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/backing-dev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/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 ext4_lazy_init *ext4_li_info;
  57 static struct mutex ext4_li_mtx;
  58 static struct ratelimit_state ext4_mount_msg_ratelimit;
  59
  60 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  61                              unsigned long journal_devnum);
  62 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  63 static int ext4_commit_super(struct super_block *sb, int sync);
  64 static void ext4_mark_recovery_complete(struct super_block *sb,
  65                                         struct ext4_super_block *es);
  66 static void ext4_clear_journal_err(struct super_block *sb,
  67                                    struct ext4_super_block *es);
  68 static int ext4_sync_fs(struct super_block *sb, int wait);
  69 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  70 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  71 static int ext4_unfreeze(struct super_block *sb);
  72 static int ext4_freeze(struct super_block *sb);
  73 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  74                        const char *dev_name, void *data);
  75 static inline int ext2_feature_set_ok(struct super_block *sb);
  76 static inline int ext3_feature_set_ok(struct super_block *sb);
  77 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  78 static void ext4_destroy_lazyinit_thread(void);
  79 static void ext4_unregister_li_request(struct super_block *sb);
  80 static void ext4_clear_request_list(void);
  81
  82 /*
  83  * Lock ordering
  84  *
  85  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
  86  * i_mmap_rwsem (inode->i_mmap_rwsem)!
  87  *
  88  * page fault path:
  89  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
  90  *   page lock -> i_data_sem (rw)
  91  *
  92  * buffered write path:
  93  * sb_start_write -> i_mutex -> mmap_sem
  94  * sb_start_write -> i_mutex -> transaction start -> page lock ->
  95  *   i_data_sem (rw)
  96  *
  97  * truncate:
  98  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
  99  *   i_mmap_rwsem (w) -> page lock
 100  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 101  *   transaction start -> i_data_sem (rw)
 102  *
 103  * direct IO:
 104  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
 105  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
 106  *   transaction start -> i_data_sem (rw)
 107  *
 108  * writepages:
 109  * transaction start -> page lock(s) -> i_data_sem (rw)
 110  */
 111
 112 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 113 static struct file_system_type ext2_fs_type = {
 114         .owner          = THIS_MODULE,
 115         .name           = "ext2",
 116         .mount          = ext4_mount,
 117         .kill_sb        = kill_block_super,
 118         .fs_flags       = FS_REQUIRES_DEV,
 119 };
 120 MODULE_ALIAS_FS("ext2");
 121 MODULE_ALIAS("ext2");
 122 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
 123 #else
 124 #define IS_EXT2_SB(sb) (0)
 125 #endif
 126
 127
 128 static struct file_system_type ext3_fs_type = {
 129         .owner          = THIS_MODULE,
 130         .name           = "ext3",
 131         .mount          = ext4_mount,
 132         .kill_sb        = kill_block_super,
 133         .fs_flags       = FS_REQUIRES_DEV,
 134 };
 135 MODULE_ALIAS_FS("ext3");
 136 MODULE_ALIAS("ext3");
 137 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 138
 139 static int ext4_verify_csum_type(struct super_block *sb,
 140                                  struct ext4_super_block *es)
 141 {
 142         if (!ext4_has_feature_metadata_csum(sb))
 143                 return 1;
 144
 145         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 146 }
 147
 148 static __le32 ext4_superblock_csum(struct super_block *sb,
 149                                    struct ext4_super_block *es)
 150 {
 151         struct ext4_sb_info *sbi = EXT4_SB(sb);
 152         int offset = offsetof(struct ext4_super_block, s_checksum);
 153         __u32 csum;
 154
 155         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 156
 157         return cpu_to_le32(csum);
 158 }
 159
 160 static int ext4_superblock_csum_verify(struct super_block *sb,
 161                                        struct ext4_super_block *es)
 162 {
 163         if (!ext4_has_metadata_csum(sb))
 164                 return 1;
 165
 166         return es->s_checksum == ext4_superblock_csum(sb, es);
 167 }
 168
 169 void ext4_superblock_csum_set(struct super_block *sb)
 170 {
 171         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 172
 173         if (!ext4_has_metadata_csum(sb))
 174                 return;
 175
 176         es->s_checksum = ext4_superblock_csum(sb, es);
 177 }
 178
 179 void *ext4_kvmalloc(size_t size, gfp_t flags)
 180 {
 181         void *ret;
 182
 183         ret = kmalloc(size, flags | __GFP_NOWARN);
 184         if (!ret)
 185                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 186         return ret;
 187 }
 188
 189 void *ext4_kvzalloc(size_t size, gfp_t flags)
 190 {
 191         void *ret;
 192
 193         ret = kzalloc(size, flags | __GFP_NOWARN);
 194         if (!ret)
 195                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 196         return ret;
 197 }
 198
 199 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 200                                struct ext4_group_desc *bg)
 201 {
 202         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 203                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 204                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 205 }
 206
 207 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 208                                struct ext4_group_desc *bg)
 209 {
 210         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 211                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 212                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 213 }
 214
 215 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 216                               struct ext4_group_desc *bg)
 217 {
 218         return le32_to_cpu(bg->bg_inode_table_lo) |
 219                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 220                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 221 }
 222
 223 __u32 ext4_free_group_clusters(struct super_block *sb,
 224                                struct ext4_group_desc *bg)
 225 {
 226         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 227                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 228                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 229 }
 230
 231 __u32 ext4_free_inodes_count(struct super_block *sb,
 232                               struct ext4_group_desc *bg)
 233 {
 234         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 235                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 236                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 237 }
 238
 239 __u32 ext4_used_dirs_count(struct super_block *sb,
 240                               struct ext4_group_desc *bg)
 241 {
 242         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 243                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 244                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 245 }
 246
 247 __u32 ext4_itable_unused_count(struct super_block *sb,
 248                               struct ext4_group_desc *bg)
 249 {
 250         return le16_to_cpu(bg->bg_itable_unused_lo) |
 251                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 252                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 253 }
 254
 255 void ext4_block_bitmap_set(struct super_block *sb,
 256                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 257 {
 258         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 259         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 260                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 261 }
 262
 263 void ext4_inode_bitmap_set(struct super_block *sb,
 264                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 265 {
 266         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 267         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 268                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 269 }
 270
 271 void ext4_inode_table_set(struct super_block *sb,
 272                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 273 {
 274         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 275         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 276                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 277 }
 278
 279 void ext4_free_group_clusters_set(struct super_block *sb,
 280                                   struct ext4_group_desc *bg, __u32 count)
 281 {
 282         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 283         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 284                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 285 }
 286
 287 void ext4_free_inodes_set(struct super_block *sb,
 288                           struct ext4_group_desc *bg, __u32 count)
 289 {
 290         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 291         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 292                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 293 }
 294
 295 void ext4_used_dirs_set(struct super_block *sb,
 296                           struct ext4_group_desc *bg, __u32 count)
 297 {
 298         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 299         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 300                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 301 }
 302
 303 void ext4_itable_unused_set(struct super_block *sb,
 304                           struct ext4_group_desc *bg, __u32 count)
 305 {
 306         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 307         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 308                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 309 }
 310
 311
 312 static void __save_error_info(struct super_block *sb, const char *func,
 313                             unsigned int line)
 314 {
 315         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 316
 317         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 318         if (bdev_read_only(sb->s_bdev))
 319                 return;
 320         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 321         es->s_last_error_time = cpu_to_le32(get_seconds());
 322         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 323         es->s_last_error_line = cpu_to_le32(line);
 324         if (!es->s_first_error_time) {
 325                 es->s_first_error_time = es->s_last_error_time;
 326                 strncpy(es->s_first_error_func, func,
 327                         sizeof(es->s_first_error_func));
 328                 es->s_first_error_line = cpu_to_le32(line);
 329                 es->s_first_error_ino = es->s_last_error_ino;
 330                 es->s_first_error_block = es->s_last_error_block;
 331         }
 332         /*
 333          * Start the daily error reporting function if it hasn't been
 334          * started already
 335          */
 336         if (!es->s_error_count)
 337                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 338         le32_add_cpu(&es->s_error_count, 1);
 339 }
 340
 341 static void save_error_info(struct super_block *sb, const char *func,
 342                             unsigned int line)
 343 {
 344         __save_error_info(sb, func, line);
 345         ext4_commit_super(sb, 1);
 346 }
 347
 348 /*
 349  * The del_gendisk() function uninitializes the disk-specific data
 350  * structures, including the bdi structure, without telling anyone
 351  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 352  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 353  * This is a kludge to prevent these oops until we can put in a proper
 354  * hook in del_gendisk() to inform the VFS and file system layers.
 355  */
 356 static int block_device_ejected(struct super_block *sb)
 357 {
 358         struct inode *bd_inode = sb->s_bdev->bd_inode;
 359         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 360
 361         return bdi->dev == NULL;
 362 }
 363
 364 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 365 {
 366         struct super_block              *sb = journal->j_private;
 367         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 368         int                             error = is_journal_aborted(journal);
 369         struct ext4_journal_cb_entry    *jce;
 370
 371         BUG_ON(txn->t_state == T_FINISHED);
 372         spin_lock(&sbi->s_md_lock);
 373         while (!list_empty(&txn->t_private_list)) {
 374                 jce = list_entry(txn->t_private_list.next,
 375                                  struct ext4_journal_cb_entry, jce_list);
 376                 list_del_init(&jce->jce_list);
 377                 spin_unlock(&sbi->s_md_lock);
 378                 jce->jce_func(sb, jce, error);
 379                 spin_lock(&sbi->s_md_lock);
 380         }
 381         spin_unlock(&sbi->s_md_lock);
 382 }
 383
 384 /* Deal with the reporting of failure conditions on a filesystem such as
 385  * inconsistencies detected or read IO failures.
 386  *
 387  * On ext2, we can store the error state of the filesystem in the
 388  * superblock.  That is not possible on ext4, because we may have other
 389  * write ordering constraints on the superblock which prevent us from
 390  * writing it out straight away; and given that the journal is about to
 391  * be aborted, we can't rely on the current, or future, transactions to
 392  * write out the superblock safely.
 393  *
 394  * We'll just use the jbd2_journal_abort() error code to record an error in
 395  * the journal instead.  On recovery, the journal will complain about
 396  * that error until we've noted it down and cleared it.
 397  */
 398
 399 static void ext4_handle_error(struct super_block *sb)
 400 {
 401         if (sb->s_flags & MS_RDONLY)
 402                 return;
 403
 404         if (!test_opt(sb, ERRORS_CONT)) {
 405                 journal_t *journal = EXT4_SB(sb)->s_journal;
 406
 407                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 408                 if (journal)
 409                         jbd2_journal_abort(journal, -EIO);
 410         }
 411         if (test_opt(sb, ERRORS_RO)) {
 412                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 413                 /*
 414                  * Make sure updated value of ->s_mount_flags will be visible
 415                  * before ->s_flags update
 416                  */
 417                 smp_wmb();
 418                 sb->s_flags |= MS_RDONLY;
 419         }
 420         if (test_opt(sb, ERRORS_PANIC)) {
 421                 if (EXT4_SB(sb)->s_journal &&
 422                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 423                         return;
 424                 panic("EXT4-fs (device %s): panic forced after error\n",
 425                         sb->s_id);
 426         }
 427 }
 428
 429 #define ext4_error_ratelimit(sb)                                        \
 430                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 431                              "EXT4-fs error")
 432
 433 void __ext4_error(struct super_block *sb, const char *function,
 434                   unsigned int line, const char *fmt, ...)
 435 {
 436         struct va_format vaf;
 437         va_list args;
 438
 439         if (ext4_error_ratelimit(sb)) {
 440                 va_start(args, fmt);
 441                 vaf.fmt = fmt;
 442                 vaf.va = &args;
 443                 printk(KERN_CRIT
 444                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 445                        sb->s_id, function, line, current->comm, &vaf);
 446                 va_end(args);
 447         }
 448         save_error_info(sb, function, line);
 449         ext4_handle_error(sb);
 450 }
 451
 452 void __ext4_error_inode(struct inode *inode, const char *function,
 453                         unsigned int line, ext4_fsblk_t block,
 454                         const char *fmt, ...)
 455 {
 456         va_list args;
 457         struct va_format vaf;
 458         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 459
 460         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 461         es->s_last_error_block = cpu_to_le64(block);
 462         if (ext4_error_ratelimit(inode->i_sb)) {
 463                 va_start(args, fmt);
 464                 vaf.fmt = fmt;
 465                 vaf.va = &args;
 466                 if (block)
 467                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 468                                "inode #%lu: block %llu: comm %s: %pV\n",
 469                                inode->i_sb->s_id, function, line, inode->i_ino,
 470                                block, current->comm, &vaf);
 471                 else
 472                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 473                                "inode #%lu: comm %s: %pV\n",
 474                                inode->i_sb->s_id, function, line, inode->i_ino,
 475                                current->comm, &vaf);
 476                 va_end(args);
 477         }
 478         save_error_info(inode->i_sb, function, line);
 479         ext4_handle_error(inode->i_sb);
 480 }
 481
 482 void __ext4_error_file(struct file *file, const char *function,
 483                        unsigned int line, ext4_fsblk_t block,
 484                        const char *fmt, ...)
 485 {
 486         va_list args;
 487         struct va_format vaf;
 488         struct ext4_super_block *es;
 489         struct inode *inode = file_inode(file);
 490         char pathname[80], *path;
 491
 492         es = EXT4_SB(inode->i_sb)->s_es;
 493         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 494         if (ext4_error_ratelimit(inode->i_sb)) {
 495                 path = file_path(file, pathname, sizeof(pathname));
 496                 if (IS_ERR(path))
 497                         path = "(unknown)";
 498                 va_start(args, fmt);
 499                 vaf.fmt = fmt;
 500                 vaf.va = &args;
 501                 if (block)
 502                         printk(KERN_CRIT
 503                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 504                                "block %llu: comm %s: path %s: %pV\n",
 505                                inode->i_sb->s_id, function, line, inode->i_ino,
 506                                block, current->comm, path, &vaf);
 507                 else
 508                         printk(KERN_CRIT
 509                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 510                                "comm %s: path %s: %pV\n",
 511                                inode->i_sb->s_id, function, line, inode->i_ino,
 512                                current->comm, path, &vaf);
 513                 va_end(args);
 514         }
 515         save_error_info(inode->i_sb, function, line);
 516         ext4_handle_error(inode->i_sb);
 517 }
 518
 519 const char *ext4_decode_error(struct super_block *sb, int errno,
 520                               char nbuf[16])
 521 {
 522         char *errstr = NULL;
 523
 524         switch (errno) {
 525         case -EFSCORRUPTED:
 526                 errstr = "Corrupt filesystem";
 527                 break;
 528         case -EFSBADCRC:
 529                 errstr = "Filesystem failed CRC";
 530                 break;
 531         case -EIO:
 532                 errstr = "IO failure";
 533                 break;
 534         case -ENOMEM:
 535                 errstr = "Out of memory";
 536                 break;
 537         case -EROFS:
 538                 if (!sb || (EXT4_SB(sb)->s_journal &&
 539                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 540                         errstr = "Journal has aborted";
 541                 else
 542                         errstr = "Readonly filesystem";
 543                 break;
 544         default:
 545                 /* If the caller passed in an extra buffer for unknown
 546                  * errors, textualise them now.  Else we just return
 547                  * NULL. */
 548                 if (nbuf) {
 549                         /* Check for truncated error codes... */
 550                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 551                                 errstr = nbuf;
 552                 }
 553                 break;
 554         }
 555
 556         return errstr;
 557 }
 558
 559 /* __ext4_std_error decodes expected errors from journaling functions
 560  * automatically and invokes the appropriate error response.  */
 561
 562 void __ext4_std_error(struct super_block *sb, const char *function,
 563                       unsigned int line, int errno)
 564 {
 565         char nbuf[16];
 566         const char *errstr;
 567
 568         /* Special case: if the error is EROFS, and we're not already
 569          * inside a transaction, then there's really no point in logging
 570          * an error. */
 571         if (errno == -EROFS && journal_current_handle() == NULL &&
 572             (sb->s_flags & MS_RDONLY))
 573                 return;
 574
 575         if (ext4_error_ratelimit(sb)) {
 576                 errstr = ext4_decode_error(sb, errno, nbuf);
 577                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 578                        sb->s_id, function, line, errstr);
 579         }
 580
 581         save_error_info(sb, function, line);
 582         ext4_handle_error(sb);
 583 }
 584
 585 /*
 586  * ext4_abort is a much stronger failure handler than ext4_error.  The
 587  * abort function may be used to deal with unrecoverable failures such
 588  * as journal IO errors or ENOMEM at a critical moment in log management.
 589  *
 590  * We unconditionally force the filesystem into an ABORT|READONLY state,
 591  * unless the error response on the fs has been set to panic in which
 592  * case we take the easy way out and panic immediately.
 593  */
 594
 595 void __ext4_abort(struct super_block *sb, const char *function,
 596                 unsigned int line, const char *fmt, ...)
 597 {
 598         va_list args;
 599
 600         save_error_info(sb, function, line);
 601         va_start(args, fmt);
 602         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 603                function, line);
 604         vprintk(fmt, args);
 605         printk("\n");
 606         va_end(args);
 607
 608         if ((sb->s_flags & MS_RDONLY) == 0) {
 609                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 610                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 611                 /*
 612                  * Make sure updated value of ->s_mount_flags will be visible
 613                  * before ->s_flags update
 614                  */
 615                 smp_wmb();
 616                 sb->s_flags |= MS_RDONLY;
 617                 if (EXT4_SB(sb)->s_journal)
 618                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 619                 save_error_info(sb, function, line);
 620         }
 621         if (test_opt(sb, ERRORS_PANIC)) {
 622                 if (EXT4_SB(sb)->s_journal &&
 623                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 624                         return;
 625                 panic("EXT4-fs panic from previous error\n");
 626         }
 627 }
 628
 629 void __ext4_msg(struct super_block *sb,
 630                 const char *prefix, const char *fmt, ...)
 631 {
 632         struct va_format vaf;
 633         va_list args;
 634
 635         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 636                 return;
 637
 638         va_start(args, fmt);
 639         vaf.fmt = fmt;
 640         vaf.va = &args;
 641         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 642         va_end(args);
 643 }
 644
 645 #define ext4_warning_ratelimit(sb)                                      \
 646                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 647                              "EXT4-fs warning")
 648
 649 void __ext4_warning(struct super_block *sb, const char *function,
 650                     unsigned int line, const char *fmt, ...)
 651 {
 652         struct va_format vaf;
 653         va_list args;
 654
 655         if (!ext4_warning_ratelimit(sb))
 656                 return;
 657
 658         va_start(args, fmt);
 659         vaf.fmt = fmt;
 660         vaf.va = &args;
 661         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 662                sb->s_id, function, line, &vaf);
 663         va_end(args);
 664 }
 665
 666 void __ext4_warning_inode(const struct inode *inode, const char *function,
 667                           unsigned int line, const char *fmt, ...)
 668 {
 669         struct va_format vaf;
 670         va_list args;
 671
 672         if (!ext4_warning_ratelimit(inode->i_sb))
 673                 return;
 674
 675         va_start(args, fmt);
 676         vaf.fmt = fmt;
 677         vaf.va = &args;
 678         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 679                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 680                function, line, inode->i_ino, current->comm, &vaf);
 681         va_end(args);
 682 }
 683
 684 void __ext4_grp_locked_error(const char *function, unsigned int line,
 685                              struct super_block *sb, ext4_group_t grp,
 686                              unsigned long ino, ext4_fsblk_t block,
 687                              const char *fmt, ...)
 688 __releases(bitlock)
 689 __acquires(bitlock)
 690 {
 691         struct va_format vaf;
 692         va_list args;
 693         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 694
 695         es->s_last_error_ino = cpu_to_le32(ino);
 696         es->s_last_error_block = cpu_to_le64(block);
 697         __save_error_info(sb, function, line);
 698
 699         if (ext4_error_ratelimit(sb)) {
 700                 va_start(args, fmt);
 701                 vaf.fmt = fmt;
 702                 vaf.va = &args;
 703                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 704                        sb->s_id, function, line, grp);
 705                 if (ino)
 706                         printk(KERN_CONT "inode %lu: ", ino);
 707                 if (block)
 708                         printk(KERN_CONT "block %llu:",
 709                                (unsigned long long) block);
 710                 printk(KERN_CONT "%pV\n", &vaf);
 711                 va_end(args);
 712         }
 713
 714         if (test_opt(sb, ERRORS_CONT)) {
 715                 ext4_commit_super(sb, 0);
 716                 return;
 717         }
 718
 719         ext4_unlock_group(sb, grp);
 720         ext4_handle_error(sb);
 721         /*
 722          * We only get here in the ERRORS_RO case; relocking the group
 723          * may be dangerous, but nothing bad will happen since the
 724          * filesystem will have already been marked read/only and the
 725          * journal has been aborted.  We return 1 as a hint to callers
 726          * who might what to use the return value from
 727          * ext4_grp_locked_error() to distinguish between the
 728          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 729          * aggressively from the ext4 function in question, with a
 730          * more appropriate error code.
