Pileus Git - ~andy/linux/blob - 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_remount(struct super_block *sb, int *flags, char *data);
  73 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  74 static int ext4_unfreeze(struct super_block *sb);
  75 static int ext4_freeze(struct super_block *sb);
  76 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  77                        const char *dev_name, void *data);
  78 static inline int ext2_feature_set_ok(struct super_block *sb);
  79 static inline int ext3_feature_set_ok(struct super_block *sb);
  80 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  81 static void ext4_destroy_lazyinit_thread(void);
  82 static void ext4_unregister_li_request(struct super_block *sb);
  83 static void ext4_clear_request_list(void);
  84
  85 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  86 static struct file_system_type ext2_fs_type = {
  87         .owner          = THIS_MODULE,
  88         .name           = "ext2",
  89         .mount          = ext4_mount,
  90         .kill_sb        = kill_block_super,
  91         .fs_flags       = FS_REQUIRES_DEV,
  92 };
  93 MODULE_ALIAS_FS("ext2");
  94 MODULE_ALIAS("ext2");
  95 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  96 #else
  97 #define IS_EXT2_SB(sb) (0)
  98 #endif
  99
 100
 101 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 102 static struct file_system_type ext3_fs_type = {
 103         .owner          = THIS_MODULE,
 104         .name           = "ext3",
 105         .mount          = ext4_mount,
 106         .kill_sb        = kill_block_super,
 107         .fs_flags       = FS_REQUIRES_DEV,
 108 };
 109 MODULE_ALIAS_FS("ext3");
 110 MODULE_ALIAS("ext3");
 111 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 112 #else
 113 #define IS_EXT3_SB(sb) (0)
 114 #endif
 115
 116 static int ext4_verify_csum_type(struct super_block *sb,
 117                                  struct ext4_super_block *es)
 118 {
 119         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 120                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 121                 return 1;
 122
 123         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 124 }
 125
 126 static __le32 ext4_superblock_csum(struct super_block *sb,
 127                                    struct ext4_super_block *es)
 128 {
 129         struct ext4_sb_info *sbi = EXT4_SB(sb);
 130         int offset = offsetof(struct ext4_super_block, s_checksum);
 131         __u32 csum;
 132
 133         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 134
 135         return cpu_to_le32(csum);
 136 }
 137
 138 int ext4_superblock_csum_verify(struct super_block *sb,
 139                                 struct ext4_super_block *es)
 140 {
 141         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 142                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 143                 return 1;
 144
 145         return es->s_checksum == ext4_superblock_csum(sb, es);
 146 }
 147
 148 void ext4_superblock_csum_set(struct super_block *sb)
 149 {
 150         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 151
 152         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 153                 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 154                 return;
 155
 156         es->s_checksum = ext4_superblock_csum(sb, es);
 157 }
 158
 159 void *ext4_kvmalloc(size_t size, gfp_t flags)
 160 {
 161         void *ret;
 162
 163         ret = kmalloc(size, flags);
 164         if (!ret)
 165                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 166         return ret;
 167 }
 168
 169 void *ext4_kvzalloc(size_t size, gfp_t flags)
 170 {
 171         void *ret;
 172
 173         ret = kzalloc(size, flags);
 174         if (!ret)
 175                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 176         return ret;
 177 }
 178
 179 void ext4_kvfree(void *ptr)
 180 {
 181         if (is_vmalloc_addr(ptr))
 182                 vfree(ptr);
 183         else
 184                 kfree(ptr);
 185
 186 }
 187
 188 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 189                                struct ext4_group_desc *bg)
 190 {
 191         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 192                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 193                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 194 }
 195
 196 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 197                                struct ext4_group_desc *bg)
 198 {
 199         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 200                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 201                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 202 }
 203
 204 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 205                               struct ext4_group_desc *bg)
 206 {
 207         return le32_to_cpu(bg->bg_inode_table_lo) |
 208                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 209                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 210 }
 211
 212 __u32 ext4_free_group_clusters(struct super_block *sb,
 213                                struct ext4_group_desc *bg)
 214 {
 215         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 216                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 217                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 218 }
 219
 220 __u32 ext4_free_inodes_count(struct super_block *sb,
 221                               struct ext4_group_desc *bg)
 222 {
 223         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 224                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 225                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 226 }
 227
 228 __u32 ext4_used_dirs_count(struct super_block *sb,
 229                               struct ext4_group_desc *bg)
 230 {
 231         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 232                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 233                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 234 }
 235
 236 __u32 ext4_itable_unused_count(struct super_block *sb,
 237                               struct ext4_group_desc *bg)
 238 {
 239         return le16_to_cpu(bg->bg_itable_unused_lo) |
 240                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 241                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 242 }
 243
 244 void ext4_block_bitmap_set(struct super_block *sb,
 245                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 246 {
 247         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 248         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 249                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 250 }
 251
 252 void ext4_inode_bitmap_set(struct super_block *sb,
 253                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 254 {
 255         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 256         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 257                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 258 }
 259
 260 void ext4_inode_table_set(struct super_block *sb,
 261                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 262 {
 263         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 264         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 265                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 266 }
 267
 268 void ext4_free_group_clusters_set(struct super_block *sb,
 269                                   struct ext4_group_desc *bg, __u32 count)
 270 {
 271         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 272         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 273                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 274 }
 275
 276 void ext4_free_inodes_set(struct super_block *sb,
 277                           struct ext4_group_desc *bg, __u32 count)
 278 {
 279         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 280         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 281                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 282 }
 283
 284 void ext4_used_dirs_set(struct super_block *sb,
 285                           struct ext4_group_desc *bg, __u32 count)
 286 {
 287         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 288         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 289                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 290 }
 291
 292 void ext4_itable_unused_set(struct super_block *sb,
 293                           struct ext4_group_desc *bg, __u32 count)
 294 {
 295         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 296         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 297                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 298 }
 299
 300
 301 static void __save_error_info(struct super_block *sb, const char *func,
 302                             unsigned int line)
 303 {
 304         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 305
 306         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 307         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 308         es->s_last_error_time = cpu_to_le32(get_seconds());
 309         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 310         es->s_last_error_line = cpu_to_le32(line);
 311         if (!es->s_first_error_time) {
 312                 es->s_first_error_time = es->s_last_error_time;
 313                 strncpy(es->s_first_error_func, func,
 314                         sizeof(es->s_first_error_func));
 315                 es->s_first_error_line = cpu_to_le32(line);
 316                 es->s_first_error_ino = es->s_last_error_ino;
 317                 es->s_first_error_block = es->s_last_error_block;
 318         }
 319         /*
 320          * Start the daily error reporting function if it hasn't been
 321          * started already
 322          */
 323         if (!es->s_error_count)
 324                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 325         le32_add_cpu(&es->s_error_count, 1);
 326 }
 327
 328 static void save_error_info(struct super_block *sb, const char *func,
 329                             unsigned int line)
 330 {
 331         __save_error_info(sb, func, line);
 332         ext4_commit_super(sb, 1);
 333 }
 334
 335 /*
 336  * The del_gendisk() function uninitializes the disk-specific data
 337  * structures, including the bdi structure, without telling anyone
 338  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 339  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 340  * This is a kludge to prevent these oops until we can put in a proper
 341  * hook in del_gendisk() to inform the VFS and file system layers.
 342  */
 343 static int block_device_ejected(struct super_block *sb)
 344 {
 345         struct inode *bd_inode = sb->s_bdev->bd_inode;
 346         struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
 347
 348         return bdi->dev == NULL;
 349 }
 350
 351 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 352 {
 353         struct super_block              *sb = journal->j_private;
 354         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 355         int                             error = is_journal_aborted(journal);
 356         struct ext4_journal_cb_entry    *jce;
 357
 358         BUG_ON(txn->t_state == T_FINISHED);
 359         spin_lock(&sbi->s_md_lock);
 360         while (!list_empty(&txn->t_private_list)) {
 361                 jce = list_entry(txn->t_private_list.next,
 362                                  struct ext4_journal_cb_entry, jce_list);
 363                 list_del_init(&jce->jce_list);
 364                 spin_unlock(&sbi->s_md_lock);
 365                 jce->jce_func(sb, jce, error);
 366                 spin_lock(&sbi->s_md_lock);
 367         }
 368         spin_unlock(&sbi->s_md_lock);
 369 }
 370
 371 /* Deal with the reporting of failure conditions on a filesystem such as
 372  * inconsistencies detected or read IO failures.
 373  *
 374  * On ext2, we can store the error state of the filesystem in the
 375  * superblock.  That is not possible on ext4, because we may have other
 376  * write ordering constraints on the superblock which prevent us from
 377  * writing it out straight away; and given that the journal is about to
 378  * be aborted, we can't rely on the current, or future, transactions to
 379  * write out the superblock safely.
 380  *
 381  * We'll just use the jbd2_journal_abort() error code to record an error in
 382  * the journal instead.  On recovery, the journal will complain about
 383  * that error until we've noted it down and cleared it.
 384  */
 385
 386 static void ext4_handle_error(struct super_block *sb)
 387 {
 388         if (sb->s_flags & MS_RDONLY)
 389                 return;
 390
 391         if (!test_opt(sb, ERRORS_CONT)) {
 392                 journal_t *journal = EXT4_SB(sb)->s_journal;
 393
 394                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 395                 if (journal)
 396                         jbd2_journal_abort(journal, -EIO);
 397         }
 398         if (test_opt(sb, ERRORS_RO)) {
 399                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 400                 sb->s_flags |= MS_RDONLY;
 401         }
 402         if (test_opt(sb, ERRORS_PANIC))
 403                 panic("EXT4-fs (device %s): panic forced after error\n",
 404                         sb->s_id);
 405 }
 406
 407 void __ext4_error(struct super_block *sb, const char *function,
 408                   unsigned int line, const char *fmt, ...)
 409 {
 410         struct va_format vaf;
 411         va_list args;
 412
 413         va_start(args, fmt);
 414         vaf.fmt = fmt;
 415         vaf.va = &args;
 416         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 417                sb->s_id, function, line, current->comm, &vaf);
 418         va_end(args);
 419         save_error_info(sb, function, line);
 420
 421         ext4_handle_error(sb);
 422 }
 423
 424 void ext4_error_inode(struct inode *inode, const char *function,
 425                       unsigned int line, ext4_fsblk_t block,
 426                       const char *fmt, ...)
 427 {
 428         va_list args;
 429         struct va_format vaf;
 430         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 431
 432         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 433         es->s_last_error_block = cpu_to_le64(block);
 434         save_error_info(inode->i_sb, function, line);
 435         va_start(args, fmt);
 436         vaf.fmt = fmt;
 437         vaf.va = &args;
 438         if (block)
 439                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 440                        "inode #%lu: block %llu: comm %s: %pV\n",
 441                        inode->i_sb->s_id, function, line, inode->i_ino,
 442                        block, current->comm, &vaf);
 443         else
 444                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 445                        "inode #%lu: comm %s: %pV\n",
 446                        inode->i_sb->s_id, function, line, inode->i_ino,
 447                        current->comm, &vaf);
 448         va_end(args);
 449
 450         ext4_handle_error(inode->i_sb);
 451 }
 452
 453 void ext4_error_file(struct file *file, const char *function,
 454                      unsigned int line, ext4_fsblk_t block,
 455                      const char *fmt, ...)
 456 {
 457         va_list args;
 458         struct va_format vaf;
 459         struct ext4_super_block *es;
 460         struct inode *inode = file_inode(file);
 461         char pathname[80], *path;
 462
 463         es = EXT4_SB(inode->i_sb)->s_es;
 464         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 465         save_error_info(inode->i_sb, function, line);
 466         path = d_path(&(file->f_path), pathname, sizeof(pathname));
 467         if (IS_ERR(path))
 468                 path = "(unknown)";
 469         va_start(args, fmt);
 470         vaf.fmt = fmt;
 471         vaf.va = &args;
 472         if (block)
 473                 printk(KERN_CRIT
 474                        "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 475                        "block %llu: comm %s: path %s: %pV\n",
 476                        inode->i_sb->s_id, function, line, inode->i_ino,
 477                        block, current->comm, path, &vaf);
 478         else
 479                 printk(KERN_CRIT
 480                        "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 481                        "comm %s: path %s: %pV\n",
 482                        inode->i_sb->s_id, function, line, inode->i_ino,
 483                        current->comm, path, &vaf);
 484         va_end(args);
 485
 486         ext4_handle_error(inode->i_sb);
 487 }
 488
 489 const char *ext4_decode_error(struct super_block *sb, int errno,
 490                               char nbuf[16])
 491 {
 492         char *errstr = NULL;
 493
 494         switch (errno) {
 495         case -EIO:
 496                 errstr = "IO failure";
 497                 break;
 498         case -ENOMEM:
 499                 errstr = "Out of memory";
 500                 break;
 501         case -EROFS:
 502                 if (!sb || (EXT4_SB(sb)->s_journal &&
 503                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 504                         errstr = "Journal has aborted";
 505                 else
 506                         errstr = "Readonly filesystem";
 507                 break;
 508         default:
 509                 /* If the caller passed in an extra buffer for unknown
 510                  * errors, textualise them now.  Else we just return
 511                  * NULL. */
 512                 if (nbuf) {
 513                         /* Check for truncated error codes... */
 514                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 515                                 errstr = nbuf;
 516                 }
 517                 break;
 518         }
 519
 520         return errstr;
 521 }
 522
 523 /* __ext4_std_error decodes expected errors from journaling functions
 524  * automatically and invokes the appropriate error response.  */
 525
 526 void __ext4_std_error(struct super_block *sb, const char *function,
 527                       unsigned int line, int errno)
 528 {
 529         char nbuf[16];
 530         const char *errstr;
 531
 532         /* Special case: if the error is EROFS, and we're not already
 533          * inside a transaction, then there's really no point in logging
 534          * an error. */
 535         if (errno == -EROFS && journal_current_handle() == NULL &&
 536             (sb->s_flags & MS_RDONLY))
 537                 return;
 538
 539         errstr = ext4_decode_error(sb, errno, nbuf);
 540         printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 541                sb->s_id, function, line, errstr);
 542         save_error_info(sb, function, line);
 543
 544         ext4_handle_error(sb);
 545 }
 546
 547 /*
 548  * ext4_abort is a much stronger failure handler than ext4_error.  The
 549  * abort function may be used to deal with unrecoverable failures such
 550  * as journal IO errors or ENOMEM at a critical moment in log management.
 551  *
 552  * We unconditionally force the filesystem into an ABORT|READONLY state,
 553  * unless the error response on the fs has been set to panic in which
 554  * case we take the easy way out and panic immediately.
 555  */
 556
 557 void __ext4_abort(struct super_block *sb, const char *function,
 558                 unsigned int line, const char *fmt, ...)
 559 {
 560         va_list args;
 561
 562         save_error_info(sb, function, line);
 563         va_start(args, fmt);
 564         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 565                function, line);
 566         vprintk(fmt, args);
 567         printk("\n");
 568         va_end(args);
 569
 570         if ((sb->s_flags & MS_RDONLY) == 0) {
 571                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 572                 sb->s_flags |= MS_RDONLY;
 573                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 574                 if (EXT4_SB(sb)->s_journal)
 575                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 576                 save_error_info(sb, function, line);
 577         }
 578         if (test_opt(sb, ERRORS_PANIC))
 579                 panic("EXT4-fs panic from previous error\n");
 580 }
 581
 582 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
 583 {
 584         struct va_format vaf;
 585         va_list args;
 586
 587         va_start(args, fmt);
 588         vaf.fmt = fmt;
 589         vaf.va = &args;
 590         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 591         va_end(args);
 592 }
 593
 594 void __ext4_warning(struct super_block *sb, const char *function,
 595                     unsigned int line, 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(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 604                sb->s_id, function, line, &vaf);
 605         va_end(args);
 606 }
 607
 608 void __ext4_grp_locked_error(const char *function, unsigned int line,
 609                              struct super_block *sb, ext4_group_t grp,
 610                              unsigned long ino, ext4_fsblk_t block,
 611                              const char *fmt, ...)
 612 __releases(bitlock)
 613 __acquires(bitlock)
 614 {
 615         struct va_format vaf;
 616         va_list args;
 617         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 618
 619         es->s_last_error_ino = cpu_to_le32(ino);
 620         es->s_last_error_block = cpu_to_le64(block);
 621         __save_error_info(sb, function, line);
 622
 623         va_start(args, fmt);
 624
 625         vaf.fmt = fmt;
 626         vaf.va = &args;
 627         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 628                sb->s_id, function, line, grp);
 629         if (ino)
 630                 printk(KERN_CONT "inode %lu: ", ino);
 631         if (block)
 632                 printk(KERN_CONT "block %llu:", (unsigned long long) block);
 633         printk(KERN_CONT "%pV\n", &vaf);
 634         va_end(args);
 635
 636         if (test_opt(sb, ERRORS_CONT)) {
 637                 ext4_commit_super(sb, 0);
 638                 return;
 639         }
 640
 641         ext4_unlock_group(sb, grp);
 642         ext4_handle_error(sb);
 643         /*
 644          * We only get here in the ERRORS_RO case; relocking the group
 645          * may be dangerous, but nothing bad will happen since the
 646          * filesystem will have already been marked read/only and the
 647          * journal has been aborted.  We return 1 as a hint to callers
 648          * who might what to use the return value from
 649          * ext4_grp_locked_error() to distinguish between the
 650          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 651          * aggressively from the ext4 function in question, with a
 652          * more appropriate error code.
 653          */
 654         ext4_lock_group(sb, grp);
 655         return;
 656 }
 657
 658 void ext4_update_dynamic_rev(struct super_block *sb)
 659 {
 660         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 661
 662         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 663                 return;
 664
 665         ext4_warning(sb,
 666                      "updating to rev %d because of new feature flag, "
 667                      "running e2fsck is recommended",
 668                      EXT4_DYNAMIC_REV);
 669
 670         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 671         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 672         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 673         /* leave es->s_feature_*compat flags alone */
 674         /* es->s_uuid will be set by e2fsck if empty */
 675
 676         /*
 677          * The rest of the superblock fields should be zero, and if not it
 678          * means they are likely already in use, so leave them alone.  We
 679          * can leave it up to e2fsck to clean up any inconsistencies there.
 680          */
 681 }
 682
 683 /*
 684  * Open the external journal device
 685  */
 686 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 687 {
 688         struct block_device *bdev;
 689         char b[BDEVNAME_SIZE];
 690
 691         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 692         if (IS_ERR(bdev))
 693                 goto fail;
 694         return bdev;
 695
 696 fail:
 697         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 698                         __bdevname(dev, b), PTR_ERR(bdev));
 699         return NULL;
 700 }
 701
 702 /*
 703  * Release the journal device
 704  */
 705 static int ext4_blkdev_put(struct block_device *bdev)
 706 {
 707         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 708 }
 709
 710 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 711 {
 712         struct block_device *bdev;
 713         int ret = -ENODEV;
 714
 715         bdev = sbi->journal_bdev;
 716         if (bdev) {
 717                 ret = ext4_blkdev_put(bdev);
 718                 sbi->journal_bdev = NULL;
 719         }
 720         return ret;
 721 }
 722
 723 static inline struct inode *orphan_list_entry(struct list_head *l)
 724 {
 725         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 726 }
 727
 728 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 729 {
 730         struct list_head *l;
 731
 732         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 733                  le32_to_cpu(sbi->s_es->s_last_orphan));
 734
 735         printk(KERN_ERR "sb_info orphan list:\n");
 736         list_for_each(l, &sbi->s_orphan) {
 737                 struct inode *inode = orphan_list_entry(l);
 738                 printk(KERN_ERR "  "
 739                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 740                        inode->i_sb->s_id, inode->i_ino, inode,
 741                        inode->i_mode, inode->i_nlink,
 742                        NEXT_ORPHAN(inode));
 743         }
 744 }
 745
 746 static void ext4_put_super(struct super_block *sb)
 747 {
 748         struct ext4_sb_info *sbi = EXT4_SB(sb);
 749         struct ext4_super_block *es = sbi->s_es;
 750         int i, err;
 751
 752         ext4_unregister_li_request(sb);
 753         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 754
 755         flush_workqueue(sbi->dio_unwritten_wq);
 756         destroy_workqueue(sbi->dio_unwritten_wq);
 757
 758         if (sbi->s_journal) {
 759                 err = jbd2_journal_destroy(sbi->s_journal);
 760                 sbi->s_journal = NULL;
 761                 if (err < 0)
 762                         ext4_abort(sb, "Couldn't clean up the journal");
 763         }
 764
 765         ext4_es_unregister_shrinker(sb);
 766         del_timer(&sbi->s_err_report);
 767         ext4_release_system_zone(sb);
 768         ext4_mb_release(sb);
 769         ext4_ext_release(sb);
 770         ext4_xattr_put_super(sb);
 771
 772         if (!(sb->s_flags & MS_RDONLY)) {
 773                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 774                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 775         }
 776         if (!(sb->s_flags & MS_RDONLY))
 777                 ext4_commit_super(sb, 1);
 778
 779         if (sbi->s_proc) {
 780                 remove_proc_entry("options", sbi->s_proc);
 781                 remove_proc_entry(sb->s_id, ext4_proc_root);
 782         }
 783         kobject_del(&sbi->s_kobj);
 784
 785         for (i = 0; i < sbi->s_gdb_count; i++)
 786                 brelse(sbi->s_group_desc[i]);
 787         ext4_kvfree(sbi->s_group_desc);
 788         ext4_kvfree(sbi->s_flex_groups);
 789         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 790         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 791         percpu_counter_destroy(&sbi->s_dirs_counter);
 792         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 793         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
 794         brelse(sbi->s_sbh);
 795 #ifdef CONFIG_QUOTA
 796         for (i = 0; i < MAXQUOTAS; i++)
 797                 kfree(sbi->s_qf_names[i]);
 798 #endif
 799
 800         /* Debugging code just in case the in-memory inode orphan list
 801          * isn't empty.  The on-disk one can be non-empty if we've
 802          * detected an error and taken the fs readonly, but the
 803          * in-memory list had better be clean by this point. */
 804         if (!list_empty(&sbi->s_orphan))
 805                 dump_orphan_list(sb, sbi);
 806         J_ASSERT(list_empty(&sbi->s_orphan));
 807
 808         invalidate_bdev(sb->s_bdev);
 809         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 810                 /*
 811                  * Invalidate the journal device's buffers.  We don't want them
 812                  * floating about in memory - the physical journal device may
 813                  * hotswapped, and it breaks the `ro-after' testing code.
