -1ULL, &val))
2556                 return -EINVAL;
2557         ret = ext4_reserve_clusters(sbi, val);
2558
2559         return ret ? ret : count;
2560 }
2561
2562 static ssize_t trigger_test_error(struct ext4_attr *a,
2563                                   struct ext4_sb_info *sbi,
2564                                   const char *buf, size_t count)
2565 {
2566         int len = count;
2567
2568         if (!capable(CAP_SYS_ADMIN))
2569                 return -EPERM;
2570
2571         if (len && buf[len-1] == '\n')
2572                 len--;
2573
2574         if (len)
2575                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2576         return count;
2577 }
2578
2579 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2580                                    struct ext4_sb_info *sbi, char *buf)
2581 {
2582         return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2583 }
2584
2585 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2586 static struct ext4_attr ext4_attr_##_name = {                   \
2587         .attr = {.name = __stringify(_name), .mode = _mode },   \
2588         .show   = _show,                                        \
2589         .store  = _store,                                       \
2590         .u = {                                                  \
2591                 .offset = offsetof(struct ext4_sb_info, _elname),\
2592         },                                                      \
2593 }
2594
2595 #define EXT4_ATTR_OFFSET_ES(_name,_mode,_show,_store,_elname)           \
2596 static struct ext4_attr ext4_attr_##_name = {                           \
2597         .attr = {.name = __stringify(_name), .mode = _mode },           \
2598         .show   = _show,                                                \
2599         .store  = _store,                                               \
2600         .u = {                                                          \
2601                 .offset = offsetof(struct ext4_super_block, _elname),   \
2602         },                                                              \
2603 }
2604
2605 #define EXT4_ATTR(name, mode, show, store) \
2606 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2607
2608 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2609 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2610 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2611
2612 #define EXT4_RO_ATTR_ES_UI(name, elname)        \
2613         EXT4_ATTR_OFFSET_ES(name, 0444, es_ui_show, NULL, elname)
2614 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2615         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2616
2617 #define ATTR_LIST(name) &ext4_attr_##name.attr
2618 #define EXT4_DEPRECATED_ATTR(_name, _val)       \
2619 static struct ext4_attr ext4_attr_##_name = {                   \
2620         .attr = {.name = __stringify(_name), .mode = 0444 },    \
2621         .show   = sbi_deprecated_show,                          \
2622         .u = {                                                  \
2623                 .deprecated_val = _val,                         \
2624         },                                                      \
2625 }
2626
2627 EXT4_RO_ATTR(delayed_allocation_blocks);
2628 EXT4_RO_ATTR(session_write_kbytes);
2629 EXT4_RO_ATTR(lifetime_write_kbytes);
2630 EXT4_RW_ATTR(reserved_clusters);
2631 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2632                  inode_readahead_blks_store, s_inode_readahead_blks);
2633 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2634 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2635 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2636 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2637 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2638 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2639 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2640 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2641 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2642 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2643 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2644 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2645 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2646 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2647 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2648 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2649 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
2650 EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
2651 EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
2652
2653 static struct attribute *ext4_attrs[] = {
2654         ATTR_LIST(delayed_allocation_blocks),
2655         ATTR_LIST(session_write_kbytes),
2656         ATTR_LIST(lifetime_write_kbytes),
2657         ATTR_LIST(reserved_clusters),
2658         ATTR_LIST(inode_readahead_blks),
2659         ATTR_LIST(inode_goal),
2660         ATTR_LIST(mb_stats),
2661         ATTR_LIST(mb_max_to_scan),
2662         ATTR_LIST(mb_min_to_scan),
2663         ATTR_LIST(mb_order2_req),
2664         ATTR_LIST(mb_stream_req),
2665         ATTR_LIST(mb_group_prealloc),
2666         ATTR_LIST(max_writeback_mb_bump),
2667         ATTR_LIST(extent_max_zeroout_kb),
2668         ATTR_LIST(trigger_fs_error),
2669         ATTR_LIST(err_ratelimit_interval_ms),
2670         ATTR_LIST(err_ratelimit_burst),
2671         ATTR_LIST(warning_ratelimit_interval_ms),
2672         ATTR_LIST(warning_ratelimit_burst),
2673         ATTR_LIST(msg_ratelimit_interval_ms),
2674         ATTR_LIST(msg_ratelimit_burst),
2675         ATTR_LIST(errors_count),
2676         ATTR_LIST(first_error_time),
2677         ATTR_LIST(last_error_time),
2678         NULL,
2679 };
2680
2681 /* Features this copy of ext4 supports */
2682 EXT4_INFO_ATTR(lazy_itable_init);
2683 EXT4_INFO_ATTR(batched_discard);
2684 EXT4_INFO_ATTR(meta_bg_resize);
2685
2686 static struct attribute *ext4_feat_attrs[] = {
2687         ATTR_LIST(lazy_itable_init),
2688         ATTR_LIST(batched_discard),
2689         ATTR_LIST(meta_bg_resize),
2690         NULL,
2691 };
2692
2693 static ssize_t ext4_attr_show(struct kobject *kobj,
2694                               struct attribute *attr, char *buf)
2695 {
2696         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2697                                                 s_kobj);
2698         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2699
2700         return a->show ? a->show(a, sbi, buf) : 0;
2701 }
2702
2703 static ssize_t ext4_attr_store(struct kobject *kobj,
2704                                struct attribute *attr,
2705                                const char *buf, size_t len)
2706 {
2707         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2708                                                 s_kobj);
2709         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2710
2711         return a->store ? a->store(a, sbi, buf, len) : 0;
2712 }
2713
2714 static void ext4_sb_release(struct kobject *kobj)
2715 {
2716         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2717                                                 s_kobj);
2718         complete(&sbi->s_kobj_unregister);
2719 }
2720
2721 static const struct sysfs_ops ext4_attr_ops = {
2722         .show   = ext4_attr_show,
2723         .store  = ext4_attr_store,
2724 };
2725
2726 static struct kobj_type ext4_ktype = {
2727         .default_attrs  = ext4_attrs,
2728         .sysfs_ops      = &ext4_attr_ops,
2729         .release        = ext4_sb_release,
2730 };
2731
2732 static void ext4_feat_release(struct kobject *kobj)
2733 {
2734         complete(&ext4_feat->f_kobj_unregister);
2735 }
2736
2737 static ssize_t ext4_feat_show(struct kobject *kobj,
2738                               struct attribute *attr, char *buf)
2739 {
2740         return snprintf(buf, PAGE_SIZE, "supported\n");
2741 }
2742
2743 /*
2744  * We can not use ext4_attr_show/store because it relies on the kobject
2745  * being embedded in the ext4_sb_info structure which is definitely not
2746  * true in this case.
2747  */
2748 static const struct sysfs_ops ext4_feat_ops = {
2749         .show   = ext4_feat_show,
2750         .store  = NULL,
2751 };
2752
2753 static struct kobj_type ext4_feat_ktype = {
2754         .default_attrs  = ext4_feat_attrs,
2755         .sysfs_ops      = &ext4_feat_ops,
2756         .release        = ext4_feat_release,
2757 };
2758
2759 /*
2760  * Check whether this filesystem can be mounted based on
2761  * the features present and the RDONLY/RDWR mount requested.
2762  * Returns 1 if this filesystem can be mounted as requested,
2763  * 0 if it cannot be.
2764  */
2765 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2766 {
2767         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2768                 ext4_msg(sb, KERN_ERR,
2769                         "Couldn't mount because of "
2770                         "unsupported optional features (%x)",
2771                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2772                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2773                 return 0;
2774         }
2775
2776         if (readonly)
2777                 return 1;
2778
2779         /* Check that feature set is OK for a read-write mount */
2780         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2781                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2782                          "unsupported optional features (%x)",
2783                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2784                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2785                 return 0;
2786         }
2787         /*
2788          * Large file size enabled file system can only be mounted
2789          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2790          */
2791         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2792                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2793                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2794                                  "cannot be mounted RDWR without "
2795                                  "CONFIG_LBDAF");
2796                         return 0;
2797                 }
2798         }
2799         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2800             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2801                 ext4_msg(sb, KERN_ERR,
2802                          "Can't support bigalloc feature without "
2803                          "extents feature\n");
2804                 return 0;
2805         }
2806
2807 #ifndef CONFIG_QUOTA
2808         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2809             !readonly) {
2810                 ext4_msg(sb, KERN_ERR,
2811                          "Filesystem with quota feature cannot be mounted RDWR "
2812                          "without CONFIG_QUOTA");
2813                 return 0;
2814         }
2815 #endif  /* CONFIG_QUOTA */
2816         return 1;
2817 }
2818
2819 /*
2820  * This function is called once a day if we have errors logged
2821  * on the file system
2822  */
2823 static void print_daily_error_info(unsigned long arg)
2824 {
2825         struct super_block *sb = (struct super_block *) arg;
2826         struct ext4_sb_info *sbi;
2827         struct ext4_super_block *es;
2828
2829         sbi = EXT4_SB(sb);
2830         es = sbi->s_es;
2831
2832         if (es->s_error_count)
2833                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2834                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2835                          le32_to_cpu(es->s_error_count));
2836         if (es->s_first_error_time) {
2837                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2838                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2839                        (int) sizeof(es->s_first_error_func),
2840                        es->s_first_error_func,
2841                        le32_to_cpu(es->s_first_error_line));
2842                 if (es->s_first_error_ino)
2843                         printk(": inode %u",
2844                                le32_to_cpu(es->s_first_error_ino));
2845                 if (es->s_first_error_block)
2846                         printk(": block %llu", (unsigned long long)
2847                                le64_to_cpu(es->s_first_error_block));
2848                 printk("\n");
2849         }
2850         if (es->s_last_error_time) {
2851                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2852                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2853                        (int) sizeof(es->s_last_error_func),
2854                        es->s_last_error_func,
2855                        le32_to_cpu(es->s_last_error_line));
2856                 if (es->s_last_error_ino)
2857                         printk(": inode %u",
2858                                le32_to_cpu(es->s_last_error_ino));
2859                 if (es->s_last_error_block)
2860                         printk(": block %llu", (unsigned long long)
2861                                le64_to_cpu(es->s_last_error_block));
2862                 printk("\n");
2863         }
2864         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2865 }
2866
2867 /* Find next suitable group and run ext4_init_inode_table */
2868 static int ext4_run_li_request(struct ext4_li_request *elr)
2869 {
2870         struct ext4_group_desc *gdp = NULL;
2871         ext4_group_t group, ngroups;
2872         struct super_block *sb;
2873         unsigned long timeout = 0;
2874         int ret = 0;
2875
2876         sb = elr->lr_super;
2877         ngroups = EXT4_SB(sb)->s_groups_count;
2878
2879         sb_start_write(sb);
2880         for (group = elr->lr_next_group; group < ngroups; group++) {
2881                 gdp = ext4_get_group_desc(sb, group, NULL);
2882                 if (!gdp) {
2883                         ret = 1;
2884                         break;
2885                 }
2886
2887                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2888                         break;
2889         }
2890
2891         if (group >= ngroups)
2892                 ret = 1;
2893
2894         if (!ret) {
2895                 timeout = jiffies;
2896                 ret = ext4_init_inode_table(sb, group,
2897                                             elr->lr_timeout ? 0 : 1);
2898                 if (elr->lr_timeout == 0) {
2899                         timeout = (jiffies - timeout) *
2900                                   elr->lr_sbi->s_li_wait_mult;
2901                         elr->lr_timeout = timeout;
2902                 }
2903                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2904                 elr->lr_next_group = group + 1;
2905         }
2906         sb_end_write(sb);
2907
2908         return ret;
2909 }
2910
2911 /*
2912  * Remove lr_request from the list_request and free the
2913  * request structure. Should be called with li_list_mtx held
2914  */
2915 static void ext4_remove_li_request(struct ext4_li_request *elr)
2916 {
2917         struct ext4_sb_info *sbi;
2918
2919         if (!elr)
2920                 return;
2921
2922         sbi = elr->lr_sbi;
2923
2924         list_del(&elr->lr_request);
2925         sbi->s_li_request = NULL;
2926         kfree(elr);
2927 }
2928
2929 static void ext4_unregister_li_request(struct super_block *sb)
2930 {
2931         mutex_lock(&ext4_li_mtx);
2932         if (!ext4_li_info) {
2933                 mutex_unlock(&ext4_li_mtx);
2934                 return;
2935         }
2936
2937         mutex_lock(&ext4_li_info->li_list_mtx);
2938         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2939         mutex_unlock(&ext4_li_info->li_list_mtx);
2940         mutex_unlock(&ext4_li_mtx);
2941 }
2942
2943 static struct task_struct *ext4_lazyinit_task;
2944
2945 /*
2946  * This is the function where ext4lazyinit thread lives. It walks
2947  * through the request list searching for next scheduled filesystem.
