fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/jbd2.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/ctype.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <linux/cleancache.h>
  42 #include <asm/uaccess.h>
  43
  44 #include <linux/kthread.h>
  45 #include <linux/freezer.h>
  46
  47 #include "ext4.h"
  48 #include "ext4_extents.h"       /* Needed for trace points definition */
  49 #include "ext4_jbd2.h"
  50 #include "xattr.h"
  51 #include "acl.h"
  52 #include "mballoc.h"
  53
  54 #define CREATE_TRACE_POINTS
  55 #include <trace/events/ext4.h>
  56
  57 static struct proc_dir_entry *ext4_proc_root;
  58 static struct kset *ext4_kset;
  59 static struct ext4_lazy_init *ext4_li_info;
  60 static struct mutex ext4_li_mtx;
  61 static struct ext4_features *ext4_feat;
  62
  63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  64                              unsigned long journal_devnum);
  65 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  66 static int ext4_commit_super(struct super_block *sb, int sync);
  67 static void ext4_mark_recovery_complete(struct super_block *sb,
  68                                         struct ext4_super_block *es);
  69 static void ext4_clear_journal_err(struct super_block *sb,
  70                                    struct ext4_super_block *es);
  71 static int ext4_sync_fs(struct super_block *sb, int wait);
  72 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait);
  73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  75 static int ext4_unfreeze(struct super_block *sb);
  76 static int ext4_freeze(struct super_block *sb);
  77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  78                        const char *dev_name, void *data);
  79 static inline int ext2_feature_set_ok(struct super_block *sb);
  80 static inline int ext3_feature_set_ok(struct super_block *sb);
  81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  82 static void ext4_destroy_lazyinit_thread(void);
  83 static void ext4_unregister_li_request(struct super_block *sb);
  84 static void ext4_clear_request_list(void);
  85 static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
  86
  87 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  88 static struct file_system_type ext2_fs_type = {
  89         .owner          = THIS_MODULE,
  90         .name           = "ext2",
  91         .mount          = ext4_mount,
  92         .kill_sb        = kill_block_super,
  93         .fs_flags       = FS_REQUIRES_DEV,
  94 };
  95 MODULE_ALIAS_FS("ext2");
  96 MODULE_ALIAS("ext2");
  97 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  98 #else
  99 #define IS_EXT2_SB(sb) (0)
 100 #endif
 101
 102
 103 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 104 static struct file_system_type ext3_fs_type = {
 105         .owner          = THIS_MODULE,
 106         .name           = "ext3",
 107         .mount          = ext4_mount,
 108         .kill_sb        = kill_block_super,
 109         .fs_flags       = FS_REQUIRES_DEV,
 110 };
 111 MODULE_ALIAS_FS("ext3");
 112 MODULE_ALIAS("ext3");
 113 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 114 #else
 115 #define IS_EXT3_SB(sb) (0)
 116 #endif
 117
 118 static int ext4_verify_csum_type(struct super_block *sb,
 119                                  struct ext4_super_block *es)
 120 {
 121         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 122                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 123                 return 1;
 124
 125         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 126 }
 127
 128 static __le32 ext4_superblock_csum(struct super_block *sb,
 129                                    struct ext4_super_block *es)
 130 {
 131         struct ext4_sb_info *sbi = EXT4_SB(sb);
 132         int offset = offsetof(struct ext4_super_block, s_checksum);
 133         __u32 csum;
 134
 135         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 136
 137         return cpu_to_le32(csum);
 138 }
 139
 140 int ext4_superblock_csum_verify(struct super_block *sb,
 141                                 struct ext4_super_block *es)
 142 {
 143         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 144                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 145                 return 1;
 146
 147         return es->s_checksum == ext4_superblock_csum(sb, es);
 148 }
 149
 150 void ext4_superblock_csum_set(struct super_block *sb)
 151 {
 152         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 153
 154         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 155                 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 156                 return;
 157
 158         es->s_checksum = ext4_superblock_csum(sb, es);
 159 }
 160
 161 void *ext4_kvmalloc(size_t size, gfp_t flags)
 162 {
 163         void *ret;
 164
 165         ret = kmalloc(size, flags | __GFP_NOWARN);
 166         if (!ret)
 167                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 168         return ret;
 169 }
 170
 171 void *ext4_kvzalloc(size_t size, gfp_t flags)
 172 {
 173         void *ret;
 174
 175         ret = kzalloc(size, flags | __GFP_NOWARN);
 176         if (!ret)
 177                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 178         return ret;
 179 }
 180
 181 void ext4_kvfree(void *ptr)
 182 {
 183         if (is_vmalloc_addr(ptr))
 184                 vfree(ptr);
 185         else
 186                 kfree(ptr);
 187
 188 }
 189
 190 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 191                                struct ext4_group_desc *bg)
 192 {
 193         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 194                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 195                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 196 }
 197
 198 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 199                                struct ext4_group_desc *bg)
 200 {
 201         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 202                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 203                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 204 }
 205
 206 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 207                               struct ext4_group_desc *bg)
 208 {
 209         return le32_to_cpu(bg->bg_inode_table_lo) |
 210                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 211                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 212 }
 213
 214 __u32 ext4_free_group_clusters(struct super_block *sb,
 215                                struct ext4_group_desc *bg)
 216 {
 217         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 218                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 219                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 220 }
 221
 222 __u32 ext4_free_inodes_count(struct super_block *sb,
 223                               struct ext4_group_desc *bg)
 224 {
 225         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 226                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 227                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 228 }
 229
 230 __u32 ext4_used_dirs_count(struct super_block *sb,
 231                               struct ext4_group_desc *bg)
 232 {
 233         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 234                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 235                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 236 }
 237
 238 __u32 ext4_itable_unused_count(struct super_block *sb,
 239                               struct ext4_group_desc *bg)
 240 {
 241         return le16_to_cpu(bg->bg_itable_unused_lo) |
 242                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 243                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 244 }
 245
 246 void ext4_block_bitmap_set(struct super_block *sb,
 247                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 248 {
 249         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 250         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 251                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 252 }
 253
 254 void ext4_inode_bitmap_set(struct super_block *sb,
 255                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 256 {
 257         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 258         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 259                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 260 }
 261
 262 void ext4_inode_table_set(struct super_block *sb,
 263                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 264 {
 265         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 266         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 267                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 268 }
 269
 270 void ext4_free_group_clusters_set(struct super_block *sb,
 271                                   struct ext4_group_desc *bg, __u32 count)
 272 {
 273         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 274         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 275                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 276 }
 277
 278 void ext4_free_inodes_set(struct super_block *sb,
 279                           struct ext4_group_desc *bg, __u32 count)
 280 {
 281         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 282         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 283                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 284 }
 285
 286 void ext4_used_dirs_set(struct super_block *sb,
 287                           struct ext4_group_desc *bg, __u32 count)
 288 {
 289         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 290         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 291                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 292 }
 293
 294 void ext4_itable_unused_set(struct super_block *sb,
 295                           struct ext4_group_desc *bg, __u32 count)
 296 {
 297         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 298         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 299                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 300 }
 301
 302
 303 static void __save_error_info(struct super_block *sb, const char *func,
 304                             unsigned int line)
 305 {
 306         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 307
 308         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 309         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 310         es->s_last_error_time = cpu_to_le32(get_seconds());
 311         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 312         es->s_last_error_line = cpu_to_le32(line);
 313         if (!es->s_first_error_time) {
 314                 es->s_first_error_time = es->s_last_error_time;
 315                 strncpy(es->s_first_error_func, func,
 316                         sizeof(es->s_first_error_func));
 317                 es->s_first_error_line = cpu_to_le32(line);
 318                 es->s_first_error_ino = es->s_last_error_ino;
 319                 es->s_first_error_block = es->s_last_error_block;
 320         }
 321         /*
 322          * Start the daily error reporting function if it hasn't been
 323          * started already
 324          */
 325         if (!es->s_error_count)
 326                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 327         le32_add_cpu(&es->s_error_count, 1);
 328 }
 329
 330 static void save_error_info(struct super_block *sb, const char *func,
 331                             unsigned int line)
 332 {
 333         __save_error_info(sb, func, line);
 334         ext4_commit_super(sb, 1);
 335 }
 336
 337 /*
 338  * The del_gendisk() function uninitializes the disk-specific data
 339  * structures, including the bdi structure, without telling anyone
 340  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 341  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 342  * This is a kludge to prevent these oops until we can put in a proper
 343  * hook in del_gendisk() to inform the VFS and file system layers.
 344  */
 345 static int block_device_ejected(struct super_block *sb)
 346 {
 347         struct inode *bd_inode = sb->s_bdev->bd_inode;
 348         struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
 349
 350         return bdi->dev == NULL;
 351 }
 352
 353 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 354 {
 355         struct super_block              *sb = journal->j_private;
 356         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 357         int                             error = is_journal_aborted(journal);
 358         struct ext4_journal_cb_entry    *jce;
 359
 360         BUG_ON(txn->t_state == T_FINISHED);
 361         spin_lock(&sbi->s_md_lock);
 362         while (!list_empty(&txn->t_private_list)) {
 363                 jce = list_entry(txn->t_private_list.next,
 364                                  struct ext4_journal_cb_entry, jce_list);
 365                 list_del_init(&jce->jce_list);
 366                 spin_unlock(&sbi->s_md_lock);
 367                 jce->jce_func(sb, jce, error);
 368                 spin_lock(&sbi->s_md_lock);
 369         }
 370         spin_unlock(&sbi->s_md_lock);
 371 }
 372
 373 /* Deal with the reporting of failure conditions on a filesystem such as
 374  * inconsistencies detected or read IO failures.
 375  *
 376  * On ext2, we can store the error state of the filesystem in the
 377  * superblock.  That is not possible on ext4, because we may have other
 378  * write ordering constraints on the superblock which prevent us from
 379  * writing it out straight away; and given that the journal is about to
 380  * be aborted, we can't rely on the current, or future, transactions to
 381  * write out the superblock safely.
 382  *
 383  * We'll just use the jbd2_journal_abort() error code to record an error in
 384  * the journal instead.  On recovery, the journal will complain about
 385  * that error until we've noted it down and cleared it.
 386  */
 387
 388 static void ext4_handle_error(struct super_block *sb)
 389 {
 390         if (sb->s_flags & MS_RDONLY)
 391                 return;
 392
 393         if (!test_opt(sb, ERRORS_CONT)) {
 394                 journal_t *journal = EXT4_SB(sb)->s_journal;
 395
 396                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 397                 if (journal)
 398                         jbd2_journal_abort(journal, -EIO);
 399         }
 400         if (test_opt(sb, ERRORS_RO)) {
 401                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 402                 /*
 403                  * Make sure updated value of ->s_mount_flags will be visible
 404                  * before ->s_flags update
 405                  */
 406                 smp_wmb();
 407                 sb->s_flags |= MS_RDONLY;
 408         }
 409         if (test_opt(sb, ERRORS_PANIC))
 410                 panic("EXT4-fs (device %s): panic forced after error\n",
 411                         sb->s_id);
 412 }
 413
 414 void __ext4_error(struct super_block *sb, const char *function,
 415                   unsigned int line, const char *fmt, ...)
 416 {
 417         struct va_format vaf;
 418         va_list args;
 419
 420         va_start(args, fmt);
 421         vaf.fmt = fmt;
 422         vaf.va = &args;
 423         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 424                sb->s_id, function, line, current->comm, &vaf);
 425         va_end(args);
 426         save_error_info(sb, function, line);
 427
 428         ext4_handle_error(sb);
 429 }
 430
 431 void __ext4_error_inode(struct inode *inode, const char *function,
 432                         unsigned int line, ext4_fsblk_t block,
 433                         const char *fmt, ...)
 434 {
 435         va_list args;
 436         struct va_format vaf;
 437         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 438
 439         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 440         es->s_last_error_block = cpu_to_le64(block);
 441         save_error_info(inode->i_sb, function, line);
 442         va_start(args, fmt);
 443         vaf.fmt = fmt;
 444         vaf.va = &args;
 445         if (block)
 446                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 447                        "inode #%lu: block %llu: comm %s: %pV\n",
 448                        inode->i_sb->s_id, function, line, inode->i_ino,
 449                        block, current->comm, &vaf);
 450         else
 451                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 452                        "inode #%lu: comm %s: %pV\n",
 453                        inode->i_sb->s_id, function, line, inode->i_ino,
 454                        current->comm, &vaf);
 455         va_end(args);
 456
 457         ext4_handle_error(inode->i_sb);
 458 }
 459
 460 void __ext4_error_file(struct file *file, const char *function,
 461                        unsigned int line, ext4_fsblk_t block,
 462                        const char *fmt, ...)
 463 {
 464         va_list args;
 465         struct va_format vaf;
 466         struct ext4_super_block *es;
 467         struct inode *inode = file_inode(file);
 468         char pathname[80], *path;
 469
 470         es = EXT4_SB(inode->i_sb)->s_es;
 471         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 472         save_error_info(inode->i_sb, function, line);
 473         path = d_path(&(file->f_path), pathname, sizeof(pathname));
 474         if (IS_ERR(path))
 475                 path = "(unknown)";
 476         va_start(args, fmt);
 477         vaf.fmt = fmt;
 478         vaf.va = &args;
 479         if (block)
 480                 printk(KERN_CRIT
 481                        "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 482                        "block %llu: comm %s: path %s: %pV\n",
 483                        inode->i_sb->s_id, function, line, inode->i_ino,
 484                        block, current->comm, path, &vaf);
 485         else
 486                 printk(KERN_CRIT
 487                        "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 488                        "comm %s: path %s: %pV\n",
 489                        inode->i_sb->s_id, function, line, inode->i_ino,
 490                        current->comm, path, &vaf);
 491         va_end(args);
 492
 493         ext4_handle_error(inode->i_sb);
 494 }
 495
 496 const char *ext4_decode_error(struct super_block *sb, int errno,
 497                               char nbuf[16])
 498 {
 499         char *errstr = NULL;
 500
 501         switch (errno) {
 502         case -EIO:
 503                 errstr = "IO failure";
 504                 break;
 505         case -ENOMEM:
 506                 errstr = "Out of memory";
 507                 break;
 508         case -EROFS:
 509                 if (!sb || (EXT4_SB(sb)->s_journal &&
 510                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 511                         errstr = "Journal has aborted";
 512                 else
 513                         errstr = "Readonly filesystem";
 514                 break;
 515         default:
 516                 /* If the caller passed in an extra buffer for unknown
 517                  * errors, textualise them now.  Else we just return
 518                  * NULL. */
 519                 if (nbuf) {
 520                         /* Check for truncated error codes... */
 521                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 522                                 errstr = nbuf;
 523                 }
 524                 break;
 525         }
 526
 527         return errstr;
 528 }
 529
 530 /* __ext4_std_error decodes expected errors from journaling functions
 531  * automatically and invokes the appropriate error response.  */
 532
 533 void __ext4_std_error(struct super_block *sb, const char *function,
 534                       unsigned int line, int errno)
 535 {
 536         char nbuf[16];
 537         const char *errstr;
 538
 539         /* Special case: if the error is EROFS, and we're not already
 540          * inside a transaction, then there's really no point in logging
 541          * an error. */
 542         if (errno == -EROFS && journal_current_handle() == NULL &&
 543             (sb->s_flags & MS_RDONLY))
 544                 return;
 545
 546         errstr = ext4_decode_error(sb, errno, nbuf);
 547         printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 548                sb->s_id, function, line, errstr);
 549         save_error_info(sb, function, line);
 550
 551         ext4_handle_error(sb);
 552 }
 553
 554 /*
 555  * ext4_abort is a much stronger failure handler than ext4_error.  The
 556  * abort function may be used to deal with unrecoverable failures such
 557  * as journal IO errors or ENOMEM at a critical moment in log management.
 558  *
 559  * We unconditionally force the filesystem into an ABORT|READONLY state,
 560  * unless the error response on the fs has been set to panic in which
 561  * case we take the easy way out and panic immediately.
 562  */
 563
 564 void __ext4_abort(struct super_block *sb, const char *function,
 565                 unsigned int line, const char *fmt, ...)
 566 {
 567         va_list args;
 568
 569         save_error_info(sb, function, line);
 570         va_start(args, fmt);
 571         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 572                function, line);
 573         vprintk(fmt, args);
 574         printk("\n");
 575         va_end(args);
 576
 577         if ((sb->s_flags & MS_RDONLY) == 0) {
 578                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 579                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 580                 /*
 581                  * Make sure updated value of ->s_mount_flags will be visible
 582                  * before ->s_flags update
 583                  */
 584                 smp_wmb();
 585                 sb->s_flags |= MS_RDONLY;
 586                 if (EXT4_SB(sb)->s_journal)
 587                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 588                 save_error_info(sb, function, line);
 589         }
 590         if (test_opt(sb, ERRORS_PANIC))
 591                 panic("EXT4-fs panic from previous error\n");
 592 }
 593
 594 void __ext4_msg(struct super_block *sb,
 595                 const char *prefix, const char *fmt, ...)
 596 {
 597         struct va_format vaf;
 598         va_list args;
 599
 600         va_start(args, fmt);
 601         vaf.fmt = fmt;
 602         vaf.va = &args;
 603         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 604         va_end(args);
 605 }
 606
 607 void __ext4_warning(struct super_block *sb, const char *function,
 608                     unsigned int line, const char *fmt, ...)
 609 {
 610         struct va_format vaf;
 611         va_list args;
 612
 613         va_start(args, fmt);
 614         vaf.fmt = fmt;
 615         vaf.va = &args;
 616         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 617                sb->s_id, function, line, &vaf);
 618         va_end(args);
 619 }
 620
 621 void __ext4_grp_locked_error(const char *function, unsigned int line,
 622                              struct super_block *sb, ext4_group_t grp,
 623                              unsigned long ino, ext4_fsblk_t block,
 624                              const char *fmt, ...)
 625 __releases(bitlock)
 626 __acquires(bitlock)
 627 {
 628         struct va_format vaf;
 629         va_list args;
 630         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 631
 632         es->s_last_error_ino = cpu_to_le32(ino);
 633         es->s_last_error_block = cpu_to_le64(block);
 634         __save_error_info(sb, function, line);
 635
 636         va_start(args, fmt);
 637
 638         vaf.fmt = fmt;
 639         vaf.va = &args;
 640         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 641                sb->s_id, function, line, grp);
 642         if (ino)
 643                 printk(KERN_CONT "inode %lu: ", ino);
 644         if (block)
 645                 printk(KERN_CONT "block %llu:", (unsigned long long) block);
 646         printk(KERN_CONT "%pV\n", &vaf);
 647         va_end(args);
 648
 649         if (test_opt(sb, ERRORS_CONT)) {
 650                 ext4_commit_super(sb, 0);
 651                 return;
 652         }
 653
 654         ext4_unlock_group(sb, grp);
 655         ext4_handle_error(sb);
 656         /*
 657          * We only get here in the ERRORS_RO case; relocking the group
 658          * may be dangerous, but nothing bad will happen since the
 659          * filesystem will have already been marked read/only and the
 660          * journal has been aborted.  We return 1 as a hint to callers
 661          * who might what to use the return value from
 662          * ext4_grp_locked_error() to distinguish between the
 663          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 664          * aggressively from the ext4 function in question, with a
 665          * more appropriate error code.
 666          */
 667         ext4_lock_group(sb, grp);
 668         return;
 669 }
 670
 671 void ext4_update_dynamic_rev(struct super_block *sb)
 672 {
 673         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 674
 675         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 676                 return;
 677
 678         ext4_warning(sb,
 679                      "updating to rev %d because of new feature flag, "
 680                      "running e2fsck is recommended",
 681                      EXT4_DYNAMIC_REV);
 682
 683         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 684         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 685         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 686         /* leave es->s_feature_*compat flags alone */
 687         /* es->s_uuid will be set by e2fsck if empty */
 688
 689         /*
 690          * The rest of the superblock fields should be zero, and if not it
 691          * means they are likely already in use, so leave them alone.  We
 692          * can leave it up to e2fsck to clean up any inconsistencies there.
