kernel/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/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/parser.h>
  28 #include <linux/buffer_head.h>
  29 #include <linux/exportfs.h>
  30 #include <linux/vfs.h>
  31 #include <linux/random.h>
  32 #include <linux/mount.h>
  33 #include <linux/namei.h>
  34 #include <linux/quotaops.h>
  35 #include <linux/seq_file.h>
  36 #include <linux/proc_fs.h>
  37 #include <linux/ctype.h>
  38 #include <linux/log2.h>
  39 #include <linux/crc16.h>
  40 #include <linux/cleancache.h>
  41 #include <asm/uaccess.h>
  42
  43 #include <linux/kthread.h>
  44 #include <linux/freezer.h>
  45
  46 #include "ext4.h"
  47 #include "ext4_extents.h"       /* Needed for trace points definition */
  48 #include "ext4_jbd2.h"
  49 #include "xattr.h"
  50 #include "acl.h"
  51 #include "mballoc.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/ext4.h>
  55
  56 static struct proc_dir_entry *ext4_proc_root;
  57 static struct kset *ext4_kset;
  58 static struct ext4_lazy_init *ext4_li_info;
  59 static struct mutex ext4_li_mtx;
  60 static struct ext4_features *ext4_feat;
  61 static int ext4_mballoc_ready;
  62
  63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  64                              unsigned long journal_devnum);
  65 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  66 static int ext4_commit_super(struct super_block *sb, int sync);
  67 static void ext4_mark_recovery_complete(struct super_block *sb,
  68                                         struct ext4_super_block *es);
  69 static void ext4_clear_journal_err(struct super_block *sb,
  70                                    struct ext4_super_block *es);
  71 static int ext4_sync_fs(struct super_block *sb, int wait);
  72 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  73 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  74 static int ext4_unfreeze(struct super_block *sb);
  75 static int ext4_freeze(struct super_block *sb);
  76 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  77                        const char *dev_name, void *data);
  78 static inline int ext2_feature_set_ok(struct super_block *sb);
  79 static inline int ext3_feature_set_ok(struct super_block *sb);
  80 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  81 static void ext4_destroy_lazyinit_thread(void);
  82 static void ext4_unregister_li_request(struct super_block *sb);
  83 static void ext4_clear_request_list(void);
  84 static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
  85
  86 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  87 static struct file_system_type ext2_fs_type = {
  88         .owner          = THIS_MODULE,
  89         .name           = "ext2",
  90         .mount          = ext4_mount,
  91         .kill_sb        = kill_block_super,
  92         .fs_flags       = FS_REQUIRES_DEV,
  93 };
  94 MODULE_ALIAS_FS("ext2");
  95 MODULE_ALIAS("ext2");
  96 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  97 #else
  98 #define IS_EXT2_SB(sb) (0)
  99 #endif
 100
 101
 102 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 103 static struct file_system_type ext3_fs_type = {
 104         .owner          = THIS_MODULE,
 105         .name           = "ext3",
 106         .mount          = ext4_mount,
 107         .kill_sb        = kill_block_super,
 108         .fs_flags       = FS_REQUIRES_DEV,
 109 };
 110 MODULE_ALIAS_FS("ext3");
 111 MODULE_ALIAS("ext3");
 112 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 113 #else
 114 #define IS_EXT3_SB(sb) (0)
 115 #endif
 116
 117 static int ext4_verify_csum_type(struct super_block *sb,
 118                                  struct ext4_super_block *es)
 119 {
 120         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 121                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 122                 return 1;
 123
 124         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 125 }
 126
 127 static __le32 ext4_superblock_csum(struct super_block *sb,
 128                                    struct ext4_super_block *es)
 129 {
 130         struct ext4_sb_info *sbi = EXT4_SB(sb);
 131         int offset = offsetof(struct ext4_super_block, s_checksum);
 132         __u32 csum;
 133
 134         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 135
 136         return cpu_to_le32(csum);
 137 }
 138
 139 static int ext4_superblock_csum_verify(struct super_block *sb,
 140                                        struct ext4_super_block *es)
 141 {
 142         if (!ext4_has_metadata_csum(sb))
 143                 return 1;
 144
 145         return es->s_checksum == ext4_superblock_csum(sb, es);
 146 }
 147
 148 void ext4_superblock_csum_set(struct super_block *sb)
 149 {
 150         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 151
 152         if (!ext4_has_metadata_csum(sb))
 153                 return;
 154
 155         es->s_checksum = ext4_superblock_csum(sb, es);
 156 }
 157
 158 void *ext4_kvmalloc(size_t size, gfp_t flags)
 159 {
 160         void *ret;
 161
 162         ret = kmalloc(size, flags | __GFP_NOWARN);
 163         if (!ret)
 164                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 165         return ret;
 166 }
 167
 168 void *ext4_kvzalloc(size_t size, gfp_t flags)
 169 {
 170         void *ret;
 171
 172         ret = kzalloc(size, flags | __GFP_NOWARN);
 173         if (!ret)
 174                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 175         return ret;
 176 }
 177
 178 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 179                                struct ext4_group_desc *bg)
 180 {
 181         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 182                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 183                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 184 }
 185
 186 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 187                                struct ext4_group_desc *bg)
 188 {
 189         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 190                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 191                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 192 }
 193
 194 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 195                               struct ext4_group_desc *bg)
 196 {
 197         return le32_to_cpu(bg->bg_inode_table_lo) |
 198                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 199                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 200 }
 201
 202 __u32 ext4_free_group_clusters(struct super_block *sb,
 203                                struct ext4_group_desc *bg)
 204 {
 205         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 206                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 207                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 208 }
 209
 210 __u32 ext4_free_inodes_count(struct super_block *sb,
 211                               struct ext4_group_desc *bg)
 212 {
 213         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 214                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 215                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 216 }
 217
 218 __u32 ext4_used_dirs_count(struct super_block *sb,
 219                               struct ext4_group_desc *bg)
 220 {
 221         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 222                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 223                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 224 }
 225
 226 __u32 ext4_itable_unused_count(struct super_block *sb,
 227                               struct ext4_group_desc *bg)
 228 {
 229         return le16_to_cpu(bg->bg_itable_unused_lo) |
 230                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 231                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 232 }
 233
 234 void ext4_block_bitmap_set(struct super_block *sb,
 235                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 236 {
 237         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 238         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 239                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 240 }
 241
 242 void ext4_inode_bitmap_set(struct super_block *sb,
 243                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 244 {
 245         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 246         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 247                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 248 }
 249
 250 void ext4_inode_table_set(struct super_block *sb,
 251                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 252 {
 253         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 254         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 255                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 256 }
 257
 258 void ext4_free_group_clusters_set(struct super_block *sb,
 259                                   struct ext4_group_desc *bg, __u32 count)
 260 {
 261         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 262         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 263                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 264 }
 265
 266 void ext4_free_inodes_set(struct super_block *sb,
 267                           struct ext4_group_desc *bg, __u32 count)
 268 {
 269         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 270         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 271                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 272 }
 273
 274 void ext4_used_dirs_set(struct super_block *sb,
 275                           struct ext4_group_desc *bg, __u32 count)
 276 {
 277         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 278         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 279                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 280 }
 281
 282 void ext4_itable_unused_set(struct super_block *sb,
 283                           struct ext4_group_desc *bg, __u32 count)
 284 {
 285         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 286         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 287                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 288 }
 289
 290
 291 static void __save_error_info(struct super_block *sb, const char *func,
 292                             unsigned int line)
 293 {
 294         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 295
 296         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 297         if (bdev_read_only(sb->s_bdev))
 298                 return;
 299         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 300         es->s_last_error_time = cpu_to_le32(get_seconds());
 301         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 302         es->s_last_error_line = cpu_to_le32(line);
 303         if (!es->s_first_error_time) {
 304                 es->s_first_error_time = es->s_last_error_time;
 305                 strncpy(es->s_first_error_func, func,
 306                         sizeof(es->s_first_error_func));
 307                 es->s_first_error_line = cpu_to_le32(line);
 308                 es->s_first_error_ino = es->s_last_error_ino;
 309                 es->s_first_error_block = es->s_last_error_block;
 310         }
 311         /*
 312          * Start the daily error reporting function if it hasn't been
 313          * started already
 314          */
 315         if (!es->s_error_count)
 316                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 317         le32_add_cpu(&es->s_error_count, 1);
 318 }
 319
 320 static void save_error_info(struct super_block *sb, const char *func,
 321                             unsigned int line)
 322 {
 323         __save_error_info(sb, func, line);
 324         ext4_commit_super(sb, 1);
 325 }
 326
 327 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 328 {
 329         struct super_block              *sb = journal->j_private;
 330         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 331         int                             error = is_journal_aborted(journal);
 332         struct ext4_journal_cb_entry    *jce;
 333
 334         BUG_ON(txn->t_state == T_FINISHED);
 335         spin_lock(&sbi->s_md_lock);
 336         while (!list_empty(&txn->t_private_list)) {
 337                 jce = list_entry(txn->t_private_list.next,
 338                                  struct ext4_journal_cb_entry, jce_list);
 339                 list_del_init(&jce->jce_list);
 340                 spin_unlock(&sbi->s_md_lock);
 341                 jce->jce_func(sb, jce, error);
 342                 spin_lock(&sbi->s_md_lock);
 343         }
 344         spin_unlock(&sbi->s_md_lock);
 345 }
 346
 347 /* Deal with the reporting of failure conditions on a filesystem such as
 348  * inconsistencies detected or read IO failures.
 349  *
 350  * On ext2, we can store the error state of the filesystem in the
 351  * superblock.  That is not possible on ext4, because we may have other
 352  * write ordering constraints on the superblock which prevent us from
 353  * writing it out straight away; and given that the journal is about to
 354  * be aborted, we can't rely on the current, or future, transactions to
 355  * write out the superblock safely.
 356  *
 357  * We'll just use the jbd2_journal_abort() error code to record an error in
 358  * the journal instead.  On recovery, the journal will complain about
 359  * that error until we've noted it down and cleared it.
 360  */
 361
 362 static void ext4_handle_error(struct super_block *sb)
 363 {
 364         if (sb->s_flags & MS_RDONLY)
 365                 return;
 366
 367         if (!test_opt(sb, ERRORS_CONT)) {
 368                 journal_t *journal = EXT4_SB(sb)->s_journal;
 369
 370                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 371                 if (journal)
 372                         jbd2_journal_abort(journal, -EIO);
 373         }
 374         if (test_opt(sb, ERRORS_RO)) {
 375                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 376                 /*
 377                  * Make sure updated value of ->s_mount_flags will be visible
 378                  * before ->s_flags update
 379                  */
 380                 smp_wmb();
 381                 sb->s_flags |= MS_RDONLY;
 382         }
 383         if (test_opt(sb, ERRORS_PANIC))
 384                 panic("EXT4-fs (device %s): panic forced after error\n",
 385                         sb->s_id);
 386 }
 387
 388 #define ext4_error_ratelimit(sb)                                        \
 389                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 390                              "EXT4-fs error")
 391
 392 void __ext4_error(struct super_block *sb, const char *function,
 393                   unsigned int line, const char *fmt, ...)
 394 {
 395         struct va_format vaf;
 396         va_list args;
 397
 398         if (ext4_error_ratelimit(sb)) {
 399                 va_start(args, fmt);
 400                 vaf.fmt = fmt;
 401                 vaf.va = &args;
 402                 printk(KERN_CRIT
 403                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 404                        sb->s_id, function, line, current->comm, &vaf);
 405                 va_end(args);
 406         }
 407         save_error_info(sb, function, line);
 408         ext4_handle_error(sb);
 409 }
 410
 411 void __ext4_error_inode(struct inode *inode, const char *function,
 412                         unsigned int line, ext4_fsblk_t block,
 413                         const char *fmt, ...)
 414 {
 415         va_list args;
 416         struct va_format vaf;
 417         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 418
 419         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 420         es->s_last_error_block = cpu_to_le64(block);
 421         if (ext4_error_ratelimit(inode->i_sb)) {
 422                 va_start(args, fmt);
 423                 vaf.fmt = fmt;
 424                 vaf.va = &args;
 425                 if (block)
 426                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 427                                "inode #%lu: block %llu: comm %s: %pV\n",
 428                                inode->i_sb->s_id, function, line, inode->i_ino,
 429                                block, current->comm, &vaf);
 430                 else
 431                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 432                                "inode #%lu: comm %s: %pV\n",
 433                                inode->i_sb->s_id, function, line, inode->i_ino,
 434                                current->comm, &vaf);
 435                 va_end(args);
 436         }
 437         save_error_info(inode->i_sb, function, line);
 438         ext4_handle_error(inode->i_sb);
 439 }
 440
 441 void __ext4_error_file(struct file *file, const char *function,
 442                        unsigned int line, ext4_fsblk_t block,
 443                        const char *fmt, ...)
 444 {
 445         va_list args;
 446         struct va_format vaf;
 447         struct ext4_super_block *es;
 448         struct inode *inode = file_inode(file);
 449         char pathname[80], *path;
 450
 451         es = EXT4_SB(inode->i_sb)->s_es;
 452         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 453         if (ext4_error_ratelimit(inode->i_sb)) {
 454                 path = d_path(&(file->f_path), pathname, sizeof(pathname));
 455                 if (IS_ERR(path))
 456                         path = "(unknown)";
 457                 va_start(args, fmt);
 458                 vaf.fmt = fmt;
 459                 vaf.va = &args;
 460                 if (block)
 461                         printk(KERN_CRIT
 462                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 463                                "block %llu: comm %s: path %s: %pV\n",
 464                                inode->i_sb->s_id, function, line, inode->i_ino,
 465                                block, current->comm, path, &vaf);
 466                 else
 467                         printk(KERN_CRIT
 468                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 469                                "comm %s: path %s: %pV\n",
 470                                inode->i_sb->s_id, function, line, inode->i_ino,
 471                                current->comm, path, &vaf);
 472                 va_end(args);
 473         }
 474         save_error_info(inode->i_sb, function, line);
 475         ext4_handle_error(inode->i_sb);
 476 }
 477
 478 const char *ext4_decode_error(struct super_block *sb, int errno,
 479                               char nbuf[16])
 480 {
 481         char *errstr = NULL;
 482
 483         switch (errno) {
 484         case -EIO:
 485                 errstr = "IO failure";
 486                 break;
 487         case -ENOMEM:
 488                 errstr = "Out of memory";
 489                 break;
 490         case -EROFS:
 491                 if (!sb || (EXT4_SB(sb)->s_journal &&
 492                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 493                         errstr = "Journal has aborted";
 494                 else
 495                         errstr = "Readonly filesystem";
 496                 break;
 497         default:
 498                 /* If the caller passed in an extra buffer for unknown
 499                  * errors, textualise them now.  Else we just return
 500                  * NULL. */
 501                 if (nbuf) {
 502                         /* Check for truncated error codes... */
 503                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 504                                 errstr = nbuf;
 505                 }
 506                 break;
 507         }
 508
 509         return errstr;
 510 }
 511
 512 /* __ext4_std_error decodes expected errors from journaling functions
 513  * automatically and invokes the appropriate error response.  */
 514
 515 void __ext4_std_error(struct super_block *sb, const char *function,
 516                       unsigned int line, int errno)
 517 {
 518         char nbuf[16];
 519         const char *errstr;
 520
 521         /* Special case: if the error is EROFS, and we're not already
 522          * inside a transaction, then there's really no point in logging
 523          * an error. */
 524         if (errno == -EROFS && journal_current_handle() == NULL &&
 525             (sb->s_flags & MS_RDONLY))
 526                 return;
 527
 528         if (ext4_error_ratelimit(sb)) {
 529                 errstr = ext4_decode_error(sb, errno, nbuf);
 530                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 531                        sb->s_id, function, line, errstr);
 532         }
 533
 534         save_error_info(sb, function, line);
 535         ext4_handle_error(sb);
 536 }
 537
 538 /*
 539  * ext4_abort is a much stronger failure handler than ext4_error.  The
 540  * abort function may be used to deal with unrecoverable failures such
 541  * as journal IO errors or ENOMEM at a critical moment in log management.
 542  *
 543  * We unconditionally force the filesystem into an ABORT|READONLY state,
 544  * unless the error response on the fs has been set to panic in which
 545  * case we take the easy way out and panic immediately.
 546  */
 547
 548 void __ext4_abort(struct super_block *sb, const char *function,
 549                 unsigned int line, const char *fmt, ...)
 550 {
 551         va_list args;
 552
 553         save_error_info(sb, function, line);
 554         va_start(args, fmt);
 555         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 556                function, line);
 557         vprintk(fmt, args);
 558         printk("\n");
 559         va_end(args);
 560
 561         if ((sb->s_flags & MS_RDONLY) == 0) {
 562                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 563                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 564                 /*
 565                  * Make sure updated value of ->s_mount_flags will be visible
 566                  * before ->s_flags update
 567                  */
 568                 smp_wmb();
 569                 sb->s_flags |= MS_RDONLY;
 570                 if (EXT4_SB(sb)->s_journal)
 571                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 572                 save_error_info(sb, function, line);
 573         }
 574         if (test_opt(sb, ERRORS_PANIC))
 575                 panic("EXT4-fs panic from previous error\n");
 576 }
 577
 578 void __ext4_msg(struct super_block *sb,
 579                 const char *prefix, const char *fmt, ...)
 580 {
 581         struct va_format vaf;
 582         va_list args;
 583
 584         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 585                 return;
 586
 587         va_start(args, fmt);
 588         vaf.fmt = fmt;
 589         vaf.va = &args;
 590         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 591         va_end(args);
 592 }
 593
 594 void __ext4_warning(struct super_block *sb, const char *function,
 595                     unsigned int line, const char *fmt, ...)
 596 {
 597         struct va_format vaf;
 598         va_list args;
 599
 600         if (!___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
 601                           "EXT4-fs warning"))
 602                 return;
 603
 604         va_start(args, fmt);
 605         vaf.fmt = fmt;
 606         vaf.va = &args;
 607         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 608                sb->s_id, function, line, &vaf);
 609         va_end(args);
 610 }
 611
 612 void __ext4_grp_locked_error(const char *function, unsigned int line,
 613                              struct super_block *sb, ext4_group_t grp,
 614                              unsigned long ino, ext4_fsblk_t block,
 615                              const char *fmt, ...)
 616 __releases(bitlock)
 617 __acquires(bitlock)
 618 {
 619         struct va_format vaf;
 620         va_list args;
 621         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 622
 623         es->s_last_error_ino = cpu_to_le32(ino);
 624         es->s_last_error_block = cpu_to_le64(block);
 625         __save_error_info(sb, function, line);
 626
 627         if (ext4_error_ratelimit(sb)) {
 628                 va_start(args, fmt);
 629                 vaf.fmt = fmt;
 630                 vaf.va = &args;
 631                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 632                        sb->s_id, function, line, grp);
 633                 if (ino)
 634                         printk(KERN_CONT "inode %lu: ", ino);
 635                 if (block)
 636                         printk(KERN_CONT "block %llu:",
 637                                (unsigned long long) block);
 638                 printk(KERN_CONT "%pV\n", &vaf);
 639                 va_end(args);
 640         }
 641
 642         if (test_opt(sb, ERRORS_CONT)) {
 643                 ext4_commit_super(sb, 0);
 644                 return;
 645         }
 646
 647         ext4_unlock_group(sb, grp);
 648         ext4_handle_error(sb);
 649         /*
 650          * We only get here in the ERRORS_RO case; relocking the group
 651          * may be dangerous, but nothing bad will happen since the
 652          * filesystem will have already been marked read/only and the
 653          * journal has been aborted.  We return 1 as a hint to callers
 654          * who might what to use the return value from
 655          * ext4_grp_locked_error() to distinguish between the
 656          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 657          * aggressively from the ext4 function in question, with a
 658          * more appropriate error code.
 659          */
 660         ext4_lock_group(sb, grp);
 661         return;
 662 }
 663
 664 void ext4_update_dynamic_rev(struct super_block *sb)
 665 {
 666         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 667
 668         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 669                 return;
 670
 671         ext4_warning(sb,
 672                      "updating to rev %d because of new feature flag, "
 673                      "running e2fsck is recommended",
 674                      EXT4_DYNAMIC_REV);
 675
 676         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 677         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 678         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 679         /* leave es->s_feature_*compat flags alone */
 680         /* es->s_uuid will be set by e2fsck if empty */
 681
 682         /*
 683          * The rest of the superblock fields should be zero, and if not it
 684          * means they are likely already in use, so leave them alone.  We
 685          * can leave it up to e2fsck to clean up any inconsistencies there.
