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 int ext4_mballoc_ready;
  59 static struct ratelimit_state ext4_mount_msg_ratelimit;
  60
  61 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  62                              unsigned long journal_devnum);
  63 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  64 static int ext4_commit_super(struct super_block *sb, int sync);
  65 static void ext4_mark_recovery_complete(struct super_block *sb,
  66                                         struct ext4_super_block *es);
  67 static void ext4_clear_journal_err(struct super_block *sb,
  68                                    struct ext4_super_block *es);
  69 static int ext4_sync_fs(struct super_block *sb, int wait);
  70 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  71 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  72 static int ext4_unfreeze(struct super_block *sb);
  73 static int ext4_freeze(struct super_block *sb);
  74 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  75                        const char *dev_name, void *data);
  76 static inline int ext2_feature_set_ok(struct super_block *sb);
  77 static inline int ext3_feature_set_ok(struct super_block *sb);
  78 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  79 static void ext4_destroy_lazyinit_thread(void);
  80 static void ext4_unregister_li_request(struct super_block *sb);
  81 static void ext4_clear_request_list(void);
  82
  83 /*
  84  * Lock ordering
  85  *
  86  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
  87  * i_mmap_rwsem (inode->i_mmap_rwsem)!
  88  *
  89  * page fault path:
  90  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
  91  *   page lock -> i_data_sem (rw)
  92  *
  93  * buffered write path:
  94  * sb_start_write -> i_mutex -> mmap_sem
  95  * sb_start_write -> i_mutex -> transaction start -> page lock ->
  96  *   i_data_sem (rw)
  97  *
  98  * truncate:
  99  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 100  *   i_mmap_rwsem (w) -> page lock
 101  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 102  *   transaction start -> i_data_sem (rw)
 103  *
 104  * direct IO:
 105  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
 106  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
 107  *   transaction start -> i_data_sem (rw)
 108  *
 109  * writepages:
 110  * transaction start -> page lock(s) -> i_data_sem (rw)
 111  */
 112
 113 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 114 static struct file_system_type ext2_fs_type = {
 115         .owner          = THIS_MODULE,
 116         .name           = "ext2",
 117         .mount          = ext4_mount,
 118         .kill_sb        = kill_block_super,
 119         .fs_flags       = FS_REQUIRES_DEV,
 120 };
 121 MODULE_ALIAS_FS("ext2");
 122 MODULE_ALIAS("ext2");
 123 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
 124 #else
 125 #define IS_EXT2_SB(sb) (0)
 126 #endif
 127
 128
 129 static struct file_system_type ext3_fs_type = {
 130         .owner          = THIS_MODULE,
 131         .name           = "ext3",
 132         .mount          = ext4_mount,
 133         .kill_sb        = kill_block_super,
 134         .fs_flags       = FS_REQUIRES_DEV,
 135 };
 136 MODULE_ALIAS_FS("ext3");
 137 MODULE_ALIAS("ext3");
 138 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 139
 140 static int ext4_verify_csum_type(struct super_block *sb,
 141                                  struct ext4_super_block *es)
 142 {
 143         if (!ext4_has_feature_metadata_csum(sb))
 144                 return 1;
 145
 146         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 147 }
 148
 149 static __le32 ext4_superblock_csum(struct super_block *sb,
 150                                    struct ext4_super_block *es)
 151 {
 152         struct ext4_sb_info *sbi = EXT4_SB(sb);
 153         int offset = offsetof(struct ext4_super_block, s_checksum);
 154         __u32 csum;
 155
 156         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 157
 158         return cpu_to_le32(csum);
 159 }
 160
 161 static int ext4_superblock_csum_verify(struct super_block *sb,
 162                                        struct ext4_super_block *es)
 163 {
 164         if (!ext4_has_metadata_csum(sb))
 165                 return 1;
 166
 167         return es->s_checksum == ext4_superblock_csum(sb, es);
 168 }
 169
 170 void ext4_superblock_csum_set(struct super_block *sb)
 171 {
 172         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 173
 174         if (!ext4_has_metadata_csum(sb))
 175                 return;
 176
 177         es->s_checksum = ext4_superblock_csum(sb, es);
 178 }
 179
 180 void *ext4_kvmalloc(size_t size, gfp_t flags)
 181 {
 182         void *ret;
 183
 184         ret = kmalloc(size, flags | __GFP_NOWARN);
 185         if (!ret)
 186                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 187         return ret;
 188 }
 189
 190 void *ext4_kvzalloc(size_t size, gfp_t flags)
 191 {
 192         void *ret;
 193
 194         ret = kzalloc(size, flags | __GFP_NOWARN);
 195         if (!ret)
 196                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 197         return ret;
 198 }
 199
 200 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 201                                struct ext4_group_desc *bg)
 202 {
 203         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 204                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 205                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 206 }
 207
 208 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 209                                struct ext4_group_desc *bg)
 210 {
 211         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 212                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 213                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 214 }
 215
 216 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 217                               struct ext4_group_desc *bg)
 218 {
 219         return le32_to_cpu(bg->bg_inode_table_lo) |
 220                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 221                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 222 }
 223
 224 __u32 ext4_free_group_clusters(struct super_block *sb,
 225                                struct ext4_group_desc *bg)
 226 {
 227         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 228                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 229                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 230 }
 231
 232 __u32 ext4_free_inodes_count(struct super_block *sb,
 233                               struct ext4_group_desc *bg)
 234 {
 235         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 236                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 237                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 238 }
 239
 240 __u32 ext4_used_dirs_count(struct super_block *sb,
 241                               struct ext4_group_desc *bg)
 242 {
 243         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 244                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 245                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 246 }
 247
 248 __u32 ext4_itable_unused_count(struct super_block *sb,
 249                               struct ext4_group_desc *bg)
 250 {
 251         return le16_to_cpu(bg->bg_itable_unused_lo) |
 252                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 253                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 254 }
 255
 256 void ext4_block_bitmap_set(struct super_block *sb,
 257                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 258 {
 259         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 260         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 261                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 262 }
 263
 264 void ext4_inode_bitmap_set(struct super_block *sb,
 265                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 266 {
 267         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 268         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 269                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 270 }
 271
 272 void ext4_inode_table_set(struct super_block *sb,
 273                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 274 {
 275         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 276         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 277                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 278 }
 279
 280 void ext4_free_group_clusters_set(struct super_block *sb,
 281                                   struct ext4_group_desc *bg, __u32 count)
 282 {
 283         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 284         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 285                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 286 }
 287
 288 void ext4_free_inodes_set(struct super_block *sb,
 289                           struct ext4_group_desc *bg, __u32 count)
 290 {
 291         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 292         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 293                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 294 }
 295
 296 void ext4_used_dirs_set(struct super_block *sb,
 297                           struct ext4_group_desc *bg, __u32 count)
 298 {
 299         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 300         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 301                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 302 }
 303
 304 void ext4_itable_unused_set(struct super_block *sb,
 305                           struct ext4_group_desc *bg, __u32 count)
 306 {
 307         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 308         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 309                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 310 }
 311
 312
 313 static void __save_error_info(struct super_block *sb, const char *func,
 314                             unsigned int line)
 315 {
 316         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 317
 318         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 319         if (bdev_read_only(sb->s_bdev))
 320                 return;
 321         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 322         es->s_last_error_time = cpu_to_le32(get_seconds());
 323         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 324         es->s_last_error_line = cpu_to_le32(line);
 325         if (!es->s_first_error_time) {
 326                 es->s_first_error_time = es->s_last_error_time;
 327                 strncpy(es->s_first_error_func, func,
 328                         sizeof(es->s_first_error_func));
 329                 es->s_first_error_line = cpu_to_le32(line);
 330                 es->s_first_error_ino = es->s_last_error_ino;
 331                 es->s_first_error_block = es->s_last_error_block;
 332         }
 333         /*
 334          * Start the daily error reporting function if it hasn't been
 335          * started already
 336          */
 337         if (!es->s_error_count)
 338                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 339         le32_add_cpu(&es->s_error_count, 1);
 340 }
 341
 342 static void save_error_info(struct super_block *sb, const char *func,
 343                             unsigned int line)
 344 {
 345         __save_error_info(sb, func, line);
 346         ext4_commit_super(sb, 1);
 347 }
 348
 349 /*
 350  * The del_gendisk() function uninitializes the disk-specific data
 351  * structures, including the bdi structure, without telling anyone
 352  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 353  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 354  * This is a kludge to prevent these oops until we can put in a proper
 355  * hook in del_gendisk() to inform the VFS and file system layers.
 356  */
 357 static int block_device_ejected(struct super_block *sb)
 358 {
 359         struct inode *bd_inode = sb->s_bdev->bd_inode;
 360         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 361
 362         return bdi->dev == NULL;
 363 }
 364
 365 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 366 {
 367         struct super_block              *sb = journal->j_private;
 368         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 369         int                             error = is_journal_aborted(journal);
 370         struct ext4_journal_cb_entry    *jce;
 371
 372         BUG_ON(txn->t_state == T_FINISHED);
 373         spin_lock(&sbi->s_md_lock);
 374         while (!list_empty(&txn->t_private_list)) {
 375                 jce = list_entry(txn->t_private_list.next,
 376                                  struct ext4_journal_cb_entry, jce_list);
 377                 list_del_init(&jce->jce_list);
 378                 spin_unlock(&sbi->s_md_lock);
 379                 jce->jce_func(sb, jce, error);
 380                 spin_lock(&sbi->s_md_lock);
 381         }
 382         spin_unlock(&sbi->s_md_lock);
 383 }
 384
 385 /* Deal with the reporting of failure conditions on a filesystem such as
 386  * inconsistencies detected or read IO failures.
 387  *
 388  * On ext2, we can store the error state of the filesystem in the
 389  * superblock.  That is not possible on ext4, because we may have other
 390  * write ordering constraints on the superblock which prevent us from
 391  * writing it out straight away; and given that the journal is about to
 392  * be aborted, we can't rely on the current, or future, transactions to
 393  * write out the superblock safely.
 394  *
 395  * We'll just use the jbd2_journal_abort() error code to record an error in
 396  * the journal instead.  On recovery, the journal will complain about
 397  * that error until we've noted it down and cleared it.
 398  */
 399
 400 static void ext4_handle_error(struct super_block *sb)
 401 {
 402         if (sb->s_flags & MS_RDONLY)
 403                 return;
 404
 405         if (!test_opt(sb, ERRORS_CONT)) {
 406                 journal_t *journal = EXT4_SB(sb)->s_journal;
 407
 408                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 409                 if (journal)
 410                         jbd2_journal_abort(journal, -EIO);
 411         }
 412         if (test_opt(sb, ERRORS_RO)) {
 413                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 414                 /*
 415                  * Make sure updated value of ->s_mount_flags will be visible
 416                  * before ->s_flags update
 417                  */
 418                 smp_wmb();
 419                 sb->s_flags |= MS_RDONLY;
 420         }
 421         if (test_opt(sb, ERRORS_PANIC)) {
 422                 if (EXT4_SB(sb)->s_journal &&
 423                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 424                         return;
 425                 panic("EXT4-fs (device %s): panic forced after error\n",
 426                         sb->s_id);
 427         }
 428 }
 429
 430 #define ext4_error_ratelimit(sb)                                        \
 431                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 432                              "EXT4-fs error")
 433
 434 void __ext4_error(struct super_block *sb, const char *function,
 435                   unsigned int line, const char *fmt, ...)
 436 {
 437         struct va_format vaf;
 438         va_list args;
 439
 440         if (ext4_error_ratelimit(sb)) {
 441                 va_start(args, fmt);
 442                 vaf.fmt = fmt;
 443                 vaf.va = &args;
 444                 printk(KERN_CRIT
 445                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 446                        sb->s_id, function, line, current->comm, &vaf);
 447                 va_end(args);
 448         }
 449         save_error_info(sb, function, line);
 450         ext4_handle_error(sb);
 451 }
 452
 453 void __ext4_error_inode(struct inode *inode, const char *function,
 454                         unsigned int line, ext4_fsblk_t block,
 455                         const char *fmt, ...)
 456 {
 457         va_list args;
 458         struct va_format vaf;
 459         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 460
 461         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 462         es->s_last_error_block = cpu_to_le64(block);
 463         if (ext4_error_ratelimit(inode->i_sb)) {
 464                 va_start(args, fmt);
 465                 vaf.fmt = fmt;
 466                 vaf.va = &args;
 467                 if (block)
 468                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 469                                "inode #%lu: block %llu: comm %s: %pV\n",
 470                                inode->i_sb->s_id, function, line, inode->i_ino,
 471                                block, current->comm, &vaf);
 472                 else
 473                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 474                                "inode #%lu: comm %s: %pV\n",
 475                                inode->i_sb->s_id, function, line, inode->i_ino,
 476                                current->comm, &vaf);
 477                 va_end(args);
 478         }
 479         save_error_info(inode->i_sb, function, line);
 480         ext4_handle_error(inode->i_sb);
 481 }
 482
 483 void __ext4_error_file(struct file *file, const char *function,
 484                        unsigned int line, ext4_fsblk_t block,
 485                        const char *fmt, ...)
 486 {
 487         va_list args;
 488         struct va_format vaf;
 489         struct ext4_super_block *es;
 490         struct inode *inode = file_inode(file);
 491         char pathname[80], *path;
 492
 493         es = EXT4_SB(inode->i_sb)->s_es;
 494         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 495         if (ext4_error_ratelimit(inode->i_sb)) {
 496                 path = file_path(file, pathname, sizeof(pathname));
 497                 if (IS_ERR(path))
 498                         path = "(unknown)";
 499                 va_start(args, fmt);
 500                 vaf.fmt = fmt;
 501                 vaf.va = &args;
 502                 if (block)
 503                         printk(KERN_CRIT
 504                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 505                                "block %llu: comm %s: path %s: %pV\n",
 506                                inode->i_sb->s_id, function, line, inode->i_ino,
 507                                block, current->comm, path, &vaf);
 508                 else
 509                         printk(KERN_CRIT
 510                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 511                                "comm %s: path %s: %pV\n",
 512                                inode->i_sb->s_id, function, line, inode->i_ino,
 513                                current->comm, path, &vaf);
 514                 va_end(args);
 515         }
 516         save_error_info(inode->i_sb, function, line);
 517         ext4_handle_error(inode->i_sb);
 518 }
 519
 520 const char *ext4_decode_error(struct super_block *sb, int errno,
 521                               char nbuf[16])
 522 {
 523         char *errstr = NULL;
 524
 525         switch (errno) {
 526         case -EFSCORRUPTED:
 527                 errstr = "Corrupt filesystem";
 528                 break;
 529         case -EFSBADCRC:
 530                 errstr = "Filesystem failed CRC";
 531                 break;
 532         case -EIO:
 533                 errstr = "IO failure";
 534                 break;
 535         case -ENOMEM:
 536                 errstr = "Out of memory";
 537                 break;
 538         case -EROFS:
 539                 if (!sb || (EXT4_SB(sb)->s_journal &&
 540                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 541                         errstr = "Journal has aborted";
 542                 else
 543                         errstr = "Readonly filesystem";
 544                 break;
 545         default:
 546                 /* If the caller passed in an extra buffer for unknown
 547                  * errors, textualise them now.  Else we just return
 548                  * NULL. */
 549                 if (nbuf) {
 550                         /* Check for truncated error codes... */
 551                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 552                                 errstr = nbuf;
 553                 }
 554                 break;
 555         }
 556
 557         return errstr;
 558 }
 559
 560 /* __ext4_std_error decodes expected errors from journaling functions
 561  * automatically and invokes the appropriate error response.  */
 562
 563 void __ext4_std_error(struct super_block *sb, const char *function,
 564                       unsigned int line, int errno)
 565 {
 566         char nbuf[16];
 567         const char *errstr;
 568
 569         /* Special case: if the error is EROFS, and we're not already
 570          * inside a transaction, then there's really no point in logging
 571          * an error. */
 572         if (errno == -EROFS && journal_current_handle() == NULL &&
 573             (sb->s_flags & MS_RDONLY))
 574                 return;
 575
 576         if (ext4_error_ratelimit(sb)) {
 577                 errstr = ext4_decode_error(sb, errno, nbuf);
 578                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 579                        sb->s_id, function, line, errstr);
 580         }
 581
 582         save_error_info(sb, function, line);
 583         ext4_handle_error(sb);
 584 }
 585
 586 /*
 587  * ext4_abort is a much stronger failure handler than ext4_error.  The
 588  * abort function may be used to deal with unrecoverable failures such
 589  * as journal IO errors or ENOMEM at a critical moment in log management.
 590  *
 591  * We unconditionally force the filesystem into an ABORT|READONLY state,
 592  * unless the error response on the fs has been set to panic in which
 593  * case we take the easy way out and panic immediately.
 594  */
 595
 596 void __ext4_abort(struct super_block *sb, const char *function,
 597                 unsigned int line, const char *fmt, ...)
 598 {
 599         va_list args;
 600
 601         save_error_info(sb, function, line);
 602         va_start(args, fmt);
 603         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 604                function, line);
 605         vprintk(fmt, args);
 606         printk("\n");
 607         va_end(args);
 608
 609         if ((sb->s_flags & MS_RDONLY) == 0) {
 610                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 611                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 612                 /*
 613                  * Make sure updated value of ->s_mount_flags will be visible
 614                  * before ->s_flags update
 615                  */
 616                 smp_wmb();
 617                 sb->s_flags |= MS_RDONLY;
 618                 if (EXT4_SB(sb)->s_journal)
 619                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 620                 save_error_info(sb, function, line);
 621         }
 622         if (test_opt(sb, ERRORS_PANIC)) {
 623                 if (EXT4_SB(sb)->s_journal &&
 624                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 625                         return;
 626                 panic("EXT4-fs panic from previous error\n");
 627         }
 628 }
 629
 630 void __ext4_msg(struct super_block *sb,
 631                 const char *prefix, const char *fmt, ...)
 632 {
 633         struct va_format vaf;
 634         va_list args;
 635
 636         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 637                 return;
 638
 639         va_start(args, fmt);
 640         vaf.fmt = fmt;
 641         vaf.va = &args;
 642         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 643         va_end(args);
 644 }
 645
 646 #define ext4_warning_ratelimit(sb)                                      \
 647                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 648                              "EXT4-fs warning")
 649
 650 void __ext4_warning(struct super_block *sb, const char *function,
 651                     unsigned int line, const char *fmt, ...)
 652 {
 653         struct va_format vaf;
 654         va_list args;
 655
 656         if (!ext4_warning_ratelimit(sb))
 657                 return;
 658
 659         va_start(args, fmt);
 660         vaf.fmt = fmt;
 661         vaf.va = &args;
 662         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 663                sb->s_id, function, line, &vaf);
 664         va_end(args);
 665 }
 666
 667 void __ext4_warning_inode(const struct inode *inode, const char *function,
 668                           unsigned int line, const char *fmt, ...)
 669 {
 670         struct va_format vaf;
 671         va_list args;
 672
 673         if (!ext4_warning_ratelimit(inode->i_sb))
 674                 return;
 675
 676         va_start(args, fmt);
 677         vaf.fmt = fmt;
 678         vaf.va = &args;
 679         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 680                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 681                function, line, inode->i_ino, current->comm, &vaf);
 682         va_end(args);
 683 }
 684
 685 void __ext4_grp_locked_error(const char *function, unsigned int line,
 686                              struct super_block *sb, ext4_group_t grp,
 687                              unsigned long ino, ext4_fsblk_t block,
 688                              const char *fmt, ...)
 689 __releases(bitlock)
 690 __acquires(bitlock)
 691 {
 692         struct va_format vaf;
 693         va_list args;
 694         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 695
 696         es->s_last_error_ino = cpu_to_le32(ino);
 697         es->s_last_error_block = cpu_to_le64(block);
 698         __save_error_info(sb, function, line);
 699
 700         if (ext4_error_ratelimit(sb)) {
 701                 va_start(args, fmt);
 702                 vaf.fmt = fmt;
 703                 vaf.va = &args;
 704                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 705                        sb->s_id, function, line, grp);
 706                 if (ino)
 707                         printk(KERN_CONT "inode %lu: ", ino);
 708                 if (block)
 709                         printk(KERN_CONT "block %llu:",
 710                                (unsigned long long) block);
 711                 printk(KERN_CONT "%pV\n", &vaf);
 712                 va_end(args);
 713         }
 714
 715         if (test_opt(sb, ERRORS_CONT)) {
 716                 ext4_commit_super(sb, 0);
 717                 return;
 718         }
 719
 720         ext4_unlock_group(sb, grp);
 721         ext4_handle_error(sb);
 722         /*
 723          * We only get here in the ERRORS_RO case; relocking the group
 724          * may be dangerous, but nothing bad will happen since the
 725          * filesystem will have already been marked read/only and the
 726          * journal has been aborted.  We return 1 as a hint to callers
 727          * who might what to use the return value from
 728          * ext4_grp_locked_error() to distinguish between the
 729          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 730          * aggressively from the ext4 function in question, with a
 731          * more appropriate error code.