2948  * When such a fs is found, run the lazy initialization request
2949  * (ext4_rn_li_request) and keep track of the time spend in this
2950  * function. Based on that time we compute next schedule time of
2951  * the request. When walking through the list is complete, compute
2952  * next waking time and put itself into sleep.
2953  */
2954 static int ext4_lazyinit_thread(void *arg)
2955 {
2956         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2957         struct list_head *pos, *n;
2958         struct ext4_li_request *elr;
2959         unsigned long next_wakeup, cur;
2960
2961         BUG_ON(NULL == eli);
2962
2963 cont_thread:
2964         while (true) {
2965                 next_wakeup = MAX_JIFFY_OFFSET;
2966
2967                 mutex_lock(&eli->li_list_mtx);
2968                 if (list_empty(&eli->li_request_list)) {
2969                         mutex_unlock(&eli->li_list_mtx);
2970                         goto exit_thread;
2971                 }
2972
2973                 list_for_each_safe(pos, n, &eli->li_request_list) {
2974                         elr = list_entry(pos, struct ext4_li_request,
2975                                          lr_request);
2976
2977                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2978                                 if (ext4_run_li_request(elr) != 0) {
2979                                         /* error, remove the lazy_init job */
2980                                         ext4_remove_li_request(elr);
2981                                         continue;
2982                                 }
2983                         }
2984
2985                         if (time_before(elr->lr_next_sched, next_wakeup))
2986                                 next_wakeup = elr->lr_next_sched;
2987                 }
2988                 mutex_unlock(&eli->li_list_mtx);
2989
2990                 try_to_freeze();
2991
2992                 cur = jiffies;
2993                 if ((time_after_eq(cur, next_wakeup)) ||
2994                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2995                         cond_resched();
2996                         continue;
2997                 }
2998
2999                 schedule_timeout_interruptible(next_wakeup - cur);
3000
3001                 if (kthread_should_stop()) {
3002                         ext4_clear_request_list();
3003                         goto exit_thread;
3004                 }
3005         }
3006
3007 exit_thread:
3008         /*
3009          * It looks like the request list is empty, but we need
3010          * to check it under the li_list_mtx lock, to prevent any
3011          * additions into it, and of course we should lock ext4_li_mtx
3012          * to atomically free the list and ext4_li_info, because at
3013          * this point another ext4 filesystem could be registering
3014          * new one.
3015          */
3016         mutex_lock(&ext4_li_mtx);
3017         mutex_lock(&eli->li_list_mtx);
3018         if (!list_empty(&eli->li_request_list)) {
3019                 mutex_unlock(&eli->li_list_mtx);
3020                 mutex_unlock(&ext4_li_mtx);
3021                 goto cont_thread;
3022         }
3023         mutex_unlock(&eli->li_list_mtx);
3024         kfree(ext4_li_info);
3025         ext4_li_info = NULL;
3026         mutex_unlock(&ext4_li_mtx);
3027
3028         return 0;
3029 }
3030
3031 static void ext4_clear_request_list(void)
3032 {
3033         struct list_head *pos, *n;
3034         struct ext4_li_request *elr;
3035
3036         mutex_lock(&ext4_li_info->li_list_mtx);
3037         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3038                 elr = list_entry(pos, struct ext4_li_request,
3039                                  lr_request);
3040                 ext4_remove_li_request(elr);
3041         }
3042         mutex_unlock(&ext4_li_info->li_list_mtx);
3043 }
3044
3045 static int ext4_run_lazyinit_thread(void)
3046 {
3047         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3048                                          ext4_li_info, "ext4lazyinit");
3049         if (IS_ERR(ext4_lazyinit_task)) {
3050                 int err = PTR_ERR(ext4_lazyinit_task);
3051                 ext4_clear_request_list();
3052                 kfree(ext4_li_info);
3053                 ext4_li_info = NULL;
3054                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3055                                  "initialization thread\n",
3056                                  err);
3057                 return err;
3058         }
3059         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3060         return 0;
3061 }
3062
3063 /*
3064  * Check whether it make sense to run itable init. thread or not.
3065  * If there is at least one uninitialized inode table, return
3066  * corresponding group number, else the loop goes through all
3067  * groups and return total number of groups.
3068  */
3069 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3070 {
3071         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3072         struct ext4_group_desc *gdp = NULL;
3073
3074         for (group = 0; group < ngroups; group++) {
3075                 gdp = ext4_get_group_desc(sb, group, NULL);
3076                 if (!gdp)
3077                         continue;
3078
3079                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3080                         break;
3081         }
3082
3083         return group;
3084 }
3085
3086 static int ext4_li_info_new(void)
3087 {
3088         struct ext4_lazy_init *eli = NULL;
3089
3090         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3091         if (!eli)
3092                 return -ENOMEM;
3093
3094         INIT_LIST_HEAD(&eli->li_request_list);
3095         mutex_init(&eli->li_list_mtx);
3096
3097         eli->li_state |= EXT4_LAZYINIT_QUIT;
3098
3099         ext4_li_info = eli;
3100
3101         return 0;
3102 }
3103
3104 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3105                                             ext4_group_t start)
3106 {
3107         struct ext4_sb_info *sbi = EXT4_SB(sb);
3108         struct ext4_li_request *elr;
3109
3110         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3111         if (!elr)
3112                 return NULL;
3113
3114         elr->lr_super = sb;
3115         elr->lr_sbi = sbi;
3116         elr->lr_next_group = start;
3117
3118         /*
3119          * Randomize first schedule time of the request to
3120          * spread the inode table initialization requests
3121          * better.
3122          */
3123         elr->lr_next_sched = jiffies + (prandom_u32() %
3124                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3125         return elr;
3126 }
3127
3128 int ext4_register_li_request(struct super_block *sb,
3129                              ext4_group_t first_not_zeroed)
3130 {
3131         struct ext4_sb_info *sbi = EXT4_SB(sb);
3132         struct ext4_li_request *elr = NULL;
3133         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3134         int ret = 0;
3135
3136         mutex_lock(&ext4_li_mtx);
3137         if (sbi->s_li_request != NULL) {
3138                 /*
3139                  * Reset timeout so it can be computed again, because
3140                  * s_li_wait_mult might have changed.
3141                  */
3142                 sbi->s_li_request->lr_timeout = 0;
3143                 goto out;
3144         }
3145
3146         if (first_not_zeroed == ngroups ||
3147             (sb->s_flags & MS_RDONLY) ||
3148             !test_opt(sb, INIT_INODE_TABLE))
3149                 goto out;
3150
3151         elr = ext4_li_request_new(sb, first_not_zeroed);
3152         if (!elr) {
3153                 ret = -ENOMEM;
3154                 goto out;
3155         }
3156
3157         if (NULL == ext4_li_info) {
3158                 ret = ext4_li_info_new();
3159                 if (ret)
3160                         goto out;
3161         }
3162
3163         mutex_lock(&ext4_li_info->li_list_mtx);
3164         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3165         mutex_unlock(&ext4_li_info->li_list_mtx);
3166
3167         sbi->s_li_request = elr;
3168         /*
3169          * set elr to NULL here since it has been inserted to
3170          * the request_list and the removal and free of it is
3171          * handled by ext4_clear_request_list from now on.
3172          */
3173         elr = NULL;
3174
3175         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3176                 ret = ext4_run_lazyinit_thread();
3177                 if (ret)
3178                         goto out;
3179         }
3180 out:
3181         mutex_unlock(&ext4_li_mtx);
3182         if (ret)
3183                 kfree(elr);
3184         return ret;
3185 }
3186
3187 /*
3188  * We do not need to lock anything since this is called on
3189  * module unload.
3190  */
3191 static void ext4_destroy_lazyinit_thread(void)
3192 {
3193         /*
3194          * If thread exited earlier
3195          * there's nothing to be done.
3196          */
3197         if (!ext4_li_info || !ext4_lazyinit_task)
3198                 return;
3199
3200         kthread_stop(ext4_lazyinit_task);
3201 }
3202
3203 static int set_journal_csum_feature_set(struct super_block *sb)
3204 {
3205         int ret = 1;
3206         int compat, incompat;
3207         struct ext4_sb_info *sbi = EXT4_SB(sb);
3208
3209         if (ext4_has_metadata_csum(sb)) {
3210                 /* journal checksum v3 */
3211                 compat = 0;
3212                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3213         } else {
3214                 /* journal checksum v1 */
3215                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3216                 incompat = 0;
3217         }
3218
3219         jbd2_journal_clear_features(sbi->s_journal,
3220                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3221                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3222                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3223         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3224                 ret = jbd2_journal_set_features(sbi->s_journal,
3225                                 compat, 0,
3226                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3227                                 incompat);
3228         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3229                 ret = jbd2_journal_set_features(sbi->s_journal,
3230                                 compat, 0,
3231                                 incompat);
3232                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3233                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3234         } else {
3235                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3236                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3237         }
3238
3239         return ret;
3240 }
3241
3242 /*
3243  * Note: calculating the overhead so we can be compatible with
3244  * historical BSD practice is quite difficult in the face of
3245  * clusters/bigalloc.  This is because multiple metadata blocks from
3246  * different block group can end up in the same allocation cluster.
3247  * Calculating the exact overhead in the face of clustered allocation
3248  * requires either O(all block bitmaps) in memory or O(number of block
3249  * groups**2) in time.  We will still calculate the superblock for
3250  * older file systems --- and if we come across with a bigalloc file
3251  * system with zero in s_overhead_clusters the estimate will be close to
3252  * correct especially for very large cluster sizes --- but for newer
3253  * file systems, it's better to calculate this figure once at mkfs
3254  * time, and store it in the superblock.  If the superblock value is
3255  * present (even for non-bigalloc file systems), we will use it.
3256  */
3257 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3258                           char *buf)
3259 {
3260         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3261         struct ext4_group_desc  *gdp;
3262         ext4_fsblk_t            first_block, last_block, b;
3263         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3264         int                     s, j, count = 0;
3265
3266         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3267                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3268                         sbi->s_itb_per_group + 2);
3269
3270         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3271                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3272         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3273         for (i = 0; i < ngroups; i++) {
3274                 gdp = ext4_get_group_desc(sb, i, NULL);
3275                 b = ext4_block_bitmap(sb, gdp);
3276                 if (b >= first_block && b <= last_block) {
3277                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3278                         count++;
3279                 }
3280                 b = ext4_inode_bitmap(sb, gdp);
3281                 if (b >= first_block && b <= last_block) {
3282                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3283                         count++;
3284                 }
3285                 b = ext4_inode_table(sb, gdp);
3286                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3287                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3288                                 int c = EXT4_B2C(sbi, b - first_block);
3289                                 ext4_set_bit(c, buf);
3290                                 count++;
3291                         }
3292                 if (i != grp)
3293                         continue;
3294                 s = 0;
3295                 if (ext4_bg_has_super(sb, grp)) {
3296                         ext4_set_bit(s++, buf);
3297                         count++;
3298                 }
3299                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3300                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3301                         count++;
3302                 }
3303         }
3304         if (!count)
3305                 return 0;
3306         return EXT4_CLUSTERS_PER_GROUP(sb) -
3307                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3308 }
3309
3310 /*
3311  * Compute the overhead and stash it in sbi->s_overhead
3312  */
3313 int ext4_calculate_overhead(struct super_block *sb)
3314 {
3315         struct ext4_sb_info *sbi = EXT4_SB(sb);
3316         struct ext4_super_block *es = sbi->s_es;
3317         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3318         ext4_fsblk_t overhead = 0;
3319         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3320
3321         if (!buf)
3322                 return -ENOMEM;
3323
3324         /*
3325          * Compute the overhead (FS structures).  This is constant
3326          * for a given filesystem unless the number of block groups
3327          * changes so we cache the previous value until it does.
