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
  63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  64                              unsigned long journal_devnum);
  65 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  66 static int ext4_commit_super(struct super_block *sb, int sync);
  67 static void ext4_mark_recovery_complete(struct super_block *sb,
  68                                         struct ext4_super_block *es);
  69 static void ext4_clear_journal_err(struct super_block *sb,
  70                                    struct ext4_super_block *es);
  71 static int ext4_sync_fs(struct super_block *sb, int wait);
  72 static int ext4_sync_fs_nojournal(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 int ext4_superblock_csum_verify(struct super_block *sb,
 141                                 struct ext4_super_block *es)
 142 {
 143         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 144                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 145                 return 1;
 146
 147         return es->s_checksum == ext4_superblock_csum(sb, es);
 148 }
 149
 150 void ext4_superblock_csum_set(struct super_block *sb)
 151 {
 152         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 153
 154         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 155                 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 156                 return;
 157
 158         es->s_checksum = ext4_superblock_csum(sb, es);
 159 }
 160
 161 void *ext4_kvmalloc(size_t size, gfp_t flags)
 162 {
 163         void *ret;
 164
 165         ret = kmalloc(size, flags);
 166         if (!ret)
 167                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 168         return ret;
 169 }
 170
 171 void *ext4_kvzalloc(size_t size, gfp_t flags)
 172 {
 173         void *ret;
 174
 175         ret = kzalloc(size, flags);
 176         if (!ret)
 177                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 178         return ret;
 179 }
 180
 181 void ext4_kvfree(void *ptr)
 182 {
 183         if (is_vmalloc_addr(ptr))
 184                 vfree(ptr);
 185         else
 186                 kfree(ptr);
 187
 188 }
 189
 190 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 191                                struct ext4_group_desc *bg)
 192 {
 193         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 194                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 195                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 196 }
 197
 198 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 199                                struct ext4_group_desc *bg)
 200 {
 201         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 202                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 203                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 204 }
 205
 206 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 207                               struct ext4_group_desc *bg)
 208 {
 209         return le32_to_cpu(bg->bg_inode_table_lo) |
 210                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 211                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 212 }
 213
 214 __u32 ext4_free_group_clusters(struct super_block *sb,
 215                                struct ext4_group_desc *bg)
 216 {
 217         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 218                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 219                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 220 }
 221
 222 __u32 ext4_free_inodes_count(struct super_block *sb,
 223                               struct ext4_group_desc *bg)
 224 {
 225         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 226                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 227                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 228 }
 229
 230 __u32 ext4_used_dirs_count(struct super_block *sb,
 231                               struct ext4_group_desc *bg)
 232 {
 233         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 234                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 235                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 236 }
 237
 238 __u32 ext4_itable_unused_count(struct super_block *sb,
 239                               struct ext4_group_desc *bg)
 240 {
 241         return le16_to_cpu(bg->bg_itable_unused_lo) |
 242                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 243                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 244 }
 245
 246 void ext4_block_bitmap_set(struct super_block *sb,
 247                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 248 {
 249         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 250         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 251                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 252 }
 253
 254 void ext4_inode_bitmap_set(struct super_block *sb,
 255                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 256 {
 257         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 258         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 259                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 260 }
 261
 262 void ext4_inode_table_set(struct super_block *sb,
 263                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 264 {
 265         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 266         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 267                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 268 }
 269
 270 void ext4_free_group_clusters_set(struct super_block *sb,
 271                                   struct ext4_group_desc *bg, __u32 count)
 272 {
 273         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 274         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 275                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 276 }
 277
 278 void ext4_free_inodes_set(struct super_block *sb,
 279                           struct ext4_group_desc *bg, __u32 count)
 280 {
 281         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 282         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 283                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 284 }
 285
 286 void ext4_used_dirs_set(struct super_block *sb,
 287                           struct ext4_group_desc *bg, __u32 count)
 288 {
 289         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 290         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 291                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 292 }
 293
 294 void ext4_itable_unused_set(struct super_block *sb,
 295                           struct ext4_group_desc *bg, __u32 count)
 296 {
 297         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 298         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 299                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 300 }
 301
 302
 303 static void __save_error_info(struct super_block *sb, const char *func,
 304                             unsigned int line)
 305 {
 306         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 307
 308         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 309         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 310         es->s_last_error_time = cpu_to_le32(get_seconds());
 311         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 312         es->s_last_error_line = cpu_to_le32(line);
 313         if (!es->s_first_error_time) {
 314                 es->s_first_error_time = es->s_last_error_time;
 315                 strncpy(es->s_first_error_func, func,
 316                         sizeof(es->s_first_error_func));
 317                 es->s_first_error_line = cpu_to_le32(line);
 318                 es->s_first_error_ino = es->s_last_error_ino;
 319                 es->s_first_error_block = es->s_last_error_block;
 320         }
 321         /*
 322          * Start the daily error reporting function if it hasn't been
 323          * started already
 324          */
 325         if (!es->s_error_count)
 326                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 327         le32_add_cpu(&es->s_error_count, 1);
 328 }
 329
 330 static void save_error_info(struct super_block *sb, const char *func,
 331                             unsigned int line)
 332 {
 333         __save_error_info(sb, func, line);
 334         ext4_commit_super(sb, 1);
 335 }
 336
 337 /*
 338  * The del_gendisk() function uninitializes the disk-specific data
 339  * structures, including the bdi structure, without telling anyone
 340  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 341  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 342  * This is a kludge to prevent these oops until we can put in a proper
 343  * hook in del_gendisk() to inform the VFS and file system layers.
 344  */
 345 static int block_device_ejected(struct super_block *sb)
 346 {
 347         struct inode *bd_inode = sb->s_bdev->bd_inode;
 348         struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
 349
 350         return bdi->dev == NULL;
 351 }
 352
 353 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 354 {
 355         struct super_block              *sb = journal->j_private;
 356         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 357         int                             error = is_journal_aborted(journal);
 358         struct ext4_journal_cb_entry    *jce;
 359
 360         BUG_ON(txn->t_state == T_FINISHED);
 361         spin_lock(&sbi->s_md_lock);
 362         while (!list_empty(&txn->t_private_list)) {
 363                 jce = list_entry(txn->t_private_list.next,
 364                                  struct ext4_journal_cb_entry, jce_list);
 365                 list_del_init(&jce->jce_list);
 366                 spin_unlock(&sbi->s_md_lock);
 367                 jce->jce_func(sb, jce, error);
 368                 spin_lock(&sbi->s_md_lock);
 369         }
 370         spin_unlock(&sbi->s_md_lock);
 371 }
 372
 373 /* Deal with the reporting of failure conditions on a filesystem such as
 374  * inconsistencies detected or read IO failures.
 375  *
 376  * On ext2, we can store the error state of the filesystem in the
 377  * superblock.  That is not possible on ext4, because we may have other
 378  * write ordering constraints on the superblock which prevent us from
 379  * writing it out straight away; and given that the journal is about to
 380  * be aborted, we can't rely on the current, or future, transactions to
 381  * write out the superblock safely.
 382  *
 383  * We'll just use the jbd2_journal_abort() error code to record an error in
 384  * the journal instead.  On recovery, the journal will complain about
 385  * that error until we've noted it down and cleared it.
 386  */
 387
 388 static void ext4_handle_error(struct super_block *sb)
 389 {
 390         if (sb->s_flags & MS_RDONLY)
 391                 return;
 392
 393         if (!test_opt(sb, ERRORS_CONT)) {
 394                 journal_t *journal = EXT4_SB(sb)->s_journal;
 395
 396                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 397                 if (journal)
 398                         jbd2_journal_abort(journal, -EIO);
 399         }
 400         if (test_opt(sb, ERRORS_RO)) {
 401                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 402                 /*
 403                  * Make sure updated value of ->s_mount_flags will be visible
 404                  * before ->s_flags update
 405                  */
 406                 smp_wmb();
 407                 sb->s_flags |= MS_RDONLY;
 408         }
 409         if (test_opt(sb, ERRORS_PANIC))
 410                 panic("EXT4-fs (device %s): panic forced after error\n",
 411                         sb->s_id);
 412 }
 413
 414 void __ext4_error(struct super_block *sb, const char *function,
 415                   unsigned int line, const char *fmt, ...)
 416 {
 417         struct va_format vaf;
 418         va_list args;
 419
 420         va_start(args, fmt);
 421         vaf.fmt = fmt;
 422         vaf.va = &args;
 423         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 424                sb->s_id, function, line, current->comm, &vaf);
 425         va_end(args);
 426         save_error_info(sb, function, line);
 427
 428         ext4_handle_error(sb);
 429 }
 430
 431 void __ext4_error_inode(struct inode *inode, const char *function,
 432                         unsigned int line, ext4_fsblk_t block,
 433                         const char *fmt, ...)
 434 {
 435         va_list args;
 436         struct va_format vaf;
 437         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 438
 439         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 440         es->s_last_error_block = cpu_to_le64(block);
 441         save_error_info(inode->i_sb, function, line);
 442         va_start(args, fmt);
 443         vaf.fmt = fmt;
 444         vaf.va = &args;
 445         if (block)
 446                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 447                        "inode #%lu: block %llu: comm %s: %pV\n",
 448                        inode->i_sb->s_id, function, line, inode->i_ino,
 449                        block, current->comm, &vaf);
 450         else
 451                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 452                        "inode #%lu: comm %s: %pV\n",
 453                        inode->i_sb->s_id, function, line, inode->i_ino,
 454                        current->comm, &vaf);
 455         va_end(args);
 456
 457         ext4_handle_error(inode->i_sb);
 458 }
 459
 460 void __ext4_error_file(struct file *file, const char *function,
 461                        unsigned int line, ext4_fsblk_t block,
 462                        const char *fmt, ...)
 463 {
 464         va_list args;
 465         struct va_format vaf;
 466         struct ext4_super_block *es;
 467         struct inode *inode = file_inode(file);
 468         char pathname[80], *path;
 469
 470         es = EXT4_SB(inode->i_sb)->s_es;
 471         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 472         save_error_info(inode->i_sb, function, line);
 473         path = d_path(&(file->f_path), pathname, sizeof(pathname));
 474         if (IS_ERR(path))
 475                 path = "(unknown)";
 476         va_start(args, fmt);
 477         vaf.fmt = fmt;
 478         vaf.va = &args;
 479         if (block)
 480                 printk(KERN_CRIT
 481                        "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 482                        "block %llu: comm %s: path %s: %pV\n",
 483                        inode->i_sb->s_id, function, line, inode->i_ino,
 484                        block, current->comm, path, &vaf);
 485         else
 486                 printk(KERN_CRIT
 487                        "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 488                        "comm %s: path %s: %pV\n",
 489                        inode->i_sb->s_id, function, line, inode->i_ino,
 490                        current->comm, path, &vaf);
 491         va_end(args);
 492
 493         ext4_handle_error(inode->i_sb);
 494 }
 495
 496 const char *ext4_decode_error(struct super_block *sb, int errno,
 497                               char nbuf[16])
 498 {
 499         char *errstr = NULL;
 500
 501         switch (errno) {
 502         case -EIO:
 503                 errstr = "IO failure";
 504                 break;
 505         case -ENOMEM:
 506                 errstr = "Out of memory";
 507                 break;
 508         case -EROFS:
 509                 if (!sb || (EXT4_SB(sb)->s_journal &&
 510                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 511                         errstr = "Journal has aborted";
 512                 else
 513                         errstr = "Readonly filesystem";
 514                 break;
 515         default:
 516                 /* If the caller passed in an extra buffer for unknown
 517                  * errors, textualise them now.  Else we just return
 518                  * NULL. */
 519                 if (nbuf) {
 520                         /* Check for truncated error codes... */
 521                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 522                                 errstr = nbuf;
 523                 }
 524                 break;
 525         }
 526
 527         return errstr;
 528 }
 529
 530 /* __ext4_std_error decodes expected errors from journaling functions
 531  * automatically and invokes the appropriate error response.  */
 532
 533 void __ext4_std_error(struct super_block *sb, const char *function,
 534                       unsigned int line, int errno)
 535 {
 536         char nbuf[16];
 537         const char *errstr;
 538
 539         /* Special case: if the error is EROFS, and we're not already
 540          * inside a transaction, then there's really no point in logging
 541          * an error. */
 542         if (errno == -EROFS && journal_current_handle() == NULL &&
 543             (sb->s_flags & MS_RDONLY))
 544                 return;
 545
 546         errstr = ext4_decode_error(sb, errno, nbuf);
 547         printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 548                sb->s_id, function, line, errstr);
 549         save_error_info(sb, function, line);
 550
 551         ext4_handle_error(sb);
 552 }
 553
 554 /*
 555  * ext4_abort is a much stronger failure handler than ext4_error.  The
 556  * abort function may be used to deal with unrecoverable failures such
 557  * as journal IO errors or ENOMEM at a critical moment in log management.
 558  *
 559  * We unconditionally force the filesystem into an ABORT|READONLY state,
 560  * unless the error response on the fs has been set to panic in which
 561  * case we take the easy way out and panic immediately.
 562  */
 563
 564 void __ext4_abort(struct super_block *sb, const char *function,
 565                 unsigned int line, const char *fmt, ...)
 566 {
 567         va_list args;
 568
 569         save_error_info(sb, function, line);
 570         va_start(args, fmt);
 571         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 572                function, line);
 573         vprintk(fmt, args);
 574         printk("\n");
 575         va_end(args);
 576
 577         if ((sb->s_flags & MS_RDONLY) == 0) {
 578                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 579                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 580                 /*
 581                  * Make sure updated value of ->s_mount_flags will be visible
 582                  * before ->s_flags update
 583                  */
 584                 smp_wmb();
 585                 sb->s_flags |= MS_RDONLY;
 586                 if (EXT4_SB(sb)->s_journal)
 587                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 588                 save_error_info(sb, function, line);
 589         }
 590         if (test_opt(sb, ERRORS_PANIC))
 591                 panic("EXT4-fs panic from previous error\n");
 592 }
 593
 594 void __ext4_msg(struct super_block *sb,
 595                 const char *prefix, const char *fmt, ...)
 596 {
 597         struct va_format vaf;
 598         va_list args;
 599
 600         va_start(args, fmt);
 601         vaf.fmt = fmt;
 602         vaf.va = &args;
 603         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 604         va_end(args);
 605 }
 606
 607 void __ext4_warning(struct super_block *sb, const char *function,
 608                     unsigned int line, const char *fmt, ...)
 609 {
 610         struct va_format vaf;
 611         va_list args;
 612
 613         va_start(args, fmt);
 614         vaf.fmt = fmt;
 615         vaf.va = &args;
 616         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 617                sb->s_id, function, line, &vaf);
 618         va_end(args);
 619 }
 620
 621 void __ext4_grp_locked_error(const char *function, unsigned int line,
 622                              struct super_block *sb, ext4_group_t grp,
 623                              unsigned long ino, ext4_fsblk_t block,
 624                              const char *fmt, ...)
 625 __releases(bitlock)
 626 __acquires(bitlock)
 627 {
 628         struct va_format vaf;
 629         va_list args;
 630         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 631
 632         es->s_last_error_ino = cpu_to_le32(ino);
 633         es->s_last_error_block = cpu_to_le64(block);
 634         __save_error_info(sb, function, line);
 635
 636         va_start(args, fmt);
 637
 638         vaf.fmt = fmt;
 639         vaf.va = &args;
 640         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 641                sb->s_id, function, line, grp);
 642         if (ino)
 643                 printk(KERN_CONT "inode %lu: ", ino);
 644         if (block)
 645                 printk(KERN_CONT "block %llu:", (unsigned long long) block);
 646         printk(KERN_CONT "%pV\n", &vaf);
 647         va_end(args);
 648
 649         if (test_opt(sb, ERRORS_CONT)) {
 650                 ext4_commit_super(sb, 0);
 651                 return;
 652         }
 653
 654         ext4_unlock_group(sb, grp);
 655         ext4_handle_error(sb);
 656         /*
 657          * We only get here in the ERRORS_RO case; relocking the group
 658          * may be dangerous, but nothing bad will happen since the
 659          * filesystem will have already been marked read/only and the
 660          * journal has been aborted.  We return 1 as a hint to callers
 661          * who might what to use the return value from
 662          * ext4_grp_locked_error() to distinguish between the
 663          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 664          * aggressively from the ext4 function in question, with a
 665          * more appropriate error code.
 666          */
 667         ext4_lock_group(sb, grp);
 668         return;
 669 }
 670
 671 void ext4_update_dynamic_rev(struct super_block *sb)
 672 {
 673         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 674
 675         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 676                 return;
 677
 678         ext4_warning(sb,
 679                      "updating to rev %d because of new feature flag, "
 680                      "running e2fsck is recommended",
 681                      EXT4_DYNAMIC_REV);
 682
 683         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 684         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 685         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 686         /* leave es->s_feature_*compat flags alone */
 687         /* es->s_uuid will be set by e2fsck if empty */
 688
 689         /*
 690          * The rest of the superblock fields should be zero, and if not it
 691          * means they are likely already in use, so leave them alone.  We
 692          * can leave it up to e2fsck to clean up any inconsistencies there.
 693          */
 694 }
 695
 696 /*
 697  * Open the external journal device
 698  */
 699 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 700 {
 701         struct block_device *bdev;
 702         char b[BDEVNAME_SIZE];
 703
 704         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 705         if (IS_ERR(bdev))
 706                 goto fail;
 707         return bdev;
 708
 709 fail:
 710         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 711                         __bdevname(dev, b), PTR_ERR(bdev));
 712         return NULL;
 713 }
 714
 715 /*
 716  * Release the journal device
 717  */
 718 static void ext4_blkdev_put(struct block_device *bdev)
 719 {
 720         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 721 }
 722
 723 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 724 {
 725         struct block_device *bdev;
 726         bdev = sbi->journal_bdev;
 727         if (bdev) {
 728                 ext4_blkdev_put(bdev);
 729                 sbi->journal_bdev = NULL;
 730         }
 731 }
 732
 733 static inline struct inode *orphan_list_entry(struct list_head *l)
 734 {
 735         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 736 }
 737
 738 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 739 {
 740         struct list_head *l;
 741
 742         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 743                  le32_to_cpu(sbi->s_es->s_last_orphan));
 744
 745         printk(KERN_ERR "sb_info orphan list:\n");
 746         list_for_each(l, &sbi->s_orphan) {
 747                 struct inode *inode = orphan_list_entry(l);
 748                 printk(KERN_ERR "  "
 749                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 750                        inode->i_sb->s_id, inode->i_ino, inode,
 751                        inode->i_mode, inode->i_nlink,
 752                        NEXT_ORPHAN(inode));
 753         }
 754 }
 755
 756 static void ext4_put_super(struct super_block *sb)
 757 {
 758         struct ext4_sb_info *sbi = EXT4_SB(sb);
 759         struct ext4_super_block *es = sbi->s_es;
 760         int i, err;
 761
 762         ext4_unregister_li_request(sb);
 763         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 764
 765         flush_workqueue(sbi->unrsv_conversion_wq);
 766         flush_workqueue(sbi->rsv_conversion_wq);
 767         destroy_workqueue(sbi->unrsv_conversion_wq);
 768         destroy_workqueue(sbi->rsv_conversion_wq);
 769
 770         if (sbi->s_journal) {
 771                 err = jbd2_journal_destroy(sbi->s_journal);
 772                 sbi->s_journal = NULL;
 773                 if (err < 0)
 774                         ext4_abort(sb, "Couldn't clean up the journal");
 775         }
 776
 777         ext4_es_unregister_shrinker(sbi);
 778         del_timer(&sbi->s_err_report);
 779         ext4_release_system_zone(sb);
 780         ext4_mb_release(sb);
 781         ext4_ext_release(sb);
 782         ext4_xattr_put_super(sb);
 783
 784         if (!(sb->s_flags & MS_RDONLY)) {
 785                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 786                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 787         }
 788         if (!(sb->s_flags & MS_RDONLY))
 789                 ext4_commit_super(sb, 1);
 790
 791         if (sbi->s_proc) {
 792                 remove_proc_entry("options", sbi->s_proc);
 793                 remove_proc_entry(sb->s_id, ext4_proc_root);
 794         }
 795         kobject_del(&sbi->s_kobj);
 796
 797         for (i = 0; i < sbi->s_gdb_count; i++)
 798                 brelse(sbi->s_group_desc[i]);
 799         ext4_kvfree(sbi->s_group_desc);
 800         ext4_kvfree(sbi->s_flex_groups);
 801         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 802         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 803         percpu_counter_destroy(&sbi->s_dirs_counter);
 804         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 805         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
 806         brelse(sbi->s_sbh);
 807 #ifdef CONFIG_QUOTA
 808         for (i = 0; i < MAXQUOTAS; i++)
 809                 kfree(sbi->s_qf_names[i]);
 810 #endif
 811
 812         /* Debugging code just in case the in-memory inode orphan list
 813          * isn't empty.  The on-disk one can be non-empty if we've
 814          * detected an error and taken the fs readonly, but the
 815          * in-memory list had better be clean by this point. */
 816         if (!list_empty(&sbi->s_orphan))
 817                 dump_orphan_list(sb, sbi);
 818         J_ASSERT(list_empty(&sbi->s_orphan));
 819
 820         invalidate_bdev(sb->s_bdev);
 821         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 822                 /*
 823                  * Invalidate the journal device's buffers.  We don't want them
 824                  * floating about in memory - the physical journal device may
 825                  * hotswapped, and it breaks the `ro-after' testing code.