 814                  */
 815                 sync_blockdev(sbi->journal_bdev);
 816                 invalidate_bdev(sbi->journal_bdev);
 817                 ext4_blkdev_remove(sbi);
 818         }
 819         if (sbi->s_mmp_tsk)
 820                 kthread_stop(sbi->s_mmp_tsk);
 821         sb->s_fs_info = NULL;
 822         /*
 823          * Now that we are completely done shutting down the
 824          * superblock, we need to actually destroy the kobject.
 825          */
 826         kobject_put(&sbi->s_kobj);
 827         wait_for_completion(&sbi->s_kobj_unregister);
 828         if (sbi->s_chksum_driver)
 829                 crypto_free_shash(sbi->s_chksum_driver);
 830         kfree(sbi->s_blockgroup_lock);
 831         kfree(sbi);
 832 }
 833
 834 static struct kmem_cache *ext4_inode_cachep;
 835
 836 /*
 837  * Called inside transaction, so use GFP_NOFS
 838  */
 839 static struct inode *ext4_alloc_inode(struct super_block *sb)
 840 {
 841         struct ext4_inode_info *ei;
 842
 843         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 844         if (!ei)
 845                 return NULL;
 846
 847         ei->vfs_inode.i_version = 1;
 848         INIT_LIST_HEAD(&ei->i_prealloc_list);
 849         spin_lock_init(&ei->i_prealloc_lock);
 850         ext4_es_init_tree(&ei->i_es_tree);
 851         rwlock_init(&ei->i_es_lock);
 852         INIT_LIST_HEAD(&ei->i_es_lru);
 853         ei->i_es_lru_nr = 0;
 854         ei->i_reserved_data_blocks = 0;
 855         ei->i_reserved_meta_blocks = 0;
 856         ei->i_allocated_meta_blocks = 0;
 857         ei->i_da_metadata_calc_len = 0;
 858         ei->i_da_metadata_calc_last_lblock = 0;
 859         spin_lock_init(&(ei->i_block_reservation_lock));
 860 #ifdef CONFIG_QUOTA
 861         ei->i_reserved_quota = 0;
 862 #endif
 863         ei->jinode = NULL;
 864         INIT_LIST_HEAD(&ei->i_completed_io_list);
 865         spin_lock_init(&ei->i_completed_io_lock);
 866         ei->i_sync_tid = 0;
 867         ei->i_datasync_tid = 0;
 868         atomic_set(&ei->i_ioend_count, 0);
 869         atomic_set(&ei->i_unwritten, 0);
 870         INIT_WORK(&ei->i_unwritten_work, ext4_end_io_work);
 871
 872         return &ei->vfs_inode;
 873 }
 874
 875 static int ext4_drop_inode(struct inode *inode)
 876 {
 877         int drop = generic_drop_inode(inode);
 878
 879         trace_ext4_drop_inode(inode, drop);
 880         return drop;
 881 }
 882
 883 static void ext4_i_callback(struct rcu_head *head)
 884 {
 885         struct inode *inode = container_of(head, struct inode, i_rcu);
 886         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 887 }
 888
 889 static void ext4_destroy_inode(struct inode *inode)
 890 {
 891         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 892                 ext4_msg(inode->i_sb, KERN_ERR,
 893                          "Inode %lu (%p): orphan list check failed!",
 894                          inode->i_ino, EXT4_I(inode));
 895                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 896                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 897                                 true);
 898                 dump_stack();
 899         }
 900         call_rcu(&inode->i_rcu, ext4_i_callback);
 901 }
 902
 903 static void init_once(void *foo)
 904 {
 905         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 906
 907         INIT_LIST_HEAD(&ei->i_orphan);
 908         init_rwsem(&ei->xattr_sem);
 909         init_rwsem(&ei->i_data_sem);
 910         inode_init_once(&ei->vfs_inode);
 911 }
 912
 913 static int init_inodecache(void)
 914 {
 915         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 916                                              sizeof(struct ext4_inode_info),
 917                                              0, (SLAB_RECLAIM_ACCOUNT|
 918                                                 SLAB_MEM_SPREAD),
 919                                              init_once);
 920         if (ext4_inode_cachep == NULL)
 921                 return -ENOMEM;
 922         return 0;
 923 }
 924
 925 static void destroy_inodecache(void)
 926 {
 927         /*
 928          * Make sure all delayed rcu free inodes are flushed before we
 929          * destroy cache.
 930          */
 931         rcu_barrier();
 932         kmem_cache_destroy(ext4_inode_cachep);
 933 }
 934
 935 void ext4_clear_inode(struct inode *inode)
 936 {
 937         invalidate_inode_buffers(inode);
 938         clear_inode(inode);
 939         dquot_drop(inode);
 940         ext4_discard_preallocations(inode);
 941         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 942         ext4_es_lru_del(inode);
 943         if (EXT4_I(inode)->jinode) {
 944                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 945                                                EXT4_I(inode)->jinode);
 946                 jbd2_free_inode(EXT4_I(inode)->jinode);
 947                 EXT4_I(inode)->jinode = NULL;
 948         }
 949 }
 950
 951 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 952                                         u64 ino, u32 generation)
 953 {
 954         struct inode *inode;
 955
 956         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 957                 return ERR_PTR(-ESTALE);
 958         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 959                 return ERR_PTR(-ESTALE);
 960
 961         /* iget isn't really right if the inode is currently unallocated!!
 962          *
 963          * ext4_read_inode will return a bad_inode if the inode had been
 964          * deleted, so we should be safe.
 965          *
 966          * Currently we don't know the generation for parent directory, so
 967          * a generation of 0 means "accept any"
 968          */
 969         inode = ext4_iget(sb, ino);
 970         if (IS_ERR(inode))
 971                 return ERR_CAST(inode);
 972         if (generation && inode->i_generation != generation) {
 973                 iput(inode);
 974                 return ERR_PTR(-ESTALE);
 975         }
 976
 977         return inode;
 978 }
 979
 980 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 981                                         int fh_len, int fh_type)
 982 {
 983         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 984                                     ext4_nfs_get_inode);
 985 }
 986
 987 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 988                                         int fh_len, int fh_type)
 989 {
 990         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 991                                     ext4_nfs_get_inode);
 992 }
 993
 994 /*
 995  * Try to release metadata pages (indirect blocks, directories) which are
 996  * mapped via the block device.  Since these pages could have journal heads
 997  * which would prevent try_to_free_buffers() from freeing them, we must use
 998  * jbd2 layer's try_to_free_buffers() function to release them.
 999  */
1000 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1001                                  gfp_t wait)
1002 {
1003         journal_t *journal = EXT4_SB(sb)->s_journal;
1004
1005         WARN_ON(PageChecked(page));
1006         if (!page_has_buffers(page))
1007                 return 0;
1008         if (journal)
1009                 return jbd2_journal_try_to_free_buffers(journal, page,
1010                                                         wait & ~__GFP_WAIT);
1011         return try_to_free_buffers(page);
1012 }
1013
1014 #ifdef CONFIG_QUOTA
1015 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1016 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1017
1018 static int ext4_write_dquot(struct dquot *dquot);
1019 static int ext4_acquire_dquot(struct dquot *dquot);
1020 static int ext4_release_dquot(struct dquot *dquot);
1021 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1022 static int ext4_write_info(struct super_block *sb, int type);
1023 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1024                          struct path *path);
1025 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1026                                  int format_id);
1027 static int ext4_quota_off(struct super_block *sb, int type);
1028 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1029 static int ext4_quota_on_mount(struct super_block *sb, int type);
1030 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1031                                size_t len, loff_t off);
1032 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1033                                 const char *data, size_t len, loff_t off);
1034 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1035                              unsigned int flags);
1036 static int ext4_enable_quotas(struct super_block *sb);
1037
1038 static const struct dquot_operations ext4_quota_operations = {
1039         .get_reserved_space = ext4_get_reserved_space,
1040         .write_dquot    = ext4_write_dquot,
1041         .acquire_dquot  = ext4_acquire_dquot,
1042         .release_dquot  = ext4_release_dquot,
1043         .mark_dirty     = ext4_mark_dquot_dirty,
1044         .write_info     = ext4_write_info,
1045         .alloc_dquot    = dquot_alloc,
1046         .destroy_dquot  = dquot_destroy,
1047 };
1048
1049 static const struct quotactl_ops ext4_qctl_operations = {
1050         .quota_on       = ext4_quota_on,
1051         .quota_off      = ext4_quota_off,
1052         .quota_sync     = dquot_quota_sync,
1053         .get_info       = dquot_get_dqinfo,
1054         .set_info       = dquot_set_dqinfo,
1055         .get_dqblk      = dquot_get_dqblk,
1056         .set_dqblk      = dquot_set_dqblk
1057 };
1058
1059 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1060         .quota_on_meta  = ext4_quota_on_sysfile,
1061         .quota_off      = ext4_quota_off_sysfile,
1062         .quota_sync     = dquot_quota_sync,
1063         .get_info       = dquot_get_dqinfo,
1064         .set_info       = dquot_set_dqinfo,
1065         .get_dqblk      = dquot_get_dqblk,
1066         .set_dqblk      = dquot_set_dqblk
1067 };
1068 #endif
1069
1070 static const struct super_operations ext4_sops = {
1071         .alloc_inode    = ext4_alloc_inode,
1072         .destroy_inode  = ext4_destroy_inode,
1073         .write_inode    = ext4_write_inode,
1074         .dirty_inode    = ext4_dirty_inode,
1075         .drop_inode     = ext4_drop_inode,
1076         .evict_inode    = ext4_evict_inode,
1077         .put_super      = ext4_put_super,
1078         .sync_fs        = ext4_sync_fs,
1079         .freeze_fs      = ext4_freeze,
1080         .unfreeze_fs    = ext4_unfreeze,
1081         .statfs         = ext4_statfs,
1082         .remount_fs     = ext4_remount,
1083         .show_options   = ext4_show_options,
1084 #ifdef CONFIG_QUOTA
1085         .quota_read     = ext4_quota_read,
1086         .quota_write    = ext4_quota_write,
1087 #endif
1088         .bdev_try_to_free_page = bdev_try_to_free_page,
1089 };
1090
1091 static const struct super_operations ext4_nojournal_sops = {
1092         .alloc_inode    = ext4_alloc_inode,
1093         .destroy_inode  = ext4_destroy_inode,
1094         .write_inode    = ext4_write_inode,
1095         .dirty_inode    = ext4_dirty_inode,
1096         .drop_inode     = ext4_drop_inode,
1097         .evict_inode    = ext4_evict_inode,
1098         .put_super      = ext4_put_super,
1099         .statfs         = ext4_statfs,
1100         .remount_fs     = ext4_remount,
1101         .show_options   = ext4_show_options,
1102 #ifdef CONFIG_QUOTA
1103         .quota_read     = ext4_quota_read,
1104         .quota_write    = ext4_quota_write,
1105 #endif
1106         .bdev_try_to_free_page = bdev_try_to_free_page,
1107 };
1108
1109 static const struct export_operations ext4_export_ops = {
1110         .fh_to_dentry = ext4_fh_to_dentry,
1111         .fh_to_parent = ext4_fh_to_parent,
1112         .get_parent = ext4_get_parent,
1113 };
1114
1115 enum {
1116         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1117         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1118         Opt_nouid32, Opt_debug, Opt_removed,
1119         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1120         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1121         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1122         Opt_journal_dev, Opt_journal_checksum, Opt_journal_async_commit,
1123         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1124         Opt_data_err_abort, Opt_data_err_ignore,
1125         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1126         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1127         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1128         Opt_usrquota, Opt_grpquota, Opt_i_version,
1129         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1130         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1131         Opt_inode_readahead_blks, Opt_journal_ioprio,
1132         Opt_dioread_nolock, Opt_dioread_lock,
1133         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1134         Opt_max_dir_size_kb,
1135 };
1136
1137 static const match_table_t tokens = {
1138         {Opt_bsd_df, "bsddf"},
1139         {Opt_minix_df, "minixdf"},
1140         {Opt_grpid, "grpid"},
1141         {Opt_grpid, "bsdgroups"},
1142         {Opt_nogrpid, "nogrpid"},
1143         {Opt_nogrpid, "sysvgroups"},
1144         {Opt_resgid, "resgid=%u"},
1145         {Opt_resuid, "resuid=%u"},
1146         {Opt_sb, "sb=%u"},
1147         {Opt_err_cont, "errors=continue"},
1148         {Opt_err_panic, "errors=panic"},
1149         {Opt_err_ro, "errors=remount-ro"},
1150         {Opt_nouid32, "nouid32"},
1151         {Opt_debug, "debug"},
1152         {Opt_removed, "oldalloc"},
1153         {Opt_removed, "orlov"},
1154         {Opt_user_xattr, "user_xattr"},
1155         {Opt_nouser_xattr, "nouser_xattr"},
1156         {Opt_acl, "acl"},
1157         {Opt_noacl, "noacl"},
1158         {Opt_noload, "norecovery"},
1159         {Opt_noload, "noload"},
1160         {Opt_removed, "nobh"},
1161         {Opt_removed, "bh"},
1162         {Opt_commit, "commit=%u"},
1163         {Opt_min_batch_time, "min_batch_time=%u"},
1164         {Opt_max_batch_time, "max_batch_time=%u"},
1165         {Opt_journal_dev, "journal_dev=%u"},
1166         {Opt_journal_checksum, "journal_checksum"},
1167         {Opt_journal_async_commit, "journal_async_commit"},
1168         {Opt_abort, "abort"},
1169         {Opt_data_journal, "data=journal"},
1170         {Opt_data_ordered, "data=ordered"},
1171         {Opt_data_writeback, "data=writeback"},
1172         {Opt_data_err_abort, "data_err=abort"},
1173         {Opt_data_err_ignore, "data_err=ignore"},
1174         {Opt_offusrjquota, "usrjquota="},
1175         {Opt_usrjquota, "usrjquota=%s"},
1176         {Opt_offgrpjquota, "grpjquota="},
1177         {Opt_grpjquota, "grpjquota=%s"},
1178         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1179         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1180         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1181         {Opt_grpquota, "grpquota"},
1182         {Opt_noquota, "noquota"},
1183         {Opt_quota, "quota"},
1184         {Opt_usrquota, "usrquota"},
1185         {Opt_barrier, "barrier=%u"},
1186         {Opt_barrier, "barrier"},
1187         {Opt_nobarrier, "nobarrier"},
1188         {Opt_i_version, "i_version"},
1189         {Opt_stripe, "stripe=%u"},
1190         {Opt_delalloc, "delalloc"},
1191         {Opt_nodelalloc, "nodelalloc"},
1192         {Opt_removed, "mblk_io_submit"},
1193         {Opt_removed, "nomblk_io_submit"},
1194         {Opt_block_validity, "block_validity"},
1195         {Opt_noblock_validity, "noblock_validity"},
1196         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1197         {Opt_journal_ioprio, "journal_ioprio=%u"},
1198         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1199         {Opt_auto_da_alloc, "auto_da_alloc"},
1200         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1201         {Opt_dioread_nolock, "dioread_nolock"},
1202         {Opt_dioread_lock, "dioread_lock"},
1203         {Opt_discard, "discard"},
1204         {Opt_nodiscard, "nodiscard"},
1205         {Opt_init_itable, "init_itable=%u"},
1206         {Opt_init_itable, "init_itable"},
1207         {Opt_noinit_itable, "noinit_itable"},
1208         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1209         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1210         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1211         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1212         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1213         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1214         {Opt_err, NULL},
1215 };
1216
1217 static ext4_fsblk_t get_sb_block(void **data)
1218 {
1219         ext4_fsblk_t    sb_block;
1220         char            *options = (char *) *data;
1221
1222         if (!options || strncmp(options, "sb=", 3) != 0)
1223                 return 1;       /* Default location */
1224
1225         options += 3;
1226         /* TODO: use simple_strtoll with >32bit ext4 */
1227         sb_block = simple_strtoul(options, &options, 0);
1228         if (*options && *options != ',') {
1229                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1230                        (char *) *data);
1231                 return 1;
1232         }
1233         if (*options == ',')
1234                 options++;
1235         *data = (void *) options;
1236
1237         return sb_block;
1238 }
1239
1240 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1241 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1242         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1243
1244 #ifdef CONFIG_QUOTA
1245 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1246 {
1247         struct ext4_sb_info *sbi = EXT4_SB(sb);
1248         char *qname;
1249         int ret = -1;
1250
1251         if (sb_any_quota_loaded(sb) &&
1252                 !sbi->s_qf_names[qtype]) {
1253                 ext4_msg(sb, KERN_ERR,
1254                         "Cannot change journaled "
1255                         "quota options when quota turned on");
1256                 return -1;
1257         }
1258         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1259                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1260                          "when QUOTA feature is enabled");
1261                 return -1;
1262         }
1263         qname = match_strdup(args);
1264         if (!qname) {
1265                 ext4_msg(sb, KERN_ERR,
1266                         "Not enough memory for storing quotafile name");
1267                 return -1;
1268         }
1269         if (sbi->s_qf_names[qtype]) {
1270                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1271                         ret = 1;
1272                 else
1273                         ext4_msg(sb, KERN_ERR,
1274                                  "%s quota file already specified",
1275                                  QTYPE2NAME(qtype));
1276                 goto errout;
1277         }
1278         if (strchr(qname, '/')) {
1279                 ext4_msg(sb, KERN_ERR,
1280                         "quotafile must be on filesystem root");
1281                 goto errout;
1282         }
1283         sbi->s_qf_names[qtype] = qname;
1284         set_opt(sb, QUOTA);
1285         return 1;
1286 errout:
1287         kfree(qname);
1288         return ret;
1289 }
1290
1291 static int clear_qf_name(struct super_block *sb, int qtype)
1292 {
1293
1294         struct ext4_sb_info *sbi = EXT4_SB(sb);
1295
1296         if (sb_any_quota_loaded(sb) &&
1297                 sbi->s_qf_names[qtype]) {
1298                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1299                         " when quota turned on");
1300                 return -1;
1301         }
1302         kfree(sbi->s_qf_names[qtype]);
1303         sbi->s_qf_names[qtype] = NULL;
1304         return 1;
1305 }
1306 #endif
1307
1308 #define MOPT_SET        0x0001
1309 #define MOPT_CLEAR      0x0002
1310 #define MOPT_NOSUPPORT  0x0004
1311 #define MOPT_EXPLICIT   0x0008
1312 #define MOPT_CLEAR_ERR  0x0010
1313 #define MOPT_GTE0       0x0020
1314 #ifdef CONFIG_QUOTA
1315 #define MOPT_Q          0
1316 #define MOPT_QFMT       0x0040
1317 #else
1318 #define MOPT_Q          MOPT_NOSUPPORT
1319 #define MOPT_QFMT       MOPT_NOSUPPORT
1320 #endif
1321 #define MOPT_DATAJ      0x0080
1322 #define MOPT_NO_EXT2    0x0100
1323 #define MOPT_NO_EXT3    0x0200
1324 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1325
1326 static const struct mount_opts {
1327         int     token;
1328         int     mount_opt;
1329         int     flags;
1330 } ext4_mount_opts[] = {
1331         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1332         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1333         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1334         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1335         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1336         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1337         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1338          MOPT_EXT4_ONLY | MOPT_SET},
1339         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1340          MOPT_EXT4_ONLY | MOPT_CLEAR},
1341         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1342         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1343         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1344          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1345         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1346          MOPT_EXT4_ONLY | MOPT_CLEAR | MOPT_EXPLICIT},
1347         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1348          MOPT_EXT4_ONLY | MOPT_SET},
1349         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1350                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1351          MOPT_EXT4_ONLY | MOPT_SET},
1352         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1353         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1354         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1355         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1356         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1357          MOPT_NO_EXT2 | MOPT_SET},
1358         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1359          MOPT_NO_EXT2 | MOPT_CLEAR},
1360         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1361         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1362         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1363         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1364         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1365         {Opt_commit, 0, MOPT_GTE0},
1366         {Opt_max_batch_time, 0, MOPT_GTE0},
1367         {Opt_min_batch_time, 0, MOPT_GTE0},
1368         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1369         {Opt_init_itable, 0, MOPT_GTE0},
1370         {Opt_stripe, 0, MOPT_GTE0},
1371         {Opt_resuid, 0, MOPT_GTE0},
1372         {Opt_resgid, 0, MOPT_GTE0},
1373         {Opt_journal_dev, 0, MOPT_GTE0},
1374         {Opt_journal_ioprio, 0, MOPT_GTE0},
1375         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1376         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1377         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1378          MOPT_NO_EXT2 | MOPT_DATAJ},
1379         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1380         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1381 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1382         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1383         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1384 #else
1385         {Opt_acl, 0, MOPT_NOSUPPORT},
1386         {Opt_noacl, 0, MOPT_NOSUPPORT},
1387 #endif
1388         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1389         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1390         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1391         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1392                                                         MOPT_SET | MOPT_Q},
1393         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1394                                                         MOPT_SET | MOPT_Q},
1395         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1396                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1397         {Opt_usrjquota, 0, MOPT_Q},
1398         {Opt_grpjquota, 0, MOPT_Q},
1399         {Opt_offusrjquota, 0, MOPT_Q},
1400         {Opt_offgrpjquota, 0, MOPT_Q},
1401         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1402         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1403         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1404         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1405         {Opt_err, 0, 0}
1406 };
1407
1408 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1409                             substring_t *args, unsigned long *journal_devnum,
1410                             unsigned int *journal_ioprio, int is_remount)
1411 {
1412         struct ext4_sb_info *sbi = EXT4_SB(sb);
1413         const struct mount_opts *m;
1414         kuid_t uid;
1415         kgid_t gid;
1416         int arg = 0;
1417
1418 #ifdef CONFIG_QUOTA
1419         if (token == Opt_usrjquota)
1420                 return set_qf_name(sb, USRQUOTA, &args[0]);
1421         else if (token == Opt_grpjquota)
1422                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1423         else if (token == Opt_offusrjquota)
1424                 return clear_qf_name(sb, USRQUOTA);
1425         else if (token == Opt_offgrpjquota)
1426                 return clear_qf_name(sb, GRPQUOTA);
1427 #endif
1428         switch (token) {
1429         case Opt_noacl:
1430         case Opt_nouser_xattr:
1431                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1432                 break;
1433         case Opt_sb:
1434                 return 1;       /* handled by get_sb_block() */
1435         case Opt_removed:
1436                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1437                 return 1;
1438         case Opt_abort:
1439                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1440                 return 1;
1441         case Opt_i_version:
1442                 sb->s_flags |= MS_I_VERSION;
1443                 return 1;
1444         }
1445
1446         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1447                 if (token == m->token)
1448                         break;
1449
1450         if (m->token == Opt_err) {
1451                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1452                          "or missing value", opt);
1453                 return -1;
1454         }
1455
1456         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1457                 ext4_msg(sb, KERN_ERR,
1458                          "Mount option \"%s\" incompatible with ext2", opt);
1459                 return -1;
1460         }
1461         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1462                 ext4_msg(sb, KERN_ERR,
1463                          "Mount option \"%s\" incompatible with ext3", opt);
1464                 return -1;
1465         }
1466
1467         if (args->from && match_int(args, &arg))