 732          */
 733         ext4_lock_group(sb, grp);
 734         return;
 735 }
 736
 737 void ext4_update_dynamic_rev(struct super_block *sb)
 738 {
 739         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 740
 741         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 742                 return;
 743
 744         ext4_warning(sb,
 745                      "updating to rev %d because of new feature flag, "
 746                      "running e2fsck is recommended",
 747                      EXT4_DYNAMIC_REV);
 748
 749         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 750         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 751         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 752         /* leave es->s_feature_*compat flags alone */
 753         /* es->s_uuid will be set by e2fsck if empty */
 754
 755         /*
 756          * The rest of the superblock fields should be zero, and if not it
 757          * means they are likely already in use, so leave them alone.  We
 758          * can leave it up to e2fsck to clean up any inconsistencies there.
 759          */
 760 }
 761
 762 /*
 763  * Open the external journal device
 764  */
 765 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 766 {
 767         struct block_device *bdev;
 768         char b[BDEVNAME_SIZE];
 769
 770         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 771         if (IS_ERR(bdev))
 772                 goto fail;
 773         return bdev;
 774
 775 fail:
 776         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 777                         __bdevname(dev, b), PTR_ERR(bdev));
 778         return NULL;
 779 }
 780
 781 /*
 782  * Release the journal device
 783  */
 784 static void ext4_blkdev_put(struct block_device *bdev)
 785 {
 786         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 787 }
 788
 789 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 790 {
 791         struct block_device *bdev;
 792         bdev = sbi->journal_bdev;
 793         if (bdev) {
 794                 ext4_blkdev_put(bdev);
 795                 sbi->journal_bdev = NULL;
 796         }
 797 }
 798
 799 static inline struct inode *orphan_list_entry(struct list_head *l)
 800 {
 801         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 802 }
 803
 804 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 805 {
 806         struct list_head *l;
 807
 808         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 809                  le32_to_cpu(sbi->s_es->s_last_orphan));
 810
 811         printk(KERN_ERR "sb_info orphan list:\n");
 812         list_for_each(l, &sbi->s_orphan) {
 813                 struct inode *inode = orphan_list_entry(l);
 814                 printk(KERN_ERR "  "
 815                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 816                        inode->i_sb->s_id, inode->i_ino, inode,
 817                        inode->i_mode, inode->i_nlink,
 818                        NEXT_ORPHAN(inode));
 819         }
 820 }
 821
 822 static void ext4_put_super(struct super_block *sb)
 823 {
 824         struct ext4_sb_info *sbi = EXT4_SB(sb);
 825         struct ext4_super_block *es = sbi->s_es;
 826         int i, err;
 827
 828         ext4_unregister_li_request(sb);
 829         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 830
 831         flush_workqueue(sbi->rsv_conversion_wq);
 832         destroy_workqueue(sbi->rsv_conversion_wq);
 833
 834         if (sbi->s_journal) {
 835                 err = jbd2_journal_destroy(sbi->s_journal);
 836                 sbi->s_journal = NULL;
 837                 if (err < 0)
 838                         ext4_abort(sb, "Couldn't clean up the journal");
 839         }
 840
 841         ext4_unregister_sysfs(sb);
 842         ext4_es_unregister_shrinker(sbi);
 843         del_timer_sync(&sbi->s_err_report);
 844         ext4_release_system_zone(sb);
 845         ext4_mb_release(sb);
 846         ext4_ext_release(sb);
 847         ext4_xattr_put_super(sb);
 848
 849         if (!(sb->s_flags & MS_RDONLY)) {
 850                 ext4_clear_feature_journal_needs_recovery(sb);
 851                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 852         }
 853         if (!(sb->s_flags & MS_RDONLY))
 854                 ext4_commit_super(sb, 1);
 855
 856         for (i = 0; i < sbi->s_gdb_count; i++)
 857                 brelse(sbi->s_group_desc[i]);
 858         kvfree(sbi->s_group_desc);
 859         kvfree(sbi->s_flex_groups);
 860         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 861         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 862         percpu_counter_destroy(&sbi->s_dirs_counter);
 863         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 864         brelse(sbi->s_sbh);
 865 #ifdef CONFIG_QUOTA
 866         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 867                 kfree(sbi->s_qf_names[i]);
 868 #endif
 869
 870         /* Debugging code just in case the in-memory inode orphan list
 871          * isn't empty.  The on-disk one can be non-empty if we've
 872          * detected an error and taken the fs readonly, but the
 873          * in-memory list had better be clean by this point. */
 874         if (!list_empty(&sbi->s_orphan))
 875                 dump_orphan_list(sb, sbi);
 876         J_ASSERT(list_empty(&sbi->s_orphan));
 877
 878         sync_blockdev(sb->s_bdev);
 879         invalidate_bdev(sb->s_bdev);
 880         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 881                 /*
 882                  * Invalidate the journal device's buffers.  We don't want them
 883                  * floating about in memory - the physical journal device may
 884                  * hotswapped, and it breaks the `ro-after' testing code.
 885                  */
 886                 sync_blockdev(sbi->journal_bdev);
 887                 invalidate_bdev(sbi->journal_bdev);
 888                 ext4_blkdev_remove(sbi);
 889         }
 890         if (sbi->s_mb_cache) {
 891                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 892                 sbi->s_mb_cache = NULL;
 893         }
 894         if (sbi->s_mmp_tsk)
 895                 kthread_stop(sbi->s_mmp_tsk);
 896         sb->s_fs_info = NULL;
 897         /*
 898          * Now that we are completely done shutting down the
 899          * superblock, we need to actually destroy the kobject.
 900          */
 901         kobject_put(&sbi->s_kobj);
 902         wait_for_completion(&sbi->s_kobj_unregister);
 903         if (sbi->s_chksum_driver)
 904                 crypto_free_shash(sbi->s_chksum_driver);
 905         kfree(sbi->s_blockgroup_lock);
 906         kfree(sbi);
 907 }
 908
 909 static struct kmem_cache *ext4_inode_cachep;
 910
 911 /*
 912  * Called inside transaction, so use GFP_NOFS
 913  */
 914 static struct inode *ext4_alloc_inode(struct super_block *sb)
 915 {
 916         struct ext4_inode_info *ei;
 917
 918         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 919         if (!ei)
 920                 return NULL;
 921
 922         ei->vfs_inode.i_version = 1;
 923         spin_lock_init(&ei->i_raw_lock);
 924         INIT_LIST_HEAD(&ei->i_prealloc_list);
 925         spin_lock_init(&ei->i_prealloc_lock);
 926         ext4_es_init_tree(&ei->i_es_tree);
 927         rwlock_init(&ei->i_es_lock);
 928         INIT_LIST_HEAD(&ei->i_es_list);
 929         ei->i_es_all_nr = 0;
 930         ei->i_es_shk_nr = 0;
 931         ei->i_es_shrink_lblk = 0;
 932         ei->i_reserved_data_blocks = 0;
 933         ei->i_reserved_meta_blocks = 0;
 934         ei->i_allocated_meta_blocks = 0;
 935         ei->i_da_metadata_calc_len = 0;
 936         ei->i_da_metadata_calc_last_lblock = 0;
 937         spin_lock_init(&(ei->i_block_reservation_lock));
 938 #ifdef CONFIG_QUOTA
 939         ei->i_reserved_quota = 0;
 940         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 941 #endif
 942         ei->jinode = NULL;
 943         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 944         spin_lock_init(&ei->i_completed_io_lock);
 945         ei->i_sync_tid = 0;
 946         ei->i_datasync_tid = 0;
 947         atomic_set(&ei->i_ioend_count, 0);
 948         atomic_set(&ei->i_unwritten, 0);
 949         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 950 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 951         ei->i_crypt_info = NULL;
 952 #endif
 953         return &ei->vfs_inode;
 954 }
 955
 956 static int ext4_drop_inode(struct inode *inode)
 957 {
 958         int drop = generic_drop_inode(inode);
 959
 960         trace_ext4_drop_inode(inode, drop);
 961         return drop;
 962 }
 963
 964 static void ext4_i_callback(struct rcu_head *head)
 965 {
 966         struct inode *inode = container_of(head, struct inode, i_rcu);
 967         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 968 }
 969
 970 static void ext4_destroy_inode(struct inode *inode)
 971 {
 972         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 973                 ext4_msg(inode->i_sb, KERN_ERR,
 974                          "Inode %lu (%p): orphan list check failed!",
 975                          inode->i_ino, EXT4_I(inode));
 976                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 977                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 978                                 true);
 979                 dump_stack();
 980         }
 981         call_rcu(&inode->i_rcu, ext4_i_callback);
 982 }
 983
 984 static void init_once(void *foo)
 985 {
 986         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 987
 988         INIT_LIST_HEAD(&ei->i_orphan);
 989         init_rwsem(&ei->xattr_sem);
 990         init_rwsem(&ei->i_data_sem);
 991         init_rwsem(&ei->i_mmap_sem);
 992         inode_init_once(&ei->vfs_inode);
 993 }
 994
 995 static int __init init_inodecache(void)
 996 {
 997         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 998                                              sizeof(struct ext4_inode_info),
 999                                              0, (SLAB_RECLAIM_ACCOUNT|
1000                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1001                                              init_once);
1002         if (ext4_inode_cachep == NULL)
1003                 return -ENOMEM;
1004         return 0;
1005 }
1006
1007 static void destroy_inodecache(void)
1008 {
1009         /*
1010          * Make sure all delayed rcu free inodes are flushed before we
1011          * destroy cache.
1012          */
1013         rcu_barrier();
1014         kmem_cache_destroy(ext4_inode_cachep);
1015 }
1016
1017 void ext4_clear_inode(struct inode *inode)
1018 {
1019         invalidate_inode_buffers(inode);
1020         clear_inode(inode);
1021         dquot_drop(inode);
1022         ext4_discard_preallocations(inode);
1023         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1024         if (EXT4_I(inode)->jinode) {
1025                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1026                                                EXT4_I(inode)->jinode);
1027                 jbd2_free_inode(EXT4_I(inode)->jinode);
1028                 EXT4_I(inode)->jinode = NULL;
1029         }
1030 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1031         if (EXT4_I(inode)->i_crypt_info)
1032                 ext4_free_encryption_info(inode, EXT4_I(inode)->i_crypt_info);
1033 #endif
1034 }
1035
1036 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1037                                         u64 ino, u32 generation)
1038 {
1039         struct inode *inode;
1040
1041         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1042                 return ERR_PTR(-ESTALE);
1043         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1044                 return ERR_PTR(-ESTALE);
1045
1046         /* iget isn't really right if the inode is currently unallocated!!
1047          *
1048          * ext4_read_inode will return a bad_inode if the inode had been
1049          * deleted, so we should be safe.
1050          *
1051          * Currently we don't know the generation for parent directory, so
1052          * a generation of 0 means "accept any"
1053          */
1054         inode = ext4_iget_normal(sb, ino);
1055         if (IS_ERR(inode))
1056                 return ERR_CAST(inode);
1057         if (generation && inode->i_generation != generation) {
1058                 iput(inode);
1059                 return ERR_PTR(-ESTALE);
1060         }
1061
1062         return inode;
1063 }
1064
1065 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1066                                         int fh_len, int fh_type)
1067 {
1068         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1069                                     ext4_nfs_get_inode);
1070 }
1071
1072 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1073                                         int fh_len, int fh_type)
1074 {
1075         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1076                                     ext4_nfs_get_inode);
1077 }
1078
1079 /*
1080  * Try to release metadata pages (indirect blocks, directories) which are
1081  * mapped via the block device.  Since these pages could have journal heads
1082  * which would prevent try_to_free_buffers() from freeing them, we must use
1083  * jbd2 layer's try_to_free_buffers() function to release them.
1084  */
1085 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1086                                  gfp_t wait)
1087 {
1088         journal_t *journal = EXT4_SB(sb)->s_journal;
1089
1090         WARN_ON(PageChecked(page));
1091         if (!page_has_buffers(page))
1092                 return 0;
1093         if (journal)
1094                 return jbd2_journal_try_to_free_buffers(journal, page,
1095                                                 wait & ~__GFP_DIRECT_RECLAIM);
1096         return try_to_free_buffers(page);
1097 }
1098
1099 #ifdef CONFIG_QUOTA
1100 static char *quotatypes[] = INITQFNAMES;
1101 #define QTYPE2NAME(t) (quotatypes[t])
1102
1103 static int ext4_write_dquot(struct dquot *dquot);
1104 static int ext4_acquire_dquot(struct dquot *dquot);
1105 static int ext4_release_dquot(struct dquot *dquot);
1106 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1107 static int ext4_write_info(struct super_block *sb, int type);
1108 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1109                          struct path *path);
1110 static int ext4_quota_off(struct super_block *sb, int type);
1111 static int ext4_quota_on_mount(struct super_block *sb, int type);
1112 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1113                                size_t len, loff_t off);
1114 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1115                                 const char *data, size_t len, loff_t off);
1116 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1117                              unsigned int flags);
1118 static int ext4_enable_quotas(struct super_block *sb);
1119
1120 static struct dquot **ext4_get_dquots(struct inode *inode)
1121 {
1122         return EXT4_I(inode)->i_dquot;
1123 }
1124
1125 static const struct dquot_operations ext4_quota_operations = {
1126         .get_reserved_space = ext4_get_reserved_space,
1127         .write_dquot    = ext4_write_dquot,
1128         .acquire_dquot  = ext4_acquire_dquot,
1129         .release_dquot  = ext4_release_dquot,
1130         .mark_dirty     = ext4_mark_dquot_dirty,
1131         .write_info     = ext4_write_info,
1132         .alloc_dquot    = dquot_alloc,
1133         .destroy_dquot  = dquot_destroy,
1134         .get_projid     = ext4_get_projid,
1135         .get_next_id    = dquot_get_next_id,
1136 };
1137
1138 static const struct quotactl_ops ext4_qctl_operations = {
1139         .quota_on       = ext4_quota_on,
1140         .quota_off      = ext4_quota_off,
1141         .quota_sync     = dquot_quota_sync,
1142         .get_state      = dquot_get_state,
1143         .set_info       = dquot_set_dqinfo,
1144         .get_dqblk      = dquot_get_dqblk,
1145         .set_dqblk      = dquot_set_dqblk
1146 };
1147 #endif
1148
1149 static const struct super_operations ext4_sops = {
1150         .alloc_inode    = ext4_alloc_inode,
1151         .destroy_inode  = ext4_destroy_inode,
1152         .write_inode    = ext4_write_inode,
1153         .dirty_inode    = ext4_dirty_inode,
1154         .drop_inode     = ext4_drop_inode,
1155         .evict_inode    = ext4_evict_inode,
1156         .put_super      = ext4_put_super,
1157         .sync_fs        = ext4_sync_fs,
1158         .freeze_fs      = ext4_freeze,
1159         .unfreeze_fs    = ext4_unfreeze,
1160         .statfs         = ext4_statfs,
1161         .remount_fs     = ext4_remount,
1162         .show_options   = ext4_show_options,
1163 #ifdef CONFIG_QUOTA
1164         .quota_read     = ext4_quota_read,
1165         .quota_write    = ext4_quota_write,
1166         .get_dquots     = ext4_get_dquots,
1167 #endif
1168         .bdev_try_to_free_page = bdev_try_to_free_page,
1169 };
1170
1171 static const struct export_operations ext4_export_ops = {
1172         .fh_to_dentry = ext4_fh_to_dentry,
1173         .fh_to_parent = ext4_fh_to_parent,
1174         .get_parent = ext4_get_parent,
1175 };
1176
1177 enum {
1178         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1179         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1180         Opt_nouid32, Opt_debug, Opt_removed,
1181         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1182         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1183         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1184         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1185         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1186         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1187         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1188         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1189         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1190         Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
1191         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1192         Opt_lazytime, Opt_nolazytime,
1193         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1194         Opt_inode_readahead_blks, Opt_journal_ioprio,
1195         Opt_dioread_nolock, Opt_dioread_lock,
1196         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1197         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1198 };
1199
1200 static const match_table_t tokens = {
1201         {Opt_bsd_df, "bsddf"},
1202         {Opt_minix_df, "minixdf"},
1203         {Opt_grpid, "grpid"},
1204         {Opt_grpid, "bsdgroups"},
1205         {Opt_nogrpid, "nogrpid"},
1206         {Opt_nogrpid, "sysvgroups"},
1207         {Opt_resgid, "resgid=%u"},
1208         {Opt_resuid, "resuid=%u"},
1209         {Opt_sb, "sb=%u"},
1210         {Opt_err_cont, "errors=continue"},
1211         {Opt_err_panic, "errors=panic"},
1212         {Opt_err_ro, "errors=remount-ro"},
1213         {Opt_nouid32, "nouid32"},
1214         {Opt_debug, "debug"},
1215         {Opt_removed, "oldalloc"},
1216         {Opt_removed, "orlov"},
1217         {Opt_user_xattr, "user_xattr"},
1218         {Opt_nouser_xattr, "nouser_xattr"},
1219         {Opt_acl, "acl"},
1220         {Opt_noacl, "noacl"},
1221         {Opt_noload, "norecovery"},
1222         {Opt_noload, "noload"},
1223         {Opt_removed, "nobh"},
1224         {Opt_removed, "bh"},
1225         {Opt_commit, "commit=%u"},
1226         {Opt_min_batch_time, "min_batch_time=%u"},
1227         {Opt_max_batch_time, "max_batch_time=%u"},
1228         {Opt_journal_dev, "journal_dev=%u"},
1229         {Opt_journal_path, "journal_path=%s"},
1230         {Opt_journal_checksum, "journal_checksum"},
1231         {Opt_nojournal_checksum, "nojournal_checksum"},
1232         {Opt_journal_async_commit, "journal_async_commit"},
1233         {Opt_abort, "abort"},
1234         {Opt_data_journal, "data=journal"},
1235         {Opt_data_ordered, "data=ordered"},
1236         {Opt_data_writeback, "data=writeback"},
1237         {Opt_data_err_abort, "data_err=abort"},
1238         {Opt_data_err_ignore, "data_err=ignore"},
1239         {Opt_offusrjquota, "usrjquota="},
1240         {Opt_usrjquota, "usrjquota=%s"},
1241         {Opt_offgrpjquota, "grpjquota="},
1242         {Opt_grpjquota, "grpjquota=%s"},
1243         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1244         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1245         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1246         {Opt_grpquota, "grpquota"},
1247         {Opt_noquota, "noquota"},
1248         {Opt_quota, "quota"},
1249         {Opt_usrquota, "usrquota"},
1250         {Opt_barrier, "barrier=%u"},
1251         {Opt_barrier, "barrier"},
1252         {Opt_nobarrier, "nobarrier"},
1253         {Opt_i_version, "i_version"},
1254         {Opt_dax, "dax"},
1255         {Opt_stripe, "stripe=%u"},
1256         {Opt_delalloc, "delalloc"},
1257         {Opt_lazytime, "lazytime"},
1258         {Opt_nolazytime, "nolazytime"},
1259         {Opt_nodelalloc, "nodelalloc"},
1260         {Opt_removed, "mblk_io_submit"},
1261         {Opt_removed, "nomblk_io_submit"},
1262         {Opt_block_validity, "block_validity"},
1263         {Opt_noblock_validity, "noblock_validity"},
1264         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1265         {Opt_journal_ioprio, "journal_ioprio=%u"},
1266         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1267         {Opt_auto_da_alloc, "auto_da_alloc"},
1268         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1269         {Opt_dioread_nolock, "dioread_nolock"},
1270         {Opt_dioread_lock, "dioread_lock"},
1271         {Opt_discard, "discard"},
1272         {Opt_nodiscard, "nodiscard"},
1273         {Opt_init_itable, "init_itable=%u"},
1274         {Opt_init_itable, "init_itable"},
1275         {Opt_noinit_itable, "noinit_itable"},
1276         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1277         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1278         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1279         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1280         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1281         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1282         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1283         {Opt_err, NULL},
1284 };
1285
1286 static ext4_fsblk_t get_sb_block(void **data)
1287 {
1288         ext4_fsblk_t    sb_block;
1289         char            *options = (char *) *data;
1290
1291         if (!options || strncmp(options, "sb=", 3) != 0)
1292                 return 1;       /* Default location */
1293
1294         options += 3;
1295         /* TODO: use simple_strtoll with >32bit ext4 */
1296         sb_block = simple_strtoul(options, &options, 0);
1297         if (*options && *options != ',') {
1298                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1299                        (char *) *data);
1300                 return 1;
1301         }
1302         if (*options == ',')
1303                 options++;
1304         *data = (void *) options;
1305
1306         return sb_block;
1307 }
1308
1309 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1310 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1311         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1312
1313 #ifdef CONFIG_QUOTA
1314 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1315 {
1316         struct ext4_sb_info *sbi = EXT4_SB(sb);
1317         char *qname;
1318         int ret = -1;
1319
1320         if (sb_any_quota_loaded(sb) &&
1321                 !sbi->s_qf_names[qtype]) {
1322                 ext4_msg(sb, KERN_ERR,
1323                         "Cannot change journaled "
1324                         "quota options when quota turned on");
1325                 return -1;
1326         }
1327         if (ext4_has_feature_quota(sb)) {
1328                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1329                          "when QUOTA feature is enabled");
1330                 return -1;
1331         }
1332         qname = match_strdup(args);
1333         if (!qname) {
1334                 ext4_msg(sb, KERN_ERR,
1335                         "Not enough memory for storing quotafile name");
1336                 return -1;
1337         }
1338         if (sbi->s_qf_names[qtype]) {
1339                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1340                         ret = 1;
1341                 else
1342                         ext4_msg(sb, KERN_ERR,
1343                                  "%s quota file already specified",
1344                                  QTYPE2NAME(qtype));
1345                 goto errout;
1346         }
1347         if (strchr(qname, '/')) {
1348                 ext4_msg(sb, KERN_ERR,
1349                         "quotafile must be on filesystem root");
1350                 goto errout;
1351         }
1352         sbi->s_qf_names[qtype] = qname;
1353         set_opt(sb, QUOTA);
1354         return 1;
1355 errout:
1356         kfree(qname);
1357         return ret;
1358 }
1359
1360 static int clear_qf_name(struct super_block *sb, int qtype)
1361 {
1362
1363         struct ext4_sb_info *sbi = EXT4_SB(sb);
1364
1365         if (sb_any_quota_loaded(sb) &&
1366                 sbi->s_qf_names[qtype]) {
1367                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1368                         " when quota turned on");
1369                 return -1;
1370         }
1371         kfree(sbi->s_qf_names[qtype]);
1372         sbi->s_qf_names[qtype] = NULL;
1373         return 1;
1374 }
1375 #endif
1376
1377 #define MOPT_SET        0x0001
1378 #define MOPT_CLEAR      0x0002
1379 #define MOPT_NOSUPPORT  0x0004
1380 #define MOPT_EXPLICIT   0x0008
1381 #define MOPT_CLEAR_ERR  0x0010
1382 #define MOPT_GTE0       0x0020
1383 #ifdef CONFIG_QUOTA
1384 #define MOPT_Q          0
1385 #define MOPT_QFMT       0x0040
1386 #else
1387 #define MOPT_Q          MOPT_NOSUPPORT
1388 #define MOPT_QFMT       MOPT_NOSUPPORT
1389 #endif
1390 #define MOPT_DATAJ      0x0080
1391 #define MOPT_NO_EXT2    0x0100
1392 #define MOPT_NO_EXT3    0x0200
1393 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1394 #define MOPT_STRING     0x0400
1395
1396 static const struct mount_opts {
1397         int     token;
1398         int     mount_opt;
1399         int     flags;
1400 } ext4_mount_opts[] = {
1401         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1402         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1403         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1404         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1405         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1406         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1407         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1408          MOPT_EXT4_ONLY | MOPT_SET},
1409         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1410          MOPT_EXT4_ONLY | MOPT_CLEAR},
1411         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1412         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1413         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1414          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1415         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1416          MOPT_EXT4_ONLY | MOPT_CLEAR},
1417         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1418          MOPT_EXT4_ONLY | MOPT_CLEAR},
1419         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1420          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1421         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1422                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1423          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1424         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1425         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1426         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1427         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1428         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1429          MOPT_NO_EXT2 | MOPT_SET},
1430         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1431          MOPT_NO_EXT2 | MOPT_CLEAR},
1432         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1433         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1434         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1435         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1436         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1437         {Opt_commit, 0, MOPT_GTE0},
1438         {Opt_max_batch_time, 0, MOPT_GTE0},
1439         {Opt_min_batch_time, 0, MOPT_GTE0},
1440         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1441         {Opt_init_itable, 0, MOPT_GTE0},
1442         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1443         {Opt_stripe, 0, MOPT_GTE0},
1444         {Opt_resuid, 0, MOPT_GTE0},
1445         {Opt_resgid, 0, MOPT_GTE0},
1446         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1447         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1448         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1449         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1450         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1451         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1452          MOPT_NO_EXT2 | MOPT_DATAJ},
1453         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1454         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1455 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1456         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1457         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1458 #else
1459         {Opt_acl, 0, MOPT_NOSUPPORT},
1460         {Opt_noacl, 0, MOPT_NOSUPPORT},
1461 #endif
1462         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1463         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1464         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1465         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1466                                                         MOPT_SET | MOPT_Q},
1467         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1468                                                         MOPT_SET | MOPT_Q},
1469         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1470                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1471         {Opt_usrjquota, 0, MOPT_Q},
1472         {Opt_grpjquota, 0, MOPT_Q},
1473         {Opt_offusrjquota, 0, MOPT_Q},
1474         {Opt_offgrpjquota, 0, MOPT_Q},
1475         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1476         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1477         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1478         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1479         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1480         {Opt_err, 0, 0}
1481 };
1482
1483 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1484                             substring_t *args, unsigned long *journal_devnum,
1485                             unsigned int *journal_ioprio, int is_remount)
1486 {
1487         struct ext4_sb_info *sbi = EXT4_SB(sb);