 826                  */
 827                 sync_blockdev(sbi->journal_bdev);
 828                 invalidate_bdev(sbi->journal_bdev);
 829                 ext4_blkdev_remove(sbi);
 830         }
 831         if (sbi->s_mmp_tsk)
 832                 kthread_stop(sbi->s_mmp_tsk);
 833         sb->s_fs_info = NULL;
 834         /*
 835          * Now that we are completely done shutting down the
 836          * superblock, we need to actually destroy the kobject.
 837          */
 838         kobject_put(&sbi->s_kobj);
 839         wait_for_completion(&sbi->s_kobj_unregister);
 840         if (sbi->s_chksum_driver)
 841                 crypto_free_shash(sbi->s_chksum_driver);
 842         kfree(sbi->s_blockgroup_lock);
 843         kfree(sbi);
 844 }
 845
 846 static struct kmem_cache *ext4_inode_cachep;
 847
 848 /*
 849  * Called inside transaction, so use GFP_NOFS
 850  */
 851 static struct inode *ext4_alloc_inode(struct super_block *sb)
 852 {
 853         struct ext4_inode_info *ei;
 854
 855         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 856         if (!ei)
 857                 return NULL;
 858
 859         ei->vfs_inode.i_version = 1;
 860         INIT_LIST_HEAD(&ei->i_prealloc_list);
 861         spin_lock_init(&ei->i_prealloc_lock);
 862         ext4_es_init_tree(&ei->i_es_tree);
 863         rwlock_init(&ei->i_es_lock);
 864         INIT_LIST_HEAD(&ei->i_es_lru);
 865         ei->i_es_lru_nr = 0;
 866         ei->i_touch_when = 0;
 867         ei->i_reserved_data_blocks = 0;
 868         ei->i_reserved_meta_blocks = 0;
 869         ei->i_allocated_meta_blocks = 0;
 870         ei->i_da_metadata_calc_len = 0;
 871         ei->i_da_metadata_calc_last_lblock = 0;
 872         spin_lock_init(&(ei->i_block_reservation_lock));
 873 #ifdef CONFIG_QUOTA
 874         ei->i_reserved_quota = 0;
 875 #endif
 876         ei->jinode = NULL;
 877         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 878         INIT_LIST_HEAD(&ei->i_unrsv_conversion_list);
 879         spin_lock_init(&ei->i_completed_io_lock);
 880         ei->i_sync_tid = 0;
 881         ei->i_datasync_tid = 0;
 882         atomic_set(&ei->i_ioend_count, 0);
 883         atomic_set(&ei->i_unwritten, 0);
 884         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 885         INIT_WORK(&ei->i_unrsv_conversion_work, ext4_end_io_unrsv_work);
 886
 887         return &ei->vfs_inode;
 888 }
 889
 890 static int ext4_drop_inode(struct inode *inode)
 891 {
 892         int drop = generic_drop_inode(inode);
 893
 894         trace_ext4_drop_inode(inode, drop);
 895         return drop;
 896 }
 897
 898 static void ext4_i_callback(struct rcu_head *head)
 899 {
 900         struct inode *inode = container_of(head, struct inode, i_rcu);
 901         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 902 }
 903
 904 static void ext4_destroy_inode(struct inode *inode)
 905 {
 906         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 907                 ext4_msg(inode->i_sb, KERN_ERR,
 908                          "Inode %lu (%p): orphan list check failed!",
 909                          inode->i_ino, EXT4_I(inode));
 910                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 911                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 912                                 true);
 913                 dump_stack();
 914         }
 915         call_rcu(&inode->i_rcu, ext4_i_callback);
 916 }
 917
 918 static void init_once(void *foo)
 919 {
 920         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 921
 922         INIT_LIST_HEAD(&ei->i_orphan);
 923         init_rwsem(&ei->xattr_sem);
 924         init_rwsem(&ei->i_data_sem);
 925         inode_init_once(&ei->vfs_inode);
 926 }
 927
 928 static int init_inodecache(void)
 929 {
 930         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 931                                              sizeof(struct ext4_inode_info),
 932                                              0, (SLAB_RECLAIM_ACCOUNT|
 933                                                 SLAB_MEM_SPREAD),
 934                                              init_once);
 935         if (ext4_inode_cachep == NULL)
 936                 return -ENOMEM;
 937         return 0;
 938 }
 939
 940 static void destroy_inodecache(void)
 941 {
 942         /*
 943          * Make sure all delayed rcu free inodes are flushed before we
 944          * destroy cache.
 945          */
 946         rcu_barrier();
 947         kmem_cache_destroy(ext4_inode_cachep);
 948 }
 949
 950 void ext4_clear_inode(struct inode *inode)
 951 {
 952         invalidate_inode_buffers(inode);
 953         clear_inode(inode);
 954         dquot_drop(inode);
 955         ext4_discard_preallocations(inode);
 956         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 957         ext4_es_lru_del(inode);
 958         if (EXT4_I(inode)->jinode) {
 959                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 960                                                EXT4_I(inode)->jinode);
 961                 jbd2_free_inode(EXT4_I(inode)->jinode);
 962                 EXT4_I(inode)->jinode = NULL;
 963         }
 964 }
 965
 966 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 967                                         u64 ino, u32 generation)
 968 {
 969         struct inode *inode;
 970
 971         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 972                 return ERR_PTR(-ESTALE);
 973         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 974                 return ERR_PTR(-ESTALE);
 975
 976         /* iget isn't really right if the inode is currently unallocated!!
 977          *
 978          * ext4_read_inode will return a bad_inode if the inode had been
 979          * deleted, so we should be safe.
 980          *
 981          * Currently we don't know the generation for parent directory, so
 982          * a generation of 0 means "accept any"
 983          */
 984         inode = ext4_iget(sb, ino);
 985         if (IS_ERR(inode))
 986                 return ERR_CAST(inode);
 987         if (generation && inode->i_generation != generation) {
 988                 iput(inode);
 989                 return ERR_PTR(-ESTALE);
 990         }
 991
 992         return inode;
 993 }
 994
 995 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 996                                         int fh_len, int fh_type)
 997 {
 998         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 999                                     ext4_nfs_get_inode);
1000 }
1001
1002 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1003                                         int fh_len, int fh_type)
1004 {
1005         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1006                                     ext4_nfs_get_inode);
1007 }
1008
1009 /*
1010  * Try to release metadata pages (indirect blocks, directories) which are
1011  * mapped via the block device.  Since these pages could have journal heads
1012  * which would prevent try_to_free_buffers() from freeing them, we must use
1013  * jbd2 layer's try_to_free_buffers() function to release them.
1014  */
1015 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1016                                  gfp_t wait)
1017 {
1018         journal_t *journal = EXT4_SB(sb)->s_journal;
1019
1020         WARN_ON(PageChecked(page));
1021         if (!page_has_buffers(page))
1022                 return 0;
1023         if (journal)
1024                 return jbd2_journal_try_to_free_buffers(journal, page,
1025                                                         wait & ~__GFP_WAIT);
1026         return try_to_free_buffers(page);
1027 }
1028
1029 #ifdef CONFIG_QUOTA
1030 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1031 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1032
1033 static int ext4_write_dquot(struct dquot *dquot);
1034 static int ext4_acquire_dquot(struct dquot *dquot);
1035 static int ext4_release_dquot(struct dquot *dquot);
1036 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1037 static int ext4_write_info(struct super_block *sb, int type);
1038 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1039                          struct path *path);
1040 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1041                                  int format_id);
1042 static int ext4_quota_off(struct super_block *sb, int type);
1043 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1044 static int ext4_quota_on_mount(struct super_block *sb, int type);
1045 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1046                                size_t len, loff_t off);
1047 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1048                                 const char *data, size_t len, loff_t off);
1049 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1050                              unsigned int flags);
1051 static int ext4_enable_quotas(struct super_block *sb);
1052
1053 static const struct dquot_operations ext4_quota_operations = {
1054         .get_reserved_space = ext4_get_reserved_space,
1055         .write_dquot    = ext4_write_dquot,
1056         .acquire_dquot  = ext4_acquire_dquot,
1057         .release_dquot  = ext4_release_dquot,
1058         .mark_dirty     = ext4_mark_dquot_dirty,
1059         .write_info     = ext4_write_info,
1060         .alloc_dquot    = dquot_alloc,
1061         .destroy_dquot  = dquot_destroy,
1062 };
1063
1064 static const struct quotactl_ops ext4_qctl_operations = {
1065         .quota_on       = ext4_quota_on,
1066         .quota_off      = ext4_quota_off,
1067         .quota_sync     = dquot_quota_sync,
1068         .get_info       = dquot_get_dqinfo,
1069         .set_info       = dquot_set_dqinfo,
1070         .get_dqblk      = dquot_get_dqblk,
1071         .set_dqblk      = dquot_set_dqblk
1072 };
1073
1074 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1075         .quota_on_meta  = ext4_quota_on_sysfile,
1076         .quota_off      = ext4_quota_off_sysfile,
1077         .quota_sync     = dquot_quota_sync,
1078         .get_info       = dquot_get_dqinfo,
1079         .set_info       = dquot_set_dqinfo,
1080         .get_dqblk      = dquot_get_dqblk,
1081         .set_dqblk      = dquot_set_dqblk
1082 };
1083 #endif
1084
1085 static const struct super_operations ext4_sops = {
1086         .alloc_inode    = ext4_alloc_inode,
1087         .destroy_inode  = ext4_destroy_inode,
1088         .write_inode    = ext4_write_inode,
1089         .dirty_inode    = ext4_dirty_inode,
1090         .drop_inode     = ext4_drop_inode,
1091         .evict_inode    = ext4_evict_inode,
1092         .put_super      = ext4_put_super,
1093         .sync_fs        = ext4_sync_fs,
1094         .freeze_fs      = ext4_freeze,
1095         .unfreeze_fs    = ext4_unfreeze,
1096         .statfs         = ext4_statfs,
1097         .remount_fs     = ext4_remount,
1098         .show_options   = ext4_show_options,
1099 #ifdef CONFIG_QUOTA
1100         .quota_read     = ext4_quota_read,
1101         .quota_write    = ext4_quota_write,
1102 #endif
1103         .bdev_try_to_free_page = bdev_try_to_free_page,
1104 };
1105
1106 static const struct super_operations ext4_nojournal_sops = {
1107         .alloc_inode    = ext4_alloc_inode,
1108         .destroy_inode  = ext4_destroy_inode,
1109         .write_inode    = ext4_write_inode,
1110         .dirty_inode    = ext4_dirty_inode,
1111         .drop_inode     = ext4_drop_inode,
1112         .evict_inode    = ext4_evict_inode,
1113         .sync_fs        = ext4_sync_fs_nojournal,
1114         .put_super      = ext4_put_super,
1115         .statfs         = ext4_statfs,
1116         .remount_fs     = ext4_remount,
1117         .show_options   = ext4_show_options,
1118 #ifdef CONFIG_QUOTA
1119         .quota_read     = ext4_quota_read,
1120         .quota_write    = ext4_quota_write,
1121 #endif
1122         .bdev_try_to_free_page = bdev_try_to_free_page,
1123 };
1124
1125 static const struct export_operations ext4_export_ops = {
1126         .fh_to_dentry = ext4_fh_to_dentry,
1127         .fh_to_parent = ext4_fh_to_parent,
1128         .get_parent = ext4_get_parent,
1129 };
1130
1131 enum {
1132         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1133         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1134         Opt_nouid32, Opt_debug, Opt_removed,
1135         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1136         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1137         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1138         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1139         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1140         Opt_data_err_abort, Opt_data_err_ignore,
1141         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1142         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1143         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1144         Opt_usrquota, Opt_grpquota, Opt_i_version,
1145         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1146         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1147         Opt_inode_readahead_blks, Opt_journal_ioprio,
1148         Opt_dioread_nolock, Opt_dioread_lock,
1149         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1150         Opt_max_dir_size_kb,
1151 };
1152
1153 static const match_table_t tokens = {
1154         {Opt_bsd_df, "bsddf"},
1155         {Opt_minix_df, "minixdf"},
1156         {Opt_grpid, "grpid"},
1157         {Opt_grpid, "bsdgroups"},
1158         {Opt_nogrpid, "nogrpid"},
1159         {Opt_nogrpid, "sysvgroups"},
1160         {Opt_resgid, "resgid=%u"},
1161         {Opt_resuid, "resuid=%u"},
1162         {Opt_sb, "sb=%u"},
1163         {Opt_err_cont, "errors=continue"},
1164         {Opt_err_panic, "errors=panic"},
1165         {Opt_err_ro, "errors=remount-ro"},
1166         {Opt_nouid32, "nouid32"},
1167         {Opt_debug, "debug"},
1168         {Opt_removed, "oldalloc"},
1169         {Opt_removed, "orlov"},
1170         {Opt_user_xattr, "user_xattr"},
1171         {Opt_nouser_xattr, "nouser_xattr"},
1172         {Opt_acl, "acl"},
1173         {Opt_noacl, "noacl"},
1174         {Opt_noload, "norecovery"},
1175         {Opt_noload, "noload"},
1176         {Opt_removed, "nobh"},
1177         {Opt_removed, "bh"},
1178         {Opt_commit, "commit=%u"},
1179         {Opt_min_batch_time, "min_batch_time=%u"},
1180         {Opt_max_batch_time, "max_batch_time=%u"},
1181         {Opt_journal_dev, "journal_dev=%u"},
1182         {Opt_journal_path, "journal_path=%s"},
1183         {Opt_journal_checksum, "journal_checksum"},
1184         {Opt_journal_async_commit, "journal_async_commit"},
1185         {Opt_abort, "abort"},
1186         {Opt_data_journal, "data=journal"},
1187         {Opt_data_ordered, "data=ordered"},
1188         {Opt_data_writeback, "data=writeback"},
1189         {Opt_data_err_abort, "data_err=abort"},
1190         {Opt_data_err_ignore, "data_err=ignore"},
1191         {Opt_offusrjquota, "usrjquota="},
1192         {Opt_usrjquota, "usrjquota=%s"},
1193         {Opt_offgrpjquota, "grpjquota="},
1194         {Opt_grpjquota, "grpjquota=%s"},
1195         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1196         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1197         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1198         {Opt_grpquota, "grpquota"},
1199         {Opt_noquota, "noquota"},
1200         {Opt_quota, "quota"},
1201         {Opt_usrquota, "usrquota"},
1202         {Opt_barrier, "barrier=%u"},
1203         {Opt_barrier, "barrier"},
1204         {Opt_nobarrier, "nobarrier"},
1205         {Opt_i_version, "i_version"},
1206         {Opt_stripe, "stripe=%u"},
1207         {Opt_delalloc, "delalloc"},
1208         {Opt_nodelalloc, "nodelalloc"},
1209         {Opt_removed, "mblk_io_submit"},
1210         {Opt_removed, "nomblk_io_submit"},
1211         {Opt_block_validity, "block_validity"},
1212         {Opt_noblock_validity, "noblock_validity"},
1213         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1214         {Opt_journal_ioprio, "journal_ioprio=%u"},
1215         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1216         {Opt_auto_da_alloc, "auto_da_alloc"},
1217         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1218         {Opt_dioread_nolock, "dioread_nolock"},
1219         {Opt_dioread_lock, "dioread_lock"},
1220         {Opt_discard, "discard"},
1221         {Opt_nodiscard, "nodiscard"},
1222         {Opt_init_itable, "init_itable=%u"},
1223         {Opt_init_itable, "init_itable"},
1224         {Opt_noinit_itable, "noinit_itable"},
1225         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1226         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1227         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1228         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1229         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1230         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1231         {Opt_err, NULL},
1232 };
1233
1234 static ext4_fsblk_t get_sb_block(void **data)
1235 {
1236         ext4_fsblk_t    sb_block;
1237         char            *options = (char *) *data;
1238
1239         if (!options || strncmp(options, "sb=", 3) != 0)
1240                 return 1;       /* Default location */
1241
1242         options += 3;
1243         /* TODO: use simple_strtoll with >32bit ext4 */
1244         sb_block = simple_strtoul(options, &options, 0);
1245         if (*options && *options != ',') {
1246                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1247                        (char *) *data);
1248                 return 1;
1249         }
1250         if (*options == ',')
1251                 options++;
1252         *data = (void *) options;
1253
1254         return sb_block;
1255 }
1256
1257 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1258 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1259         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1260
1261 #ifdef CONFIG_QUOTA
1262 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1263 {
1264         struct ext4_sb_info *sbi = EXT4_SB(sb);
1265         char *qname;
1266         int ret = -1;
1267
1268         if (sb_any_quota_loaded(sb) &&
1269                 !sbi->s_qf_names[qtype]) {
1270                 ext4_msg(sb, KERN_ERR,
1271                         "Cannot change journaled "
1272                         "quota options when quota turned on");
1273                 return -1;
1274         }
1275         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1276                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1277                          "when QUOTA feature is enabled");
1278                 return -1;
1279         }
1280         qname = match_strdup(args);
1281         if (!qname) {
1282                 ext4_msg(sb, KERN_ERR,
1283                         "Not enough memory for storing quotafile name");
1284                 return -1;
1285         }
1286         if (sbi->s_qf_names[qtype]) {
1287                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1288                         ret = 1;
1289                 else
1290                         ext4_msg(sb, KERN_ERR,
1291                                  "%s quota file already specified",
1292                                  QTYPE2NAME(qtype));
1293                 goto errout;
1294         }
1295         if (strchr(qname, '/')) {
1296                 ext4_msg(sb, KERN_ERR,
1297                         "quotafile must be on filesystem root");
1298                 goto errout;
1299         }
1300         sbi->s_qf_names[qtype] = qname;
1301         set_opt(sb, QUOTA);
1302         return 1;
1303 errout:
1304         kfree(qname);
1305         return ret;
1306 }
1307
1308 static int clear_qf_name(struct super_block *sb, int qtype)
1309 {
1310
1311         struct ext4_sb_info *sbi = EXT4_SB(sb);
1312
1313         if (sb_any_quota_loaded(sb) &&
1314                 sbi->s_qf_names[qtype]) {
1315                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1316                         " when quota turned on");
1317                 return -1;
1318         }
1319         kfree(sbi->s_qf_names[qtype]);
1320         sbi->s_qf_names[qtype] = NULL;
1321         return 1;
1322 }
1323 #endif
1324
1325 #define MOPT_SET        0x0001
1326 #define MOPT_CLEAR      0x0002
1327 #define MOPT_NOSUPPORT  0x0004
1328 #define MOPT_EXPLICIT   0x0008
1329 #define MOPT_CLEAR_ERR  0x0010
1330 #define MOPT_GTE0       0x0020
1331 #ifdef CONFIG_QUOTA
1332 #define MOPT_Q          0
1333 #define MOPT_QFMT       0x0040
1334 #else
1335 #define MOPT_Q          MOPT_NOSUPPORT
1336 #define MOPT_QFMT       MOPT_NOSUPPORT
1337 #endif
1338 #define MOPT_DATAJ      0x0080
1339 #define MOPT_NO_EXT2    0x0100
1340 #define MOPT_NO_EXT3    0x0200
1341 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1342 #define MOPT_STRING     0x0400
1343
1344 static const struct mount_opts {
1345         int     token;
1346         int     mount_opt;
1347         int     flags;
1348 } ext4_mount_opts[] = {
1349         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1350         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1351         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1352         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1353         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1354         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1355         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1356          MOPT_EXT4_ONLY | MOPT_SET},
1357         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1358          MOPT_EXT4_ONLY | MOPT_CLEAR},
1359         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1360         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1361         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1362          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1363         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1364          MOPT_EXT4_ONLY | MOPT_CLEAR},
1365         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1366          MOPT_EXT4_ONLY | MOPT_SET},
1367         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1368                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1369          MOPT_EXT4_ONLY | MOPT_SET},
1370         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1371         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1372         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1373         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1374         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1375          MOPT_NO_EXT2 | MOPT_SET},
1376         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1377          MOPT_NO_EXT2 | MOPT_CLEAR},
1378         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1379         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1380         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1381         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1382         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1383         {Opt_commit, 0, MOPT_GTE0},
1384         {Opt_max_batch_time, 0, MOPT_GTE0},
1385         {Opt_min_batch_time, 0, MOPT_GTE0},
1386         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1387         {Opt_init_itable, 0, MOPT_GTE0},
1388         {Opt_stripe, 0, MOPT_GTE0},
1389         {Opt_resuid, 0, MOPT_GTE0},
1390         {Opt_resgid, 0, MOPT_GTE0},
1391         {Opt_journal_dev, 0, MOPT_GTE0},
1392         {Opt_journal_path, 0, MOPT_STRING},
1393         {Opt_journal_ioprio, 0, MOPT_GTE0},
1394         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1395         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1396         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1397          MOPT_NO_EXT2 | MOPT_DATAJ},
1398         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1399         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1400 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1401         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1402         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1403 #else
1404         {Opt_acl, 0, MOPT_NOSUPPORT},
1405         {Opt_noacl, 0, MOPT_NOSUPPORT},
1406 #endif
1407         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1408         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1409         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1410         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1411                                                         MOPT_SET | MOPT_Q},
1412         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1413                                                         MOPT_SET | MOPT_Q},
1414         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1415                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1416         {Opt_usrjquota, 0, MOPT_Q},
1417         {Opt_grpjquota, 0, MOPT_Q},
1418         {Opt_offusrjquota, 0, MOPT_Q},
1419         {Opt_offgrpjquota, 0, MOPT_Q},
1420         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1421         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1422         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1423         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1424         {Opt_err, 0, 0}
1425 };
1426
1427 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1428                             substring_t *args, unsigned long *journal_devnum,
1429                             unsigned int *journal_ioprio, int is_remount)
1430 {
1431         struct ext4_sb_info *sbi = EXT4_SB(sb);
1432         const struct mount_opts *m;
1433         kuid_t uid;
1434         kgid_t gid;
1435         int arg = 0;
1436
1437 #ifdef CONFIG_QUOTA
1438         if (token == Opt_usrjquota)
1439                 return set_qf_name(sb, USRQUOTA, &args[0]);
1440         else if (token == Opt_grpjquota)
1441                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1442         else if (token == Opt_offusrjquota)
1443                 return clear_qf_name(sb, USRQUOTA);
1444         else if (token == Opt_offgrpjquota)
1445                 return clear_qf_name(sb, GRPQUOTA);
1446 #endif
1447         switch (token) {
1448         case Opt_noacl:
1449         case Opt_nouser_xattr:
1450                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1451                 break;
1452         case Opt_sb:
1453                 return 1;       /* handled by get_sb_block() */
1454         case Opt_removed:
1455                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1456                 return 1;
1457         case Opt_abort:
1458                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1459                 return 1;
1460         case Opt_i_version:
1461                 sb->s_flags |= MS_I_VERSION;
1462                 return 1;
1463         }
1464
1465         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1466                 if (token == m->token)
1467                         break;
1468
1469         if (m->token == Opt_err) {
1470                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1471                          "or missing value", opt);
1472                 return -1;
1473         }
1474
1475         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1476                 ext4_msg(sb, KERN_ERR,
1477                          "Mount option \"%s\" incompatible with ext2", opt);
1478                 return -1;
1479         }
1480         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1481                 ext4_msg(sb, KERN_ERR,
1482                          "Mount option \"%s\" incompatible with ext3", opt);
1483                 return -1;
1484         }
1485
1486         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1487                 return -1;
1488         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1489                 return -1;
1490         if (m->flags & MOPT_EXPLICIT)
1491                 set_opt2(sb, EXPLICIT_DELALLOC);
1492         if (m->flags & MOPT_CLEAR_ERR)
1493                 clear_opt(sb, ERRORS_MASK);
1494         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1495                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1496                          "options when quota turned on");