 686          */
 687 }
 688
 689 /*
 690  * Open the external journal device
 691  */
 692 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 693 {
 694         struct block_device *bdev;
 695         char b[BDEVNAME_SIZE];
 696
 697         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 698         if (IS_ERR(bdev))
 699                 goto fail;
 700         return bdev;
 701
 702 fail:
 703         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 704                         __bdevname(dev, b), PTR_ERR(bdev));
 705         return NULL;
 706 }
 707
 708 /*
 709  * Release the journal device
 710  */
 711 static void ext4_blkdev_put(struct block_device *bdev)
 712 {
 713         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 714 }
 715
 716 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 717 {
 718         struct block_device *bdev;
 719         bdev = sbi->journal_bdev;
 720         if (bdev) {
 721                 ext4_blkdev_put(bdev);
 722                 sbi->journal_bdev = NULL;
 723         }
 724 }
 725
 726 static inline struct inode *orphan_list_entry(struct list_head *l)
 727 {
 728         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 729 }
 730
 731 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 732 {
 733         struct list_head *l;
 734
 735         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 736                  le32_to_cpu(sbi->s_es->s_last_orphan));
 737
 738         printk(KERN_ERR "sb_info orphan list:\n");
 739         list_for_each(l, &sbi->s_orphan) {
 740                 struct inode *inode = orphan_list_entry(l);
 741                 printk(KERN_ERR "  "
 742                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 743                        inode->i_sb->s_id, inode->i_ino, inode,
 744                        inode->i_mode, inode->i_nlink,
 745                        NEXT_ORPHAN(inode));
 746         }
 747 }
 748
 749 static void ext4_put_super(struct super_block *sb)
 750 {
 751         struct ext4_sb_info *sbi = EXT4_SB(sb);
 752         struct ext4_super_block *es = sbi->s_es;
 753         int i, err;
 754
 755         ext4_unregister_li_request(sb);
 756         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 757
 758         flush_workqueue(sbi->rsv_conversion_wq);
 759         destroy_workqueue(sbi->rsv_conversion_wq);
 760
 761         if (sbi->s_journal) {
 762                 err = jbd2_journal_destroy(sbi->s_journal);
 763                 sbi->s_journal = NULL;
 764                 if (err < 0)
 765                         ext4_abort(sb, "Couldn't clean up the journal");
 766         }
 767
 768         ext4_es_unregister_shrinker(sbi);
 769         del_timer_sync(&sbi->s_err_report);
 770         ext4_release_system_zone(sb);
 771         ext4_mb_release(sb);
 772         ext4_ext_release(sb);
 773         ext4_xattr_put_super(sb);
 774
 775         if (!(sb->s_flags & MS_RDONLY)) {
 776                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 777                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 778         }
 779         if (!(sb->s_flags & MS_RDONLY))
 780                 ext4_commit_super(sb, 1);
 781
 782         if (sbi->s_proc) {
 783                 remove_proc_entry("options", sbi->s_proc);
 784                 remove_proc_entry(sb->s_id, ext4_proc_root);
 785         }
 786         kobject_del(&sbi->s_kobj);
 787
 788         for (i = 0; i < sbi->s_gdb_count; i++)
 789                 brelse(sbi->s_group_desc[i]);
 790         kvfree(sbi->s_group_desc);
 791         kvfree(sbi->s_flex_groups);
 792         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 793         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 794         percpu_counter_destroy(&sbi->s_dirs_counter);
 795         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 796         brelse(sbi->s_sbh);
 797 #ifdef CONFIG_QUOTA
 798         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 799                 kfree(sbi->s_qf_names[i]);
 800 #endif
 801
 802         /* Debugging code just in case the in-memory inode orphan list
 803          * isn't empty.  The on-disk one can be non-empty if we've
 804          * detected an error and taken the fs readonly, but the
 805          * in-memory list had better be clean by this point. */
 806         if (!list_empty(&sbi->s_orphan))
 807                 dump_orphan_list(sb, sbi);
 808         J_ASSERT(list_empty(&sbi->s_orphan));
 809
 810         invalidate_bdev(sb->s_bdev);
 811         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 812                 /*
 813                  * Invalidate the journal device's buffers.  We don't want them
 814                  * floating about in memory - the physical journal device may
 815                  * hotswapped, and it breaks the `ro-after' testing code.
 816                  */
 817                 sync_blockdev(sbi->journal_bdev);
 818                 invalidate_bdev(sbi->journal_bdev);
 819                 ext4_blkdev_remove(sbi);
 820         }
 821         if (sbi->s_mb_cache) {
 822                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 823                 sbi->s_mb_cache = NULL;
 824         }
 825         if (sbi->s_mmp_tsk)
 826                 kthread_stop(sbi->s_mmp_tsk);
 827         sb->s_fs_info = NULL;
 828         /*
 829          * Now that we are completely done shutting down the
 830          * superblock, we need to actually destroy the kobject.
 831          */
 832         kobject_put(&sbi->s_kobj);
 833         wait_for_completion(&sbi->s_kobj_unregister);
 834         if (sbi->s_chksum_driver)
 835                 crypto_free_shash(sbi->s_chksum_driver);
 836         kfree(sbi->s_blockgroup_lock);
 837         kfree(sbi);
 838 }
 839
 840 static struct kmem_cache *ext4_inode_cachep;
 841
 842 /*
 843  * Called inside transaction, so use GFP_NOFS
 844  */
 845 static struct inode *ext4_alloc_inode(struct super_block *sb)
 846 {
 847         struct ext4_inode_info *ei;
 848
 849         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 850         if (!ei)
 851                 return NULL;
 852
 853         ei->vfs_inode.i_version = 1;
 854         spin_lock_init(&ei->i_raw_lock);
 855         INIT_LIST_HEAD(&ei->i_prealloc_list);
 856         spin_lock_init(&ei->i_prealloc_lock);
 857         ext4_es_init_tree(&ei->i_es_tree);
 858         rwlock_init(&ei->i_es_lock);
 859         INIT_LIST_HEAD(&ei->i_es_list);
 860         ei->i_es_all_nr = 0;
 861         ei->i_es_shk_nr = 0;
 862         ei->i_es_shrink_lblk = 0;
 863         ei->i_reserved_data_blocks = 0;
 864         ei->i_reserved_meta_blocks = 0;
 865         ei->i_allocated_meta_blocks = 0;
 866         ei->i_da_metadata_calc_len = 0;
 867         ei->i_da_metadata_calc_last_lblock = 0;
 868         spin_lock_init(&(ei->i_block_reservation_lock));
 869 #ifdef CONFIG_QUOTA
 870         ei->i_reserved_quota = 0;
 871         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 872 #endif
 873         ei->jinode = NULL;
 874         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 875         spin_lock_init(&ei->i_completed_io_lock);
 876         ei->i_sync_tid = 0;
 877         ei->i_datasync_tid = 0;
 878         atomic_set(&ei->i_ioend_count, 0);
 879         atomic_set(&ei->i_unwritten, 0);
 880         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 881 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 882         ei->i_encryption_key.mode = EXT4_ENCRYPTION_MODE_INVALID;
 883 #endif
 884
 885         return &ei->vfs_inode;
 886 }
 887
 888 static int ext4_drop_inode(struct inode *inode)
 889 {
 890         int drop = generic_drop_inode(inode);
 891
 892         trace_ext4_drop_inode(inode, drop);
 893         return drop;
 894 }
 895
 896 static void ext4_i_callback(struct rcu_head *head)
 897 {
 898         struct inode *inode = container_of(head, struct inode, i_rcu);
 899         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 900 }
 901
 902 static void ext4_destroy_inode(struct inode *inode)
 903 {
 904         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 905                 ext4_msg(inode->i_sb, KERN_ERR,
 906                          "Inode %lu (%p): orphan list check failed!",
 907                          inode->i_ino, EXT4_I(inode));
 908                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 909                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 910                                 true);
 911                 dump_stack();
 912         }
 913         call_rcu(&inode->i_rcu, ext4_i_callback);
 914 }
 915
 916 static void init_once(void *foo)
 917 {
 918         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 919
 920         INIT_LIST_HEAD(&ei->i_orphan);
 921         init_rwsem(&ei->xattr_sem);
 922         init_rwsem(&ei->i_data_sem);
 923         inode_init_once(&ei->vfs_inode);
 924 }
 925
 926 static int __init init_inodecache(void)
 927 {
 928         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 929                                              sizeof(struct ext4_inode_info),
 930                                              0, (SLAB_RECLAIM_ACCOUNT|
 931                                                 SLAB_MEM_SPREAD),
 932                                              init_once);
 933         if (ext4_inode_cachep == NULL)
 934                 return -ENOMEM;
 935         return 0;
 936 }
 937
 938 static void destroy_inodecache(void)
 939 {
 940         /*
 941          * Make sure all delayed rcu free inodes are flushed before we
 942          * destroy cache.
 943          */
 944         rcu_barrier();
 945         kmem_cache_destroy(ext4_inode_cachep);
 946 }
 947
 948 void ext4_clear_inode(struct inode *inode)
 949 {
 950         invalidate_inode_buffers(inode);
 951         clear_inode(inode);
 952         dquot_drop(inode);
 953         ext4_discard_preallocations(inode);
 954         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 955         if (EXT4_I(inode)->jinode) {
 956                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 957                                                EXT4_I(inode)->jinode);
 958                 jbd2_free_inode(EXT4_I(inode)->jinode);
 959                 EXT4_I(inode)->jinode = NULL;
 960         }
 961 }
 962
 963 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 964                                         u64 ino, u32 generation)
 965 {
 966         struct inode *inode;
 967
 968         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 969                 return ERR_PTR(-ESTALE);
 970         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 971                 return ERR_PTR(-ESTALE);
 972
 973         /* iget isn't really right if the inode is currently unallocated!!
 974          *
 975          * ext4_read_inode will return a bad_inode if the inode had been
 976          * deleted, so we should be safe.
 977          *
 978          * Currently we don't know the generation for parent directory, so
 979          * a generation of 0 means "accept any"
 980          */
 981         inode = ext4_iget_normal(sb, ino);
 982         if (IS_ERR(inode))
 983                 return ERR_CAST(inode);
 984         if (generation && inode->i_generation != generation) {
 985                 iput(inode);
 986                 return ERR_PTR(-ESTALE);
 987         }
 988
 989         return inode;
 990 }
 991
 992 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 993                                         int fh_len, int fh_type)
 994 {
 995         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 996                                     ext4_nfs_get_inode);
 997 }
 998
 999 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1000                                         int fh_len, int fh_type)
1001 {
1002         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1003                                     ext4_nfs_get_inode);
1004 }
1005
1006 /*
1007  * Try to release metadata pages (indirect blocks, directories) which are
1008  * mapped via the block device.  Since these pages could have journal heads
1009  * which would prevent try_to_free_buffers() from freeing them, we must use
1010  * jbd2 layer's try_to_free_buffers() function to release them.
1011  */
1012 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1013                                  gfp_t wait)
1014 {
1015         journal_t *journal = EXT4_SB(sb)->s_journal;
1016
1017         WARN_ON(PageChecked(page));
1018         if (!page_has_buffers(page))
1019                 return 0;
1020         if (journal)
1021                 return jbd2_journal_try_to_free_buffers(journal, page,
1022                                                         wait & ~__GFP_WAIT);
1023         return try_to_free_buffers(page);
1024 }
1025
1026 #ifdef CONFIG_QUOTA
1027 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1028 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1029
1030 static int ext4_write_dquot(struct dquot *dquot);
1031 static int ext4_acquire_dquot(struct dquot *dquot);
1032 static int ext4_release_dquot(struct dquot *dquot);
1033 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1034 static int ext4_write_info(struct super_block *sb, int type);
1035 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1036                          struct path *path);
1037 static int ext4_quota_off(struct super_block *sb, int type);
1038 static int ext4_quota_on_mount(struct super_block *sb, int type);
1039 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1040                                size_t len, loff_t off);
1041 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1042                                 const char *data, size_t len, loff_t off);
1043 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1044                              unsigned int flags);
1045 static int ext4_enable_quotas(struct super_block *sb);
1046
1047 static struct dquot **ext4_get_dquots(struct inode *inode)
1048 {
1049         return EXT4_I(inode)->i_dquot;
1050 }
1051
1052 static const struct dquot_operations ext4_quota_operations = {
1053         .get_reserved_space = ext4_get_reserved_space,
1054         .write_dquot    = ext4_write_dquot,
1055         .acquire_dquot  = ext4_acquire_dquot,
1056         .release_dquot  = ext4_release_dquot,
1057         .mark_dirty     = ext4_mark_dquot_dirty,
1058         .write_info     = ext4_write_info,
1059         .alloc_dquot    = dquot_alloc,
1060         .destroy_dquot  = dquot_destroy,
1061 };
1062
1063 static const struct quotactl_ops ext4_qctl_operations = {
1064         .quota_on       = ext4_quota_on,
1065         .quota_off      = ext4_quota_off,
1066         .quota_sync     = dquot_quota_sync,
1067         .get_state      = dquot_get_state,
1068         .set_info       = dquot_set_dqinfo,
1069         .get_dqblk      = dquot_get_dqblk,
1070         .set_dqblk      = dquot_set_dqblk
1071 };
1072 #endif
1073
1074 static const struct super_operations ext4_sops = {
1075         .alloc_inode    = ext4_alloc_inode,
1076         .destroy_inode  = ext4_destroy_inode,
1077         .write_inode    = ext4_write_inode,
1078         .dirty_inode    = ext4_dirty_inode,
1079         .drop_inode     = ext4_drop_inode,
1080         .evict_inode    = ext4_evict_inode,
1081         .put_super      = ext4_put_super,
1082         .sync_fs        = ext4_sync_fs,
1083         .freeze_fs      = ext4_freeze,
1084         .unfreeze_fs    = ext4_unfreeze,
1085         .statfs         = ext4_statfs,
1086         .remount_fs     = ext4_remount,
1087         .show_options   = ext4_show_options,
1088 #ifdef CONFIG_QUOTA
1089         .quota_read     = ext4_quota_read,
1090         .quota_write    = ext4_quota_write,
1091         .get_dquots     = ext4_get_dquots,
1092 #endif
1093         .bdev_try_to_free_page = bdev_try_to_free_page,
1094 };
1095
1096 static const struct export_operations ext4_export_ops = {
1097         .fh_to_dentry = ext4_fh_to_dentry,
1098         .fh_to_parent = ext4_fh_to_parent,
1099         .get_parent = ext4_get_parent,
1100 };
1101
1102 enum {
1103         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1104         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1105         Opt_nouid32, Opt_debug, Opt_removed,
1106         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1107         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1108         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1109         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1110         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1111         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1112         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1113         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1114         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1115         Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
1116         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1117         Opt_lazytime, Opt_nolazytime,
1118         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1119         Opt_inode_readahead_blks, Opt_journal_ioprio,
1120         Opt_dioread_nolock, Opt_dioread_lock,
1121         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1122         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1123 };
1124
1125 static const match_table_t tokens = {
1126         {Opt_bsd_df, "bsddf"},
1127         {Opt_minix_df, "minixdf"},
1128         {Opt_grpid, "grpid"},
1129         {Opt_grpid, "bsdgroups"},
1130         {Opt_nogrpid, "nogrpid"},
1131         {Opt_nogrpid, "sysvgroups"},
1132         {Opt_resgid, "resgid=%u"},
1133         {Opt_resuid, "resuid=%u"},
1134         {Opt_sb, "sb=%u"},
1135         {Opt_err_cont, "errors=continue"},
1136         {Opt_err_panic, "errors=panic"},
1137         {Opt_err_ro, "errors=remount-ro"},
1138         {Opt_nouid32, "nouid32"},
1139         {Opt_debug, "debug"},
1140         {Opt_removed, "oldalloc"},
1141         {Opt_removed, "orlov"},
1142         {Opt_user_xattr, "user_xattr"},
1143         {Opt_nouser_xattr, "nouser_xattr"},
1144         {Opt_acl, "acl"},
1145         {Opt_noacl, "noacl"},
1146         {Opt_noload, "norecovery"},
1147         {Opt_noload, "noload"},
1148         {Opt_removed, "nobh"},
1149         {Opt_removed, "bh"},
1150         {Opt_commit, "commit=%u"},
1151         {Opt_min_batch_time, "min_batch_time=%u"},
1152         {Opt_max_batch_time, "max_batch_time=%u"},
1153         {Opt_journal_dev, "journal_dev=%u"},
1154         {Opt_journal_path, "journal_path=%s"},
1155         {Opt_journal_checksum, "journal_checksum"},
1156         {Opt_nojournal_checksum, "nojournal_checksum"},
1157         {Opt_journal_async_commit, "journal_async_commit"},
1158         {Opt_abort, "abort"},
1159         {Opt_data_journal, "data=journal"},
1160         {Opt_data_ordered, "data=ordered"},
1161         {Opt_data_writeback, "data=writeback"},
1162         {Opt_data_err_abort, "data_err=abort"},
1163         {Opt_data_err_ignore, "data_err=ignore"},
1164         {Opt_offusrjquota, "usrjquota="},
1165         {Opt_usrjquota, "usrjquota=%s"},
1166         {Opt_offgrpjquota, "grpjquota="},
1167         {Opt_grpjquota, "grpjquota=%s"},
1168         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1169         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1170         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1171         {Opt_grpquota, "grpquota"},
1172         {Opt_noquota, "noquota"},
1173         {Opt_quota, "quota"},
1174         {Opt_usrquota, "usrquota"},
1175         {Opt_barrier, "barrier=%u"},
1176         {Opt_barrier, "barrier"},
1177         {Opt_nobarrier, "nobarrier"},
1178         {Opt_i_version, "i_version"},
1179         {Opt_dax, "dax"},
1180         {Opt_stripe, "stripe=%u"},
1181         {Opt_delalloc, "delalloc"},
1182         {Opt_lazytime, "lazytime"},
1183         {Opt_nolazytime, "nolazytime"},
1184         {Opt_nodelalloc, "nodelalloc"},
1185         {Opt_removed, "mblk_io_submit"},
1186         {Opt_removed, "nomblk_io_submit"},
1187         {Opt_block_validity, "block_validity"},
1188         {Opt_noblock_validity, "noblock_validity"},
1189         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1190         {Opt_journal_ioprio, "journal_ioprio=%u"},
1191         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1192         {Opt_auto_da_alloc, "auto_da_alloc"},
1193         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1194         {Opt_dioread_nolock, "dioread_nolock"},
1195         {Opt_dioread_lock, "dioread_lock"},
1196         {Opt_discard, "discard"},
1197         {Opt_nodiscard, "nodiscard"},
1198         {Opt_init_itable, "init_itable=%u"},
1199         {Opt_init_itable, "init_itable"},
1200         {Opt_noinit_itable, "noinit_itable"},
1201         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1202         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1203         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1204         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1205         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1206         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1207         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1208         {Opt_err, NULL},
1209 };
1210
1211 static ext4_fsblk_t get_sb_block(void **data)
1212 {
1213         ext4_fsblk_t    sb_block;
1214         char            *options = (char *) *data;
1215
1216         if (!options || strncmp(options, "sb=", 3) != 0)
1217                 return 1;       /* Default location */
1218
1219         options += 3;
1220         /* TODO: use simple_strtoll with >32bit ext4 */
1221         sb_block = simple_strtoul(options, &options, 0);
1222         if (*options && *options != ',') {
1223                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1224                        (char *) *data);
1225                 return 1;
1226         }
1227         if (*options == ',')
1228                 options++;
1229         *data = (void *) options;
1230
1231         return sb_block;
1232 }
1233
1234 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1235 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1236         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1237
1238 #ifdef CONFIG_QUOTA
1239 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1240 {
1241         struct ext4_sb_info *sbi = EXT4_SB(sb);
1242         char *qname;
1243         int ret = -1;
1244
1245         if (sb_any_quota_loaded(sb) &&
1246                 !sbi->s_qf_names[qtype]) {
1247                 ext4_msg(sb, KERN_ERR,
1248                         "Cannot change journaled "
1249                         "quota options when quota turned on");
1250                 return -1;
1251         }
1252         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1253                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1254                          "when QUOTA feature is enabled");
1255                 return -1;
1256         }
1257         qname = match_strdup(args);
1258         if (!qname) {
1259                 ext4_msg(sb, KERN_ERR,
1260                         "Not enough memory for storing quotafile name");
1261                 return -1;
1262         }
1263         if (sbi->s_qf_names[qtype]) {
1264                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1265                         ret = 1;
1266                 else
1267                         ext4_msg(sb, KERN_ERR,
1268                                  "%s quota file already specified",
1269                                  QTYPE2NAME(qtype));
1270                 goto errout;
1271         }
1272         if (strchr(qname, '/')) {
1273                 ext4_msg(sb, KERN_ERR,
1274                         "quotafile must be on filesystem root");
1275                 goto errout;
1276         }
1277         sbi->s_qf_names[qtype] = qname;
1278         set_opt(sb, QUOTA);
1279         return 1;
1280 errout:
1281         kfree(qname);
1282         return ret;
1283 }
1284
1285 static int clear_qf_name(struct super_block *sb, int qtype)
1286 {
1287
1288         struct ext4_sb_info *sbi = EXT4_SB(sb);
1289
1290         if (sb_any_quota_loaded(sb) &&
1291                 sbi->s_qf_names[qtype]) {
1292                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1293                         " when quota turned on");
1294                 return -1;
1295         }
1296         kfree(sbi->s_qf_names[qtype]);
1297         sbi->s_qf_names[qtype] = NULL;
1298         return 1;
1299 }
1300 #endif
1301
1302 #define MOPT_SET        0x0001
1303 #define MOPT_CLEAR      0x0002
1304 #define MOPT_NOSUPPORT  0x0004
1305 #define MOPT_EXPLICIT   0x0008
1306 #define MOPT_CLEAR_ERR  0x0010
1307 #define MOPT_GTE0       0x0020
1308 #ifdef CONFIG_QUOTA
1309 #define MOPT_Q          0
1310 #define MOPT_QFMT       0x0040
1311 #else
1312 #define MOPT_Q          MOPT_NOSUPPORT
1313 #define MOPT_QFMT       MOPT_NOSUPPORT
1314 #endif
1315 #define MOPT_DATAJ      0x0080
1316 #define MOPT_NO_EXT2    0x0100
1317 #define MOPT_NO_EXT3    0x0200
1318 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1319 #define MOPT_STRING     0x0400
1320
1321 static const struct mount_opts {
1322         int     token;
1323         int     mount_opt;
1324         int     flags;
1325 } ext4_mount_opts[] = {
1326         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1327         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1328         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1329         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1330         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1331         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1332         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1333          MOPT_EXT4_ONLY | MOPT_SET},
1334         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1335          MOPT_EXT4_ONLY | MOPT_CLEAR},
1336         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1337         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1338         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1339          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1340         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1341          MOPT_EXT4_ONLY | MOPT_CLEAR},
1342         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1343          MOPT_EXT4_ONLY | MOPT_CLEAR},
1344         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1345          MOPT_EXT4_ONLY | MOPT_SET},
1346         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1347                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1348          MOPT_EXT4_ONLY | MOPT_SET},
1349         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1350         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1351         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1352         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1353         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1354          MOPT_NO_EXT2 | MOPT_SET},
1355         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1356          MOPT_NO_EXT2 | MOPT_CLEAR},
1357         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1358         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1359         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1360         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1361         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1362         {Opt_commit, 0, MOPT_GTE0},
1363         {Opt_max_batch_time, 0, MOPT_GTE0},
1364         {Opt_min_batch_time, 0, MOPT_GTE0},
1365         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1366         {Opt_init_itable, 0, MOPT_GTE0},
1367         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1368         {Opt_stripe, 0, MOPT_GTE0},
1369         {Opt_resuid, 0, MOPT_GTE0},
1370         {Opt_resgid, 0, MOPT_GTE0},
1371         {Opt_journal_dev, 0, MOPT_GTE0},
1372         {Opt_journal_path, 0, MOPT_STRING},
1373         {Opt_journal_ioprio, 0, MOPT_GTE0},
1374         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1375         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1376         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1377          MOPT_NO_EXT2 | MOPT_DATAJ},
1378         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1379         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1380 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1381         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1382         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1383 #else
1384         {Opt_acl, 0, MOPT_NOSUPPORT},
1385         {Opt_noacl, 0, MOPT_NOSUPPORT},
1386 #endif
1387         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1388         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1389         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1390         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1391                                                         MOPT_SET | MOPT_Q},
1392         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1393                                                         MOPT_SET | MOPT_Q},
1394         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1395                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1396         {Opt_usrjquota, 0, MOPT_Q},
1397         {Opt_grpjquota, 0, MOPT_Q},
1398         {Opt_offusrjquota, 0, MOPT_Q},
1399         {Opt_offgrpjquota, 0, MOPT_Q},
1400         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1401         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1402         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1403         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1404         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1405         {Opt_err, 0, 0}
1406 };
1407
1408 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1409                             substring_t *args, unsigned long *journal_devnum,
1410                             unsigned int *journal_ioprio, int is_remount)
1411 {
1412         struct ext4_sb_info *sbi = EXT4_SB(sb);
1413         const struct mount_opts *m;
1414         kuid_t uid;
1415         kgid_t gid;
1416         int arg = 0;
1417
1418 #ifdef CONFIG_QUOTA
1419         if (token == Opt_usrjquota)
1420                 return set_qf_name(sb, USRQUOTA, &args[0]);
1421         else if (token == Opt_grpjquota)
1422                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1423         else if (token == Opt_offusrjquota)
1424                 return clear_qf_name(sb, USRQUOTA);
1425         else if (token == Opt_offgrpjquota)
1426                 return clear_qf_name(sb, GRPQUOTA);
1427 #endif
1428         switch (token) {
1429         case Opt_noacl:
1430         case Opt_nouser_xattr:
1431                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1432                 break;