1488         const struct mount_opts *m;
1489         kuid_t uid;
1490         kgid_t gid;
1491         int arg = 0;
1492
1493 #ifdef CONFIG_QUOTA
1494         if (token == Opt_usrjquota)
1495                 return set_qf_name(sb, USRQUOTA, &args[0]);
1496         else if (token == Opt_grpjquota)
1497                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1498         else if (token == Opt_offusrjquota)
1499                 return clear_qf_name(sb, USRQUOTA);
1500         else if (token == Opt_offgrpjquota)
1501                 return clear_qf_name(sb, GRPQUOTA);
1502 #endif
1503         switch (token) {
1504         case Opt_noacl:
1505         case Opt_nouser_xattr:
1506                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1507                 break;
1508         case Opt_sb:
1509                 return 1;       /* handled by get_sb_block() */
1510         case Opt_removed:
1511                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1512                 return 1;
1513         case Opt_abort:
1514                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1515                 return 1;
1516         case Opt_i_version:
1517                 sb->s_flags |= MS_I_VERSION;
1518                 return 1;
1519         case Opt_lazytime:
1520                 sb->s_flags |= MS_LAZYTIME;
1521                 return 1;
1522         case Opt_nolazytime:
1523                 sb->s_flags &= ~MS_LAZYTIME;
1524                 return 1;
1525         }
1526
1527         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1528                 if (token == m->token)
1529                         break;
1530
1531         if (m->token == Opt_err) {
1532                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1533                          "or missing value", opt);
1534                 return -1;
1535         }
1536
1537         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1538                 ext4_msg(sb, KERN_ERR,
1539                          "Mount option \"%s\" incompatible with ext2", opt);
1540                 return -1;
1541         }
1542         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1543                 ext4_msg(sb, KERN_ERR,
1544                          "Mount option \"%s\" incompatible with ext3", opt);
1545                 return -1;
1546         }
1547
1548         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1549                 return -1;
1550         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1551                 return -1;
1552         if (m->flags & MOPT_EXPLICIT) {
1553                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1554                         set_opt2(sb, EXPLICIT_DELALLOC);
1555                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1556                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1557                 } else
1558                         return -1;
1559         }
1560         if (m->flags & MOPT_CLEAR_ERR)
1561                 clear_opt(sb, ERRORS_MASK);
1562         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1563                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1564                          "options when quota turned on");
1565                 return -1;
1566         }
1567
1568         if (m->flags & MOPT_NOSUPPORT) {
1569                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1570         } else if (token == Opt_commit) {
1571                 if (arg == 0)
1572                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1573                 sbi->s_commit_interval = HZ * arg;
1574         } else if (token == Opt_max_batch_time) {
1575                 sbi->s_max_batch_time = arg;
1576         } else if (token == Opt_min_batch_time) {
1577                 sbi->s_min_batch_time = arg;
1578         } else if (token == Opt_inode_readahead_blks) {
1579                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1580                         ext4_msg(sb, KERN_ERR,
1581                                  "EXT4-fs: inode_readahead_blks must be "
1582                                  "0 or a power of 2 smaller than 2^31");
1583                         return -1;
1584                 }
1585                 sbi->s_inode_readahead_blks = arg;
1586         } else if (token == Opt_init_itable) {
1587                 set_opt(sb, INIT_INODE_TABLE);
1588                 if (!args->from)
1589                         arg = EXT4_DEF_LI_WAIT_MULT;
1590                 sbi->s_li_wait_mult = arg;
1591         } else if (token == Opt_max_dir_size_kb) {
1592                 sbi->s_max_dir_size_kb = arg;
1593         } else if (token == Opt_stripe) {
1594                 sbi->s_stripe = arg;
1595         } else if (token == Opt_resuid) {
1596                 uid = make_kuid(current_user_ns(), arg);
1597                 if (!uid_valid(uid)) {
1598                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1599                         return -1;
1600                 }
1601                 sbi->s_resuid = uid;
1602         } else if (token == Opt_resgid) {
1603                 gid = make_kgid(current_user_ns(), arg);
1604                 if (!gid_valid(gid)) {
1605                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1606                         return -1;
1607                 }
1608                 sbi->s_resgid = gid;
1609         } else if (token == Opt_journal_dev) {
1610                 if (is_remount) {
1611                         ext4_msg(sb, KERN_ERR,
1612                                  "Cannot specify journal on remount");
1613                         return -1;
1614                 }
1615                 *journal_devnum = arg;
1616         } else if (token == Opt_journal_path) {
1617                 char *journal_path;
1618                 struct inode *journal_inode;
1619                 struct path path;
1620                 int error;
1621
1622                 if (is_remount) {
1623                         ext4_msg(sb, KERN_ERR,
1624                                  "Cannot specify journal on remount");
1625                         return -1;
1626                 }
1627                 journal_path = match_strdup(&args[0]);
1628                 if (!journal_path) {
1629                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1630                                 "journal device string");
1631                         return -1;
1632                 }
1633
1634                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1635                 if (error) {
1636                         ext4_msg(sb, KERN_ERR, "error: could not find "
1637                                 "journal device path: error %d", error);
1638                         kfree(journal_path);
1639                         return -1;
1640                 }
1641
1642                 journal_inode = d_inode(path.dentry);
1643                 if (!S_ISBLK(journal_inode->i_mode)) {
1644                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1645                                 "is not a block device", journal_path);
1646                         path_put(&path);
1647                         kfree(journal_path);
1648                         return -1;
1649                 }
1650
1651                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1652                 path_put(&path);
1653                 kfree(journal_path);
1654         } else if (token == Opt_journal_ioprio) {
1655                 if (arg > 7) {
1656                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1657                                  " (must be 0-7)");
1658                         return -1;
1659                 }
1660                 *journal_ioprio =
1661                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1662         } else if (token == Opt_test_dummy_encryption) {
1663 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1664                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1665                 ext4_msg(sb, KERN_WARNING,
1666                          "Test dummy encryption mode enabled");
1667 #else
1668                 ext4_msg(sb, KERN_WARNING,
1669                          "Test dummy encryption mount option ignored");
1670 #endif
1671         } else if (m->flags & MOPT_DATAJ) {
1672                 if (is_remount) {
1673                         if (!sbi->s_journal)
1674                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1675                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1676                                 ext4_msg(sb, KERN_ERR,
1677                                          "Cannot change data mode on remount");
1678                                 return -1;
1679                         }
1680                 } else {
1681                         clear_opt(sb, DATA_FLAGS);
1682                         sbi->s_mount_opt |= m->mount_opt;
1683                 }
1684 #ifdef CONFIG_QUOTA
1685         } else if (m->flags & MOPT_QFMT) {
1686                 if (sb_any_quota_loaded(sb) &&
1687                     sbi->s_jquota_fmt != m->mount_opt) {
1688                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1689                                  "quota options when quota turned on");
1690                         return -1;
1691                 }
1692                 if (ext4_has_feature_quota(sb)) {
1693                         ext4_msg(sb, KERN_ERR,
1694                                  "Cannot set journaled quota options "
1695                                  "when QUOTA feature is enabled");
1696                         return -1;
1697                 }
1698                 sbi->s_jquota_fmt = m->mount_opt;
1699 #endif
1700         } else if (token == Opt_dax) {
1701 #ifdef CONFIG_FS_DAX
1702                 ext4_msg(sb, KERN_WARNING,
1703                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1704                         sbi->s_mount_opt |= m->mount_opt;
1705 #else
1706                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1707                 return -1;
1708 #endif
1709         } else {
1710                 if (!args->from)
1711                         arg = 1;
1712                 if (m->flags & MOPT_CLEAR)
1713                         arg = !arg;
1714                 else if (unlikely(!(m->flags & MOPT_SET))) {
1715                         ext4_msg(sb, KERN_WARNING,
1716                                  "buggy handling of option %s", opt);
1717                         WARN_ON(1);
1718                         return -1;
1719                 }
1720                 if (arg != 0)
1721                         sbi->s_mount_opt |= m->mount_opt;
1722                 else
1723                         sbi->s_mount_opt &= ~m->mount_opt;
1724         }
1725         return 1;
1726 }
1727
1728 static int parse_options(char *options, struct super_block *sb,
1729                          unsigned long *journal_devnum,
1730                          unsigned int *journal_ioprio,
1731                          int is_remount)
1732 {
1733         struct ext4_sb_info *sbi = EXT4_SB(sb);
1734         char *p;
1735         substring_t args[MAX_OPT_ARGS];
1736         int token;
1737
1738         if (!options)
1739                 return 1;
1740
1741         while ((p = strsep(&options, ",")) != NULL) {
1742                 if (!*p)
1743                         continue;
1744                 /*
1745                  * Initialize args struct so we know whether arg was
1746                  * found; some options take optional arguments.
1747                  */
1748                 args[0].to = args[0].from = NULL;
1749                 token = match_token(p, tokens, args);
1750                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1751                                      journal_ioprio, is_remount) < 0)
1752                         return 0;
1753         }
1754 #ifdef CONFIG_QUOTA
1755         if (ext4_has_feature_quota(sb) &&
1756             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1757                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1758                          "feature is enabled");
1759                 return 0;
1760         }
1761         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1762                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1763                         clear_opt(sb, USRQUOTA);
1764
1765                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1766                         clear_opt(sb, GRPQUOTA);
1767
1768                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1769                         ext4_msg(sb, KERN_ERR, "old and new quota "
1770                                         "format mixing");
1771                         return 0;
1772                 }
1773
1774                 if (!sbi->s_jquota_fmt) {
1775                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1776                                         "not specified");
1777                         return 0;
1778                 }
1779         }
1780 #endif
1781         if (test_opt(sb, DIOREAD_NOLOCK)) {
1782                 int blocksize =
1783                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1784
1785                 if (blocksize < PAGE_CACHE_SIZE) {
1786                         ext4_msg(sb, KERN_ERR, "can't mount with "
1787                                  "dioread_nolock if block size != PAGE_SIZE");
1788                         return 0;
1789                 }
1790         }
1791         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1792             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1793                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1794                          "in data=ordered mode");
1795                 return 0;
1796         }
1797         return 1;
1798 }
1799
1800 static inline void ext4_show_quota_options(struct seq_file *seq,
1801                                            struct super_block *sb)
1802 {
1803 #if defined(CONFIG_QUOTA)
1804         struct ext4_sb_info *sbi = EXT4_SB(sb);
1805
1806         if (sbi->s_jquota_fmt) {
1807                 char *fmtname = "";
1808
1809                 switch (sbi->s_jquota_fmt) {
1810                 case QFMT_VFS_OLD:
1811                         fmtname = "vfsold";
1812                         break;
1813                 case QFMT_VFS_V0:
1814                         fmtname = "vfsv0";
1815                         break;
1816                 case QFMT_VFS_V1:
1817                         fmtname = "vfsv1";
1818                         break;
1819                 }
1820                 seq_printf(seq, ",jqfmt=%s", fmtname);
1821         }
1822
1823         if (sbi->s_qf_names[USRQUOTA])
1824                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1825
1826         if (sbi->s_qf_names[GRPQUOTA])
1827                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1828 #endif
1829 }
1830
1831 static const char *token2str(int token)
1832 {
1833         const struct match_token *t;
1834
1835         for (t = tokens; t->token != Opt_err; t++)
1836                 if (t->token == token && !strchr(t->pattern, '='))
1837                         break;
1838         return t->pattern;
1839 }
1840
1841 /*
1842  * Show an option if
1843  *  - it's set to a non-default value OR
1844  *  - if the per-sb default is different from the global default
1845  */
1846 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1847                               int nodefs)
1848 {
1849         struct ext4_sb_info *sbi = EXT4_SB(sb);
1850         struct ext4_super_block *es = sbi->s_es;
1851         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1852         const struct mount_opts *m;
1853         char sep = nodefs ? '\n' : ',';
1854
1855 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1856 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1857
1858         if (sbi->s_sb_block != 1)
1859                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1860
1861         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1862                 int want_set = m->flags & MOPT_SET;
1863                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1864                     (m->flags & MOPT_CLEAR_ERR))
1865                         continue;
1866                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1867                         continue; /* skip if same as the default */
1868                 if ((want_set &&
1869                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1870                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1871                         continue; /* select Opt_noFoo vs Opt_Foo */
1872                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1873         }
1874
1875         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1876             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1877                 SEQ_OPTS_PRINT("resuid=%u",
1878                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1879         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1880             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1881                 SEQ_OPTS_PRINT("resgid=%u",
1882                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1883         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1884         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1885                 SEQ_OPTS_PUTS("errors=remount-ro");
1886         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1887                 SEQ_OPTS_PUTS("errors=continue");
1888         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1889                 SEQ_OPTS_PUTS("errors=panic");
1890         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1891                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1892         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1893                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1894         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1895                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1896         if (sb->s_flags & MS_I_VERSION)
1897                 SEQ_OPTS_PUTS("i_version");
1898         if (nodefs || sbi->s_stripe)
1899                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1900         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1901                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1902                         SEQ_OPTS_PUTS("data=journal");
1903                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1904                         SEQ_OPTS_PUTS("data=ordered");
1905                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1906                         SEQ_OPTS_PUTS("data=writeback");
1907         }
1908         if (nodefs ||
1909             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1910                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1911                                sbi->s_inode_readahead_blks);
1912
1913         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1914                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1915                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1916         if (nodefs || sbi->s_max_dir_size_kb)
1917                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1918
1919         ext4_show_quota_options(seq, sb);
1920         return 0;
1921 }
1922
1923 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1924 {
1925         return _ext4_show_options(seq, root->d_sb, 0);
1926 }
1927
1928 int ext4_seq_options_show(struct seq_file *seq, void *offset)
1929 {
1930         struct super_block *sb = seq->private;
1931         int rc;
1932
1933         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1934         rc = _ext4_show_options(seq, sb, 1);
1935         seq_puts(seq, "\n");
1936         return rc;
1937 }
1938
1939 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1940                             int read_only)
1941 {
1942         struct ext4_sb_info *sbi = EXT4_SB(sb);
1943         int res = 0;
1944
1945         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1946                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1947                          "forcing read-only mode");
1948                 res = MS_RDONLY;
1949         }
1950         if (read_only)
1951                 goto done;
1952         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1953                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1954                          "running e2fsck is recommended");
1955         else if (sbi->s_mount_state & EXT4_ERROR_FS)
1956                 ext4_msg(sb, KERN_WARNING,
1957                          "warning: mounting fs with errors, "
1958                          "running e2fsck is recommended");
1959         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1960                  le16_to_cpu(es->s_mnt_count) >=
1961                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1962                 ext4_msg(sb, KERN_WARNING,
1963                          "warning: maximal mount count reached, "
1964                          "running e2fsck is recommended");
1965         else if (le32_to_cpu(es->s_checkinterval) &&
1966                 (le32_to_cpu(es->s_lastcheck) +
1967                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1968                 ext4_msg(sb, KERN_WARNING,
1969                          "warning: checktime reached, "
1970                          "running e2fsck is recommended");
1971         if (!sbi->s_journal)
1972                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1973         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1974                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1975         le16_add_cpu(&es->s_mnt_count, 1);
1976         es->s_mtime = cpu_to_le32(get_seconds());
1977         ext4_update_dynamic_rev(sb);
1978         if (sbi->s_journal)
1979                 ext4_set_feature_journal_needs_recovery(sb);
1980
1981         ext4_commit_super(sb, 1);
1982 done:
1983         if (test_opt(sb, DEBUG))
1984                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1985                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1986                         sb->s_blocksize,
1987                         sbi->s_groups_count,
1988                         EXT4_BLOCKS_PER_GROUP(sb),
1989                         EXT4_INODES_PER_GROUP(sb),
1990                         sbi->s_mount_opt, sbi->s_mount_opt2);
1991
1992         cleancache_init_fs(sb);
1993         return res;
1994 }
1995
1996 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1997 {
1998         struct ext4_sb_info *sbi = EXT4_SB(sb);
1999         struct flex_groups *new_groups;
2000         int size;
2001
2002         if (!sbi->s_log_groups_per_flex)
2003                 return 0;
2004
2005         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2006         if (size <= sbi->s_flex_groups_allocated)
2007                 return 0;
2008
2009         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2010         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2011         if (!new_groups) {
2012                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2013                          size / (int) sizeof(struct flex_groups));
2014                 return -ENOMEM;
2015         }
2016
2017         if (sbi->s_flex_groups) {
2018                 memcpy(new_groups, sbi->s_flex_groups,
2019                        (sbi->s_flex_groups_allocated *
2020                         sizeof(struct flex_groups)));
2021                 kvfree(sbi->s_flex_groups);
2022         }
2023         sbi->s_flex_groups = new_groups;
2024         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2025         return 0;
2026 }
2027
2028 static int ext4_fill_flex_info(struct super_block *sb)
2029 {
2030         struct ext4_sb_info *sbi = EXT4_SB(sb);
2031         struct ext4_group_desc *gdp = NULL;
2032         ext4_group_t flex_group;
2033         int i, err;
2034
2035         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2036         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2037                 sbi->s_log_groups_per_flex = 0;
2038                 return 1;
2039         }
2040
2041         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2042         if (err)
2043                 goto failed;
2044
2045         for (i = 0; i < sbi->s_groups_count; i++) {
2046                 gdp = ext4_get_group_desc(sb, i, NULL);
2047
2048                 flex_group = ext4_flex_group(sbi, i);
2049                 atomic_add(ext4_free_inodes_count(sb, gdp),
2050                            &sbi->s_flex_groups[flex_group].free_inodes);
2051                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2052                              &sbi->s_flex_groups[flex_group].free_clusters);
2053                 atomic_add(ext4_used_dirs_count(sb, gdp),
2054                            &sbi->s_flex_groups[flex_group].used_dirs);
2055         }
2056
2057         return 1;
2058 failed:
2059         return 0;
2060 }
2061
2062 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2063                                    struct ext4_group_desc *gdp)
2064 {
2065         int offset;
2066         __u16 crc = 0;
2067         __le32 le_group = cpu_to_le32(block_group);
2068         struct ext4_sb_info *sbi = EXT4_SB(sb);
2069
2070         if (ext4_has_metadata_csum(sbi->s_sb)) {
2071                 /* Use new metadata_csum algorithm */
2072                 __le16 save_csum;
2073                 __u32 csum32;
2074
2075                 save_csum = gdp->bg_checksum;
2076                 gdp->bg_checksum = 0;
2077                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2078                                      sizeof(le_group));
2079                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2080                                      sbi->s_desc_size);
2081                 gdp->bg_checksum = save_csum;
2082
2083                 crc = csum32 & 0xFFFF;
2084                 goto out;
2085         }
2086
2087         /* old crc16 code */
2088         if (!ext4_has_feature_gdt_csum(sb))
2089                 return 0;
2090
2091         offset = offsetof(struct ext4_group_desc, bg_checksum);
2092
2093         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2094         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2095         crc = crc16(crc, (__u8 *)gdp, offset);
2096         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2097         /* for checksum of struct ext4_group_desc do the rest...*/
2098         if (ext4_has_feature_64bit(sb) &&
2099             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2100                 crc = crc16(crc, (__u8 *)gdp + offset,
2101                             le16_to_cpu(sbi->s_es->s_desc_size) -
2102                                 offset);
2103
2104 out:
2105         return cpu_to_le16(crc);
2106 }
2107
2108 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2109                                 struct ext4_group_desc *gdp)
2110 {
2111         if (ext4_has_group_desc_csum(sb) &&
2112             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2113                 return 0;
2114
2115         return 1;
2116 }
2117
2118 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2119                               struct ext4_group_desc *gdp)
2120 {
2121         if (!ext4_has_group_desc_csum(sb))
2122                 return;
2123         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2124 }
2125
2126 /* Called at mount-time, super-block is locked */
2127 static int ext4_check_descriptors(struct super_block *sb,
2128                                   ext4_group_t *first_not_zeroed)
2129 {
2130         struct ext4_sb_info *sbi = EXT4_SB(sb);
2131         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2132         ext4_fsblk_t last_block;
2133         ext4_fsblk_t block_bitmap;
2134         ext4_fsblk_t inode_bitmap;
2135         ext4_fsblk_t inode_table;
2136         int flexbg_flag = 0;
2137         ext4_group_t i, grp = sbi->s_groups_count;
2138
2139         if (ext4_has_feature_flex_bg(sb))
2140                 flexbg_flag = 1;
2141
2142         ext4_debug("Checking group descriptors");
2143
2144         for (i = 0; i < sbi->s_groups_count; i++) {
2145                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2146
2147                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2148                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2149                 else
2150                         last_block = first_block +
2151                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2152
2153                 if ((grp == sbi->s_groups_count) &&
2154                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2155                         grp = i;
2156
2157                 block_bitmap = ext4_block_bitmap(sb, gdp);
2158                 if (block_bitmap < first_block || block_bitmap > last_block) {
2159                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2160                                "Block bitmap for group %u not in group "
2161                                "(block %llu)!", i, block_bitmap);
2162                         return 0;
2163                 }
2164                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2165                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2166                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2167                                "Inode bitmap for group %u not in group "
2168                                "(block %llu)!", i, inode_bitmap);
2169                         return 0;
2170                 }
2171                 inode_table = ext4_inode_table(sb, gdp);
2172                 if (inode_table < first_block ||
2173                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2174                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2175                                "Inode table for group %u not in group "
2176                                "(block %llu)!", i, inode_table);
2177                         return 0;
2178                 }
2179                 ext4_lock_group(sb, i);
2180                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2181                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2182                                  "Checksum for group %u failed (%u!=%u)",
2183                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2184                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2185                         if (!(sb->s_flags & MS_RDONLY)) {
2186                                 ext4_unlock_group(sb, i);
2187                                 return 0;
2188                         }
2189                 }
2190                 ext4_unlock_group(sb, i);
2191                 if (!flexbg_flag)
2192                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2193         }
2194         if (NULL != first_not_zeroed)
2195                 *first_not_zeroed = grp;
2196         return 1;
2197 }
2198
2199 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2200  * the superblock) which were deleted from all directories, but held open by
2201  * a process at the time of a crash.  We walk the list and try to delete these
2202  * inodes at recovery time (only with a read-write filesystem).