1468                 return -1;
1469         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1470                 return -1;
1471         if (m->flags & MOPT_EXPLICIT)
1472                 set_opt2(sb, EXPLICIT_DELALLOC);
1473         if (m->flags & MOPT_CLEAR_ERR)
1474                 clear_opt(sb, ERRORS_MASK);
1475         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1476                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1477                          "options when quota turned on");
1478                 return -1;
1479         }
1480
1481         if (m->flags & MOPT_NOSUPPORT) {
1482                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1483         } else if (token == Opt_commit) {
1484                 if (arg == 0)
1485                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1486                 sbi->s_commit_interval = HZ * arg;
1487         } else if (token == Opt_max_batch_time) {
1488                 if (arg == 0)
1489                         arg = EXT4_DEF_MAX_BATCH_TIME;
1490                 sbi->s_max_batch_time = arg;
1491         } else if (token == Opt_min_batch_time) {
1492                 sbi->s_min_batch_time = arg;
1493         } else if (token == Opt_inode_readahead_blks) {
1494                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1495                         ext4_msg(sb, KERN_ERR,
1496                                  "EXT4-fs: inode_readahead_blks must be "
1497                                  "0 or a power of 2 smaller than 2^31");
1498                         return -1;
1499                 }
1500                 sbi->s_inode_readahead_blks = arg;
1501         } else if (token == Opt_init_itable) {
1502                 set_opt(sb, INIT_INODE_TABLE);
1503                 if (!args->from)
1504                         arg = EXT4_DEF_LI_WAIT_MULT;
1505                 sbi->s_li_wait_mult = arg;
1506         } else if (token == Opt_max_dir_size_kb) {
1507                 sbi->s_max_dir_size_kb = arg;
1508         } else if (token == Opt_stripe) {
1509                 sbi->s_stripe = arg;
1510         } else if (token == Opt_resuid) {
1511                 uid = make_kuid(current_user_ns(), arg);
1512                 if (!uid_valid(uid)) {
1513                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1514                         return -1;
1515                 }
1516                 sbi->s_resuid = uid;
1517         } else if (token == Opt_resgid) {
1518                 gid = make_kgid(current_user_ns(), arg);
1519                 if (!gid_valid(gid)) {
1520                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1521                         return -1;
1522                 }
1523                 sbi->s_resgid = gid;
1524         } else if (token == Opt_journal_dev) {
1525                 if (is_remount) {
1526                         ext4_msg(sb, KERN_ERR,
1527                                  "Cannot specify journal on remount");
1528                         return -1;
1529                 }
1530                 *journal_devnum = arg;
1531         } else if (token == Opt_journal_ioprio) {
1532                 if (arg > 7) {
1533                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1534                                  " (must be 0-7)");
1535                         return -1;
1536                 }
1537                 *journal_ioprio =
1538                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1539         } else if (m->flags & MOPT_DATAJ) {
1540                 if (is_remount) {
1541                         if (!sbi->s_journal)
1542                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1543                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1544                                 ext4_msg(sb, KERN_ERR,
1545                                          "Cannot change data mode on remount");
1546                                 return -1;
1547                         }
1548                 } else {
1549                         clear_opt(sb, DATA_FLAGS);
1550                         sbi->s_mount_opt |= m->mount_opt;
1551                 }
1552 #ifdef CONFIG_QUOTA
1553         } else if (m->flags & MOPT_QFMT) {
1554                 if (sb_any_quota_loaded(sb) &&
1555                     sbi->s_jquota_fmt != m->mount_opt) {
1556                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1557                                  "quota options when quota turned on");
1558                         return -1;
1559                 }
1560                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1561                                                EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1562                         ext4_msg(sb, KERN_ERR,
1563                                  "Cannot set journaled quota options "
1564                                  "when QUOTA feature is enabled");
1565                         return -1;
1566                 }
1567                 sbi->s_jquota_fmt = m->mount_opt;
1568 #endif
1569         } else {
1570                 if (!args->from)
1571                         arg = 1;
1572                 if (m->flags & MOPT_CLEAR)
1573                         arg = !arg;
1574                 else if (unlikely(!(m->flags & MOPT_SET))) {
1575                         ext4_msg(sb, KERN_WARNING,
1576                                  "buggy handling of option %s", opt);
1577                         WARN_ON(1);
1578                         return -1;
1579                 }
1580                 if (arg != 0)
1581                         sbi->s_mount_opt |= m->mount_opt;
1582                 else
1583                         sbi->s_mount_opt &= ~m->mount_opt;
1584         }
1585         return 1;
1586 }
1587
1588 static int parse_options(char *options, struct super_block *sb,
1589                          unsigned long *journal_devnum,
1590                          unsigned int *journal_ioprio,
1591                          int is_remount)
1592 {
1593         struct ext4_sb_info *sbi = EXT4_SB(sb);
1594         char *p;
1595         substring_t args[MAX_OPT_ARGS];
1596         int token;
1597
1598         if (!options)
1599                 return 1;
1600
1601         while ((p = strsep(&options, ",")) != NULL) {
1602                 if (!*p)
1603                         continue;
1604                 /*
1605                  * Initialize args struct so we know whether arg was
1606                  * found; some options take optional arguments.
1607                  */
1608                 args[0].to = args[0].from = NULL;
1609                 token = match_token(p, tokens, args);
1610                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1611                                      journal_ioprio, is_remount) < 0)
1612                         return 0;
1613         }
1614 #ifdef CONFIG_QUOTA
1615         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1616             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1617                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1618                          "feature is enabled");
1619                 return 0;
1620         }
1621         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1622                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1623                         clear_opt(sb, USRQUOTA);
1624
1625                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1626                         clear_opt(sb, GRPQUOTA);
1627
1628                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1629                         ext4_msg(sb, KERN_ERR, "old and new quota "
1630                                         "format mixing");
1631                         return 0;
1632                 }
1633
1634                 if (!sbi->s_jquota_fmt) {
1635                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1636                                         "not specified");
1637                         return 0;
1638                 }
1639         } else {
1640                 if (sbi->s_jquota_fmt) {
1641                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1642                                         "specified with no journaling "
1643                                         "enabled");
1644                         return 0;
1645                 }
1646         }
1647 #endif
1648         if (test_opt(sb, DIOREAD_NOLOCK)) {
1649                 int blocksize =
1650                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1651
1652                 if (blocksize < PAGE_CACHE_SIZE) {
1653                         ext4_msg(sb, KERN_ERR, "can't mount with "
1654                                  "dioread_nolock if block size != PAGE_SIZE");
1655                         return 0;
1656                 }
1657         }
1658         return 1;
1659 }
1660
1661 static inline void ext4_show_quota_options(struct seq_file *seq,
1662                                            struct super_block *sb)
1663 {
1664 #if defined(CONFIG_QUOTA)
1665         struct ext4_sb_info *sbi = EXT4_SB(sb);
1666
1667         if (sbi->s_jquota_fmt) {
1668                 char *fmtname = "";
1669
1670                 switch (sbi->s_jquota_fmt) {
1671                 case QFMT_VFS_OLD:
1672                         fmtname = "vfsold";
1673                         break;
1674                 case QFMT_VFS_V0:
1675                         fmtname = "vfsv0";
1676                         break;
1677                 case QFMT_VFS_V1:
1678                         fmtname = "vfsv1";
1679                         break;
1680                 }
1681                 seq_printf(seq, ",jqfmt=%s", fmtname);
1682         }
1683
1684         if (sbi->s_qf_names[USRQUOTA])
1685                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1686
1687         if (sbi->s_qf_names[GRPQUOTA])
1688                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1689
1690         if (test_opt(sb, USRQUOTA))
1691                 seq_puts(seq, ",usrquota");
1692
1693         if (test_opt(sb, GRPQUOTA))
1694                 seq_puts(seq, ",grpquota");
1695 #endif
1696 }
1697
1698 static const char *token2str(int token)
1699 {
1700         const struct match_token *t;
1701
1702         for (t = tokens; t->token != Opt_err; t++)
1703                 if (t->token == token && !strchr(t->pattern, '='))
1704                         break;
1705         return t->pattern;
1706 }
1707
1708 /*
1709  * Show an option if
1710  *  - it's set to a non-default value OR
1711  *  - if the per-sb default is different from the global default
1712  */
1713 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1714                               int nodefs)
1715 {
1716         struct ext4_sb_info *sbi = EXT4_SB(sb);
1717         struct ext4_super_block *es = sbi->s_es;
1718         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1719         const struct mount_opts *m;
1720         char sep = nodefs ? '\n' : ',';
1721
1722 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1723 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1724
1725         if (sbi->s_sb_block != 1)
1726                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1727
1728         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1729                 int want_set = m->flags & MOPT_SET;
1730                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1731                     (m->flags & MOPT_CLEAR_ERR))
1732                         continue;
1733                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1734                         continue; /* skip if same as the default */
1735                 if ((want_set &&
1736                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1737                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1738                         continue; /* select Opt_noFoo vs Opt_Foo */
1739                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1740         }
1741
1742         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1743             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1744                 SEQ_OPTS_PRINT("resuid=%u",
1745                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1746         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1747             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1748                 SEQ_OPTS_PRINT("resgid=%u",
1749                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1750         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1751         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1752                 SEQ_OPTS_PUTS("errors=remount-ro");
1753         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1754                 SEQ_OPTS_PUTS("errors=continue");
1755         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1756                 SEQ_OPTS_PUTS("errors=panic");
1757         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1758                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1759         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1760                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1761         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1762                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1763         if (sb->s_flags & MS_I_VERSION)
1764                 SEQ_OPTS_PUTS("i_version");
1765         if (nodefs || sbi->s_stripe)
1766                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1767         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1768                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1769                         SEQ_OPTS_PUTS("data=journal");
1770                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1771                         SEQ_OPTS_PUTS("data=ordered");
1772                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1773                         SEQ_OPTS_PUTS("data=writeback");
1774         }
1775         if (nodefs ||
1776             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1777                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1778                                sbi->s_inode_readahead_blks);
1779
1780         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1781                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1782                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1783         if (nodefs || sbi->s_max_dir_size_kb)
1784                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1785
1786         ext4_show_quota_options(seq, sb);
1787         return 0;
1788 }
1789
1790 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1791 {
1792         return _ext4_show_options(seq, root->d_sb, 0);
1793 }
1794
1795 static int options_seq_show(struct seq_file *seq, void *offset)
1796 {
1797         struct super_block *sb = seq->private;
1798         int rc;
1799
1800         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1801         rc = _ext4_show_options(seq, sb, 1);
1802         seq_puts(seq, "\n");
1803         return rc;
1804 }
1805
1806 static int options_open_fs(struct inode *inode, struct file *file)
1807 {
1808         return single_open(file, options_seq_show, PDE(inode)->data);
1809 }
1810
1811 static const struct file_operations ext4_seq_options_fops = {
1812         .owner = THIS_MODULE,
1813         .open = options_open_fs,
1814         .read = seq_read,
1815         .llseek = seq_lseek,
1816         .release = single_release,
1817 };
1818
1819 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1820                             int read_only)
1821 {
1822         struct ext4_sb_info *sbi = EXT4_SB(sb);
1823         int res = 0;
1824
1825         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1826                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1827                          "forcing read-only mode");
1828                 res = MS_RDONLY;
1829         }
1830         if (read_only)
1831                 goto done;
1832         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1833                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1834                          "running e2fsck is recommended");
1835         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1836                 ext4_msg(sb, KERN_WARNING,
1837                          "warning: mounting fs with errors, "
1838                          "running e2fsck is recommended");
1839         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1840                  le16_to_cpu(es->s_mnt_count) >=
1841                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1842                 ext4_msg(sb, KERN_WARNING,
1843                          "warning: maximal mount count reached, "
1844                          "running e2fsck is recommended");
1845         else if (le32_to_cpu(es->s_checkinterval) &&
1846                 (le32_to_cpu(es->s_lastcheck) +
1847                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1848                 ext4_msg(sb, KERN_WARNING,
1849                          "warning: checktime reached, "
1850                          "running e2fsck is recommended");
1851         if (!sbi->s_journal)
1852                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1853         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1854                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1855         le16_add_cpu(&es->s_mnt_count, 1);
1856         es->s_mtime = cpu_to_le32(get_seconds());
1857         ext4_update_dynamic_rev(sb);
1858         if (sbi->s_journal)
1859                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1860
1861         ext4_commit_super(sb, 1);
1862 done:
1863         if (test_opt(sb, DEBUG))
1864                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1865                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1866                         sb->s_blocksize,
1867                         sbi->s_groups_count,
1868                         EXT4_BLOCKS_PER_GROUP(sb),
1869                         EXT4_INODES_PER_GROUP(sb),
1870                         sbi->s_mount_opt, sbi->s_mount_opt2);
1871
1872         cleancache_init_fs(sb);
1873         return res;
1874 }
1875
1876 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1877 {
1878         struct ext4_sb_info *sbi = EXT4_SB(sb);
1879         struct flex_groups *new_groups;
1880         int size;
1881
1882         if (!sbi->s_log_groups_per_flex)
1883                 return 0;
1884
1885         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1886         if (size <= sbi->s_flex_groups_allocated)
1887                 return 0;
1888
1889         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1890         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1891         if (!new_groups) {
1892                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1893                          size / (int) sizeof(struct flex_groups));
1894                 return -ENOMEM;
1895         }
1896
1897         if (sbi->s_flex_groups) {
1898                 memcpy(new_groups, sbi->s_flex_groups,
1899                        (sbi->s_flex_groups_allocated *
1900                         sizeof(struct flex_groups)));
1901                 ext4_kvfree(sbi->s_flex_groups);
1902         }
1903         sbi->s_flex_groups = new_groups;
1904         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1905         return 0;
1906 }
1907
1908 static int ext4_fill_flex_info(struct super_block *sb)
1909 {
1910         struct ext4_sb_info *sbi = EXT4_SB(sb);
1911         struct ext4_group_desc *gdp = NULL;
1912         ext4_group_t flex_group;
1913         unsigned int groups_per_flex = 0;
1914         int i, err;
1915
1916         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1917         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1918                 sbi->s_log_groups_per_flex = 0;
1919                 return 1;
1920         }
1921         groups_per_flex = 1U << sbi->s_log_groups_per_flex;
1922
1923         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1924         if (err)
1925                 goto failed;
1926
1927         for (i = 0; i < sbi->s_groups_count; i++) {
1928                 gdp = ext4_get_group_desc(sb, i, NULL);
1929
1930                 flex_group = ext4_flex_group(sbi, i);
1931                 atomic_add(ext4_free_inodes_count(sb, gdp),
1932                            &sbi->s_flex_groups[flex_group].free_inodes);
1933                 atomic64_add(ext4_free_group_clusters(sb, gdp),
1934                              &sbi->s_flex_groups[flex_group].free_clusters);
1935                 atomic_add(ext4_used_dirs_count(sb, gdp),
1936                            &sbi->s_flex_groups[flex_group].used_dirs);
1937         }
1938
1939         return 1;
1940 failed:
1941         return 0;
1942 }
1943
1944 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1945                                    struct ext4_group_desc *gdp)
1946 {
1947         int offset;
1948         __u16 crc = 0;
1949         __le32 le_group = cpu_to_le32(block_group);
1950
1951         if ((sbi->s_es->s_feature_ro_compat &
1952              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
1953                 /* Use new metadata_csum algorithm */
1954                 __u16 old_csum;
1955                 __u32 csum32;
1956
1957                 old_csum = gdp->bg_checksum;
1958                 gdp->bg_checksum = 0;
1959                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
1960                                      sizeof(le_group));
1961                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
1962                                      sbi->s_desc_size);
1963                 gdp->bg_checksum = old_csum;
1964
1965                 crc = csum32 & 0xFFFF;
1966                 goto out;
1967         }
1968
1969         /* old crc16 code */
1970         offset = offsetof(struct ext4_group_desc, bg_checksum);
1971
1972         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1973         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1974         crc = crc16(crc, (__u8 *)gdp, offset);
1975         offset += sizeof(gdp->bg_checksum); /* skip checksum */
1976         /* for checksum of struct ext4_group_desc do the rest...*/
1977         if ((sbi->s_es->s_feature_incompat &
1978              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1979             offset < le16_to_cpu(sbi->s_es->s_desc_size))
1980                 crc = crc16(crc, (__u8 *)gdp + offset,
1981                             le16_to_cpu(sbi->s_es->s_desc_size) -
1982                                 offset);
1983
1984 out:
1985         return cpu_to_le16(crc);
1986 }
1987
1988 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
1989                                 struct ext4_group_desc *gdp)
1990 {
1991         if (ext4_has_group_desc_csum(sb) &&
1992             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
1993                                                       block_group, gdp)))
1994                 return 0;
1995
1996         return 1;
1997 }
1998
1999 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2000                               struct ext4_group_desc *gdp)
2001 {
2002         if (!ext4_has_group_desc_csum(sb))
2003                 return;
2004         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2005 }
2006
2007 /* Called at mount-time, super-block is locked */
2008 static int ext4_check_descriptors(struct super_block *sb,
2009                                   ext4_group_t *first_not_zeroed)
2010 {
2011         struct ext4_sb_info *sbi = EXT4_SB(sb);
2012         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2013         ext4_fsblk_t last_block;
2014         ext4_fsblk_t block_bitmap;
2015         ext4_fsblk_t inode_bitmap;
2016         ext4_fsblk_t inode_table;
2017         int flexbg_flag = 0;
2018         ext4_group_t i, grp = sbi->s_groups_count;
2019
2020         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2021                 flexbg_flag = 1;
2022
2023         ext4_debug("Checking group descriptors");
2024
2025         for (i = 0; i < sbi->s_groups_count; i++) {
2026                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2027
2028                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2029                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2030                 else
2031                         last_block = first_block +
2032                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2033
2034                 if ((grp == sbi->s_groups_count) &&
2035                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2036                         grp = i;
2037
2038                 block_bitmap = ext4_block_bitmap(sb, gdp);
2039                 if (block_bitmap < first_block || block_bitmap > last_block) {
2040                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2041                                "Block bitmap for group %u not in group "
2042                                "(block %llu)!", i, block_bitmap);
2043                         return 0;
2044                 }
2045                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2046                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2047                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2048                                "Inode bitmap for group %u not in group "
2049                                "(block %llu)!", i, inode_bitmap);
2050                         return 0;
2051                 }
2052                 inode_table = ext4_inode_table(sb, gdp);
2053                 if (inode_table < first_block ||
2054                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2055                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2056                                "Inode table for group %u not in group "
2057                                "(block %llu)!", i, inode_table);
2058                         return 0;
2059                 }
2060                 ext4_lock_group(sb, i);
2061                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2062                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2063                                  "Checksum for group %u failed (%u!=%u)",
2064                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2065                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2066                         if (!(sb->s_flags & MS_RDONLY)) {
2067                                 ext4_unlock_group(sb, i);
2068                                 return 0;
2069                         }
2070                 }
2071                 ext4_unlock_group(sb, i);
2072                 if (!flexbg_flag)
2073                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2074         }
2075         if (NULL != first_not_zeroed)
2076                 *first_not_zeroed = grp;
2077
2078         ext4_free_blocks_count_set(sbi->s_es,
2079                                    EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2080         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2081         return 1;
2082 }
2083
2084 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2085  * the superblock) which were deleted from all directories, but held open by
2086  * a process at the time of a crash.  We walk the list and try to delete these
2087  * inodes at recovery time (only with a read-write filesystem).