1433         case Opt_sb:
1434                 return 1;       /* handled by get_sb_block() */
1435         case Opt_removed:
1436                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1437                 return 1;
1438         case Opt_abort:
1439                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1440                 return 1;
1441         case Opt_i_version:
1442                 sb->s_flags |= MS_I_VERSION;
1443                 return 1;
1444         case Opt_lazytime:
1445                 sb->s_flags |= MS_LAZYTIME;
1446                 return 1;
1447         case Opt_nolazytime:
1448                 sb->s_flags &= ~MS_LAZYTIME;
1449                 return 1;
1450         }
1451
1452         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1453                 if (token == m->token)
1454                         break;
1455
1456         if (m->token == Opt_err) {
1457                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1458                          "or missing value", opt);
1459                 return -1;
1460         }
1461
1462         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1463                 ext4_msg(sb, KERN_ERR,
1464                          "Mount option \"%s\" incompatible with ext2", opt);
1465                 return -1;
1466         }
1467         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1468                 ext4_msg(sb, KERN_ERR,
1469                          "Mount option \"%s\" incompatible with ext3", opt);
1470                 return -1;
1471         }
1472
1473         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1474                 return -1;
1475         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1476                 return -1;
1477         if (m->flags & MOPT_EXPLICIT)
1478                 set_opt2(sb, EXPLICIT_DELALLOC);
1479         if (m->flags & MOPT_CLEAR_ERR)
1480                 clear_opt(sb, ERRORS_MASK);
1481         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1482                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1483                          "options when quota turned on");
1484                 return -1;
1485         }
1486
1487         if (m->flags & MOPT_NOSUPPORT) {
1488                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1489         } else if (token == Opt_commit) {
1490                 if (arg == 0)
1491                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1492                 sbi->s_commit_interval = HZ * arg;
1493         } else if (token == Opt_max_batch_time) {
1494                 sbi->s_max_batch_time = arg;
1495         } else if (token == Opt_min_batch_time) {
1496                 sbi->s_min_batch_time = arg;
1497         } else if (token == Opt_inode_readahead_blks) {
1498                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1499                         ext4_msg(sb, KERN_ERR,
1500                                  "EXT4-fs: inode_readahead_blks must be "
1501                                  "0 or a power of 2 smaller than 2^31");
1502                         return -1;
1503                 }
1504                 sbi->s_inode_readahead_blks = arg;
1505         } else if (token == Opt_init_itable) {
1506                 set_opt(sb, INIT_INODE_TABLE);
1507                 if (!args->from)
1508                         arg = EXT4_DEF_LI_WAIT_MULT;
1509                 sbi->s_li_wait_mult = arg;
1510         } else if (token == Opt_max_dir_size_kb) {
1511                 sbi->s_max_dir_size_kb = arg;
1512         } else if (token == Opt_stripe) {
1513                 sbi->s_stripe = arg;
1514         } else if (token == Opt_resuid) {
1515                 uid = make_kuid(current_user_ns(), arg);
1516                 if (!uid_valid(uid)) {
1517                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1518                         return -1;
1519                 }
1520                 sbi->s_resuid = uid;
1521         } else if (token == Opt_resgid) {
1522                 gid = make_kgid(current_user_ns(), arg);
1523                 if (!gid_valid(gid)) {
1524                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1525                         return -1;
1526                 }
1527                 sbi->s_resgid = gid;
1528         } else if (token == Opt_journal_dev) {
1529                 if (is_remount) {
1530                         ext4_msg(sb, KERN_ERR,
1531                                  "Cannot specify journal on remount");
1532                         return -1;
1533                 }
1534                 *journal_devnum = arg;
1535         } else if (token == Opt_journal_path) {
1536                 char *journal_path;
1537                 struct inode *journal_inode;
1538                 struct path path;
1539                 int error;
1540
1541                 if (is_remount) {
1542                         ext4_msg(sb, KERN_ERR,
1543                                  "Cannot specify journal on remount");
1544                         return -1;
1545                 }
1546                 journal_path = match_strdup(&args[0]);
1547                 if (!journal_path) {
1548                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1549                                 "journal device string");
1550                         return -1;
1551                 }
1552
1553                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1554                 if (error) {
1555                         ext4_msg(sb, KERN_ERR, "error: could not find "
1556                                 "journal device path: error %d", error);
1557                         kfree(journal_path);
1558                         return -1;
1559                 }
1560
1561                 journal_inode = d_inode(path.dentry);
1562                 if (!S_ISBLK(journal_inode->i_mode)) {
1563                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1564                                 "is not a block device", journal_path);
1565                         path_put(&path);
1566                         kfree(journal_path);
1567                         return -1;
1568                 }
1569
1570                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1571                 path_put(&path);
1572                 kfree(journal_path);
1573         } else if (token == Opt_journal_ioprio) {
1574                 if (arg > 7) {
1575                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1576                                  " (must be 0-7)");
1577                         return -1;
1578                 }
1579                 *journal_ioprio =
1580                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1581         } else if (token == Opt_test_dummy_encryption) {
1582 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1583                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1584                 ext4_msg(sb, KERN_WARNING,
1585                          "Test dummy encryption mode enabled");
1586 #else
1587                 ext4_msg(sb, KERN_WARNING,
1588                          "Test dummy encryption mount option ignored");
1589 #endif
1590         } else if (m->flags & MOPT_DATAJ) {
1591                 if (is_remount) {
1592                         if (!sbi->s_journal)
1593                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1594                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1595                                 ext4_msg(sb, KERN_ERR,
1596                                          "Cannot change data mode on remount");
1597                                 return -1;
1598                         }
1599                 } else {
1600                         clear_opt(sb, DATA_FLAGS);
1601                         sbi->s_mount_opt |= m->mount_opt;
1602                 }
1603 #ifdef CONFIG_QUOTA
1604         } else if (m->flags & MOPT_QFMT) {
1605                 if (sb_any_quota_loaded(sb) &&
1606                     sbi->s_jquota_fmt != m->mount_opt) {
1607                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1608                                  "quota options when quota turned on");
1609                         return -1;
1610                 }
1611                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1612                                                EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1613                         ext4_msg(sb, KERN_ERR,
1614                                  "Cannot set journaled quota options "
1615                                  "when QUOTA feature is enabled");
1616                         return -1;
1617                 }
1618                 sbi->s_jquota_fmt = m->mount_opt;
1619 #endif
1620 #ifndef CONFIG_FS_DAX
1621         } else if (token == Opt_dax) {
1622                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1623                 return -1;
1624 #endif
1625         } else {
1626                 if (!args->from)
1627                         arg = 1;
1628                 if (m->flags & MOPT_CLEAR)
1629                         arg = !arg;
1630                 else if (unlikely(!(m->flags & MOPT_SET))) {
1631                         ext4_msg(sb, KERN_WARNING,
1632                                  "buggy handling of option %s", opt);
1633                         WARN_ON(1);
1634                         return -1;
1635                 }
1636                 if (arg != 0)
1637                         sbi->s_mount_opt |= m->mount_opt;
1638                 else
1639                         sbi->s_mount_opt &= ~m->mount_opt;
1640         }
1641         return 1;
1642 }
1643
1644 static int parse_options(char *options, struct super_block *sb,
1645                          unsigned long *journal_devnum,
1646                          unsigned int *journal_ioprio,
1647                          int is_remount)
1648 {
1649         struct ext4_sb_info *sbi = EXT4_SB(sb);
1650         char *p;
1651         substring_t args[MAX_OPT_ARGS];
1652         int token;
1653
1654         if (!options)
1655                 return 1;
1656
1657         while ((p = strsep(&options, ",")) != NULL) {
1658                 if (!*p)
1659                         continue;
1660                 /*
1661                  * Initialize args struct so we know whether arg was
1662                  * found; some options take optional arguments.
1663                  */
1664                 args[0].to = args[0].from = NULL;
1665                 token = match_token(p, tokens, args);
1666                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1667                                      journal_ioprio, is_remount) < 0)
1668                         return 0;
1669         }
1670 #ifdef CONFIG_QUOTA
1671         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1672             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1673                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1674                          "feature is enabled");
1675                 return 0;
1676         }
1677         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1678                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1679                         clear_opt(sb, USRQUOTA);
1680
1681                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1682                         clear_opt(sb, GRPQUOTA);
1683
1684                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1685                         ext4_msg(sb, KERN_ERR, "old and new quota "
1686                                         "format mixing");
1687                         return 0;
1688                 }
1689
1690                 if (!sbi->s_jquota_fmt) {
1691                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1692                                         "not specified");
1693                         return 0;
1694                 }
1695         }
1696 #endif
1697         if (test_opt(sb, DIOREAD_NOLOCK)) {
1698                 int blocksize =
1699                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1700
1701                 if (blocksize < PAGE_CACHE_SIZE) {
1702                         ext4_msg(sb, KERN_ERR, "can't mount with "
1703                                  "dioread_nolock if block size != PAGE_SIZE");
1704                         return 0;
1705                 }
1706         }
1707         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1708             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1709                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1710                          "in data=ordered mode");
1711                 return 0;
1712         }
1713         return 1;
1714 }
1715
1716 static inline void ext4_show_quota_options(struct seq_file *seq,
1717                                            struct super_block *sb)
1718 {
1719 #if defined(CONFIG_QUOTA)
1720         struct ext4_sb_info *sbi = EXT4_SB(sb);
1721
1722         if (sbi->s_jquota_fmt) {
1723                 char *fmtname = "";
1724
1725                 switch (sbi->s_jquota_fmt) {
1726                 case QFMT_VFS_OLD:
1727                         fmtname = "vfsold";
1728                         break;
1729                 case QFMT_VFS_V0:
1730                         fmtname = "vfsv0";
1731                         break;
1732                 case QFMT_VFS_V1:
1733                         fmtname = "vfsv1";
1734                         break;
1735                 }
1736                 seq_printf(seq, ",jqfmt=%s", fmtname);
1737         }
1738
1739         if (sbi->s_qf_names[USRQUOTA])
1740                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1741
1742         if (sbi->s_qf_names[GRPQUOTA])
1743                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1744 #endif
1745 }
1746
1747 static const char *token2str(int token)
1748 {
1749         const struct match_token *t;
1750
1751         for (t = tokens; t->token != Opt_err; t++)
1752                 if (t->token == token && !strchr(t->pattern, '='))
1753                         break;
1754         return t->pattern;
1755 }
1756
1757 /*
1758  * Show an option if
1759  *  - it's set to a non-default value OR
1760  *  - if the per-sb default is different from the global default
1761  */
1762 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1763                               int nodefs)
1764 {
1765         struct ext4_sb_info *sbi = EXT4_SB(sb);
1766         struct ext4_super_block *es = sbi->s_es;
1767         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1768         const struct mount_opts *m;
1769         char sep = nodefs ? '\n' : ',';
1770
1771 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1772 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1773
1774         if (sbi->s_sb_block != 1)
1775                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1776
1777         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1778                 int want_set = m->flags & MOPT_SET;
1779                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1780                     (m->flags & MOPT_CLEAR_ERR))
1781                         continue;
1782                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1783                         continue; /* skip if same as the default */
1784                 if ((want_set &&
1785                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1786                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1787                         continue; /* select Opt_noFoo vs Opt_Foo */
1788                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1789         }
1790
1791         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1792             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1793                 SEQ_OPTS_PRINT("resuid=%u",
1794                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1795         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1796             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1797                 SEQ_OPTS_PRINT("resgid=%u",
1798                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1799         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1800         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1801                 SEQ_OPTS_PUTS("errors=remount-ro");
1802         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1803                 SEQ_OPTS_PUTS("errors=continue");
1804         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1805                 SEQ_OPTS_PUTS("errors=panic");
1806         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1807                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1808         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1809                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1810         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1811                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1812         if (sb->s_flags & MS_I_VERSION)
1813                 SEQ_OPTS_PUTS("i_version");
1814         if (nodefs || sbi->s_stripe)
1815                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1816         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1817                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1818                         SEQ_OPTS_PUTS("data=journal");
1819                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1820                         SEQ_OPTS_PUTS("data=ordered");
1821                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1822                         SEQ_OPTS_PUTS("data=writeback");
1823         }
1824         if (nodefs ||
1825             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1826                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1827                                sbi->s_inode_readahead_blks);
1828
1829         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1830                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1831                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1832         if (nodefs || sbi->s_max_dir_size_kb)
1833                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1834
1835         ext4_show_quota_options(seq, sb);
1836         return 0;
1837 }
1838
1839 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1840 {
1841         return _ext4_show_options(seq, root->d_sb, 0);
1842 }
1843
1844 static int options_seq_show(struct seq_file *seq, void *offset)
1845 {
1846         struct super_block *sb = seq->private;
1847         int rc;
1848
1849         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1850         rc = _ext4_show_options(seq, sb, 1);
1851         seq_puts(seq, "\n");
1852         return rc;
1853 }
1854
1855 static int options_open_fs(struct inode *inode, struct file *file)
1856 {
1857         return single_open(file, options_seq_show, PDE_DATA(inode));
1858 }
1859
1860 static const struct file_operations ext4_seq_options_fops = {
1861         .owner = THIS_MODULE,
1862         .open = options_open_fs,
1863         .read = seq_read,
1864         .llseek = seq_lseek,
1865         .release = single_release,
1866 };
1867
1868 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1869                             int read_only)
1870 {
1871         struct ext4_sb_info *sbi = EXT4_SB(sb);
1872         int res = 0;
1873
1874         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1875                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1876                          "forcing read-only mode");
1877                 res = MS_RDONLY;
1878         }
1879         if (read_only)
1880                 goto done;
1881         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1882                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1883                          "running e2fsck is recommended");
1884         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1885                 ext4_msg(sb, KERN_WARNING,
1886                          "warning: mounting fs with errors, "
1887                          "running e2fsck is recommended");
1888         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1889                  le16_to_cpu(es->s_mnt_count) >=
1890                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1891                 ext4_msg(sb, KERN_WARNING,
1892                          "warning: maximal mount count reached, "
1893                          "running e2fsck is recommended");
1894         else if (le32_to_cpu(es->s_checkinterval) &&
1895                 (le32_to_cpu(es->s_lastcheck) +
1896                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1897                 ext4_msg(sb, KERN_WARNING,
1898                          "warning: checktime reached, "
1899                          "running e2fsck is recommended");
1900         if (!sbi->s_journal)
1901                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1902         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1903                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1904         le16_add_cpu(&es->s_mnt_count, 1);
1905         es->s_mtime = cpu_to_le32(get_seconds());
1906         ext4_update_dynamic_rev(sb);
1907         if (sbi->s_journal)
1908                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1909
1910         ext4_commit_super(sb, 1);
1911 done:
1912         if (test_opt(sb, DEBUG))
1913                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1914                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1915                         sb->s_blocksize,
1916                         sbi->s_groups_count,
1917                         EXT4_BLOCKS_PER_GROUP(sb),
1918                         EXT4_INODES_PER_GROUP(sb),
1919                         sbi->s_mount_opt, sbi->s_mount_opt2);
1920
1921         cleancache_init_fs(sb);
1922         return res;
1923 }
1924
1925 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1926 {
1927         struct ext4_sb_info *sbi = EXT4_SB(sb);
1928         struct flex_groups *new_groups;
1929         int size;
1930
1931         if (!sbi->s_log_groups_per_flex)
1932                 return 0;
1933
1934         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1935         if (size <= sbi->s_flex_groups_allocated)
1936                 return 0;
1937
1938         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1939         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1940         if (!new_groups) {
1941                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1942                          size / (int) sizeof(struct flex_groups));
1943                 return -ENOMEM;
1944         }
1945
1946         if (sbi->s_flex_groups) {
1947                 memcpy(new_groups, sbi->s_flex_groups,
1948                        (sbi->s_flex_groups_allocated *
1949                         sizeof(struct flex_groups)));
1950                 kvfree(sbi->s_flex_groups);
1951         }
1952         sbi->s_flex_groups = new_groups;
1953         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1954         return 0;
1955 }
1956
1957 static int ext4_fill_flex_info(struct super_block *sb)
1958 {
1959         struct ext4_sb_info *sbi = EXT4_SB(sb);
1960         struct ext4_group_desc *gdp = NULL;
1961         ext4_group_t flex_group;
1962         int i, err;
1963
1964         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1965         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1966                 sbi->s_log_groups_per_flex = 0;
1967                 return 1;
1968         }
1969
1970         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1971         if (err)
1972                 goto failed;
1973
1974         for (i = 0; i < sbi->s_groups_count; i++) {
1975                 gdp = ext4_get_group_desc(sb, i, NULL);
1976
1977                 flex_group = ext4_flex_group(sbi, i);
1978                 atomic_add(ext4_free_inodes_count(sb, gdp),
1979                            &sbi->s_flex_groups[flex_group].free_inodes);
1980                 atomic64_add(ext4_free_group_clusters(sb, gdp),
1981                              &sbi->s_flex_groups[flex_group].free_clusters);
1982                 atomic_add(ext4_used_dirs_count(sb, gdp),
1983                            &sbi->s_flex_groups[flex_group].used_dirs);
1984         }
1985
1986         return 1;
1987 failed:
1988         return 0;
1989 }
1990
1991 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1992                                    struct ext4_group_desc *gdp)
1993 {
1994         int offset;
1995         __u16 crc = 0;
1996         __le32 le_group = cpu_to_le32(block_group);
1997
1998         if (ext4_has_metadata_csum(sbi->s_sb)) {
1999                 /* Use new metadata_csum algorithm */
2000                 __le16 save_csum;
2001                 __u32 csum32;
2002
2003                 save_csum = gdp->bg_checksum;
2004                 gdp->bg_checksum = 0;
2005                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2006                                      sizeof(le_group));
2007                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2008                                      sbi->s_desc_size);
2009                 gdp->bg_checksum = save_csum;
2010
2011                 crc = csum32 & 0xFFFF;
2012                 goto out;
2013         }
2014
2015         /* old crc16 code */
2016         if (!(sbi->s_es->s_feature_ro_compat &
2017               cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
2018                 return 0;
2019
2020         offset = offsetof(struct ext4_group_desc, bg_checksum);
2021
2022         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2023         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2024         crc = crc16(crc, (__u8 *)gdp, offset);
2025         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2026         /* for checksum of struct ext4_group_desc do the rest...*/
2027         if ((sbi->s_es->s_feature_incompat &
2028              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2029             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2030                 crc = crc16(crc, (__u8 *)gdp + offset,
2031                             le16_to_cpu(sbi->s_es->s_desc_size) -
2032                                 offset);
2033
2034 out:
2035         return cpu_to_le16(crc);
2036 }
2037
2038 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2039                                 struct ext4_group_desc *gdp)
2040 {
2041         if (ext4_has_group_desc_csum(sb) &&
2042             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2043                                                       block_group, gdp)))
2044                 return 0;
2045
2046         return 1;
2047 }
2048
2049 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2050                               struct ext4_group_desc *gdp)
2051 {
2052         if (!ext4_has_group_desc_csum(sb))
2053                 return;
2054         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2055 }
2056
2057 /* Called at mount-time, super-block is locked */
2058 static int ext4_check_descriptors(struct super_block *sb,
2059                                   ext4_group_t *first_not_zeroed)
2060 {
2061         struct ext4_sb_info *sbi = EXT4_SB(sb);
2062         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2063         ext4_fsblk_t last_block;
2064         ext4_fsblk_t block_bitmap;
2065         ext4_fsblk_t inode_bitmap;
2066         ext4_fsblk_t inode_table;
2067         int flexbg_flag = 0;
2068         ext4_group_t i, grp = sbi->s_groups_count;
2069
2070         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2071                 flexbg_flag = 1;
2072
2073         ext4_debug("Checking group descriptors");
2074
2075         for (i = 0; i < sbi->s_groups_count; i++) {
2076                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2077
2078                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2079                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2080                 else
2081                         last_block = first_block +
2082                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2083
2084                 if ((grp == sbi->s_groups_count) &&
2085                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2086                         grp = i;
2087
2088                 block_bitmap = ext4_block_bitmap(sb, gdp);
2089                 if (block_bitmap < first_block || block_bitmap > last_block) {
2090                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2091                                "Block bitmap for group %u not in group "
2092                                "(block %llu)!", i, block_bitmap);
2093                         return 0;
2094                 }
2095                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2096                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2097                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2098                                "Inode bitmap for group %u not in group "
2099                                "(block %llu)!", i, inode_bitmap);
2100                         return 0;
2101                 }
2102                 inode_table = ext4_inode_table(sb, gdp);
2103                 if (inode_table < first_block ||
2104                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2105                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2106                                "Inode table for group %u not in group "
2107                                "(block %llu)!", i, inode_table);
2108                         return 0;
2109                 }
2110                 ext4_lock_group(sb, i);
2111                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2112                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2113                                  "Checksum for group %u failed (%u!=%u)",
2114                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2115                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2116                         if (!(sb->s_flags & MS_RDONLY)) {
2117                                 ext4_unlock_group(sb, i);
2118                                 return 0;
2119                         }
2120                 }
2121                 ext4_unlock_group(sb, i);
2122                 if (!flexbg_flag)
2123                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2124         }
2125         if (NULL != first_not_zeroed)
2126                 *first_not_zeroed = grp;
2127         return 1;
2128 }
2129
2130 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2131  * the superblock) which were deleted from all directories, but held open by
2132  * a process at the time of a crash.  We walk the list and try to delete these
2133  * inodes at recovery time (only with a read-write filesystem).