 693          */
 694 }
 695
 696 /*
 697  * Open the external journal device
 698  */
 699 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 700 {
 701         struct block_device *bdev;
 702         char b[BDEVNAME_SIZE];
 703
 704         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 705         if (IS_ERR(bdev))
 706                 goto fail;
 707         return bdev;
 708
 709 fail:
 710         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 711                         __bdevname(dev, b), PTR_ERR(bdev));
 712         return NULL;
 713 }
 714
 715 /*
 716  * Release the journal device
 717  */
 718 static void ext4_blkdev_put(struct block_device *bdev)
 719 {
 720         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 721 }
 722
 723 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 724 {
 725         struct block_device *bdev;
 726         bdev = sbi->journal_bdev;
 727         if (bdev) {
 728                 ext4_blkdev_put(bdev);
 729                 sbi->journal_bdev = NULL;
 730         }
 731 }
 732
 733 static inline struct inode *orphan_list_entry(struct list_head *l)
 734 {
 735         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 736 }
 737
 738 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 739 {
 740         struct list_head *l;
 741
 742         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 743                  le32_to_cpu(sbi->s_es->s_last_orphan));
 744
 745         printk(KERN_ERR "sb_info orphan list:\n");
 746         list_for_each(l, &sbi->s_orphan) {
 747                 struct inode *inode = orphan_list_entry(l);
 748                 printk(KERN_ERR "  "
 749                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 750                        inode->i_sb->s_id, inode->i_ino, inode,
 751                        inode->i_mode, inode->i_nlink,
 752                        NEXT_ORPHAN(inode));
 753         }
 754 }
 755
 756 static void ext4_put_super(struct super_block *sb)
 757 {
 758         struct ext4_sb_info *sbi = EXT4_SB(sb);
 759         struct ext4_super_block *es = sbi->s_es;
 760         int i, err;
 761
 762         ext4_unregister_li_request(sb);
 763         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 764
 765         flush_workqueue(sbi->rsv_conversion_wq);
 766         destroy_workqueue(sbi->rsv_conversion_wq);
 767
 768         if (sbi->s_journal) {
 769                 err = jbd2_journal_destroy(sbi->s_journal);
 770                 sbi->s_journal = NULL;
 771                 if (err < 0)
 772                         ext4_abort(sb, "Couldn't clean up the journal");
 773         }
 774
 775         ext4_es_unregister_shrinker(sbi);
 776         del_timer(&sbi->s_err_report);
 777         ext4_release_system_zone(sb);
 778         ext4_mb_release(sb);
 779         ext4_ext_release(sb);
 780         ext4_xattr_put_super(sb);
 781
 782         if (!(sb->s_flags & MS_RDONLY)) {
 783                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 784                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 785         }
 786         if (!(sb->s_flags & MS_RDONLY))
 787                 ext4_commit_super(sb, 1);
 788
 789         if (sbi->s_proc) {
 790                 remove_proc_entry("options", sbi->s_proc);
 791                 remove_proc_entry(sb->s_id, ext4_proc_root);
 792         }
 793         kobject_del(&sbi->s_kobj);
 794
 795         for (i = 0; i < sbi->s_gdb_count; i++)
 796                 brelse(sbi->s_group_desc[i]);
 797         ext4_kvfree(sbi->s_group_desc);
 798         ext4_kvfree(sbi->s_flex_groups);
 799         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 800         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 801         percpu_counter_destroy(&sbi->s_dirs_counter);
 802         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 803         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
 804         brelse(sbi->s_sbh);
 805 #ifdef CONFIG_QUOTA
 806         for (i = 0; i < MAXQUOTAS; i++)
 807                 kfree(sbi->s_qf_names[i]);
 808 #endif
 809
 810         /* Debugging code just in case the in-memory inode orphan list
 811          * isn't empty.  The on-disk one can be non-empty if we've
 812          * detected an error and taken the fs readonly, but the
 813          * in-memory list had better be clean by this point. */
 814         if (!list_empty(&sbi->s_orphan))
 815                 dump_orphan_list(sb, sbi);
 816         J_ASSERT(list_empty(&sbi->s_orphan));
 817
 818         invalidate_bdev(sb->s_bdev);
 819         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 820                 /*
 821                  * Invalidate the journal device's buffers.  We don't want them
 822                  * floating about in memory - the physical journal device may
 823                  * hotswapped, and it breaks the `ro-after' testing code.
 824                  */
 825                 sync_blockdev(sbi->journal_bdev);
 826                 invalidate_bdev(sbi->journal_bdev);
 827                 ext4_blkdev_remove(sbi);
 828         }
 829         if (sbi->s_mmp_tsk)
 830                 kthread_stop(sbi->s_mmp_tsk);
 831         sb->s_fs_info = NULL;
 832         /*
 833          * Now that we are completely done shutting down the
 834          * superblock, we need to actually destroy the kobject.
 835          */
 836         kobject_put(&sbi->s_kobj);
 837         wait_for_completion(&sbi->s_kobj_unregister);
 838         if (sbi->s_chksum_driver)
 839                 crypto_free_shash(sbi->s_chksum_driver);
 840         kfree(sbi->s_blockgroup_lock);
 841         kfree(sbi);
 842 }
 843
 844 static struct kmem_cache *ext4_inode_cachep;
 845
 846 /*
 847  * Called inside transaction, so use GFP_NOFS
 848  */
 849 static struct inode *ext4_alloc_inode(struct super_block *sb)
 850 {
 851         struct ext4_inode_info *ei;
 852
 853         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 854         if (!ei)
 855                 return NULL;
 856
 857         ei->vfs_inode.i_version = 1;
 858         INIT_LIST_HEAD(&ei->i_prealloc_list);
 859         spin_lock_init(&ei->i_prealloc_lock);
 860         ext4_es_init_tree(&ei->i_es_tree);
 861         rwlock_init(&ei->i_es_lock);
 862         INIT_LIST_HEAD(&ei->i_es_lru);
 863         ei->i_es_lru_nr = 0;
 864         ei->i_touch_when = 0;
 865         ei->i_reserved_data_blocks = 0;
 866         ei->i_reserved_meta_blocks = 0;
 867         ei->i_allocated_meta_blocks = 0;
 868         ei->i_da_metadata_calc_len = 0;
 869         ei->i_da_metadata_calc_last_lblock = 0;
 870         spin_lock_init(&(ei->i_block_reservation_lock));
 871 #ifdef CONFIG_QUOTA
 872         ei->i_reserved_quota = 0;
 873 #endif
 874         ei->jinode = NULL;
 875         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 876         spin_lock_init(&ei->i_completed_io_lock);
 877         ei->i_sync_tid = 0;
 878         ei->i_datasync_tid = 0;
 879         atomic_set(&ei->i_ioend_count, 0);
 880         atomic_set(&ei->i_unwritten, 0);
 881         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 882
 883         return &ei->vfs_inode;
 884 }
 885
 886 static int ext4_drop_inode(struct inode *inode)
 887 {
 888         int drop = generic_drop_inode(inode);
 889
 890         trace_ext4_drop_inode(inode, drop);
 891         return drop;
 892 }
 893
 894 static void ext4_i_callback(struct rcu_head *head)
 895 {
 896         struct inode *inode = container_of(head, struct inode, i_rcu);
 897         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 898 }
 899
 900 static void ext4_destroy_inode(struct inode *inode)
 901 {
 902         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 903                 ext4_msg(inode->i_sb, KERN_ERR,
 904                          "Inode %lu (%p): orphan list check failed!",
 905                          inode->i_ino, EXT4_I(inode));
 906                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 907                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 908                                 true);
 909                 dump_stack();
 910         }
 911         call_rcu(&inode->i_rcu, ext4_i_callback);
 912 }
 913
 914 static void init_once(void *foo)
 915 {
 916         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 917
 918         INIT_LIST_HEAD(&ei->i_orphan);
 919         init_rwsem(&ei->xattr_sem);
 920         init_rwsem(&ei->i_data_sem);
 921         inode_init_once(&ei->vfs_inode);
 922 }
 923
 924 static int init_inodecache(void)
 925 {
 926         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 927                                              sizeof(struct ext4_inode_info),
 928                                              0, (SLAB_RECLAIM_ACCOUNT|
 929                                                 SLAB_MEM_SPREAD),
 930                                              init_once);
 931         if (ext4_inode_cachep == NULL)
 932                 return -ENOMEM;
 933         return 0;
 934 }
 935
 936 static void destroy_inodecache(void)
 937 {
 938         /*
 939          * Make sure all delayed rcu free inodes are flushed before we
 940          * destroy cache.
 941          */
 942         rcu_barrier();
 943         kmem_cache_destroy(ext4_inode_cachep);
 944 }
 945
 946 void ext4_clear_inode(struct inode *inode)
 947 {
 948         invalidate_inode_buffers(inode);
 949         clear_inode(inode);
 950         dquot_drop(inode);
 951         ext4_discard_preallocations(inode);
 952         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 953         ext4_es_lru_del(inode);
 954         if (EXT4_I(inode)->jinode) {
 955                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 956                                                EXT4_I(inode)->jinode);
 957                 jbd2_free_inode(EXT4_I(inode)->jinode);
 958                 EXT4_I(inode)->jinode = NULL;
 959         }
 960 }
 961
 962 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 963                                         u64 ino, u32 generation)
 964 {
 965         struct inode *inode;
 966
 967         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 968                 return ERR_PTR(-ESTALE);
 969         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 970                 return ERR_PTR(-ESTALE);
 971
 972         /* iget isn't really right if the inode is currently unallocated!!
 973          *
 974          * ext4_read_inode will return a bad_inode if the inode had been
 975          * deleted, so we should be safe.
 976          *
 977          * Currently we don't know the generation for parent directory, so
 978          * a generation of 0 means "accept any"
 979          */
 980         inode = ext4_iget(sb, ino);
 981         if (IS_ERR(inode))
 982                 return ERR_CAST(inode);
 983         if (generation && inode->i_generation != generation) {
 984                 iput(inode);
 985                 return ERR_PTR(-ESTALE);
 986         }
 987
 988         return inode;
 989 }
 990
 991 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 992                                         int fh_len, int fh_type)
 993 {
 994         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 995                                     ext4_nfs_get_inode);
 996 }
 997
 998 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 999                                         int fh_len, int fh_type)
1000 {
1001         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1002                                     ext4_nfs_get_inode);
1003 }
1004
1005 /*
1006  * Try to release metadata pages (indirect blocks, directories) which are
1007  * mapped via the block device.  Since these pages could have journal heads
1008  * which would prevent try_to_free_buffers() from freeing them, we must use
1009  * jbd2 layer's try_to_free_buffers() function to release them.
1010  */
1011 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1012                                  gfp_t wait)
1013 {
1014         journal_t *journal = EXT4_SB(sb)->s_journal;
1015
1016         WARN_ON(PageChecked(page));
1017         if (!page_has_buffers(page))
1018                 return 0;
1019         if (journal)
1020                 return jbd2_journal_try_to_free_buffers(journal, page,
1021                                                         wait & ~__GFP_WAIT);
1022         return try_to_free_buffers(page);
1023 }
1024
1025 #ifdef CONFIG_QUOTA
1026 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1027 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1028
1029 static int ext4_write_dquot(struct dquot *dquot);
1030 static int ext4_acquire_dquot(struct dquot *dquot);
1031 static int ext4_release_dquot(struct dquot *dquot);
1032 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1033 static int ext4_write_info(struct super_block *sb, int type);
1034 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1035                          struct path *path);
1036 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1037                                  int format_id);
1038 static int ext4_quota_off(struct super_block *sb, int type);
1039 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1040 static int ext4_quota_on_mount(struct super_block *sb, int type);
1041 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1042                                size_t len, loff_t off);
1043 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1044                                 const char *data, size_t len, loff_t off);
1045 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1046                              unsigned int flags);
1047 static int ext4_enable_quotas(struct super_block *sb);
1048
1049 static const struct dquot_operations ext4_quota_operations = {
1050         .get_reserved_space = ext4_get_reserved_space,
1051         .write_dquot    = ext4_write_dquot,
1052         .acquire_dquot  = ext4_acquire_dquot,
1053         .release_dquot  = ext4_release_dquot,
1054         .mark_dirty     = ext4_mark_dquot_dirty,
1055         .write_info     = ext4_write_info,
1056         .alloc_dquot    = dquot_alloc,
1057         .destroy_dquot  = dquot_destroy,
1058 };
1059
1060 static const struct quotactl_ops ext4_qctl_operations = {
1061         .quota_on       = ext4_quota_on,
1062         .quota_off      = ext4_quota_off,
1063         .quota_sync     = dquot_quota_sync,
1064         .get_info       = dquot_get_dqinfo,
1065         .set_info       = dquot_set_dqinfo,
1066         .get_dqblk      = dquot_get_dqblk,
1067         .set_dqblk      = dquot_set_dqblk
1068 };
1069
1070 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1071         .quota_on_meta  = ext4_quota_on_sysfile,
1072         .quota_off      = ext4_quota_off_sysfile,
1073         .quota_sync     = dquot_quota_sync,
1074         .get_info       = dquot_get_dqinfo,
1075         .set_info       = dquot_set_dqinfo,
1076         .get_dqblk      = dquot_get_dqblk,
1077         .set_dqblk      = dquot_set_dqblk
1078 };
1079 #endif
1080
1081 static const struct super_operations ext4_sops = {
1082         .alloc_inode    = ext4_alloc_inode,
1083         .destroy_inode  = ext4_destroy_inode,
1084         .write_inode    = ext4_write_inode,
1085         .dirty_inode    = ext4_dirty_inode,
1086         .drop_inode     = ext4_drop_inode,
1087         .evict_inode    = ext4_evict_inode,
1088         .put_super      = ext4_put_super,
1089         .sync_fs        = ext4_sync_fs,
1090         .freeze_fs      = ext4_freeze,
1091         .unfreeze_fs    = ext4_unfreeze,
1092         .statfs         = ext4_statfs,
1093         .remount_fs     = ext4_remount,
1094         .show_options   = ext4_show_options,
1095 #ifdef CONFIG_QUOTA
1096         .quota_read     = ext4_quota_read,
1097         .quota_write    = ext4_quota_write,
1098 #endif
1099         .bdev_try_to_free_page = bdev_try_to_free_page,
1100 };
1101
1102 static const struct super_operations ext4_nojournal_sops = {
1103         .alloc_inode    = ext4_alloc_inode,
1104         .destroy_inode  = ext4_destroy_inode,
1105         .write_inode    = ext4_write_inode,
1106         .dirty_inode    = ext4_dirty_inode,
1107         .drop_inode     = ext4_drop_inode,
1108         .evict_inode    = ext4_evict_inode,
1109         .sync_fs        = ext4_sync_fs_nojournal,
1110         .put_super      = ext4_put_super,
1111         .statfs         = ext4_statfs,
1112         .remount_fs     = ext4_remount,
1113         .show_options   = ext4_show_options,
1114 #ifdef CONFIG_QUOTA
1115         .quota_read     = ext4_quota_read,
1116         .quota_write    = ext4_quota_write,
1117 #endif
1118         .bdev_try_to_free_page = bdev_try_to_free_page,
1119 };
1120
1121 static const struct export_operations ext4_export_ops = {
1122         .fh_to_dentry = ext4_fh_to_dentry,
1123         .fh_to_parent = ext4_fh_to_parent,
1124         .get_parent = ext4_get_parent,
1125 };
1126
1127 enum {
1128         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1129         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1130         Opt_nouid32, Opt_debug, Opt_removed,
1131         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1132         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1133         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1134         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1135         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1136         Opt_data_err_abort, Opt_data_err_ignore,
1137         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1138         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1139         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1140         Opt_usrquota, Opt_grpquota, Opt_i_version,
1141         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1142         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1143         Opt_inode_readahead_blks, Opt_journal_ioprio,
1144         Opt_dioread_nolock, Opt_dioread_lock,
1145         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1146         Opt_max_dir_size_kb,
1147 };
1148
1149 static const match_table_t tokens = {
1150         {Opt_bsd_df, "bsddf"},
1151         {Opt_minix_df, "minixdf"},
1152         {Opt_grpid, "grpid"},
1153         {Opt_grpid, "bsdgroups"},
1154         {Opt_nogrpid, "nogrpid"},
1155         {Opt_nogrpid, "sysvgroups"},
1156         {Opt_resgid, "resgid=%u"},
1157         {Opt_resuid, "resuid=%u"},
1158         {Opt_sb, "sb=%u"},
1159         {Opt_err_cont, "errors=continue"},
1160         {Opt_err_panic, "errors=panic"},
1161         {Opt_err_ro, "errors=remount-ro"},
1162         {Opt_nouid32, "nouid32"},
1163         {Opt_debug, "debug"},
1164         {Opt_removed, "oldalloc"},
1165         {Opt_removed, "orlov"},
1166         {Opt_user_xattr, "user_xattr"},
1167         {Opt_nouser_xattr, "nouser_xattr"},
1168         {Opt_acl, "acl"},
1169         {Opt_noacl, "noacl"},
1170         {Opt_noload, "norecovery"},
1171         {Opt_noload, "noload"},
1172         {Opt_removed, "nobh"},
1173         {Opt_removed, "bh"},
1174         {Opt_commit, "commit=%u"},
1175         {Opt_min_batch_time, "min_batch_time=%u"},
1176         {Opt_max_batch_time, "max_batch_time=%u"},
1177         {Opt_journal_dev, "journal_dev=%u"},
1178         {Opt_journal_path, "journal_path=%s"},
1179         {Opt_journal_checksum, "journal_checksum"},
1180         {Opt_journal_async_commit, "journal_async_commit"},
1181         {Opt_abort, "abort"},
1182         {Opt_data_journal, "data=journal"},
1183         {Opt_data_ordered, "data=ordered"},
1184         {Opt_data_writeback, "data=writeback"},
1185         {Opt_data_err_abort, "data_err=abort"},
1186         {Opt_data_err_ignore, "data_err=ignore"},
1187         {Opt_offusrjquota, "usrjquota="},
1188         {Opt_usrjquota, "usrjquota=%s"},
1189         {Opt_offgrpjquota, "grpjquota="},
1190         {Opt_grpjquota, "grpjquota=%s"},
1191         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1192         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1193         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1194         {Opt_grpquota, "grpquota"},
1195         {Opt_noquota, "noquota"},
1196         {Opt_quota, "quota"},
1197         {Opt_usrquota, "usrquota"},
1198         {Opt_barrier, "barrier=%u"},
1199         {Opt_barrier, "barrier"},
1200         {Opt_nobarrier, "nobarrier"},
1201         {Opt_i_version, "i_version"},
1202         {Opt_stripe, "stripe=%u"},
1203         {Opt_delalloc, "delalloc"},
1204         {Opt_nodelalloc, "nodelalloc"},
1205         {Opt_removed, "mblk_io_submit"},
1206         {Opt_removed, "nomblk_io_submit"},
1207         {Opt_block_validity, "block_validity"},
1208         {Opt_noblock_validity, "noblock_validity"},
1209         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1210         {Opt_journal_ioprio, "journal_ioprio=%u"},
1211         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1212         {Opt_auto_da_alloc, "auto_da_alloc"},
1213         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1214         {Opt_dioread_nolock, "dioread_nolock"},
1215         {Opt_dioread_lock, "dioread_lock"},
1216         {Opt_discard, "discard"},
1217         {Opt_nodiscard, "nodiscard"},
1218         {Opt_init_itable, "init_itable=%u"},
1219         {Opt_init_itable, "init_itable"},
1220         {Opt_noinit_itable, "noinit_itable"},
1221         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1222         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1223         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1224         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1225         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1226         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1227         {Opt_err, NULL},
1228 };
1229
1230 static ext4_fsblk_t get_sb_block(void **data)
1231 {
1232         ext4_fsblk_t    sb_block;
1233         char            *options = (char *) *data;
1234
1235         if (!options || strncmp(options, "sb=", 3) != 0)
1236                 return 1;       /* Default location */
1237
1238         options += 3;
1239         /* TODO: use simple_strtoll with >32bit ext4 */
1240         sb_block = simple_strtoul(options, &options, 0);
1241         if (*options && *options != ',') {
1242                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1243                        (char *) *data);
1244                 return 1;
1245         }
1246         if (*options == ',')
1247                 options++;
1248         *data = (void *) options;
1249
1250         return sb_block;
1251 }
1252
1253 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1254 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1255         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1256
1257 #ifdef CONFIG_QUOTA
1258 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1259 {
1260         struct ext4_sb_info *sbi = EXT4_SB(sb);
1261         char *qname;
1262         int ret = -1;
1263
1264         if (sb_any_quota_loaded(sb) &&
1265                 !sbi->s_qf_names[qtype]) {
1266                 ext4_msg(sb, KERN_ERR,
1267                         "Cannot change journaled "
1268                         "quota options when quota turned on");
1269                 return -1;
1270         }
1271         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1272                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1273                          "when QUOTA feature is enabled");
1274                 return -1;
1275         }
1276         qname = match_strdup(args);
1277         if (!qname) {
1278                 ext4_msg(sb, KERN_ERR,
1279                         "Not enough memory for storing quotafile name");
1280                 return -1;
1281         }
1282         if (sbi->s_qf_names[qtype]) {
1283                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1284                         ret = 1;
1285                 else
1286                         ext4_msg(sb, KERN_ERR,
1287                                  "%s quota file already specified",
1288                                  QTYPE2NAME(qtype));
1289                 goto errout;
1290         }
1291         if (strchr(qname, '/')) {
1292                 ext4_msg(sb, KERN_ERR,
1293                         "quotafile must be on filesystem root");
1294                 goto errout;
1295         }
1296         sbi->s_qf_names[qtype] = qname;
1297         set_opt(sb, QUOTA);
1298         return 1;
1299 errout:
1300         kfree(qname);
1301         return ret;
1302 }
1303
1304 static int clear_qf_name(struct super_block *sb, int qtype)
1305 {
1306
1307         struct ext4_sb_info *sbi = EXT4_SB(sb);
1308
1309         if (sb_any_quota_loaded(sb) &&
1310                 sbi->s_qf_names[qtype]) {
1311                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1312                         " when quota turned on");
1313                 return -1;
1314         }
1315         kfree(sbi->s_qf_names[qtype]);
1316         sbi->s_qf_names[qtype] = NULL;
1317         return 1;
1318 }
1319 #endif
1320
1321 #define MOPT_SET        0x0001
1322 #define MOPT_CLEAR      0x0002
1323 #define MOPT_NOSUPPORT  0x0004
1324 #define MOPT_EXPLICIT   0x0008
1325 #define MOPT_CLEAR_ERR  0x0010
1326 #define MOPT_GTE0       0x0020
1327 #ifdef CONFIG_QUOTA
1328 #define MOPT_Q          0
1329 #define MOPT_QFMT       0x0040
1330 #else
1331 #define MOPT_Q          MOPT_NOSUPPORT
1332 #define MOPT_QFMT       MOPT_NOSUPPORT
1333 #endif
1334 #define MOPT_DATAJ      0x0080
1335 #define MOPT_NO_EXT2    0x0100
1336 #define MOPT_NO_EXT3    0x0200
1337 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1338 #define MOPT_STRING     0x0400
1339
1340 static const struct mount_opts {
1341         int     token;
1342         int     mount_opt;
1343         int     flags;
1344 } ext4_mount_opts[] = {
1345         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1346         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1347         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1348         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1349         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1350         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1351         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1352          MOPT_EXT4_ONLY | MOPT_SET},
1353         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1354          MOPT_EXT4_ONLY | MOPT_CLEAR},
1355         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1356         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1357         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1358          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1359         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1360          MOPT_EXT4_ONLY | MOPT_CLEAR},
1361         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1362          MOPT_EXT4_ONLY | MOPT_SET},
1363         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1364                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1365          MOPT_EXT4_ONLY | MOPT_SET},
1366         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1367         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1368         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1369         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1370         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1371          MOPT_NO_EXT2 | MOPT_SET},
1372         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1373          MOPT_NO_EXT2 | MOPT_CLEAR},
1374         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1375         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1376         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1377         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1378         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1379         {Opt_commit, 0, MOPT_GTE0},
1380         {Opt_max_batch_time, 0, MOPT_GTE0},
1381         {Opt_min_batch_time, 0, MOPT_GTE0},
1382         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1383         {Opt_init_itable, 0, MOPT_GTE0},
1384         {Opt_stripe, 0, MOPT_GTE0},
1385         {Opt_resuid, 0, MOPT_GTE0},
1386         {Opt_resgid, 0, MOPT_GTE0},
1387         {Opt_journal_dev, 0, MOPT_GTE0},
1388         {Opt_journal_path, 0, MOPT_STRING},
1389         {Opt_journal_ioprio, 0, MOPT_GTE0},
1390         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1391         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1392         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1393          MOPT_NO_EXT2 | MOPT_DATAJ},
1394         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1395         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1396 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1397         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1398         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1399 #else
1400         {Opt_acl, 0, MOPT_NOSUPPORT},
1401         {Opt_noacl, 0, MOPT_NOSUPPORT},
1402 #endif
1403         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1404         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1405         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1406         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1407                                                         MOPT_SET | MOPT_Q},
1408         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1409                                                         MOPT_SET | MOPT_Q},
1410         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1411                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1412         {Opt_usrjquota, 0, MOPT_Q},
1413         {Opt_grpjquota, 0, MOPT_Q},
1414         {Opt_offusrjquota, 0, MOPT_Q},
1415         {Opt_offgrpjquota, 0, MOPT_Q},
1416         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1417         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1418         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1419         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1420         {Opt_err, 0, 0}
1421 };
1422
1423 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1424                             substring_t *args, unsigned long *journal_devnum,
1425                             unsigned int *journal_ioprio, int is_remount)
1426 {
1427         struct ext4_sb_info *sbi = EXT4_SB(sb);
1428         const struct mount_opts *m;
1429         kuid_t uid;
1430         kgid_t gid;
1431         int arg = 0;
1432
1433 #ifdef CONFIG_QUOTA
1434         if (token == Opt_usrjquota)
1435                 return set_qf_name(sb, USRQUOTA, &args[0]);
1436         else if (token == Opt_grpjquota)