 731          */
 732         ext4_lock_group(sb, grp);
 733         return;
 734 }
 735
 736 void ext4_update_dynamic_rev(struct super_block *sb)
 737 {
 738         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 739
 740         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 741                 return;
 742
 743         ext4_warning(sb,
 744                      "updating to rev %d because of new feature flag, "
 745                      "running e2fsck is recommended",
 746                      EXT4_DYNAMIC_REV);
 747
 748         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 749         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 750         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 751         /* leave es->s_feature_*compat flags alone */
 752         /* es->s_uuid will be set by e2fsck if empty */
 753
 754         /*
 755          * The rest of the superblock fields should be zero, and if not it
 756          * means they are likely already in use, so leave them alone.  We
 757          * can leave it up to e2fsck to clean up any inconsistencies there.
 758          */
 759 }
 760
 761 /*
 762  * Open the external journal device
 763  */
 764 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 765 {
 766         struct block_device *bdev;
 767         char b[BDEVNAME_SIZE];
 768
 769         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 770         if (IS_ERR(bdev))
 771                 goto fail;
 772         return bdev;
 773
 774 fail:
 775         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 776                         __bdevname(dev, b), PTR_ERR(bdev));
 777         return NULL;
 778 }
 779
 780 /*
 781  * Release the journal device
 782  */
 783 static void ext4_blkdev_put(struct block_device *bdev)
 784 {
 785         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 786 }
 787
 788 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 789 {
 790         struct block_device *bdev;
 791         bdev = sbi->journal_bdev;
 792         if (bdev) {
 793                 ext4_blkdev_put(bdev);
 794                 sbi->journal_bdev = NULL;
 795         }
 796 }
 797
 798 static inline struct inode *orphan_list_entry(struct list_head *l)
 799 {
 800         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 801 }
 802
 803 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 804 {
 805         struct list_head *l;
 806
 807         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 808                  le32_to_cpu(sbi->s_es->s_last_orphan));
 809
 810         printk(KERN_ERR "sb_info orphan list:\n");
 811         list_for_each(l, &sbi->s_orphan) {
 812                 struct inode *inode = orphan_list_entry(l);
 813                 printk(KERN_ERR "  "
 814                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 815                        inode->i_sb->s_id, inode->i_ino, inode,
 816                        inode->i_mode, inode->i_nlink,
 817                        NEXT_ORPHAN(inode));
 818         }
 819 }
 820
 821 static void ext4_put_super(struct super_block *sb)
 822 {
 823         struct ext4_sb_info *sbi = EXT4_SB(sb);
 824         struct ext4_super_block *es = sbi->s_es;
 825         int i, err;
 826
 827         ext4_unregister_li_request(sb);
 828         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 829
 830         flush_workqueue(sbi->rsv_conversion_wq);
 831         destroy_workqueue(sbi->rsv_conversion_wq);
 832
 833         if (sbi->s_journal) {
 834                 err = jbd2_journal_destroy(sbi->s_journal);
 835                 sbi->s_journal = NULL;
 836                 if (err < 0)
 837                         ext4_abort(sb, "Couldn't clean up the journal");
 838         }
 839
 840         ext4_unregister_sysfs(sb);
 841         ext4_es_unregister_shrinker(sbi);
 842         del_timer_sync(&sbi->s_err_report);
 843         ext4_release_system_zone(sb);
 844         ext4_mb_release(sb);
 845         ext4_ext_release(sb);
 846
 847         if (!(sb->s_flags & MS_RDONLY)) {
 848                 ext4_clear_feature_journal_needs_recovery(sb);
 849                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 850         }
 851         if (!(sb->s_flags & MS_RDONLY))
 852                 ext4_commit_super(sb, 1);
 853
 854         for (i = 0; i < sbi->s_gdb_count; i++)
 855                 brelse(sbi->s_group_desc[i]);
 856         kvfree(sbi->s_group_desc);
 857         kvfree(sbi->s_flex_groups);
 858         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 859         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 860         percpu_counter_destroy(&sbi->s_dirs_counter);
 861         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 862         brelse(sbi->s_sbh);
 863 #ifdef CONFIG_QUOTA
 864         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 865                 kfree(sbi->s_qf_names[i]);
 866 #endif
 867
 868         /* Debugging code just in case the in-memory inode orphan list
 869          * isn't empty.  The on-disk one can be non-empty if we've
 870          * detected an error and taken the fs readonly, but the
 871          * in-memory list had better be clean by this point. */
 872         if (!list_empty(&sbi->s_orphan))
 873                 dump_orphan_list(sb, sbi);
 874         J_ASSERT(list_empty(&sbi->s_orphan));
 875
 876         sync_blockdev(sb->s_bdev);
 877         invalidate_bdev(sb->s_bdev);
 878         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 879                 /*
 880                  * Invalidate the journal device's buffers.  We don't want them
 881                  * floating about in memory - the physical journal device may
 882                  * hotswapped, and it breaks the `ro-after' testing code.
 883                  */
 884                 sync_blockdev(sbi->journal_bdev);
 885                 invalidate_bdev(sbi->journal_bdev);
 886                 ext4_blkdev_remove(sbi);
 887         }
 888         if (sbi->s_mb_cache) {
 889                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 890                 sbi->s_mb_cache = NULL;
 891         }
 892         if (sbi->s_mmp_tsk)
 893                 kthread_stop(sbi->s_mmp_tsk);
 894         sb->s_fs_info = NULL;
 895         /*
 896          * Now that we are completely done shutting down the
 897          * superblock, we need to actually destroy the kobject.
 898          */
 899         kobject_put(&sbi->s_kobj);
 900         wait_for_completion(&sbi->s_kobj_unregister);
 901         if (sbi->s_chksum_driver)
 902                 crypto_free_shash(sbi->s_chksum_driver);
 903         kfree(sbi->s_blockgroup_lock);
 904         kfree(sbi);
 905 }
 906
 907 static struct kmem_cache *ext4_inode_cachep;
 908
 909 /*
 910  * Called inside transaction, so use GFP_NOFS
 911  */
 912 static struct inode *ext4_alloc_inode(struct super_block *sb)
 913 {
 914         struct ext4_inode_info *ei;
 915
 916         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 917         if (!ei)
 918                 return NULL;
 919
 920         ei->vfs_inode.i_version = 1;
 921         spin_lock_init(&ei->i_raw_lock);
 922         INIT_LIST_HEAD(&ei->i_prealloc_list);
 923         spin_lock_init(&ei->i_prealloc_lock);
 924         ext4_es_init_tree(&ei->i_es_tree);
 925         rwlock_init(&ei->i_es_lock);
 926         INIT_LIST_HEAD(&ei->i_es_list);
 927         ei->i_es_all_nr = 0;
 928         ei->i_es_shk_nr = 0;
 929         ei->i_es_shrink_lblk = 0;
 930         ei->i_reserved_data_blocks = 0;
 931         ei->i_reserved_meta_blocks = 0;
 932         ei->i_allocated_meta_blocks = 0;
 933         ei->i_da_metadata_calc_len = 0;
 934         ei->i_da_metadata_calc_last_lblock = 0;
 935         spin_lock_init(&(ei->i_block_reservation_lock));
 936 #ifdef CONFIG_QUOTA
 937         ei->i_reserved_quota = 0;
 938         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 939 #endif
 940         ei->jinode = NULL;
 941         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 942         spin_lock_init(&ei->i_completed_io_lock);
 943         ei->i_sync_tid = 0;
 944         ei->i_datasync_tid = 0;
 945         atomic_set(&ei->i_unwritten, 0);
 946         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 947 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 948         ei->i_crypt_info = NULL;
 949 #endif
 950         return &ei->vfs_inode;
 951 }
 952
 953 static int ext4_drop_inode(struct inode *inode)
 954 {
 955         int drop = generic_drop_inode(inode);
 956
 957         trace_ext4_drop_inode(inode, drop);
 958         return drop;
 959 }
 960
 961 static void ext4_i_callback(struct rcu_head *head)
 962 {
 963         struct inode *inode = container_of(head, struct inode, i_rcu);
 964         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 965 }
 966
 967 static void ext4_destroy_inode(struct inode *inode)
 968 {
 969         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 970                 ext4_msg(inode->i_sb, KERN_ERR,
 971                          "Inode %lu (%p): orphan list check failed!",
 972                          inode->i_ino, EXT4_I(inode));
 973                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 974                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 975                                 true);
 976                 dump_stack();
 977         }
 978         call_rcu(&inode->i_rcu, ext4_i_callback);
 979 }
 980
 981 static void init_once(void *foo)
 982 {
 983         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 984
 985         INIT_LIST_HEAD(&ei->i_orphan);
 986         init_rwsem(&ei->xattr_sem);
 987         init_rwsem(&ei->i_data_sem);
 988         init_rwsem(&ei->i_mmap_sem);
 989         inode_init_once(&ei->vfs_inode);
 990 }
 991
 992 static int __init init_inodecache(void)
 993 {
 994         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 995                                              sizeof(struct ext4_inode_info),
 996                                              0, (SLAB_RECLAIM_ACCOUNT|
 997                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 998                                              init_once);
 999         if (ext4_inode_cachep == NULL)
1000                 return -ENOMEM;
1001         return 0;
1002 }
1003
1004 static void destroy_inodecache(void)
1005 {
1006         /*
1007          * Make sure all delayed rcu free inodes are flushed before we
1008          * destroy cache.
1009          */
1010         rcu_barrier();
1011         kmem_cache_destroy(ext4_inode_cachep);
1012 }
1013
1014 void ext4_clear_inode(struct inode *inode)
1015 {
1016         invalidate_inode_buffers(inode);
1017         clear_inode(inode);
1018         dquot_drop(inode);
1019         ext4_discard_preallocations(inode);
1020         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1021         if (EXT4_I(inode)->jinode) {
1022                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1023                                                EXT4_I(inode)->jinode);
1024                 jbd2_free_inode(EXT4_I(inode)->jinode);
1025                 EXT4_I(inode)->jinode = NULL;
1026         }
1027 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1028         if (EXT4_I(inode)->i_crypt_info)
1029                 ext4_free_encryption_info(inode, EXT4_I(inode)->i_crypt_info);
1030 #endif
1031 }
1032
1033 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1034                                         u64 ino, u32 generation)
1035 {
1036         struct inode *inode;
1037
1038         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1039                 return ERR_PTR(-ESTALE);
1040         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1041                 return ERR_PTR(-ESTALE);
1042
1043         /* iget isn't really right if the inode is currently unallocated!!
1044          *
1045          * ext4_read_inode will return a bad_inode if the inode had been
1046          * deleted, so we should be safe.
1047          *
1048          * Currently we don't know the generation for parent directory, so
1049          * a generation of 0 means "accept any"
1050          */
1051         inode = ext4_iget_normal(sb, ino);
1052         if (IS_ERR(inode))
1053                 return ERR_CAST(inode);
1054         if (generation && inode->i_generation != generation) {
1055                 iput(inode);
1056                 return ERR_PTR(-ESTALE);
1057         }
1058
1059         return inode;
1060 }
1061
1062 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1063                                         int fh_len, int fh_type)
1064 {
1065         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1066                                     ext4_nfs_get_inode);
1067 }
1068
1069 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1070                                         int fh_len, int fh_type)
1071 {
1072         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1073                                     ext4_nfs_get_inode);
1074 }
1075
1076 /*
1077  * Try to release metadata pages (indirect blocks, directories) which are
1078  * mapped via the block device.  Since these pages could have journal heads
1079  * which would prevent try_to_free_buffers() from freeing them, we must use
1080  * jbd2 layer's try_to_free_buffers() function to release them.
1081  */
1082 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1083                                  gfp_t wait)
1084 {
1085         journal_t *journal = EXT4_SB(sb)->s_journal;
1086
1087         WARN_ON(PageChecked(page));
1088         if (!page_has_buffers(page))
1089                 return 0;
1090         if (journal)
1091                 return jbd2_journal_try_to_free_buffers(journal, page,
1092                                                 wait & ~__GFP_DIRECT_RECLAIM);
1093         return try_to_free_buffers(page);
1094 }
1095
1096 #ifdef CONFIG_QUOTA
1097 static char *quotatypes[] = INITQFNAMES;
1098 #define QTYPE2NAME(t) (quotatypes[t])
1099
1100 static int ext4_write_dquot(struct dquot *dquot);
1101 static int ext4_acquire_dquot(struct dquot *dquot);
1102 static int ext4_release_dquot(struct dquot *dquot);
1103 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1104 static int ext4_write_info(struct super_block *sb, int type);
1105 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1106                          struct path *path);
1107 static int ext4_quota_off(struct super_block *sb, int type);
1108 static int ext4_quota_on_mount(struct super_block *sb, int type);
1109 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1110                                size_t len, loff_t off);
1111 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1112                                 const char *data, size_t len, loff_t off);
1113 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1114                              unsigned int flags);
1115 static int ext4_enable_quotas(struct super_block *sb);
1116
1117 static struct dquot **ext4_get_dquots(struct inode *inode)
1118 {
1119         return EXT4_I(inode)->i_dquot;
1120 }
1121
1122 static const struct dquot_operations ext4_quota_operations = {
1123         .get_reserved_space = ext4_get_reserved_space,
1124         .write_dquot    = ext4_write_dquot,
1125         .acquire_dquot  = ext4_acquire_dquot,
1126         .release_dquot  = ext4_release_dquot,
1127         .mark_dirty     = ext4_mark_dquot_dirty,
1128         .write_info     = ext4_write_info,
1129         .alloc_dquot    = dquot_alloc,
1130         .destroy_dquot  = dquot_destroy,
1131         .get_projid     = ext4_get_projid,
1132         .get_next_id    = dquot_get_next_id,
1133 };
1134
1135 static const struct quotactl_ops ext4_qctl_operations = {
1136         .quota_on       = ext4_quota_on,
1137         .quota_off      = ext4_quota_off,
1138         .quota_sync     = dquot_quota_sync,
1139         .get_state      = dquot_get_state,
1140         .set_info       = dquot_set_dqinfo,
1141         .get_dqblk      = dquot_get_dqblk,
1142         .set_dqblk      = dquot_set_dqblk,
1143         .get_nextdqblk  = dquot_get_next_dqblk,
1144 };
1145 #endif
1146
1147 static const struct super_operations ext4_sops = {
1148         .alloc_inode    = ext4_alloc_inode,
1149         .destroy_inode  = ext4_destroy_inode,
1150         .write_inode    = ext4_write_inode,
1151         .dirty_inode    = ext4_dirty_inode,
1152         .drop_inode     = ext4_drop_inode,
1153         .evict_inode    = ext4_evict_inode,
1154         .put_super      = ext4_put_super,
1155         .sync_fs        = ext4_sync_fs,
1156         .freeze_fs      = ext4_freeze,
1157         .unfreeze_fs    = ext4_unfreeze,
1158         .statfs         = ext4_statfs,
1159         .remount_fs     = ext4_remount,
1160         .show_options   = ext4_show_options,
1161 #ifdef CONFIG_QUOTA
1162         .quota_read     = ext4_quota_read,
1163         .quota_write    = ext4_quota_write,
1164         .get_dquots     = ext4_get_dquots,
1165 #endif
1166         .bdev_try_to_free_page = bdev_try_to_free_page,
1167 };
1168
1169 static const struct export_operations ext4_export_ops = {
1170         .fh_to_dentry = ext4_fh_to_dentry,
1171         .fh_to_parent = ext4_fh_to_parent,
1172         .get_parent = ext4_get_parent,
1173 };
1174
1175 enum {
1176         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1177         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1178         Opt_nouid32, Opt_debug, Opt_removed,
1179         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1180         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1181         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1182         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1183         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1184         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1185         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1186         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1187         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1188         Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
1189         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1190         Opt_lazytime, Opt_nolazytime,
1191         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1192         Opt_inode_readahead_blks, Opt_journal_ioprio,
1193         Opt_dioread_nolock, Opt_dioread_lock,
1194         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1195         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1196 };
1197
1198 static const match_table_t tokens = {
1199         {Opt_bsd_df, "bsddf"},
1200         {Opt_minix_df, "minixdf"},
1201         {Opt_grpid, "grpid"},
1202         {Opt_grpid, "bsdgroups"},
1203         {Opt_nogrpid, "nogrpid"},
1204         {Opt_nogrpid, "sysvgroups"},
1205         {Opt_resgid, "resgid=%u"},
1206         {Opt_resuid, "resuid=%u"},
1207         {Opt_sb, "sb=%u"},
1208         {Opt_err_cont, "errors=continue"},
1209         {Opt_err_panic, "errors=panic"},
1210         {Opt_err_ro, "errors=remount-ro"},
1211         {Opt_nouid32, "nouid32"},
1212         {Opt_debug, "debug"},
1213         {Opt_removed, "oldalloc"},
1214         {Opt_removed, "orlov"},
1215         {Opt_user_xattr, "user_xattr"},
1216         {Opt_nouser_xattr, "nouser_xattr"},
1217         {Opt_acl, "acl"},
1218         {Opt_noacl, "noacl"},
1219         {Opt_noload, "norecovery"},
1220         {Opt_noload, "noload"},
1221         {Opt_removed, "nobh"},
1222         {Opt_removed, "bh"},
1223         {Opt_commit, "commit=%u"},
1224         {Opt_min_batch_time, "min_batch_time=%u"},
1225         {Opt_max_batch_time, "max_batch_time=%u"},
1226         {Opt_journal_dev, "journal_dev=%u"},
1227         {Opt_journal_path, "journal_path=%s"},
1228         {Opt_journal_checksum, "journal_checksum"},
1229         {Opt_nojournal_checksum, "nojournal_checksum"},
1230         {Opt_journal_async_commit, "journal_async_commit"},
1231         {Opt_abort, "abort"},
1232         {Opt_data_journal, "data=journal"},
1233         {Opt_data_ordered, "data=ordered"},
1234         {Opt_data_writeback, "data=writeback"},
1235         {Opt_data_err_abort, "data_err=abort"},
1236         {Opt_data_err_ignore, "data_err=ignore"},
1237         {Opt_offusrjquota, "usrjquota="},
1238         {Opt_usrjquota, "usrjquota=%s"},
1239         {Opt_offgrpjquota, "grpjquota="},
1240         {Opt_grpjquota, "grpjquota=%s"},
1241         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1242         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1243         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1244         {Opt_grpquota, "grpquota"},
1245         {Opt_noquota, "noquota"},
1246         {Opt_quota, "quota"},
1247         {Opt_usrquota, "usrquota"},
1248         {Opt_barrier, "barrier=%u"},
1249         {Opt_barrier, "barrier"},
1250         {Opt_nobarrier, "nobarrier"},
1251         {Opt_i_version, "i_version"},
1252         {Opt_dax, "dax"},
1253         {Opt_stripe, "stripe=%u"},
1254         {Opt_delalloc, "delalloc"},
1255         {Opt_lazytime, "lazytime"},
1256         {Opt_nolazytime, "nolazytime"},
1257         {Opt_nodelalloc, "nodelalloc"},
1258         {Opt_removed, "mblk_io_submit"},
1259         {Opt_removed, "nomblk_io_submit"},
1260         {Opt_block_validity, "block_validity"},
1261         {Opt_noblock_validity, "noblock_validity"},
1262         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1263         {Opt_journal_ioprio, "journal_ioprio=%u"},
1264         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1265         {Opt_auto_da_alloc, "auto_da_alloc"},
1266         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1267         {Opt_dioread_nolock, "dioread_nolock"},
1268         {Opt_dioread_lock, "dioread_lock"},
1269         {Opt_discard, "discard"},
1270         {Opt_nodiscard, "nodiscard"},
1271         {Opt_init_itable, "init_itable=%u"},
1272         {Opt_init_itable, "init_itable"},
1273         {Opt_noinit_itable, "noinit_itable"},
1274         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1275         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1276         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1277         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1278         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1279         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1280         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1281         {Opt_err, NULL},
1282 };
1283
1284 static ext4_fsblk_t get_sb_block(void **data)
1285 {
1286         ext4_fsblk_t    sb_block;
1287         char            *options = (char *) *data;
1288
1289         if (!options || strncmp(options, "sb=", 3) != 0)
1290                 return 1;       /* Default location */
1291
1292         options += 3;
1293         /* TODO: use simple_strtoll with >32bit ext4 */
1294         sb_block = simple_strtoul(options, &options, 0);
1295         if (*options && *options != ',') {
1296                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1297                        (char *) *data);
1298                 return 1;
1299         }
1300         if (*options == ',')
1301                 options++;
1302         *data = (void *) options;
1303
1304         return sb_block;
1305 }
1306
1307 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1308 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1309         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1310
1311 #ifdef CONFIG_QUOTA
1312 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1313 {
1314         struct ext4_sb_info *sbi = EXT4_SB(sb);
1315         char *qname;
1316         int ret = -1;
1317
1318         if (sb_any_quota_loaded(sb) &&
1319                 !sbi->s_qf_names[qtype]) {
1320                 ext4_msg(sb, KERN_ERR,
1321                         "Cannot change journaled "
1322                         "quota options when quota turned on");
1323                 return -1;
1324         }
1325         if (ext4_has_feature_quota(sb)) {
1326                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1327                          "when QUOTA feature is enabled");
1328                 return -1;
1329         }
1330         qname = match_strdup(args);
1331         if (!qname) {
1332                 ext4_msg(sb, KERN_ERR,
1333                         "Not enough memory for storing quotafile name");
1334                 return -1;
1335         }
1336         if (sbi->s_qf_names[qtype]) {
1337                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1338                         ret = 1;
1339                 else
1340                         ext4_msg(sb, KERN_ERR,
1341                                  "%s quota file already specified",
1342                                  QTYPE2NAME(qtype));
1343                 goto errout;
1344         }
1345         if (strchr(qname, '/')) {
1346                 ext4_msg(sb, KERN_ERR,
1347                         "quotafile must be on filesystem root");
1348                 goto errout;
1349         }
1350         sbi->s_qf_names[qtype] = qname;
1351         set_opt(sb, QUOTA);
1352         return 1;
1353 errout:
1354         kfree(qname);
1355         return ret;
1356 }
1357
1358 static int clear_qf_name(struct super_block *sb, int qtype)
1359 {
1360
1361         struct ext4_sb_info *sbi = EXT4_SB(sb);
1362
1363         if (sb_any_quota_loaded(sb) &&
1364                 sbi->s_qf_names[qtype]) {
1365                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1366                         " when quota turned on");
1367                 return -1;
1368         }
1369         kfree(sbi->s_qf_names[qtype]);
1370         sbi->s_qf_names[qtype] = NULL;
1371         return 1;
1372 }
1373 #endif
1374
1375 #define MOPT_SET        0x0001
1376 #define MOPT_CLEAR      0x0002
1377 #define MOPT_NOSUPPORT  0x0004
1378 #define MOPT_EXPLICIT   0x0008
1379 #define MOPT_CLEAR_ERR  0x0010
1380 #define MOPT_GTE0       0x0020
1381 #ifdef CONFIG_QUOTA
1382 #define MOPT_Q          0
1383 #define MOPT_QFMT       0x0040
1384 #else
1385 #define MOPT_Q          MOPT_NOSUPPORT
1386 #define MOPT_QFMT       MOPT_NOSUPPORT
1387 #endif
1388 #define MOPT_DATAJ      0x0080
1389 #define MOPT_NO_EXT2    0x0100
1390 #define MOPT_NO_EXT3    0x0200
1391 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1392 #define MOPT_STRING     0x0400
1393
1394 static const struct mount_opts {
1395         int     token;
1396         int     mount_opt;
1397         int     flags;
1398 } ext4_mount_opts[] = {
1399         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1400         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1401         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1402         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1403         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1404         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1405         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1406          MOPT_EXT4_ONLY | MOPT_SET},
1407         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1408          MOPT_EXT4_ONLY | MOPT_CLEAR},
1409         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1410         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1411         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1412          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1413         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1414          MOPT_EXT4_ONLY | MOPT_CLEAR},
1415         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1416          MOPT_EXT4_ONLY | MOPT_CLEAR},
1417         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1418          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1419         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1420                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1421          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1422         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1423         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1424         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1425         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1426         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1427          MOPT_NO_EXT2},
1428         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1429          MOPT_NO_EXT2},
1430         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1431         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1432         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1433         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1434         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1435         {Opt_commit, 0, MOPT_GTE0},
1436         {Opt_max_batch_time, 0, MOPT_GTE0},
1437         {Opt_min_batch_time, 0, MOPT_GTE0},
1438         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1439         {Opt_init_itable, 0, MOPT_GTE0},
1440         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1441         {Opt_stripe, 0, MOPT_GTE0},
1442         {Opt_resuid, 0, MOPT_GTE0},
1443         {Opt_resgid, 0, MOPT_GTE0},
1444         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1445         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1446         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1447         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1448         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1449         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1450          MOPT_NO_EXT2 | MOPT_DATAJ},
1451         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1452         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1453 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1454         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1455         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1456 #else
1457         {Opt_acl, 0, MOPT_NOSUPPORT},
1458         {Opt_noacl, 0, MOPT_NOSUPPORT},
1459 #endif
1460         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1461         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1462         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1463         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1464                                                         MOPT_SET | MOPT_Q},
1465         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1466                                                         MOPT_SET | MOPT_Q},
1467         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1468                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1469         {Opt_usrjquota, 0, MOPT_Q},
1470         {Opt_grpjquota, 0, MOPT_Q},
1471         {Opt_offusrjquota, 0, MOPT_Q},
1472         {Opt_offgrpjquota, 0, MOPT_Q},
1473         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1474         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1475         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1476         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1477         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1478         {Opt_err, 0, 0}
1479 };
1480
1481 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1482                             substring_t *args, unsigned long *journal_devnum,
1483                             unsigned int *journal_ioprio, int is_remount)
1484 {
1485         struct ext4_sb_info *sbi = EXT4_SB(sb);
1486         const struct mount_opts *m;
1487         kuid_t uid;
1488         kgid_t gid;
1489         int arg = 0;
1490
1491 #ifdef CONFIG_QUOTA
1492         if (token == Opt_usrjquota)