2088  *
2089  * In order to keep the orphan inode chain consistent during traversal (in
2090  * case of crash during recovery), we link each inode into the superblock
2091  * orphan list_head and handle it the same way as an inode deletion during
2092  * normal operation (which journals the operations for us).
2093  *
2094  * We only do an iget() and an iput() on each inode, which is very safe if we
2095  * accidentally point at an in-use or already deleted inode.  The worst that
2096  * can happen in this case is that we get a "bit already cleared" message from
2097  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2098  * e2fsck was run on this filesystem, and it must have already done the orphan
2099  * inode cleanup for us, so we can safely abort without any further action.
2100  */
2101 static void ext4_orphan_cleanup(struct super_block *sb,
2102                                 struct ext4_super_block *es)
2103 {
2104         unsigned int s_flags = sb->s_flags;
2105         int nr_orphans = 0, nr_truncates = 0;
2106 #ifdef CONFIG_QUOTA
2107         int i;
2108 #endif
2109         if (!es->s_last_orphan) {
2110                 jbd_debug(4, "no orphan inodes to clean up\n");
2111                 return;
2112         }
2113
2114         if (bdev_read_only(sb->s_bdev)) {
2115                 ext4_msg(sb, KERN_ERR, "write access "
2116                         "unavailable, skipping orphan cleanup");
2117                 return;
2118         }
2119
2120         /* Check if feature set would not allow a r/w mount */
2121         if (!ext4_feature_set_ok(sb, 0)) {
2122                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2123                          "unknown ROCOMPAT features");
2124                 return;
2125         }
2126
2127         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2128                 /* don't clear list on RO mount w/ errors */
2129                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2130                         jbd_debug(1, "Errors on filesystem, "
2131                                   "clearing orphan list.\n");
2132                         es->s_last_orphan = 0;
2133                 }
2134                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2135                 return;
2136         }
2137
2138         if (s_flags & MS_RDONLY) {
2139                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2140                 sb->s_flags &= ~MS_RDONLY;
2141         }
2142 #ifdef CONFIG_QUOTA
2143         /* Needed for iput() to work correctly and not trash data */
2144         sb->s_flags |= MS_ACTIVE;
2145         /* Turn on quotas so that they are updated correctly */
2146         for (i = 0; i < MAXQUOTAS; i++) {
2147                 if (EXT4_SB(sb)->s_qf_names[i]) {
2148                         int ret = ext4_quota_on_mount(sb, i);
2149                         if (ret < 0)
2150                                 ext4_msg(sb, KERN_ERR,
2151                                         "Cannot turn on journaled "
2152                                         "quota: error %d", ret);
2153                 }
2154         }
2155 #endif
2156
2157         while (es->s_last_orphan) {
2158                 struct inode *inode;
2159
2160                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2161                 if (IS_ERR(inode)) {
2162                         es->s_last_orphan = 0;
2163                         break;
2164                 }
2165
2166                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2167                 dquot_initialize(inode);
2168                 if (inode->i_nlink) {
2169                         ext4_msg(sb, KERN_DEBUG,
2170                                 "%s: truncating inode %lu to %lld bytes",
2171                                 __func__, inode->i_ino, inode->i_size);
2172                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2173                                   inode->i_ino, inode->i_size);
2174                         mutex_lock(&inode->i_mutex);
2175                         ext4_truncate(inode);
2176                         mutex_unlock(&inode->i_mutex);
2177                         nr_truncates++;
2178                 } else {
2179                         ext4_msg(sb, KERN_DEBUG,
2180                                 "%s: deleting unreferenced inode %lu",
2181                                 __func__, inode->i_ino);
2182                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2183                                   inode->i_ino);
2184                         nr_orphans++;
2185                 }
2186                 iput(inode);  /* The delete magic happens here! */
2187         }
2188
2189 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2190
2191         if (nr_orphans)
2192                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2193                        PLURAL(nr_orphans));
2194         if (nr_truncates)
2195                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2196                        PLURAL(nr_truncates));
2197 #ifdef CONFIG_QUOTA
2198         /* Turn quotas off */
2199         for (i = 0; i < MAXQUOTAS; i++) {
2200                 if (sb_dqopt(sb)->files[i])
2201                         dquot_quota_off(sb, i);
2202         }
2203 #endif
2204         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2205 }
2206
2207 /*
2208  * Maximal extent format file size.
2209  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2210  * extent format containers, within a sector_t, and within i_blocks
2211  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2212  * so that won't be a limiting factor.
2213  *
2214  * However there is other limiting factor. We do store extents in the form
2215  * of starting block and length, hence the resulting length of the extent
2216  * covering maximum file size must fit into on-disk format containers as
2217  * well. Given that length is always by 1 unit bigger than max unit (because
2218  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2219  *
2220  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2221  */
2222 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2223 {
2224         loff_t res;
2225         loff_t upper_limit = MAX_LFS_FILESIZE;
2226
2227         /* small i_blocks in vfs inode? */
2228         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2229                 /*
2230                  * CONFIG_LBDAF is not enabled implies the inode
2231                  * i_block represent total blocks in 512 bytes
2232                  * 32 == size of vfs inode i_blocks * 8
2233                  */
2234                 upper_limit = (1LL << 32) - 1;
2235
2236                 /* total blocks in file system block size */
2237                 upper_limit >>= (blkbits - 9);
2238                 upper_limit <<= blkbits;
2239         }
2240
2241         /*
2242          * 32-bit extent-start container, ee_block. We lower the maxbytes
2243          * by one fs block, so ee_len can cover the extent of maximum file
2244          * size
2245          */
2246         res = (1LL << 32) - 1;
2247         res <<= blkbits;
2248
2249         /* Sanity check against vm- & vfs- imposed limits */
2250         if (res > upper_limit)
2251                 res = upper_limit;
2252
2253         return res;
2254 }
2255
2256 /*
2257  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2258  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2259  * We need to be 1 filesystem block less than the 2^48 sector limit.
2260  */
2261 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2262 {
2263         loff_t res = EXT4_NDIR_BLOCKS;
2264         int meta_blocks;
2265         loff_t upper_limit;
2266         /* This is calculated to be the largest file size for a dense, block
2267          * mapped file such that the file's total number of 512-byte sectors,
2268          * including data and all indirect blocks, does not exceed (2^48 - 1).
2269          *
2270          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2271          * number of 512-byte sectors of the file.
2272          */
2273
2274         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2275                 /*
2276                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2277                  * the inode i_block field represents total file blocks in
2278                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2279                  */
2280                 upper_limit = (1LL << 32) - 1;
2281
2282                 /* total blocks in file system block size */
2283                 upper_limit >>= (bits - 9);
2284
2285         } else {
2286                 /*
2287                  * We use 48 bit ext4_inode i_blocks
2288                  * With EXT4_HUGE_FILE_FL set the i_blocks
2289                  * represent total number of blocks in
2290                  * file system block size
2291                  */
2292                 upper_limit = (1LL << 48) - 1;
2293
2294         }
2295
2296         /* indirect blocks */
2297         meta_blocks = 1;
2298         /* double indirect blocks */
2299         meta_blocks += 1 + (1LL << (bits-2));
2300         /* tripple indirect blocks */
2301         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2302
2303         upper_limit -= meta_blocks;
2304         upper_limit <<= bits;
2305
2306         res += 1LL << (bits-2);
2307         res += 1LL << (2*(bits-2));
2308         res += 1LL << (3*(bits-2));
2309         res <<= bits;
2310         if (res > upper_limit)
2311                 res = upper_limit;
2312
2313         if (res > MAX_LFS_FILESIZE)
2314                 res = MAX_LFS_FILESIZE;
2315
2316         return res;
2317 }
2318
2319 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2320                                    ext4_fsblk_t logical_sb_block, int nr)
2321 {
2322         struct ext4_sb_info *sbi = EXT4_SB(sb);
2323         ext4_group_t bg, first_meta_bg;
2324         int has_super = 0;
2325
2326         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2327
2328         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2329             nr < first_meta_bg)
2330                 return logical_sb_block + nr + 1;
2331         bg = sbi->s_desc_per_block * nr;
2332         if (ext4_bg_has_super(sb, bg))
2333                 has_super = 1;
2334
2335         return (has_super + ext4_group_first_block_no(sb, bg));
2336 }
2337
2338 /**
2339  * ext4_get_stripe_size: Get the stripe size.
2340  * @sbi: In memory super block info
2341  *
2342  * If we have specified it via mount option, then
2343  * use the mount option value. If the value specified at mount time is
2344  * greater than the blocks per group use the super block value.
2345  * If the super block value is greater than blocks per group return 0.
2346  * Allocator needs it be less than blocks per group.
2347  *
2348  */
2349 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2350 {
2351         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2352         unsigned long stripe_width =
2353                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2354         int ret;
2355
2356         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2357                 ret = sbi->s_stripe;
2358         else if (stripe_width <= sbi->s_blocks_per_group)
2359                 ret = stripe_width;
2360         else if (stride <= sbi->s_blocks_per_group)
2361                 ret = stride;
2362         else
2363                 ret = 0;
2364
2365         /*
2366          * If the stripe width is 1, this makes no sense and
2367          * we set it to 0 to turn off stripe handling code.
2368          */
2369         if (ret <= 1)
2370                 ret = 0;
2371
2372         return ret;
2373 }
2374
2375 /* sysfs supprt */
2376
2377 struct ext4_attr {
2378         struct attribute attr;
2379         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2380         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2381                          const char *, size_t);
2382         int offset;
2383 };
2384
2385 static int parse_strtoul(const char *buf,
2386                 unsigned long max, unsigned long *value)
2387 {
2388         char *endp;
2389
2390         *value = simple_strtoul(skip_spaces(buf), &endp, 0);
2391         endp = skip_spaces(endp);
2392         if (*endp || *value > max)
2393                 return -EINVAL;
2394
2395         return 0;
2396 }
2397
2398 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2399                                               struct ext4_sb_info *sbi,
2400                                               char *buf)
2401 {
2402         return snprintf(buf, PAGE_SIZE, "%llu\n",
2403                 (s64) EXT4_C2B(sbi,
2404                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2405 }
2406
2407 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2408                                          struct ext4_sb_info *sbi, char *buf)
2409 {
2410         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2411
2412         if (!sb->s_bdev->bd_part)
2413                 return snprintf(buf, PAGE_SIZE, "0\n");
2414         return snprintf(buf, PAGE_SIZE, "%lu\n",
2415                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2416                          sbi->s_sectors_written_start) >> 1);
2417 }
2418
2419 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2420                                           struct ext4_sb_info *sbi, char *buf)
2421 {
2422         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2423
2424         if (!sb->s_bdev->bd_part)
2425                 return snprintf(buf, PAGE_SIZE, "0\n");
2426         return snprintf(buf, PAGE_SIZE, "%llu\n",
2427                         (unsigned long long)(sbi->s_kbytes_written +
2428                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2429                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2430 }
2431
2432 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2433                                           struct ext4_sb_info *sbi,
2434                                           const char *buf, size_t count)
2435 {
2436         unsigned long t;
2437
2438         if (parse_strtoul(buf, 0x40000000, &t))
2439                 return -EINVAL;
2440
2441         if (t && !is_power_of_2(t))
2442                 return -EINVAL;
2443
2444         sbi->s_inode_readahead_blks = t;
2445         return count;
2446 }
2447
2448 static ssize_t sbi_ui_show(struct ext4_attr *a,
2449                            struct ext4_sb_info *sbi, char *buf)
2450 {
2451         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2452
2453         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2454 }
2455
2456 static ssize_t sbi_ui_store(struct ext4_attr *a,
2457                             struct ext4_sb_info *sbi,
2458                             const char *buf, size_t count)
2459 {
2460         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2461         unsigned long t;
2462
2463         if (parse_strtoul(buf, 0xffffffff, &t))
2464                 return -EINVAL;
2465         *ui = t;
2466         return count;
2467 }
2468
2469 static ssize_t trigger_test_error(struct ext4_attr *a,
2470                                   struct ext4_sb_info *sbi,
2471                                   const char *buf, size_t count)
2472 {
2473         int len = count;
2474
2475         if (!capable(CAP_SYS_ADMIN))
2476                 return -EPERM;
2477
2478         if (len && buf[len-1] == '\n')
2479                 len--;
2480
2481         if (len)
2482                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2483         return count;
2484 }
2485
2486 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2487 static struct ext4_attr ext4_attr_##_name = {                   \
2488         .attr = {.name = __stringify(_name), .mode = _mode },   \
2489         .show   = _show,                                        \
2490         .store  = _store,                                       \
2491         .offset = offsetof(struct ext4_sb_info, _elname),       \
2492 }
2493 #define EXT4_ATTR(name, mode, show, store) \
2494 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2495
2496 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2497 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2498 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2499 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2500         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2501 #define ATTR_LIST(name) &ext4_attr_##name.attr
2502
2503 EXT4_RO_ATTR(delayed_allocation_blocks);
2504 EXT4_RO_ATTR(session_write_kbytes);
2505 EXT4_RO_ATTR(lifetime_write_kbytes);
2506 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2507                  inode_readahead_blks_store, s_inode_readahead_blks);
2508 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2509 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2510 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2511 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2512 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2513 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2514 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2515 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2516 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2517 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2518
2519 static struct attribute *ext4_attrs[] = {
2520         ATTR_LIST(delayed_allocation_blocks),
2521         ATTR_LIST(session_write_kbytes),
2522         ATTR_LIST(lifetime_write_kbytes),
2523         ATTR_LIST(inode_readahead_blks),
2524         ATTR_LIST(inode_goal),
2525         ATTR_LIST(mb_stats),
2526         ATTR_LIST(mb_max_to_scan),
2527         ATTR_LIST(mb_min_to_scan),
2528         ATTR_LIST(mb_order2_req),
2529         ATTR_LIST(mb_stream_req),
2530         ATTR_LIST(mb_group_prealloc),
2531         ATTR_LIST(max_writeback_mb_bump),
2532         ATTR_LIST(extent_max_zeroout_kb),
2533         ATTR_LIST(trigger_fs_error),
2534         NULL,
2535 };
2536
2537 /* Features this copy of ext4 supports */
2538 EXT4_INFO_ATTR(lazy_itable_init);
2539 EXT4_INFO_ATTR(batched_discard);
2540 EXT4_INFO_ATTR(meta_bg_resize);
2541
2542 static struct attribute *ext4_feat_attrs[] = {
2543         ATTR_LIST(lazy_itable_init),
2544         ATTR_LIST(batched_discard),
2545         ATTR_LIST(meta_bg_resize),
2546         NULL,
2547 };
2548
2549 static ssize_t ext4_attr_show(struct kobject *kobj,
2550                               struct attribute *attr, char *buf)
2551 {
2552         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2553                                                 s_kobj);
2554         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2555
2556         return a->show ? a->show(a, sbi, buf) : 0;
2557 }
2558
2559 static ssize_t ext4_attr_store(struct kobject *kobj,
2560                                struct attribute *attr,
2561                                const char *buf, size_t len)
2562 {
2563         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2564                                                 s_kobj);
2565         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2566
2567         return a->store ? a->store(a, sbi, buf, len) : 0;
2568 }
2569
2570 static void ext4_sb_release(struct kobject *kobj)
2571 {
2572         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2573                                                 s_kobj);
2574         complete(&sbi->s_kobj_unregister);
2575 }
2576
2577 static const struct sysfs_ops ext4_attr_ops = {
2578         .show   = ext4_attr_show,
2579         .store  = ext4_attr_store,
2580 };
2581
2582 static struct kobj_type ext4_ktype = {
2583         .default_attrs  = ext4_attrs,
2584         .sysfs_ops      = &ext4_attr_ops,
2585         .release        = ext4_sb_release,
2586 };
2587
2588 static void ext4_feat_release(struct kobject *kobj)
2589 {
2590         complete(&ext4_feat->f_kobj_unregister);
2591 }
2592
2593 static struct kobj_type ext4_feat_ktype = {
2594         .default_attrs  = ext4_feat_attrs,
2595         .sysfs_ops      = &ext4_attr_ops,
2596         .release        = ext4_feat_release,
2597 };
2598
2599 /*
2600  * Check whether this filesystem can be mounted based on
2601  * the features present and the RDONLY/RDWR mount requested.
2602  * Returns 1 if this filesystem can be mounted as requested,
2603  * 0 if it cannot be.