2203  *
2204  * In order to keep the orphan inode chain consistent during traversal (in
2205  * case of crash during recovery), we link each inode into the superblock
2206  * orphan list_head and handle it the same way as an inode deletion during
2207  * normal operation (which journals the operations for us).
2208  *
2209  * We only do an iget() and an iput() on each inode, which is very safe if we
2210  * accidentally point at an in-use or already deleted inode.  The worst that
2211  * can happen in this case is that we get a "bit already cleared" message from
2212  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2213  * e2fsck was run on this filesystem, and it must have already done the orphan
2214  * inode cleanup for us, so we can safely abort without any further action.
2215  */
2216 static void ext4_orphan_cleanup(struct super_block *sb,
2217                                 struct ext4_super_block *es)
2218 {
2219         unsigned int s_flags = sb->s_flags;
2220         int nr_orphans = 0, nr_truncates = 0;
2221 #ifdef CONFIG_QUOTA
2222         int i;
2223 #endif
2224         if (!es->s_last_orphan) {
2225                 jbd_debug(4, "no orphan inodes to clean up\n");
2226                 return;
2227         }
2228
2229         if (bdev_read_only(sb->s_bdev)) {
2230                 ext4_msg(sb, KERN_ERR, "write access "
2231                         "unavailable, skipping orphan cleanup");
2232                 return;
2233         }
2234
2235         /* Check if feature set would not allow a r/w mount */
2236         if (!ext4_feature_set_ok(sb, 0)) {
2237                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2238                          "unknown ROCOMPAT features");
2239                 return;
2240         }
2241
2242         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2243                 /* don't clear list on RO mount w/ errors */
2244                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2245                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2246                                   "clearing orphan list.\n");
2247                         es->s_last_orphan = 0;
2248                 }
2249                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2250                 return;
2251         }
2252
2253         if (s_flags & MS_RDONLY) {
2254                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2255                 sb->s_flags &= ~MS_RDONLY;
2256         }
2257 #ifdef CONFIG_QUOTA
2258         /* Needed for iput() to work correctly and not trash data */
2259         sb->s_flags |= MS_ACTIVE;
2260         /* Turn on quotas so that they are updated correctly */
2261         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2262                 if (EXT4_SB(sb)->s_qf_names[i]) {
2263                         int ret = ext4_quota_on_mount(sb, i);
2264                         if (ret < 0)
2265                                 ext4_msg(sb, KERN_ERR,
2266                                         "Cannot turn on journaled "
2267                                         "quota: error %d", ret);
2268                 }
2269         }
2270 #endif
2271
2272         while (es->s_last_orphan) {
2273                 struct inode *inode;
2274
2275                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2276                 if (IS_ERR(inode)) {
2277                         es->s_last_orphan = 0;
2278                         break;
2279                 }
2280
2281                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2282                 dquot_initialize(inode);
2283                 if (inode->i_nlink) {
2284                         if (test_opt(sb, DEBUG))
2285                                 ext4_msg(sb, KERN_DEBUG,
2286                                         "%s: truncating inode %lu to %lld bytes",
2287                                         __func__, inode->i_ino, inode->i_size);
2288                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2289                                   inode->i_ino, inode->i_size);
2290                         inode_lock(inode);
2291                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2292                         ext4_truncate(inode);
2293                         inode_unlock(inode);
2294                         nr_truncates++;
2295                 } else {
2296                         if (test_opt(sb, DEBUG))
2297                                 ext4_msg(sb, KERN_DEBUG,
2298                                         "%s: deleting unreferenced inode %lu",
2299                                         __func__, inode->i_ino);
2300                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2301                                   inode->i_ino);
2302                         nr_orphans++;
2303                 }
2304                 iput(inode);  /* The delete magic happens here! */
2305         }
2306
2307 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2308
2309         if (nr_orphans)
2310                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2311                        PLURAL(nr_orphans));
2312         if (nr_truncates)
2313                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2314                        PLURAL(nr_truncates));
2315 #ifdef CONFIG_QUOTA
2316         /* Turn quotas off */
2317         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2318                 if (sb_dqopt(sb)->files[i])
2319                         dquot_quota_off(sb, i);
2320         }
2321 #endif
2322         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2323 }
2324
2325 /*
2326  * Maximal extent format file size.
2327  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2328  * extent format containers, within a sector_t, and within i_blocks
2329  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2330  * so that won't be a limiting factor.
2331  *
2332  * However there is other limiting factor. We do store extents in the form
2333  * of starting block and length, hence the resulting length of the extent
2334  * covering maximum file size must fit into on-disk format containers as
2335  * well. Given that length is always by 1 unit bigger than max unit (because
2336  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2337  *
2338  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2339  */
2340 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2341 {
2342         loff_t res;
2343         loff_t upper_limit = MAX_LFS_FILESIZE;
2344
2345         /* small i_blocks in vfs inode? */
2346         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2347                 /*
2348                  * CONFIG_LBDAF is not enabled implies the inode
2349                  * i_block represent total blocks in 512 bytes
2350                  * 32 == size of vfs inode i_blocks * 8
2351                  */
2352                 upper_limit = (1LL << 32) - 1;
2353
2354                 /* total blocks in file system block size */
2355                 upper_limit >>= (blkbits - 9);
2356                 upper_limit <<= blkbits;
2357         }
2358
2359         /*
2360          * 32-bit extent-start container, ee_block. We lower the maxbytes
2361          * by one fs block, so ee_len can cover the extent of maximum file
2362          * size
2363          */
2364         res = (1LL << 32) - 1;
2365         res <<= blkbits;
2366
2367         /* Sanity check against vm- & vfs- imposed limits */
2368         if (res > upper_limit)
2369                 res = upper_limit;
2370
2371         return res;
2372 }
2373
2374 /*
2375  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2376  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2377  * We need to be 1 filesystem block less than the 2^48 sector limit.
2378  */
2379 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2380 {
2381         loff_t res = EXT4_NDIR_BLOCKS;
2382         int meta_blocks;
2383         loff_t upper_limit;
2384         /* This is calculated to be the largest file size for a dense, block
2385          * mapped file such that the file's total number of 512-byte sectors,
2386          * including data and all indirect blocks, does not exceed (2^48 - 1).
2387          *
2388          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2389          * number of 512-byte sectors of the file.
2390          */
2391
2392         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2393                 /*
2394                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2395                  * the inode i_block field represents total file blocks in
2396                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2397                  */
2398                 upper_limit = (1LL << 32) - 1;
2399
2400                 /* total blocks in file system block size */
2401                 upper_limit >>= (bits - 9);
2402
2403         } else {
2404                 /*
2405                  * We use 48 bit ext4_inode i_blocks
2406                  * With EXT4_HUGE_FILE_FL set the i_blocks
2407                  * represent total number of blocks in
2408                  * file system block size
2409                  */
2410                 upper_limit = (1LL << 48) - 1;
2411
2412         }
2413
2414         /* indirect blocks */
2415         meta_blocks = 1;
2416         /* double indirect blocks */
2417         meta_blocks += 1 + (1LL << (bits-2));
2418         /* tripple indirect blocks */
2419         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2420
2421         upper_limit -= meta_blocks;
2422         upper_limit <<= bits;
2423
2424         res += 1LL << (bits-2);
2425         res += 1LL << (2*(bits-2));
2426         res += 1LL << (3*(bits-2));
2427         res <<= bits;
2428         if (res > upper_limit)
2429                 res = upper_limit;
2430
2431         if (res > MAX_LFS_FILESIZE)
2432                 res = MAX_LFS_FILESIZE;
2433
2434         return res;
2435 }
2436
2437 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2438                                    ext4_fsblk_t logical_sb_block, int nr)
2439 {
2440         struct ext4_sb_info *sbi = EXT4_SB(sb);
2441         ext4_group_t bg, first_meta_bg;
2442         int has_super = 0;
2443
2444         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2445
2446         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2447                 return logical_sb_block + nr + 1;
2448         bg = sbi->s_desc_per_block * nr;
2449         if (ext4_bg_has_super(sb, bg))
2450                 has_super = 1;
2451
2452         /*
2453          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2454          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2455          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2456          * compensate.
2457          */
2458         if (sb->s_blocksize == 1024 && nr == 0 &&
2459             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2460                 has_super++;
2461
2462         return (has_super + ext4_group_first_block_no(sb, bg));
2463 }
2464
2465 /**
2466  * ext4_get_stripe_size: Get the stripe size.
2467  * @sbi: In memory super block info
2468  *
2469  * If we have specified it via mount option, then
2470  * use the mount option value. If the value specified at mount time is
2471  * greater than the blocks per group use the super block value.
2472  * If the super block value is greater than blocks per group return 0.
2473  * Allocator needs it be less than blocks per group.
2474  *
2475  */
2476 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2477 {
2478         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2479         unsigned long stripe_width =
2480                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2481         int ret;
2482
2483         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2484                 ret = sbi->s_stripe;
2485         else if (stripe_width <= sbi->s_blocks_per_group)
2486                 ret = stripe_width;
2487         else if (stride <= sbi->s_blocks_per_group)
2488                 ret = stride;
2489         else
2490                 ret = 0;
2491
2492         /*
2493          * If the stripe width is 1, this makes no sense and
2494          * we set it to 0 to turn off stripe handling code.
2495          */
2496         if (ret <= 1)
2497                 ret = 0;
2498
2499         return ret;
2500 }
2501
2502 /*
2503  * Check whether this filesystem can be mounted based on
2504  * the features present and the RDONLY/RDWR mount requested.
2505  * Returns 1 if this filesystem can be mounted as requested,
2506  * 0 if it cannot be.
2507  */
2508 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2509 {
2510         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2511                 ext4_msg(sb, KERN_ERR,
2512                         "Couldn't mount because of "
2513                         "unsupported optional features (%x)",
2514                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2515                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2516                 return 0;
2517         }
2518
2519         if (readonly)
2520                 return 1;
2521
2522         if (ext4_has_feature_readonly(sb)) {
2523                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2524                 sb->s_flags |= MS_RDONLY;
2525                 return 1;
2526         }
2527
2528         /* Check that feature set is OK for a read-write mount */
2529         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2530                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2531                          "unsupported optional features (%x)",
2532                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2533                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2534                 return 0;
2535         }
2536         /*
2537          * Large file size enabled file system can only be mounted
2538          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2539          */
2540         if (ext4_has_feature_huge_file(sb)) {
2541                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2542                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2543                                  "cannot be mounted RDWR without "
2544                                  "CONFIG_LBDAF");
2545                         return 0;
2546                 }
2547         }
2548         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2549                 ext4_msg(sb, KERN_ERR,
2550                          "Can't support bigalloc feature without "
2551                          "extents feature\n");
2552                 return 0;
2553         }
2554
2555 #ifndef CONFIG_QUOTA
2556         if (ext4_has_feature_quota(sb) && !readonly) {
2557                 ext4_msg(sb, KERN_ERR,
2558                          "Filesystem with quota feature cannot be mounted RDWR "
2559                          "without CONFIG_QUOTA");
2560                 return 0;
2561         }
2562         if (ext4_has_feature_project(sb) && !readonly) {
2563                 ext4_msg(sb, KERN_ERR,
2564                          "Filesystem with project quota feature cannot be mounted RDWR "
2565                          "without CONFIG_QUOTA");
2566                 return 0;
2567         }
2568 #endif  /* CONFIG_QUOTA */
2569         return 1;
2570 }
2571
2572 /*
2573  * This function is called once a day if we have errors logged
2574  * on the file system
2575  */
2576 static void print_daily_error_info(unsigned long arg)
2577 {
2578         struct super_block *sb = (struct super_block *) arg;
2579         struct ext4_sb_info *sbi;
2580         struct ext4_super_block *es;
2581
2582         sbi = EXT4_SB(sb);
2583         es = sbi->s_es;
2584
2585         if (es->s_error_count)
2586                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2587                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2588                          le32_to_cpu(es->s_error_count));
2589         if (es->s_first_error_time) {
2590                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2591                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2592                        (int) sizeof(es->s_first_error_func),
2593                        es->s_first_error_func,
2594                        le32_to_cpu(es->s_first_error_line));
2595                 if (es->s_first_error_ino)
2596                         printk(": inode %u",
2597                                le32_to_cpu(es->s_first_error_ino));
2598                 if (es->s_first_error_block)
2599                         printk(": block %llu", (unsigned long long)
2600                                le64_to_cpu(es->s_first_error_block));
2601                 printk("\n");
2602         }
2603         if (es->s_last_error_time) {
2604                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2605                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2606                        (int) sizeof(es->s_last_error_func),
2607                        es->s_last_error_func,
2608                        le32_to_cpu(es->s_last_error_line));
2609                 if (es->s_last_error_ino)
2610                         printk(": inode %u",
2611                                le32_to_cpu(es->s_last_error_ino));
2612                 if (es->s_last_error_block)
2613                         printk(": block %llu", (unsigned long long)
2614                                le64_to_cpu(es->s_last_error_block));
2615                 printk("\n");
2616         }
2617         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2618 }
2619
2620 /* Find next suitable group and run ext4_init_inode_table */
2621 static int ext4_run_li_request(struct ext4_li_request *elr)
2622 {
2623         struct ext4_group_desc *gdp = NULL;
2624         ext4_group_t group, ngroups;
2625         struct super_block *sb;
2626         unsigned long timeout = 0;
2627         int ret = 0;
2628
2629         sb = elr->lr_super;
2630         ngroups = EXT4_SB(sb)->s_groups_count;
2631
2632         sb_start_write(sb);
2633         for (group = elr->lr_next_group; group < ngroups; group++) {
2634                 gdp = ext4_get_group_desc(sb, group, NULL);
2635                 if (!gdp) {
2636                         ret = 1;
2637                         break;
2638                 }
2639
2640                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2641                         break;
2642         }
2643
2644         if (group >= ngroups)
2645                 ret = 1;
2646
2647         if (!ret) {
2648                 timeout = jiffies;
2649                 ret = ext4_init_inode_table(sb, group,
2650                                             elr->lr_timeout ? 0 : 1);
2651                 if (elr->lr_timeout == 0) {
2652                         timeout = (jiffies - timeout) *
2653                                   elr->lr_sbi->s_li_wait_mult;
2654                         elr->lr_timeout = timeout;
2655                 }
2656                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2657                 elr->lr_next_group = group + 1;
2658         }
2659         sb_end_write(sb);
2660
2661         return ret;
2662 }
2663
2664 /*
2665  * Remove lr_request from the list_request and free the
2666  * request structure. Should be called with li_list_mtx held
2667  */
2668 static void ext4_remove_li_request(struct ext4_li_request *elr)
2669 {
2670         struct ext4_sb_info *sbi;
2671
2672         if (!elr)
2673                 return;
2674
2675         sbi = elr->lr_sbi;
2676
2677         list_del(&elr->lr_request);
2678         sbi->s_li_request = NULL;
2679         kfree(elr);
2680 }
2681
2682 static void ext4_unregister_li_request(struct super_block *sb)
2683 {
2684         mutex_lock(&ext4_li_mtx);
2685         if (!ext4_li_info) {
2686                 mutex_unlock(&ext4_li_mtx);
2687                 return;
2688         }
2689
2690         mutex_lock(&ext4_li_info->li_list_mtx);
2691         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2692         mutex_unlock(&ext4_li_info->li_list_mtx);
2693         mutex_unlock(&ext4_li_mtx);
2694 }
2695
2696 static struct task_struct *ext4_lazyinit_task;
2697
2698 /*
2699  * This is the function where ext4lazyinit thread lives. It walks
2700  * through the request list searching for next scheduled filesystem.