2134  *
2135  * In order to keep the orphan inode chain consistent during traversal (in
2136  * case of crash during recovery), we link each inode into the superblock
2137  * orphan list_head and handle it the same way as an inode deletion during
2138  * normal operation (which journals the operations for us).
2139  *
2140  * We only do an iget() and an iput() on each inode, which is very safe if we
2141  * accidentally point at an in-use or already deleted inode.  The worst that
2142  * can happen in this case is that we get a "bit already cleared" message from
2143  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2144  * e2fsck was run on this filesystem, and it must have already done the orphan
2145  * inode cleanup for us, so we can safely abort without any further action.
2146  */
2147 static void ext4_orphan_cleanup(struct super_block *sb,
2148                                 struct ext4_super_block *es)
2149 {
2150         unsigned int s_flags = sb->s_flags;
2151         int nr_orphans = 0, nr_truncates = 0;
2152 #ifdef CONFIG_QUOTA
2153         int i;
2154 #endif
2155         if (!es->s_last_orphan) {
2156                 jbd_debug(4, "no orphan inodes to clean up\n");
2157                 return;
2158         }
2159
2160         if (bdev_read_only(sb->s_bdev)) {
2161                 ext4_msg(sb, KERN_ERR, "write access "
2162                         "unavailable, skipping orphan cleanup");
2163                 return;
2164         }
2165
2166         /* Check if feature set would not allow a r/w mount */
2167         if (!ext4_feature_set_ok(sb, 0)) {
2168                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2169                          "unknown ROCOMPAT features");
2170                 return;
2171         }
2172
2173         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2174                 /* don't clear list on RO mount w/ errors */
2175                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2176                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2177                                   "clearing orphan list.\n");
2178                         es->s_last_orphan = 0;
2179                 }
2180                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2181                 return;
2182         }
2183
2184         if (s_flags & MS_RDONLY) {
2185                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2186                 sb->s_flags &= ~MS_RDONLY;
2187         }
2188 #ifdef CONFIG_QUOTA
2189         /* Needed for iput() to work correctly and not trash data */
2190         sb->s_flags |= MS_ACTIVE;
2191         /* Turn on quotas so that they are updated correctly */
2192         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2193                 if (EXT4_SB(sb)->s_qf_names[i]) {
2194                         int ret = ext4_quota_on_mount(sb, i);
2195                         if (ret < 0)
2196                                 ext4_msg(sb, KERN_ERR,
2197                                         "Cannot turn on journaled "
2198                                         "quota: error %d", ret);
2199                 }
2200         }
2201 #endif
2202
2203         while (es->s_last_orphan) {
2204                 struct inode *inode;
2205
2206                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2207                 if (IS_ERR(inode)) {
2208                         es->s_last_orphan = 0;
2209                         break;
2210                 }
2211
2212                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2213                 dquot_initialize(inode);
2214                 if (inode->i_nlink) {
2215                         if (test_opt(sb, DEBUG))
2216                                 ext4_msg(sb, KERN_DEBUG,
2217                                         "%s: truncating inode %lu to %lld bytes",
2218                                         __func__, inode->i_ino, inode->i_size);
2219                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2220                                   inode->i_ino, inode->i_size);
2221                         mutex_lock(&inode->i_mutex);
2222                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2223                         ext4_truncate(inode);
2224                         mutex_unlock(&inode->i_mutex);
2225                         nr_truncates++;
2226                 } else {
2227                         if (test_opt(sb, DEBUG))
2228                                 ext4_msg(sb, KERN_DEBUG,
2229                                         "%s: deleting unreferenced inode %lu",
2230                                         __func__, inode->i_ino);
2231                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2232                                   inode->i_ino);
2233                         nr_orphans++;
2234                 }
2235                 iput(inode);  /* The delete magic happens here! */
2236         }
2237
2238 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2239
2240         if (nr_orphans)
2241                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2242                        PLURAL(nr_orphans));
2243         if (nr_truncates)
2244                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2245                        PLURAL(nr_truncates));
2246 #ifdef CONFIG_QUOTA
2247         /* Turn quotas off */
2248         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2249                 if (sb_dqopt(sb)->files[i])
2250                         dquot_quota_off(sb, i);
2251         }
2252 #endif
2253         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2254 }
2255
2256 /*
2257  * Maximal extent format file size.
2258  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2259  * extent format containers, within a sector_t, and within i_blocks
2260  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2261  * so that won't be a limiting factor.
2262  *
2263  * However there is other limiting factor. We do store extents in the form
2264  * of starting block and length, hence the resulting length of the extent
2265  * covering maximum file size must fit into on-disk format containers as
2266  * well. Given that length is always by 1 unit bigger than max unit (because
2267  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2268  *
2269  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2270  */
2271 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2272 {
2273         loff_t res;
2274         loff_t upper_limit = MAX_LFS_FILESIZE;
2275
2276         /* small i_blocks in vfs inode? */
2277         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2278                 /*
2279                  * CONFIG_LBDAF is not enabled implies the inode
2280                  * i_block represent total blocks in 512 bytes
2281                  * 32 == size of vfs inode i_blocks * 8
2282                  */
2283                 upper_limit = (1LL << 32) - 1;
2284
2285                 /* total blocks in file system block size */
2286                 upper_limit >>= (blkbits - 9);
2287                 upper_limit <<= blkbits;
2288         }
2289
2290         /*
2291          * 32-bit extent-start container, ee_block. We lower the maxbytes
2292          * by one fs block, so ee_len can cover the extent of maximum file
2293          * size
2294          */
2295         res = (1LL << 32) - 1;
2296         res <<= blkbits;
2297
2298         /* Sanity check against vm- & vfs- imposed limits */
2299         if (res > upper_limit)
2300                 res = upper_limit;
2301
2302         return res;
2303 }
2304
2305 /*
2306  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2307  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2308  * We need to be 1 filesystem block less than the 2^48 sector limit.
2309  */
2310 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2311 {
2312         loff_t res = EXT4_NDIR_BLOCKS;
2313         int meta_blocks;
2314         loff_t upper_limit;
2315         /* This is calculated to be the largest file size for a dense, block
2316          * mapped file such that the file's total number of 512-byte sectors,
2317          * including data and all indirect blocks, does not exceed (2^48 - 1).
2318          *
2319          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2320          * number of 512-byte sectors of the file.
2321          */
2322
2323         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2324                 /*
2325                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2326                  * the inode i_block field represents total file blocks in
2327                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2328                  */
2329                 upper_limit = (1LL << 32) - 1;
2330
2331                 /* total blocks in file system block size */
2332                 upper_limit >>= (bits - 9);
2333
2334         } else {
2335                 /*
2336                  * We use 48 bit ext4_inode i_blocks
2337                  * With EXT4_HUGE_FILE_FL set the i_blocks
2338                  * represent total number of blocks in
2339                  * file system block size
2340                  */
2341                 upper_limit = (1LL << 48) - 1;
2342
2343         }
2344
2345         /* indirect blocks */
2346         meta_blocks = 1;
2347         /* double indirect blocks */
2348         meta_blocks += 1 + (1LL << (bits-2));
2349         /* tripple indirect blocks */
2350         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2351
2352         upper_limit -= meta_blocks;
2353         upper_limit <<= bits;
2354
2355         res += 1LL << (bits-2);
2356         res += 1LL << (2*(bits-2));
2357         res += 1LL << (3*(bits-2));
2358         res <<= bits;
2359         if (res > upper_limit)
2360                 res = upper_limit;
2361
2362         if (res > MAX_LFS_FILESIZE)
2363                 res = MAX_LFS_FILESIZE;
2364
2365         return res;
2366 }
2367
2368 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2369                                    ext4_fsblk_t logical_sb_block, int nr)
2370 {
2371         struct ext4_sb_info *sbi = EXT4_SB(sb);
2372         ext4_group_t bg, first_meta_bg;
2373         int has_super = 0;
2374
2375         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2376
2377         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2378             nr < first_meta_bg)
2379                 return logical_sb_block + nr + 1;
2380         bg = sbi->s_desc_per_block * nr;
2381         if (ext4_bg_has_super(sb, bg))
2382                 has_super = 1;
2383
2384         /*
2385          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2386          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2387          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2388          * compensate.
2389          */
2390         if (sb->s_blocksize == 1024 && nr == 0 &&
2391             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2392                 has_super++;
2393
2394         return (has_super + ext4_group_first_block_no(sb, bg));
2395 }
2396
2397 /**
2398  * ext4_get_stripe_size: Get the stripe size.
2399  * @sbi: In memory super block info
2400  *
2401  * If we have specified it via mount option, then
2402  * use the mount option value. If the value specified at mount time is
2403  * greater than the blocks per group use the super block value.
2404  * If the super block value is greater than blocks per group return 0.
2405  * Allocator needs it be less than blocks per group.
2406  *
2407  */
2408 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2409 {
2410         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2411         unsigned long stripe_width =
2412                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2413         int ret;
2414
2415         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2416                 ret = sbi->s_stripe;
2417         else if (stripe_width <= sbi->s_blocks_per_group)
2418                 ret = stripe_width;
2419         else if (stride <= sbi->s_blocks_per_group)
2420                 ret = stride;
2421         else
2422                 ret = 0;
2423
2424         /*
2425          * If the stripe width is 1, this makes no sense and
2426          * we set it to 0 to turn off stripe handling code.
2427          */
2428         if (ret <= 1)
2429                 ret = 0;
2430
2431         return ret;
2432 }
2433
2434 /* sysfs supprt */
2435
2436 struct ext4_attr {
2437         struct attribute attr;
2438         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2439         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2440                          const char *, size_t);
2441         union {
2442                 int offset;
2443                 int deprecated_val;
2444         } u;
2445 };
2446
2447 static int parse_strtoull(const char *buf,
2448                 unsigned long long max, unsigned long long *value)
2449 {
2450         int ret;
2451
2452         ret = kstrtoull(skip_spaces(buf), 0, value);
2453         if (!ret && *value > max)
2454                 ret = -EINVAL;
2455         return ret;
2456 }
2457
2458 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2459                                               struct ext4_sb_info *sbi,
2460                                               char *buf)
2461 {
2462         return snprintf(buf, PAGE_SIZE, "%llu\n",
2463                 (s64) EXT4_C2B(sbi,
2464                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2465 }
2466
2467 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2468                                          struct ext4_sb_info *sbi, char *buf)
2469 {
2470         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2471
2472         if (!sb->s_bdev->bd_part)
2473                 return snprintf(buf, PAGE_SIZE, "0\n");
2474         return snprintf(buf, PAGE_SIZE, "%lu\n",
2475                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2476                          sbi->s_sectors_written_start) >> 1);
2477 }
2478
2479 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2480                                           struct ext4_sb_info *sbi, char *buf)
2481 {
2482         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2483
2484         if (!sb->s_bdev->bd_part)
2485                 return snprintf(buf, PAGE_SIZE, "0\n");
2486         return snprintf(buf, PAGE_SIZE, "%llu\n",
2487                         (unsigned long long)(sbi->s_kbytes_written +
2488                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2489                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2490 }
2491
2492 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2493                                           struct ext4_sb_info *sbi,
2494                                           const char *buf, size_t count)
2495 {
2496         unsigned long t;
2497         int ret;
2498
2499         ret = kstrtoul(skip_spaces(buf), 0, &t);
2500         if (ret)
2501                 return ret;
2502
2503         if (t && (!is_power_of_2(t) || t > 0x40000000))
2504                 return -EINVAL;
2505
2506         sbi->s_inode_readahead_blks = t;
2507         return count;
2508 }
2509
2510 static ssize_t sbi_ui_show(struct ext4_attr *a,
2511                            struct ext4_sb_info *sbi, char *buf)
2512 {
2513         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2514
2515         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2516 }
2517
2518 static ssize_t sbi_ui_store(struct ext4_attr *a,
2519                             struct ext4_sb_info *sbi,
2520                             const char *buf, size_t count)
2521 {
2522         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2523         unsigned long t;
2524         int ret;
2525
2526         ret = kstrtoul(skip_spaces(buf), 0, &t);
2527         if (ret)
2528                 return ret;
2529         *ui = t;
2530         return count;
2531 }
2532
2533 static ssize_t es_ui_show(struct ext4_attr *a,
2534                            struct ext4_sb_info *sbi, char *buf)
2535 {
2536
2537         unsigned int *ui = (unsigned int *) (((char *) sbi->s_es) +
2538                            a->u.offset);
2539
2540         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2541 }
2542
2543 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2544                                   struct ext4_sb_info *sbi, char *buf)
2545 {
2546         return snprintf(buf, PAGE_SIZE, "%llu\n",
2547                 (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2548 }
2549
2550 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2551                                    struct ext4_sb_info *sbi,
2552                                    const char *buf, size_t count)
2553 {
2554         unsigned long long val;
2555         int ret;
2556
2557         if (parse_strtoull(buf, -1ULL, &val))
2558                 return -EINVAL;
2559         ret = ext4_reserve_clusters(sbi, val);
2560
2561         return ret ? ret : count;
2562 }
2563
2564 static ssize_t trigger_test_error(struct ext4_attr *a,
2565                                   struct ext4_sb_info *sbi,
2566                                   const char *buf, size_t count)
2567 {
2568         int len = count;
2569
2570         if (!capable(CAP_SYS_ADMIN))
2571                 return -EPERM;
2572
2573         if (len && buf[len-1] == '\n')
2574                 len--;
2575
2576         if (len)
2577                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2578         return count;
2579 }
2580
2581 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2582                                    struct ext4_sb_info *sbi, char *buf)
2583 {
2584         return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2585 }
2586
2587 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2588 static struct ext4_attr ext4_attr_##_name = {                   \
2589         .attr = {.name = __stringify(_name), .mode = _mode },   \
2590         .show   = _show,                                        \
2591         .store  = _store,                                       \
2592         .u = {                                                  \
2593                 .offset = offsetof(struct ext4_sb_info, _elname),\
2594         },                                                      \
2595 }
2596
2597 #define EXT4_ATTR_OFFSET_ES(_name,_mode,_show,_store,_elname)           \
2598 static struct ext4_attr ext4_attr_##_name = {                           \
2599         .attr = {.name = __stringify(_name), .mode = _mode },           \
2600         .show   = _show,                                                \
2601         .store  = _store,                                               \
2602         .u = {                                                          \
2603                 .offset = offsetof(struct ext4_super_block, _elname),   \
2604         },                                                              \
2605 }
2606
2607 #define EXT4_ATTR(name, mode, show, store) \
2608 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2609
2610 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2611 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2612 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2613
2614 #define EXT4_RO_ATTR_ES_UI(name, elname)        \
2615         EXT4_ATTR_OFFSET_ES(name, 0444, es_ui_show, NULL, elname)
2616 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2617         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2618
2619 #define ATTR_LIST(name) &ext4_attr_##name.attr
2620 #define EXT4_DEPRECATED_ATTR(_name, _val)       \
2621 static struct ext4_attr ext4_attr_##_name = {                   \
2622         .attr = {.name = __stringify(_name), .mode = 0444 },    \
2623         .show   = sbi_deprecated_show,                          \
2624         .u = {                                                  \
2625                 .deprecated_val = _val,                         \
2626         },                                                      \
2627 }
2628
2629 EXT4_RO_ATTR(delayed_allocation_blocks);
2630 EXT4_RO_ATTR(session_write_kbytes);
2631 EXT4_RO_ATTR(lifetime_write_kbytes);
2632 EXT4_RW_ATTR(reserved_clusters);
2633 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2634                  inode_readahead_blks_store, s_inode_readahead_blks);
2635 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2636 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2637 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2638 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2639 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2640 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2641 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2642 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2643 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2644 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2645 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2646 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2647 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2648 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2649 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2650 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2651 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
2652 EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
2653 EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
2654
2655 static struct attribute *ext4_attrs[] = {
2656         ATTR_LIST(delayed_allocation_blocks),
2657         ATTR_LIST(session_write_kbytes),
2658         ATTR_LIST(lifetime_write_kbytes),
2659         ATTR_LIST(reserved_clusters),
2660         ATTR_LIST(inode_readahead_blks),
2661         ATTR_LIST(inode_goal),
2662         ATTR_LIST(mb_stats),
2663         ATTR_LIST(mb_max_to_scan),
2664         ATTR_LIST(mb_min_to_scan),
2665         ATTR_LIST(mb_order2_req),
2666         ATTR_LIST(mb_stream_req),
2667         ATTR_LIST(mb_group_prealloc),
2668         ATTR_LIST(max_writeback_mb_bump),
2669         ATTR_LIST(extent_max_zeroout_kb),
2670         ATTR_LIST(trigger_fs_error),
2671         ATTR_LIST(err_ratelimit_interval_ms),
2672         ATTR_LIST(err_ratelimit_burst),
2673         ATTR_LIST(warning_ratelimit_interval_ms),
2674         ATTR_LIST(warning_ratelimit_burst),
2675         ATTR_LIST(msg_ratelimit_interval_ms),
2676         ATTR_LIST(msg_ratelimit_burst),
2677         ATTR_LIST(errors_count),
2678         ATTR_LIST(first_error_time),
2679         ATTR_LIST(last_error_time),
2680         NULL,
2681 };
2682
2683 /* Features this copy of ext4 supports */
2684 EXT4_INFO_ATTR(lazy_itable_init);
2685 EXT4_INFO_ATTR(batched_discard);
2686 EXT4_INFO_ATTR(meta_bg_resize);
2687 EXT4_INFO_ATTR(encryption);
2688
2689 static struct attribute *ext4_feat_attrs[] = {
2690         ATTR_LIST(lazy_itable_init),
2691         ATTR_LIST(batched_discard),
2692         ATTR_LIST(meta_bg_resize),
2693         ATTR_LIST(encryption),
2694         NULL,
2695 };
2696
2697 static ssize_t ext4_attr_show(struct kobject *kobj,
2698                               struct attribute *attr, char *buf)
2699 {
2700         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2701                                                 s_kobj);
2702         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2703
2704         return a->show ? a->show(a, sbi, buf) : 0;
2705 }
2706
2707 static ssize_t ext4_attr_store(struct kobject *kobj,
2708                                struct attribute *attr,
2709                                const char *buf, size_t len)
2710 {
2711         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2712                                                 s_kobj);
2713         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2714
2715         return a->store ? a->store(a, sbi, buf, len) : 0;
2716 }
2717
2718 static void ext4_sb_release(struct kobject *kobj)
2719 {
2720         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2721                                                 s_kobj);
2722         complete(&sbi->s_kobj_unregister);
2723 }
2724
2725 static const struct sysfs_ops ext4_attr_ops = {
2726         .show   = ext4_attr_show,
2727         .store  = ext4_attr_store,
2728 };
2729
2730 static struct kobj_type ext4_ktype = {
2731         .default_attrs  = ext4_attrs,
2732         .sysfs_ops      = &ext4_attr_ops,
2733         .release        = ext4_sb_release,
2734 };
2735
2736 static void ext4_feat_release(struct kobject *kobj)
2737 {
2738         complete(&ext4_feat->f_kobj_unregister);
2739 }
2740
2741 static ssize_t ext4_feat_show(struct kobject *kobj,
2742                               struct attribute *attr, char *buf)
2743 {
2744         return snprintf(buf, PAGE_SIZE, "supported\n");
2745 }
2746
2747 /*
2748  * We can not use ext4_attr_show/store because it relies on the kobject
2749  * being embedded in the ext4_sb_info structure which is definitely not
2750  * true in this case.
2751  */
2752 static const struct sysfs_ops ext4_feat_ops = {
2753         .show   = ext4_feat_show,
2754         .store  = NULL,
2755 };
2756
2757 static struct kobj_type ext4_feat_ktype = {
2758         .default_attrs  = ext4_feat_attrs,
2759         .sysfs_ops      = &ext4_feat_ops,
2760         .release        = ext4_feat_release,
2761 };
2762
2763 /*
2764  * Check whether this filesystem can be mounted based on
2765  * the features present and the RDONLY/RDWR mount requested.
2766  * Returns 1 if this filesystem can be mounted as requested,
2767  * 0 if it cannot be.