3328          */
3329
3330         /*
3331          * All of the blocks before first_data_block are overhead
3332          */
3333         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3334
3335         /*
3336          * Add the overhead found in each block group
3337          */
3338         for (i = 0; i < ngroups; i++) {
3339                 int blks;
3340
3341                 blks = count_overhead(sb, i, buf);
3342                 overhead += blks;
3343                 if (blks)
3344                         memset(buf, 0, PAGE_SIZE);
3345                 cond_resched();
3346         }
3347         /* Add the internal journal blocks as well */
3348         if (sbi->s_journal && !sbi->journal_bdev)
3349                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3350
3351         sbi->s_overhead = overhead;
3352         smp_wmb();
3353         free_page((unsigned long) buf);
3354         return 0;
3355 }
3356
3357
3358 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3359 {
3360         ext4_fsblk_t resv_clusters;
3361
3362         /*
3363          * There's no need to reserve anything when we aren't using extents.
3364          * The space estimates are exact, there are no unwritten extents,
3365          * hole punching doesn't need new metadata... This is needed especially
3366          * to keep ext2/3 backward compatibility.
3367          */
3368         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3369                 return 0;
3370         /*
3371          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3372          * This should cover the situations where we can not afford to run
3373          * out of space like for example punch hole, or converting
3374          * unwritten extents in delalloc path. In most cases such
3375          * allocation would require 1, or 2 blocks, higher numbers are
3376          * very rare.
3377          */
3378         resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3379                         EXT4_SB(sb)->s_cluster_bits;
3380
3381         do_div(resv_clusters, 50);
3382         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3383
3384         return resv_clusters;
3385 }
3386
3387
3388 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3389 {
3390         ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3391                                 sbi->s_cluster_bits;
3392
3393         if (count >= clusters)
3394                 return -EINVAL;
3395
3396         atomic64_set(&sbi->s_resv_clusters, count);
3397         return 0;
3398 }
3399
3400 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3401 {
3402         char *orig_data = kstrdup(data, GFP_KERNEL);
3403         struct buffer_head *bh;
3404         struct ext4_super_block *es = NULL;
3405         struct ext4_sb_info *sbi;
3406         ext4_fsblk_t block;
3407         ext4_fsblk_t sb_block = get_sb_block(&data);
3408         ext4_fsblk_t logical_sb_block;
3409         unsigned long offset = 0;
3410         unsigned long journal_devnum = 0;
3411         unsigned long def_mount_opts;
3412         struct inode *root;
3413         char *cp;
3414         const char *descr;
3415         int ret = -ENOMEM;
3416         int blocksize, clustersize;
3417         unsigned int db_count;
3418         unsigned int i;
3419         int needs_recovery, has_huge_files, has_bigalloc;
3420         __u64 blocks_count;
3421         int err = 0;
3422         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3423         ext4_group_t first_not_zeroed;
3424
3425         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3426         if (!sbi)
3427                 goto out_free_orig;
3428
3429         sbi->s_blockgroup_lock =
3430                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3431         if (!sbi->s_blockgroup_lock) {
3432                 kfree(sbi);
3433                 goto out_free_orig;
3434         }
3435         sb->s_fs_info = sbi;
3436         sbi->s_sb = sb;
3437         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3438         sbi->s_sb_block = sb_block;
3439         if (sb->s_bdev->bd_part)
3440                 sbi->s_sectors_written_start =
3441                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3442
3443         /* Cleanup superblock name */
3444         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3445                 *cp = '!';
3446
3447         /* -EINVAL is default */
3448         ret = -EINVAL;
3449         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3450         if (!blocksize) {
3451                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3452                 goto out_fail;
3453         }
3454
3455         /*
3456          * The ext4 superblock will not be buffer aligned for other than 1kB
3457          * block sizes.  We need to calculate the offset from buffer start.
3458          */
3459         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3460                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3461                 offset = do_div(logical_sb_block, blocksize);
3462         } else {
3463                 logical_sb_block = sb_block;
3464         }
3465
3466         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3467                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3468                 goto out_fail;
3469         }
3470         /*
3471          * Note: s_es must be initialized as soon as possible because
3472          *       some ext4 macro-instructions depend on its value
3473          */
3474         es = (struct ext4_super_block *) (bh->b_data + offset);
3475         sbi->s_es = es;
3476         sb->s_magic = le16_to_cpu(es->s_magic);
3477         if (sb->s_magic != EXT4_SUPER_MAGIC)
3478                 goto cantfind_ext4;
3479         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3480
3481         /* Warn if metadata_csum and gdt_csum are both set. */
3482         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3483                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3484             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3485                 ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3486                              "redundant flags; please run fsck.");
3487
3488         /* Check for a known checksum algorithm */
3489         if (!ext4_verify_csum_type(sb, es)) {
3490                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3491                          "unknown checksum algorithm.");
3492                 silent = 1;
3493                 goto cantfind_ext4;
3494         }
3495
3496         /* Load the checksum driver */
3497         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3498                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3499                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3500                 if (IS_ERR(sbi->s_chksum_driver)) {
3501                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3502                         ret = PTR_ERR(sbi->s_chksum_driver);
3503                         sbi->s_chksum_driver = NULL;
3504                         goto failed_mount;
3505                 }
3506         }
3507
3508         /* Check superblock checksum */
3509         if (!ext4_superblock_csum_verify(sb, es)) {
3510                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3511                          "invalid superblock checksum.  Run e2fsck?");
3512                 silent = 1;
3513                 goto cantfind_ext4;
3514         }
3515
3516         /* Precompute checksum seed for all metadata */
3517         if (ext4_has_metadata_csum(sb))
3518                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3519                                                sizeof(es->s_uuid));
3520
3521         /* Set defaults before we parse the mount options */
3522         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3523         set_opt(sb, INIT_INODE_TABLE);
3524         if (def_mount_opts & EXT4_DEFM_DEBUG)
3525                 set_opt(sb, DEBUG);
3526         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3527                 set_opt(sb, GRPID);
3528         if (def_mount_opts & EXT4_DEFM_UID16)
3529                 set_opt(sb, NO_UID32);
3530         /* xattr user namespace & acls are now defaulted on */
3531         set_opt(sb, XATTR_USER);
3532 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3533         set_opt(sb, POSIX_ACL);
3534 #endif
3535         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3536         if (ext4_has_metadata_csum(sb))
3537                 set_opt(sb, JOURNAL_CHECKSUM);
3538
3539         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3540                 set_opt(sb, JOURNAL_DATA);
3541         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3542                 set_opt(sb, ORDERED_DATA);
3543         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3544                 set_opt(sb, WRITEBACK_DATA);
3545
3546         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3547                 set_opt(sb, ERRORS_PANIC);
3548         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3549                 set_opt(sb, ERRORS_CONT);
3550         else
3551                 set_opt(sb, ERRORS_RO);
3552         /* block_validity enabled by default; disable with noblock_validity */
3553         set_opt(sb, BLOCK_VALIDITY);
3554         if (def_mount_opts & EXT4_DEFM_DISCARD)
3555                 set_opt(sb, DISCARD);
3556
3557         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3558         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3559         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3560         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3561         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3562
3563         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3564                 set_opt(sb, BARRIER);
3565
3566         /*
3567          * enable delayed allocation by default
3568          * Use -o nodelalloc to turn it off
3569          */
3570         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3571             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3572                 set_opt(sb, DELALLOC);
3573
3574         /*
3575          * set default s_li_wait_mult for lazyinit, for the case there is
3576          * no mount option specified.
3577          */
3578         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3579
3580         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3581                            &journal_devnum, &journal_ioprio, 0)) {
3582                 ext4_msg(sb, KERN_WARNING,
3583                          "failed to parse options in superblock: %s",
3584                          sbi->s_es->s_mount_opts);
3585         }
3586         sbi->s_def_mount_opt = sbi->s_mount_opt;
3587         if (!parse_options((char *) data, sb, &journal_devnum,
3588                            &journal_ioprio, 0))
3589                 goto failed_mount;
3590
3591         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3592                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3593                             "with data=journal disables delayed "
3594                             "allocation and O_DIRECT support!\n");
3595                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3596                         ext4_msg(sb, KERN_ERR, "can't mount with "
3597                                  "both data=journal and delalloc");
3598                         goto failed_mount;
3599                 }
3600                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3601                         ext4_msg(sb, KERN_ERR, "can't mount with "
3602                                  "both data=journal and dioread_nolock");
3603                         goto failed_mount;
3604                 }
3605                 if (test_opt(sb, DELALLOC))
3606                         clear_opt(sb, DELALLOC);
3607         }
3608
3609         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3610                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3611
3612         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3613             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3614              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3615              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3616                 ext4_msg(sb, KERN_WARNING,
3617                        "feature flags set on rev 0 fs, "
3618                        "running e2fsck is recommended");
3619
3620         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3621                 set_opt2(sb, HURD_COMPAT);
3622                 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
3623                                               EXT4_FEATURE_INCOMPAT_64BIT)) {
3624                         ext4_msg(sb, KERN_ERR,
3625                                  "The Hurd can't support 64-bit file systems");
3626                         goto failed_mount;
3627                 }
3628         }
3629
3630         if (IS_EXT2_SB(sb)) {
3631                 if (ext2_feature_set_ok(sb))
3632                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3633                                  "using the ext4 subsystem");
3634                 else {
3635                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3636                                  "to feature incompatibilities");
3637                         goto failed_mount;
3638                 }
3639         }
3640
3641         if (IS_EXT3_SB(sb)) {
3642                 if (ext3_feature_set_ok(sb))
3643                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3644                                  "using the ext4 subsystem");
3645                 else {
3646                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3647                                  "to feature incompatibilities");
3648                         goto failed_mount;
3649                 }
3650         }
3651
3652         /*
3653          * Check feature flags regardless of the revision level, since we
3654          * previously didn't change the revision level when setting the flags,
3655          * so there is a chance incompat flags are set on a rev 0 filesystem.