2701  * When such a fs is found, run the lazy initialization request
2702  * (ext4_rn_li_request) and keep track of the time spend in this
2703  * function. Based on that time we compute next schedule time of
2704  * the request. When walking through the list is complete, compute
2705  * next waking time and put itself into sleep.
2706  */
2707 static int ext4_lazyinit_thread(void *arg)
2708 {
2709         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2710         struct list_head *pos, *n;
2711         struct ext4_li_request *elr;
2712         unsigned long next_wakeup, cur;
2713
2714         BUG_ON(NULL == eli);
2715
2716 cont_thread:
2717         while (true) {
2718                 next_wakeup = MAX_JIFFY_OFFSET;
2719
2720                 mutex_lock(&eli->li_list_mtx);
2721                 if (list_empty(&eli->li_request_list)) {
2722                         mutex_unlock(&eli->li_list_mtx);
2723                         goto exit_thread;
2724                 }
2725
2726                 list_for_each_safe(pos, n, &eli->li_request_list) {
2727                         elr = list_entry(pos, struct ext4_li_request,
2728                                          lr_request);
2729
2730                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2731                                 if (ext4_run_li_request(elr) != 0) {
2732                                         /* error, remove the lazy_init job */
2733                                         ext4_remove_li_request(elr);
2734                                         continue;
2735                                 }
2736                         }
2737
2738                         if (time_before(elr->lr_next_sched, next_wakeup))
2739                                 next_wakeup = elr->lr_next_sched;
2740                 }
2741                 mutex_unlock(&eli->li_list_mtx);
2742
2743                 try_to_freeze();
2744
2745                 cur = jiffies;
2746                 if ((time_after_eq(cur, next_wakeup)) ||
2747                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2748                         cond_resched();
2749                         continue;
2750                 }
2751
2752                 schedule_timeout_interruptible(next_wakeup - cur);
2753
2754                 if (kthread_should_stop()) {
2755                         ext4_clear_request_list();
2756                         goto exit_thread;
2757                 }
2758         }
2759
2760 exit_thread:
2761         /*
2762          * It looks like the request list is empty, but we need
2763          * to check it under the li_list_mtx lock, to prevent any
2764          * additions into it, and of course we should lock ext4_li_mtx
2765          * to atomically free the list and ext4_li_info, because at
2766          * this point another ext4 filesystem could be registering
2767          * new one.
2768          */
2769         mutex_lock(&ext4_li_mtx);
2770         mutex_lock(&eli->li_list_mtx);
2771         if (!list_empty(&eli->li_request_list)) {
2772                 mutex_unlock(&eli->li_list_mtx);
2773                 mutex_unlock(&ext4_li_mtx);
2774                 goto cont_thread;
2775         }
2776         mutex_unlock(&eli->li_list_mtx);
2777         kfree(ext4_li_info);
2778         ext4_li_info = NULL;
2779         mutex_unlock(&ext4_li_mtx);
2780
2781         return 0;
2782 }
2783
2784 static void ext4_clear_request_list(void)
2785 {
2786         struct list_head *pos, *n;
2787         struct ext4_li_request *elr;
2788
2789         mutex_lock(&ext4_li_info->li_list_mtx);
2790         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2791                 elr = list_entry(pos, struct ext4_li_request,
2792                                  lr_request);
2793                 ext4_remove_li_request(elr);
2794         }
2795         mutex_unlock(&ext4_li_info->li_list_mtx);
2796 }
2797
2798 static int ext4_run_lazyinit_thread(void)
2799 {
2800         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2801                                          ext4_li_info, "ext4lazyinit");
2802         if (IS_ERR(ext4_lazyinit_task)) {
2803                 int err = PTR_ERR(ext4_lazyinit_task);
2804                 ext4_clear_request_list();
2805                 kfree(ext4_li_info);
2806                 ext4_li_info = NULL;
2807                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2808                                  "initialization thread\n",
2809                                  err);
2810                 return err;
2811         }
2812         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2813         return 0;
2814 }
2815
2816 /*
2817  * Check whether it make sense to run itable init. thread or not.
2818  * If there is at least one uninitialized inode table, return
2819  * corresponding group number, else the loop goes through all
2820  * groups and return total number of groups.
2821  */
2822 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2823 {
2824         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2825         struct ext4_group_desc *gdp = NULL;
2826
2827         for (group = 0; group < ngroups; group++) {
2828                 gdp = ext4_get_group_desc(sb, group, NULL);
2829                 if (!gdp)
2830                         continue;
2831
2832                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2833                         break;
2834         }
2835
2836         return group;
2837 }
2838
2839 static int ext4_li_info_new(void)
2840 {
2841         struct ext4_lazy_init *eli = NULL;
2842
2843         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2844         if (!eli)
2845                 return -ENOMEM;
2846
2847         INIT_LIST_HEAD(&eli->li_request_list);
2848         mutex_init(&eli->li_list_mtx);
2849
2850         eli->li_state |= EXT4_LAZYINIT_QUIT;
2851
2852         ext4_li_info = eli;
2853
2854         return 0;
2855 }
2856
2857 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2858                                             ext4_group_t start)
2859 {
2860         struct ext4_sb_info *sbi = EXT4_SB(sb);
2861         struct ext4_li_request *elr;
2862
2863         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2864         if (!elr)
2865                 return NULL;
2866
2867         elr->lr_super = sb;
2868         elr->lr_sbi = sbi;
2869         elr->lr_next_group = start;
2870
2871         /*
2872          * Randomize first schedule time of the request to
2873          * spread the inode table initialization requests
2874          * better.
2875          */
2876         elr->lr_next_sched = jiffies + (prandom_u32() %
2877                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2878         return elr;
2879 }
2880
2881 int ext4_register_li_request(struct super_block *sb,
2882                              ext4_group_t first_not_zeroed)
2883 {
2884         struct ext4_sb_info *sbi = EXT4_SB(sb);
2885         struct ext4_li_request *elr = NULL;
2886         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2887         int ret = 0;
2888
2889         mutex_lock(&ext4_li_mtx);
2890         if (sbi->s_li_request != NULL) {
2891                 /*
2892                  * Reset timeout so it can be computed again, because
2893                  * s_li_wait_mult might have changed.
2894                  */
2895                 sbi->s_li_request->lr_timeout = 0;
2896                 goto out;
2897         }
2898
2899         if (first_not_zeroed == ngroups ||
2900             (sb->s_flags & MS_RDONLY) ||
2901             !test_opt(sb, INIT_INODE_TABLE))
2902                 goto out;
2903
2904         elr = ext4_li_request_new(sb, first_not_zeroed);
2905         if (!elr) {
2906                 ret = -ENOMEM;
2907                 goto out;
2908         }
2909
2910         if (NULL == ext4_li_info) {
2911                 ret = ext4_li_info_new();
2912                 if (ret)
2913                         goto out;
2914         }
2915
2916         mutex_lock(&ext4_li_info->li_list_mtx);
2917         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
2918         mutex_unlock(&ext4_li_info->li_list_mtx);
2919
2920         sbi->s_li_request = elr;
2921         /*
2922          * set elr to NULL here since it has been inserted to
2923          * the request_list and the removal and free of it is
2924          * handled by ext4_clear_request_list from now on.
2925          */
2926         elr = NULL;
2927
2928         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
2929                 ret = ext4_run_lazyinit_thread();
2930                 if (ret)
2931                         goto out;
2932         }
2933 out:
2934         mutex_unlock(&ext4_li_mtx);
2935         if (ret)
2936                 kfree(elr);
2937         return ret;
2938 }
2939
2940 /*
2941  * We do not need to lock anything since this is called on
2942  * module unload.
2943  */
2944 static void ext4_destroy_lazyinit_thread(void)
2945 {
2946         /*
2947          * If thread exited earlier
2948          * there's nothing to be done.
2949          */
2950         if (!ext4_li_info || !ext4_lazyinit_task)
2951                 return;
2952
2953         kthread_stop(ext4_lazyinit_task);
2954 }
2955
2956 static int set_journal_csum_feature_set(struct super_block *sb)
2957 {
2958         int ret = 1;
2959         int compat, incompat;
2960         struct ext4_sb_info *sbi = EXT4_SB(sb);
2961
2962         if (ext4_has_metadata_csum(sb)) {
2963                 /* journal checksum v3 */
2964                 compat = 0;
2965                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
2966         } else {
2967                 /* journal checksum v1 */
2968                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
2969                 incompat = 0;
2970         }
2971
2972         jbd2_journal_clear_features(sbi->s_journal,
2973                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2974                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
2975                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
2976         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2977                 ret = jbd2_journal_set_features(sbi->s_journal,
2978                                 compat, 0,
2979                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
2980                                 incompat);
2981         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2982                 ret = jbd2_journal_set_features(sbi->s_journal,
2983                                 compat, 0,
2984                                 incompat);
2985                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2986                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2987         } else {
2988                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2989                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2990         }
2991
2992         return ret;
2993 }
2994
2995 /*
2996  * Note: calculating the overhead so we can be compatible with
2997  * historical BSD practice is quite difficult in the face of
2998  * clusters/bigalloc.  This is because multiple metadata blocks from
2999  * different block group can end up in the same allocation cluster.
3000  * Calculating the exact overhead in the face of clustered allocation
3001  * requires either O(all block bitmaps) in memory or O(number of block
3002  * groups**2) in time.  We will still calculate the superblock for
3003  * older file systems --- and if we come across with a bigalloc file
3004  * system with zero in s_overhead_clusters the estimate will be close to
3005  * correct especially for very large cluster sizes --- but for newer
3006  * file systems, it's better to calculate this figure once at mkfs
3007  * time, and store it in the superblock.  If the superblock value is
3008  * present (even for non-bigalloc file systems), we will use it.
3009  */
3010 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3011                           char *buf)
3012 {
3013         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3014         struct ext4_group_desc  *gdp;
3015         ext4_fsblk_t            first_block, last_block, b;
3016         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3017         int                     s, j, count = 0;
3018
3019         if (!ext4_has_feature_bigalloc(sb))
3020                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3021                         sbi->s_itb_per_group + 2);
3022
3023         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3024                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3025         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3026         for (i = 0; i < ngroups; i++) {
3027                 gdp = ext4_get_group_desc(sb, i, NULL);
3028                 b = ext4_block_bitmap(sb, gdp);
3029                 if (b >= first_block && b <= last_block) {
3030                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3031                         count++;
3032                 }
3033                 b = ext4_inode_bitmap(sb, gdp);
3034                 if (b >= first_block && b <= last_block) {
3035                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3036                         count++;
3037                 }
3038                 b = ext4_inode_table(sb, gdp);
3039                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3040                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3041                                 int c = EXT4_B2C(sbi, b - first_block);
3042                                 ext4_set_bit(c, buf);
3043                                 count++;
3044                         }
3045                 if (i != grp)
3046                         continue;
3047                 s = 0;
3048                 if (ext4_bg_has_super(sb, grp)) {
3049                         ext4_set_bit(s++, buf);
3050                         count++;
3051                 }
3052                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3053                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3054                         count++;
3055                 }
3056         }
3057         if (!count)
3058                 return 0;
3059         return EXT4_CLUSTERS_PER_GROUP(sb) -
3060                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3061 }
3062
3063 /*
3064  * Compute the overhead and stash it in sbi->s_overhead
3065  */
3066 int ext4_calculate_overhead(struct super_block *sb)
3067 {
3068         struct ext4_sb_info *sbi = EXT4_SB(sb);
3069         struct ext4_super_block *es = sbi->s_es;
3070         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3071         ext4_fsblk_t overhead = 0;
3072         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3073
3074         if (!buf)
3075                 return -ENOMEM;
3076
3077         /*
3078          * Compute the overhead (FS structures).  This is constant
3079          * for a given filesystem unless the number of block groups
3080          * changes so we cache the previous value until it does.
3081          */
3082
3083         /*
3084          * All of the blocks before first_data_block are overhead
3085          */
3086         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3087
3088         /*
3089          * Add the overhead found in each block group
3090          */
3091         for (i = 0; i < ngroups; i++) {
3092                 int blks;
3093
3094                 blks = count_overhead(sb, i, buf);
3095                 overhead += blks;
3096                 if (blks)
3097                         memset(buf, 0, PAGE_SIZE);
3098                 cond_resched();
3099         }
3100         /* Add the internal journal blocks as well */
3101         if (sbi->s_journal && !sbi->journal_bdev)
3102                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3103
3104         sbi->s_overhead = overhead;
3105         smp_wmb();
3106         free_page((unsigned long) buf);
3107         return 0;
3108 }
3109
3110 static void ext4_set_resv_clusters(struct super_block *sb)
3111 {
3112         ext4_fsblk_t resv_clusters;
3113         struct ext4_sb_info *sbi = EXT4_SB(sb);
3114
3115         /*
3116          * There's no need to reserve anything when we aren't using extents.
3117          * The space estimates are exact, there are no unwritten extents,
3118          * hole punching doesn't need new metadata... This is needed especially
3119          * to keep ext2/3 backward compatibility.
3120          */
3121         if (!ext4_has_feature_extents(sb))
3122                 return;
3123         /*
3124          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3125          * This should cover the situations where we can not afford to run
3126          * out of space like for example punch hole, or converting
3127          * unwritten extents in delalloc path. In most cases such
3128          * allocation would require 1, or 2 blocks, higher numbers are
3129          * very rare.
3130          */
3131         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3132                          sbi->s_cluster_bits);
3133
3134         do_div(resv_clusters, 50);
3135         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3136
3137         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3138 }
3139
3140 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3141 {
3142         char *orig_data = kstrdup(data, GFP_KERNEL);
3143         struct buffer_head *bh;
3144         struct ext4_super_block *es = NULL;
3145         struct ext4_sb_info *sbi;
3146         ext4_fsblk_t block;
3147         ext4_fsblk_t sb_block = get_sb_block(&data);
3148         ext4_fsblk_t logical_sb_block;
3149         unsigned long offset = 0;
3150         unsigned long journal_devnum = 0;
3151         unsigned long def_mount_opts;
3152         struct inode *root;
3153         const char *descr;
3154         int ret = -ENOMEM;
3155         int blocksize, clustersize;
3156         unsigned int db_count;
3157         unsigned int i;
3158         int needs_recovery, has_huge_files, has_bigalloc;
3159         __u64 blocks_count;
3160         int err = 0;
3161         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3162         ext4_group_t first_not_zeroed;
3163
3164         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3165         if (!sbi)
3166                 goto out_free_orig;
3167
3168         sbi->s_blockgroup_lock =
3169                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3170         if (!sbi->s_blockgroup_lock) {
3171                 kfree(sbi);
3172                 goto out_free_orig;
3173         }
3174         sb->s_fs_info = sbi;
3175         sbi->s_sb = sb;
3176         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3177         sbi->s_sb_block = sb_block;
3178         if (sb->s_bdev->bd_part)
3179                 sbi->s_sectors_written_start =
3180                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3181
3182         /* Cleanup superblock name */
3183         strreplace(sb->s_id, '/', '!');
3184
3185         /* -EINVAL is default */
3186         ret = -EINVAL;
3187         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3188         if (!blocksize) {
3189                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3190                 goto out_fail;
3191         }
3192
3193         /*
3194          * The ext4 superblock will not be buffer aligned for other than 1kB
3195          * block sizes.  We need to calculate the offset from buffer start.
3196          */
3197         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3198                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3199                 offset = do_div(logical_sb_block, blocksize);
3200         } else {
3201                 logical_sb_block = sb_block;
3202         }
3203
3204         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3205                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3206                 goto out_fail;
3207         }
3208         /*
3209          * Note: s_es must be initialized as soon as possible because
3210          *       some ext4 macro-instructions depend on its value
3211          */
3212         es = (struct ext4_super_block *) (bh->b_data + offset);
3213         sbi->s_es = es;
3214         sb->s_magic = le16_to_cpu(es->s_magic);
3215         if (sb->s_magic != EXT4_SUPER_MAGIC)
3216                 goto cantfind_ext4;
3217         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3218
3219         /* Warn if metadata_csum and gdt_csum are both set. */
3220         if (ext4_has_feature_metadata_csum(sb) &&
3221             ext4_has_feature_gdt_csum(sb))
3222                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3223                              "redundant flags; please run fsck.");
3224
3225         /* Check for a known checksum algorithm */
3226         if (!ext4_verify_csum_type(sb, es)) {
3227                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3228                          "unknown checksum algorithm.");
3229                 silent = 1;
3230                 goto cantfind_ext4;
3231         }
3232
3233         /* Load the checksum driver */
3234         if (ext4_has_feature_metadata_csum(sb)) {
3235                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3236                 if (IS_ERR(sbi->s_chksum_driver)) {
3237                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3238                         ret = PTR_ERR(sbi->s_chksum_driver);
3239                         sbi->s_chksum_driver = NULL;
3240                         goto failed_mount;
3241                 }
3242         }
3243
3244         /* Check superblock checksum */
3245         if (!ext4_superblock_csum_verify(sb, es)) {
3246                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3247                          "invalid superblock checksum.  Run e2fsck?");
3248                 silent = 1;
3249                 ret = -EFSBADCRC;
3250                 goto cantfind_ext4;
3251         }
3252
3253         /* Precompute checksum seed for all metadata */
3254         if (ext4_has_feature_csum_seed(sb))
3255                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3256         else if (ext4_has_metadata_csum(sb))
3257                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3258                                                sizeof(es->s_uuid));
3259
3260         /* Set defaults before we parse the mount options */
3261         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3262         set_opt(sb, INIT_INODE_TABLE);
3263         if (def_mount_opts & EXT4_DEFM_DEBUG)
3264                 set_opt(sb, DEBUG);
3265         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3266                 set_opt(sb, GRPID);
3267         if (def_mount_opts & EXT4_DEFM_UID16)
3268                 set_opt(sb, NO_UID32);
3269         /* xattr user namespace & acls are now defaulted on */
3270         set_opt(sb, XATTR_USER);
3271 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3272         set_opt(sb, POSIX_ACL);
3273 #endif
3274         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3275         if (ext4_has_metadata_csum(sb))
3276                 set_opt(sb, JOURNAL_CHECKSUM);
3277
3278         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3279                 set_opt(sb, JOURNAL_DATA);
3280         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3281                 set_opt(sb, ORDERED_DATA);
3282         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3283                 set_opt(sb, WRITEBACK_DATA);
3284
3285         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3286                 set_opt(sb, ERRORS_PANIC);
3287         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3288                 set_opt(sb, ERRORS_CONT);
3289         else
3290                 set_opt(sb, ERRORS_RO);
3291         /* block_validity enabled by default; disable with noblock_validity */
3292         set_opt(sb, BLOCK_VALIDITY);
3293         if (def_mount_opts & EXT4_DEFM_DISCARD)
3294                 set_opt(sb, DISCARD);
3295
3296         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3297         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3298         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3299         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3300         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3301
3302         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3303                 set_opt(sb, BARRIER);
3304
3305         /*
3306          * enable delayed allocation by default
3307          * Use -o nodelalloc to turn it off
3308          */
3309         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3310             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3311                 set_opt(sb, DELALLOC);
3312
3313         /*
3314          * set default s_li_wait_mult for lazyinit, for the case there is
3315          * no mount option specified.
3316          */
3317         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3318
3319         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3320                            &journal_devnum, &journal_ioprio, 0)) {
3321                 ext4_msg(sb, KERN_WARNING,
3322                          "failed to parse options in superblock: %s",
3323                          sbi->s_es->s_mount_opts);
3324         }
3325         sbi->s_def_mount_opt = sbi->s_mount_opt;
3326         if (!parse_options((char *) data, sb, &journal_devnum,
3327                            &journal_ioprio, 0))
3328                 goto failed_mount;
3329
3330         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3331                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3332                             "with data=journal disables delayed "
3333                             "allocation and O_DIRECT support!\n");
3334                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3335                         ext4_msg(sb, KERN_ERR, "can't mount with "
3336                                  "both data=journal and delalloc");
3337                         goto failed_mount;
3338                 }
3339                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3340                         ext4_msg(sb, KERN_ERR, "can't mount with "
3341                                  "both data=journal and dioread_nolock");
3342                         goto failed_mount;
3343                 }
3344                 if (test_opt(sb, DAX)) {
3345                         ext4_msg(sb, KERN_ERR, "can't mount with "
3346                                  "both data=journal and dax");
3347                         goto failed_mount;
3348                 }
3349                 if (test_opt(sb, DELALLOC))
3350                         clear_opt(sb, DELALLOC);
3351         } else {
3352                 sb->s_iflags |= SB_I_CGROUPWB;
3353         }
3354
3355         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3356                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3357
3358         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3359             (ext4_has_compat_features(sb) ||
3360              ext4_has_ro_compat_features(sb) ||
3361              ext4_has_incompat_features(sb)))
3362                 ext4_msg(sb, KERN_WARNING,
3363                        "feature flags set on rev 0 fs, "
3364                        "running e2fsck is recommended");
3365
3366         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3367                 set_opt2(sb, HURD_COMPAT);
3368                 if (ext4_has_feature_64bit(sb)) {
3369                         ext4_msg(sb, KERN_ERR,
3370                                  "The Hurd can't support 64-bit file systems");
3371                         goto failed_mount;
3372                 }
3373         }
3374
3375         if (IS_EXT2_SB(sb)) {
3376                 if (ext2_feature_set_ok(sb))
3377                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3378                                  "using the ext4 subsystem");
3379                 else {
3380                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3381                                  "to feature incompatibilities");
3382                         goto failed_mount;
3383                 }
3384         }
3385
3386         if (IS_EXT3_SB(sb)) {
3387                 if (ext3_feature_set_ok(sb))
3388                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3389                                  "using the ext4 subsystem");
3390                 else {
3391                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3392                                  "to feature incompatibilities");
3393                         goto failed_mount;
3394                 }
3395         }
3396
3397         /*
3398          * Check feature flags regardless of the revision level, since we
3399          * previously didn't change the revision level when setting the flags,
3400          * so there is a chance incompat flags are set on a rev 0 filesystem.