2768  */
2769 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2770 {
2771         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2772                 ext4_msg(sb, KERN_ERR,
2773                         "Couldn't mount because of "
2774                         "unsupported optional features (%x)",
2775                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2776                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2777                 return 0;
2778         }
2779
2780         if (readonly)
2781                 return 1;
2782
2783         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_READONLY)) {
2784                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2785                 sb->s_flags |= MS_RDONLY;
2786                 return 1;
2787         }
2788
2789         /* Check that feature set is OK for a read-write mount */
2790         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2791                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2792                          "unsupported optional features (%x)",
2793                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2794                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2795                 return 0;
2796         }
2797         /*
2798          * Large file size enabled file system can only be mounted
2799          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2800          */
2801         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2802                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2803                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2804                                  "cannot be mounted RDWR without "
2805                                  "CONFIG_LBDAF");
2806                         return 0;
2807                 }
2808         }
2809         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2810             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2811                 ext4_msg(sb, KERN_ERR,
2812                          "Can't support bigalloc feature without "
2813                          "extents feature\n");
2814                 return 0;
2815         }
2816
2817 #ifndef CONFIG_QUOTA
2818         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2819             !readonly) {
2820                 ext4_msg(sb, KERN_ERR,
2821                          "Filesystem with quota feature cannot be mounted RDWR "
2822                          "without CONFIG_QUOTA");
2823                 return 0;
2824         }
2825 #endif  /* CONFIG_QUOTA */
2826         return 1;
2827 }
2828
2829 /*
2830  * This function is called once a day if we have errors logged
2831  * on the file system
2832  */
2833 static void print_daily_error_info(unsigned long arg)
2834 {
2835         struct super_block *sb = (struct super_block *) arg;
2836         struct ext4_sb_info *sbi;
2837         struct ext4_super_block *es;
2838
2839         sbi = EXT4_SB(sb);
2840         es = sbi->s_es;
2841
2842         if (es->s_error_count)
2843                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2844                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2845                          le32_to_cpu(es->s_error_count));
2846         if (es->s_first_error_time) {
2847                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2848                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2849                        (int) sizeof(es->s_first_error_func),
2850                        es->s_first_error_func,
2851                        le32_to_cpu(es->s_first_error_line));
2852                 if (es->s_first_error_ino)
2853                         printk(": inode %u",
2854                                le32_to_cpu(es->s_first_error_ino));
2855                 if (es->s_first_error_block)
2856                         printk(": block %llu", (unsigned long long)
2857                                le64_to_cpu(es->s_first_error_block));
2858                 printk("\n");
2859         }
2860         if (es->s_last_error_time) {
2861                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2862                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2863                        (int) sizeof(es->s_last_error_func),
2864                        es->s_last_error_func,
2865                        le32_to_cpu(es->s_last_error_line));
2866                 if (es->s_last_error_ino)
2867                         printk(": inode %u",
2868                                le32_to_cpu(es->s_last_error_ino));
2869                 if (es->s_last_error_block)
2870                         printk(": block %llu", (unsigned long long)
2871                                le64_to_cpu(es->s_last_error_block));
2872                 printk("\n");
2873         }
2874         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2875 }
2876
2877 /* Find next suitable group and run ext4_init_inode_table */
2878 static int ext4_run_li_request(struct ext4_li_request *elr)
2879 {
2880         struct ext4_group_desc *gdp = NULL;
2881         ext4_group_t group, ngroups;
2882         struct super_block *sb;
2883         unsigned long timeout = 0;
2884         int ret = 0;
2885
2886         sb = elr->lr_super;
2887         ngroups = EXT4_SB(sb)->s_groups_count;
2888
2889         sb_start_write(sb);
2890         for (group = elr->lr_next_group; group < ngroups; group++) {
2891                 gdp = ext4_get_group_desc(sb, group, NULL);
2892                 if (!gdp) {
2893                         ret = 1;
2894                         break;
2895                 }
2896
2897                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2898                         break;
2899         }
2900
2901         if (group >= ngroups)
2902                 ret = 1;
2903
2904         if (!ret) {
2905                 timeout = jiffies;
2906                 ret = ext4_init_inode_table(sb, group,
2907                                             elr->lr_timeout ? 0 : 1);
2908                 if (elr->lr_timeout == 0) {
2909                         timeout = (jiffies - timeout) *
2910                                   elr->lr_sbi->s_li_wait_mult;
2911                         elr->lr_timeout = timeout;
2912                 }
2913                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2914                 elr->lr_next_group = group + 1;
2915         }
2916         sb_end_write(sb);
2917
2918         return ret;
2919 }
2920
2921 /*
2922  * Remove lr_request from the list_request and free the
2923  * request structure. Should be called with li_list_mtx held
2924  */
2925 static void ext4_remove_li_request(struct ext4_li_request *elr)
2926 {
2927         struct ext4_sb_info *sbi;
2928
2929         if (!elr)
2930                 return;
2931
2932         sbi = elr->lr_sbi;
2933
2934         list_del(&elr->lr_request);
2935         sbi->s_li_request = NULL;
2936         kfree(elr);
2937 }
2938
2939 static void ext4_unregister_li_request(struct super_block *sb)
2940 {
2941         mutex_lock(&ext4_li_mtx);
2942         if (!ext4_li_info) {
2943                 mutex_unlock(&ext4_li_mtx);
2944                 return;
2945         }
2946
2947         mutex_lock(&ext4_li_info->li_list_mtx);
2948         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2949         mutex_unlock(&ext4_li_info->li_list_mtx);
2950         mutex_unlock(&ext4_li_mtx);
2951 }
2952
2953 static struct task_struct *ext4_lazyinit_task;
2954
2955 /*
2956  * This is the function where ext4lazyinit thread lives. It walks
2957  * through the request list searching for next scheduled filesystem.
2958  * When such a fs is found, run the lazy initialization request
2959  * (ext4_rn_li_request) and keep track of the time spend in this
2960  * function. Based on that time we compute next schedule time of
2961  * the request. When walking through the list is complete, compute
2962  * next waking time and put itself into sleep.
2963  */
2964 static int ext4_lazyinit_thread(void *arg)
2965 {
2966         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2967         struct list_head *pos, *n;
2968         struct ext4_li_request *elr;
2969         unsigned long next_wakeup, cur;
2970
2971         BUG_ON(NULL == eli);
2972
2973 cont_thread:
2974         while (true) {
2975                 next_wakeup = MAX_JIFFY_OFFSET;
2976
2977                 mutex_lock(&eli->li_list_mtx);
2978                 if (list_empty(&eli->li_request_list)) {
2979                         mutex_unlock(&eli->li_list_mtx);
2980                         goto exit_thread;
2981                 }
2982
2983                 list_for_each_safe(pos, n, &eli->li_request_list) {
2984                         elr = list_entry(pos, struct ext4_li_request,
2985                                          lr_request);
2986
2987                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2988                                 if (ext4_run_li_request(elr) != 0) {
2989                                         /* error, remove the lazy_init job */
2990                                         ext4_remove_li_request(elr);
2991                                         continue;
2992                                 }
2993                         }
2994
2995                         if (time_before(elr->lr_next_sched, next_wakeup))
2996                                 next_wakeup = elr->lr_next_sched;
2997                 }
2998                 mutex_unlock(&eli->li_list_mtx);
2999
3000                 try_to_freeze();
3001
3002                 cur = jiffies;
3003                 if ((time_after_eq(cur, next_wakeup)) ||
3004                     (MAX_JIFFY_OFFSET == next_wakeup)) {
3005                         cond_resched();
3006                         continue;
3007                 }
3008
3009                 schedule_timeout_interruptible(next_wakeup - cur);
3010
3011                 if (kthread_should_stop()) {
3012                         ext4_clear_request_list();
3013                         goto exit_thread;
3014                 }
3015         }
3016
3017 exit_thread:
3018         /*
3019          * It looks like the request list is empty, but we need
3020          * to check it under the li_list_mtx lock, to prevent any
3021          * additions into it, and of course we should lock ext4_li_mtx
3022          * to atomically free the list and ext4_li_info, because at
3023          * this point another ext4 filesystem could be registering
3024          * new one.
3025          */
3026         mutex_lock(&ext4_li_mtx);
3027         mutex_lock(&eli->li_list_mtx);
3028         if (!list_empty(&eli->li_request_list)) {
3029                 mutex_unlock(&eli->li_list_mtx);
3030                 mutex_unlock(&ext4_li_mtx);
3031                 goto cont_thread;
3032         }
3033         mutex_unlock(&eli->li_list_mtx);
3034         kfree(ext4_li_info);
3035         ext4_li_info = NULL;
3036         mutex_unlock(&ext4_li_mtx);
3037
3038         return 0;
3039 }
3040
3041 static void ext4_clear_request_list(void)
3042 {
3043         struct list_head *pos, *n;
3044         struct ext4_li_request *elr;
3045
3046         mutex_lock(&ext4_li_info->li_list_mtx);
3047         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3048                 elr = list_entry(pos, struct ext4_li_request,
3049                                  lr_request);
3050                 ext4_remove_li_request(elr);
3051         }
3052         mutex_unlock(&ext4_li_info->li_list_mtx);
3053 }
3054
3055 static int ext4_run_lazyinit_thread(void)
3056 {
3057         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3058                                          ext4_li_info, "ext4lazyinit");
3059         if (IS_ERR(ext4_lazyinit_task)) {
3060                 int err = PTR_ERR(ext4_lazyinit_task);
3061                 ext4_clear_request_list();
3062                 kfree(ext4_li_info);
3063                 ext4_li_info = NULL;
3064                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3065                                  "initialization thread\n",
3066                                  err);
3067                 return err;
3068         }
3069         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3070         return 0;
3071 }
3072
3073 /*
3074  * Check whether it make sense to run itable init. thread or not.
3075  * If there is at least one uninitialized inode table, return
3076  * corresponding group number, else the loop goes through all
3077  * groups and return total number of groups.
3078  */
3079 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3080 {
3081         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3082         struct ext4_group_desc *gdp = NULL;
3083
3084         for (group = 0; group < ngroups; group++) {
3085                 gdp = ext4_get_group_desc(sb, group, NULL);
3086                 if (!gdp)
3087                         continue;
3088
3089                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3090                         break;
3091         }
3092
3093         return group;
3094 }
3095
3096 static int ext4_li_info_new(void)
3097 {
3098         struct ext4_lazy_init *eli = NULL;
3099
3100         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3101         if (!eli)
3102                 return -ENOMEM;
3103
3104         INIT_LIST_HEAD(&eli->li_request_list);
3105         mutex_init(&eli->li_list_mtx);
3106
3107         eli->li_state |= EXT4_LAZYINIT_QUIT;
3108
3109         ext4_li_info = eli;
3110
3111         return 0;
3112 }
3113
3114 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3115                                             ext4_group_t start)
3116 {
3117         struct ext4_sb_info *sbi = EXT4_SB(sb);
3118         struct ext4_li_request *elr;
3119
3120         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3121         if (!elr)
3122                 return NULL;
3123
3124         elr->lr_super = sb;
3125         elr->lr_sbi = sbi;
3126         elr->lr_next_group = start;
3127
3128         /*
3129          * Randomize first schedule time of the request to
3130          * spread the inode table initialization requests
3131          * better.
3132          */
3133         elr->lr_next_sched = jiffies + (prandom_u32() %
3134                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3135         return elr;
3136 }
3137
3138 int ext4_register_li_request(struct super_block *sb,
3139                              ext4_group_t first_not_zeroed)
3140 {
3141         struct ext4_sb_info *sbi = EXT4_SB(sb);
3142         struct ext4_li_request *elr = NULL;
3143         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3144         int ret = 0;
3145
3146         mutex_lock(&ext4_li_mtx);
3147         if (sbi->s_li_request != NULL) {
3148                 /*
3149                  * Reset timeout so it can be computed again, because
3150                  * s_li_wait_mult might have changed.
3151                  */
3152                 sbi->s_li_request->lr_timeout = 0;
3153                 goto out;
3154         }
3155
3156         if (first_not_zeroed == ngroups ||
3157             (sb->s_flags & MS_RDONLY) ||
3158             !test_opt(sb, INIT_INODE_TABLE))
3159                 goto out;
3160
3161         elr = ext4_li_request_new(sb, first_not_zeroed);
3162         if (!elr) {
3163                 ret = -ENOMEM;
3164                 goto out;
3165         }
3166
3167         if (NULL == ext4_li_info) {
3168                 ret = ext4_li_info_new();
3169                 if (ret)
3170                         goto out;
3171         }
3172
3173         mutex_lock(&ext4_li_info->li_list_mtx);
3174         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3175         mutex_unlock(&ext4_li_info->li_list_mtx);
3176
3177         sbi->s_li_request = elr;
3178         /*
3179          * set elr to NULL here since it has been inserted to
3180          * the request_list and the removal and free of it is
3181          * handled by ext4_clear_request_list from now on.
3182          */
3183         elr = NULL;
3184
3185         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3186                 ret = ext4_run_lazyinit_thread();
3187                 if (ret)
3188                         goto out;
3189         }
3190 out:
3191         mutex_unlock(&ext4_li_mtx);
3192         if (ret)
3193                 kfree(elr);
3194         return ret;
3195 }
3196
3197 /*
3198  * We do not need to lock anything since this is called on
3199  * module unload.
3200  */
3201 static void ext4_destroy_lazyinit_thread(void)
3202 {
3203         /*
3204          * If thread exited earlier
3205          * there's nothing to be done.
3206          */
3207         if (!ext4_li_info || !ext4_lazyinit_task)
3208                 return;
3209
3210         kthread_stop(ext4_lazyinit_task);
3211 }
3212
3213 static int set_journal_csum_feature_set(struct super_block *sb)
3214 {
3215         int ret = 1;
3216         int compat, incompat;
3217         struct ext4_sb_info *sbi = EXT4_SB(sb);
3218
3219         if (ext4_has_metadata_csum(sb)) {
3220                 /* journal checksum v3 */
3221                 compat = 0;
3222                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3223         } else {
3224                 /* journal checksum v1 */
3225                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3226                 incompat = 0;
3227         }
3228
3229         jbd2_journal_clear_features(sbi->s_journal,
3230                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3231                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3232                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3233         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3234                 ret = jbd2_journal_set_features(sbi->s_journal,
3235                                 compat, 0,
3236                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3237                                 incompat);
3238         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3239                 ret = jbd2_journal_set_features(sbi->s_journal,
3240                                 compat, 0,
3241                                 incompat);
3242                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3243                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3244         } else {
3245                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3246                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3247         }
3248
3249         return ret;
3250 }
3251
3252 /*
3253  * Note: calculating the overhead so we can be compatible with
3254  * historical BSD practice is quite difficult in the face of
3255  * clusters/bigalloc.  This is because multiple metadata blocks from
3256  * different block group can end up in the same allocation cluster.
3257  * Calculating the exact overhead in the face of clustered allocation
3258  * requires either O(all block bitmaps) in memory or O(number of block
3259  * groups**2) in time.  We will still calculate the superblock for
3260  * older file systems --- and if we come across with a bigalloc file
3261  * system with zero in s_overhead_clusters the estimate will be close to
3262  * correct especially for very large cluster sizes --- but for newer
3263  * file systems, it's better to calculate this figure once at mkfs
3264  * time, and store it in the superblock.  If the superblock value is
3265  * present (even for non-bigalloc file systems), we will use it.
3266  */
3267 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3268                           char *buf)
3269 {
3270         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3271         struct ext4_group_desc  *gdp;
3272         ext4_fsblk_t            first_block, last_block, b;
3273         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3274         int                     s, j, count = 0;
3275
3276         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3277                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3278                         sbi->s_itb_per_group + 2);
3279
3280         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3281                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3282         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3283         for (i = 0; i < ngroups; i++) {
3284                 gdp = ext4_get_group_desc(sb, i, NULL);
3285                 b = ext4_block_bitmap(sb, gdp);
3286                 if (b >= first_block && b <= last_block) {
3287                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3288                         count++;
3289                 }
3290                 b = ext4_inode_bitmap(sb, gdp);
3291                 if (b >= first_block && b <= last_block) {
3292                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3293                         count++;
3294                 }
3295                 b = ext4_inode_table(sb, gdp);
3296                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3297                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3298                                 int c = EXT4_B2C(sbi, b - first_block);
3299                                 ext4_set_bit(c, buf);
3300                                 count++;
3301                         }
3302                 if (i != grp)
3303                         continue;
3304                 s = 0;
3305                 if (ext4_bg_has_super(sb, grp)) {
3306                         ext4_set_bit(s++, buf);
3307                         count++;
3308                 }
3309                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3310                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3311                         count++;
3312                 }
3313         }
3314         if (!count)
3315                 return 0;
3316         return EXT4_CLUSTERS_PER_GROUP(sb) -
3317                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3318 }
3319
3320 /*
3321  * Compute the overhead and stash it in sbi->s_overhead
3322  */
3323 int ext4_calculate_overhead(struct super_block *sb)
3324 {
3325         struct ext4_sb_info *sbi = EXT4_SB(sb);
3326         struct ext4_super_block *es = sbi->s_es;
3327         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3328         ext4_fsblk_t overhead = 0;
3329         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3330
3331         if (!buf)
3332                 return -ENOMEM;
3333
3334         /*
3335          * Compute the overhead (FS structures).  This is constant
3336          * for a given filesystem unless the number of block groups
3337          * changes so we cache the previous value until it does.
3338          */
3339
3340         /*
3341          * All of the blocks before first_data_block are overhead
3342          */
3343         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3344
3345         /*
3346          * Add the overhead found in each block group
3347          */
3348         for (i = 0; i < ngroups; i++) {
3349                 int blks;
3350
3351                 blks = count_overhead(sb, i, buf);
3352                 overhead += blks;
3353                 if (blks)
3354                         memset(buf, 0, PAGE_SIZE);
3355                 cond_resched();
3356         }
3357         /* Add the internal journal blocks as well */
3358         if (sbi->s_journal && !sbi->journal_bdev)
3359                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3360
3361         sbi->s_overhead = overhead;
3362         smp_wmb();
3363         free_page((unsigned long) buf);
3364         return 0;
3365 }
3366
3367
3368 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3369 {
3370         ext4_fsblk_t resv_clusters;
3371
3372         /*
3373          * There's no need to reserve anything when we aren't using extents.
3374          * The space estimates are exact, there are no unwritten extents,
3375          * hole punching doesn't need new metadata... This is needed especially
3376          * to keep ext2/3 backward compatibility.
3377          */
3378         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3379                 return 0;
3380         /*
3381          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3382          * This should cover the situations where we can not afford to run
3383          * out of space like for example punch hole, or converting
3384          * unwritten extents in delalloc path. In most cases such
3385          * allocation would require 1, or 2 blocks, higher numbers are
3386          * very rare.
3387          */
3388         resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3389                         EXT4_SB(sb)->s_cluster_bits;
3390
3391         do_div(resv_clusters, 50);
3392         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3393
3394         return resv_clusters;
3395 }
3396
3397
3398 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3399 {
3400         ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3401                                 sbi->s_cluster_bits;
3402
3403         if (count >= clusters)
3404                 return -EINVAL;
3405
3406         atomic64_set(&sbi->s_resv_clusters, count);
3407         return 0;
3408 }
3409
3410 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3411 {
3412         char *orig_data = kstrdup(data, GFP_KERNEL);
3413         struct buffer_head *bh;
3414         struct ext4_super_block *es = NULL;
3415         struct ext4_sb_info *sbi;
3416         ext4_fsblk_t block;
3417         ext4_fsblk_t sb_block = get_sb_block(&data);
3418         ext4_fsblk_t logical_sb_block;
3419         unsigned long offset = 0;
3420         unsigned long journal_devnum = 0;
3421         unsigned long def_mount_opts;
3422         struct inode *root;
3423         char *cp;
3424         const char *descr;
3425         int ret = -ENOMEM;
3426         int blocksize, clustersize;
3427         unsigned int db_count;
3428         unsigned int i;
3429         int needs_recovery, has_huge_files, has_bigalloc;
3430         __u64 blocks_count;
3431         int err = 0;
3432         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3433         ext4_group_t first_not_zeroed;
3434
3435         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3436         if (!sbi)
3437                 goto out_free_orig;
3438
3439         sbi->s_blockgroup_lock =
3440                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3441         if (!sbi->s_blockgroup_lock) {
3442                 kfree(sbi);
3443                 goto out_free_orig;
3444         }
3445         sb->s_fs_info = sbi;
3446         sbi->s_sb = sb;
3447         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3448         sbi->s_sb_block = sb_block;
3449         if (sb->s_bdev->bd_part)
3450                 sbi->s_sectors_written_start =
3451                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3452 #ifdef CONFIG_EXT4_FS_ENCRYPTION
3453         /* Modes of operations for file and directory encryption. */
3454         sbi->s_file_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_XTS;
3455         sbi->s_dir_encryption_mode = EXT4_ENCRYPTION_MODE_INVALID;
3456 #endif
3457
3458         /* Cleanup superblock name */
3459         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3460                 *cp = '!';
3461
3462         /* -EINVAL is default */
3463         ret = -EINVAL;
3464         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3465         if (!blocksize) {
3466                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3467                 goto out_fail;
3468         }
3469
3470         /*
3471          * The ext4 superblock will not be buffer aligned for other than 1kB
3472          * block sizes.  We need to calculate the offset from buffer start.