1437                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1438         else if (token == Opt_offusrjquota)
1439                 return clear_qf_name(sb, USRQUOTA);
1440         else if (token == Opt_offgrpjquota)
1441                 return clear_qf_name(sb, GRPQUOTA);
1442 #endif
1443         switch (token) {
1444         case Opt_noacl:
1445         case Opt_nouser_xattr:
1446                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1447                 break;
1448         case Opt_sb:
1449                 return 1;       /* handled by get_sb_block() */
1450         case Opt_removed:
1451                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1452                 return 1;
1453         case Opt_abort:
1454                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1455                 return 1;
1456         case Opt_i_version:
1457                 sb->s_flags |= MS_I_VERSION;
1458                 return 1;
1459         }
1460
1461         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1462                 if (token == m->token)
1463                         break;
1464
1465         if (m->token == Opt_err) {
1466                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1467                          "or missing value", opt);
1468                 return -1;
1469         }
1470
1471         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1472                 ext4_msg(sb, KERN_ERR,
1473                          "Mount option \"%s\" incompatible with ext2", opt);
1474                 return -1;
1475         }
1476         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1477                 ext4_msg(sb, KERN_ERR,
1478                          "Mount option \"%s\" incompatible with ext3", opt);
1479                 return -1;
1480         }
1481
1482         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1483                 return -1;
1484         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1485                 return -1;
1486         if (m->flags & MOPT_EXPLICIT)
1487                 set_opt2(sb, EXPLICIT_DELALLOC);
1488         if (m->flags & MOPT_CLEAR_ERR)
1489                 clear_opt(sb, ERRORS_MASK);
1490         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1491                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1492                          "options when quota turned on");
1493                 return -1;
1494         }
1495
1496         if (m->flags & MOPT_NOSUPPORT) {
1497                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1498         } else if (token == Opt_commit) {
1499                 if (arg == 0)
1500                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1501                 sbi->s_commit_interval = HZ * arg;
1502         } else if (token == Opt_max_batch_time) {
1503                 if (arg == 0)
1504                         arg = EXT4_DEF_MAX_BATCH_TIME;
1505                 sbi->s_max_batch_time = arg;
1506         } else if (token == Opt_min_batch_time) {
1507                 sbi->s_min_batch_time = arg;
1508         } else if (token == Opt_inode_readahead_blks) {
1509                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1510                         ext4_msg(sb, KERN_ERR,
1511                                  "EXT4-fs: inode_readahead_blks must be "
1512                                  "0 or a power of 2 smaller than 2^31");
1513                         return -1;
1514                 }
1515                 sbi->s_inode_readahead_blks = arg;
1516         } else if (token == Opt_init_itable) {
1517                 set_opt(sb, INIT_INODE_TABLE);
1518                 if (!args->from)
1519                         arg = EXT4_DEF_LI_WAIT_MULT;
1520                 sbi->s_li_wait_mult = arg;
1521         } else if (token == Opt_max_dir_size_kb) {
1522                 sbi->s_max_dir_size_kb = arg;
1523         } else if (token == Opt_stripe) {
1524                 sbi->s_stripe = arg;
1525         } else if (token == Opt_resuid) {
1526                 uid = make_kuid(current_user_ns(), arg);
1527                 if (!uid_valid(uid)) {
1528                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1529                         return -1;
1530                 }
1531                 sbi->s_resuid = uid;
1532         } else if (token == Opt_resgid) {
1533                 gid = make_kgid(current_user_ns(), arg);
1534                 if (!gid_valid(gid)) {
1535                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1536                         return -1;
1537                 }
1538                 sbi->s_resgid = gid;
1539         } else if (token == Opt_journal_dev) {
1540                 if (is_remount) {
1541                         ext4_msg(sb, KERN_ERR,
1542                                  "Cannot specify journal on remount");
1543                         return -1;
1544                 }
1545                 *journal_devnum = arg;
1546         } else if (token == Opt_journal_path) {
1547                 char *journal_path;
1548                 struct inode *journal_inode;
1549                 struct path path;
1550                 int error;
1551
1552                 if (is_remount) {
1553                         ext4_msg(sb, KERN_ERR,
1554                                  "Cannot specify journal on remount");
1555                         return -1;
1556                 }
1557                 journal_path = match_strdup(&args[0]);
1558                 if (!journal_path) {
1559                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1560                                 "journal device string");
1561                         return -1;
1562                 }
1563
1564                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1565                 if (error) {
1566                         ext4_msg(sb, KERN_ERR, "error: could not find "
1567                                 "journal device path: error %d", error);
1568                         kfree(journal_path);
1569                         return -1;
1570                 }
1571
1572                 journal_inode = path.dentry->d_inode;
1573                 if (!S_ISBLK(journal_inode->i_mode)) {
1574                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1575                                 "is not a block device", journal_path);
1576                         path_put(&path);
1577                         kfree(journal_path);
1578                         return -1;
1579                 }
1580
1581                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1582                 path_put(&path);
1583                 kfree(journal_path);
1584         } else if (token == Opt_journal_ioprio) {
1585                 if (arg > 7) {
1586                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1587                                  " (must be 0-7)");
1588                         return -1;
1589                 }
1590                 *journal_ioprio =
1591                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1592         } else if (m->flags & MOPT_DATAJ) {
1593                 if (is_remount) {
1594                         if (!sbi->s_journal)
1595                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1596                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1597                                 ext4_msg(sb, KERN_ERR,
1598                                          "Cannot change data mode on remount");
1599                                 return -1;
1600                         }
1601                 } else {
1602                         clear_opt(sb, DATA_FLAGS);
1603                         sbi->s_mount_opt |= m->mount_opt;
1604                 }
1605 #ifdef CONFIG_QUOTA
1606         } else if (m->flags & MOPT_QFMT) {
1607                 if (sb_any_quota_loaded(sb) &&
1608                     sbi->s_jquota_fmt != m->mount_opt) {
1609                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1610                                  "quota options when quota turned on");
1611                         return -1;
1612                 }
1613                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1614                                                EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1615                         ext4_msg(sb, KERN_ERR,
1616                                  "Cannot set journaled quota options "
1617                                  "when QUOTA feature is enabled");
1618                         return -1;
1619                 }
1620                 sbi->s_jquota_fmt = m->mount_opt;
1621 #endif
1622         } else {
1623                 if (!args->from)
1624                         arg = 1;
1625                 if (m->flags & MOPT_CLEAR)
1626                         arg = !arg;
1627                 else if (unlikely(!(m->flags & MOPT_SET))) {
1628                         ext4_msg(sb, KERN_WARNING,
1629                                  "buggy handling of option %s", opt);
1630                         WARN_ON(1);
1631                         return -1;
1632                 }
1633                 if (arg != 0)
1634                         sbi->s_mount_opt |= m->mount_opt;
1635                 else
1636                         sbi->s_mount_opt &= ~m->mount_opt;
1637         }
1638         return 1;
1639 }
1640
1641 static int parse_options(char *options, struct super_block *sb,
1642                          unsigned long *journal_devnum,
1643                          unsigned int *journal_ioprio,
1644                          int is_remount)
1645 {
1646         struct ext4_sb_info *sbi = EXT4_SB(sb);
1647         char *p;
1648         substring_t args[MAX_OPT_ARGS];
1649         int token;
1650
1651         if (!options)
1652                 return 1;
1653
1654         while ((p = strsep(&options, ",")) != NULL) {
1655                 if (!*p)
1656                         continue;
1657                 /*
1658                  * Initialize args struct so we know whether arg was
1659                  * found; some options take optional arguments.
1660                  */
1661                 args[0].to = args[0].from = NULL;
1662                 token = match_token(p, tokens, args);
1663                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1664                                      journal_ioprio, is_remount) < 0)
1665                         return 0;
1666         }
1667 #ifdef CONFIG_QUOTA
1668         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1669             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1670                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1671                          "feature is enabled");
1672                 return 0;
1673         }
1674         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1675                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1676                         clear_opt(sb, USRQUOTA);
1677
1678                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1679                         clear_opt(sb, GRPQUOTA);
1680
1681                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1682                         ext4_msg(sb, KERN_ERR, "old and new quota "
1683                                         "format mixing");
1684                         return 0;
1685                 }
1686
1687                 if (!sbi->s_jquota_fmt) {
1688                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1689                                         "not specified");
1690                         return 0;
1691                 }
1692         } else {
1693                 if (sbi->s_jquota_fmt) {
1694                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1695                                         "specified with no journaling "
1696                                         "enabled");
1697                         return 0;
1698                 }
1699         }
1700 #endif
1701         if (test_opt(sb, DIOREAD_NOLOCK)) {
1702                 int blocksize =
1703                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1704
1705                 if (blocksize < PAGE_CACHE_SIZE) {
1706                         ext4_msg(sb, KERN_ERR, "can't mount with "
1707                                  "dioread_nolock if block size != PAGE_SIZE");
1708                         return 0;
1709                 }
1710         }
1711         return 1;
1712 }
1713
1714 static inline void ext4_show_quota_options(struct seq_file *seq,
1715                                            struct super_block *sb)
1716 {
1717 #if defined(CONFIG_QUOTA)
1718         struct ext4_sb_info *sbi = EXT4_SB(sb);
1719
1720         if (sbi->s_jquota_fmt) {
1721                 char *fmtname = "";
1722
1723                 switch (sbi->s_jquota_fmt) {
1724                 case QFMT_VFS_OLD:
1725                         fmtname = "vfsold";
1726                         break;
1727                 case QFMT_VFS_V0:
1728                         fmtname = "vfsv0";
1729                         break;
1730                 case QFMT_VFS_V1:
1731                         fmtname = "vfsv1";
1732                         break;
1733                 }
1734                 seq_printf(seq, ",jqfmt=%s", fmtname);
1735         }
1736
1737         if (sbi->s_qf_names[USRQUOTA])
1738                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1739
1740         if (sbi->s_qf_names[GRPQUOTA])
1741                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1742 #endif
1743 }
1744
1745 static const char *token2str(int token)
1746 {
1747         const struct match_token *t;
1748
1749         for (t = tokens; t->token != Opt_err; t++)
1750                 if (t->token == token && !strchr(t->pattern, '='))
1751                         break;
1752         return t->pattern;
1753 }
1754
1755 /*
1756  * Show an option if
1757  *  - it's set to a non-default value OR
1758  *  - if the per-sb default is different from the global default
1759  */
1760 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1761                               int nodefs)
1762 {
1763         struct ext4_sb_info *sbi = EXT4_SB(sb);
1764         struct ext4_super_block *es = sbi->s_es;
1765         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1766         const struct mount_opts *m;
1767         char sep = nodefs ? '\n' : ',';
1768
1769 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1770 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1771
1772         if (sbi->s_sb_block != 1)
1773                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1774
1775         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1776                 int want_set = m->flags & MOPT_SET;
1777                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1778                     (m->flags & MOPT_CLEAR_ERR))
1779                         continue;
1780                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1781                         continue; /* skip if same as the default */
1782                 if ((want_set &&
1783                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1784                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1785                         continue; /* select Opt_noFoo vs Opt_Foo */
1786                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1787         }
1788
1789         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1790             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1791                 SEQ_OPTS_PRINT("resuid=%u",
1792                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1793         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1794             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1795                 SEQ_OPTS_PRINT("resgid=%u",
1796                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1797         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1798         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1799                 SEQ_OPTS_PUTS("errors=remount-ro");
1800         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1801                 SEQ_OPTS_PUTS("errors=continue");
1802         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1803                 SEQ_OPTS_PUTS("errors=panic");
1804         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1805                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1806         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1807                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1808         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1809                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1810         if (sb->s_flags & MS_I_VERSION)
1811                 SEQ_OPTS_PUTS("i_version");
1812         if (nodefs || sbi->s_stripe)
1813                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1814         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1815                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1816                         SEQ_OPTS_PUTS("data=journal");
1817                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1818                         SEQ_OPTS_PUTS("data=ordered");
1819                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1820                         SEQ_OPTS_PUTS("data=writeback");
1821         }
1822         if (nodefs ||
1823             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1824                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1825                                sbi->s_inode_readahead_blks);
1826
1827         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1828                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1829                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1830         if (nodefs || sbi->s_max_dir_size_kb)
1831                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1832
1833         ext4_show_quota_options(seq, sb);
1834         return 0;
1835 }
1836
1837 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1838 {
1839         return _ext4_show_options(seq, root->d_sb, 0);
1840 }
1841
1842 static int options_seq_show(struct seq_file *seq, void *offset)
1843 {
1844         struct super_block *sb = seq->private;
1845         int rc;
1846
1847         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1848         rc = _ext4_show_options(seq, sb, 1);
1849         seq_puts(seq, "\n");
1850         return rc;
1851 }
1852
1853 static int options_open_fs(struct inode *inode, struct file *file)
1854 {
1855         return single_open(file, options_seq_show, PDE_DATA(inode));
1856 }
1857
1858 static const struct file_operations ext4_seq_options_fops = {
1859         .owner = THIS_MODULE,
1860         .open = options_open_fs,
1861         .read = seq_read,
1862         .llseek = seq_lseek,
1863         .release = single_release,
1864 };
1865
1866 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1867                             int read_only)
1868 {
1869         struct ext4_sb_info *sbi = EXT4_SB(sb);
1870         int res = 0;
1871
1872         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1873                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1874                          "forcing read-only mode");
1875                 res = MS_RDONLY;
1876         }
1877         if (read_only)
1878                 goto done;
1879         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1880                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1881                          "running e2fsck is recommended");
1882         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1883                 ext4_msg(sb, KERN_WARNING,
1884                          "warning: mounting fs with errors, "
1885                          "running e2fsck is recommended");
1886         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1887                  le16_to_cpu(es->s_mnt_count) >=
1888                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1889                 ext4_msg(sb, KERN_WARNING,
1890                          "warning: maximal mount count reached, "
1891                          "running e2fsck is recommended");
1892         else if (le32_to_cpu(es->s_checkinterval) &&
1893                 (le32_to_cpu(es->s_lastcheck) +
1894                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1895                 ext4_msg(sb, KERN_WARNING,
1896                          "warning: checktime reached, "
1897                          "running e2fsck is recommended");
1898         if (!sbi->s_journal)
1899                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1900         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1901                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1902         le16_add_cpu(&es->s_mnt_count, 1);
1903         es->s_mtime = cpu_to_le32(get_seconds());
1904         ext4_update_dynamic_rev(sb);
1905         if (sbi->s_journal)
1906                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1907
1908         ext4_commit_super(sb, 1);
1909 done:
1910         if (test_opt(sb, DEBUG))
1911                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1912                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1913                         sb->s_blocksize,
1914                         sbi->s_groups_count,
1915                         EXT4_BLOCKS_PER_GROUP(sb),
1916                         EXT4_INODES_PER_GROUP(sb),
1917                         sbi->s_mount_opt, sbi->s_mount_opt2);
1918
1919         cleancache_init_fs(sb);
1920         return res;
1921 }
1922
1923 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1924 {
1925         struct ext4_sb_info *sbi = EXT4_SB(sb);
1926         struct flex_groups *new_groups;
1927         int size;
1928
1929         if (!sbi->s_log_groups_per_flex)
1930                 return 0;
1931
1932         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1933         if (size <= sbi->s_flex_groups_allocated)
1934                 return 0;
1935
1936         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1937         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1938         if (!new_groups) {
1939                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1940                          size / (int) sizeof(struct flex_groups));
1941                 return -ENOMEM;
1942         }
1943
1944         if (sbi->s_flex_groups) {
1945                 memcpy(new_groups, sbi->s_flex_groups,
1946                        (sbi->s_flex_groups_allocated *
1947                         sizeof(struct flex_groups)));
1948                 ext4_kvfree(sbi->s_flex_groups);
1949         }
1950         sbi->s_flex_groups = new_groups;
1951         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1952         return 0;
1953 }
1954
1955 static int ext4_fill_flex_info(struct super_block *sb)
1956 {
1957         struct ext4_sb_info *sbi = EXT4_SB(sb);
1958         struct ext4_group_desc *gdp = NULL;
1959         ext4_group_t flex_group;
1960         int i, err;
1961
1962         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1963         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1964                 sbi->s_log_groups_per_flex = 0;
1965                 return 1;
1966         }
1967
1968         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1969         if (err)
1970                 goto failed;
1971
1972         for (i = 0; i < sbi->s_groups_count; i++) {
1973                 gdp = ext4_get_group_desc(sb, i, NULL);
1974
1975                 flex_group = ext4_flex_group(sbi, i);
1976                 atomic_add(ext4_free_inodes_count(sb, gdp),
1977                            &sbi->s_flex_groups[flex_group].free_inodes);
1978                 atomic64_add(ext4_free_group_clusters(sb, gdp),
1979                              &sbi->s_flex_groups[flex_group].free_clusters);
1980                 atomic_add(ext4_used_dirs_count(sb, gdp),
1981                            &sbi->s_flex_groups[flex_group].used_dirs);
1982         }
1983
1984         return 1;
1985 failed:
1986         return 0;
1987 }
1988
1989 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1990                                    struct ext4_group_desc *gdp)
1991 {
1992         int offset;
1993         __u16 crc = 0;
1994         __le32 le_group = cpu_to_le32(block_group);
1995
1996         if ((sbi->s_es->s_feature_ro_compat &
1997              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
1998                 /* Use new metadata_csum algorithm */
1999                 __le16 save_csum;
2000                 __u32 csum32;
2001
2002                 save_csum = gdp->bg_checksum;
2003                 gdp->bg_checksum = 0;
2004                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2005                                      sizeof(le_group));
2006                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2007                                      sbi->s_desc_size);
2008                 gdp->bg_checksum = save_csum;
2009
2010                 crc = csum32 & 0xFFFF;
2011                 goto out;
2012         }
2013
2014         /* old crc16 code */
2015         offset = offsetof(struct ext4_group_desc, bg_checksum);
2016
2017         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2018         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2019         crc = crc16(crc, (__u8 *)gdp, offset);
2020         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2021         /* for checksum of struct ext4_group_desc do the rest...*/
2022         if ((sbi->s_es->s_feature_incompat &
2023              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2024             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2025                 crc = crc16(crc, (__u8 *)gdp + offset,
2026                             le16_to_cpu(sbi->s_es->s_desc_size) -
2027                                 offset);
2028
2029 out:
2030         return cpu_to_le16(crc);
2031 }
2032
2033 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2034                                 struct ext4_group_desc *gdp)
2035 {
2036         if (ext4_has_group_desc_csum(sb) &&
2037             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2038                                                       block_group, gdp)))
2039                 return 0;
2040
2041         return 1;
2042 }
2043
2044 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2045                               struct ext4_group_desc *gdp)
2046 {
2047         if (!ext4_has_group_desc_csum(sb))
2048                 return;
2049         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2050 }
2051
2052 /* Called at mount-time, super-block is locked */
2053 static int ext4_check_descriptors(struct super_block *sb,
2054                                   ext4_group_t *first_not_zeroed)
2055 {
2056         struct ext4_sb_info *sbi = EXT4_SB(sb);
2057         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2058         ext4_fsblk_t last_block;
2059         ext4_fsblk_t block_bitmap;
2060         ext4_fsblk_t inode_bitmap;
2061         ext4_fsblk_t inode_table;
2062         int flexbg_flag = 0;
2063         ext4_group_t i, grp = sbi->s_groups_count;
2064
2065         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2066                 flexbg_flag = 1;
2067
2068         ext4_debug("Checking group descriptors");
2069
2070         for (i = 0; i < sbi->s_groups_count; i++) {
2071                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2072
2073                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2074                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2075                 else
2076                         last_block = first_block +
2077                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2078
2079                 if ((grp == sbi->s_groups_count) &&
2080                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2081                         grp = i;
2082
2083                 block_bitmap = ext4_block_bitmap(sb, gdp);
2084                 if (block_bitmap < first_block || block_bitmap > last_block) {
2085                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2086                                "Block bitmap for group %u not in group "
2087                                "(block %llu)!", i, block_bitmap);
2088                         return 0;
2089                 }
2090                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2091                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2092                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2093                                "Inode bitmap for group %u not in group "
2094                                "(block %llu)!", i, inode_bitmap);
2095                         return 0;
2096                 }
2097                 inode_table = ext4_inode_table(sb, gdp);
2098                 if (inode_table < first_block ||
2099                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2100                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2101                                "Inode table for group %u not in group "
2102                                "(block %llu)!", i, inode_table);
2103                         return 0;
2104                 }
2105                 ext4_lock_group(sb, i);
2106                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2107                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2108                                  "Checksum for group %u failed (%u!=%u)",
2109                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2110                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2111                         if (!(sb->s_flags & MS_RDONLY)) {
2112                                 ext4_unlock_group(sb, i);
2113                                 return 0;
2114                         }
2115                 }
2116                 ext4_unlock_group(sb, i);
2117                 if (!flexbg_flag)
2118                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2119         }
2120         if (NULL != first_not_zeroed)
2121                 *first_not_zeroed = grp;
2122
2123         ext4_free_blocks_count_set(sbi->s_es,
2124                                    EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2125         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2126         return 1;
2127 }
2128
2129 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2130  * the superblock) which were deleted from all directories, but held open by
2131  * a process at the time of a crash.  We walk the list and try to delete these
2132  * inodes at recovery time (only with a read-write filesystem).