1497                 return -1;
1498         }
1499
1500         if (m->flags & MOPT_NOSUPPORT) {
1501                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1502         } else if (token == Opt_commit) {
1503                 if (arg == 0)
1504                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1505                 sbi->s_commit_interval = HZ * arg;
1506         } else if (token == Opt_max_batch_time) {
1507                 if (arg == 0)
1508                         arg = EXT4_DEF_MAX_BATCH_TIME;
1509                 sbi->s_max_batch_time = arg;
1510         } else if (token == Opt_min_batch_time) {
1511                 sbi->s_min_batch_time = arg;
1512         } else if (token == Opt_inode_readahead_blks) {
1513                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1514                         ext4_msg(sb, KERN_ERR,
1515                                  "EXT4-fs: inode_readahead_blks must be "
1516                                  "0 or a power of 2 smaller than 2^31");
1517                         return -1;
1518                 }
1519                 sbi->s_inode_readahead_blks = arg;
1520         } else if (token == Opt_init_itable) {
1521                 set_opt(sb, INIT_INODE_TABLE);
1522                 if (!args->from)
1523                         arg = EXT4_DEF_LI_WAIT_MULT;
1524                 sbi->s_li_wait_mult = arg;
1525         } else if (token == Opt_max_dir_size_kb) {
1526                 sbi->s_max_dir_size_kb = arg;
1527         } else if (token == Opt_stripe) {
1528                 sbi->s_stripe = arg;
1529         } else if (token == Opt_resuid) {
1530                 uid = make_kuid(current_user_ns(), arg);
1531                 if (!uid_valid(uid)) {
1532                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1533                         return -1;
1534                 }
1535                 sbi->s_resuid = uid;
1536         } else if (token == Opt_resgid) {
1537                 gid = make_kgid(current_user_ns(), arg);
1538                 if (!gid_valid(gid)) {
1539                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1540                         return -1;
1541                 }
1542                 sbi->s_resgid = gid;
1543         } else if (token == Opt_journal_dev) {
1544                 if (is_remount) {
1545                         ext4_msg(sb, KERN_ERR,
1546                                  "Cannot specify journal on remount");
1547                         return -1;
1548                 }
1549                 *journal_devnum = arg;
1550         } else if (token == Opt_journal_path) {
1551                 char *journal_path;
1552                 struct inode *journal_inode;
1553                 struct path path;
1554                 int error;
1555
1556                 if (is_remount) {
1557                         ext4_msg(sb, KERN_ERR,
1558                                  "Cannot specify journal on remount");
1559                         return -1;
1560                 }
1561                 journal_path = match_strdup(&args[0]);
1562                 if (!journal_path) {
1563                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1564                                 "journal device string");
1565                         return -1;
1566                 }
1567
1568                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1569                 if (error) {
1570                         ext4_msg(sb, KERN_ERR, "error: could not find "
1571                                 "journal device path: error %d", error);
1572                         kfree(journal_path);
1573                         return -1;
1574                 }
1575
1576                 journal_inode = path.dentry->d_inode;
1577                 if (!S_ISBLK(journal_inode->i_mode)) {
1578                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1579                                 "is not a block device", journal_path);
1580                         path_put(&path);
1581                         kfree(journal_path);
1582                         return -1;
1583                 }
1584
1585                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1586                 path_put(&path);
1587                 kfree(journal_path);
1588         } else if (token == Opt_journal_ioprio) {
1589                 if (arg > 7) {
1590                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1591                                  " (must be 0-7)");
1592                         return -1;
1593                 }
1594                 *journal_ioprio =
1595                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1596         } else if (m->flags & MOPT_DATAJ) {
1597                 if (is_remount) {
1598                         if (!sbi->s_journal)
1599                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1600                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1601                                 ext4_msg(sb, KERN_ERR,
1602                                          "Cannot change data mode on remount");
1603                                 return -1;
1604                         }
1605                 } else {
1606                         clear_opt(sb, DATA_FLAGS);
1607                         sbi->s_mount_opt |= m->mount_opt;
1608                 }
1609 #ifdef CONFIG_QUOTA
1610         } else if (m->flags & MOPT_QFMT) {
1611                 if (sb_any_quota_loaded(sb) &&
1612                     sbi->s_jquota_fmt != m->mount_opt) {
1613                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1614                                  "quota options when quota turned on");
1615                         return -1;
1616                 }
1617                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1618                                                EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1619                         ext4_msg(sb, KERN_ERR,
1620                                  "Cannot set journaled quota options "
1621                                  "when QUOTA feature is enabled");
1622                         return -1;
1623                 }
1624                 sbi->s_jquota_fmt = m->mount_opt;
1625 #endif
1626         } else {
1627                 if (!args->from)
1628                         arg = 1;
1629                 if (m->flags & MOPT_CLEAR)
1630                         arg = !arg;
1631                 else if (unlikely(!(m->flags & MOPT_SET))) {
1632                         ext4_msg(sb, KERN_WARNING,
1633                                  "buggy handling of option %s", opt);
1634                         WARN_ON(1);
1635                         return -1;
1636                 }
1637                 if (arg != 0)
1638                         sbi->s_mount_opt |= m->mount_opt;
1639                 else
1640                         sbi->s_mount_opt &= ~m->mount_opt;
1641         }
1642         return 1;
1643 }
1644
1645 static int parse_options(char *options, struct super_block *sb,
1646                          unsigned long *journal_devnum,
1647                          unsigned int *journal_ioprio,
1648                          int is_remount)
1649 {
1650         struct ext4_sb_info *sbi = EXT4_SB(sb);
1651         char *p;
1652         substring_t args[MAX_OPT_ARGS];
1653         int token;
1654
1655         if (!options)
1656                 return 1;
1657
1658         while ((p = strsep(&options, ",")) != NULL) {
1659                 if (!*p)
1660                         continue;
1661                 /*
1662                  * Initialize args struct so we know whether arg was
1663                  * found; some options take optional arguments.
1664                  */
1665                 args[0].to = args[0].from = NULL;
1666                 token = match_token(p, tokens, args);
1667                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1668                                      journal_ioprio, is_remount) < 0)
1669                         return 0;
1670         }
1671 #ifdef CONFIG_QUOTA
1672         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1673             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1674                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1675                          "feature is enabled");
1676                 return 0;
1677         }
1678         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1679                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1680                         clear_opt(sb, USRQUOTA);
1681
1682                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1683                         clear_opt(sb, GRPQUOTA);
1684
1685                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1686                         ext4_msg(sb, KERN_ERR, "old and new quota "
1687                                         "format mixing");
1688                         return 0;
1689                 }
1690
1691                 if (!sbi->s_jquota_fmt) {
1692                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1693                                         "not specified");
1694                         return 0;
1695                 }
1696         } else {
1697                 if (sbi->s_jquota_fmt) {
1698                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1699                                         "specified with no journaling "
1700                                         "enabled");
1701                         return 0;
1702                 }
1703         }
1704 #endif
1705         if (test_opt(sb, DIOREAD_NOLOCK)) {
1706                 int blocksize =
1707                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1708
1709                 if (blocksize < PAGE_CACHE_SIZE) {
1710                         ext4_msg(sb, KERN_ERR, "can't mount with "
1711                                  "dioread_nolock if block size != PAGE_SIZE");
1712                         return 0;
1713                 }
1714         }
1715         return 1;
1716 }
1717
1718 static inline void ext4_show_quota_options(struct seq_file *seq,
1719                                            struct super_block *sb)
1720 {
1721 #if defined(CONFIG_QUOTA)
1722         struct ext4_sb_info *sbi = EXT4_SB(sb);
1723
1724         if (sbi->s_jquota_fmt) {
1725                 char *fmtname = "";
1726
1727                 switch (sbi->s_jquota_fmt) {
1728                 case QFMT_VFS_OLD:
1729                         fmtname = "vfsold";
1730                         break;
1731                 case QFMT_VFS_V0:
1732                         fmtname = "vfsv0";
1733                         break;
1734                 case QFMT_VFS_V1:
1735                         fmtname = "vfsv1";
1736                         break;
1737                 }
1738                 seq_printf(seq, ",jqfmt=%s", fmtname);
1739         }
1740
1741         if (sbi->s_qf_names[USRQUOTA])
1742                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1743
1744         if (sbi->s_qf_names[GRPQUOTA])
1745                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1746 #endif
1747 }
1748
1749 static const char *token2str(int token)
1750 {
1751         const struct match_token *t;
1752
1753         for (t = tokens; t->token != Opt_err; t++)
1754                 if (t->token == token && !strchr(t->pattern, '='))
1755                         break;
1756         return t->pattern;
1757 }
1758
1759 /*
1760  * Show an option if
1761  *  - it's set to a non-default value OR
1762  *  - if the per-sb default is different from the global default
1763  */
1764 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1765                               int nodefs)
1766 {
1767         struct ext4_sb_info *sbi = EXT4_SB(sb);
1768         struct ext4_super_block *es = sbi->s_es;
1769         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1770         const struct mount_opts *m;
1771         char sep = nodefs ? '\n' : ',';
1772
1773 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1774 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1775
1776         if (sbi->s_sb_block != 1)
1777                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1778
1779         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1780                 int want_set = m->flags & MOPT_SET;
1781                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1782                     (m->flags & MOPT_CLEAR_ERR))
1783                         continue;
1784                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1785                         continue; /* skip if same as the default */
1786                 if ((want_set &&
1787                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1788                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1789                         continue; /* select Opt_noFoo vs Opt_Foo */
1790                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1791         }
1792
1793         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1794             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1795                 SEQ_OPTS_PRINT("resuid=%u",
1796                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1797         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1798             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1799                 SEQ_OPTS_PRINT("resgid=%u",
1800                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1801         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1802         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1803                 SEQ_OPTS_PUTS("errors=remount-ro");
1804         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1805                 SEQ_OPTS_PUTS("errors=continue");
1806         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1807                 SEQ_OPTS_PUTS("errors=panic");
1808         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1809                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1810         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1811                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1812         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1813                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1814         if (sb->s_flags & MS_I_VERSION)
1815                 SEQ_OPTS_PUTS("i_version");
1816         if (nodefs || sbi->s_stripe)
1817                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1818         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1819                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1820                         SEQ_OPTS_PUTS("data=journal");
1821                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1822                         SEQ_OPTS_PUTS("data=ordered");
1823                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1824                         SEQ_OPTS_PUTS("data=writeback");
1825         }
1826         if (nodefs ||
1827             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1828                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1829                                sbi->s_inode_readahead_blks);
1830
1831         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1832                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1833                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1834         if (nodefs || sbi->s_max_dir_size_kb)
1835                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1836
1837         ext4_show_quota_options(seq, sb);
1838         return 0;
1839 }
1840
1841 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1842 {
1843         return _ext4_show_options(seq, root->d_sb, 0);
1844 }
1845
1846 static int options_seq_show(struct seq_file *seq, void *offset)
1847 {
1848         struct super_block *sb = seq->private;
1849         int rc;
1850
1851         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1852         rc = _ext4_show_options(seq, sb, 1);
1853         seq_puts(seq, "\n");
1854         return rc;
1855 }
1856
1857 static int options_open_fs(struct inode *inode, struct file *file)
1858 {
1859         return single_open(file, options_seq_show, PDE_DATA(inode));
1860 }
1861
1862 static const struct file_operations ext4_seq_options_fops = {
1863         .owner = THIS_MODULE,
1864         .open = options_open_fs,
1865         .read = seq_read,
1866         .llseek = seq_lseek,
1867         .release = single_release,
1868 };
1869
1870 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1871                             int read_only)
1872 {
1873         struct ext4_sb_info *sbi = EXT4_SB(sb);
1874         int res = 0;
1875
1876         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1877                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1878                          "forcing read-only mode");
1879                 res = MS_RDONLY;
1880         }
1881         if (read_only)
1882                 goto done;
1883         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1884                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1885                          "running e2fsck is recommended");
1886         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1887                 ext4_msg(sb, KERN_WARNING,
1888                          "warning: mounting fs with errors, "
1889                          "running e2fsck is recommended");
1890         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1891                  le16_to_cpu(es->s_mnt_count) >=
1892                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1893                 ext4_msg(sb, KERN_WARNING,
1894                          "warning: maximal mount count reached, "
1895                          "running e2fsck is recommended");
1896         else if (le32_to_cpu(es->s_checkinterval) &&
1897                 (le32_to_cpu(es->s_lastcheck) +
1898                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1899                 ext4_msg(sb, KERN_WARNING,
1900                          "warning: checktime reached, "
1901                          "running e2fsck is recommended");
1902         if (!sbi->s_journal)
1903                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1904         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1905                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1906         le16_add_cpu(&es->s_mnt_count, 1);
1907         es->s_mtime = cpu_to_le32(get_seconds());
1908         ext4_update_dynamic_rev(sb);
1909         if (sbi->s_journal)
1910                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1911
1912         ext4_commit_super(sb, 1);
1913 done:
1914         if (test_opt(sb, DEBUG))
1915                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1916                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1917                         sb->s_blocksize,
1918                         sbi->s_groups_count,
1919                         EXT4_BLOCKS_PER_GROUP(sb),
1920                         EXT4_INODES_PER_GROUP(sb),
1921                         sbi->s_mount_opt, sbi->s_mount_opt2);
1922
1923         cleancache_init_fs(sb);
1924         return res;
1925 }
1926
1927 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1928 {
1929         struct ext4_sb_info *sbi = EXT4_SB(sb);
1930         struct flex_groups *new_groups;
1931         int size;
1932
1933         if (!sbi->s_log_groups_per_flex)
1934                 return 0;
1935
1936         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1937         if (size <= sbi->s_flex_groups_allocated)
1938                 return 0;
1939
1940         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1941         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1942         if (!new_groups) {
1943                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1944                          size / (int) sizeof(struct flex_groups));
1945                 return -ENOMEM;
1946         }
1947
1948         if (sbi->s_flex_groups) {
1949                 memcpy(new_groups, sbi->s_flex_groups,
1950                        (sbi->s_flex_groups_allocated *
1951                         sizeof(struct flex_groups)));
1952                 ext4_kvfree(sbi->s_flex_groups);
1953         }
1954         sbi->s_flex_groups = new_groups;
1955         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1956         return 0;
1957 }
1958
1959 static int ext4_fill_flex_info(struct super_block *sb)
1960 {
1961         struct ext4_sb_info *sbi = EXT4_SB(sb);
1962         struct ext4_group_desc *gdp = NULL;
1963         ext4_group_t flex_group;
1964         int i, err;
1965
1966         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1967         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1968                 sbi->s_log_groups_per_flex = 0;
1969                 return 1;
1970         }
1971
1972         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1973         if (err)
1974                 goto failed;
1975
1976         for (i = 0; i < sbi->s_groups_count; i++) {
1977                 gdp = ext4_get_group_desc(sb, i, NULL);
1978
1979                 flex_group = ext4_flex_group(sbi, i);
1980                 atomic_add(ext4_free_inodes_count(sb, gdp),
1981                            &sbi->s_flex_groups[flex_group].free_inodes);
1982                 atomic64_add(ext4_free_group_clusters(sb, gdp),
1983                              &sbi->s_flex_groups[flex_group].free_clusters);
1984                 atomic_add(ext4_used_dirs_count(sb, gdp),
1985                            &sbi->s_flex_groups[flex_group].used_dirs);
1986         }
1987
1988         return 1;
1989 failed:
1990         return 0;
1991 }
1992
1993 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1994                                    struct ext4_group_desc *gdp)
1995 {
1996         int offset;
1997         __u16 crc = 0;
1998         __le32 le_group = cpu_to_le32(block_group);
1999
2000         if ((sbi->s_es->s_feature_ro_compat &
2001              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
2002                 /* Use new metadata_csum algorithm */
2003                 __le16 save_csum;
2004                 __u32 csum32;
2005
2006                 save_csum = gdp->bg_checksum;
2007                 gdp->bg_checksum = 0;
2008                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2009                                      sizeof(le_group));
2010                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2011                                      sbi->s_desc_size);
2012                 gdp->bg_checksum = save_csum;
2013
2014                 crc = csum32 & 0xFFFF;
2015                 goto out;
2016         }
2017
2018         /* old crc16 code */
2019         offset = offsetof(struct ext4_group_desc, bg_checksum);
2020
2021         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2022         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2023         crc = crc16(crc, (__u8 *)gdp, offset);
2024         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2025         /* for checksum of struct ext4_group_desc do the rest...*/
2026         if ((sbi->s_es->s_feature_incompat &
2027              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2028             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2029                 crc = crc16(crc, (__u8 *)gdp + offset,
2030                             le16_to_cpu(sbi->s_es->s_desc_size) -
2031                                 offset);
2032
2033 out:
2034         return cpu_to_le16(crc);
2035 }
2036
2037 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2038                                 struct ext4_group_desc *gdp)
2039 {
2040         if (ext4_has_group_desc_csum(sb) &&
2041             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2042                                                       block_group, gdp)))
2043                 return 0;
2044
2045         return 1;
2046 }
2047
2048 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2049                               struct ext4_group_desc *gdp)
2050 {
2051         if (!ext4_has_group_desc_csum(sb))
2052                 return;
2053         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2054 }
2055
2056 /* Called at mount-time, super-block is locked */
2057 static int ext4_check_descriptors(struct super_block *sb,
2058                                   ext4_group_t *first_not_zeroed)
2059 {
2060         struct ext4_sb_info *sbi = EXT4_SB(sb);
2061         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2062         ext4_fsblk_t last_block;
2063         ext4_fsblk_t block_bitmap;
2064         ext4_fsblk_t inode_bitmap;
2065         ext4_fsblk_t inode_table;
2066         int flexbg_flag = 0;
2067         ext4_group_t i, grp = sbi->s_groups_count;
2068
2069         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2070                 flexbg_flag = 1;
2071
2072         ext4_debug("Checking group descriptors");
2073
2074         for (i = 0; i < sbi->s_groups_count; i++) {
2075                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2076
2077                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2078                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2079                 else
2080                         last_block = first_block +
2081                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2082
2083                 if ((grp == sbi->s_groups_count) &&
2084                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2085                         grp = i;
2086
2087                 block_bitmap = ext4_block_bitmap(sb, gdp);
2088                 if (block_bitmap < first_block || block_bitmap > last_block) {
2089                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2090                                "Block bitmap for group %u not in group "
2091                                "(block %llu)!", i, block_bitmap);
2092                         return 0;
2093                 }
2094                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2095                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2096                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2097                                "Inode bitmap for group %u not in group "
2098                                "(block %llu)!", i, inode_bitmap);
2099                         return 0;
2100                 }
2101                 inode_table = ext4_inode_table(sb, gdp);
2102                 if (inode_table < first_block ||
2103                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2104                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2105                                "Inode table for group %u not in group "
2106                                "(block %llu)!", i, inode_table);
2107                         return 0;
2108                 }
2109                 ext4_lock_group(sb, i);
2110                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2111                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2112                                  "Checksum for group %u failed (%u!=%u)",
2113                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2114                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2115                         if (!(sb->s_flags & MS_RDONLY)) {
2116                                 ext4_unlock_group(sb, i);
2117                                 return 0;
2118                         }
2119                 }
2120                 ext4_unlock_group(sb, i);
2121                 if (!flexbg_flag)
2122                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2123         }
2124         if (NULL != first_not_zeroed)
2125                 *first_not_zeroed = grp;
2126
2127         ext4_free_blocks_count_set(sbi->s_es,
2128                                    EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2129         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2130         return 1;
2131 }
2132
2133 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2134  * the superblock) which were deleted from all directories, but held open by
2135  * a process at the time of a crash.  We walk the list and try to delete these
2136  * inodes at recovery time (only with a read-write filesystem).