1493                 return set_qf_name(sb, USRQUOTA, &args[0]);
1494         else if (token == Opt_grpjquota)
1495                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1496         else if (token == Opt_offusrjquota)
1497                 return clear_qf_name(sb, USRQUOTA);
1498         else if (token == Opt_offgrpjquota)
1499                 return clear_qf_name(sb, GRPQUOTA);
1500 #endif
1501         switch (token) {
1502         case Opt_noacl:
1503         case Opt_nouser_xattr:
1504                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1505                 break;
1506         case Opt_sb:
1507                 return 1;       /* handled by get_sb_block() */
1508         case Opt_removed:
1509                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1510                 return 1;
1511         case Opt_abort:
1512                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1513                 return 1;
1514         case Opt_i_version:
1515                 sb->s_flags |= MS_I_VERSION;
1516                 return 1;
1517         case Opt_lazytime:
1518                 sb->s_flags |= MS_LAZYTIME;
1519                 return 1;
1520         case Opt_nolazytime:
1521                 sb->s_flags &= ~MS_LAZYTIME;
1522                 return 1;
1523         }
1524
1525         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1526                 if (token == m->token)
1527                         break;
1528
1529         if (m->token == Opt_err) {
1530                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1531                          "or missing value", opt);
1532                 return -1;
1533         }
1534
1535         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1536                 ext4_msg(sb, KERN_ERR,
1537                          "Mount option \"%s\" incompatible with ext2", opt);
1538                 return -1;
1539         }
1540         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1541                 ext4_msg(sb, KERN_ERR,
1542                          "Mount option \"%s\" incompatible with ext3", opt);
1543                 return -1;
1544         }
1545
1546         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1547                 return -1;
1548         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1549                 return -1;
1550         if (m->flags & MOPT_EXPLICIT) {
1551                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1552                         set_opt2(sb, EXPLICIT_DELALLOC);
1553                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1554                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1555                 } else
1556                         return -1;
1557         }
1558         if (m->flags & MOPT_CLEAR_ERR)
1559                 clear_opt(sb, ERRORS_MASK);
1560         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1561                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1562                          "options when quota turned on");
1563                 return -1;
1564         }
1565
1566         if (m->flags & MOPT_NOSUPPORT) {
1567                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1568         } else if (token == Opt_commit) {
1569                 if (arg == 0)
1570                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1571                 sbi->s_commit_interval = HZ * arg;
1572         } else if (token == Opt_max_batch_time) {
1573                 sbi->s_max_batch_time = arg;
1574         } else if (token == Opt_min_batch_time) {
1575                 sbi->s_min_batch_time = arg;
1576         } else if (token == Opt_inode_readahead_blks) {
1577                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1578                         ext4_msg(sb, KERN_ERR,
1579                                  "EXT4-fs: inode_readahead_blks must be "
1580                                  "0 or a power of 2 smaller than 2^31");
1581                         return -1;
1582                 }
1583                 sbi->s_inode_readahead_blks = arg;
1584         } else if (token == Opt_init_itable) {
1585                 set_opt(sb, INIT_INODE_TABLE);
1586                 if (!args->from)
1587                         arg = EXT4_DEF_LI_WAIT_MULT;
1588                 sbi->s_li_wait_mult = arg;
1589         } else if (token == Opt_max_dir_size_kb) {
1590                 sbi->s_max_dir_size_kb = arg;
1591         } else if (token == Opt_stripe) {
1592                 sbi->s_stripe = arg;
1593         } else if (token == Opt_resuid) {
1594                 uid = make_kuid(current_user_ns(), arg);
1595                 if (!uid_valid(uid)) {
1596                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1597                         return -1;
1598                 }
1599                 sbi->s_resuid = uid;
1600         } else if (token == Opt_resgid) {
1601                 gid = make_kgid(current_user_ns(), arg);
1602                 if (!gid_valid(gid)) {
1603                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1604                         return -1;
1605                 }
1606                 sbi->s_resgid = gid;
1607         } else if (token == Opt_journal_dev) {
1608                 if (is_remount) {
1609                         ext4_msg(sb, KERN_ERR,
1610                                  "Cannot specify journal on remount");
1611                         return -1;
1612                 }
1613                 *journal_devnum = arg;
1614         } else if (token == Opt_journal_path) {
1615                 char *journal_path;
1616                 struct inode *journal_inode;
1617                 struct path path;
1618                 int error;
1619
1620                 if (is_remount) {
1621                         ext4_msg(sb, KERN_ERR,
1622                                  "Cannot specify journal on remount");
1623                         return -1;
1624                 }
1625                 journal_path = match_strdup(&args[0]);
1626                 if (!journal_path) {
1627                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1628                                 "journal device string");
1629                         return -1;
1630                 }
1631
1632                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1633                 if (error) {
1634                         ext4_msg(sb, KERN_ERR, "error: could not find "
1635                                 "journal device path: error %d", error);
1636                         kfree(journal_path);
1637                         return -1;
1638                 }
1639
1640                 journal_inode = d_inode(path.dentry);
1641                 if (!S_ISBLK(journal_inode->i_mode)) {
1642                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1643                                 "is not a block device", journal_path);
1644                         path_put(&path);
1645                         kfree(journal_path);
1646                         return -1;
1647                 }
1648
1649                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1650                 path_put(&path);
1651                 kfree(journal_path);
1652         } else if (token == Opt_journal_ioprio) {
1653                 if (arg > 7) {
1654                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1655                                  " (must be 0-7)");
1656                         return -1;
1657                 }
1658                 *journal_ioprio =
1659                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1660         } else if (token == Opt_test_dummy_encryption) {
1661 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1662                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1663                 ext4_msg(sb, KERN_WARNING,
1664                          "Test dummy encryption mode enabled");
1665 #else
1666                 ext4_msg(sb, KERN_WARNING,
1667                          "Test dummy encryption mount option ignored");
1668 #endif
1669         } else if (m->flags & MOPT_DATAJ) {
1670                 if (is_remount) {
1671                         if (!sbi->s_journal)
1672                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1673                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1674                                 ext4_msg(sb, KERN_ERR,
1675                                          "Cannot change data mode on remount");
1676                                 return -1;
1677                         }
1678                 } else {
1679                         clear_opt(sb, DATA_FLAGS);
1680                         sbi->s_mount_opt |= m->mount_opt;
1681                 }
1682 #ifdef CONFIG_QUOTA
1683         } else if (m->flags & MOPT_QFMT) {
1684                 if (sb_any_quota_loaded(sb) &&
1685                     sbi->s_jquota_fmt != m->mount_opt) {
1686                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1687                                  "quota options when quota turned on");
1688                         return -1;
1689                 }
1690                 if (ext4_has_feature_quota(sb)) {
1691                         ext4_msg(sb, KERN_ERR,
1692                                  "Cannot set journaled quota options "
1693                                  "when QUOTA feature is enabled");
1694                         return -1;
1695                 }
1696                 sbi->s_jquota_fmt = m->mount_opt;
1697 #endif
1698         } else if (token == Opt_dax) {
1699 #ifdef CONFIG_FS_DAX
1700                 ext4_msg(sb, KERN_WARNING,
1701                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1702                         sbi->s_mount_opt |= m->mount_opt;
1703 #else
1704                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1705                 return -1;
1706 #endif
1707         } else if (token == Opt_data_err_abort) {
1708                 sbi->s_mount_opt |= m->mount_opt;
1709         } else if (token == Opt_data_err_ignore) {
1710                 sbi->s_mount_opt &= ~m->mount_opt;
1711         } else {
1712                 if (!args->from)
1713                         arg = 1;
1714                 if (m->flags & MOPT_CLEAR)
1715                         arg = !arg;
1716                 else if (unlikely(!(m->flags & MOPT_SET))) {
1717                         ext4_msg(sb, KERN_WARNING,
1718                                  "buggy handling of option %s", opt);
1719                         WARN_ON(1);
1720                         return -1;
1721                 }
1722                 if (arg != 0)
1723                         sbi->s_mount_opt |= m->mount_opt;
1724                 else
1725                         sbi->s_mount_opt &= ~m->mount_opt;
1726         }
1727         return 1;
1728 }
1729
1730 static int parse_options(char *options, struct super_block *sb,
1731                          unsigned long *journal_devnum,
1732                          unsigned int *journal_ioprio,
1733                          int is_remount)
1734 {
1735         struct ext4_sb_info *sbi = EXT4_SB(sb);
1736         char *p;
1737         substring_t args[MAX_OPT_ARGS];
1738         int token;
1739
1740         if (!options)
1741                 return 1;
1742
1743         while ((p = strsep(&options, ",")) != NULL) {
1744                 if (!*p)
1745                         continue;
1746                 /*
1747                  * Initialize args struct so we know whether arg was
1748                  * found; some options take optional arguments.
1749                  */
1750                 args[0].to = args[0].from = NULL;
1751                 token = match_token(p, tokens, args);
1752                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1753                                      journal_ioprio, is_remount) < 0)
1754                         return 0;
1755         }
1756 #ifdef CONFIG_QUOTA
1757         if (ext4_has_feature_quota(sb) &&
1758             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1759                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1760                          "feature is enabled");
1761                 return 0;
1762         }
1763         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1764                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1765                         clear_opt(sb, USRQUOTA);
1766
1767                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1768                         clear_opt(sb, GRPQUOTA);
1769
1770                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1771                         ext4_msg(sb, KERN_ERR, "old and new quota "
1772                                         "format mixing");
1773                         return 0;
1774                 }
1775
1776                 if (!sbi->s_jquota_fmt) {
1777                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1778                                         "not specified");
1779                         return 0;
1780                 }
1781         }
1782 #endif
1783         if (test_opt(sb, DIOREAD_NOLOCK)) {
1784                 int blocksize =
1785                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1786
1787                 if (blocksize < PAGE_CACHE_SIZE) {
1788                         ext4_msg(sb, KERN_ERR, "can't mount with "
1789                                  "dioread_nolock if block size != PAGE_SIZE");
1790                         return 0;
1791                 }
1792         }
1793         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1794             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1795                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1796                          "in data=ordered mode");
1797                 return 0;
1798         }
1799         return 1;
1800 }
1801
1802 static inline void ext4_show_quota_options(struct seq_file *seq,
1803                                            struct super_block *sb)
1804 {
1805 #if defined(CONFIG_QUOTA)
1806         struct ext4_sb_info *sbi = EXT4_SB(sb);
1807
1808         if (sbi->s_jquota_fmt) {
1809                 char *fmtname = "";
1810
1811                 switch (sbi->s_jquota_fmt) {
1812                 case QFMT_VFS_OLD:
1813                         fmtname = "vfsold";
1814                         break;
1815                 case QFMT_VFS_V0:
1816                         fmtname = "vfsv0";
1817                         break;
1818                 case QFMT_VFS_V1:
1819                         fmtname = "vfsv1";
1820                         break;
1821                 }
1822                 seq_printf(seq, ",jqfmt=%s", fmtname);
1823         }
1824
1825         if (sbi->s_qf_names[USRQUOTA])
1826                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1827
1828         if (sbi->s_qf_names[GRPQUOTA])
1829                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1830 #endif
1831 }
1832
1833 static const char *token2str(int token)
1834 {
1835         const struct match_token *t;
1836
1837         for (t = tokens; t->token != Opt_err; t++)
1838                 if (t->token == token && !strchr(t->pattern, '='))
1839                         break;
1840         return t->pattern;
1841 }
1842
1843 /*
1844  * Show an option if
1845  *  - it's set to a non-default value OR
1846  *  - if the per-sb default is different from the global default
1847  */
1848 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1849                               int nodefs)
1850 {
1851         struct ext4_sb_info *sbi = EXT4_SB(sb);
1852         struct ext4_super_block *es = sbi->s_es;
1853         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1854         const struct mount_opts *m;
1855         char sep = nodefs ? '\n' : ',';
1856
1857 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1858 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1859
1860         if (sbi->s_sb_block != 1)
1861                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1862
1863         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1864                 int want_set = m->flags & MOPT_SET;
1865                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1866                     (m->flags & MOPT_CLEAR_ERR))
1867                         continue;
1868                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1869                         continue; /* skip if same as the default */
1870                 if ((want_set &&
1871                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1872                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1873                         continue; /* select Opt_noFoo vs Opt_Foo */
1874                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1875         }
1876
1877         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1878             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1879                 SEQ_OPTS_PRINT("resuid=%u",
1880                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1881         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1882             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1883                 SEQ_OPTS_PRINT("resgid=%u",
1884                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1885         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1886         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1887                 SEQ_OPTS_PUTS("errors=remount-ro");
1888         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1889                 SEQ_OPTS_PUTS("errors=continue");
1890         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1891                 SEQ_OPTS_PUTS("errors=panic");
1892         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1893                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1894         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1895                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1896         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1897                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1898         if (sb->s_flags & MS_I_VERSION)
1899                 SEQ_OPTS_PUTS("i_version");
1900         if (nodefs || sbi->s_stripe)
1901                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1902         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1903                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1904                         SEQ_OPTS_PUTS("data=journal");
1905                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1906                         SEQ_OPTS_PUTS("data=ordered");
1907                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1908                         SEQ_OPTS_PUTS("data=writeback");
1909         }
1910         if (nodefs ||
1911             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1912                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1913                                sbi->s_inode_readahead_blks);
1914
1915         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1916                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1917                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1918         if (nodefs || sbi->s_max_dir_size_kb)
1919                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1920         if (test_opt(sb, DATA_ERR_ABORT))
1921                 SEQ_OPTS_PUTS("data_err=abort");
1922
1923         ext4_show_quota_options(seq, sb);
1924         return 0;
1925 }
1926
1927 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1928 {
1929         return _ext4_show_options(seq, root->d_sb, 0);
1930 }
1931
1932 int ext4_seq_options_show(struct seq_file *seq, void *offset)
1933 {
1934         struct super_block *sb = seq->private;
1935         int rc;
1936
1937         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1938         rc = _ext4_show_options(seq, sb, 1);
1939         seq_puts(seq, "\n");
1940         return rc;
1941 }
1942
1943 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1944                             int read_only)
1945 {
1946         struct ext4_sb_info *sbi = EXT4_SB(sb);
1947         int res = 0;
1948
1949         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1950                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1951                          "forcing read-only mode");
1952                 res = MS_RDONLY;
1953         }
1954         if (read_only)
1955                 goto done;
1956         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1957                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1958                          "running e2fsck is recommended");
1959         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1960                 ext4_msg(sb, KERN_WARNING,
1961                          "warning: mounting fs with errors, "
1962                          "running e2fsck is recommended");
1963         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1964                  le16_to_cpu(es->s_mnt_count) >=
1965                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1966                 ext4_msg(sb, KERN_WARNING,
1967                          "warning: maximal mount count reached, "
1968                          "running e2fsck is recommended");
1969         else if (le32_to_cpu(es->s_checkinterval) &&
1970                 (le32_to_cpu(es->s_lastcheck) +
1971                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1972                 ext4_msg(sb, KERN_WARNING,
1973                          "warning: checktime reached, "
1974                          "running e2fsck is recommended");
1975         if (!sbi->s_journal)
1976                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1977         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1978                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1979         le16_add_cpu(&es->s_mnt_count, 1);
1980         es->s_mtime = cpu_to_le32(get_seconds());
1981         ext4_update_dynamic_rev(sb);
1982         if (sbi->s_journal)
1983                 ext4_set_feature_journal_needs_recovery(sb);
1984
1985         ext4_commit_super(sb, 1);
1986 done:
1987         if (test_opt(sb, DEBUG))
1988                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1989                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1990                         sb->s_blocksize,
1991                         sbi->s_groups_count,
1992                         EXT4_BLOCKS_PER_GROUP(sb),
1993                         EXT4_INODES_PER_GROUP(sb),
1994                         sbi->s_mount_opt, sbi->s_mount_opt2);
1995
1996         cleancache_init_fs(sb);
1997         return res;
1998 }
1999
2000 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2001 {
2002         struct ext4_sb_info *sbi = EXT4_SB(sb);
2003         struct flex_groups *new_groups;
2004         int size;
2005
2006         if (!sbi->s_log_groups_per_flex)
2007                 return 0;
2008
2009         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2010         if (size <= sbi->s_flex_groups_allocated)
2011                 return 0;
2012
2013         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2014         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2015         if (!new_groups) {
2016                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2017                          size / (int) sizeof(struct flex_groups));
2018                 return -ENOMEM;
2019         }
2020
2021         if (sbi->s_flex_groups) {
2022                 memcpy(new_groups, sbi->s_flex_groups,
2023                        (sbi->s_flex_groups_allocated *
2024                         sizeof(struct flex_groups)));
2025                 kvfree(sbi->s_flex_groups);
2026         }
2027         sbi->s_flex_groups = new_groups;
2028         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2029         return 0;
2030 }
2031
2032 static int ext4_fill_flex_info(struct super_block *sb)
2033 {
2034         struct ext4_sb_info *sbi = EXT4_SB(sb);
2035         struct ext4_group_desc *gdp = NULL;
2036         ext4_group_t flex_group;
2037         int i, err;
2038
2039         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2040         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2041                 sbi->s_log_groups_per_flex = 0;
2042                 return 1;
2043         }
2044
2045         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2046         if (err)
2047                 goto failed;
2048
2049         for (i = 0; i < sbi->s_groups_count; i++) {
2050                 gdp = ext4_get_group_desc(sb, i, NULL);
2051
2052                 flex_group = ext4_flex_group(sbi, i);
2053                 atomic_add(ext4_free_inodes_count(sb, gdp),
2054                            &sbi->s_flex_groups[flex_group].free_inodes);
2055                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2056                              &sbi->s_flex_groups[flex_group].free_clusters);
2057                 atomic_add(ext4_used_dirs_count(sb, gdp),
2058                            &sbi->s_flex_groups[flex_group].used_dirs);
2059         }
2060
2061         return 1;
2062 failed:
2063         return 0;
2064 }
2065
2066 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2067                                    struct ext4_group_desc *gdp)
2068 {
2069         int offset;
2070         __u16 crc = 0;
2071         __le32 le_group = cpu_to_le32(block_group);
2072         struct ext4_sb_info *sbi = EXT4_SB(sb);
2073
2074         if (ext4_has_metadata_csum(sbi->s_sb)) {
2075                 /* Use new metadata_csum algorithm */
2076                 __le16 save_csum;
2077                 __u32 csum32;
2078
2079                 save_csum = gdp->bg_checksum;
2080                 gdp->bg_checksum = 0;
2081                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2082                                      sizeof(le_group));
2083                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2084                                      sbi->s_desc_size);
2085                 gdp->bg_checksum = save_csum;
2086
2087                 crc = csum32 & 0xFFFF;
2088                 goto out;
2089         }
2090
2091         /* old crc16 code */
2092         if (!ext4_has_feature_gdt_csum(sb))
2093                 return 0;
2094
2095         offset = offsetof(struct ext4_group_desc, bg_checksum);
2096
2097         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2098         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2099         crc = crc16(crc, (__u8 *)gdp, offset);
2100         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2101         /* for checksum of struct ext4_group_desc do the rest...*/
2102         if (ext4_has_feature_64bit(sb) &&
2103             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2104                 crc = crc16(crc, (__u8 *)gdp + offset,
2105                             le16_to_cpu(sbi->s_es->s_desc_size) -
2106                                 offset);
2107
2108 out:
2109         return cpu_to_le16(crc);
2110 }
2111
2112 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2113                                 struct ext4_group_desc *gdp)
2114 {
2115         if (ext4_has_group_desc_csum(sb) &&
2116             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2117                 return 0;
2118
2119         return 1;
2120 }
2121
2122 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2123                               struct ext4_group_desc *gdp)
2124 {
2125         if (!ext4_has_group_desc_csum(sb))
2126                 return;
2127         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2128 }
2129
2130 /* Called at mount-time, super-block is locked */
2131 static int ext4_check_descriptors(struct super_block *sb,
2132                                   ext4_group_t *first_not_zeroed)
2133 {
2134         struct ext4_sb_info *sbi = EXT4_SB(sb);
2135         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2136         ext4_fsblk_t last_block;
2137         ext4_fsblk_t block_bitmap;
2138         ext4_fsblk_t inode_bitmap;
2139         ext4_fsblk_t inode_table;
2140         int flexbg_flag = 0;
2141         ext4_group_t i, grp = sbi->s_groups_count;
2142
2143         if (ext4_has_feature_flex_bg(sb))
2144                 flexbg_flag = 1;
2145
2146         ext4_debug("Checking group descriptors");
2147
2148         for (i = 0; i < sbi->s_groups_count; i++) {
2149                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2150
2151                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2152                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2153                 else
2154                         last_block = first_block +
2155                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2156
2157                 if ((grp == sbi->s_groups_count) &&
2158                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2159                         grp = i;
2160
2161                 block_bitmap = ext4_block_bitmap(sb, gdp);
2162                 if (block_bitmap < first_block || block_bitmap > last_block) {
2163                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2164                                "Block bitmap for group %u not in group "
2165                                "(block %llu)!", i, block_bitmap);
2166                         return 0;
2167                 }
2168                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2169                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2170                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2171                                "Inode bitmap for group %u not in group "
2172                                "(block %llu)!", i, inode_bitmap);
2173                         return 0;
2174                 }
2175                 inode_table = ext4_inode_table(sb, gdp);
2176                 if (inode_table < first_block ||
2177                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2178                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2179                                "Inode table for group %u not in group "
2180                                "(block %llu)!", i, inode_table);
2181                         return 0;
2182                 }
2183                 ext4_lock_group(sb, i);
2184                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2185                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2186                                  "Checksum for group %u failed (%u!=%u)",
2187                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2188                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2189                         if (!(sb->s_flags & MS_RDONLY)) {
2190                                 ext4_unlock_group(sb, i);
2191                                 return 0;
2192                         }
2193                 }
2194                 ext4_unlock_group(sb, i);
2195                 if (!flexbg_flag)
2196                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2197         }
2198         if (NULL != first_not_zeroed)
2199                 *first_not_zeroed = grp;
2200         return 1;
2201 }
2202
2203 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2204  * the superblock) which were deleted from all directories, but held open by
2205  * a process at the time of a crash.  We walk the list and try to delete these
2206  * inodes at recovery time (only with a read-write filesystem).