3656          */
3657         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3658                 goto failed_mount;
3659
3660         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3661         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3662             blocksize > EXT4_MAX_BLOCK_SIZE) {
3663                 ext4_msg(sb, KERN_ERR,
3664                        "Unsupported filesystem blocksize %d", blocksize);
3665                 goto failed_mount;
3666         }
3667
3668         if (sb->s_blocksize != blocksize) {
3669                 /* Validate the filesystem blocksize */
3670                 if (!sb_set_blocksize(sb, blocksize)) {
3671                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3672                                         blocksize);
3673                         goto failed_mount;
3674                 }
3675
3676                 brelse(bh);
3677                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3678                 offset = do_div(logical_sb_block, blocksize);
3679                 bh = sb_bread_unmovable(sb, logical_sb_block);
3680                 if (!bh) {
3681                         ext4_msg(sb, KERN_ERR,
3682                                "Can't read superblock on 2nd try");
3683                         goto failed_mount;
3684                 }
3685                 es = (struct ext4_super_block *)(bh->b_data + offset);
3686                 sbi->s_es = es;
3687                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3688                         ext4_msg(sb, KERN_ERR,
3689                                "Magic mismatch, very weird!");
3690                         goto failed_mount;
3691                 }
3692         }
3693
3694         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3695                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3696         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3697                                                       has_huge_files);
3698         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3699
3700         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3701                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3702                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3703         } else {
3704                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3705                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3706                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3707                     (!is_power_of_2(sbi->s_inode_size)) ||
3708                     (sbi->s_inode_size > blocksize)) {
3709                         ext4_msg(sb, KERN_ERR,
3710                                "unsupported inode size: %d",
3711                                sbi->s_inode_size);
3712                         goto failed_mount;
3713                 }
3714                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3715                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3716         }
3717
3718         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3719         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3720                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3721                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3722                     !is_power_of_2(sbi->s_desc_size)) {
3723                         ext4_msg(sb, KERN_ERR,
3724                                "unsupported descriptor size %lu",
3725                                sbi->s_desc_size);
3726                         goto failed_mount;
3727                 }
3728         } else
3729                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3730
3731         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3732         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3733         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3734                 goto cantfind_ext4;
3735
3736         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3737         if (sbi->s_inodes_per_block == 0)
3738                 goto cantfind_ext4;
3739         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3740                                         sbi->s_inodes_per_block;
3741         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3742         sbi->s_sbh = bh;
3743         sbi->s_mount_state = le16_to_cpu(es->s_state);
3744         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3745         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3746
3747         for (i = 0; i < 4; i++)
3748                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3749         sbi->s_def_hash_version = es->s_def_hash_version;
3750         if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3751                 i = le32_to_cpu(es->s_flags);
3752                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3753                         sbi->s_hash_unsigned = 3;
3754                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3755 #ifdef __CHAR_UNSIGNED__
3756                         if (!(sb->s_flags & MS_RDONLY))
3757                                 es->s_flags |=
3758                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3759                         sbi->s_hash_unsigned = 3;
3760 #else
3761                         if (!(sb->s_flags & MS_RDONLY))
3762                                 es->s_flags |=
3763                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3764 #endif
3765                 }
3766         }
3767
3768         /* Handle clustersize */
3769         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3770         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3771                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3772         if (has_bigalloc) {
3773                 if (clustersize < blocksize) {
3774                         ext4_msg(sb, KERN_ERR,
3775                                  "cluster size (%d) smaller than "
3776                                  "block size (%d)", clustersize, blocksize);
3777                         goto failed_mount;
3778                 }
3779                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3780                         le32_to_cpu(es->s_log_block_size);
3781                 sbi->s_clusters_per_group =
3782                         le32_to_cpu(es->s_clusters_per_group);
3783                 if (sbi->s_clusters_per_group > blocksize * 8) {
3784                         ext4_msg(sb, KERN_ERR,
3785                                  "#clusters per group too big: %lu",
3786                                  sbi->s_clusters_per_group);
3787                         goto failed_mount;
3788                 }
3789                 if (sbi->s_blocks_per_group !=
3790                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3791                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3792                                  "clusters per group (%lu) inconsistent",
3793                                  sbi->s_blocks_per_group,
3794                                  sbi->s_clusters_per_group);
3795                         goto failed_mount;
3796                 }
3797         } else {
3798                 if (clustersize != blocksize) {
3799                         ext4_warning(sb, "fragment/cluster size (%d) != "
3800                                      "block size (%d)", clustersize,
3801                                      blocksize);
3802                         clustersize = blocksize;
3803                 }
3804                 if (sbi->s_blocks_per_group > blocksize * 8) {
3805                         ext4_msg(sb, KERN_ERR,
3806                                  "#blocks per group too big: %lu",
3807                                  sbi->s_blocks_per_group);
3808                         goto failed_mount;
3809                 }
3810                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3811                 sbi->s_cluster_bits = 0;
3812         }
3813         sbi->s_cluster_ratio = clustersize / blocksize;
3814
3815         if (sbi->s_inodes_per_group > blocksize * 8) {
3816                 ext4_msg(sb, KERN_ERR,
3817                        "#inodes per group too big: %lu",
3818                        sbi->s_inodes_per_group);
3819                 goto failed_mount;
3820         }
3821
3822         /* Do we have standard group size of clustersize * 8 blocks ? */
3823         if (sbi->s_blocks_per_group == clustersize << 3)
3824                 set_opt2(sb, STD_GROUP_SIZE);
3825
3826         /*
3827          * Test whether we have more sectors than will fit in sector_t,
3828          * and whether the max offset is addressable by the page cache.
3829          */
3830         err = generic_check_addressable(sb->s_blocksize_bits,
3831                                         ext4_blocks_count(es));
3832         if (err) {
3833                 ext4_msg(sb, KERN_ERR, "filesystem"
3834                          " too large to mount safely on this system");
3835                 if (sizeof(sector_t) < 8)
3836                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3837                 goto failed_mount;
3838         }
3839
3840         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3841                 goto cantfind_ext4;
3842
3843         /* check blocks count against device size */
3844         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3845         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3846                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3847                        "exceeds size of device (%llu blocks)",
3848                        ext4_blocks_count(es), blocks_count);
3849                 goto failed_mount;
3850         }
3851
3852         /*
3853          * It makes no sense for the first data block to be beyond the end
3854          * of the filesystem.
3855          */
3856         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3857                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3858                          "block %u is beyond end of filesystem (%llu)",
3859                          le32_to_cpu(es->s_first_data_block),
3860                          ext4_blocks_count(es));
3861                 goto failed_mount;
3862         }
3863         blocks_count = (ext4_blocks_count(es) -
3864                         le32_to_cpu(es->s_first_data_block) +
3865                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3866         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3867         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3868                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3869                        "(block count %llu, first data block %u, "
3870                        "blocks per group %lu)", sbi->s_groups_count,
3871                        ext4_blocks_count(es),
3872                        le32_to_cpu(es->s_first_data_block),
3873                        EXT4_BLOCKS_PER_GROUP(sb));
3874                 goto failed_mount;
3875         }
3876         sbi->s_groups_count = blocks_count;
3877         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3878                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3879         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3880                    EXT4_DESC_PER_BLOCK(sb);
3881         sbi->s_group_desc = ext4_kvmalloc(db_count *
3882                                           sizeof(struct buffer_head *),
3883                                           GFP_KERNEL);
3884         if (sbi->s_group_desc == NULL) {
3885                 ext4_msg(sb, KERN_ERR, "not enough memory");
3886                 ret = -ENOMEM;
3887                 goto failed_mount;
3888         }
3889
3890         if (ext4_proc_root)
3891                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3892
3893         if (sbi->s_proc)
3894                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3895                                  &ext4_seq_options_fops, sb);
3896
3897         bgl_lock_init(sbi->s_blockgroup_lock);
3898
3899         for (i = 0; i < db_count; i++) {
3900                 block = descriptor_loc(sb, logical_sb_block, i);
3901                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3902                 if (!sbi->s_group_desc[i]) {
3903                         ext4_msg(sb, KERN_ERR,
3904                                "can't read group descriptor %d", i);
3905                         db_count = i;
3906                         goto failed_mount2;
3907                 }
3908         }
3909         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3910                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3911                 goto failed_mount2;
3912         }
3913
3914         sbi->s_gdb_count = db_count;
3915         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3916         spin_lock_init(&sbi->s_next_gen_lock);
3917
3918         init_timer(&sbi->s_err_report);
3919         sbi->s_err_report.function = print_daily_error_info;
3920         sbi->s_err_report.data = (unsigned long) sb;
3921
3922         /* Register extent status tree shrinker */
3923         if (ext4_es_register_shrinker(sbi))
3924                 goto failed_mount3;
3925
3926         sbi->s_stripe = ext4_get_stripe_size(sbi);
3927         sbi->s_extent_max_zeroout_kb = 32;
3928
3929         /*
3930          * set up enough so that it can read an inode
3931          */
3932         sb->s_op = &ext4_sops;
3933         sb->s_export_op = &ext4_export_ops;
3934         sb->s_xattr = ext4_xattr_handlers;
3935 #ifdef CONFIG_QUOTA
3936         sb->dq_op = &ext4_quota_operations;
3937         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3938                 sb->s_qcop = &ext4_qctl_sysfile_operations;
3939         else
3940                 sb->s_qcop = &ext4_qctl_operations;
3941         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
3942 #endif
3943         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3944
3945         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3946         mutex_init(&sbi->s_orphan_lock);
3947
3948         sb->s_root = NULL;
3949
3950         needs_recovery = (es->s_last_orphan != 0 ||
3951                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3952                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3953
3954         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3955             !(sb->s_flags & MS_RDONLY))
3956                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3957                         goto failed_mount3a;
3958
3959         /*
3960          * The first inode we look at is the journal inode.  Don't try
3961          * root first: it may be modified in the journal!
3962          */
3963         if (!test_opt(sb, NOLOAD) &&
3964             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3965                 if (ext4_load_journal(sb, es, journal_devnum))
3966                         goto failed_mount3a;
3967         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3968               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3969                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3970                        "suppressed and not mounted read-only");
3971                 goto failed_mount_wq;
3972         } else {
3973                 clear_opt(sb, DATA_FLAGS);
3974                 sbi->s_journal = NULL;
3975                 needs_recovery = 0;
3976                 goto no_journal;
3977         }
3978
3979         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3980             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3981                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3982                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3983                 goto failed_mount_wq;
3984         }
3985
3986         if (!set_journal_csum_feature_set(sb)) {
3987                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3988                          "feature set");
3989                 goto failed_mount_wq;
3990         }
3991
3992         /* We have now updated the journal if required, so we can
3993          * validate the data journaling mode. */
3994         switch (test_opt(sb, DATA_FLAGS)) {
3995         case 0:
3996                 /* No mode set, assume a default based on the journal
3997                  * capabilities: ORDERED_DATA if the journal can
3998                  * cope, else JOURNAL_DATA
3999                  */
4000                 if (jbd2_journal_check_available_features
4001                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4002                         set_opt(sb, ORDERED_DATA);
4003                 else
4004                         set_opt(sb, JOURNAL_DATA);
4005                 break;
4006
4007         case EXT4_MOUNT_ORDERED_DATA:
4008         case EXT4_MOUNT_WRITEBACK_DATA:
4009                 if (!jbd2_journal_check_available_features
4010                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4011                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4012                                "requested data journaling mode");
4013                         goto failed_mount_wq;
4014                 }
4015         default:
4016                 break;
4017         }
4018         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4019
4020         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4021
4022 no_journal:
4023         if (ext4_mballoc_ready) {
4024                 sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
4025                 if (!sbi->s_mb_cache) {
4026                         ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4027                         goto failed_mount_wq;
4028                 }
4029         }
4030
4031         /*
4032          * Get the # of file system overhead blocks from the
4033          * superblock if present.
4034          */
4035         if (es->s_overhead_clusters)
4036                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4037         else {
4038                 err = ext4_calculate_overhead(sb);
4039                 if (err)
4040                         goto failed_mount_wq;
4041         }
4042
4043         /*
4044          * The maximum number of concurrent works can be high and
4045          * concurrency isn't really necessary.  Limit it to 1.
4046          */
4047         EXT4_SB(sb)->rsv_conversion_wq =
4048                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4049         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4050                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4051                 ret = -ENOMEM;
4052                 goto failed_mount4;
4053         }
4054
4055         /*
4056          * The jbd2_journal_load will have done any necessary log recovery,
4057          * so we can safely mount the rest of the filesystem now.