2137  *
2138  * In order to keep the orphan inode chain consistent during traversal (in
2139  * case of crash during recovery), we link each inode into the superblock
2140  * orphan list_head and handle it the same way as an inode deletion during
2141  * normal operation (which journals the operations for us).
2142  *
2143  * We only do an iget() and an iput() on each inode, which is very safe if we
2144  * accidentally point at an in-use or already deleted inode.  The worst that
2145  * can happen in this case is that we get a "bit already cleared" message from
2146  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2147  * e2fsck was run on this filesystem, and it must have already done the orphan
2148  * inode cleanup for us, so we can safely abort without any further action.
2149  */
2150 static void ext4_orphan_cleanup(struct super_block *sb,
2151                                 struct ext4_super_block *es)
2152 {
2153         unsigned int s_flags = sb->s_flags;
2154         int nr_orphans = 0, nr_truncates = 0;
2155 #ifdef CONFIG_QUOTA
2156         int i;
2157 #endif
2158         if (!es->s_last_orphan) {
2159                 jbd_debug(4, "no orphan inodes to clean up\n");
2160                 return;
2161         }
2162
2163         if (bdev_read_only(sb->s_bdev)) {
2164                 ext4_msg(sb, KERN_ERR, "write access "
2165                         "unavailable, skipping orphan cleanup");
2166                 return;
2167         }
2168
2169         /* Check if feature set would not allow a r/w mount */
2170         if (!ext4_feature_set_ok(sb, 0)) {
2171                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2172                          "unknown ROCOMPAT features");
2173                 return;
2174         }
2175
2176         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2177                 /* don't clear list on RO mount w/ errors */
2178                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2179                         jbd_debug(1, "Errors on filesystem, "
2180                                   "clearing orphan list.\n");
2181                         es->s_last_orphan = 0;
2182                 }
2183                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2184                 return;
2185         }
2186
2187         if (s_flags & MS_RDONLY) {
2188                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2189                 sb->s_flags &= ~MS_RDONLY;
2190         }
2191 #ifdef CONFIG_QUOTA
2192         /* Needed for iput() to work correctly and not trash data */
2193         sb->s_flags |= MS_ACTIVE;
2194         /* Turn on quotas so that they are updated correctly */
2195         for (i = 0; i < MAXQUOTAS; i++) {
2196                 if (EXT4_SB(sb)->s_qf_names[i]) {
2197                         int ret = ext4_quota_on_mount(sb, i);
2198                         if (ret < 0)
2199                                 ext4_msg(sb, KERN_ERR,
2200                                         "Cannot turn on journaled "
2201                                         "quota: error %d", ret);
2202                 }
2203         }
2204 #endif
2205
2206         while (es->s_last_orphan) {
2207                 struct inode *inode;
2208
2209                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2210                 if (IS_ERR(inode)) {
2211                         es->s_last_orphan = 0;
2212                         break;
2213                 }
2214
2215                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2216                 dquot_initialize(inode);
2217                 if (inode->i_nlink) {
2218                         if (test_opt(sb, DEBUG))
2219                                 ext4_msg(sb, KERN_DEBUG,
2220                                         "%s: truncating inode %lu to %lld bytes",
2221                                         __func__, inode->i_ino, inode->i_size);
2222                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2223                                   inode->i_ino, inode->i_size);
2224                         mutex_lock(&inode->i_mutex);
2225                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2226                         ext4_truncate(inode);
2227                         mutex_unlock(&inode->i_mutex);
2228                         nr_truncates++;
2229                 } else {
2230                         if (test_opt(sb, DEBUG))
2231                                 ext4_msg(sb, KERN_DEBUG,
2232                                         "%s: deleting unreferenced inode %lu",
2233                                         __func__, inode->i_ino);
2234                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2235                                   inode->i_ino);
2236                         nr_orphans++;
2237                 }
2238                 iput(inode);  /* The delete magic happens here! */
2239         }
2240
2241 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2242
2243         if (nr_orphans)
2244                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2245                        PLURAL(nr_orphans));
2246         if (nr_truncates)
2247                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2248                        PLURAL(nr_truncates));
2249 #ifdef CONFIG_QUOTA
2250         /* Turn quotas off */
2251         for (i = 0; i < MAXQUOTAS; i++) {
2252                 if (sb_dqopt(sb)->files[i])
2253                         dquot_quota_off(sb, i);
2254         }
2255 #endif
2256         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2257 }
2258
2259 /*
2260  * Maximal extent format file size.
2261  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2262  * extent format containers, within a sector_t, and within i_blocks
2263  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2264  * so that won't be a limiting factor.
2265  *
2266  * However there is other limiting factor. We do store extents in the form
2267  * of starting block and length, hence the resulting length of the extent
2268  * covering maximum file size must fit into on-disk format containers as
2269  * well. Given that length is always by 1 unit bigger than max unit (because
2270  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2271  *
2272  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2273  */
2274 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2275 {
2276         loff_t res;
2277         loff_t upper_limit = MAX_LFS_FILESIZE;
2278
2279         /* small i_blocks in vfs inode? */
2280         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2281                 /*
2282                  * CONFIG_LBDAF is not enabled implies the inode
2283                  * i_block represent total blocks in 512 bytes
2284                  * 32 == size of vfs inode i_blocks * 8
2285                  */
2286                 upper_limit = (1LL << 32) - 1;
2287
2288                 /* total blocks in file system block size */
2289                 upper_limit >>= (blkbits - 9);
2290                 upper_limit <<= blkbits;
2291         }
2292
2293         /*
2294          * 32-bit extent-start container, ee_block. We lower the maxbytes
2295          * by one fs block, so ee_len can cover the extent of maximum file
2296          * size
2297          */
2298         res = (1LL << 32) - 1;
2299         res <<= blkbits;
2300
2301         /* Sanity check against vm- & vfs- imposed limits */
2302         if (res > upper_limit)
2303                 res = upper_limit;
2304
2305         return res;
2306 }
2307
2308 /*
2309  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2310  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2311  * We need to be 1 filesystem block less than the 2^48 sector limit.
2312  */
2313 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2314 {
2315         loff_t res = EXT4_NDIR_BLOCKS;
2316         int meta_blocks;
2317         loff_t upper_limit;
2318         /* This is calculated to be the largest file size for a dense, block
2319          * mapped file such that the file's total number of 512-byte sectors,
2320          * including data and all indirect blocks, does not exceed (2^48 - 1).
2321          *
2322          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2323          * number of 512-byte sectors of the file.
2324          */
2325
2326         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2327                 /*
2328                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2329                  * the inode i_block field represents total file blocks in
2330                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2331                  */
2332                 upper_limit = (1LL << 32) - 1;
2333
2334                 /* total blocks in file system block size */
2335                 upper_limit >>= (bits - 9);
2336
2337         } else {
2338                 /*
2339                  * We use 48 bit ext4_inode i_blocks
2340                  * With EXT4_HUGE_FILE_FL set the i_blocks
2341                  * represent total number of blocks in
2342                  * file system block size
2343                  */
2344                 upper_limit = (1LL << 48) - 1;
2345
2346         }
2347
2348         /* indirect blocks */
2349         meta_blocks = 1;
2350         /* double indirect blocks */
2351         meta_blocks += 1 + (1LL << (bits-2));
2352         /* tripple indirect blocks */
2353         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2354
2355         upper_limit -= meta_blocks;
2356         upper_limit <<= bits;
2357
2358         res += 1LL << (bits-2);
2359         res += 1LL << (2*(bits-2));
2360         res += 1LL << (3*(bits-2));
2361         res <<= bits;
2362         if (res > upper_limit)
2363                 res = upper_limit;
2364
2365         if (res > MAX_LFS_FILESIZE)
2366                 res = MAX_LFS_FILESIZE;
2367
2368         return res;
2369 }
2370
2371 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2372                                    ext4_fsblk_t logical_sb_block, int nr)
2373 {
2374         struct ext4_sb_info *sbi = EXT4_SB(sb);
2375         ext4_group_t bg, first_meta_bg;
2376         int has_super = 0;
2377
2378         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2379
2380         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2381             nr < first_meta_bg)
2382                 return logical_sb_block + nr + 1;
2383         bg = sbi->s_desc_per_block * nr;
2384         if (ext4_bg_has_super(sb, bg))
2385                 has_super = 1;
2386
2387         return (has_super + ext4_group_first_block_no(sb, bg));
2388 }
2389
2390 /**
2391  * ext4_get_stripe_size: Get the stripe size.
2392  * @sbi: In memory super block info
2393  *
2394  * If we have specified it via mount option, then
2395  * use the mount option value. If the value specified at mount time is
2396  * greater than the blocks per group use the super block value.
2397  * If the super block value is greater than blocks per group return 0.
2398  * Allocator needs it be less than blocks per group.
2399  *
2400  */
2401 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2402 {
2403         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2404         unsigned long stripe_width =
2405                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2406         int ret;
2407
2408         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2409                 ret = sbi->s_stripe;
2410         else if (stripe_width <= sbi->s_blocks_per_group)
2411                 ret = stripe_width;
2412         else if (stride <= sbi->s_blocks_per_group)
2413                 ret = stride;
2414         else
2415                 ret = 0;
2416
2417         /*
2418          * If the stripe width is 1, this makes no sense and
2419          * we set it to 0 to turn off stripe handling code.
2420          */
2421         if (ret <= 1)
2422                 ret = 0;
2423
2424         return ret;
2425 }
2426
2427 /* sysfs supprt */
2428
2429 struct ext4_attr {
2430         struct attribute attr;
2431         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2432         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2433                          const char *, size_t);
2434         union {
2435                 int offset;
2436                 int deprecated_val;
2437         } u;
2438 };
2439
2440 static int parse_strtoull(const char *buf,
2441                 unsigned long long max, unsigned long long *value)
2442 {
2443         int ret;
2444
2445         ret = kstrtoull(skip_spaces(buf), 0, value);
2446         if (!ret && *value > max)
2447                 ret = -EINVAL;
2448         return ret;
2449 }
2450
2451 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2452                                               struct ext4_sb_info *sbi,
2453                                               char *buf)
2454 {
2455         return snprintf(buf, PAGE_SIZE, "%llu\n",
2456                 (s64) EXT4_C2B(sbi,
2457                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2458 }
2459
2460 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2461                                          struct ext4_sb_info *sbi, char *buf)
2462 {
2463         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2464
2465         if (!sb->s_bdev->bd_part)
2466                 return snprintf(buf, PAGE_SIZE, "0\n");
2467         return snprintf(buf, PAGE_SIZE, "%lu\n",
2468                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2469                          sbi->s_sectors_written_start) >> 1);
2470 }
2471
2472 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2473                                           struct ext4_sb_info *sbi, char *buf)
2474 {
2475         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2476
2477         if (!sb->s_bdev->bd_part)
2478                 return snprintf(buf, PAGE_SIZE, "0\n");
2479         return snprintf(buf, PAGE_SIZE, "%llu\n",
2480                         (unsigned long long)(sbi->s_kbytes_written +
2481                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2482                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2483 }
2484
2485 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2486                                           struct ext4_sb_info *sbi,
2487                                           const char *buf, size_t count)
2488 {
2489         unsigned long t;
2490         int ret;
2491
2492         ret = kstrtoul(skip_spaces(buf), 0, &t);
2493         if (ret)
2494                 return ret;
2495
2496         if (t && (!is_power_of_2(t) || t > 0x40000000))
2497                 return -EINVAL;
2498
2499         sbi->s_inode_readahead_blks = t;
2500         return count;
2501 }
2502
2503 static ssize_t sbi_ui_show(struct ext4_attr *a,
2504                            struct ext4_sb_info *sbi, char *buf)
2505 {
2506         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2507
2508         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2509 }
2510
2511 static ssize_t sbi_ui_store(struct ext4_attr *a,
2512                             struct ext4_sb_info *sbi,
2513                             const char *buf, size_t count)
2514 {
2515         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2516         unsigned long t;
2517         int ret;
2518
2519         ret = kstrtoul(skip_spaces(buf), 0, &t);
2520         if (ret)
2521                 return ret;
2522         *ui = t;
2523         return count;
2524 }
2525
2526 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2527                                   struct ext4_sb_info *sbi, char *buf)
2528 {
2529         return snprintf(buf, PAGE_SIZE, "%llu\n",
2530                 (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2531 }
2532
2533 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2534                                    struct ext4_sb_info *sbi,
2535                                    const char *buf, size_t count)
2536 {
2537         unsigned long long val;
2538         int ret;
2539
2540         if (parse_strtoull(buf, -1ULL, &val))
2541                 return -EINVAL;
2542         ret = ext4_reserve_clusters(sbi, val);
2543
2544         return ret ? ret : count;
2545 }
2546
2547 static ssize_t trigger_test_error(struct ext4_attr *a,
2548                                   struct ext4_sb_info *sbi,
2549                                   const char *buf, size_t count)
2550 {
2551         int len = count;
2552
2553         if (!capable(CAP_SYS_ADMIN))
2554                 return -EPERM;
2555
2556         if (len && buf[len-1] == '\n')
2557                 len--;
2558
2559         if (len)
2560                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2561         return count;
2562 }
2563
2564 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2565                                    struct ext4_sb_info *sbi, char *buf)
2566 {
2567         return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2568 }
2569
2570 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2571 static struct ext4_attr ext4_attr_##_name = {                   \
2572         .attr = {.name = __stringify(_name), .mode = _mode },   \
2573         .show   = _show,                                        \
2574         .store  = _store,                                       \
2575         .u = {                                                  \
2576                 .offset = offsetof(struct ext4_sb_info, _elname),\
2577         },                                                      \
2578 }
2579 #define EXT4_ATTR(name, mode, show, store) \
2580 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2581
2582 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2583 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2584 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2585 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2586         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2587 #define ATTR_LIST(name) &ext4_attr_##name.attr
2588 #define EXT4_DEPRECATED_ATTR(_name, _val)       \
2589 static struct ext4_attr ext4_attr_##_name = {                   \
2590         .attr = {.name = __stringify(_name), .mode = 0444 },    \
2591         .show   = sbi_deprecated_show,                          \
2592         .u = {                                                  \
2593                 .deprecated_val = _val,                         \
2594         },                                                      \
2595 }
2596
2597 EXT4_RO_ATTR(delayed_allocation_blocks);
2598 EXT4_RO_ATTR(session_write_kbytes);
2599 EXT4_RO_ATTR(lifetime_write_kbytes);
2600 EXT4_RW_ATTR(reserved_clusters);
2601 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2602                  inode_readahead_blks_store, s_inode_readahead_blks);
2603 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2604 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2605 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2606 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2607 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2608 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2609 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2610 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2611 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2612 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2613
2614 static struct attribute *ext4_attrs[] = {
2615         ATTR_LIST(delayed_allocation_blocks),
2616         ATTR_LIST(session_write_kbytes),
2617         ATTR_LIST(lifetime_write_kbytes),
2618         ATTR_LIST(reserved_clusters),
2619         ATTR_LIST(inode_readahead_blks),
2620         ATTR_LIST(inode_goal),
2621         ATTR_LIST(mb_stats),
2622         ATTR_LIST(mb_max_to_scan),
2623         ATTR_LIST(mb_min_to_scan),
2624         ATTR_LIST(mb_order2_req),
2625         ATTR_LIST(mb_stream_req),
2626         ATTR_LIST(mb_group_prealloc),
2627         ATTR_LIST(max_writeback_mb_bump),
2628         ATTR_LIST(extent_max_zeroout_kb),
2629         ATTR_LIST(trigger_fs_error),
2630         NULL,
2631 };
2632
2633 /* Features this copy of ext4 supports */
2634 EXT4_INFO_ATTR(lazy_itable_init);
2635 EXT4_INFO_ATTR(batched_discard);
2636 EXT4_INFO_ATTR(meta_bg_resize);
2637
2638 static struct attribute *ext4_feat_attrs[] = {
2639         ATTR_LIST(lazy_itable_init),
2640         ATTR_LIST(batched_discard),
2641         ATTR_LIST(meta_bg_resize),
2642         NULL,
2643 };
2644
2645 static ssize_t ext4_attr_show(struct kobject *kobj,
2646                               struct attribute *attr, char *buf)
2647 {
2648         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2649                                                 s_kobj);
2650         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2651
2652         return a->show ? a->show(a, sbi, buf) : 0;
2653 }
2654
2655 static ssize_t ext4_attr_store(struct kobject *kobj,
2656                                struct attribute *attr,
2657                                const char *buf, size_t len)
2658 {
2659         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2660                                                 s_kobj);
2661         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2662
2663         return a->store ? a->store(a, sbi, buf, len) : 0;
2664 }
2665
2666 static void ext4_sb_release(struct kobject *kobj)
2667 {
2668         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2669                                                 s_kobj);
2670         complete(&sbi->s_kobj_unregister);
2671 }
2672
2673 static const struct sysfs_ops ext4_attr_ops = {
2674         .show   = ext4_attr_show,
2675         .store  = ext4_attr_store,
2676 };
2677
2678 static struct kobj_type ext4_ktype = {
2679         .default_attrs  = ext4_attrs,
2680         .sysfs_ops      = &ext4_attr_ops,
2681         .release        = ext4_sb_release,
2682 };
2683
2684 static void ext4_feat_release(struct kobject *kobj)
2685 {
2686         complete(&ext4_feat->f_kobj_unregister);
2687 }
2688
2689 static struct kobj_type ext4_feat_ktype = {
2690         .default_attrs  = ext4_feat_attrs,
2691         .sysfs_ops      = &ext4_attr_ops,
2692         .release        = ext4_feat_release,
2693 };
2694
2695 /*
2696  * Check whether this filesystem can be mounted based on
2697  * the features present and the RDONLY/RDWR mount requested.
2698  * Returns 1 if this filesystem can be mounted as requested,
2699  * 0 if it cannot be.