2133  *
2134  * In order to keep the orphan inode chain consistent during traversal (in
2135  * case of crash during recovery), we link each inode into the superblock
2136  * orphan list_head and handle it the same way as an inode deletion during
2137  * normal operation (which journals the operations for us).
2138  *
2139  * We only do an iget() and an iput() on each inode, which is very safe if we
2140  * accidentally point at an in-use or already deleted inode.  The worst that
2141  * can happen in this case is that we get a "bit already cleared" message from
2142  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2143  * e2fsck was run on this filesystem, and it must have already done the orphan
2144  * inode cleanup for us, so we can safely abort without any further action.
2145  */
2146 static void ext4_orphan_cleanup(struct super_block *sb,
2147                                 struct ext4_super_block *es)
2148 {
2149         unsigned int s_flags = sb->s_flags;
2150         int nr_orphans = 0, nr_truncates = 0;
2151 #ifdef CONFIG_QUOTA
2152         int i;
2153 #endif
2154         if (!es->s_last_orphan) {
2155                 jbd_debug(4, "no orphan inodes to clean up\n");
2156                 return;
2157         }
2158
2159         if (bdev_read_only(sb->s_bdev)) {
2160                 ext4_msg(sb, KERN_ERR, "write access "
2161                         "unavailable, skipping orphan cleanup");
2162                 return;
2163         }
2164
2165         /* Check if feature set would not allow a r/w mount */
2166         if (!ext4_feature_set_ok(sb, 0)) {
2167                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2168                          "unknown ROCOMPAT features");
2169                 return;
2170         }
2171
2172         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2173                 /* don't clear list on RO mount w/ errors */
2174                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2175                         jbd_debug(1, "Errors on filesystem, "
2176                                   "clearing orphan list.\n");
2177                         es->s_last_orphan = 0;
2178                 }
2179                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2180                 return;
2181         }
2182
2183         if (s_flags & MS_RDONLY) {
2184                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2185                 sb->s_flags &= ~MS_RDONLY;
2186         }
2187 #ifdef CONFIG_QUOTA
2188         /* Needed for iput() to work correctly and not trash data */
2189         sb->s_flags |= MS_ACTIVE;
2190         /* Turn on quotas so that they are updated correctly */
2191         for (i = 0; i < MAXQUOTAS; i++) {
2192                 if (EXT4_SB(sb)->s_qf_names[i]) {
2193                         int ret = ext4_quota_on_mount(sb, i);
2194                         if (ret < 0)
2195                                 ext4_msg(sb, KERN_ERR,
2196                                         "Cannot turn on journaled "
2197                                         "quota: error %d", ret);
2198                 }
2199         }
2200 #endif
2201
2202         while (es->s_last_orphan) {
2203                 struct inode *inode;
2204
2205                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2206                 if (IS_ERR(inode)) {
2207                         es->s_last_orphan = 0;
2208                         break;
2209                 }
2210
2211                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2212                 dquot_initialize(inode);
2213                 if (inode->i_nlink) {
2214                         if (test_opt(sb, DEBUG))
2215                                 ext4_msg(sb, KERN_DEBUG,
2216                                         "%s: truncating inode %lu to %lld bytes",
2217                                         __func__, inode->i_ino, inode->i_size);
2218                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2219                                   inode->i_ino, inode->i_size);
2220                         mutex_lock(&inode->i_mutex);
2221                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2222                         ext4_truncate(inode);
2223                         mutex_unlock(&inode->i_mutex);
2224                         nr_truncates++;
2225                 } else {
2226                         if (test_opt(sb, DEBUG))
2227                                 ext4_msg(sb, KERN_DEBUG,
2228                                         "%s: deleting unreferenced inode %lu",
2229                                         __func__, inode->i_ino);
2230                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2231                                   inode->i_ino);
2232                         nr_orphans++;
2233                 }
2234                 iput(inode);  /* The delete magic happens here! */
2235         }
2236
2237 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2238
2239         if (nr_orphans)
2240                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2241                        PLURAL(nr_orphans));
2242         if (nr_truncates)
2243                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2244                        PLURAL(nr_truncates));
2245 #ifdef CONFIG_QUOTA
2246         /* Turn quotas off */
2247         for (i = 0; i < MAXQUOTAS; i++) {
2248                 if (sb_dqopt(sb)->files[i])
2249                         dquot_quota_off(sb, i);
2250         }
2251 #endif
2252         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2253 }
2254
2255 /*
2256  * Maximal extent format file size.
2257  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2258  * extent format containers, within a sector_t, and within i_blocks
2259  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2260  * so that won't be a limiting factor.
2261  *
2262  * However there is other limiting factor. We do store extents in the form
2263  * of starting block and length, hence the resulting length of the extent
2264  * covering maximum file size must fit into on-disk format containers as
2265  * well. Given that length is always by 1 unit bigger than max unit (because
2266  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2267  *
2268  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2269  */
2270 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2271 {
2272         loff_t res;
2273         loff_t upper_limit = MAX_LFS_FILESIZE;
2274
2275         /* small i_blocks in vfs inode? */
2276         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2277                 /*
2278                  * CONFIG_LBDAF is not enabled implies the inode
2279                  * i_block represent total blocks in 512 bytes
2280                  * 32 == size of vfs inode i_blocks * 8
2281                  */
2282                 upper_limit = (1LL << 32) - 1;
2283
2284                 /* total blocks in file system block size */
2285                 upper_limit >>= (blkbits - 9);
2286                 upper_limit <<= blkbits;
2287         }
2288
2289         /*
2290          * 32-bit extent-start container, ee_block. We lower the maxbytes
2291          * by one fs block, so ee_len can cover the extent of maximum file
2292          * size
2293          */
2294         res = (1LL << 32) - 1;
2295         res <<= blkbits;
2296
2297         /* Sanity check against vm- & vfs- imposed limits */
2298         if (res > upper_limit)
2299                 res = upper_limit;
2300
2301         return res;
2302 }
2303
2304 /*
2305  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2306  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2307  * We need to be 1 filesystem block less than the 2^48 sector limit.
2308  */
2309 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2310 {
2311         loff_t res = EXT4_NDIR_BLOCKS;
2312         int meta_blocks;
2313         loff_t upper_limit;
2314         /* This is calculated to be the largest file size for a dense, block
2315          * mapped file such that the file's total number of 512-byte sectors,
2316          * including data and all indirect blocks, does not exceed (2^48 - 1).
2317          *
2318          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2319          * number of 512-byte sectors of the file.
2320          */
2321
2322         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2323                 /*
2324                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2325                  * the inode i_block field represents total file blocks in
2326                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2327                  */
2328                 upper_limit = (1LL << 32) - 1;
2329
2330                 /* total blocks in file system block size */
2331                 upper_limit >>= (bits - 9);
2332
2333         } else {
2334                 /*
2335                  * We use 48 bit ext4_inode i_blocks
2336                  * With EXT4_HUGE_FILE_FL set the i_blocks
2337                  * represent total number of blocks in
2338                  * file system block size
2339                  */
2340                 upper_limit = (1LL << 48) - 1;
2341
2342         }
2343
2344         /* indirect blocks */
2345         meta_blocks = 1;
2346         /* double indirect blocks */
2347         meta_blocks += 1 + (1LL << (bits-2));
2348         /* tripple indirect blocks */
2349         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2350
2351         upper_limit -= meta_blocks;
2352         upper_limit <<= bits;
2353
2354         res += 1LL << (bits-2);
2355         res += 1LL << (2*(bits-2));
2356         res += 1LL << (3*(bits-2));
2357         res <<= bits;
2358         if (res > upper_limit)
2359                 res = upper_limit;
2360
2361         if (res > MAX_LFS_FILESIZE)
2362                 res = MAX_LFS_FILESIZE;
2363
2364         return res;
2365 }
2366
2367 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2368                                    ext4_fsblk_t logical_sb_block, int nr)
2369 {
2370         struct ext4_sb_info *sbi = EXT4_SB(sb);
2371         ext4_group_t bg, first_meta_bg;
2372         int has_super = 0;
2373
2374         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2375
2376         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2377             nr < first_meta_bg)
2378                 return logical_sb_block + nr + 1;
2379         bg = sbi->s_desc_per_block * nr;
2380         if (ext4_bg_has_super(sb, bg))
2381                 has_super = 1;
2382
2383         return (has_super + ext4_group_first_block_no(sb, bg));
2384 }
2385
2386 /**
2387  * ext4_get_stripe_size: Get the stripe size.
2388  * @sbi: In memory super block info
2389  *
2390  * If we have specified it via mount option, then
2391  * use the mount option value. If the value specified at mount time is
2392  * greater than the blocks per group use the super block value.
2393  * If the super block value is greater than blocks per group return 0.
2394  * Allocator needs it be less than blocks per group.
2395  *
2396  */
2397 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2398 {
2399         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2400         unsigned long stripe_width =
2401                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2402         int ret;
2403
2404         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2405                 ret = sbi->s_stripe;
2406         else if (stripe_width <= sbi->s_blocks_per_group)
2407                 ret = stripe_width;
2408         else if (stride <= sbi->s_blocks_per_group)
2409                 ret = stride;
2410         else
2411                 ret = 0;
2412
2413         /*
2414          * If the stripe width is 1, this makes no sense and
2415          * we set it to 0 to turn off stripe handling code.
2416          */
2417         if (ret <= 1)
2418                 ret = 0;
2419
2420         return ret;
2421 }
2422
2423 /* sysfs supprt */
2424
2425 struct ext4_attr {
2426         struct attribute attr;
2427         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2428         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2429                          const char *, size_t);
2430         union {
2431                 int offset;
2432                 int deprecated_val;
2433         } u;
2434 };
2435
2436 static int parse_strtoull(const char *buf,
2437                 unsigned long long max, unsigned long long *value)
2438 {
2439         int ret;
2440
2441         ret = kstrtoull(skip_spaces(buf), 0, value);
2442         if (!ret && *value > max)
2443                 ret = -EINVAL;
2444         return ret;
2445 }
2446
2447 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2448                                               struct ext4_sb_info *sbi,
2449                                               char *buf)
2450 {
2451         return snprintf(buf, PAGE_SIZE, "%llu\n",
2452                 (s64) EXT4_C2B(sbi,
2453                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2454 }
2455
2456 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2457                                          struct ext4_sb_info *sbi, char *buf)
2458 {
2459         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2460
2461         if (!sb->s_bdev->bd_part)
2462                 return snprintf(buf, PAGE_SIZE, "0\n");
2463         return snprintf(buf, PAGE_SIZE, "%lu\n",
2464                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2465                          sbi->s_sectors_written_start) >> 1);
2466 }
2467
2468 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2469                                           struct ext4_sb_info *sbi, char *buf)
2470 {
2471         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2472
2473         if (!sb->s_bdev->bd_part)
2474                 return snprintf(buf, PAGE_SIZE, "0\n");
2475         return snprintf(buf, PAGE_SIZE, "%llu\n",
2476                         (unsigned long long)(sbi->s_kbytes_written +
2477                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2478                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2479 }
2480
2481 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2482                                           struct ext4_sb_info *sbi,
2483                                           const char *buf, size_t count)
2484 {
2485         unsigned long t;
2486         int ret;
2487
2488         ret = kstrtoul(skip_spaces(buf), 0, &t);
2489         if (ret)
2490                 return ret;
2491
2492         if (t && (!is_power_of_2(t) || t > 0x40000000))
2493                 return -EINVAL;
2494
2495         sbi->s_inode_readahead_blks = t;
2496         return count;
2497 }
2498
2499 static ssize_t sbi_ui_show(struct ext4_attr *a,
2500                            struct ext4_sb_info *sbi, char *buf)
2501 {
2502         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2503
2504         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2505 }
2506
2507 static ssize_t sbi_ui_store(struct ext4_attr *a,
2508                             struct ext4_sb_info *sbi,
2509                             const char *buf, size_t count)
2510 {
2511         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2512         unsigned long t;
2513         int ret;
2514
2515         ret = kstrtoul(skip_spaces(buf), 0, &t);
2516         if (ret)
2517                 return ret;
2518         *ui = t;
2519         return count;
2520 }
2521
2522 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2523                                   struct ext4_sb_info *sbi, char *buf)
2524 {
2525         return snprintf(buf, PAGE_SIZE, "%llu\n",
2526                 (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2527 }
2528
2529 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2530                                    struct ext4_sb_info *sbi,
2531                                    const char *buf, size_t count)
2532 {
2533         unsigned long long val;
2534         int ret;
2535
2536         if (parse_strtoull(buf, -1ULL, &val))
2537                 return -EINVAL;
2538         ret = ext4_reserve_clusters(sbi, val);
2539
2540         return ret ? ret : count;
2541 }
2542
2543 static ssize_t trigger_test_error(struct ext4_attr *a,
2544                                   struct ext4_sb_info *sbi,
2545                                   const char *buf, size_t count)
2546 {
2547         int len = count;
2548
2549         if (!capable(CAP_SYS_ADMIN))
2550                 return -EPERM;
2551
2552         if (len && buf[len-1] == '\n')
2553                 len--;
2554
2555         if (len)
2556                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2557         return count;
2558 }
2559
2560 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2561                                    struct ext4_sb_info *sbi, char *buf)
2562 {
2563         return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2564 }
2565
2566 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2567 static struct ext4_attr ext4_attr_##_name = {                   \
2568         .attr = {.name = __stringify(_name), .mode = _mode },   \
2569         .show   = _show,                                        \
2570         .store  = _store,                                       \
2571         .u = {                                                  \
2572                 .offset = offsetof(struct ext4_sb_info, _elname),\
2573         },                                                      \
2574 }
2575 #define EXT4_ATTR(name, mode, show, store) \
2576 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2577
2578 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2579 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2580 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2581 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2582         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2583 #define ATTR_LIST(name) &ext4_attr_##name.attr
2584 #define EXT4_DEPRECATED_ATTR(_name, _val)       \
2585 static struct ext4_attr ext4_attr_##_name = {                   \
2586         .attr = {.name = __stringify(_name), .mode = 0444 },    \
2587         .show   = sbi_deprecated_show,                          \
2588         .u = {                                                  \
2589                 .deprecated_val = _val,                         \
2590         },                                                      \
2591 }
2592
2593 EXT4_RO_ATTR(delayed_allocation_blocks);
2594 EXT4_RO_ATTR(session_write_kbytes);
2595 EXT4_RO_ATTR(lifetime_write_kbytes);
2596 EXT4_RW_ATTR(reserved_clusters);
2597 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2598                  inode_readahead_blks_store, s_inode_readahead_blks);
2599 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2600 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2601 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2602 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2603 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2604 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2605 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2606 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2607 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2608 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2609
2610 static struct attribute *ext4_attrs[] = {
2611         ATTR_LIST(delayed_allocation_blocks),
2612         ATTR_LIST(session_write_kbytes),
2613         ATTR_LIST(lifetime_write_kbytes),
2614         ATTR_LIST(reserved_clusters),
2615         ATTR_LIST(inode_readahead_blks),
2616         ATTR_LIST(inode_goal),
2617         ATTR_LIST(mb_stats),
2618         ATTR_LIST(mb_max_to_scan),
2619         ATTR_LIST(mb_min_to_scan),
2620         ATTR_LIST(mb_order2_req),
2621         ATTR_LIST(mb_stream_req),
2622         ATTR_LIST(mb_group_prealloc),
2623         ATTR_LIST(max_writeback_mb_bump),
2624         ATTR_LIST(extent_max_zeroout_kb),
2625         ATTR_LIST(trigger_fs_error),
2626         NULL,
2627 };
2628
2629 /* Features this copy of ext4 supports */
2630 EXT4_INFO_ATTR(lazy_itable_init);
2631 EXT4_INFO_ATTR(batched_discard);
2632 EXT4_INFO_ATTR(meta_bg_resize);
2633
2634 static struct attribute *ext4_feat_attrs[] = {
2635         ATTR_LIST(lazy_itable_init),
2636         ATTR_LIST(batched_discard),
2637         ATTR_LIST(meta_bg_resize),
2638         NULL,
2639 };
2640
2641 static ssize_t ext4_attr_show(struct kobject *kobj,
2642                               struct attribute *attr, char *buf)
2643 {
2644         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2645                                                 s_kobj);
2646         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2647
2648         return a->show ? a->show(a, sbi, buf) : 0;
2649 }
2650
2651 static ssize_t ext4_attr_store(struct kobject *kobj,
2652                                struct attribute *attr,
2653                                const char *buf, size_t len)
2654 {
2655         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2656                                                 s_kobj);
2657         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2658
2659         return a->store ? a->store(a, sbi, buf, len) : 0;
2660 }
2661
2662 static void ext4_sb_release(struct kobject *kobj)
2663 {
2664         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2665                                                 s_kobj);
2666         complete(&sbi->s_kobj_unregister);
2667 }
2668
2669 static const struct sysfs_ops ext4_attr_ops = {
2670         .show   = ext4_attr_show,
2671         .store  = ext4_attr_store,
2672 };
2673
2674 static struct kobj_type ext4_ktype = {
2675         .default_attrs  = ext4_attrs,
2676         .sysfs_ops      = &ext4_attr_ops,
2677         .release        = ext4_sb_release,
2678 };
2679
2680 static void ext4_feat_release(struct kobject *kobj)
2681 {
2682         complete(&ext4_feat->f_kobj_unregister);
2683 }
2684
2685 static struct kobj_type ext4_feat_ktype = {
2686         .default_attrs  = ext4_feat_attrs,
2687         .sysfs_ops      = &ext4_attr_ops,
2688         .release        = ext4_feat_release,
2689 };
2690
2691 /*
2692  * Check whether this filesystem can be mounted based on
2693  * the features present and the RDONLY/RDWR mount requested.
2694  * Returns 1 if this filesystem can be mounted as requested,
2695  * 0 if it cannot be.
