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