2700  */
2701 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2702 {
2703         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2704                 ext4_msg(sb, KERN_ERR,
2705                         "Couldn't mount because of "
2706                         "unsupported optional features (%x)",
2707                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2708                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2709                 return 0;
2710         }
2711
2712         if (readonly)
2713                 return 1;
2714
2715         /* Check that feature set is OK for a read-write mount */
2716         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2717                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2718                          "unsupported optional features (%x)",
2719                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2720                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2721                 return 0;
2722         }
2723         /*
2724          * Large file size enabled file system can only be mounted
2725          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2726          */
2727         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2728                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2729                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2730                                  "cannot be mounted RDWR without "
2731                                  "CONFIG_LBDAF");
2732                         return 0;
2733                 }
2734         }
2735         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2736             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2737                 ext4_msg(sb, KERN_ERR,
2738                          "Can't support bigalloc feature without "
2739                          "extents feature\n");
2740                 return 0;
2741         }
2742
2743 #ifndef CONFIG_QUOTA
2744         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2745             !readonly) {
2746                 ext4_msg(sb, KERN_ERR,
2747                          "Filesystem with quota feature cannot be mounted RDWR "
2748                          "without CONFIG_QUOTA");
2749                 return 0;
2750         }
2751 #endif  /* CONFIG_QUOTA */
2752         return 1;
2753 }
2754
2755 /*
2756  * This function is called once a day if we have errors logged
2757  * on the file system
2758  */
2759 static void print_daily_error_info(unsigned long arg)
2760 {
2761         struct super_block *sb = (struct super_block *) arg;
2762         struct ext4_sb_info *sbi;
2763         struct ext4_super_block *es;
2764
2765         sbi = EXT4_SB(sb);
2766         es = sbi->s_es;
2767
2768         if (es->s_error_count)
2769                 ext4_msg(sb, KERN_NOTICE, "error count: %u",
2770                          le32_to_cpu(es->s_error_count));
2771         if (es->s_first_error_time) {
2772                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2773                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2774                        (int) sizeof(es->s_first_error_func),
2775                        es->s_first_error_func,
2776                        le32_to_cpu(es->s_first_error_line));
2777                 if (es->s_first_error_ino)
2778                         printk(": inode %u",
2779                                le32_to_cpu(es->s_first_error_ino));
2780                 if (es->s_first_error_block)
2781                         printk(": block %llu", (unsigned long long)
2782                                le64_to_cpu(es->s_first_error_block));
2783                 printk("\n");
2784         }
2785         if (es->s_last_error_time) {
2786                 printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2787                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2788                        (int) sizeof(es->s_last_error_func),
2789                        es->s_last_error_func,
2790                        le32_to_cpu(es->s_last_error_line));
2791                 if (es->s_last_error_ino)
2792                         printk(": inode %u",
2793                                le32_to_cpu(es->s_last_error_ino));
2794                 if (es->s_last_error_block)
2795                         printk(": block %llu", (unsigned long long)
2796                                le64_to_cpu(es->s_last_error_block));
2797                 printk("\n");
2798         }
2799         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2800 }
2801
2802 /* Find next suitable group and run ext4_init_inode_table */
2803 static int ext4_run_li_request(struct ext4_li_request *elr)
2804 {
2805         struct ext4_group_desc *gdp = NULL;
2806         ext4_group_t group, ngroups;
2807         struct super_block *sb;
2808         unsigned long timeout = 0;
2809         int ret = 0;
2810
2811         sb = elr->lr_super;
2812         ngroups = EXT4_SB(sb)->s_groups_count;
2813
2814         sb_start_write(sb);
2815         for (group = elr->lr_next_group; group < ngroups; group++) {
2816                 gdp = ext4_get_group_desc(sb, group, NULL);
2817                 if (!gdp) {
2818                         ret = 1;
2819                         break;
2820                 }
2821
2822                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2823                         break;
2824         }
2825
2826         if (group >= ngroups)
2827                 ret = 1;
2828
2829         if (!ret) {
2830                 timeout = jiffies;
2831                 ret = ext4_init_inode_table(sb, group,
2832                                             elr->lr_timeout ? 0 : 1);
2833                 if (elr->lr_timeout == 0) {
2834                         timeout = (jiffies - timeout) *
2835                                   elr->lr_sbi->s_li_wait_mult;
2836                         elr->lr_timeout = timeout;
2837                 }
2838                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2839                 elr->lr_next_group = group + 1;
2840         }
2841         sb_end_write(sb);
2842
2843         return ret;
2844 }
2845
2846 /*
2847  * Remove lr_request from the list_request and free the
2848  * request structure. Should be called with li_list_mtx held
2849  */
2850 static void ext4_remove_li_request(struct ext4_li_request *elr)
2851 {
2852         struct ext4_sb_info *sbi;
2853
2854         if (!elr)
2855                 return;
2856
2857         sbi = elr->lr_sbi;
2858
2859         list_del(&elr->lr_request);
2860         sbi->s_li_request = NULL;
2861         kfree(elr);
2862 }
2863
2864 static void ext4_unregister_li_request(struct super_block *sb)
2865 {
2866         mutex_lock(&ext4_li_mtx);
2867         if (!ext4_li_info) {
2868                 mutex_unlock(&ext4_li_mtx);
2869                 return;
2870         }
2871
2872         mutex_lock(&ext4_li_info->li_list_mtx);
2873         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2874         mutex_unlock(&ext4_li_info->li_list_mtx);
2875         mutex_unlock(&ext4_li_mtx);
2876 }
2877
2878 static struct task_struct *ext4_lazyinit_task;
2879
2880 /*
2881  * This is the function where ext4lazyinit thread lives. It walks
2882  * through the request list searching for next scheduled filesystem.
2883  * When such a fs is found, run the lazy initialization request
2884  * (ext4_rn_li_request) and keep track of the time spend in this
2885  * function. Based on that time we compute next schedule time of
2886  * the request. When walking through the list is complete, compute
2887  * next waking time and put itself into sleep.
2888  */
2889 static int ext4_lazyinit_thread(void *arg)
2890 {
2891         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2892         struct list_head *pos, *n;
2893         struct ext4_li_request *elr;
2894         unsigned long next_wakeup, cur;
2895
2896         BUG_ON(NULL == eli);
2897
2898 cont_thread:
2899         while (true) {
2900                 next_wakeup = MAX_JIFFY_OFFSET;
2901
2902                 mutex_lock(&eli->li_list_mtx);
2903                 if (list_empty(&eli->li_request_list)) {
2904                         mutex_unlock(&eli->li_list_mtx);
2905                         goto exit_thread;
2906                 }
2907
2908                 list_for_each_safe(pos, n, &eli->li_request_list) {
2909                         elr = list_entry(pos, struct ext4_li_request,
2910                                          lr_request);
2911
2912                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2913                                 if (ext4_run_li_request(elr) != 0) {
2914                                         /* error, remove the lazy_init job */
2915                                         ext4_remove_li_request(elr);
2916                                         continue;
2917                                 }
2918                         }
2919
2920                         if (time_before(elr->lr_next_sched, next_wakeup))
2921                                 next_wakeup = elr->lr_next_sched;
2922                 }
2923                 mutex_unlock(&eli->li_list_mtx);
2924
2925                 try_to_freeze();
2926
2927                 cur = jiffies;
2928                 if ((time_after_eq(cur, next_wakeup)) ||
2929                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2930                         cond_resched();
2931                         continue;
2932                 }
2933
2934                 schedule_timeout_interruptible(next_wakeup - cur);
2935
2936                 if (kthread_should_stop()) {
2937                         ext4_clear_request_list();
2938                         goto exit_thread;
2939                 }
2940         }
2941
2942 exit_thread:
2943         /*
2944          * It looks like the request list is empty, but we need
2945          * to check it under the li_list_mtx lock, to prevent any
2946          * additions into it, and of course we should lock ext4_li_mtx
2947          * to atomically free the list and ext4_li_info, because at
2948          * this point another ext4 filesystem could be registering
2949          * new one.
2950          */
2951         mutex_lock(&ext4_li_mtx);
2952         mutex_lock(&eli->li_list_mtx);
2953         if (!list_empty(&eli->li_request_list)) {
2954                 mutex_unlock(&eli->li_list_mtx);
2955                 mutex_unlock(&ext4_li_mtx);
2956                 goto cont_thread;
2957         }
2958         mutex_unlock(&eli->li_list_mtx);
2959         kfree(ext4_li_info);
2960         ext4_li_info = NULL;
2961         mutex_unlock(&ext4_li_mtx);
2962
2963         return 0;
2964 }
2965
2966 static void ext4_clear_request_list(void)
2967 {
2968         struct list_head *pos, *n;
2969         struct ext4_li_request *elr;
2970
2971         mutex_lock(&ext4_li_info->li_list_mtx);
2972         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2973                 elr = list_entry(pos, struct ext4_li_request,
2974                                  lr_request);
2975                 ext4_remove_li_request(elr);
2976         }
2977         mutex_unlock(&ext4_li_info->li_list_mtx);
2978 }
2979
2980 static int ext4_run_lazyinit_thread(void)
2981 {
2982         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2983                                          ext4_li_info, "ext4lazyinit");
2984         if (IS_ERR(ext4_lazyinit_task)) {
2985                 int err = PTR_ERR(ext4_lazyinit_task);
2986                 ext4_clear_request_list();
2987                 kfree(ext4_li_info);
2988                 ext4_li_info = NULL;
2989                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2990                                  "initialization thread\n",
2991                                  err);
2992                 return err;
2993         }
2994         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2995         return 0;
2996 }
2997
2998 /*
2999  * Check whether it make sense to run itable init. thread or not.
3000  * If there is at least one uninitialized inode table, return
3001  * corresponding group number, else the loop goes through all
3002  * groups and return total number of groups.
3003  */
3004 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3005 {
3006         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3007         struct ext4_group_desc *gdp = NULL;
3008
3009         for (group = 0; group < ngroups; group++) {
3010                 gdp = ext4_get_group_desc(sb, group, NULL);
3011                 if (!gdp)
3012                         continue;
3013
3014                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3015                         break;
3016         }
3017
3018         return group;
3019 }
3020
3021 static int ext4_li_info_new(void)
3022 {
3023         struct ext4_lazy_init *eli = NULL;
3024
3025         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3026         if (!eli)
3027                 return -ENOMEM;
3028
3029         INIT_LIST_HEAD(&eli->li_request_list);
3030         mutex_init(&eli->li_list_mtx);
3031
3032         eli->li_state |= EXT4_LAZYINIT_QUIT;
3033
3034         ext4_li_info = eli;
3035
3036         return 0;
3037 }
3038
3039 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3040                                             ext4_group_t start)
3041 {
3042         struct ext4_sb_info *sbi = EXT4_SB(sb);
3043         struct ext4_li_request *elr;
3044         unsigned long rnd;
3045
3046         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3047         if (!elr)
3048                 return NULL;
3049
3050         elr->lr_super = sb;
3051         elr->lr_sbi = sbi;
3052         elr->lr_next_group = start;
3053
3054         /*
3055          * Randomize first schedule time of the request to
3056          * spread the inode table initialization requests
3057          * better.
3058          */
3059         get_random_bytes(&rnd, sizeof(rnd));
3060         elr->lr_next_sched = jiffies + (unsigned long)rnd %
3061                              (EXT4_DEF_LI_MAX_START_DELAY * HZ);
3062
3063         return elr;
3064 }
3065
3066 int ext4_register_li_request(struct super_block *sb,
3067                              ext4_group_t first_not_zeroed)
3068 {
3069         struct ext4_sb_info *sbi = EXT4_SB(sb);
3070         struct ext4_li_request *elr = NULL;
3071         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3072         int ret = 0;
3073
3074         mutex_lock(&ext4_li_mtx);
3075         if (sbi->s_li_request != NULL) {
3076                 /*
3077                  * Reset timeout so it can be computed again, because
3078                  * s_li_wait_mult might have changed.
3079                  */
3080                 sbi->s_li_request->lr_timeout = 0;
3081                 goto out;
3082         }
3083
3084         if (first_not_zeroed == ngroups ||
3085             (sb->s_flags & MS_RDONLY) ||
3086             !test_opt(sb, INIT_INODE_TABLE))
3087                 goto out;
3088
3089         elr = ext4_li_request_new(sb, first_not_zeroed);
3090         if (!elr) {
3091                 ret = -ENOMEM;
3092                 goto out;
3093         }
3094
3095         if (NULL == ext4_li_info) {
3096                 ret = ext4_li_info_new();
3097                 if (ret)
3098                         goto out;
3099         }
3100
3101         mutex_lock(&ext4_li_info->li_list_mtx);
3102         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3103         mutex_unlock(&ext4_li_info->li_list_mtx);
3104
3105         sbi->s_li_request = elr;
3106         /*
3107          * set elr to NULL here since it has been inserted to
3108          * the request_list and the removal and free of it is
3109          * handled by ext4_clear_request_list from now on.
3110          */
3111         elr = NULL;
3112
3113         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3114                 ret = ext4_run_lazyinit_thread();
3115                 if (ret)
3116                         goto out;
3117         }
3118 out:
3119         mutex_unlock(&ext4_li_mtx);
3120         if (ret)
3121                 kfree(elr);
3122         return ret;
3123 }
3124
3125 /*
3126  * We do not need to lock anything since this is called on
3127  * module unload.
3128  */
3129 static void ext4_destroy_lazyinit_thread(void)
3130 {
3131         /*
3132          * If thread exited earlier
3133          * there's nothing to be done.
3134          */
3135         if (!ext4_li_info || !ext4_lazyinit_task)
3136                 return;
3137
3138         kthread_stop(ext4_lazyinit_task);
3139 }
3140
3141 static int set_journal_csum_feature_set(struct super_block *sb)
3142 {
3143         int ret = 1;
3144         int compat, incompat;
3145         struct ext4_sb_info *sbi = EXT4_SB(sb);
3146
3147         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3148                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3149                 /* journal checksum v2 */
3150                 compat = 0;
3151                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3152         } else {
3153                 /* journal checksum v1 */
3154                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3155                 incompat = 0;
3156         }
3157
3158         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3159                 ret = jbd2_journal_set_features(sbi->s_journal,
3160                                 compat, 0,
3161                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3162                                 incompat);
3163         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3164                 ret = jbd2_journal_set_features(sbi->s_journal,
3165                                 compat, 0,
3166                                 incompat);
3167                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3168                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3169         } else {
3170                 jbd2_journal_clear_features(sbi->s_journal,
3171                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3172                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3173                                 JBD2_FEATURE_INCOMPAT_CSUM_V2);
3174         }
3175
3176         return ret;
3177 }
3178
3179 /*
3180  * Note: calculating the overhead so we can be compatible with
3181  * historical BSD practice is quite difficult in the face of
3182  * clusters/bigalloc.  This is because multiple metadata blocks from
3183  * different block group can end up in the same allocation cluster.
3184  * Calculating the exact overhead in the face of clustered allocation
3185  * requires either O(all block bitmaps) in memory or O(number of block
3186  * groups**2) in time.  We will still calculate the superblock for
3187  * older file systems --- and if we come across with a bigalloc file
3188  * system with zero in s_overhead_clusters the estimate will be close to
3189  * correct especially for very large cluster sizes --- but for newer
3190  * file systems, it's better to calculate this figure once at mkfs
3191  * time, and store it in the superblock.  If the superblock value is
3192  * present (even for non-bigalloc file systems), we will use it.
3193  */
3194 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3195                           char *buf)
3196 {
3197         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3198         struct ext4_group_desc  *gdp;
3199         ext4_fsblk_t            first_block, last_block, b;
3200         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3201         int                     s, j, count = 0;
3202
3203         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3204                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3205                         sbi->s_itb_per_group + 2);
3206
3207         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3208                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3209         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3210         for (i = 0; i < ngroups; i++) {
3211                 gdp = ext4_get_group_desc(sb, i, NULL);
3212                 b = ext4_block_bitmap(sb, gdp);
3213                 if (b >= first_block && b <= last_block) {
3214                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3215                         count++;
3216                 }
3217                 b = ext4_inode_bitmap(sb, gdp);
3218                 if (b >= first_block && b <= last_block) {
3219                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3220                         count++;
3221                 }
3222                 b = ext4_inode_table(sb, gdp);
3223                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3224                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3225                                 int c = EXT4_B2C(sbi, b - first_block);
3226                                 ext4_set_bit(c, buf);
3227                                 count++;
3228                         }
3229                 if (i != grp)
3230                         continue;
3231                 s = 0;
3232                 if (ext4_bg_has_super(sb, grp)) {
3233                         ext4_set_bit(s++, buf);
3234                         count++;
3235                 }
3236                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3237                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3238                         count++;
3239                 }
3240         }
3241         if (!count)
3242                 return 0;
3243         return EXT4_CLUSTERS_PER_GROUP(sb) -
3244                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3245 }
3246
3247 /*
3248  * Compute the overhead and stash it in sbi->s_overhead
3249  */
3250 int ext4_calculate_overhead(struct super_block *sb)
3251 {
3252         struct ext4_sb_info *sbi = EXT4_SB(sb);
3253         struct ext4_super_block *es = sbi->s_es;
3254         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3255         ext4_fsblk_t overhead = 0;
3256         char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3257
3258         if (!buf)
3259                 return -ENOMEM;
3260
3261         /*
3262          * Compute the overhead (FS structures).  This is constant
3263          * for a given filesystem unless the number of block groups
3264          * changes so we cache the previous value until it does.
3265          */
3266
3267         /*
3268          * All of the blocks before first_data_block are overhead
3269          */
3270         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3271
3272         /*
3273          * Add the overhead found in each block group
3274          */
3275         for (i = 0; i < ngroups; i++) {
3276                 int blks;
3277
3278                 blks = count_overhead(sb, i, buf);
3279                 overhead += blks;
3280                 if (blks)
3281                         memset(buf, 0, PAGE_SIZE);
3282                 cond_resched();
3283         }
3284         /* Add the journal blocks as well */
3285         if (sbi->s_journal)
3286                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3287
3288         sbi->s_overhead = overhead;
3289         smp_wmb();
3290         free_page((unsigned long) buf);
3291         return 0;
3292 }
3293
3294
3295 static ext4_fsblk_t ext4_calculate_resv_clusters(struct ext4_sb_info *sbi)
3296 {
3297         ext4_fsblk_t resv_clusters;
3298
3299         /*
3300          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3301          * This should cover the situations where we can not afford to run
3302          * out of space like for example punch hole, or converting
3303          * uninitialized extents in delalloc path. In most cases such
3304          * allocation would require 1, or 2 blocks, higher numbers are
3305          * very rare.
3306          */
3307         resv_clusters = ext4_blocks_count(sbi->s_es) >> sbi->s_cluster_bits;
3308
3309         do_div(resv_clusters, 50);
3310         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3311
3312         return resv_clusters;
3313 }
3314
3315
3316 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3317 {
3318         ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3319                                 sbi->s_cluster_bits;
3320
3321         if (count >= clusters)
3322                 return -EINVAL;
3323
3324         atomic64_set(&sbi->s_resv_clusters, count);
3325         return 0;
3326 }
3327
3328 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3329 {
3330         char *orig_data = kstrdup(data, GFP_KERNEL);
3331         struct buffer_head *bh;
3332         struct ext4_super_block *es = NULL;
3333         struct ext4_sb_info *sbi;
3334         ext4_fsblk_t block;
3335         ext4_fsblk_t sb_block = get_sb_block(&data);
3336         ext4_fsblk_t logical_sb_block;
3337         unsigned long offset = 0;
3338         unsigned long journal_devnum = 0;
3339         unsigned long def_mount_opts;
3340         struct inode *root;
3341         char *cp;
3342         const char *descr;
3343         int ret = -ENOMEM;
3344         int blocksize, clustersize;
3345         unsigned int db_count;
3346         unsigned int i;
3347         int needs_recovery, has_huge_files, has_bigalloc;
3348         __u64 blocks_count;
3349         int err = 0;
3350         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3351         ext4_group_t first_not_zeroed;
3352
3353         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3354         if (!sbi)
3355                 goto out_free_orig;
3356
3357         sbi->s_blockgroup_lock =
3358                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3359         if (!sbi->s_blockgroup_lock) {
3360                 kfree(sbi);
3361                 goto out_free_orig;
3362         }
3363         sb->s_fs_info = sbi;
3364         sbi->s_sb = sb;
3365         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3366         sbi->s_sb_block = sb_block;
3367         if (sb->s_bdev->bd_part)
3368                 sbi->s_sectors_written_start =
3369                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3370
3371         /* Cleanup superblock name */
3372         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3373                 *cp = '!';
3374
3375         /* -EINVAL is default */
3376         ret = -EINVAL;
3377         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3378         if (!blocksize) {
3379                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3380                 goto out_fail;
3381         }
3382
3383         /*
3384          * The ext4 superblock will not be buffer aligned for other than 1kB
3385          * block sizes.  We need to calculate the offset from buffer start.
3386          */
3387         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3388                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3389                 offset = do_div(logical_sb_block, blocksize);
3390         } else {
3391                 logical_sb_block = sb_block;
3392         }
3393
3394         if (!(bh = sb_bread(sb, logical_sb_block))) {
3395                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3396                 goto out_fail;
3397         }
3398         /*
3399          * Note: s_es must be initialized as soon as possible because
3400          *       some ext4 macro-instructions depend on its value
3401          */
3402         es = (struct ext4_super_block *) (bh->b_data + offset);
3403         sbi->s_es = es;
3404         sb->s_magic = le16_to_cpu(es->s_magic);
3405         if (sb->s_magic != EXT4_SUPER_MAGIC)
3406                 goto cantfind_ext4;
3407         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3408
3409         /* Warn if metadata_csum and gdt_csum are both set. */
3410         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3411                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3412             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3413                 ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3414                              "redundant flags; please run fsck.");
3415
3416         /* Check for a known checksum algorithm */
3417         if (!ext4_verify_csum_type(sb, es)) {
3418                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3419                          "unknown checksum algorithm.");
3420                 silent = 1;
3421                 goto cantfind_ext4;
3422         }
3423
3424         /* Load the checksum driver */
3425         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3426                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3427                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3428                 if (IS_ERR(sbi->s_chksum_driver)) {
3429                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3430                         ret = PTR_ERR(sbi->s_chksum_driver);
3431                         sbi->s_chksum_driver = NULL;
3432                         goto failed_mount;
3433                 }
3434         }
3435
3436         /* Check superblock checksum */
3437         if (!ext4_superblock_csum_verify(sb, es)) {
3438                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3439                          "invalid superblock checksum.  Run e2fsck?");
3440                 silent = 1;
3441                 goto cantfind_ext4;
3442         }
3443
3444         /* Precompute checksum seed for all metadata */
3445         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3446                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3447                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3448                                                sizeof(es->s_uuid));
3449
3450         /* Set defaults before we parse the mount options */
3451         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3452         set_opt(sb, INIT_INODE_TABLE);
3453         if (def_mount_opts & EXT4_DEFM_DEBUG)
3454                 set_opt(sb, DEBUG);
3455         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3456                 set_opt(sb, GRPID);
3457         if (def_mount_opts & EXT4_DEFM_UID16)
3458                 set_opt(sb, NO_UID32);
3459         /* xattr user namespace & acls are now defaulted on */
3460         set_opt(sb, XATTR_USER);
3461 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3462         set_opt(sb, POSIX_ACL);
3463 #endif
3464         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3465                 set_opt(sb, JOURNAL_DATA);
3466         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3467                 set_opt(sb, ORDERED_DATA);
3468         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3469                 set_opt(sb, WRITEBACK_DATA);
3470
3471         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3472                 set_opt(sb, ERRORS_PANIC);
3473         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3474                 set_opt(sb, ERRORS_CONT);
3475         else
3476                 set_opt(sb, ERRORS_RO);
3477         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3478                 set_opt(sb, BLOCK_VALIDITY);
3479         if (def_mount_opts & EXT4_DEFM_DISCARD)
3480                 set_opt(sb, DISCARD);
3481
3482         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3483         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3484         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3485         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3486         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3487
3488         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3489                 set_opt(sb, BARRIER);
3490
3491         /*
3492          * enable delayed allocation by default
3493          * Use -o nodelalloc to turn it off
3494          */
3495         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3496             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3497                 set_opt(sb, DELALLOC);
3498
3499         /*
3500          * set default s_li_wait_mult for lazyinit, for the case there is
3501          * no mount option specified.