4058          */
4059
4060         root = ext4_iget(sb, EXT4_ROOT_INO);
4061         if (IS_ERR(root)) {
4062                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4063                 ret = PTR_ERR(root);
4064                 root = NULL;
4065                 goto failed_mount4;
4066         }
4067         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4068                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4069                 iput(root);
4070                 goto failed_mount4;
4071         }
4072         sb->s_root = d_make_root(root);
4073         if (!sb->s_root) {
4074                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4075                 ret = -ENOMEM;
4076                 goto failed_mount4;
4077         }
4078
4079         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4080                 sb->s_flags |= MS_RDONLY;
4081
4082         /* determine the minimum size of new large inodes, if present */
4083         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4084                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4085                                                      EXT4_GOOD_OLD_INODE_SIZE;
4086                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4087                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4088                         if (sbi->s_want_extra_isize <
4089                             le16_to_cpu(es->s_want_extra_isize))
4090                                 sbi->s_want_extra_isize =
4091                                         le16_to_cpu(es->s_want_extra_isize);
4092                         if (sbi->s_want_extra_isize <
4093                             le16_to_cpu(es->s_min_extra_isize))
4094                                 sbi->s_want_extra_isize =
4095                                         le16_to_cpu(es->s_min_extra_isize);
4096                 }
4097         }
4098         /* Check if enough inode space is available */
4099         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4100                                                         sbi->s_inode_size) {
4101                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4102                                                        EXT4_GOOD_OLD_INODE_SIZE;
4103                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4104                          "available");
4105         }
4106
4107         err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4108         if (err) {
4109                 ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4110                          "reserved pool", ext4_calculate_resv_clusters(sb));
4111                 goto failed_mount4a;
4112         }
4113
4114         err = ext4_setup_system_zone(sb);
4115         if (err) {
4116                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4117                          "zone (%d)", err);
4118                 goto failed_mount4a;
4119         }
4120
4121         ext4_ext_init(sb);
4122         err = ext4_mb_init(sb);
4123         if (err) {
4124                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4125                          err);
4126                 goto failed_mount5;
4127         }
4128
4129         block = ext4_count_free_clusters(sb);
4130         ext4_free_blocks_count_set(sbi->s_es,
4131                                    EXT4_C2B(sbi, block));
4132         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4133                                   GFP_KERNEL);
4134         if (!err) {
4135                 unsigned long freei = ext4_count_free_inodes(sb);
4136                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4137                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4138                                           GFP_KERNEL);
4139         }
4140         if (!err)
4141                 err = percpu_counter_init(&sbi->s_dirs_counter,
4142                                           ext4_count_dirs(sb), GFP_KERNEL);
4143         if (!err)
4144                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4145                                           GFP_KERNEL);
4146         if (err) {
4147                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4148                 goto failed_mount6;
4149         }
4150
4151         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
4152                 if (!ext4_fill_flex_info(sb)) {
4153                         ext4_msg(sb, KERN_ERR,
4154                                "unable to initialize "
4155                                "flex_bg meta info!");
4156                         goto failed_mount6;
4157                 }
4158
4159         err = ext4_register_li_request(sb, first_not_zeroed);
4160         if (err)
4161                 goto failed_mount6;
4162
4163         sbi->s_kobj.kset = ext4_kset;
4164         init_completion(&sbi->s_kobj_unregister);
4165         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4166                                    "%s", sb->s_id);
4167         if (err)
4168                 goto failed_mount7;
4169
4170 #ifdef CONFIG_QUOTA
4171         /* Enable quota usage during mount. */
4172         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4173             !(sb->s_flags & MS_RDONLY)) {
4174                 err = ext4_enable_quotas(sb);
4175                 if (err)
4176                         goto failed_mount8;
4177         }
4178 #endif  /* CONFIG_QUOTA */
4179
4180         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4181         ext4_orphan_cleanup(sb, es);
4182         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4183         if (needs_recovery) {
4184                 ext4_msg(sb, KERN_INFO, "recovery complete");
4185                 ext4_mark_recovery_complete(sb, es);
4186         }
4187         if (EXT4_SB(sb)->s_journal) {
4188                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4189                         descr = " journalled data mode";
4190                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4191                         descr = " ordered data mode";
4192                 else
4193                         descr = " writeback data mode";
4194         } else
4195                 descr = "out journal";
4196
4197         if (test_opt(sb, DISCARD)) {
4198                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4199                 if (!blk_queue_discard(q))
4200                         ext4_msg(sb, KERN_WARNING,
4201                                  "mounting with \"discard\" option, but "
4202                                  "the device does not support discard");
4203         }
4204
4205         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4206                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4207                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4208
4209         if (es->s_error_count)
4210                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4211
4212         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4213         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4214         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4215         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4216
4217         kfree(orig_data);
4218         return 0;
4219
4220 cantfind_ext4:
4221         if (!silent)
4222                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4223         goto failed_mount;
4224
4225 #ifdef CONFIG_QUOTA
4226 failed_mount8:
4227         kobject_del(&sbi->s_kobj);
4228 #endif
4229 failed_mount7:
4230         ext4_unregister_li_request(sb);
4231 failed_mount6:
4232         ext4_mb_release(sb);
4233         if (sbi->s_flex_groups)
4234                 kvfree(sbi->s_flex_groups);
4235         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4236         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4237         percpu_counter_destroy(&sbi->s_dirs_counter);
4238         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4239 failed_mount5:
4240         ext4_ext_release(sb);
4241         ext4_release_system_zone(sb);
4242 failed_mount4a:
4243         dput(sb->s_root);
4244         sb->s_root = NULL;
4245 failed_mount4:
4246         ext4_msg(sb, KERN_ERR, "mount failed");
4247         if (EXT4_SB(sb)->rsv_conversion_wq)
4248                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4249 failed_mount_wq:
4250         if (sbi->s_journal) {
4251                 jbd2_journal_destroy(sbi->s_journal);
4252                 sbi->s_journal = NULL;
4253         }
4254 failed_mount3a:
4255         ext4_es_unregister_shrinker(sbi);
4256 failed_mount3:
4257         del_timer_sync(&sbi->s_err_report);
4258         if (sbi->s_mmp_tsk)
4259                 kthread_stop(sbi->s_mmp_tsk);
4260 failed_mount2:
4261         for (i = 0; i < db_count; i++)
4262                 brelse(sbi->s_group_desc[i]);
4263         kvfree(sbi->s_group_desc);
4264 failed_mount:
4265         if (sbi->s_chksum_driver)
4266                 crypto_free_shash(sbi->s_chksum_driver);
4267         if (sbi->s_proc) {
4268                 remove_proc_entry("options", sbi->s_proc);
4269                 remove_proc_entry(sb->s_id, ext4_proc_root);
4270         }
4271 #ifdef CONFIG_QUOTA
4272         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4273                 kfree(sbi->s_qf_names[i]);
4274 #endif
4275         ext4_blkdev_remove(sbi);
4276         brelse(bh);
4277 out_fail:
4278         sb->s_fs_info = NULL;
4279         kfree(sbi->s_blockgroup_lock);
4280         kfree(sbi);
4281 out_free_orig:
4282         kfree(orig_data);
4283         return err ? err : ret;
4284 }
4285
4286 /*
4287  * Setup any per-fs journal parameters now.  We'll do this both on
4288  * initial mount, once the journal has been initialised but before we've
4289  * done any recovery; and again on any subsequent remount.
4290  */
4291 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4292 {
4293         struct ext4_sb_info *sbi = EXT4_SB(sb);
4294
4295         journal->j_commit_interval = sbi->s_commit_interval;
4296         journal->j_min_batch_time = sbi->s_min_batch_time;
4297         journal->j_max_batch_time = sbi->s_max_batch_time;
4298
4299         write_lock(&journal->j_state_lock);
4300         if (test_opt(sb, BARRIER))
4301                 journal->j_flags |= JBD2_BARRIER;
4302         else
4303                 journal->j_flags &= ~JBD2_BARRIER;
4304         if (test_opt(sb, DATA_ERR_ABORT))
4305                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4306         else
4307                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4308         write_unlock(&journal->j_state_lock);
4309 }
4310
4311 static journal_t *ext4_get_journal(struct super_block *sb,
4312                                    unsigned int journal_inum)
4313 {
4314         struct inode *journal_inode;
4315         journal_t *journal;
4316
4317         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4318
4319         /* First, test for the existence of a valid inode on disk.  Bad
4320          * things happen if we iget() an unused inode, as the subsequent
4321          * iput() will try to delete it. */
4322
4323         journal_inode = ext4_iget(sb, journal_inum);
4324         if (IS_ERR(journal_inode)) {
4325                 ext4_msg(sb, KERN_ERR, "no journal found");
4326                 return NULL;
4327         }
4328         if (!journal_inode->i_nlink) {
4329                 make_bad_inode(journal_inode);
4330                 iput(journal_inode);
4331                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4332                 return NULL;
4333         }
4334
4335         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4336                   journal_inode, journal_inode->i_size);
4337         if (!S_ISREG(journal_inode->i_mode)) {
4338                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4339                 iput(journal_inode);
4340                 return NULL;
4341         }
4342
4343         journal = jbd2_journal_init_inode(journal_inode);
4344         if (!journal) {
4345                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4346                 iput(journal_inode);
4347                 return NULL;
4348         }
4349         journal->j_private = sb;
4350         ext4_init_journal_params(sb, journal);
4351         return journal;
4352 }
4353
4354 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4355                                        dev_t j_dev)
4356 {
4357         struct buffer_head *bh;
4358         journal_t *journal;
4359         ext4_fsblk_t start;
4360         ext4_fsblk_t len;
4361         int hblock, blocksize;
4362         ext4_fsblk_t sb_block;
4363         unsigned long offset;
4364         struct ext4_super_block *es;
4365         struct block_device *bdev;
4366
4367         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4368
4369         bdev = ext4_blkdev_get(j_dev, sb);
4370         if (bdev == NULL)
4371                 return NULL;
4372
4373         blocksize = sb->s_blocksize;
4374         hblock = bdev_logical_block_size(bdev);
4375         if (blocksize < hblock) {
4376                 ext4_msg(sb, KERN_ERR,
4377                         "blocksize too small for journal device");
4378                 goto out_bdev;
4379         }
4380
4381         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4382         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4383         set_blocksize(bdev, blocksize);
4384         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4385                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4386                        "external journal");
4387                 goto out_bdev;
4388         }
4389
4390         es = (struct ext4_super_block *) (bh->b_data + offset);
4391         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4392             !(le32_to_cpu(es->s_feature_incompat) &
4393               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4394                 ext4_msg(sb, KERN_ERR, "external journal has "
4395                                         "bad superblock");
4396                 brelse(bh);
4397                 goto out_bdev;
4398         }
4399
4400         if ((le32_to_cpu(es->s_feature_ro_compat) &
4401              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4402             es->s_checksum != ext4_superblock_csum(sb, es)) {
4403                 ext4_msg(sb, KERN_ERR, "external journal has "
4404                                        "corrupt superblock");
4405                 brelse(bh);
4406                 goto out_bdev;
4407         }
4408
4409         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4410                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4411                 brelse(bh);
4412                 goto out_bdev;
4413         }
4414
4415         len = ext4_blocks_count(es);
4416         start = sb_block + 1;
4417         brelse(bh);     /* we're done with the superblock */
4418
4419         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4420                                         start, len, blocksize);
4421         if (!journal) {
4422                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4423                 goto out_bdev;
4424         }
4425         journal->j_private = sb;
4426         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4427         wait_on_buffer(journal->j_sb_buffer);
4428         if (!buffer_uptodate(journal->j_sb_buffer)) {
4429                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4430                 goto out_journal;
4431         }
4432         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4433                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4434                                         "user (unsupported) - %d",
4435                         be32_to_cpu(journal->j_superblock->s_nr_users));
4436                 goto out_journal;
4437         }
4438         EXT4_SB(sb)->journal_bdev = bdev;
4439         ext4_init_journal_params(sb, journal);
4440         return journal;
4441
4442 out_journal:
4443         jbd2_journal_destroy(journal);
4444 out_bdev:
4445         ext4_blkdev_put(bdev);
4446         return NULL;
4447 }
4448
4449 static int ext4_load_journal(struct super_block *sb,
4450                              struct ext4_super_block *es,
4451                              unsigned long journal_devnum)
4452 {
4453         journal_t *journal;
4454         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4455         dev_t journal_dev;
4456         int err = 0;
4457         int really_read_only;
4458
4459         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4460
4461         if (journal_devnum &&
4462             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4463                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4464                         "numbers have changed");
4465                 journal_dev = new_decode_dev(journal_devnum);
4466         } else
4467                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4468
4469         really_read_only = bdev_read_only(sb->s_bdev);
4470
4471         /*
4472          * Are we loading a blank journal or performing recovery after a
4473          * crash?  For recovery, we need to check in advance whether we
4474          * can get read-write access to the device.