2696  */
2697 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2698 {
2699         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2700                 ext4_msg(sb, KERN_ERR,
2701                         "Couldn't mount because of "
2702                         "unsupported optional features (%x)",
2703                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2704                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2705                 return 0;
2706         }
2707
2708         if (readonly)
2709                 return 1;
2710
2711         /* Check that feature set is OK for a read-write mount */
2712         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2713                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2714                          "unsupported optional features (%x)",
2715                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2716                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2717                 return 0;
2718         }
2719         /*
2720          * Large file size enabled file system can only be mounted
2721          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2722          */
2723         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2724                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2725                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2726                                  "cannot be mounted RDWR without "
2727                                  "CONFIG_LBDAF");
2728                         return 0;
2729                 }
2730         }
2731         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2732             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2733                 ext4_msg(sb, KERN_ERR,
2734                          "Can't support bigalloc feature without "
2735                          "extents feature\n");
2736                 return 0;
2737         }
2738
2739 #ifndef CONFIG_QUOTA
2740         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2741             !readonly) {
2742                 ext4_msg(sb, KERN_ERR,
2743                          "Filesystem with quota feature cannot be mounted RDWR "
2744                          "without CONFIG_QUOTA");
2745                 return 0;
2746         }
2747 #endif  /* CONFIG_QUOTA */
2748         return 1;
2749 }
2750
2751 /*
2752  * This function is called once a day if we have errors logged
2753  * on the file system
2754  */
2755 static void print_daily_error_info(unsigned long arg)
2756 {
2757         struct super_block *sb = (struct super_block *) arg;
2758         struct ext4_sb_info *sbi;
2759         struct ext4_super_block *es;
2760
2761         sbi = EXT4_SB(sb);
2762         es = sbi->s_es;
2763
2764         if (es->s_error_count)
2765                 ext4_msg(sb, KERN_NOTICE, "error count: %u",
2766                          le32_to_cpu(es->s_error_count));
2767         if (es->s_first_error_time) {
2768                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2769                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2770                        (int) sizeof(es->s_first_error_func),
2771                        es->s_first_error_func,
2772                        le32_to_cpu(es->s_first_error_line));
2773                 if (es->s_first_error_ino)
2774                         printk(": inode %u",
2775                                le32_to_cpu(es->s_first_error_ino));
2776                 if (es->s_first_error_block)
2777                         printk(": block %llu", (unsigned long long)
2778                                le64_to_cpu(es->s_first_error_block));
2779                 printk("\n");
2780         }
2781         if (es->s_last_error_time) {
2782                 printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2783                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2784                        (int) sizeof(es->s_last_error_func),
2785                        es->s_last_error_func,
2786                        le32_to_cpu(es->s_last_error_line));
2787                 if (es->s_last_error_ino)
2788                         printk(": inode %u",
2789                                le32_to_cpu(es->s_last_error_ino));
2790                 if (es->s_last_error_block)
2791                         printk(": block %llu", (unsigned long long)
2792                                le64_to_cpu(es->s_last_error_block));
2793                 printk("\n");
2794         }
2795         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2796 }
2797
2798 /* Find next suitable group and run ext4_init_inode_table */
2799 static int ext4_run_li_request(struct ext4_li_request *elr)
2800 {
2801         struct ext4_group_desc *gdp = NULL;
2802         ext4_group_t group, ngroups;
2803         struct super_block *sb;
2804         unsigned long timeout = 0;
2805         int ret = 0;
2806
2807         sb = elr->lr_super;
2808         ngroups = EXT4_SB(sb)->s_groups_count;
2809
2810         sb_start_write(sb);
2811         for (group = elr->lr_next_group; group < ngroups; group++) {
2812                 gdp = ext4_get_group_desc(sb, group, NULL);
2813                 if (!gdp) {
2814                         ret = 1;
2815                         break;
2816                 }
2817
2818                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2819                         break;
2820         }
2821
2822         if (group >= ngroups)
2823                 ret = 1;
2824
2825         if (!ret) {
2826                 timeout = jiffies;
2827                 ret = ext4_init_inode_table(sb, group,
2828                                             elr->lr_timeout ? 0 : 1);
2829                 if (elr->lr_timeout == 0) {
2830                         timeout = (jiffies - timeout) *
2831                                   elr->lr_sbi->s_li_wait_mult;
2832                         elr->lr_timeout = timeout;
2833                 }
2834                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2835                 elr->lr_next_group = group + 1;
2836         }
2837         sb_end_write(sb);
2838
2839         return ret;
2840 }
2841
2842 /*
2843  * Remove lr_request from the list_request and free the
2844  * request structure. Should be called with li_list_mtx held
2845  */
2846 static void ext4_remove_li_request(struct ext4_li_request *elr)
2847 {
2848         struct ext4_sb_info *sbi;
2849
2850         if (!elr)
2851                 return;
2852
2853         sbi = elr->lr_sbi;
2854
2855         list_del(&elr->lr_request);
2856         sbi->s_li_request = NULL;
2857         kfree(elr);
2858 }
2859
2860 static void ext4_unregister_li_request(struct super_block *sb)
2861 {
2862         mutex_lock(&ext4_li_mtx);
2863         if (!ext4_li_info) {
2864                 mutex_unlock(&ext4_li_mtx);
2865                 return;
2866         }
2867
2868         mutex_lock(&ext4_li_info->li_list_mtx);
2869         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2870         mutex_unlock(&ext4_li_info->li_list_mtx);
2871         mutex_unlock(&ext4_li_mtx);
2872 }
2873
2874 static struct task_struct *ext4_lazyinit_task;
2875
2876 /*
2877  * This is the function where ext4lazyinit thread lives. It walks
2878  * through the request list searching for next scheduled filesystem.
2879  * When such a fs is found, run the lazy initialization request
2880  * (ext4_rn_li_request) and keep track of the time spend in this
2881  * function. Based on that time we compute next schedule time of
2882  * the request. When walking through the list is complete, compute
2883  * next waking time and put itself into sleep.
2884  */
2885 static int ext4_lazyinit_thread(void *arg)
2886 {
2887         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2888         struct list_head *pos, *n;
2889         struct ext4_li_request *elr;
2890         unsigned long next_wakeup, cur;
2891
2892         BUG_ON(NULL == eli);
2893
2894 cont_thread:
2895         while (true) {
2896                 next_wakeup = MAX_JIFFY_OFFSET;
2897
2898                 mutex_lock(&eli->li_list_mtx);
2899                 if (list_empty(&eli->li_request_list)) {
2900                         mutex_unlock(&eli->li_list_mtx);
2901                         goto exit_thread;
2902                 }
2903
2904                 list_for_each_safe(pos, n, &eli->li_request_list) {
2905                         elr = list_entry(pos, struct ext4_li_request,
2906                                          lr_request);
2907
2908                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2909                                 if (ext4_run_li_request(elr) != 0) {
2910                                         /* error, remove the lazy_init job */
2911                                         ext4_remove_li_request(elr);
2912                                         continue;
2913                                 }
2914                         }
2915
2916                         if (time_before(elr->lr_next_sched, next_wakeup))
2917                                 next_wakeup = elr->lr_next_sched;
2918                 }
2919                 mutex_unlock(&eli->li_list_mtx);
2920
2921                 try_to_freeze();
2922
2923                 cur = jiffies;
2924                 if ((time_after_eq(cur, next_wakeup)) ||
2925                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2926                         cond_resched();
2927                         continue;
2928                 }
2929
2930                 schedule_timeout_interruptible(next_wakeup - cur);
2931
2932                 if (kthread_should_stop()) {
2933                         ext4_clear_request_list();
2934                         goto exit_thread;
2935                 }
2936         }
2937
2938 exit_thread:
2939         /*
2940          * It looks like the request list is empty, but we need
2941          * to check it under the li_list_mtx lock, to prevent any
2942          * additions into it, and of course we should lock ext4_li_mtx
2943          * to atomically free the list and ext4_li_info, because at
2944          * this point another ext4 filesystem could be registering
2945          * new one.
2946          */
2947         mutex_lock(&ext4_li_mtx);
2948         mutex_lock(&eli->li_list_mtx);
2949         if (!list_empty(&eli->li_request_list)) {
2950                 mutex_unlock(&eli->li_list_mtx);
2951                 mutex_unlock(&ext4_li_mtx);
2952                 goto cont_thread;
2953         }
2954         mutex_unlock(&eli->li_list_mtx);
2955         kfree(ext4_li_info);
2956         ext4_li_info = NULL;
2957         mutex_unlock(&ext4_li_mtx);
2958
2959         return 0;
2960 }
2961
2962 static void ext4_clear_request_list(void)
2963 {
2964         struct list_head *pos, *n;
2965         struct ext4_li_request *elr;
2966
2967         mutex_lock(&ext4_li_info->li_list_mtx);
2968         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2969                 elr = list_entry(pos, struct ext4_li_request,
2970                                  lr_request);
2971                 ext4_remove_li_request(elr);
2972         }
2973         mutex_unlock(&ext4_li_info->li_list_mtx);
2974 }
2975
2976 static int ext4_run_lazyinit_thread(void)
2977 {
2978         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2979                                          ext4_li_info, "ext4lazyinit");
2980         if (IS_ERR(ext4_lazyinit_task)) {
2981                 int err = PTR_ERR(ext4_lazyinit_task);
2982                 ext4_clear_request_list();
2983                 kfree(ext4_li_info);
2984                 ext4_li_info = NULL;
2985                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2986                                  "initialization thread\n",
2987                                  err);
2988                 return err;
2989         }
2990         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2991         return 0;
2992 }
2993
2994 /*
2995  * Check whether it make sense to run itable init. thread or not.
2996  * If there is at least one uninitialized inode table, return
2997  * corresponding group number, else the loop goes through all
2998  * groups and return total number of groups.
2999  */
3000 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3001 {
3002         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3003         struct ext4_group_desc *gdp = NULL;
3004
3005         for (group = 0; group < ngroups; group++) {
3006                 gdp = ext4_get_group_desc(sb, group, NULL);
3007                 if (!gdp)
3008                         continue;
3009
3010                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3011                         break;
3012         }
3013
3014         return group;
3015 }
3016
3017 static int ext4_li_info_new(void)
3018 {
3019         struct ext4_lazy_init *eli = NULL;
3020
3021         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3022         if (!eli)
3023                 return -ENOMEM;
3024
3025         INIT_LIST_HEAD(&eli->li_request_list);
3026         mutex_init(&eli->li_list_mtx);
3027
3028         eli->li_state |= EXT4_LAZYINIT_QUIT;
3029
3030         ext4_li_info = eli;
3031
3032         return 0;
3033 }
3034
3035 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3036                                             ext4_group_t start)
3037 {
3038         struct ext4_sb_info *sbi = EXT4_SB(sb);
3039         struct ext4_li_request *elr;
3040         unsigned long rnd;
3041
3042         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3043         if (!elr)
3044                 return NULL;
3045
3046         elr->lr_super = sb;
3047         elr->lr_sbi = sbi;
3048         elr->lr_next_group = start;
3049
3050         /*
3051          * Randomize first schedule time of the request to
3052          * spread the inode table initialization requests
3053          * better.
3054          */
3055         get_random_bytes(&rnd, sizeof(rnd));
3056         elr->lr_next_sched = jiffies + (unsigned long)rnd %
3057                              (EXT4_DEF_LI_MAX_START_DELAY * HZ);
3058
3059         return elr;
3060 }
3061
3062 int ext4_register_li_request(struct super_block *sb,
3063                              ext4_group_t first_not_zeroed)
3064 {
3065         struct ext4_sb_info *sbi = EXT4_SB(sb);
3066         struct ext4_li_request *elr = NULL;
3067         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3068         int ret = 0;
3069
3070         mutex_lock(&ext4_li_mtx);
3071         if (sbi->s_li_request != NULL) {
3072                 /*
3073                  * Reset timeout so it can be computed again, because
3074                  * s_li_wait_mult might have changed.
3075                  */
3076                 sbi->s_li_request->lr_timeout = 0;
3077                 goto out;
3078         }
3079
3080         if (first_not_zeroed == ngroups ||
3081             (sb->s_flags & MS_RDONLY) ||
3082             !test_opt(sb, INIT_INODE_TABLE))
3083                 goto out;
3084
3085         elr = ext4_li_request_new(sb, first_not_zeroed);
3086         if (!elr) {
3087                 ret = -ENOMEM;
3088                 goto out;
3089         }
3090
3091         if (NULL == ext4_li_info) {
3092                 ret = ext4_li_info_new();
3093                 if (ret)
3094                         goto out;
3095         }
3096
3097         mutex_lock(&ext4_li_info->li_list_mtx);
3098         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3099         mutex_unlock(&ext4_li_info->li_list_mtx);
3100
3101         sbi->s_li_request = elr;
3102         /*
3103          * set elr to NULL here since it has been inserted to
3104          * the request_list and the removal and free of it is
3105          * handled by ext4_clear_request_list from now on.
3106          */
3107         elr = NULL;
3108
3109         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3110                 ret = ext4_run_lazyinit_thread();
3111                 if (ret)
3112                         goto out;
3113         }
3114 out:
3115         mutex_unlock(&ext4_li_mtx);
3116         if (ret)
3117                 kfree(elr);
3118         return ret;
3119 }
3120
3121 /*
3122  * We do not need to lock anything since this is called on
3123  * module unload.
3124  */
3125 static void ext4_destroy_lazyinit_thread(void)
3126 {
3127         /*
3128          * If thread exited earlier
3129          * there's nothing to be done.
3130          */
3131         if (!ext4_li_info || !ext4_lazyinit_task)
3132                 return;
3133
3134         kthread_stop(ext4_lazyinit_task);
3135 }
3136
3137 static int set_journal_csum_feature_set(struct super_block *sb)
3138 {
3139         int ret = 1;
3140         int compat, incompat;
3141         struct ext4_sb_info *sbi = EXT4_SB(sb);
3142
3143         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3144                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3145                 /* journal checksum v2 */
3146                 compat = 0;
3147                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3148         } else {
3149                 /* journal checksum v1 */
3150                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3151                 incompat = 0;
3152         }
3153
3154         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3155                 ret = jbd2_journal_set_features(sbi->s_journal,
3156                                 compat, 0,
3157                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3158                                 incompat);
3159         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3160                 ret = jbd2_journal_set_features(sbi->s_journal,
3161                                 compat, 0,
3162                                 incompat);
3163                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3164                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3165         } else {
3166                 jbd2_journal_clear_features(sbi->s_journal,
3167                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3168                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3169                                 JBD2_FEATURE_INCOMPAT_CSUM_V2);
3170         }
3171
3172         return ret;
3173 }
3174
3175 /*
3176  * Note: calculating the overhead so we can be compatible with
3177  * historical BSD practice is quite difficult in the face of
3178  * clusters/bigalloc.  This is because multiple metadata blocks from
3179  * different block group can end up in the same allocation cluster.
3180  * Calculating the exact overhead in the face of clustered allocation
3181  * requires either O(all block bitmaps) in memory or O(number of block
3182  * groups**2) in time.  We will still calculate the superblock for
3183  * older file systems --- and if we come across with a bigalloc file
3184  * system with zero in s_overhead_clusters the estimate will be close to
3185  * correct especially for very large cluster sizes --- but for newer
3186  * file systems, it's better to calculate this figure once at mkfs
3187  * time, and store it in the superblock.  If the superblock value is
3188  * present (even for non-bigalloc file systems), we will use it.
3189  */
3190 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3191                           char *buf)
3192 {
3193         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3194         struct ext4_group_desc  *gdp;
3195         ext4_fsblk_t            first_block, last_block, b;
3196         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3197         int                     s, j, count = 0;
3198
3199         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3200                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3201                         sbi->s_itb_per_group + 2);
3202
3203         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3204                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3205         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3206         for (i = 0; i < ngroups; i++) {
3207                 gdp = ext4_get_group_desc(sb, i, NULL);
3208                 b = ext4_block_bitmap(sb, gdp);
3209                 if (b >= first_block && b <= last_block) {
3210                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3211                         count++;
3212                 }
3213                 b = ext4_inode_bitmap(sb, gdp);
3214                 if (b >= first_block && b <= last_block) {
3215                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3216                         count++;
3217                 }
3218                 b = ext4_inode_table(sb, gdp);
3219                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3220                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3221                                 int c = EXT4_B2C(sbi, b - first_block);
3222                                 ext4_set_bit(c, buf);
3223                                 count++;
3224                         }
3225                 if (i != grp)
3226                         continue;
3227                 s = 0;
3228                 if (ext4_bg_has_super(sb, grp)) {
3229                         ext4_set_bit(s++, buf);
3230                         count++;
3231                 }
3232                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3233                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3234                         count++;
3235                 }
3236         }
3237         if (!count)
3238                 return 0;
3239         return EXT4_CLUSTERS_PER_GROUP(sb) -
3240                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3241 }
3242
3243 /*
3244  * Compute the overhead and stash it in sbi->s_overhead
3245  */
3246 int ext4_calculate_overhead(struct super_block *sb)
3247 {
3248         struct ext4_sb_info *sbi = EXT4_SB(sb);
3249         struct ext4_super_block *es = sbi->s_es;
3250         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3251         ext4_fsblk_t overhead = 0;
3252         char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3253
3254         if (!buf)
3255                 return -ENOMEM;
3256
3257         /*
3258          * Compute the overhead (FS structures).  This is constant
3259          * for a given filesystem unless the number of block groups
3260          * changes so we cache the previous value until it does.
3261          */
3262
3263         /*
3264          * All of the blocks before first_data_block are overhead
3265          */
3266         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3267
3268         /*
3269          * Add the overhead found in each block group
3270          */
3271         for (i = 0; i < ngroups; i++) {
3272                 int blks;
3273
3274                 blks = count_overhead(sb, i, buf);
3275                 overhead += blks;
3276                 if (blks)
3277                         memset(buf, 0, PAGE_SIZE);
3278                 cond_resched();
3279         }
3280         /* Add the journal blocks as well */
3281         if (sbi->s_journal)
3282                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3283
3284         sbi->s_overhead = overhead;
3285         smp_wmb();
3286         free_page((unsigned long) buf);
3287         return 0;
3288 }
3289
3290
3291 static ext4_fsblk_t ext4_calculate_resv_clusters(struct ext4_sb_info *sbi)
3292 {
3293         ext4_fsblk_t resv_clusters;
3294
3295         /*
3296          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3297          * This should cover the situations where we can not afford to run
3298          * out of space like for example punch hole, or converting
3299          * uninitialized extents in delalloc path. In most cases such
3300          * allocation would require 1, or 2 blocks, higher numbers are
3301          * very rare.
3302          */
3303         resv_clusters = ext4_blocks_count(sbi->s_es) >> sbi->s_cluster_bits;
3304
3305         do_div(resv_clusters, 50);
3306         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3307
3308         return resv_clusters;
3309 }
3310
3311
3312 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3313 {
3314         ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3315                                 sbi->s_cluster_bits;
3316
3317         if (count >= clusters)
3318                 return -EINVAL;
3319
3320         atomic64_set(&sbi->s_resv_clusters, count);
3321         return 0;
3322 }
3323
3324 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3325 {
3326         char *orig_data = kstrdup(data, GFP_KERNEL);
3327         struct buffer_head *bh;
3328         struct ext4_super_block *es = NULL;
3329         struct ext4_sb_info *sbi;
3330         ext4_fsblk_t block;
3331         ext4_fsblk_t sb_block = get_sb_block(&data);
3332         ext4_fsblk_t logical_sb_block;
3333         unsigned long offset = 0;
3334         unsigned long journal_devnum = 0;
3335         unsigned long def_mount_opts;
3336         struct inode *root;
3337         char *cp;
3338         const char *descr;
3339         int ret = -ENOMEM;
3340         int blocksize, clustersize;
3341         unsigned int db_count;
3342         unsigned int i;
3343         int needs_recovery, has_huge_files, has_bigalloc;
3344         __u64 blocks_count;
3345         int err = 0;
3346         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3347         ext4_group_t first_not_zeroed;
3348
3349         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3350         if (!sbi)
3351                 goto out_free_orig;
3352
3353         sbi->s_blockgroup_lock =
3354                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3355         if (!sbi->s_blockgroup_lock) {
3356                 kfree(sbi);
3357                 goto out_free_orig;
3358         }
3359         sb->s_fs_info = sbi;
3360         sbi->s_sb = sb;
3361         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3362         sbi->s_sb_block = sb_block;
3363         if (sb->s_bdev->bd_part)
3364                 sbi->s_sectors_written_start =
3365                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3366
3367         /* Cleanup superblock name */
3368         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3369                 *cp = '!';
3370
3371         /* -EINVAL is default */
3372         ret = -EINVAL;
3373         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3374         if (!blocksize) {
3375                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3376                 goto out_fail;
3377         }
3378
3379         /*
3380          * The ext4 superblock will not be buffer aligned for other than 1kB
3381          * block sizes.  We need to calculate the offset from buffer start.