3502          */
3503         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3504
3505         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3506                            &journal_devnum, &journal_ioprio, 0)) {
3507                 ext4_msg(sb, KERN_WARNING,
3508                          "failed to parse options in superblock: %s",
3509                          sbi->s_es->s_mount_opts);
3510         }
3511         sbi->s_def_mount_opt = sbi->s_mount_opt;
3512         if (!parse_options((char *) data, sb, &journal_devnum,
3513                            &journal_ioprio, 0))
3514                 goto failed_mount;
3515
3516         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3517                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3518                             "with data=journal disables delayed "
3519                             "allocation and O_DIRECT support!\n");
3520                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3521                         ext4_msg(sb, KERN_ERR, "can't mount with "
3522                                  "both data=journal and delalloc");
3523                         goto failed_mount;
3524                 }
3525                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3526                         ext4_msg(sb, KERN_ERR, "can't mount with "
3527                                  "both data=journal and dioread_nolock");
3528                         goto failed_mount;
3529                 }
3530                 if (test_opt(sb, DELALLOC))
3531                         clear_opt(sb, DELALLOC);
3532         }
3533
3534         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3535                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3536
3537         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3538             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3539              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3540              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3541                 ext4_msg(sb, KERN_WARNING,
3542                        "feature flags set on rev 0 fs, "
3543                        "running e2fsck is recommended");
3544
3545         if (IS_EXT2_SB(sb)) {
3546                 if (ext2_feature_set_ok(sb))
3547                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3548                                  "using the ext4 subsystem");
3549                 else {
3550                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3551                                  "to feature incompatibilities");
3552                         goto failed_mount;
3553                 }
3554         }
3555
3556         if (IS_EXT3_SB(sb)) {
3557                 if (ext3_feature_set_ok(sb))
3558                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3559                                  "using the ext4 subsystem");
3560                 else {
3561                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3562                                  "to feature incompatibilities");
3563                         goto failed_mount;
3564                 }
3565         }
3566
3567         /*
3568          * Check feature flags regardless of the revision level, since we
3569          * previously didn't change the revision level when setting the flags,
3570          * so there is a chance incompat flags are set on a rev 0 filesystem.
3571          */
3572         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3573                 goto failed_mount;
3574
3575         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3576         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3577             blocksize > EXT4_MAX_BLOCK_SIZE) {
3578                 ext4_msg(sb, KERN_ERR,
3579                        "Unsupported filesystem blocksize %d", blocksize);
3580                 goto failed_mount;
3581         }
3582
3583         if (sb->s_blocksize != blocksize) {
3584                 /* Validate the filesystem blocksize */
3585                 if (!sb_set_blocksize(sb, blocksize)) {
3586                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3587                                         blocksize);
3588                         goto failed_mount;
3589                 }
3590
3591                 brelse(bh);
3592                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3593                 offset = do_div(logical_sb_block, blocksize);
3594                 bh = sb_bread(sb, logical_sb_block);
3595                 if (!bh) {
3596                         ext4_msg(sb, KERN_ERR,
3597                                "Can't read superblock on 2nd try");
3598                         goto failed_mount;
3599                 }
3600                 es = (struct ext4_super_block *)(bh->b_data + offset);
3601                 sbi->s_es = es;
3602                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3603                         ext4_msg(sb, KERN_ERR,
3604                                "Magic mismatch, very weird!");
3605                         goto failed_mount;
3606                 }
3607         }
3608
3609         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3610                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3611         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3612                                                       has_huge_files);
3613         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3614
3615         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3616                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3617                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3618         } else {
3619                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3620                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3621                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3622                     (!is_power_of_2(sbi->s_inode_size)) ||
3623                     (sbi->s_inode_size > blocksize)) {
3624                         ext4_msg(sb, KERN_ERR,
3625                                "unsupported inode size: %d",
3626                                sbi->s_inode_size);
3627                         goto failed_mount;
3628                 }
3629                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3630                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3631         }
3632
3633         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3634         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3635                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3636                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3637                     !is_power_of_2(sbi->s_desc_size)) {
3638                         ext4_msg(sb, KERN_ERR,
3639                                "unsupported descriptor size %lu",
3640                                sbi->s_desc_size);
3641                         goto failed_mount;
3642                 }
3643         } else
3644                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3645
3646         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3647         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3648         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3649                 goto cantfind_ext4;
3650
3651         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3652         if (sbi->s_inodes_per_block == 0)
3653                 goto cantfind_ext4;
3654         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3655                                         sbi->s_inodes_per_block;
3656         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3657         sbi->s_sbh = bh;
3658         sbi->s_mount_state = le16_to_cpu(es->s_state);
3659         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3660         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3661
3662         for (i = 0; i < 4; i++)
3663                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3664         sbi->s_def_hash_version = es->s_def_hash_version;
3665         i = le32_to_cpu(es->s_flags);
3666         if (i & EXT2_FLAGS_UNSIGNED_HASH)
3667                 sbi->s_hash_unsigned = 3;
3668         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3669 #ifdef __CHAR_UNSIGNED__
3670                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3671                 sbi->s_hash_unsigned = 3;
3672 #else
3673                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3674 #endif
3675         }
3676
3677         /* Handle clustersize */
3678         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3679         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3680                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3681         if (has_bigalloc) {
3682                 if (clustersize < blocksize) {
3683                         ext4_msg(sb, KERN_ERR,
3684                                  "cluster size (%d) smaller than "
3685                                  "block size (%d)", clustersize, blocksize);
3686                         goto failed_mount;
3687                 }
3688                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3689                         le32_to_cpu(es->s_log_block_size);
3690                 sbi->s_clusters_per_group =
3691                         le32_to_cpu(es->s_clusters_per_group);
3692                 if (sbi->s_clusters_per_group > blocksize * 8) {
3693                         ext4_msg(sb, KERN_ERR,
3694                                  "#clusters per group too big: %lu",
3695                                  sbi->s_clusters_per_group);
3696                         goto failed_mount;
3697                 }
3698                 if (sbi->s_blocks_per_group !=
3699                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3700                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3701                                  "clusters per group (%lu) inconsistent",
3702                                  sbi->s_blocks_per_group,
3703                                  sbi->s_clusters_per_group);
3704                         goto failed_mount;
3705                 }
3706         } else {
3707                 if (clustersize != blocksize) {
3708                         ext4_warning(sb, "fragment/cluster size (%d) != "
3709                                      "block size (%d)", clustersize,
3710                                      blocksize);
3711                         clustersize = blocksize;
3712                 }
3713                 if (sbi->s_blocks_per_group > blocksize * 8) {
3714                         ext4_msg(sb, KERN_ERR,
3715                                  "#blocks per group too big: %lu",
3716                                  sbi->s_blocks_per_group);
3717                         goto failed_mount;
3718                 }
3719                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3720                 sbi->s_cluster_bits = 0;
3721         }
3722         sbi->s_cluster_ratio = clustersize / blocksize;
3723
3724         if (sbi->s_inodes_per_group > blocksize * 8) {
3725                 ext4_msg(sb, KERN_ERR,
3726                        "#inodes per group too big: %lu",
3727                        sbi->s_inodes_per_group);
3728                 goto failed_mount;
3729         }
3730
3731         /* Do we have standard group size of clustersize * 8 blocks ? */
3732         if (sbi->s_blocks_per_group == clustersize << 3)
3733                 set_opt2(sb, STD_GROUP_SIZE);
3734
3735         /*
3736          * Test whether we have more sectors than will fit in sector_t,
3737          * and whether the max offset is addressable by the page cache.
3738          */
3739         err = generic_check_addressable(sb->s_blocksize_bits,
3740                                         ext4_blocks_count(es));
3741         if (err) {
3742                 ext4_msg(sb, KERN_ERR, "filesystem"
3743                          " too large to mount safely on this system");
3744                 if (sizeof(sector_t) < 8)
3745                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3746                 goto failed_mount;
3747         }
3748
3749         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3750                 goto cantfind_ext4;
3751
3752         /* check blocks count against device size */
3753         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3754         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3755                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3756                        "exceeds size of device (%llu blocks)",
3757                        ext4_blocks_count(es), blocks_count);
3758                 goto failed_mount;
3759         }
3760
3761         /*
3762          * It makes no sense for the first data block to be beyond the end
3763          * of the filesystem.
3764          */
3765         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3766                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3767                          "block %u is beyond end of filesystem (%llu)",
3768                          le32_to_cpu(es->s_first_data_block),
3769                          ext4_blocks_count(es));
3770                 goto failed_mount;
3771         }
3772         blocks_count = (ext4_blocks_count(es) -
3773                         le32_to_cpu(es->s_first_data_block) +
3774                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3775         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3776         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3777                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3778                        "(block count %llu, first data block %u, "
3779                        "blocks per group %lu)", sbi->s_groups_count,
3780                        ext4_blocks_count(es),
3781                        le32_to_cpu(es->s_first_data_block),
3782                        EXT4_BLOCKS_PER_GROUP(sb));
3783                 goto failed_mount;
3784         }
3785         sbi->s_groups_count = blocks_count;
3786         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3787                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3788         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3789                    EXT4_DESC_PER_BLOCK(sb);
3790         sbi->s_group_desc = ext4_kvmalloc(db_count *
3791                                           sizeof(struct buffer_head *),
3792                                           GFP_KERNEL);
3793         if (sbi->s_group_desc == NULL) {
3794                 ext4_msg(sb, KERN_ERR, "not enough memory");
3795                 ret = -ENOMEM;
3796                 goto failed_mount;
3797         }
3798
3799         if (ext4_proc_root)
3800                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3801
3802         if (sbi->s_proc)
3803                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3804                                  &ext4_seq_options_fops, sb);
3805
3806         bgl_lock_init(sbi->s_blockgroup_lock);
3807
3808         for (i = 0; i < db_count; i++) {
3809                 block = descriptor_loc(sb, logical_sb_block, i);
3810                 sbi->s_group_desc[i] = sb_bread(sb, block);
3811                 if (!sbi->s_group_desc[i]) {
3812                         ext4_msg(sb, KERN_ERR,
3813                                "can't read group descriptor %d", i);
3814                         db_count = i;
3815                         goto failed_mount2;
3816                 }
3817         }
3818         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3819                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3820                 goto failed_mount2;
3821         }
3822         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3823                 if (!ext4_fill_flex_info(sb)) {
3824                         ext4_msg(sb, KERN_ERR,
3825                                "unable to initialize "
3826                                "flex_bg meta info!");
3827                         goto failed_mount2;
3828                 }
3829
3830         sbi->s_gdb_count = db_count;
3831         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3832         spin_lock_init(&sbi->s_next_gen_lock);
3833
3834         init_timer(&sbi->s_err_report);
3835         sbi->s_err_report.function = print_daily_error_info;
3836         sbi->s_err_report.data = (unsigned long) sb;
3837
3838         /* Register extent status tree shrinker */
3839         ext4_es_register_shrinker(sbi);
3840
3841         err = percpu_counter_init(&sbi->s_freeclusters_counter,
3842                         ext4_count_free_clusters(sb));
3843         if (!err) {
3844                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
3845                                 ext4_count_free_inodes(sb));
3846         }
3847         if (!err) {
3848                 err = percpu_counter_init(&sbi->s_dirs_counter,
3849                                 ext4_count_dirs(sb));
3850         }
3851         if (!err) {
3852                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3853         }
3854         if (!err) {
3855                 err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
3856         }
3857         if (err) {
3858                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3859                 goto failed_mount3;
3860         }
3861
3862         sbi->s_stripe = ext4_get_stripe_size(sbi);
3863         sbi->s_extent_max_zeroout_kb = 32;
3864
3865         /*
3866          * set up enough so that it can read an inode
3867          */
3868         if (!test_opt(sb, NOLOAD) &&
3869             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3870                 sb->s_op = &ext4_sops;
3871         else
3872                 sb->s_op = &ext4_nojournal_sops;
3873         sb->s_export_op = &ext4_export_ops;
3874         sb->s_xattr = ext4_xattr_handlers;
3875 #ifdef CONFIG_QUOTA
3876         sb->dq_op = &ext4_quota_operations;
3877         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3878                 sb->s_qcop = &ext4_qctl_sysfile_operations;
3879         else
3880                 sb->s_qcop = &ext4_qctl_operations;
3881 #endif
3882         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3883
3884         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3885         mutex_init(&sbi->s_orphan_lock);
3886
3887         sb->s_root = NULL;
3888
3889         needs_recovery = (es->s_last_orphan != 0 ||
3890                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3891                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3892
3893         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3894             !(sb->s_flags & MS_RDONLY))
3895                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3896                         goto failed_mount3;
3897
3898         /*
3899          * The first inode we look at is the journal inode.  Don't try
3900          * root first: it may be modified in the journal!
3901          */
3902         if (!test_opt(sb, NOLOAD) &&
3903             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3904                 if (ext4_load_journal(sb, es, journal_devnum))
3905                         goto failed_mount3;
3906         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3907               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3908                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3909                        "suppressed and not mounted read-only");
3910                 goto failed_mount_wq;
3911         } else {
3912                 clear_opt(sb, DATA_FLAGS);
3913                 sbi->s_journal = NULL;
3914                 needs_recovery = 0;
3915                 goto no_journal;
3916         }
3917
3918         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3919             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3920                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3921                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3922                 goto failed_mount_wq;
3923         }
3924
3925         if (!set_journal_csum_feature_set(sb)) {
3926                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3927                          "feature set");
3928                 goto failed_mount_wq;
3929         }
3930
3931         /* We have now updated the journal if required, so we can
3932          * validate the data journaling mode. */
3933         switch (test_opt(sb, DATA_FLAGS)) {
3934         case 0:
3935                 /* No mode set, assume a default based on the journal
3936                  * capabilities: ORDERED_DATA if the journal can
3937                  * cope, else JOURNAL_DATA
3938                  */
3939                 if (jbd2_journal_check_available_features
3940                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3941                         set_opt(sb, ORDERED_DATA);
3942                 else
3943                         set_opt(sb, JOURNAL_DATA);
3944                 break;
3945
3946         case EXT4_MOUNT_ORDERED_DATA:
3947         case EXT4_MOUNT_WRITEBACK_DATA:
3948                 if (!jbd2_journal_check_available_features
3949                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3950                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3951                                "requested data journaling mode");
3952                         goto failed_mount_wq;
3953                 }
3954         default:
3955                 break;
3956         }
3957         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3958
3959         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3960
3961         /*
3962          * The journal may have updated the bg summary counts, so we
3963          * need to update the global counters.
3964          */
3965         percpu_counter_set(&sbi->s_freeclusters_counter,
3966                            ext4_count_free_clusters(sb));
3967         percpu_counter_set(&sbi->s_freeinodes_counter,
3968                            ext4_count_free_inodes(sb));
3969         percpu_counter_set(&sbi->s_dirs_counter,
3970                            ext4_count_dirs(sb));
3971         percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3972
3973 no_journal:
3974         /*
3975          * Get the # of file system overhead blocks from the
3976          * superblock if present.
3977          */
3978         if (es->s_overhead_clusters)
3979                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3980         else {
3981                 err = ext4_calculate_overhead(sb);
3982                 if (err)
3983                         goto failed_mount_wq;
3984         }
3985
3986         /*
3987          * The maximum number of concurrent works can be high and
3988          * concurrency isn't really necessary.  Limit it to 1.
3989          */
3990         EXT4_SB(sb)->rsv_conversion_wq =
3991                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3992         if (!EXT4_SB(sb)->rsv_conversion_wq) {
3993                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3994                 ret = -ENOMEM;
3995                 goto failed_mount4;
3996         }
3997
3998         EXT4_SB(sb)->unrsv_conversion_wq =
3999                 alloc_workqueue("ext4-unrsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4000         if (!EXT4_SB(sb)->unrsv_conversion_wq) {
4001                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4002                 ret = -ENOMEM;
4003                 goto failed_mount4;
4004         }
4005
4006         /*
4007          * The jbd2_journal_load will have done any necessary log recovery,
4008          * so we can safely mount the rest of the filesystem now.
4009          */
4010
4011         root = ext4_iget(sb, EXT4_ROOT_INO);
4012         if (IS_ERR(root)) {
4013                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4014                 ret = PTR_ERR(root);
4015                 root = NULL;
4016                 goto failed_mount4;
4017         }
4018         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4019                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4020                 iput(root);
4021                 goto failed_mount4;
4022         }
4023         sb->s_root = d_make_root(root);
4024         if (!sb->s_root) {
4025                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4026                 ret = -ENOMEM;
4027                 goto failed_mount4;
4028         }
4029
4030         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4031                 sb->s_flags |= MS_RDONLY;
4032
4033         /* determine the minimum size of new large inodes, if present */
4034         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4035                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4036                                                      EXT4_GOOD_OLD_INODE_SIZE;
4037                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4038                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4039                         if (sbi->s_want_extra_isize <
4040                             le16_to_cpu(es->s_want_extra_isize))
4041                                 sbi->s_want_extra_isize =
4042                                         le16_to_cpu(es->s_want_extra_isize);
4043                         if (sbi->s_want_extra_isize <
4044                             le16_to_cpu(es->s_min_extra_isize))
4045                                 sbi->s_want_extra_isize =
4046                                         le16_to_cpu(es->s_min_extra_isize);
4047                 }
4048         }
4049         /* Check if enough inode space is available */
4050         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4051                                                         sbi->s_inode_size) {
4052                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4053                                                        EXT4_GOOD_OLD_INODE_SIZE;
4054                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4055                          "available");
4056         }
4057
4058         err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sbi));
4059         if (err) {
4060                 ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4061                          "reserved pool", ext4_calculate_resv_clusters(sbi));
4062                 goto failed_mount4a;
4063         }
4064
4065         err = ext4_setup_system_zone(sb);
4066         if (err) {
4067                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4068                          "zone (%d)", err);
4069                 goto failed_mount4a;
4070         }
4071
4072         ext4_ext_init(sb);
4073         err = ext4_mb_init(sb);
4074         if (err) {
4075                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4076                          err);
4077                 goto failed_mount5;
4078         }
4079
4080         err = ext4_register_li_request(sb, first_not_zeroed);
4081         if (err)
4082                 goto failed_mount6;
4083
4084         sbi->s_kobj.kset = ext4_kset;
4085         init_completion(&sbi->s_kobj_unregister);
4086         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4087                                    "%s", sb->s_id);
4088         if (err)
4089                 goto failed_mount7;
4090
4091 #ifdef CONFIG_QUOTA
4092         /* Enable quota usage during mount. */
4093         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4094             !(sb->s_flags & MS_RDONLY)) {
4095                 err = ext4_enable_quotas(sb);
4096                 if (err)
4097                         goto failed_mount8;
4098         }
4099 #endif  /* CONFIG_QUOTA */
4100
4101         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4102         ext4_orphan_cleanup(sb, es);
4103         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4104         if (needs_recovery) {
4105                 ext4_msg(sb, KERN_INFO, "recovery complete");
4106                 ext4_mark_recovery_complete(sb, es);
4107         }
4108         if (EXT4_SB(sb)->s_journal) {
4109                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4110                         descr = " journalled data mode";
4111                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4112                         descr = " ordered data mode";
4113                 else
4114                         descr = " writeback data mode";
4115         } else
4116                 descr = "out journal";
4117
4118         if (test_opt(sb, DISCARD)) {
4119                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4120                 if (!blk_queue_discard(q))
4121                         ext4_msg(sb, KERN_WARNING,
4122                                  "mounting with \"discard\" option, but "
4123                                  "the device does not support discard");
4124         }
4125
4126         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4127                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4128                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4129
4130         if (es->s_error_count)
4131                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4132
4133         kfree(orig_data);
4134         return 0;
4135
4136 cantfind_ext4:
4137         if (!silent)
4138                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4139         goto failed_mount;
4140
4141 #ifdef CONFIG_QUOTA
4142 failed_mount8:
4143         kobject_del(&sbi->s_kobj);
4144 #endif
4145 failed_mount7:
4146         ext4_unregister_li_request(sb);
4147 failed_mount6:
4148         ext4_mb_release(sb);
4149 failed_mount5:
4150         ext4_ext_release(sb);
4151         ext4_release_system_zone(sb);
4152 failed_mount4a:
4153         dput(sb->s_root);
4154         sb->s_root = NULL;
4155 failed_mount4:
4156         ext4_msg(sb, KERN_ERR, "mount failed");
4157         if (EXT4_SB(sb)->rsv_conversion_wq)
4158                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4159         if (EXT4_SB(sb)->unrsv_conversion_wq)
4160                 destroy_workqueue(EXT4_SB(sb)->unrsv_conversion_wq);
4161 failed_mount_wq:
4162         if (sbi->s_journal) {
4163                 jbd2_journal_destroy(sbi->s_journal);
4164                 sbi->s_journal = NULL;
4165         }
4166 failed_mount3:
4167         ext4_es_unregister_shrinker(sbi);
4168         del_timer(&sbi->s_err_report);
4169         if (sbi->s_flex_groups)
4170                 ext4_kvfree(sbi->s_flex_groups);
4171         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4172         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4173         percpu_counter_destroy(&sbi->s_dirs_counter);
4174         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4175         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
4176         if (sbi->s_mmp_tsk)
4177                 kthread_stop(sbi->s_mmp_tsk);
4178 failed_mount2:
4179         for (i = 0; i < db_count; i++)
4180                 brelse(sbi->s_group_desc[i]);
4181         ext4_kvfree(sbi->s_group_desc);
4182 failed_mount:
4183         if (sbi->s_chksum_driver)
4184                 crypto_free_shash(sbi->s_chksum_driver);
4185         if (sbi->s_proc) {
4186                 remove_proc_entry("options", sbi->s_proc);
4187                 remove_proc_entry(sb->s_id, ext4_proc_root);
4188         }
4189 #ifdef CONFIG_QUOTA
4190         for (i = 0; i < MAXQUOTAS; i++)
4191                 kfree(sbi->s_qf_names[i]);
4192 #endif
4193         ext4_blkdev_remove(sbi);
4194         brelse(bh);
4195 out_fail:
4196         sb->s_fs_info = NULL;
4197         kfree(sbi->s_blockgroup_lock);
4198         kfree(sbi);
4199 out_free_orig:
4200         kfree(orig_data);
4201         return err ? err : ret;
4202 }
4203
4204 /*
4205  * Setup any per-fs journal parameters now.  We'll do this both on
4206  * initial mount, once the journal has been initialised but before we've
4207  * done any recovery; and again on any subsequent remount.