2207  *
2208  * In order to keep the orphan inode chain consistent during traversal (in
2209  * case of crash during recovery), we link each inode into the superblock
2210  * orphan list_head and handle it the same way as an inode deletion during
2211  * normal operation (which journals the operations for us).
2212  *
2213  * We only do an iget() and an iput() on each inode, which is very safe if we
2214  * accidentally point at an in-use or already deleted inode.  The worst that
2215  * can happen in this case is that we get a "bit already cleared" message from
2216  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2217  * e2fsck was run on this filesystem, and it must have already done the orphan
2218  * inode cleanup for us, so we can safely abort without any further action.
2219  */
2220 static void ext4_orphan_cleanup(struct super_block *sb,
2221                                 struct ext4_super_block *es)
2222 {
2223         unsigned int s_flags = sb->s_flags;
2224         int nr_orphans = 0, nr_truncates = 0;
2225 #ifdef CONFIG_QUOTA
2226         int i;
2227 #endif
2228         if (!es->s_last_orphan) {
2229                 jbd_debug(4, "no orphan inodes to clean up\n");
2230                 return;
2231         }
2232
2233         if (bdev_read_only(sb->s_bdev)) {
2234                 ext4_msg(sb, KERN_ERR, "write access "
2235                         "unavailable, skipping orphan cleanup");
2236                 return;
2237         }
2238
2239         /* Check if feature set would not allow a r/w mount */
2240         if (!ext4_feature_set_ok(sb, 0)) {
2241                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2242                          "unknown ROCOMPAT features");
2243                 return;
2244         }
2245
2246         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2247                 /* don't clear list on RO mount w/ errors */
2248                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2249                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2250                                   "clearing orphan list.\n");
2251                         es->s_last_orphan = 0;
2252                 }
2253                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2254                 return;
2255         }
2256
2257         if (s_flags & MS_RDONLY) {
2258                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2259                 sb->s_flags &= ~MS_RDONLY;
2260         }
2261 #ifdef CONFIG_QUOTA
2262         /* Needed for iput() to work correctly and not trash data */
2263         sb->s_flags |= MS_ACTIVE;
2264         /* Turn on quotas so that they are updated correctly */
2265         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2266                 if (EXT4_SB(sb)->s_qf_names[i]) {
2267                         int ret = ext4_quota_on_mount(sb, i);
2268                         if (ret < 0)
2269                                 ext4_msg(sb, KERN_ERR,
2270                                         "Cannot turn on journaled "
2271                                         "quota: error %d", ret);
2272                 }
2273         }
2274 #endif
2275
2276         while (es->s_last_orphan) {
2277                 struct inode *inode;
2278
2279                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2280                 if (IS_ERR(inode)) {
2281                         es->s_last_orphan = 0;
2282                         break;
2283                 }
2284
2285                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2286                 dquot_initialize(inode);
2287                 if (inode->i_nlink) {
2288                         if (test_opt(sb, DEBUG))
2289                                 ext4_msg(sb, KERN_DEBUG,
2290                                         "%s: truncating inode %lu to %lld bytes",
2291                                         __func__, inode->i_ino, inode->i_size);
2292                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2293                                   inode->i_ino, inode->i_size);
2294                         inode_lock(inode);
2295                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2296                         ext4_truncate(inode);
2297                         inode_unlock(inode);
2298                         nr_truncates++;
2299                 } else {
2300                         if (test_opt(sb, DEBUG))
2301                                 ext4_msg(sb, KERN_DEBUG,
2302                                         "%s: deleting unreferenced inode %lu",
2303                                         __func__, inode->i_ino);
2304                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2305                                   inode->i_ino);
2306                         nr_orphans++;
2307                 }
2308                 iput(inode);  /* The delete magic happens here! */
2309         }
2310
2311 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2312
2313         if (nr_orphans)
2314                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2315                        PLURAL(nr_orphans));
2316         if (nr_truncates)
2317                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2318                        PLURAL(nr_truncates));
2319 #ifdef CONFIG_QUOTA
2320         /* Turn quotas off */
2321         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2322                 if (sb_dqopt(sb)->files[i])
2323                         dquot_quota_off(sb, i);
2324         }
2325 #endif
2326         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2327 }
2328
2329 /*
2330  * Maximal extent format file size.
2331  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2332  * extent format containers, within a sector_t, and within i_blocks
2333  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2334  * so that won't be a limiting factor.
2335  *
2336  * However there is other limiting factor. We do store extents in the form
2337  * of starting block and length, hence the resulting length of the extent
2338  * covering maximum file size must fit into on-disk format containers as
2339  * well. Given that length is always by 1 unit bigger than max unit (because
2340  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2341  *
2342  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2343  */
2344 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2345 {
2346         loff_t res;
2347         loff_t upper_limit = MAX_LFS_FILESIZE;
2348
2349         /* small i_blocks in vfs inode? */
2350         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2351                 /*
2352                  * CONFIG_LBDAF is not enabled implies the inode
2353                  * i_block represent total blocks in 512 bytes
2354                  * 32 == size of vfs inode i_blocks * 8
2355                  */
2356                 upper_limit = (1LL << 32) - 1;
2357
2358                 /* total blocks in file system block size */
2359                 upper_limit >>= (blkbits - 9);
2360                 upper_limit <<= blkbits;
2361         }
2362
2363         /*
2364          * 32-bit extent-start container, ee_block. We lower the maxbytes
2365          * by one fs block, so ee_len can cover the extent of maximum file
2366          * size
2367          */
2368         res = (1LL << 32) - 1;
2369         res <<= blkbits;
2370
2371         /* Sanity check against vm- & vfs- imposed limits */
2372         if (res > upper_limit)
2373                 res = upper_limit;
2374
2375         return res;
2376 }
2377
2378 /*
2379  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2380  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2381  * We need to be 1 filesystem block less than the 2^48 sector limit.
2382  */
2383 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2384 {
2385         loff_t res = EXT4_NDIR_BLOCKS;
2386         int meta_blocks;
2387         loff_t upper_limit;
2388         /* This is calculated to be the largest file size for a dense, block
2389          * mapped file such that the file's total number of 512-byte sectors,
2390          * including data and all indirect blocks, does not exceed (2^48 - 1).
2391          *
2392          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2393          * number of 512-byte sectors of the file.
2394          */
2395
2396         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2397                 /*
2398                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2399                  * the inode i_block field represents total file blocks in
2400                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2401                  */
2402                 upper_limit = (1LL << 32) - 1;
2403
2404                 /* total blocks in file system block size */
2405                 upper_limit >>= (bits - 9);
2406
2407         } else {
2408                 /*
2409                  * We use 48 bit ext4_inode i_blocks
2410                  * With EXT4_HUGE_FILE_FL set the i_blocks
2411                  * represent total number of blocks in
2412                  * file system block size
2413                  */
2414                 upper_limit = (1LL << 48) - 1;
2415
2416         }
2417
2418         /* indirect blocks */
2419         meta_blocks = 1;
2420         /* double indirect blocks */
2421         meta_blocks += 1 + (1LL << (bits-2));
2422         /* tripple indirect blocks */
2423         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2424
2425         upper_limit -= meta_blocks;
2426         upper_limit <<= bits;
2427
2428         res += 1LL << (bits-2);
2429         res += 1LL << (2*(bits-2));
2430         res += 1LL << (3*(bits-2));
2431         res <<= bits;
2432         if (res > upper_limit)
2433                 res = upper_limit;
2434
2435         if (res > MAX_LFS_FILESIZE)
2436                 res = MAX_LFS_FILESIZE;
2437
2438         return res;
2439 }
2440
2441 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2442                                    ext4_fsblk_t logical_sb_block, int nr)
2443 {
2444         struct ext4_sb_info *sbi = EXT4_SB(sb);
2445         ext4_group_t bg, first_meta_bg;
2446         int has_super = 0;
2447
2448         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2449
2450         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2451                 return logical_sb_block + nr + 1;
2452         bg = sbi->s_desc_per_block * nr;
2453         if (ext4_bg_has_super(sb, bg))
2454                 has_super = 1;
2455
2456         /*
2457          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2458          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2459          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2460          * compensate.
2461          */
2462         if (sb->s_blocksize == 1024 && nr == 0 &&
2463             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2464                 has_super++;
2465
2466         return (has_super + ext4_group_first_block_no(sb, bg));
2467 }
2468
2469 /**
2470  * ext4_get_stripe_size: Get the stripe size.
2471  * @sbi: In memory super block info
2472  *
2473  * If we have specified it via mount option, then
2474  * use the mount option value. If the value specified at mount time is
2475  * greater than the blocks per group use the super block value.
2476  * If the super block value is greater than blocks per group return 0.
2477  * Allocator needs it be less than blocks per group.
2478  *
2479  */
2480 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2481 {
2482         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2483         unsigned long stripe_width =
2484                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2485         int ret;
2486
2487         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2488                 ret = sbi->s_stripe;
2489         else if (stripe_width <= sbi->s_blocks_per_group)
2490                 ret = stripe_width;
2491         else if (stride <= sbi->s_blocks_per_group)
2492                 ret = stride;
2493         else
2494                 ret = 0;
2495
2496         /*
2497          * If the stripe width is 1, this makes no sense and
2498          * we set it to 0 to turn off stripe handling code.
2499          */
2500         if (ret <= 1)
2501                 ret = 0;
2502
2503         return ret;
2504 }
2505
2506 /*
2507  * Check whether this filesystem can be mounted based on
2508  * the features present and the RDONLY/RDWR mount requested.
2509  * Returns 1 if this filesystem can be mounted as requested,
2510  * 0 if it cannot be.
2511  */
2512 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2513 {
2514         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2515                 ext4_msg(sb, KERN_ERR,
2516                         "Couldn't mount because of "
2517                         "unsupported optional features (%x)",
2518                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2519                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2520                 return 0;
2521         }
2522
2523         if (readonly)
2524                 return 1;
2525
2526         if (ext4_has_feature_readonly(sb)) {
2527                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2528                 sb->s_flags |= MS_RDONLY;
2529                 return 1;
2530         }
2531
2532         /* Check that feature set is OK for a read-write mount */
2533         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2534                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2535                          "unsupported optional features (%x)",
2536                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2537                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2538                 return 0;
2539         }
2540         /*
2541          * Large file size enabled file system can only be mounted
2542          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2543          */
2544         if (ext4_has_feature_huge_file(sb)) {
2545                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2546                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2547                                  "cannot be mounted RDWR without "
2548                                  "CONFIG_LBDAF");
2549                         return 0;
2550                 }
2551         }
2552         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2553                 ext4_msg(sb, KERN_ERR,
2554                          "Can't support bigalloc feature without "
2555                          "extents feature\n");
2556                 return 0;
2557         }
2558
2559 #ifndef CONFIG_QUOTA
2560         if (ext4_has_feature_quota(sb) && !readonly) {
2561                 ext4_msg(sb, KERN_ERR,
2562                          "Filesystem with quota feature cannot be mounted RDWR "
2563                          "without CONFIG_QUOTA");
2564                 return 0;
2565         }
2566         if (ext4_has_feature_project(sb) && !readonly) {
2567                 ext4_msg(sb, KERN_ERR,
2568                          "Filesystem with project quota feature cannot be mounted RDWR "
2569                          "without CONFIG_QUOTA");
2570                 return 0;
2571         }
2572 #endif  /* CONFIG_QUOTA */
2573         return 1;
2574 }
2575
2576 /*
2577  * This function is called once a day if we have errors logged
2578  * on the file system
2579  */
2580 static void print_daily_error_info(unsigned long arg)
2581 {
2582         struct super_block *sb = (struct super_block *) arg;
2583         struct ext4_sb_info *sbi;
2584         struct ext4_super_block *es;
2585
2586         sbi = EXT4_SB(sb);
2587         es = sbi->s_es;
2588
2589         if (es->s_error_count)
2590                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2591                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2592                          le32_to_cpu(es->s_error_count));
2593         if (es->s_first_error_time) {
2594                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2595                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2596                        (int) sizeof(es->s_first_error_func),
2597                        es->s_first_error_func,
2598                        le32_to_cpu(es->s_first_error_line));
2599                 if (es->s_first_error_ino)
2600                         printk(": inode %u",
2601                                le32_to_cpu(es->s_first_error_ino));
2602                 if (es->s_first_error_block)
2603                         printk(": block %llu", (unsigned long long)
2604                                le64_to_cpu(es->s_first_error_block));
2605                 printk("\n");
2606         }
2607         if (es->s_last_error_time) {
2608                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2609                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2610                        (int) sizeof(es->s_last_error_func),
2611                        es->s_last_error_func,
2612                        le32_to_cpu(es->s_last_error_line));
2613                 if (es->s_last_error_ino)
2614                         printk(": inode %u",
2615                                le32_to_cpu(es->s_last_error_ino));
2616                 if (es->s_last_error_block)
2617                         printk(": block %llu", (unsigned long long)
2618                                le64_to_cpu(es->s_last_error_block));
2619                 printk("\n");
2620         }
2621         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2622 }
2623
2624 /* Find next suitable group and run ext4_init_inode_table */
2625 static int ext4_run_li_request(struct ext4_li_request *elr)
2626 {
2627         struct ext4_group_desc *gdp = NULL;
2628         ext4_group_t group, ngroups;
2629         struct super_block *sb;
2630         unsigned long timeout = 0;
2631         int ret = 0;
2632
2633         sb = elr->lr_super;
2634         ngroups = EXT4_SB(sb)->s_groups_count;
2635
2636         sb_start_write(sb);
2637         for (group = elr->lr_next_group; group < ngroups; group++) {
2638                 gdp = ext4_get_group_desc(sb, group, NULL);
2639                 if (!gdp) {
2640                         ret = 1;
2641                         break;
2642                 }
2643
2644                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2645                         break;
2646         }
2647
2648         if (group >= ngroups)
2649                 ret = 1;
2650
2651         if (!ret) {
2652                 timeout = jiffies;
2653                 ret = ext4_init_inode_table(sb, group,
2654                                             elr->lr_timeout ? 0 : 1);
2655                 if (elr->lr_timeout == 0) {
2656                         timeout = (jiffies - timeout) *
2657                                   elr->lr_sbi->s_li_wait_mult;
2658                         elr->lr_timeout = timeout;
2659                 }
2660                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2661                 elr->lr_next_group = group + 1;
2662         }
2663         sb_end_write(sb);
2664
2665         return ret;
2666 }
2667
2668 /*
2669  * Remove lr_request from the list_request and free the
2670  * request structure. Should be called with li_list_mtx held
2671  */
2672 static void ext4_remove_li_request(struct ext4_li_request *elr)
2673 {
2674         struct ext4_sb_info *sbi;
2675
2676         if (!elr)
2677                 return;
2678
2679         sbi = elr->lr_sbi;
2680
2681         list_del(&elr->lr_request);
2682         sbi->s_li_request = NULL;
2683         kfree(elr);
2684 }
2685
2686 static void ext4_unregister_li_request(struct super_block *sb)
2687 {
2688         mutex_lock(&ext4_li_mtx);
2689         if (!ext4_li_info) {
2690                 mutex_unlock(&ext4_li_mtx);
2691                 return;
2692         }
2693
2694         mutex_lock(&ext4_li_info->li_list_mtx);
2695         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2696         mutex_unlock(&ext4_li_info->li_list_mtx);
2697         mutex_unlock(&ext4_li_mtx);
2698 }
2699
2700 static struct task_struct *ext4_lazyinit_task;
2701
2702 /*
2703  * This is the function where ext4lazyinit thread lives. It walks
2704  * through the request list searching for next scheduled filesystem.