3382          */
3383         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3384                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3385                 offset = do_div(logical_sb_block, blocksize);
3386         } else {
3387                 logical_sb_block = sb_block;
3388         }
3389
3390         if (!(bh = sb_bread(sb, logical_sb_block))) {
3391                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3392                 goto out_fail;
3393         }
3394         /*
3395          * Note: s_es must be initialized as soon as possible because
3396          *       some ext4 macro-instructions depend on its value
3397          */
3398         es = (struct ext4_super_block *) (bh->b_data + offset);
3399         sbi->s_es = es;
3400         sb->s_magic = le16_to_cpu(es->s_magic);
3401         if (sb->s_magic != EXT4_SUPER_MAGIC)
3402                 goto cantfind_ext4;
3403         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3404
3405         /* Warn if metadata_csum and gdt_csum are both set. */
3406         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3407                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3408             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3409                 ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3410                              "redundant flags; please run fsck.");
3411
3412         /* Check for a known checksum algorithm */
3413         if (!ext4_verify_csum_type(sb, es)) {
3414                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3415                          "unknown checksum algorithm.");
3416                 silent = 1;
3417                 goto cantfind_ext4;
3418         }
3419
3420         /* Load the checksum driver */
3421         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3422                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3423                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3424                 if (IS_ERR(sbi->s_chksum_driver)) {
3425                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3426                         ret = PTR_ERR(sbi->s_chksum_driver);
3427                         sbi->s_chksum_driver = NULL;
3428                         goto failed_mount;
3429                 }
3430         }
3431
3432         /* Check superblock checksum */
3433         if (!ext4_superblock_csum_verify(sb, es)) {
3434                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3435                          "invalid superblock checksum.  Run e2fsck?");
3436                 silent = 1;
3437                 goto cantfind_ext4;
3438         }
3439
3440         /* Precompute checksum seed for all metadata */
3441         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3442                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3443                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3444                                                sizeof(es->s_uuid));
3445
3446         /* Set defaults before we parse the mount options */
3447         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3448         set_opt(sb, INIT_INODE_TABLE);
3449         if (def_mount_opts & EXT4_DEFM_DEBUG)
3450                 set_opt(sb, DEBUG);
3451         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3452                 set_opt(sb, GRPID);
3453         if (def_mount_opts & EXT4_DEFM_UID16)
3454                 set_opt(sb, NO_UID32);
3455         /* xattr user namespace & acls are now defaulted on */
3456         set_opt(sb, XATTR_USER);
3457 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3458         set_opt(sb, POSIX_ACL);
3459 #endif
3460         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3461                 set_opt(sb, JOURNAL_DATA);
3462         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3463                 set_opt(sb, ORDERED_DATA);
3464         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3465                 set_opt(sb, WRITEBACK_DATA);
3466
3467         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3468                 set_opt(sb, ERRORS_PANIC);
3469         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3470                 set_opt(sb, ERRORS_CONT);
3471         else
3472                 set_opt(sb, ERRORS_RO);
3473         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3474                 set_opt(sb, BLOCK_VALIDITY);
3475         if (def_mount_opts & EXT4_DEFM_DISCARD)
3476                 set_opt(sb, DISCARD);
3477
3478         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3479         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3480         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3481         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3482         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3483
3484         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3485                 set_opt(sb, BARRIER);
3486
3487         /*
3488          * enable delayed allocation by default
3489          * Use -o nodelalloc to turn it off
3490          */
3491         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3492             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3493                 set_opt(sb, DELALLOC);
3494
3495         /*
3496          * set default s_li_wait_mult for lazyinit, for the case there is
3497          * no mount option specified.
3498          */
3499         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3500
3501         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3502                            &journal_devnum, &journal_ioprio, 0)) {
3503                 ext4_msg(sb, KERN_WARNING,
3504                          "failed to parse options in superblock: %s",
3505                          sbi->s_es->s_mount_opts);
3506         }
3507         sbi->s_def_mount_opt = sbi->s_mount_opt;
3508         if (!parse_options((char *) data, sb, &journal_devnum,
3509                            &journal_ioprio, 0))
3510                 goto failed_mount;
3511
3512         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3513                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3514                             "with data=journal disables delayed "
3515                             "allocation and O_DIRECT support!\n");
3516                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3517                         ext4_msg(sb, KERN_ERR, "can't mount with "
3518                                  "both data=journal and delalloc");
3519                         goto failed_mount;
3520                 }
3521                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3522                         ext4_msg(sb, KERN_ERR, "can't mount with "
3523                                  "both data=journal and dioread_nolock");
3524                         goto failed_mount;
3525                 }
3526                 if (test_opt(sb, DELALLOC))
3527                         clear_opt(sb, DELALLOC);
3528         }
3529
3530         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3531                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3532
3533         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3534             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3535              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3536              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3537                 ext4_msg(sb, KERN_WARNING,
3538                        "feature flags set on rev 0 fs, "
3539                        "running e2fsck is recommended");
3540
3541         if (IS_EXT2_SB(sb)) {
3542                 if (ext2_feature_set_ok(sb))
3543                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3544                                  "using the ext4 subsystem");
3545                 else {
3546                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3547                                  "to feature incompatibilities");
3548                         goto failed_mount;
3549                 }
3550         }
3551
3552         if (IS_EXT3_SB(sb)) {
3553                 if (ext3_feature_set_ok(sb))
3554                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3555                                  "using the ext4 subsystem");
3556                 else {
3557                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3558                                  "to feature incompatibilities");
3559                         goto failed_mount;
3560                 }
3561         }
3562
3563         /*
3564          * Check feature flags regardless of the revision level, since we
3565          * previously didn't change the revision level when setting the flags,
3566          * so there is a chance incompat flags are set on a rev 0 filesystem.
3567          */
3568         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3569                 goto failed_mount;
3570
3571         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3572         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3573             blocksize > EXT4_MAX_BLOCK_SIZE) {
3574                 ext4_msg(sb, KERN_ERR,
3575                        "Unsupported filesystem blocksize %d", blocksize);
3576                 goto failed_mount;
3577         }
3578
3579         if (sb->s_blocksize != blocksize) {
3580                 /* Validate the filesystem blocksize */
3581                 if (!sb_set_blocksize(sb, blocksize)) {
3582                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3583                                         blocksize);
3584                         goto failed_mount;
3585                 }
3586
3587                 brelse(bh);
3588                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3589                 offset = do_div(logical_sb_block, blocksize);
3590                 bh = sb_bread(sb, logical_sb_block);
3591                 if (!bh) {
3592                         ext4_msg(sb, KERN_ERR,
3593                                "Can't read superblock on 2nd try");
3594                         goto failed_mount;
3595                 }
3596                 es = (struct ext4_super_block *)(bh->b_data + offset);
3597                 sbi->s_es = es;
3598                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3599                         ext4_msg(sb, KERN_ERR,
3600                                "Magic mismatch, very weird!");
3601                         goto failed_mount;
3602                 }
3603         }
3604
3605         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3606                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3607         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3608                                                       has_huge_files);
3609         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3610
3611         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3612                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3613                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3614         } else {
3615                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3616                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3617                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3618                     (!is_power_of_2(sbi->s_inode_size)) ||
3619                     (sbi->s_inode_size > blocksize)) {
3620                         ext4_msg(sb, KERN_ERR,
3621                                "unsupported inode size: %d",
3622                                sbi->s_inode_size);
3623                         goto failed_mount;
3624                 }
3625                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3626                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3627         }
3628
3629         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3630         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3631                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3632                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3633                     !is_power_of_2(sbi->s_desc_size)) {
3634                         ext4_msg(sb, KERN_ERR,
3635                                "unsupported descriptor size %lu",
3636                                sbi->s_desc_size);
3637                         goto failed_mount;
3638                 }
3639         } else
3640                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3641
3642         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3643         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3644         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3645                 goto cantfind_ext4;
3646
3647         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3648         if (sbi->s_inodes_per_block == 0)
3649                 goto cantfind_ext4;
3650         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3651                                         sbi->s_inodes_per_block;
3652         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3653         sbi->s_sbh = bh;
3654         sbi->s_mount_state = le16_to_cpu(es->s_state);
3655         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3656         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3657
3658         for (i = 0; i < 4; i++)
3659                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3660         sbi->s_def_hash_version = es->s_def_hash_version;
3661         i = le32_to_cpu(es->s_flags);
3662         if (i & EXT2_FLAGS_UNSIGNED_HASH)
3663                 sbi->s_hash_unsigned = 3;
3664         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3665 #ifdef __CHAR_UNSIGNED__
3666                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3667                 sbi->s_hash_unsigned = 3;
3668 #else
3669                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3670 #endif
3671         }
3672
3673         /* Handle clustersize */
3674         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3675         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3676                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3677         if (has_bigalloc) {
3678                 if (clustersize < blocksize) {
3679                         ext4_msg(sb, KERN_ERR,
3680                                  "cluster size (%d) smaller than "
3681                                  "block size (%d)", clustersize, blocksize);
3682                         goto failed_mount;
3683                 }
3684                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3685                         le32_to_cpu(es->s_log_block_size);
3686                 sbi->s_clusters_per_group =
3687                         le32_to_cpu(es->s_clusters_per_group);
3688                 if (sbi->s_clusters_per_group > blocksize * 8) {
3689                         ext4_msg(sb, KERN_ERR,
3690                                  "#clusters per group too big: %lu",
3691                                  sbi->s_clusters_per_group);
3692                         goto failed_mount;
3693                 }
3694                 if (sbi->s_blocks_per_group !=
3695                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3696                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3697                                  "clusters per group (%lu) inconsistent",
3698                                  sbi->s_blocks_per_group,
3699                                  sbi->s_clusters_per_group);
3700                         goto failed_mount;
3701                 }
3702         } else {
3703                 if (clustersize != blocksize) {
3704                         ext4_warning(sb, "fragment/cluster size (%d) != "
3705                                      "block size (%d)", clustersize,
3706                                      blocksize);
3707                         clustersize = blocksize;
3708                 }
3709                 if (sbi->s_blocks_per_group > blocksize * 8) {
3710                         ext4_msg(sb, KERN_ERR,
3711                                  "#blocks per group too big: %lu",
3712                                  sbi->s_blocks_per_group);
3713                         goto failed_mount;
3714                 }
3715                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3716                 sbi->s_cluster_bits = 0;
3717         }
3718         sbi->s_cluster_ratio = clustersize / blocksize;
3719
3720         if (sbi->s_inodes_per_group > blocksize * 8) {
3721                 ext4_msg(sb, KERN_ERR,
3722                        "#inodes per group too big: %lu",
3723                        sbi->s_inodes_per_group);
3724                 goto failed_mount;
3725         }
3726
3727         /* Do we have standard group size of clustersize * 8 blocks ? */
3728         if (sbi->s_blocks_per_group == clustersize << 3)
3729                 set_opt2(sb, STD_GROUP_SIZE);
3730
3731         /*
3732          * Test whether we have more sectors than will fit in sector_t,
3733          * and whether the max offset is addressable by the page cache.
3734          */
3735         err = generic_check_addressable(sb->s_blocksize_bits,
3736                                         ext4_blocks_count(es));
3737         if (err) {
3738                 ext4_msg(sb, KERN_ERR, "filesystem"
3739                          " too large to mount safely on this system");
3740                 if (sizeof(sector_t) < 8)
3741                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3742                 goto failed_mount;
3743         }
3744
3745         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3746                 goto cantfind_ext4;
3747
3748         /* check blocks count against device size */
3749         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3750         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3751                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3752                        "exceeds size of device (%llu blocks)",
3753                        ext4_blocks_count(es), blocks_count);
3754                 goto failed_mount;
3755         }
3756
3757         /*
3758          * It makes no sense for the first data block to be beyond the end
3759          * of the filesystem.
3760          */
3761         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3762                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3763                          "block %u is beyond end of filesystem (%llu)",
3764                          le32_to_cpu(es->s_first_data_block),
3765                          ext4_blocks_count(es));
3766                 goto failed_mount;
3767         }
3768         blocks_count = (ext4_blocks_count(es) -
3769                         le32_to_cpu(es->s_first_data_block) +
3770                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3771         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3772         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3773                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3774                        "(block count %llu, first data block %u, "
3775                        "blocks per group %lu)", sbi->s_groups_count,
3776                        ext4_blocks_count(es),
3777                        le32_to_cpu(es->s_first_data_block),
3778                        EXT4_BLOCKS_PER_GROUP(sb));
3779                 goto failed_mount;
3780         }
3781         sbi->s_groups_count = blocks_count;
3782         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3783                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3784         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3785                    EXT4_DESC_PER_BLOCK(sb);
3786         sbi->s_group_desc = ext4_kvmalloc(db_count *
3787                                           sizeof(struct buffer_head *),
3788                                           GFP_KERNEL);
3789         if (sbi->s_group_desc == NULL) {
3790                 ext4_msg(sb, KERN_ERR, "not enough memory");
3791                 ret = -ENOMEM;
3792                 goto failed_mount;
3793         }
3794
3795         if (ext4_proc_root)
3796                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3797
3798         if (sbi->s_proc)
3799                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3800                                  &ext4_seq_options_fops, sb);
3801
3802         bgl_lock_init(sbi->s_blockgroup_lock);
3803
3804         for (i = 0; i < db_count; i++) {
3805                 block = descriptor_loc(sb, logical_sb_block, i);
3806                 sbi->s_group_desc[i] = sb_bread(sb, block);
3807                 if (!sbi->s_group_desc[i]) {
3808                         ext4_msg(sb, KERN_ERR,
3809                                "can't read group descriptor %d", i);
3810                         db_count = i;
3811                         goto failed_mount2;
3812                 }
3813         }
3814         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3815                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3816                 goto failed_mount2;
3817         }
3818         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3819                 if (!ext4_fill_flex_info(sb)) {
3820                         ext4_msg(sb, KERN_ERR,
3821                                "unable to initialize "
3822                                "flex_bg meta info!");
3823                         goto failed_mount2;
3824                 }
3825
3826         sbi->s_gdb_count = db_count;
3827         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3828         spin_lock_init(&sbi->s_next_gen_lock);
3829
3830         init_timer(&sbi->s_err_report);
3831         sbi->s_err_report.function = print_daily_error_info;
3832         sbi->s_err_report.data = (unsigned long) sb;
3833
3834         /* Register extent status tree shrinker */
3835         ext4_es_register_shrinker(sbi);
3836
3837         err = percpu_counter_init(&sbi->s_freeclusters_counter,
3838                         ext4_count_free_clusters(sb));
3839         if (!err) {
3840                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
3841                                 ext4_count_free_inodes(sb));
3842         }
3843         if (!err) {
3844                 err = percpu_counter_init(&sbi->s_dirs_counter,
3845                                 ext4_count_dirs(sb));
3846         }
3847         if (!err) {
3848                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3849         }
3850         if (!err) {
3851                 err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
3852         }
3853         if (err) {
3854                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3855                 goto failed_mount3;
3856         }
3857
3858         sbi->s_stripe = ext4_get_stripe_size(sbi);
3859         sbi->s_extent_max_zeroout_kb = 32;
3860
3861         /*
3862          * set up enough so that it can read an inode
3863          */
3864         if (!test_opt(sb, NOLOAD) &&
3865             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3866                 sb->s_op = &ext4_sops;
3867         else
3868                 sb->s_op = &ext4_nojournal_sops;
3869         sb->s_export_op = &ext4_export_ops;
3870         sb->s_xattr = ext4_xattr_handlers;
3871 #ifdef CONFIG_QUOTA
3872         sb->dq_op = &ext4_quota_operations;
3873         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3874                 sb->s_qcop = &ext4_qctl_sysfile_operations;
3875         else
3876                 sb->s_qcop = &ext4_qctl_operations;
3877 #endif
3878         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3879
3880         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3881         mutex_init(&sbi->s_orphan_lock);
3882
3883         sb->s_root = NULL;
3884
3885         needs_recovery = (es->s_last_orphan != 0 ||
3886                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3887                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3888
3889         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3890             !(sb->s_flags & MS_RDONLY))
3891                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3892                         goto failed_mount3;
3893
3894         /*
3895          * The first inode we look at is the journal inode.  Don't try
3896          * root first: it may be modified in the journal!
3897          */
3898         if (!test_opt(sb, NOLOAD) &&
3899             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3900                 if (ext4_load_journal(sb, es, journal_devnum))
3901                         goto failed_mount3;
3902         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3903               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3904                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3905                        "suppressed and not mounted read-only");
3906                 goto failed_mount_wq;
3907         } else {
3908                 clear_opt(sb, DATA_FLAGS);
3909                 sbi->s_journal = NULL;
3910                 needs_recovery = 0;
3911                 goto no_journal;
3912         }
3913
3914         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3915             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3916                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3917                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3918                 goto failed_mount_wq;
3919         }
3920
3921         if (!set_journal_csum_feature_set(sb)) {
3922                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3923                          "feature set");
3924                 goto failed_mount_wq;
3925         }
3926
3927         /* We have now updated the journal if required, so we can
3928          * validate the data journaling mode. */
3929         switch (test_opt(sb, DATA_FLAGS)) {
3930         case 0:
3931                 /* No mode set, assume a default based on the journal
3932                  * capabilities: ORDERED_DATA if the journal can
3933                  * cope, else JOURNAL_DATA
3934                  */
3935                 if (jbd2_journal_check_available_features
3936                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3937                         set_opt(sb, ORDERED_DATA);
3938                 else
3939                         set_opt(sb, JOURNAL_DATA);
3940                 break;
3941
3942         case EXT4_MOUNT_ORDERED_DATA:
3943         case EXT4_MOUNT_WRITEBACK_DATA:
3944                 if (!jbd2_journal_check_available_features
3945                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3946                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3947                                "requested data journaling mode");
3948                         goto failed_mount_wq;
3949                 }
3950         default:
3951                 break;
3952         }
3953         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3954
3955         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3956
3957         /*
3958          * The journal may have updated the bg summary counts, so we
3959          * need to update the global counters.
3960          */
3961         percpu_counter_set(&sbi->s_freeclusters_counter,
3962                            ext4_count_free_clusters(sb));
3963         percpu_counter_set(&sbi->s_freeinodes_counter,
3964                            ext4_count_free_inodes(sb));
3965         percpu_counter_set(&sbi->s_dirs_counter,
3966                            ext4_count_dirs(sb));
3967         percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3968
3969 no_journal:
3970         /*
3971          * Get the # of file system overhead blocks from the
3972          * superblock if present.
3973          */
3974         if (es->s_overhead_clusters)
3975                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3976         else {
3977                 err = ext4_calculate_overhead(sb);
3978                 if (err)
3979                         goto failed_mount_wq;
3980         }
3981
3982         /*
3983          * The maximum number of concurrent works can be high and
3984          * concurrency isn't really necessary.  Limit it to 1.
3985          */
3986         EXT4_SB(sb)->rsv_conversion_wq =
3987                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3988         if (!EXT4_SB(sb)->rsv_conversion_wq) {
3989                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3990                 ret = -ENOMEM;
3991                 goto failed_mount4;
3992         }
3993
3994         /*
3995          * The jbd2_journal_load will have done any necessary log recovery,
3996          * so we can safely mount the rest of the filesystem now.