4475          */
4476         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4477                 if (sb->s_flags & MS_RDONLY) {
4478                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4479                                         "required on readonly filesystem");
4480                         if (really_read_only) {
4481                                 ext4_msg(sb, KERN_ERR, "write access "
4482                                         "unavailable, cannot proceed");
4483                                 return -EROFS;
4484                         }
4485                         ext4_msg(sb, KERN_INFO, "write access will "
4486                                "be enabled during recovery");
4487                 }
4488         }
4489
4490         if (journal_inum && journal_dev) {
4491                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4492                        "and inode journals!");
4493                 return -EINVAL;
4494         }
4495
4496         if (journal_inum) {
4497                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4498                         return -EINVAL;
4499         } else {
4500                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4501                         return -EINVAL;
4502         }
4503
4504         if (!(journal->j_flags & JBD2_BARRIER))
4505                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4506
4507         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4508                 err = jbd2_journal_wipe(journal, !really_read_only);
4509         if (!err) {
4510                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4511                 if (save)
4512                         memcpy(save, ((char *) es) +
4513                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4514                 err = jbd2_journal_load(journal);
4515                 if (save)
4516                         memcpy(((char *) es) + EXT4_S_ERR_START,
4517                                save, EXT4_S_ERR_LEN);
4518                 kfree(save);
4519         }
4520
4521         if (err) {
4522                 ext4_msg(sb, KERN_ERR, "error loading journal");
4523                 jbd2_journal_destroy(journal);
4524                 return err;
4525         }
4526
4527         EXT4_SB(sb)->s_journal = journal;
4528         ext4_clear_journal_err(sb, es);
4529
4530         if (!really_read_only && journal_devnum &&
4531             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4532                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4533
4534                 /* Make sure we flush the recovery flag to disk. */
4535                 ext4_commit_super(sb, 1);
4536         }
4537
4538         return 0;
4539 }
4540
4541 static int ext4_commit_super(struct super_block *sb, int sync)
4542 {
4543         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4544         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4545         int error = 0;
4546
4547         if (!sbh || block_device_ejected(sb))
4548                 return error;
4549         if (buffer_write_io_error(sbh)) {
4550                 /*
4551                  * Oh, dear.  A previous attempt to write the
4552                  * superblock failed.  This could happen because the
4553                  * USB device was yanked out.  Or it could happen to
4554                  * be a transient write error and maybe the block will
4555                  * be remapped.  Nothing we can do but to retry the
4556                  * write and hope for the best.
4557                  */
4558                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4559                        "superblock detected");
4560                 clear_buffer_write_io_error(sbh);
4561                 set_buffer_uptodate(sbh);
4562         }
4563         /*
4564          * If the file system is mounted read-only, don't update the
4565          * superblock write time.  This avoids updating the superblock
4566          * write time when we are mounting the root file system
4567          * read/only but we need to replay the journal; at that point,
4568          * for people who are east of GMT and who make their clock
4569          * tick in localtime for Windows bug-for-bug compatibility,
4570          * the clock is set in the future, and this will cause e2fsck
4571          * to complain and force a full file system check.
4572          */
4573         if (!(sb->s_flags & MS_RDONLY))
4574                 es->s_wtime = cpu_to_le32(get_seconds());
4575         if (sb->s_bdev->bd_part)
4576                 es->s_kbytes_written =
4577                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4578                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4579                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4580         else
4581                 es->s_kbytes_written =
4582                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4583         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4584                 ext4_free_blocks_count_set(es,
4585                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4586                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4587         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4588                 es->s_free_inodes_count =
4589                         cpu_to_le32(percpu_counter_sum_positive(
4590                                 &EXT4_SB(sb)->s_freeinodes_counter));
4591         BUFFER_TRACE(sbh, "marking dirty");
4592         ext4_superblock_csum_set(sb);
4593         mark_buffer_dirty(sbh);
4594         if (sync) {
4595                 error = sync_dirty_buffer(sbh);
4596                 if (error)
4597                         return error;
4598
4599                 error = buffer_write_io_error(sbh);
4600                 if (error) {
4601                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4602                                "superblock");
4603                         clear_buffer_write_io_error(sbh);
4604                         set_buffer_uptodate(sbh);
4605                 }
4606         }
4607         return error;
4608 }
4609
4610 /*
4611  * Have we just finished recovery?  If so, and if we are mounting (or
4612  * remounting) the filesystem readonly, then we will end up with a
4613  * consistent fs on disk.  Record that fact.
4614  */
4615 static void ext4_mark_recovery_complete(struct super_block *sb,
4616                                         struct ext4_super_block *es)
4617 {
4618         journal_t *journal = EXT4_SB(sb)->s_journal;
4619
4620         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4621                 BUG_ON(journal != NULL);
4622                 return;
4623         }
4624         jbd2_journal_lock_updates(journal);
4625         if (jbd2_journal_flush(journal) < 0)
4626                 goto out;
4627
4628         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4629             sb->s_flags & MS_RDONLY) {
4630                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4631                 ext4_commit_super(sb, 1);
4632         }
4633
4634 out:
4635         jbd2_journal_unlock_updates(journal);
4636 }
4637
4638 /*
4639  * If we are mounting (or read-write remounting) a filesystem whose journal
4640  * has recorded an error from a previous lifetime, move that error to the
4641  * main filesystem now.
4642  */
4643 static void ext4_clear_journal_err(struct super_block *sb,
4644                                    struct ext4_super_block *es)
4645 {
4646         journal_t *journal;
4647         int j_errno;
4648         const char *errstr;
4649
4650         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4651
4652         journal = EXT4_SB(sb)->s_journal;
4653
4654         /*
4655          * Now check for any error status which may have been recorded in the
4656          * journal by a prior ext4_error() or ext4_abort()
4657          */
4658
4659         j_errno = jbd2_journal_errno(journal);
4660         if (j_errno) {
4661                 char nbuf[16];
4662
4663                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4664                 ext4_warning(sb, "Filesystem error recorded "
4665                              "from previous mount: %s", errstr);
4666                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4667
4668                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4669                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4670                 ext4_commit_super(sb, 1);
4671
4672                 jbd2_journal_clear_err(journal);
4673                 jbd2_journal_update_sb_errno(journal);
4674         }
4675 }
4676
4677 /*
4678  * Force the running and committing transactions to commit,
4679  * and wait on the commit.
4680  */
4681 int ext4_force_commit(struct super_block *sb)
4682 {
4683         journal_t *journal;
4684
4685         if (sb->s_flags & MS_RDONLY)
4686                 return 0;
4687
4688         journal = EXT4_SB(sb)->s_journal;
4689         return ext4_journal_force_commit(journal);
4690 }
4691
4692 static int ext4_sync_fs(struct super_block *sb, int wait)
4693 {
4694         int ret = 0;
4695         tid_t target;
4696         bool needs_barrier = false;
4697         struct ext4_sb_info *sbi = EXT4_SB(sb);
4698
4699         trace_ext4_sync_fs(sb, wait);
4700         flush_workqueue(sbi->rsv_conversion_wq);
4701         /*
4702          * Writeback quota in non-journalled quota case - journalled quota has
4703          * no dirty dquots
4704          */
4705         dquot_writeback_dquots(sb, -1);
4706         /*
4707          * Data writeback is possible w/o journal transaction, so barrier must
4708          * being sent at the end of the function. But we can skip it if
4709          * transaction_commit will do it for us.
4710          */
4711         if (sbi->s_journal) {
4712                 target = jbd2_get_latest_transaction(sbi->s_journal);
4713                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4714                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4715                         needs_barrier = true;
4716
4717                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4718                         if (wait)
4719                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4720                                                            target);
4721                 }
4722         } else if (wait && test_opt(sb, BARRIER))
4723                 needs_barrier = true;
4724         if (needs_barrier) {
4725                 int err;
4726                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4727                 if (!ret)
4728                         ret = err;
4729         }
4730
4731         return ret;
4732 }
4733
4734 /*
4735  * LVM calls this function before a (read-only) snapshot is created.  This
4736  * gives us a chance to flush the journal completely and mark the fs clean.
4737  *
4738  * Note that only this function cannot bring a filesystem to be in a clean
4739  * state independently. It relies on upper layer to stop all data & metadata
4740  * modifications.
4741  */
4742 static int ext4_freeze(struct super_block *sb)
4743 {
4744         int error = 0;
4745         journal_t *journal;
4746
4747         if (sb->s_flags & MS_RDONLY)
4748                 return 0;
4749
4750         journal = EXT4_SB(sb)->s_journal;
4751
4752         if (journal) {
4753                 /* Now we set up the journal barrier. */
4754                 jbd2_journal_lock_updates(journal);
4755
4756                 /*
4757                  * Don't clear the needs_recovery flag if we failed to
4758                  * flush the journal.
4759                  */
4760                 error = jbd2_journal_flush(journal);
4761                 if (error < 0)
4762                         goto out;
4763         }
4764
4765         /* Journal blocked and flushed, clear needs_recovery flag. */
4766         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4767         error = ext4_commit_super(sb, 1);
4768 out:
4769         if (journal)
4770                 /* we rely on upper layer to stop further updates */
4771                 jbd2_journal_unlock_updates(journal);
4772         return error;
4773 }
4774
4775 /*
4776  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4777  * flag here, even though the filesystem is not technically dirty yet.
4778  */
4779 static int ext4_unfreeze(struct super_block *sb)
4780 {
4781         if (sb->s_flags & MS_RDONLY)
4782                 return 0;
4783
4784         /* Reset the needs_recovery flag before the fs is unlocked. */
4785         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4786         ext4_commit_super(sb, 1);
4787         return 0;
4788 }
4789
4790 /*
4791  * Structure to save mount options for ext4_remount's benefit
4792  */
4793 struct ext4_mount_options {
4794         unsigned long s_mount_opt;
4795         unsigned long s_mount_opt2;
4796         kuid_t s_resuid;
4797         kgid_t s_resgid;
4798         unsigned long s_commit_interval;
4799         u32 s_min_batch_time, s_max_batch_time;
4800 #ifdef CONFIG_QUOTA
4801         int s_jquota_fmt;
4802         char *s_qf_names[EXT4_MAXQUOTAS];
4803 #endif
4804 };
4805
4806 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4807 {
4808         struct ext4_super_block *es;
4809         struct ext4_sb_info *sbi = EXT4_SB(sb);
4810         unsigned long old_sb_flags;
4811         struct ext4_mount_options old_opts;
4812         int enable_quota = 0;
4813         ext4_group_t g;
4814         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4815         int err = 0;
4816 #ifdef CONFIG_QUOTA
4817         int i, j;
4818 #endif
4819         char *orig_data = kstrdup(data, GFP_KERNEL);
4820
4821         /* Store the original options */
4822         old_sb_flags = sb->s_flags;
4823         old_opts.s_mount_opt = sbi->s_mount_opt;
4824         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4825         old_opts.s_resuid = sbi->s_resuid;
4826         old_opts.s_resgid = sbi->s_resgid;
4827         old_opts.s_commit_interval = sbi->s_commit_interval;
4828         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4829         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4830 #ifdef CONFIG_QUOTA
4831         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4832         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4833                 if (sbi->s_qf_names[i]) {
4834                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4835                                                          GFP_KERNEL);
4836                         if (!old_opts.s_qf_names[i]) {
4837                                 for (j = 0; j < i; j++)
4838                                         kfree(old_opts.s_qf_names[j]);
4839                                 kfree(orig_data);
4840                                 return -ENOMEM;
4841                         }
4842                 } else
4843                         old_opts.s_qf_names[i] = NULL;
4844 #endif
4845         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4846                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4847
4848         /*
4849          * Allow the "check" option to be passed as a remount option.