3401          */
3402         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3403                 goto failed_mount;
3404
3405         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3406         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3407             blocksize > EXT4_MAX_BLOCK_SIZE) {
3408                 ext4_msg(sb, KERN_ERR,
3409                        "Unsupported filesystem blocksize %d", blocksize);
3410                 goto failed_mount;
3411         }
3412
3413         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3414                 if (blocksize != PAGE_SIZE) {
3415                         ext4_msg(sb, KERN_ERR,
3416                                         "error: unsupported blocksize for dax");
3417                         goto failed_mount;
3418                 }
3419                 if (!sb->s_bdev->bd_disk->fops->direct_access) {
3420                         ext4_msg(sb, KERN_ERR,
3421                                         "error: device does not support dax");
3422                         goto failed_mount;
3423                 }
3424         }
3425
3426         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3427                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3428                          es->s_encryption_level);
3429                 goto failed_mount;
3430         }
3431
3432         if (sb->s_blocksize != blocksize) {
3433                 /* Validate the filesystem blocksize */
3434                 if (!sb_set_blocksize(sb, blocksize)) {
3435                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3436                                         blocksize);
3437                         goto failed_mount;
3438                 }
3439
3440                 brelse(bh);
3441                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3442                 offset = do_div(logical_sb_block, blocksize);
3443                 bh = sb_bread_unmovable(sb, logical_sb_block);
3444                 if (!bh) {
3445                         ext4_msg(sb, KERN_ERR,
3446                                "Can't read superblock on 2nd try");
3447                         goto failed_mount;
3448                 }
3449                 es = (struct ext4_super_block *)(bh->b_data + offset);
3450                 sbi->s_es = es;
3451                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3452                         ext4_msg(sb, KERN_ERR,
3453                                "Magic mismatch, very weird!");
3454                         goto failed_mount;
3455                 }
3456         }
3457
3458         has_huge_files = ext4_has_feature_huge_file(sb);
3459         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3460                                                       has_huge_files);
3461         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3462
3463         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3464                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3465                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3466         } else {
3467                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3468                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3469                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3470                     (!is_power_of_2(sbi->s_inode_size)) ||
3471                     (sbi->s_inode_size > blocksize)) {
3472                         ext4_msg(sb, KERN_ERR,
3473                                "unsupported inode size: %d",
3474                                sbi->s_inode_size);
3475                         goto failed_mount;
3476                 }
3477                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3478                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3479         }
3480
3481         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3482         if (ext4_has_feature_64bit(sb)) {
3483                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3484                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3485                     !is_power_of_2(sbi->s_desc_size)) {
3486                         ext4_msg(sb, KERN_ERR,
3487                                "unsupported descriptor size %lu",
3488                                sbi->s_desc_size);
3489                         goto failed_mount;
3490                 }
3491         } else
3492                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3493
3494         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3495         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3496         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3497                 goto cantfind_ext4;
3498
3499         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3500         if (sbi->s_inodes_per_block == 0)
3501                 goto cantfind_ext4;
3502         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3503                                         sbi->s_inodes_per_block;
3504         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3505         sbi->s_sbh = bh;
3506         sbi->s_mount_state = le16_to_cpu(es->s_state);
3507         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3508         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3509
3510         for (i = 0; i < 4; i++)
3511                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3512         sbi->s_def_hash_version = es->s_def_hash_version;
3513         if (ext4_has_feature_dir_index(sb)) {
3514                 i = le32_to_cpu(es->s_flags);
3515                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3516                         sbi->s_hash_unsigned = 3;
3517                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3518 #ifdef __CHAR_UNSIGNED__
3519                         if (!(sb->s_flags & MS_RDONLY))
3520                                 es->s_flags |=
3521                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3522                         sbi->s_hash_unsigned = 3;
3523 #else
3524                         if (!(sb->s_flags & MS_RDONLY))
3525                                 es->s_flags |=
3526                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3527 #endif
3528                 }
3529         }
3530
3531         /* Handle clustersize */
3532         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3533         has_bigalloc = ext4_has_feature_bigalloc(sb);
3534         if (has_bigalloc) {
3535                 if (clustersize < blocksize) {
3536                         ext4_msg(sb, KERN_ERR,
3537                                  "cluster size (%d) smaller than "
3538                                  "block size (%d)", clustersize, blocksize);
3539                         goto failed_mount;
3540                 }
3541                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3542                         le32_to_cpu(es->s_log_block_size);
3543                 sbi->s_clusters_per_group =
3544                         le32_to_cpu(es->s_clusters_per_group);
3545                 if (sbi->s_clusters_per_group > blocksize * 8) {
3546                         ext4_msg(sb, KERN_ERR,
3547                                  "#clusters per group too big: %lu",
3548                                  sbi->s_clusters_per_group);
3549                         goto failed_mount;
3550                 }
3551                 if (sbi->s_blocks_per_group !=
3552                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3553                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3554                                  "clusters per group (%lu) inconsistent",
3555                                  sbi->s_blocks_per_group,
3556                                  sbi->s_clusters_per_group);
3557                         goto failed_mount;
3558                 }
3559         } else {
3560                 if (clustersize != blocksize) {
3561                         ext4_warning(sb, "fragment/cluster size (%d) != "
3562                                      "block size (%d)", clustersize,
3563                                      blocksize);
3564                         clustersize = blocksize;
3565                 }
3566                 if (sbi->s_blocks_per_group > blocksize * 8) {
3567                         ext4_msg(sb, KERN_ERR,
3568                                  "#blocks per group too big: %lu",
3569                                  sbi->s_blocks_per_group);
3570                         goto failed_mount;
3571                 }
3572                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3573                 sbi->s_cluster_bits = 0;
3574         }
3575         sbi->s_cluster_ratio = clustersize / blocksize;
3576
3577         if (sbi->s_inodes_per_group > blocksize * 8) {
3578                 ext4_msg(sb, KERN_ERR,
3579                        "#inodes per group too big: %lu",
3580                        sbi->s_inodes_per_group);
3581                 goto failed_mount;
3582         }
3583
3584         /* Do we have standard group size of clustersize * 8 blocks ? */
3585         if (sbi->s_blocks_per_group == clustersize << 3)
3586                 set_opt2(sb, STD_GROUP_SIZE);
3587
3588         /*
3589          * Test whether we have more sectors than will fit in sector_t,
3590          * and whether the max offset is addressable by the page cache.
3591          */
3592         err = generic_check_addressable(sb->s_blocksize_bits,
3593                                         ext4_blocks_count(es));
3594         if (err) {
3595                 ext4_msg(sb, KERN_ERR, "filesystem"
3596                          " too large to mount safely on this system");
3597                 if (sizeof(sector_t) < 8)
3598                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3599                 goto failed_mount;
3600         }
3601
3602         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3603                 goto cantfind_ext4;
3604
3605         /* check blocks count against device size */
3606         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3607         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3608                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3609                        "exceeds size of device (%llu blocks)",
3610                        ext4_blocks_count(es), blocks_count);
3611                 goto failed_mount;
3612         }
3613
3614         /*
3615          * It makes no sense for the first data block to be beyond the end
3616          * of the filesystem.
3617          */
3618         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3619                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3620                          "block %u is beyond end of filesystem (%llu)",
3621                          le32_to_cpu(es->s_first_data_block),
3622                          ext4_blocks_count(es));
3623                 goto failed_mount;
3624         }
3625         blocks_count = (ext4_blocks_count(es) -
3626                         le32_to_cpu(es->s_first_data_block) +
3627                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3628         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3629         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3630                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3631                        "(block count %llu, first data block %u, "
3632                        "blocks per group %lu)", sbi->s_groups_count,
3633                        ext4_blocks_count(es),
3634                        le32_to_cpu(es->s_first_data_block),
3635                        EXT4_BLOCKS_PER_GROUP(sb));
3636                 goto failed_mount;
3637         }
3638         sbi->s_groups_count = blocks_count;
3639         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3640                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3641         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3642                    EXT4_DESC_PER_BLOCK(sb);
3643         sbi->s_group_desc = ext4_kvmalloc(db_count *
3644                                           sizeof(struct buffer_head *),
3645                                           GFP_KERNEL);
3646         if (sbi->s_group_desc == NULL) {
3647                 ext4_msg(sb, KERN_ERR, "not enough memory");
3648                 ret = -ENOMEM;
3649                 goto failed_mount;
3650         }
3651
3652         bgl_lock_init(sbi->s_blockgroup_lock);
3653
3654         for (i = 0; i < db_count; i++) {
3655                 block = descriptor_loc(sb, logical_sb_block, i);
3656                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3657                 if (!sbi->s_group_desc[i]) {
3658                         ext4_msg(sb, KERN_ERR,
3659                                "can't read group descriptor %d", i);
3660                         db_count = i;
3661                         goto failed_mount2;
3662                 }
3663         }
3664         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3665                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3666                 ret = -EFSCORRUPTED;
3667                 goto failed_mount2;
3668         }
3669
3670         sbi->s_gdb_count = db_count;
3671         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3672         spin_lock_init(&sbi->s_next_gen_lock);
3673
3674         setup_timer(&sbi->s_err_report, print_daily_error_info,
3675                 (unsigned long) sb);
3676
3677         /* Register extent status tree shrinker */
3678         if (ext4_es_register_shrinker(sbi))
3679                 goto failed_mount3;
3680
3681         sbi->s_stripe = ext4_get_stripe_size(sbi);
3682         sbi->s_extent_max_zeroout_kb = 32;
3683
3684         /*
3685          * set up enough so that it can read an inode
3686          */
3687         sb->s_op = &ext4_sops;
3688         sb->s_export_op = &ext4_export_ops;
3689         sb->s_xattr = ext4_xattr_handlers;
3690 #ifdef CONFIG_QUOTA
3691         sb->dq_op = &ext4_quota_operations;
3692         if (ext4_has_feature_quota(sb))
3693                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3694         else
3695                 sb->s_qcop = &ext4_qctl_operations;
3696         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3697 #endif
3698         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3699
3700         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3701         mutex_init(&sbi->s_orphan_lock);
3702
3703         sb->s_root = NULL;
3704
3705         needs_recovery = (es->s_last_orphan != 0 ||
3706                           ext4_has_feature_journal_needs_recovery(sb));
3707
3708         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3709                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3710                         goto failed_mount3a;
3711
3712         /*
3713          * The first inode we look at is the journal inode.  Don't try
3714          * root first: it may be modified in the journal!
3715          */
3716         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3717                 if (ext4_load_journal(sb, es, journal_devnum))
3718                         goto failed_mount3a;
3719         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3720                    ext4_has_feature_journal_needs_recovery(sb)) {
3721                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3722                        "suppressed and not mounted read-only");
3723                 goto failed_mount_wq;
3724         } else {
3725                 /* Nojournal mode, all journal mount options are illegal */
3726                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3727                         ext4_msg(sb, KERN_ERR, "can't mount with "
3728                                  "journal_checksum, fs mounted w/o journal");
3729                         goto failed_mount_wq;
3730                 }
3731                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3732                         ext4_msg(sb, KERN_ERR, "can't mount with "
3733                                  "journal_async_commit, fs mounted w/o journal");
3734                         goto failed_mount_wq;
3735                 }
3736                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3737                         ext4_msg(sb, KERN_ERR, "can't mount with "
3738                                  "commit=%lu, fs mounted w/o journal",
3739                                  sbi->s_commit_interval / HZ);
3740                         goto failed_mount_wq;
3741                 }
3742                 if (EXT4_MOUNT_DATA_FLAGS &
3743                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3744                         ext4_msg(sb, KERN_ERR, "can't mount with "
3745                                  "data=, fs mounted w/o journal");
3746                         goto failed_mount_wq;
3747                 }
3748                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3749                 clear_opt(sb, JOURNAL_CHECKSUM);
3750                 clear_opt(sb, DATA_FLAGS);
3751                 sbi->s_journal = NULL;
3752                 needs_recovery = 0;
3753                 goto no_journal;
3754         }
3755
3756         if (ext4_has_feature_64bit(sb) &&
3757             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3758                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3759                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3760                 goto failed_mount_wq;
3761         }
3762
3763         if (!set_journal_csum_feature_set(sb)) {
3764                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3765                          "feature set");
3766                 goto failed_mount_wq;
3767         }
3768
3769         /* We have now updated the journal if required, so we can
3770          * validate the data journaling mode. */
3771         switch (test_opt(sb, DATA_FLAGS)) {
3772         case 0:
3773                 /* No mode set, assume a default based on the journal
3774                  * capabilities: ORDERED_DATA if the journal can
3775                  * cope, else JOURNAL_DATA
3776                  */
3777                 if (jbd2_journal_check_available_features
3778                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3779                         set_opt(sb, ORDERED_DATA);
3780                 else
3781                         set_opt(sb, JOURNAL_DATA);
3782                 break;
3783
3784         case EXT4_MOUNT_ORDERED_DATA:
3785         case EXT4_MOUNT_WRITEBACK_DATA:
3786                 if (!jbd2_journal_check_available_features
3787                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3788                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3789                                "requested data journaling mode");
3790                         goto failed_mount_wq;
3791                 }
3792         default:
3793                 break;
3794         }
3795         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3796
3797         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3798
3799 no_journal:
3800         if (ext4_mballoc_ready) {
3801                 sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
3802                 if (!sbi->s_mb_cache) {
3803                         ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
3804                         goto failed_mount_wq;
3805                 }
3806         }
3807
3808         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
3809             (blocksize != PAGE_CACHE_SIZE)) {
3810                 ext4_msg(sb, KERN_ERR,
3811                          "Unsupported blocksize for fs encryption");
3812                 goto failed_mount_wq;
3813         }
3814
3815         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
3816             !ext4_has_feature_encrypt(sb)) {
3817                 ext4_set_feature_encrypt(sb);
3818                 ext4_commit_super(sb, 1);
3819         }
3820
3821         /*
3822          * Get the # of file system overhead blocks from the
3823          * superblock if present.
3824          */
3825         if (es->s_overhead_clusters)
3826                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3827         else {
3828                 err = ext4_calculate_overhead(sb);
3829                 if (err)
3830                         goto failed_mount_wq;
3831         }
3832
3833         /*
3834          * The maximum number of concurrent works can be high and
3835          * concurrency isn't really necessary.  Limit it to 1.
3836          */
3837         EXT4_SB(sb)->rsv_conversion_wq =
3838                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3839         if (!EXT4_SB(sb)->rsv_conversion_wq) {
3840                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3841                 ret = -ENOMEM;
3842                 goto failed_mount4;
3843         }
3844
3845         /*
3846          * The jbd2_journal_load will have done any necessary log recovery,
3847          * so we can safely mount the rest of the filesystem now.
3848          */
3849
3850         root = ext4_iget(sb, EXT4_ROOT_INO);
3851         if (IS_ERR(root)) {
3852                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3853                 ret = PTR_ERR(root);
3854                 root = NULL;
3855                 goto failed_mount4;
3856         }
3857         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3858                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3859                 iput(root);
3860                 goto failed_mount4;
3861         }
3862         sb->s_root = d_make_root(root);
3863         if (!sb->s_root) {
3864                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3865                 ret = -ENOMEM;
3866                 goto failed_mount4;
3867         }
3868
3869         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3870                 sb->s_flags |= MS_RDONLY;
3871
3872         /* determine the minimum size of new large inodes, if present */
3873         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3874                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3875                                                      EXT4_GOOD_OLD_INODE_SIZE;
3876                 if (ext4_has_feature_extra_isize(sb)) {
3877                         if (sbi->s_want_extra_isize <
3878                             le16_to_cpu(es->s_want_extra_isize))
3879                                 sbi->s_want_extra_isize =
3880                                         le16_to_cpu(es->s_want_extra_isize);
3881                         if (sbi->s_want_extra_isize <
3882                             le16_to_cpu(es->s_min_extra_isize))
3883                                 sbi->s_want_extra_isize =
3884                                         le16_to_cpu(es->s_min_extra_isize);
3885                 }
3886         }
3887         /* Check if enough inode space is available */
3888         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3889                                                         sbi->s_inode_size) {
3890                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3891                                                        EXT4_GOOD_OLD_INODE_SIZE;
3892                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3893                          "available");
3894         }
3895
3896         ext4_set_resv_clusters(sb);
3897
3898         err = ext4_setup_system_zone(sb);
3899         if (err) {
3900                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3901                          "zone (%d)", err);
3902                 goto failed_mount4a;
3903         }
3904
3905         ext4_ext_init(sb);
3906         err = ext4_mb_init(sb);
3907         if (err) {
3908                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3909                          err);
3910                 goto failed_mount5;
3911         }
3912
3913         block = ext4_count_free_clusters(sb);
3914         ext4_free_blocks_count_set(sbi->s_es,
3915                                    EXT4_C2B(sbi, block));
3916         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
3917                                   GFP_KERNEL);
3918         if (!err) {
3919                 unsigned long freei = ext4_count_free_inodes(sb);
3920                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
3921                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
3922                                           GFP_KERNEL);
3923         }
3924         if (!err)
3925                 err = percpu_counter_init(&sbi->s_dirs_counter,
3926                                           ext4_count_dirs(sb), GFP_KERNEL);
3927         if (!err)
3928                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
3929                                           GFP_KERNEL);
3930         if (err) {
3931                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3932                 goto failed_mount6;
3933         }
3934
3935         if (ext4_has_feature_flex_bg(sb))
3936                 if (!ext4_fill_flex_info(sb)) {
3937                         ext4_msg(sb, KERN_ERR,
3938                                "unable to initialize "
3939                                "flex_bg meta info!");
3940                         goto failed_mount6;
3941                 }
3942
3943         err = ext4_register_li_request(sb, first_not_zeroed);
3944         if (err)
3945                 goto failed_mount6;
3946
3947         err = ext4_register_sysfs(sb);
3948         if (err)
3949                 goto failed_mount7;
3950
3951 #ifdef CONFIG_QUOTA
3952         /* Enable quota usage during mount. */
3953         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
3954                 err = ext4_enable_quotas(sb);
3955                 if (err)
3956                         goto failed_mount8;
3957         }
3958 #endif  /* CONFIG_QUOTA */
3959
3960         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3961         ext4_orphan_cleanup(sb, es);
3962         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3963         if (needs_recovery) {
3964                 ext4_msg(sb, KERN_INFO, "recovery complete");
3965                 ext4_mark_recovery_complete(sb, es);
3966         }
3967         if (EXT4_SB(sb)->s_journal) {
3968                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3969                         descr = " journalled data mode";
3970                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3971                         descr = " ordered data mode";
3972                 else
3973                         descr = " writeback data mode";
3974         } else
3975                 descr = "out journal";
3976
3977         if (test_opt(sb, DISCARD)) {
3978                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
3979                 if (!blk_queue_discard(q))
3980                         ext4_msg(sb, KERN_WARNING,
3981                                  "mounting with \"discard\" option, but "
3982                                  "the device does not support discard");
3983         }
3984
3985         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
3986                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3987                          "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3988                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3989
3990         if (es->s_error_count)
3991                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3992
3993         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
3994         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
3995         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
3996         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
3997
3998         kfree(orig_data);
3999         return 0;
4000
4001 cantfind_ext4:
4002         if (!silent)
4003                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4004         goto failed_mount;
4005
4006 #ifdef CONFIG_QUOTA
4007 failed_mount8:
4008         ext4_unregister_sysfs(sb);
4009 #endif
4010 failed_mount7:
4011         ext4_unregister_li_request(sb);
4012 failed_mount6:
4013         ext4_mb_release(sb);
4014         if (sbi->s_flex_groups)
4015                 kvfree(sbi->s_flex_groups);
4016         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4017         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4018         percpu_counter_destroy(&sbi->s_dirs_counter);
4019         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4020 failed_mount5:
4021         ext4_ext_release(sb);
4022         ext4_release_system_zone(sb);
4023 failed_mount4a:
4024         dput(sb->s_root);
4025         sb->s_root = NULL;
4026 failed_mount4:
4027         ext4_msg(sb, KERN_ERR, "mount failed");
4028         if (EXT4_SB(sb)->rsv_conversion_wq)
4029                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4030 failed_mount_wq:
4031         if (sbi->s_journal) {
4032                 jbd2_journal_destroy(sbi->s_journal);
4033                 sbi->s_journal = NULL;
4034         }
4035 failed_mount3a:
4036         ext4_es_unregister_shrinker(sbi);
4037 failed_mount3:
4038         del_timer_sync(&sbi->s_err_report);
4039         if (sbi->s_mmp_tsk)
4040                 kthread_stop(sbi->s_mmp_tsk);
4041 failed_mount2:
4042         for (i = 0; i < db_count; i++)
4043                 brelse(sbi->s_group_desc[i]);
4044         kvfree(sbi->s_group_desc);
4045 failed_mount:
4046         if (sbi->s_chksum_driver)
4047                 crypto_free_shash(sbi->s_chksum_driver);
4048 #ifdef CONFIG_QUOTA
4049         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4050                 kfree(sbi->s_qf_names[i]);
4051 #endif
4052         ext4_blkdev_remove(sbi);
4053         brelse(bh);
4054 out_fail:
4055         sb->s_fs_info = NULL;
4056         kfree(sbi->s_blockgroup_lock);
4057         kfree(sbi);
4058 out_free_orig:
4059         kfree(orig_data);
4060         return err ? err : ret;
4061 }
4062
4063 /*
4064  * Setup any per-fs journal parameters now.  We'll do this both on
4065  * initial mount, once the journal has been initialised but before we've
4066  * done any recovery; and again on any subsequent remount.