3473          */
3474         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3475                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3476                 offset = do_div(logical_sb_block, blocksize);
3477         } else {
3478                 logical_sb_block = sb_block;
3479         }
3480
3481         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3482                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3483                 goto out_fail;
3484         }
3485         /*
3486          * Note: s_es must be initialized as soon as possible because
3487          *       some ext4 macro-instructions depend on its value
3488          */
3489         es = (struct ext4_super_block *) (bh->b_data + offset);
3490         sbi->s_es = es;
3491         sb->s_magic = le16_to_cpu(es->s_magic);
3492         if (sb->s_magic != EXT4_SUPER_MAGIC)
3493                 goto cantfind_ext4;
3494         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3495
3496         /* Warn if metadata_csum and gdt_csum are both set. */
3497         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3498                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3499             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3500                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3501                              "redundant flags; please run fsck.");
3502
3503         /* Check for a known checksum algorithm */
3504         if (!ext4_verify_csum_type(sb, es)) {
3505                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3506                          "unknown checksum algorithm.");
3507                 silent = 1;
3508                 goto cantfind_ext4;
3509         }
3510
3511         /* Load the checksum driver */
3512         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3513                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3514                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3515                 if (IS_ERR(sbi->s_chksum_driver)) {
3516                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3517                         ret = PTR_ERR(sbi->s_chksum_driver);
3518                         sbi->s_chksum_driver = NULL;
3519                         goto failed_mount;
3520                 }
3521         }
3522
3523         /* Check superblock checksum */
3524         if (!ext4_superblock_csum_verify(sb, es)) {
3525                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3526                          "invalid superblock checksum.  Run e2fsck?");
3527                 silent = 1;
3528                 goto cantfind_ext4;
3529         }
3530
3531         /* Precompute checksum seed for all metadata */
3532         if (ext4_has_metadata_csum(sb))
3533                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3534                                                sizeof(es->s_uuid));
3535
3536         /* Set defaults before we parse the mount options */
3537         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3538         set_opt(sb, INIT_INODE_TABLE);
3539         if (def_mount_opts & EXT4_DEFM_DEBUG)
3540                 set_opt(sb, DEBUG);
3541         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3542                 set_opt(sb, GRPID);
3543         if (def_mount_opts & EXT4_DEFM_UID16)
3544                 set_opt(sb, NO_UID32);
3545         /* xattr user namespace & acls are now defaulted on */
3546         set_opt(sb, XATTR_USER);
3547 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3548         set_opt(sb, POSIX_ACL);
3549 #endif
3550         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3551         if (ext4_has_metadata_csum(sb))
3552                 set_opt(sb, JOURNAL_CHECKSUM);
3553
3554         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3555                 set_opt(sb, JOURNAL_DATA);
3556         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3557                 set_opt(sb, ORDERED_DATA);
3558         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3559                 set_opt(sb, WRITEBACK_DATA);
3560
3561         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3562                 set_opt(sb, ERRORS_PANIC);
3563         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3564                 set_opt(sb, ERRORS_CONT);
3565         else
3566                 set_opt(sb, ERRORS_RO);
3567         /* block_validity enabled by default; disable with noblock_validity */
3568         set_opt(sb, BLOCK_VALIDITY);
3569         if (def_mount_opts & EXT4_DEFM_DISCARD)
3570                 set_opt(sb, DISCARD);
3571
3572         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3573         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3574         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3575         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3576         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3577
3578         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3579                 set_opt(sb, BARRIER);
3580
3581         /*
3582          * enable delayed allocation by default
3583          * Use -o nodelalloc to turn it off
3584          */
3585         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3586             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3587                 set_opt(sb, DELALLOC);
3588
3589         /*
3590          * set default s_li_wait_mult for lazyinit, for the case there is
3591          * no mount option specified.
3592          */
3593         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3594
3595         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3596                            &journal_devnum, &journal_ioprio, 0)) {
3597                 ext4_msg(sb, KERN_WARNING,
3598                          "failed to parse options in superblock: %s",
3599                          sbi->s_es->s_mount_opts);
3600         }
3601         sbi->s_def_mount_opt = sbi->s_mount_opt;
3602         if (!parse_options((char *) data, sb, &journal_devnum,
3603                            &journal_ioprio, 0))
3604                 goto failed_mount;
3605
3606         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3607                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3608                             "with data=journal disables delayed "
3609                             "allocation and O_DIRECT support!\n");
3610                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3611                         ext4_msg(sb, KERN_ERR, "can't mount with "
3612                                  "both data=journal and delalloc");
3613                         goto failed_mount;
3614                 }
3615                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3616                         ext4_msg(sb, KERN_ERR, "can't mount with "
3617                                  "both data=journal and dioread_nolock");
3618                         goto failed_mount;
3619                 }
3620                 if (test_opt(sb, DAX)) {
3621                         ext4_msg(sb, KERN_ERR, "can't mount with "
3622                                  "both data=journal and dax");
3623                         goto failed_mount;
3624                 }
3625                 if (test_opt(sb, DELALLOC))
3626                         clear_opt(sb, DELALLOC);
3627         }
3628
3629         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3630                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3631
3632         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3633             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3634              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3635              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3636                 ext4_msg(sb, KERN_WARNING,
3637                        "feature flags set on rev 0 fs, "
3638                        "running e2fsck is recommended");
3639
3640         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3641                 set_opt2(sb, HURD_COMPAT);
3642                 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
3643                                               EXT4_FEATURE_INCOMPAT_64BIT)) {
3644                         ext4_msg(sb, KERN_ERR,
3645                                  "The Hurd can't support 64-bit file systems");
3646                         goto failed_mount;
3647                 }
3648         }
3649
3650         if (IS_EXT2_SB(sb)) {
3651                 if (ext2_feature_set_ok(sb))
3652                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3653                                  "using the ext4 subsystem");
3654                 else {
3655                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3656                                  "to feature incompatibilities");
3657                         goto failed_mount;
3658                 }
3659         }
3660
3661         if (IS_EXT3_SB(sb)) {
3662                 if (ext3_feature_set_ok(sb))
3663                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3664                                  "using the ext4 subsystem");
3665                 else {
3666                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3667                                  "to feature incompatibilities");
3668                         goto failed_mount;
3669                 }
3670         }
3671
3672         /*
3673          * Check feature flags regardless of the revision level, since we
3674          * previously didn't change the revision level when setting the flags,
3675          * so there is a chance incompat flags are set on a rev 0 filesystem.
3676          */
3677         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3678                 goto failed_mount;
3679
3680         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3681         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3682             blocksize > EXT4_MAX_BLOCK_SIZE) {
3683                 ext4_msg(sb, KERN_ERR,
3684                        "Unsupported filesystem blocksize %d", blocksize);
3685                 goto failed_mount;
3686         }
3687
3688         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3689                 if (blocksize != PAGE_SIZE) {
3690                         ext4_msg(sb, KERN_ERR,
3691                                         "error: unsupported blocksize for dax");
3692                         goto failed_mount;
3693                 }
3694                 if (!sb->s_bdev->bd_disk->fops->direct_access) {
3695                         ext4_msg(sb, KERN_ERR,
3696                                         "error: device does not support dax");
3697                         goto failed_mount;
3698                 }
3699         }
3700
3701         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT) &&
3702             es->s_encryption_level) {
3703                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3704                          es->s_encryption_level);
3705                 goto failed_mount;
3706         }
3707
3708         if (sb->s_blocksize != blocksize) {
3709                 /* Validate the filesystem blocksize */
3710                 if (!sb_set_blocksize(sb, blocksize)) {
3711                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3712                                         blocksize);
3713                         goto failed_mount;
3714                 }
3715
3716                 brelse(bh);
3717                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3718                 offset = do_div(logical_sb_block, blocksize);
3719                 bh = sb_bread_unmovable(sb, logical_sb_block);
3720                 if (!bh) {
3721                         ext4_msg(sb, KERN_ERR,
3722                                "Can't read superblock on 2nd try");
3723                         goto failed_mount;
3724                 }
3725                 es = (struct ext4_super_block *)(bh->b_data + offset);
3726                 sbi->s_es = es;
3727                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3728                         ext4_msg(sb, KERN_ERR,
3729                                "Magic mismatch, very weird!");
3730                         goto failed_mount;
3731                 }
3732         }
3733
3734         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3735                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3736         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3737                                                       has_huge_files);
3738         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3739
3740         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3741                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3742                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3743         } else {
3744                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3745                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3746                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3747                     (!is_power_of_2(sbi->s_inode_size)) ||
3748                     (sbi->s_inode_size > blocksize)) {
3749                         ext4_msg(sb, KERN_ERR,
3750                                "unsupported inode size: %d",
3751                                sbi->s_inode_size);
3752                         goto failed_mount;
3753                 }
3754                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3755                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3756         }
3757
3758         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3759         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3760                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3761                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3762                     !is_power_of_2(sbi->s_desc_size)) {
3763                         ext4_msg(sb, KERN_ERR,
3764                                "unsupported descriptor size %lu",
3765                                sbi->s_desc_size);
3766                         goto failed_mount;
3767                 }
3768         } else
3769                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3770
3771         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3772         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3773         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3774                 goto cantfind_ext4;
3775
3776         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3777         if (sbi->s_inodes_per_block == 0)
3778                 goto cantfind_ext4;
3779         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3780                                         sbi->s_inodes_per_block;
3781         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3782         sbi->s_sbh = bh;
3783         sbi->s_mount_state = le16_to_cpu(es->s_state);
3784         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3785         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3786
3787         for (i = 0; i < 4; i++)
3788                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3789         sbi->s_def_hash_version = es->s_def_hash_version;
3790         if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3791                 i = le32_to_cpu(es->s_flags);
3792                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3793                         sbi->s_hash_unsigned = 3;
3794                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3795 #ifdef __CHAR_UNSIGNED__
3796                         if (!(sb->s_flags & MS_RDONLY))
3797                                 es->s_flags |=
3798                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3799                         sbi->s_hash_unsigned = 3;
3800 #else
3801                         if (!(sb->s_flags & MS_RDONLY))
3802                                 es->s_flags |=
3803                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3804 #endif
3805                 }
3806         }
3807
3808         /* Handle clustersize */
3809         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3810         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3811                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3812         if (has_bigalloc) {
3813                 if (clustersize < blocksize) {
3814                         ext4_msg(sb, KERN_ERR,
3815                                  "cluster size (%d) smaller than "
3816                                  "block size (%d)", clustersize, blocksize);
3817                         goto failed_mount;
3818                 }
3819                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3820                         le32_to_cpu(es->s_log_block_size);
3821                 sbi->s_clusters_per_group =
3822                         le32_to_cpu(es->s_clusters_per_group);
3823                 if (sbi->s_clusters_per_group > blocksize * 8) {
3824                         ext4_msg(sb, KERN_ERR,
3825                                  "#clusters per group too big: %lu",
3826                                  sbi->s_clusters_per_group);
3827                         goto failed_mount;
3828                 }
3829                 if (sbi->s_blocks_per_group !=
3830                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3831                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3832                                  "clusters per group (%lu) inconsistent",
3833                                  sbi->s_blocks_per_group,
3834                                  sbi->s_clusters_per_group);
3835                         goto failed_mount;
3836                 }
3837         } else {
3838                 if (clustersize != blocksize) {
3839                         ext4_warning(sb, "fragment/cluster size (%d) != "
3840                                      "block size (%d)", clustersize,
3841                                      blocksize);
3842                         clustersize = blocksize;
3843                 }
3844                 if (sbi->s_blocks_per_group > blocksize * 8) {
3845                         ext4_msg(sb, KERN_ERR,
3846                                  "#blocks per group too big: %lu",
3847                                  sbi->s_blocks_per_group);
3848                         goto failed_mount;
3849                 }
3850                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3851                 sbi->s_cluster_bits = 0;
3852         }
3853         sbi->s_cluster_ratio = clustersize / blocksize;
3854
3855         if (sbi->s_inodes_per_group > blocksize * 8) {
3856                 ext4_msg(sb, KERN_ERR,
3857                        "#inodes per group too big: %lu",
3858                        sbi->s_inodes_per_group);
3859                 goto failed_mount;
3860         }
3861
3862         /* Do we have standard group size of clustersize * 8 blocks ? */
3863         if (sbi->s_blocks_per_group == clustersize << 3)
3864                 set_opt2(sb, STD_GROUP_SIZE);
3865
3866         /*
3867          * Test whether we have more sectors than will fit in sector_t,
3868          * and whether the max offset is addressable by the page cache.
3869          */
3870         err = generic_check_addressable(sb->s_blocksize_bits,
3871                                         ext4_blocks_count(es));
3872         if (err) {
3873                 ext4_msg(sb, KERN_ERR, "filesystem"
3874                          " too large to mount safely on this system");
3875                 if (sizeof(sector_t) < 8)
3876                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3877                 goto failed_mount;
3878         }
3879
3880         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3881                 goto cantfind_ext4;
3882
3883         /* check blocks count against device size */
3884         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3885         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3886                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3887                        "exceeds size of device (%llu blocks)",
3888                        ext4_blocks_count(es), blocks_count);
3889                 goto failed_mount;
3890         }
3891
3892         /*
3893          * It makes no sense for the first data block to be beyond the end
3894          * of the filesystem.
3895          */
3896         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3897                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3898                          "block %u is beyond end of filesystem (%llu)",
3899                          le32_to_cpu(es->s_first_data_block),
3900                          ext4_blocks_count(es));
3901                 goto failed_mount;
3902         }
3903         blocks_count = (ext4_blocks_count(es) -
3904                         le32_to_cpu(es->s_first_data_block) +
3905                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3906         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3907         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3908                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3909                        "(block count %llu, first data block %u, "
3910                        "blocks per group %lu)", sbi->s_groups_count,
3911                        ext4_blocks_count(es),
3912                        le32_to_cpu(es->s_first_data_block),
3913                        EXT4_BLOCKS_PER_GROUP(sb));
3914                 goto failed_mount;
3915         }
3916         sbi->s_groups_count = blocks_count;
3917         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3918                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3919         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3920                    EXT4_DESC_PER_BLOCK(sb);
3921         sbi->s_group_desc = ext4_kvmalloc(db_count *
3922                                           sizeof(struct buffer_head *),
3923                                           GFP_KERNEL);
3924         if (sbi->s_group_desc == NULL) {
3925                 ext4_msg(sb, KERN_ERR, "not enough memory");
3926                 ret = -ENOMEM;
3927                 goto failed_mount;
3928         }
3929
3930         if (ext4_proc_root)
3931                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3932
3933         if (sbi->s_proc)
3934                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3935                                  &ext4_seq_options_fops, sb);
3936
3937         bgl_lock_init(sbi->s_blockgroup_lock);
3938
3939         for (i = 0; i < db_count; i++) {
3940                 block = descriptor_loc(sb, logical_sb_block, i);
3941                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3942                 if (!sbi->s_group_desc[i]) {
3943                         ext4_msg(sb, KERN_ERR,
3944                                "can't read group descriptor %d", i);
3945                         db_count = i;
3946                         goto failed_mount2;
3947                 }
3948         }
3949         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3950                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3951                 goto failed_mount2;
3952         }
3953
3954         sbi->s_gdb_count = db_count;
3955         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3956         spin_lock_init(&sbi->s_next_gen_lock);
3957
3958         setup_timer(&sbi->s_err_report, print_daily_error_info,
3959                 (unsigned long) sb);
3960
3961         /* Register extent status tree shrinker */
3962         if (ext4_es_register_shrinker(sbi))
3963                 goto failed_mount3;
3964
3965         sbi->s_stripe = ext4_get_stripe_size(sbi);
3966         sbi->s_extent_max_zeroout_kb = 32;
3967
3968         /*
3969          * set up enough so that it can read an inode
3970          */
3971         sb->s_op = &ext4_sops;
3972         sb->s_export_op = &ext4_export_ops;
3973         sb->s_xattr = ext4_xattr_handlers;
3974 #ifdef CONFIG_QUOTA
3975         sb->dq_op = &ext4_quota_operations;
3976         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3977                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3978         else
3979                 sb->s_qcop = &ext4_qctl_operations;
3980         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
3981 #endif
3982         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3983
3984         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3985         mutex_init(&sbi->s_orphan_lock);
3986
3987         sb->s_root = NULL;
3988
3989         needs_recovery = (es->s_last_orphan != 0 ||
3990                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3991                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3992
3993         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3994             !(sb->s_flags & MS_RDONLY))
3995                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3996                         goto failed_mount3a;
3997
3998         /*
3999          * The first inode we look at is the journal inode.  Don't try
4000          * root first: it may be modified in the journal!
4001          */
4002         if (!test_opt(sb, NOLOAD) &&
4003             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4004                 if (ext4_load_journal(sb, es, journal_devnum))
4005                         goto failed_mount3a;
4006         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
4007               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4008                 ext4_msg(sb, KERN_ERR, "required journal recovery "
4009                        "suppressed and not mounted read-only");
4010                 goto failed_mount_wq;
4011         } else {
4012                 clear_opt(sb, DATA_FLAGS);
4013                 sbi->s_journal = NULL;
4014                 needs_recovery = 0;
4015                 goto no_journal;
4016         }
4017
4018         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
4019             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4020                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
4021                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4022                 goto failed_mount_wq;
4023         }
4024
4025         if (!set_journal_csum_feature_set(sb)) {
4026                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4027                          "feature set");
4028                 goto failed_mount_wq;
4029         }
4030
4031         /* We have now updated the journal if required, so we can
4032          * validate the data journaling mode. */
4033         switch (test_opt(sb, DATA_FLAGS)) {
4034         case 0:
4035                 /* No mode set, assume a default based on the journal
4036                  * capabilities: ORDERED_DATA if the journal can
4037                  * cope, else JOURNAL_DATA
4038                  */
4039                 if (jbd2_journal_check_available_features
4040                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4041                         set_opt(sb, ORDERED_DATA);
4042                 else
4043                         set_opt(sb, JOURNAL_DATA);
4044                 break;
4045
4046         case EXT4_MOUNT_ORDERED_DATA:
4047         case EXT4_MOUNT_WRITEBACK_DATA:
4048                 if (!jbd2_journal_check_available_features
4049                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4050                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4051                                "requested data journaling mode");
4052                         goto failed_mount_wq;
4053                 }
4054         default:
4055                 break;
4056         }
4057         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4058
4059         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4060
4061 no_journal:
4062         if (ext4_mballoc_ready) {
4063                 sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
4064                 if (!sbi->s_mb_cache) {
4065                         ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4066                         goto failed_mount_wq;
4067                 }
4068         }
4069
4070         if (unlikely(sbi->s_mount_flags & EXT4_MF_TEST_DUMMY_ENCRYPTION) &&
4071             !(sb->s_flags & MS_RDONLY) &&
4072             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT)) {
4073                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT);
4074                 ext4_commit_super(sb, 1);
4075         }
4076
4077         /*
4078          * Get the # of file system overhead blocks from the
4079          * superblock if present.
4080          */
4081         if (es->s_overhead_clusters)
4082                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4083         else {
4084                 err = ext4_calculate_overhead(sb);
4085                 if (err)
4086                         goto failed_mount_wq;
4087         }
4088
4089         /*
4090          * The maximum number of concurrent works can be high and
4091          * concurrency isn't really necessary.  Limit it to 1.
4092          */
4093         EXT4_SB(sb)->rsv_conversion_wq =
4094                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4095         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4096                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4097                 ret = -ENOMEM;
4098                 goto failed_mount4;
4099         }
4100
4101         /*
4102          * The jbd2_journal_load will have done any necessary log recovery,
4103          * so we can safely mount the rest of the filesystem now.