2705  * When such a fs is found, run the lazy initialization request
2706  * (ext4_rn_li_request) and keep track of the time spend in this
2707  * function. Based on that time we compute next schedule time of
2708  * the request. When walking through the list is complete, compute
2709  * next waking time and put itself into sleep.
2710  */
2711 static int ext4_lazyinit_thread(void *arg)
2712 {
2713         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2714         struct list_head *pos, *n;
2715         struct ext4_li_request *elr;
2716         unsigned long next_wakeup, cur;
2717
2718         BUG_ON(NULL == eli);
2719
2720 cont_thread:
2721         while (true) {
2722                 next_wakeup = MAX_JIFFY_OFFSET;
2723
2724                 mutex_lock(&eli->li_list_mtx);
2725                 if (list_empty(&eli->li_request_list)) {
2726                         mutex_unlock(&eli->li_list_mtx);
2727                         goto exit_thread;
2728                 }
2729
2730                 list_for_each_safe(pos, n, &eli->li_request_list) {
2731                         elr = list_entry(pos, struct ext4_li_request,
2732                                          lr_request);
2733
2734                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2735                                 if (ext4_run_li_request(elr) != 0) {
2736                                         /* error, remove the lazy_init job */
2737                                         ext4_remove_li_request(elr);
2738                                         continue;
2739                                 }
2740                         }
2741
2742                         if (time_before(elr->lr_next_sched, next_wakeup))
2743                                 next_wakeup = elr->lr_next_sched;
2744                 }
2745                 mutex_unlock(&eli->li_list_mtx);
2746
2747                 try_to_freeze();
2748
2749                 cur = jiffies;
2750                 if ((time_after_eq(cur, next_wakeup)) ||
2751                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2752                         cond_resched();
2753                         continue;
2754                 }
2755
2756                 schedule_timeout_interruptible(next_wakeup - cur);
2757
2758                 if (kthread_should_stop()) {
2759                         ext4_clear_request_list();
2760                         goto exit_thread;
2761                 }
2762         }
2763
2764 exit_thread:
2765         /*
2766          * It looks like the request list is empty, but we need
2767          * to check it under the li_list_mtx lock, to prevent any
2768          * additions into it, and of course we should lock ext4_li_mtx
2769          * to atomically free the list and ext4_li_info, because at
2770          * this point another ext4 filesystem could be registering
2771          * new one.
2772          */
2773         mutex_lock(&ext4_li_mtx);
2774         mutex_lock(&eli->li_list_mtx);
2775         if (!list_empty(&eli->li_request_list)) {
2776                 mutex_unlock(&eli->li_list_mtx);
2777                 mutex_unlock(&ext4_li_mtx);
2778                 goto cont_thread;
2779         }
2780         mutex_unlock(&eli->li_list_mtx);
2781         kfree(ext4_li_info);
2782         ext4_li_info = NULL;
2783         mutex_unlock(&ext4_li_mtx);
2784
2785         return 0;
2786 }
2787
2788 static void ext4_clear_request_list(void)
2789 {
2790         struct list_head *pos, *n;
2791         struct ext4_li_request *elr;
2792
2793         mutex_lock(&ext4_li_info->li_list_mtx);
2794         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2795                 elr = list_entry(pos, struct ext4_li_request,
2796                                  lr_request);
2797                 ext4_remove_li_request(elr);
2798         }
2799         mutex_unlock(&ext4_li_info->li_list_mtx);
2800 }
2801
2802 static int ext4_run_lazyinit_thread(void)
2803 {
2804         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2805                                          ext4_li_info, "ext4lazyinit");
2806         if (IS_ERR(ext4_lazyinit_task)) {
2807                 int err = PTR_ERR(ext4_lazyinit_task);
2808                 ext4_clear_request_list();
2809                 kfree(ext4_li_info);
2810                 ext4_li_info = NULL;
2811                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2812                                  "initialization thread\n",
2813                                  err);
2814                 return err;
2815         }
2816         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2817         return 0;
2818 }
2819
2820 /*
2821  * Check whether it make sense to run itable init. thread or not.
2822  * If there is at least one uninitialized inode table, return
2823  * corresponding group number, else the loop goes through all
2824  * groups and return total number of groups.
2825  */
2826 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2827 {
2828         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2829         struct ext4_group_desc *gdp = NULL;
2830
2831         for (group = 0; group < ngroups; group++) {
2832                 gdp = ext4_get_group_desc(sb, group, NULL);
2833                 if (!gdp)
2834                         continue;
2835
2836                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2837                         break;
2838         }
2839
2840         return group;
2841 }
2842
2843 static int ext4_li_info_new(void)
2844 {
2845         struct ext4_lazy_init *eli = NULL;
2846
2847         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2848         if (!eli)
2849                 return -ENOMEM;
2850
2851         INIT_LIST_HEAD(&eli->li_request_list);
2852         mutex_init(&eli->li_list_mtx);
2853
2854         eli->li_state |= EXT4_LAZYINIT_QUIT;
2855
2856         ext4_li_info = eli;
2857
2858         return 0;
2859 }
2860
2861 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2862                                             ext4_group_t start)
2863 {
2864         struct ext4_sb_info *sbi = EXT4_SB(sb);
2865         struct ext4_li_request *elr;
2866
2867         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2868         if (!elr)
2869                 return NULL;
2870
2871         elr->lr_super = sb;
2872         elr->lr_sbi = sbi;
2873         elr->lr_next_group = start;
2874
2875         /*
2876          * Randomize first schedule time of the request to
2877          * spread the inode table initialization requests
2878          * better.
2879          */
2880         elr->lr_next_sched = jiffies + (prandom_u32() %
2881                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2882         return elr;
2883 }
2884
2885 int ext4_register_li_request(struct super_block *sb,
2886                              ext4_group_t first_not_zeroed)
2887 {
2888         struct ext4_sb_info *sbi = EXT4_SB(sb);
2889         struct ext4_li_request *elr = NULL;
2890         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2891         int ret = 0;
2892
2893         mutex_lock(&ext4_li_mtx);
2894         if (sbi->s_li_request != NULL) {
2895                 /*
2896                  * Reset timeout so it can be computed again, because
2897                  * s_li_wait_mult might have changed.
2898                  */
2899                 sbi->s_li_request->lr_timeout = 0;
2900                 goto out;
2901         }
2902
2903         if (first_not_zeroed == ngroups ||
2904             (sb->s_flags & MS_RDONLY) ||
2905             !test_opt(sb, INIT_INODE_TABLE))
2906                 goto out;
2907
2908         elr = ext4_li_request_new(sb, first_not_zeroed);
2909         if (!elr) {
2910                 ret = -ENOMEM;
2911                 goto out;
2912         }
2913
2914         if (NULL == ext4_li_info) {
2915                 ret = ext4_li_info_new();
2916                 if (ret)
2917                         goto out;
2918         }
2919
2920         mutex_lock(&ext4_li_info->li_list_mtx);
2921         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
2922         mutex_unlock(&ext4_li_info->li_list_mtx);
2923
2924         sbi->s_li_request = elr;
2925         /*
2926          * set elr to NULL here since it has been inserted to
2927          * the request_list and the removal and free of it is
2928          * handled by ext4_clear_request_list from now on.
2929          */
2930         elr = NULL;
2931
2932         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
2933                 ret = ext4_run_lazyinit_thread();
2934                 if (ret)
2935                         goto out;
2936         }
2937 out:
2938         mutex_unlock(&ext4_li_mtx);
2939         if (ret)
2940                 kfree(elr);
2941         return ret;
2942 }
2943
2944 /*
2945  * We do not need to lock anything since this is called on
2946  * module unload.
2947  */
2948 static void ext4_destroy_lazyinit_thread(void)
2949 {
2950         /*
2951          * If thread exited earlier
2952          * there's nothing to be done.
2953          */
2954         if (!ext4_li_info || !ext4_lazyinit_task)
2955                 return;
2956
2957         kthread_stop(ext4_lazyinit_task);
2958 }
2959
2960 static int set_journal_csum_feature_set(struct super_block *sb)
2961 {
2962         int ret = 1;
2963         int compat, incompat;
2964         struct ext4_sb_info *sbi = EXT4_SB(sb);
2965
2966         if (ext4_has_metadata_csum(sb)) {
2967                 /* journal checksum v3 */
2968                 compat = 0;
2969                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
2970         } else {
2971                 /* journal checksum v1 */
2972                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
2973                 incompat = 0;
2974         }
2975
2976         jbd2_journal_clear_features(sbi->s_journal,
2977                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2978                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
2979                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
2980         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2981                 ret = jbd2_journal_set_features(sbi->s_journal,
2982                                 compat, 0,
2983                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
2984                                 incompat);
2985         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2986                 ret = jbd2_journal_set_features(sbi->s_journal,
2987                                 compat, 0,
2988                                 incompat);
2989                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2990                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2991         } else {
2992                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2993                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2994         }
2995
2996         return ret;
2997 }
2998
2999 /*
3000  * Note: calculating the overhead so we can be compatible with
3001  * historical BSD practice is quite difficult in the face of
3002  * clusters/bigalloc.  This is because multiple metadata blocks from
3003  * different block group can end up in the same allocation cluster.
3004  * Calculating the exact overhead in the face of clustered allocation
3005  * requires either O(all block bitmaps) in memory or O(number of block
3006  * groups**2) in time.  We will still calculate the superblock for
3007  * older file systems --- and if we come across with a bigalloc file
3008  * system with zero in s_overhead_clusters the estimate will be close to
3009  * correct especially for very large cluster sizes --- but for newer
3010  * file systems, it's better to calculate this figure once at mkfs
3011  * time, and store it in the superblock.  If the superblock value is
3012  * present (even for non-bigalloc file systems), we will use it.
3013  */
3014 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3015                           char *buf)
3016 {
3017         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3018         struct ext4_group_desc  *gdp;
3019         ext4_fsblk_t            first_block, last_block, b;
3020         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3021         int                     s, j, count = 0;
3022
3023         if (!ext4_has_feature_bigalloc(sb))
3024                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3025                         sbi->s_itb_per_group + 2);
3026
3027         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3028                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3029         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3030         for (i = 0; i < ngroups; i++) {
3031                 gdp = ext4_get_group_desc(sb, i, NULL);
3032                 b = ext4_block_bitmap(sb, gdp);
3033                 if (b >= first_block && b <= last_block) {
3034                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3035                         count++;
3036                 }
3037                 b = ext4_inode_bitmap(sb, gdp);
3038                 if (b >= first_block && b <= last_block) {
3039                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3040                         count++;
3041                 }
3042                 b = ext4_inode_table(sb, gdp);
3043                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3044                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3045                                 int c = EXT4_B2C(sbi, b - first_block);
3046                                 ext4_set_bit(c, buf);
3047                                 count++;
3048                         }
3049                 if (i != grp)
3050                         continue;
3051                 s = 0;
3052                 if (ext4_bg_has_super(sb, grp)) {
3053                         ext4_set_bit(s++, buf);
3054                         count++;
3055                 }
3056                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3057                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3058                         count++;
3059                 }
3060         }
3061         if (!count)
3062                 return 0;
3063         return EXT4_CLUSTERS_PER_GROUP(sb) -
3064                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3065 }
3066
3067 /*
3068  * Compute the overhead and stash it in sbi->s_overhead
3069  */
3070 int ext4_calculate_overhead(struct super_block *sb)
3071 {
3072         struct ext4_sb_info *sbi = EXT4_SB(sb);
3073         struct ext4_super_block *es = sbi->s_es;
3074         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3075         ext4_fsblk_t overhead = 0;
3076         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3077
3078         if (!buf)
3079                 return -ENOMEM;
3080
3081         /*
3082          * Compute the overhead (FS structures).  This is constant
3083          * for a given filesystem unless the number of block groups
3084          * changes so we cache the previous value until it does.
3085          */
3086
3087         /*
3088          * All of the blocks before first_data_block are overhead
3089          */
3090         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3091
3092         /*
3093          * Add the overhead found in each block group
3094          */
3095         for (i = 0; i < ngroups; i++) {
3096                 int blks;
3097
3098                 blks = count_overhead(sb, i, buf);
3099                 overhead += blks;
3100                 if (blks)
3101                         memset(buf, 0, PAGE_SIZE);
3102                 cond_resched();
3103         }
3104         /* Add the internal journal blocks as well */
3105         if (sbi->s_journal && !sbi->journal_bdev)
3106                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3107
3108         sbi->s_overhead = overhead;
3109         smp_wmb();
3110         free_page((unsigned long) buf);
3111         return 0;
3112 }
3113
3114 static void ext4_set_resv_clusters(struct super_block *sb)
3115 {
3116         ext4_fsblk_t resv_clusters;
3117         struct ext4_sb_info *sbi = EXT4_SB(sb);
3118
3119         /*
3120          * There's no need to reserve anything when we aren't using extents.
3121          * The space estimates are exact, there are no unwritten extents,
3122          * hole punching doesn't need new metadata... This is needed especially
3123          * to keep ext2/3 backward compatibility.
3124          */
3125         if (!ext4_has_feature_extents(sb))
3126                 return;
3127         /*
3128          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3129          * This should cover the situations where we can not afford to run
3130          * out of space like for example punch hole, or converting
3131          * unwritten extents in delalloc path. In most cases such
3132          * allocation would require 1, or 2 blocks, higher numbers are
3133          * very rare.
3134          */
3135         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3136                          sbi->s_cluster_bits);
3137
3138         do_div(resv_clusters, 50);
3139         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3140
3141         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3142 }
3143
3144 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3145 {
3146         char *orig_data = kstrdup(data, GFP_KERNEL);
3147         struct buffer_head *bh;
3148         struct ext4_super_block *es = NULL;
3149         struct ext4_sb_info *sbi;
3150         ext4_fsblk_t block;
3151         ext4_fsblk_t sb_block = get_sb_block(&data);
3152         ext4_fsblk_t logical_sb_block;
3153         unsigned long offset = 0;
3154         unsigned long journal_devnum = 0;
3155         unsigned long def_mount_opts;
3156         struct inode *root;
3157         const char *descr;
3158         int ret = -ENOMEM;
3159         int blocksize, clustersize;
3160         unsigned int db_count;
3161         unsigned int i;
3162         int needs_recovery, has_huge_files, has_bigalloc;
3163         __u64 blocks_count;
3164         int err = 0;
3165         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3166         ext4_group_t first_not_zeroed;
3167
3168         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3169         if (!sbi)
3170                 goto out_free_orig;
3171
3172         sbi->s_blockgroup_lock =
3173                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3174         if (!sbi->s_blockgroup_lock) {
3175                 kfree(sbi);
3176                 goto out_free_orig;
3177         }
3178         sb->s_fs_info = sbi;
3179         sbi->s_sb = sb;
3180         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3181         sbi->s_sb_block = sb_block;
3182         if (sb->s_bdev->bd_part)
3183                 sbi->s_sectors_written_start =
3184                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3185
3186         /* Cleanup superblock name */
3187         strreplace(sb->s_id, '/', '!');
3188
3189         /* -EINVAL is default */
3190         ret = -EINVAL;
3191         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3192         if (!blocksize) {
3193                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3194                 goto out_fail;
3195         }
3196
3197         /*
3198          * The ext4 superblock will not be buffer aligned for other than 1kB
3199          * block sizes.  We need to calculate the offset from buffer start.
3200          */
3201         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3202                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3203                 offset = do_div(logical_sb_block, blocksize);
3204         } else {
3205                 logical_sb_block = sb_block;
3206         }
3207
3208         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3209                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3210                 goto out_fail;
3211         }
3212         /*
3213          * Note: s_es must be initialized as soon as possible because
3214          *       some ext4 macro-instructions depend on its value
3215          */
3216         es = (struct ext4_super_block *) (bh->b_data + offset);
3217         sbi->s_es = es;
3218         sb->s_magic = le16_to_cpu(es->s_magic);
3219         if (sb->s_magic != EXT4_SUPER_MAGIC)
3220                 goto cantfind_ext4;
3221         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3222
3223         /* Warn if metadata_csum and gdt_csum are both set. */
3224         if (ext4_has_feature_metadata_csum(sb) &&
3225             ext4_has_feature_gdt_csum(sb))
3226                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3227                              "redundant flags; please run fsck.");
3228
3229         /* Check for a known checksum algorithm */
3230         if (!ext4_verify_csum_type(sb, es)) {
3231                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3232                          "unknown checksum algorithm.");
3233                 silent = 1;
3234                 goto cantfind_ext4;
3235         }
3236
3237         /* Load the checksum driver */
3238         if (ext4_has_feature_metadata_csum(sb)) {
3239                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3240                 if (IS_ERR(sbi->s_chksum_driver)) {
3241                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3242                         ret = PTR_ERR(sbi->s_chksum_driver);
3243                         sbi->s_chksum_driver = NULL;
3244                         goto failed_mount;
3245                 }
3246         }
3247
3248         /* Check superblock checksum */
3249         if (!ext4_superblock_csum_verify(sb, es)) {
3250                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3251                          "invalid superblock checksum.  Run e2fsck?");
3252                 silent = 1;
3253                 ret = -EFSBADCRC;
3254                 goto cantfind_ext4;
3255         }
3256
3257         /* Precompute checksum seed for all metadata */
3258         if (ext4_has_feature_csum_seed(sb))
3259                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3260         else if (ext4_has_metadata_csum(sb))
3261                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3262                                                sizeof(es->s_uuid));
3263
3264         /* Set defaults before we parse the mount options */
3265         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3266         set_opt(sb, INIT_INODE_TABLE);
3267         if (def_mount_opts & EXT4_DEFM_DEBUG)
3268                 set_opt(sb, DEBUG);
3269         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3270                 set_opt(sb, GRPID);
3271         if (def_mount_opts & EXT4_DEFM_UID16)
3272                 set_opt(sb, NO_UID32);
3273         /* xattr user namespace & acls are now defaulted on */
3274         set_opt(sb, XATTR_USER);
3275 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3276         set_opt(sb, POSIX_ACL);
3277 #endif
3278         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3279         if (ext4_has_metadata_csum(sb))
3280                 set_opt(sb, JOURNAL_CHECKSUM);
3281
3282         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3283                 set_opt(sb, JOURNAL_DATA);
3284         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3285                 set_opt(sb, ORDERED_DATA);
3286         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3287                 set_opt(sb, WRITEBACK_DATA);
3288
3289         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3290                 set_opt(sb, ERRORS_PANIC);
3291         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3292                 set_opt(sb, ERRORS_CONT);
3293         else
3294                 set_opt(sb, ERRORS_RO);
3295         /* block_validity enabled by default; disable with noblock_validity */
3296         set_opt(sb, BLOCK_VALIDITY);
3297         if (def_mount_opts & EXT4_DEFM_DISCARD)
3298                 set_opt(sb, DISCARD);
3299
3300         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3301         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3302         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3303         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3304         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3305
3306         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3307                 set_opt(sb, BARRIER);
3308
3309         /*
3310          * enable delayed allocation by default
3311          * Use -o nodelalloc to turn it off
3312          */
3313         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3314             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3315                 set_opt(sb, DELALLOC);
3316
3317         /*
3318          * set default s_li_wait_mult for lazyinit, for the case there is
3319          * no mount option specified.
3320          */
3321         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3322
3323         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3324                            &journal_devnum, &journal_ioprio, 0)) {
3325                 ext4_msg(sb, KERN_WARNING,
3326                          "failed to parse options in superblock: %s",
3327                          sbi->s_es->s_mount_opts);
3328         }
3329         sbi->s_def_mount_opt = sbi->s_mount_opt;
3330         if (!parse_options((char *) data, sb, &journal_devnum,
3331                            &journal_ioprio, 0))
3332                 goto failed_mount;
3333
3334         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3335                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3336                             "with data=journal disables delayed "
3337                             "allocation and O_DIRECT support!\n");
3338                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3339                         ext4_msg(sb, KERN_ERR, "can't mount with "
3340                                  "both data=journal and delalloc");
3341                         goto failed_mount;
3342                 }
3343                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3344                         ext4_msg(sb, KERN_ERR, "can't mount with "
3345                                  "both data=journal and dioread_nolock");
3346                         goto failed_mount;
3347                 }
3348                 if (test_opt(sb, DAX)) {
3349                         ext4_msg(sb, KERN_ERR, "can't mount with "
3350                                  "both data=journal and dax");
3351                         goto failed_mount;
3352                 }
3353                 if (test_opt(sb, DELALLOC))
3354                         clear_opt(sb, DELALLOC);
3355         } else {
3356                 sb->s_iflags |= SB_I_CGROUPWB;
3357         }
3358
3359         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3360                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3361
3362         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3363             (ext4_has_compat_features(sb) ||
3364              ext4_has_ro_compat_features(sb) ||
3365              ext4_has_incompat_features(sb)))
3366                 ext4_msg(sb, KERN_WARNING,
3367                        "feature flags set on rev 0 fs, "
3368                        "running e2fsck is recommended");
3369
3370         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3371                 set_opt2(sb, HURD_COMPAT);
3372                 if (ext4_has_feature_64bit(sb)) {
3373                         ext4_msg(sb, KERN_ERR,
3374                                  "The Hurd can't support 64-bit file systems");
3375                         goto failed_mount;
3376                 }
3377         }
3378
3379         if (IS_EXT2_SB(sb)) {
3380                 if (ext2_feature_set_ok(sb))
3381                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3382                                  "using the ext4 subsystem");
3383                 else {
3384                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3385                                  "to feature incompatibilities");
3386                         goto failed_mount;
3387                 }
3388         }
3389
3390         if (IS_EXT3_SB(sb)) {
3391                 if (ext3_feature_set_ok(sb))
3392                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3393                                  "using the ext4 subsystem");
3394                 else {
3395                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3396                                  "to feature incompatibilities");
3397                         goto failed_mount;
3398                 }
3399         }
3400
3401         /*
3402          * Check feature flags regardless of the revision level, since we
3403          * previously didn't change the revision level when setting the flags,
3404          * so there is a chance incompat flags are set on a rev 0 filesystem.