4067  */
4068 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4069 {
4070         struct ext4_sb_info *sbi = EXT4_SB(sb);
4071
4072         journal->j_commit_interval = sbi->s_commit_interval;
4073         journal->j_min_batch_time = sbi->s_min_batch_time;
4074         journal->j_max_batch_time = sbi->s_max_batch_time;
4075
4076         write_lock(&journal->j_state_lock);
4077         if (test_opt(sb, BARRIER))
4078                 journal->j_flags |= JBD2_BARRIER;
4079         else
4080                 journal->j_flags &= ~JBD2_BARRIER;
4081         if (test_opt(sb, DATA_ERR_ABORT))
4082                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4083         else
4084                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4085         write_unlock(&journal->j_state_lock);
4086 }
4087
4088 static journal_t *ext4_get_journal(struct super_block *sb,
4089                                    unsigned int journal_inum)
4090 {
4091         struct inode *journal_inode;
4092         journal_t *journal;
4093
4094         BUG_ON(!ext4_has_feature_journal(sb));
4095
4096         /* First, test for the existence of a valid inode on disk.  Bad
4097          * things happen if we iget() an unused inode, as the subsequent
4098          * iput() will try to delete it. */
4099
4100         journal_inode = ext4_iget(sb, journal_inum);
4101         if (IS_ERR(journal_inode)) {
4102                 ext4_msg(sb, KERN_ERR, "no journal found");
4103                 return NULL;
4104         }
4105         if (!journal_inode->i_nlink) {
4106                 make_bad_inode(journal_inode);
4107                 iput(journal_inode);
4108                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4109                 return NULL;
4110         }
4111
4112         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4113                   journal_inode, journal_inode->i_size);
4114         if (!S_ISREG(journal_inode->i_mode)) {
4115                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4116                 iput(journal_inode);
4117                 return NULL;
4118         }
4119
4120         journal = jbd2_journal_init_inode(journal_inode);
4121         if (!journal) {
4122                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4123                 iput(journal_inode);
4124                 return NULL;
4125         }
4126         journal->j_private = sb;
4127         ext4_init_journal_params(sb, journal);
4128         return journal;
4129 }
4130
4131 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4132                                        dev_t j_dev)
4133 {
4134         struct buffer_head *bh;
4135         journal_t *journal;
4136         ext4_fsblk_t start;
4137         ext4_fsblk_t len;
4138         int hblock, blocksize;
4139         ext4_fsblk_t sb_block;
4140         unsigned long offset;
4141         struct ext4_super_block *es;
4142         struct block_device *bdev;
4143
4144         BUG_ON(!ext4_has_feature_journal(sb));
4145
4146         bdev = ext4_blkdev_get(j_dev, sb);
4147         if (bdev == NULL)
4148                 return NULL;
4149
4150         blocksize = sb->s_blocksize;
4151         hblock = bdev_logical_block_size(bdev);
4152         if (blocksize < hblock) {
4153                 ext4_msg(sb, KERN_ERR,
4154                         "blocksize too small for journal device");
4155                 goto out_bdev;
4156         }
4157
4158         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4159         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4160         set_blocksize(bdev, blocksize);
4161         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4162                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4163                        "external journal");
4164                 goto out_bdev;
4165         }
4166
4167         es = (struct ext4_super_block *) (bh->b_data + offset);
4168         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4169             !(le32_to_cpu(es->s_feature_incompat) &
4170               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4171                 ext4_msg(sb, KERN_ERR, "external journal has "
4172                                         "bad superblock");
4173                 brelse(bh);
4174                 goto out_bdev;
4175         }
4176
4177         if ((le32_to_cpu(es->s_feature_ro_compat) &
4178              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4179             es->s_checksum != ext4_superblock_csum(sb, es)) {
4180                 ext4_msg(sb, KERN_ERR, "external journal has "
4181                                        "corrupt superblock");
4182                 brelse(bh);
4183                 goto out_bdev;
4184         }
4185
4186         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4187                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4188                 brelse(bh);
4189                 goto out_bdev;
4190         }
4191
4192         len = ext4_blocks_count(es);
4193         start = sb_block + 1;
4194         brelse(bh);     /* we're done with the superblock */
4195
4196         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4197                                         start, len, blocksize);
4198         if (!journal) {
4199                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4200                 goto out_bdev;
4201         }
4202         journal->j_private = sb;
4203         ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4204         wait_on_buffer(journal->j_sb_buffer);
4205         if (!buffer_uptodate(journal->j_sb_buffer)) {
4206                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4207                 goto out_journal;
4208         }
4209         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4210                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4211                                         "user (unsupported) - %d",
4212                         be32_to_cpu(journal->j_superblock->s_nr_users));
4213                 goto out_journal;
4214         }
4215         EXT4_SB(sb)->journal_bdev = bdev;
4216         ext4_init_journal_params(sb, journal);
4217         return journal;
4218
4219 out_journal:
4220         jbd2_journal_destroy(journal);
4221 out_bdev:
4222         ext4_blkdev_put(bdev);
4223         return NULL;
4224 }
4225
4226 static int ext4_load_journal(struct super_block *sb,
4227                              struct ext4_super_block *es,
4228                              unsigned long journal_devnum)
4229 {
4230         journal_t *journal;
4231         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4232         dev_t journal_dev;
4233         int err = 0;
4234         int really_read_only;
4235
4236         BUG_ON(!ext4_has_feature_journal(sb));
4237
4238         if (journal_devnum &&
4239             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4240                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4241                         "numbers have changed");
4242                 journal_dev = new_decode_dev(journal_devnum);
4243         } else
4244                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4245
4246         really_read_only = bdev_read_only(sb->s_bdev);
4247
4248         /*
4249          * Are we loading a blank journal or performing recovery after a
4250          * crash?  For recovery, we need to check in advance whether we
4251          * can get read-write access to the device.
4252          */
4253         if (ext4_has_feature_journal_needs_recovery(sb)) {
4254                 if (sb->s_flags & MS_RDONLY) {
4255                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4256                                         "required on readonly filesystem");
4257                         if (really_read_only) {
4258                                 ext4_msg(sb, KERN_ERR, "write access "
4259                                         "unavailable, cannot proceed");
4260                                 return -EROFS;
4261                         }
4262                         ext4_msg(sb, KERN_INFO, "write access will "
4263                                "be enabled during recovery");
4264                 }
4265         }
4266
4267         if (journal_inum && journal_dev) {
4268                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4269                        "and inode journals!");
4270                 return -EINVAL;
4271         }
4272
4273         if (journal_inum) {
4274                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4275                         return -EINVAL;
4276         } else {
4277                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4278                         return -EINVAL;
4279         }
4280
4281         if (!(journal->j_flags & JBD2_BARRIER))
4282                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4283
4284         if (!ext4_has_feature_journal_needs_recovery(sb))
4285                 err = jbd2_journal_wipe(journal, !really_read_only);
4286         if (!err) {
4287                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4288                 if (save)
4289                         memcpy(save, ((char *) es) +
4290                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4291                 err = jbd2_journal_load(journal);
4292                 if (save)
4293                         memcpy(((char *) es) + EXT4_S_ERR_START,
4294                                save, EXT4_S_ERR_LEN);
4295                 kfree(save);
4296         }
4297
4298         if (err) {
4299                 ext4_msg(sb, KERN_ERR, "error loading journal");
4300                 jbd2_journal_destroy(journal);
4301                 return err;
4302         }
4303
4304         EXT4_SB(sb)->s_journal = journal;
4305         ext4_clear_journal_err(sb, es);
4306
4307         if (!really_read_only && journal_devnum &&
4308             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4309                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4310
4311                 /* Make sure we flush the recovery flag to disk. */
4312                 ext4_commit_super(sb, 1);
4313         }
4314
4315         return 0;
4316 }
4317
4318 static int ext4_commit_super(struct super_block *sb, int sync)
4319 {
4320         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4321         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4322         int error = 0;
4323
4324         if (!sbh || block_device_ejected(sb))
4325                 return error;
4326         if (buffer_write_io_error(sbh)) {
4327                 /*
4328                  * Oh, dear.  A previous attempt to write the
4329                  * superblock failed.  This could happen because the
4330                  * USB device was yanked out.  Or it could happen to
4331                  * be a transient write error and maybe the block will
4332                  * be remapped.  Nothing we can do but to retry the
4333                  * write and hope for the best.
4334                  */
4335                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4336                        "superblock detected");
4337                 clear_buffer_write_io_error(sbh);
4338                 set_buffer_uptodate(sbh);
4339         }
4340         /*
4341          * If the file system is mounted read-only, don't update the
4342          * superblock write time.  This avoids updating the superblock
4343          * write time when we are mounting the root file system
4344          * read/only but we need to replay the journal; at that point,
4345          * for people who are east of GMT and who make their clock
4346          * tick in localtime for Windows bug-for-bug compatibility,
4347          * the clock is set in the future, and this will cause e2fsck
4348          * to complain and force a full file system check.
4349          */
4350         if (!(sb->s_flags & MS_RDONLY))
4351                 es->s_wtime = cpu_to_le32(get_seconds());
4352         if (sb->s_bdev->bd_part)
4353                 es->s_kbytes_written =
4354                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4355                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4356                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4357         else
4358                 es->s_kbytes_written =
4359                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4360         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4361                 ext4_free_blocks_count_set(es,
4362                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4363                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4364         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4365                 es->s_free_inodes_count =
4366                         cpu_to_le32(percpu_counter_sum_positive(
4367                                 &EXT4_SB(sb)->s_freeinodes_counter));
4368         BUFFER_TRACE(sbh, "marking dirty");
4369         ext4_superblock_csum_set(sb);
4370         mark_buffer_dirty(sbh);
4371         if (sync) {
4372                 error = __sync_dirty_buffer(sbh,
4373                         test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
4374                 if (error)
4375                         return error;
4376
4377                 error = buffer_write_io_error(sbh);
4378                 if (error) {
4379                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4380                                "superblock");
4381                         clear_buffer_write_io_error(sbh);
4382                         set_buffer_uptodate(sbh);
4383                 }
4384         }
4385         return error;
4386 }
4387
4388 /*
4389  * Have we just finished recovery?  If so, and if we are mounting (or
4390  * remounting) the filesystem readonly, then we will end up with a
4391  * consistent fs on disk.  Record that fact.
4392  */
4393 static void ext4_mark_recovery_complete(struct super_block *sb,
4394                                         struct ext4_super_block *es)
4395 {
4396         journal_t *journal = EXT4_SB(sb)->s_journal;
4397
4398         if (!ext4_has_feature_journal(sb)) {
4399                 BUG_ON(journal != NULL);
4400                 return;
4401         }
4402         jbd2_journal_lock_updates(journal);
4403         if (jbd2_journal_flush(journal) < 0)
4404                 goto out;
4405
4406         if (ext4_has_feature_journal_needs_recovery(sb) &&
4407             sb->s_flags & MS_RDONLY) {
4408                 ext4_clear_feature_journal_needs_recovery(sb);
4409                 ext4_commit_super(sb, 1);
4410         }
4411
4412 out:
4413         jbd2_journal_unlock_updates(journal);
4414 }
4415
4416 /*
4417  * If we are mounting (or read-write remounting) a filesystem whose journal
4418  * has recorded an error from a previous lifetime, move that error to the
4419  * main filesystem now.
4420  */
4421 static void ext4_clear_journal_err(struct super_block *sb,
4422                                    struct ext4_super_block *es)
4423 {
4424         journal_t *journal;
4425         int j_errno;
4426         const char *errstr;
4427
4428         BUG_ON(!ext4_has_feature_journal(sb));
4429
4430         journal = EXT4_SB(sb)->s_journal;
4431
4432         /*
4433          * Now check for any error status which may have been recorded in the
4434          * journal by a prior ext4_error() or ext4_abort()
4435          */
4436
4437         j_errno = jbd2_journal_errno(journal);
4438         if (j_errno) {
4439                 char nbuf[16];
4440
4441                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4442                 ext4_warning(sb, "Filesystem error recorded "
4443                              "from previous mount: %s", errstr);
4444                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4445
4446                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4447                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4448                 ext4_commit_super(sb, 1);
4449
4450                 jbd2_journal_clear_err(journal);
4451                 jbd2_journal_update_sb_errno(journal);
4452         }
4453 }
4454
4455 /*
4456  * Force the running and committing transactions to commit,
4457  * and wait on the commit.
4458  */
4459 int ext4_force_commit(struct super_block *sb)
4460 {
4461         journal_t *journal;
4462
4463         if (sb->s_flags & MS_RDONLY)
4464                 return 0;
4465
4466         journal = EXT4_SB(sb)->s_journal;
4467         return ext4_journal_force_commit(journal);
4468 }
4469
4470 static int ext4_sync_fs(struct super_block *sb, int wait)
4471 {
4472         int ret = 0;
4473         tid_t target;
4474         bool needs_barrier = false;
4475         struct ext4_sb_info *sbi = EXT4_SB(sb);
4476
4477         trace_ext4_sync_fs(sb, wait);
4478         flush_workqueue(sbi->rsv_conversion_wq);
4479         /*
4480          * Writeback quota in non-journalled quota case - journalled quota has
4481          * no dirty dquots
4482          */
4483         dquot_writeback_dquots(sb, -1);
4484         /*
4485          * Data writeback is possible w/o journal transaction, so barrier must
4486          * being sent at the end of the function. But we can skip it if
4487          * transaction_commit will do it for us.
4488          */
4489         if (sbi->s_journal) {
4490                 target = jbd2_get_latest_transaction(sbi->s_journal);
4491                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4492                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4493                         needs_barrier = true;
4494
4495                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4496                         if (wait)
4497                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4498                                                            target);
4499                 }
4500         } else if (wait && test_opt(sb, BARRIER))
4501                 needs_barrier = true;
4502         if (needs_barrier) {
4503                 int err;
4504                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4505                 if (!ret)
4506                         ret = err;
4507         }
4508
4509         return ret;
4510 }
4511
4512 /*
4513  * LVM calls this function before a (read-only) snapshot is created.  This
4514  * gives us a chance to flush the journal completely and mark the fs clean.
4515  *
4516  * Note that only this function cannot bring a filesystem to be in a clean
4517  * state independently. It relies on upper layer to stop all data & metadata
4518  * modifications.
4519  */
4520 static int ext4_freeze(struct super_block *sb)
4521 {
4522         int error = 0;
4523         journal_t *journal;
4524
4525         if (sb->s_flags & MS_RDONLY)
4526                 return 0;
4527
4528         journal = EXT4_SB(sb)->s_journal;
4529
4530         if (journal) {
4531                 /* Now we set up the journal barrier. */
4532                 jbd2_journal_lock_updates(journal);
4533
4534                 /*
4535                  * Don't clear the needs_recovery flag if we failed to
4536                  * flush the journal.
4537                  */
4538                 error = jbd2_journal_flush(journal);
4539                 if (error < 0)
4540                         goto out;
4541
4542                 /* Journal blocked and flushed, clear needs_recovery flag. */
4543                 ext4_clear_feature_journal_needs_recovery(sb);
4544         }
4545
4546         error = ext4_commit_super(sb, 1);
4547 out:
4548         if (journal)
4549                 /* we rely on upper layer to stop further updates */
4550                 jbd2_journal_unlock_updates(journal);
4551         return error;
4552 }
4553
4554 /*
4555  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4556  * flag here, even though the filesystem is not technically dirty yet.
4557  */
4558 static int ext4_unfreeze(struct super_block *sb)
4559 {
4560         if (sb->s_flags & MS_RDONLY)
4561                 return 0;
4562
4563         if (EXT4_SB(sb)->s_journal) {
4564                 /* Reset the needs_recovery flag before the fs is unlocked. */
4565                 ext4_set_feature_journal_needs_recovery(sb);
4566         }
4567
4568         ext4_commit_super(sb, 1);
4569         return 0;
4570 }
4571
4572 /*
4573  * Structure to save mount options for ext4_remount's benefit
4574  */
4575 struct ext4_mount_options {
4576         unsigned long s_mount_opt;
4577         unsigned long s_mount_opt2;
4578         kuid_t s_resuid;
4579         kgid_t s_resgid;
4580         unsigned long s_commit_interval;
4581         u32 s_min_batch_time, s_max_batch_time;
4582 #ifdef CONFIG_QUOTA
4583         int s_jquota_fmt;
4584         char *s_qf_names[EXT4_MAXQUOTAS];
4585 #endif
4586 };
4587
4588 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4589 {
4590         struct ext4_super_block *es;
4591         struct ext4_sb_info *sbi = EXT4_SB(sb);
4592         unsigned long old_sb_flags;
4593         struct ext4_mount_options old_opts;
4594         int enable_quota = 0;
4595         ext4_group_t g;
4596         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4597         int err = 0;
4598 #ifdef CONFIG_QUOTA
4599         int i, j;
4600 #endif
4601         char *orig_data = kstrdup(data, GFP_KERNEL);
4602
4603         /* Store the original options */
4604         old_sb_flags = sb->s_flags;
4605         old_opts.s_mount_opt = sbi->s_mount_opt;
4606         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4607         old_opts.s_resuid = sbi->s_resuid;
4608         old_opts.s_resgid = sbi->s_resgid;
4609         old_opts.s_commit_interval = sbi->s_commit_interval;
4610         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4611         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4612 #ifdef CONFIG_QUOTA
4613         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4614         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4615                 if (sbi->s_qf_names[i]) {
4616                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4617                                                          GFP_KERNEL);
4618                         if (!old_opts.s_qf_names[i]) {
4619                                 for (j = 0; j < i; j++)
4620                                         kfree(old_opts.s_qf_names[j]);
4621                                 kfree(orig_data);
4622                                 return -ENOMEM;
4623                         }
4624                 } else
4625                         old_opts.s_qf_names[i] = NULL;
4626 #endif
4627         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4628                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4629
4630         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4631                 err = -EINVAL;
4632                 goto restore_opts;
4633         }
4634
4635         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4636             test_opt(sb, JOURNAL_CHECKSUM)) {
4637                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4638                          "during remount not supported; ignoring");
4639                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4640         }
4641
4642         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4643                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4644                         ext4_msg(sb, KERN_ERR, "can't mount with "
4645                                  "both data=journal and delalloc");
4646                         err = -EINVAL;
4647                         goto restore_opts;
4648                 }
4649                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4650                         ext4_msg(sb, KERN_ERR, "can't mount with "
4651                                  "both data=journal and dioread_nolock");
4652                         err = -EINVAL;
4653                         goto restore_opts;
4654                 }
4655                 if (test_opt(sb, DAX)) {
4656                         ext4_msg(sb, KERN_ERR, "can't mount with "
4657                                  "both data=journal and dax");
4658                         err = -EINVAL;
4659                         goto restore_opts;
4660                 }
4661         }
4662
4663         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4664                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4665                         "dax flag with busy inodes while remounting");
4666                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4667         }
4668
4669         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4670                 ext4_abort(sb, "Abort forced by user");
4671
4672         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4673                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4674
4675         es = sbi->s_es;
4676
4677         if (sbi->s_journal) {
4678                 ext4_init_journal_params(sb, sbi->s_journal);
4679                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4680         }
4681
4682         if (*flags & MS_LAZYTIME)
4683                 sb->s_flags |= MS_LAZYTIME;
4684
4685         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4686                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4687                         err = -EROFS;
4688                         goto restore_opts;
4689                 }
4690
4691                 if (*flags & MS_RDONLY) {
4692                         err = sync_filesystem(sb);
4693                         if (err < 0)
4694                                 goto restore_opts;
4695                         err = dquot_suspend(sb, -1);
4696                         if (err < 0)
4697                                 goto restore_opts;
4698
4699                         /*
4700                          * First of all, the unconditional stuff we have to do
4701                          * to disable replay of the journal when we next remount
4702                          */
4703                         sb->s_flags |= MS_RDONLY;
4704
4705                         /*
4706                          * OK, test if we are remounting a valid rw partition
4707                          * readonly, and if so set the rdonly flag and then
4708                          * mark the partition as valid again.