2604  */
2605 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2606 {
2607         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2608                 ext4_msg(sb, KERN_ERR,
2609                         "Couldn't mount because of "
2610                         "unsupported optional features (%x)",
2611                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2612                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2613                 return 0;
2614         }
2615
2616         if (readonly)
2617                 return 1;
2618
2619         /* Check that feature set is OK for a read-write mount */
2620         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2621                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2622                          "unsupported optional features (%x)",
2623                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2624                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2625                 return 0;
2626         }
2627         /*
2628          * Large file size enabled file system can only be mounted
2629          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2630          */
2631         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2632                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2633                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2634                                  "cannot be mounted RDWR without "
2635                                  "CONFIG_LBDAF");
2636                         return 0;
2637                 }
2638         }
2639         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2640             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2641                 ext4_msg(sb, KERN_ERR,
2642                          "Can't support bigalloc feature without "
2643                          "extents feature\n");
2644                 return 0;
2645         }
2646
2647 #ifndef CONFIG_QUOTA
2648         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2649             !readonly) {
2650                 ext4_msg(sb, KERN_ERR,
2651                          "Filesystem with quota feature cannot be mounted RDWR "
2652                          "without CONFIG_QUOTA");
2653                 return 0;
2654         }
2655 #endif  /* CONFIG_QUOTA */
2656         return 1;
2657 }
2658
2659 /*
2660  * This function is called once a day if we have errors logged
2661  * on the file system
2662  */
2663 static void print_daily_error_info(unsigned long arg)
2664 {
2665         struct super_block *sb = (struct super_block *) arg;
2666         struct ext4_sb_info *sbi;
2667         struct ext4_super_block *es;
2668
2669         sbi = EXT4_SB(sb);
2670         es = sbi->s_es;
2671
2672         if (es->s_error_count)
2673                 ext4_msg(sb, KERN_NOTICE, "error count: %u",
2674                          le32_to_cpu(es->s_error_count));
2675         if (es->s_first_error_time) {
2676                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2677                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2678                        (int) sizeof(es->s_first_error_func),
2679                        es->s_first_error_func,
2680                        le32_to_cpu(es->s_first_error_line));
2681                 if (es->s_first_error_ino)
2682                         printk(": inode %u",
2683                                le32_to_cpu(es->s_first_error_ino));
2684                 if (es->s_first_error_block)
2685                         printk(": block %llu", (unsigned long long)
2686                                le64_to_cpu(es->s_first_error_block));
2687                 printk("\n");
2688         }
2689         if (es->s_last_error_time) {
2690                 printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2691                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2692                        (int) sizeof(es->s_last_error_func),
2693                        es->s_last_error_func,
2694                        le32_to_cpu(es->s_last_error_line));
2695                 if (es->s_last_error_ino)
2696                         printk(": inode %u",
2697                                le32_to_cpu(es->s_last_error_ino));
2698                 if (es->s_last_error_block)
2699                         printk(": block %llu", (unsigned long long)
2700                                le64_to_cpu(es->s_last_error_block));
2701                 printk("\n");
2702         }
2703         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2704 }
2705
2706 /* Find next suitable group and run ext4_init_inode_table */
2707 static int ext4_run_li_request(struct ext4_li_request *elr)
2708 {
2709         struct ext4_group_desc *gdp = NULL;
2710         ext4_group_t group, ngroups;
2711         struct super_block *sb;
2712         unsigned long timeout = 0;
2713         int ret = 0;
2714
2715         sb = elr->lr_super;
2716         ngroups = EXT4_SB(sb)->s_groups_count;
2717
2718         sb_start_write(sb);
2719         for (group = elr->lr_next_group; group < ngroups; group++) {
2720                 gdp = ext4_get_group_desc(sb, group, NULL);
2721                 if (!gdp) {
2722                         ret = 1;
2723                         break;
2724                 }
2725
2726                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2727                         break;
2728         }
2729
2730         if (group >= ngroups)
2731                 ret = 1;
2732
2733         if (!ret) {
2734                 timeout = jiffies;
2735                 ret = ext4_init_inode_table(sb, group,
2736                                             elr->lr_timeout ? 0 : 1);
2737                 if (elr->lr_timeout == 0) {
2738                         timeout = (jiffies - timeout) *
2739                                   elr->lr_sbi->s_li_wait_mult;
2740                         elr->lr_timeout = timeout;
2741                 }
2742                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2743                 elr->lr_next_group = group + 1;
2744         }
2745         sb_end_write(sb);
2746
2747         return ret;
2748 }
2749
2750 /*
2751  * Remove lr_request from the list_request and free the
2752  * request structure. Should be called with li_list_mtx held
2753  */
2754 static void ext4_remove_li_request(struct ext4_li_request *elr)
2755 {
2756         struct ext4_sb_info *sbi;
2757
2758         if (!elr)
2759                 return;
2760
2761         sbi = elr->lr_sbi;
2762
2763         list_del(&elr->lr_request);
2764         sbi->s_li_request = NULL;
2765         kfree(elr);
2766 }
2767
2768 static void ext4_unregister_li_request(struct super_block *sb)
2769 {
2770         mutex_lock(&ext4_li_mtx);
2771         if (!ext4_li_info) {
2772                 mutex_unlock(&ext4_li_mtx);
2773                 return;
2774         }
2775
2776         mutex_lock(&ext4_li_info->li_list_mtx);
2777         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2778         mutex_unlock(&ext4_li_info->li_list_mtx);
2779         mutex_unlock(&ext4_li_mtx);
2780 }
2781
2782 static struct task_struct *ext4_lazyinit_task;
2783
2784 /*
2785  * This is the function where ext4lazyinit thread lives. It walks
2786  * through the request list searching for next scheduled filesystem.
2787  * When such a fs is found, run the lazy initialization request
2788  * (ext4_rn_li_request) and keep track of the time spend in this
2789  * function. Based on that time we compute next schedule time of
2790  * the request. When walking through the list is complete, compute
2791  * next waking time and put itself into sleep.
2792  */
2793 static int ext4_lazyinit_thread(void *arg)
2794 {
2795         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2796         struct list_head *pos, *n;
2797         struct ext4_li_request *elr;
2798         unsigned long next_wakeup, cur;
2799
2800         BUG_ON(NULL == eli);
2801
2802 cont_thread:
2803         while (true) {
2804                 next_wakeup = MAX_JIFFY_OFFSET;
2805
2806                 mutex_lock(&eli->li_list_mtx);
2807                 if (list_empty(&eli->li_request_list)) {
2808                         mutex_unlock(&eli->li_list_mtx);
2809                         goto exit_thread;
2810                 }
2811
2812                 list_for_each_safe(pos, n, &eli->li_request_list) {
2813                         elr = list_entry(pos, struct ext4_li_request,
2814                                          lr_request);
2815
2816                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2817                                 if (ext4_run_li_request(elr) != 0) {
2818                                         /* error, remove the lazy_init job */
2819                                         ext4_remove_li_request(elr);
2820                                         continue;
2821                                 }
2822                         }
2823
2824                         if (time_before(elr->lr_next_sched, next_wakeup))
2825                                 next_wakeup = elr->lr_next_sched;
2826                 }
2827                 mutex_unlock(&eli->li_list_mtx);
2828
2829                 try_to_freeze();
2830
2831                 cur = jiffies;
2832                 if ((time_after_eq(cur, next_wakeup)) ||
2833                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2834                         cond_resched();
2835                         continue;
2836                 }
2837
2838                 schedule_timeout_interruptible(next_wakeup - cur);
2839
2840                 if (kthread_should_stop()) {
2841                         ext4_clear_request_list();
2842                         goto exit_thread;
2843                 }
2844         }
2845
2846 exit_thread:
2847         /*
2848          * It looks like the request list is empty, but we need
2849          * to check it under the li_list_mtx lock, to prevent any
2850          * additions into it, and of course we should lock ext4_li_mtx
2851          * to atomically free the list and ext4_li_info, because at
2852          * this point another ext4 filesystem could be registering
2853          * new one.
2854          */
2855         mutex_lock(&ext4_li_mtx);
2856         mutex_lock(&eli->li_list_mtx);
2857         if (!list_empty(&eli->li_request_list)) {
2858                 mutex_unlock(&eli->li_list_mtx);
2859                 mutex_unlock(&ext4_li_mtx);
2860                 goto cont_thread;
2861         }
2862         mutex_unlock(&eli->li_list_mtx);
2863         kfree(ext4_li_info);
2864         ext4_li_info = NULL;
2865         mutex_unlock(&ext4_li_mtx);
2866
2867         return 0;
2868 }
2869
2870 static void ext4_clear_request_list(void)
2871 {
2872         struct list_head *pos, *n;
2873         struct ext4_li_request *elr;
2874
2875         mutex_lock(&ext4_li_info->li_list_mtx);
2876         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2877                 elr = list_entry(pos, struct ext4_li_request,
2878                                  lr_request);
2879                 ext4_remove_li_request(elr);
2880         }
2881         mutex_unlock(&ext4_li_info->li_list_mtx);
2882 }
2883
2884 static int ext4_run_lazyinit_thread(void)
2885 {
2886         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2887                                          ext4_li_info, "ext4lazyinit");
2888         if (IS_ERR(ext4_lazyinit_task)) {
2889                 int err = PTR_ERR(ext4_lazyinit_task);
2890                 ext4_clear_request_list();
2891                 kfree(ext4_li_info);
2892                 ext4_li_info = NULL;
2893                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2894                                  "initialization thread\n",
2895                                  err);
2896                 return err;
2897         }
2898         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2899         return 0;
2900 }
2901
2902 /*
2903  * Check whether it make sense to run itable init. thread or not.
2904  * If there is at least one uninitialized inode table, return
2905  * corresponding group number, else the loop goes through all
2906  * groups and return total number of groups.
2907  */
2908 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2909 {
2910         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2911         struct ext4_group_desc *gdp = NULL;
2912
2913         for (group = 0; group < ngroups; group++) {
2914                 gdp = ext4_get_group_desc(sb, group, NULL);
2915                 if (!gdp)
2916                         continue;
2917
2918                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2919                         break;
2920         }
2921
2922         return group;
2923 }
2924
2925 static int ext4_li_info_new(void)
2926 {
2927         struct ext4_lazy_init *eli = NULL;
2928
2929         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2930         if (!eli)
2931                 return -ENOMEM;
2932
2933         INIT_LIST_HEAD(&eli->li_request_list);
2934         mutex_init(&eli->li_list_mtx);
2935
2936         eli->li_state |= EXT4_LAZYINIT_QUIT;
2937
2938         ext4_li_info = eli;
2939
2940         return 0;
2941 }
2942
2943 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2944                                             ext4_group_t start)
2945 {
2946         struct ext4_sb_info *sbi = EXT4_SB(sb);
2947         struct ext4_li_request *elr;
2948         unsigned long rnd;
2949
2950         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2951         if (!elr)
2952                 return NULL;
2953
2954         elr->lr_super = sb;
2955         elr->lr_sbi = sbi;
2956         elr->lr_next_group = start;
2957
2958         /*
2959          * Randomize first schedule time of the request to
2960          * spread the inode table initialization requests
2961          * better.
2962          */
2963         get_random_bytes(&rnd, sizeof(rnd));
2964         elr->lr_next_sched = jiffies + (unsigned long)rnd %
2965                              (EXT4_DEF_LI_MAX_START_DELAY * HZ);
2966
2967         return elr;
2968 }
2969
2970 int ext4_register_li_request(struct super_block *sb,
2971                              ext4_group_t first_not_zeroed)
2972 {
2973         struct ext4_sb_info *sbi = EXT4_SB(sb);
2974         struct ext4_li_request *elr = NULL;
2975         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2976         int ret = 0;
2977
2978         mutex_lock(&ext4_li_mtx);
2979         if (sbi->s_li_request != NULL) {
2980                 /*
2981                  * Reset timeout so it can be computed again, because
2982                  * s_li_wait_mult might have changed.
2983                  */
2984                 sbi->s_li_request->lr_timeout = 0;
2985                 goto out;
2986         }
2987
2988         if (first_not_zeroed == ngroups ||
2989             (sb->s_flags & MS_RDONLY) ||
2990             !test_opt(sb, INIT_INODE_TABLE))
2991                 goto out;
2992
2993         elr = ext4_li_request_new(sb, first_not_zeroed);
2994         if (!elr) {
2995                 ret = -ENOMEM;
2996                 goto out;
2997         }
2998
2999         if (NULL == ext4_li_info) {
3000                 ret = ext4_li_info_new();
3001                 if (ret)
3002                         goto out;
3003         }
3004
3005         mutex_lock(&ext4_li_info->li_list_mtx);
3006         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3007         mutex_unlock(&ext4_li_info->li_list_mtx);
3008
3009         sbi->s_li_request = elr;
3010         /*
3011          * set elr to NULL here since it has been inserted to
3012          * the request_list and the removal and free of it is
3013          * handled by ext4_clear_request_list from now on.
3014          */
3015         elr = NULL;
3016
3017         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3018                 ret = ext4_run_lazyinit_thread();
3019                 if (ret)
3020                         goto out;
3021         }
3022 out:
3023         mutex_unlock(&ext4_li_mtx);
3024         if (ret)
3025                 kfree(elr);
3026         return ret;
3027 }
3028
3029 /*
3030  * We do not need to lock anything since this is called on
3031  * module unload.
3032  */
3033 static void ext4_destroy_lazyinit_thread(void)
3034 {
3035         /*
3036          * If thread exited earlier
3037          * there's nothing to be done.
3038          */
3039         if (!ext4_li_info || !ext4_lazyinit_task)
3040                 return;
3041
3042         kthread_stop(ext4_lazyinit_task);
3043 }
3044
3045 static int set_journal_csum_feature_set(struct super_block *sb)
3046 {
3047         int ret = 1;
3048         int compat, incompat;
3049         struct ext4_sb_info *sbi = EXT4_SB(sb);
3050
3051         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3052                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3053                 /* journal checksum v2 */
3054                 compat = 0;
3055                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3056         } else {
3057                 /* journal checksum v1 */
3058                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3059                 incompat = 0;
3060         }
3061
3062         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3063                 ret = jbd2_journal_set_features(sbi->s_journal,
3064                                 compat, 0,
3065                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3066                                 incompat);
3067         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3068                 ret = jbd2_journal_set_features(sbi->s_journal,
3069                                 compat, 0,
3070                                 incompat);
3071                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3072                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3073         } else {
3074                 jbd2_journal_clear_features(sbi->s_journal,
3075                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3076                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3077                                 JBD2_FEATURE_INCOMPAT_CSUM_V2);
3078         }
3079
3080         return ret;
3081 }
3082
3083 /*
3084  * Note: calculating the overhead so we can be compatible with
3085  * historical BSD practice is quite difficult in the face of
3086  * clusters/bigalloc.  This is because multiple metadata blocks from
3087  * different block group can end up in the same allocation cluster.
3088  * Calculating the exact overhead in the face of clustered allocation
3089  * requires either O(all block bitmaps) in memory or O(number of block
3090  * groups**2) in time.  We will still calculate the superblock for
3091  * older file systems --- and if we come across with a bigalloc file
3092  * system with zero in s_overhead_clusters the estimate will be close to
3093  * correct especially for very large cluster sizes --- but for newer
3094  * file systems, it's better to calculate this figure once at mkfs
3095  * time, and store it in the superblock.  If the superblock value is
3096  * present (even for non-bigalloc file systems), we will use it.
3097  */
3098 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3099                           char *buf)
3100 {
3101         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3102         struct ext4_group_desc  *gdp;
3103         ext4_fsblk_t            first_block, last_block, b;
3104         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3105         int                     s, j, count = 0;
3106
3107         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3108                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3109                         sbi->s_itb_per_group + 2);
3110
3111         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3112                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3113         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3114         for (i = 0; i < ngroups; i++) {
3115                 gdp = ext4_get_group_desc(sb, i, NULL);
3116                 b = ext4_block_bitmap(sb, gdp);
3117                 if (b >= first_block && b <= last_block) {
3118                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3119                         count++;
3120                 }
3121                 b = ext4_inode_bitmap(sb, gdp);
3122                 if (b >= first_block && b <= last_block) {
3123                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3124                         count++;
3125                 }
3126                 b = ext4_inode_table(sb, gdp);
3127                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3128                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3129                                 int c = EXT4_B2C(sbi, b - first_block);
3130                                 ext4_set_bit(c, buf);
3131                                 count++;
3132                         }
3133                 if (i != grp)
3134                         continue;
3135                 s = 0;
3136                 if (ext4_bg_has_super(sb, grp)) {
3137                         ext4_set_bit(s++, buf);
3138                         count++;
3139                 }
3140                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3141                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3142                         count++;
3143                 }
3144         }
3145         if (!count)
3146                 return 0;
3147         return EXT4_CLUSTERS_PER_GROUP(sb) -
3148                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3149 }
3150
3151 /*
3152  * Compute the overhead and stash it in sbi->s_overhead
3153  */
3154 int ext4_calculate_overhead(struct super_block *sb)
3155 {
3156         struct ext4_sb_info *sbi = EXT4_SB(sb);
3157         struct ext4_super_block *es = sbi->s_es;
3158         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3159         ext4_fsblk_t overhead = 0;
3160         char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3161
3162         if (!buf)
3163                 return -ENOMEM;
3164
3165         /*
3166          * Compute the overhead (FS structures).  This is constant
3167          * for a given filesystem unless the number of block groups
3168          * changes so we cache the previous value until it does.
3169          */
3170
3171         /*
3172          * All of the blocks before first_data_block are overhead
3173          */
3174         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3175
3176         /*
3177          * Add the overhead found in each block group
3178          */
3179         for (i = 0; i < ngroups; i++) {
3180                 int blks;
3181
3182                 blks = count_overhead(sb, i, buf);
3183                 overhead += blks;
3184                 if (blks)
3185                         memset(buf, 0, PAGE_SIZE);
3186                 cond_resched();
3187         }
3188         /* Add the journal blocks as well */
3189         if (sbi->s_journal)
3190                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3191
3192         sbi->s_overhead = overhead;
3193         smp_wmb();
3194         free_page((unsigned long) buf);
3195         return 0;
3196 }
3197
3198 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3199 {
3200         char *orig_data = kstrdup(data, GFP_KERNEL);
3201         struct buffer_head *bh;
3202         struct ext4_super_block *es = NULL;
3203         struct ext4_sb_info *sbi;
3204         ext4_fsblk_t block;
3205         ext4_fsblk_t sb_block = get_sb_block(&data);
3206         ext4_fsblk_t logical_sb_block;
3207         unsigned long offset = 0;
3208         unsigned long journal_devnum = 0;
3209         unsigned long def_mount_opts;
3210         struct inode *root;
3211         char *cp;
3212         const char *descr;
3213         int ret = -ENOMEM;
3214         int blocksize, clustersize;
3215         unsigned int db_count;
3216         unsigned int i;
3217         int needs_recovery, has_huge_files, has_bigalloc;
3218         __u64 blocks_count;
3219         int err = 0;
3220         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3221         ext4_group_t first_not_zeroed;
3222
3223         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3224         if (!sbi)
3225                 goto out_free_orig;
3226
3227         sbi->s_blockgroup_lock =
3228                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3229         if (!sbi->s_blockgroup_lock) {
3230                 kfree(sbi);
3231                 goto out_free_orig;
3232         }
3233         sb->s_fs_info = sbi;
3234         sbi->s_sb = sb;
3235         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3236         sbi->s_sb_block = sb_block;
3237         if (sb->s_bdev->bd_part)
3238                 sbi->s_sectors_written_start =
3239                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3240
3241         /* Cleanup superblock name */
3242         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3243                 *cp = '!';
3244
3245         /* -EINVAL is default */
3246         ret = -EINVAL;
3247         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3248         if (!blocksize) {
3249                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3250                 goto out_fail;
3251         }
3252
3253         /*
3254          * The ext4 superblock will not be buffer aligned for other than 1kB
3255          * block sizes.  We need to calculate the offset from buffer start.