3405          */
3406         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3407                 goto failed_mount;
3408
3409         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3410         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3411             blocksize > EXT4_MAX_BLOCK_SIZE) {
3412                 ext4_msg(sb, KERN_ERR,
3413                        "Unsupported filesystem blocksize %d", blocksize);
3414                 goto failed_mount;
3415         }
3416
3417         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3418                 if (blocksize != PAGE_SIZE) {
3419                         ext4_msg(sb, KERN_ERR,
3420                                         "error: unsupported blocksize for dax");
3421                         goto failed_mount;
3422                 }
3423                 if (!sb->s_bdev->bd_disk->fops->direct_access) {
3424                         ext4_msg(sb, KERN_ERR,
3425                                         "error: device does not support dax");
3426                         goto failed_mount;
3427                 }
3428         }
3429
3430         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3431                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3432                          es->s_encryption_level);
3433                 goto failed_mount;
3434         }
3435
3436         if (sb->s_blocksize != blocksize) {
3437                 /* Validate the filesystem blocksize */
3438                 if (!sb_set_blocksize(sb, blocksize)) {
3439                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3440                                         blocksize);
3441                         goto failed_mount;
3442                 }
3443
3444                 brelse(bh);
3445                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3446                 offset = do_div(logical_sb_block, blocksize);
3447                 bh = sb_bread_unmovable(sb, logical_sb_block);
3448                 if (!bh) {
3449                         ext4_msg(sb, KERN_ERR,
3450                                "Can't read superblock on 2nd try");
3451                         goto failed_mount;
3452                 }
3453                 es = (struct ext4_super_block *)(bh->b_data + offset);
3454                 sbi->s_es = es;
3455                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3456                         ext4_msg(sb, KERN_ERR,
3457                                "Magic mismatch, very weird!");
3458                         goto failed_mount;
3459                 }
3460         }
3461
3462         has_huge_files = ext4_has_feature_huge_file(sb);
3463         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3464                                                       has_huge_files);
3465         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3466
3467         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3468                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3469                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3470         } else {
3471                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3472                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3473                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3474                     (!is_power_of_2(sbi->s_inode_size)) ||
3475                     (sbi->s_inode_size > blocksize)) {
3476                         ext4_msg(sb, KERN_ERR,
3477                                "unsupported inode size: %d",
3478                                sbi->s_inode_size);
3479                         goto failed_mount;
3480                 }
3481                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3482                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3483         }
3484
3485         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3486         if (ext4_has_feature_64bit(sb)) {
3487                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3488                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3489                     !is_power_of_2(sbi->s_desc_size)) {
3490                         ext4_msg(sb, KERN_ERR,
3491                                "unsupported descriptor size %lu",
3492                                sbi->s_desc_size);
3493                         goto failed_mount;
3494                 }
3495         } else
3496                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3497
3498         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3499         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3500         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3501                 goto cantfind_ext4;
3502
3503         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3504         if (sbi->s_inodes_per_block == 0)
3505                 goto cantfind_ext4;
3506         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3507                                         sbi->s_inodes_per_block;
3508         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3509         sbi->s_sbh = bh;
3510         sbi->s_mount_state = le16_to_cpu(es->s_state);
3511         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3512         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3513
3514         for (i = 0; i < 4; i++)
3515                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3516         sbi->s_def_hash_version = es->s_def_hash_version;
3517         if (ext4_has_feature_dir_index(sb)) {
3518                 i = le32_to_cpu(es->s_flags);
3519                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3520                         sbi->s_hash_unsigned = 3;
3521                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3522 #ifdef __CHAR_UNSIGNED__
3523                         if (!(sb->s_flags & MS_RDONLY))
3524                                 es->s_flags |=
3525                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3526                         sbi->s_hash_unsigned = 3;
3527 #else
3528                         if (!(sb->s_flags & MS_RDONLY))
3529                                 es->s_flags |=
3530                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3531 #endif
3532                 }
3533         }
3534
3535         /* Handle clustersize */
3536         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3537         has_bigalloc = ext4_has_feature_bigalloc(sb);
3538         if (has_bigalloc) {
3539                 if (clustersize < blocksize) {
3540                         ext4_msg(sb, KERN_ERR,
3541                                  "cluster size (%d) smaller than "
3542                                  "block size (%d)", clustersize, blocksize);
3543                         goto failed_mount;
3544                 }
3545                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3546                         le32_to_cpu(es->s_log_block_size);
3547                 sbi->s_clusters_per_group =
3548                         le32_to_cpu(es->s_clusters_per_group);
3549                 if (sbi->s_clusters_per_group > blocksize * 8) {
3550                         ext4_msg(sb, KERN_ERR,
3551                                  "#clusters per group too big: %lu",
3552                                  sbi->s_clusters_per_group);
3553                         goto failed_mount;
3554                 }
3555                 if (sbi->s_blocks_per_group !=
3556                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3557                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3558                                  "clusters per group (%lu) inconsistent",
3559                                  sbi->s_blocks_per_group,
3560                                  sbi->s_clusters_per_group);
3561                         goto failed_mount;
3562                 }
3563         } else {
3564                 if (clustersize != blocksize) {
3565                         ext4_warning(sb, "fragment/cluster size (%d) != "
3566                                      "block size (%d)", clustersize,
3567                                      blocksize);
3568                         clustersize = blocksize;
3569                 }
3570                 if (sbi->s_blocks_per_group > blocksize * 8) {
3571                         ext4_msg(sb, KERN_ERR,
3572                                  "#blocks per group too big: %lu",
3573                                  sbi->s_blocks_per_group);
3574                         goto failed_mount;
3575                 }
3576                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3577                 sbi->s_cluster_bits = 0;
3578         }
3579         sbi->s_cluster_ratio = clustersize / blocksize;
3580
3581         if (sbi->s_inodes_per_group > blocksize * 8) {
3582                 ext4_msg(sb, KERN_ERR,
3583                        "#inodes per group too big: %lu",
3584                        sbi->s_inodes_per_group);
3585                 goto failed_mount;
3586         }
3587
3588         /* Do we have standard group size of clustersize * 8 blocks ? */
3589         if (sbi->s_blocks_per_group == clustersize << 3)
3590                 set_opt2(sb, STD_GROUP_SIZE);
3591
3592         /*
3593          * Test whether we have more sectors than will fit in sector_t,
3594          * and whether the max offset is addressable by the page cache.
3595          */
3596         err = generic_check_addressable(sb->s_blocksize_bits,
3597                                         ext4_blocks_count(es));
3598         if (err) {
3599                 ext4_msg(sb, KERN_ERR, "filesystem"
3600                          " too large to mount safely on this system");
3601                 if (sizeof(sector_t) < 8)
3602                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3603                 goto failed_mount;
3604         }
3605
3606         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3607                 goto cantfind_ext4;
3608
3609         /* check blocks count against device size */
3610         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3611         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3612                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3613                        "exceeds size of device (%llu blocks)",
3614                        ext4_blocks_count(es), blocks_count);
3615                 goto failed_mount;
3616         }
3617
3618         /*
3619          * It makes no sense for the first data block to be beyond the end
3620          * of the filesystem.
3621          */
3622         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3623                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3624                          "block %u is beyond end of filesystem (%llu)",
3625                          le32_to_cpu(es->s_first_data_block),
3626                          ext4_blocks_count(es));
3627                 goto failed_mount;
3628         }
3629         blocks_count = (ext4_blocks_count(es) -
3630                         le32_to_cpu(es->s_first_data_block) +
3631                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3632         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3633         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3634                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3635                        "(block count %llu, first data block %u, "
3636                        "blocks per group %lu)", sbi->s_groups_count,
3637                        ext4_blocks_count(es),
3638                        le32_to_cpu(es->s_first_data_block),
3639                        EXT4_BLOCKS_PER_GROUP(sb));
3640                 goto failed_mount;
3641         }
3642         sbi->s_groups_count = blocks_count;
3643         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3644                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3645         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3646                    EXT4_DESC_PER_BLOCK(sb);
3647         sbi->s_group_desc = ext4_kvmalloc(db_count *
3648                                           sizeof(struct buffer_head *),
3649                                           GFP_KERNEL);
3650         if (sbi->s_group_desc == NULL) {
3651                 ext4_msg(sb, KERN_ERR, "not enough memory");
3652                 ret = -ENOMEM;
3653                 goto failed_mount;
3654         }
3655
3656         bgl_lock_init(sbi->s_blockgroup_lock);
3657
3658         for (i = 0; i < db_count; i++) {
3659                 block = descriptor_loc(sb, logical_sb_block, i);
3660                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3661                 if (!sbi->s_group_desc[i]) {
3662                         ext4_msg(sb, KERN_ERR,
3663                                "can't read group descriptor %d", i);
3664                         db_count = i;
3665                         goto failed_mount2;
3666                 }
3667         }
3668         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3669                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3670                 ret = -EFSCORRUPTED;
3671                 goto failed_mount2;
3672         }
3673
3674         sbi->s_gdb_count = db_count;
3675         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3676         spin_lock_init(&sbi->s_next_gen_lock);
3677
3678         setup_timer(&sbi->s_err_report, print_daily_error_info,
3679                 (unsigned long) sb);
3680
3681         /* Register extent status tree shrinker */
3682         if (ext4_es_register_shrinker(sbi))
3683                 goto failed_mount3;
3684
3685         sbi->s_stripe = ext4_get_stripe_size(sbi);
3686         sbi->s_extent_max_zeroout_kb = 32;
3687
3688         /*
3689          * set up enough so that it can read an inode
3690          */
3691         sb->s_op = &ext4_sops;
3692         sb->s_export_op = &ext4_export_ops;
3693         sb->s_xattr = ext4_xattr_handlers;
3694 #ifdef CONFIG_QUOTA
3695         sb->dq_op = &ext4_quota_operations;
3696         if (ext4_has_feature_quota(sb))
3697                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3698         else
3699                 sb->s_qcop = &ext4_qctl_operations;
3700         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3701 #endif
3702         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3703
3704         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3705         mutex_init(&sbi->s_orphan_lock);
3706
3707         sb->s_root = NULL;
3708
3709         needs_recovery = (es->s_last_orphan != 0 ||
3710                           ext4_has_feature_journal_needs_recovery(sb));
3711
3712         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3713                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3714                         goto failed_mount3a;
3715
3716         /*
3717          * The first inode we look at is the journal inode.  Don't try
3718          * root first: it may be modified in the journal!
3719          */
3720         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3721                 if (ext4_load_journal(sb, es, journal_devnum))
3722                         goto failed_mount3a;
3723         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3724                    ext4_has_feature_journal_needs_recovery(sb)) {
3725                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3726                        "suppressed and not mounted read-only");
3727                 goto failed_mount_wq;
3728         } else {
3729                 /* Nojournal mode, all journal mount options are illegal */
3730                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3731                         ext4_msg(sb, KERN_ERR, "can't mount with "
3732                                  "journal_checksum, fs mounted w/o journal");
3733                         goto failed_mount_wq;
3734                 }
3735                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3736                         ext4_msg(sb, KERN_ERR, "can't mount with "
3737                                  "journal_async_commit, fs mounted w/o journal");
3738                         goto failed_mount_wq;
3739                 }
3740                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3741                         ext4_msg(sb, KERN_ERR, "can't mount with "
3742                                  "commit=%lu, fs mounted w/o journal",
3743                                  sbi->s_commit_interval / HZ);
3744                         goto failed_mount_wq;
3745                 }
3746                 if (EXT4_MOUNT_DATA_FLAGS &
3747                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3748                         ext4_msg(sb, KERN_ERR, "can't mount with "
3749                                  "data=, fs mounted w/o journal");
3750                         goto failed_mount_wq;
3751                 }
3752                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3753                 clear_opt(sb, JOURNAL_CHECKSUM);
3754                 clear_opt(sb, DATA_FLAGS);
3755                 sbi->s_journal = NULL;
3756                 needs_recovery = 0;
3757                 goto no_journal;
3758         }
3759
3760         if (ext4_has_feature_64bit(sb) &&
3761             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3762                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3763                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3764                 goto failed_mount_wq;
3765         }
3766
3767         if (!set_journal_csum_feature_set(sb)) {
3768                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3769                          "feature set");
3770                 goto failed_mount_wq;
3771         }
3772
3773         /* We have now updated the journal if required, so we can
3774          * validate the data journaling mode. */
3775         switch (test_opt(sb, DATA_FLAGS)) {
3776         case 0:
3777                 /* No mode set, assume a default based on the journal
3778                  * capabilities: ORDERED_DATA if the journal can
3779                  * cope, else JOURNAL_DATA
3780                  */
3781                 if (jbd2_journal_check_available_features
3782                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3783                         set_opt(sb, ORDERED_DATA);
3784                 else
3785                         set_opt(sb, JOURNAL_DATA);
3786                 break;
3787
3788         case EXT4_MOUNT_ORDERED_DATA:
3789         case EXT4_MOUNT_WRITEBACK_DATA:
3790                 if (!jbd2_journal_check_available_features
3791                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3792                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3793                                "requested data journaling mode");
3794                         goto failed_mount_wq;
3795                 }
3796         default:
3797                 break;
3798         }
3799         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3800
3801         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3802
3803 no_journal:
3804         sbi->s_mb_cache = ext4_xattr_create_cache();
3805         if (!sbi->s_mb_cache) {
3806                 ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
3807                 goto failed_mount_wq;
3808         }
3809
3810         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
3811             (blocksize != PAGE_CACHE_SIZE)) {
3812                 ext4_msg(sb, KERN_ERR,
3813                          "Unsupported blocksize for fs encryption");
3814                 goto failed_mount_wq;
3815         }
3816
3817         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
3818             !ext4_has_feature_encrypt(sb)) {
3819                 ext4_set_feature_encrypt(sb);
3820                 ext4_commit_super(sb, 1);
3821         }
3822
3823         /*
3824          * Get the # of file system overhead blocks from the
3825          * superblock if present.
3826          */
3827         if (es->s_overhead_clusters)
3828                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3829         else {
3830                 err = ext4_calculate_overhead(sb);
3831                 if (err)
3832                         goto failed_mount_wq;
3833         }
3834
3835         /*
3836          * The maximum number of concurrent works can be high and
3837          * concurrency isn't really necessary.  Limit it to 1.
3838          */
3839         EXT4_SB(sb)->rsv_conversion_wq =
3840                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3841         if (!EXT4_SB(sb)->rsv_conversion_wq) {
3842                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3843                 ret = -ENOMEM;
3844                 goto failed_mount4;
3845         }
3846
3847         /*
3848          * The jbd2_journal_load will have done any necessary log recovery,
3849          * so we can safely mount the rest of the filesystem now.
3850          */
3851
3852         root = ext4_iget(sb, EXT4_ROOT_INO);
3853         if (IS_ERR(root)) {
3854                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3855                 ret = PTR_ERR(root);
3856                 root = NULL;
3857                 goto failed_mount4;
3858         }
3859         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3860                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3861                 iput(root);
3862                 goto failed_mount4;
3863         }
3864         sb->s_root = d_make_root(root);
3865         if (!sb->s_root) {
3866                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3867                 ret = -ENOMEM;
3868                 goto failed_mount4;
3869         }
3870
3871         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3872                 sb->s_flags |= MS_RDONLY;
3873
3874         /* determine the minimum size of new large inodes, if present */
3875         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3876                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3877                                                      EXT4_GOOD_OLD_INODE_SIZE;
3878                 if (ext4_has_feature_extra_isize(sb)) {
3879                         if (sbi->s_want_extra_isize <
3880                             le16_to_cpu(es->s_want_extra_isize))
3881                                 sbi->s_want_extra_isize =
3882                                         le16_to_cpu(es->s_want_extra_isize);
3883                         if (sbi->s_want_extra_isize <
3884                             le16_to_cpu(es->s_min_extra_isize))
3885                                 sbi->s_want_extra_isize =
3886                                         le16_to_cpu(es->s_min_extra_isize);
3887                 }
3888         }
3889         /* Check if enough inode space is available */
3890         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3891                                                         sbi->s_inode_size) {
3892                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3893                                                        EXT4_GOOD_OLD_INODE_SIZE;
3894                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3895                          "available");
3896         }
3897
3898         ext4_set_resv_clusters(sb);
3899
3900         err = ext4_setup_system_zone(sb);
3901         if (err) {
3902                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3903                          "zone (%d)", err);
3904                 goto failed_mount4a;
3905         }
3906
3907         ext4_ext_init(sb);
3908         err = ext4_mb_init(sb);
3909         if (err) {
3910                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3911                          err);
3912                 goto failed_mount5;
3913         }
3914
3915         block = ext4_count_free_clusters(sb);
3916         ext4_free_blocks_count_set(sbi->s_es,
3917                                    EXT4_C2B(sbi, block));
3918         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
3919                                   GFP_KERNEL);
3920         if (!err) {
3921                 unsigned long freei = ext4_count_free_inodes(sb);
3922                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
3923                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
3924                                           GFP_KERNEL);
3925         }
3926         if (!err)
3927                 err = percpu_counter_init(&sbi->s_dirs_counter,
3928                                           ext4_count_dirs(sb), GFP_KERNEL);
3929         if (!err)
3930                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
3931                                           GFP_KERNEL);
3932         if (err) {
3933                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3934                 goto failed_mount6;
3935         }
3936
3937         if (ext4_has_feature_flex_bg(sb))
3938                 if (!ext4_fill_flex_info(sb)) {
3939                         ext4_msg(sb, KERN_ERR,
3940                                "unable to initialize "
3941                                "flex_bg meta info!");
3942                         goto failed_mount6;
3943                 }
3944
3945         err = ext4_register_li_request(sb, first_not_zeroed);
3946         if (err)
3947                 goto failed_mount6;
3948
3949         err = ext4_register_sysfs(sb);
3950         if (err)
3951                 goto failed_mount7;
3952
3953 #ifdef CONFIG_QUOTA
3954         /* Enable quota usage during mount. */
3955         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
3956                 err = ext4_enable_quotas(sb);
3957                 if (err)
3958                         goto failed_mount8;
3959         }
3960 #endif  /* CONFIG_QUOTA */
3961
3962         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3963         ext4_orphan_cleanup(sb, es);
3964         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3965         if (needs_recovery) {
3966                 ext4_msg(sb, KERN_INFO, "recovery complete");
3967                 ext4_mark_recovery_complete(sb, es);
3968         }
3969         if (EXT4_SB(sb)->s_journal) {
3970                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3971                         descr = " journalled data mode";
3972                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3973                         descr = " ordered data mode";
3974                 else
3975                         descr = " writeback data mode";
3976         } else
3977                 descr = "out journal";
3978
3979         if (test_opt(sb, DISCARD)) {
3980                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
3981                 if (!blk_queue_discard(q))
3982                         ext4_msg(sb, KERN_WARNING,
3983                                  "mounting with \"discard\" option, but "
3984                                  "the device does not support discard");
3985         }
3986
3987         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
3988                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3989                          "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3990                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3991
3992         if (es->s_error_count)
3993                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3994
3995         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
3996         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
3997         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
3998         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
3999
4000         kfree(orig_data);
4001         return 0;
4002
4003 cantfind_ext4:
4004         if (!silent)
4005                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4006         goto failed_mount;
4007
4008 #ifdef CONFIG_QUOTA
4009 failed_mount8:
4010         ext4_unregister_sysfs(sb);
4011 #endif
4012 failed_mount7:
4013         ext4_unregister_li_request(sb);
4014 failed_mount6:
4015         ext4_mb_release(sb);
4016         if (sbi->s_flex_groups)
4017                 kvfree(sbi->s_flex_groups);
4018         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4019         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4020         percpu_counter_destroy(&sbi->s_dirs_counter);
4021         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4022 failed_mount5:
4023         ext4_ext_release(sb);
4024         ext4_release_system_zone(sb);
4025 failed_mount4a:
4026         dput(sb->s_root);
4027         sb->s_root = NULL;
4028 failed_mount4:
4029         ext4_msg(sb, KERN_ERR, "mount failed");
4030         if (EXT4_SB(sb)->rsv_conversion_wq)
4031                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4032 failed_mount_wq:
4033         if (sbi->s_mb_cache) {
4034                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
4035                 sbi->s_mb_cache = NULL;
4036         }
4037         if (sbi->s_journal) {
4038                 jbd2_journal_destroy(sbi->s_journal);
4039                 sbi->s_journal = NULL;
4040         }
4041 failed_mount3a:
4042         ext4_es_unregister_shrinker(sbi);
4043 failed_mount3:
4044         del_timer_sync(&sbi->s_err_report);
4045         if (sbi->s_mmp_tsk)
4046                 kthread_stop(sbi->s_mmp_tsk);
4047 failed_mount2:
4048         for (i = 0; i < db_count; i++)
4049                 brelse(sbi->s_group_desc[i]);
4050         kvfree(sbi->s_group_desc);
4051 failed_mount:
4052         if (sbi->s_chksum_driver)
4053                 crypto_free_shash(sbi->s_chksum_driver);
4054 #ifdef CONFIG_QUOTA
4055         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4056                 kfree(sbi->s_qf_names[i]);
4057 #endif
4058         ext4_blkdev_remove(sbi);
4059         brelse(bh);
4060 out_fail:
4061         sb->s_fs_info = NULL;
4062         kfree(sbi->s_blockgroup_lock);
4063         kfree(sbi);
4064 out_free_orig:
4065         kfree(orig_data);
4066         return err ? err : ret;
4067 }
4068
4069 /*
4070  * Setup any per-fs journal parameters now.  We'll do this both on
4071  * initial mount, once the journal has been initialised but before we've
4072  * done any recovery; and again on any subsequent remount.