4850          */
4851         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4852                 err = -EINVAL;
4853                 goto restore_opts;
4854         }
4855
4856         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4857             test_opt(sb, JOURNAL_CHECKSUM)) {
4858                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4859                          "during remount not supported");
4860                 err = -EINVAL;
4861                 goto restore_opts;
4862         }
4863
4864         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4865             test_opt(sb, JOURNAL_CHECKSUM)) {
4866                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4867                          "during remount not supported");
4868                 err = -EINVAL;
4869                 goto restore_opts;
4870         }
4871
4872         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4873                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4874                         ext4_msg(sb, KERN_ERR, "can't mount with "
4875                                  "both data=journal and delalloc");
4876                         err = -EINVAL;
4877                         goto restore_opts;
4878                 }
4879                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4880                         ext4_msg(sb, KERN_ERR, "can't mount with "
4881                                  "both data=journal and dioread_nolock");
4882                         err = -EINVAL;
4883                         goto restore_opts;
4884                 }
4885         }
4886
4887         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4888                 ext4_abort(sb, "Abort forced by user");
4889
4890         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4891                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4892
4893         es = sbi->s_es;
4894
4895         if (sbi->s_journal) {
4896                 ext4_init_journal_params(sb, sbi->s_journal);
4897                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4898         }
4899
4900         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4901                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4902                         err = -EROFS;
4903                         goto restore_opts;
4904                 }
4905
4906                 if (*flags & MS_RDONLY) {
4907                         err = sync_filesystem(sb);
4908                         if (err < 0)
4909                                 goto restore_opts;
4910                         err = dquot_suspend(sb, -1);
4911                         if (err < 0)
4912                                 goto restore_opts;
4913
4914                         /*
4915                          * First of all, the unconditional stuff we have to do
4916                          * to disable replay of the journal when we next remount
4917                          */
4918                         sb->s_flags |= MS_RDONLY;
4919
4920                         /*
4921                          * OK, test if we are remounting a valid rw partition
4922                          * readonly, and if so set the rdonly flag and then
4923                          * mark the partition as valid again.
4924                          */
4925                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4926                             (sbi->s_mount_state & EXT4_VALID_FS))
4927                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4928
4929                         if (sbi->s_journal)
4930                                 ext4_mark_recovery_complete(sb, es);
4931                 } else {
4932                         /* Make sure we can mount this feature set readwrite */
4933                         if (!ext4_feature_set_ok(sb, 0)) {
4934                                 err = -EROFS;
4935                                 goto restore_opts;
4936                         }
4937                         /*
4938                          * Make sure the group descriptor checksums
4939                          * are sane.  If they aren't, refuse to remount r/w.
4940                          */
4941                         for (g = 0; g < sbi->s_groups_count; g++) {
4942                                 struct ext4_group_desc *gdp =
4943                                         ext4_get_group_desc(sb, g, NULL);
4944
4945                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4946                                         ext4_msg(sb, KERN_ERR,
4947                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4948                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4949                                                le16_to_cpu(gdp->bg_checksum));
4950                                         err = -EINVAL;
4951                                         goto restore_opts;
4952                                 }
4953                         }
4954
4955                         /*
4956                          * If we have an unprocessed orphan list hanging
4957                          * around from a previously readonly bdev mount,
4958                          * require a full umount/remount for now.
4959                          */
4960                         if (es->s_last_orphan) {
4961                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4962                                        "remount RDWR because of unprocessed "
4963                                        "orphan inode list.  Please "
4964                                        "umount/remount instead");
4965                                 err = -EINVAL;
4966                                 goto restore_opts;
4967                         }
4968
4969                         /*
4970                          * Mounting a RDONLY partition read-write, so reread
4971                          * and store the current valid flag.  (It may have
4972                          * been changed by e2fsck since we originally mounted
4973                          * the partition.)
4974                          */
4975                         if (sbi->s_journal)
4976                                 ext4_clear_journal_err(sb, es);
4977                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4978                         if (!ext4_setup_super(sb, es, 0))
4979                                 sb->s_flags &= ~MS_RDONLY;
4980                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4981                                                      EXT4_FEATURE_INCOMPAT_MMP))
4982                                 if (ext4_multi_mount_protect(sb,
4983                                                 le64_to_cpu(es->s_mmp_block))) {
4984                                         err = -EROFS;
4985                                         goto restore_opts;
4986                                 }
4987                         enable_quota = 1;
4988                 }
4989         }
4990
4991         /*
4992          * Reinitialize lazy itable initialization thread based on
4993          * current settings
4994          */
4995         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4996                 ext4_unregister_li_request(sb);
4997         else {
4998                 ext4_group_t first_not_zeroed;
4999                 first_not_zeroed = ext4_has_uninit_itable(sb);
5000                 ext4_register_li_request(sb, first_not_zeroed);
5001         }
5002
5003         ext4_setup_system_zone(sb);
5004         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5005                 ext4_commit_super(sb, 1);
5006
5007 #ifdef CONFIG_QUOTA
5008         /* Release old quota file names */
5009         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5010                 kfree(old_opts.s_qf_names[i]);
5011         if (enable_quota) {
5012                 if (sb_any_quota_suspended(sb))
5013                         dquot_resume(sb, -1);
5014                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
5015                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
5016                         err = ext4_enable_quotas(sb);
5017                         if (err)
5018                                 goto restore_opts;
5019                 }
5020         }
5021 #endif
5022
5023         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5024         kfree(orig_data);
5025         return 0;
5026
5027 restore_opts:
5028         sb->s_flags = old_sb_flags;
5029         sbi->s_mount_opt = old_opts.s_mount_opt;
5030         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5031         sbi->s_resuid = old_opts.s_resuid;
5032         sbi->s_resgid = old_opts.s_resgid;
5033         sbi->s_commit_interval = old_opts.s_commit_interval;
5034         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5035         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5036 #ifdef CONFIG_QUOTA
5037         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5038         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5039                 kfree(sbi->s_qf_names[i]);
5040                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5041         }
5042 #endif
5043         kfree(orig_data);
5044         return err;
5045 }
5046
5047 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5048 {
5049         struct super_block *sb = dentry->d_sb;
5050         struct ext4_sb_info *sbi = EXT4_SB(sb);
5051         struct ext4_super_block *es = sbi->s_es;
5052         ext4_fsblk_t overhead = 0, resv_blocks;
5053         u64 fsid;
5054         s64 bfree;
5055         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5056
5057         if (!test_opt(sb, MINIX_DF))
5058                 overhead = sbi->s_overhead;
5059
5060         buf->f_type = EXT4_SUPER_MAGIC;
5061         buf->f_bsize = sb->s_blocksize;
5062         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5063         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5064                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5065         /* prevent underflow in case that few free space is available */
5066         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5067         buf->f_bavail = buf->f_bfree -
5068                         (ext4_r_blocks_count(es) + resv_blocks);
5069         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5070                 buf->f_bavail = 0;
5071         buf->f_files = le32_to_cpu(es->s_inodes_count);
5072         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5073         buf->f_namelen = EXT4_NAME_LEN;
5074         fsid = le64_to_cpup((void *)es->s_uuid) ^
5075                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5076         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5077         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5078
5079         return 0;
5080 }
5081
5082 /* Helper function for writing quotas on sync - we need to start transaction
5083  * before quota file is locked for write. Otherwise the are possible deadlocks:
5084  * Process 1                         Process 2
5085  * ext4_create()                     quota_sync()
5086  *   jbd2_journal_start()                  write_dquot()
5087  *   dquot_initialize()                         down(dqio_mutex)
5088  *     down(dqio_mutex)                    jbd2_journal_start()
5089  *
5090  */
5091
5092 #ifdef CONFIG_QUOTA
5093
5094 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5095 {
5096         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5097 }
5098
5099 static int ext4_write_dquot(struct dquot *dquot)
5100 {
5101         int ret, err;
5102         handle_t *handle;
5103         struct inode *inode;
5104
5105         inode = dquot_to_inode(dquot);
5106         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5107                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5108         if (IS_ERR(handle))
5109                 return PTR_ERR(handle);
5110         ret = dquot_commit(dquot);
5111         err = ext4_journal_stop(handle);
5112         if (!ret)
5113                 ret = err;
5114         return ret;
5115 }
5116
5117 static int ext4_acquire_dquot(struct dquot *dquot)
5118 {
5119         int ret, err;
5120         handle_t *handle;
5121
5122         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5123                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5124         if (IS_ERR(handle))
5125                 return PTR_ERR(handle);
5126         ret = dquot_acquire(dquot);
5127         err = ext4_journal_stop(handle);
5128         if (!ret)
5129                 ret = err;
5130         return ret;
5131 }
5132
5133 static int ext4_release_dquot(struct dquot *dquot)
5134 {
5135         int ret, err;
5136         handle_t *handle;
5137
5138         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5139                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5140         if (IS_ERR(handle)) {
5141                 /* Release dquot anyway to avoid endless cycle in dqput() */
5142                 dquot_release(dquot);
5143                 return PTR_ERR(handle);
5144         }
5145         ret = dquot_release(dquot);
5146         err = ext4_journal_stop(handle);
5147         if (!ret)
5148                 ret = err;
5149         return ret;
5150 }
5151
5152 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5153 {
5154         struct super_block *sb = dquot->dq_sb;
5155         struct ext4_sb_info *sbi = EXT4_SB(sb);
5156
5157         /* Are we journaling quotas? */
5158         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5159             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5160                 dquot_mark_dquot_dirty(dquot);
5161                 return ext4_write_dquot(dquot);
5162         } else {
5163                 return dquot_mark_dquot_dirty(dquot);
5164         }
5165 }
5166
5167 static int ext4_write_info(struct super_block *sb, int type)
5168 {
5169         int ret, err;
5170         handle_t *handle;
5171
5172         /* Data block + inode block */
5173         handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5174         if (IS_ERR(handle))
5175                 return PTR_ERR(handle);
5176         ret = dquot_commit_info(sb, type);
5177         err = ext4_journal_stop(handle);
5178         if (!ret)
5179                 ret = err;
5180         return ret;
5181 }
5182
5183 /*
5184  * Turn on quotas during mount time - we need to find
5185  * the quota file and such...
5186  */
5187 static int ext4_quota_on_mount(struct super_block *sb, int type)
5188 {
5189         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5190                                         EXT4_SB(sb)->s_jquota_fmt, type);
5191 }
5192
5193 /*
5194  * Standard function to be called on quota_on
5195  */
5196 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5197                          struct path *path)
5198 {
5199         int err;
5200
5201         if (!test_opt(sb, QUOTA))
5202                 return -EINVAL;
5203
5204         /* Quotafile not on the same filesystem? */
5205         if (path->dentry->d_sb != sb)
5206                 return -EXDEV;
5207         /* Journaling quota? */
5208         if (EXT4_SB(sb)->s_qf_names[type]) {
5209                 /* Quotafile not in fs root? */
5210                 if (path->dentry->d_parent != sb->s_root)
5211                         ext4_msg(sb, KERN_WARNING,
5212                                 "Quota file not on filesystem root. "
5213                                 "Journaled quota will not work");
5214         }
5215
5216         /*
5217          * When we journal data on quota file, we have to flush journal to see
5218          * all updates to the file when we bypass pagecache...
5219          */
5220         if (EXT4_SB(sb)->s_journal &&
5221             ext4_should_journal_data(path->dentry->d_inode)) {
5222                 /*
5223                  * We don't need to lock updates but journal_flush() could
5224                  * otherwise be livelocked...