3997          */
3998
3999         root = ext4_iget(sb, EXT4_ROOT_INO);
4000         if (IS_ERR(root)) {
4001                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4002                 ret = PTR_ERR(root);
4003                 root = NULL;
4004                 goto failed_mount4;
4005         }
4006         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4007                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4008                 iput(root);
4009                 goto failed_mount4;
4010         }
4011         sb->s_root = d_make_root(root);
4012         if (!sb->s_root) {
4013                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4014                 ret = -ENOMEM;
4015                 goto failed_mount4;
4016         }
4017
4018         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4019                 sb->s_flags |= MS_RDONLY;
4020
4021         /* determine the minimum size of new large inodes, if present */
4022         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4023                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4024                                                      EXT4_GOOD_OLD_INODE_SIZE;
4025                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4026                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4027                         if (sbi->s_want_extra_isize <
4028                             le16_to_cpu(es->s_want_extra_isize))
4029                                 sbi->s_want_extra_isize =
4030                                         le16_to_cpu(es->s_want_extra_isize);
4031                         if (sbi->s_want_extra_isize <
4032                             le16_to_cpu(es->s_min_extra_isize))
4033                                 sbi->s_want_extra_isize =
4034                                         le16_to_cpu(es->s_min_extra_isize);
4035                 }
4036         }
4037         /* Check if enough inode space is available */
4038         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4039                                                         sbi->s_inode_size) {
4040                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4041                                                        EXT4_GOOD_OLD_INODE_SIZE;
4042                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4043                          "available");
4044         }
4045
4046         err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sbi));
4047         if (err) {
4048                 ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4049                          "reserved pool", ext4_calculate_resv_clusters(sbi));
4050                 goto failed_mount4a;
4051         }
4052
4053         err = ext4_setup_system_zone(sb);
4054         if (err) {
4055                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4056                          "zone (%d)", err);
4057                 goto failed_mount4a;
4058         }
4059
4060         ext4_ext_init(sb);
4061         err = ext4_mb_init(sb);
4062         if (err) {
4063                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4064                          err);
4065                 goto failed_mount5;
4066         }
4067
4068         err = ext4_register_li_request(sb, first_not_zeroed);
4069         if (err)
4070                 goto failed_mount6;
4071
4072         sbi->s_kobj.kset = ext4_kset;
4073         init_completion(&sbi->s_kobj_unregister);
4074         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4075                                    "%s", sb->s_id);
4076         if (err)
4077                 goto failed_mount7;
4078
4079 #ifdef CONFIG_QUOTA
4080         /* Enable quota usage during mount. */
4081         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4082             !(sb->s_flags & MS_RDONLY)) {
4083                 err = ext4_enable_quotas(sb);
4084                 if (err)
4085                         goto failed_mount8;
4086         }
4087 #endif  /* CONFIG_QUOTA */
4088
4089         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4090         ext4_orphan_cleanup(sb, es);
4091         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4092         if (needs_recovery) {
4093                 ext4_msg(sb, KERN_INFO, "recovery complete");
4094                 ext4_mark_recovery_complete(sb, es);
4095         }
4096         if (EXT4_SB(sb)->s_journal) {
4097                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4098                         descr = " journalled data mode";
4099                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4100                         descr = " ordered data mode";
4101                 else
4102                         descr = " writeback data mode";
4103         } else
4104                 descr = "out journal";
4105
4106         if (test_opt(sb, DISCARD)) {
4107                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4108                 if (!blk_queue_discard(q))
4109                         ext4_msg(sb, KERN_WARNING,
4110                                  "mounting with \"discard\" option, but "
4111                                  "the device does not support discard");
4112         }
4113
4114         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4115                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4116                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4117
4118         if (es->s_error_count)
4119                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4120
4121         kfree(orig_data);
4122         return 0;
4123
4124 cantfind_ext4:
4125         if (!silent)
4126                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4127         goto failed_mount;
4128
4129 #ifdef CONFIG_QUOTA
4130 failed_mount8:
4131         kobject_del(&sbi->s_kobj);
4132 #endif
4133 failed_mount7:
4134         ext4_unregister_li_request(sb);
4135 failed_mount6:
4136         ext4_mb_release(sb);
4137 failed_mount5:
4138         ext4_ext_release(sb);
4139         ext4_release_system_zone(sb);
4140 failed_mount4a:
4141         dput(sb->s_root);
4142         sb->s_root = NULL;
4143 failed_mount4:
4144         ext4_msg(sb, KERN_ERR, "mount failed");
4145         if (EXT4_SB(sb)->rsv_conversion_wq)
4146                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4147 failed_mount_wq:
4148         if (sbi->s_journal) {
4149                 jbd2_journal_destroy(sbi->s_journal);
4150                 sbi->s_journal = NULL;
4151         }
4152 failed_mount3:
4153         ext4_es_unregister_shrinker(sbi);
4154         del_timer(&sbi->s_err_report);
4155         if (sbi->s_flex_groups)
4156                 ext4_kvfree(sbi->s_flex_groups);
4157         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4158         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4159         percpu_counter_destroy(&sbi->s_dirs_counter);
4160         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4161         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
4162         if (sbi->s_mmp_tsk)
4163                 kthread_stop(sbi->s_mmp_tsk);
4164 failed_mount2:
4165         for (i = 0; i < db_count; i++)
4166                 brelse(sbi->s_group_desc[i]);
4167         ext4_kvfree(sbi->s_group_desc);
4168 failed_mount:
4169         if (sbi->s_chksum_driver)
4170                 crypto_free_shash(sbi->s_chksum_driver);
4171         if (sbi->s_proc) {
4172                 remove_proc_entry("options", sbi->s_proc);
4173                 remove_proc_entry(sb->s_id, ext4_proc_root);
4174         }
4175 #ifdef CONFIG_QUOTA
4176         for (i = 0; i < MAXQUOTAS; i++)
4177                 kfree(sbi->s_qf_names[i]);
4178 #endif
4179         ext4_blkdev_remove(sbi);
4180         brelse(bh);
4181 out_fail:
4182         sb->s_fs_info = NULL;
4183         kfree(sbi->s_blockgroup_lock);
4184         kfree(sbi);
4185 out_free_orig:
4186         kfree(orig_data);
4187         return err ? err : ret;
4188 }
4189
4190 /*
4191  * Setup any per-fs journal parameters now.  We'll do this both on
4192  * initial mount, once the journal has been initialised but before we've
4193  * done any recovery; and again on any subsequent remount.
4194  */
4195 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4196 {
4197         struct ext4_sb_info *sbi = EXT4_SB(sb);
4198
4199         journal->j_commit_interval = sbi->s_commit_interval;
4200         journal->j_min_batch_time = sbi->s_min_batch_time;
4201         journal->j_max_batch_time = sbi->s_max_batch_time;
4202
4203         write_lock(&journal->j_state_lock);
4204         if (test_opt(sb, BARRIER))
4205                 journal->j_flags |= JBD2_BARRIER;
4206         else
4207                 journal->j_flags &= ~JBD2_BARRIER;
4208         if (test_opt(sb, DATA_ERR_ABORT))
4209                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4210         else
4211                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4212         write_unlock(&journal->j_state_lock);
4213 }
4214
4215 static journal_t *ext4_get_journal(struct super_block *sb,
4216                                    unsigned int journal_inum)
4217 {
4218         struct inode *journal_inode;
4219         journal_t *journal;
4220
4221         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4222
4223         /* First, test for the existence of a valid inode on disk.  Bad
4224          * things happen if we iget() an unused inode, as the subsequent
4225          * iput() will try to delete it. */
4226
4227         journal_inode = ext4_iget(sb, journal_inum);
4228         if (IS_ERR(journal_inode)) {
4229                 ext4_msg(sb, KERN_ERR, "no journal found");
4230                 return NULL;
4231         }
4232         if (!journal_inode->i_nlink) {
4233                 make_bad_inode(journal_inode);
4234                 iput(journal_inode);
4235                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4236                 return NULL;
4237         }
4238
4239         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4240                   journal_inode, journal_inode->i_size);
4241         if (!S_ISREG(journal_inode->i_mode)) {
4242                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4243                 iput(journal_inode);
4244                 return NULL;
4245         }
4246
4247         journal = jbd2_journal_init_inode(journal_inode);
4248         if (!journal) {
4249                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4250                 iput(journal_inode);
4251                 return NULL;
4252         }
4253         journal->j_private = sb;
4254         ext4_init_journal_params(sb, journal);
4255         return journal;
4256 }
4257
4258 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4259                                        dev_t j_dev)
4260 {
4261         struct buffer_head *bh;
4262         journal_t *journal;
4263         ext4_fsblk_t start;
4264         ext4_fsblk_t len;
4265         int hblock, blocksize;
4266         ext4_fsblk_t sb_block;
4267         unsigned long offset;
4268         struct ext4_super_block *es;
4269         struct block_device *bdev;
4270
4271         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4272
4273         bdev = ext4_blkdev_get(j_dev, sb);
4274         if (bdev == NULL)
4275                 return NULL;
4276
4277         blocksize = sb->s_blocksize;
4278         hblock = bdev_logical_block_size(bdev);
4279         if (blocksize < hblock) {
4280                 ext4_msg(sb, KERN_ERR,
4281                         "blocksize too small for journal device");
4282                 goto out_bdev;
4283         }
4284
4285         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4286         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4287         set_blocksize(bdev, blocksize);
4288         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4289                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4290                        "external journal");
4291                 goto out_bdev;
4292         }
4293
4294         es = (struct ext4_super_block *) (bh->b_data + offset);
4295         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4296             !(le32_to_cpu(es->s_feature_incompat) &
4297               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4298                 ext4_msg(sb, KERN_ERR, "external journal has "
4299                                         "bad superblock");
4300                 brelse(bh);
4301                 goto out_bdev;
4302         }
4303
4304         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4305                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4306                 brelse(bh);
4307                 goto out_bdev;
4308         }
4309
4310         len = ext4_blocks_count(es);
4311         start = sb_block + 1;
4312         brelse(bh);     /* we're done with the superblock */
4313
4314         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4315                                         start, len, blocksize);
4316         if (!journal) {
4317                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4318                 goto out_bdev;
4319         }
4320         journal->j_private = sb;
4321         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4322         wait_on_buffer(journal->j_sb_buffer);
4323         if (!buffer_uptodate(journal->j_sb_buffer)) {
4324                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4325                 goto out_journal;
4326         }
4327         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4328                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4329                                         "user (unsupported) - %d",
4330                         be32_to_cpu(journal->j_superblock->s_nr_users));
4331                 goto out_journal;
4332         }
4333         EXT4_SB(sb)->journal_bdev = bdev;
4334         ext4_init_journal_params(sb, journal);
4335         return journal;
4336
4337 out_journal:
4338         jbd2_journal_destroy(journal);
4339 out_bdev:
4340         ext4_blkdev_put(bdev);
4341         return NULL;
4342 }
4343
4344 static int ext4_load_journal(struct super_block *sb,
4345                              struct ext4_super_block *es,
4346                              unsigned long journal_devnum)
4347 {
4348         journal_t *journal;
4349         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4350         dev_t journal_dev;
4351         int err = 0;
4352         int really_read_only;
4353
4354         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4355
4356         if (journal_devnum &&
4357             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4358                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4359                         "numbers have changed");
4360                 journal_dev = new_decode_dev(journal_devnum);
4361         } else
4362                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4363
4364         really_read_only = bdev_read_only(sb->s_bdev);
4365
4366         /*
4367          * Are we loading a blank journal or performing recovery after a
4368          * crash?  For recovery, we need to check in advance whether we
4369          * can get read-write access to the device.
4370          */
4371         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4372                 if (sb->s_flags & MS_RDONLY) {
4373                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4374                                         "required on readonly filesystem");
4375                         if (really_read_only) {
4376                                 ext4_msg(sb, KERN_ERR, "write access "
4377                                         "unavailable, cannot proceed");
4378                                 return -EROFS;
4379                         }
4380                         ext4_msg(sb, KERN_INFO, "write access will "
4381                                "be enabled during recovery");
4382                 }
4383         }
4384
4385         if (journal_inum && journal_dev) {
4386                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4387                        "and inode journals!");
4388                 return -EINVAL;
4389         }
4390
4391         if (journal_inum) {
4392                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4393                         return -EINVAL;
4394         } else {
4395                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4396                         return -EINVAL;
4397         }
4398
4399         if (!(journal->j_flags & JBD2_BARRIER))
4400                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4401
4402         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4403                 err = jbd2_journal_wipe(journal, !really_read_only);
4404         if (!err) {
4405                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4406                 if (save)
4407                         memcpy(save, ((char *) es) +
4408                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4409                 err = jbd2_journal_load(journal);
4410                 if (save)
4411                         memcpy(((char *) es) + EXT4_S_ERR_START,
4412                                save, EXT4_S_ERR_LEN);
4413                 kfree(save);
4414         }
4415
4416         if (err) {
4417                 ext4_msg(sb, KERN_ERR, "error loading journal");
4418                 jbd2_journal_destroy(journal);
4419                 return err;
4420         }
4421
4422         EXT4_SB(sb)->s_journal = journal;
4423         ext4_clear_journal_err(sb, es);
4424
4425         if (!really_read_only && journal_devnum &&
4426             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4427                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4428
4429                 /* Make sure we flush the recovery flag to disk. */
4430                 ext4_commit_super(sb, 1);
4431         }
4432
4433         return 0;
4434 }
4435
4436 static int ext4_commit_super(struct super_block *sb, int sync)
4437 {
4438         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4439         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4440         int error = 0;
4441
4442         if (!sbh || block_device_ejected(sb))
4443                 return error;
4444         if (buffer_write_io_error(sbh)) {
4445                 /*
4446                  * Oh, dear.  A previous attempt to write the
4447                  * superblock failed.  This could happen because the
4448                  * USB device was yanked out.  Or it could happen to
4449                  * be a transient write error and maybe the block will
4450                  * be remapped.  Nothing we can do but to retry the
4451                  * write and hope for the best.
4452                  */
4453                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4454                        "superblock detected");
4455                 clear_buffer_write_io_error(sbh);
4456                 set_buffer_uptodate(sbh);
4457         }
4458         /*
4459          * If the file system is mounted read-only, don't update the
4460          * superblock write time.  This avoids updating the superblock
4461          * write time when we are mounting the root file system
4462          * read/only but we need to replay the journal; at that point,
4463          * for people who are east of GMT and who make their clock
4464          * tick in localtime for Windows bug-for-bug compatibility,
4465          * the clock is set in the future, and this will cause e2fsck
4466          * to complain and force a full file system check.
4467          */
4468         if (!(sb->s_flags & MS_RDONLY))
4469                 es->s_wtime = cpu_to_le32(get_seconds());
4470         if (sb->s_bdev->bd_part)
4471                 es->s_kbytes_written =
4472                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4473                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4474                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4475         else
4476                 es->s_kbytes_written =
4477                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4478         ext4_free_blocks_count_set(es,
4479                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4480                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4481         es->s_free_inodes_count =
4482                 cpu_to_le32(percpu_counter_sum_positive(
4483                                 &EXT4_SB(sb)->s_freeinodes_counter));
4484         BUFFER_TRACE(sbh, "marking dirty");
4485         ext4_superblock_csum_set(sb);
4486         mark_buffer_dirty(sbh);
4487         if (sync) {
4488                 error = sync_dirty_buffer(sbh);
4489                 if (error)
4490                         return error;
4491
4492                 error = buffer_write_io_error(sbh);
4493                 if (error) {
4494                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4495                                "superblock");
4496                         clear_buffer_write_io_error(sbh);
4497                         set_buffer_uptodate(sbh);
4498                 }
4499         }
4500         return error;
4501 }
4502
4503 /*
4504  * Have we just finished recovery?  If so, and if we are mounting (or
4505  * remounting) the filesystem readonly, then we will end up with a
4506  * consistent fs on disk.  Record that fact.
4507  */
4508 static void ext4_mark_recovery_complete(struct super_block *sb,
4509                                         struct ext4_super_block *es)
4510 {
4511         journal_t *journal = EXT4_SB(sb)->s_journal;
4512
4513         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4514                 BUG_ON(journal != NULL);
4515                 return;
4516         }
4517         jbd2_journal_lock_updates(journal);
4518         if (jbd2_journal_flush(journal) < 0)
4519                 goto out;
4520
4521         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4522             sb->s_flags & MS_RDONLY) {
4523                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4524                 ext4_commit_super(sb, 1);
4525         }
4526
4527 out:
4528         jbd2_journal_unlock_updates(journal);
4529 }
4530
4531 /*
4532  * If we are mounting (or read-write remounting) a filesystem whose journal
4533  * has recorded an error from a previous lifetime, move that error to the
4534  * main filesystem now.
4535  */
4536 static void ext4_clear_journal_err(struct super_block *sb,
4537                                    struct ext4_super_block *es)
4538 {
4539         journal_t *journal;
4540         int j_errno;
4541         const char *errstr;
4542
4543         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4544
4545         journal = EXT4_SB(sb)->s_journal;
4546
4547         /*
4548          * Now check for any error status which may have been recorded in the
4549          * journal by a prior ext4_error() or ext4_abort()
4550          */
4551
4552         j_errno = jbd2_journal_errno(journal);
4553         if (j_errno) {
4554                 char nbuf[16];
4555
4556                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4557                 ext4_warning(sb, "Filesystem error recorded "
4558                              "from previous mount: %s", errstr);
4559                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4560
4561                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4562                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4563                 ext4_commit_super(sb, 1);
4564
4565                 jbd2_journal_clear_err(journal);
4566                 jbd2_journal_update_sb_errno(journal);
4567         }
4568 }
4569
4570 /*
4571  * Force the running and committing transactions to commit,
4572  * and wait on the commit.
4573  */
4574 int ext4_force_commit(struct super_block *sb)
4575 {
4576         journal_t *journal;
4577
4578         if (sb->s_flags & MS_RDONLY)
4579                 return 0;
4580
4581         journal = EXT4_SB(sb)->s_journal;
4582         return ext4_journal_force_commit(journal);
4583 }
4584
4585 static int ext4_sync_fs(struct super_block *sb, int wait)
4586 {
4587         int ret = 0;
4588         tid_t target;
4589         bool needs_barrier = false;
4590         struct ext4_sb_info *sbi = EXT4_SB(sb);
4591
4592         trace_ext4_sync_fs(sb, wait);
4593         flush_workqueue(sbi->rsv_conversion_wq);
4594         /*
4595          * Writeback quota in non-journalled quota case - journalled quota has
4596          * no dirty dquots
4597          */
4598         dquot_writeback_dquots(sb, -1);
4599         /*
4600          * Data writeback is possible w/o journal transaction, so barrier must
4601          * being sent at the end of the function. But we can skip it if
4602          * transaction_commit will do it for us.
4603          */
4604         target = jbd2_get_latest_transaction(sbi->s_journal);
4605         if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4606             !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4607                 needs_barrier = true;
4608
4609         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4610                 if (wait)
4611                         ret = jbd2_log_wait_commit(sbi->s_journal, target);
4612         }
4613         if (needs_barrier) {
4614                 int err;
4615                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4616                 if (!ret)
4617                         ret = err;
4618         }
4619
4620         return ret;
4621 }
4622
4623 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait)
4624 {
4625         int ret = 0;
4626
4627         trace_ext4_sync_fs(sb, wait);
4628         flush_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4629         dquot_writeback_dquots(sb, -1);
4630         if (wait && test_opt(sb, BARRIER))
4631                 ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4632
4633         return ret;
4634 }
4635
4636 /*
4637  * LVM calls this function before a (read-only) snapshot is created.  This
4638  * gives us a chance to flush the journal completely and mark the fs clean.
4639  *
4640  * Note that only this function cannot bring a filesystem to be in a clean
4641  * state independently. It relies on upper layer to stop all data & metadata
4642  * modifications.
4643  */
4644 static int ext4_freeze(struct super_block *sb)
4645 {
4646         int error = 0;
4647         journal_t *journal;
4648
4649         if (sb->s_flags & MS_RDONLY)
4650                 return 0;
4651
4652         journal = EXT4_SB(sb)->s_journal;
4653
4654         /* Now we set up the journal barrier. */
4655         jbd2_journal_lock_updates(journal);
4656
4657         /*
4658          * Don't clear the needs_recovery flag if we failed to flush
4659          * the journal.
4660          */
4661         error = jbd2_journal_flush(journal);
4662         if (error < 0)
4663                 goto out;
4664
4665         /* Journal blocked and flushed, clear needs_recovery flag. */
4666         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4667         error = ext4_commit_super(sb, 1);
4668 out:
4669         /* we rely on upper layer to stop further updates */
4670         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4671         return error;
4672 }
4673
4674 /*
4675  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4676  * flag here, even though the filesystem is not technically dirty yet.
4677  */
4678 static int ext4_unfreeze(struct super_block *sb)
4679 {
4680         if (sb->s_flags & MS_RDONLY)
4681                 return 0;
4682
4683         /* Reset the needs_recovery flag before the fs is unlocked. */
4684         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4685         ext4_commit_super(sb, 1);
4686         return 0;
4687 }
4688
4689 /*
4690  * Structure to save mount options for ext4_remount's benefit
4691  */
4692 struct ext4_mount_options {
4693         unsigned long s_mount_opt;
4694         unsigned long s_mount_opt2;
4695         kuid_t s_resuid;
4696         kgid_t s_resgid;
4697         unsigned long s_commit_interval;
4698         u32 s_min_batch_time, s_max_batch_time;
4699 #ifdef CONFIG_QUOTA
4700         int s_jquota_fmt;
4701         char *s_qf_names[MAXQUOTAS];
4702 #endif
4703 };
4704
4705 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4706 {
4707         struct ext4_super_block *es;
4708         struct ext4_sb_info *sbi = EXT4_SB(sb);
4709         unsigned long old_sb_flags;
4710         struct ext4_mount_options old_opts;
4711         int enable_quota = 0;
4712         ext4_group_t g;
4713         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4714         int err = 0;
4715 #ifdef CONFIG_QUOTA
4716         int i, j;
4717 #endif
4718         char *orig_data = kstrdup(data, GFP_KERNEL);
4719
4720         /* Store the original options */
4721         old_sb_flags = sb->s_flags;
4722         old_opts.s_mount_opt = sbi->s_mount_opt;
4723         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4724         old_opts.s_resuid = sbi->s_resuid;
4725         old_opts.s_resgid = sbi->s_resgid;
4726         old_opts.s_commit_interval = sbi->s_commit_interval;
4727         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4728         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4729 #ifdef CONFIG_QUOTA
4730         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4731         for (i = 0; i < MAXQUOTAS; i++)
4732                 if (sbi->s_qf_names[i]) {
4733                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4734                                                          GFP_KERNEL);
4735                         if (!old_opts.s_qf_names[i]) {
4736                                 for (j = 0; j < i; j++)
4737                                         kfree(old_opts.s_qf_names[j]);
4738                                 kfree(orig_data);
4739                                 return -ENOMEM;
4740                         }
4741                 } else
4742                         old_opts.s_qf_names[i] = NULL;
4743 #endif
4744         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4745                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4746
4747         /*
4748          * Allow the "check" option to be passed as a remount option.
4749          */
4750         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4751                 err = -EINVAL;
4752                 goto restore_opts;
4753         }
4754
4755         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4756                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4757                         ext4_msg(sb, KERN_ERR, "can't mount with "
4758                                  "both data=journal and delalloc");
4759                         err = -EINVAL;
4760                         goto restore_opts;
4761                 }
4762                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4763                         ext4_msg(sb, KERN_ERR, "can't mount with "
4764                                  "both data=journal and dioread_nolock");
4765                         err = -EINVAL;
4766                         goto restore_opts;
4767                 }
4768         }
4769
4770         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4771                 ext4_abort(sb, "Abort forced by user");
4772
4773         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4774                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4775
4776         es = sbi->s_es;
4777
4778         if (sbi->s_journal) {
4779                 ext4_init_journal_params(sb, sbi->s_journal);
4780                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4781         }
4782
4783         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4784                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4785                         err = -EROFS;
4786                         goto restore_opts;
4787                 }
4788
4789                 if (*flags & MS_RDONLY) {
4790                         err = dquot_suspend(sb, -1);
4791                         if (err < 0)
4792                                 goto restore_opts;
4793
4794                         /*
4795                          * First of all, the unconditional stuff we have to do
4796                          * to disable replay of the journal when we next remount
4797                          */
4798                         sb->s_flags |= MS_RDONLY;
4799
4800                         /*
4801                          * OK, test if we are remounting a valid rw partition
4802                          * readonly, and if so set the rdonly flag and then
4803                          * mark the partition as valid again.