4073  */
4074 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4075 {
4076         struct ext4_sb_info *sbi = EXT4_SB(sb);
4077
4078         journal->j_commit_interval = sbi->s_commit_interval;
4079         journal->j_min_batch_time = sbi->s_min_batch_time;
4080         journal->j_max_batch_time = sbi->s_max_batch_time;
4081
4082         write_lock(&journal->j_state_lock);
4083         if (test_opt(sb, BARRIER))
4084                 journal->j_flags |= JBD2_BARRIER;
4085         else
4086                 journal->j_flags &= ~JBD2_BARRIER;
4087         if (test_opt(sb, DATA_ERR_ABORT))
4088                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4089         else
4090                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4091         write_unlock(&journal->j_state_lock);
4092 }
4093
4094 static journal_t *ext4_get_journal(struct super_block *sb,
4095                                    unsigned int journal_inum)
4096 {
4097         struct inode *journal_inode;
4098         journal_t *journal;
4099
4100         BUG_ON(!ext4_has_feature_journal(sb));
4101
4102         /* First, test for the existence of a valid inode on disk.  Bad
4103          * things happen if we iget() an unused inode, as the subsequent
4104          * iput() will try to delete it. */
4105
4106         journal_inode = ext4_iget(sb, journal_inum);
4107         if (IS_ERR(journal_inode)) {
4108                 ext4_msg(sb, KERN_ERR, "no journal found");
4109                 return NULL;
4110         }
4111         if (!journal_inode->i_nlink) {
4112                 make_bad_inode(journal_inode);
4113                 iput(journal_inode);
4114                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4115                 return NULL;
4116         }
4117
4118         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4119                   journal_inode, journal_inode->i_size);
4120         if (!S_ISREG(journal_inode->i_mode)) {
4121                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4122                 iput(journal_inode);
4123                 return NULL;
4124         }
4125
4126         journal = jbd2_journal_init_inode(journal_inode);
4127         if (!journal) {
4128                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4129                 iput(journal_inode);
4130                 return NULL;
4131         }
4132         journal->j_private = sb;
4133         ext4_init_journal_params(sb, journal);
4134         return journal;
4135 }
4136
4137 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4138                                        dev_t j_dev)
4139 {
4140         struct buffer_head *bh;
4141         journal_t *journal;
4142         ext4_fsblk_t start;
4143         ext4_fsblk_t len;
4144         int hblock, blocksize;
4145         ext4_fsblk_t sb_block;
4146         unsigned long offset;
4147         struct ext4_super_block *es;
4148         struct block_device *bdev;
4149
4150         BUG_ON(!ext4_has_feature_journal(sb));
4151
4152         bdev = ext4_blkdev_get(j_dev, sb);
4153         if (bdev == NULL)
4154                 return NULL;
4155
4156         blocksize = sb->s_blocksize;
4157         hblock = bdev_logical_block_size(bdev);
4158         if (blocksize < hblock) {
4159                 ext4_msg(sb, KERN_ERR,
4160                         "blocksize too small for journal device");
4161                 goto out_bdev;
4162         }
4163
4164         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4165         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4166         set_blocksize(bdev, blocksize);
4167         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4168                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4169                        "external journal");
4170                 goto out_bdev;
4171         }
4172
4173         es = (struct ext4_super_block *) (bh->b_data + offset);
4174         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4175             !(le32_to_cpu(es->s_feature_incompat) &
4176               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4177                 ext4_msg(sb, KERN_ERR, "external journal has "
4178                                         "bad superblock");
4179                 brelse(bh);
4180                 goto out_bdev;
4181         }
4182
4183         if ((le32_to_cpu(es->s_feature_ro_compat) &
4184              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4185             es->s_checksum != ext4_superblock_csum(sb, es)) {
4186                 ext4_msg(sb, KERN_ERR, "external journal has "
4187                                        "corrupt superblock");
4188                 brelse(bh);
4189                 goto out_bdev;
4190         }
4191
4192         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4193                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4194                 brelse(bh);
4195                 goto out_bdev;
4196         }
4197
4198         len = ext4_blocks_count(es);
4199         start = sb_block + 1;
4200         brelse(bh);     /* we're done with the superblock */
4201
4202         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4203                                         start, len, blocksize);
4204         if (!journal) {
4205                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4206                 goto out_bdev;
4207         }
4208         journal->j_private = sb;
4209         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4210         wait_on_buffer(journal->j_sb_buffer);
4211         if (!buffer_uptodate(journal->j_sb_buffer)) {
4212                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4213                 goto out_journal;
4214         }
4215         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4216                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4217                                         "user (unsupported) - %d",
4218                         be32_to_cpu(journal->j_superblock->s_nr_users));
4219                 goto out_journal;
4220         }
4221         EXT4_SB(sb)->journal_bdev = bdev;
4222         ext4_init_journal_params(sb, journal);
4223         return journal;
4224
4225 out_journal:
4226         jbd2_journal_destroy(journal);
4227 out_bdev:
4228         ext4_blkdev_put(bdev);
4229         return NULL;
4230 }
4231
4232 static int ext4_load_journal(struct super_block *sb,
4233                              struct ext4_super_block *es,
4234                              unsigned long journal_devnum)
4235 {
4236         journal_t *journal;
4237         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4238         dev_t journal_dev;
4239         int err = 0;
4240         int really_read_only;
4241
4242         BUG_ON(!ext4_has_feature_journal(sb));
4243
4244         if (journal_devnum &&
4245             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4246                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4247                         "numbers have changed");
4248                 journal_dev = new_decode_dev(journal_devnum);
4249         } else
4250                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4251
4252         really_read_only = bdev_read_only(sb->s_bdev);
4253
4254         /*
4255          * Are we loading a blank journal or performing recovery after a
4256          * crash?  For recovery, we need to check in advance whether we
4257          * can get read-write access to the device.
4258          */
4259         if (ext4_has_feature_journal_needs_recovery(sb)) {
4260                 if (sb->s_flags & MS_RDONLY) {
4261                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4262                                         "required on readonly filesystem");
4263                         if (really_read_only) {
4264                                 ext4_msg(sb, KERN_ERR, "write access "
4265                                         "unavailable, cannot proceed");
4266                                 return -EROFS;
4267                         }
4268                         ext4_msg(sb, KERN_INFO, "write access will "
4269                                "be enabled during recovery");
4270                 }
4271         }
4272
4273         if (journal_inum && journal_dev) {
4274                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4275                        "and inode journals!");
4276                 return -EINVAL;
4277         }
4278
4279         if (journal_inum) {
4280                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4281                         return -EINVAL;
4282         } else {
4283                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4284                         return -EINVAL;
4285         }
4286
4287         if (!(journal->j_flags & JBD2_BARRIER))
4288                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4289
4290         if (!ext4_has_feature_journal_needs_recovery(sb))
4291                 err = jbd2_journal_wipe(journal, !really_read_only);
4292         if (!err) {
4293                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4294                 if (save)
4295                         memcpy(save, ((char *) es) +
4296                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4297                 err = jbd2_journal_load(journal);
4298                 if (save)
4299                         memcpy(((char *) es) + EXT4_S_ERR_START,
4300                                save, EXT4_S_ERR_LEN);
4301                 kfree(save);
4302         }
4303
4304         if (err) {
4305                 ext4_msg(sb, KERN_ERR, "error loading journal");
4306                 jbd2_journal_destroy(journal);
4307                 return err;
4308         }
4309
4310         EXT4_SB(sb)->s_journal = journal;
4311         ext4_clear_journal_err(sb, es);
4312
4313         if (!really_read_only && journal_devnum &&
4314             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4315                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4316
4317                 /* Make sure we flush the recovery flag to disk. */
4318                 ext4_commit_super(sb, 1);
4319         }
4320
4321         return 0;
4322 }
4323
4324 static int ext4_commit_super(struct super_block *sb, int sync)
4325 {
4326         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4327         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4328         int error = 0;
4329
4330         if (!sbh || block_device_ejected(sb))
4331                 return error;
4332         if (buffer_write_io_error(sbh)) {
4333                 /*
4334                  * Oh, dear.  A previous attempt to write the
4335                  * superblock failed.  This could happen because the
4336                  * USB device was yanked out.  Or it could happen to
4337                  * be a transient write error and maybe the block will
4338                  * be remapped.  Nothing we can do but to retry the
4339                  * write and hope for the best.
4340                  */
4341                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4342                        "superblock detected");
4343                 clear_buffer_write_io_error(sbh);
4344                 set_buffer_uptodate(sbh);
4345         }
4346         /*
4347          * If the file system is mounted read-only, don't update the
4348          * superblock write time.  This avoids updating the superblock
4349          * write time when we are mounting the root file system
4350          * read/only but we need to replay the journal; at that point,
4351          * for people who are east of GMT and who make their clock
4352          * tick in localtime for Windows bug-for-bug compatibility,
4353          * the clock is set in the future, and this will cause e2fsck
4354          * to complain and force a full file system check.
4355          */
4356         if (!(sb->s_flags & MS_RDONLY))
4357                 es->s_wtime = cpu_to_le32(get_seconds());
4358         if (sb->s_bdev->bd_part)
4359                 es->s_kbytes_written =
4360                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4361                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4362                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4363         else
4364                 es->s_kbytes_written =
4365                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4366         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4367                 ext4_free_blocks_count_set(es,
4368                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4369                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4370         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4371                 es->s_free_inodes_count =
4372                         cpu_to_le32(percpu_counter_sum_positive(
4373                                 &EXT4_SB(sb)->s_freeinodes_counter));
4374         BUFFER_TRACE(sbh, "marking dirty");
4375         ext4_superblock_csum_set(sb);
4376         mark_buffer_dirty(sbh);
4377         if (sync) {
4378                 error = __sync_dirty_buffer(sbh,
4379                         test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
4380                 if (error)
4381                         return error;
4382
4383                 error = buffer_write_io_error(sbh);
4384                 if (error) {
4385                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4386                                "superblock");
4387                         clear_buffer_write_io_error(sbh);
4388                         set_buffer_uptodate(sbh);
4389                 }
4390         }
4391         return error;
4392 }
4393
4394 /*
4395  * Have we just finished recovery?  If so, and if we are mounting (or
4396  * remounting) the filesystem readonly, then we will end up with a
4397  * consistent fs on disk.  Record that fact.
4398  */
4399 static void ext4_mark_recovery_complete(struct super_block *sb,
4400                                         struct ext4_super_block *es)
4401 {
4402         journal_t *journal = EXT4_SB(sb)->s_journal;
4403
4404         if (!ext4_has_feature_journal(sb)) {
4405                 BUG_ON(journal != NULL);
4406                 return;
4407         }
4408         jbd2_journal_lock_updates(journal);
4409         if (jbd2_journal_flush(journal) < 0)
4410                 goto out;
4411
4412         if (ext4_has_feature_journal_needs_recovery(sb) &&
4413             sb->s_flags & MS_RDONLY) {
4414                 ext4_clear_feature_journal_needs_recovery(sb);
4415                 ext4_commit_super(sb, 1);
4416         }
4417
4418 out:
4419         jbd2_journal_unlock_updates(journal);
4420 }
4421
4422 /*
4423  * If we are mounting (or read-write remounting) a filesystem whose journal
4424  * has recorded an error from a previous lifetime, move that error to the
4425  * main filesystem now.
4426  */
4427 static void ext4_clear_journal_err(struct super_block *sb,
4428                                    struct ext4_super_block *es)
4429 {
4430         journal_t *journal;
4431         int j_errno;
4432         const char *errstr;
4433
4434         BUG_ON(!ext4_has_feature_journal(sb));
4435
4436         journal = EXT4_SB(sb)->s_journal;
4437
4438         /*
4439          * Now check for any error status which may have been recorded in the
4440          * journal by a prior ext4_error() or ext4_abort()
4441          */
4442
4443         j_errno = jbd2_journal_errno(journal);
4444         if (j_errno) {
4445                 char nbuf[16];
4446
4447                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4448                 ext4_warning(sb, "Filesystem error recorded "
4449                              "from previous mount: %s", errstr);
4450                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4451
4452                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4453                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4454                 ext4_commit_super(sb, 1);
4455
4456                 jbd2_journal_clear_err(journal);
4457                 jbd2_journal_update_sb_errno(journal);
4458         }
4459 }
4460
4461 /*
4462  * Force the running and committing transactions to commit,
4463  * and wait on the commit.
4464  */
4465 int ext4_force_commit(struct super_block *sb)
4466 {
4467         journal_t *journal;
4468
4469         if (sb->s_flags & MS_RDONLY)
4470                 return 0;
4471
4472         journal = EXT4_SB(sb)->s_journal;
4473         return ext4_journal_force_commit(journal);
4474 }
4475
4476 static int ext4_sync_fs(struct super_block *sb, int wait)
4477 {
4478         int ret = 0;
4479         tid_t target;
4480         bool needs_barrier = false;
4481         struct ext4_sb_info *sbi = EXT4_SB(sb);
4482
4483         trace_ext4_sync_fs(sb, wait);
4484         flush_workqueue(sbi->rsv_conversion_wq);
4485         /*
4486          * Writeback quota in non-journalled quota case - journalled quota has
4487          * no dirty dquots
4488          */
4489         dquot_writeback_dquots(sb, -1);
4490         /*
4491          * Data writeback is possible w/o journal transaction, so barrier must
4492          * being sent at the end of the function. But we can skip it if
4493          * transaction_commit will do it for us.
4494          */
4495         if (sbi->s_journal) {
4496                 target = jbd2_get_latest_transaction(sbi->s_journal);
4497                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4498                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4499                         needs_barrier = true;
4500
4501                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4502                         if (wait)
4503                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4504                                                            target);
4505                 }
4506         } else if (wait && test_opt(sb, BARRIER))
4507                 needs_barrier = true;
4508         if (needs_barrier) {
4509                 int err;
4510                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4511                 if (!ret)
4512                         ret = err;
4513         }
4514
4515         return ret;
4516 }
4517
4518 /*
4519  * LVM calls this function before a (read-only) snapshot is created.  This
4520  * gives us a chance to flush the journal completely and mark the fs clean.
4521  *
4522  * Note that only this function cannot bring a filesystem to be in a clean
4523  * state independently. It relies on upper layer to stop all data & metadata
4524  * modifications.
4525  */
4526 static int ext4_freeze(struct super_block *sb)
4527 {
4528         int error = 0;
4529         journal_t *journal;
4530
4531         if (sb->s_flags & MS_RDONLY)
4532                 return 0;
4533
4534         journal = EXT4_SB(sb)->s_journal;
4535
4536         if (journal) {
4537                 /* Now we set up the journal barrier. */
4538                 jbd2_journal_lock_updates(journal);
4539
4540                 /*
4541                  * Don't clear the needs_recovery flag if we failed to
4542                  * flush the journal.
4543                  */
4544                 error = jbd2_journal_flush(journal);
4545                 if (error < 0)
4546                         goto out;
4547
4548                 /* Journal blocked and flushed, clear needs_recovery flag. */
4549                 ext4_clear_feature_journal_needs_recovery(sb);
4550         }
4551
4552         error = ext4_commit_super(sb, 1);
4553 out:
4554         if (journal)
4555                 /* we rely on upper layer to stop further updates */
4556                 jbd2_journal_unlock_updates(journal);
4557         return error;
4558 }
4559
4560 /*
4561  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4562  * flag here, even though the filesystem is not technically dirty yet.
4563  */
4564 static int ext4_unfreeze(struct super_block *sb)
4565 {
4566         if (sb->s_flags & MS_RDONLY)
4567                 return 0;
4568
4569         if (EXT4_SB(sb)->s_journal) {
4570                 /* Reset the needs_recovery flag before the fs is unlocked. */
4571                 ext4_set_feature_journal_needs_recovery(sb);
4572         }
4573
4574         ext4_commit_super(sb, 1);
4575         return 0;
4576 }
4577
4578 /*
4579  * Structure to save mount options for ext4_remount's benefit
4580  */
4581 struct ext4_mount_options {
4582         unsigned long s_mount_opt;
4583         unsigned long s_mount_opt2;
4584         kuid_t s_resuid;
4585         kgid_t s_resgid;
4586         unsigned long s_commit_interval;
4587         u32 s_min_batch_time, s_max_batch_time;
4588 #ifdef CONFIG_QUOTA
4589         int s_jquota_fmt;
4590         char *s_qf_names[EXT4_MAXQUOTAS];
4591 #endif
4592 };
4593
4594 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4595 {
4596         struct ext4_super_block *es;
4597         struct ext4_sb_info *sbi = EXT4_SB(sb);
4598         unsigned long old_sb_flags;
4599         struct ext4_mount_options old_opts;
4600         int enable_quota = 0;
4601         ext4_group_t g;
4602         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4603         int err = 0;
4604 #ifdef CONFIG_QUOTA
4605         int i, j;
4606 #endif
4607         char *orig_data = kstrdup(data, GFP_KERNEL);
4608
4609         /* Store the original options */
4610         old_sb_flags = sb->s_flags;
4611         old_opts.s_mount_opt = sbi->s_mount_opt;
4612         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4613         old_opts.s_resuid = sbi->s_resuid;
4614         old_opts.s_resgid = sbi->s_resgid;
4615         old_opts.s_commit_interval = sbi->s_commit_interval;
4616         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4617         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4618 #ifdef CONFIG_QUOTA
4619         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4620         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4621                 if (sbi->s_qf_names[i]) {
4622                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4623                                                          GFP_KERNEL);
4624                         if (!old_opts.s_qf_names[i]) {
4625                                 for (j = 0; j < i; j++)
4626                                         kfree(old_opts.s_qf_names[j]);
4627                                 kfree(orig_data);
4628                                 return -ENOMEM;
4629                         }
4630                 } else
4631                         old_opts.s_qf_names[i] = NULL;
4632 #endif
4633         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4634                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4635
4636         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4637                 err = -EINVAL;
4638                 goto restore_opts;
4639         }
4640
4641         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4642             test_opt(sb, JOURNAL_CHECKSUM)) {
4643                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4644                          "during remount not supported; ignoring");
4645                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4646         }
4647
4648         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4649                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4650                         ext4_msg(sb, KERN_ERR, "can't mount with "
4651                                  "both data=journal and delalloc");
4652                         err = -EINVAL;
4653                         goto restore_opts;
4654                 }
4655                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4656                         ext4_msg(sb, KERN_ERR, "can't mount with "
4657                                  "both data=journal and dioread_nolock");
4658                         err = -EINVAL;
4659                         goto restore_opts;
4660                 }
4661                 if (test_opt(sb, DAX)) {
4662                         ext4_msg(sb, KERN_ERR, "can't mount with "
4663                                  "both data=journal and dax");
4664                         err = -EINVAL;
4665                         goto restore_opts;
4666                 }
4667         }
4668
4669         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4670                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4671                         "dax flag with busy inodes while remounting");
4672                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4673         }
4674
4675         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4676                 ext4_abort(sb, "Abort forced by user");
4677
4678         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4679                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4680
4681         es = sbi->s_es;
4682
4683         if (sbi->s_journal) {
4684                 ext4_init_journal_params(sb, sbi->s_journal);
4685                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4686         }
4687
4688         if (*flags & MS_LAZYTIME)
4689                 sb->s_flags |= MS_LAZYTIME;
4690
4691         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4692                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4693                         err = -EROFS;
4694                         goto restore_opts;
4695                 }
4696
4697                 if (*flags & MS_RDONLY) {
4698                         err = sync_filesystem(sb);
4699                         if (err < 0)
4700                                 goto restore_opts;
4701                         err = dquot_suspend(sb, -1);
4702                         if (err < 0)
4703                                 goto restore_opts;
4704
4705                         /*
4706                          * First of all, the unconditional stuff we have to do
4707                          * to disable replay of the journal when we next remount
4708                          */
4709                         sb->s_flags |= MS_RDONLY;
4710
4711                         /*
4712                          * OK, test if we are remounting a valid rw partition
4713                          * readonly, and if so set the rdonly flag and then
4714                          * mark the partition as valid again.