5225                  */
5226                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5227                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5228                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5229                 if (err)
5230                         return err;
5231         }
5232
5233         return dquot_quota_on(sb, type, format_id, path);
5234 }
5235
5236 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5237                              unsigned int flags)
5238 {
5239         int err;
5240         struct inode *qf_inode;
5241         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5242                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5243                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5244         };
5245
5246         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5247
5248         if (!qf_inums[type])
5249                 return -EPERM;
5250
5251         qf_inode = ext4_iget(sb, qf_inums[type]);
5252         if (IS_ERR(qf_inode)) {
5253                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5254                 return PTR_ERR(qf_inode);
5255         }
5256
5257         /* Don't account quota for quota files to avoid recursion */
5258         qf_inode->i_flags |= S_NOQUOTA;
5259         err = dquot_enable(qf_inode, type, format_id, flags);
5260         iput(qf_inode);
5261
5262         return err;
5263 }
5264
5265 /* Enable usage tracking for all quota types. */
5266 static int ext4_enable_quotas(struct super_block *sb)
5267 {
5268         int type, err = 0;
5269         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5270                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5271                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5272         };
5273
5274         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5275         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5276                 if (qf_inums[type]) {
5277                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5278                                                 DQUOT_USAGE_ENABLED);
5279                         if (err) {
5280                                 ext4_warning(sb,
5281                                         "Failed to enable quota tracking "
5282                                         "(type=%d, err=%d). Please run "
5283                                         "e2fsck to fix.", type, err);
5284                                 return err;
5285                         }
5286                 }
5287         }
5288         return 0;
5289 }
5290
5291 /*
5292  * quota_on function that is used when QUOTA feature is set.
5293  */
5294 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5295                                  int format_id)
5296 {
5297         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5298                 return -EINVAL;
5299
5300         /*
5301          * USAGE was enabled at mount time. Only need to enable LIMITS now.
5302          */
5303         return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5304 }
5305
5306 static int ext4_quota_off(struct super_block *sb, int type)
5307 {
5308         struct inode *inode = sb_dqopt(sb)->files[type];
5309         handle_t *handle;
5310
5311         /* Force all delayed allocation blocks to be allocated.
5312          * Caller already holds s_umount sem */
5313         if (test_opt(sb, DELALLOC))
5314                 sync_filesystem(sb);
5315
5316         if (!inode)
5317                 goto out;
5318
5319         /* Update modification times of quota files when userspace can
5320          * start looking at them */
5321         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5322         if (IS_ERR(handle))
5323                 goto out;
5324         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5325         ext4_mark_inode_dirty(handle, inode);
5326         ext4_journal_stop(handle);
5327
5328 out:
5329         return dquot_quota_off(sb, type);
5330 }
5331
5332 /*
5333  * quota_off function that is used when QUOTA feature is set.
5334  */
5335 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5336 {
5337         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5338                 return -EINVAL;
5339
5340         /* Disable only the limits. */
5341         return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5342 }
5343
5344 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5345  * acquiring the locks... As quota files are never truncated and quota code
5346  * itself serializes the operations (and no one else should touch the files)
5347  * we don't have to be afraid of races */
5348 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5349                                size_t len, loff_t off)
5350 {
5351         struct inode *inode = sb_dqopt(sb)->files[type];
5352         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5353         int offset = off & (sb->s_blocksize - 1);
5354         int tocopy;
5355         size_t toread;
5356         struct buffer_head *bh;
5357         loff_t i_size = i_size_read(inode);
5358
5359         if (off > i_size)
5360                 return 0;
5361         if (off+len > i_size)
5362                 len = i_size-off;
5363         toread = len;
5364         while (toread > 0) {
5365                 tocopy = sb->s_blocksize - offset < toread ?
5366                                 sb->s_blocksize - offset : toread;
5367                 bh = ext4_bread(NULL, inode, blk, 0);
5368                 if (IS_ERR(bh))
5369                         return PTR_ERR(bh);
5370                 if (!bh)        /* A hole? */
5371                         memset(data, 0, tocopy);
5372                 else
5373                         memcpy(data, bh->b_data+offset, tocopy);
5374                 brelse(bh);
5375                 offset = 0;
5376                 toread -= tocopy;
5377                 data += tocopy;
5378                 blk++;
5379         }
5380         return len;
5381 }
5382
5383 /* Write to quotafile (we know the transaction is already started and has
5384  * enough credits) */
5385 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5386                                 const char *data, size_t len, loff_t off)
5387 {
5388         struct inode *inode = sb_dqopt(sb)->files[type];
5389         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5390         int err, offset = off & (sb->s_blocksize - 1);
5391         struct buffer_head *bh;
5392         handle_t *handle = journal_current_handle();
5393
5394         if (EXT4_SB(sb)->s_journal && !handle) {
5395                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5396                         " cancelled because transaction is not started",
5397                         (unsigned long long)off, (unsigned long long)len);
5398                 return -EIO;
5399         }
5400         /*
5401          * Since we account only one data block in transaction credits,
5402          * then it is impossible to cross a block boundary.
5403          */
5404         if (sb->s_blocksize - offset < len) {
5405                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5406                         " cancelled because not block aligned",
5407                         (unsigned long long)off, (unsigned long long)len);
5408                 return -EIO;
5409         }
5410
5411         bh = ext4_bread(handle, inode, blk, 1);
5412         if (IS_ERR(bh))
5413                 return PTR_ERR(bh);
5414         if (!bh)
5415                 goto out;
5416         BUFFER_TRACE(bh, "get write access");
5417         err = ext4_journal_get_write_access(handle, bh);
5418         if (err) {
5419                 brelse(bh);
5420                 return err;
5421         }
5422         lock_buffer(bh);
5423         memcpy(bh->b_data+offset, data, len);
5424         flush_dcache_page(bh->b_page);
5425         unlock_buffer(bh);
5426         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5427         brelse(bh);
5428 out:
5429         if (inode->i_size < off + len) {
5430                 i_size_write(inode, off + len);
5431                 EXT4_I(inode)->i_disksize = inode->i_size;
5432                 ext4_mark_inode_dirty(handle, inode);
5433         }
5434         return len;
5435 }
5436
5437 #endif
5438
5439 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5440                        const char *dev_name, void *data)
5441 {
5442         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5443 }
5444
5445 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5446 static inline void register_as_ext2(void)
5447 {
5448         int err = register_filesystem(&ext2_fs_type);
5449         if (err)
5450                 printk(KERN_WARNING
5451                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5452 }
5453
5454 static inline void unregister_as_ext2(void)
5455 {
5456         unregister_filesystem(&ext2_fs_type);
5457 }
5458
5459 static inline int ext2_feature_set_ok(struct super_block *sb)
5460 {
5461         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5462                 return 0;
5463         if (sb->s_flags & MS_RDONLY)
5464                 return 1;
5465         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5466                 return 0;
5467         return 1;
5468 }
5469 #else
5470 static inline void register_as_ext2(void) { }
5471 static inline void unregister_as_ext2(void) { }
5472 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5473 #endif
5474
5475 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5476 static inline void register_as_ext3(void)
5477 {
5478         int err = register_filesystem(&ext3_fs_type);
5479         if (err)
5480                 printk(KERN_WARNING
5481                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5482 }
5483
5484 static inline void unregister_as_ext3(void)
5485 {
5486         unregister_filesystem(&ext3_fs_type);
5487 }
5488
5489 static inline int ext3_feature_set_ok(struct super_block *sb)
5490 {
5491         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5492                 return 0;
5493         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5494                 return 0;
5495         if (sb->s_flags & MS_RDONLY)
5496                 return 1;
5497         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5498                 return 0;
5499         return 1;
5500 }
5501 #else
5502 static inline void register_as_ext3(void) { }
5503 static inline void unregister_as_ext3(void) { }
5504 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5505 #endif
5506
5507 static struct file_system_type ext4_fs_type = {
5508         .owner          = THIS_MODULE,
5509         .name           = "ext4",
5510         .mount          = ext4_mount,
5511         .kill_sb        = kill_block_super,
5512         .fs_flags       = FS_REQUIRES_DEV,
5513 };
5514 MODULE_ALIAS_FS("ext4");
5515
5516 static int __init ext4_init_feat_adverts(void)
5517 {
5518         struct ext4_features *ef;
5519         int ret = -ENOMEM;
5520
5521         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5522         if (!ef)
5523                 goto out;
5524
5525         ef->f_kobj.kset = ext4_kset;
5526         init_completion(&ef->f_kobj_unregister);
5527         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5528                                    "features");
5529         if (ret) {
5530                 kfree(ef);
5531                 goto out;
5532         }
5533
5534         ext4_feat = ef;
5535         ret = 0;
5536 out:
5537         return ret;
5538 }
5539
5540 static void ext4_exit_feat_adverts(void)
5541 {
5542         kobject_put(&ext4_feat->f_kobj);
5543         wait_for_completion(&ext4_feat->f_kobj_unregister);
5544         kfree(ext4_feat);
5545 }
5546
5547 /* Shared across all ext4 file systems */
5548 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5549 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5550
5551 static int __init ext4_init_fs(void)
5552 {
5553         int i, err;
5554
5555         ext4_li_info = NULL;
5556         mutex_init(&ext4_li_mtx);
5557
5558         /* Build-time check for flags consistency */
5559         ext4_check_flag_values();
5560
5561         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5562                 mutex_init(&ext4__aio_mutex[i]);
5563                 init_waitqueue_head(&ext4__ioend_wq[i]);
5564         }
5565
5566         err = ext4_init_es();
5567         if (err)
5568                 return err;
5569
5570         err = ext4_init_pageio();
5571         if (err)
5572                 goto out7;
5573
5574         err = ext4_init_system_zone();
5575         if (err)
5576                 goto out6;
5577         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5578         if (!ext4_kset) {
5579                 err = -ENOMEM;
5580                 goto out5;
5581         }
5582         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5583
5584         err = ext4_init_feat_adverts();
5585         if (err)
5586                 goto out4;
5587
5588         err = ext4_init_mballoc();
5589         if (err)
5590                 goto out2;
5591         else
5592                 ext4_mballoc_ready = 1;
5593         err = init_inodecache();
5594         if (err)
5595                 goto out1;
5596         register_as_ext3();
5597         register_as_ext2();
5598         err = register_filesystem(&ext4_fs_type);
5599         if (err)
5600                 goto out;
5601
5602         return 0;
5603 out:
5604         unregister_as_ext2();
5605         unregister_as_ext3();
5606         destroy_inodecache();
5607 out1:
5608         ext4_mballoc_ready = 0;
5609         ext4_exit_mballoc();
5610 out2:
5611         ext4_exit_feat_adverts();
5612 out4:
5613         if (ext4_proc_root)
5614                 remove_proc_entry("fs/ext4", NULL);
5615         kset_unregister(ext4_kset);
5616 out5:
5617         ext4_exit_system_zone();
5618 out6:
5619         ext4_exit_pageio();
5620 out7:
5621         ext4_exit_es();
5622
5623         return err;
5624 }
5625
5626 static void __exit ext4_exit_fs(void)
5627 {
5628         ext4_destroy_lazyinit_thread();
5629         unregister_as_ext2();
5630         unregister_as_ext3();
5631         unregister_filesystem(&ext4_fs_type);
5632         destroy_inodecache();
5633         ext4_exit_mballoc();
5634         ext4_exit_feat_adverts();
5635         remove_proc_entry("fs/ext4", NULL);
5636         kset_unregister(ext4_kset);
5637         ext4_exit_system_zone();
5638         ext4_exit_pageio();
5639         ext4_exit_es();
5640 }
5641
5642 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5643 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5644 MODULE_LICENSE("GPL");
5645 module_init(ext4_init_fs)
5646 module_exit(ext4_exit_fs)