4804                          */
4805                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4806                             (sbi->s_mount_state & EXT4_VALID_FS))
4807                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4808
4809                         if (sbi->s_journal)
4810                                 ext4_mark_recovery_complete(sb, es);
4811                 } else {
4812                         /* Make sure we can mount this feature set readwrite */
4813                         if (!ext4_feature_set_ok(sb, 0)) {
4814                                 err = -EROFS;
4815                                 goto restore_opts;
4816                         }
4817                         /*
4818                          * Make sure the group descriptor checksums
4819                          * are sane.  If they aren't, refuse to remount r/w.
4820                          */
4821                         for (g = 0; g < sbi->s_groups_count; g++) {
4822                                 struct ext4_group_desc *gdp =
4823                                         ext4_get_group_desc(sb, g, NULL);
4824
4825                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4826                                         ext4_msg(sb, KERN_ERR,
4827                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4828                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4829                                                le16_to_cpu(gdp->bg_checksum));
4830                                         err = -EINVAL;
4831                                         goto restore_opts;
4832                                 }
4833                         }
4834
4835                         /*
4836                          * If we have an unprocessed orphan list hanging
4837                          * around from a previously readonly bdev mount,
4838                          * require a full umount/remount for now.
4839                          */
4840                         if (es->s_last_orphan) {
4841                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4842                                        "remount RDWR because of unprocessed "
4843                                        "orphan inode list.  Please "
4844                                        "umount/remount instead");
4845                                 err = -EINVAL;
4846                                 goto restore_opts;
4847                         }
4848
4849                         /*
4850                          * Mounting a RDONLY partition read-write, so reread
4851                          * and store the current valid flag.  (It may have
4852                          * been changed by e2fsck since we originally mounted
4853                          * the partition.)
4854                          */
4855                         if (sbi->s_journal)
4856                                 ext4_clear_journal_err(sb, es);
4857                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4858                         if (!ext4_setup_super(sb, es, 0))
4859                                 sb->s_flags &= ~MS_RDONLY;
4860                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4861                                                      EXT4_FEATURE_INCOMPAT_MMP))
4862                                 if (ext4_multi_mount_protect(sb,
4863                                                 le64_to_cpu(es->s_mmp_block))) {
4864                                         err = -EROFS;
4865                                         goto restore_opts;
4866                                 }
4867                         enable_quota = 1;
4868                 }
4869         }
4870
4871         /*
4872          * Reinitialize lazy itable initialization thread based on
4873          * current settings
4874          */
4875         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4876                 ext4_unregister_li_request(sb);
4877         else {
4878                 ext4_group_t first_not_zeroed;
4879                 first_not_zeroed = ext4_has_uninit_itable(sb);
4880                 ext4_register_li_request(sb, first_not_zeroed);
4881         }
4882
4883         ext4_setup_system_zone(sb);
4884         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4885                 ext4_commit_super(sb, 1);
4886
4887 #ifdef CONFIG_QUOTA
4888         /* Release old quota file names */
4889         for (i = 0; i < MAXQUOTAS; i++)
4890                 kfree(old_opts.s_qf_names[i]);
4891         if (enable_quota) {
4892                 if (sb_any_quota_suspended(sb))
4893                         dquot_resume(sb, -1);
4894                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4895                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4896                         err = ext4_enable_quotas(sb);
4897                         if (err)
4898                                 goto restore_opts;
4899                 }
4900         }
4901 #endif
4902
4903         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4904         kfree(orig_data);
4905         return 0;
4906
4907 restore_opts:
4908         sb->s_flags = old_sb_flags;
4909         sbi->s_mount_opt = old_opts.s_mount_opt;
4910         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4911         sbi->s_resuid = old_opts.s_resuid;
4912         sbi->s_resgid = old_opts.s_resgid;
4913         sbi->s_commit_interval = old_opts.s_commit_interval;
4914         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4915         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4916 #ifdef CONFIG_QUOTA
4917         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4918         for (i = 0; i < MAXQUOTAS; i++) {
4919                 kfree(sbi->s_qf_names[i]);
4920                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4921         }
4922 #endif
4923         kfree(orig_data);
4924         return err;
4925 }
4926
4927 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4928 {
4929         struct super_block *sb = dentry->d_sb;
4930         struct ext4_sb_info *sbi = EXT4_SB(sb);
4931         struct ext4_super_block *es = sbi->s_es;
4932         ext4_fsblk_t overhead = 0, resv_blocks;
4933         u64 fsid;
4934         s64 bfree;
4935         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4936
4937         if (!test_opt(sb, MINIX_DF))
4938                 overhead = sbi->s_overhead;
4939
4940         buf->f_type = EXT4_SUPER_MAGIC;
4941         buf->f_bsize = sb->s_blocksize;
4942         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4943         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4944                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4945         /* prevent underflow in case that few free space is available */
4946         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4947         buf->f_bavail = buf->f_bfree -
4948                         (ext4_r_blocks_count(es) + resv_blocks);
4949         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4950                 buf->f_bavail = 0;
4951         buf->f_files = le32_to_cpu(es->s_inodes_count);
4952         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4953         buf->f_namelen = EXT4_NAME_LEN;
4954         fsid = le64_to_cpup((void *)es->s_uuid) ^
4955                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4956         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4957         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4958
4959         return 0;
4960 }
4961
4962 /* Helper function for writing quotas on sync - we need to start transaction
4963  * before quota file is locked for write. Otherwise the are possible deadlocks:
4964  * Process 1                         Process 2
4965  * ext4_create()                     quota_sync()
4966  *   jbd2_journal_start()                  write_dquot()
4967  *   dquot_initialize()                         down(dqio_mutex)
4968  *     down(dqio_mutex)                    jbd2_journal_start()
4969  *
4970  */
4971
4972 #ifdef CONFIG_QUOTA
4973
4974 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4975 {
4976         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4977 }
4978
4979 static int ext4_write_dquot(struct dquot *dquot)
4980 {
4981         int ret, err;
4982         handle_t *handle;
4983         struct inode *inode;
4984
4985         inode = dquot_to_inode(dquot);
4986         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4987                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4988         if (IS_ERR(handle))
4989                 return PTR_ERR(handle);
4990         ret = dquot_commit(dquot);
4991         err = ext4_journal_stop(handle);
4992         if (!ret)
4993                 ret = err;
4994         return ret;
4995 }
4996
4997 static int ext4_acquire_dquot(struct dquot *dquot)
4998 {
4999         int ret, err;
5000         handle_t *handle;
5001
5002         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5003                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5004         if (IS_ERR(handle))
5005                 return PTR_ERR(handle);
5006         ret = dquot_acquire(dquot);
5007         err = ext4_journal_stop(handle);
5008         if (!ret)
5009                 ret = err;
5010         return ret;
5011 }
5012
5013 static int ext4_release_dquot(struct dquot *dquot)
5014 {
5015         int ret, err;
5016         handle_t *handle;
5017
5018         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5019                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5020         if (IS_ERR(handle)) {
5021                 /* Release dquot anyway to avoid endless cycle in dqput() */
5022                 dquot_release(dquot);
5023                 return PTR_ERR(handle);
5024         }
5025         ret = dquot_release(dquot);
5026         err = ext4_journal_stop(handle);
5027         if (!ret)
5028                 ret = err;
5029         return ret;
5030 }
5031
5032 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5033 {
5034         struct super_block *sb = dquot->dq_sb;
5035         struct ext4_sb_info *sbi = EXT4_SB(sb);
5036
5037         /* Are we journaling quotas? */
5038         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5039             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5040                 dquot_mark_dquot_dirty(dquot);
5041                 return ext4_write_dquot(dquot);
5042         } else {
5043                 return dquot_mark_dquot_dirty(dquot);
5044         }
5045 }
5046
5047 static int ext4_write_info(struct super_block *sb, int type)
5048 {
5049         int ret, err;
5050         handle_t *handle;
5051
5052         /* Data block + inode block */
5053         handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5054         if (IS_ERR(handle))
5055                 return PTR_ERR(handle);
5056         ret = dquot_commit_info(sb, type);
5057         err = ext4_journal_stop(handle);
5058         if (!ret)
5059                 ret = err;
5060         return ret;
5061 }
5062
5063 /*
5064  * Turn on quotas during mount time - we need to find
5065  * the quota file and such...
5066  */
5067 static int ext4_quota_on_mount(struct super_block *sb, int type)
5068 {
5069         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5070                                         EXT4_SB(sb)->s_jquota_fmt, type);
5071 }
5072
5073 /*
5074  * Standard function to be called on quota_on
5075  */
5076 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5077                          struct path *path)
5078 {
5079         int err;
5080
5081         if (!test_opt(sb, QUOTA))
5082                 return -EINVAL;
5083
5084         /* Quotafile not on the same filesystem? */
5085         if (path->dentry->d_sb != sb)
5086                 return -EXDEV;
5087         /* Journaling quota? */
5088         if (EXT4_SB(sb)->s_qf_names[type]) {
5089                 /* Quotafile not in fs root? */
5090                 if (path->dentry->d_parent != sb->s_root)
5091                         ext4_msg(sb, KERN_WARNING,
5092                                 "Quota file not on filesystem root. "
5093                                 "Journaled quota will not work");
5094         }
5095
5096         /*
5097          * When we journal data on quota file, we have to flush journal to see
5098          * all updates to the file when we bypass pagecache...
5099          */
5100         if (EXT4_SB(sb)->s_journal &&
5101             ext4_should_journal_data(path->dentry->d_inode)) {
5102                 /*
5103                  * We don't need to lock updates but journal_flush() could
5104                  * otherwise be livelocked...
5105                  */
5106                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5107                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5108                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5109                 if (err)
5110                         return err;
5111         }
5112
5113         return dquot_quota_on(sb, type, format_id, path);
5114 }
5115
5116 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5117                              unsigned int flags)
5118 {
5119         int err;
5120         struct inode *qf_inode;
5121         unsigned long qf_inums[MAXQUOTAS] = {
5122                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5123                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5124         };
5125
5126         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5127
5128         if (!qf_inums[type])
5129                 return -EPERM;
5130
5131         qf_inode = ext4_iget(sb, qf_inums[type]);
5132         if (IS_ERR(qf_inode)) {
5133                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5134                 return PTR_ERR(qf_inode);
5135         }
5136
5137         /* Don't account quota for quota files to avoid recursion */
5138         qf_inode->i_flags |= S_NOQUOTA;
5139         err = dquot_enable(qf_inode, type, format_id, flags);
5140         iput(qf_inode);
5141
5142         return err;
5143 }
5144
5145 /* Enable usage tracking for all quota types. */
5146 static int ext4_enable_quotas(struct super_block *sb)
5147 {
5148         int type, err = 0;
5149         unsigned long qf_inums[MAXQUOTAS] = {
5150                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5151                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5152         };
5153
5154         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5155         for (type = 0; type < MAXQUOTAS; type++) {
5156                 if (qf_inums[type]) {
5157                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5158                                                 DQUOT_USAGE_ENABLED);
5159                         if (err) {
5160                                 ext4_warning(sb,
5161                                         "Failed to enable quota tracking "
5162                                         "(type=%d, err=%d). Please run "
5163                                         "e2fsck to fix.", type, err);
5164                                 return err;
5165                         }
5166                 }
5167         }
5168         return 0;
5169 }
5170
5171 /*
5172  * quota_on function that is used when QUOTA feature is set.
5173  */
5174 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5175                                  int format_id)
5176 {
5177         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5178                 return -EINVAL;
5179
5180         /*
5181          * USAGE was enabled at mount time. Only need to enable LIMITS now.
5182          */
5183         return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5184 }
5185
5186 static int ext4_quota_off(struct super_block *sb, int type)
5187 {
5188         struct inode *inode = sb_dqopt(sb)->files[type];
5189         handle_t *handle;
5190
5191         /* Force all delayed allocation blocks to be allocated.
5192          * Caller already holds s_umount sem */
5193         if (test_opt(sb, DELALLOC))
5194                 sync_filesystem(sb);
5195
5196         if (!inode)
5197                 goto out;
5198
5199         /* Update modification times of quota files when userspace can
5200          * start looking at them */
5201         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5202         if (IS_ERR(handle))
5203                 goto out;
5204         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5205         ext4_mark_inode_dirty(handle, inode);
5206         ext4_journal_stop(handle);
5207
5208 out:
5209         return dquot_quota_off(sb, type);
5210 }
5211
5212 /*
5213  * quota_off function that is used when QUOTA feature is set.
5214  */
5215 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5216 {
5217         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5218                 return -EINVAL;
5219
5220         /* Disable only the limits. */
5221         return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5222 }
5223
5224 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5225  * acquiring the locks... As quota files are never truncated and quota code
5226  * itself serializes the operations (and no one else should touch the files)
5227  * we don't have to be afraid of races */
5228 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5229                                size_t len, loff_t off)
5230 {
5231         struct inode *inode = sb_dqopt(sb)->files[type];
5232         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5233         int err = 0;
5234         int offset = off & (sb->s_blocksize - 1);
5235         int tocopy;
5236         size_t toread;
5237         struct buffer_head *bh;
5238         loff_t i_size = i_size_read(inode);
5239
5240         if (off > i_size)
5241                 return 0;
5242         if (off+len > i_size)
5243                 len = i_size-off;
5244         toread = len;
5245         while (toread > 0) {
5246                 tocopy = sb->s_blocksize - offset < toread ?
5247                                 sb->s_blocksize - offset : toread;
5248                 bh = ext4_bread(NULL, inode, blk, 0, &err);
5249                 if (err)
5250                         return err;
5251                 if (!bh)        /* A hole? */
5252                         memset(data, 0, tocopy);
5253                 else
5254                         memcpy(data, bh->b_data+offset, tocopy);
5255                 brelse(bh);
5256                 offset = 0;
5257                 toread -= tocopy;
5258                 data += tocopy;
5259                 blk++;
5260         }
5261         return len;
5262 }
5263
5264 /* Write to quotafile (we know the transaction is already started and has
5265  * enough credits) */
5266 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5267                                 const char *data, size_t len, loff_t off)
5268 {
5269         struct inode *inode = sb_dqopt(sb)->files[type];
5270         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5271         int err = 0;
5272         int offset = off & (sb->s_blocksize - 1);
5273         struct buffer_head *bh;
5274         handle_t *handle = journal_current_handle();
5275
5276         if (EXT4_SB(sb)->s_journal && !handle) {
5277                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5278                         " cancelled because transaction is not started",
5279                         (unsigned long long)off, (unsigned long long)len);
5280                 return -EIO;
5281         }
5282         /*
5283          * Since we account only one data block in transaction credits,
5284          * then it is impossible to cross a block boundary.
5285          */
5286         if (sb->s_blocksize - offset < len) {
5287                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5288                         " cancelled because not block aligned",
5289                         (unsigned long long)off, (unsigned long long)len);
5290                 return -EIO;
5291         }
5292
5293         bh = ext4_bread(handle, inode, blk, 1, &err);
5294         if (!bh)
5295                 goto out;
5296         err = ext4_journal_get_write_access(handle, bh);
5297         if (err) {
5298                 brelse(bh);
5299                 goto out;
5300         }
5301         lock_buffer(bh);
5302         memcpy(bh->b_data+offset, data, len);
5303         flush_dcache_page(bh->b_page);
5304         unlock_buffer(bh);
5305         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5306         brelse(bh);
5307 out:
5308         if (err)
5309                 return err;
5310         if (inode->i_size < off + len) {
5311                 i_size_write(inode, off + len);
5312                 EXT4_I(inode)->i_disksize = inode->i_size;
5313                 ext4_mark_inode_dirty(handle, inode);
5314         }
5315         return len;
5316 }
5317
5318 #endif
5319
5320 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5321                        const char *dev_name, void *data)
5322 {
5323         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5324 }
5325
5326 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5327 static inline void register_as_ext2(void)
5328 {
5329         int err = register_filesystem(&ext2_fs_type);
5330         if (err)
5331                 printk(KERN_WARNING
5332                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5333 }
5334
5335 static inline void unregister_as_ext2(void)
5336 {
5337         unregister_filesystem(&ext2_fs_type);
5338 }
5339
5340 static inline int ext2_feature_set_ok(struct super_block *sb)
5341 {
5342         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5343                 return 0;
5344         if (sb->s_flags & MS_RDONLY)
5345                 return 1;
5346         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5347                 return 0;
5348         return 1;
5349 }
5350 #else
5351 static inline void register_as_ext2(void) { }
5352 static inline void unregister_as_ext2(void) { }
5353 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5354 #endif
5355
5356 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5357 static inline void register_as_ext3(void)
5358 {
5359         int err = register_filesystem(&ext3_fs_type);
5360         if (err)
5361                 printk(KERN_WARNING
5362                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5363 }
5364
5365 static inline void unregister_as_ext3(void)
5366 {
5367         unregister_filesystem(&ext3_fs_type);
5368 }
5369
5370 static inline int ext3_feature_set_ok(struct super_block *sb)
5371 {
5372         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5373                 return 0;
5374         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5375                 return 0;
5376         if (sb->s_flags & MS_RDONLY)
5377                 return 1;
5378         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5379                 return 0;
5380         return 1;
5381 }
5382 #else
5383 static inline void register_as_ext3(void) { }
5384 static inline void unregister_as_ext3(void) { }
5385 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5386 #endif
5387
5388 static struct file_system_type ext4_fs_type = {
5389         .owner          = THIS_MODULE,
5390         .name           = "ext4",
5391         .mount          = ext4_mount,
5392         .kill_sb        = kill_block_super,
5393         .fs_flags       = FS_REQUIRES_DEV,
5394 };
5395 MODULE_ALIAS_FS("ext4");
5396
5397 static int __init ext4_init_feat_adverts(void)
5398 {
5399         struct ext4_features *ef;
5400         int ret = -ENOMEM;
5401
5402         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5403         if (!ef)
5404                 goto out;
5405
5406         ef->f_kobj.kset = ext4_kset;
5407         init_completion(&ef->f_kobj_unregister);
5408         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5409                                    "features");
5410         if (ret) {
5411                 kfree(ef);
5412                 goto out;
5413         }
5414
5415         ext4_feat = ef;
5416         ret = 0;
5417 out:
5418         return ret;
5419 }
5420
5421 static void ext4_exit_feat_adverts(void)
5422 {
5423         kobject_put(&ext4_feat->f_kobj);
5424         wait_for_completion(&ext4_feat->f_kobj_unregister);
5425         kfree(ext4_feat);
5426 }
5427
5428 /* Shared across all ext4 file systems */
5429 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5430 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5431
5432 static int __init ext4_init_fs(void)
5433 {
5434         int i, err;
5435
5436         ext4_li_info = NULL;
5437         mutex_init(&ext4_li_mtx);
5438
5439         /* Build-time check for flags consistency */
5440         ext4_check_flag_values();
5441
5442         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5443                 mutex_init(&ext4__aio_mutex[i]);
5444                 init_waitqueue_head(&ext4__ioend_wq[i]);
5445         }
5446
5447         err = ext4_init_es();
5448         if (err)
5449                 return err;
5450
5451         err = ext4_init_pageio();
5452         if (err)
5453                 goto out7;
5454
5455         err = ext4_init_system_zone();
5456         if (err)
5457                 goto out6;
5458         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5459         if (!ext4_kset) {
5460                 err = -ENOMEM;
5461                 goto out5;
5462         }
5463         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5464
5465         err = ext4_init_feat_adverts();
5466         if (err)
5467                 goto out4;
5468
5469         err = ext4_init_mballoc();
5470         if (err)
5471                 goto out3;
5472
5473         err = ext4_init_xattr();
5474         if (err)
5475                 goto out2;
5476         err = init_inodecache();
5477         if (err)
5478                 goto out1;
5479         register_as_ext3();
5480         register_as_ext2();
5481         err = register_filesystem(&ext4_fs_type);
5482         if (err)
5483                 goto out;
5484
5485         return 0;
5486 out:
5487         unregister_as_ext2();
5488         unregister_as_ext3();
5489         destroy_inodecache();
5490 out1:
5491         ext4_exit_xattr();
5492 out2:
5493         ext4_exit_mballoc();
5494 out3:
5495         ext4_exit_feat_adverts();
5496 out4:
5497         if (ext4_proc_root)
5498                 remove_proc_entry("fs/ext4", NULL);
5499         kset_unregister(ext4_kset);
5500 out5:
5501         ext4_exit_system_zone();
5502 out6:
5503         ext4_exit_pageio();
5504 out7:
5505         ext4_exit_es();
5506
5507         return err;
5508 }
5509
5510 static void __exit ext4_exit_fs(void)
5511 {
5512         ext4_destroy_lazyinit_thread();
5513         unregister_as_ext2();
5514         unregister_as_ext3();
5515         unregister_filesystem(&ext4_fs_type);
5516         destroy_inodecache();
5517         ext4_exit_xattr();
5518         ext4_exit_mballoc();
5519         ext4_exit_feat_adverts();
5520         remove_proc_entry("fs/ext4", NULL);
5521         kset_unregister(ext4_kset);
5522         ext4_exit_system_zone();
5523         ext4_exit_pageio();
5524         ext4_exit_es();
5525 }
5526
5527 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5528 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5529 MODULE_LICENSE("GPL");
5530 module_init(ext4_init_fs)
5531 module_exit(ext4_exit_fs)