4715                          */
4716                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4717                             (sbi->s_mount_state & EXT4_VALID_FS))
4718                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4719
4720                         if (sbi->s_journal)
4721                                 ext4_mark_recovery_complete(sb, es);
4722                 } else {
4723                         /* Make sure we can mount this feature set readwrite */
4724                         if (ext4_has_feature_readonly(sb) ||
4725                             !ext4_feature_set_ok(sb, 0)) {
4726                                 err = -EROFS;
4727                                 goto restore_opts;
4728                         }
4729                         /*
4730                          * Make sure the group descriptor checksums
4731                          * are sane.  If they aren't, refuse to remount r/w.
4732                          */
4733                         for (g = 0; g < sbi->s_groups_count; g++) {
4734                                 struct ext4_group_desc *gdp =
4735                                         ext4_get_group_desc(sb, g, NULL);
4736
4737                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4738                                         ext4_msg(sb, KERN_ERR,
4739                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4740                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
4741                                                le16_to_cpu(gdp->bg_checksum));
4742                                         err = -EFSBADCRC;
4743                                         goto restore_opts;
4744                                 }
4745                         }
4746
4747                         /*
4748                          * If we have an unprocessed orphan list hanging
4749                          * around from a previously readonly bdev mount,
4750                          * require a full umount/remount for now.
4751                          */
4752                         if (es->s_last_orphan) {
4753                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4754                                        "remount RDWR because of unprocessed "
4755                                        "orphan inode list.  Please "
4756                                        "umount/remount instead");
4757                                 err = -EINVAL;
4758                                 goto restore_opts;
4759                         }
4760
4761                         /*
4762                          * Mounting a RDONLY partition read-write, so reread
4763                          * and store the current valid flag.  (It may have
4764                          * been changed by e2fsck since we originally mounted
4765                          * the partition.)
4766                          */
4767                         if (sbi->s_journal)
4768                                 ext4_clear_journal_err(sb, es);
4769                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4770                         if (!ext4_setup_super(sb, es, 0))
4771                                 sb->s_flags &= ~MS_RDONLY;
4772                         if (ext4_has_feature_mmp(sb))
4773                                 if (ext4_multi_mount_protect(sb,
4774                                                 le64_to_cpu(es->s_mmp_block))) {
4775                                         err = -EROFS;
4776                                         goto restore_opts;
4777                                 }
4778                         enable_quota = 1;
4779                 }
4780         }
4781
4782         /*
4783          * Reinitialize lazy itable initialization thread based on
4784          * current settings
4785          */
4786         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4787                 ext4_unregister_li_request(sb);
4788         else {
4789                 ext4_group_t first_not_zeroed;
4790                 first_not_zeroed = ext4_has_uninit_itable(sb);
4791                 ext4_register_li_request(sb, first_not_zeroed);
4792         }
4793
4794         ext4_setup_system_zone(sb);
4795         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4796                 ext4_commit_super(sb, 1);
4797
4798 #ifdef CONFIG_QUOTA
4799         /* Release old quota file names */
4800         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4801                 kfree(old_opts.s_qf_names[i]);
4802         if (enable_quota) {
4803                 if (sb_any_quota_suspended(sb))
4804                         dquot_resume(sb, -1);
4805                 else if (ext4_has_feature_quota(sb)) {
4806                         err = ext4_enable_quotas(sb);
4807                         if (err)
4808                                 goto restore_opts;
4809                 }
4810         }
4811 #endif
4812
4813         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
4814         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4815         kfree(orig_data);
4816         return 0;
4817
4818 restore_opts:
4819         sb->s_flags = old_sb_flags;
4820         sbi->s_mount_opt = old_opts.s_mount_opt;
4821         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4822         sbi->s_resuid = old_opts.s_resuid;
4823         sbi->s_resgid = old_opts.s_resgid;
4824         sbi->s_commit_interval = old_opts.s_commit_interval;
4825         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4826         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4827 #ifdef CONFIG_QUOTA
4828         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4829         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
4830                 kfree(sbi->s_qf_names[i]);
4831                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4832         }
4833 #endif
4834         kfree(orig_data);
4835         return err;
4836 }
4837
4838 #ifdef CONFIG_QUOTA
4839 static int ext4_statfs_project(struct super_block *sb,
4840                                kprojid_t projid, struct kstatfs *buf)
4841 {
4842         struct kqid qid;
4843         struct dquot *dquot;
4844         u64 limit;
4845         u64 curblock;
4846
4847         qid = make_kqid_projid(projid);
4848         dquot = dqget(sb, qid);
4849         if (IS_ERR(dquot))
4850                 return PTR_ERR(dquot);
4851         spin_lock(&dq_data_lock);
4852
4853         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
4854                  dquot->dq_dqb.dqb_bsoftlimit :
4855                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
4856         if (limit && buf->f_blocks > limit) {
4857                 curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
4858                 buf->f_blocks = limit;
4859                 buf->f_bfree = buf->f_bavail =
4860                         (buf->f_blocks > curblock) ?
4861                          (buf->f_blocks - curblock) : 0;
4862         }
4863
4864         limit = dquot->dq_dqb.dqb_isoftlimit ?
4865                 dquot->dq_dqb.dqb_isoftlimit :
4866                 dquot->dq_dqb.dqb_ihardlimit;
4867         if (limit && buf->f_files > limit) {
4868                 buf->f_files = limit;
4869                 buf->f_ffree =
4870                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
4871                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
4872         }
4873
4874         spin_unlock(&dq_data_lock);
4875         dqput(dquot);
4876         return 0;
4877 }
4878 #endif
4879
4880 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4881 {
4882         struct super_block *sb = dentry->d_sb;
4883         struct ext4_sb_info *sbi = EXT4_SB(sb);
4884         struct ext4_super_block *es = sbi->s_es;
4885         ext4_fsblk_t overhead = 0, resv_blocks;
4886         u64 fsid;
4887         s64 bfree;
4888         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4889
4890         if (!test_opt(sb, MINIX_DF))
4891                 overhead = sbi->s_overhead;
4892
4893         buf->f_type = EXT4_SUPER_MAGIC;
4894         buf->f_bsize = sb->s_blocksize;
4895         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4896         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4897                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4898         /* prevent underflow in case that few free space is available */
4899         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4900         buf->f_bavail = buf->f_bfree -
4901                         (ext4_r_blocks_count(es) + resv_blocks);
4902         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4903                 buf->f_bavail = 0;
4904         buf->f_files = le32_to_cpu(es->s_inodes_count);
4905         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4906         buf->f_namelen = EXT4_NAME_LEN;
4907         fsid = le64_to_cpup((void *)es->s_uuid) ^
4908                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4909         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4910         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4911
4912 #ifdef CONFIG_QUOTA
4913         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
4914             sb_has_quota_limits_enabled(sb, PRJQUOTA))
4915                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
4916 #endif
4917         return 0;
4918 }
4919
4920 /* Helper function for writing quotas on sync - we need to start transaction
4921  * before quota file is locked for write. Otherwise the are possible deadlocks:
4922  * Process 1                         Process 2
4923  * ext4_create()                     quota_sync()
4924  *   jbd2_journal_start()                  write_dquot()
4925  *   dquot_initialize()                         down(dqio_mutex)
4926  *     down(dqio_mutex)                    jbd2_journal_start()
4927  *
4928  */
4929
4930 #ifdef CONFIG_QUOTA
4931
4932 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4933 {
4934         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4935 }
4936
4937 static int ext4_write_dquot(struct dquot *dquot)
4938 {
4939         int ret, err;
4940         handle_t *handle;
4941         struct inode *inode;
4942
4943         inode = dquot_to_inode(dquot);
4944         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4945                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4946         if (IS_ERR(handle))
4947                 return PTR_ERR(handle);
4948         ret = dquot_commit(dquot);
4949         err = ext4_journal_stop(handle);
4950         if (!ret)
4951                 ret = err;
4952         return ret;
4953 }
4954
4955 static int ext4_acquire_dquot(struct dquot *dquot)
4956 {
4957         int ret, err;
4958         handle_t *handle;
4959
4960         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4961                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4962         if (IS_ERR(handle))
4963                 return PTR_ERR(handle);
4964         ret = dquot_acquire(dquot);
4965         err = ext4_journal_stop(handle);
4966         if (!ret)
4967                 ret = err;
4968         return ret;
4969 }
4970
4971 static int ext4_release_dquot(struct dquot *dquot)
4972 {
4973         int ret, err;
4974         handle_t *handle;
4975
4976         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4977                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4978         if (IS_ERR(handle)) {
4979                 /* Release dquot anyway to avoid endless cycle in dqput() */
4980                 dquot_release(dquot);
4981                 return PTR_ERR(handle);
4982         }
4983         ret = dquot_release(dquot);
4984         err = ext4_journal_stop(handle);
4985         if (!ret)
4986                 ret = err;
4987         return ret;
4988 }
4989
4990 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4991 {
4992         struct super_block *sb = dquot->dq_sb;
4993         struct ext4_sb_info *sbi = EXT4_SB(sb);
4994
4995         /* Are we journaling quotas? */
4996         if (ext4_has_feature_quota(sb) ||
4997             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
4998                 dquot_mark_dquot_dirty(dquot);
4999                 return ext4_write_dquot(dquot);
5000         } else {
5001                 return dquot_mark_dquot_dirty(dquot);
5002         }
5003 }
5004
5005 static int ext4_write_info(struct super_block *sb, int type)
5006 {
5007         int ret, err;
5008         handle_t *handle;
5009
5010         /* Data block + inode block */
5011         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5012         if (IS_ERR(handle))
5013                 return PTR_ERR(handle);
5014         ret = dquot_commit_info(sb, type);
5015         err = ext4_journal_stop(handle);
5016         if (!ret)
5017                 ret = err;
5018         return ret;
5019 }
5020
5021 /*
5022  * Turn on quotas during mount time - we need to find
5023  * the quota file and such...
5024  */
5025 static int ext4_quota_on_mount(struct super_block *sb, int type)
5026 {
5027         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5028                                         EXT4_SB(sb)->s_jquota_fmt, type);
5029 }
5030
5031 /*
5032  * Standard function to be called on quota_on
5033  */
5034 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5035                          struct path *path)
5036 {
5037         int err;
5038
5039         if (!test_opt(sb, QUOTA))
5040                 return -EINVAL;
5041
5042         /* Quotafile not on the same filesystem? */
5043         if (path->dentry->d_sb != sb)
5044                 return -EXDEV;
5045         /* Journaling quota? */
5046         if (EXT4_SB(sb)->s_qf_names[type]) {
5047                 /* Quotafile not in fs root? */
5048                 if (path->dentry->d_parent != sb->s_root)
5049                         ext4_msg(sb, KERN_WARNING,
5050                                 "Quota file not on filesystem root. "
5051                                 "Journaled quota will not work");
5052         }
5053
5054         /*
5055          * When we journal data on quota file, we have to flush journal to see
5056          * all updates to the file when we bypass pagecache...
5057          */
5058         if (EXT4_SB(sb)->s_journal &&
5059             ext4_should_journal_data(d_inode(path->dentry))) {
5060                 /*
5061                  * We don't need to lock updates but journal_flush() could
5062                  * otherwise be livelocked...
5063                  */
5064                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5065                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5066                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5067                 if (err)
5068                         return err;
5069         }
5070
5071         return dquot_quota_on(sb, type, format_id, path);
5072 }
5073
5074 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5075                              unsigned int flags)
5076 {
5077         int err;
5078         struct inode *qf_inode;
5079         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5080                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5081                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5082                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5083         };
5084
5085         BUG_ON(!ext4_has_feature_quota(sb));
5086
5087         if (!qf_inums[type])
5088                 return -EPERM;
5089
5090         qf_inode = ext4_iget(sb, qf_inums[type]);
5091         if (IS_ERR(qf_inode)) {
5092                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5093                 return PTR_ERR(qf_inode);
5094         }
5095
5096         /* Don't account quota for quota files to avoid recursion */
5097         qf_inode->i_flags |= S_NOQUOTA;
5098         err = dquot_enable(qf_inode, type, format_id, flags);
5099         iput(qf_inode);
5100
5101         return err;
5102 }
5103
5104 /* Enable usage tracking for all quota types. */
5105 static int ext4_enable_quotas(struct super_block *sb)
5106 {
5107         int type, err = 0;
5108         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5109                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5110                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5111                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5112         };
5113
5114         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5115         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5116                 if (qf_inums[type]) {
5117                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5118                                                 DQUOT_USAGE_ENABLED);
5119                         if (err) {
5120                                 ext4_warning(sb,
5121                                         "Failed to enable quota tracking "
5122                                         "(type=%d, err=%d). Please run "
5123                                         "e2fsck to fix.", type, err);
5124                                 return err;
5125                         }
5126                 }
5127         }
5128         return 0;
5129 }
5130
5131 static int ext4_quota_off(struct super_block *sb, int type)
5132 {
5133         struct inode *inode = sb_dqopt(sb)->files[type];
5134         handle_t *handle;
5135
5136         /* Force all delayed allocation blocks to be allocated.
5137          * Caller already holds s_umount sem */
5138         if (test_opt(sb, DELALLOC))
5139                 sync_filesystem(sb);
5140
5141         if (!inode)
5142                 goto out;
5143
5144         /* Update modification times of quota files when userspace can
5145          * start looking at them */
5146         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5147         if (IS_ERR(handle))
5148                 goto out;
5149         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5150         ext4_mark_inode_dirty(handle, inode);
5151         ext4_journal_stop(handle);
5152
5153 out:
5154         return dquot_quota_off(sb, type);
5155 }
5156
5157 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5158  * acquiring the locks... As quota files are never truncated and quota code
5159  * itself serializes the operations (and no one else should touch the files)
5160  * we don't have to be afraid of races */
5161 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5162                                size_t len, loff_t off)
5163 {
5164         struct inode *inode = sb_dqopt(sb)->files[type];
5165         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5166         int offset = off & (sb->s_blocksize - 1);
5167         int tocopy;
5168         size_t toread;
5169         struct buffer_head *bh;
5170         loff_t i_size = i_size_read(inode);
5171
5172         if (off > i_size)
5173                 return 0;
5174         if (off+len > i_size)
5175                 len = i_size-off;
5176         toread = len;
5177         while (toread > 0) {
5178                 tocopy = sb->s_blocksize - offset < toread ?
5179                                 sb->s_blocksize - offset : toread;
5180                 bh = ext4_bread(NULL, inode, blk, 0);
5181                 if (IS_ERR(bh))
5182                         return PTR_ERR(bh);
5183                 if (!bh)        /* A hole? */
5184                         memset(data, 0, tocopy);
5185                 else
5186                         memcpy(data, bh->b_data+offset, tocopy);
5187                 brelse(bh);
5188                 offset = 0;
5189                 toread -= tocopy;
5190                 data += tocopy;
5191                 blk++;
5192         }
5193         return len;
5194 }
5195
5196 /* Write to quotafile (we know the transaction is already started and has
5197  * enough credits) */
5198 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5199                                 const char *data, size_t len, loff_t off)
5200 {
5201         struct inode *inode = sb_dqopt(sb)->files[type];
5202         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5203         int err, offset = off & (sb->s_blocksize - 1);
5204         int retries = 0;
5205         struct buffer_head *bh;
5206         handle_t *handle = journal_current_handle();
5207
5208         if (EXT4_SB(sb)->s_journal && !handle) {
5209                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5210                         " cancelled because transaction is not started",
5211                         (unsigned long long)off, (unsigned long long)len);
5212                 return -EIO;
5213         }
5214         /*
5215          * Since we account only one data block in transaction credits,
5216          * then it is impossible to cross a block boundary.
5217          */
5218         if (sb->s_blocksize - offset < len) {
5219                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5220                         " cancelled because not block aligned",
5221                         (unsigned long long)off, (unsigned long long)len);
5222                 return -EIO;
5223         }
5224
5225         do {
5226                 bh = ext4_bread(handle, inode, blk,
5227                                 EXT4_GET_BLOCKS_CREATE |
5228                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5229         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5230                  ext4_should_retry_alloc(inode->i_sb, &retries));
5231         if (IS_ERR(bh))
5232                 return PTR_ERR(bh);
5233         if (!bh)
5234                 goto out;
5235         BUFFER_TRACE(bh, "get write access");
5236         err = ext4_journal_get_write_access(handle, bh);
5237         if (err) {
5238                 brelse(bh);
5239                 return err;
5240         }
5241         lock_buffer(bh);
5242         memcpy(bh->b_data+offset, data, len);
5243         flush_dcache_page(bh->b_page);
5244         unlock_buffer(bh);
5245         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5246         brelse(bh);
5247 out:
5248         if (inode->i_size < off + len) {
5249                 i_size_write(inode, off + len);
5250                 EXT4_I(inode)->i_disksize = inode->i_size;
5251                 ext4_mark_inode_dirty(handle, inode);
5252         }
5253         return len;
5254 }
5255
5256 #endif
5257
5258 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5259                        const char *dev_name, void *data)
5260 {
5261         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5262 }
5263
5264 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5265 static inline void register_as_ext2(void)
5266 {
5267         int err = register_filesystem(&ext2_fs_type);
5268         if (err)
5269                 printk(KERN_WARNING
5270                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5271 }
5272
5273 static inline void unregister_as_ext2(void)
5274 {
5275         unregister_filesystem(&ext2_fs_type);
5276 }
5277
5278 static inline int ext2_feature_set_ok(struct super_block *sb)
5279 {
5280         if (ext4_has_unknown_ext2_incompat_features(sb))
5281                 return 0;
5282         if (sb->s_flags & MS_RDONLY)
5283                 return 1;
5284         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5285                 return 0;
5286         return 1;
5287 }
5288 #else
5289 static inline void register_as_ext2(void) { }
5290 static inline void unregister_as_ext2(void) { }
5291 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5292 #endif
5293
5294 static inline void register_as_ext3(void)
5295 {
5296         int err = register_filesystem(&ext3_fs_type);
5297         if (err)
5298                 printk(KERN_WARNING
5299                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5300 }
5301
5302 static inline void unregister_as_ext3(void)
5303 {
5304         unregister_filesystem(&ext3_fs_type);
5305 }
5306
5307 static inline int ext3_feature_set_ok(struct super_block *sb)
5308 {
5309         if (ext4_has_unknown_ext3_incompat_features(sb))
5310                 return 0;
5311         if (!ext4_has_feature_journal(sb))
5312                 return 0;
5313         if (sb->s_flags & MS_RDONLY)
5314                 return 1;
5315         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5316                 return 0;
5317         return 1;
5318 }
5319
5320 static struct file_system_type ext4_fs_type = {
5321         .owner          = THIS_MODULE,
5322         .name           = "ext4",
5323         .mount          = ext4_mount,
5324         .kill_sb        = kill_block_super,
5325         .fs_flags       = FS_REQUIRES_DEV,
5326 };
5327 MODULE_ALIAS_FS("ext4");
5328
5329 /* Shared across all ext4 file systems */
5330 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5331
5332 static int __init ext4_init_fs(void)
5333 {
5334         int i, err;
5335
5336         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5337         ext4_li_info = NULL;
5338         mutex_init(&ext4_li_mtx);
5339
5340         /* Build-time check for flags consistency */
5341         ext4_check_flag_values();
5342
5343         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5344                 init_waitqueue_head(&ext4__ioend_wq[i]);
5345
5346         err = ext4_init_es();
5347         if (err)
5348                 return err;
5349
5350         err = ext4_init_pageio();
5351         if (err)
5352                 goto out5;
5353
5354         err = ext4_init_system_zone();
5355         if (err)
5356                 goto out4;
5357
5358         err = ext4_init_sysfs();
5359         if (err)
5360                 goto out3;
5361
5362         err = ext4_init_mballoc();
5363         if (err)
5364                 goto out2;
5365         err = init_inodecache();
5366         if (err)
5367                 goto out1;
5368         register_as_ext3();
5369         register_as_ext2();
5370         err = register_filesystem(&ext4_fs_type);
5371         if (err)
5372                 goto out;
5373
5374         return 0;
5375 out:
5376         unregister_as_ext2();
5377         unregister_as_ext3();
5378         destroy_inodecache();
5379 out1:
5380         ext4_exit_mballoc();
5381 out2:
5382         ext4_exit_sysfs();
5383 out3:
5384         ext4_exit_system_zone();
5385 out4:
5386         ext4_exit_pageio();
5387 out5:
5388         ext4_exit_es();
5389
5390         return err;
5391 }
5392
5393 static void __exit ext4_exit_fs(void)
5394 {
5395         ext4_exit_crypto();
5396         ext4_destroy_lazyinit_thread();
5397         unregister_as_ext2();
5398         unregister_as_ext3();
5399         unregister_filesystem(&ext4_fs_type);
5400         destroy_inodecache();
5401         ext4_exit_mballoc();
5402         ext4_exit_sysfs();
5403         ext4_exit_system_zone();
5404         ext4_exit_pageio();
5405         ext4_exit_es();
5406 }
5407
5408 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5409 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5410 MODULE_LICENSE("GPL");
5411 module_init(ext4_init_fs)
5412 module_exit(ext4_exit_fs)