3256          */
3257         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3258                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3259                 offset = do_div(logical_sb_block, blocksize);
3260         } else {
3261                 logical_sb_block = sb_block;
3262         }
3263
3264         if (!(bh = sb_bread(sb, logical_sb_block))) {
3265                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3266                 goto out_fail;
3267         }
3268         /*
3269          * Note: s_es must be initialized as soon as possible because
3270          *       some ext4 macro-instructions depend on its value
3271          */
3272         es = (struct ext4_super_block *) (bh->b_data + offset);
3273         sbi->s_es = es;
3274         sb->s_magic = le16_to_cpu(es->s_magic);
3275         if (sb->s_magic != EXT4_SUPER_MAGIC)
3276                 goto cantfind_ext4;
3277         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3278
3279         /* Warn if metadata_csum and gdt_csum are both set. */
3280         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3281                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3282             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3283                 ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3284                              "redundant flags; please run fsck.");
3285
3286         /* Check for a known checksum algorithm */
3287         if (!ext4_verify_csum_type(sb, es)) {
3288                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3289                          "unknown checksum algorithm.");
3290                 silent = 1;
3291                 goto cantfind_ext4;
3292         }
3293
3294         /* Load the checksum driver */
3295         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3296                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3297                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3298                 if (IS_ERR(sbi->s_chksum_driver)) {
3299                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3300                         ret = PTR_ERR(sbi->s_chksum_driver);
3301                         sbi->s_chksum_driver = NULL;
3302                         goto failed_mount;
3303                 }
3304         }
3305
3306         /* Check superblock checksum */
3307         if (!ext4_superblock_csum_verify(sb, es)) {
3308                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3309                          "invalid superblock checksum.  Run e2fsck?");
3310                 silent = 1;
3311                 goto cantfind_ext4;
3312         }
3313
3314         /* Precompute checksum seed for all metadata */
3315         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3316                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3317                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3318                                                sizeof(es->s_uuid));
3319
3320         /* Set defaults before we parse the mount options */
3321         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3322         set_opt(sb, INIT_INODE_TABLE);
3323         if (def_mount_opts & EXT4_DEFM_DEBUG)
3324                 set_opt(sb, DEBUG);
3325         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3326                 set_opt(sb, GRPID);
3327         if (def_mount_opts & EXT4_DEFM_UID16)
3328                 set_opt(sb, NO_UID32);
3329         /* xattr user namespace & acls are now defaulted on */
3330         set_opt(sb, XATTR_USER);
3331 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3332         set_opt(sb, POSIX_ACL);
3333 #endif
3334         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3335                 set_opt(sb, JOURNAL_DATA);
3336         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3337                 set_opt(sb, ORDERED_DATA);
3338         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3339                 set_opt(sb, WRITEBACK_DATA);
3340
3341         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3342                 set_opt(sb, ERRORS_PANIC);
3343         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3344                 set_opt(sb, ERRORS_CONT);
3345         else
3346                 set_opt(sb, ERRORS_RO);
3347         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3348                 set_opt(sb, BLOCK_VALIDITY);
3349         if (def_mount_opts & EXT4_DEFM_DISCARD)
3350                 set_opt(sb, DISCARD);
3351
3352         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3353         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3354         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3355         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3356         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3357
3358         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3359                 set_opt(sb, BARRIER);
3360
3361         /*
3362          * enable delayed allocation by default
3363          * Use -o nodelalloc to turn it off
3364          */
3365         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3366             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3367                 set_opt(sb, DELALLOC);
3368
3369         /*
3370          * set default s_li_wait_mult for lazyinit, for the case there is
3371          * no mount option specified.
3372          */
3373         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3374
3375         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3376                            &journal_devnum, &journal_ioprio, 0)) {
3377                 ext4_msg(sb, KERN_WARNING,
3378                          "failed to parse options in superblock: %s",
3379                          sbi->s_es->s_mount_opts);
3380         }
3381         sbi->s_def_mount_opt = sbi->s_mount_opt;
3382         if (!parse_options((char *) data, sb, &journal_devnum,
3383                            &journal_ioprio, 0))
3384                 goto failed_mount;
3385
3386         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3387                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3388                             "with data=journal disables delayed "
3389                             "allocation and O_DIRECT support!\n");
3390                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3391                         ext4_msg(sb, KERN_ERR, "can't mount with "
3392                                  "both data=journal and delalloc");
3393                         goto failed_mount;
3394                 }
3395                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3396                         ext4_msg(sb, KERN_ERR, "can't mount with "
3397                                  "both data=journal and delalloc");
3398                         goto failed_mount;
3399                 }
3400                 if (test_opt(sb, DELALLOC))
3401                         clear_opt(sb, DELALLOC);
3402         }
3403
3404         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3405                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3406
3407         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3408             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3409              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3410              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3411                 ext4_msg(sb, KERN_WARNING,
3412                        "feature flags set on rev 0 fs, "
3413                        "running e2fsck is recommended");
3414
3415         if (IS_EXT2_SB(sb)) {
3416                 if (ext2_feature_set_ok(sb))
3417                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3418                                  "using the ext4 subsystem");
3419                 else {
3420                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3421                                  "to feature incompatibilities");
3422                         goto failed_mount;
3423                 }
3424         }
3425
3426         if (IS_EXT3_SB(sb)) {
3427                 if (ext3_feature_set_ok(sb))
3428                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3429                                  "using the ext4 subsystem");
3430                 else {
3431                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3432                                  "to feature incompatibilities");
3433                         goto failed_mount;
3434                 }
3435         }
3436
3437         /*
3438          * Check feature flags regardless of the revision level, since we
3439          * previously didn't change the revision level when setting the flags,
3440          * so there is a chance incompat flags are set on a rev 0 filesystem.
3441          */
3442         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3443                 goto failed_mount;
3444
3445         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3446         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3447             blocksize > EXT4_MAX_BLOCK_SIZE) {
3448                 ext4_msg(sb, KERN_ERR,
3449                        "Unsupported filesystem blocksize %d", blocksize);
3450                 goto failed_mount;
3451         }
3452
3453         if (sb->s_blocksize != blocksize) {
3454                 /* Validate the filesystem blocksize */
3455                 if (!sb_set_blocksize(sb, blocksize)) {
3456                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3457                                         blocksize);
3458                         goto failed_mount;
3459                 }
3460
3461                 brelse(bh);
3462                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3463                 offset = do_div(logical_sb_block, blocksize);
3464                 bh = sb_bread(sb, logical_sb_block);
3465                 if (!bh) {
3466                         ext4_msg(sb, KERN_ERR,
3467                                "Can't read superblock on 2nd try");
3468                         goto failed_mount;
3469                 }
3470                 es = (struct ext4_super_block *)(bh->b_data + offset);
3471                 sbi->s_es = es;
3472                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3473                         ext4_msg(sb, KERN_ERR,
3474                                "Magic mismatch, very weird!");
3475                         goto failed_mount;
3476                 }
3477         }
3478
3479         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3480                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3481         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3482                                                       has_huge_files);
3483         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3484
3485         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3486                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3487                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3488         } else {
3489                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3490                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3491                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3492                     (!is_power_of_2(sbi->s_inode_size)) ||
3493                     (sbi->s_inode_size > blocksize)) {
3494                         ext4_msg(sb, KERN_ERR,
3495                                "unsupported inode size: %d",
3496                                sbi->s_inode_size);
3497                         goto failed_mount;
3498                 }
3499                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3500                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3501         }
3502
3503         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3504         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3505                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3506                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3507                     !is_power_of_2(sbi->s_desc_size)) {
3508                         ext4_msg(sb, KERN_ERR,
3509                                "unsupported descriptor size %lu",
3510                                sbi->s_desc_size);
3511                         goto failed_mount;
3512                 }
3513         } else
3514                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3515
3516         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3517         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3518         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3519                 goto cantfind_ext4;
3520
3521         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3522         if (sbi->s_inodes_per_block == 0)
3523                 goto cantfind_ext4;
3524         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3525                                         sbi->s_inodes_per_block;
3526         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3527         sbi->s_sbh = bh;
3528         sbi->s_mount_state = le16_to_cpu(es->s_state);
3529         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3530         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3531
3532         /* Do we have standard group size of blocksize * 8 blocks ? */
3533         if (sbi->s_blocks_per_group == blocksize << 3)
3534                 set_opt2(sb, STD_GROUP_SIZE);
3535
3536         for (i = 0; i < 4; i++)
3537                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3538         sbi->s_def_hash_version = es->s_def_hash_version;
3539         i = le32_to_cpu(es->s_flags);
3540         if (i & EXT2_FLAGS_UNSIGNED_HASH)
3541                 sbi->s_hash_unsigned = 3;
3542         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3543 #ifdef __CHAR_UNSIGNED__
3544                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3545                 sbi->s_hash_unsigned = 3;
3546 #else
3547                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3548 #endif
3549         }
3550
3551         /* Handle clustersize */
3552         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3553         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3554                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3555         if (has_bigalloc) {
3556                 if (clustersize < blocksize) {
3557                         ext4_msg(sb, KERN_ERR,
3558                                  "cluster size (%d) smaller than "
3559                                  "block size (%d)", clustersize, blocksize);
3560                         goto failed_mount;
3561                 }
3562                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3563                         le32_to_cpu(es->s_log_block_size);
3564                 sbi->s_clusters_per_group =
3565                         le32_to_cpu(es->s_clusters_per_group);
3566                 if (sbi->s_clusters_per_group > blocksize * 8) {
3567                         ext4_msg(sb, KERN_ERR,
3568                                  "#clusters per group too big: %lu",
3569                                  sbi->s_clusters_per_group);
3570                         goto failed_mount;
3571                 }
3572                 if (sbi->s_blocks_per_group !=
3573                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3574                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3575                                  "clusters per group (%lu) inconsistent",
3576                                  sbi->s_blocks_per_group,
3577                                  sbi->s_clusters_per_group);
3578                         goto failed_mount;
3579                 }
3580         } else {
3581                 if (clustersize != blocksize) {
3582                         ext4_warning(sb, "fragment/cluster size (%d) != "
3583                                      "block size (%d)", clustersize,
3584                                      blocksize);
3585                         clustersize = blocksize;
3586                 }
3587                 if (sbi->s_blocks_per_group > blocksize * 8) {
3588                         ext4_msg(sb, KERN_ERR,
3589                                  "#blocks per group too big: %lu",
3590                                  sbi->s_blocks_per_group);
3591                         goto failed_mount;
3592                 }
3593                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3594                 sbi->s_cluster_bits = 0;
3595         }
3596         sbi->s_cluster_ratio = clustersize / blocksize;
3597
3598         if (sbi->s_inodes_per_group > blocksize * 8) {
3599                 ext4_msg(sb, KERN_ERR,
3600                        "#inodes per group too big: %lu",
3601                        sbi->s_inodes_per_group);
3602                 goto failed_mount;
3603         }
3604
3605         /*
3606          * Test whether we have more sectors than will fit in sector_t,
3607          * and whether the max offset is addressable by the page cache.
3608          */
3609         err = generic_check_addressable(sb->s_blocksize_bits,
3610                                         ext4_blocks_count(es));
3611         if (err) {
3612                 ext4_msg(sb, KERN_ERR, "filesystem"
3613                          " too large to mount safely on this system");
3614                 if (sizeof(sector_t) < 8)
3615                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3616                 goto failed_mount;
3617         }
3618
3619         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3620                 goto cantfind_ext4;
3621
3622         /* check blocks count against device size */
3623         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3624         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3625                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3626                        "exceeds size of device (%llu blocks)",
3627                        ext4_blocks_count(es), blocks_count);
3628                 goto failed_mount;
3629         }
3630
3631         /*
3632          * It makes no sense for the first data block to be beyond the end
3633          * of the filesystem.
3634          */
3635         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3636                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3637                          "block %u is beyond end of filesystem (%llu)",
3638                          le32_to_cpu(es->s_first_data_block),
3639                          ext4_blocks_count(es));
3640                 goto failed_mount;
3641         }
3642         blocks_count = (ext4_blocks_count(es) -
3643                         le32_to_cpu(es->s_first_data_block) +
3644                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3645         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3646         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3647                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3648                        "(block count %llu, first data block %u, "
3649                        "blocks per group %lu)", sbi->s_groups_count,
3650                        ext4_blocks_count(es),
3651                        le32_to_cpu(es->s_first_data_block),
3652                        EXT4_BLOCKS_PER_GROUP(sb));
3653                 goto failed_mount;
3654         }
3655         sbi->s_groups_count = blocks_count;
3656         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3657                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3658         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3659                    EXT4_DESC_PER_BLOCK(sb);
3660         sbi->s_group_desc = ext4_kvmalloc(db_count *
3661                                           sizeof(struct buffer_head *),
3662                                           GFP_KERNEL);
3663         if (sbi->s_group_desc == NULL) {
3664                 ext4_msg(sb, KERN_ERR, "not enough memory");
3665                 ret = -ENOMEM;
3666                 goto failed_mount;
3667         }
3668
3669         if (ext4_proc_root)
3670                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3671
3672         if (sbi->s_proc)
3673                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3674                                  &ext4_seq_options_fops, sb);
3675
3676         bgl_lock_init(sbi->s_blockgroup_lock);
3677
3678         for (i = 0; i < db_count; i++) {
3679                 block = descriptor_loc(sb, logical_sb_block, i);
3680                 sbi->s_group_desc[i] = sb_bread(sb, block);
3681                 if (!sbi->s_group_desc[i]) {
3682                         ext4_msg(sb, KERN_ERR,
3683                                "can't read group descriptor %d", i);
3684                         db_count = i;
3685                         goto failed_mount2;
3686                 }
3687         }
3688         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3689                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3690                 goto failed_mount2;
3691         }
3692         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3693                 if (!ext4_fill_flex_info(sb)) {
3694                         ext4_msg(sb, KERN_ERR,
3695                                "unable to initialize "
3696                                "flex_bg meta info!");
3697                         goto failed_mount2;
3698                 }
3699
3700         sbi->s_gdb_count = db_count;
3701         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3702         spin_lock_init(&sbi->s_next_gen_lock);
3703
3704         init_timer(&sbi->s_err_report);
3705         sbi->s_err_report.function = print_daily_error_info;
3706         sbi->s_err_report.data = (unsigned long) sb;
3707
3708         /* Register extent status tree shrinker */
3709         ext4_es_register_shrinker(sb);
3710
3711         err = percpu_counter_init(&sbi->s_freeclusters_counter,
3712                         ext4_count_free_clusters(sb));
3713         if (!err) {
3714                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
3715                                 ext4_count_free_inodes(sb));
3716         }
3717         if (!err) {
3718                 err = percpu_counter_init(&sbi->s_dirs_counter,
3719                                 ext4_count_dirs(sb));
3720         }
3721         if (!err) {
3722                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3723         }
3724         if (!err) {
3725                 err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
3726         }
3727         if (err) {
3728                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3729                 goto failed_mount3;
3730         }
3731
3732         sbi->s_stripe = ext4_get_stripe_size(sbi);
3733         sbi->s_max_writeback_mb_bump = 128;
3734         sbi->s_extent_max_zeroout_kb = 32;
3735
3736         /*
3737          * set up enough so that it can read an inode
3738          */
3739         if (!test_opt(sb, NOLOAD) &&
3740             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3741                 sb->s_op = &ext4_sops;
3742         else
3743                 sb->s_op = &ext4_nojournal_sops;
3744         sb->s_export_op = &ext4_export_ops;
3745         sb->s_xattr = ext4_xattr_handlers;
3746 #ifdef CONFIG_QUOTA
3747         sb->dq_op = &ext4_quota_operations;
3748         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3749                 sb->s_qcop = &ext4_qctl_sysfile_operations;
3750         else
3751                 sb->s_qcop = &ext4_qctl_operations;
3752 #endif
3753         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3754
3755         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3756         mutex_init(&sbi->s_orphan_lock);
3757
3758         sb->s_root = NULL;
3759
3760         needs_recovery = (es->s_last_orphan != 0 ||
3761                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3762                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3763
3764         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3765             !(sb->s_flags & MS_RDONLY))
3766                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3767                         goto failed_mount3;
3768
3769         /*
3770          * The first inode we look at is the journal inode.  Don't try
3771          * root first: it may be modified in the journal!
3772          */
3773         if (!test_opt(sb, NOLOAD) &&
3774             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3775                 if (ext4_load_journal(sb, es, journal_devnum))
3776                         goto failed_mount3;
3777         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3778               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3779                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3780                        "suppressed and not mounted read-only");
3781                 goto failed_mount_wq;
3782         } else {
3783                 clear_opt(sb, DATA_FLAGS);
3784                 sbi->s_journal = NULL;
3785                 needs_recovery = 0;
3786                 goto no_journal;
3787         }
3788
3789         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3790             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3791                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3792                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3793                 goto failed_mount_wq;
3794         }
3795
3796         if (!set_journal_csum_feature_set(sb)) {
3797                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3798                          "feature set");
3799                 goto failed_mount_wq;
3800         }
3801
3802         /* We have now updated the journal if required, so we can
3803          * validate the data journaling mode. */
3804         switch (test_opt(sb, DATA_FLAGS)) {
3805         case 0:
3806                 /* No mode set, assume a default based on the journal
3807                  * capabilities: ORDERED_DATA if the journal can
3808                  * cope, else JOURNAL_DATA
3809                  */
3810                 if (jbd2_journal_check_available_features
3811                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3812                         set_opt(sb, ORDERED_DATA);
3813                 else
3814                         set_opt(sb, JOURNAL_DATA);
3815                 break;
3816
3817         case EXT4_MOUNT_ORDERED_DATA:
3818         case EXT4_MOUNT_WRITEBACK_DATA:
3819                 if (!jbd2_journal_check_available_features
3820                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3821                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3822                                "requested data journaling mode");
3823                         goto failed_mount_wq;
3824                 }
3825         default:
3826                 break;
3827         }
3828         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3829
3830         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3831
3832         /*
3833          * The journal may have updated the bg summary counts, so we
3834          * need to update the global counters.
3835          */
3836         percpu_counter_set(&sbi->s_freeclusters_counter,
3837                            ext4_count_free_clusters(sb));
3838         percpu_counter_set(&sbi->s_freeinodes_counter,
3839                            ext4_count_free_inodes(sb));
3840         percpu_counter_set(&sbi->s_dirs_counter,
3841                            ext4_count_dirs(sb));
3842         percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3843
3844 no_journal:
3845         /*
3846          * Get the # of file system overhead blocks from the
3847          * superblock if present.
3848          */
3849         if (es->s_overhead_clusters)
3850                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3851         else {
3852                 err = ext4_calculate_overhead(sb);
3853                 if (err)
3854                         goto failed_mount_wq;
3855         }
3856
3857         /*
3858          * The maximum number of concurrent works can be high and
3859          * concurrency isn't really necessary.  Limit it to 1.
3860          */
3861         EXT4_SB(sb)->dio_unwritten_wq =
3862                 alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3863         if (!EXT4_SB(sb)->dio_unwritten_wq) {
3864                 printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3865                 ret = -ENOMEM;
3866                 goto failed_mount_wq;
3867         }
3868
3869         /*
3870          * The jbd2_journal_load will have done any necessary log recovery,
3871          * so we can safely mount the rest of the filesystem now.
3872          */
3873
3874         root = ext4_iget(sb, EXT4_ROOT_INO);
3875         if (IS_ERR(root)) {
3876                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3877                 ret = PTR_ERR(root);
3878                 root = NULL;
3879                 goto failed_mount4;
3880         }
3881         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3882                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3883                 iput(root);
3884                 goto failed_mount4;
3885         }
3886         sb->s_root = d_make_root(root);
3887         if (!sb->s_root) {
3888                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3889                 ret = -ENOMEM;
3890                 goto failed_mount4;
3891         }
3892
3893         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3894                 sb->s_flags |= MS_RDONLY;
3895
3896         /* determine the minimum size of new large inodes, if present */
3897         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3898                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3899                                                      EXT4_GOOD_OLD_INODE_SIZE;
3900                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3901                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3902                         if (sbi->s_want_extra_isize <
3903                             le16_to_cpu(es->s_want_extra_isize))
3904                                 sbi->s_want_extra_isize =
3905                                         le16_to_cpu(es->s_want_extra_isize);
3906                         if (sbi->s_want_extra_isize <
3907                             le16_to_cpu(es->s_min_extra_isize))
3908                                 sbi->s_want_extra_isize =
3909                                         le16_to_cpu(es->s_min_extra_isize);
3910                 }
3911         }
3912         /* Check if enough inode space is available */
3913         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3914                                                         sbi->s_inode_size) {
3915                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3916                                                        EXT4_GOOD_OLD_INODE_SIZE;
3917                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3918                          "available");
3919         }
3920
3921         err = ext4_setup_system_zone(sb);
3922         if (err) {
3923                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3924                          "zone (%d)", err);
3925                 goto failed_mount4a;
3926         }
3927
3928         ext4_ext_init(sb);
3929         err = ext4_mb_init(sb);
3930         if (err) {
3931                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3932                          err);
3933                 goto failed_mount5;
3934         }
3935
3936         err = ext4_register_li_request(sb, first_not_zeroed);
3937         if (err)
3938                 goto failed_mount6;
3939
3940         sbi->s_kobj.kset = ext4_kset;
3941         init_completion(&sbi->s_kobj_unregister);
3942         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3943                                    "%s", sb->s_id);
3944         if (err)
3945                 goto failed_mount7;
3946
3947 #ifdef CONFIG_QUOTA
3948         /* Enable quota usage during mount. */
3949         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
3950             !(sb->s_flags & MS_RDONLY)) {
3951                 err = ext4_enable_quotas(sb);
3952                 if (err)
3953                         goto failed_mount8;
3954         }
3955 #endif  /* CONFIG_QUOTA */
3956
3957         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3958         ext4_orphan_cleanup(sb, es);
3959         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3960         if (needs_recovery) {
3961                 ext4_msg(sb, KERN_INFO, "recovery complete");
3962                 ext4_mark_recovery_complete(sb, es);
3963         }
3964         if (EXT4_SB(sb)->s_journal) {
3965                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3966                         descr = " journalled data mode";
3967                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3968                         descr = " ordered data mode";
3969                 else
3970                         descr = " writeback data mode";
3971         } else
3972                 descr = "out journal";
3973
3974         if (test_opt(sb, DISCARD)) {
3975                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
3976                 if (!blk_queue_discard(q))
3977                         ext4_msg(sb, KERN_WARNING,
3978                                  "mounting with \"discard\" option, but "
3979                                  "the device does not support discard");
3980         }
3981
3982         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3983                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3984                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3985
3986         if (es->s_error_count)
3987                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3988
3989         kfree(orig_data);
3990         return 0;
3991
3992 cantfind_ext4:
3993         if (!silent)
3994                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3995         goto failed_mount;
3996
3997 #ifdef CONFIG_QUOTA
3998 failed_mount8:
3999         kobject_del(&sbi->s_kobj);
4000 #endif
4001 failed_mount7:
4002         ext4_unregister_li_request(sb);
4003 failed_mount6:
4004         ext4_mb_release(sb);
4005 failed_mount5:
4006         ext4_ext_release(sb);
4007         ext4_release_system_zone(sb);
4008 failed_mount4a:
4009         dput(sb->s_root);
4010         sb->s_root = NULL;
4011 failed_mount4:
4012         ext4_msg(sb, KERN_ERR, "mount failed");
4013         destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
4014 failed_mount_wq:
4015         if (sbi->s_journal) {
4016                 jbd2_journal_destroy(sbi->s_journal);
4017                 sbi->s_journal = NULL;
4018         }
4019 failed_mount3:
4020         ext4_es_unregister_shrinker(sb);
4021         del_timer(&sbi->s_err_report);
4022         if (sbi->s_flex_groups)
4023                 ext4_kvfree(sbi->s_flex_groups);
4024         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4025         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4026         percpu_counter_destroy(&sbi->s_dirs_counter);
4027         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4028         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
4029         if (sbi->s_mmp_tsk)
4030                 kthread_stop(sbi->s_mmp_tsk);
4031 failed_mount2:
4032         for (i = 0; i < db_count; i++)
4033                 brelse(sbi->s_group_desc[i]);
4034         ext4_kvfree(sbi->s_group_desc);
4035 failed_mount:
4036         if (sbi->s_chksum_driver)
4037                 crypto_free_shash(sbi->s_chksum_driver);
4038         if (sbi->s_proc) {
4039                 remove_proc_entry("options", sbi->s_proc);
4040                 remove_proc_entry(sb->s_id, ext4_proc_root);
4041         }
4042 #ifdef CONFIG_QUOTA
4043         for (i = 0; i < MAXQUOTAS; i++)
4044                 kfree(sbi->s_qf_names[i]);
4045 #endif
4046         ext4_blkdev_remove(sbi);
4047         brelse(bh);
4048 out_fail:
4049         sb->s_fs_info = NULL;
4050         kfree(sbi->s_blockgroup_lock);
4051         kfree(sbi);
4052 out_free_orig:
4053         kfree(orig_data);
4054         return err ? err : ret;
4055 }
4056
4057 /*
4058  * Setup any per-fs journal parameters now.  We'll do this both on
4059  * initial mount, once the journal has been initialised but before we've
4060  * done any recovery; and again on any subsequent remount.