4104          */
4105
4106         root = ext4_iget(sb, EXT4_ROOT_INO);
4107         if (IS_ERR(root)) {
4108                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4109                 ret = PTR_ERR(root);
4110                 root = NULL;
4111                 goto failed_mount4;
4112         }
4113         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4114                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4115                 iput(root);
4116                 goto failed_mount4;
4117         }
4118         sb->s_root = d_make_root(root);
4119         if (!sb->s_root) {
4120                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4121                 ret = -ENOMEM;
4122                 goto failed_mount4;
4123         }
4124
4125         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4126                 sb->s_flags |= MS_RDONLY;
4127
4128         /* determine the minimum size of new large inodes, if present */
4129         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4130                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4131                                                      EXT4_GOOD_OLD_INODE_SIZE;
4132                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4133                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4134                         if (sbi->s_want_extra_isize <
4135                             le16_to_cpu(es->s_want_extra_isize))
4136                                 sbi->s_want_extra_isize =
4137                                         le16_to_cpu(es->s_want_extra_isize);
4138                         if (sbi->s_want_extra_isize <
4139                             le16_to_cpu(es->s_min_extra_isize))
4140                                 sbi->s_want_extra_isize =
4141                                         le16_to_cpu(es->s_min_extra_isize);
4142                 }
4143         }
4144         /* Check if enough inode space is available */
4145         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4146                                                         sbi->s_inode_size) {
4147                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4148                                                        EXT4_GOOD_OLD_INODE_SIZE;
4149                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4150                          "available");
4151         }
4152
4153         err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4154         if (err) {
4155                 ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4156                          "reserved pool", ext4_calculate_resv_clusters(sb));
4157                 goto failed_mount4a;
4158         }
4159
4160         err = ext4_setup_system_zone(sb);
4161         if (err) {
4162                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4163                          "zone (%d)", err);
4164                 goto failed_mount4a;
4165         }
4166
4167         ext4_ext_init(sb);
4168         err = ext4_mb_init(sb);
4169         if (err) {
4170                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4171                          err);
4172                 goto failed_mount5;
4173         }
4174
4175         block = ext4_count_free_clusters(sb);
4176         ext4_free_blocks_count_set(sbi->s_es,
4177                                    EXT4_C2B(sbi, block));
4178         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4179                                   GFP_KERNEL);
4180         if (!err) {
4181                 unsigned long freei = ext4_count_free_inodes(sb);
4182                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4183                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4184                                           GFP_KERNEL);
4185         }
4186         if (!err)
4187                 err = percpu_counter_init(&sbi->s_dirs_counter,
4188                                           ext4_count_dirs(sb), GFP_KERNEL);
4189         if (!err)
4190                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4191                                           GFP_KERNEL);
4192         if (err) {
4193                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4194                 goto failed_mount6;
4195         }
4196
4197         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
4198                 if (!ext4_fill_flex_info(sb)) {
4199                         ext4_msg(sb, KERN_ERR,
4200                                "unable to initialize "
4201                                "flex_bg meta info!");
4202                         goto failed_mount6;
4203                 }
4204
4205         err = ext4_register_li_request(sb, first_not_zeroed);
4206         if (err)
4207                 goto failed_mount6;
4208
4209         sbi->s_kobj.kset = ext4_kset;
4210         init_completion(&sbi->s_kobj_unregister);
4211         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4212                                    "%s", sb->s_id);
4213         if (err)
4214                 goto failed_mount7;
4215
4216 #ifdef CONFIG_QUOTA
4217         /* Enable quota usage during mount. */
4218         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4219             !(sb->s_flags & MS_RDONLY)) {
4220                 err = ext4_enable_quotas(sb);
4221                 if (err)
4222                         goto failed_mount8;
4223         }
4224 #endif  /* CONFIG_QUOTA */
4225
4226         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4227         ext4_orphan_cleanup(sb, es);
4228         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4229         if (needs_recovery) {
4230                 ext4_msg(sb, KERN_INFO, "recovery complete");
4231                 ext4_mark_recovery_complete(sb, es);
4232         }
4233         if (EXT4_SB(sb)->s_journal) {
4234                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4235                         descr = " journalled data mode";
4236                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4237                         descr = " ordered data mode";
4238                 else
4239                         descr = " writeback data mode";
4240         } else
4241                 descr = "out journal";
4242
4243         if (test_opt(sb, DISCARD)) {
4244                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4245                 if (!blk_queue_discard(q))
4246                         ext4_msg(sb, KERN_WARNING,
4247                                  "mounting with \"discard\" option, but "
4248                                  "the device does not support discard");
4249         }
4250
4251         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4252                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4253                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4254
4255         if (es->s_error_count)
4256                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4257
4258         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4259         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4260         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4261         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4262
4263         kfree(orig_data);
4264         return 0;
4265
4266 cantfind_ext4:
4267         if (!silent)
4268                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4269         goto failed_mount;
4270
4271 #ifdef CONFIG_QUOTA
4272 failed_mount8:
4273         kobject_del(&sbi->s_kobj);
4274 #endif
4275 failed_mount7:
4276         ext4_unregister_li_request(sb);
4277 failed_mount6:
4278         ext4_mb_release(sb);
4279         if (sbi->s_flex_groups)
4280                 kvfree(sbi->s_flex_groups);
4281         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4282         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4283         percpu_counter_destroy(&sbi->s_dirs_counter);
4284         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4285 failed_mount5:
4286         ext4_ext_release(sb);
4287         ext4_release_system_zone(sb);
4288 failed_mount4a:
4289         dput(sb->s_root);
4290         sb->s_root = NULL;
4291 failed_mount4:
4292         ext4_msg(sb, KERN_ERR, "mount failed");
4293         if (EXT4_SB(sb)->rsv_conversion_wq)
4294                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4295 failed_mount_wq:
4296         if (sbi->s_journal) {
4297                 jbd2_journal_destroy(sbi->s_journal);
4298                 sbi->s_journal = NULL;
4299         }
4300 failed_mount3a:
4301         ext4_es_unregister_shrinker(sbi);
4302 failed_mount3:
4303         del_timer_sync(&sbi->s_err_report);
4304         if (sbi->s_mmp_tsk)
4305                 kthread_stop(sbi->s_mmp_tsk);
4306 failed_mount2:
4307         for (i = 0; i < db_count; i++)
4308                 brelse(sbi->s_group_desc[i]);
4309         kvfree(sbi->s_group_desc);
4310 failed_mount:
4311         if (sbi->s_chksum_driver)
4312                 crypto_free_shash(sbi->s_chksum_driver);
4313         if (sbi->s_proc) {
4314                 remove_proc_entry("options", sbi->s_proc);
4315                 remove_proc_entry(sb->s_id, ext4_proc_root);
4316         }
4317 #ifdef CONFIG_QUOTA
4318         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4319                 kfree(sbi->s_qf_names[i]);
4320 #endif
4321         ext4_blkdev_remove(sbi);
4322         brelse(bh);
4323 out_fail:
4324         sb->s_fs_info = NULL;
4325         kfree(sbi->s_blockgroup_lock);
4326         kfree(sbi);
4327 out_free_orig:
4328         kfree(orig_data);
4329         return err ? err : ret;
4330 }
4331
4332 /*
4333  * Setup any per-fs journal parameters now.  We'll do this both on
4334  * initial mount, once the journal has been initialised but before we've
4335  * done any recovery; and again on any subsequent remount.
4336  */
4337 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4338 {
4339         struct ext4_sb_info *sbi = EXT4_SB(sb);
4340
4341         journal->j_commit_interval = sbi->s_commit_interval;
4342         journal->j_min_batch_time = sbi->s_min_batch_time;
4343         journal->j_max_batch_time = sbi->s_max_batch_time;
4344
4345         write_lock(&journal->j_state_lock);
4346         if (test_opt(sb, BARRIER))
4347                 journal->j_flags |= JBD2_BARRIER;
4348         else
4349                 journal->j_flags &= ~JBD2_BARRIER;
4350         if (test_opt(sb, DATA_ERR_ABORT))
4351                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4352         else
4353                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4354         write_unlock(&journal->j_state_lock);
4355 }
4356
4357 static journal_t *ext4_get_journal(struct super_block *sb,
4358                                    unsigned int journal_inum)
4359 {
4360         struct inode *journal_inode;
4361         journal_t *journal;
4362
4363         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4364
4365         /* First, test for the existence of a valid inode on disk.  Bad
4366          * things happen if we iget() an unused inode, as the subsequent
4367          * iput() will try to delete it. */
4368
4369         journal_inode = ext4_iget(sb, journal_inum);
4370         if (IS_ERR(journal_inode)) {
4371                 ext4_msg(sb, KERN_ERR, "no journal found");
4372                 return NULL;
4373         }
4374         if (!journal_inode->i_nlink) {
4375                 make_bad_inode(journal_inode);
4376                 iput(journal_inode);
4377                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4378                 return NULL;
4379         }
4380
4381         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4382                   journal_inode, journal_inode->i_size);
4383         if (!S_ISREG(journal_inode->i_mode)) {
4384                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4385                 iput(journal_inode);
4386                 return NULL;
4387         }
4388
4389         journal = jbd2_journal_init_inode(journal_inode);
4390         if (!journal) {
4391                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4392                 iput(journal_inode);
4393                 return NULL;
4394         }
4395         journal->j_private = sb;
4396         ext4_init_journal_params(sb, journal);
4397         return journal;
4398 }
4399
4400 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4401                                        dev_t j_dev)
4402 {
4403         struct buffer_head *bh;
4404         journal_t *journal;
4405         ext4_fsblk_t start;
4406         ext4_fsblk_t len;
4407         int hblock, blocksize;
4408         ext4_fsblk_t sb_block;
4409         unsigned long offset;
4410         struct ext4_super_block *es;
4411         struct block_device *bdev;
4412
4413         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4414
4415         bdev = ext4_blkdev_get(j_dev, sb);
4416         if (bdev == NULL)
4417                 return NULL;
4418
4419         blocksize = sb->s_blocksize;
4420         hblock = bdev_logical_block_size(bdev);
4421         if (blocksize < hblock) {
4422                 ext4_msg(sb, KERN_ERR,
4423                         "blocksize too small for journal device");
4424                 goto out_bdev;
4425         }
4426
4427         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4428         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4429         set_blocksize(bdev, blocksize);
4430         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4431                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4432                        "external journal");
4433                 goto out_bdev;
4434         }
4435
4436         es = (struct ext4_super_block *) (bh->b_data + offset);
4437         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4438             !(le32_to_cpu(es->s_feature_incompat) &
4439               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4440                 ext4_msg(sb, KERN_ERR, "external journal has "
4441                                         "bad superblock");
4442                 brelse(bh);
4443                 goto out_bdev;
4444         }
4445
4446         if ((le32_to_cpu(es->s_feature_ro_compat) &
4447              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4448             es->s_checksum != ext4_superblock_csum(sb, es)) {
4449                 ext4_msg(sb, KERN_ERR, "external journal has "
4450                                        "corrupt superblock");
4451                 brelse(bh);
4452                 goto out_bdev;
4453         }
4454
4455         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4456                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4457                 brelse(bh);
4458                 goto out_bdev;
4459         }
4460
4461         len = ext4_blocks_count(es);
4462         start = sb_block + 1;
4463         brelse(bh);     /* we're done with the superblock */
4464
4465         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4466                                         start, len, blocksize);
4467         if (!journal) {
4468                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4469                 goto out_bdev;
4470         }
4471         journal->j_private = sb;
4472         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4473         wait_on_buffer(journal->j_sb_buffer);
4474         if (!buffer_uptodate(journal->j_sb_buffer)) {
4475                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4476                 goto out_journal;
4477         }
4478         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4479                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4480                                         "user (unsupported) - %d",
4481                         be32_to_cpu(journal->j_superblock->s_nr_users));
4482                 goto out_journal;
4483         }
4484         EXT4_SB(sb)->journal_bdev = bdev;
4485         ext4_init_journal_params(sb, journal);
4486         return journal;
4487
4488 out_journal:
4489         jbd2_journal_destroy(journal);
4490 out_bdev:
4491         ext4_blkdev_put(bdev);
4492         return NULL;
4493 }
4494
4495 static int ext4_load_journal(struct super_block *sb,
4496                              struct ext4_super_block *es,
4497                              unsigned long journal_devnum)
4498 {
4499         journal_t *journal;
4500         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4501         dev_t journal_dev;
4502         int err = 0;
4503         int really_read_only;
4504
4505         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4506
4507         if (journal_devnum &&
4508             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4509                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4510                         "numbers have changed");
4511                 journal_dev = new_decode_dev(journal_devnum);
4512         } else
4513                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4514
4515         really_read_only = bdev_read_only(sb->s_bdev);
4516
4517         /*
4518          * Are we loading a blank journal or performing recovery after a
4519          * crash?  For recovery, we need to check in advance whether we
4520          * can get read-write access to the device.
4521          */
4522         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4523                 if (sb->s_flags & MS_RDONLY) {
4524                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4525                                         "required on readonly filesystem");
4526                         if (really_read_only) {
4527                                 ext4_msg(sb, KERN_ERR, "write access "
4528                                         "unavailable, cannot proceed");
4529                                 return -EROFS;
4530                         }
4531                         ext4_msg(sb, KERN_INFO, "write access will "
4532                                "be enabled during recovery");
4533                 }
4534         }
4535
4536         if (journal_inum && journal_dev) {
4537                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4538                        "and inode journals!");
4539                 return -EINVAL;
4540         }
4541
4542         if (journal_inum) {
4543                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4544                         return -EINVAL;
4545         } else {
4546                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4547                         return -EINVAL;
4548         }
4549
4550         if (!(journal->j_flags & JBD2_BARRIER))
4551                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4552
4553         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4554                 err = jbd2_journal_wipe(journal, !really_read_only);
4555         if (!err) {
4556                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4557                 if (save)
4558                         memcpy(save, ((char *) es) +
4559                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4560                 err = jbd2_journal_load(journal);
4561                 if (save)
4562                         memcpy(((char *) es) + EXT4_S_ERR_START,
4563                                save, EXT4_S_ERR_LEN);
4564                 kfree(save);
4565         }
4566
4567         if (err) {
4568                 ext4_msg(sb, KERN_ERR, "error loading journal");
4569                 jbd2_journal_destroy(journal);
4570                 return err;
4571         }
4572
4573         EXT4_SB(sb)->s_journal = journal;
4574         ext4_clear_journal_err(sb, es);
4575
4576         if (!really_read_only && journal_devnum &&
4577             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4578                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4579
4580                 /* Make sure we flush the recovery flag to disk. */
4581                 ext4_commit_super(sb, 1);
4582         }
4583
4584         return 0;
4585 }
4586
4587 static int ext4_commit_super(struct super_block *sb, int sync)
4588 {
4589         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4590         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4591         int error = 0;
4592
4593         if (!sbh)
4594                 return error;
4595         if (buffer_write_io_error(sbh)) {
4596                 /*
4597                  * Oh, dear.  A previous attempt to write the
4598                  * superblock failed.  This could happen because the
4599                  * USB device was yanked out.  Or it could happen to
4600                  * be a transient write error and maybe the block will
4601                  * be remapped.  Nothing we can do but to retry the
4602                  * write and hope for the best.
4603                  */
4604                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4605                        "superblock detected");
4606                 clear_buffer_write_io_error(sbh);
4607                 set_buffer_uptodate(sbh);
4608         }
4609         /*
4610          * If the file system is mounted read-only, don't update the
4611          * superblock write time.  This avoids updating the superblock
4612          * write time when we are mounting the root file system
4613          * read/only but we need to replay the journal; at that point,
4614          * for people who are east of GMT and who make their clock
4615          * tick in localtime for Windows bug-for-bug compatibility,
4616          * the clock is set in the future, and this will cause e2fsck
4617          * to complain and force a full file system check.
4618          */
4619         if (!(sb->s_flags & MS_RDONLY))
4620                 es->s_wtime = cpu_to_le32(get_seconds());
4621         if (sb->s_bdev->bd_part)
4622                 es->s_kbytes_written =
4623                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4624                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4625                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4626         else
4627                 es->s_kbytes_written =
4628                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4629         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4630                 ext4_free_blocks_count_set(es,
4631                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4632                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4633         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4634                 es->s_free_inodes_count =
4635                         cpu_to_le32(percpu_counter_sum_positive(
4636                                 &EXT4_SB(sb)->s_freeinodes_counter));
4637         BUFFER_TRACE(sbh, "marking dirty");
4638         ext4_superblock_csum_set(sb);
4639         mark_buffer_dirty(sbh);
4640         if (sync) {
4641                 error = sync_dirty_buffer(sbh);
4642                 if (error)
4643                         return error;
4644
4645                 error = buffer_write_io_error(sbh);
4646                 if (error) {
4647                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4648                                "superblock");
4649                         clear_buffer_write_io_error(sbh);
4650                         set_buffer_uptodate(sbh);
4651                 }
4652         }
4653         return error;
4654 }
4655
4656 /*
4657  * Have we just finished recovery?  If so, and if we are mounting (or
4658  * remounting) the filesystem readonly, then we will end up with a
4659  * consistent fs on disk.  Record that fact.
4660  */
4661 static void ext4_mark_recovery_complete(struct super_block *sb,
4662                                         struct ext4_super_block *es)
4663 {
4664         journal_t *journal = EXT4_SB(sb)->s_journal;
4665
4666         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4667                 BUG_ON(journal != NULL);
4668                 return;
4669         }
4670         jbd2_journal_lock_updates(journal);
4671         if (jbd2_journal_flush(journal) < 0)
4672                 goto out;
4673
4674         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4675             sb->s_flags & MS_RDONLY) {
4676                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4677                 ext4_commit_super(sb, 1);
4678         }
4679
4680 out:
4681         jbd2_journal_unlock_updates(journal);
4682 }
4683
4684 /*
4685  * If we are mounting (or read-write remounting) a filesystem whose journal
4686  * has recorded an error from a previous lifetime, move that error to the
4687  * main filesystem now.
4688  */
4689 static void ext4_clear_journal_err(struct super_block *sb,
4690                                    struct ext4_super_block *es)
4691 {
4692         journal_t *journal;
4693         int j_errno;
4694         const char *errstr;
4695
4696         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4697
4698         journal = EXT4_SB(sb)->s_journal;
4699
4700         /*
4701          * Now check for any error status which may have been recorded in the
4702          * journal by a prior ext4_error() or ext4_abort()
4703          */
4704
4705         j_errno = jbd2_journal_errno(journal);
4706         if (j_errno) {
4707                 char nbuf[16];
4708
4709                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4710                 ext4_warning(sb, "Filesystem error recorded "
4711                              "from previous mount: %s", errstr);
4712                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4713
4714                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4715                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4716                 ext4_commit_super(sb, 1);
4717
4718                 jbd2_journal_clear_err(journal);
4719                 jbd2_journal_update_sb_errno(journal);
4720         }
4721 }
4722
4723 /*
4724  * Force the running and committing transactions to commit,
4725  * and wait on the commit.
4726  */
4727 int ext4_force_commit(struct super_block *sb)
4728 {
4729         journal_t *journal;
4730
4731         if (sb->s_flags & MS_RDONLY)
4732                 return 0;
4733
4734         journal = EXT4_SB(sb)->s_journal;
4735         return ext4_journal_force_commit(journal);
4736 }
4737
4738 static int ext4_sync_fs(struct super_block *sb, int wait)
4739 {
4740         int ret = 0;
4741         tid_t target;
4742         bool needs_barrier = false;
4743         struct ext4_sb_info *sbi = EXT4_SB(sb);
4744
4745         trace_ext4_sync_fs(sb, wait);
4746         flush_workqueue(sbi->rsv_conversion_wq);
4747         /*
4748          * Writeback quota in non-journalled quota case - journalled quota has
4749          * no dirty dquots
4750          */
4751         dquot_writeback_dquots(sb, -1);
4752         /*
4753          * Data writeback is possible w/o journal transaction, so barrier must
4754          * being sent at the end of the function. But we can skip it if
4755          * transaction_commit will do it for us.
4756          */
4757         if (sbi->s_journal) {
4758                 target = jbd2_get_latest_transaction(sbi->s_journal);
4759                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4760                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4761                         needs_barrier = true;
4762
4763                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4764                         if (wait)
4765                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4766                                                            target);
4767                 }
4768         } else if (wait && test_opt(sb, BARRIER))
4769                 needs_barrier = true;
4770         if (needs_barrier) {
4771                 int err;
4772                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4773                 if (!ret)
4774                         ret = err;
4775         }
4776
4777         return ret;
4778 }
4779
4780 /*
4781  * LVM calls this function before a (read-only) snapshot is created.  This
4782  * gives us a chance to flush the journal completely and mark the fs clean.
4783  *
4784  * Note that only this function cannot bring a filesystem to be in a clean
4785  * state independently. It relies on upper layer to stop all data & metadata
4786  * modifications.
4787  */
4788 static int ext4_freeze(struct super_block *sb)
4789 {
4790         int error = 0;
4791         journal_t *journal;
4792
4793         if (sb->s_flags & MS_RDONLY)
4794                 return 0;
4795
4796         journal = EXT4_SB(sb)->s_journal;
4797
4798         if (journal) {
4799                 /* Now we set up the journal barrier. */
4800                 jbd2_journal_lock_updates(journal);
4801
4802                 /*
4803                  * Don't clear the needs_recovery flag if we failed to
4804                  * flush the journal.
4805                  */
4806                 error = jbd2_journal_flush(journal);
4807                 if (error < 0)
4808                         goto out;
4809         }
4810
4811         /* Journal blocked and flushed, clear needs_recovery flag. */
4812         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4813         error = ext4_commit_super(sb, 1);
4814 out:
4815         if (journal)
4816                 /* we rely on upper layer to stop further updates */
4817                 jbd2_journal_unlock_updates(journal);
4818         return error;
4819 }
4820
4821 /*
4822  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4823  * flag here, even though the filesystem is not technically dirty yet.
4824  */
4825 static int ext4_unfreeze(struct super_block *sb)
4826 {
4827         if (sb->s_flags & MS_RDONLY)
4828                 return 0;
4829
4830         /* Reset the needs_recovery flag before the fs is unlocked. */
4831         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4832         ext4_commit_super(sb, 1);
4833         return 0;
4834 }
4835
4836 /*
4837  * Structure to save mount options for ext4_remount's benefit
4838  */
4839 struct ext4_mount_options {
4840         unsigned long s_mount_opt;
4841         unsigned long s_mount_opt2;
4842         kuid_t s_resuid;
4843         kgid_t s_resgid;
4844         unsigned long s_commit_interval;
4845         u32 s_min_batch_time, s_max_batch_time;
4846 #ifdef CONFIG_QUOTA
4847         int s_jquota_fmt;
4848         char *s_qf_names[EXT4_MAXQUOTAS];
4849 #endif
4850 };
4851
4852 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4853 {
4854         struct ext4_super_block *es;
4855         struct ext4_sb_info *sbi = EXT4_SB(sb);
4856         unsigned long old_sb_flags;
4857         struct ext4_mount_options old_opts;
4858         int enable_quota = 0;
4859         ext4_group_t g;
4860         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4861         int err = 0;
4862 #ifdef CONFIG_QUOTA
4863         int i, j;
4864 #endif
4865         char *orig_data = kstrdup(data, GFP_KERNEL);
4866
4867         /* Store the original options */
4868         old_sb_flags = sb->s_flags;
4869         old_opts.s_mount_opt = sbi->s_mount_opt;
4870         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4871         old_opts.s_resuid = sbi->s_resuid;
4872         old_opts.s_resgid = sbi->s_resgid;
4873         old_opts.s_commit_interval = sbi->s_commit_interval;
4874         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4875         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4876 #ifdef CONFIG_QUOTA
4877         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4878         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4879                 if (sbi->s_qf_names[i]) {
4880                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4881                                                          GFP_KERNEL);
4882                         if (!old_opts.s_qf_names[i]) {
4883                                 for (j = 0; j < i; j++)
4884                                         kfree(old_opts.s_qf_names[j]);
4885                                 kfree(orig_data);
4886                                 return -ENOMEM;
4887                         }
4888                 } else
4889                         old_opts.s_qf_names[i] = NULL;
4890 #endif
4891         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4892                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4893
4894         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4895                 err = -EINVAL;
4896                 goto restore_opts;
4897         }
4898
4899         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4900             test_opt(sb, JOURNAL_CHECKSUM)) {
4901                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4902                          "during remount not supported; ignoring");
4903                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4904         }
4905
4906         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4907                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4908                         ext4_msg(sb, KERN_ERR, "can't mount with "
4909                                  "both data=journal and delalloc");
4910                         err = -EINVAL;
4911                         goto restore_opts;
4912                 }
4913                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4914                         ext4_msg(sb, KERN_ERR, "can't mount with "
4915                                  "both data=journal and dioread_nolock");
4916                         err = -EINVAL;
4917                         goto restore_opts;
4918                 }
4919                 if (test_opt(sb, DAX)) {
4920                         ext4_msg(sb, KERN_ERR, "can't mount with "
4921                                  "both data=journal and dax");
4922                         err = -EINVAL;
4923                         goto restore_opts;
4924                 }
4925         }
4926
4927         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4928                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4929                         "dax flag with busy inodes while remounting");
4930                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4931         }
4932
4933         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4934                 ext4_abort(sb, "Abort forced by user");
4935
4936         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4937                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4938
4939         es = sbi->s_es;
4940
4941         if (sbi->s_journal) {
4942                 ext4_init_journal_params(sb, sbi->s_journal);
4943                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4944         }
4945
4946         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4947                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4948                         err = -EROFS;
4949                         goto restore_opts;
4950                 }
4951
4952                 if (*flags & MS_RDONLY) {
4953                         err = sync_filesystem(sb);
4954                         if (err < 0)
4955                                 goto restore_opts;
4956                         err = dquot_suspend(sb, -1);
4957                         if (err < 0)
4958                                 goto restore_opts;
4959
4960                         /*
4961                          * First of all, the unconditional stuff we have to do
4962                          * to disable replay of the journal when we next remount
4963                          */
4964                         sb->s_flags |= MS_RDONLY;
4965
4966                         /*
4967                          * OK, test if we are remounting a valid rw partition
4968                          * readonly, and if so set the rdonly flag and then
4969                          * mark the partition as valid again.