4208  */
4209 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4210 {
4211         struct ext4_sb_info *sbi = EXT4_SB(sb);
4212
4213         journal->j_commit_interval = sbi->s_commit_interval;
4214         journal->j_min_batch_time = sbi->s_min_batch_time;
4215         journal->j_max_batch_time = sbi->s_max_batch_time;
4216
4217         write_lock(&journal->j_state_lock);
4218         if (test_opt(sb, BARRIER))
4219                 journal->j_flags |= JBD2_BARRIER;
4220         else
4221                 journal->j_flags &= ~JBD2_BARRIER;
4222         if (test_opt(sb, DATA_ERR_ABORT))
4223                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4224         else
4225                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4226         write_unlock(&journal->j_state_lock);
4227 }
4228
4229 static journal_t *ext4_get_journal(struct super_block *sb,
4230                                    unsigned int journal_inum)
4231 {
4232         struct inode *journal_inode;
4233         journal_t *journal;
4234
4235         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4236
4237         /* First, test for the existence of a valid inode on disk.  Bad
4238          * things happen if we iget() an unused inode, as the subsequent
4239          * iput() will try to delete it. */
4240
4241         journal_inode = ext4_iget(sb, journal_inum);
4242         if (IS_ERR(journal_inode)) {
4243                 ext4_msg(sb, KERN_ERR, "no journal found");
4244                 return NULL;
4245         }
4246         if (!journal_inode->i_nlink) {
4247                 make_bad_inode(journal_inode);
4248                 iput(journal_inode);
4249                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4250                 return NULL;
4251         }
4252
4253         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4254                   journal_inode, journal_inode->i_size);
4255         if (!S_ISREG(journal_inode->i_mode)) {
4256                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4257                 iput(journal_inode);
4258                 return NULL;
4259         }
4260
4261         journal = jbd2_journal_init_inode(journal_inode);
4262         if (!journal) {
4263                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4264                 iput(journal_inode);
4265                 return NULL;
4266         }
4267         journal->j_private = sb;
4268         ext4_init_journal_params(sb, journal);
4269         return journal;
4270 }
4271
4272 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4273                                        dev_t j_dev)
4274 {
4275         struct buffer_head *bh;
4276         journal_t *journal;
4277         ext4_fsblk_t start;
4278         ext4_fsblk_t len;
4279         int hblock, blocksize;
4280         ext4_fsblk_t sb_block;
4281         unsigned long offset;
4282         struct ext4_super_block *es;
4283         struct block_device *bdev;
4284
4285         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4286
4287         bdev = ext4_blkdev_get(j_dev, sb);
4288         if (bdev == NULL)
4289                 return NULL;
4290
4291         blocksize = sb->s_blocksize;
4292         hblock = bdev_logical_block_size(bdev);
4293         if (blocksize < hblock) {
4294                 ext4_msg(sb, KERN_ERR,
4295                         "blocksize too small for journal device");
4296                 goto out_bdev;
4297         }
4298
4299         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4300         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4301         set_blocksize(bdev, blocksize);
4302         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4303                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4304                        "external journal");
4305                 goto out_bdev;
4306         }
4307
4308         es = (struct ext4_super_block *) (bh->b_data + offset);
4309         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4310             !(le32_to_cpu(es->s_feature_incompat) &
4311               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4312                 ext4_msg(sb, KERN_ERR, "external journal has "
4313                                         "bad superblock");
4314                 brelse(bh);
4315                 goto out_bdev;
4316         }
4317
4318         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4319                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4320                 brelse(bh);
4321                 goto out_bdev;
4322         }
4323
4324         len = ext4_blocks_count(es);
4325         start = sb_block + 1;
4326         brelse(bh);     /* we're done with the superblock */
4327
4328         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4329                                         start, len, blocksize);
4330         if (!journal) {
4331                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4332                 goto out_bdev;
4333         }
4334         journal->j_private = sb;
4335         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4336         wait_on_buffer(journal->j_sb_buffer);
4337         if (!buffer_uptodate(journal->j_sb_buffer)) {
4338                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4339                 goto out_journal;
4340         }
4341         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4342                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4343                                         "user (unsupported) - %d",
4344                         be32_to_cpu(journal->j_superblock->s_nr_users));
4345                 goto out_journal;
4346         }
4347         EXT4_SB(sb)->journal_bdev = bdev;
4348         ext4_init_journal_params(sb, journal);
4349         return journal;
4350
4351 out_journal:
4352         jbd2_journal_destroy(journal);
4353 out_bdev:
4354         ext4_blkdev_put(bdev);
4355         return NULL;
4356 }
4357
4358 static int ext4_load_journal(struct super_block *sb,
4359                              struct ext4_super_block *es,
4360                              unsigned long journal_devnum)
4361 {
4362         journal_t *journal;
4363         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4364         dev_t journal_dev;
4365         int err = 0;
4366         int really_read_only;
4367
4368         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4369
4370         if (journal_devnum &&
4371             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4372                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4373                         "numbers have changed");
4374                 journal_dev = new_decode_dev(journal_devnum);
4375         } else
4376                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4377
4378         really_read_only = bdev_read_only(sb->s_bdev);
4379
4380         /*
4381          * Are we loading a blank journal or performing recovery after a
4382          * crash?  For recovery, we need to check in advance whether we
4383          * can get read-write access to the device.
4384          */
4385         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4386                 if (sb->s_flags & MS_RDONLY) {
4387                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4388                                         "required on readonly filesystem");
4389                         if (really_read_only) {
4390                                 ext4_msg(sb, KERN_ERR, "write access "
4391                                         "unavailable, cannot proceed");
4392                                 return -EROFS;
4393                         }
4394                         ext4_msg(sb, KERN_INFO, "write access will "
4395                                "be enabled during recovery");
4396                 }
4397         }
4398
4399         if (journal_inum && journal_dev) {
4400                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4401                        "and inode journals!");
4402                 return -EINVAL;
4403         }
4404
4405         if (journal_inum) {
4406                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4407                         return -EINVAL;
4408         } else {
4409                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4410                         return -EINVAL;
4411         }
4412
4413         if (!(journal->j_flags & JBD2_BARRIER))
4414                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4415
4416         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4417                 err = jbd2_journal_wipe(journal, !really_read_only);
4418         if (!err) {
4419                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4420                 if (save)
4421                         memcpy(save, ((char *) es) +
4422                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4423                 err = jbd2_journal_load(journal);
4424                 if (save)
4425                         memcpy(((char *) es) + EXT4_S_ERR_START,
4426                                save, EXT4_S_ERR_LEN);
4427                 kfree(save);
4428         }
4429
4430         if (err) {
4431                 ext4_msg(sb, KERN_ERR, "error loading journal");
4432                 jbd2_journal_destroy(journal);
4433                 return err;
4434         }
4435
4436         EXT4_SB(sb)->s_journal = journal;
4437         ext4_clear_journal_err(sb, es);
4438
4439         if (!really_read_only && journal_devnum &&
4440             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4441                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4442
4443                 /* Make sure we flush the recovery flag to disk. */
4444                 ext4_commit_super(sb, 1);
4445         }
4446
4447         return 0;
4448 }
4449
4450 static int ext4_commit_super(struct super_block *sb, int sync)
4451 {
4452         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4453         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4454         int error = 0;
4455
4456         if (!sbh || block_device_ejected(sb))
4457                 return error;
4458         if (buffer_write_io_error(sbh)) {
4459                 /*
4460                  * Oh, dear.  A previous attempt to write the
4461                  * superblock failed.  This could happen because the
4462                  * USB device was yanked out.  Or it could happen to
4463                  * be a transient write error and maybe the block will
4464                  * be remapped.  Nothing we can do but to retry the
4465                  * write and hope for the best.
4466                  */
4467                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4468                        "superblock detected");
4469                 clear_buffer_write_io_error(sbh);
4470                 set_buffer_uptodate(sbh);
4471         }
4472         /*
4473          * If the file system is mounted read-only, don't update the
4474          * superblock write time.  This avoids updating the superblock
4475          * write time when we are mounting the root file system
4476          * read/only but we need to replay the journal; at that point,
4477          * for people who are east of GMT and who make their clock
4478          * tick in localtime for Windows bug-for-bug compatibility,
4479          * the clock is set in the future, and this will cause e2fsck
4480          * to complain and force a full file system check.
4481          */
4482         if (!(sb->s_flags & MS_RDONLY))
4483                 es->s_wtime = cpu_to_le32(get_seconds());
4484         if (sb->s_bdev->bd_part)
4485                 es->s_kbytes_written =
4486                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4487                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4488                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4489         else
4490                 es->s_kbytes_written =
4491                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4492         ext4_free_blocks_count_set(es,
4493                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4494                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4495         es->s_free_inodes_count =
4496                 cpu_to_le32(percpu_counter_sum_positive(
4497                                 &EXT4_SB(sb)->s_freeinodes_counter));
4498         BUFFER_TRACE(sbh, "marking dirty");
4499         ext4_superblock_csum_set(sb);
4500         mark_buffer_dirty(sbh);
4501         if (sync) {
4502                 error = sync_dirty_buffer(sbh);
4503                 if (error)
4504                         return error;
4505
4506                 error = buffer_write_io_error(sbh);
4507                 if (error) {
4508                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4509                                "superblock");
4510                         clear_buffer_write_io_error(sbh);
4511                         set_buffer_uptodate(sbh);
4512                 }
4513         }
4514         return error;
4515 }
4516
4517 /*
4518  * Have we just finished recovery?  If so, and if we are mounting (or
4519  * remounting) the filesystem readonly, then we will end up with a
4520  * consistent fs on disk.  Record that fact.
4521  */
4522 static void ext4_mark_recovery_complete(struct super_block *sb,
4523                                         struct ext4_super_block *es)
4524 {
4525         journal_t *journal = EXT4_SB(sb)->s_journal;
4526
4527         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4528                 BUG_ON(journal != NULL);
4529                 return;
4530         }
4531         jbd2_journal_lock_updates(journal);
4532         if (jbd2_journal_flush(journal) < 0)
4533                 goto out;
4534
4535         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4536             sb->s_flags & MS_RDONLY) {
4537                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4538                 ext4_commit_super(sb, 1);
4539         }
4540
4541 out:
4542         jbd2_journal_unlock_updates(journal);
4543 }
4544
4545 /*
4546  * If we are mounting (or read-write remounting) a filesystem whose journal
4547  * has recorded an error from a previous lifetime, move that error to the
4548  * main filesystem now.
4549  */
4550 static void ext4_clear_journal_err(struct super_block *sb,
4551                                    struct ext4_super_block *es)
4552 {
4553         journal_t *journal;
4554         int j_errno;
4555         const char *errstr;
4556
4557         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4558
4559         journal = EXT4_SB(sb)->s_journal;
4560
4561         /*
4562          * Now check for any error status which may have been recorded in the
4563          * journal by a prior ext4_error() or ext4_abort()
4564          */
4565
4566         j_errno = jbd2_journal_errno(journal);
4567         if (j_errno) {
4568                 char nbuf[16];
4569
4570                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4571                 ext4_warning(sb, "Filesystem error recorded "
4572                              "from previous mount: %s", errstr);
4573                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4574
4575                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4576                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4577                 ext4_commit_super(sb, 1);
4578
4579                 jbd2_journal_clear_err(journal);
4580                 jbd2_journal_update_sb_errno(journal);
4581         }
4582 }
4583
4584 /*
4585  * Force the running and committing transactions to commit,
4586  * and wait on the commit.
4587  */
4588 int ext4_force_commit(struct super_block *sb)
4589 {
4590         journal_t *journal;
4591
4592         if (sb->s_flags & MS_RDONLY)
4593                 return 0;
4594
4595         journal = EXT4_SB(sb)->s_journal;
4596         return ext4_journal_force_commit(journal);
4597 }
4598
4599 static int ext4_sync_fs(struct super_block *sb, int wait)
4600 {
4601         int ret = 0;
4602         tid_t target;
4603         bool needs_barrier = false;
4604         struct ext4_sb_info *sbi = EXT4_SB(sb);
4605
4606         trace_ext4_sync_fs(sb, wait);
4607         flush_workqueue(sbi->rsv_conversion_wq);
4608         flush_workqueue(sbi->unrsv_conversion_wq);
4609         /*
4610          * Writeback quota in non-journalled quota case - journalled quota has
4611          * no dirty dquots
4612          */
4613         dquot_writeback_dquots(sb, -1);
4614         /*
4615          * Data writeback is possible w/o journal transaction, so barrier must
4616          * being sent at the end of the function. But we can skip it if
4617          * transaction_commit will do it for us.
4618          */
4619         target = jbd2_get_latest_transaction(sbi->s_journal);
4620         if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4621             !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4622                 needs_barrier = true;
4623
4624         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4625                 if (wait)
4626                         ret = jbd2_log_wait_commit(sbi->s_journal, target);
4627         }
4628         if (needs_barrier) {
4629                 int err;
4630                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4631                 if (!ret)
4632                         ret = err;
4633         }
4634
4635         return ret;
4636 }
4637
4638 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait)
4639 {
4640         int ret = 0;
4641
4642         trace_ext4_sync_fs(sb, wait);
4643         flush_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4644         flush_workqueue(EXT4_SB(sb)->unrsv_conversion_wq);
4645         dquot_writeback_dquots(sb, -1);
4646         if (wait && test_opt(sb, BARRIER))
4647                 ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4648
4649         return ret;
4650 }
4651
4652 /*
4653  * LVM calls this function before a (read-only) snapshot is created.  This
4654  * gives us a chance to flush the journal completely and mark the fs clean.
4655  *
4656  * Note that only this function cannot bring a filesystem to be in a clean
4657  * state independently. It relies on upper layer to stop all data & metadata
4658  * modifications.
4659  */
4660 static int ext4_freeze(struct super_block *sb)
4661 {
4662         int error = 0;
4663         journal_t *journal;
4664
4665         if (sb->s_flags & MS_RDONLY)
4666                 return 0;
4667
4668         journal = EXT4_SB(sb)->s_journal;
4669
4670         /* Now we set up the journal barrier. */
4671         jbd2_journal_lock_updates(journal);
4672
4673         /*
4674          * Don't clear the needs_recovery flag if we failed to flush
4675          * the journal.
4676          */
4677         error = jbd2_journal_flush(journal);
4678         if (error < 0)
4679                 goto out;
4680
4681         /* Journal blocked and flushed, clear needs_recovery flag. */
4682         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4683         error = ext4_commit_super(sb, 1);
4684 out:
4685         /* we rely on upper layer to stop further updates */
4686         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4687         return error;
4688 }
4689
4690 /*
4691  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4692  * flag here, even though the filesystem is not technically dirty yet.
4693  */
4694 static int ext4_unfreeze(struct super_block *sb)
4695 {
4696         if (sb->s_flags & MS_RDONLY)
4697                 return 0;
4698
4699         /* Reset the needs_recovery flag before the fs is unlocked. */
4700         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4701         ext4_commit_super(sb, 1);
4702         return 0;
4703 }
4704
4705 /*
4706  * Structure to save mount options for ext4_remount's benefit
4707  */
4708 struct ext4_mount_options {
4709         unsigned long s_mount_opt;
4710         unsigned long s_mount_opt2;
4711         kuid_t s_resuid;
4712         kgid_t s_resgid;
4713         unsigned long s_commit_interval;
4714         u32 s_min_batch_time, s_max_batch_time;
4715 #ifdef CONFIG_QUOTA
4716         int s_jquota_fmt;
4717         char *s_qf_names[MAXQUOTAS];
4718 #endif
4719 };
4720
4721 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4722 {
4723         struct ext4_super_block *es;
4724         struct ext4_sb_info *sbi = EXT4_SB(sb);
4725         unsigned long old_sb_flags;
4726         struct ext4_mount_options old_opts;
4727         int enable_quota = 0;
4728         ext4_group_t g;
4729         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4730         int err = 0;
4731 #ifdef CONFIG_QUOTA
4732         int i, j;
4733 #endif
4734         char *orig_data = kstrdup(data, GFP_KERNEL);
4735
4736         /* Store the original options */
4737         old_sb_flags = sb->s_flags;
4738         old_opts.s_mount_opt = sbi->s_mount_opt;
4739         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4740         old_opts.s_resuid = sbi->s_resuid;
4741         old_opts.s_resgid = sbi->s_resgid;
4742         old_opts.s_commit_interval = sbi->s_commit_interval;
4743         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4744         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4745 #ifdef CONFIG_QUOTA
4746         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4747         for (i = 0; i < MAXQUOTAS; i++)
4748                 if (sbi->s_qf_names[i]) {
4749                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4750                                                          GFP_KERNEL);
4751                         if (!old_opts.s_qf_names[i]) {
4752                                 for (j = 0; j < i; j++)
4753                                         kfree(old_opts.s_qf_names[j]);
4754                                 kfree(orig_data);
4755                                 return -ENOMEM;
4756                         }
4757                 } else
4758                         old_opts.s_qf_names[i] = NULL;
4759 #endif
4760         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4761                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4762
4763         /*
4764          * Allow the "check" option to be passed as a remount option.
4765          */
4766         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4767                 err = -EINVAL;
4768                 goto restore_opts;
4769         }
4770
4771         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4772                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4773                         ext4_msg(sb, KERN_ERR, "can't mount with "
4774                                  "both data=journal and delalloc");
4775                         err = -EINVAL;
4776                         goto restore_opts;
4777                 }
4778                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4779                         ext4_msg(sb, KERN_ERR, "can't mount with "
4780                                  "both data=journal and dioread_nolock");
4781                         err = -EINVAL;
4782                         goto restore_opts;
4783                 }
4784         }
4785
4786         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4787                 ext4_abort(sb, "Abort forced by user");
4788
4789         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4790                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4791
4792         es = sbi->s_es;
4793
4794         if (sbi->s_journal) {
4795                 ext4_init_journal_params(sb, sbi->s_journal);
4796                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4797         }
4798
4799         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4800                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4801                         err = -EROFS;
4802                         goto restore_opts;
4803                 }
4804
4805                 if (*flags & MS_RDONLY) {
4806                         err = dquot_suspend(sb, -1);
4807                         if (err < 0)
4808                                 goto restore_opts;
4809
4810                         /*
4811                          * First of all, the unconditional stuff we have to do
4812                          * to disable replay of the journal when we next remount
4813                          */
4814                         sb->s_flags |= MS_RDONLY;
4815
4816                         /*
4817                          * OK, test if we are remounting a valid rw partition
4818                          * readonly, and if so set the rdonly flag and then
4819                          * mark the partition as valid again.