4061  */
4062 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4063 {
4064         struct ext4_sb_info *sbi = EXT4_SB(sb);
4065
4066         journal->j_commit_interval = sbi->s_commit_interval;
4067         journal->j_min_batch_time = sbi->s_min_batch_time;
4068         journal->j_max_batch_time = sbi->s_max_batch_time;
4069
4070         write_lock(&journal->j_state_lock);
4071         if (test_opt(sb, BARRIER))
4072                 journal->j_flags |= JBD2_BARRIER;
4073         else
4074                 journal->j_flags &= ~JBD2_BARRIER;
4075         if (test_opt(sb, DATA_ERR_ABORT))
4076                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4077         else
4078                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4079         write_unlock(&journal->j_state_lock);
4080 }
4081
4082 static journal_t *ext4_get_journal(struct super_block *sb,
4083                                    unsigned int journal_inum)
4084 {
4085         struct inode *journal_inode;
4086         journal_t *journal;
4087
4088         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4089
4090         /* First, test for the existence of a valid inode on disk.  Bad
4091          * things happen if we iget() an unused inode, as the subsequent
4092          * iput() will try to delete it. */
4093
4094         journal_inode = ext4_iget(sb, journal_inum);
4095         if (IS_ERR(journal_inode)) {
4096                 ext4_msg(sb, KERN_ERR, "no journal found");
4097                 return NULL;
4098         }
4099         if (!journal_inode->i_nlink) {
4100                 make_bad_inode(journal_inode);
4101                 iput(journal_inode);
4102                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4103                 return NULL;
4104         }
4105
4106         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4107                   journal_inode, journal_inode->i_size);
4108         if (!S_ISREG(journal_inode->i_mode)) {
4109                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4110                 iput(journal_inode);
4111                 return NULL;
4112         }
4113
4114         journal = jbd2_journal_init_inode(journal_inode);
4115         if (!journal) {
4116                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4117                 iput(journal_inode);
4118                 return NULL;
4119         }
4120         journal->j_private = sb;
4121         ext4_init_journal_params(sb, journal);
4122         return journal;
4123 }
4124
4125 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4126                                        dev_t j_dev)
4127 {
4128         struct buffer_head *bh;
4129         journal_t *journal;
4130         ext4_fsblk_t start;
4131         ext4_fsblk_t len;
4132         int hblock, blocksize;
4133         ext4_fsblk_t sb_block;
4134         unsigned long offset;
4135         struct ext4_super_block *es;
4136         struct block_device *bdev;
4137
4138         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4139
4140         bdev = ext4_blkdev_get(j_dev, sb);
4141         if (bdev == NULL)
4142                 return NULL;
4143
4144         blocksize = sb->s_blocksize;
4145         hblock = bdev_logical_block_size(bdev);
4146         if (blocksize < hblock) {
4147                 ext4_msg(sb, KERN_ERR,
4148                         "blocksize too small for journal device");
4149                 goto out_bdev;
4150         }
4151
4152         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4153         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4154         set_blocksize(bdev, blocksize);
4155         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4156                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4157                        "external journal");
4158                 goto out_bdev;
4159         }
4160
4161         es = (struct ext4_super_block *) (bh->b_data + offset);
4162         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4163             !(le32_to_cpu(es->s_feature_incompat) &
4164               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4165                 ext4_msg(sb, KERN_ERR, "external journal has "
4166                                         "bad superblock");
4167                 brelse(bh);
4168                 goto out_bdev;
4169         }
4170
4171         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4172                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4173                 brelse(bh);
4174                 goto out_bdev;
4175         }
4176
4177         len = ext4_blocks_count(es);
4178         start = sb_block + 1;
4179         brelse(bh);     /* we're done with the superblock */
4180
4181         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4182                                         start, len, blocksize);
4183         if (!journal) {
4184                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4185                 goto out_bdev;
4186         }
4187         journal->j_private = sb;
4188         ll_rw_block(READ, 1, &journal->j_sb_buffer);
4189         wait_on_buffer(journal->j_sb_buffer);
4190         if (!buffer_uptodate(journal->j_sb_buffer)) {
4191                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4192                 goto out_journal;
4193         }
4194         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4195                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4196                                         "user (unsupported) - %d",
4197                         be32_to_cpu(journal->j_superblock->s_nr_users));
4198                 goto out_journal;
4199         }
4200         EXT4_SB(sb)->journal_bdev = bdev;
4201         ext4_init_journal_params(sb, journal);
4202         return journal;
4203
4204 out_journal:
4205         jbd2_journal_destroy(journal);
4206 out_bdev:
4207         ext4_blkdev_put(bdev);
4208         return NULL;
4209 }
4210
4211 static int ext4_load_journal(struct super_block *sb,
4212                              struct ext4_super_block *es,
4213                              unsigned long journal_devnum)
4214 {
4215         journal_t *journal;
4216         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4217         dev_t journal_dev;
4218         int err = 0;
4219         int really_read_only;
4220
4221         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4222
4223         if (journal_devnum &&
4224             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4225                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4226                         "numbers have changed");
4227                 journal_dev = new_decode_dev(journal_devnum);
4228         } else
4229                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4230
4231         really_read_only = bdev_read_only(sb->s_bdev);
4232
4233         /*
4234          * Are we loading a blank journal or performing recovery after a
4235          * crash?  For recovery, we need to check in advance whether we
4236          * can get read-write access to the device.
4237          */
4238         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4239                 if (sb->s_flags & MS_RDONLY) {
4240                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4241                                         "required on readonly filesystem");
4242                         if (really_read_only) {
4243                                 ext4_msg(sb, KERN_ERR, "write access "
4244                                         "unavailable, cannot proceed");
4245                                 return -EROFS;
4246                         }
4247                         ext4_msg(sb, KERN_INFO, "write access will "
4248                                "be enabled during recovery");
4249                 }
4250         }
4251
4252         if (journal_inum && journal_dev) {
4253                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4254                        "and inode journals!");
4255                 return -EINVAL;
4256         }
4257
4258         if (journal_inum) {
4259                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4260                         return -EINVAL;
4261         } else {
4262                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4263                         return -EINVAL;
4264         }
4265
4266         if (!(journal->j_flags & JBD2_BARRIER))
4267                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4268
4269         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4270                 err = jbd2_journal_wipe(journal, !really_read_only);
4271         if (!err) {
4272                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4273                 if (save)
4274                         memcpy(save, ((char *) es) +
4275                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4276                 err = jbd2_journal_load(journal);
4277                 if (save)
4278                         memcpy(((char *) es) + EXT4_S_ERR_START,
4279                                save, EXT4_S_ERR_LEN);
4280                 kfree(save);
4281         }
4282
4283         if (err) {
4284                 ext4_msg(sb, KERN_ERR, "error loading journal");
4285                 jbd2_journal_destroy(journal);
4286                 return err;
4287         }
4288
4289         EXT4_SB(sb)->s_journal = journal;
4290         ext4_clear_journal_err(sb, es);
4291
4292         if (!really_read_only && journal_devnum &&
4293             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4294                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4295
4296                 /* Make sure we flush the recovery flag to disk. */
4297                 ext4_commit_super(sb, 1);
4298         }
4299
4300         return 0;
4301 }
4302
4303 static int ext4_commit_super(struct super_block *sb, int sync)
4304 {
4305         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4306         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4307         int error = 0;
4308
4309         if (!sbh || block_device_ejected(sb))
4310                 return error;
4311         if (buffer_write_io_error(sbh)) {
4312                 /*
4313                  * Oh, dear.  A previous attempt to write the
4314                  * superblock failed.  This could happen because the
4315                  * USB device was yanked out.  Or it could happen to
4316                  * be a transient write error and maybe the block will
4317                  * be remapped.  Nothing we can do but to retry the
4318                  * write and hope for the best.
4319                  */
4320                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4321                        "superblock detected");
4322                 clear_buffer_write_io_error(sbh);
4323                 set_buffer_uptodate(sbh);
4324         }
4325         /*
4326          * If the file system is mounted read-only, don't update the
4327          * superblock write time.  This avoids updating the superblock
4328          * write time when we are mounting the root file system
4329          * read/only but we need to replay the journal; at that point,
4330          * for people who are east of GMT and who make their clock
4331          * tick in localtime for Windows bug-for-bug compatibility,
4332          * the clock is set in the future, and this will cause e2fsck
4333          * to complain and force a full file system check.
4334          */
4335         if (!(sb->s_flags & MS_RDONLY))
4336                 es->s_wtime = cpu_to_le32(get_seconds());
4337         if (sb->s_bdev->bd_part)
4338                 es->s_kbytes_written =
4339                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4340                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4341                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4342         else
4343                 es->s_kbytes_written =
4344                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4345         ext4_free_blocks_count_set(es,
4346                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4347                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4348         es->s_free_inodes_count =
4349                 cpu_to_le32(percpu_counter_sum_positive(
4350                                 &EXT4_SB(sb)->s_freeinodes_counter));
4351         BUFFER_TRACE(sbh, "marking dirty");
4352         ext4_superblock_csum_set(sb);
4353         mark_buffer_dirty(sbh);
4354         if (sync) {
4355                 error = sync_dirty_buffer(sbh);
4356                 if (error)
4357                         return error;
4358
4359                 error = buffer_write_io_error(sbh);
4360                 if (error) {
4361                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4362                                "superblock");
4363                         clear_buffer_write_io_error(sbh);
4364                         set_buffer_uptodate(sbh);
4365                 }
4366         }
4367         return error;
4368 }
4369
4370 /*
4371  * Have we just finished recovery?  If so, and if we are mounting (or
4372  * remounting) the filesystem readonly, then we will end up with a
4373  * consistent fs on disk.  Record that fact.
4374  */
4375 static void ext4_mark_recovery_complete(struct super_block *sb,
4376                                         struct ext4_super_block *es)
4377 {
4378         journal_t *journal = EXT4_SB(sb)->s_journal;
4379
4380         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4381                 BUG_ON(journal != NULL);
4382                 return;
4383         }
4384         jbd2_journal_lock_updates(journal);
4385         if (jbd2_journal_flush(journal) < 0)
4386                 goto out;
4387
4388         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4389             sb->s_flags & MS_RDONLY) {
4390                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4391                 ext4_commit_super(sb, 1);
4392         }
4393
4394 out:
4395         jbd2_journal_unlock_updates(journal);
4396 }
4397
4398 /*
4399  * If we are mounting (or read-write remounting) a filesystem whose journal
4400  * has recorded an error from a previous lifetime, move that error to the
4401  * main filesystem now.
4402  */
4403 static void ext4_clear_journal_err(struct super_block *sb,
4404                                    struct ext4_super_block *es)
4405 {
4406         journal_t *journal;
4407         int j_errno;
4408         const char *errstr;
4409
4410         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4411
4412         journal = EXT4_SB(sb)->s_journal;
4413
4414         /*
4415          * Now check for any error status which may have been recorded in the
4416          * journal by a prior ext4_error() or ext4_abort()
4417          */
4418
4419         j_errno = jbd2_journal_errno(journal);
4420         if (j_errno) {
4421                 char nbuf[16];
4422
4423                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4424                 ext4_warning(sb, "Filesystem error recorded "
4425                              "from previous mount: %s", errstr);
4426                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4427
4428                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4429                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4430                 ext4_commit_super(sb, 1);
4431
4432                 jbd2_journal_clear_err(journal);
4433                 jbd2_journal_update_sb_errno(journal);
4434         }
4435 }
4436
4437 /*
4438  * Force the running and committing transactions to commit,
4439  * and wait on the commit.
4440  */
4441 int ext4_force_commit(struct super_block *sb)
4442 {
4443         journal_t *journal;
4444
4445         if (sb->s_flags & MS_RDONLY)
4446                 return 0;
4447
4448         journal = EXT4_SB(sb)->s_journal;
4449         return ext4_journal_force_commit(journal);
4450 }
4451
4452 static int ext4_sync_fs(struct super_block *sb, int wait)
4453 {
4454         int ret = 0;
4455         tid_t target;
4456         struct ext4_sb_info *sbi = EXT4_SB(sb);
4457
4458         trace_ext4_sync_fs(sb, wait);
4459         flush_workqueue(sbi->dio_unwritten_wq);
4460         /*
4461          * Writeback quota in non-journalled quota case - journalled quota has
4462          * no dirty dquots
4463          */
4464         dquot_writeback_dquots(sb, -1);
4465         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4466                 if (wait)
4467                         jbd2_log_wait_commit(sbi->s_journal, target);
4468         }
4469         return ret;
4470 }
4471
4472 /*
4473  * LVM calls this function before a (read-only) snapshot is created.  This
4474  * gives us a chance to flush the journal completely and mark the fs clean.
4475  *
4476  * Note that only this function cannot bring a filesystem to be in a clean
4477  * state independently. It relies on upper layer to stop all data & metadata
4478  * modifications.
4479  */
4480 static int ext4_freeze(struct super_block *sb)
4481 {
4482         int error = 0;
4483         journal_t *journal;
4484
4485         if (sb->s_flags & MS_RDONLY)
4486                 return 0;
4487
4488         journal = EXT4_SB(sb)->s_journal;
4489
4490         /* Now we set up the journal barrier. */
4491         jbd2_journal_lock_updates(journal);
4492
4493         /*
4494          * Don't clear the needs_recovery flag if we failed to flush
4495          * the journal.
4496          */
4497         error = jbd2_journal_flush(journal);
4498         if (error < 0)
4499                 goto out;
4500
4501         /* Journal blocked and flushed, clear needs_recovery flag. */
4502         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4503         error = ext4_commit_super(sb, 1);
4504 out:
4505         /* we rely on upper layer to stop further updates */
4506         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4507         return error;
4508 }
4509
4510 /*
4511  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4512  * flag here, even though the filesystem is not technically dirty yet.
4513  */
4514 static int ext4_unfreeze(struct super_block *sb)
4515 {
4516         if (sb->s_flags & MS_RDONLY)
4517                 return 0;
4518
4519         /* Reset the needs_recovery flag before the fs is unlocked. */
4520         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4521         ext4_commit_super(sb, 1);
4522         return 0;
4523 }
4524
4525 /*
4526  * Structure to save mount options for ext4_remount's benefit
4527  */
4528 struct ext4_mount_options {
4529         unsigned long s_mount_opt;
4530         unsigned long s_mount_opt2;
4531         kuid_t s_resuid;
4532         kgid_t s_resgid;
4533         unsigned long s_commit_interval;
4534         u32 s_min_batch_time, s_max_batch_time;
4535 #ifdef CONFIG_QUOTA
4536         int s_jquota_fmt;
4537         char *s_qf_names[MAXQUOTAS];
4538 #endif
4539 };
4540
4541 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4542 {
4543         struct ext4_super_block *es;
4544         struct ext4_sb_info *sbi = EXT4_SB(sb);
4545         unsigned long old_sb_flags;
4546         struct ext4_mount_options old_opts;
4547         int enable_quota = 0;
4548         ext4_group_t g;
4549         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4550         int err = 0;
4551 #ifdef CONFIG_QUOTA
4552         int i, j;
4553 #endif
4554         char *orig_data = kstrdup(data, GFP_KERNEL);
4555
4556         /* Store the original options */
4557         old_sb_flags = sb->s_flags;
4558         old_opts.s_mount_opt = sbi->s_mount_opt;
4559         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4560         old_opts.s_resuid = sbi->s_resuid;
4561         old_opts.s_resgid = sbi->s_resgid;
4562         old_opts.s_commit_interval = sbi->s_commit_interval;
4563         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4564         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4565 #ifdef CONFIG_QUOTA
4566         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4567         for (i = 0; i < MAXQUOTAS; i++)
4568                 if (sbi->s_qf_names[i]) {
4569                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4570                                                          GFP_KERNEL);
4571                         if (!old_opts.s_qf_names[i]) {
4572                                 for (j = 0; j < i; j++)
4573                                         kfree(old_opts.s_qf_names[j]);
4574                                 kfree(orig_data);
4575                                 return -ENOMEM;
4576                         }
4577                 } else
4578                         old_opts.s_qf_names[i] = NULL;
4579 #endif
4580         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4581                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4582
4583         /*
4584          * Allow the "check" option to be passed as a remount option.
4585          */
4586         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4587                 err = -EINVAL;
4588                 goto restore_opts;
4589         }
4590
4591         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4592                 ext4_abort(sb, "Abort forced by user");
4593
4594         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4595                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4596
4597         es = sbi->s_es;
4598
4599         if (sbi->s_journal) {
4600                 ext4_init_journal_params(sb, sbi->s_journal);
4601                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4602         }
4603
4604         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4605                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4606                         err = -EROFS;
4607                         goto restore_opts;
4608                 }
4609
4610                 if (*flags & MS_RDONLY) {
4611                         err = dquot_suspend(sb, -1);
4612                         if (err < 0)
4613                                 goto restore_opts;
4614
4615                         /*
4616                          * First of all, the unconditional stuff we have to do
4617                          * to disable replay of the journal when we next remount
4618                          */
4619                         sb->s_flags |= MS_RDONLY;
4620
4621                         /*
4622                          * OK, test if we are remounting a valid rw partition
4623                          * readonly, and if so set the rdonly flag and then
4624                          * mark the partition as valid again.
4625                          */
4626                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4627                             (sbi->s_mount_state & EXT4_VALID_FS))
4628                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4629
4630                         if (sbi->s_journal)
4631                                 ext4_mark_recovery_complete(sb, es);
4632                 } else {
4633                         /* Make sure we can mount this feature set readwrite */
4634                         if (!ext4_feature_set_ok(sb, 0)) {
4635                                 err = -EROFS;
4636                                 goto restore_opts;
4637                         }
4638                         /*
4639                          * Make sure the group descriptor checksums
4640                          * are sane.  If they aren't, refuse to remount r/w.