4709                          */
4710                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4711                             (sbi->s_mount_state & EXT4_VALID_FS))
4712                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4713
4714                         if (sbi->s_journal)
4715                                 ext4_mark_recovery_complete(sb, es);
4716                 } else {
4717                         /* Make sure we can mount this feature set readwrite */
4718                         if (ext4_has_feature_readonly(sb) ||
4719                             !ext4_feature_set_ok(sb, 0)) {
4720                                 err = -EROFS;
4721                                 goto restore_opts;
4722                         }
4723                         /*
4724                          * Make sure the group descriptor checksums
4725                          * are sane.  If they aren't, refuse to remount r/w.
4726                          */
4727                         for (g = 0; g < sbi->s_groups_count; g++) {
4728                                 struct ext4_group_desc *gdp =
4729                                         ext4_get_group_desc(sb, g, NULL);
4730
4731                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4732                                         ext4_msg(sb, KERN_ERR,
4733                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4734                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
4735                                                le16_to_cpu(gdp->bg_checksum));
4736                                         err = -EFSBADCRC;
4737                                         goto restore_opts;
4738                                 }
4739                         }
4740
4741                         /*
4742                          * If we have an unprocessed orphan list hanging
4743                          * around from a previously readonly bdev mount,
4744                          * require a full umount/remount for now.
4745                          */
4746                         if (es->s_last_orphan) {
4747                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4748                                        "remount RDWR because of unprocessed "
4749                                        "orphan inode list.  Please "
4750                                        "umount/remount instead");
4751                                 err = -EINVAL;
4752                                 goto restore_opts;
4753                         }
4754
4755                         /*
4756                          * Mounting a RDONLY partition read-write, so reread
4757                          * and store the current valid flag.  (It may have
4758                          * been changed by e2fsck since we originally mounted
4759                          * the partition.)
4760                          */
4761                         if (sbi->s_journal)
4762                                 ext4_clear_journal_err(sb, es);
4763                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4764                         if (!ext4_setup_super(sb, es, 0))
4765                                 sb->s_flags &= ~MS_RDONLY;
4766                         if (ext4_has_feature_mmp(sb))
4767                                 if (ext4_multi_mount_protect(sb,
4768                                                 le64_to_cpu(es->s_mmp_block))) {
4769                                         err = -EROFS;
4770                                         goto restore_opts;
4771                                 }
4772                         enable_quota = 1;
4773                 }
4774         }
4775
4776         /*
4777          * Reinitialize lazy itable initialization thread based on
4778          * current settings
4779          */
4780         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4781                 ext4_unregister_li_request(sb);
4782         else {
4783                 ext4_group_t first_not_zeroed;
4784                 first_not_zeroed = ext4_has_uninit_itable(sb);
4785                 ext4_register_li_request(sb, first_not_zeroed);
4786         }
4787
4788         ext4_setup_system_zone(sb);
4789         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4790                 ext4_commit_super(sb, 1);
4791
4792 #ifdef CONFIG_QUOTA
4793         /* Release old quota file names */
4794         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4795                 kfree(old_opts.s_qf_names[i]);
4796         if (enable_quota) {
4797                 if (sb_any_quota_suspended(sb))
4798                         dquot_resume(sb, -1);
4799                 else if (ext4_has_feature_quota(sb)) {
4800                         err = ext4_enable_quotas(sb);
4801                         if (err)
4802                                 goto restore_opts;
4803                 }
4804         }
4805 #endif
4806
4807         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
4808         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4809         kfree(orig_data);
4810         return 0;
4811
4812 restore_opts:
4813         sb->s_flags = old_sb_flags;
4814         sbi->s_mount_opt = old_opts.s_mount_opt;
4815         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4816         sbi->s_resuid = old_opts.s_resuid;
4817         sbi->s_resgid = old_opts.s_resgid;
4818         sbi->s_commit_interval = old_opts.s_commit_interval;
4819         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4820         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4821 #ifdef CONFIG_QUOTA
4822         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4823         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
4824                 kfree(sbi->s_qf_names[i]);
4825                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4826         }
4827 #endif
4828         kfree(orig_data);
4829         return err;
4830 }
4831
4832 #ifdef CONFIG_QUOTA
4833 static int ext4_statfs_project(struct super_block *sb,
4834                                kprojid_t projid, struct kstatfs *buf)
4835 {
4836         struct kqid qid;
4837         struct dquot *dquot;
4838         u64 limit;
4839         u64 curblock;
4840
4841         qid = make_kqid_projid(projid);
4842         dquot = dqget(sb, qid);
4843         if (IS_ERR(dquot))
4844                 return PTR_ERR(dquot);
4845         spin_lock(&dq_data_lock);
4846
4847         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
4848                  dquot->dq_dqb.dqb_bsoftlimit :
4849                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
4850         if (limit && buf->f_blocks > limit) {
4851                 curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
4852                 buf->f_blocks = limit;
4853                 buf->f_bfree = buf->f_bavail =
4854                         (buf->f_blocks > curblock) ?
4855                          (buf->f_blocks - curblock) : 0;
4856         }
4857
4858         limit = dquot->dq_dqb.dqb_isoftlimit ?
4859                 dquot->dq_dqb.dqb_isoftlimit :
4860                 dquot->dq_dqb.dqb_ihardlimit;
4861         if (limit && buf->f_files > limit) {
4862                 buf->f_files = limit;
4863                 buf->f_ffree =
4864                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
4865                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
4866         }
4867
4868         spin_unlock(&dq_data_lock);
4869         dqput(dquot);
4870         return 0;
4871 }
4872 #endif
4873
4874 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4875 {
4876         struct super_block *sb = dentry->d_sb;
4877         struct ext4_sb_info *sbi = EXT4_SB(sb);
4878         struct ext4_super_block *es = sbi->s_es;
4879         ext4_fsblk_t overhead = 0, resv_blocks;
4880         u64 fsid;
4881         s64 bfree;
4882         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4883
4884         if (!test_opt(sb, MINIX_DF))
4885                 overhead = sbi->s_overhead;
4886
4887         buf->f_type = EXT4_SUPER_MAGIC;
4888         buf->f_bsize = sb->s_blocksize;
4889         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4890         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4891                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4892         /* prevent underflow in case that few free space is available */
4893         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4894         buf->f_bavail = buf->f_bfree -
4895                         (ext4_r_blocks_count(es) + resv_blocks);
4896         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4897                 buf->f_bavail = 0;
4898         buf->f_files = le32_to_cpu(es->s_inodes_count);
4899         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4900         buf->f_namelen = EXT4_NAME_LEN;
4901         fsid = le64_to_cpup((void *)es->s_uuid) ^
4902                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4903         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4904         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4905
4906 #ifdef CONFIG_QUOTA
4907         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
4908             sb_has_quota_limits_enabled(sb, PRJQUOTA))
4909                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
4910 #endif
4911         return 0;
4912 }
4913
4914 /* Helper function for writing quotas on sync - we need to start transaction
4915  * before quota file is locked for write. Otherwise the are possible deadlocks:
4916  * Process 1                         Process 2
4917  * ext4_create()                     quota_sync()
4918  *   jbd2_journal_start()                  write_dquot()
4919  *   dquot_initialize()                         down(dqio_mutex)
4920  *     down(dqio_mutex)                    jbd2_journal_start()
4921  *
4922  */
4923
4924 #ifdef CONFIG_QUOTA
4925
4926 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4927 {
4928         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4929 }
4930
4931 static int ext4_write_dquot(struct dquot *dquot)
4932 {
4933         int ret, err;
4934         handle_t *handle;
4935         struct inode *inode;
4936
4937         inode = dquot_to_inode(dquot);
4938         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4939                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4940         if (IS_ERR(handle))
4941                 return PTR_ERR(handle);
4942         ret = dquot_commit(dquot);
4943         err = ext4_journal_stop(handle);
4944         if (!ret)
4945                 ret = err;
4946         return ret;
4947 }
4948
4949 static int ext4_acquire_dquot(struct dquot *dquot)
4950 {
4951         int ret, err;
4952         handle_t *handle;
4953
4954         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4955                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4956         if (IS_ERR(handle))
4957                 return PTR_ERR(handle);
4958         ret = dquot_acquire(dquot);
4959         err = ext4_journal_stop(handle);
4960         if (!ret)
4961                 ret = err;
4962         return ret;
4963 }
4964
4965 static int ext4_release_dquot(struct dquot *dquot)
4966 {
4967         int ret, err;
4968         handle_t *handle;
4969
4970         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4971                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4972         if (IS_ERR(handle)) {
4973                 /* Release dquot anyway to avoid endless cycle in dqput() */
4974                 dquot_release(dquot);
4975                 return PTR_ERR(handle);
4976         }
4977         ret = dquot_release(dquot);
4978         err = ext4_journal_stop(handle);
4979         if (!ret)
4980                 ret = err;
4981         return ret;
4982 }
4983
4984 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4985 {
4986         struct super_block *sb = dquot->dq_sb;
4987         struct ext4_sb_info *sbi = EXT4_SB(sb);
4988
4989         /* Are we journaling quotas? */
4990         if (ext4_has_feature_quota(sb) ||
4991             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
4992                 dquot_mark_dquot_dirty(dquot);
4993                 return ext4_write_dquot(dquot);
4994         } else {
4995                 return dquot_mark_dquot_dirty(dquot);
4996         }
4997 }
4998
4999 static int ext4_write_info(struct super_block *sb, int type)
5000 {
5001         int ret, err;
5002         handle_t *handle;
5003
5004         /* Data block + inode block */
5005         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5006         if (IS_ERR(handle))
5007                 return PTR_ERR(handle);
5008         ret = dquot_commit_info(sb, type);
5009         err = ext4_journal_stop(handle);
5010         if (!ret)
5011                 ret = err;
5012         return ret;
5013 }
5014
5015 /*
5016  * Turn on quotas during mount time - we need to find
5017  * the quota file and such...
5018  */
5019 static int ext4_quota_on_mount(struct super_block *sb, int type)
5020 {
5021         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5022                                         EXT4_SB(sb)->s_jquota_fmt, type);
5023 }
5024
5025 /*
5026  * Standard function to be called on quota_on
5027  */
5028 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5029                          struct path *path)
5030 {
5031         int err;
5032
5033         if (!test_opt(sb, QUOTA))
5034                 return -EINVAL;
5035
5036         /* Quotafile not on the same filesystem? */
5037         if (path->dentry->d_sb != sb)
5038                 return -EXDEV;
5039         /* Journaling quota? */
5040         if (EXT4_SB(sb)->s_qf_names[type]) {
5041                 /* Quotafile not in fs root? */
5042                 if (path->dentry->d_parent != sb->s_root)
5043                         ext4_msg(sb, KERN_WARNING,
5044                                 "Quota file not on filesystem root. "
5045                                 "Journaled quota will not work");
5046         }
5047
5048         /*
5049          * When we journal data on quota file, we have to flush journal to see
5050          * all updates to the file when we bypass pagecache...
5051          */
5052         if (EXT4_SB(sb)->s_journal &&
5053             ext4_should_journal_data(d_inode(path->dentry))) {
5054                 /*
5055                  * We don't need to lock updates but journal_flush() could
5056                  * otherwise be livelocked...
5057                  */
5058                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5059                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5060                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5061                 if (err)
5062                         return err;
5063         }
5064
5065         return dquot_quota_on(sb, type, format_id, path);
5066 }
5067
5068 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5069                              unsigned int flags)
5070 {
5071         int err;
5072         struct inode *qf_inode;
5073         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5074                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5075                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5076                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5077         };
5078
5079         BUG_ON(!ext4_has_feature_quota(sb));
5080
5081         if (!qf_inums[type])
5082                 return -EPERM;
5083
5084         qf_inode = ext4_iget(sb, qf_inums[type]);
5085         if (IS_ERR(qf_inode)) {
5086                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5087                 return PTR_ERR(qf_inode);
5088         }
5089
5090         /* Don't account quota for quota files to avoid recursion */
5091         qf_inode->i_flags |= S_NOQUOTA;
5092         err = dquot_enable(qf_inode, type, format_id, flags);
5093         iput(qf_inode);
5094
5095         return err;
5096 }
5097
5098 /* Enable usage tracking for all quota types. */
5099 static int ext4_enable_quotas(struct super_block *sb)
5100 {
5101         int type, err = 0;
5102         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5103                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5104                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5105                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5106         };
5107
5108         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5109         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5110                 if (qf_inums[type]) {
5111                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5112                                                 DQUOT_USAGE_ENABLED);
5113                         if (err) {
5114                                 ext4_warning(sb,
5115                                         "Failed to enable quota tracking "
5116                                         "(type=%d, err=%d). Please run "
5117                                         "e2fsck to fix.", type, err);
5118                                 return err;
5119                         }
5120                 }
5121         }
5122         return 0;
5123 }
5124
5125 static int ext4_quota_off(struct super_block *sb, int type)
5126 {
5127         struct inode *inode = sb_dqopt(sb)->files[type];
5128         handle_t *handle;
5129
5130         /* Force all delayed allocation blocks to be allocated.
5131          * Caller already holds s_umount sem */
5132         if (test_opt(sb, DELALLOC))
5133                 sync_filesystem(sb);
5134
5135         if (!inode)
5136                 goto out;
5137
5138         /* Update modification times of quota files when userspace can
5139          * start looking at them */
5140         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5141         if (IS_ERR(handle))
5142                 goto out;
5143         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5144         ext4_mark_inode_dirty(handle, inode);
5145         ext4_journal_stop(handle);
5146
5147 out:
5148         return dquot_quota_off(sb, type);
5149 }
5150
5151 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5152  * acquiring the locks... As quota files are never truncated and quota code
5153  * itself serializes the operations (and no one else should touch the files)
5154  * we don't have to be afraid of races */
5155 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5156                                size_t len, loff_t off)
5157 {
5158         struct inode *inode = sb_dqopt(sb)->files[type];
5159         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5160         int offset = off & (sb->s_blocksize - 1);
5161         int tocopy;
5162         size_t toread;
5163         struct buffer_head *bh;
5164         loff_t i_size = i_size_read(inode);
5165
5166         if (off > i_size)
5167                 return 0;
5168         if (off+len > i_size)
5169                 len = i_size-off;
5170         toread = len;
5171         while (toread > 0) {
5172                 tocopy = sb->s_blocksize - offset < toread ?
5173                                 sb->s_blocksize - offset : toread;
5174                 bh = ext4_bread(NULL, inode, blk, 0);
5175                 if (IS_ERR(bh))
5176                         return PTR_ERR(bh);
5177                 if (!bh)        /* A hole? */
5178                         memset(data, 0, tocopy);
5179                 else
5180                         memcpy(data, bh->b_data+offset, tocopy);
5181                 brelse(bh);
5182                 offset = 0;
5183                 toread -= tocopy;
5184                 data += tocopy;
5185                 blk++;
5186         }
5187         return len;
5188 }
5189
5190 /* Write to quotafile (we know the transaction is already started and has
5191  * enough credits) */
5192 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5193                                 const char *data, size_t len, loff_t off)
5194 {
5195         struct inode *inode = sb_dqopt(sb)->files[type];
5196         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5197         int err, offset = off & (sb->s_blocksize - 1);
5198         int retries = 0;
5199         struct buffer_head *bh;
5200         handle_t *handle = journal_current_handle();
5201
5202         if (EXT4_SB(sb)->s_journal && !handle) {
5203                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5204                         " cancelled because transaction is not started",
5205                         (unsigned long long)off, (unsigned long long)len);
5206                 return -EIO;
5207         }
5208         /*
5209          * Since we account only one data block in transaction credits,
5210          * then it is impossible to cross a block boundary.
5211          */
5212         if (sb->s_blocksize - offset < len) {
5213                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5214                         " cancelled because not block aligned",
5215                         (unsigned long long)off, (unsigned long long)len);
5216                 return -EIO;
5217         }
5218
5219         do {
5220                 bh = ext4_bread(handle, inode, blk,
5221                                 EXT4_GET_BLOCKS_CREATE |
5222                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5223         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5224                  ext4_should_retry_alloc(inode->i_sb, &retries));
5225         if (IS_ERR(bh))
5226                 return PTR_ERR(bh);
5227         if (!bh)
5228                 goto out;
5229         BUFFER_TRACE(bh, "get write access");
5230         err = ext4_journal_get_write_access(handle, bh);
5231         if (err) {
5232                 brelse(bh);
5233                 return err;
5234         }
5235         lock_buffer(bh);
5236         memcpy(bh->b_data+offset, data, len);
5237         flush_dcache_page(bh->b_page);
5238         unlock_buffer(bh);
5239         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5240         brelse(bh);
5241 out:
5242         if (inode->i_size < off + len) {
5243                 i_size_write(inode, off + len);
5244                 EXT4_I(inode)->i_disksize = inode->i_size;
5245                 ext4_mark_inode_dirty(handle, inode);
5246         }
5247         return len;
5248 }
5249
5250 #endif
5251
5252 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5253                        const char *dev_name, void *data)
5254 {
5255         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5256 }
5257
5258 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5259 static inline void register_as_ext2(void)
5260 {
5261         int err = register_filesystem(&ext2_fs_type);
5262         if (err)
5263                 printk(KERN_WARNING
5264                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5265 }
5266
5267 static inline void unregister_as_ext2(void)
5268 {
5269         unregister_filesystem(&ext2_fs_type);
5270 }
5271
5272 static inline int ext2_feature_set_ok(struct super_block *sb)
5273 {
5274         if (ext4_has_unknown_ext2_incompat_features(sb))
5275                 return 0;
5276         if (sb->s_flags & MS_RDONLY)
5277                 return 1;
5278         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5279                 return 0;
5280         return 1;
5281 }
5282 #else
5283 static inline void register_as_ext2(void) { }
5284 static inline void unregister_as_ext2(void) { }
5285 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5286 #endif
5287
5288 static inline void register_as_ext3(void)
5289 {
5290         int err = register_filesystem(&ext3_fs_type);
5291         if (err)
5292                 printk(KERN_WARNING
5293                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5294 }
5295
5296 static inline void unregister_as_ext3(void)
5297 {
5298         unregister_filesystem(&ext3_fs_type);
5299 }
5300
5301 static inline int ext3_feature_set_ok(struct super_block *sb)
5302 {
5303         if (ext4_has_unknown_ext3_incompat_features(sb))
5304                 return 0;
5305         if (!ext4_has_feature_journal(sb))
5306                 return 0;
5307         if (sb->s_flags & MS_RDONLY)
5308                 return 1;
5309         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5310                 return 0;
5311         return 1;
5312 }
5313
5314 static struct file_system_type ext4_fs_type = {
5315         .owner          = THIS_MODULE,
5316         .name           = "ext4",
5317         .mount          = ext4_mount,
5318         .kill_sb        = kill_block_super,
5319         .fs_flags       = FS_REQUIRES_DEV,
5320 };
5321 MODULE_ALIAS_FS("ext4");
5322
5323 /* Shared across all ext4 file systems */
5324 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5325 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5326
5327 static int __init ext4_init_fs(void)
5328 {
5329         int i, err;
5330
5331         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5332         ext4_li_info = NULL;
5333         mutex_init(&ext4_li_mtx);
5334
5335         /* Build-time check for flags consistency */
5336         ext4_check_flag_values();
5337
5338         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5339                 mutex_init(&ext4__aio_mutex[i]);
5340                 init_waitqueue_head(&ext4__ioend_wq[i]);
5341         }
5342
5343         err = ext4_init_es();
5344         if (err)
5345                 return err;
5346
5347         err = ext4_init_pageio();
5348         if (err)
5349                 goto out5;
5350
5351         err = ext4_init_system_zone();
5352         if (err)
5353                 goto out4;
5354
5355         err = ext4_init_sysfs();
5356         if (err)
5357                 goto out3;
5358
5359         err = ext4_init_mballoc();
5360         if (err)
5361                 goto out2;
5362         else
5363                 ext4_mballoc_ready = 1;
5364         err = init_inodecache();
5365         if (err)
5366                 goto out1;
5367         register_as_ext3();
5368         register_as_ext2();
5369         err = register_filesystem(&ext4_fs_type);
5370         if (err)
5371                 goto out;
5372
5373         return 0;
5374 out:
5375         unregister_as_ext2();
5376         unregister_as_ext3();
5377         destroy_inodecache();
5378 out1:
5379         ext4_mballoc_ready = 0;
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)