4820                          */
4821                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4822                             (sbi->s_mount_state & EXT4_VALID_FS))
4823                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4824
4825                         if (sbi->s_journal)
4826                                 ext4_mark_recovery_complete(sb, es);
4827                 } else {
4828                         /* Make sure we can mount this feature set readwrite */
4829                         if (!ext4_feature_set_ok(sb, 0)) {
4830                                 err = -EROFS;
4831                                 goto restore_opts;
4832                         }
4833                         /*
4834                          * Make sure the group descriptor checksums
4835                          * are sane.  If they aren't, refuse to remount r/w.
4836                          */
4837                         for (g = 0; g < sbi->s_groups_count; g++) {
4838                                 struct ext4_group_desc *gdp =
4839                                         ext4_get_group_desc(sb, g, NULL);
4840
4841                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4842                                         ext4_msg(sb, KERN_ERR,
4843                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4844                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4845                                                le16_to_cpu(gdp->bg_checksum));
4846                                         err = -EINVAL;
4847                                         goto restore_opts;
4848                                 }
4849                         }
4850
4851                         /*
4852                          * If we have an unprocessed orphan list hanging
4853                          * around from a previously readonly bdev mount,
4854                          * require a full umount/remount for now.
4855                          */
4856                         if (es->s_last_orphan) {
4857                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4858                                        "remount RDWR because of unprocessed "
4859                                        "orphan inode list.  Please "
4860                                        "umount/remount instead");
4861                                 err = -EINVAL;
4862                                 goto restore_opts;
4863                         }
4864
4865                         /*
4866                          * Mounting a RDONLY partition read-write, so reread
4867                          * and store the current valid flag.  (It may have
4868                          * been changed by e2fsck since we originally mounted
4869                          * the partition.)
4870                          */
4871                         if (sbi->s_journal)
4872                                 ext4_clear_journal_err(sb, es);
4873                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4874                         if (!ext4_setup_super(sb, es, 0))
4875                                 sb->s_flags &= ~MS_RDONLY;
4876                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4877                                                      EXT4_FEATURE_INCOMPAT_MMP))
4878                                 if (ext4_multi_mount_protect(sb,
4879                                                 le64_to_cpu(es->s_mmp_block))) {
4880                                         err = -EROFS;
4881                                         goto restore_opts;
4882                                 }
4883                         enable_quota = 1;
4884                 }
4885         }
4886
4887         /*
4888          * Reinitialize lazy itable initialization thread based on
4889          * current settings
4890          */
4891         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4892                 ext4_unregister_li_request(sb);
4893         else {
4894                 ext4_group_t first_not_zeroed;
4895                 first_not_zeroed = ext4_has_uninit_itable(sb);
4896                 ext4_register_li_request(sb, first_not_zeroed);
4897         }
4898
4899         ext4_setup_system_zone(sb);
4900         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4901                 ext4_commit_super(sb, 1);
4902
4903 #ifdef CONFIG_QUOTA
4904         /* Release old quota file names */
4905         for (i = 0; i < MAXQUOTAS; i++)
4906                 kfree(old_opts.s_qf_names[i]);
4907         if (enable_quota) {
4908                 if (sb_any_quota_suspended(sb))
4909                         dquot_resume(sb, -1);
4910                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4911                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4912                         err = ext4_enable_quotas(sb);
4913                         if (err)
4914                                 goto restore_opts;
4915                 }
4916         }
4917 #endif
4918
4919         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4920         kfree(orig_data);
4921         return 0;
4922
4923 restore_opts:
4924         sb->s_flags = old_sb_flags;
4925         sbi->s_mount_opt = old_opts.s_mount_opt;
4926         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4927         sbi->s_resuid = old_opts.s_resuid;
4928         sbi->s_resgid = old_opts.s_resgid;
4929         sbi->s_commit_interval = old_opts.s_commit_interval;
4930         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4931         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4932 #ifdef CONFIG_QUOTA
4933         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4934         for (i = 0; i < MAXQUOTAS; i++) {
4935                 kfree(sbi->s_qf_names[i]);
4936                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4937         }
4938 #endif
4939         kfree(orig_data);
4940         return err;
4941 }
4942
4943 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4944 {
4945         struct super_block *sb = dentry->d_sb;
4946         struct ext4_sb_info *sbi = EXT4_SB(sb);
4947         struct ext4_super_block *es = sbi->s_es;
4948         ext4_fsblk_t overhead = 0, resv_blocks;
4949         u64 fsid;
4950         s64 bfree;
4951         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4952
4953         if (!test_opt(sb, MINIX_DF))
4954                 overhead = sbi->s_overhead;
4955
4956         buf->f_type = EXT4_SUPER_MAGIC;
4957         buf->f_bsize = sb->s_blocksize;
4958         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4959         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4960                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4961         /* prevent underflow in case that few free space is available */
4962         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4963         buf->f_bavail = buf->f_bfree -
4964                         (ext4_r_blocks_count(es) + resv_blocks);
4965         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4966                 buf->f_bavail = 0;
4967         buf->f_files = le32_to_cpu(es->s_inodes_count);
4968         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4969         buf->f_namelen = EXT4_NAME_LEN;
4970         fsid = le64_to_cpup((void *)es->s_uuid) ^
4971                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4972         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4973         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4974
4975         return 0;
4976 }
4977
4978 /* Helper function for writing quotas on sync - we need to start transaction
4979  * before quota file is locked for write. Otherwise the are possible deadlocks:
4980  * Process 1                         Process 2
4981  * ext4_create()                     quota_sync()
4982  *   jbd2_journal_start()                  write_dquot()
4983  *   dquot_initialize()                         down(dqio_mutex)
4984  *     down(dqio_mutex)                    jbd2_journal_start()
4985  *
4986  */
4987
4988 #ifdef CONFIG_QUOTA
4989
4990 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4991 {
4992         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4993 }
4994
4995 static int ext4_write_dquot(struct dquot *dquot)
4996 {
4997         int ret, err;
4998         handle_t *handle;
4999         struct inode *inode;
5000
5001         inode = dquot_to_inode(dquot);
5002         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5003                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5004         if (IS_ERR(handle))
5005                 return PTR_ERR(handle);
5006         ret = dquot_commit(dquot);
5007         err = ext4_journal_stop(handle);
5008         if (!ret)
5009                 ret = err;
5010         return ret;
5011 }
5012
5013 static int ext4_acquire_dquot(struct dquot *dquot)
5014 {
5015         int ret, err;
5016         handle_t *handle;
5017
5018         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5019                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5020         if (IS_ERR(handle))
5021                 return PTR_ERR(handle);
5022         ret = dquot_acquire(dquot);
5023         err = ext4_journal_stop(handle);
5024         if (!ret)
5025                 ret = err;
5026         return ret;
5027 }
5028
5029 static int ext4_release_dquot(struct dquot *dquot)
5030 {
5031         int ret, err;
5032         handle_t *handle;
5033
5034         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5035                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5036         if (IS_ERR(handle)) {
5037                 /* Release dquot anyway to avoid endless cycle in dqput() */
5038                 dquot_release(dquot);
5039                 return PTR_ERR(handle);
5040         }
5041         ret = dquot_release(dquot);
5042         err = ext4_journal_stop(handle);
5043         if (!ret)
5044                 ret = err;
5045         return ret;
5046 }
5047
5048 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5049 {
5050         struct super_block *sb = dquot->dq_sb;
5051         struct ext4_sb_info *sbi = EXT4_SB(sb);
5052
5053         /* Are we journaling quotas? */
5054         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5055             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5056                 dquot_mark_dquot_dirty(dquot);
5057                 return ext4_write_dquot(dquot);
5058         } else {
5059                 return dquot_mark_dquot_dirty(dquot);
5060         }
5061 }
5062
5063 static int ext4_write_info(struct super_block *sb, int type)
5064 {
5065         int ret, err;
5066         handle_t *handle;
5067
5068         /* Data block + inode block */
5069         handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5070         if (IS_ERR(handle))
5071                 return PTR_ERR(handle);
5072         ret = dquot_commit_info(sb, type);
5073         err = ext4_journal_stop(handle);
5074         if (!ret)
5075                 ret = err;
5076         return ret;
5077 }
5078
5079 /*
5080  * Turn on quotas during mount time - we need to find
5081  * the quota file and such...
5082  */
5083 static int ext4_quota_on_mount(struct super_block *sb, int type)
5084 {
5085         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5086                                         EXT4_SB(sb)->s_jquota_fmt, type);
5087 }
5088
5089 /*
5090  * Standard function to be called on quota_on
5091  */
5092 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5093                          struct path *path)
5094 {
5095         int err;
5096
5097         if (!test_opt(sb, QUOTA))
5098                 return -EINVAL;
5099
5100         /* Quotafile not on the same filesystem? */
5101         if (path->dentry->d_sb != sb)
5102                 return -EXDEV;
5103         /* Journaling quota? */
5104         if (EXT4_SB(sb)->s_qf_names[type]) {
5105                 /* Quotafile not in fs root? */
5106                 if (path->dentry->d_parent != sb->s_root)
5107                         ext4_msg(sb, KERN_WARNING,
5108                                 "Quota file not on filesystem root. "
5109                                 "Journaled quota will not work");
5110         }
5111
5112         /*
5113          * When we journal data on quota file, we have to flush journal to see
5114          * all updates to the file when we bypass pagecache...
5115          */
5116         if (EXT4_SB(sb)->s_journal &&
5117             ext4_should_journal_data(path->dentry->d_inode)) {
5118                 /*
5119                  * We don't need to lock updates but journal_flush() could
5120                  * otherwise be livelocked...
5121                  */
5122                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5123                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5124                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5125                 if (err)
5126                         return err;
5127         }
5128
5129         return dquot_quota_on(sb, type, format_id, path);
5130 }
5131
5132 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5133                              unsigned int flags)
5134 {
5135         int err;
5136         struct inode *qf_inode;
5137         unsigned long qf_inums[MAXQUOTAS] = {
5138                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5139                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5140         };
5141
5142         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5143
5144         if (!qf_inums[type])
5145                 return -EPERM;
5146
5147         qf_inode = ext4_iget(sb, qf_inums[type]);
5148         if (IS_ERR(qf_inode)) {
5149                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5150                 return PTR_ERR(qf_inode);
5151         }
5152
5153         /* Don't account quota for quota files to avoid recursion */
5154         qf_inode->i_flags |= S_NOQUOTA;
5155         err = dquot_enable(qf_inode, type, format_id, flags);
5156         iput(qf_inode);
5157
5158         return err;
5159 }
5160
5161 /* Enable usage tracking for all quota types. */
5162 static int ext4_enable_quotas(struct super_block *sb)
5163 {
5164         int type, err = 0;
5165         unsigned long qf_inums[MAXQUOTAS] = {
5166                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5167                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5168         };
5169
5170         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5171         for (type = 0; type < MAXQUOTAS; type++) {
5172                 if (qf_inums[type]) {
5173                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5174                                                 DQUOT_USAGE_ENABLED);
5175                         if (err) {
5176                                 ext4_warning(sb,
5177                                         "Failed to enable quota tracking "
5178                                         "(type=%d, err=%d). Please run "
5179                                         "e2fsck to fix.", type, err);
5180                                 return err;
5181                         }
5182                 }
5183         }
5184         return 0;
5185 }
5186
5187 /*
5188  * quota_on function that is used when QUOTA feature is set.
5189  */
5190 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5191                                  int format_id)
5192 {
5193         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5194                 return -EINVAL;
5195
5196         /*
5197          * USAGE was enabled at mount time. Only need to enable LIMITS now.
5198          */
5199         return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5200 }
5201
5202 static int ext4_quota_off(struct super_block *sb, int type)
5203 {
5204         struct inode *inode = sb_dqopt(sb)->files[type];
5205         handle_t *handle;
5206
5207         /* Force all delayed allocation blocks to be allocated.
5208          * Caller already holds s_umount sem */
5209         if (test_opt(sb, DELALLOC))
5210                 sync_filesystem(sb);
5211
5212         if (!inode)
5213                 goto out;
5214
5215         /* Update modification times of quota files when userspace can
5216          * start looking at them */
5217         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5218         if (IS_ERR(handle))
5219                 goto out;
5220         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5221         ext4_mark_inode_dirty(handle, inode);
5222         ext4_journal_stop(handle);
5223
5224 out:
5225         return dquot_quota_off(sb, type);
5226 }
5227
5228 /*
5229  * quota_off function that is used when QUOTA feature is set.
5230  */
5231 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5232 {
5233         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5234                 return -EINVAL;
5235
5236         /* Disable only the limits. */
5237         return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5238 }
5239
5240 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5241  * acquiring the locks... As quota files are never truncated and quota code
5242  * itself serializes the operations (and no one else should touch the files)
5243  * we don't have to be afraid of races */
5244 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5245                                size_t len, loff_t off)
5246 {
5247         struct inode *inode = sb_dqopt(sb)->files[type];
5248         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5249         int err = 0;
5250         int offset = off & (sb->s_blocksize - 1);
5251         int tocopy;
5252         size_t toread;
5253         struct buffer_head *bh;
5254         loff_t i_size = i_size_read(inode);
5255
5256         if (off > i_size)
5257                 return 0;
5258         if (off+len > i_size)
5259                 len = i_size-off;
5260         toread = len;
5261         while (toread > 0) {
5262                 tocopy = sb->s_blocksize - offset < toread ?
5263                                 sb->s_blocksize - offset : toread;
5264                 bh = ext4_bread(NULL, inode, blk, 0, &err);
5265                 if (err)
5266                         return err;
5267                 if (!bh)        /* A hole? */
5268                         memset(data, 0, tocopy);
5269                 else
5270                         memcpy(data, bh->b_data+offset, tocopy);
5271                 brelse(bh);
5272                 offset = 0;
5273                 toread -= tocopy;
5274                 data += tocopy;
5275                 blk++;
5276         }
5277         return len;
5278 }
5279
5280 /* Write to quotafile (we know the transaction is already started and has
5281  * enough credits) */
5282 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5283                                 const char *data, size_t len, loff_t off)
5284 {
5285         struct inode *inode = sb_dqopt(sb)->files[type];
5286         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5287         int err = 0;
5288         int offset = off & (sb->s_blocksize - 1);
5289         struct buffer_head *bh;
5290         handle_t *handle = journal_current_handle();
5291
5292         if (EXT4_SB(sb)->s_journal && !handle) {
5293                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5294                         " cancelled because transaction is not started",
5295                         (unsigned long long)off, (unsigned long long)len);
5296                 return -EIO;
5297         }
5298         /*
5299          * Since we account only one data block in transaction credits,
5300          * then it is impossible to cross a block boundary.
5301          */
5302         if (sb->s_blocksize - offset < len) {
5303                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5304                         " cancelled because not block aligned",
5305                         (unsigned long long)off, (unsigned long long)len);
5306                 return -EIO;
5307         }
5308
5309         bh = ext4_bread(handle, inode, blk, 1, &err);
5310         if (!bh)
5311                 goto out;
5312         err = ext4_journal_get_write_access(handle, bh);
5313         if (err) {
5314                 brelse(bh);
5315                 goto out;
5316         }
5317         lock_buffer(bh);
5318         memcpy(bh->b_data+offset, data, len);
5319         flush_dcache_page(bh->b_page);
5320         unlock_buffer(bh);
5321         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5322         brelse(bh);
5323 out:
5324         if (err)
5325                 return err;
5326         if (inode->i_size < off + len) {
5327                 i_size_write(inode, off + len);
5328                 EXT4_I(inode)->i_disksize = inode->i_size;
5329                 ext4_mark_inode_dirty(handle, inode);
5330         }
5331         return len;
5332 }
5333
5334 #endif
5335
5336 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5337                        const char *dev_name, void *data)
5338 {
5339         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5340 }
5341
5342 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5343 static inline void register_as_ext2(void)
5344 {
5345         int err = register_filesystem(&ext2_fs_type);
5346         if (err)
5347                 printk(KERN_WARNING
5348                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5349 }
5350
5351 static inline void unregister_as_ext2(void)
5352 {
5353         unregister_filesystem(&ext2_fs_type);
5354 }
5355
5356 static inline int ext2_feature_set_ok(struct super_block *sb)
5357 {
5358         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5359                 return 0;
5360         if (sb->s_flags & MS_RDONLY)
5361                 return 1;
5362         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5363                 return 0;
5364         return 1;
5365 }
5366 #else
5367 static inline void register_as_ext2(void) { }
5368 static inline void unregister_as_ext2(void) { }
5369 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5370 #endif
5371
5372 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5373 static inline void register_as_ext3(void)
5374 {
5375         int err = register_filesystem(&ext3_fs_type);
5376         if (err)
5377                 printk(KERN_WARNING
5378                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5379 }
5380
5381 static inline void unregister_as_ext3(void)
5382 {
5383         unregister_filesystem(&ext3_fs_type);
5384 }
5385
5386 static inline int ext3_feature_set_ok(struct super_block *sb)
5387 {
5388         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5389                 return 0;
5390         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5391                 return 0;
5392         if (sb->s_flags & MS_RDONLY)
5393                 return 1;
5394         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5395                 return 0;
5396         return 1;
5397 }
5398 #else
5399 static inline void register_as_ext3(void) { }
5400 static inline void unregister_as_ext3(void) { }
5401 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5402 #endif
5403
5404 static struct file_system_type ext4_fs_type = {
5405         .owner          = THIS_MODULE,
5406         .name           = "ext4",
5407         .mount          = ext4_mount,
5408         .kill_sb        = kill_block_super,
5409         .fs_flags       = FS_REQUIRES_DEV,
5410 };
5411 MODULE_ALIAS_FS("ext4");
5412
5413 static int __init ext4_init_feat_adverts(void)
5414 {
5415         struct ext4_features *ef;
5416         int ret = -ENOMEM;
5417
5418         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5419         if (!ef)
5420                 goto out;
5421
5422         ef->f_kobj.kset = ext4_kset;
5423         init_completion(&ef->f_kobj_unregister);
5424         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5425                                    "features");
5426         if (ret) {
5427                 kfree(ef);
5428                 goto out;
5429         }
5430
5431         ext4_feat = ef;
5432         ret = 0;
5433 out:
5434         return ret;
5435 }
5436
5437 static void ext4_exit_feat_adverts(void)
5438 {
5439         kobject_put(&ext4_feat->f_kobj);
5440         wait_for_completion(&ext4_feat->f_kobj_unregister);
5441         kfree(ext4_feat);
5442 }
5443
5444 /* Shared across all ext4 file systems */
5445 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5446 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5447
5448 static int __init ext4_init_fs(void)
5449 {
5450         int i, err;
5451
5452         ext4_li_info = NULL;
5453         mutex_init(&ext4_li_mtx);
5454
5455         /* Build-time check for flags consistency */
5456         ext4_check_flag_values();
5457
5458         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5459                 mutex_init(&ext4__aio_mutex[i]);
5460                 init_waitqueue_head(&ext4__ioend_wq[i]);
5461         }
5462
5463         err = ext4_init_es();
5464         if (err)
5465                 return err;
5466
5467         err = ext4_init_pageio();
5468         if (err)
5469                 goto out7;
5470
5471         err = ext4_init_system_zone();
5472         if (err)
5473                 goto out6;
5474         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5475         if (!ext4_kset) {
5476                 err = -ENOMEM;
5477                 goto out5;
5478         }
5479         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5480
5481         err = ext4_init_feat_adverts();
5482         if (err)
5483                 goto out4;
5484
5485         err = ext4_init_mballoc();
5486         if (err)
5487                 goto out3;
5488
5489         err = ext4_init_xattr();
5490         if (err)
5491                 goto out2;
5492         err = init_inodecache();
5493         if (err)
5494                 goto out1;
5495         register_as_ext3();
5496         register_as_ext2();
5497         err = register_filesystem(&ext4_fs_type);
5498         if (err)
5499                 goto out;
5500
5501         return 0;
5502 out:
5503         unregister_as_ext2();
5504         unregister_as_ext3();
5505         destroy_inodecache();
5506 out1:
5507         ext4_exit_xattr();
5508 out2:
5509         ext4_exit_mballoc();
5510 out3:
5511         ext4_exit_feat_adverts();
5512 out4:
5513         if (ext4_proc_root)
5514                 remove_proc_entry("fs/ext4", NULL);
5515         kset_unregister(ext4_kset);
5516 out5:
5517         ext4_exit_system_zone();
5518 out6:
5519         ext4_exit_pageio();
5520 out7:
5521         ext4_exit_es();
5522
5523         return err;
5524 }
5525
5526 static void __exit ext4_exit_fs(void)
5527 {
5528         ext4_destroy_lazyinit_thread();
5529         unregister_as_ext2();
5530         unregister_as_ext3();
5531         unregister_filesystem(&ext4_fs_type);
5532         destroy_inodecache();
5533         ext4_exit_xattr();
5534         ext4_exit_mballoc();
5535         ext4_exit_feat_adverts();
5536         remove_proc_entry("fs/ext4", NULL);
5537         kset_unregister(ext4_kset);
5538         ext4_exit_system_zone();
5539         ext4_exit_pageio();
5540         ext4_exit_es();
5541 }
5542
5543 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5544 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5545 MODULE_LICENSE("GPL");
5546 module_init(ext4_init_fs)
5547 module_exit(ext4_exit_fs)