4641                          */
4642                         for (g = 0; g < sbi->s_groups_count; g++) {
4643                                 struct ext4_group_desc *gdp =
4644                                         ext4_get_group_desc(sb, g, NULL);
4645
4646                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4647                                         ext4_msg(sb, KERN_ERR,
4648                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4649                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4650                                                le16_to_cpu(gdp->bg_checksum));
4651                                         err = -EINVAL;
4652                                         goto restore_opts;
4653                                 }
4654                         }
4655
4656                         /*
4657                          * If we have an unprocessed orphan list hanging
4658                          * around from a previously readonly bdev mount,
4659                          * require a full umount/remount for now.
4660                          */
4661                         if (es->s_last_orphan) {
4662                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4663                                        "remount RDWR because of unprocessed "
4664                                        "orphan inode list.  Please "
4665                                        "umount/remount instead");
4666                                 err = -EINVAL;
4667                                 goto restore_opts;
4668                         }
4669
4670                         /*
4671                          * Mounting a RDONLY partition read-write, so reread
4672                          * and store the current valid flag.  (It may have
4673                          * been changed by e2fsck since we originally mounted
4674                          * the partition.)
4675                          */
4676                         if (sbi->s_journal)
4677                                 ext4_clear_journal_err(sb, es);
4678                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4679                         if (!ext4_setup_super(sb, es, 0))
4680                                 sb->s_flags &= ~MS_RDONLY;
4681                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4682                                                      EXT4_FEATURE_INCOMPAT_MMP))
4683                                 if (ext4_multi_mount_protect(sb,
4684                                                 le64_to_cpu(es->s_mmp_block))) {
4685                                         err = -EROFS;
4686                                         goto restore_opts;
4687                                 }
4688                         enable_quota = 1;
4689                 }
4690         }
4691
4692         /*
4693          * Reinitialize lazy itable initialization thread based on
4694          * current settings
4695          */
4696         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4697                 ext4_unregister_li_request(sb);
4698         else {
4699                 ext4_group_t first_not_zeroed;
4700                 first_not_zeroed = ext4_has_uninit_itable(sb);
4701                 ext4_register_li_request(sb, first_not_zeroed);
4702         }
4703
4704         ext4_setup_system_zone(sb);
4705         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4706                 ext4_commit_super(sb, 1);
4707
4708 #ifdef CONFIG_QUOTA
4709         /* Release old quota file names */
4710         for (i = 0; i < MAXQUOTAS; i++)
4711                 kfree(old_opts.s_qf_names[i]);
4712         if (enable_quota) {
4713                 if (sb_any_quota_suspended(sb))
4714                         dquot_resume(sb, -1);
4715                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4716                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4717                         err = ext4_enable_quotas(sb);
4718                         if (err)
4719                                 goto restore_opts;
4720                 }
4721         }
4722 #endif
4723
4724         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4725         kfree(orig_data);
4726         return 0;
4727
4728 restore_opts:
4729         sb->s_flags = old_sb_flags;
4730         sbi->s_mount_opt = old_opts.s_mount_opt;
4731         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4732         sbi->s_resuid = old_opts.s_resuid;
4733         sbi->s_resgid = old_opts.s_resgid;
4734         sbi->s_commit_interval = old_opts.s_commit_interval;
4735         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4736         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4737 #ifdef CONFIG_QUOTA
4738         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4739         for (i = 0; i < MAXQUOTAS; i++) {
4740                 kfree(sbi->s_qf_names[i]);
4741                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4742         }
4743 #endif
4744         kfree(orig_data);
4745         return err;
4746 }
4747
4748 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4749 {
4750         struct super_block *sb = dentry->d_sb;
4751         struct ext4_sb_info *sbi = EXT4_SB(sb);
4752         struct ext4_super_block *es = sbi->s_es;
4753         ext4_fsblk_t overhead = 0;
4754         u64 fsid;
4755         s64 bfree;
4756
4757         if (!test_opt(sb, MINIX_DF))
4758                 overhead = sbi->s_overhead;
4759
4760         buf->f_type = EXT4_SUPER_MAGIC;
4761         buf->f_bsize = sb->s_blocksize;
4762         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4763         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4764                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4765         /* prevent underflow in case that few free space is available */
4766         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4767         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4768         if (buf->f_bfree < ext4_r_blocks_count(es))
4769                 buf->f_bavail = 0;
4770         buf->f_files = le32_to_cpu(es->s_inodes_count);
4771         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4772         buf->f_namelen = EXT4_NAME_LEN;
4773         fsid = le64_to_cpup((void *)es->s_uuid) ^
4774                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4775         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4776         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4777
4778         return 0;
4779 }
4780
4781 /* Helper function for writing quotas on sync - we need to start transaction
4782  * before quota file is locked for write. Otherwise the are possible deadlocks:
4783  * Process 1                         Process 2
4784  * ext4_create()                     quota_sync()
4785  *   jbd2_journal_start()                  write_dquot()
4786  *   dquot_initialize()                         down(dqio_mutex)
4787  *     down(dqio_mutex)                    jbd2_journal_start()
4788  *
4789  */
4790
4791 #ifdef CONFIG_QUOTA
4792
4793 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4794 {
4795         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4796 }
4797
4798 static int ext4_write_dquot(struct dquot *dquot)
4799 {
4800         int ret, err;
4801         handle_t *handle;
4802         struct inode *inode;
4803
4804         inode = dquot_to_inode(dquot);
4805         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4806                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4807         if (IS_ERR(handle))
4808                 return PTR_ERR(handle);
4809         ret = dquot_commit(dquot);
4810         err = ext4_journal_stop(handle);
4811         if (!ret)
4812                 ret = err;
4813         return ret;
4814 }
4815
4816 static int ext4_acquire_dquot(struct dquot *dquot)
4817 {
4818         int ret, err;
4819         handle_t *handle;
4820
4821         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4822                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4823         if (IS_ERR(handle))
4824                 return PTR_ERR(handle);
4825         ret = dquot_acquire(dquot);
4826         err = ext4_journal_stop(handle);
4827         if (!ret)
4828                 ret = err;
4829         return ret;
4830 }
4831
4832 static int ext4_release_dquot(struct dquot *dquot)
4833 {
4834         int ret, err;
4835         handle_t *handle;
4836
4837         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4838                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4839         if (IS_ERR(handle)) {
4840                 /* Release dquot anyway to avoid endless cycle in dqput() */
4841                 dquot_release(dquot);
4842                 return PTR_ERR(handle);
4843         }
4844         ret = dquot_release(dquot);
4845         err = ext4_journal_stop(handle);
4846         if (!ret)
4847                 ret = err;
4848         return ret;
4849 }
4850
4851 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4852 {
4853         struct super_block *sb = dquot->dq_sb;
4854         struct ext4_sb_info *sbi = EXT4_SB(sb);
4855
4856         /* Are we journaling quotas? */
4857         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
4858             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
4859                 dquot_mark_dquot_dirty(dquot);
4860                 return ext4_write_dquot(dquot);
4861         } else {
4862                 return dquot_mark_dquot_dirty(dquot);
4863         }
4864 }
4865
4866 static int ext4_write_info(struct super_block *sb, int type)
4867 {
4868         int ret, err;
4869         handle_t *handle;
4870
4871         /* Data block + inode block */
4872         handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
4873         if (IS_ERR(handle))
4874                 return PTR_ERR(handle);
4875         ret = dquot_commit_info(sb, type);
4876         err = ext4_journal_stop(handle);
4877         if (!ret)
4878                 ret = err;
4879         return ret;
4880 }
4881
4882 /*
4883  * Turn on quotas during mount time - we need to find
4884  * the quota file and such...
4885  */
4886 static int ext4_quota_on_mount(struct super_block *sb, int type)
4887 {
4888         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4889                                         EXT4_SB(sb)->s_jquota_fmt, type);
4890 }
4891
4892 /*
4893  * Standard function to be called on quota_on
4894  */
4895 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4896                          struct path *path)
4897 {
4898         int err;
4899
4900         if (!test_opt(sb, QUOTA))
4901                 return -EINVAL;
4902
4903         /* Quotafile not on the same filesystem? */
4904         if (path->dentry->d_sb != sb)
4905                 return -EXDEV;
4906         /* Journaling quota? */
4907         if (EXT4_SB(sb)->s_qf_names[type]) {
4908                 /* Quotafile not in fs root? */
4909                 if (path->dentry->d_parent != sb->s_root)
4910                         ext4_msg(sb, KERN_WARNING,
4911                                 "Quota file not on filesystem root. "
4912                                 "Journaled quota will not work");
4913         }
4914
4915         /*
4916          * When we journal data on quota file, we have to flush journal to see
4917          * all updates to the file when we bypass pagecache...
4918          */
4919         if (EXT4_SB(sb)->s_journal &&
4920             ext4_should_journal_data(path->dentry->d_inode)) {
4921                 /*
4922                  * We don't need to lock updates but journal_flush() could
4923                  * otherwise be livelocked...
4924                  */
4925                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4926                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4927                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4928                 if (err)
4929                         return err;
4930         }
4931
4932         return dquot_quota_on(sb, type, format_id, path);
4933 }
4934
4935 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
4936                              unsigned int flags)
4937 {
4938         int err;
4939         struct inode *qf_inode;
4940         unsigned long qf_inums[MAXQUOTAS] = {
4941                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4942                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4943         };
4944
4945         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
4946
4947         if (!qf_inums[type])
4948                 return -EPERM;
4949
4950         qf_inode = ext4_iget(sb, qf_inums[type]);
4951         if (IS_ERR(qf_inode)) {
4952                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
4953                 return PTR_ERR(qf_inode);
4954         }
4955
4956         err = dquot_enable(qf_inode, type, format_id, flags);
4957         iput(qf_inode);
4958
4959         return err;
4960 }
4961
4962 /* Enable usage tracking for all quota types. */
4963 static int ext4_enable_quotas(struct super_block *sb)
4964 {
4965         int type, err = 0;
4966         unsigned long qf_inums[MAXQUOTAS] = {
4967                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4968                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4969         };
4970
4971         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
4972         for (type = 0; type < MAXQUOTAS; type++) {
4973                 if (qf_inums[type]) {
4974                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
4975                                                 DQUOT_USAGE_ENABLED);
4976                         if (err) {
4977                                 ext4_warning(sb,
4978                                         "Failed to enable quota tracking "
4979                                         "(type=%d, err=%d). Please run "
4980                                         "e2fsck to fix.", type, err);
4981                                 return err;
4982                         }
4983                 }
4984         }
4985         return 0;
4986 }
4987
4988 /*
4989  * quota_on function that is used when QUOTA feature is set.
4990  */
4991 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
4992                                  int format_id)
4993 {
4994         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
4995                 return -EINVAL;
4996
4997         /*
4998          * USAGE was enabled at mount time. Only need to enable LIMITS now.
4999          */
5000         return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5001 }
5002
5003 static int ext4_quota_off(struct super_block *sb, int type)
5004 {
5005         struct inode *inode = sb_dqopt(sb)->files[type];
5006         handle_t *handle;
5007
5008         /* Force all delayed allocation blocks to be allocated.
5009          * Caller already holds s_umount sem */
5010         if (test_opt(sb, DELALLOC))
5011                 sync_filesystem(sb);
5012
5013         if (!inode)
5014                 goto out;
5015
5016         /* Update modification times of quota files when userspace can
5017          * start looking at them */
5018         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5019         if (IS_ERR(handle))
5020                 goto out;
5021         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5022         ext4_mark_inode_dirty(handle, inode);
5023         ext4_journal_stop(handle);
5024
5025 out:
5026         return dquot_quota_off(sb, type);
5027 }
5028
5029 /*
5030  * quota_off function that is used when QUOTA feature is set.
5031  */
5032 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5033 {
5034         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5035                 return -EINVAL;
5036
5037         /* Disable only the limits. */
5038         return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5039 }
5040
5041 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5042  * acquiring the locks... As quota files are never truncated and quota code
5043  * itself serializes the operations (and no one else should touch the files)
5044  * we don't have to be afraid of races */
5045 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5046                                size_t len, loff_t off)
5047 {
5048         struct inode *inode = sb_dqopt(sb)->files[type];
5049         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5050         int err = 0;
5051         int offset = off & (sb->s_blocksize - 1);
5052         int tocopy;
5053         size_t toread;
5054         struct buffer_head *bh;
5055         loff_t i_size = i_size_read(inode);
5056
5057         if (off > i_size)
5058                 return 0;
5059         if (off+len > i_size)
5060                 len = i_size-off;
5061         toread = len;
5062         while (toread > 0) {
5063                 tocopy = sb->s_blocksize - offset < toread ?
5064                                 sb->s_blocksize - offset : toread;
5065                 bh = ext4_bread(NULL, inode, blk, 0, &err);
5066                 if (err)
5067                         return err;
5068                 if (!bh)        /* A hole? */
5069                         memset(data, 0, tocopy);
5070                 else
5071                         memcpy(data, bh->b_data+offset, tocopy);
5072                 brelse(bh);
5073                 offset = 0;
5074                 toread -= tocopy;
5075                 data += tocopy;
5076                 blk++;
5077         }
5078         return len;
5079 }
5080
5081 /* Write to quotafile (we know the transaction is already started and has
5082  * enough credits) */
5083 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5084                                 const char *data, size_t len, loff_t off)
5085 {
5086         struct inode *inode = sb_dqopt(sb)->files[type];
5087         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5088         int err = 0;
5089         int offset = off & (sb->s_blocksize - 1);
5090         struct buffer_head *bh;
5091         handle_t *handle = journal_current_handle();
5092
5093         if (EXT4_SB(sb)->s_journal && !handle) {
5094                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5095                         " cancelled because transaction is not started",
5096                         (unsigned long long)off, (unsigned long long)len);
5097                 return -EIO;
5098         }
5099         /*
5100          * Since we account only one data block in transaction credits,
5101          * then it is impossible to cross a block boundary.
5102          */
5103         if (sb->s_blocksize - offset < len) {
5104                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5105                         " cancelled because not block aligned",
5106                         (unsigned long long)off, (unsigned long long)len);
5107                 return -EIO;
5108         }
5109
5110         bh = ext4_bread(handle, inode, blk, 1, &err);
5111         if (!bh)
5112                 goto out;
5113         err = ext4_journal_get_write_access(handle, bh);
5114         if (err) {
5115                 brelse(bh);
5116                 goto out;
5117         }
5118         lock_buffer(bh);
5119         memcpy(bh->b_data+offset, data, len);
5120         flush_dcache_page(bh->b_page);
5121         unlock_buffer(bh);
5122         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5123         brelse(bh);
5124 out:
5125         if (err)
5126                 return err;
5127         if (inode->i_size < off + len) {
5128                 i_size_write(inode, off + len);
5129                 EXT4_I(inode)->i_disksize = inode->i_size;
5130                 ext4_mark_inode_dirty(handle, inode);
5131         }
5132         return len;
5133 }
5134
5135 #endif
5136
5137 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5138                        const char *dev_name, void *data)
5139 {
5140         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5141 }
5142
5143 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5144 static inline void register_as_ext2(void)
5145 {
5146         int err = register_filesystem(&ext2_fs_type);
5147         if (err)
5148                 printk(KERN_WARNING
5149                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5150 }
5151
5152 static inline void unregister_as_ext2(void)
5153 {
5154         unregister_filesystem(&ext2_fs_type);
5155 }
5156
5157 static inline int ext2_feature_set_ok(struct super_block *sb)
5158 {
5159         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5160                 return 0;
5161         if (sb->s_flags & MS_RDONLY)
5162                 return 1;
5163         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5164                 return 0;
5165         return 1;
5166 }
5167 #else
5168 static inline void register_as_ext2(void) { }
5169 static inline void unregister_as_ext2(void) { }
5170 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5171 #endif
5172
5173 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5174 static inline void register_as_ext3(void)
5175 {
5176         int err = register_filesystem(&ext3_fs_type);
5177         if (err)
5178                 printk(KERN_WARNING
5179                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5180 }
5181
5182 static inline void unregister_as_ext3(void)
5183 {
5184         unregister_filesystem(&ext3_fs_type);
5185 }
5186
5187 static inline int ext3_feature_set_ok(struct super_block *sb)
5188 {
5189         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5190                 return 0;
5191         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5192                 return 0;
5193         if (sb->s_flags & MS_RDONLY)
5194                 return 1;
5195         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5196                 return 0;
5197         return 1;
5198 }
5199 #else
5200 static inline void register_as_ext3(void) { }
5201 static inline void unregister_as_ext3(void) { }
5202 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5203 #endif
5204
5205 static struct file_system_type ext4_fs_type = {
5206         .owner          = THIS_MODULE,
5207         .name           = "ext4",
5208         .mount          = ext4_mount,
5209         .kill_sb        = kill_block_super,
5210         .fs_flags       = FS_REQUIRES_DEV,
5211 };
5212 MODULE_ALIAS_FS("ext4");
5213
5214 static int __init ext4_init_feat_adverts(void)
5215 {
5216         struct ext4_features *ef;
5217         int ret = -ENOMEM;
5218
5219         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5220         if (!ef)
5221                 goto out;
5222
5223         ef->f_kobj.kset = ext4_kset;
5224         init_completion(&ef->f_kobj_unregister);
5225         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5226                                    "features");
5227         if (ret) {
5228                 kfree(ef);
5229                 goto out;
5230         }
5231
5232         ext4_feat = ef;
5233         ret = 0;
5234 out:
5235         return ret;
5236 }
5237
5238 static void ext4_exit_feat_adverts(void)
5239 {
5240         kobject_put(&ext4_feat->f_kobj);
5241         wait_for_completion(&ext4_feat->f_kobj_unregister);
5242         kfree(ext4_feat);
5243 }
5244
5245 /* Shared across all ext4 file systems */
5246 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5247 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5248
5249 static int __init ext4_init_fs(void)
5250 {
5251         int i, err;
5252
5253         ext4_li_info = NULL;
5254         mutex_init(&ext4_li_mtx);
5255
5256         /* Build-time check for flags consistency */
5257         ext4_check_flag_values();
5258
5259         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5260                 mutex_init(&ext4__aio_mutex[i]);
5261                 init_waitqueue_head(&ext4__ioend_wq[i]);
5262         }
5263
5264         err = ext4_init_es();
5265         if (err)
5266                 return err;
5267
5268         err = ext4_init_pageio();
5269         if (err)
5270                 goto out7;
5271
5272         err = ext4_init_system_zone();
5273         if (err)
5274                 goto out6;
5275         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5276         if (!ext4_kset) {
5277                 err = -ENOMEM;
5278                 goto out5;
5279         }
5280         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5281
5282         err = ext4_init_feat_adverts();
5283         if (err)
5284                 goto out4;
5285
5286         err = ext4_init_mballoc();
5287         if (err)
5288                 goto out3;
5289
5290         err = ext4_init_xattr();
5291         if (err)
5292                 goto out2;
5293         err = init_inodecache();
5294         if (err)
5295                 goto out1;
5296         register_as_ext3();
5297         register_as_ext2();
5298         err = register_filesystem(&ext4_fs_type);
5299         if (err)
5300                 goto out;
5301
5302         return 0;
5303 out:
5304         unregister_as_ext2();
5305         unregister_as_ext3();
5306         destroy_inodecache();
5307 out1:
5308         ext4_exit_xattr();
5309 out2:
5310         ext4_exit_mballoc();
5311 out3:
5312         ext4_exit_feat_adverts();
5313 out4:
5314         if (ext4_proc_root)
5315                 remove_proc_entry("fs/ext4", NULL);
5316         kset_unregister(ext4_kset);
5317 out5:
5318         ext4_exit_system_zone();
5319 out6:
5320         ext4_exit_pageio();
5321 out7:
5322         ext4_exit_es();
5323
5324         return err;
5325 }
5326
5327 static void __exit ext4_exit_fs(void)
5328 {
5329         ext4_destroy_lazyinit_thread();
5330         unregister_as_ext2();
5331         unregister_as_ext3();
5332         unregister_filesystem(&ext4_fs_type);
5333         destroy_inodecache();
5334         ext4_exit_xattr();
5335         ext4_exit_mballoc();
5336         ext4_exit_feat_adverts();
5337         remove_proc_entry("fs/ext4", NULL);
5338         kset_unregister(ext4_kset);
5339         ext4_exit_system_zone();
5340         ext4_exit_pageio();
5341 }
5342
5343 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5344 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5345 MODULE_LICENSE("GPL");
5346 module_init(ext4_init_fs)
5347 module_exit(ext4_exit_fs)