4970                          */
4971                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4972                             (sbi->s_mount_state & EXT4_VALID_FS))
4973                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4974
4975                         if (sbi->s_journal)
4976                                 ext4_mark_recovery_complete(sb, es);
4977                 } else {
4978                         /* Make sure we can mount this feature set readwrite */
4979                         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4980                                         EXT4_FEATURE_RO_COMPAT_READONLY) ||
4981                             !ext4_feature_set_ok(sb, 0)) {
4982                                 err = -EROFS;
4983                                 goto restore_opts;
4984                         }
4985                         /*
4986                          * Make sure the group descriptor checksums
4987                          * are sane.  If they aren't, refuse to remount r/w.
4988                          */
4989                         for (g = 0; g < sbi->s_groups_count; g++) {
4990                                 struct ext4_group_desc *gdp =
4991                                         ext4_get_group_desc(sb, g, NULL);
4992
4993                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4994                                         ext4_msg(sb, KERN_ERR,
4995                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4996                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4997                                                le16_to_cpu(gdp->bg_checksum));
4998                                         err = -EINVAL;
4999                                         goto restore_opts;
5000                                 }
5001                         }
5002
5003                         /*
5004                          * If we have an unprocessed orphan list hanging
5005                          * around from a previously readonly bdev mount,
5006                          * require a full umount/remount for now.
5007                          */
5008                         if (es->s_last_orphan) {
5009                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
5010                                        "remount RDWR because of unprocessed "
5011                                        "orphan inode list.  Please "
5012                                        "umount/remount instead");
5013                                 err = -EINVAL;
5014                                 goto restore_opts;
5015                         }
5016
5017                         /*
5018                          * Mounting a RDONLY partition read-write, so reread
5019                          * and store the current valid flag.  (It may have
5020                          * been changed by e2fsck since we originally mounted
5021                          * the partition.)
5022                          */
5023                         if (sbi->s_journal)
5024                                 ext4_clear_journal_err(sb, es);
5025                         sbi->s_mount_state = le16_to_cpu(es->s_state);
5026                         if (!ext4_setup_super(sb, es, 0))
5027                                 sb->s_flags &= ~MS_RDONLY;
5028                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
5029                                                      EXT4_FEATURE_INCOMPAT_MMP))
5030                                 if (ext4_multi_mount_protect(sb,
5031                                                 le64_to_cpu(es->s_mmp_block))) {
5032                                         err = -EROFS;
5033                                         goto restore_opts;
5034                                 }
5035                         enable_quota = 1;
5036                 }
5037         }
5038
5039         /*
5040          * Reinitialize lazy itable initialization thread based on
5041          * current settings
5042          */
5043         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5044                 ext4_unregister_li_request(sb);
5045         else {
5046                 ext4_group_t first_not_zeroed;
5047                 first_not_zeroed = ext4_has_uninit_itable(sb);
5048                 ext4_register_li_request(sb, first_not_zeroed);
5049         }
5050
5051         ext4_setup_system_zone(sb);
5052         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5053                 ext4_commit_super(sb, 1);
5054
5055 #ifdef CONFIG_QUOTA
5056         /* Release old quota file names */
5057         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5058                 kfree(old_opts.s_qf_names[i]);
5059         if (enable_quota) {
5060                 if (sb_any_quota_suspended(sb))
5061                         dquot_resume(sb, -1);
5062                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
5063                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
5064                         err = ext4_enable_quotas(sb);
5065                         if (err)
5066                                 goto restore_opts;
5067                 }
5068         }
5069 #endif
5070
5071         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5072         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5073         kfree(orig_data);
5074         return 0;
5075
5076 restore_opts:
5077         sb->s_flags = old_sb_flags;
5078         sbi->s_mount_opt = old_opts.s_mount_opt;
5079         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5080         sbi->s_resuid = old_opts.s_resuid;
5081         sbi->s_resgid = old_opts.s_resgid;
5082         sbi->s_commit_interval = old_opts.s_commit_interval;
5083         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5084         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5085 #ifdef CONFIG_QUOTA
5086         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5087         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5088                 kfree(sbi->s_qf_names[i]);
5089                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5090         }
5091 #endif
5092         kfree(orig_data);
5093         return err;
5094 }
5095
5096 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5097 {
5098         struct super_block *sb = dentry->d_sb;
5099         struct ext4_sb_info *sbi = EXT4_SB(sb);
5100         struct ext4_super_block *es = sbi->s_es;
5101         ext4_fsblk_t overhead = 0, resv_blocks;
5102         u64 fsid;
5103         s64 bfree;
5104         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5105
5106         if (!test_opt(sb, MINIX_DF))
5107                 overhead = sbi->s_overhead;
5108
5109         buf->f_type = EXT4_SUPER_MAGIC;
5110         buf->f_bsize = sb->s_blocksize;
5111         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5112         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5113                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5114         /* prevent underflow in case that few free space is available */
5115         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5116         buf->f_bavail = buf->f_bfree -
5117                         (ext4_r_blocks_count(es) + resv_blocks);
5118         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5119                 buf->f_bavail = 0;
5120         buf->f_files = le32_to_cpu(es->s_inodes_count);
5121         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5122         buf->f_namelen = EXT4_NAME_LEN;
5123         fsid = le64_to_cpup((void *)es->s_uuid) ^
5124                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5125         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5126         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5127
5128         return 0;
5129 }
5130
5131 /* Helper function for writing quotas on sync - we need to start transaction
5132  * before quota file is locked for write. Otherwise the are possible deadlocks:
5133  * Process 1                         Process 2
5134  * ext4_create()                     quota_sync()
5135  *   jbd2_journal_start()                  write_dquot()
5136  *   dquot_initialize()                         down(dqio_mutex)
5137  *     down(dqio_mutex)                    jbd2_journal_start()
5138  *
5139  */
5140
5141 #ifdef CONFIG_QUOTA
5142
5143 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5144 {
5145         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5146 }
5147
5148 static int ext4_write_dquot(struct dquot *dquot)
5149 {
5150         int ret, err;
5151         handle_t *handle;
5152         struct inode *inode;
5153
5154         inode = dquot_to_inode(dquot);
5155         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5156                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5157         if (IS_ERR(handle))
5158                 return PTR_ERR(handle);
5159         ret = dquot_commit(dquot);
5160         err = ext4_journal_stop(handle);
5161         if (!ret)
5162                 ret = err;
5163         return ret;
5164 }
5165
5166 static int ext4_acquire_dquot(struct dquot *dquot)
5167 {
5168         int ret, err;
5169         handle_t *handle;
5170
5171         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5172                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5173         if (IS_ERR(handle))
5174                 return PTR_ERR(handle);
5175         ret = dquot_acquire(dquot);
5176         err = ext4_journal_stop(handle);
5177         if (!ret)
5178                 ret = err;
5179         return ret;
5180 }
5181
5182 static int ext4_release_dquot(struct dquot *dquot)
5183 {
5184         int ret, err;
5185         handle_t *handle;
5186
5187         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5188                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5189         if (IS_ERR(handle)) {
5190                 /* Release dquot anyway to avoid endless cycle in dqput() */
5191                 dquot_release(dquot);
5192                 return PTR_ERR(handle);
5193         }
5194         ret = dquot_release(dquot);
5195         err = ext4_journal_stop(handle);
5196         if (!ret)
5197                 ret = err;
5198         return ret;
5199 }
5200
5201 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5202 {
5203         struct super_block *sb = dquot->dq_sb;
5204         struct ext4_sb_info *sbi = EXT4_SB(sb);
5205
5206         /* Are we journaling quotas? */
5207         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5208             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5209                 dquot_mark_dquot_dirty(dquot);
5210                 return ext4_write_dquot(dquot);
5211         } else {
5212                 return dquot_mark_dquot_dirty(dquot);
5213         }
5214 }
5215
5216 static int ext4_write_info(struct super_block *sb, int type)
5217 {
5218         int ret, err;
5219         handle_t *handle;
5220
5221         /* Data block + inode block */
5222         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5223         if (IS_ERR(handle))
5224                 return PTR_ERR(handle);
5225         ret = dquot_commit_info(sb, type);
5226         err = ext4_journal_stop(handle);
5227         if (!ret)
5228                 ret = err;
5229         return ret;
5230 }
5231
5232 /*
5233  * Turn on quotas during mount time - we need to find
5234  * the quota file and such...
5235  */
5236 static int ext4_quota_on_mount(struct super_block *sb, int type)
5237 {
5238         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5239                                         EXT4_SB(sb)->s_jquota_fmt, type);
5240 }
5241
5242 /*
5243  * Standard function to be called on quota_on
5244  */
5245 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5246                          struct path *path)
5247 {
5248         int err;
5249
5250         if (!test_opt(sb, QUOTA))
5251                 return -EINVAL;
5252
5253         /* Quotafile not on the same filesystem? */
5254         if (path->dentry->d_sb != sb)
5255                 return -EXDEV;
5256         /* Journaling quota? */
5257         if (EXT4_SB(sb)->s_qf_names[type]) {
5258                 /* Quotafile not in fs root? */
5259                 if (path->dentry->d_parent != sb->s_root)
5260                         ext4_msg(sb, KERN_WARNING,
5261                                 "Quota file not on filesystem root. "
5262                                 "Journaled quota will not work");
5263         }
5264
5265         /*
5266          * When we journal data on quota file, we have to flush journal to see
5267          * all updates to the file when we bypass pagecache...
5268          */
5269         if (EXT4_SB(sb)->s_journal &&
5270             ext4_should_journal_data(d_inode(path->dentry))) {
5271                 /*
5272                  * We don't need to lock updates but journal_flush() could
5273                  * otherwise be livelocked...
5274                  */
5275                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5276                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5277                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5278                 if (err)
5279                         return err;
5280         }
5281
5282         return dquot_quota_on(sb, type, format_id, path);
5283 }
5284
5285 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5286                              unsigned int flags)
5287 {
5288         int err;
5289         struct inode *qf_inode;
5290         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5291                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5292                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5293         };
5294
5295         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5296
5297         if (!qf_inums[type])
5298                 return -EPERM;
5299
5300         qf_inode = ext4_iget(sb, qf_inums[type]);
5301         if (IS_ERR(qf_inode)) {
5302                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5303                 return PTR_ERR(qf_inode);
5304         }
5305
5306         /* Don't account quota for quota files to avoid recursion */
5307         qf_inode->i_flags |= S_NOQUOTA;
5308         err = dquot_enable(qf_inode, type, format_id, flags);
5309         iput(qf_inode);
5310
5311         return err;
5312 }
5313
5314 /* Enable usage tracking for all quota types. */
5315 static int ext4_enable_quotas(struct super_block *sb)
5316 {
5317         int type, err = 0;
5318         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5319                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5320                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5321         };
5322
5323         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5324         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5325                 if (qf_inums[type]) {
5326                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5327                                                 DQUOT_USAGE_ENABLED);
5328                         if (err) {
5329                                 ext4_warning(sb,
5330                                         "Failed to enable quota tracking "
5331                                         "(type=%d, err=%d). Please run "
5332                                         "e2fsck to fix.", type, err);
5333                                 return err;
5334                         }
5335                 }
5336         }
5337         return 0;
5338 }
5339
5340 static int ext4_quota_off(struct super_block *sb, int type)
5341 {
5342         struct inode *inode = sb_dqopt(sb)->files[type];
5343         handle_t *handle;
5344
5345         /* Force all delayed allocation blocks to be allocated.
5346          * Caller already holds s_umount sem */
5347         if (test_opt(sb, DELALLOC))
5348                 sync_filesystem(sb);
5349
5350         if (!inode)
5351                 goto out;
5352
5353         /* Update modification times of quota files when userspace can
5354          * start looking at them */
5355         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5356         if (IS_ERR(handle))
5357                 goto out;
5358         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5359         ext4_mark_inode_dirty(handle, inode);
5360         ext4_journal_stop(handle);
5361
5362 out:
5363         return dquot_quota_off(sb, type);
5364 }
5365
5366 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5367  * acquiring the locks... As quota files are never truncated and quota code
5368  * itself serializes the operations (and no one else should touch the files)
5369  * we don't have to be afraid of races */
5370 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5371                                size_t len, loff_t off)
5372 {
5373         struct inode *inode = sb_dqopt(sb)->files[type];
5374         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5375         int offset = off & (sb->s_blocksize - 1);
5376         int tocopy;
5377         size_t toread;
5378         struct buffer_head *bh;
5379         loff_t i_size = i_size_read(inode);
5380
5381         if (off > i_size)
5382                 return 0;
5383         if (off+len > i_size)
5384                 len = i_size-off;
5385         toread = len;
5386         while (toread > 0) {
5387                 tocopy = sb->s_blocksize - offset < toread ?
5388                                 sb->s_blocksize - offset : toread;
5389                 bh = ext4_bread(NULL, inode, blk, 0);
5390                 if (IS_ERR(bh))
5391                         return PTR_ERR(bh);
5392                 if (!bh)        /* A hole? */
5393                         memset(data, 0, tocopy);
5394                 else
5395                         memcpy(data, bh->b_data+offset, tocopy);
5396                 brelse(bh);
5397                 offset = 0;
5398                 toread -= tocopy;
5399                 data += tocopy;
5400                 blk++;
5401         }
5402         return len;
5403 }
5404
5405 /* Write to quotafile (we know the transaction is already started and has
5406  * enough credits) */
5407 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5408                                 const char *data, size_t len, loff_t off)
5409 {
5410         struct inode *inode = sb_dqopt(sb)->files[type];
5411         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5412         int err, offset = off & (sb->s_blocksize - 1);
5413         struct buffer_head *bh;
5414         handle_t *handle = journal_current_handle();
5415
5416         if (EXT4_SB(sb)->s_journal && !handle) {
5417                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5418                         " cancelled because transaction is not started",
5419                         (unsigned long long)off, (unsigned long long)len);
5420                 return -EIO;
5421         }
5422         /*
5423          * Since we account only one data block in transaction credits,
5424          * then it is impossible to cross a block boundary.
5425          */
5426         if (sb->s_blocksize - offset < len) {
5427                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5428                         " cancelled because not block aligned",
5429                         (unsigned long long)off, (unsigned long long)len);
5430                 return -EIO;
5431         }
5432
5433         bh = ext4_bread(handle, inode, blk, 1);
5434         if (IS_ERR(bh))
5435                 return PTR_ERR(bh);
5436         if (!bh)
5437                 goto out;
5438         BUFFER_TRACE(bh, "get write access");
5439         err = ext4_journal_get_write_access(handle, bh);
5440         if (err) {
5441                 brelse(bh);
5442                 return err;
5443         }
5444         lock_buffer(bh);
5445         memcpy(bh->b_data+offset, data, len);
5446         flush_dcache_page(bh->b_page);
5447         unlock_buffer(bh);
5448         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5449         brelse(bh);
5450 out:
5451         if (inode->i_size < off + len) {
5452                 i_size_write(inode, off + len);
5453                 EXT4_I(inode)->i_disksize = inode->i_size;
5454                 ext4_mark_inode_dirty(handle, inode);
5455         }
5456         return len;
5457 }
5458
5459 #endif
5460
5461 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5462                        const char *dev_name, void *data)
5463 {
5464         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5465 }
5466
5467 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5468 static inline void register_as_ext2(void)
5469 {
5470         int err = register_filesystem(&ext2_fs_type);
5471         if (err)
5472                 printk(KERN_WARNING
5473                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5474 }
5475
5476 static inline void unregister_as_ext2(void)
5477 {
5478         unregister_filesystem(&ext2_fs_type);
5479 }
5480
5481 static inline int ext2_feature_set_ok(struct super_block *sb)
5482 {
5483         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5484                 return 0;
5485         if (sb->s_flags & MS_RDONLY)
5486                 return 1;
5487         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5488                 return 0;
5489         return 1;
5490 }
5491 #else
5492 static inline void register_as_ext2(void) { }
5493 static inline void unregister_as_ext2(void) { }
5494 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5495 #endif
5496
5497 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5498 static inline void register_as_ext3(void)
5499 {
5500         int err = register_filesystem(&ext3_fs_type);
5501         if (err)
5502                 printk(KERN_WARNING
5503                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5504 }
5505
5506 static inline void unregister_as_ext3(void)
5507 {
5508         unregister_filesystem(&ext3_fs_type);
5509 }
5510
5511 static inline int ext3_feature_set_ok(struct super_block *sb)
5512 {
5513         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5514                 return 0;
5515         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5516                 return 0;
5517         if (sb->s_flags & MS_RDONLY)
5518                 return 1;
5519         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5520                 return 0;
5521         return 1;
5522 }
5523 #else
5524 static inline void register_as_ext3(void) { }
5525 static inline void unregister_as_ext3(void) { }
5526 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5527 #endif
5528
5529 static struct file_system_type ext4_fs_type = {
5530         .owner          = THIS_MODULE,
5531         .name           = "ext4",
5532         .mount          = ext4_mount,
5533         .kill_sb        = kill_block_super,
5534         .fs_flags       = FS_REQUIRES_DEV,
5535 };
5536 MODULE_ALIAS_FS("ext4");
5537
5538 static int __init ext4_init_feat_adverts(void)
5539 {
5540         struct ext4_features *ef;
5541         int ret = -ENOMEM;
5542
5543         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5544         if (!ef)
5545                 goto out;
5546
5547         ef->f_kobj.kset = ext4_kset;
5548         init_completion(&ef->f_kobj_unregister);
5549         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5550                                    "features");
5551         if (ret) {
5552                 kfree(ef);
5553                 goto out;
5554         }
5555
5556         ext4_feat = ef;
5557         ret = 0;
5558 out:
5559         return ret;
5560 }
5561
5562 static void ext4_exit_feat_adverts(void)
5563 {
5564         kobject_put(&ext4_feat->f_kobj);
5565         wait_for_completion(&ext4_feat->f_kobj_unregister);
5566         kfree(ext4_feat);
5567 }
5568
5569 /* Shared across all ext4 file systems */
5570 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5571 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5572
5573 static int __init ext4_init_fs(void)
5574 {
5575         int i, err;
5576
5577         ext4_li_info = NULL;
5578         mutex_init(&ext4_li_mtx);
5579
5580         /* Build-time check for flags consistency */
5581         ext4_check_flag_values();
5582
5583         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5584                 mutex_init(&ext4__aio_mutex[i]);
5585                 init_waitqueue_head(&ext4__ioend_wq[i]);
5586         }
5587
5588         err = ext4_init_es();
5589         if (err)
5590                 return err;
5591
5592         err = ext4_init_pageio();
5593         if (err)
5594                 goto out7;
5595
5596         err = ext4_init_system_zone();
5597         if (err)
5598                 goto out6;
5599         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5600         if (!ext4_kset) {
5601                 err = -ENOMEM;
5602                 goto out5;
5603         }
5604         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5605
5606         err = ext4_init_feat_adverts();
5607         if (err)
5608                 goto out4;
5609
5610         err = ext4_init_mballoc();
5611         if (err)
5612                 goto out2;
5613         else
5614                 ext4_mballoc_ready = 1;
5615         err = init_inodecache();
5616         if (err)
5617                 goto out1;
5618         register_as_ext3();
5619         register_as_ext2();
5620         err = register_filesystem(&ext4_fs_type);
5621         if (err)
5622                 goto out;
5623
5624         return 0;
5625 out:
5626         unregister_as_ext2();
5627         unregister_as_ext3();
5628         destroy_inodecache();
5629 out1:
5630         ext4_mballoc_ready = 0;
5631         ext4_exit_mballoc();
5632 out2:
5633         ext4_exit_feat_adverts();
5634 out4:
5635         if (ext4_proc_root)
5636                 remove_proc_entry("fs/ext4", NULL);
5637         kset_unregister(ext4_kset);
5638 out5:
5639         ext4_exit_system_zone();
5640 out6:
5641         ext4_exit_pageio();
5642 out7:
5643         ext4_exit_es();
5644
5645         return err;
5646 }
5647
5648 static void __exit ext4_exit_fs(void)
5649 {
5650         ext4_destroy_lazyinit_thread();
5651         unregister_as_ext2();
5652         unregister_as_ext3();
5653         unregister_filesystem(&ext4_fs_type);
5654         destroy_inodecache();
5655         ext4_exit_mballoc();
5656         ext4_exit_feat_adverts();
5657         remove_proc_entry("fs/ext4", NULL);
5658         kset_unregister(ext4_kset);
5659         ext4_exit_system_zone();
5660         ext4_exit_pageio();
5661         ext4_exit_es();
5662 }
5663
5664 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5665 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5666 MODULE_LICENSE("GPL");
5667 module_init(ext4_init_fs)
5668 module_exit(ext4_exit_fs)